Paraquat Exposure at Home, Workplace May Increase Risk for Parkinson’s Disease

Over the past several years, the agricultural pesticide paraquat has been linked to Parkinson’s disease. Moreover, paraquat does not just pose a risk to agricultural workers who toil in fields where the pesticide’s been sprayed, but may also threaten people who merely live in the vicinity of those fields.

There is no home garden or residential uses for either paraquat currently registered with the U.S. Environmental Protection Agency (EPA). Paraquat use has long been restricted to certified applicators, largely due to concerns based on studies of animal models of Parkinson’s disease. But pesticides like paraquat can travel through the air once they’ve been sprayed on fields, possibly making their way into homes and workplaces.

In 2009, UCLA researchers found that the Parkinson’s disease risk among people who simply lived in California’s Central Valley near where farm fields were sprayed with paraquat and the fungicide maneb increased by 75 percent. The same researchers followed up their study with another published earlier this summer in the European Journal of Epidemiology. This time, they looked at people who either lived or worked near pesticide-sprayed fields in California’s Central Valley. They found that:

• People exposed at their workplaces to the three pesticides studied ziram, maneb and paraquat tripled their risk of Parkinson’s.
• Workplace exposure to both ziram and paraquat nearly doubled Parkinson’s risk.
• Pesticide exposure in workplaces was higher than in homes near the pesticide-sprayed fields.
• People who both lived and worked near fields sprayed with pesticides had the highest Parkinson’s risk.
• People with younger onset Parkinson’s disease had higher exposures to pesticides both at work and at home.

Another study published in June in Environmental Health Perspectives found that people who worked with either paraquat or the pesticide rotenone were 2.5 times more likely to develop Parkinson’s disease than those who did not work with the pesticides. The authors, scientists from the National Institute of Environmental Health Sciences and the Parkinson’s Institute and Clinical Center, studied 110 people with Parkinson’s disease and 358 matched controls from the Farming and Movement Evaluation (FAME) Study.

“Paraquat increases production of certain oxygen derivatives that may harm cellular structures,” study co-author Freya Kamel, Ph.D said in a press release announcing the study. “People who used these pesticides or others with a similar mechanism of action were more likely to develop Parkinson’s disease.”