Do Pesticides Cause Cancer?

Lisa Lawler’s family has been farming since the Homestead Act of 1862. But in recent years, Lawler, her neighbors, and friends in rural Hardin County, Iowa, have suffered setbacks, not related to their crops, but to their health.

Lawler said her mother was diagnosed with breast cancer and died in 2016. Nine years later, Lawler was told she had breast cancer, a diagnosis that didn’t surprise her.

“With how many people seem to get cancer in our community, you just assume you will get it,” Lawler told Investigate Midwest, an independent nonprofit newsroom covering the practices of agricultural corporations and institutions. “But no one really talks about what’s causing it.”

Lawler was tested to see if her cancer was genetic, which could mean a recurrence and might lead to the removal of her entire breast.

“The genetic test they ran for me was one that covered 81 genes that are typically related to breast cancer,” Lawler told Investigate Midwest. “After the test, they told me my cancer is likely not genetic, but likely environmental, based on these 81 genes. Your next thought is, then what’s in the environment that’s causing my cancer?”

Pesticides are contributing to rising cancer rates among agricultural communities in the United States, according to Investigate Midwest, environmental organizations, farmers, and researchers. In addition to cancer, some farmers and pesticide users have developed neurological and respiratory problems. The pesticides’ association with cancer has led to thousands of lawsuits filed against pesticide manufacturers.

A nationwide study published in Frontiers in Cancer Control and Society revealed that exposure to pesticides in agriculture carries a cancer risk comparable to—and in some cases, greater than—smoking.

“In our study we found that for some cancers, the effect of agricultural pesticide usage is comparable in magnitude to the effect of smoking,” said the study’s senior author, Dr Isain Zapata, associate professor at the Rocky Vista University, College of Osteopathic Medicine in Colorado.

What are Pesticides?

Pesticides are chemicals that help plants grow by killing, repelling, or controlling pests. There are a variety of pesticides that include:

• Insecticides that take care of pesky insects.

• Fungicides that keep mold and mildew at bay.

• Disinfectants that focus on bacteria.

• Compounds that repel mice and rats.

Farmers commonly use pesticides to boost crop yields, such as corn and soybeans, which are used for food, fuel, and animal feed. Pesticides used on farms are sprayed from airplanes, drones, tractors, or handheld devices.

The chemicals, however, can drift through the air or run off into nearby rivers and streams. Homeowners use different pesticides to care for their lawns, shrubs, trees, and gardens.

Studies Found Pesticides An Occupational Hazard

Although most people are exposed to pesticides every day in some way, experts say people who use pesticides occasionally have a low risk of developing cancer. The cancer risks largely depend on several factors, such as whether the pesticide is a carcinogen (a substance that can cause cancer), how often people are exposed, and the level of exposure

“Those at highest risk include agricultural workers, pesticide applicators, and landscapers who may handle these chemicals regularly over many years,” Lauren R. Teras, the senior scientific director of epidemiology research at the American Cancer Society, told EveryDayHealth.com.

An analysis of 62 studies supports the claim that occupational exposure to pesticides increases the risk of cancer. In addition, the researchers discovered many associations between occupational pesticide exposure and cancer. For example, the researchers found:

Exposure to dichlorodiphenyltrichloroethane (DDT) was linked to increased risk of prostate cancer.

Exposure to lindane was 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.

Researchers noted that workers often had high pesticide exposure over many years, and the studies didn’t account for all other substances to which participants may have been exposed.

A major new study published in April in the journal Nature Health found that living in areas with high pesticide levels could raise cancer risk by as much as 150 percent, even when the chemicals are considered “safe” on their own.

The researchers said they conducted their study in Peru because the country has “intensive agriculture in certain regions, a wide variety of climates and ecosystems, and significant social and territorial inequalities.” In addition, cancer has become a public health priority in Peru, and pesticide contamination levels in the population are raising alarms.

The investigators compared regions where there were high pesticide exposure with health data from more than 150,000 cancer patients recorded between 2007 and 2020.

Researchers found that pesticide exposure can impact the body long before cancer is diagnosed. The study suggests that pesticide mixtures disrupt processes that preserve normal cell function and identity. These disruptions occur early and may accumulate over time without noticeable symptoms. According to the study, these changes could make tissues more susceptible to harmful influences, including infections, inflammation, and environmental stress.

“This is the first time we have been able to link pesticide exposure, on a national scale, to biological changes suggesting an increased risk of cancer,” explains Stéphane Bertani, a researcher in molecular biology at the French National Research Institute for Sustainable Development (IRD), at the PHARMA-DEV laboratory (IRD/University of Toulouse).

Can Pesticides on Fruits and Vegetables Cause Cancer?

With all the concerns about pesticides, some individuals may question whether they might develop cancer after eating fruits and vegetables with pesticide residue. Public health officials say that low levels of pesticides on produce are not harmful to people. What’s more, government agencies regulate and monitor how much pesticide can be left on food. For instance, in the United States, the U.S. Environmental Protection Agency regulates pesticide levels on food, while the Health and Safety Executive tracks pesticide levels in the United Kingdom.

Public health officials recommend washing fruit and vegetables before eating them to remove soil and bacteria.

Prolonged Pesticide Exposure Linked To Breast Cancer

A review of previous research, published in Science of The Total Environment, concluded that women who have had substantial exposure to pesticides may face a higher risk of breast cancer, especially through agricultural work, pesticide drift, contaminated clothing, household handling, or polluted water especially through agricultural work.

Lisa Lawler had long-term exposure to pesticides. She grew up on her family’s 400-acre farm in Hardin County, Iowa, where her father grew corn and used 2,4-D, a pesticide made by Dow Chemicals. Lawler and her siblings moved out of state after high school, but she returned in 2010.

Lawler acknowledged that pesticides are essential for farming, but she hopes more people would ask questions about the risks.

“We change products all the time when we learn about the health impacts,” Lawler said.

Story Links:

https://www.everydayhealth.com/healthy-living/do-pesticides-cause-cancer/
https://www.cancerresearchuk.org/about-cancer/causes-of-cancer/cancer-myths-questions/do-pesticides-cause-cancer
https://www.frontiersin.org/news/2024/07/25/pesticides-smoking-risk-cancer
https://investigatemidwest.org/2026/02/18/pesticide-use-and-cancer-risk-rise-together-across-americas-heartland/
https://ecancer.org/en/news/27991-pesticides-and-cancer-a-study-reveals-the-biological-mechanisms-behind-an-environmental-health-risk
https://www.sciencedirect.com/science/article/pii/S0048969724031358
https://npic.orst.edu/faq/cancerrisk.html