Want more news about agriculture? Sign up for the Harvest newsletter for our latest reporting, plus behind-the-scenes exclusives.
Rinsing your fruits and vegetables with tap water reduces how much pesticide you inadvertently eat — and a few other tricks can help you cut down the residue further.
That’s the takeaway after an environmental group analyzed nearly 50 peer-reviewed studies on typical household methods for getting agricultural chemicals off of produce.
Dayna de Montagnac, a scientist at the nonprofit Environmental Working Group, says fruits and vegetables are important sources of nutrition, so the findings can help people reduce their exposure while eating healthy.
“ People deserve to enjoy the health benefits of fresh fruits and vegetables,” she said, “without the worry of exposing themselves and their families to pesticide residues.”
De Montagnac is the lead author of the new paper published in the peer-reviewed scientific journal Frontiers in Environmental Health.
After scrutinizing dozens of studies, the authors found that rinsing produce under a faucet or soaking it in tap water both help — and that soaking fruits and veggies in a solution that includes baking soda or vinegar is even more effective.
“We know that’s not feasible for everybody,” she said, so the point is to at least rinse or soak produce in tap water.
“It’s still moving the needle in reducing those residues, and it’s still something that people should do no matter what.”
The studies that the authors reviewed focus largely on removing insecticide and fungicide from produce. They found that less research was available about herbicide residue.
Pesticides commonly turn up in people’s urine in health studies — a sign of how prevalent the substances have become. The D.C.-based advocacy group argues that’s problematic, because evidence suggests some of these chemicals can harm human health.
Matt Simcik, an environmental chemist who was not involved in the Environmental Working Group’s research, said it makes sense that washing helps remove pesticides.
“The way pesticides are applied is they’re dissolved in water and then sprayed,” said Simcik, a professor at the University of Minnesota’s School of Public Health. “So they’re water soluble.”
How to wash residue off of fruits and veggies
The simplest options for cleaning your produce are to put it under a running faucet for at least 20 seconds or to soak it in tap water for 10 or 15 minutes.
To use baking soda or vinegar, mix some with water in a large bowl. The Environmental Working Group recommends 1 teaspoon of baking soda per cup of water, or a ratio of 1 part food-grade vinegar (such as distilled white vinegar) to 3 parts water. Let the produce soak — but not long enough to impact the flavor.
“You want to be able to soak your berries, but you don’t want to pickle them,” de Montagnac said. “I think 10 minutes is a pretty good Goldilocks.”
Lift the produce out of the bowl, instead of dumping it out. This will leave behind any dirt that settles to the bottom of the bowl. Then rinse the produce under running water.
The environmental group has created a produce-washing guide with more tips and details. It recommends scrubbing firm items like potatoes with a produce brush.
Pesticides mostly get on the surface of fruits and vegetables, where washing can help remove them. However, they can also get into the flesh, where rinsing won’t help. This is especially true of chemicals called systemic pesticides that are designed to spread within an entire plant.
Although peeling fruit and veggies is another way to get rid of surface pesticides, it means losing the nutritional value of discarded, edible peels. This is why the group doesn’t simply tell people to avoid peels.
It also doesn’t suggest commercial produce washes, like the ones you might spot in the produce section of your grocery store. This is because the U.S. Food and Drug Administration has cautioned against using those products, as they haven’t been evaluated for safety or effectiveness.
Some produce has more pesticide residue
The Environmental Working Group uses data from the U.S. Department of Agriculture and the U.S. Food and Drug Administration to collate a list of the most contaminated fruits and veggies.
These agencies, particularly the USDA, test for pesticides on samples of produce from markets and grocery stores.
Leafy favorites like spinach, kale and collard greens top the list. Strawberries, grapes and peaches are a few other examples of the most-contaminated types of produce.
The group also publishes a list of the least-contaminated fruits and veggies, which includes sweet corn and onions.
Eating organic produce is one way to reduce pesticide exposure, but the higher price is cost-prohibitive for many people.
De Montagnac said if you have room in your budget for some organic produce, you can prioritize spending those dollars on items that appear on the most-contaminated list. Also, she said, sometimes the frozen foods aisle has organic produce that is cheaper than fresh organic options.
Some farming groups have taken issue with the Environmental Working Group’s list of fruits and vegetables with the most pesticide residue on them.
The California-based Alliance for Food and Farming, funded by trade groups such as the California Strawberry Commission and the Produce Marketing Association, says pesticide residue is too minimal to harm consumers.
Digging into how pesticides affect people
When federal scientists looked for a handful of insecticides in the urine of about 3,000 people, they concluded that about half of the country’s population has detectable levels of these chemicals.
Scientists published the findings in 2019. The sampling took place through the National Health and Nutrition Examination Survey, an ongoing effort run by the U.S. Centers for Disease Control and Prevention to measure the health of thousands of voluntary participants each year.
The national survey also showed in 2022 that the herbicide glyphosate — the active ingredient in Roundup weedkiller — turned up in 80% of more than 2,000 urine samples.
The International Agency for Research on Cancer concluded a decade ago that glyphosate is “probably carcinogenic to humans.” The U.S. Environmental Protection Agency concluded the opposite in 2020.
Federal data on the prevalence of pesticides in urine do not in themselves include any conclusions on whether the chemicals cause illnesses or conditions.
Hundreds of pesticides are legal in the U.S., but that doesn’t mean that their impacts on human health are fully understood.
Eleanor Rogan, professor and associate dean at the University of Nebraska Medical Center’s College of Public Health, says scientists are finding associations between cancer rates and chronic low exposure to agrochemicals.
“This is definitely a growing area of research,” she said.
To her, it makes washing fruits and vegetables a simple choice.
“It’s a good idea to wash your produce and get rid of as much of what’s on the exterior as you can,” said Rogan, who wasn’t involved in the Environmental Working Group study.
For years, she has studied why some areas of her state have higher rates of certain cancers, including childhood cancers. Her research has found associations with how much agrochemical gets applied locally and how much accumulates in drinking water sources. This includes herbicides, other pesticides and nitrates.
Rogan and her peers hope to shed more light in the coming years by comparing the specific biological effects of chemicals to the symptoms observed in cancer patients.
As for exposure from residue on food, Harvard University scientists published a 2018 commentary in the Journal of the American Medical Association saying that the implications for cancer remain unknown. They called urgently for more research, given that pesticide residue is widespread and most Americans have such chemicals in their urine.
But they also said eating fruit and veggies carries so many health benefits that it likely outweighs the risk of pesticides, and hence people shouldn’t forgo eating them.
Simcik, at the University of Minnesota, said if people are worried, then washing produce is a simple way to reduce exposure. It could make particular sense for vulnerable populations, he said, such as people who are immunocompromised or pregnant.
“When you talk about a developing fetus and children, they are much more susceptible to the effects of (chemicals) because they are developing,” he said.
Food is just one way people can come into contact with pesticides. They can also be exposed by working in agriculture, living in areas where the chemicals get sprayed or through drinking water.
Celia Llopis-Jepsen is an environment reporter for Harvest Public Media and host of the environmental podcast Up From Dust. You can follow her on Bluesky or email her at celia (at) kcur (dot) org.
Harvest Public Media is a collaboration of public media newsrooms in the Midwest and Great Plains. It reports on food systems, agriculture and rural issues.
