Pesticides in Food: Diet Linked to Chemical Levels in Body, Study Finds

Certain fruits and vegetables may be increasing the amount of pesticide chemicals accumulating in people’s bodies, according to a latest study published in the International Journal of Hygiene and Environmental Health. The research, conducted by scientists at the Environmental Working Group (EWG), found a correlation between the consumption of produce with higher pesticide residues and elevated levels of those chemicals detected in participants’ urine.

Pesticides have been linked to a range of health problems, including cancer, reproductive issues, hormone disruption, and neurotoxicity in children, researchers noted. Because pesticide residues are frequently found on fruits and vegetables, dietary intake represents a significant pathway for exposure.

“The findings reinforce that what we eat directly affects the level of pesticides in our bodies,” said Alexis Temkin, Ph.D., vice president for science at EWG and lead author of the study. “Eating produce is essential to a healthy diet, but it can also increase exposure to pesticides.”

The study analyzed data from 1,837 participants in the Centers for Disease Control and Prevention’s National Health and Nutrition Examination Survey (NHANES) between 2015 and 2016. Researchers combined this data with U.S. Department of Agriculture pesticide residue data collected from 2013 to 2018. They developed a “dietary pesticide exposure score” to estimate individual exposure based on produce consumption and residue levels.

Participants who reported eating more strawberries, spinach, and bell peppers – produce known to carry higher pesticide residues – exhibited significantly higher levels of pesticide biomarkers in their urine compared to those who consumed produce with lower residue levels. Researchers measured biomarkers representing three major pesticide categories: organophosphates, pyrethroids, and neonicotinoids.

The analysis revealed that diet plays a major role in pesticide exposure. However, the study also highlighted gaps in current monitoring efforts. NHANES currently tracks only a portion of the pesticides found on food, meaning total exposure may be wider than current biomonitoring captures. Researchers found measurable residues of 178 different pesticides in the produce tested by the USDA, but only 42 of those corresponded to biomarkers measured in urine samples.

The research also noted complexities in analyzing the impact of potato consumption. The link between produce intake and pesticide levels became clearer only after potatoes were removed from the dataset, suggesting that more research is needed to understand how potato consumption affects overall pesticide exposure due to the variety of ways potatoes are consumed.

The findings raise questions about the adequacy of current pesticide safety standards set by the Environmental Protection Agency (EPA). Whereas the EPA establishes limits for individual pesticides, these standards do not typically account for cumulative exposure to multiple pesticide residues, which are commonly found together on produce.

“This study was only possible thanks to robust federal data, highlighting why strong public health agencies must remain a top priority for policymakers,” said Varun Subramaniam, EWG science analyst. “The pesticide residue tests and CDC biomonitoring data represent the kind of essential research that only the government can provide — at a scale that no private sector or academic effort could match.”

EWG recommends prioritizing organic purchases for produce listed on its “Dirty Dozen” list, which identifies the fruits and vegetables with the highest pesticide residues. The organization also publishes a “Clean Fifteen” list of items with the lowest residues. Research indicates that switching to organic produce can significantly lower pesticide biomarkers in the body within a few days.