Determination of pesticide residues in locally consumed vegetables in Kenya

Abstract

Background: Pesticides are being used today to control a variety of insects, weeds and plant diseases. Some of these pesticides can act as toxins to plants, animals and humans when found in significant concentrations. Objective: The purpose of this study was to determine pesticide residues in locally consumed vegetables. This was done by analyzing vegetable samples from supermarkets and local markets in Nairobi and its environs. Materials and methods: A total of 112 samples (kales 94, French beans 18) were collected from the study area and analyzed using gas chromatography for pesticide residues. Samples collection was done during the hot/dry season and cold/wet season. Results: The pesticide residues were found especially during the hot/dry season and were mainly organophosphates. However, on washing and cooking the residue levels reduced were by 17% and 40% -respectively. Adherence to recommended pre harvest intervals resulted in 99% reduction of the pesticide residues. Conclusion: This study clearly shows that adherence to good agricultural practice would significantly lower the levels of pesticide residues in vegetables.