Exposure to Paraquat, Chlorpyrifos, Glyphosate and Other Pesticides Linked To Increased Lou Gehrig’s Disease Risks: Study

Researchers warn that there appears to be an increased risk of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig’s Disease), associated with exposure to several widely used pesticides.

In a study published last month in the journal NeuroToxicology, researchers from Dartmouth College looked at the rate of ALS among residents who live in close proximity to areas where more than 400 pesticides are used, and found the largest correlations between ALS diagnosis and the pesticides glyphosate (the active ingredient in Roundup), chlorpyrifos, 2,4-D and the insecticide carbaryl. However, the researchers also found some small, but statistically significant, links to Paraquat and others.

Despite decades of research, health experts have been unable to establish any familial or genetic trait to the majority of incidence of ALS, which is a progressive and debilitating neurogenerative disease, which causes loss of muscle control. However, they have always suspected pesticide exposure, among other environmental factors, to be a potential contributor.

In this latest study, researchers noted that previous investigations have found links between pesticides and ALS among agricultural workers who have direct exposure. However, they wanted to see whether there was any link between the use of the pesticides and the development of ALS among residents who live near areas which are heavily sprayed or otherwise treated with the weed and pest killers.

The researchers looked at data from the SYMPHONY Integrated Dataverse and examined the residential locations of 26,000 ALS patients nationwide, and matched them with non-ALS control subjects. They also looked at county-level U.S. Geological Survey data on the use of 423 different pesticides.

According to the findings, the pesticides with the largest positive statistically significant associations included 2,4-D, which was linked to a 25% increased risk of ALS among nearby residents, glyphosate, which was linked toa 29% increased risk; the insecticide carbaryl, linked to a 32% risk; and chlorpyrifos, which was associated with a 25% increased risk.

However, they also found smaller, but significant, associations with Paraquat, which is already known to be highly toxic, and has been linked to an increased risk of Parkinson’s disease, which is another neurodegenerative disease.

“Our analysis identified several herbicides, insecticides, and fungicides that have been implicated in the literature as being neuro toxic as potential ALS risk factors,” the researchers concluded. “Other less-studied pesticides that we identified also may warrant further investigation in the laboratory to assess mechanisms, their potential as etiologic contributors to sporadic ALS risk, and as targets for exposure mitigation.”

Paraquat Lawsuits and Roundup Lawsuits

The findings come amid increasing concerns about illnesses linked to pesticides widely used throughout the United States.

In recent years, more than 120,000 Roundup lawsuits have been filed against Monsanto by users of the weed killer, alleging that glyphosate caused non-Hodgkins lymphoma and other injuries. Following several massive jury verdicts, more than $10 billion in settlements have been paid to resolve claims, and new lawsuits continue to be filed as former users are diagnosed.

A growing number of Paraquat lawsuits are also now being filed by farmers and agricultural workers diagnosed with Parkinson’s disease after spraying, mixing or handling the toxic herbicide.

Although Paraquat has been banned in several countries, it remains available throughout the United States under restrictions that require users to go through a training certification process, since ingesting even a small amount can cause fatal poisoning. However, lawsuits now allege that the manufacturers failed to warn that Paraquat may cause Parkinson’s disease even when all of the recommended precautions are followed.

While genetics are often believed to be a major cause of Parkinson’s disease, similar to ALS, growing research indicates genes are only believed to be associated with about one-in-ten cases. Exposure to herbicides and pesticides are increasingly considered a leading risk, especially when combined with other factors that place individuals at risk of the development of Parkinson’s.

Given common questions of fact and law raised in complaints filed throughout the U.S., the federal Paraquat litigation has been centralized before one judge for coordinated discovery and pretrial proceedings, where the parties are preparing a series of bellwether cases for trial dates expected to begin in November 2022.