Agency draft report backs Paraquat’s safety but lawsuit’s plaintiffs say EPA ignored evidence of Parkinson’s risk.

The US Environmental Protection Agency is doubling down on its controversial finding that a toxic herbicide is safe for use across millions of acres of American cropland, despite what public health advocates characterize as virtual “scientific proof” the product causes Parkinson’s disease.

The agency in 2021 reapproved paraquat-based herbicides for use, but a coalition of agricultural and public health groups sued, charging that the EPA had ignored broad scientific consensus linking the substance to Parkinson’s.

The EPA agreed to reassess the most current science, but last week released a new draft report reaffirming the substance’s safety. But the lawsuit’s plaintiffs say the agency again ignored evidence of the Parkinson’s risk, including dozens of peer-reviewed studies sent to it by the Michael J Fox Foundation for Parkinson’s Research.

By re-approving the “highly lethal” substance, the EPA has “violated the law” and put industry interests before public health, the plaintiffs allege.

“There is an incredibly overwhelming body of evidence on this that has been accepted by scientists across the globe, and the EPA’s decision really placed it at odds with the best available science,” said Jonathan Kalmuss-Katz, a senior attorney with Earthjustice, the suit’s lead plaintiff.

The EPA’s decision is the latest salvo in a decades-long battle over the use of paraquat, which is a highly effective weed killer. Elsewhere, Syngenta, which produces the substance, has lost – nearly 60 countries have banned paraquat. A state-owned Chinese company bought Syngenta in 2017, but China still prohibits the product, as do the UK and EU.

About 8m pounds annually are sprayed on US grapes, almonds, soya beans, cotton and other crops, most commonly in California’s Central Valley, Iowa and the Mississippi River Valley. The substance’s use tripled in the US between 2008 and 2018.

Research shows the paraquat interferes with dopamine production and regulation, and people with Parkinson’s have reduced dopamine levels. Paraquat is also linked to respiratory damage and kidney disease, and ingestion of a single teaspoon is considered deadly.

By law, the EPA must review pesticides every 15 years and cannot approve those that create an “unreasonable risk” to human health. “Literally hundreds” of research papers – including epidemiological, animal and cellular studies – have linked the substance to Parkinson’s, Kalmuss-Katz said.

Agricultural workers and communities are most at risk – an epidemiological study of central California farming communities exposed to paraquat and another herbicide clearly showed an increased risk of Parkinson’s.

The EPA has touted its strict regulations around paraquat’s application, and requires farmers to be trained and certified to use it while wearing protective gear.

But even with the regulations, agricultural workers still face a high risk, Kalmuss-Katz said, which the EPA even acknowledged in its report. The agency stated it “concluded that these risks were outweighed by the benefits of the use of paraquat”. However, the Parkinson’s risk was not factored in, Kalmuss-Katz said.

The re-evaluation comes from the same notorious division in the EPA that whistleblowers say has been captured by industry. The Guardian last year revealed how internal corporate documents showed Syngenta has sought to influence regulators’ decision making around the chemical, withheld risks from the public and attempted to edit unfavorable studies. Meanwhile, it maintained a “Swat team” that responded to independent reports that could interfere with its “freedom to sell” paraquat.

Although the EPA’s latest decision suggests it intends to keep paraquat on the market, it has said it will review more science, and could change course when issuing a final report next year.

“The EPA can still correct its flawed decision, but it needs to follow the science and join dozens of other countries in banning paraquat,” Kalmuss-Katz said.


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Updated: August 16, 2017