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Freshwater biodiversity, from fish to frogs and microbes to macrophytes, provides a vast array of services to people. Mounting concerns focus on the accelerating pace of biodiversity loss and declining ecological function within freshwater ecosystems that continue to threaten these natural benefits. Here, we catalog nine fundamental ecosystem services that the biotic components of indigenous freshwater biodiversity provide to people, organized into three categories: material (food; health and genetic resources; material goods), nonmaterial (culture; education and science; recreation), and regulating (catchment integrity; climate regulation; water purification and nutrient cycling). If freshwater biodiversity is protected, conserved, and restored in an integrated manner, as well as more broadly appreciated by humanity, it will continue to contribute to human well-being and our sustainable future via this wide range of services and associated nature-based solutions to our sustainable future.

Introduction: Intercropping cereals with legumes can intensify rainfed cereal monocropping for improved household food and nutritional security. However, there is scant literature confirming the associated nutritional benefits. Methodology: A systematic review and meta-analysis of nutritional water productivity (NWP) and nutrient contribution (NC) of selected cereal-legume intercrop systems was conducted through literature searches in Scopus, Web of Science and ScienceDirect databases. After the assessment, only nine articles written in English that were field experiments comprising grain cereal and legume intercrop systems were retained. Using the R statistical software (version 3.6.0), paired t-tests were used to determine if differences existed between the intercrop system and the corresponding cereal monocrop for yield (Y), water productivity (WP), NC, and NWP. Results: The intercropped cereal or legume yield was 10 to 35% lower than that for the corresponding monocrop system. In most instances, intercropping cereals with legumes improved NY, NWP, and NC due to their added nutrients. Substantial improvements were observed for calcium (Ca), where NY, NWP, and NC improved by 658, 82, and 256%, respectively. Discussion: Results showed that cereal-legume intercrop systems could improve nutrient yield in water-limited environments. Promoting cereal legume intercrops that feature nutrient-dense legume component crops could contribute toward addressing the SDGs of Zero Hunger (SDG 3), Good Health and Well-3 (SDG 2) and Responsible consumption and production (SDG 12).

Motivation: COVID-19 has revived focus on improving equitable access to water, sanitation and hygiene (WASH) and health services in developing countries. Most public programming tends to rely on economic indicators to identify and target vulnerable groups. Can expanded targeting criteria that include social status help to improve not only targeting, but also equity in access to WASH and health services? Purpose: This paper assesses the role of social identity in mediating access to WASH and health services, controlling for economic disadvantages such as household wealth, income sources and assets. Methods and approach: We use regression analysis applied to the 2016 Nepal Demographic and Health Survey (DHS) to estimate the relationships between social identity and access to WASH and health services, controlling for wealth (using wealth index quantiles), and remittances (using indicator variables for domestic and international remittances). Findings: We find that differences in access are mediated in large part by caste, and religious and ethnic identity, especially in rural areas; suggesting that the supply of such services is lower for historically disadvantaged communities. In addition, communities with lowest access are not necessarily the most economically disadvantaged, indicating that relying solely on traditional economic indicators to target programs and interventions may not be sufficient to improve equity in access to public health services. Policy implications: The results make a case for broadening indicators beyond the economic criteria for improving targeting of public funds for more inclusive development.

A combination of climate change and accelerated population growth is instigating some of the worst challenges that humankind faces today that include resource depletion and degradation. Both built environment and ecological infrastructure have been modified and are creating novel socioecological interactions posing the risk of novel infectious diseases transmission to humans. The experiences of the COVID-19 exposed the vulnerability of human health from wildlife and the risk of novel socioecological interactions on livelihoods. This chapter enhances the preparedness and improves the resilience against novel pathogens by assessing vulnerability and the available options to reduce risk through the water–health–ecosystem–nutrition nexus. As a transformative, nexus planning provides integrated pathways toward resilience and preparedness to reduce health risks on humans posed by novel pathogens. A systematic review of literature facilitated an understanding of the trends of novel infectious diseases and the available options to improve sanitation, nutrition, and adaptative capacity in the advent of novel socioecological interactions. The aim is to guide policy formulations to achieve Sustainable Development Goals such as 3 (good health and wellbeing), 6 (clean water and sanitation), and 13 (climate action). Risk reduction framing in the health sector through nexus planning provides pathways toward healthy environments and mutual socioecological interactions.

The United Nations Food Systems Summit aimed to chart a path toward transforming food systems toward achieving the Sustainable Development Goals. Despite the essentiality of water for food systems, however, the Summit has not sufficiently considered the role of water for food systems transformation. This focus is even more important due to rapidly worsening climate change and its pervasive impacts on food systems that are mediated through water. To avoid that water “breaks” food systems, key food systems actors should 1) Strengthen efforts to retain water-dependent ecosystems, their functions and services; 2) Improve agricultural water management; 3) Reduce water and food losses beyond the farmgate; 4) Coordinate water with nutrition and health interventions; 5) Increase the environmental sustainability of food systems; 6) Explicitly address social inequities; and 7) Improve data quality and monitoring for water-food system linkages.

Fish inhabiting freshwater environments are susceptible to the ingestion of microplastics (MPs). Knowledge regarding MPs in freshwater fish in South Africa is very limited. In this study, the uptake of MPs by common carp (Cyprinus carpio) in the Vaal River in South Africa was assessed. MPs were detected in all of the twenty-six fish examined, 682 particles of MPs were recovered from the gastrointestinal tracts of the fish with an average of 26.23 12.57 particles/fish, and an average abundance of 41.18 52.81 particles/kg. The examination of the physical properties of MPs revealed a predominance on fibers (69%), small-sized particles of less than 0.5 mm (48%), as well as prevelance of coloured MPs (94%), mostly green, blue, and black. Using Raman Spectroscopy, the following plastic polymers were identified: high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET), and polytetrafluoroethylene (PTFE). To the best of our knowledge, this study, is the first to report MPs uptake by freshwater biota in the Vaal River using common carp as a target organism. It provided evidence of MP contamination in the Vaal.

The use of polluted water to irrigate is an increasing problem in the developing world. Lebanon is a case in point, with heavily polluted irrigation waters, particularly in the Litani River Basin. This study evaluated the potential health risks of irrigating vegetables (radishes, parsley, onions, and lettuce) using three water sources (groundwater, river water, and treated wastewater) and three irrigation methods (drip, sprinkler, and surface) over two growing seasons in 2019 and 2020. Water, crop, and soil samples were analyzed for physicochemical parameters, pathogens, and metals (Cu, Cd, Ni, Cr, and Zn). In addition, the bioaccumulation factor, estimated dietary intakes, health risk index, and target hazard quotients were calculated to assess the health risk associated with metal contamination. The study showed that, for water with less than 2 log E. coli CFU/100 mL, no pathogens (Escherichia coli, salmonella, parasite eggs) were detected in irrigated vegetables, irrespective of the irrigation method. With over 2 log E. coli CFU/100 mL in the water, 8.33% of the sprinkler-and surface-irrigated vegetables, and 2.78% of the drip-irrigated root crops (radishes and onions), showed some degree of parasitic contamination. E. coli appeared only on root crops when irrigated with water having over 3 log CFU/100 mL. The concentrations of most metals were significantly lower than the safe limits of the FAO/WHO of the Food Standards Programme Codex, except for zinc and chromium. The trends in the bioaccumulation factor and the estimated dietary intakes of metals were in the order of Cu lt; Cd lt; Ni lt; Cr lt; Zn. The target hazard quotient values for all metals were lower than 1.0. Under trial conditions, the adoption of drip irrigation with water with less than 3 log E. coli CFU/100 mL proved to be safe, even for vegetables consumed raw, except for root crops such as onions and radishes that should not be irrigated with water having over 2 log E. coli CFU/100 mL. Treated wastewater had no adverse effect on vegetable quality compared to vegetables irrigated with other water sources. These results support efforts to update the Lebanese standards for water reuse in agriculture; standards proposed in 2011 by the FAO, and currently being reviewed by the Lebanese Institution of Standards. This research will inform a sustainable water management policy aimed at protecting the Litani River watershed by monitoring water quality.

In Addis Ababa and its environs, most urban wastewater is discharged into rivers without treatment. This study related urban wastewater characteristics to the prevalence of faecal, antibiotic resistant, and potentially pathogenic bacteria in rivers of the Akaki catchment across six locations, for the dry and wet season. Spatiotemporal variation in bacterial hazards across the catchment was up to 6 log10 units. Cooccurrence of sewage pollution marker gene HF183 in all river samples testing positive for the Vibrio cholerae marker gene ompW, and high levels of these two genes in untreated wastewater, identified human sewage as the likely source of Vibrio cholerae hazards in the catchment. Levels of the marker genes rodA for E. coli, HF183 for human host associated Bacteroides, ciaB for Arcobacter, and ompW for Vibrio cholerae were all higher in the dry season than in the wet season. Marker gene gyrB for Pseudomonas aeruginosa was not detected in the samples. From the sequencing data, notable bacterial genera in the dry season included wastewater pollution indicators Arcobacter and Aeromonas, whereas soil erosion may explain the greater prominence of Legionella, Vicinamibacter, and Sphingomonas during the wet season. Except for the most upstream location, all faecal coliform (FC) counts exceeded WHO standards of 1000 CFU/100 mL for unrestricted irrigation. Concerningly, 0.6–20% of FC had ESBL producing antimicrobial resistance traits. In conclusion, multiple bacterial hazards were of concern for river water users in the Akaki catchment, and elevated in the dry season, when the river water is being used for irrigation of vegetable fields that supply the markets of Addis Ababa. This reflects inadequate treatment and limited dilution of urban wastewater by the natural river flows during periods of low rainfall.

Globally, the use of untreated, often diluted, or partly treated wastewater in agriculture covers about 30 million ha, far exceeding the area under the planned use of well-treated (reclaimed) wastewater which has been estimated in this paper at around 1.0 million ha. This gap has likely increased over the last decade despite significant investments in treatment capacities, due to the even larger increases in population, water consumption, and wastewater generation. To minimize the human health risks from unsafe wastewater irrigation, the WHO’s related 2006 guidelines suggest a broader concept than the previous (1989) edition by emphasizing, especially for low-income countries, the importance of risk-reducing practices from ‘farm to fork’. This shift from relying on technical solutions to facilitating and monitoring human behaviour change is, however, challenging. Another challenge concerns local capacities for quantitative risk assessment and the determination of a risk reduction target. Being aware of these challenges, the WHO has invested in a sanitation safety planning manual which has helped to operationalize the rather academic 2006 guidelines, but without addressing key questions, e.g., on how to trigger, support, and sustain the expected behaviour change, as training alone is unlikely to increase the adoption of health-related practices. This review summarizes the perceived challenges and suggests several considerations for further editions or national adaptations of the WHO guidelines.

The COVID-19 pandemic brought unprecedented socio-economic changes, ushering in a “new (ab)normal” way of living and human interaction. The water sector was not spared from the effects of the pandemic, a period in which the sector had to adapt rapidly and continue providing innovative water and sanitation solutions. This study unpacks and interrogates approaches, products, and services adopted by the water sector in response to the unprecedented lockdowns, heralding novel terrains, and fundamental paradigm shifts, both at the community and the workplace. The study highlights the wider societal perspective regarding the water and sanitation challenges that grappled society before, during, after, and beyond the pandemic. The premise is to provide plausible transitional pathways towards a new (ab)normal in adopting new models, as evidenced by the dismantling of the normal way of conducting business at the workplace and human interaction in an era inundated with social media, virtual communication, and disruptive technologies, which have transitioned absolutely everything into a virtual way of life. As such, the novel approaches have fast-tracked a transition into the 4th Industrial Revolution (4IR), with significant trade-offs to traditional business models and human interactions.

Environmental exposure to active pharmaceutical ingredients (APIs) can have negative effects on the health of ecosystems and humans. While numerous studies have monitored APIs in rivers, these employ different analytical methods, measure different APIs, and have ignored many of the countries of the world. This makes it difficult to quantify the scale of the problem from a global perspective. Furthermore, comparison of the existing data, generated for different studies/regions/continents, is challenging due to the vast differences between the analytical methodologies employed. Here, we present a global-scale study of API pollution in 258 of the world’s rivers, representing the environmental influence of 471.4 million people across 137 geographic regions. Samples were obtained from 1,052 locations in 104 countries (representing all continents and 36 countries not previously studied for API contamination) and analyzed for 61 APIs. Highest cumulative API concentrations were observed in sub-Saharan Africa, south Asia, and South America. The most contaminated sites were in low- to middle-income countries and were associated with areas with poor wastewater and waste management infrastructure and pharmaceutical manufacturing. The most frequently detected APIs were carbamazepine, metformin, and caffeine (a compound also arising from lifestyle use), which were detected at over half of the sites monitored. Concentrations of at least one API at 25.7% of the sampling sites were greater than concentrations considered safe for aquatic organisms, or which are of concern in terms of selection for antimicrobial resistance. Therefore, pharmaceutical pollution poses a global threat to environmental and human health, as well as to delivery of the United Nations Sustainable Development Goals.

Non-technical summary: We summarize what we assess as the past yearapos;s most important findings within climate change research: limits to adaptation, vulnerability hotspots, new threats coming from the climate–health nexus, climate (im)mobility and security, sustainable practices for land use and finance, losses and damages, inclusive societal climate decisions and ways to overcome structural barriers to accelerate mitigation and limit global warming to below 2C. Technical summary: We synthesize 10 topics within climate research where there have been significant advances or emerging scientific consensus since January 2021. The selection of these insights was based on input from an international open call with broad disciplinary scope. Findings concern: (1) new aspects of soft and hard limits to adaptation; (2) the emergence of regional vulnerability hotspots from climate impacts and human vulnerability; (3) new threats on the climate–health horizon – some involving plants and animals; (4) climate (im)mobility and the need for anticipatory action; (5) security and climate; (6) sustainable land management as a prerequisite to land-based solutions; (7) sustainable finance practices in the private sector and the need for political guidance; (8) the urgent planetary imperative for addressing losses and damages; (9) inclusive societal choices for climate-resilient development and (10) how to overcome barriers to accelerate mitigation and limit global warming to below 2C. Social media summary: Science has evidence on barriers to mitigation and how to overcome them to avoid limits to adaptation across multiple fields.

Access to sufficient and clean freshwater is essential for all life. Water is also essential for food system functioning: as a key input into food production, but also in processing and preparation, and as a food itself. Water scarcity and pollution are growing, affecting poorer populations, particularly food producers. Malnutrition levels are also on the rise, and this is closely linked to water scarcity. The achievement of Sustainable Development Goal (SDG) 2 and SDG 6 are co-dependent. Solutions to jointly improve food systems and water security outcomes that the United Nations Food Security Summit (UNFSS) should consider include: 1) strengthening efforts to retain water-based ecosystems and their functions; 2) improving agricultural water management for better diets for all; 3) reducing water and food losses beyond the farmgate; 4) coordinating water with nutrition and health interventions; 5) increasing the environmental sustainability of food systems; 6) explicitly addressing social inequities in water-nutrition linkages; and 7) improving data quality and monitoring for water-food system linkages, drawing on innovations in information and communications technology (ICT).

Existing climate projections and impact assessments in Nepal only consider a limited number of generic climate indices such as means. Few studies have explored climate extremes and their sectoral implications. This study evaluates future scenarios of extreme climate indices from the list of the Expert Team on Sector-specific Climate Indices (ET-SCI) and their sectoral implications in the Karnali Basin in western Nepal. First, future projections of 26 climate indices relevant to six climate-sensitive sectors in Karnali are made for the near (2021–2045), mid (2046–2070), and far (2071–2095) future for low-and high-emission scenarios (RCP4.5 and RCP8.5, respectively) using bias-corrected ensembles of 19 regional climate models from the COordinated Regional Downscaling EXperiment for South Asia (CORDEX-SA). Second, a qualitative analysis based on expert interviews and a literature review on the impact of the projected climate extremes on the climate-sensitive sectors is undertaken. Both the temperature and precipitation patterns are projected to deviate significantly from the historical reference already from the near future with increased occurrences of extreme events. Winter in the highlands is expected to become warmer and dryer. The hot and wet tropical summer in the lowlands will become hotter with longer warm spells and fewer cold days. Low-intensity precipitation events will decline, but the magnitude and frequency of extreme precipitation events will increase. The compounding effects of the increase in extreme temperature and precipitation events will have largely negative implications for the six climate-sensitive sectors considered here.

Wastewater-fed aquaculture has a long history, especially in Asia. This report examines three empirical cases of integrated wastewater treatment and aquaculture production. From an aquaculture entrepreneur’s perspective, the combination of fish farming and wastewater treatment in common waste stabilization ponds allows significant savings on capital (pond infrastructure) and running costs (wastewater supporting fish feed). On the other hand, the treatment plant owner will have the benefit of a partner taking over plant maintenance. Given the importance of food safety and related perceptions, the report is focusing on innovative business models where the marketed fish is not in direct contact with the treated wastewater, but only the brood stock or fish feed. The financial analysis of the presented systems shows profitable options for the fish farmer, operational and in part capital cost recovery for the treatment plant, and as the treatment plant operators can stop charging households a sanitation fee, eventually a triple-win situation for both partners and the served community.

Access to sufficient and clean freshwater is essential for all life. Water is also essential for food system functioning: as a key input into food production, but also in processing and preparation, and as a food itself. Water scarcity and pollution are growing, affecting poorer populations, particularly food producers. Malnutrition levels are also on the rise, and this is closely linked to water scarcity. Achievement of Sustainable Development Goal 2 (SDG 2) and Sustainable Development Goal 6 (SDG 6) are co-dependent. Solutions to jointly improve food systems and water security outcomes that the United Nations Food Security Summit (UNFSS) should consider include: 1) Strengthening efforts to retain water-based ecosystems and their functions; 2) Improving agricultural water management for better diets for all; 3) Reducing water and food losses beyond the farmgate; 4) Coordinating water with nutrition and health interventions; 5) Increasing the environmental sustainability of food systems; 6) Explicitly addressing social inequities in water-nutrition linkages; and 7) Improving data quality and monitoring for water-food system linkages, drawing on innovations in information and communications technology (ICT).

Little is known about the occurrence of emerging pollutants (EPs) in waters in the Middle East and North Africa (MENA) region despite the extensive use of low-quality water there. Available data dealing with the sources, occurrence and removal of EPs within the MENA region in different categories of water is collected, presented and analyzed in this literature review. According to the collected database, the occurrence and removal efficiency of EPs in the water matrix in the MENA region is available, respectively, for 13 and six countries of the 18 in total; no available data is registered for the rest. Altogether, 290 EPs have been observed in different water matrices across the MENA countries, stemming mainly from industrial effluents, agricultural practices, and discharge or reuse of treated wastewater (TWW). Pharmaceutical compounds figure among the most frequently reported compounds in wastewater, TWW, surface water, and drinking water. Nevertheless, pesticides are the most frequently detected pollutants in groundwater. Worryingly, 57 cases of EPs have been reported in different fresh and drinking waters, exceeding World Health Organization (WHO) and European Commission (EC) thresholds. Overall, pharmaceuticals, organic compounds, and pesticides are the most concerning EP groups. The review revealed the ineffectiveness of treatment processes used in the region to remove EPs. Negative removals of some EPs such as carbamazepine, erythromycin, and sulfamethoxazole were recorded, suggesting their possible accumulation or release during treatment. This underlines the need to set in place and strengthen control measures, treatment procedures, standards, and policies for such pollutants in the region.

