EPA Ignores the Science Linking Widely Used Herbicide to Parkinson’s Disease

At least 58 countries have banned paraquat, a highly toxic herbicide, because of its severe health harms


Zahra Ahmad, zahmad@earthjustice.org, (517) 898-0924

The Environmental Protection Agency today released proposed findings that ignore the scientific proof that farmworkers and agricultural communities exposed to the herbicide paraquat are more likely to develop Parkinson’s disease.

In response to a legal challenge brought by Earthjustice on behalf of farmworkers, public health, and environmental organizations, EPA prepared a new analysis of several issues raised in EPA’s 2021 registration review decision for paraquat, a widely used herbicide that is linked to Parkinson’s disease and other severe harms.  That analysis largely affirms the findings in EPA’s prior registration, including EPA’s dismissal of the broad scientific evidence connecting paraquat use and Parkinson’s disease.  EPA admits that it did not consider the latest science in its revaluation, including dozens of studies submitted to EPA by the Michael J. Fox Foundation for Parkinson’s Research.

“This is EPA’s opportunity to accept the science and protect farmworkers from Parkinson’s disease. Instead, it is doubling down on its past mistakes and leaving farmworkers and agricultural communities at risk,” said Jonathan Kalmuss-Katz, a senior attorney with Earthjustice. “EPA can still correct its flawed registration decision, but it needs to follow the science and join dozens of other countries in banning paraquat.”

Fifty-eight countries, including China and members of the European Union, have banned paraquat because of its extreme toxicity, including its connection to Parkinson’s disease. Research shows that farmworkers exposed to paraquat are more than twice as likely to develop Parkinson’s disease, a finding supported by extensive animal testing and other evidence.  Paraquat is also associated with respiratory and kidney harm, and ingestion of a single teaspoon of paraquat can be deadly.  However, paraquat remains widely used in the United States, with approximately eight million pounds sprayed on grapes, almonds, soybeans, cotton, and other crops each year.

In 2021, the EPA re-approved its registration for paraquat, authorizing the chemical’s continued use.  A coalition of farmworker, public health, and environmental organizations, represented by Earthjustice, filed suit to overturn that registration review decision, which understated paraquat’s serious health risks and violated EPA’s obligation to eliminate paraquat’s unreasonable risks. In response to that lawsuit, the EPA agreed to revisit its analyses of paraquat’s health effects, risks, and benefits, and it released the preliminary results of that reconsideration for public comment today.

The petitioners challenging EPA’s paraquat registration review decision are the California Rural Legal Assistance Foundation, Farmworker Association of Florida, Michael J. Fox Foundation for Parkinson’s Research, Farmworker Justice, Alianza Nacional De Campesinas, Pesticide Action Network North American, the Center for Biological Diversity, and Toxic Free North Carolina.

Quotes from our partners and clients

“Our stance is clear: the health and safety of farmworkers must be prioritized,” said Jeannie Economos, Pesticide Safety and Environmental Health Project Coordinator, Farmworker Association of Florida. “We urge the EPA to take decisive action by banning the use and manufacturing of paraquat in the U.S., aligning with the precautionary measures already taken by many other countries.”

“Paraquat is a deadly pesticide with irreversible health impacts,” said Alexis Luckey, Executive Director of Toxic Free North Carolina. “We call on EPA to prioritize the health and safety of our farmworkers over the re-registration of this toxic product.”

“The science is clear that this highly lethal pesticide threatens all living things, including our country’s wildlife,” said Nathan Donley, environmental health science director at the Center for Biological Diversity. “The EPA should follow the lead of nearly every other major agricultural country in the world and ban this dangerous stuff for good.”

A child walks through a field.
(Rob Marmion / Shutterstock)

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