Paraquat: Exposure Risks, Parkinson’s Disease & Regulatory Actions

Paraquat is a toxic herbicide. Your body absorbs it quickly, leading to cell damage that can spread to vital organs, including the lungs, liver and kidneys. Swallowing just one teaspoon can kill you.

Additionally, research suggests paraquat exposure can cause neurological damage and Parkinson’s disease.

Paraquat is banned in 69 countries and limited to “restricted use” by the Environmental Protection Agency (EPA) in the United States. This means only people with special licenses can use it.

How Does Paraquat Exposure Immediately Affect Your Health?

Exposure to paraquat can impact your health through immediate poisoning and long-term neurological damage.

Paraquat poisoning can be life-threatening, especially if it affects your lungs. It can cause fluid buildup, leading to scarring and bleeding that makes breathing challenging.

As the poisoning worsens, it can become difficult for your heart to pump blood. This can eventually lead to multiorgan failure.

Paraquat’s Effects on the Body’s Nervous System

In addition to acute poisoning, paraquat exposure can cause immediate 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 parts of the brain 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.

Scientific Evidence Links Paraquat to Parkinson’s Disease

Researchers have linked paraquat exposure to Parkinson’s disease. A study published in 2011 in Environmental Health Perspectives found people exposed to paraquat and another pesticide, 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:

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

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 (EU) has taken a more conservative approach, banning paraquat since 2007.

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 April 2025, 5,911 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 paraquat to Parkinson’s disease. They point out that scientists use paraquat to create Parkinson’s-like conditions in lab animals, similar to what is seen in humans with the disease.

The lawsuits also claim that:

• 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.
• 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.
  Additionally, people filing lawsuits state 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 both 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 5,911 lawsuits and the Roundup MDL has 4,415 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.

Paraquat lawsuits and news investigations claim 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?

Syngenta, previously known as ICI, knew as early as 1967 that the chemical paraquat could enter the bloodstream of workers handling it, according to court documents reviewed by Investigate Midwest. A study conducted on rodents by ICI in 1973 further confirmed that, at least in mice, once paraquat entered the body, it could reach the spine and brain.

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, saying there was 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 must now complete specialized training every three years. Closed-system packaging is also required for paraquat to prevent accidental exposure.

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 country 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 limited steps to ban or restrict 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 exposure, tracking 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.