This report examines social equality aspects related to resource recovery through solid waste composting and wastewater irrigation. The report shows that women are represented in greatest numbers at the base of the recycling chain, most often as informal waste pickers and as sorters of recyclables with limited access to resources and upward mobility. Despite a wide gender gap in the solid waste and sanitation sectors, women play a key role in both municipal waste reduction and food safety where irrigation water is unsafe. Analyzing the gender dimension is important for understanding household responses to recycling programs, differences between the formal and informal sectors as well as along the waste-to-resource value chain from collection to treatment and reuse. The report stresses the important role of women in household waste management, including waste segregation, and the power of women-dominated waste picker associations, where the informal sector plays an essential role alongside the formal sector.

Commercial farming of banana for export has rapidly expanded across northern uplands of Laos since 2008 with the establishment of new plantations by foreign companies. Heavy reliance on agrochemical usage warrants examination of possible environmental and human health risks. This study presents a preliminary assessment of the environmental risks from pesticide usage associated with bananas and other major crops in Oudomxay province. Surface water, groundwater, soil and sediment samples collected from the study area were analyzed for pesticide residues in the laboratory during the wet and dry seasons. Results of the analysis revealed that samples from banana farms had higher concentrations of residues from currently used (CU) pesticides compared with samples from adjacent farms producing maize, rubber, upland rice and gourd. Residues from highly persistent organochlorine (OC) pesticides, such as dichlorodiphenyltrichloroethane, heptachlor, dieldrin and lindane, which are no longer used in Laos, were also detected. Laboratory results were compared against a low-cost pesticide residue detection method and a simple pesticide risk assessment tool. However, neither approach was comparable to laboratory analysis. The potential environmental risk from pesticides and pesticide breakdown products was found to be substantial. For example, concentrations of some CU compounds exceeded the limits set by the World Health Organization. The report highlights several mitigation measures to reduce the environmental risks from hazardous pesticides: (i) increase efforts to eliminate the import and use of hazardous and persistent pesticides; (ii) promote targeted education programs to implement best practices, including the selection and use of pesticides as per international standards, and Integrated Pest Management techniques; (iii) identify and protect drinking water sources with a high risk of contamination; and (iv) maintain vegetated buffers and sediment traps to detain farm runoff, which will allow CU pesticides to degrade to safe levels before entering watercourses.

Unmanned Aerial Vehicles (UAVs) are an alternative to costly and time-consuming traditional methods to improve agricultural water management and crop productivity through the acquisition, processing, and analyses of high-resolution spatial and temporal crop data at field scale. UAVs mounted with multispectral and thermal cameras facilitate the monitoring of crops throughout the crop growing cycle, allowing for timely detection and intervention in case of any anomalies. The use of UAVs in smallholder agriculture is poised to ensure food security at household level and improve agricultural water management in developing countries. This review synthesises the use of UAVs in smallholder agriculture in the smallholder agriculture sector in developing countries. The review highlights the role of UAV derived normalised difference vegetation index (NDVI) in assessing crop health, evapotranspiration, water stress and disaster risk reduction. The focus is to provide more accurate statistics on irrigated areas, crop water requirements and to improve water productivity and crop yield. UAVs facilitate access to agro-meteorological information at field scale and in near real-time, important information for irrigation scheduling and other on-field decision-making. The technology improves smallholder agriculture by facilitating access to information on crop biophysical parameters in near real-time for improved preparedness and operational decision-making. Coupled with accurate meteorological data, the technology allows for precise estimations of crop water requirements and crop evapotranspiration at high spatial resolution. Timely access to crop health information helps inform operational decisions at the farm level, and thus, enhancing rural livelihoods and wellbeing.

Urbanisation will be one of the 21st centuryapos;s most transformative trends. By 2050, it will increase from 55% to 68%, more than doubling the urban population in South Asia and Sub-Saharan Africa. Urbanisation has multifarious (positive as well as negative) impacts on the wellbeing of humans and the environment. The 17 UN Sustainable Development Goals (SDGs) form the blueprint to achieve a sustainable future for all. Clean Water and Sanitation is a specific goal (SDG 6) within the suite of 17 interconnected goals. Here we provide an overview of some of the challenges that urbanisation poses in relation to SDG 6, especially in developing economies. Worldwide, several cities are on the verge of water crisis. Water distribution to informal settlements or slums in megacities (e.g. N50% population in the megacities of India) is essentially non-existent and limits access to adequate safe water supply. Besides due to poor sewer connectivity in the emerging economies, there is a heavy reliance on septic tanks, and other on-site sanitation (OSS) system and by 2030, 4.9 billion people are expected to rely on OSS. About 62–93% of the urban population in Vietnam, Sri Lanka, the Philippines and Indonesia rely on septic tanks, where septage treatment is rare. Globally, over 80% of wastewater is released to the environment without adequate treatment. About 11% of all irrigated croplands is irrigated with such untreated or poorly treated wastewater. In addition to acute and chronic health effects, this also results in significant pollution of often-limited surface and groundwater resources in Sub-Saharan Africa and Asia. Direct and indirect water reuse plays a key role in global water and food security. Here we offer several suggestions to mitigate water and food insecurity in emerging economies.

Agriculture is critical to the economies of developing countries. It is the basic source of food supply and a major contributor to economic development. But there is a cost. Today, agricultural water pollution undermines economic growth and threatens the environmental and physical health of millions of people around the world. The annual social and economic costs of agricultural water pollution could reach trillions of dollars. Yet the issue receives scant attention in global research and debate.

This chapter focuses on the human health impacts associated with changes in water quality and quantity due to climate change. Trends in morbidity and mortality are examined in the context of health risks associated with climate change, and response options related to water supply and sanitation are presented.

This paper examines whether there are systematic differences in the historical behaviors of households that are affected and unaffected by chronic kidney disease (CKD) in Sri Lanka pertaining to their water source choices, water treatment practices, and agrochemical use. This analysis is motivated by the Sri Lankan government’s largest policy response to this epidemic – to encourage communities to switch from untreated well water to publicly provided alternatives. We use recall methods to elicit information on the drinking water source and treatment choices of households over an 18-year period from 2000– 2017. Our analysis is based on a survey of 1497 rural ground-water dependent households in the most CKD-affected areas of the 10 districts of Sri Lanka with the highest prevalence of CKD. Our main findings are that (a) households that have ever used a pump to extract (typically deep) drinking water from a household well are more likely to be affected by CKD; (b) we fail to find a relationship between disease status and households’ use of buckets to extract (typically shallow) groundwater from their wells; and (c) those who have ever treated their shallow well water by boiling it are less likely to be affected by CKD. We also find that a greater share of CKD affected households historically used agrochemicals, used wells that were geographically removed from surface water sources, and displayed lower proxies of wealth. The implications of these findings are fourfold. First, since the systematic differences in the historical patterns of water sources and treatments used by CKD affected and non-affected households are modest, the sources of water and the treatment practices themselves may not be the sole risk factors in developing CKD. Second, although we find a negative association between boiling water and the probability of CKD, it is not obvious that a public policy campaign to promote boiling water is an appropriate response. Third, the hydrochemistry of deep and shallow well water needs to be better understood in order to shed light on the positive relationship between deep well water and disease status, and on why boiling shallow but not deep well water is associated with a lower probability of CKD. Fourth, there is a need for a deeper understanding of other risk factors and of the efficacy of preventative programs that provide alternative sources of household drinking water.

Over the last decade, the International Water Management Institute (IWMI) has explored the use of fecal sludge (FS) in combination with other organic waste sources to optimize FS treatment and composting for the production of a safe organic fertilizer, which can – depending on demand – be enriched with crop nutrients or pelletized for volume reduction, delayed decomposition or easier application. Based on IWMI’s experience, this training manual has been compiled for plant managers and trainers to help ensure that staff involved in FS treatment and production, and application of an FS-based co-compost adopt best practices in all processes involved. The manual can be adapted to local needs as required. It also includes information on compost registration and certification, as well as guidelines for co-compost application in the field.

Background: The impact of large dams on malaria has received widespread attention. However, understanding how dam topography and transmission endemicity influence malaria incidences is limited. ; Methods: Data from the European Commission’s Joint Research Center and Shuttle Radar Topography Mission were used to determine reservoir perimeters and shoreline slope of African dams. Georeferenced data from the Malaria Atlas Project (MAP) were used to estimate malaria incidence rates in communities near reservoir shorelines. Population data from the WorldPop database were used to estimate the population at risk of malaria around dams in stable and unstable areas. ; Results: The data showed that people living near (lt; 5 km) large dams in sub-Saharan Africa grew from 14.4 million in 2000 to 18.7 million in 2015. Overall, across sub-Saharan Africa between 0.7 and 1.6 million malaria cases per year are attributable to large dams. Whilst annual malaria incidence declined markedly in both stable and unstable areas between 2000 and 2015, the malaria impact of dams appeared to increase in unstable areas, but decreased in stable areas. Shoreline slope was found to be the most important malaria risk factor in dam-affected geographies, explaining 41–82% (P lt; 0.001) of the variation in malaria incidence around reservoirs. ; Conclusion: Gentler, more gradual shoreline slopes were associated with much greater malaria risk. Dam-related environmental variables such as dam topography and shoreline slopes are an important factor that should be considered in efforts to predict and control malaria around dams.

This analysis provides new estimates of chronic kidney disease (CKD) prevalence – including CKD of unknown etiology (CKDu) – across ten districts most affected by CKD in Sri Lanka, including an examination of rural householdsapos; historical reliance on groundwater consumption. A carefully designed household survey provides information on whether these households self-reported having a member in the decade prior to 2018, who had been clinically diagnosed with CKD. Households were classified according to whether or not they had used groundwater (from household wells, agro-wells or springs) as their primary source for drinking or cooking for at least five years between 1999 and 2018. More than 98% of households reported having consumed groundwater as their primary source of drinking or cooking water for at least five of those years and gt;15% of households reported having at least one CKD-affected member in the ten-year period up to 2018, but these numbers varied across and within districts. The reported characteristics of symptomatic individuals reveal that the incidence of CKD was significantly higher among females (62%) than males (38%). In addition to CKD, about 63% of symptomatic individuals had hypertension and about one-third of them also had diabetes. About 33% of the symptomatic individuals had neither diabetes nor hypertension, where this group most closely fits commonly used definitions of CKDu. With a survey response of over 8000 households comprising as many as 30,000 individuals, these data illustrate the scale of CKD in the most-affected districts of Sri Lanka on an aggregate basis as well as revealing differences across districts and at the sub-district level.

About 60% of southern Africa’s population lives in rural areas with limited access to basic services and amenities such as clean and safe water, affordable and clean energy, and balanced and nutritious diets. Resource scarcity has direct and indirect impacts on nutrition, human health, and well-being of mostly poor rural communities. Climate change impacts in the region are manifesting through low crop yields, upsurge of vector borne diseases (malaria and dengue fever), and water and food-borne diseases (cholera and diarrhoea). This study applied a water–energy–food (WEF) nexus analytical livelihoods model with complex systems understanding to assess rural livelihoods, health, and well-being in southern Africa, recommending tailor-made adaptation strategies for the region aimed at building resilient rural communities. The WEF nexus is a decision support tool that improves rural livelihoods through integrated resource distribution, planning, and management, and ensures inclusive socio-economic transformation and development, and addresses related sustainable development goals, particularly goals 2, 3, 6 and 7. The integrated WEF nexus index for the region was calculated at 0.145, which is marginally sustainable, and indicating the region’s exposure to vulnerabilities, and reveals a major reason why the region fails to meet its developmental targets. The integrated relationship among WEF resources in southern Africa shows an imbalance and uneven resource allocation, utilisation and distribution, which normally results from a ‘siloed’ approach in resource management. The WEF nexus provides better adaptation options, as it guides decision making processes by identifying priority areas needing intervention, enhancing synergies, and minimising trade-offs necessary for resilient rural communities. Our results identified (i) the trade-offs and unintended negative consequences for poor rural households’ livelihoods of current silo approaches, (ii) mechanisms for sustainably enhancing household water, energy and food security, whilst (iii) providing direction for achieving SDGs 2, 3, 6 and 7.

Small reservoirs are a critical coping mechanism in water-stressed rural areas in Africa, providing immense livelihood benefits that include improved food and water security, entrepreneurial activities and climate resilience. Challenges associated with the implementation of investments in small reservoirs include appropriate site selection, weak institutions, insufficient maintenance and sedimentation. The findings from this study suggest that the benefits of small reservoirs may be tapped more efficiently by rehabilitating old sites rather than building new infrastructure. However, the findings also point to broader lessons on the need to change the way of doing business, i.e., to adopt a long-term, more holistic approach (or model) to the construction and maintenance of small reservoirs that matches the degree of the challenge associated with sustainably tapping the benefits of the water that they store.

This study assesses the microbial and heavy metal distribution in African catfish (Clarias gariepinus) cultured in waste stabilization pond, and their subsequent suitability for human consumption. Treated wastewater-fed pond (WFP) was used in the culture of the fish with a non-wastewater fed pond (NWFP), fed with ground and rain water as control. Pond water, sediments and fish tissue (gill, liver, gut and skin) samples from both sources were analyzed for pathogens and heavy metal levels. Escherichia coli populations in the sediments and water from the WFP exceeded the maximum permissible limit by 2–3 log units as expected. Significantly higher levels of pathogen contamination were detected in the gut and skin of fish from the WFP than the NWFP. Heavy metal concentrations in all samples fell within the Food and Agricultural Organization (FAO)/World Health Organization (WHO) and National Oceanic and Atmospheric Administration (NOAA) permissible limits except for iron and cadmium. There were significantly higher heavy metal concentrations in gill and liver than the muscle. Even though iron recorded the highest concentrations in fish tissue, the concentrations (0.1–2.0 mg kg-1) were below the expected daily nutritional requirement (1–2 mg) for humans and pose no toxicological risk. However, catfish from WFP would require precautionary measures such as cooking/grilling prior to consumption to avoid pathogen infection.

Diarrhoea caused by waterborne pathogens still has a large burden of disease. We introduce a modelling and scenario analysis framework that enables better understanding of sources of and possible future changes in the disease burden due to environmental change and management implementation. The state-of-the-art research that can contribute to the development of the framework at the large scale is analysed, together with research gaps and opportunities for future research. Priorities have been identified and these include implementation of Quantitative Microbial Risk Assessment and application of the models in scenario analyses. The credibility of the model outputs should be central in the analysis, for example by developing stochastic models. Implementation of the framework contributes towards achieving the Sustainable Development Goals.

Globally, many populations face structural and environmental barriers to access safe water, sanitation and hygiene (WASH) services. Among these populations are many of the 200 million pastoralists whose livelihood patterns and extreme environmental settings challenge conventional WASH programming approaches. In this paper, we studied the Afar pastoralists in Ethiopia to identify WASH interventions that can mostly alleviate public health risks, within the populationapos;s structural and environmental living constraints. Surveys were carried out with 148 individuals and observational assessments made in 12 households as part of a Pastoralist Community WASH Risk Assessment. The results show that low levels of access to infrastructure are further compounded by risky behaviours related to water containment, storage and transportation. Additional behavioural risk factors were identified related to sanitation, hygiene and animal husbandry. The Pastoralist Community WASH Risk Assessment visually interprets the seriousness of the risks against the difficulty of addressing the problem. The assessment recommends interventions on household behaviours, environmental cleanliness, water storage, treatment and hand hygiene via small-scale educational interventions. The framework provides an approach for assessing risks in other marginal populations that are poorly understood and served through conventional approaches.

Current patterns of agricultural expansion and intensification are bringing unprecedented environmental externalities, including impacts on water quality. While water pollution is slowly starting to receive the attention it deserves, the contribution of agriculture to this problem has not yet received sufficient consideration. We need a much better understanding of the causes and effects of agricultural water pollution as well as effective means to prevent and remedy the problem. In the existing literature, information on water pollution from agriculture is highly dispersed. This repost is a comprehensive review and covers different agricultural sectors (including crops, livestock and aquaculture), and examines the drivers of water pollution in these sectors as well as the resulting pressures and changes in water bodies, the associated impacts on human health and the environment, and the responses needed to prevent pollution and mitigate its risks.

Degradation of freshwater ecosystems and the services they provide is a primary cause of increasing water insecurity, raising the need for integrated solutions to freshwater management. While methods for characterizing the multi-faceted challenges of managing freshwater ecosystems abound, they tend to emphasize either social or ecological dimensions and fall short of being truly integrative. This paper suggests that management for sustainability of freshwater systems needs to consider the linkages between human water uses, freshwater ecosystems and governance. We present a conceptualization of freshwater resources as part of an integrated social-ecological system and propose a set of corresponding indicators to monitor freshwater ecosystem health and to highlight priorities for management. We demonstrate an application of this new framework —the Freshwater Health Index (FHI) — in the Dongjiang River Basin in southern China, where stakeholders are addressing multiple and conflicting freshwater demands. By combining empirical and modeled datasets with surveys to gauge stakeholdersapos; preferences and elicit expert information about governance mechanisms, the FHI helps stakeholders understand the status of freshwater ecosystems in their basin, how ecosystems are being manipulated to enhance or decrease water-related services, and how well the existing water resource management regime is equipped to govern these dynamics over time. This framework helps to operationalize a truly integrated approach to water resource management by recognizing the interplay between governance, stakeholders, freshwater ecosystems and the services they provide.

This paper provides an overview of policy responses to arsenic in groundwater in rural Bangladesh to assess their role and potential effectiveness in reducing exposure. With 97% of the country consuming groundwater for drinking, there is a continuing crisis of tens of millions of people exposed to elevated levels of arsenic. An examination of the number of people protected through two major remediation efforts suggests that recent progress may not be sufficient to keep up with the increasing population or to resolve the crisis during this century. Recent developments in remedial options are examined to identify their potential role in an evolving policy and research agenda. There appears to be growing agreement about future research and policy responses that can scale remedial options and make them widely accessible. These include: (1) the need for a reliable and affordable programme of arsenic testing and retesting; (2) attention to risks from other soluble contaminants and pathogens; (3) explicit priority setting across locations, time and to address fairness; and (4) development of value chains to ensure remedial options are supported over time.

The karst dolomite aquifers of the North West Province in South Africa are among the most important in the nation. They serve as key water sources for municipal water supply and irrigation, and are also ecologically important in supplying springs that feed important rivers. Over-abstraction and consequent falling groundwater levels jeopardize water supply security, with increasing costs and risks to sustainable development. Better aquifer and conjunctive water management would improve water supply security and lower costs, with wider benefits to many sectors. This GRIPP Case Profile discusses these challenges and management experiences through the examples of two representative North West dolomite aquifers - the Grootfontein and Steenkoppies aquifers. These aquifers are relatively well understood hydrogeologically, and modern South African water law mandates sustainable use. Yet, underperforming collaboration between stakeholders using and managing the aquifers at various levels, and poor support from the national authority have led to an entrenched suboptimal equilibrium where stakeholders are reluctant to change behavior, despite awareness of the negative outcomes. Neither prescriptive local nor top-down organization has been effective. The synthesis argues for prioritized input from a legally mandated and capacitated convening authority (the national Department of Water and Sanitation) to catalyze and support effective local stakeholder groups and other governance initiatives. It calls for a renewed effort by this convening authority and other stakeholders, emphasizing mutually beneficial or “win-win” outcomes.

