Thousands of U.S. farmers have Parkinson’s. They blame a deadly pesticide.
Paraquat is banned in more than 70 countries, but still legal in the United States. Now, a growing number of U.S. farmers are blaming the toxic pesticide for their Parkinson's disease in a large lawsuit.
Paul Friday remembers when his hand started flopping in the cold weather – the first sign nerve cells in his brain were dying.He was eventually diagnosed with Parkinson’s, a brain disease that gets worse over time. His limbs got stiffer. He struggled to walk. He couldn’t keep living on his family farm. Shortly afterward, Friday came to believe that decades of spraying a pesticide called paraquat at his peach orchard in southwestern Michigan may be the culprit.“It explained to me why I have Parkinson’s disease,” said Friday, who is now 83, and makes that claim in a pending lawsuit.The pesticide, a weed killer, is extremely toxic.With evidence of its harms stacking up, it’s already been banned in dozens of countries all over the world, including the United Kingdom and China, where it’s made. Yet last year, its manufacturer Syngenta, a subsidiary of a company owned by the Chinese government, continued selling paraquat in the United States and other nations that haven’t banned it. Health statistics are limited. Critics point to research linking paraquat exposure to Parkinson’s, while the manufacturer pushes back, saying none of it is peer-reviewed. But the lawsuits are mounting across the United States, as farmers confront Parkinson’s after a lifetime of use, and much of the globe is turning away from paraquat. It has many critics wrestling with the question: What will it take to ban paraquat in the United States? “What we’ve seen over the course of decades is a systemic failure to protect farmworkers and the agricultural community from pesticides,” said Jonathan Kalmuss-Katz, a senior attorney at Earthjustice, an environmental law organization that advocates against paraquat.Paul Friday was a lifelong peach farmer in Coloma, Michigan until he developed Parkinson's Disease in 2017. Photo provided by Luiba FridayThousands of lawsuits pile upIt was hard for Ruth Anne Krause to watch her husband of 58 years struggle to move his hands. He was an avid woodcarver, shaving intricate details into his creations, before it became too difficult for him to hold the tools.Jim Krause was diagnosed with Parkinson’s disease in 2019, after he spent decades operating a 20-acre stone fruit farm in central California. His wife says he often donned a mask and yellow rubber boots to spray paraquat on the fields.Krause, who had no family history of neurological disease as is typical, died in 2024.“I want people to know what happened,” said Ruth Anne Krause, who is worried that paraquat is still being sold to American farmers. Krause is one of thousands of people who have sued Syngenta, a manufacturer, and Chevron USA, a seller, over paraquat exposure. They’re alleging the chemical companies failed to warn of the dangers of paraquat despite knowing it could damage human nerve cells and studies showing it’s linked to Parkinson’s disease. Between 11 million and 17 million pounds of paraquat are sprayed annually on American farms, according to the latest data from the U.S. Geological Survey. The pesticide is used as a burn down, meaning farmers spray it to quickly clear a field or kill weeds. It's effective, but highly toxic. (Julie Bennett | preps@al.com) Julie Bennett | preps@al.comChevron, which never manufactured paraquat and hasn’t sold it since 1986, has “long maintained that it should not be liable in any paraquat litigation.”“And 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,” the company said in a statement.Syngenta has emphasized there is no evidence that paraquat causes Parkinson’s disease.“We have great sympathy for those suffering from the debilitating effects of Parkinson’s disease,” a Syngenta spokesperson said in a statement. “However, it is important to note that the scientific evidence simply does not support a causal link between paraquat and Parkinson’s disease, and that paraquat is safe when used as directed.”More than 6,400 lawsuits against Syngenta and Chevron that allege a link between paraquat and Parkinson’s are pending in the U.S. District Court of Southern Illinois. Another 1,300 cases have been brought in Pennsylvania, 450 in California and more are scattered throughout state courts.