Potential environmental impacts of pesticide use in the vegetable sub-sector in Kenya
Systematic studies on negative pesticide impacts are scarce in developing countries including Kenya. This paper reports the current pesticide use and associated impacts in Kenya. As a proxy for assessing the impact, the Environmental Impact Quotient (EIQ) model was applied. Results showed that in vegetable production 62 products, comprising of 36 active ingredients are in use. Approximately 263 tons of pesticides were applied at an average rate of 0.82 kg/ha. About 35% of the volumes belong to the organophosphates, 25% carbamates, 22% pyrethroids, 7% tetranortriterpenoids, and 7% inorganics. Of the pesticides, 8% were classified as highly hazardous compounds by the World Health Organization, 25% as carcinogens, while 43% are said to be possible carcinogens. Approximately 60% of the pesticides quantities were indicated to be bad actor chemicals, 64% to be ground water contaminants, and 47% very harmful to beneficial insects. Calculated mean EIQ-values were 22, 6 and 82 for farm workers, consumers and the environment, respectively, with an overall average of 37. The present results indicate that the sub-sector potentially has environmental pesticide negative impacts. The EIQ field use rating, which is based on the percent active ingredient and application rate clearly demonstrate that some pesticides that pose fairly low threat can be chosen to manage pests.