A new study has found pesticide residues in nearly 80% of vegetable samples collected from Kenyan markets, raising fresh concerns about food safety while showing that simple household preparation methods can substantially reduce consumers’ exposure.
The research, presented during the Food Safety in Kenya: From Evidence to Action forum in Nairobi, found pesticide residues in 78 per cent of tomatoes, kale, spinach and onion analysed.
Almost one-third of the samples contained pesticide concentrations exceeding the European Union’s Maximum Residue Limits (MRLs), with tomatoes recording the highest levels of contamination.
Researchers, however, found that soaking vegetables in salty water, washing them thoroughly under running water and cooking them reduced pesticide residues by an average of 72% before consumption.
The findings come as Kenya continues to grapple with questions over pesticide use in agriculture. The country is among Africa’s largest users of agricultural pesticides, with farmers relying heavily on chemical pest control to protect crops and improve yields.
Consumer groups and health researchers have repeatedly raised concerns over the use of highly hazardous pesticides, poor compliance with recommended application practices, inadequate enforcement and limited routine monitoring of pesticide residues in food sold on local markets.
Food safety has also attracted international attention after some Kenyan horticultural exports were intercepted or rejected in export markets over pesticide residue concerns, prompting calls for stronger regulation throughout the agricultural value chain.
Against this backdrop, researchers doing the study sought to determine not only the extent of pesticide residues in vegetables commonly consumed by Kenyan households but also whether ordinary food preparation methods could reduce exposure.
The study analysed four of Kenya’s most widely consumed vegetables, tomatoes, kale, spinach and onions. Researchers found pesticide residues in 78 per cent of all samples tested, with nearly one-third exceeding European Union maximum residue limits. Tomatoes accounted for almost two-thirds of the non-compliant samples, while onions recorded the lowest residue levels.
According to the research, the most effective approach to reduce pesticide residues is soaking vegetables in salty water, thorough washing and cooking, which reduce pesticide residues by an average of 72%. Onions responded particularly well to washing and blanching, with some samples becoming almost free of detectable residues after preparation.
Despite the encouraging findings, experts cautioned that consumers cannot shoulder responsibility for food safety on their own. “Food safety is everyone’s responsibility,” said Eustace Kiare, Executive Director of KOAN. “This dialogue brings together evidence, experience and diverse voices to identify practical actions that can strengthen Kenya’s food system, from the farm to the consumer’s table.”
“The right to food is not only about having enough food,” said Dr Harun Warui of the Route to Food Initiative. “It is also about ensuring that the food people consume is safe. This research provides evidence that can inform policy, support farmers and equip consumers with practical knowledge.”
Dr Warui said simple kitchen practices should complement rather than replace stronger regulation throughout the food system: “Today’s findings offer households practical ways to reduce pesticide exposure, but they cannot stand alone as the solution,” he said. “Without stronger regulation and effective enforcement, food containing hazardous pesticide residues will continue reaching consumers.”
He added that expanding agroecological farming practices and integrated pest management would reduce dependence on hazardous pesticides over the long term while helping build a safer and more sustainable food system.
Participants called for tighter regulation of pesticide use, routine residue surveillance, stronger extension services to support farmers, greater public awareness and more effective enforcement of food safety standards.
The discussions also highlighted ongoing efforts to strengthen regulation through the proposed Pest Control Products Bill, which seeks to improve oversight of pesticide registration, distribution and use.