“I do think it’s important to be clear that number is probably not even close to representative of how many people have been impacted by this,” said Christian Simmons, a legal expert for Drugwatch. Syngenta told its shareholders in March that an additional 1,600 cases have been voluntarily dismissed or resolved. In 2021, the company settled an unspecified number in California and Illinois for $187.5 million, according to a company financial report. Some others have been dismissed for missing court deadlines. None have gone to trial yet. Behind these thousands of lawsuits, a list growing nearly every day, is a person suffering from Parkinson’s disease.In Ohio, there’s Dave Jilbert a winemaker who sprayed the pesticide on his vineyard south of Cleveland. He was diagnosed with Parkinson’s in 2020 and now he is suing and working to get paraquat banned. Terri McGrath believes years of exposure to paraquat at her family farm in rural Southwest Michigan likely contributed to her Parkinson’s. Six other family members also have the disease. And in south Alabama, Mac Barlow is suing after receiving a similar diagnosis following years of relying on paraquat.“For about 40 years off and on, I’ve been using that stuff,” Barlow said. “I’ll be honest with you, if I knew it was going to be that bad, I would have tried to figure out something else.”In Alabama, farmer Mac Barlow was diagnosed with Parkinson's after years of spraying paraquat. Teri McGrath believes years of exposure to paraquat at her family farm in rural Southwest Michigan contributed to her Parkinson’s. In Ohio, there’s Dave Jilbert a winemaker who sprayed the pesticide on his vineyard. He was diagnosed with Parkinson’s in 2020. Like Barlow, Jilbert is now suing. Photos by Julie Bennett, Isaac Ritchey and David PetkiewiczParaquat in the United StatesSince hitting the market in the 1960s, paraquat has been used in farming to quickly “burn” weeds before planting crops. The pesticide, originally developed by Syngenta and sold by Chevron, rips tissue apart, destroying plants on a molecular level within hours.“It’s used because it’s effective at what it does. It’s highly toxic. It’s very good at killing things,” said Geoff Horsfield, policy director at the Environmental Working Group. “And unfortunately, when a pesticide like this is so effective that also means there’s usually human health impacts as well.”By the 1970s, it became a tool in the war on drugs, sprayed to kill Mexican marijuana plants. In 1998, that history landed it in Hollywood when the Dude in “The Big Lebowski” calls someone a “human paraquat,” a buzzkill.Today, between 11 million and 17 million pounds of paraquat are sprayed annually to help grow cotton, soybean and corn fields, among other crops, throughout the country, the U.S. Geological Survey, USGS, reports. And despite the alleged known risks, its use is increasing, according to the most current federal data, more than doubling from 2012 to 2018. The USGS says on its website new pesticide use data will be released in 2025. It hasn’t been published yet. Because paraquat kills any growth it touches, it’s typically used to clear a field before any crops are planted. Low levels of paraquat residue can linger on food crops, but the foremost threat is direct exposure. Pesticides are among the most common means of suicide worldwide, according to the World Health Organization, and paraquat is frequently used because of its lethality. After some nations, like South Korea and Sri Lanka, banned it, they saw a significant drop in suicides, research shows.The U.S. Environmental Protection Agency already restricts paraquat, labeling it as “registered use,” with a skull and crossbones, meaning it can only be used by people who have a license. Because of its toxicity, the federal government requires it to have blue dye, a sharp smell and a vomiting agent, according to the U.S. Centers for Disease Control, CDC. Sprayers are also told to wear protective gear. Despite those safety measures, U.S. poison centers have gotten hundreds of paraquat-related calls in the past decade, their annual reports show.Swallowing is the most likely way to be poisoned by paraquat, according to the CDC, but skin exposure can also be deadly. In fact, if it spills on someone, health officials say they should wash it off immediately and quickly cut off their clothes. That way they don’t risk spreading more deadly pesticide on their body as they pull their shirt over their head. In one 2023 case documented by America’s Poison Centers, a 50-year-old man accidentally sipped blue liquid from a Gatorade bottle that turned out to be paraquat. After trying to throw it up, he went to the emergency room, struggling