"Paraquat Lawsuits Heat Up as Parkinson's Link Sparks Legal Battle"

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Paraquat and Parkinson’s: A Toxic Legacy in Court

The "Paraquat Papers": Internal Records Fuel Neurotoxicity Allegations

Commercially introduced in 1962 under the brand name Gramoxone, paraquat has been a dominant global herbicide for over six decades.

Its history is marred by controversy, ranging from its use in U.S. funded marijuana eradication programs in Mexico during the 1970s to its ban in the European Union in 2007 due to high toxicity.

While known for causing fatal lung fibrosis upon ingestion, the current legal battleground focuses on its neurotoxic potential.

Scientific literature links paraquat to Parkinson’s disease (PD) through a mechanism of oxidative stress that damages dopaminergic neurons in the brain.

Although regulatory bodies like the U.S. EPA and California’s Department of Pesticide Regulation currently state that epidemiological evidence is insufficient to prove a direct causal association, they acknowledge data consistent with a possible role in PD development.

Plaintiffs point to internal corporate records, known as the "Paraquat Papers," which allegedly show that manufacturer Syngenta was aware of these neurotoxic risks for decades and attempted to obscure the scientific evidence.

This dispute has consolidated into a massive Multidistrict Litigation (MDL) in the U.S. District Court for the Southern District of Illinois. As of December 2, 2025, there were 6,470 lawsuits pending in the MDL out of over 8,000 filed against defendants Syngenta and Chevron.

The litigation saw major developments in 2025, with reports surfacing in April of a sweeping agreement to settle thousands of cases, though Syngenta denies liability.

Despite settlement talks, the first bellwether trial is scheduled for October 2025. Simultaneously, legislative pressure is mounting; in late 2025, over 50 U.S. Senators urged the EPA to implement a nationwide ban, citing links to Parkinson’s and other health harms.

As of late 2025, the litigation remains a critical intersection of agricultural utility, corporate accountability, and public health.