Paraquat

Paraquat is a toxic herbicide. Your body will absorb it quickly if you are exposed to it, which could result in damage to your heart, kidneys, liver and lungs. Swallowing just one teaspoon could kill you.

Research also suggests paraquat exposure is linked to an increased risk of developing Parkinson’s disease.

Steve Rosas, President of Omega Environmental, evaluates paraquat exposure through the skin, inhalation and swallowing.

“The most overlooked aspect in current paraquat discussions is the cumulative exposure factor through multiple pathways,” Rosas told Drugwatch. “Paraquat’s persistence in soil means communities can experience ongoing exposure long after initial application through vapor intrusion and groundwater contamination.”

Paraquat is banned in over 70 countries and limited to “restricted use” by the Environmental Protection Agency (EPA) in the United States. This means only people who are trained and certified to apply the herbicide can use it.

How Does Paraquat Exposure Immediately Affect Your Health?

The initial symptoms of Paraquat exposure depend on how you were exposed. You may experience eye or throat irritation, burning pain in your mouth, skin dryness and more.

Paraquat poisoning can be life-threatening, especially if it affects your vital organs. It can also lead to death.

Get medical help immediately if you think you’ve been exposed to paraquat. The faster you receive care, the better your chances of minimizing the potential harm associated with exposure.

Paraquat’s Effects on the Body’s Nervous System

In addition to poisoning, paraquat exposure can cause damage to your central nervous system. A study in Neurotoxicity used magnetic resonance imaging to examine people who survived acute paraquat poisoning.

Researchers found abnormal signals in the brain, particularly in the areas that regulate movements and control memory, learning and emotion.

Another study in Neurotoxicology found increased oxidative stress in neurons in specific brain areas of rats exposed to paraquat. The impacted areas play an important role in movement and brain chemistry.

Psychologist Bambi Rattner, Psy.D., of Intensive Therapy Retreats, warns that the neurological effects of paraquat go beyond physical motor function and can cause trauma for family members.

“The most concerning gap I see is the complete absence of mental health considerations in paraquat risk assessments,” Rattner told Drugwatch. “When someone develops early cognitive decline or mood disorders from toxic exposure, their family system enters a state of chronic hypervigilance that mirrors combat-related trauma patterns.”

Scientific Evidence Links Paraquat to Parkinson’s Disease

Researchers have linked paraquat exposure to Parkinson’s disease. A 2011 study published in Environmental Health Perspectives found that people exposed to paraquat and another pesticide called rotenone were 2.5 times more likely to develop Parkinson’s.

Since then, multiple studies have supported the paraquat link to Parkinson’s disease.

Based on the latest research, people most likely to develop paraquat-related Parkinson’s disease in the United States include:

• Farmers and other workers on land where paraquat is applied
• Licensed paraquat applicators
• People living or working within 500 meters of land where paraquat is applied
• People who have suffered a previous brain injury
• Spouses of those farmers and farmworkers

In January 2025, the EPA told a federal court that it still needs “at least four years” to study paraquat’s health effects. The European Union has taken a more conservative approach, banning paraquat since 2007.

Community Impacts of Paraquat Exposure

Rattner also points out that paraquat exposure can have community-wide psychological consequences.

“What regulatory discussions miss entirely is how environmental toxins create what I call ‘invisible trauma communities,’” Rattner said. “These are neighborhoods and families living in constant anticipation of illness, watching for early signs of neurological decline in themselves and loved ones.”

She says the psychological toll of living near agricultural areas with heavy pesticide use can create anxiety disorders that require specialized treatment approaches.

People who developed Parkinson’s disease or lost a loved one after exposure to the herbicide have filed thousands of paraquat lawsuits against its manufacturers. As of August 2025, 6,311 of these lawsuits were combined in a multidistrict litigation (MDL) in a Southern Illinois federal court.

Three companies are named as defendants in the Paraquat lawsuit. These include two different divisions of Syngenta, which first produced the herbicide.

People who may qualify to file a paraquat lawsuit include those who live or work on a farm or who use or mix herbicides containing paraquat and have developed Parkinson’s disease.

The Case Against Paraquat Manufacturers

Paraquat lawsuits argue there is strong evidence linking the herbicide to Parkinson’s disease. They point out that paraquat results in Parkinson’s-like conditions in lab animals, similar to what is seen in humans with the disease.

The lawsuits also claim that:

• Paraquat can be inhaled, ingested or absorbed through the skin, posing dangers to users and those nearby.
• Repeated exposure may cause severe brain damage, including Parkinson’s disease.
• Scientific studies indicate people exposed to paraquat, primarily through their jobs, are two to five times more likely to develop Parkinson’s than those who aren’t.

