Pesticide Linked to Parkinson’s Raises Concerns

Paul Friday recalls the moment he noticed his hand behaving oddly in cold weather—that was the first hint that nerve cells in his brain were deteriorating. Eventually, he received a Parkinson’s diagnosis, a progressive brain disease that affected his mobility and ultimately forced him off his family farm in southwestern Michigan. In his later years, Friday began to suspect that years spent spraying a pesticide called paraquat on his peach orchard might have led to his condition.

“It made sense to me why I developed Parkinson’s,” said Friday, now 83, as he embarks on a legal battle regarding this claim.

Paraquat, a highly toxic weed killer, has been banned in numerous countries, including the UK and China, where it’s manufactured. However, last year, its producer, Syngenta (part of a company owned by the Chinese government), continued to market it in the U.S. and other nations that haven’t outlawed it.

While research linking paraquat with Parkinson’s disease exists, it’s often disputed by the manufacturer, which claims the studies aren’t peer-reviewed. Despite this, a surge of lawsuits has emerged in the U.S. from farmers grappling with Parkinson’s after prolonged pesticide use.

This proliferation of legal action raises the question: what will it take for the U.S. to ban paraquat?

Jonathan Kalmuss-Katz, an attorney at Earthjustice, an environmental advocacy group, remarked, “Over the years, there has been a systemic failure to protect farmworkers and the agricultural community from harmful pesticides.”

Mounting Legal Challenges

Ruth Anne Krause watches her husband, Jim, struggle to perform once-simple tasks. An avid woodcarver, he found it increasingly difficult to hold his tools after being diagnosed with Parkinson’s in 2019. Having operated a 20-acre fruit farm in central California and having sprayed paraquat in the fields, Jim succumbed to the disease in 2024.

“I want people to know what happened,” Ruth Anne expresses, concerned that paraquat remains accessible to American farmers.

She is one among thousands who have filed suits against Syngenta and Chevron, alleging that the companies failed to disclose the pesticide’s potential hazards, even with existing evidence linking it to nerve damage and Parkinson’s.

According to data from the U.S. Geological Survey, between 11 million and 17 million pounds of paraquat are applied annually across American farms. It’s primarily utilized to kill weeds quickly—a method effective though perilous.

Even though Chevron no longer sells paraquat, they assert that they should not be held accountable for related injuries. The company insists that extensive studies haven’t definitively proven a connection between paraquat exposure and Parkinson’s.

Syngenta echoes this sentiment, stating that scientific evidence does not establish such a causal relationship.

Currently, over 6,400 lawsuits alleging a connection between paraquat and Parkinson’s are underway in various jurisdictions of the U.S.

Christian Simmons, a legal expert for Drugwatch, believes this figure doesn’t adequately represent the extent of the issue: “I think it’s vital to clarify that this number probably doesn’t capture the total number of people affected.”

It’s not just seasoned farmers: there are people like Dave Jilbert, a winemaker from Ohio who was diagnosed with Parkinson’s after years of using paraquat on his vineyard, and Terri McGrath, who suspects her family’s long-term pesticide exposure led to multiple Parkinson’s diagnoses within her household.

“For about 40 years off and on, I’ve been using that stuff,” Mac Barlow, a farmer from Alabama, admits. “Honestly, if I had known it would turn out this way, I would have sought alternatives.”

Assessing the Danger of Paraquat

Since its introduction in the 1960s, paraquat has proven effective in quickly clearing fields before planting. This pesticide can destroy plant tissue within hours, which is why it remains a staple in agricultural practices today. Unfortunately, given its powerful toxicity, the implications for human health are troubling.

By the 1970s, it was even used as a tool in the war on drugs, helping to eradicate illegal marijuana crops. It even made its way into pop culture; the cult film “The Big Lebowski” includes a humorous reference to its harsh effects.

Despite its dangers, the usage of paraquat has surged, doubling from 2012 to 2018 according to federal records. New pesticide data is anticipated in 2025.

Paraquat kills anything it touches, so it’s primarily used to clear fields before crops take root. Low levels can remain on food crops, but the direct exposure risks are of greater concern.

It’s noteworthy that paraquat is known as one of the leading pesticides in cases of suicide worldwide. Following bans in countries like South Korea and Sri Lanka, there were notable declines in suicide rates.

The U.S. Environmental Protection Agency (EPA) heavily regulates paraquat, permitting only licensed users to apply it, and mandating safety measures such as a distinctive blue dye and strong odor as deterrents. Even so, exposure continues to be a serious risk, as evidenced by numerous incidents reported to poison control centers.

In one incident last year, a man mistakenly consumed paraquat thinking it was Gatorade, resulting in a tragic death within days. Another case involved severe burns and subsequent kidney failure after skin contact with the pesticide.

Detailed records regarding paraquat’s toxic effects are patchy, making it difficult to ascertain the true extent of injuries and fatalities tied to its use.

Reports indicate 114 instances and one death related to paraquat in 2023 alone, with more than a thousand calls logged during the preceding decade.

Even secondary exposure proves hazardous; healthcare personnel can find themselves imperiled just from treating patients who have come into contact with the chemical.

Of even greater concern is the potential for low-level, long-term exposure to paraquat, which might slowly impact health without immediate symptoms.

Parkinson’s Disease Trends

Parkinson’s is the fastest-growing neurological disorder globally, with projections suggesting cases could double by 2050. The disease arises when dopamine-producing brain cells deteriorate.

The complete origins of Parkinson’s disease remain elusive, with a presumed mix of genetic and environmental causes. Notably, 87% of those diagnosed lack genetic predispositions, hinting that external factors, possibly including pesticide exposure, play a significant role.

Dr. Ray Dorsey, a neurologist and researcher, labels Parkinson’s largely preventable and argues that cleaning up the environment could significantly mitigate its prevalence.

The environmental factors associated with Parkinson’s are numerous, but pesticides stand out as one of the most significant threats, according to Dorsey.

Current Legal Landscape

As the legal battle over paraquat inches closer to resolution, most lawsuits are being directed through multi-district litigation in Illinois. This framework facilitates the management of numerous cases by consolidating them under one federal judge, allowing representative cases to be selected more effectively.

In April, an agreement was reached to settle thousands of pending lawsuits, but details are still under negotiation and could face trial if not ironed out.

While assertions of paraquat’s safety are maintained by Syngenta and Chevron, their defense reflects a broader challenge in proving causation; Parkinson’s can develop years post-exposure. The argument is complicated by the need for extensive scientific validation of any claims linking the pesticide to adverse health outcomes.

Why Hasn’t the EPA Taken Action?

Norway was the first to outlaw paraquat in 1981, followed by several other countries. Yet, Syngenta continues to produce it in regions with such bans. Although paraquat is prohibited in the UK and China, about two-thirds of imported paraquat in the U.S. in recent years has come from Chinese government-owned companies.

This ongoing reliance on paraquat raises serious questions, particularly as its use is projected to increase. The EPA reviewed paraquat in 2021 and upheld its safety standards despite widespread international disapproval.

Various stakeholders, from farmers to advocacy groups, have voiced their concerns regarding paraquat’s presence on U.S. farms, urging for a deeper evaluation of its health impacts.

Despite the potential risks of paraquat, its effectiveness in agriculture has created a complex debate about safety and necessity. Critics call for a ban, citing rampant health implications, while advocates defend its usefulness in controlling resistant weed populations.

As the conflict continues, the reality remains stark: paraquat is still prevalent, and nearly 90,000 individuals receive Parkinson’s diagnoses each year. Many believe that the evidence against paraquat’s safety is compelling enough for an outright ban.