to breathe, nauseous and vomiting.Doctors rushed to treat the man, but he turned blue from a lack of oxygen and his organs failed. He died within three days.In another poison center report, a 65-year-old man spilled paraquat on his clothes and kept working. Ten days later, he went to the emergency room with second-degree burns on his stomach. Dizzy and nauseous, he was admitted for two days before going home.A week later, he went back to the ICU as his kidney, lungs and heart stopped working. He died 34 days after the spill.These annual poison center case summaries provide insight into paraquat’s toxicity, but it’s unclear exactly how many people in the U.S. have been injured or killed by the weed killer, because there’s only a patchwork of data creating an uneven and incomplete picture.The latest annual National Poison Data System report logged 114 reports and one death caused by paraquat in 2023. Over a decade, from 2014 to 2023, this system documented 1,151 paraquat calls. And a separate database shows the EPA has investigated 82 human exposure cases since 2014.Even secondary exposure can be dangerous. One case published in the Rhode Island Medical Journal described an instance where a 50-year-old man accidentally ingested paraquat, and the nurse treating him was burned by his urine that splashed onto her forearms. Within a day, her skin blistered and sloughed off.And a former Michigan State horticulture student is suing the university for $100 million, claiming that she developed thyroid cancer from her exposure to pesticides including paraquat, glyphosate and oxyfluorfen.Meanwhile, a much more widespread threat looms large in the background: long-term, low-level exposure.Parkinson’s on the riseParkinson’s disease is the fastest growing neurological disorder in the world, with cases projected to double by 2050, partly due to an aging population, according to a study published in The BMJ, a peer-reviewed medical journal. It occurs when the brain cells that make dopamine, a chemical that controls movement, stop working or die.The exact cause is unknown, likely a mix of genetic and, largely, environmental factors. A Parkinson’s Foundation study found that 87% of those with the disease do not have any genetic risk factors. That means, “for the vast majority of Americans, the cause of Parkinson’s disease lies not within us, but outside of us, in our environment,” said neurologist and researcher Ray Dorsey.That’s why Dorsey, who literally wrote the book on Parkinson’s, calls the disease “largely preventable.”There’s a long list of environmental factors linked to Parkinson’s, but pesticides are one of the biggest threats, according to Dorsey.“If we clean up our environment, we get rid of Parkinson’s disease,” he said. Paul Friday dedicated his life to growing peaches on his 50-acre farm in Coloma, Michigan. After buying 50 acres of land in 1962, he started experimenting with crossbreeding to develop the perfect peach. He is now one of thousands of farmers who have filed lawsuits claiming a toxic pesticide called paraquat is to blame for their Parkinson's, a neurological disease. Photo courtesy of Paul FridayResearch, dating back decades, has explored this link.An early 1987 case report published in Neurology discusses the case of a 32-year-old citrus farmer who started experiencing tremors, stiffness and clumsiness after 15 years of spraying paraquat. But “a cause-and-effect relationship is difficult to establish,” a doctor wrote at the time.A decade later, an animal study from Parkinson’s researcher Deborah Cory-Slechta found that paraquat absorbed by mice destroys the specific type of dopamine neuron that dies in Parkinson’s disease. More recently, her research has found paraquat that’s inhaled can also bypass the blood-brain barrier, threatening neurons. “It’s quite clear that it gets into the brain from inhalation models,” Cory-Slechta said. Critics point to other epidemiological studies being more definitive.In 2011, researchers studied farmworkers exposed to two pesticides, rotenone and paraquat, and determined those exposures increased the risk of developing Parkinson’s by 150%. Another study, published last year, looked at 829 Parkinson’s patients in central California. It found people who live or work near farmland where paraquat is used have a higher risk of developing the disease. “It’s kind of like secondhand smoke,” Dorsey said. “You can just live or work near where it’s sprayed and be at risk.”This is a growing concern in American suburbs where new houses press up against well-maintained golf courses. A study published in JAMA this year found that living within a mile of a golf course increased the risk of Parkinson’s disease by 126%. It didn’t name specific chemicals but did point to pesticides.The EPA in 2021 banned paraquat from golf courses “to prevent severe injury and/or death” from ingestion.Despite all that, it’s difficult to prove whether paraquat directly causes Parkinson’s because it develops years after exposure.