Center for Biological Diversity

For Immediate Release, November 4, 2022


Jonathan Evans, Center for Biological Diversity, (213) 598-1466,
Jane Sellen, Californians for Pesticide Reform, (510) 788-9025 x 6,

California Regulators Urged to Ban Herbicide Linked to Parkinson’s Disease

Dozens of Countries Have Banned Paraquat, But U.S. Use Is Increasing

OAKLAND, Calif.— Conservation and public health groups today called on the California Department of Pesticide Regulation to reevaluate approval of the herbicide paraquat and ban its use in the state.

Banned in 58 countries, paraquat is one of the most lethal herbicides still approved for use in the United States and has been linked to Parkinson’s disease.

“The only way to stop this dangerous herbicide from continuing to poison our environment and farming communities is to ban it,” said Jonathan Evans, environmental health legal director at the Center for Biological Diversity. “We can’t keep ignoring paraquat’s proven role in causing needless deaths and its links to devastating health conditions like cancer and Parkinson’s disease.”

The groups’ letter requesting that California ban paraquat comes after a 2021 lawsuit challenging the Environmental Protection Agency’s reapproval of the pesticide’s use nationwide. The lawsuit prompted the EPA to tell the 9th Circuit Court of Appeals in September that EPA needed to reassess the safety and risks of paraquat. A public comment period that’s part of California’s annual pesticide renewal process ends this week.

There is no antidote for paraquat poisoning. The pesticide’s severe toxicity is highlighted on an EPA website titled “Paraquat Dichloride: One Sip Can Kill.”

Despite paraquat’s well-documented risks, California used more than 1.3 million pounds of it in 2018 alone. Use of paraquat is heavily concentrated in the San Joaquin Valley, with more than three-quarters of the total used in just eight San Joaquin Valley counties. Paraquat is one of the state’s five most-used herbicides.

“The research is clear that paraquat poses a severe risk to human health. There’s a huge disparity in who bears the greatest risk of exposure, with use overwhelmingly concentrated in the predominantly Latinx farm-working communities of the San Joaquin Valley," said Jane Sellen, co-director of Californians for Pesticide Reform. “Our state government should follow the science and act to protect the health of Californians, especially in farm-working communities.”

Ingesting or inhaling paraquat, or exposing it to the skin, can lead to a range of health risks short of death, including cancer, heart failure, kidney failure, liver failure and scarring of the lungs. Farmworkers and agricultural communities are at greater risk of inhaling paraquat because the herbicide can volatize or spread on dust that blows in fields and into neighborhoods.

Paraquat has been linked to Parkinson’s disease, a devastating neurological condition with no known cure. Researchers found that paraquat exposure in California’s agricultural communities leads to increased risks of Parkinson’s and thyroid cancer.

“The Michael J. Fox Foundation has a single, urgent goal: eliminating Parkinson’s disease in our lifetime,” said Ted Thompson, JD, senior vice president of public policy at The Michael J. Fox Foundation . “As a science-based organization, our research partners have studied the ample and compelling evidence showing paraquat’s association with neurological degradation and symptoms related to Parkinson's disease. We believe California state regulators, the federal government and the EPA should use every tool at their disposal to eliminate its risk.”

Pesticide manufacturers have known about paraquat’s association with Parkinson’s disease for years. But they have worked to refute research showing that link and aggressively lobbied regulators to refrain from taking greater steps to protect the public from those risks.

Paraquat manufacturers are facing a growing number of personal injury lawsuits related to its use and long-term impacts on human health. The pesticide is also deadly to wildlife — including many of California’s most imperiled species, like San Joaquin kit foxes and Swainson’s hawks.

The 2021 lawsuit challenging the EPA’s reapproval of paraquat — brought by farmworker groups, environmentalists and health organizations, represented by Earthjustice — is ongoing.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

Californians for Pesticide Reform is a statewide coalition of more than 190 organizations to protect public health, improve environmental quality and expand a sustainable and just agriculture system by building a diverse movement across California to change statewide and local pesticide policies and practices.

The Michael J. Fox Foundation is dedicated to finding a cure for Parkinson's disease through an aggressively funded research agenda and to ensuring the development of improved therapies for those living with Parkinson's today.

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