Paraquat Health Side Effects Hidden By Syngenta Since 1950s, Uncovered Documents Reveal

An investigative news report has highlighted concerning information found in internal documents from Syngenta, which were uncovered as part of the discovery proceedings in thousands of Paraquat lawsuits being pursued by individual diagnosed with Parkinson’s disease, revealing that the company suspected that its widely used weed killer could cause severe health problems as early as the 1950s, and was concerned about the link between Paraquat and Parkinson’s disease specifically by 2001.

A report on the so-called “Paraquat Papers” was published late last year in The Guardian, which worked with investigators from The New Lede, an environmental news initiative supported by the Environmental Working Group.

History of Paraquat Health Risks

Paraquat was originally developed in the 1950s by Imperial Chemical Industries, PLC (ICI), which is a legacy company of Syngenta, and the weed killer was first marketed under the brand name Gramoxone in the 1960s. However, over the subsequent decades Syngenta sold Paraquat formulations under a variety of names, and promoted the weed killer without warning users about the long-term Paraquat health side effects they may face from exposure.

Although it has been widely used for decades, and is already heavily restricted in the United States due to the risk of Paraquat toxicity if even a small amount of the weed killer is ingested, there are now a growing number of Paraquat lawsuits being pursued by former users diagnosed with Parkinson’s disease, pointing to studies that have found exposure may cause a two- to five-fold increased risk among individuals regularly handling, mixing and spraying Paraquat, compared to populations that do not have such occupational exposure.

Plaintiffs allege that Syngenta and other manufacturers failed to warn about the known health side effects of Paraquat, including Parkinson’s disease, and withheld critical safety information which may have allowed them to avoid the diagnosis. However, the manufacturers have continued to defend the safety of herbicide in Court.

Documents Highlight Concerns About Paraquat Health Effects

According a cache of internal documents, produced through the Paraquat lawsuit discovery process, The Guardian reports that Syngenta began to suspect problems with Paraquat long before they were publicly known, and participated in efforts to refute scientific literature and worked behind the scenes to keep scientists who may criticize the pesticide off of an U.S. Environmental Protection Agency advisory committee. The company then tried to cover up its efforts.

Documents revealed from 1975 showed the company had concerns it could face massive Paraquat lawsuit payouts over long-term health side effects, even then.

While the documents do not specifically point to Parkinson’s disease as the threat, Syngenta was aware of research linking Paraquat to Parkinson’s disease at least as early as 2001, as detailed in notes from a Paraquat/Parkinson’s Disease Task Team meeting (PDF) from that year.

“A range of studies (principally in mice) have emerged and continue to emerge, that claim to demonstrate that [Paraquat]…can cause site-specific effects in the substantia nigra – the area of the brain that is affected in classic [Parkinson’s disease] PD,” the meeting notes state. “Some of the more recent studies postulate that mice exposed…have shown an increased susceptibility to PD-like symptoms.”

Other documents from 2003 mention an “influencing” strategy to protect the Paraquat brand, to maintain its regulatory approval status, noting that the company would target academia, regulatory and non-government organizations. Syngenta records indicate its ‘freedom to sell” Paraquat was its top priority, and that it would vigorously defend its $400 million in global Paraquat sales.

It is only over the last couple years that many former farm workers and agricultural users have learned that their Parkinson’s disease may be linked to Paraquat exposure.

March 2023 Paraquat Parkinson’s Disease Lawsuit Update

There are currently more than 2,000 product liability cases filed against Syngenta and other defendants in the federal court system, each raising similar allegations that the companies failed to warn about the link between Paraquat and Parkinson’s disease, which research has found may develop years after regularly spraying, mixing, transporting or handling the weed killer.

Given common questions of fact and law raised in the litigation, the federal cases have been centralized as part of a Paraquat MDL (multi-district litigation), which is consolidated before U.S. District Judge Nancy J. Rosenstengel in the Southern District of Illinois, for coordinated discovery and pretrial proceedings.

To help the parties gauge how juries may respond to certain evidence and testimony that will be presented throughout the Paraquat litigation, the Court set an aggressive schedule that originally anticipated the first Parkinson’s bellwether trial dates going before a jury in late 2022. However, as a growing number of claims continue to be filed, the start of that first jury trial has been pushed back to mid-2023.

Judge Rosenstengel previously had the parties complete case-specific discovery in a group of 16 Paraquat bellwether cases selected earlier this year, which were designed to be representative of issues and injuries that will be repeated throughout the litigation.

While the outcome of these early bellwether trials will not be binding on other claims in the litigation, the amounts of any Paraquat lawsuit payouts is expected to have a large impact on the amounts of any Parkinson’s disease settlements that may be offered to plaintiffs to avoid the need for each individual claim to go before a jury.