When we talk about pesticides and cancer, it’s important to distinguish between exposure to pesticides while working in agricultural settings and individual pesticide exposure from consuming fresh fruits and vegetables or using other common household products, experts say.
Increased Cancer Risks With Some Jobs
“Those at highest risk include agricultural workers, pesticide applicators, and landscapers who may handle these chemicals regularly over many years,” Dr. Teras says.
According to research that analyzed 62 studies, occupational exposure to pesticides increases the risk of cancer. The review included studies that evaluated indirect exposure to pesticides, direct exposure, and both. Participants in the studies could have been exposed to pesticides during the application process, they might have worked at a facility where pesticides are stored, or they may have come into contact with agricultural workers’ contaminated clothing and tools.
The authors of the report found many associations between occupational pesticide exposure and cancer. For example, exposure to dichlorodiphenyltrichloroethane (DDT) is linked to increased risk of prostate cancer, and exposure to lindane is linked to increased risk of non-Hodgkin lymphoma. Some pesticides have been linked to multiple myeloma, colorectal cancer, breast cancer, and cancers of the kidney, brain, and digestive system. It’s important to remember that people exposed to pesticides at work are typically exposed to high concentrations over several years, and that the studies don’t account for all substances participants may have been exposed to.
Pesticide Exposure on Fruits and Vegetables
Some studies have linked pesticide exposure from produce to cancer. “One recent abstract from the American Association for Cancer Research made headlines suggesting that fruits and vegetable intake was associated with lung cancer due to pesticide exposure,” says Urvi A. Shah, MD, a hematologist-oncologist at Memorial Sloan Kettering Cancer Center in New York City. But the study was limited in several key ways, she explains.
“The study results have very limited data to draw these conclusions, and several hypotheses need to be tested before these conclusions are drawn in this population,” Dr. Shah says. “It is a small sample size of 187 patients studied after their diagnosis and not followed prospectively.”
The results of the study shouldn’t dissuade people from eating conventional produce. “In the absence of clear data to link the cancer to pesticides, this study may confuse patients and the general population, making them avoid healthy foods. The conclusions should have been more speculative,” Shah says.
Ultimately, the research we have isn’t strong enough to suggest that nonorganic produce is bad for you, she adds. But we do know that eating fruits and vegetables decreases the risk of several cancers, including cancers of the mouth, larynx, pharynx, stomach, lung, and esophagus. And research suggests that by regularly eating these, you might also decrease your risk of cancers of the colon, prostate, and pancreas.
Risk From Household Products Is Minimal
The Environmental Protection Agency has banned many pesticide products over the year. In general, highly harmful pesticides are controlled for occupational use. Household pesticide products are generally much less harmful. As such, the risk of developing cancer from exposure to household pesticides is negligible.
“The general public can be exposed to pesticides in a variety of everyday places like homes, parks, offices, and schools,” Teras says. “For the general public, exposures are typically lower and more intermittent, but they can be more persistent depending on the chemical and the source of the exposure.”
These exposures can have an effect. Teras points to a study from the National Institutes of Health (NIH) as an example. “The study found that one common pesticide was detected in the blood of a high proportion of both farmers and nonfarmers, but at consistently higher levels among farmers, with recent occupational use being the strongest predictor of exposure levels,” she explains.
Experts stress that pesticide exposure through household products is not thought to meaningfully increase cancer risk. “It may be helpful to keep in mind that while low-level, infrequent exposures to pesticides are not thought to be major drivers of cancer risk, there’s likely no completely risk-free option,” Teras says.
