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Killing Weeds Has Become a Significant Public Health Hazard in California

Over the past few decades, the escalating use of pesticides has become a significant public health and environmental hazard. Over 1.1 billion pounds of pesticides are applied every year to crops in the U.S., primarily in combination with genetically engineered seeds that can withstand them.

The intense pesticide use has even caused the evolution of superweeds, which require an increasingly toxic pesticide formula to kill, such as paraquat. Paraquat is one of the oldest, most used, and highly toxic pesticides.

Paraquat causes immediate adverse effects on human health, wildlife, local food sources, beneficial insects, and biodiversity. It also has chronic effects, including the risk of Parkinson’s disease. The most severe impact comes from direct exposure in use.

The Ban on Paraquat

Switzerland and the European Union have banned paraquat since 1989, respectively 2007, as it is toxic for farmers even when wearing protective equipment. China moved away from paraquat use because the herbicide is hazardous to human beings, and there is no specific antidote. Recently, Thailand and Brazil also banned the herbicide due to its toxicity. After South Korea banned paraquat in 2012, suicide deaths by pesticide ingestion halved in the following year.

Despite the widespread recognition that paraquat is harmful to human and environmental health and that individuals in residential areas cannot use it, our industrial-agricultural system still uses it.

In a 1991 decision, The Supreme Court ruled that the Federal Insecticide, Fungicide, and Rodenticide Act does not preempt local governments’ pesticide bans. Although seven states — Alaska, Hawaii, Maine, Maryland, Nevada, Utah, and Vermont — allow their governments to pass pesticide bans, they have not yet enforced a paraquat ban.

Paraquat and Farmworkers

The people most at risk from paraquat are the farm workers who apply it and work in the fields where others use it. Because of its acute toxicity, paraquat has severe and irreversible effects if absorbed. When farmers and agricultural workers suffer paraquat exposure during mixing and spraying, they are often affected by both immediate toxic effects and long-term health problems.

Short-term health effects among paraquat users include eye injury and burns to the skin and other parts of the body. Long-term exposure to paraquat can affect the lungs, nervous system or brain, skin, and reproduction.

Only a certified applicator can use paraquat. The federal government regulates how paraquat is used and sets guidelines to limit exposures; yet, applicators do not always follow these guidelines.

For example, certified farmworkers may not receive the required protective equipment. Employers may even pressure them into working in unsafe conditions; for example, they could force them to work on recently sprayed fields with unabsorbed paraquat. These barriers also mean that incidents of paraquat exposure in farmworkers could go untreated.

Parkinson’s Disease Associated with Long-Term Exposure to Paraquat

Besides acute poisoning from field exposures, paraquat can also cause longer-term health impacts for workers and even people who live around farms where workers use it. In one study published in JAMA Neurology, the data showed significant occupational associations with parkinsonism, among them pesticide use, linked to a twofold increased risk. Another study showed that for subjects ⩾ 60 years, in the entire 1974–1999 time window, the odds ratio between exposure to paraquat and developing Parkinson’s disease was 2.27.

The overall epidemiological evidence from exposure studies supports a specific association between paraquat and Parkinson’s. Also, researchers use both experiments on cells or animals in a lab setting and other studies to determine if paraquat can cause Parkinson’s disease. Therefore, there’s plenty of cause for further investigation of health impacts.

Considering the information released by the Michael J. Fox Foundation, the country’s highest number of people affected by Parkinson’s disease currently reside in California. The estimation for the last year was about 117k people having to live with this disease in California alone. The Parkinson’s Foundation estimates that by 2030, approximately 1.2 million people will be living with Parkinson’s in the U.S.

Farmworkers who are victims of paraquat may lack the resources to report incidents. Therefore, public health research often influences policy, and legislation may underestimate the real impact of paraquat. That these incidents are under-reported also means that they go uncompensated. To amend current legislation, the bill “The Protect America’s Children from Toxic Pesticides Act of 2020” calls for protective and preventive measures, including some for farmworkers.

In the meantime, several recent lawsuits allege manufacturers of the controversial herbicide have failed to provide adequate warnings and safety instructions for consumers. The manufacturers have withheld critical safety information from farmers and other agricultural workers. As a result, farmers and others exposed to the paraquat-based herbicides in prior decades indicate that they now have Parkinson’s disease.

Miguel Leyva, a case manager at Atraxia Law, specializes in supporting people injured by using paraquat, or other toxic chemicals, in gathering and organizing relevant information about their injuries.


pesticides, herbicides, paraquat exposure, Parkinson's disease, weed killer, california