A lot of the data comes from studies of farmworkers, who work with these chemicals regularly. Studies have linked long-term pesticide exposure in this group to increased risk of Alzheimer’s and Parkinson’s disease; prostate, ovarian, and other cancers; depression; and respiratory problems. There’s some suggestion that adults and children living in farm communities could also be at risk for chronic health problems.
The rest of us may not handle the stuff, but we are exposed through food, water, and air. The fact that pesticide residues are generally below EPA tolerance limits is sometimes used as “proof” that the health risks are minimal. But the research used to set these tolerances is limited.
In a 2010 report on environmental cancer risks, the President’s Cancer Panel (an expert committee that monitors the country’s cancer program) wrote: “The entire U.S. population is exposed on a daily basis to numerous agricultural chemicals. … Many of these chemicals have known or suspected carcinogenic or endocrine-disrupting properties.” Endocrine disruptors can block or mimic the action of hormones, even at low doses. “Endocrine effects aren’t sufficiently factored into the EPA pesticide-tolerance levels,” Crupain says. “And there’s concern they could cause reproductive disorders; birth defects; and breast, prostate, and other hormone-related cancers.”