A week before Election Day in November 2024, Robert F. Kennedy Jr. released a video brimming with family farm imagery and promises that, when Donald Trump was president and put him on the inside: “We’re going to ban the worst agricultural chemicals that are already prohibited in other countries.”
Yet more than a year after President Trump named Kennedy Health and Human Services secretary and asked him to oversee the Make America Healthy Again Commission, the federal government has taken no action on paraquat, an herbicide closely linked to Parkinson’s disease that has now been banned in 74 other countries.
On Jan. 9, Lee Zeldin, the administrator of the United States Environmental Protection Agency, announced news that had MAHA moms cheering.
“The Trump EPA has made the important, proactive decision to freshly reassess the safety of PARAQUAT,” Zeldin wrote on X. “It’s all about gold-standard science and radical transparency for Americans.”
That reassessment was already underway after EPA found uncertainties in industry science about how paraquat can volatize–or move into the air–in areas near agriculture. Paraquat’s case underscores the uphill battle to ban hazardous chemicals in the United States: Citizens face a high burden of proof to show a chemical is harmful. Hundreds of toxic chemical reviews are delayed. And chemical-manufacturers and agribusiness both broke records for lobbying spending in 2025, for a total of more than $350 million.
Miracle - and highly toxic - weed killer
Chevron introduced paraquat to farmers and homeowners in the 1960s as a miracle weed killer for crops and residential yards. The company’s lawn-and-garden spray, Ortho, advertised it for “driveways, walks, patios, lawns, edging, and in gardens.”
Florida barred sales to the public in 1970 amid evidence of its toxicity. It took the EPA eight more years to restrict its use to commercial applicators. It then took almost four more decades to require changing the pesticide’s label to emphasize its toxicity and prevent deaths from accidental ingestion.
Today, paraquat—technically paraquat dichloride—remains one of the most popular herbicides in the United States, where use more than doubled in the past decade to more than 10 million pounds, according to the U.S. Geological Survey.
Yet increasing numbers of U.S. neurologists and Parkinson’s advocates have called for its ban amid mounting evidence of its link to the disease. The European Union banned paraquat in 2007. China, where it’s primarily manufactured, banned paraquat in 2016.
U.S. EPA officials announced a decision to reregister paraquat for use in 2020 after testimony from farmers and agricultural associations across the country that the herbicide is vital to major crops, including soybeans, cotton, corn, peanuts, wheat, alfalfa, oranges, apples, grapes potatoes, rice, dry beans and others.
Michael J. Aerts, vice president of science and regulatory affairs for the Florida Fruit and Vegetable Association, wrote that paraquat is applied multiple times per growing cycle on more than half the state’s fresh cucumbers, 20% of fruiting vegetables, and “significant portions” of Florida’s citrus and sugar cane acreage.
Industry advocates also opposed tightening safety restrictions, including a ban on aerial application, an area where EPA deferred to industry. But, acknowledging the herbicide’s danger, the agency created new restrictions, including limiting use to certified applicators, prohibitions on hand-spraying and other safety measures.
During the pesticide reregistration process, the EPA examines “a wide variety of potential human health and environmental effects associated with use of the [pesticide].” It then weighs the risks and benefits, according to the EPA, and “if risks cannot be reduced to a reasonable level,” it can refuse to reregister it.
Earthjustice, a nonprofit environmental law firm representing a coalition of farmworker, environmental and health organizations, sued the agency over the paraquat decision in 2021, citing health effects to farmworkers and agricultural communities.
The EPA “misinterpreted the evidence and violated its own risk assessment practices to dismiss the connection between paraquat use and Parkinson’s disease,” according to the coalition’s brief, and “repeatedly understated the extent of paraquat’s adverse effects.”
“A single sip can kill, yet millions of pounds are sprayed on U.S. cropland each year, causing Parkinson’s disease, lung and kidney damage, and, when paraquat is ingested, death,” Jonathan Kalmuss-Katz, the senior attorney for toxic exposure and health at Earthjustice, wrote in the opening brief.
He said the EPA focused on the limitations of individual studies it examined during the evaluation process, instead of the weight of the body of research.