The use of wastewater to produce food crops particularly vegetables is very prevalent in Addis Ababa, Ethiopia. This practice may pose health risks to farm workers and consumers. Hence, the study was designed to evaluate farmers’ perceptions on irrigation water quality, health risks and health risk mitigation measures in four wastewater-irrigated urban vegetable farming sites in Addis Ababa. Data were collected on farm through 263 individual interviews and 12 focus group discussions. The findings showed that despite differences in levels of knowledge and awareness on health risks, farmers appear informed about the contamination of their irrigation water. The difference in perception to quality consideration of Akaki River/irrigation water is highlighted by the result of Kruskal–Wallis H test analysis which shows significant mean value (1.33) of positive perception toward the water quality by male than female farmers. Interestingly, significant difference (p lt; 0.05) in mean values of awareness toward problems of eating unwashed vegetables is also found between male and female farmers where females seemed to be more aware. Conversely, no significant difference was found in mean value of perception and awareness toward vegetables quality. Among the perceived health risks, skin problems were top-rated health risk while eye burn, sore feet and abdominal pains were rated low across the four farming sites. Although statistically not significant, perception toward consumption-related health risk differed with gender: females assigned relatively high mean score. Irrespective of the farming site and gender differences, the most accepted health risk reduction measures were health promotion programs and cessation of irrigation before harvesting. In view of crop restriction measures, females assigned significantly (p = 0.044) low mean score to planting non-food produce. Akaki-Addis farmers suitability perceptions of planting non-food produce and non-raw eaten crops were significantly (p lt; 0.001) higher than the other farming sites. Therefore, effective site and gender-specific educational programs have the potential for clarifying farmers and consumers’ risks and risk management perceptions and improving practical knowledge, which in turn may help identify adoption barriers, opportunities and incentives.

Water and nutrition are linked in multiple ways, but few of these interlinkages are well understood. What is, for example, the exact relationship between water pollution and health or between water resource management and nutrition? Even less is known about the interactions across these various linkages. The importance of better understanding these connections has been highlighted as we pursue the United Nations Sustainable Development Goals (SDGs), which challenge mankind to meet both water security as well as food and nutrition security goals, while also improving water-based ecosystems. It has become increasingly clear that progress toward these goals can only be achieved if measures in the food and nutrition space (SDG 2) do not constrain progress on water (SDG 6) and if measures undertaken to support targets under one of these SGDs also support the outcomes of the other. This paper provides an overview of water–nutrition linkages as reflected in the SDGs, and it identifies key gaps in these linkages and suggests a way forward to support the achievement of both water and nutrition goals and targets.

Climate change is a complex and cross-cutting problem that needs an integrated and transformative systems approach to respond to the challenge. Current sectoral approaches to climate change adaptation initiatives often create imbalances and retard sustainable development. Regional and international literature on climate change adaptation opportunities and challenges applicable to southern Africa from a water-energy-food (WEF) nexus perspective was reviewed. Specifically, this review highlights climate change impacts on water, energy, and food resources in southern Africa, while exploring mitigation and adaptation opportunities. The review further recommends strategies to develop cross-sectoral sustainable measures aimed at building resilient communities. Regional WEF nexus related institutions and legal frameworks were also reviewed to relate the WEF nexus to policy. Southern Africa is witnessing an increased frequency and intensity in climate change-associated extreme weather events, causing water, food, and energy insecurity. A projected reduction of 20% in annual rainfall by 2080 in southern Africa will only increase the regional socio-economic challenges. This is exacerbating regional resource scarcities and vulnerabilities. It will also have direct and indirect impacts on nutrition, human well-being, and health. Reduced agricultural production, lack of access to clean water, sanitation, and clean, sustainable energy are the major areas of concern. The region is already experiencing an upsurge of vector borne diseases (malaria and dengue fever), and water and food-borne diseases (cholera and diarrhoea). What is clear is that climate change impacts are cross-sectoral and multidimensional, and therefore require cross-sectoral mitigation and adaptation approaches. In this regard, a wellcoordinated and integrated WEF nexus approach offers opportunities to build resilient systems, harmonise interventions, and mitigate trade-offs and hence improve sustainability. This would be achieved through greater resource mobilisation and coordination, policy convergence across sectors, and targeting nexus points in the landscape. The WEF nexus approach has potential to increase the resilience of marginalised communities in southern Africa by contributing towards attaining the Sustainable Development Goals (SDGs 1, 2, 3, 6, 7, and 13).

This chapter reviews the main pollutants from agriculture, its associated impacts, and offers some key pollution mitigation options. The chapter also discusses how agriculture can be a beneficial user of wastewater, and how the practice can become safe.

When urban areas expand without concomitant increases in wastewater treatment capacity, vast quantities of wastewater are released to surface waters with little or no treatment. Downstream of many urban areas are large areas of irrigated croplands reliant on these same surface water sources. Case studies document the widespread use of untreated wastewater in irrigated agriculture, but due to the practical and political challenges of conducting a true census of this practice, its global extent is not well known except where reuse has been planned. This study used GIS-based modeling methods to develop the first spatially-explicit estimate of the global extent of irrigated croplands influenced by urban wastewater flows, including indirect wastewater use. These croplands were further classified by their likelihood of using poor quality water based on the spatial proximity of croplands to urban areas, urban wastewater return flow ratios, and proportion of wastewater treated. This study found that 65% (35.9 Mha) of downstream irrigated croplands were located in catchments with high levels of dependence on urban wastewater flows. These same catchments were home to 1.37 billion urban residents. Of these croplands, 29.3 Mha were located in countries with low levels of wastewater treatment and home to 885 million urban residents. These figures provide insight into the key role that water reuse plays in meeting the water and food needs of people around the world, and the need to invest in wastewater treatment to protect public health.

Groundwater from the shallow aquifers of the Vientiane Plain, Laos is used for domestic needs including to some extent for drinking and for household gardening. The objective of this study is to assess the groundwater quality for drinking and irrigation activities and to determine the processes that lead to the presence of major ions in groundwater. Twenty groundwater samples were collected from a village on the Plain in December 2014, January 2015, and May 2015, and analysed for major ions and selected suite of minor ions and heavy metals. Groundwater is largely acidic, fresh and soft in nature. Geochemistry showed dominant Ca–Mg–HCO3 and mixed Ca–Na–HCO3 groundwater. Sodium impacts the suitability of water for irrigation to some extent. Hydrogeochemical processes identified and verified through factor analysis indicate weathering, carbonate dissolution, ion exchange, and anthropogenic sources including salinisation, due to irrigation and use of fertilizers as sources for the occurrence of major ions at such concentrations in this area. Only concentrations of lead and iron were above the permissible limits with arsenic, copper, zinc, mercury, and uranium found to be within safe limits. Background sample (groundwater) collected 5 km from the study area and the bottled water sample were all within suitable limits for drinking. This study is the first to provide a local-level assessment of geochemical processes in groundwater of this area indicating that the groundwater does not pose any threat to human health if used for drinking based on major ions, minor ions and a suite heavy metals except for iron and lead.

Nutrients and water found in domestic treated wastewater are valuable and can be reutilized in urban agriculture as a potential strategy to provide communities with access to fresh produce. In this paper, this proposition is examined by conducting a field study in the rapidly developing city of Hyderabad, India. Urban agriculture trade-offs in water use, energy use and GHG emissions, nutrient uptake, and crop pathogen quality are evaluated, and irrigation waters of varying qualities (treated wastewater, versus untreated water and groundwater) are compared. The results are counter-intuitive, and illustrate potential synergies and key constraints relating to the food–energy–water–health (FEW–health) nexus in developing cities. First, when the impact of GHG emissions from untreated wastewater diluted in surface streams is compared with the life cycle assessment of wastewater treatment with reuse in agriculture, the treatment-plus-reuse case yields a 33% reduction in life cycle system-wide GHG emissions. Second, despite water cycling benefits in urban agriculture, only lt;1% of the nutrients are able to be captured in urban agriculture, limited by the small proportion of effluent divertible to urban agriculture due to land constraints. Thus, water treatment plus reuse in urban farms can enhance GHG mitigation and also directly save groundwater; however, very large amounts of land are needed to extract nutrients from dilute effluents. Third, although energy use for wastewater treatment results in pathogen indicator organism concentrations in irrigation water to be reduced by 99.9% (three orders of magnitude) compared to the untreated case, crop pathogen content was reduced by much less, largely due to environmental contamination and farmer behavior and harvesting practices. The study uncovers key physical, environmental, and behavioral factors that constrain benefits achievable at the FEW-health nexus in urban areas.

The International Water Management Institute (IWMI) is a non-pro t, scienti c research organization focusing on the sustainable use of water and land resources in developing countries. IWMI works in partnership with governments, civil society and the private sector to develop scalable agricultural water management solutions that have a real impact on poverty reduction, food security and ecosystem health. IWMI is a member of CGIAR, a global research partnership for a food-secure future.

The chapter discusses how adopting a holistic methodology that acknowledges socio-logical factors, including community participation, public involvement, social perception, attitudes, gender roles and public acceptance, would lead to improvements in wastewater management practice. It highlights the social dimension as a tool, a lens through which wastewater management and reuse can take on new dimensions. In this way, this chapter aims to shift the focus from perceiving wastewater as a nuisance that needs disposal, toward a resource not to be wasted, which can contribute to food security, human and environmental health, access to energy as well as water security.

Most cities in developing countries fail to treat their wastewater comprehensively. Consequently, farmers downstream use poor-quality water for irrigation. This practice implies risks for farmers, consumers and the environment. Conversely, this water supply supports the livelihood of these farmers and other stakeholders along the value chains. Linking safer options for wastewater management with irrigation could therefore be a win–win solution: removing the risks for society and maintaining the bene ts for farmers. However, in developing countries, the high investment costs for the required treatment are problematic and the willingness of farmers to pay for the water (cost recovery) is often questionable. Using a choice experiment, this paper gives insight into farmers’ preferences for wastewater use scenarios, quantifying their willingness to pay. The case study is Hyderabad, India. Farmers there prefer water treatment and are prepared to pay a surplus for this. Considering the costrecovery challenge, this information could be valuable for planning small on site wastewater treatment systems.

Recovering energy from waste offers dual benefits – a) improved waste management, and b) provision of reliable energy to households, institutions and commercial entities. In this report, we present a socioeconomic assessment of three energy business models (briquette manufacturing, on-site (public toilet) energy generation, and agro-waste electricity generation) based on feasibility studies carried out in the city of Kampala, Uganda. We assess the potential economic, environmental and social impacts of waste-to-energy business models taking into consideration a life cycle of emissions to provide decision makers with the overall costs and benefits of the models to society versus a business-as-usual scenario.

Wastewater irrigaon is not new in Maharashtra and the Government of Maharashtra as well as farmers are beginning to recognize its value as a drought response. This Highlight presents a synthesis of eld exploraons in 11 locaons in Maharashtra which cover the extent of wastewater irrigaon; economics of wastewater and freshwater use; farmersapos; preferences and percepons about wastewater; and how they are adapng to its use in agriculture.

Purpose: The purpose of this paper is to explore people’s perceptions, stated attitudes, and observed and reported behaviour to water and other environmental quality. Design/methodology/approach: The study adopted a mixed method approach. It employed a cross-sectional survey design. Ten communities were selected in Accra and its surrounding communities to indicate various levels of infrastructure provision and environmental quality. Four separate focus group discussions (FGDs) were carried out in each community, with a mixed group of older and young adult men and women, a group of men only, a group of women only, and a group of young adults only. Following the FGDs, further information was obtained through structured household questionnaire survey involving 443 respondents. Findings: Different ideas were employed to explain people’s perceptions of water quality. There were common ideas such as on health, history of water use, perceptions which affect water use, and management of community activities which affect water sources. These ideas which emerged from the focus groups helped participants to assign meaning to their environment. Reported behaviour was influenced by the ability to pay for services, their availability and the influence of shared community norms. Although citizen participation in water and environmental management decision making was very limited, community collective action can be harnessed to enhance water and other environmental management. Originality/value: Adopted an interdisciplinary approach that enabled explanations to phenomenon to emerge from the perspectives of the society rather than views being suggested to them. Thus, resulting in evidence-based issues for intervention.

On-site sanitation systems, such as septic tanks and pit latrines, are the predominant feature across rural and urban areas in most developing countries. However, their management is one of the most neglected sanitation challenges. While under the Millennium Development Goals (MDGs), the set-up of toilet systems received the most attention, business models for the sanitation service chain, including pit desludging, sludge transport, treatment and disposal or resource recovery, are only emerging. Based on the analysis of over 40 fecal sludge management (FSM) cases from Asia, Africa and Latin America, this report shows opportunities as well as bottlenecks that FSM is facing from an institutional and entrepreneurial perspective.

Wastewater may be defined as the combination of liquid wastes discharged from domestic households, farms, institutions, and commercial and industrial establishments eventually mixed with groundwater, surface water, and stormwater. Wastewater is increasingly receiving global attention as it is seen as one of the alternative solutions to increasing global water scarcity. Indeed, wastewater is globally being reused in many applications including groundwater recharge, industrial reuse like for cooling, environmental and recreational uses, nonpotable urban uses, and indirect or direct potable reuse. However, agricultural irrigation and landscaping is by far the largest wastewater use sector. Indeed, millions of farmers worldwide are involved in wastewater irrigation activities. However, wastewater contains a variety of pollutants and contaminants, which may pose health risks if not well managed. These pollutants include salts, metals, metalloids, pathogens, residual drugs, organic compounds, endocrine disruptor compounds, and active residues of personal care products. The kind and extent of health risks depend on many factors including the types and levels of contaminants as well as regional risk relevance. In low-income countries, risks from pathogens receive the most attention. This is because people in these countries are most affected by diseases caused by poor sanitation such as diarrheal diseases and helminth infections, so high loads of pathogenic microorganisms are often found in wastewater systems. Focusing on low-income contexts, this chapter presents health risks posed by wastewater irrigation activities and some practical examples on how these risks could be managed.

Although wastewater has been increasingly used to grow a range of crops for income generation and livelihood resilience in urban and peri-urban areas, irrigation with untreated or partially treated wastewater may result in negative impacts on irrigated crops, soils, and groundwater along with implications for human and environmental health through chemical and microbial risks. With the potential for environmental risks due to concentrations above the maximum allowable levels, the major chemical constituent groups that need to be addressed in wastewater-irrigated environments are metals and metalloids, essential nutrients, salts and specific ionic species, and persistent organic pollutants. To avoid potential negative impacts, conventional wastewater treatment options, which can control the release of these contaminants into the environment, remain the key to protecting water quality for beneficial uses in agriculture, aquaculture, and agroforestry systems. Effective legislation, monitoring, and enforcement are also essential and often neglected management strategies. At the farm level, some low-cost irrigation, soil, and crop management options, discussed in this chapter, are available to reduce the risk from contaminants added through wastewater irrigation.

Wastewater constitutes an alternative water source for the irrigation sector. To fully benefit from it, and reduce possible adverse effects on public health and the environment, we need to look at the regulation of the practice. A prerequisite for this is an institutional analysis, and the points to consider are the institutional mandates. We used the city of Hyderabad, India, as a case study. There, irrigation with wastewater is not supported or recognized, but it happens in practice. It takes place in an indirect and unplanned way. Institutions fail at enforcing regulations, and little attention is given to formalization of the practice. With this article, we aim to untangle the institutional setup, and by doing so, identify the constraints surrounding development of a formal practice. Ultimately, we aim at contributing to the discussion on the agricultural use of wastewater.

Chronic kidney disease of unknown (“u”) cause (CKDu) is a growing public health concern in Sri Lanka. Prior research has hypothesized a link with drinking water quality, but rigorous studies are lacking. This study assesses the relationship between nephrotoxic elements (namely arsenic (As), cadmium (Cd), lead (Pb), and uranium (U)) in drinking water, and urine samples collected from individuals with and/or without CKDu in endemic areas, and from individuals without CKDu in nonendemic areas. All water samples – from a variety of source types (i.e. shallow and deep wells, springs, piped and surface water) – contained extremely low concentrations of nephrotoxic elements, and all were well below drinking water guideline values. Concentrations in individual urine samples were higher than, and uncorrelated with, those measured in drinking water, suggesting potential exposure from other sources. Mean urinary concentrations of these elements for individuals with clinically diagnosed CKDu were consistently lower than individuals without CKDu both in endemic and nonendemic areas. This likely stems from the inability of the kidney to excrete these toxic elements via urine in CKDu patients. Urinary concentrations of individuals were also found to be within the range of reference values measured in urine of healthy unexposed individuals from international biomonitoring studies, though these reference levels may not be safe for the Sri Lankan population. The results suggest that CKDu cannot be clearly linked with the presence of these contaminants in drinking water. There remains a need to investigate potential interactions of low doses of these elements (particularly Cd and As) with other risk factors that appear linked to CKDu, prior to developing public health strategies to address this illness.

In many urban and peri-urban areas of India, wastewater is under-recognized as a major water resource. Wastewater irrigated agriculture provides direct benefits for the livelihoods and food security of many smallholder farmers. A rapidly urbanizing peri-urban micro-watershed (270 ha) in Hyderabad was assessed over a 10-year period from 2000 to 2010 for changes in land use and associated farming practices, farmer perceptions, socio-economic evaluation, land-use suitability for agriculture and challenges in potential irrigated area development towards wastewater use. This integrated approach showed that the change in the total irrigated area was marginal over the decade, whereas the built-up area within the watershed boundaries doubled and there was a distinct shift in cropping patterns from paddy rice to paragrass and leafy vegetables. Local irrigation supplies were sourced mainly from canal supplies, which accounted for three-quarters of the water used and was largely derived from wastewater. The remainder was groundwater from shallow hard-rock aquifers. Farmer perception was that the high nutrient content of the wastewater was of value, although they were also interested to pay modest amounts for additional pre-treatment. The shift in land use towards paragrass and leafy vegetables was attributed to increased profitability due to the high urban demand. The unutilised scrubland within the watershed has the potential for irrigation development, but the major constraints appear to be unavailability of labour and high land values rather than water availability. The study provides evidence to support the view that the opportunistic use of wastewater and irrigation practices, in general, will continue even under highly evolving peri-urban conditions, to meet the livelihood needs of the poor driven by market demands, as urban sprawl expands into cultivable rural hinterlands. Policy support is needed for enhanced recognition of wastewater for agriculture, with flow-on benefits including improved public health and protection of ecosystem services.

Accessibility to abundant sources of high-quality water is integral to the production of safe and wholesome fresh produce. However, access to safe water is becoming increasingly difficult in many parts of the world, and this can lead to the production of fresh produce contaminated with pathogenic microorganisms, resulting in increased risk of human disease. Water, an important raw material in the fresh produce chain, is used in considerable amounts in many operations, including irrigation and application of pesticides and fertilizers, but also as a transport medium and for cooling and washing in postharvest practices. In several reported outbreaks related to uncooked fruit and vegetable products, water has been identified as a likely source of the outbreak. The present study, initiated by the ILSI Europe Emerging Microbiological Issues Task Force in collaboration with 8 other ILSI branches and support of WHO/FAO, was undertaken to review the status of, and provide suggestions for, consideration by different stakeholders on water and sanitation and its impact on food safety and public health. A limited number of guidelines and regulations on water quality for agricultural production are available, and many of them are still heavily based on microbial standards and (debated) parameters such as fecal coliforms. Data gaps have been identified with regard to baseline studies of microbial pathogens in water sources in many regions, the need for agreement on methods and microbial parameters to be used in assessing water quality, the fate of pathogens in water, and their transfer and persistence on irrigated/processed produce.