“The disease unfolds over decades, and the seeds of Parkinson’s disease are planted early,” Dorsey said.Where do the lawsuits stand? The legal case over paraquat inched toward a settlement earlier this year.Most of the lawsuits have been brought in Illinois under what’s known as multi-district litigation. Unlike a class-action lawsuit, this puts individual cases in front of one federal judge. A few bellwether cases are then chosen to represent the masses and streamline the legal process.Syngenta, Chevron and the plaintiffs agreed to settle in April, which would wrap up thousands of cases, but an agreement is still being hammered out, court records show. If details can’t be finalized, it will go to trial.“It’s kind of like secondhand smoke. You can just live or work near where it’s sprayed and be at risk.”Ray Dorsey, a Parkinson's disease researchSyngenta has adamantly denied the lawsuits’ allegations, saying it backs paraquat as “safe and effective” when it’s used correctly and emphasizing there has been no peer-reviewed scientific analysis that shows paraquat causes Parkinson’s disease.“Syngenta believes there is no merit to the claims, but litigation can be distracting and costly,” a spokesperson said. “Entering in the agreement in no way implies that paraquat causes Parkinson’s disease or that Syngenta has done anything wrong. We stand by the safety of paraquat.”Chevron has also denied the claims saying the “scientific consensus is that paraquat has not been shown to be a cause of Parkinson’s disease.” What company files showA trove of internal documents released during litigation, as reported by The Guardian and the New Lede, appeared to show that the manufacturers were aware of evidence that paraquat could collect in the brain.But the New Lede acknowledged the documents do not show company scientists believed that paraquat causes Parkinson’s, Syngenta officials pointed out. The trail of bread crumbs started as early as 1958 when a company scientist wrote about a study of 2.2 dipyridyl, a chemical in paraquat, saying it appears to have moderate toxicity “mainly by affecting the central nervous system, and it can be absorbed through the skin,” the internal documents said. Imperial Chemical Industries, which later became Syngenta, started selling paraquat under the brand name Gramoxone in 1962, according to research. Gramoxone contains nearly 44% paraquat. Syngenta sells paraquat under the brand name Gramaxone, as a resgistered-use pesticide. It's labeled with a skull and cross bones and the warning "one sip can kill." The U.S. Environmental Protection Agency also puts the regulations and rules for use on the label. It's dyed blue and has a strong odor as safety mechanisms. (Photo by Rose White | MLive) Rose White | rwhite@MLive.comThe internal documents show by 1974, the company updated safety precautions, recommending that anyone spraying the pesticide wear a mask, as there were the first reports of human poisoning and concerns about the effects of paraquat started to grow.A year later, Ken Fletcher from Imperial Chemical wrote a letter to Chevron scientist Dr. Richard Cavelli, saying the chemical company knew of “sporadic reports of CNS (central nervous system) effects in paraquat poisoning” that he believed to be coincidental.Within months, Fletcher also indicated “possible chronic effects” of paraquat exposure, calling it “quite a terrible problem” that should be studied more, the documents say.“Due possibly to good publicity on our part, very few people here believe that paraquat causes any sort of problem in the field,” he wrote in the mid 1970s. “Consequently, any allegation of illness due to spraying never reaches serious proportions.”By the 1980s, outside research started to pick at the question of paraquat and Parkinson’s.