Pesticides are widely used in agriculture to protect crops from pests, diseases, and weeds, thereby improving productivity and food security. However, inappropriate pesticide use, including failure to observe recommended application rates and pre-harvest intervals, can result in pesticide residues remaining on/in food products at levels that may pose risks to human health and the environment. In Kenya, previous studies have reported pesticide residues exceeding Maximum Residue Limits (MRLs) in commonly consumed vegetables. However, limited information has been available on practical methods that consumers can apply to minimize these residues at the household level before consumption. This study therefore sought to address two important questions: 1. Are there pesticide residues above the acceptable levels on/in selected vegetables marketed in Kenya? 2. Which household food preparation methods are most effective in reducing pesticide residues in/on the selected vegetables while maintaining food quality? The research was implemented in two phases. The first assessed pesticide residue levels in vegetables collected from major wholesale and retail markets in Nairobi and Nakuru using advanced laboratory analysis capable of detecting more than 500 pesticide compounds. The second phase evaluated the effectiveness of commonly used household food preparation methods, including washing, blanching, soaking in different solutions, cooking, and short-term storage, under controlled laboratory conditions. The findings revealed that although most vegetable samples complied with European Union Maximum Residue Limits (EU MRLs), one-third of the samples contained pesticide residues above the acceptable limits. Tomatoes recorded the highest number of non-compliant samples, followed by spinach and kale, while onion samples remained within regulatory limits. Several of the pesticide active ingredients detected above the limits are classified by the World Health Organization as moderately hazardous. These findings demonstrate that simple household practices can significantly reduce consumer exposure to pesticide residues without requiring specialized equipment or expensive technologies. The study highlights the need to strengthen pesticide management throughout the food production chain. Preventing excessive pesticide residues remains the responsibility of producers through adherence to Good Agricultural Practices, Integrated Pest Management, and compliance with recommended pesticide application guidelines. Household preparation methods should therefore be viewed as complementary measures rather than substitutes for responsible pesticide use. The study recommends strengthening routine pesticide residue surveillance, enhancing farmer training on safe pesticide use, accelerating implementation of updated pesticide legislation, promoting Integrated Pest Management, and increasing public awareness of effective household food preparation practices that reduce dietary exposure to pesticide residues. The evidence generated by this study provides an important scientific foundation for improving food safety, protecting public health, informing national policy, and empowering consumers to make safer food preparation choices.
A Programme of Heinrich Boell Foundation
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