The reuse of treated wastewater for aquaculture has been practiced in several countries and has a potential to create a viable fish farming business in low income countries. However, wastewater aquaculture practices which satisfy health and hygiene guidelines and standards will not be viable if consumers are unwilling to purchase fish reared in treated wastewater. In this study we investigate consumers’ preference and willingness to pay for fish farmed in treated wastewater in Ghana. A consumer survey was conducted in Kumasi. We utilize a dichotomous-choice contingent valuation methodology to estimate willingness to pay for fresh Tilapia and smoked Catfish farmed in treated wastewater and analyze factors that affect consumer choice. Consumers in the survey ranked price, size and quality of fish measured by taste and freshness as the most important product attributes influencing their decision prior to purchasing fish. Source of fish is among the least important product attributes influencing consumers’ decision. Results indicate that surveyed consumers generally accept fish reared in treated wastewater if lower prices are offered. Socioeconomic factors such as household income, education and family size significantly determine consumers’ willingness to pay. Furthermore, results indicate that households with children are more likely to pay for smoked Catfish compared to fresh Tilapia indicating that postharvest processing of fish might be perceived as safer and thus increases consumers’ willingness to pay for smoked Catfish. The results of this study provide better understanding of fish consumers’ buying behavior and their perceptions of and attitude towards fish reared in treated wastewater. Moreover, results can contribute to identifying key product attributes that need to be targeted for improvement if sales of fish farmed in treated wastewater is to be achieved.

When flowing through Hyderabad, the capital of Telangana, India, the Musi River picks up (partially) treated and untreated sewage from the city. Downstream of the city, farmers use this water for the irrigation of rice and vegetables. Treatment of the river water before it is used for irrigation would address the resulting risks for health and the environment. To keep the costs and operational efforts low for the farmers, the use of constructed wetlands is viewed as a suitable option. Towards this end, the paper investigates the interests and perceptions of government stakeholders and farmers on the treatment of wastewater for irrigation and further explores the consumer willingness to pay a higher price for cleaner produced vegetables. Full cost recovery from farmers and consumers cannot be expected, if mass scale treatment of irrigation water is implemented. Instead, both consumers and farmers would expect that the government supports treatment of irrigation water. Most stakeholders associated with the government weigh health and environment so high, that these criteria outweigh cost concerns. They also support the banning of irrigation with polluted water. However, fining farmers for using untreated river water would penalize them for pollution caused by others. Therefore public funding of irrigation water treatment is recommended.

Thirsty and hungry cities are posing significant challenges for the urban-rural interface ranging from food security to inter-sectoral water allocation. Not only is the supply of resources to urban centres a growing challenge in low-income countries, but even more is the urban return flow, as investments in waste management and sanitation, ie the ‘ultimate food waste’, are not able to keep pace with population growth. And where polluted water is used in irrigation to feed the cities, food safety is becoming a crucial component of food security. Most affected by resource competition and pollution are the urban and peri-urban farming systems which are often driven by the informal sector. Urban waste is not only a challenge but also offers opportunities. It is in this interface between agriculture and sanitation where the CGIAR operates through its research programme on Water, Land and Ecosystems (WLE), addressing both the challenges and opportunities of urbanisation: by exploring novel perspectives and solutions to respond to changing population dynamics, resource demands, centralised water and nutrient flows, and ecosystem services under pressure.

This cross-sectional study explores the relationships between childrenapos;s F- exposure from drinking groundwater and urinary F- concentrations, combined with dental fluorosis (DF) in the Main Ethiopian Rift (MER) Valley.We examined the DF prevalence and severity among 491 children (10 to 15 years old) who are life-long residents of 33 rural communities in which groundwater concentrations of F- cover a wide range. A subset of 156 children was selected for urinary F- measurements. Our results showed that the mean F- concentrations in groundwater were 8.5 4.1 mg/L (range: 1.1–18 mg/L), while those in urine were 12.1 7.3 mg/L (range: 1.1–39.8 mg/L). The prevalence of mild, moderate, and severe DF in childrenapos;s teeth was 17%, 29%, and 45%, respectively, and the majority (90%; n = 140) of the children had urinary F- concentrations above 3 mg/L. Below this level most of the teeth showed mild forms of DF. The exposure–response relationship between F- and DF was positive and non-linear, with DF severity tending to level off above a F- threshold of ~6 mg/L, most likely due to the fact that at ~6 mg/L the enamel is damaged as much as it can be clinically observed in most children. We also observed differential prevalence (and severity) of DF and urinary concentration, across children exposed to similar F- concentrations in water, which highlights the importance of individual-specific factors in addition to the F- levels in drinking water. Finally, we investigated urinary F- in children from communities where defluoridation remediation was taking place. The lower F- concentration measured in urine of this population demonstrates the capacity of the urinary F- method as an effective monitoring and evaluation tool for assessing the outcome of successful F- mitigation strategy in relatively short time (months) in areas affected with severe fluorosis.

With a rapidly growing urban population in Kumasi, Ghana, the consumption of street food is increasing. Raw salads, which often accompany street food dishes, are typically composed of perishable vegetables that are grown in close proximity to the city using poor quality water for irrigation. This study assessed the risk of gastroenteritis illness (caused by rotavirus, norovirus and Ascaris lumbricoides) associated with the consumption of street food salads using Quantitative Microbial Risk Assessment (QMRA). Three different risk assessment models were constructed, based on availability of microbial concentrations: 1)Water — starting from irrigation water quality, 2) Produce — starting from the quality of produce at market, and 3) Street — using microbial quality of street food salad. In the absence of viral concentrations, published ratios between faecal coliforms and viruses were used to estimate the quality of water, produce and salad, and annual disease burdens were determined. Rotavirus dominated the estimates of annual disease burden (~10-3 Disability Adjusted Life Years per person per year (DALYs pppy)), although norovirus also exceeded the 10-4 DALY threshold for both Produce and Street models. The Water model ignored other on-farm and post-harvest sources of contamination and consistently produced lower estimates of risk; it likely underestimates disease burden and therefore is not recommended. Required log reductions of up to 5.3 (95th percentile) for rotavirus were estimated for the Street model, demonstrating that significant interventions are required to protect the health and safety of street food consumers in Kumasi. Estimates of virus concentrations were a significant source of model uncertainty and more data on pathogen concentrations is needed to refine QMRA estimates of disease burden.

This manuscript undertakes a review of current published information (peer-reviewed and grey literature) on Chronic Kidney Disease of Unknown Etiology (CKDu) in Sri Lanka. It attempts to provide an overview of the possible environmentally-induced causal factors that have been implicated in the development of the disease, and identifies the gaps in research and recommends potential areas for future research. The review specifically captures the potential role that agriculture and water resources may play as causal factors in the development of the disease, and calls for a systematic approach and stresses the need for an integrated multi-disciplinary research effort to address the problem.

There is a rich body of literature on arsenic (As) contamination of groundwater and its consequences for human health via drinking water. Less is known however, on the impacts that flow from the use of arsenic rich groundwater for irrigation or the effectiveness of arsenic remediation in agricultural systems. To partially fill this gap, we review 29 studies that examine the consequences of irrigating with arsenic contaminated groundwater and 28 studies which evaluate interventions aimed at reducing its negative impacts on human health and crops. These studies are geographically limited to West Bengal and Bangladesh (Bengal plains) as these regions constitute hubs of concerns for groundwater contamination. These studies show that there are six broad categories of interventions: deficit irrigation; soil fertilization; growing alternative field crops (other than paddy); switching to arsenic tolerant paddy cultivars; cooking methods to reduce arsenic content in rice and nutritional supplements. Importantly, these efforts target different stages of the agri-food system, some intervene in production processes and balance concerns for crop yields and human health while others focus on consumption practices and only mitigate health risks. Despite this diversity in focus, our results indicate that all treatments have positive effects, either in reducing As content in grains, its accumulation in soil and/or increase crop yields compared to control groups. However, the extent of these impacts varies as do their implications for long-term agricultural sustainability. From a policy perspective, these interventions offer promising alternatives to the extremes of restricted groundwater use on the one hand, and unregulated extraction on the other, but are yet to be integrated into mainstream extension services.

A national campaign of well testing through 2003 enabled households in rural Bangladesh to switch, at least for drinking water, from high-arsenic wells to neighboring lower arsenic wells. We study the well-switching dynamics over time by re-interviewing, in 2008, a randomly selected subset of households in the Araihazar region who had been interviewed in 2005. Contrary to concerns that the impact of arsenic information on switching behavior would erode over time, we find that not only was 2003–2005 switching highly persistent but also new switching by 2008 doubled the share of households at unsafe wells who had switched. The passage of time also had a cost: 22 per cent of households did not recall test results by 2008. The loss of arsenic knowledge led to staying at unsafe wells and switching from safe wells. Our results support ongoing well testing for arsenic to reinforce this beneficial information.

Elevated level of fluoride (F-) in drinking water is a well-recognized risk factor of dental fluorosis (DF). While considering optimization of region-specific standards for F-, it is reasonable, however, to consider how local diet, water sourcing practices, and non-F- elements in water may be related to health outcomes. In this study, we hypothesized that non-F- elements in groundwater and lifestyle and demographic characteristics may be independent predictors or modifiers of the effects of F- on teeth. Dental examinations were conducted among 1094 inhabitants from 399 randomly-selected households of 20 rural communities of the Ziway–Shala lake basin of the Main Ethiopian Rift. DF severity was evaluated using the Thylstrup-Fejerskov Index (TFI). Household surveys were performed and water samples were collected from community water sources. To consider interrelations between the teeth within individual (in terms of DF severity) and between F- and non-F- elements in groundwater, the statistical methods of regression analysis, mixed models, and principal component analysis were used. About 90% of study participants consumed water from wells with F- levels above theWHO recommended standard of 1.5 mg/l. More than 62% of the study population had DF. F- levels were a major factor associated with DF. Age, sex, and milk consumption (both cowapos;s and breastfed)were also statistically significantly (p b 0.05) associated with DF severity; these associations appear both independently and as modifiers of those identified between F- concentration and DF severity. Among 35 examined elements in groundwater, Ca, Al, Cu, and Rb were found to be significantly correlated with dental health outcomes among the residents exposed to waterwith excessive F- concentrations. Quantitative estimates obtained in our study can be used to explore new water treatment strategies, water safety and quality regulations, and lifestyle recommendations which may be more appropriate for this highly populated region.

Growing cities and their demand for water challenges the management of water resources and provides opportunities for wastewater use in irrigated agriculture. In the cases studied, large volumes of fresh water are extracted from sources often located increasingly further away from the city, while investments in wastewater disposal often lag behind. The resulting environmental impact in peri-urban areas can have multiple consequences for public health, in particular through the use of untreated or poorly treated wastewater in irrigated agriculture. Despite significant efforts to increase wastewater treatment, substantial volumes of untreated wastewater are applied in irrigated agriculture in Addis Ababa (Ethiopia), Accra (Ghana) and Hyderabad (India). Additional options for safeguarding public health are required to allow the cities to maintain the benefits from already existing, but largely informal, wastewater reuse.

This paper analyzes the effect of the shallow water table on water use of the winter wheat (Triticumaestivum L.) that has replaced alfalfa (Medicago sativa) on the irrigated lands of the Fergana Valley,upstream of the Syrdarya River, in Central Asia. The effect of the shallow water table is investigated using HYDRUS-1D. Numerical simulations show that the contribution of the groundwater to evapotranspiration increases with a rising water table and decreases with increasing irrigation applications. Under irrigation conditions, an increase in the groundwater evapotranspiration is associated mainly with an increase in evaporation loss, causing a buildup of salinity in the crop root zone. Evaporation losses from fields planted with winter wheat after the harvest amount up to 45–47% of total evaporation thus affecting soil salinity and ecosystem health. Promoting the use of groundwater for irrigation in order to lowerthe groundwater table is suggested to achieve water savings from the change in the cropping pattern.Unlocking the potential of groundwater for irrigation in the Fergana Valley can also contribute toward managing soil salinity and improving the health and resilience of water, land and ecosystems of water,land and ecosystems (WLE).

Using city wastewater in agriculture for its water and nutrient values is a widespread practice that entails varying degrees of risk depending on the context of use. This paper presents the ‘multiple realities’ of wastewater use, describing the complex set of drivers that impels prevalent practices. These drivers in turn define a set of emerging issues and priorities. The paper emphasizes that recent thinking on the use of city water in agriculture has evolved rapidly, leading to gaps between the existing knowledge base and the knowledge needed to respond effectively and maximize benefits. In this paper we attempt to address these gaps by presenting a cross section of concepts, approaches and tools that are relevant to policy and can be utilized for agenda setting and good governance.

We conducted a randomized controlled trial in rural Bangladesh to examine how household drinking-water choices were affected by two different messages about risk from naturally occurring groundwater arsenic. Households in both randomized treatment arms were informed about the arsenic level in their well and whether that level was above or below the Bangladesh standard for arsenic. Households in one group of villages were encouraged to seek water from wells below the national standard. Households in the second group of villages received additional information explaining that lower-arsenic well water is always safer and these households were encouraged to seek water from wells with lower levels of arsenic, irrespective of the national standard. A simple model of household drinking-water choice indicates that the effect of the emphasis message is theoretically ambiguous. Empirically, we find that the richer message had a negative, but insignificant, effect on well-switching rates, but the estimates are sufficiently precise that we can rule out large positive effects. The main policy implication of this finding is that a one-time oral message conveying richer information on arsenic risks, while inexpensive and easily scalable, is unlikely to be successful in reducing exposure relative to the status-quo policy.

Quantitative microbial risk assessment (QMRA) is frequently used to estimate health risks associated with wastewater irrigation and requires pathogen concentration estimates as inputs. However, human pathogens, such as viruses, are rarely quantified in water samples, and simple relationships between fecal indicator bacteria and pathogen concentrations are used instead. To provide data that can be used to refine QMRA models of wastewater-fed agriculture in Accra, stream, drain, and waste stabilization pond waters used for irrigation were sampled and analyzed for concentrations of fecal indicator microorganisms (human-specific Bacteroidales, E. coli, Enterococci, thermotolerant coliform, and somatic and F+ coliphages) and two human viruses (adenovirus and norovirus genogroup II). E. coli concentrations in all samples exceeded limits suggested by the World Health Organization, and human-specific Bacteroidales was found in all but one sample, suggesting human fecal contamination. Human viruses were detected in 16 out of 20 samples, were quantified in 12, and contained 2–3 orders of magnitude more norovirus than predicted by norovirus to E. coli concentration ratios assumed in recent publications employing indicator-based QMRA. As wastewater irrigation can be beneficial for farmers and municipalities, these results should not discourage water reuse in agriculture, but provide motivation and targets for wastewater treatment before use on farms.

Under conditions of increasing water scarcity and water quality deterioration, farmers have often little alternative to the use of raw or diluted wastewater to irrigate a range of crops. Aside from the agronomic benefits of resource recovery, the practice carries risks for farmers, public health, and the environment. A range of criteria have to be considered if such water sources are used: 1) crop selection and diversification to reduce possible health risks, accounting for market value and tolerance against ambient stresses; 2) irrigation water management covering water access, on-farm treatment, type of irrigation, application rates, and scheduling; and 3) soil-health-based considerations such as soil characteristics, soil preparation practices, and application of fertilizers and amendments. The awareness of farmers about the best management practices is essential for safe and sustainable wastewater irrigation.

High population growth, increasing urbanization and rapid economic development are exerting pressure on the already scarce water resources in India. Treatment and reuse of wastewater can play an important role in addressing some of the urban water challenges. Conventional treatment plants have many challenges, therefore, natural treatment systems (NTSs) are viewed as a cost-effective alternative, which are more suitable in the Indian context. This study builds on a desktop study of NTSs and presents a rapid sustainability assessment of 12 NTSs, highlighting the potential and viability of NTSs in India. The results show that the NTSs have a high potential for wastewater treatment. However, there are still gaps in knowledge related to aspects that hinder the sustainability of the systems. Risks associated with reuse of treated wastewater in agriculture, operational problems and social acceptance were perceived as frequent challenges. Self-sustaining financing methods and the use of by-products were viewed as added benefits.

Where wastewater is used without appropriate treatment, additional safety measures such as safer irrigation practices or careful vegetable washing are required to protect farmers and consumers. Implementing such food safety interventions in the informal farming sector is not easy, as they require behaviour change. Even where appropriate and low-cost interventions have been identified, low health risk awareness is a likely adoption barrier. Where this also concerns consumers, market demand for safer crops will be low and social marketing options have to be explored to support the desired behaviour change. Based on experiences from Ghana, where wastewater irrigation is an unplanned reality in and around all cities, the necessary steps and considerations for increasing the adoption probability are outlined under a generic framework which is based on social marketing, incentive systems, awareness creation/education and supporting regulations. Any of these approaches require accompanying research of the target groups and could gain in cost-effectiveness through a more integrated approach linking e.g. handwash and vegetable washing campaigns.

West and East Africa experience high variability of rainfall that is expected to increase with climate change. This results in uctuations in water availability for food production and other socioeconomic activities. Water harvesting and storage can mitigate the adverse effects of rainfall variability. But past studies have shown that when investments in water storage are not guided by environmental health considerations, the increased availability of open water surface may increase the transmission of waterrelated diseases. This is demonstrated for schistosomiasis associated with small reservoirs in Burkina Faso, and for malaria in Ethiopia around large dams, small dams, and water harvesting ponds. The concern is that the rush to develop water harvesting and storage for climate change adaptation may increase the risk for already vulnerable people, in some cases more than canceling out the bene ts of greater water availability. Taking health issues into account in a participatory approach to planning, design, and management of rainwater harvesting and water storage, as well as considering the full range of water storage options would enable better opportunities for enhancing resilience against climate change in vulnerable populations in sub-Saharan Africa.

More than 1 million hectares of urban land in India could be irrigated for crops if wastewater was made safe for use. Lack of systematic data collection by municipalities makes it difficult to accurately assess the wastewater generation or estimate the total amount of urban area under wastewater irrigation, so the potential of urban and peri-urban farming could be even greater. This study attempted to analyze the current status of wastewater generation, its uses and livelihood benefits especially in agriculture, based on national data and case studies from Ahmedabad, New Delhi, Hyderabad, Kanpur and Kolkata.

In Accra, Ghana, a majority of inhabitants lives in over-crowded areas with limited access to piped water supply, which is often also intermittent. This study assessed in a densely populated area the risk from microbial contamination of various sources of drinking water, by conducting a Quantitative Microbiological Risk Assessment (QMRA) to estimate the risk to human health from microorganism exposure and dose–response relationships. Furthermore the cost-effectiveness in reducing the disease burden through targeted interventions was evaluated. Five risk pathways for drinking water were identified through a survey (110 families), namely household storage, private yard taps, communal taps, communal wells and water sachets. Samples from each source were analyzed for Escherichia coli and Ascaris contamination. Published ratios between E. coli and other pathogenswere used for theQMRA and disease burden calculations. The major part of the burden of disease originated from E. coli O157:H7 (78%) and the least important contributor was Cryptosporidium (0.01%). Other pathogens contributed 16% (Campylobacter), 5% (Rotavirus) and 0.3% (Ascaris). The sum of the disease burden of these pathogens was 0.5 DALYs per person per year, which is much higher than the WHO reference level. The major contamination pathway was found to be household storage. Disinfection of water at household level was the most cost-effective intervention (b5 USD/DALY-averted) togetherwith hygiene education.Water supply network improvements were significantly less cost-effective.

