Do Pesticides Cause Cancer? What to Know About Their Risk to Human Health

Research has linked pesticide exposure and cancer for decades. But the relationship between the two is complicated. Many factors influence a person’s risk of developing cancer, including the amount of pesticides they’re exposed to and how often it happens.

“‘The dose makes the poison’ is a foundational concept in toxicology,” says Lauren R. Teras, PhD, the senior scientific director of epidemiology research at the American Cancer Society, who is based in Decatur, Georgia. “How much, how often, and how long you are exposed all play an important role in potential health effects.”

What Are Pesticides, Exactly?

• Unlikely to present acute hazard in normal use
• Slightly hazardous
• Moderately hazardous
• Highly hazardous
• Extremely hazardous

What the Science Says About Pesticides and Cancer

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.

Pesticide Exposure on Fruits and Vegetables

“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.

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.”

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.

Should You Only Buy Organic?

Can you lower the risk of cancer by consuming organic products? The answer is no. Given the minimal risk of cancer from pesticide exposure in grocery and household products, you won’t lower your risk much by buying organic produce.

“The Food Quality Protection Act passed in 1996 ensures pesticides used on food meet strict safety standards,” says Lindsey Wohlford, RD, a wellness dietitian at the University of Texas MD Anderson Cancer Center. The law limits the quantity of pesticides that can be used to grow food, which minimizes your exposure to pesticides, she adds. “In addition, the Environmental Protection Agency evaluates all pesticides, both new and existing, to ensure they are not harmful or being used in harmful amounts.”

Every year, the Environmental Working Group publishes a list of 12 foods that contain the most pesticide residue and a list of 15 foods that contain the least pesticide residue (called the Dirty Dozen and the Clean Fifteen). “The Dirty Dozen and Clean Fifteen are helpful tools for consumers who want to reduce their exposure to pesticides,” Wohlford says. “[But] consuming a diet rich in a variety of fruits, vegetables, and other plant foods is most important. If organic produce is not affordable, do not avoid fruits and vegetables.”

Practical Ways to Lower Your Pesticide Exposure

You don’t have to completely overhaul your lifestyle to reduce your exposure to pesticides. Taking some simple precautions can make a difference, experts say.

• Clean your produce. Thoroughly wash all your produce under running water before eating it, Wohlford recommends.
• Remove the skin. Peeling fruits and vegetables with a firm outer skin, such as carrots and apples, can also help, Wohlford says.
• Don’t use an excessive amount of pesticides on your lawn or garden. “Use pesticides only when needed and apply the minimum amount necessary,” Teras says.
• Follow the instructions on pesticide products you use. “This includes using recommended protective equipment and keeping children, pets, and others away from treated areas,” Teras says. You should also wash your hands after doing yardwork.
• Don’t buy pesticides you don’t need. “It’s also best to buy only what you need — excess product can increase the risk of improper storage or disposal, which can lead to additional exposure,” Teras says.
• Store fungicides, insecticides, disinfectants, and other products properly. “Keep pesticides stored safely and out of reach of children and pets,” Teras recommends.