Forschungsprojekte - Ibrahim Ndegwa Macharia

External costs of pesticides use in the vegetable sub-sector in Kenya

The negative effects (externalities) of chemical pesticides on human health and on the environment have led to a lot of concern globally. This concern is evident from many studies being conducted in the international arena to assess these externalities in monetary terms and increasingly more stringent standards on pesticide use. In Kenya, primary research findings have indicated existence of these externalities, but the magnitude and value remains unclear. To fill this research gap this study will address three main questions:

1. What are the current and historical pesticide use patterns, and what is known about their risks?

2. What are the nature, magnitude and value of these externalities in the sub sector?

3. What kind of pesticide policies exist in the sub sector, and how can they be optimized to minimize the external costs?

As the pesticide risks depends on, types, quantities, toxicological properties and handling practices, the existing documented literature and databases on these topics will be reviewed and substiate through focus group discussions. To address the second question, three stepwise approaches will be followed. The first step will comprises of the identification of the externalities relevant in the sub sector in Kenya, this will be accomplished through literature reviews and discussions in the stakeholders’ workshops. The second step will involve quantification (accounting) of the externalities which will be carried out using three methods i.e. through the analysis of the existing information, estimations by expert through a Delphi interviews technique and verification of the estimates in focus group discussions and workshops. The third step will be for valuation (monetary value) whereby two types of external costs will be estimated. Actual or damage costs, e.g. cost of treating fatalities (humans, domestic animals, wildlife), losses due to rejection of export vegetables with high maximum residue levels (MRLs), market cost of domestic animals if they die, losses by fish farmers, honey and vegetables losses due to honeybees destruction, costs incurred to clean up pesticide in drinking water, cost transfers for the values for wildlife and birds. Where no direct method of valuation of an externality will be available, an accepted method of using expenditure which society incurs in dealing with that externality (damage prevention costs) will be used. Review of the existing policies and finding out how they can be integrated and optimized to minimize the externalities will answer the third question.