By Natalie Rahhal

Exposure to pesticides may raise the risk of some forms of cancer not only for those working with the potent chemicals, but also for those living nearby, a new study has found. The research suggests pesticides are linked to an increase in rates of leukemia, non-Hodgkin's lymphoma, and bladder, colon, lung and pancreatic cancers. The elevated risk is potentially as bad as from smoking.

Chemicals used to kill insects, funguses and weeds are present in produce and in the environment in the U.S., according to the Environmental Protection Agency, but there are strategies you can use to reduce your exposures, experts say. Here’s how.

What the new study found

Researchers looked at 96 pesticides commonly used in the U.S. and compared their prevalence to the rates of various types of cancer in thousands of counties across the country. They found a close link between certain types of chemicals and elevated rates of certain forms of cancers, even after considering how much other risk factors, including smoking and socioeconomic status, might contribute to local cancer rates.

After controlling for these variables, rates of any cancer remained far higher than what would be expected in areas where high-risk pesticides and spraying methods were used. And the findings suggest that the rates of excess cancer cases are too high to only be affecting people working directly with the chemicals. “We like to think that only the person handling the jug [of pesticide] or the sprayer is going to be exposed,” said Isain Zapata, an assistant professor of biomedical research and statistics at Rocky Vista University. “But, in reality, that chemical is getting into the environment and we see how they are impacting people.”

How are people who don’t work on farms getting exposed to pesticides?

There are many potential routes of exposure, experts say. “It’s difficult to know if it’s the water, or the food or in air pollution, since we know that [pesticide] particles are suspended,” says Zapata. “My guess is that it’s all of those.”

One 2020 Food and Drug Administration report found that 59% of fruits, vegetables and grains grown in the U.S. had pesticide residue. And a National Water-Quality Assessment review published in 2022 found pesticides in 2% of ground water and 10% of surface water.

Because cancer rarely has just one direct cause — genetics, chronic health conditions, aging, smoking, diet, viral infections, chemicals and alcohol can all raise risks for the disease — it’s hard to say to what extent pesticides contribute to any one case of cancer. But, Zapata notes that we know from animal studies that high doses of many pesticides can trigger forms of the disease, and experts say it’s worth doing what you can to limit your exposure.

How to reduce pesticide exposures

Admittedly, it’s difficult to cut pesticides out of your life entirely, because they exist at least at low levels in so many places. But Dr. Avital Harari, a University of California, Los Angeles, endocrine surgeon who has studied pesticides, says that it’s worth taking the precautions you can, especially if you live near farmlands where pesticides are sprayed.

Wash your produce. Perhaps the most obvious step you can take is to always wash your fruits and vegetables, which removes much of the residue of toxic chemicals from produce, Harari says. The EPA also suggests peeling and trimming produce, when possible, to further remove portions of the plants that collect pesticide residue. You can also choose a wide variety of foods and from an array of sources to limit your exposure to any one pesticide, the EPA advises.

Eat organic. Harari and Zapata both say that eating organic foods may help reduce your exposures. But, Zapata acknowledges that eating only organic produce may be too expensive for many people. Plus, organic farming yields about 18% less food compared to crops treated with pesticides, which keep bugs, weeds and funguses from destroying plants.

Use an air filter. If possible, find out when spraying is going to happen in your area so you can stay inside, says Harari. Installing air filters, like HEPA ones, at your home can “hopefully minimize the amount of toxic chemicals you and your family are exposed to,” she says.

Install a water filter. Treatment of municipal water should help to reduce the burden of pesticides, but research suggests that combining this with other home filters can practically eliminate pesticides from water.

These steps can help anyone reduce their home exposures to pesticides, but Zapata notes that it won’t be enough to protect those most vulnerable, especially low-income people working on or near farms. That will take policy changes and a shift in societal priorities. “We want to get the best, cheapest produce, but we’re not really thinking about what we’re paying for it,” he says. “In reality, there are communities that are paying for that with their health ... and everybody has the same right to be safe, every time we purchase something.”