“It ignored the forest for the trees,” Kalmuss-Katz said.
From the cigarette playbook
Though EPA Administrator Zeldin framed it as “More MAHA Progress!,” the EPA’s reevaluation of paraquat comes five years into the lawsuit and two years after the Ninth Circuit Court of Appeals granted a request to put the case on hold to further analyze paraquat’s “volatilization.”
Volatilization refers to how a liquid converts to vapor that can move through the air, potentially impacting workers or others who live or work near treated fields. Based on mandatory reporting of a new study by Syngenta, the global agribusiness that dominates paraquat sales, the EPA concluded in November 2025 “that there is greater uncertainty regarding the potential for paraquat to volatilize than previously considered.” Syngenta announced this spring it will stop manufacturing paraquat by June, though hundreds of other companies still make and sell it.
The new EPA report, “Paraquat: Review of the Volatilization Potential of Paraquat from Field Uses” states that “concentrations of concern” of paraquat vapor could move up to 4,500 meters, or nearly 2.8 miles.
Neurologists involved in trying to change pesticide policy compare it to the tobacco battles of the 20th century. Even amid rising evidence that tobacco caused cancer, cigarette companies used science to introduce doubt, said Dr. Michael Okun, director of the University of Florida’s Norman Fixel Institute for Neurological Diseases.
The science of paraquat’s link to environmental exposures convinced Okun to call for a ban. But he said it also took his years caring for farmers with Parkinson’s who told him they had used the herbicide.
“It took policy to change smoking,” Okun said. “It's going to take policy to change other diseases that also have causes, like Parkinson's.”
Scott Faber, senior vice president of government affairs for the Environmental Working Group who also teaches farm and food law at Georgetown Law, said part of the issue is that “EPA has legal and cultural biases against banning pesticides.”
The Federal Insecticide, Fungicide, and Rodenticide Act that regulates use of pesticides in the United States "is not a public health law, it’s a pesticide registration law that requires EPA to weigh the costs and benefits of each pesticide,” Faber said.
Some of the most dangerous pesticides are regulated with mitigation measures such as certifications and protective equipment for applicators rather than bans.
Cigarettes were not banned despite decades of efforts by public health advocates, but rather regulated through federal and local policies aimed at encouraging quitting, protecting non-smokers and discouraging young people who haven’t yet picked up cigarettes.
States step up
Amid the dearth of federal action on paraquat, lawmakers in 13 states have proposed bills to ban it. Yet, opposed by agricultural and chemical industry lobbyists, almost all the proposals have died, including those in Hawaii, New York and Virginia.
Only Vermont, where the bill is before the Senate, has come close to passing a ban, though it allows limited exemptions.
Several others, including Illinois’ Senate bill, were blocked in the Agriculture Committee.
Meanwhile, the 2026 Farm Bill working its way through Congress would prohibit local governments from restricting pesticide use. The bill would also prohibit holding companies from being held liable for failing to provide safety warnings on pesticide packaging.
California passed legislation in 2024 to reevaluate paraquat's impact on human health and the environment. That review is scheduled to be completed by 2029.
A recent 60-gallon paraquat spill in Dorris, California, was a fresh reminder of the herbicide’s toxicity. Local law enforcement ordered people to shelter in place and advised anyone who drove through the spill to wash their cars.
Jane Sellen, development director of Californians for Pesticide Reform, said the spill should call attention to the broad use and transport of an herbicide that is deadly.
“The fact is the spill happened in a town,” Sellen said, “so there were certainly plenty of people that were impacted or potentially impacted that wouldn’t normally be impacted by agricultural pesticides because they’re not in an agriculture region."
Sellen said she has more faith in the reevaluation than in any notion of a ban given the importance of agriculture to California.
“It’s not impossible to get bills on pesticides through the legislature,” Sellen said. “But it’s very hard to get a ban bill through.”
This story is part of Poisoned Pathways, an investigation into chemical exposure and Parkinson’s disease supported by the Pulitzer Center and reported by the WUFT Environment & Ag Desk at the UF College of Journalism and Communications.