Irrigation using untreated wastewater poses health risks to farmers and consumers of crop products, especially vegetables. With hardly any wastewater treatment in Ghana, a multiple-barrier approach was adopted and safe re-use practices were developed through action research involving a number of stakeholders at different levels along the food chain. This paper presents an overview of safe re-use practices including farm-based water treatment methods, water application techniques, post-harvest handling practices, and washing methods. The overview is based on a comprehensive analysis of the literature and our own specific studies, which used data from a broad range of research methods and approaches. Identifying, testing, and assessment of safe practices were done with the active participation of key actors using observations, extensive microbiological laboratory assessments, and field-based measurements. The results of our work and the work of others show that the practices developed had a great potential to reduce health risks, especially when used to complement each other at different levels of the food chain. Future challenges are the development of a comprehensive framework that best combines tested risk-reduction strategies for wide application by national stakeholders as well as their potential implementation into legally enforceable national standards.

Assessment was done of heavy-metal contamination and its related health risks in urban vegetable farming in Accra. Samples of irrigation water (n = 120), soil (n = 144) and five different kinds of vegetable (n = 240) were collected and analyzed for copper, zinc, lead, cadmium, chromium, nickel and cobalt. All water, soil and vegetable samples contained detectable concentrations of each of the seven heavy metals except for irrigation water which had no detectable chromium, cadmium and cobalt. All heavy-metal levels were below permissible limits except lead on vegetables which was 1.8–3.5 times higher. Health risk assessments showed for all elements that normal consumption of each of the vegetables assessed poses no risk. The highest hazard index obtained was 42 % for wastewater irrigated cabbage. Though within permissible limits, cabbage and ayoyo had the highest potential risk. Compared with previous studies on the same sites, the data show that the risk from heavy metals is less significance than that from pathogen contamination which has positive implications for risk mitigation.

This study aims to assess the link between fluoride content in groundwater and its impact on dental health in rural communities of the Ethiopian Rift. A total of 148 water samples were collected from two drainage basins within the Main Ethiopian Rift (MER). In the Ziway–Shala basin in particular, wells had high fluoride levels (mean: 9.410.5 mg/L; range: 1.1 to 68 mg/L), with 48 of 50 exceeding the WHO drinking water guideline limit of 1.5 mg/L. Total average daily intake of fluoride from drinking groundwater (calculated per weight unit) was also found to be six times higher than the No-Observed-Adverse-Effects-Level (NOAEL) value of 0.06 mg/kg/day. The highest fluoride levels were found in highly-alkaline (pH of 7 to 8.9) groundwater characterized by high salinity; high concentrations of sodium (Na+), bicarbonate (HCO3 -), and silica (SiO2); and low concentrations of calcium (Ca2+). A progressive Ca2+ decrease along the groundwater flow path is associated with an increase of fluoride in the groundwater. The groundwater quality problem is also coupled with the presence of other toxic elements, such as arsenic (As) and uranium (U). The health impact of fluoride was evaluated based on clinical examination of dental fluorosis (DF) among local residents using the Thylstrup and Fejerskov index (TFI). In total, 200 rural inhabitants between the ages of 7 and 40 years old using water from 12 wells of fluoride range of 7.8–18 mg/L were examined. Signs of DF (TF score of =1) were observed in all individuals. Most of the teeth (52%) recorded TF scores of 5 and 6, followed by TF scores of 3 and 4 (30%), and 8.4% had TF scores of 7 or higher. Sixty percent of the teeth exhibited loss of the outermost enamel. Within the range of fluoride contents, we did not find any correlation between fluoride content and DF. Finally, preliminary data suggest that milk intake has contributed to reducing the severity of DF. The study highlights the apparent positive role of milk on DF, and emphasizes the importance of nutrition in management efforts to mitigate DF in the MER and other parts of the world.

High population growth, increasing urbanization and rapid economic development are exerting pressure on the already scarce water resources in India. Untreated wastewater from human settlements reaching natural waterways is very common contributing to environmental pollution, which directly affects the availability of fresh water for human consumption. Therefore, treatment and reuse of wastewater can play an important role in addressing some of the urban water challenges in India. Conventional treatment plants have many challenges, therefore, natural treatment systems are viewed as a cost-effective alternative, which are more suitable in the Indian context. For example, they are not reliant on electricity, easier to maintain, can be part of small decentralised systems and work well in tropical climates. This study presents a rapid sustainability assessment and a review of the potential of natural treatment systems in India. The preliminary results show that the natural treatment systems have a high potential for wastewater treatment. However, there are still gaps in knowledge related to aspects that hinder the sustainable functioning of these treatment systems.

It is the belief of many analysts that agrarian countries like Ethiopia that depend on rain-fed agriculture are significantly vulnerable to rainfall variability, the risk which tends to aggravate with global climate change. Consequently, it is believed that future increases in food supplies and economic prosperity depend heavily on effective agricultural water management. It is with this in mind that the use of low-cost technologies for rainwater and runoff control, storage, water lifting, conveyance and application have become more widespread in Ethiopia since the recent drought of 2002/2003. A range of technologies are currently used with varying levels of impacts. This paper outlines an inventory, characterization, suitability and upscaling aspects of Agricultural Water Management Technologies (AWMT) in Ethiopia. Particular characteristics of each of the technologies, their suitability for a given environment, and the necessary conditions for their successful adoption and scaling up are identified. Furthermore, a variety of combinations of technologies used for control or storage, lifting, conveyance and application of rainwater are documented. Suitability of a technology in a particular environment depends on many factors, such as, the nature of technical complexity, the existing institutional and individual capacity to implement, the costs and benefits, etc. Technical considerations include implementation (set up), operation and maintenance, affordability and environmental impact. The results of a ranking exercise of the technical complexity of a given technology are presented. Concerns related to waterborne and water-related diseases due to stagnation, water quality and possibility of mosquito breeding are discussed. Households in some parts of Ethiopia, who have practiced improved agricultural water management suitable to their local conditions, have managed to diversify their incomes through beekeeping, livestock, intercropping cash crops with food crops and setting up shops, hotels and flour mills in the nearby towns or villages. Therefore, AWMT at smallholder level meet the intended purpose, provided that they are suitable and adaptable to the local circumstances. The question is which of the technologies are suitable to which area under what socioeconomic conditions?

This report is an output of the Sustainable Urban Water Management Improves Tomorrow s City s Health (SWITCH) demonstration project, which took place in Accra, Ghana. Accra is one of the ten (10) demonstration cities under the SWITCH project. The main objective of the demo project was to demonstrate (as pilot) the potential of using urine for crop production in Accra Metropolitan Area (AMA) and provide recommendations for scaling up.

In this article the authors draw from a comparative assessment of different interventions, examining their costs, risk-reduction potential and cost-effectiveness. They consider a case study in Ghana, using an approach that integrates quantitative microbial risk assessment (QMRA), disability-adjusted life years (DALYs) and cost-effectiveness analysis. Most practices appear highly cost-effective, although only a few are likely to avert more than 80% of the DALY burden. As compliance will always be a challenge, the results support the need for a multi-barrier risk-management approach that, where possible, combines treatment and non-treatment interventions.

The increased emphasis on non- or post-treatment measures in the 2006 edition of the World Health Organization Guidelines on the safe use of wastewater in agriculture will require behaviour change along the food chain. Low health risk awareness likely limits adoption of safe food practices in many areas. Based on experiences from Ghana, where informal wastewater irrigation occurs around all cities, the necessary steps for increasing adoption probability are outlined under a generic framework, which is based on the four pillars of social marketing, incentive systems, awareness creation/education and application of regulations. Any of these approaches requires research of the target groups. Cost effectiveness can be improved by linking related efforts with other hygiene and food safety interventions.

In this article the authors assess the empirical challenges of estimating the costs and benefits of using wastewater in agriculture. The wide variation in the characteristics of wastewater irrigation complicates efforts to estimate costs and benefits, and to transfer such estimates across locations. They examine wastewater use in four countries in Africa and Asia, where research has been conducted for many years. They find a significant patchwork of results, but no satisfying overall assessment. The authors suggest focusing on the cost-effectiveness of interventions for risk reduction, rather than economic analyses of the full range of costs and benefits of using wastewater in agriculture.

This paper sets out the trends and challenges of wastewater use in agriculture; identifies the risks and benefits of wastewater irrigation; describes the risk-assessment and management framework adopted by the World Health Organization, the Food and Agriculture Organization of the United Nations and other international and national organizations; and proposes measures for applying the framework to reduce health risks by moving from unplanned to a planned, integrated, approach to wastewater use for irrigation.

Many farmers in developing countries use treated or untreated wastewater to irrigate crops, partly in designated irrigation schemes, but mostly on large areas of small farms located along streams passing through or near cities. Much of the wastewater use is informal and unplanned, as farmers divert water from streams that carry untreated or partially treated effluent from cities and towns. The farmers generate good revenue by selling fresh produce that, otherwise, might not be available in urban markets. However, wastewater irrigation also creates health risks for farmers, their families, and consumers. Public officials must consider those risks and the values generated through wastewater irrigation, as they implement policies to protect farmers and consumers from the negative health impacts. Given the increasing scarcity of fresh water in many urban and peri-urban areas of developing countries, the increasing demand for food, and the persistent desire to improve the livelihoods of small-scale farmers, the decisions faced by public officials will require careful analysis. To that end, we describe in this special issue the economics, finance, business opportunities, and methodological constraints that pertain to wastewater irrigation in developing countries.

Failure is the norm for urban sanitation infrastructure in Ghana: of the rather substantial number of wastewater and faecal sludge treatment plants, with about 70 mostly decentralized systems throughout the country, less than 10 are operating effectively. This research presents an overview of the related sanitation situation in Ghana, and compares the few successful facilities with their failed counterparts in order to decipher the factors that enable the former to prevail. The research reveals important differences in the operation and maintenance (Oamp;M) strategies, financing schemes and incentive structures in the successful versus unsuccessful facilities, which are probably not unique to Ghana. Based on the findings, we suggest a set of guiding questions for incorporation into the existing planning, funding or general decision-making framework in order to avoid commonly observed traps, which not only undermine progress in the delivery of sanitation services but also harshly affect environmental and public health.

The international chapter of the 2012 EPA Water Reuse Guidelines is currently under development. This chapter aims to identify tools and approaches used in the international context that can strengthen water reuse in the US. The main objective is to review international experiences in order to gain insights on existing and best practices for governments, international development agencies, practitioners, and development partners interested in the challenges and opportunities within water reuse. Unlike earlier versions, the updated chapter aims to more fully discuss the full spectrum of applications in a range of resource contexts and highlight successes, challenges, and lessons learned in practical applications across a range of resource settings through a collection of case studies. The focus is on local and regional best practices and considerations for ensuring that water reuse occurs in a safe and sustainable manner. This applies to planned reuse schemes, with an emphasis on engineering practices for wastewater treatment, as well as unplanned systems, with an exploration of so-called post- or non-treatment options for reducing health risks. Factors that enable safe and sustainable reuse for both planned schemes and unplanned systems, such as institutional strengthening, financial planning, stakeholder processes, and public acceptance campaigns, will be discussed along with a framework for transitioning from unplanned to planned reuse.

This factsheet provides information on the link between sanitation and agriculture as well as related implications on health, economy and environment. It shows examples of treating and using treated excreta and wastewater in a productive way and describes the potential for urban agriculture and resource recovery in rural areas. Institutional and legal aspects, business opportunities and how to manage associated health risks are also discussed. Productive sanitation is the term used for the variety of sanitation systems that make productive use of the nutrient, organic matter, water and energy content of human excreta and wastewater in agricultural production and aquaculture. These systems should enable the recovery of resources in household wastewater, minimise consumption and pollution of water resources, support the conservation of soil fertility as well as agricultural productivity and thereby contribute to food security and help to reduce undernutrition.

In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw.; Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater.; This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on ‘making wastewater an asset’.

Wastewater use in agriculture is a complex phenomenon since it transcends typical sectoral and geographical policy and planning boundaries, and is influenced by opinions and perceptions. Planning for wastewater use typically requires the involvement of a number of government agencies covering health, water, sanitation, agriculture and irrigation, as well as researchers, community groups and the private sector. Where wastewater use is already taking place spontaneously and unofficially, how can these stakeholders come together to improve the management of the system to maximize the livelihoods benefits while minimizing impacts on health and the environment? One option is the formation of multi-stakeholder platforms, which provide a space for stakeholders to share opinions and seek negotiated solutions in an open and ‘level’ environment. How effective these are, what outcomes can be expected, and how they can be improved are all questions that are still being asked. This chapter presents three case studies in which multi-stakeholder processes were used to improve wastewater management for urban agriculture. Although differences were observed, there were several cross-cutting lessons. A critical factor is the starting point, including an agreed definition of the problem to be addressed, negotiated goals and a management structure that is acceptable to all stakeholders. When multi-stakeholder processes are externally initiated, as with those reviewed here, it is essential that project priorities are commensurate with local priorities. Finding an institutional home and anchor agency an improve long-term sustainability but care must be taken in considering how this impacts on existing power structures. Participation and representation greatly influence the effectiveness of the process and much may need to be done to support this, for example by strengthening local community groups. A factor that appears to significantly improve participation and engagement is having tangible outputs, which demonstrate to stakeholders the potential of multi-stakeholder platforms.

This chapter addresses the importance of understanding farmers’ knowledge and perceptions on health-risk and risk-reduction measures for the development of mutually acceptable risk-management strategies. Drawing on studies from different countries, the chapter shows that it is not realistic to expect high risk awareness. In cases where farmers are aware of health risks, they assess mitigation measures in view of their overall impact on work efficiency and crop yield rather than only the potential health benefits to be gained. The chapter asserts that for on-farm risk-reduction measures to be successful, it is pertinent that farmers’ needs and constraints are incorporated into the formulation of recommended practices. This might happen through indigenous processes but can be supported through farm-based participatory approaches where farmers and scientists work together in developing risk reduction measures. An important first step is the identification of mutually accepted problem indicators. Where health benefits for farmers and consumers are not sufficient reasons for the adoption of safer practices, other triggers have to be identified as well as appropriate communication channels for effective outreach.

Interventions proposed and implemented for the mitigation of diarrhoeal diseases associated with wastewater reuse in agriculture have received little, if any, comparative assessment of their cost-effectiveness. This chapter assesses the costs, outcomes and cost-effectiveness of the so-called ‘treatment’ and ‘non- or post-treatment’ interventions as well as a combination of these for wastewater irrigation in urban Ghana using an approach that integrates quantitative microbial risk assessment (QMRA), disability-adjusted life years (DALYs) and cost-effectiveness analysis (CEA). The cost-effectiveness ratios (CERs) for the treatment and non-treatment interventions assessed ranged from US$31/DALY to US$812/DALY averted. Risk-reduction measures targeting farming practices and the basic rehabilitation of local wastewater treatment plants were the most attractive interventions with a CER well below the threshold of US$150/DALY, sometimes considered as the upper limit for a health intervention to be cost-effective in developing countries. All combinations associated with the basic rehabilitation of the treatment plants, with either on-farm or post-harvest interventions or both, resulted in CERs within the range of US$40/DALY to US$57/DALY. However, the CERs for the construction of a new wastewater treatment plant either as an independent intervention or in combination with on-farm and post-harvest interventions were unattractive in view of health-risk reduction for wastewater irrigation. Although attractive, the CERs of non-treatment options are largely dependent on compliance (adoption) by farmers and food vendors. In this regard, the CER increased by almost fivefold when the adoption rate was only 25 per cent by farmers and food vendors; but was attractive as long as adoption rates did not fall below 70 per cent. On the other hand, the success of the treatment option depends on the functionality of the treatment plants which is not without challenges in a country like Ghana. Thus, this chapter stresses the need for a balanced risk-management approach through a combination of treatment and non-treatment interventions to hedge against failures that may affect CERs at any end. While this chapter provides a contribution to the debate on interventions for health-risk mitigation in wastewater irrigation, more case studies would be useful to verify the data presented here.

This chapter presents farm-based measures that have been developed and tested in the informal irrigation sector to reduce microbiological health risks for consumers from wastewater irrigation of vegetables commonly eaten uncooked. The measures target poor smallholder farmers or farmer associations in developing countries as part of a multiple-barrier approach for health-risk reduction along the farm to fork pathway. Measures discussed include treatment of irrigation water using ponds, filters and wetland systems; water application techniques; irrigation scheduling; and crop selection. In addition, the chapter highlights some practical strategies to implement these measures, based largely on field experiences in Ghana. Although most measures discussed do not fully eliminate possible health risks, they can significantly complement other pathogen barriers. Which measures fit, either alone or in combination, will depend on local site characteristics and practices. Further studies are required to develop new measures or adapt them to other irrigation practices and systems in developing countries.

In and around urban areas pollution of natural water bodies is on the rise. As a result, wastewater irrigation is an increasingly common reality around most cities in the developing world. For reasons of technical capacity or economics, effective treatment may not be available for years to come; therefore, international guidelines to safeguard farmers and consumers must be practical and offer feasible riskmanagement options. This chapter provides an introduction to microbiological hazards. These can be addressed best in a step-wise risk assessment and management approach starting with wastewater treatment where possible, and supported by different pathogen barriers from farm to fork. A major change in the most recent WHO Guidelines for the safe use of wastewater, excreta and greywater in agriculture and aquaculture (WHO, 2006) agriculture is the focus on a holistic approach to achieving health-based targets, instead of prescribing irrigation waterquality threshold levels that are often unattainable. The health-based targets should not be read as absolute values but as goals to be attained in the short, medium or long term depending on the country’s technical capacity and institutional or economic conditions. Local standards and actual implementation should progressively develop as the country moves up the sanitation ladder. While healthrisk assessments are recommended to identify entry points for risk reduction and health-based targets, the Guidelines also offer shortcuts in situations where research capacities and data are constrained.

Wastewater use in agriculture is a growing practice worldwide. Drivers include increasing water stress, in part due to climate change; increasing urbanization and growing wastewater flows; and more urban households engaged in agricultural activities. The problem with this trend is that in low-income countries, but also in many middle-income countries, it either involves the direct use of untreated wastewater or the indirect use of polluted waters from rivers that receive untreated urban discharges. This poses substantial risks, in particular microbial risks to public health. To address these risks, the World Health Organization in 2006 issued new guidelines for the safe use of wastewater. This paper aims to highlight the growing importance of improving wastewater use in agriculture across the spectrum from lower to high-income countries. It presents an innovative approach linking key issues related to different aspects of wastewater irrigation to a country’s level of economic development. Based on data presented in the World Bank’s World Development Report, it differentiates between four country income levels to create a typology for analyzing current issues, trends, and priorities for improving agricultural wastewater use with a focus on reducing the risks to public health. It also presents the basic principles of the new 2006 World Health Organization Guidelines, and how to apply them. Beyond regulatory aspects, the paper also discusses other aspects that are important for achieving a more integrated approach to agricultural wastewater use, including institutional/planning, technological, economic/financial, and social issues. Finally, the paper provides recommendations for moving the wastewater irrigation agenda forward.