Additionally, people filing lawsuits claim that companies did not provide sufficient warnings, even though manufacturers knew or should have known about the risks of their products.

How Paraquat Lawsuits Compare To Other Toxic Exposure Cases

There are several similarities between the paraquat cases and Roundup lawsuits. The two litigations involve claims that herbicides cause serious health problems. Paraquat lawsuits focus on Parkinson’s disease, while Roundup cases link the product to non-Hodgkin’s lymphoma.

As of the latest monthly updates from the Judicial Panel on Multidistrict Litigation, the Paraquat MDL has 6,311 lawsuits and the Roundup MDL has 4,437 pending cases, making both among the largest active MDLs.

Monetarily, Roundup lawsuits have resulted in higher total settlements. However, depending on the exposure time and the seriousness of the injury, paraquat lawsuits could potentially result in hefty settlements.

Lawsuits and news investigations allege that paraquat manufacturers, including Syngenta and Chevron, knew about the herbicide’s dangers but continued to market and sell it without adequate safety warnings.

Simultaneously, the EPA has been slow to decide whether to ban paraquat.

What Did Paraquat Manufacturers Know About the Risks?

According to court documents reviewed by Investigate Midwest, Syngenta, previously known as ICI, knew as early as 1967 that paraquat could enter the bloodstream of workers handling it.

A study conducted on rodents by ICI in 1973 found that in mice, once paraquat entered the body, it could reach the brain and spine.

As early as the 1950s, the company knew paraquat could affect the central nervous system (CNS). An internal memo from ICI’s medical department discussed how paraquat exposure to the skin could have a toxic effect on the CNS.

Despite this knowledge, the company continued to market the product. Syngenta claims paraquat presents “no risk to human safety” if people follow “basic good agricultural practices.”

The company bases its statement on toxicology studies and “over 60 years of experience in use.”

EPA Delays Decision on Banning Paraquat

The EPA had promised to deliver a decision about banning paraquat by January 17, 2025. However, it decided to hold off, citing insufficient evidence about the risks of inhaling the chemical.

The EPA has implemented some safety measures to protect people and the environment, including more explicit product labels and new warning materials. Certified applicators are now required to complete specialized training every three years, and closed-system packaging is mandated for paraquat to prevent accidental exposure.

Rosas says that part of the problem is the EPA’s reliance on voluntary measures in the early stages.

“The EPA’s non-binding guidelines often delay real protection—we’ve seen contamination levels that exceeded safety thresholds for years before mandatory reporting kicked in,” Rosas said.

What Countries Have Banned Paraquat?

While the EPA has spent years weighing a paraquat ban, other countries prohibit its use. According to the Pesticides Action Network Europe, Norway was the first to withdraw paraquat from its markets in 1981. Sweden was the first to ban paraquat in 1983.

What Are U.S. Lawmakers Doing About Paraquat Safety?

In 2019, Representative Nydia Velázquez (D-NY) introduced the Protect Against Paraquat Act to get the EPA to ban paraquat and prevent it from being found in food. The bill didn’t advance.

State and federal lawmakers have taken steps to ban or restrict the use of paraquat. In 2023, U.S. Senator Cory Booker (D-NJ) urged the EPA to ban paraquat, citing its links to Parkinson’s disease and cancer. Booker also introduced a bill to ban paraquat, but it hasn’t moved forward in Congress.

In 2023, 47 members of Congress also sent a letter to the EPA asking the agency to ban paraquat.

California Assemblymember Laura Friedman proposed a bill in 2024 reevaluating paraquat to determine if it should be banned in the state. Governor Gavin Newsom signed the bill, requiring the Department of Pesticide Regulation to reevaluate paraquat usage by January 1, 2029.

If you or a loved one were exposed to paraquat and have developed Parkinson’s disease, taking the appropriate steps can help protect your health and legal rights. Start by documenting your exposure, tracking your symptoms and getting medical care.

You should also gather evidence of paraquat use at your job or near your home and consider speaking with a lawyer to explore your legal options.

Where To Find Legal Help for Paraquat Exposure

If you’re considering filing a paraquat lawsuit, talk to a lawyer with experience in environmental or product safety lawsuits. These cases can be complex and may require medical and scientific proof that paraquat exposure caused your Parkinson’s disease.

Drugwatch works with experienced lawyers specializing in paraquat cases and can help you find the right attorney for your situation.

Keep in mind that there are deadlines for filing these lawsuits. Depending on where you live, you might have only one year after being diagnosed with Parkinson’s disease to file your case.