More than 60 countries have banned the weedkiller paraquat because of its links to Parkinson’s disease. But the Environmental Protection Agency continues to defend its use in the U.S., based on a scientific analysis that has at least five fundamental flaws.
EPA ignores paraquat risks
The agency dismisses a growing body of research linking the toxic weedkiller paraquat to Parkinson’s disease. A recent EPA interim decision reiterating approval of the chemical ignores 90 articles of evidence, including cutting edge studies submitted by the Michael J. Fox Foundation for Parkinson’s Research, that make the connection clear.
This includes a study that reported people who sprayed paraquat were more than twice as likely to develop Parkinson’s disease as those who applied other pesticides. It also includes a 2019 analysis combining data from 13 earlier studies that reported exposure to paraquat increased the likelihood of developing Parkinson’s by 64 percent.
EPA sides with chemical companies
The EPA ignores new evidence about the potential health risks of paraquat that has emerged from legal action against its makers. Syngenta, the Swiss-based chemical giant owned by a Chinese state-owned chemical conglomerate, produces paraquat and has long understood these risks. But it spent decades hiding what they knew from the public and the EPA.
Ironically, Chinese and Swiss farmers are prohibited by their governments from using paraquat due to potential health risks from exposure to it.
EPA ignores risks to frontline communities
The EPA ignores the fact that paraquat is used far more heavily in some communities than others. More than 10 million pounds of paraquat were used in the U.S. in 2018, the most recent year for which national estimates are available. In California, which has pesticide tracking laws, more than half the paraquat used in 2021 was concentrated in a few counties, including major agriculture centers of Fresno, Kern and Kings.. In those areas, it’s used on almonds and pistachios, cotton, grapes, including those used for wine, and other crops.
A February 2024 study reported that living or working within 500 meters – about a third of a mile – increased the likelihood of developing Parkinson’s disease by 75 to 100 percent.
EPA is out of touch with how paraquat is used or its environmental impacts
The EPA continues to exclude from its paraquat analysis some of the ways people who work in or live near farm fields are exposed to toxic chemicals.
In particular, the agency excluded paraquat applications that might drift through the air and failed to consider how the chemical might be resuspended in farm dust on windy days. The EPA assumes people spraying paraquat will follow instructions designed to contain chemical drift and harm. But studies show “off label” use of pesticides that doesn’t adhere to these directions is common, with virtually no enforcement of labeling requirements.
EPA doesn't consider how communities are affected
The EPA fails to properly balance the costs and benefits of a paraquat ban, as other nations have. The agency considered the costs to farmers, but it failed to review the health and environmental costs to farmers, farm workers and people who live near farm fields, especially the costs associated with Parkinson’s disease.
Overdue paraquat ban
Instead of relying on fatal scientific flaws to justify the continued use of paraquat, the agency should follow the lead of the 60-plus countries that have banned the toxic weedkiller.
But states shouldn’t wait for the EPA to act.
Federal pesticide law sets a floor, not a ceiling – states can choose to restrict a chemical, even without an EPA ban. To protect their residents and public health, state and local governments should exercise their power to ban paraquat.
