Senators alarmed as Egerton study exposes toxic pesticide residues in potato farming
By Kiprono Keileb, August 1, 2025Kenyan senators have raised concerns over the safety of one of the country’s staple foods, potatoes, following revelations that dangerous levels of pesticide residues have been found in tubers grown in Nyandarua County.
This comes after the Senate Agriculture, Livestock and Fisheries Committee engaged Egerton University researchers on Thursday, July 31, 2025, over a damning report that paints a worrying picture of how pesticides are used in the country’s leading potato-producing region.
The study, titled “Influence of On-Farm Pesticide Practices and Processing Methods on Pesticide Residue Levels in Potato Tubers,” reveals that 98.8 per cent of smallholder farmers in Nyandarua rely on synthetic chemicals to control pests and diseases. Still, most do so with little or no adherence to safety standards.
“Only 11.85 per cent follow manufacturer instructions while most rely on agrochemical retailers or peer advice for application rates and spraying frequency,” the document reads
The result? Potatoes are landing on dinner tables across the country laced with traces of banned insecticides such as chlorpyrifos and fenitrothion, some at levels exceeding international safety limits set by the European Union and Codex Alimentarius.
The committee, chaired by Bungoma Senator Wafula Wakoli, expressed deep concern over what they described as a silent food safety crisis threatening Kenyan households. The Senators urged swift action to address regulatory loopholes and enhance farmer education on the safe use of pesticides
“Kenyan families should not unknowingly be consuming poison in the name of food. This issue touches directly on public health, and the government cannot afford to look the other way,” said Senator Catherine Mumma
The researchers noted that although household cooking methods such as boiling and frying can lower some pesticide residues, certain harmful chemicals like chlorpyrifos can persist in food even after cooking.
In their findings, the Egerton team warned that short harvesting intervals were directly contributing to unsafe residue levels. Potatoes harvested just three weeks after spraying showed dangerously high toxic compound levels.
The Senators acknowledged that misuse is partly driven by desperation among farmers who are poorly trained, poorly supported, and often misinformed. Kisumu Senator Prof. Tom Ojienda said that the situation reflected a systemic failure, citing a shortage of extension officers and weak enforcement of existing pesticide laws.
There were calls to enhance the mandate and operations of the Pest Control Products Board and to scale up farmer training programs nationwide. The committee also emphasised the importance of tighter monitoring of agrochemical imports and sales, with some Senators calling for an audit of pesticide distributors and retailers.
Also present during the session were Senators Alexander Mundigi (Embu), Moses Kajwang’ (Homa Bay), Abass Sheikh (Wajir), Wahome Wamatinga (Nyeri), and Mwenda Gataya (Tharaka Nithi), all of whom supported proposals to institutionalise regular scientific testing of food products in Kenya.
As the Senate now awaits a full report on the session, pressure is mounting on the Ministry of Agriculture and relevant state agencies to move swiftly and restore public trust in the country’s food system.