Using stream water polluted with untreated wastewater in agriculture is controversial due to its combination of benefits and negative health impacts. Using data from a household survey, ‘wastewater’ and ‘freshwater’ farmers were analysed comparatively to examine the perceived impacts of irrigation water quality on farmers’ health and to evaluate the extent of health damage. Probability of illness was estimated using the theory of utility-maximising behaviour of households subject to the conventional farm household production model, augmented by adding a health production function. Reduced model and instrumental variable probit specifications both show that perceived illness prevalence is significantly higher for household members working on wastewater irrigation farms than for those working with freshwater. Our data entails econometric complications (e.g., endogeneity of farmers’ behaviour, unobserved location-specific characteristics). Ignoring these will result in underestimation of the value of policy interventions designed to reduce potential health damage of wastewater use in irrigation.

While urban agriculture has long been valued for providing food security and nutrition within cities, it contributes to many other urban services that are seldom cited as rationales for protecting or even expanding urban food production. Articulating the actual and possible contributions of urban agriculture to municipal sanitation and health services is critical for sustaining these urban farms and their functions into the future. In the context of the low coverage and performance of wastewater treatment plants in Accra, Ghana, health risk reduction measures implemented on and off farm can substitute to a large extent for this absence of conventional wastewater treatment. We estimate that Accra generates approximately 80,000,000L of wastewater per day, of which urban vegetable farms alone use up to 11,250,000L. By mitigating the health risks for farmers and consumers associated with widespread wastewater irrigation, these urban farms have the potential to significantly contribute to the city’s sanitation needs. This could allow partial outsourcing of public health services from treatment plants to the farm, where wastewater is considered an asset instead of a problem. Urban agriculture could also significantly support buffer zone management along streams and rivers, resulting in a reduction of solid waste dumping and environmental pollution, but most importantly an improvement in flood control and related public health challenges. While urban agriculture is not the panacea for addressing these urban challenges, it can significantly contribute to their solution.

This book provides a baseline understanding of how people and wetlands are connected, why these linkages are vital and how they can be better managed. It calls for action to integrate wetland management and WASH approaches, so as to benefit the health and development of people in rural and peri-urban areas in developing countries without compromising ecosystem functioning. It has been written predominantly for the core staff, planners and coordinators of international organisations and their implementing partners dealing with either wetlands conservation and management or WASH provision.

In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw.; Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater.; This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on ‘making wastewater an asset’.

There is increasing evidence that urban grown vegetables in developing countries can be contaminated with pathogenic microorganisms. This is particularly true when wastewater is used in irrigation. The microbiological quality of wastewater grown lettuce on farms, markets and at street food vendor sites were evaluated for thermotolerant coliforms, enterococci and Salmonella using standard methods. Farm irrigation water and market refreshing water (water used in keeping the lettuce fresh) samples were also analysed. Thermotolerant coliforms on lettuce varied from 2.3 × 103 to 9.3 × 108 on farm, 6.0 ×101 to 2.3 × 108 on market and 2.3 × 106 to 2.4 × 109 at street food vendor sites. Indicator bacterial numbers on farm lettuce were higher compared to the irrigation water (1.5 × 103 to 4.3 × 106) used on the farms. Thermotolerant coliform numbers in market refreshing water (9.0 × 103 to 4.3 × 1010) were higher compared to that on the market lettuce. Enterococci numbers on lettuce were lower and ranged from 3.9 × 101 to 1.0 × 106 on farm, 6.0 × 101 to 9.0 × 104 on market and 5.1 × 103 to 2.5 × 106 at street food vendor sites. Salmonella numbers recorded at food vendor sites ranged from 1.5 × 101 to 9.3 × 102. In general, thermotolerant coliforms numbers increased by 18% while enterococci numbers reduced by 64% from the farms to the street foods. Bacterial counts on farm lettuce and irrigation water, market lettuce and refreshing water and street foods all exceeded the recommended World Health Organization (WHO) and International Commission on Microbiological Specifications for Food (ICMSF) standards of 103. Wastewater use on farms and refreshing water in markets could be the main contributors to lettuce contamination and that education on use of effective de-contamination or washing methods before eating will contribute to reducing the risk associated with the consumption of such contaminated foods.

Wastewater irrigation is becoming a global phenomenon, as a result of global water scarcity and increased pollution of water sources. While this practice offers many opportunities, human health risks from contaminated soils and crops irrigated with wastewater pose the greatest challenges to this practice. In this chapter, contaminants in wastewater of most relevance to soil and crop, such as pathogens, heavy metals and other organic contaminants as well as the related human health and environmental risks are discussed. There is a general consensus that untreated wastewater contaminates soils and crops and poses health risks, however the threats vary widely. While wastewater treatment is the best choice to address this problem, a number of low-cost technological options and health protection measures exist to address the contamination challenges especially in developing countries. These include irrigation methods, farm-based measures for improving water quality, choice of crop, water application techniques, soil phytoremediation, zoning and post-harvest measures. For comprehensive risk reduction, a combination of these measures is recommended especially where comprehensive wastewater treatment is not feasible.

Larval and adult anophelines were sampled around Ziway, Central Ethiopia. Throughout the study period, significantly higher densities of Anopheles pharoensis and An. arabiensis were found in the village with irrigation than in the village without. Canal leakage pools, irrigated fields and irrigation canals were the major sources of Anopheles larvae. Most adult anophelines were found to feed on humans, especially before 22hrs, and up to 1% were infected with malaria parasites. This study demonstrated that due to poor maintenance, irrigation schemes create conducive breeding grounds for malaria vector mosquitoes and hence increase the risk of malaria transmission.

The volume of wastewater generated by domestic, industrial and commercial sources has increased with population, urbanization, improved living conditions, and economic development. The productive use of wastewater has also increased, as millions of small-scale farmers in urban and peri-urban areas of developing countries depend on wastewater or wastewater polluted water sources to irrigate high-value edible crops for urban markets, often as they have no alternative sources of irrigation water. Undesirable constituents in wastewater can harm human health and the environment. Hence, wastewater irrigation is an issue of concern to public agencies responsible for maintaining public health and environmental quality. For diverse reasons, many developing countries are still unable to implement comprehensive wastewater treatment programs. Therefore in the near term, risk management and interim solutions are needed to prevent adverse impacts from wastewater irrigation. A combination of source control, and farm-level and post-harvest measures can be used to protect farm workers and consumers. The WHO guidelines revised in 2006 for wastewater use suggest measures beyond the traditional recommendations of producing only industrial or non-edible crops, as in many situations it is impossible to enforce a change in the current cash crop pattern, or provide alternative vegetable supply to urban markets. There are several opportunities for improving wastewater management via improved policies, institutional dialogues and financial mechanisms, which would reduce the risks in agriculture. Effluent standards combined with incentives or enforcement can motivate improvements in water management by household and industrial sectors discharging wastewater from point sources. Segregation of chemical pollutants from urban wastewater facilitates treatment and reduces risk. Strengthening institutional capacity and establishing links between water delivery and sanitation sectors through inter-institutional coordination leads to more efficient management of wastewater and risk reduction.

Wastewater irrigation is a widespread and growing phenomenon that carries varying degrees of risk. Whether spontaneously practiced in urban and periurban agriculture or planned as part of water reuse programmes, food and fodder production using untreated sewage or treated effluent can have serious human health implications for farmers and consumers, and can irreversibly degrade the environment. In low-income countries water pollution is often the result of inadequate wastewater collection and treatment, and unplanned release to receiving water bodies. Making wastewater irrigation safer depends on a location-specific combination of different pathogen barriers including, where possible, appropriate wastewater treatment. Ensuring that these strategies work in an integrated, mutually supportive manner requires a multi-sectoral paradigm shift in the common approach of wastewater management for disposal. Additionally, it is crucial to continue research (especially in developing countries) on the types and severity of risk, locally feasible mitigation options, the cost-effectiveness of safer wastewater irrigation practices compared to other interventions against diarrhoea and facilitating the adoption of ‘non-’ or ‘post-treatment’ options. This concluding chapter presents an outlook for wastewater irrigation by integrating the major findings of the present volume, synthesizing key elements of the current global status and challenges of sanitation and wastewater irrigation with emphasis on the WHO Guidelines. It also highlights wastewater-governance opportunities with the greatest potential to support safe wastewater irrigation that simultaneously address the combined challenges deriving from the global sanitation, water and food crises.

Wastewater use in agriculture is a complex phenomenon since it transcends typical sectoral and geographical policy and planning boundaries, and is influenced by opinions and perceptions. Planning for wastewater use typically requires the involvement of a number of government agencies covering health, water, sanitation, agriculture and irrigation, as well as researchers, community groups and the private sector. Where wastewater use is already taking place spontaneously and unofficially, how can these stakeholders come together to improve the management of the system to maximize the livelihoods benefits while minimizing impacts on health and the environment? One option is the formation of multi-stakeholder platforms, which provide a space for stakeholders to share opinions and seek negotiated solutions in an open and ‘level’ environment. How effective these are, what outcomes can be expected, and how they can be improved are all questions that are still being asked. This chapter presents three case studies in which multi-stakeholder processes were used to improve wastewater management for urban agriculture. Although differences were observed, there were several cross-cutting lessons. A critical factor is the starting point, including an agreed definition of the problem to be addressed, negotiated goals and a management structure that is acceptable to all stakeholders. When multi-stakeholder processes are externally initiated, as with those reviewed here, it is essential that project priorities are commensurate with local priorities. Finding an institutional home and anchor agency an improve long-term sustainability but care must be taken in considering how this impacts on existing power structures. Participation and representation greatly influence the effectiveness of the process and much may need to be done to support this, for example by strengthening local community groups. A factor that appears to significantly improve participation and engagement is having tangible outputs, which demonstrate to stakeholders the potential of multi-stakeholder platforms.

This chapter addresses the importance of understanding farmers’ knowledge and perceptions on health-risk and risk-reduction measures for the development of mutually acceptable risk-management strategies. Drawing on studies from different countries, the chapter shows that it is not realistic to expect high risk awareness. In cases where farmers are aware of health risks, they assess mitigation measures in view of their overall impact on work efficiency and crop yield rather than only the potential health benefits to be gained. The chapter asserts that for on-farm risk-reduction measures to be successful, it is pertinent that farmers’ needs and constraints are incorporated into the formulation of recommended practices. This might happen through indigenous processes but can be supported through farm-based participatory approaches where farmers and scientists work together in developing risk reduction measures. An important first step is the identification of mutually accepted problem indicators. Where health benefits for farmers and consumers are not sufficient reasons for the adoption of safer practices, other triggers have to be identified as well as appropriate communication channels for effective outreach.

Interventions proposed and implemented for the mitigation of diarrhoeal diseases associated with wastewater reuse in agriculture have received little, if any, comparative assessment of their cost-effectiveness. This chapter assesses the costs, outcomes and cost-effectiveness of the so-called ‘treatment’ and ‘non- or post-treatment’ interventions as well as a combination of these for wastewater irrigation in urban Ghana using an approach that integrates quantitative microbial risk assessment (QMRA), disability-adjusted life years (DALYs) and cost-effectiveness analysis (CEA). The cost-effectiveness ratios (CERs) for the treatment and non-treatment interventions assessed ranged from US$31/DALY to US$812/DALY averted. Risk-reduction measures targeting farming practices and the basic rehabilitation of local wastewater treatment plants were the most attractive interventions with a CER well below the threshold of US$150/DALY, sometimes considered as the upper limit for a health intervention to be cost-effective in developing countries. All combinations associated with the basic rehabilitation of the treatment plants, with either on-farm or post-harvest interventions or both, resulted in CERs within the range of US$40/DALY to US$57/DALY. However, the CERs for the construction of a new wastewater treatment plant either as an independent intervention or in combination with on-farm and post-harvest interventions were unattractive in view of health-risk reduction for wastewater irrigation. Although attractive, the CERs of non-treatment options are largely dependent on compliance (adoption) by farmers and food vendors. In this regard, the CER increased by almost fivefold when the adoption rate was only 25 per cent by farmers and food vendors; but was attractive as long as adoption rates did not fall below 70 per cent. On the other hand, the success of the treatment option depends on the functionality of the treatment plants which is not without challenges in a country like Ghana. Thus, this chapter stresses the need for a balanced risk-management approach through a combination of treatment and non-treatment interventions to hedge against failures that may affect CERs at any end. While this chapter provides a contribution to the debate on interventions for health-risk mitigation in wastewater irrigation, more case studies would be useful to verify the data presented here.

This chapter presents farm-based measures that have been developed and tested in the informal irrigation sector to reduce microbiological health risks for consumers from wastewater irrigation of vegetables commonly eaten uncooked. The measures target poor smallholder farmers or farmer associations in developing countries as part of a multiple-barrier approach for health-risk reduction along the farm to fork pathway. Measures discussed include treatment of irrigation water using ponds, filters and wetland systems; water application techniques; irrigation scheduling; and crop selection. In addition, the chapter highlights some practical strategies to implement these measures, based largely on field experiences in Ghana. Although most measures discussed do not fully eliminate possible health risks, they can significantly complement other pathogen barriers. Which measures fit, either alone or in combination, will depend on local site characteristics and practices. Further studies are required to develop new measures or adapt them to other irrigation practices and systems in developing countries.

In and around urban areas pollution of natural water bodies is on the rise. As a result, wastewater irrigation is an increasingly common reality around most cities in the developing world. For reasons of technical capacity or economics, effective treatment may not be available for years to come; therefore, international guidelines to safeguard farmers and consumers must be practical and offer feasible riskmanagement options. This chapter provides an introduction to microbiological hazards. These can be addressed best in a step-wise risk assessment and management approach starting with wastewater treatment where possible, and supported by different pathogen barriers from farm to fork. A major change in the most recent WHO Guidelines for the safe use of wastewater, excreta and greywater in agriculture and aquaculture (WHO, 2006) agriculture is the focus on a holistic approach to achieving health-based targets, instead of prescribing irrigation waterquality threshold levels that are often unattainable. The health-based targets should not be read as absolute values but as goals to be attained in the short, medium or long term depending on the country’s technical capacity and institutional or economic conditions. Local standards and actual implementation should progressively develop as the country moves up the sanitation ladder. While healthrisk assessments are recommended to identify entry points for risk reduction and health-based targets, the Guidelines also offer shortcuts in situations where research capacities and data are constrained.

In most developing countries wastewater treatment systems have very low coverage or function poorly, resulting in large-scale water pollution and the use of poor-quality water for crop irrigation, especially in the vicinity of urban centres. This can pose significant risks to public health, particularly where crops are eaten raw.; Wastewater Irrigation and Health approaches this serious problem from a practical and realistic perspective, addressing the issues of health risk assessment and reduction in developing country settings. The book therefore complements other books on the topic of wastewater which focus on high-end treatment options and the use of treated wastewater.; This book moves the debate forward by covering also the common reality of untreated wastewater, greywater and excreta use. It presents the state-of-the-art on quantitative risk assessment and low-cost options for health risk reduction, from treatment to on-farm and off-farm measures, in support of the multiple barrier approach of the 2006 guidelines for safe wastewater irrigation published by the World Health Organization. The 38 authors and co-authors are international key experts in the field of wastewater irrigation representing a mix of agronomists, engineers, social scientists and public health experts from Africa, Asia, Europe, North America and Australia. The chapters highlight experiences across the developing world with reference to various case studies from sub-Saharan Africa, Asia, Mexico and the Middle East. The book also addresses options for resource recovery and wastewater governance, thus clearly establishes a connection between agriculture, health and sanitation, which is often the missing link in the current discussion on ‘making wastewater an asset’.

Water pollution can be considered as a side-effect of economic growth and is a common phenomenon in fast growing cities in developing countries. This paper describes the situation in Addis Ababa by tracing the origins of pollution and by portraying urban and peri-urban farmers who depend on polluted water sources for irrigated agriculture. Discharge of untreated effluent from industries, solid wastes and wastewater from households and institution, are the major sources of pollution of the rivers flowing through the city. For existing industries, pollution control mechanisms such as discharge permits and limits to the disposal of effluents into the environment should be enforced. The local and state governments should enhance public sensitization programs on hygiene, sanitation and environmental issues.

Improvement of sanitation facilities and subsequent practices is considered to contribute to overall human development with far reaching benefits for the welfare of people. It can reduce wastewater flows when treatment capacities are upgraded, but it can also create a higher load of wastewater flowing into the environment downstream. Additional sanitary water requirements in a water scarce city may be difficult to meet. In this paper we explore the scale of impact of improving sanitation in Addis Ababa in terms of water quality and quantity of water flows in and out of the city. Conventional approaches to sanitary improvement at the city level, like extension of the sewage coverage and upgrading of wastewater treatment capacities will require additional water in a city that is already water scarce. Also, it will change the characteristics of irrigation water that is used by farmers in and around the city.

The goal of the project was to develop integrated and user-oriented strategies to safeguard public health concerns without compromising livelihoods and land and water productivity in wastewater irrigated urban and peri-urban vegetable farming. In this project, assessment of land and water productivity in wastewater irrigated farming was done, levels of contamination on irrigation water and vegetables quantified at different levels along the food chain (farms, markets and consumer level) and appropriate lowcost risk reduction strategies identified and participatory testing done with stakeholders at farm and consumer levels. A large number of students were involved in the project, significantly building human capacity.

Hospital effluents can be especially hazardous and toxic due to their content of chemical, pathogenic and bio-hazardous wastes. Many of these toxic pollutants are not fully removed or neutralized by traditional municipal wastewater treatment plants, which are primarily designed to address parameters such as Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), etc. They are also not easily removed by filtration, settling or flocculation. The common disposal of liquid waste from hospitals into the municipal network collection system or in cesspits is of serious concern and it requires swift and effective address. Wastewater from hospitals contains pollutants that are hazardous and require on-site management to prevent contaminating the city’s sewage system and other surface waters. Unlike industrial operations that typically have a few large volume waste streams; hospitals generate different volumes of a wide variety of wastes and emissions. Most important chemicals in hospital wastewater are disinfectants (due to their major use in hospital practice), antibiotics, cytostatic agents, anesthetics, heavy metals (silver, chromium, zinc, lead, copper, platinum, and mercury), rare earth elements (gadolinium, indium, and osmium) and iodinated X-ray contrast media. Pollution prevention strategies and Best Management Practices (BMPs) to pollutant load reduction at the source is the best solution available to overcome this problem. The pollutant load reduction can be initiated by applying pollution prevention strategies and Best Management Practices (BMPs) to practices that use these chemicals. The goal of pollution prevention in healthcare environments is the same as throughout industry do to eliminate and/or reduce pollution at the source. The major difference when undertaking pollution prevention at healthcare facilities is that they do not manufacture a ‘product’, operate a fabrication ‘process’ or generate waste materials that can be readily recycled, reused or reprocessed. Therefore, the role of Pollution Prevention Strategies, Best Management Practices and Cleaner Production will be somewhat different than other industrial sectors. Pollution Prevention Strategies, Best Management Practices and Cleaner Production applicable to hospital wastewater management in Sri Lanka and Bangladesh are addressed in this paper.

This project aims to identify the risks and benefits associated with the use of wastewater in urban and peri-urban fodder and vegetable cropping systems in India and Pakistan, where wastewater is largely untreated due to lack of public finance. Two mega-cities (Faisalabad, Pakistan and Hyderabad, India, with large untreated wastewater irrigation areas have been selected a) for comparative purposes and b) to develop and promote country-specific risk mitigation options. With a particular focus on food safety, livelihoods and livestock, the research will combine field and laboratory methods and structured interactions with producers, consumers, and authorities (urban planning, public health and water management). The goal of the project is to improve health and safeguard wastewater-dependent livelihoods of resource-poor urban and peri-urban farmers and consumers in developing countries. This overlaps with IWMI’s mission to improve water and land resources management for food, livelihoods and nature. The project’s purpose is to develop and promote the uptake of a set of risk mitigation options based on a comprehensive assessment of risks and benefits associated with wastewater irrigation in Hyderabad (India) and Faisalabad (Pakistan). The project will enable the uptake of the recommendations in two countries with large wastewater-irrigated areas and different political - institutional environments.

