EPA: No Paraquat Link to Parkinson's

LINCOLN, Neb. (DTN) -- EPA has not found a scientific link between the use of the herbicide paraquat and Parkinson's disease (PD), according to the agency's latest report in the ongoing review of the chemical released this week.

EPA conducted a new review in response to a lawsuit filed by Earthjustice on behalf of farmworkers, public health, and environmental groups.

"After a thorough review of the relevant studies, the agency concluded that the weight of evidence was insufficient to link paraquat exposure from pesticidal use of U.S.-registered paraquat products to PD in humans," the agency said in a 63-page review released on Tuesday.

EPA issued a review decision in 2021 on the chemical primarily used in cotton, re-approving paraquat's registration. The EPA is in the middle of a routine 15-year review of the chemical.

The petitioning groups raised several issues about that decision, including potential connections to Parkinson's. At that point, EPA added several additional mitigation measures to prevent human exposure to paraquat.

In its latest review, the EPA said it is continuing to study the latest research on Parkinson's but issued the new report now because of court-imposed deadlines.

EPA said it plans to implement additional information on the disease as well as other information in a new review document slated for completion by Jan. 17, 2025.

In addition, the agency this time stopped short of implementing new mitigation measures on paraquat applications.

"While the agency found potential risks of concern for aerial applications above 350 acres per applicator in a 24-hour period, EPA did not consider those risks unreasonable in light of the critical need for paraquat in cotton desiccation," the agency said in its latest review.

EPA said prohibiting aerial applications above 350 acres per applicator in 24 hours would have had "significant impacts" on growers who need paraquat for cotton desiccation.

That's because such applications typically involve larger field sizes and the timing of harvest can be crucial to yield and quality outcomes.

"EPA acknowledges that cotton harvesting technology is rapidly advancing and use practices continue to evolve," the agency said in the report.

"The agency may consider requiring label statements that prohibit tramping or raking activities when paraquat is applied as a harvest aid."

In its report, EPA says it has not reviewed all recent information on paraquat and Parkinson's disease and it will continue to seek public comment on the potential risks of using paraquat as a harvest aid.

EPA said it continues to review new information on a potential Parkinson's link as well as on paraquat's vapor pressure.

An attorney representing environmental interests in ongoing legal action against EPA on paraquat, said in a news release on Wednesday that EPA needs to review and act on new studies, rather than allowing the continued use of paraquat as that review moves forward.

"This is EPA's opportunity to accept the science and protect farmworkers from Parkinson's disease," said Jonathan Kalmuss-Katz, a senior attorney with Earthjustice.

"Instead, it is doubling down on its past mistakes and leaving farmworkers and agricultural communities at risk. EPA can still correct its flawed registration decision, but it needs to follow the science and join dozens of other countries in banning paraquat."

Thousands of lawsuits have been filed against paraquat's registrants Syngenta and Chevron Chemical Company in the past several years, primarily product liability claims and alleged connections between the chemical and Parkinson's.

Syngenta declined to comment when contacted by DTN. Chevron did not respond to DTN's request for comment.

So far, 58 countries have banned the paraquat, including China and the European Union.

Use of paraquat, which is sold under brand names such as Gramaxone, Firestorm and Parazone among others, has increased steadily in the U.S. in the past decade, in response to the development of herbicide-resistant weeds.

Read more on DTN:

"EPA Finalizes Paraquat Registration, OKs Aerial Applications for Now," https://www.dtnpf.com/…

Todd Neeley can be reached at todd.neeley@dtn.com.

Follow him on X, formerly known as Twitter, @DTNeeley.

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