The findings The study was carried out jointly by the Kenya Organic Agriculture Network (KOAN), the University of Nairobi, and SGS Kenya Laboratories, with funding from the Heinrich Böll Foundation and the Swedish Society for Nature Conservation. Researchers traced 45 vegetable samples from major food-producing counties including Kirinyaga, Kajiado, Nakuru and Kiambu through to retail hubs in Nairobi and Nakuru before testing them at SGS's laboratories. Of those samples, 35 roughly 78% contained detectable pesticide residues. Most fell within legal limits, but 15 samples, or about a third, exceeded European Union Maximum Residue Limits (EU MRLs), the international benchmark researchers used given the absence of comprehensive Kenyan thresholds for many active ingredients. Tomatoes recorded the highest share of non-compliant samples, followed by spinach and kale; onion samples were the cleanest, with none exceeding EU limits. Some kale and spinach samples carried residues from as many as seven different pesticides. Kirinyaga County recorded the highest proportion of contaminated tomato samples; Nyeri recorded the lowest. A companion arm of the study looked at whether ordinary kitchen practices help. It found that washing, soaking and peeling can cut pesticide residues by roughly 60–70% before vegetables are eaten a finding the Ministry is now leaning on heavily in its public messaging. The ministry's response Principal Secretary Muthoni was careful to frame the findings around long-term, cumulative exposure rather than acute risk from any single meal, urging counties to strengthen food safety measures without discouraging vegetable consumption outright a balance the ministry has had to strike publicly given how central leafy greens like kale (sukuma wiki) and spinach are to Kenyan diets. The Ministry of Health says it has taken note of the KOAN/University of Nairobi/SGS findings and will work with food safety regulators to review them and strengthen oversight of produce entering Kenyan markets, including guidance to counties on educating consumers about washing and preparation methods. The study's authors were more pointed in their recommendations, calling on the Pest Control Products Board (PCPB), the Kenya Plant Health Inspectorate Service (KEPHIS), the Ministry of Agriculture and Livestock Development, the Ministry of Health and county governments to strengthen national food safety systems jointly including better enforcement of pesticide regulations, regular market monitoring, and more support for farmers to adopt safer pest management practices. "Food safety requires action from everyone across the food system," KOAN Executive Director Eustace Kiare said, describing the findings as the start of a dialogue meant to bring together evidence, farmer experience and regulatory input. A regulatory system already under scrutiny The findings land amid broader, longer-running criticism of how Kenya's pesticide regulatory architecture actually functions. PCPB holds statutory authority over the importation, distribution and use of pesticides in Kenya, and is responsible for setting and enforcing Maximum Residue Levels domestically deferring to Codex Alimentarius standards where Kenyan thresholds don't yet exist. KEPHIS separately monitors and analyzes pesticide residues in fruits and vegetables and enforces phytosanitary and food safety measures, while KEBS sets broader product standards. But a parliamentary Health Committee inquiry earlier this year, chaired by Budalang'i MP Raphael Wanjala, found that KEPHIS had contravened Section 15 of the Pest Control Products Act by failing to publish available data on actual pesticide levels in food samples and failing to maintain a regular monitoring system. The same inquiry concluded PCPB had not been adhering to the joint WHO/FAO international code of conduct on pesticide management, and lawmakers pushed unsuccessfully, so far for the board to cancel registration of 267 pesticide products flagged in a petition dating back to 2019. Kenyan-grown produce has also been rejected by export markets for exceeding residue limits in the past, including a 2020 case involving fine beans containing the pesticide acephate with advocacy groups noting that produce turned away from export markets can end up redirected into local ones like Nairobi's Marikiti, Kangemi and City Market to avoid a total loss. Why it matters beyond a single study This is not Kenya's first warning on the subject. Earlier University of Nairobi research including work conducted with Wageningen University and the International Centre of Insect Physiology and Ecology (ICIPE) has repeatedly detected pesticide residues, largely organophosphates, in kale and French beans sold in and around Nairobi, with levels fluctuating seasonally and spiking in hot, dry conditions. A separate 2020 University of Nairobi study linked pesticide exposure to rising rates of birth defects among male children in Kiambu County, underscoring advocacy groups' argument that the public health risk from chronic, cumulative pesticide exposure is a slower-moving but more consequential story than any single contamination event. For now, the Ministry of Health's task force approach partnering with KEBS, KEPHIS and PCPB to tighten pre-harvest intervals and regulate chemical distribution among farmers represents an acknowledgment that oversight has lagged behind the science. Whether it translates into the kind of published, routine market monitoring that this year's parliamentary inquiry found KEPHIS was legally required to but has not been doing will likely determine whether this study becomes a turning point or another entry in a decade-long paper trail of similar warnings. Arozi Health Media will continue following the Ministry's task force rollout and county-level enforcement in the coming weeks.