Pesticide Residue Levels in Selected Fresh Vegetables Delivered in Markets in Kenya

Pesticide Residue Levels in Selected Fresh Vegetables Delivered in Markets in Kenya presents findings from a study assessing pesticide residues in tomatoes, kale, spinach and onions collected from selected markets in Nairobi and Nakuru. The research also evaluated the effectiveness of practical household food preparation methods—including washing, soaking, blanching, peeling and cooking—in reducing pesticide residues before consumption. The report provides evidence to support informed public dialogue, strengthen food safety systems, and guide policy, agricultural practice and consumer awareness in Kenya.

Key Highlights

• The study analysed vegetables commonly consumed in Kenyan households—tomatoes, kale, spinach and onions—sourced from selected markets in Nairobi and Nakuru.
• Laboratory analysis found pesticide residues in market samples, with approximately one-third (33%) of detected residues exceeding European Union Maximum Residue Levels (EU-MRLs) for the pesticides assessed.
• The baseline study detected several pesticide active ingredients, including acephate, carbendazim, difenoconazole, tebuconazole, lambda-cyhalothrin, chlorpyrifos and chlorfenapyr.
• Household food preparation methods were shown to significantly reduce pesticide residues, although effectiveness varied by vegetable and pesticide type.
• Onions recorded the highest average reduction (99.7%) when peeled, washed under running water and blanched.
• Tomatoes achieved an average 69% reduction when soaked in a 2% baking soda solution, rinsed under running water and cooked.
• For spinach, the most effective method achieved an average 65.5% reduction, while kale recorded an average 62.3% reduction using the most effective household treatment methods tested.

Key Recommendations

The report recommends:

• Strengthening routine monitoring and surveillance of pesticide residues in fresh produce to enhance food safety.
• Promoting evidence-based household food preparation practices, including washing under running water, peeling where appropriate, soaking in baking soda or vinegar solutions, blanching and cooking, to reduce pesticide residues before consumption.
• Supporting farmers to adopt good agricultural practices, including responsible pesticide use and adherence to pre-harvest intervals.
• Enhancing public awareness on safe food handling and preparation.
• Advancing research on pesticide residue reduction techniques and storage practices to further improve consumer safety.