This tool contains guidelines intended to reduce the health risks and increase the health benefits from small reservoirs. Guidelines are structured in a step-wise manner, beginning with the identification of relevant health issues and concluding with small reservoir design and operation for improved human health. The guidelines focus on: major water-related diseases associated with small reservoirs in Africa, the added value of community participation in health impact assessment, opportunities to mitigate risks and improve human health through better planning and operation of small reservoirs, and improved planning, design, and management options.

This report presents seven innovations in Local-level Integrated Water Resource Management, based on lessons learnt in the IWRM Demonstration Projects in Malawi, Mozambique, Swaziland and Zambia.

This atlas provides information on the salient findings of the project entitled quot;Ensuring Health and Food Safety from Rapidly Expanding Wastewater Irrigation in South Asiaquot; coordinated by the International Water Management Institute (Hyderabad office). The three year project funded by the German Federal Ministry of Economic Cooperation and Development (Bundesministerium fr Wirtschaftliche Zusammenarbeit und Entwicklung - BMZ) was carried out in two countries, India and Pakistan, in collaboration with a number of international and local partners. This atlas highlights the findings from India. The atlas comprises thematic maps and their corresponding descriptions highlighting the key findings of the project. The wastewater use in agriculture described here is associated with a polluted riverine system, due to all types of city discharges. As such, it can be expected that the water quality can change considerably in different stretches of the 40 km stretch of the river, with the head end being more polluted than the tail end. Therefore in order to avoid a rigid classification, the descriptions to the maps refer to the term quot;(Musi) river waterquot;. In the rest of text, the term quot;wastewaterquot; is used in the context of the chemical and biological attributes associated with agronomic and health risks in any given stretch of the river. The atlas was prepared as a summary document of the key findings of the project, to promote a discussion on the wastewater use in agriculture, at the dissemination workshop held in October 2008.

Water is essential for life. World over, there is a growing demand for water resources whether it be for agriculture, industry or domestic use. Population increases adds to this burden, and with nearly half the population projected to live in cities by 2020, competition for water resources is ever increasing. Evidence is also mounting on how this precious commodity will be in short supply in the future, while climate change is influencing its distribution in the most unexpected and unpredictable manner. Given these scenarios, it is prudent and timely to re-look at conservation and re-use strategies of water. Many countries around the world are already using reclaimed water as an alternative source for a wide range of applications, including landscape and agricultural toilet and urinal flushing, industrial processing, wetland restoration and ground water recharge. However, water reclamation and re-use is not without consequences. Human health risks associated with the re-use of recycled water is one of the areas that require closer scrutiny and good planning with guidelines and regulations prior to use. This session looks at the water reuse strategies and associated health risks

Water resources management is important for the developmental processes of any country, as the demand for water for all forms life and sectors is increasing. Closely linked to water development is health, where water acts as a vehicle for all types of diseases and plays a vital role in sanitation as well. As such, there is a great need for water resources management, to address health safeguards, which are often not looked at, in a holistic manner. Integrated Water Resources Management (IWRM) affords the best practise, for such an effort, as it aims to bring, social, economical and ecological sustainability of resources to communities. Management of water resources in relation to health requires a close collaboration of a number of stakeholders. This session looks at how different countries have looked at health opportunities through water resources management and what needs to be planned for the future in the region.

BACKGROUND: In most parts of Pakistan, untreated city effluent is utilised for growing vegetables around large urban settlements such as Faisalabad. Farmers use it as a source of irrigation water and plant nutrients. However, its continuous use may have serious environmental implications, since it also contains heavy metals. In this study the Faisalabad city effluent was examined for irrigation quality and its impact on irrigated soils and vgetables. RESULTS: Irrigation hazard of the effluent was moderate (electrical conductivity (EC) 1.1–1.7 dS m-1, Sodium adsorption ratio (SAR) 5.9–17.4mmol1/2 L-1/2, Residual sodium carbonate (RSC) 1.0–2.1mmolc L-1) at site 1 and strong (EC 3.7–4.1 dS m-1, SAR 16.1–21.8mmol1/2 L-1/2, RSC 4.0–9.1mmolc L-1) at site 2.Mean concentrations of ammonium bicarbonate/diethylene triamine pentaacetic acid (AB/DTPA)-extractable Cd, Co andMn at upper soil depth (0.0–0.2m)were respectively 0.080, 0.057 and 217.4mg kg-1 at site 1 and 0.101, 0.076 and 164.1mg kg-1 at site 2. CONCLUSION: The concentrations of Cd and Mn were above the permissible limits but that of Co was below the permissible limit for irrigation. The concentrations of Cd, Co and Mn tended to decrease with increasing soil depth. Accumulation of metals was higher in leaves irrespective of whether leaves were the edible or non-edible component of shoots. Use of untreated city effluent for irrigation without risk assessment and management could be a serious hazard, impacting soil and crop quality and ultimately human health.

Quantitative Microbial Risk Assessment (QMRA) models with 10,000 Monte Carlo simulations were applied to ascertain the risks of rotavirus and Ascaris infections for farmers using different irrigation water qualities and consumers of lettuce irrigated with the different water qualities after allowing post-harvest handling. A tolerable risk (TR) of infection of 7.7 1024 and 1 1022 per person per year were used for rotavirus and Ascaris respectively. The risk of Ascaris infection was within a magnitude of 1022 for farmers accidentally ingesting drain or stream irrigation water; ,100 for farmers accidentally ingesting farm soil and 100 for farmers ingesting any of the irrigation waters and contaminated soil. There was a very low risk (1025) of Ascaris infection for farmers using pipe 2 water. For consumers, the annual risks of Ascaris and rotavirus infections were 100 and 1023 for drain and stream irrigated lettuce respectively with slight increases for rotavirus infections along the post-harvest handling chain. Pipe irrigated lettuce recorded a rotavirus infection of 1024 with no changes due to post harvest handling. The assessment identified on-farm soil contamination as the most significant health hazard.

Even though malaria continues to cause high morbidity and mortality in most of the malaria endemic countries in the world, it is currently not a major health problem in Sri Lanka. Despite the low malaria incidence, the development and spread of anti-malarial drug resistance, combined with a recent increase in the armed conflict hindering provision of effective health services will make it difficult to control malaria in Sri Lanka. Since chloroquine (CQ) resistant Plasmodium falciparum was first reported from Dambulla area in 1984, the number has increased to more than 50% observed in vivo from various endemic areas. In concordance with this, single nucleotide polymorphisms (SNPs) in genes of P. falciparum responsible for CQ resistance are present. A limited number of trials have investigated the efficacy of the second line drug, sulfadoxine/ pyrimethamine (SP) against P. falciparum and a few cases of resistance have been reported. Moreover, SNPs in P. falciparum genes responsible for SP resistance are present and may constitute a sign of evolving SP resistance development. For P. vivax, drug resistance is not yet recorded as a problem in Sri Lanka, however the prevalence of SP resistant SNPs in P. vivax populations seems high and may pose a risk despite that SP is not used directly against P. vivax infections. Continuous monitoring of drug efficacy in vivo, as well by measuring the prevalence of SNPs related to drug resistance are major issues to be addressed.

This document was prepared by the Consumer Industry Team of the World Economic Forum as part of the Industry Partner Programme. Industry Partners are select member companies of the World Economic Forum that are actively involved in the Forum’s mission at the industry level. Partnership brings visibility and insight to strategic decision-making on the most important industry and cross-industry related issues and the opportunity to engage in actions of global corporate citizenship. Partners: Peter Brabeck-Letmathe, Chairman and Chief Executive Officer, Nestl; Member of the FoundationBoard of the World Economic Forum. Margaret Catley-Carlson, UN Secretary-General’s Advisory Board on Water and Sanitation. Colin Chartres, Director- General, International Water Management Institute (IWMI). E. Neville Isdell, Chairman and Chief Executive Officer, The Coca-Cola Company. Andrew N. Liveris, Chairman and Chief Executive Officer, The Dow Chemical Company. Graham Mackay, Chief Executive, SABMiller. Julia Marton-Lefvre, Director General, IUCN. David Molden, Coordinator, Comprehensive Assessment of Water Management, International Water Management Institute (IWMI). Indra Nooyi, Chairman and Chief Executive Officer, PepsiCo. Letitia Obeng, Chair, Global Water Partnership. Ralph R. Peterson, Chairman and Chief Executive Officer, CH2M HILL Companies. Klaus Schwab, Founder and Executive Chairman, World Economic Forum.

The world currently faces food, water and energy crisis. All are interlinked, in that water underpins food production and water is also under competition for use in the energy sector including hydropower generation and biofuels production. However, until recently, we have continued to use water as if it is an infinite resource and we squander millions of litres through inefficient management practices in many sectors of the economy. Furthermore, once used in agriculture, industry and domestically, water is returned to the environment frequently contaminated with salts, pesticides, persistent organic compounds, sewage and heavy metals. Elsewhere, literally cubic kilometers of untreated effluent are dumped in the oceans, polluting fisheries and the environment alike. Storm water runoff is often similarly discharge straight into rivers, and lakes, or the ocean rather than being seen as a valuable resource. Whilst many developed countries have done much to clean up their act with respect to sewage treatment, there are many developing countries that have few, if any, operational sewage treatment plants. Where sewage is discharged into rivers, it is often reused almost immediately in its untreated form by poor farmers. Whilst the nutrients in the water can be regarded as useful fertilizer, other contaminants including fecal coliform bacteria, helminths, viruses and chemical and metal contaminants pose immediate health risks for those using the water for irrigation and for those who consume their produce. This paper addresses some of the key issues associated with the utilization of waste water in agriculture in terms of viewing waste water as an important resource that can assist in fighting the water and food crises. It examines the major contaminants in waste water being used in agriculture and considers these from risks that they pose to human health and the environment. It also considers the types of responses that are required from government to ensure that management, regulation and policy actions are introduced to ensure that risks are adequately minimized. The paper is focused around work in developing countries and will use examples from West Africa, India, Pakistan and Sri Lanka. Wastewater use is already a common reality on some 20 million hectares, where inadequate local sanitation facilities mean that farmers often have no alternative to the use of heavily polluted irrigation water. In many cases farmers have to stand in the polluted water to extract it and the water is then irrigated directly onto the leaves of green vegetables and fodder crops. Furthermore, little may be done between the field and the point of sale to wash off biological contaminants. In other cases, heavy metals and persistent organic compounds may also be found in the irrigation water and these may accumulate in the soil and the edible leaves and tubers of food crops causing long term damage to consumers. Whilst immediate effects of contamination are usually most notic

Where rapid urbanization is outpacing urban capacities to provide sound sanitation and wastewater treatment, most water sources in city vicinity are heavily polluted. This is of great concern as many of the leafy vegetables eaten raw in the cities are produced in these areas. Following the new WHO guidelines, different non-treatment options at farm, market, and kitchen level were field tested for health risk reduction with special consideration to efficiency and adoption potential. As most households are used to vegetable washing (although ineffectively), an important entry point for risk reduction is the increased emphasis of the new guidelines on food preparation measures. A combination of safer irrigation practices (water fetching, on-farm treatment, and application), the allocation of farmland with better water sources, and improved vegetable washing in kitchens appear to be able to reduce the potential risk of infections significantly, although it might not be possible to reach the ideal threshold without some kind of wastewater treatment. The on-farm trials carried out in Ghana also explored the limitation of other risk reduction measures, such as drip irrigation, crop restrictions and cessation of irrigation under local circumstances considering possible incentives for behaviour change.

Vietnamese farmers’ health-risk awareness, knowledge, and practices related to their use of wastewater and human excreta was investigated in an anthropological study by a multidisciplinary team in peri-urban Hanoi and Nghe An Province. Farmers identified health risks associated with their use of excreta and wastewater, but they viewed these as unavoidable risks related to production. They perceived the health risks as different for the use of wastewater and human feces. They perceived health risks from wastewater as non-serious because it remained on the skin and only caused skin problems, but they considered health risks from non-composted smelly feces serious because it entered the body through ‘polluted’ air. Most farmers were more aware of threats to health from ‘dirt’ entering the domestic environment than of the health risks during their work. The concept of ‘dirt’ should be separated from understanding of germs, viruses, and parasites so that it is understood that things that carrying health risks cannot always be identified by their ‘dirtiness’ or smell. Farmers mainly considered hygiene and health as women’s issues. Men’s responsibility for the health and hygiene of the family should therefore be emphasized.

We assessed the prevalence of Cryptosporidium and Giardia infections among children using protected and unprotected water sources in the Lege Dini watershed, Eastern Ethiopia, in November 2005 and May 2006. Of 655 children examined, 80 (12.2%) were infected with Cryptosporidium and 231 (35.3%) with Giardia. No difference was observed in the prevalence of cryptosporidiosis and giardiasis (P gt; 0.05) between children drinking water from protected and unprotected sources.

Most irrigation water used in urban vegetable farming in Ghana is contaminated with untreated wastewater. This poses health risks to farmers and consumers. As part of a study to explore options for health risk reduction, this paper summarizes farmers’ perceptions on health risks and possible risk reduction measures. Participatory research methods and techniques such as focus group discussions, in-depth interviews and visualization techniques were used for data collection based on methodological triangulation. The findings showed that farmers were aware that untreated wastewater posed health risks. Occupational health risks like skin infections were perceived to have the greatest risks and not nematode infections and bacterial diseases which are usually associated with wastewater irrigation. Possible health risks to consumers were rated very low and many farmers said that they were sensitized on this through media and projects. Farmers perceived many of the risk reduction measures suggested in the international guidelines as unsuitable and identified simple and low-cost measures which they could easily adopt. They were willing to adopt risk reduction measures to avoid further pressure from the media, authorities and the general public, especially if they had some incentives. These findings demonstrate the need to involve farmers as early as possible in intervention projects especially in informal farming practices, like urban agriculture, where restrictions are difficult to implement. This will ensure that their perceptions, constraints or any other required incentives for adopting interventions are considered, hence leading to developing more appropriate interventions.

In 4 out of 5 cities in developing countries, wastewater is used to cultivate perishable crops for urban markets. Such practices create a health risk but provide important livelihood benefits. This study through an analysis of 53 cities in developing countries, contributes to understanding the factors that drive wastewater use. The main drivers are (1) increasing urban water demand without wastewater treatment causing pollution of irrigation water sources; (2) urban food demand favoring agriculture close to cities where water sources are polluted; and (3) lack of cheaper, similarly reliable or safer water sources. Poverty, which constrains the infrastructure needs of urbanization, is an added factor. The study makes policy recommendations stressing on, effectively applying the WHO guidelines, linking investments in water supply with sanitation for maximum beneficial impact on water pollution, and involving actors at both the national and local level, for water quality improvements and health risk reduction.

It is often argued that investments in water supply and sanitation (WSS) generate wide-ranging economic benefits. At the household level improved access to WSS is expected to lead to significant improvements not only in human health and welfare but also in levels of production and productivity. Investments in WSS are therefore considered important instruments for poverty reduction, but empirical evidence to support this remains quite limited. This study presents micro-evidence from a survey of 1500 households in Ethiopia on the economic impacts of improved access to WSS. We found that access to improved WSS has a strong statistical association with increased household water consumption and decreased average time spent to fetch water. Because of this time saving, household members with access to improved sources were also found to be more likely to participate in off-farm/non-farm employment. We also found strong evidence of positive impacts of improved access to WSS on health; although there are indications some type of illnesses may also have increased (e.g. water borne diseases). This evidence clearly shows that improving access to water supply infrastructure alone is not sufficient to bring about desired public health benefits. Interestingly, households with access to improved water supply and agricultural water were found to have significantly lower overall and food poverty levels in terms of incidence, depth and severity of poverty. Therefore, the pathways through which improved access to water supply has impacted poverty reduction in the study areas had to do with direct improved health benefits and through time-saving benefits induced increased participation of households in off/non-farm employment and irrigation. Determinants of off/non-farm employment and poverty were systematically analysed and factors identified and recommendations made to enhance these poverty impacts of water supply improvements.

Research undertaken over the last 40 years has confirmed that the long-term consumption of cadmium (Cd) contaminated rice contributes to human Cd disease. Rice is the staple of millions throughout South and Southeast Asia. Therefore, the ability to accurately assess the risk of rice grain Cd uptake in areas of elevated soil Cd would be a pre-requisite to protecting public health and regional export security. During 2001–2002, 308 concomitant soil and rice grain samples were collected from a Cd/Zn co-contaminated site in Western Thailand and determined for aqua regia digested soil Cd and rice grain Cd. No significant relationship was observed between total soil Cd and rice grain Cd (r 2 = 0.117). This intuitively is to be expected since total soil Cd bears no relationship to phyto-available Cd. Similarly no relationship was observed between 0.005 M DTPA extractable soil (air-dry) Cd and rice grain Cd (r 2 = 0.165). Again this result could have been predicted as the phyto-availability of Cd in paddy soils is a function of the complex interaction between soil pH, redox conditions and the presence of competing ions. Consequently, in 2003 a further study was undertaken to assess the effectiveness of commonly utilized soil extractants namely, 0.1, 0.05 and 0.01 M CaCl2 solutions at a soil extractant ratio of 1:5 and 1 M NH4NO3 for 2 h or 4 h extractions times at a soil/extractant ratio of 1:2.5. Soil samples were collected at the critical rice grain fill stage and sub-divided into Portion A which was subjected to conventional air-drying and sample preparation procedures and Portion B which was maintained at Field Condition (FC) and stored at lt;4C until extractions were undertaken. Concomitant rice grain samples were collected at maturity. The results indicate that air-dried soil samples subjected to conventional soil preparation procedures were totally ineffective at predicting the uptake of Cd by rice stem, leaf or grain, regardless of extractant. Further, the results indicate that the Stepwise Regression model incorporating 0.1 M CaCl2 extractable Cd and soil pHw determined on field moist samples accounts for 63.8% of the variability in rice grain Cd.

In India, high fluoride concentration in groundwater (greater than 1 mg/l) is widespread in the arid to semi-arid western states of Rajasthan and Gujarat and in the southern states of Andhra Pradesh, Karnataka and Tamil Nadu. A field research study conducted at six areas severely affected by fluorosis shows that affordability of safer drinking water is related to higher income level, and that the severity of fluorosis affliction is higher for lower income levels. The cost incurred on medicines and loss of wages is a significant proportion of the earnings and has a general debilitating impact on the affected families. As compared with fluorosis, the skin afflictions of arsenicosis carry greater social stigma and patients incur higher costs. In Nadia district of West Bengal, the impacts of arsenic contamination are more severe with increasing age. Cumulatively, over the entire afflicted population, both fluoride and arsenic contamination have a high cost on society and addressing the problem would require more attention from government agencies and society apart from individual awareness.

This project is funded by the European Commission under its Asia Pro Eco II Program. It is undertaken by the International Water Management Institute (IWMI), Sri Lanka; COSI, Sri Lanka; the International Water and Sanitation Centre (IRC), the Netherlands; NGO Forum for Drinking Water Supply and Sanitation, Bangladesh; and the Stockholm Environment Institute (SEI), Sweden. The project pilot cities are Rajshahi City in Bangladesh and Kurunegala City in Sri Lanka.

