Lawsuit Alleges Link Between Herbicide Paraquat and Parkinson’s Disease

Although many studies published over the past decade have found an association between Parkinson’s disease and paraquat exposure, a recently filed product liability lawsuit alleges manufacturers of the controversial herbicide have withheld critical safety information from farmers and other agricultural workers.

Syngenta and Chevron USA were named as defendants in a complaint (PDF) filed last week in the U.S. District Court for the Southern District of Illinois by Michael Joseph Kearns, who indicates he developed Parkinson’s disease following years of exposure to paraquat-based herbicides.

Kearns indicates he regularly sprayed paraquat on farm fields around Danville, Illinois between 1964 and 1981, repeatedly inhaling, ingesting or otherwise absorbing the herbicide into his body. At least part of that time he worked as a crop duster, while at other times he was exposed while spraying or handling paraquat in the normal and expected manner.

As a result of the manufacturers’ failure to warn and disclose information about the safety of the herbicide, Kearns indicates he was unaware of the link between paraquat and Parkinson’s disease, and was diagnosed with the permanent and progressive nervous system disorder in November 2019, which causes tremors and debilitating movement problems.

“No doctor or any other person told Plaintiff Michael Joseph Kearns before November 25, 2019, that his Parkinson’s disease was or could have been caused by exposure to paraquat,” the lawsuit states. “At no time when using paraquat himself was Plaintiff Michael Joseph Kearns aware that exposure to paraquat could cause any latent injury, including any neurological injury or Parkinson’s disease, or that any precautions were necessary to prevent any latent injury that could be caused by exposure to paraquat.”

Paraquat is used to kill broadleaf weeds and grasses before planting numerous types of crops, is also used to control weeds in orchards, and is sometimes sprayed on plants before harvest in order to dry them out. As a result of known risks, use of the herbicide has been banned in many countries, and it is subject to severe restrictions in the United States. However, warnings and safety instructions largely focus on the risk of paraquat poisoning, and information is still not provided for users about the long-term Parkinson’s disease risks.

Over the past decade, a series of studies have repeatedly warned that the toxic effects of Paraquat go beyond weeds and also impact animals and humans, finding that farmers using the herbicide may be several times more likely to develop Parkinson’s. Paraquat research has also found individuals with certain genetic variations may be 11 times more likely to develop Parkinson’s after routine exposure to the herbicide.

Parkinson’s disease affects more than 500,000 Americans, with approximately 50,000 new cases each year. The disease causes the loss of motor functions, causing imbalance and shaking, which gets progressively worse over time.

The case filed by Kearns joins a growing number of paraquat lawsuits are now being filed by former users diagnosed with Parkinson’s disease, alleging the manufacturers knew or should have known about the risk, yet withheld warnings from consumers.