Published October 13, 2026
Four men who were diagnosed with Parkinson's disease have sued the makers of the insecticide chlorpyrifos in Delaware, alleging that years of exposure to the chemical caused their illness. The complaint was filed in Delaware Superior Court on September 15, 2026, according to a September 23 report from AboutLawsuits.com.
The plaintiffs are Keith Lutz of Pennsylvania, Dean Larson of North Dakota, Paul Chesterson of Connecticut and Arthur Emery of Delaware. Their alleged exposure periods range from the early 1980s into the 1990s, and in Larson's case through 2019. Lutz says he mixed, loaded and applied the product himself, and was also exposed through spray drift and contact with treated areas.
The defendants are Corteva Inc., Corteva Agriscience LLC, the Dow Chemical Company and Loveland Products Inc. The men bring claims for negligence, failure to warn, design defect and deceptive business practices, and seek both compensatory and punitive damages.
The core claim is that the companies knew, or should have known, that chlorpyrifos could damage the nervous system, but never properly studied what long-term exposure does to adults and never warned users about a possible link to Parkinson's disease. The complaint also points to Dow's past failure to promptly report hundreds of adverse health incidents to the U.S. Environmental Protection Agency, which it says led to what was then the agency's largest pesticide-related fine.
The companies have not publicly responded to the Delaware suit in the coverage we reviewed, and none of the allegations have been proven.
Chlorpyrifos Parkinson's litigation is very new. The first widely reported case was brought in June 2026 by Alexander Ramos, a former pest control worker from Long Island, in the Philadelphia County Court of Common Pleas against Dow, Corteva and FMC Corp., The New Lede reported. A handful of other individual cases have followed. There is no consolidated multidistrict litigation, no trial date and no settlement program.
Plaintiffs are leaning on recent research. A study published in December 2025, co-authored by UCLA neurologist Jeff Bronstein, found that people in California farming communities with long-term chlorpyrifos exposure were more than twice as likely to later develop Parkinson's disease as people without that exposure. That is a statistical association, not proof of cause, and causation is expected to be the central fight in these cases.
Dow introduced chlorpyrifos in the mid-1960s, and it was sold under names including Dursban and Lorsban. Most household uses were phased out around 2000, but farm use continued. The EPA moved to end its use on food crops in 2021, but a federal appeals court later vacated that decision, and limited agricultural use is still allowed today.
If you were diagnosed with Parkinson's disease after years of living, working or going to school near fields treated with chlorpyrifos, see Atumio's Parkinson's disease case page for a free eligibility review, or start your case review directly.