The toxic pesticide paraquat was mishandled at Pennsylvania farms, violating safety requirements, at least 18 times between 2018 and 2023, an EWG investigation finds.
The investigation raises serious questions about the potential health risks to farmers who apply the chemical and to people living and working in communities near where it’s used.
EWG’s findings are based on state records of paraquat use violations received through a public records request.
Paraquat handling violations in Pennsylvania between 2018 and 2023
Dangerous misuse
Long-term exposure to paraquat is linked with Parkinson’s disease, a progressive and fatal brain disorder characterized by involuntary movements like tremors, stiffness and impaired balance. It is also connected to non-Hodgkin lymphoma, childhood leukemia and other harms.
EWG found that growers and spray companies often permit workers to use the harmful chemical in ways that could endanger themselves and those around them. Records show applications of the chemical without permits, a failure to provide safety equipment and training to workers, and frequent pesticide drift. These violations put farmers, workers and nearby homes at risk from exposure to the misused paraquat.
In Ivyland, officials cited sprayers for ignoring the safety requirements. Paraquat drifted in Bath, Codorus, Drumore, Gettysburg, Marion, Reading and Tyrone, potentially exposing nearby neighborhoods. In New Holland, a sprayer bought paraquat on an expired license, and in Kinzers and in Oakland Mills, paraquat was sold to an unlicensed applicator.
In an extreme case, one applicator used paraquat with a lapsed license and failed to keep adequate records for all of 2019.
Paraquat risks
Paraquat is an herbicide used mostly to clear fields and to clear rows in orchards. The chemical can stay in soil for years, but when sprayed, it can also drift through the air or linger in dust.
Paraquat is both acutely and chronically toxic – it can harm people both after a single exposure and after repeated, lower-level exposures. More than 70 countries have banned paraquat but it remains legal and used in Pennsylvania and many other states.
Each misuse of this deadly poison endangers people spraying paraquat or spending time near it.
The Environmental Protection Agency assumes all paraquat is applied as directed on the label, but EWG’s investigation shows this isn’t true. Our findings align with other research showing that “off label” use of paraquat and other pesticides is common. Studies suggest pesticide misuse in general is likely underreported and underenforced.
Despite this evidence of paraquat misuse, the EPA has downplayed such research and delayed its review of the chemical’s risks.
The EPA is required by law to review paraquat every 15 years. Since the last review, in 2021, new paraquat alternatives have emerged. In fact, farming is still productive and profitable in the over 70 countries that have banned its use, as one study shows.
Most farmers, especially in Pennsylvania, don’t use paraquat. The most recent national data shows that paraquat accounts for less than 1.3% of all pesticide use in the state.
It’s used in very small amounts for the most popular crops in Pennsylvania:
- Less than 1.4% of corn acreage
- Less than 2% of soybean acreage
- Zero percent of wheat acreage
- 0.3% of fruit and vegetable acreage
- 1.1% of orchard and grape acreage
- Less than 0.8% of alfalfa acreage
This is also true of apples, a valuable crop in Pennsylvania. Four of the top 10 apple-producing regions, including China and the European Union, representing over 77% of all global apple production, don’t use paraquat.
Link to serious illness and death
But if the amounts of paraquat used by Pennsylvania growers are so small, what’s the cause for so much concern?
The answer is that paraquat is also highly toxic – just one small dose can cause immediate serious harm. A person who ingests just a teaspoon can suffer extreme respiratory and gastrointestinal distress and organ failure, or even die.
Between 2016 and 2022, the National Poison Data System reported over 700 cases of paraquat exposure in the U.S. – the vast majority unintentional, with several resulting in death. In one example, unused paraquat was stored in a Gatorade bottle, only to be accidentally consumed by a toddler who died in the hospital two weeks later of kidney and liver failure.
And the link between chronic exposure to paraquat and Parkinson’s disease has been well established. It was first identified over 35 years ago. Since then, many other studies have connected the herbicide to the disease.
Neurologists at the Penn State Milton S. Hershey Medical Center found a connection between paraquat use and Parkinson’s in Pennsylvania farmers.
Studies have determined that people living or working near the most intense paraquat applications are also more likely to develop Parkinson’s. Other studies using data from the National Institutes of Health found that farmworkers in Iowa and North Carolina who sprayed paraquat were two and a half times more likely to develop Parkinson’s. The longer they used the herbicide, the stronger the association.
A meta-analysis found that, across 13 different studies, occupational and environmental exposure to paraquat increased the risk of developing Parkinson’s by 64%.
Animal studies show how paraquat can damage human brains. Exposure to paraquat leads to changes in behavior and overall motor function, a reduction in dopamine-producing neurons, and harmful malfunctions in the important brain protein alpha-synuclein.
All of these symptoms are hallmarks of Parkinson’s development.
The EPA ignores paraquat risks
In addition to delaying action, the EPA has dismissed the growing body of research on this risk from paraquat exposure. In particular, the agency has ignored more than 90 articles that make the Parkinson’s disease connection clear, including studies submitted by The Michael J. Fox Foundation for Parkinson’s Research.
The EPA has also ignored new evidence that has emerged from legal action against the chemical’s makers. Syngenta, the Swiss-based chemical giant owned by a Chinese state-owned chemical conglomerate, produces paraquat and has long understood these risks. But it spent decades hiding what they knew from the public and the EPA.
In 2011, at the beginning of a review of the chemical, the EPA noted dozens of occupational incidents of exposure. In 2016, the EPA proposed new guardrails to deter paraquat misuse including label changes and mandatory training.
Further evaluation of paraquat’s potential to cause occupational harm prompted the agency to announce even stricter regulations in 2021, including 10 new measures designed to lower the risks of harm, such as changing labeling and packaging, residential buffer areas and bans on certain types of application.
At the start of 2025, the EPA announced it will withdraw the 2021 measures and restart the review process. A potential agency decision on paraquat is now years away.
States shouldn’t wait for the EPA to act
States like Pennsylvania are leading the way when it comes to paraquat.
In light of the EPA’s failure to act, a bipartisan group of Pennsylvania lawmakers, led by state Reps. Natalie Mihalek (R) and Melissa Shusterman (D), have introduced House Bill 1135, which would ban the use of paraquat in the Keystone State.
Last year, California enacted Assembly Bill 1963, requiring the California Department of Pesticide Regulation to quickly review the dangerous herbicide.
Even with these and potential new safety restrictions, paraquat will never be completely safe to use or be exposed to.
The only safe solution is an outright ban. Pennsylvanians’ health can’t afford to wait.
