Paraquat Exposure Lawsuit Claims Farm Herbicide Caused Parkinson’s Disease

Lawsuit alleges years of exposure to the herbicide Paraquat led to a Parkinson’s disease diagnosis decades later.

Individuals nationwide continue to file product liability lawsuits claiming that Paraquat exposure led to the development of Parkinson’s disease, even as attorneys for plaintiffs and the manufacturers attempt to hammer out the final details of a settlement agreement.

One of the latest to file a complaint (PDF) was George Caldwell of Mississippi, who named Syngenta Crop Protection LLC and Chevron U.S.A. Inc. as defendants in a July 28 filing with the U.S. District Court for the Southern District of Illinois.

Caldwell indicates that years of Paraquat exposure beginning in the late 1960s contributed to his development of Parkinson’s disease, which was not formally diagnosed until October 2024.

Originally introduced under the brand name Gramoxone in 1964, Paraquat is an herbicide used to kill broadleaf weeds and grasses. It is also used to dry out some crops before processing.

Herbicide and Pesticide Parkinson’s Disease Lawsuits

While Paraquat has long been known to be toxic and poisonous, ties to neurological damage only arose in recent years as researchers have repeatedly linked Paraquat exposure to Parkinson’s disease.

Parkinson’s disease is a progressive and incurable neurological disorder that damages dopamine-producing brain cells responsible for controlling movement. Common symptoms include tremors, slowed movement, muscle stiffness, impaired balance, difficulty walking and, as the disease advances, loss of independence.

Caldwell’s complaint is one of nearly 6,700 Paraquat exposure lawsuits filed against Syngenta and Chevron by landscapers, farmers and other agricultural workers. Each indicates they were diagnosed with Parkinson’s disease due to exposure to the herbicide, which has already been banned in several countries.

Similarly, a series of chlorpyrifos lawsuits are now being filed over the pesticide’s potential link to Parkinson’s disease. Chlorpyrifos has been commonly sold under brand names such as Lorsban and Dursban. Those claims allege manufacturers failed to adequately investigate or warn that repeated exposure through mixing, spraying, residential pest control or pesticide drift could cause lasting neurological damage and contribute to Parkinson’s disease years or decades later.

Paraquat Parkinson’s Disease Allegations

The lawsuit indicates Caldwell was repeatedly exposed to Paraquat from 1963 to 1971 on the farm where he lived and worked in Mississippi. At the time, Caldwell reports he was not given adequate safety equipment or warned about the dangers of exposure to the herbicide.

Caldwell was diagnosed with Parkinson’s disease in October of 2024. However, it was not until further studies and science linked Paraquat to Parkinson’s disease risks that he began to associate his ailment with years of Paraquat exposure.

The lawsuit claims the manufacturers knew about these concerns yet refused to provide healthcare professionals with adequate warnings about Paraquat risks.

“Hundreds of in vitro studies have found that paraquat creates oxidative stress that results in the degeneration and death of dopaminergic neurons (and many other types of animal cells). Many epidemiological studies (studies of the patterns and causes of disease in defined populations) have found an association between paraquat exposure and PD, including multiple studies finding a two- to five-fold or greater increase in the risk of PD in populations with occupational exposure to paraquat compared to populations without such exposure.”

– George Caldwell v. Syngenta Crop Protection LLC et al.

Caldwell’s lawsuit presents claims of design defect, failure to warn, negligence, violations of the Mississippi Consumer Protection Act and breach of implied warranty of merchantability. He seeks both compensatory and punitive damages.

Paraquat Lawsuits

The complaint will be consolidated as part of a multidistrict litigation (MDL) with other federal Paraquat lawsuits under U.S. District Judge Nancy Rosenstengal in the Southern District of Illinois, where she is overseeing coordinated discovery and pretrial proceedings.

While the judge has planned out a series of “bellwether” early test trials to weigh how jurors respond to evidence and testimony that would be used throughout the litigation, plaintiffs and the manufacturers have indicated they are very close to a final agreement.

Attorneys have been indicating they are finalizing terms of the deal since April 2025. Judge Rosenstengal placed a stay on the litigation when the deal was announced. If the negotiations fall through, Judge Rosenstengal would be expected to move forward with the trial dates.

While the manufacturers still deny Paraquat’s link to Parkinson’s disease, Syngenta announced a global phaseout of all Paraquat production in June as U.S. lawmakers in a number of states began to push for Paraquat bans.

Chlorpyrifos Parkinson’s Disease Lawsuits

While negotiations continue on a potential Paraquat settlement, there is an increasing number of chlorpyrifos lawsuits being brought over that insecticide, which has also been linked to an increased risk of Parkinson’s disease.

First introduced in 1965, chlorpyrifos is a broad-spectrum insecticide used on row crops by farmers, agricultural workers, pest control employees, landscapers and groundskeepers. However, scientific evidence has recently emerged that chlorpyrifos exposure could put those users at risk of serious health problems.

Compensation may be available for individuals who have developed symptoms of Parkinson’s disease after exposure to any of the following:

• Personally mixing or applying chlorpyrifos
• Working on a farm during or after chlorpyrifos applications
• Living on a farm where chlorpyrifos was regularly used
• Using chlorpyrifos as a residential insecticide
• Working near chlorpyrifos spraying or pesticide drift
• Occupational exposure to chlorpyrifos through pest control, construction, golf course maintenance or military service during the Gulf Wars

Chlorpyrifos Parkinson’s disease lawyers are currently reviewing potential claims for those who were diagnosed with neurological damage after long-term chlorpyrifos exposure.

All chlorpyrifos lawsuits are handled on a contingency fee basis, meaning there are no fees unless a settlement is obtained.

Sign up for more legal news that could affect you or your family.