This project is funded by the European Commission under its Asia Pro Eco II Program. It is undertaken by the International Water Management Institute (IWMI), Sri Lanka; COSI, Sri Lanka; the International Water and Sanitation Centre (IRC), the Netherlands; NGO Forum for Drinking Water Supply and Sanitation, Bangladesh; and the Stockholm Environment Institute (SEI), Sweden. The project pilot cities are Rajshahi City in Bangladesh and Kurunegala City in Sri Lanka.

This project is funded by the European Commission under its Asia Pro Eco II Program. It is undertaken by the International Water Management Institute (IWMI), Sri Lanka; COSI, Sri Lanka; the International Water and Sanitation Centre (IRC), the Netherlands; NGO Forum for Drinking Water Supply and Sanitation, Bangladesh; and the Stockholm Environment Institute (SEI), Sweden. The project pilot cities are Rajshahi City in Bangladesh and Kurunegala City in Sri Lanka.

Objective and methods: Vegetables irrigated with untreated domestic wastewater were, at the time of harvest, analysed for the presence of the faecal indicator, Escherichia coli, and helminth eggs in Faisalabad, Pakistan. Vegetables from the same harvested batch were collected approximately 12 h later from the local market. Results: The survey found relatively low concentrations of E. coli (1.9 E. coli per gram), but relatively high concentrations of helminths (0.7 eggs per gram) on vegetables collected from agricultural fields. Higher concentration of both E. coli (14.3 E. coli per gram) and helminths (2.1 eggs per gram) were recovered from the vegetables collected from the market. Conclusions: The results of the survey suggest that unhygienic post harvest handling was the major source of produce contamination. Interventions at the market, such as the provision of clean water to wash produce in, are better ways to protect public health and more cost effective than wastewater treatment.

This Water Policy Briefing was produced by IWMI in partnership with the Global Water Partnership (GWP) Advisory Center at IWMI and the GWP Technical Committee. It is based on the book Wastewater Use in Irrigated Agriculture: Confronting the Livelihood and Environmental Realities, edited by C.A. Scott, N.I. Faruqui, and L.Raschid-Sally (CABI/IWMI/IDRC, 2004), and the revised WHO Guidelines for the Safe Use of Wastewater, Excreta and Greywater (2006, In Press). The brief complements Catalyzing Change, the GWP handbook for developing IWRM and water efficiency strategies and plans, and the associated policy and technical briefs. In developing countries, fast-growing urban populations are demanding more fresh water and food, while generating greater volumes of domestic wastewater. Due to the lack of comprehensive wastewater management, a major portion of the wastewater pollutes natural water bodies. These polluted sources are used in and around the cities for agriculture and other purposes. In drier climates, farmers often use the wastewater itself from drains and sewers because it is the only (reliable) source of water. Although municipalities increasingly recognize the importance of this sector in supplying cities, amongs other things with vitamin rich vegetables, they are also aware of the associated health risks through microbial crop contamination1, especially when it concerns food consumed uncooked. Among wastewater-related infections, diarrhoeal diseases are the top cause of death among children in the developing world. Fragmented attempts have been made to address this problem, by relying on technical solutions (wastewater treatment) or regulatory measures (such as banning wastewater irrigation or restricting the types of crops irrigated). Both approaches have failed in the context of low-income countries. What’s required is an integrated water resources management (IWRM) approach which looks at the whole urban water cycle and across the urban-rural continuum at environmental consequences downstream, as well as socio-economic benefits of resource recovery. This has to be combined with locally appropriate and sustainable risk reduction measures. It should also recognize that solutions require the active involvement of stakeholders from different sectors. This is a vital point in a sensitive and multi-sectoral issue like “peri-urban wastewater irrigation”, which commonly concerns different ministries and municipal departments.

One year ago, the authors of this article reported in this journal on the malaria situation in Sri Lanka prior to the tsunami that hit on 26 December 2004, and estimated the likelihood of a post-tsunami malaria outbreak to be low. Malaria incidence has decreased in 2005 as compared to 2004 in most districts, including the ones that were hit hardest by the tsunami. The malaria incidence (aggregated for the whole country) in 2005 followed the downward trend that started in 2000. However, surveillance was somewhat affected by the tsunami in some coastal areas and the actual incidence in these areas may have been higher than recorded, although there were no indications of this and it is unlikely to have affected the overall trend significantly. The focus of national and international post tsunami malaria control efforts was supply of antimalarials, distribution of impregnated mosquito nets and increased monitoring in the affected area. Internationally donated antimalarials were either redundant or did not comply with national drug policy, however, few seem to have entered circulation outside government control. Despite distribution of mosquito nets, still a large population is relatively exposed to mosquito bites due to inadequate housing. There were no indications of increased malaria vector abundance. Overall it is concluded that the tsunami has not negatively influenced the malaria situation in Sri Lanka.

This project is funded by the European Commission under its Asia Pro Eco II Program. It is undertaken by the International Water Management Institute (IWMI), Sri Lanka; COSI, Sri Lanka; the International Water and Sanitation Centre (IRC), the Netherlands; NGO Forum for Drinking Water Supply and Sanitation, Bangladesh; and the Stockholm Environment Institute (SEI), Sweden. The project pilot cities are Rajshahi City in Bangladesh and Kurunegala City in Sri Lanka.

This project is funded by the European Commission under its Asia Pro Eco II Program. It is undertaken by the International Water Management Institute (IWMI), Sri Lanka; COSI, Sri Lanka; the International Water and Sanitation Centre (IRC), the Netherlands; NGO Forum for Drinking Water Supply and Sanitation, Bangladesh; and the Stockholm Environment Institute (SEI), Sweden. The project pilot cities are Rajshahi City in Bangladesh and Kurunegala City in Sri Lanka.

The risk of Giardia duodenalis (Giardia) infection in farmers using untreated wastewater in agriculture was investigated in the city of Faisalabad, Pakistan, through a cross-sectional study. The study found a significantly increased risk of (asymptomatic) Giardia infection in wastewater farming households when compared with farming households using regular (non-wastewater) irrigation water (OR 3.3, 95% CI 2.5-4.4). Textile labourers who were employed in the city of Faisalabad but who lived in the same village as the wastewater farmers showed a risk of Giardia infection in between that of wastewater and non-wastewater farming households (OR 2.4, 95% CI 1.9-3.1). This study suggests that exposure to wastewater with high Giardia concentrations carries an increased risk for (asymptomatic) Giardia infection.

This research report discusses ecological aspects of schistosomiasis transmission and options for its control in irrigated areas in Africa through environmental measures. Human schistosomiasis is endemic in 46 African countries.After being infected by larvae emerging from human excreta and urine deposited in the water, freshwater snails act as intermediate hosts.

The objective of the current study was to investigate the role of waste stabilization ponds (WSP) and wastewater-irrigated sites for the production of mosquitoes of medical importance. Mosquito larvae were collected fortnightly from July 2001 to June 2002 in Faisalabad, Pakistan. In total, 3,132 water samples from WSP and irrigated areas yielded 606,053 Culex larvae of Þve species. In addition, 107,113 anophelines, representing eight species were collected. Anopheles subpictus (Grassi) and Culex mosquitoes, especially Culex quinquefasciatus (Say) and Culex tritaeniorhynchus (Giles), showed an overwhelming preference for anaerobic ponds, which receive untreated wastewater. Facultative ponds generated lower numbers of both Anopheles and Culex mosquitoes, whereas the last ponds in the series, the maturation ponds, were the least productive for both mosquito genera. An. subpictus and Anopheles stephensi (Liston) were the dominant Anopheles species in wastewaterirrigated sites, with Anopheles culicifacies (Giles) recorded in low numbers. This was also the pattern in nearby sites, irrigated with river water. Among the Culex species, Cx. tritaeniorhynchus was by far the most frequently recorded in both wastewater- and river water-irrigated sites with Cx. quinquefasciatus as the second most abundant species but restricted to wastewater-irrigated areas. Univariate logistic regression analysis showed that presence of An. subpictus and Culex mosquitoes was signiÞcantly associated with emergent grass vegetation and low salinity. Regular removal of emergent grass along the margins of the anaerobic ponds and changes in the concrete design of the ponds are likely to reduce the mosquito production, especially of Culex species.

The purpose of this study was to identify risk areas in Thailand where insecticide resistance in malaria mosquitoes might develop as a consequence of crop protection activities in agriculture. The study provides guidelines on how to delineate risk areas. A review of insecticide resistance in disease vectors and the potential role of agricultural insecticides is presented.

For the 13th meeting of the Commission on Sustainable Development (CSD-13), the Swedish International Development Cooperation Agency (Sida) commissioned the Stockholm International Water Institute (SIWI) to produce “Let it Reign: The New Water Paradigm for Global Food Security”. The report presents recommendations for policy and decision makers with regard to sustainable food production, sustainable food consumption and ecological sustainability. The topic addressed in this report is an issue identified as being of very high priority for Sida. The views put forward in this report, on the other hand, are expressed solely on behalf of the authors. Collaborating partners for the report have been the International Food Policy Research Institute (IFPRI), IUCN – The World Conservation Union and International Water Management Institute (IWMI).

This report analyses environmental and health impacts arising from agricultural water development in sub-Saharan Africa and recommends ways to increase the sustainability of investments in irrigation by taking into account health and environmental concerns. In many places in the region irrigation is a key means of enhancing productivity that can reduce poverty and improve livelihoods. However, failure to adequately foresee, plan and manage the negative environmental and health impacts arising from irrigation undermines the sustainability of many projects and may worsen poverty.This report is not intended as a compendium of data on environmental and health issues pertaining to agricultural water development. Rather it seeks to provide an overview and framework for understanding policy and programming issues to tackle these issues.

Wastewater reuse is particularly critical in arid and semi-arid countries. Although unregulated irrigation with wastewater does persist in some countries of this region, especially nearer smaller urban centers, the trend is towards regulated reuse of treated wastewater – as far as available capital resources allow.

Exploiting the nutrient and water value in wastewater through agriculture and aquaculture may also help limit uncontained pollution that results from unregulated disposal of wastewater in surface water bodies. Treatment processes form an important part of wastewater reuse strategies, alongside other measures to protect health, but a concerted effort to promote capacity at all levels is required to enable the benefits of wastewater reuse to be realized.

Traditionally, engineering and environment-based interventions have contributed to the prevention of malaria in Asia. However, with the introduction ofDDTand other potent insecticides, chemical control became the dominating strategy. The renewed interest in environmental-management-based approaches for the control of malaria vectors follows the rapid development of resistance by mosquitoes to the widely used insecticides, the increasing cost of developing new chemicals, logistical constraints involved in the implementation of residual-spraying programs and the environmental concerns linked to the use of persistent organic pollutants. To guide future research and operational agendas focusing on environmental-control interventions, it is necessary to learn from the successes and failures from the time before the introduction of insecticides. The objective of this paper is to describe the experiences gained in Asia with early vector control interventions focusing on cases from the former Indian Punjab, Malaysia and Sri Lanka. The paper deals primarily with the agricultural engineering and land and water management vector control interventions implemented in the period 1900–1950. The selected cases are discussed in the wider context of environment-based approaches for the control of malaria vectors, including current relevance. Clearly, some of the interventions piloted and implemented early in the last century still have relevance today but generally in a very site-specific manner and in combination with other preventive and curative activities. Some of the approaches followed earlier on to support implementation would not be acceptable or feasible today, from a social or environmental point of view.; In Boelee, E.; Konradsen, F.; van der Hoek, W. (Eds.), Malaria in irrigated agriculture: Papers and abstracts for the SIMA Special Seminar at the ICID 18th International Congress on Irrigation and Drainage, Montreal, 23 July 2002. Colombo, Sri Lanka: IWMI. pp.5-14

The case studies reported here highlight important concepts and information on the linkages between water and poverty that may not be available elsewhere. The overall objective of the studies is to draw generic lessons and identify interventions that can help policy makers, planners and other stakeholders to develop actions that are effective in water resources management for the poor. All case studies focus on poor in South Asia, but all with differing geographic contexts or thematic focci. The first two papers are based on field surveys supplemented by literature reviews. The first focusses on the impact of water on poverty in a mountainous region in Nepal, while the second focusses on the impact of drought on water availability, and hence poverty, in a district in Pakistanapos;s Baluchistan province. The final two papers both took Sri Lanka as their area of study. The first Sri Lanka paper explores the linkages between water, health and poverty and presents a conceptual framework which was used to analyze the results of previous studies. Sri Lankaapos;s dry zone is the geographic focus of the second paper, which focusses primarily on the linkages between irrigation and poverty.

A nationwide assessment in Pakistan showed that the direct use of untreated wastewater for agriculture, particularly vegetable production, was common in most cities. The main reasons for this use were the absence of alternative water sources, the reliability of the wastewater supply, the nutrient value and the proximity to urban markets. It was estimated that 26% of the total domestic vegetable production of Pakistan was cultivated with wastewater. The importance of the wastewater was reflected in high water and land fees. Policy makers have to take the importance for local livelihoods and food security into account when making decisions regarding direct wastewater use

AIMS: To assess the prevalence and distribution of developmental defects of enamel and caries in 14-year-old children who had been lifetime residents in a region with different concentrations of fluoride in drinking water in Sri Lanka.DESIGN: A cross-sectional survey. SETTING: Uda Walawe--a rural area in southern Sri Lanka where fluoride concentration in ground water is reported to be within the range of 0.05-6.10 mg/l. METHOD: A total of 518 children from six representative schools from this area were examined for developmental defects of enamel and dental caries using the modified DDE index and WHO criteria. The present analysis is limited to 486 children from whom drinking water samples were collected. RESULTS: Based on the fluoride concentration of the drinking water source the children were categorised into four groups: lt;0.3, 0.31-0.49, 0.5-0.7 and gt;0.7 mg/l. The prevalence of enamel defects ranged from 29-57% whilst 27-55% of children were affected by diffuse opacities in the four groups. Of the ten teeth examined, between 1.6-3.6 teeth per child were affected by enamel defects. Maxillary first premolars were the most commonly affected by diffuse opacities followed by the maxillary canines. Caries prevalence varied between 18-25% whilst the mean DMFT and DMFS values ranged from 0.29-0.54 and 0.45-0.67 respectively. Occlusal surfaces were the most affected by caries. CONCLUSIONS: The wide differences observed in the prevalence and severity of enamel defects indicate that there are variations in individual response to high fluoride levels in drinking water. It also demonstrates the need to ascertain the factors that could contribute to the prevalence and severity of enamel defects other than high fluoride levels in drinking water.

The WaterDome was organized by the African Water Task Force, AWTF, with IWMI as its implementing agency.

Paper presented at the National Seminar on Water for Future, World Water Day, 22 March 2003

Based on research presented in “Urban-Wastewater Reuse for Crop Production in the Water-Short Guanajuato River Basin Mexico (IWMI) Research Report 41) by C. Scott, J.A. Zarazua and G. Levine; “Urban Wastewater: AValuable Resource for Agriculture: A Case Study from Haroonabad, Pakistan (IWMI Research Report 63)” by W. van der Hoek, M. Ul Hassan, J. Ensink, S. Feenstra, L. Rachid-Sally, S. Munir, R. Aslam, N. Ali, R. Hussain and Y. Matsuno: and “Use of Untreated Wastewater in Peri-Urban Agriculture in Pakistan: Risks and Opportunities (IWMI Research Report 64)” by K Ensink, W. van der Hoek, Y. Matsuno, S. Munir and R. Aslam.; In urban and peri-urban zones in developing countries, poor farmers commonly use nutrient-rich sewage and wastewater to irrigate high-value crops. In many places, this untreated wastewater is their only source of irrigation water—so their livelihoods depend on it. But, as well as bringing benefits, the unregulated use of wastewater also poses risks to human health and the environment. The prevailing “scientific” approach to wastewater irrigation advocates treatment before use and the implementation of strict regulations. But many developing countries can’t afford to build treatment facilities and do not have the resources to enforce regulations. There are other options, as IWMI research in Mexico and Pakistan demonstrates. Well-crafted policies on wastewater use have the potential to improve the incomes of poor urban and peri-urban farmers and reduce pollution of lakes, streams and aquifers. Continuing to turn a blind eye to wastewater use can result in higher incidences of disease among farmers and consumers and in irreversible degradation of the environment. Policymakers need to develop comprehensive strategies for managing wastewater tailored to local socioeconomic and environmental conditions and for analysis of the short- and long-term risks and benefits of all available options.

The transmission of malaria in Sri Lanka is unstable; its incidence greatly fluctuates from year to year and exhibits important variations within a year. Identification of the underlying risk factors of malaria is important to target the limited resources for the most-effective control of the disease. This report presents the first results of a project on malaria risk mapping to investigate whether this tool could be utilized to forecast malaria epidemics. It documents the key malaria risk factors for the Uda Walawe region of Sri Lanka, where monthly malaria incidence data were available over a 10-year period. In the study, data on aggregate malaria-incidence rates, land-use and water-use patterns, socioeconomic features and malaria-control interventions were collected and analyzed in a geographical information system. Malaria cases were mapped at the smallest administrative level and relative risks for different variables were calculated employing multivariate analyses. The findings of the study call for malaria-control strategies that are readily adapted to different ecological and epidemiological settings.

The study was conducted to assess caries and developmental defects of enamel in relation to fluoride levels in drinking water and the association between caries experience and the severity of diffuse opacities in children living in Uda Walawe, an area with varying concentrations of fluoride in drinking water in Sri Lanka. A total of 518 14-year-old children who were lifelong residents in this area were examined for dental caries and developmental defects of enamel. But the present analysis is confined to 486 children from whom drinking water samples were collected. The prevalence of enamel defects and diffuse opacities ranged from 27 to 57% while the prevalence of caries ranged from 18 to 29% in the different fluoride exposure groups. The prevalence of enamel defects increased significantly with the increase in the fluoride level in drinking water. Both the caries prevalence and the mean caries experience were significantly higher in children with diffuse opacities than in those without in the group consuming water containing gt;0.70 mg/l of fluoride. The association between dental caries and the severity of diffuse opacities was also significant only in this group. Children with the mildest form of opacities (DDE scores 3 and 4) had the lowest DMFS (0.25 +/- 0.7), and the highest DMFS (1.1 +/- 1.7) was found in those with the most severe form of opacities (DDE score 6). In conclusion, the relationship that was observed in this study between fluoride levels in drinking water, diffuse opacities and caries suggests that the appropriate level of fluoride in drinking water for arid areas of Sri Lanka is around 0.3 mg/l. Also individuals with severe forms of enamel defects in high-fluoride areas are susceptible to dental caries.

This paper presents examples of the close interactions, intended or unintended, between the various uses and users of irrigation water. The main focus is on the close link between water used for crop production in irrigated agriculture and water used by humans for drinking and other domestic purposes, a link that has largely been ignored by policy makers, governments, donors, international organizations, and the research community. In addition, a number of reasons are given as to why, from a public health point of view, an exclusive focus on water quality issues is a mistake and why more attention needs to be paid to the availability of sufficient quantities of water for domestic use than at present. The main argument that will be advanced is that significant health opportunities are missed due to the sectoral thinking of professionals and institutions involved in managing water. Several issues are expected to become very important in the twenty-first century and reflect the close linkages between water for food and water for people. These include the overexploitation of groundwater resources for irrigation, newly emerging groundwater quality problems, and increased recycling of water.

Published in “Tropical Medicine and International Health, Vol.6, No.1, pp.46-54, January 2001.” The complete article is available on the CD-ROM version of this Annual Report.