IWMI Projects on Pesticide Use and Abuse in Irrigated Areas

Economic & environmental impact assessment of urban and peri-urban agriculture (UPA), Kumasi

Project duration: 2000 - 2001/2

Objective: To identify and quantify off-site effects of intensive urban peri-urban agriculture, including pesticide use.

Field research location: Akumadan (peri-urban) and Kumasi (urban) in Ghana


  • Kwame Nkrumah University of Science and Technology (KNUST), Kumasi
  • Water Research Institute (WRI), Ghana
  • Soil Research Institute (SRI), Ghana
  • Kumasi Centre for Collaborative Research (KCCR) in Tropical Medicine

Project description:

This project focuses on the economic assessment of different off-site impacts of intensive urban and peri-urban agriculture (UPA). The project is analyzing the impacts of pesticide use on biodiversity (animals and plant species) and human health as well as other important health and environmental factors.

The expected output is to increase awareness on potentially negative impacts of UPA farming practices, and to give practical recommendations to reduce related health risks.


Mensah, E., Amoah, P., Abaidoo, R.C. and P. Drechsel. 2001. Environmental concerns of (peri-) urban vegetable production - Case studies from Kumasi and Accra. In: Drechsel, P. and D. Kunze (eds.) Waste Composting for Urban and Peri-urban Agriculture - Closing the rural-urban nutrient cycle in sub-Saharan Africa. IWMI/FAO/CABI: Wallingford (in press).

Drechsel, P., Abaidoo, R.C., Amoah, P. and O.O. Cofie, 2000. Increasing use of poultry manure in and around Kumasi, Ghana: Is farmers' race consumers' fate? Urban Agriculture Magazine 2:25-27.

Donors: This work was carried out with support from FAO.

Contact person: : Lucy A. Gyiele at iwmi-ghana@cgiar.org

Occupational pesticide exposure

Project duration: November 1999 - December 2000

Objective: To determine the health effects on farmers of regular exposure to pesticides

Field research location: Uda Walawe Irrigation Scheme, Ruhuna basin (an IWMI Benchmark Basin), Sri Lanka


Health effects due to routine occupational exposures have not been well documented in Sri Lanka but are assumed to be common. Widely used organophosphate and N-methyl carbamate insecticides may cause acute systemic effects largely mediated through cholinesterase inhibition. In addition, long-term relatively low exposure to pesticides, particularly organophosphate insecticides, is increasingly suspected of causing adverse effects on the nervous system.

Project description:
A study was undertaken to investigate health effects due to occupational exposure. Based on the results of this study, it can be concluded that occupational pesticide exposure has a major impact on the health of farmers in Uda Walawe. Twenty-four percent of the farmers reported having suffered at least once from an acute occupational pesticide poisoning in the past.
Furthermore farmers showed increased symptom prevalence, acetylcholinesterase inhibition and nerve dysfunction likely as a result of organophosphate exposure.

Farmers who had attended Integrated Pest Management demonstrations on rice cultivation had somewhat lower acetylcholinesterase inhibition levels than other farmers, but no effect on the prevalence of symptoms was found. Promotion and implementation of intensive, participatory IPM training (e.g. the Farmer Field School concept) may be an approach to minimize the use of insecticides and have more impact on the health of Sri Lankan farmers.


Smit LAM, Van Wendel de Joode BN, Heederik D, Peiris-John RJ, Van
der Hoek W. (2003) Neurological symptoms among Sri Lankan farmers
occupationally exposed to acetylcholinesterase-inhibiting insecticides. Am J Ind Med 44:254-64.

Smit LAM (editor). (2002) Pesticides: Health impacts and
alternatives. Proceedings of a workshop held in Colombo, 24 January 2002. Working Paper 45. Colombo, Sri Lanka: International Water Management Institute. (Available online)

Eddleston M, Karalliedde L, Buckley N, Fernando R, Hutchinson G,
Isbister G, Konradsen F, Murray D, Piola JC, Senanayake N, Sheriff R, Singh S, Siwach SB, Smit L. (2002) Pesticide poisoning in the developing world - a minimum pesticides list. Lancet 360:1163-7.

Peiris-John RJ, Ruberu DK, Wickremasinghe AR, Smit LA, Van der Hoek W. (2002) Effects of occupational exposure to organophosphate pesticides on nerve and neuromuscular function. J Occup Environ Med 44:352-7.

Donors: This work was carried out with the aid of a grant from the International Development Research Centre, Ottawa, Canada.

Contact person: Lidwien Smit at L.Smit@iras.uu.nl

Acute pesticide poisoning in rural communities

Project duration: October 1994 - March 1995

Objective: To understand the leading causes of acute pesticide poisoning in Sri Lanka and to provide recommendations for prevention.

Field research location: Mahaweli H - Anuradhapura District


When visiting irrigation schemes in Sri Lanka, pesticide poisoning is often identified by farmers and health workers as the main health problem. In several agricultural districts in Sri Lanka it is even the leading cause of death. Most of the acute poisoning cases are intentional (suicide), and occur among young adults.

Project description:
A study was conducted consisting of a review of hospital records and in-depth interviews and participant observations in a village. The research showed that hazardous practices when spraying pesticides were due to the impossibility of applying recommended protective measures under the local conditions, more than to lack of knowledge.

The research also suggested that current emphasis on programs that promote the safe use of pesticides through education and training of farmers will be ineffective in Sri Lanka because knowledge is already high and because most poisoning cases are intentional. Instead, it was argued that enforcement of legislation to restrict availability of the most hazardous pesticides would result in an immediate health benefit. In the long term, improved agricultural extension services to promote alternative non-chemical methods of pest control was proposed as the most important strategy to prevent acute pesticide poisoning.

For reprints of specific journal articles please write to Ms. Himani Elangasinghe at H.Elangasinghe@cgiar.org

Van der Hoek W, Konradsen F, Atukorale K, Wanigadeva T (1998) Pesticide poisoning A major health problem in Sri Lanka. Social Science and Medicine, 46: 495-504.

Feenstra S, Jabbar A, Masih R, Jehangir WA. (2000) Health Hazards of Pesticides in Pakistan. IWMI Pakistan Report no.100. IWMI and Pakistan Agricultural Research Council.

Contact person: Lidwien Smit at L.Smit@iras.uu.nl




last updated: 15 October, 2001

On this page:

Impacts of pesticide use in urban and peri-urban agriculture

Occupational pesticide exposure

Acute pesticide poisoning in rural communities

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