This story was commissioned by the River City Journalism Fund
Swiss agrochemical giant Syngenta announced last week it will halt global production of paraquat by the end of June, citing economic pressures from smaller chemical companies that make similar versions of the toxic pesticide.
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Nonetheless, environmental groups, neurologists, and advocates for people with Parkinson’s disease cheered Syngenta’s announcement, because Syngenta is the world’s largest maker of paraquat, which is sold under the brand name Gramoxone.
Syngenta has been hammered for years by environmental groups backed by scores of studies around the world linking paraquat to Parkinson’s, the world’s fastest growing brain disease. There is also a movement in legislatures across the U.S. to ban paraquat, including Missouri and Illinois.
Michael Okun, chair of neurology at the University of Florida, told The Guardian that Syngenta’s announcement was a “public health milestone.”
“For decades we have warned that certain pesticides increase the risk of Parkinson’s and other serious diseases,” Okun said. “This moment proves that advocacy, data, and courage can change the trajectory of disease.”
Syngenta’s announcement comes barely a week after an in-depth story commissioned by the River City Journalism Fund examined some of the nearly 6,500 lawsuits filed against Syngenta in the federal courthouse in East St. Louis. The story also looked at some of the most recent scientific evidence linking exposure to paraquat to Parkinson’s disease, a debilitating movement disorder that afflicts more than 1 million Americans, and at least 10 million people worldwide.
In its press release, Syngenta did not refer to the East St. Louis court cases or the 1,500 others filed in state courts nationwide. The suits were filed mainly by farmers and agricultural workers, alleging that Syngenta had failed to warn them of paraquat’s dangers—even though internal company documents show that decades ago, its own scientists had warned of the herbicide’s harmful effects on human beings.
Nor did the company, a wholly owned subsidiary of Sinochem Holdings, the world’s largest chemical conglomerate—and an arm of the Chinese government—refer to the many studies showing clear links between exposure to paraquat and Parkinson’s disease.
That research is also why bills to ban paraquat have been filed since January in 12 state legislatures, including Missouri’s.
The House General Laws Committee is scheduled to hold a hearing on House Bill 2844 on March 11. Under the Paraquat Ban and Research Act of 2026, beginning January 1, 2027, anyone who uses, distributes or sells paraquat would pay a $250 fine for the first violation, and a $500 fine for any subsequent violations, according to a House summary.
Rep. Sherri Gallick (R-Belton) thinks the chances of passage are good since so few Missouri farmers currently use paraquat on their fields.
“Really, right now, less than 1 percent of farmers use this, and it’s very rare that they use this,” Gallick says. “If this can bring some more awareness to people and say, ‘OK, maybe I won’t use that, we’ll use something else instead,’ that’s a win.”
But the most recent federal reports show that, overall, American agriculture’s reliance on paraquat continues to grow, with usage doubling between 2012 and 2018, to about 18 million pounds. More than half of that amount is sprayed on fields in California.
That’s even though 70 countries have banned paraquat, including China—whose government owns paraquat-maker Syngenta—and the European Union. Gallick says one of the key factors driving her support for the bill “is that China has banned it, yet we’re using it.”
The state bills were launched with the help of a national lobbying campaign waged by the Michael J. Fox Foundation, a leading funder of Parkinson’s research, and the American Parkinson’s Disease Association.
Anne Hubbard, the association’s chief public policy officer, says that momentum has been building for paraquat bans. Hubbard cites a widely circulated study published by the American Medical Association in May 2025. It found that living within one mile of a golf course is associated with a 2.25 times higher risk of developing Parkinson’s disease compared to living at least six miles away.
The study’s authors hypothesized that the disparity in Parkinson’s rates stems from pesticides that drain from golf courses into local water supplies.
“And so more people are seeing these things and they’re asking, ‘Well, gee, how is that impacting me?’” Hubbard says.
The bill to ban paraquat in Illinois, the Illinois Pesticide Act, was filed last month by Sen, Laura Ellman, a Chicago area Democrat. It has yet to receive a hearing. Says Hubbard, “Parkinson’s is very much a bipartisan disease. You know, it’s something that affects everyone, regardless of your party affiliation.”
Syngenta, however, has continued to insist that paraquat is a boon to America’s farmers. “Paraquat is highly effective in controlling weeds and enables conservation agricultural practices such as no-till farming, remaining an essential component of the farming toolbox for many growers,” the company stated in its announcement.
The company’s decision to end paraquat production “is about focusing our resources where they deliver the greatest value for our business and our customers,” according to Mike Hollands, President Syngenta UK and Head of Syngenta Global Production and Supply.
Syngenta has consistently denied any causal link between paraquat and Parkinson’s disease. In court papers its lawyers have claimed there is “no credible evidence” that paraquat causes Parkinson’s.
The U.S. Environmental Protection Agency has adopted much the same line, stating that after reviewing the science, it has “not found a clear link” between paraquat exposure and Parkinson’s disease.
Gallick acknowledges that she expects to face “resistance” from some members of the agricultural industry over her bill. “Any time you put a mandate on something, even though people aren’t using it, it could be a tool in the toolbox that you might need later,” she says.
Gallick hopes to persuade them, saying, “I would rather have somebody that is familiar with the food industry and farming [sponsor the bill] than somebody who just comes out and says, ‘OK, we got to get rid of everything. We don’t want to talk about anything, this is horrible.’ Because I believe in dialogue. And I believe in bringing more awareness to this.”
The Environmental Working Group, which has long called for a worldwide ban on paraquat, welcomed Syngenta’s announcement. But Scott Faber, the group’s senior vice president for government affairs, said state governments still need to do their part to ban the herbicide.
“Until paraquat is banned, Syngenta and other companies will make this dangerous pesticide, putting farmers and rural residents at risk of Parkinson’s disease,” Faber said in a statement.
This story was commissioned by the River City Journalism Fund, which seeks to advance local journalism in St. Louis. See rcjf.org for more information.
