16: 04: 2026
What you put in your grocery basket at the local market could be directly dictating the level of pesticide toxins in your blood. A landmark study by the Environmental Working Group (EWG) scientists has shown that eating certain fruits and vegetables may raise the levels of harmful
pesticides detected in the human body.
Pesticides have long been associated with serious health risks, including cancer, reproductive complications, hormone disruption, and neurotoxic effects in children. Because traces of these chemicals are often found on produce, concerns remain about how everyday diets may contribute to long-term exposure. This latest research offers fresh insight into how consuming fruits and vegetables could influence pesticide levels in the body and, ultimately, human health.
Researchers found that produce such as strawberries, spinach, potatoes, peaches, apples, kales and grapes contained significantly higher concentrations of synthetic pesticide residue compared to produce such as sweet corn and asparagus. As a result, individuals who frequently consume high-residue produce had traces of the chemicals in their urine.
Beyond establishing a clear link between the consumption of certain fruits and vegetables and elevated pesticide levels in the human body, the scientists noted that exposure rarely occurs in isolation and that people are typically exposed to multiple pesticides simultaneously. Researchers identified 178 different pesticide residues in fruits and vegetables, yet only 42 of these corresponded with biomarkers detected in urine samples, suggesting that many chemicals people are exposed to remain untracked and require closer scrutiny.
According to Dr Alexis Temkin, EWG’s vice president for science and the study’s lead author, the findings underscore a direct link between diet and pesticide exposure. They reinforce that what we eat directly affects the level of pesticides in our bodies. “Eating produce is essential to a healthy diet, but it can also increase exposure to pesticides,” she said.
Temkin added that the findings build on earlier evidence showing that fruits and vegetables are a major pathway of pesticide exposure for millions of people. She also highlighted that vulnerable groups, particularly young children and pregnant individuals, may face greater risks from such exposure.
To arrive at these conclusions, the researchers analysed pesticide residue data collected by the US Department of Agriculture between 2013 and 2018. They combined this with dietary surveys and urine biomonitoring data from 1,837 participants in the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey conducted between 2015 and 2016. These datasets represent the most recent and comprehensive information available, with biomonitoring data extending up to 2018.
Using this information, the team developed a “dietary pesticide exposure score,” which estimates an individual’s exposure based on the types of produce consumed and the pesticide levels found on those foods. The scoring system considered how frequently specific pesticides were detected, their concentrations and toxicity.
The researchers then compared these exposure scores with 15 biomarkers found in participants’ urine, focusing on three major classes of pesticides: organophosphates, pyrethroids, and neonicotinoids. The analysis revealed a clear relationship between the types of produce consumed and the levels of these pesticides detected in the body.
In Kenya, these chemicals are registered and used for agriculture and public health for controlling pests in maize, vegetables, and potatoes, as well as mosquitoes. These products are regulated by the Pest Control Products Board, although many, including those with toxic active ingredients, are commonly applied.
Another study published in Nature Health has established a definitive link between environmental exposure to common agricultural pesticides and a surge in cancer cases. The study across Peru used a high-resolution mapping system and identified hundreds of cancer hotspots that directly correlate with areas of intense pesticide use, challenging long-held assumptions about the safety of these chemicals.
The research analysed a panel of 31 widely used pesticides, none of which are currently classified as high-level human carcinogens by international regulators. The environmental model included 19 insecticides, seven fungicides, and five herbicides, including widely used substances like glyphosate, chlorpyrifos, and paraquat—widely used in Kenya for weed and pest control in farming, particularly on maize, wheat, coffee, tea, and vegetables.
The research reveals that while none of the individual pesticides studied are classified as known human carcinogens by the International Agency for Research on Cancer, their combined presence in the environment creates a significant health risk. This spatial association was particularly robust for cancers that affect the liver and gallbladder, with the highest risk observed in intensified agricultural regions.
Instead of grouping cancers by the organ where they are found, researchers classified cases based on their developmental biological origins. This revealed that cancers derived from the “foregut” lineage, which includes the liver and biliary tract, are specifically sensitive to environmental pesticide exposure. The study found that even low-level, chronic exposure to these chemical mixtures can reprogramme gene expression in ways that promote tumour development.
Identified cancers
They identified cases of skin cancer, lung cancer, cancer of the gastrointestinal tract, liver cancer, pancreatic cancer, kidney cancer, cancers of the female genital organs, and tumours of the central nervous system and brain.
This study especially provided a definitive biological link between environmental pesticide exposure and the development of liver cancer, particularly in the Junín region of Peru. By analysing the liver, the body’s primary site for filtering toxins, the researchers were able to validate the carcinogenic risks associated with agricultural chemicals.
In Peru, hepatocellular carcinoma, the most common primary liver cancer, disproportionately affects young, indigenous individuals who do not fit the typical profile for liver cancer, such as those with cirrhosis or a history of heavy alcohol use. While Hepatitis B has long been blamed for these cases, the unique clinical features and molecular profiles of these tumours suggested that other factors were at play.
Statistical tests were used to rule out other potential causes, such as alcohol consumption, fatty liver disease, or foodborne toxins like aflatoxin. The results confirmed that the pesticide-related signature was the dominant driver of these tumours. Crucially, when this data was compared to liver cancer patients in France, Taiwan, and Turkey, this specific biological fingerprint was found only in the Peruvian patients. This confirms that the disease is a direct consequence of the unique environmental chemical cocktail present in Peru’s agricultural regions, rewriting the biology of those who live there.
Dr Lonary Ngetich, a pharmacist at the Kenyatta University Teaching Referral and Research Hospital, notes that pesticides act as potent endocrine-disrupting chemicals by essentially hacking the body’s internal communication system, often at remarkably low doses.
“These substances interfere with the hypothalamic-pituitary-gonadal axis, the critical feedback loop between the brain and reproductive organs by mimicking, blocking, or altering the natural life cycle of hormones. Some pesticides act as molecular impostors that bind to receptors to trigger abnormal cellular growth, while others function as antagonists that jam these receptors, preventing legitimate hormones from delivering their vital signals,” he explains.
“Beyond this direct interference, certain chemicals can inhibit enzymes and carrier proteins responsible for transporting and breaking down hormones like estrogen and testosterone. By throwing these delicate systems into imbalance, pesticide exposure can lead to profound and lasting disruptions in human development, metabolism, and fertility.”
Notably, the researchers detected the continued environmental footprint of monocrotophos, an insecticide officially banned in Peru since 2004, highlighting the long-term persistence of certain toxins in the soil and water. These mixtures were found to be most concentrated in areas with high irrigation and runoff, where pesticides are easily transported from fields into the broader ecosystem.
The studies come amidst increased detection of pesticides in water, soil, food, and air across East Africa, raising growing concerns about their impacts on human health, biodiversity, and ecosystems. East African scientists and activists are now calling for stronger pesticide governance in East Africa.
A 2026 March report by Route to Food shows that highly hazardous pesticides account for nearly 50 per cent of registered products in Kenya, Ghana, and South Africa, but usage data suggests they actually represent about 75 per cent of the pesticides currently in the field.
Pesticide-free soil samples
Research across these regions reveals that only 17 per cent of soil samples are pesticide-free, a troubling statistic that mirrors European contamination levels, despite Africa’s lack of comprehensive monitoring. These pesticide cocktails are most frequently composed of toxic substances that are largely banned in the EU but remain widespread in African soil and water bodies, posing severe risks to bees, fish, and earthworms.