04/22/2024 - US Expert News: Judge Rejects Key Expert Witness Who Claims Herbicide Causes Parkinson's

A key expert witness in lawsuits claiming that Syngenta's herbicide paraquat causes Parkinson's disease cannot testify in court, a federal judge ruled Wednesday, dismissing the first four cases over the product that were set to go to trial.

Lawyers for agricultural workers suing Syngenta and Chevron (CVX.N), which sold paraquat before 1986, had sought to have Cornell University professor Martin Wells testify that occupational exposure to the chemical can cause the disease. Without that testimony, U.S. District Judge Nancy Rosenstengel found, the trials cannot go forward.

Rosenstengel, in barring Wells from testifying, said his analysis of the data relied on "unscientific cherry-picking." She also said it was a "red flag" that his view "has not been adopted or independently validated in any peer-reviewed scientific analysis outside of this litigation."

Rosenstengel's ruling does not apply directly to the more than 5,000 other cases centralized in her court in East St. Louis, Illinois that would give the opportunity to name another expert witness.

In a joint statement, lead attorneys for plaintiffs in the litigation — Sarah Doles of Levin, Papantonio, Rafferty, Proctor, Buchanan, O'Brien; Peter Flowers of Meyers & Flowers; and Khaldoun Baghdadi of Walkup, Melodia, Kelly & Schoenberger — said they disagreed with the ruling and would appeal it, and they looked forward to taking a new set of cases to trial.

"We will continue to prosecute these cases on behalf of the thousands of American farmworkers diagnosed with an incurable and debilitating disease because of their exposure to paraquat," they said.

Herbicides, also commonly known as weed killers, 'are substances used to control undesired plants, also known as weeds. Selective herbicides control specific weed species while leaving the desired crop relatively unharmed, while non-selective herbicides kill plants indiscriminately'. Source: Wikipedia.

The companies have denied that paraquat causes Parkinson's. Parkinson's disease is a brain disorder that causes unintended or uncontrollable movements, such as shaking, stiffness, and difficulty with balance and coordination. Symptoms usually begin gradually and worsen over time according to The National Institute of aging
Chevron said in a statement that the decision affirmed that "despite hundreds of studies conducted over the past 60 years, the scientific consensus is that paraquat has not been shown to be a cause of Parkinson's disease." A Syngenta spokesperson said the company was pleased with the ruling, which it called "consistent with decades of peer-reviewed scientific literature."