“As more researchers dug into it, it’s only been more firmly established,” said Horsfield with the Environmental Working Group. Syngenta pushes back on this, though, saying two recent reports cast doubt on these claims. A 2024 scientific report from California pesticide regulators found recent evidence was “insufficient to demonstrate a direct causal association with exposure to paraquat and the increased risk of developing Parkinson’s disease.” And a September analysis from Douglas Weed, an epidemiologist and independent consultant, reached a similar conclusion.Syngenta also claims on its website to be a target of a “mass tort machine” that hovers behind multi-district litigation. Why hasn’t the EPA banned it?In 1981, Norway became the first country to outlaw paraquat due to the risk of poisoning. One by one, more countries followed suit. In 2007, the European Union approved a blanket ban for all 27 member countries, according to media reports. Yet Syngenta is still allowed to manufacture paraquat in countries that have banned its use. It’s been prohibited in the United Kingdom for 18 years and China banned paraquat to “safeguard people’s life, safety and health,” in 2012, according to a government announcement. Yet about two-thirds of the paraquat imported to the U.S. between 2022 and 2024 came from companies owned by the Chinese government, SinoChem and Red Sun Group, according to a joint report published by three advocacy organizations in October.It found most of the 40 million and 156 million pounds imported annually over the past eight years comes from Chinese manufacturing facilities, in either China or Syngenta’s big factory in northern England. Although hundreds of companies sell paraquat, Syngenta says it accounts for a quarter of global sales.According to previous media reports, SinoChem, a Chinese state-owned conglomerate, acquired Syngenta in a 2020 merger. SinoChem posted $3.4 billion in profits last year, but it’s unclear how much came from paraquat sales because the company doesn’t make earnings reports public. Syngenta reported $803 million in sales of its “non-selective herbicides,” the class that includes paraquat-containing Gramoxone, according to its 2024 financial report. While Chinese companies supply paraquat to American farmers, the report points out China is also a big purchaser of crops, like soybeans, that are grown with help from the pesticide.“In these two ways, China economically benefits from the application of paraquat in the U.S., where it outsources many of its associated health hazards,” the report said.Paraquat, now prohibited in more than 70 countries, according to the Environmental Working Group, was reauthorized by the EPA in 2021 when it passed a regularly scheduled 15-year review — a move challenged by critics. “EPA has the same information that those countries have,” said Kalmuss-Katz, the attorney with EarthJustice. “EPA has just reached a fundamentally different, and what we believe is a legally and scientifically unsupported position, which is: massive amounts of paraquat can continue to be sprayed without unreasonable risk.”The federal agency determined paraquat remains “an effective, inexpensive, versatile, and widely used method of weed control,” and any risks to workers are “outweighed by the benefits” of farms using the weed killer.“It is one of the mostly highly regulated pesticides available in the United States,” the agency said in a statement.This decision allowed it to be used with “new stronger safety measures to reduce exposure,” like requiring buffer zones where pesticides can’t be sprayed. For plants like cotton, alfalfa, soybeans and peanuts, the EPA wrote in its decision “growers may need to switch to alternative (weed-killers), which could have financial impacts.” Unlike other pesticides, paraquat works well in low temperatures and early in the season, according to the agency.“What we’ve seen over the course of decades is a systemic failure to protect farmworkers and the agricultural community from pesticides.”Jonathan Kalmuss-Katz from EarthJusticeMore than 200,000 public comments have been submitted to the EPA’s docket on paraquat over the years. Industry groups, farmers, advocacy organizations and others have all chimed in, arguing for or against the weed killer.One submitted by a North Dakota farmer, Trey Fischbach, urged the EPA to continue allowing paraquat to fight resistant weeds like kochia, writing it’s the “last tool in the toolbox.” The EPA also noted there weren’t many other options. “The chemical characteristics of paraquat are also beneficial as a resistance management tool, where few alternatives are available.” But farmers can get trapped on what critics call the “pesticide treadmill,” in which broad pesticide use leads to “superweeds” that require stronger and stronger pesticides to be knocked down.A comment submitted by Kay O’Laughlin, from Massachusetts, urged instead: “Do your job and ban paraquat because it is killing people. I speak as someone who lost a brother to Parkinson’s. People should not be disposable so that big agro can make ever greater profits!”The EPA’s 2021 decision was challenged within two months by environmental and farmworker groups who sued the EPA. Kalmuss-Katz said the groups challenged the EPA over reapproving paraquat without “truly grappling” with the connection to Parkinson’s.“The EPA here failed to adequately protect farmworkers,” he said.After that, the environmental agency shifted under President Joe Biden. The EPA decided to consider the issues raised in the lawsuits and started seeking additional information last year. In early 2025, it asked the courts for more time to assess the human health risks of paraquat.But the EPA wasn’t focused on Parkinson’s, saying in its decision the “weight of evidence was insufficient” to link paraquat exposure to the neurological disease. Rather, the federal question was over how the weed killer turns into a vapor that could harm people when inhaled or touched. “Parkinson’s Disease is not an expected health outcome of pesticidal use of paraquat,” the EPA said in its review. The study could take up to four years, according to the EPA, saying it’s “complex, large scale and is conducted under real world conditions,” while paraquat remains on the market. The agency in October updated the review, saying it’s now seeking additional information from Syngenta. Meanwhile, the EPA has shifted again. The Trump administration this year put four former industry lobbyists or executives, from the agricultural, chemical and cleaning industries, in charge of regulating pesticides at the EPA. And while it’s not clear where the agency stands on paraquat, there has been an early sign of backing away from opposition to controversial pesticides. Shortly after Kyle Kunkler, a recent American Soybean Association lobbyist, was tapped to lead pesticide policy, the EPA moved to reapprove the use of a different, controversial weed killer that had previously been banned by federal courts.Growing pressure to ban itBut grassroots pressure to ban paraquat continues to mount.“This is a pivotal time for whether paraquat is going to remain active in the United States,” said Simmons, a legal expert for Drugwatch.Last year, more than 50 Democratic lawmakers, expressing “grave concern” in letters, urged the EPA to ban paraquat.“Due to their heightened exposure to paraquat, farmworkers and rural residents are hardest hit by the harmful health effects of paraquat like Parkinson’s,” said an Oct. 7, 2024, letter signed by U.S. representatives. A separate letter was signed by a small group of senators. California, a heavy user of paraquat as the top agricultural state, became the first to move toward banning paraquat last year. But the bill ended up getting pared back with Gov. Gavin Newsom signing a law to fast-track reevaluating paraquat’s safety, reporting shows. Pennsylvania lawmakers are also considering banning it under state bills introduced this year. “There are better, healthier alternatives,” said state Rep. Natalie Mihalek, a Republican who introduced the Pennsylvania legislation.On a federal level, outside the EPA, pesticides appear to be in the crosshairs. Health and Human Services secretary Robert F. Kennedy Jr., has criticized chemicals being used in farming. But a new Make America Healthy Again report shows Kennedy has backed away from restricting pesticides after agricultural groups pushed back on the “inaccurate story about American agriculture and our food system.”At the same time, there’s been a reported industry effort to pass state laws that would protect pesticide manufacturers from liability. Two states, North Dakota and Georgia, already passed these laws, according to the National Agricultural Law Firm. But a federal bill introduced this year would ensure the manufacturers can’t be held responsible for harming farmers in any state.“This is a pivotal time for whether paraquat is going to remain active in the United States.”Christian Simmons, legal expert for DrugWatchAs this tug of war continues, paraquat continues to be sprayed on agricultural fields throughout the United States. The EPA is still assessing its risks. And nearly 90,000 Americans are getting diagnosed with Parkinson’s disease every year. Meanwhile for critics, the evidence seems clear: it’s too dangerous. “The easiest thing to do is we should ban paraquat,” Dorsey said.AL.com reporter Margaret Kates contributed to this story.
