Paraquat is an ingredient in a very effective herbicide application. It is used in multiple settings, including but not limited to:
- Farm fields,
- Highway shoulders and medians,
- Commercial landscaping,
- Large residential properties
After several studies, the US Environmental Protection Agency (EPA) announced in 1997 that paraquat exposure while mixing, loading and applying the herbicide as well as after the application was the main route of exposure to Paraquat. The EPA further alleged that even if not applying Paraquat, associated exposure could occur to individuals who lived near a location that the herbicide was used.
Since that initial announcement by the EPA, the scientific community has researched and studied the effects of Paraquat to humans when exposed. Much of the research has centered on a link between Parkinson’s disease and exposure to Paraquat.
The following are an encapsulation of major studies and their findings (this list is not comprehensive):
American Journal of Epidemiology: In 2009, published the results of a study that linked even nominal exposure to Paraquat resulted in a heightened risk of Parkinson’s disease (the footage used was within 1,600 feet of a home.)
Environmental Health Perspective: In 2011 in coordination with the National Institute of Environmental Health Science, published a comprehensive analysis of instances of Parkinson’s and exposure to pesticides. Part of the conclusions of this study focused on Paraquat as a “significant concern” and risk of contributing to the development of Parkinson’s.
Annual Review of Pharmacology and Toxicology: A formal review of findings related to environmental toxins and Parkinson’s reported on five case-controlled studies that found a greater risk of developing Parkinson’s when exposed to Paraquat. This review was published in 2014.
Other Developments
2016: The EPA announced it was reevaluating Paraquat, including a potential link to Parkinson’s disease.
2017: The Unified Parkinson’s Advocacy Council issued a letter to the EPA detailing the suspected links between Paraquat and Parkinson’s and urged the EPA to deny Paraquat reregistration as a legal chemical agent in the herbicides in question.
The letter further highlighted that the cost of caring for a person with Parkinson’s was about $26,000 annually and that there was an associated economic burden that was between $19.8 billion and $26.4 billion. The letter also pointed out the link between Parkinson’s disease and social programs like Medicaid, Medicare and Social Security Disability Insurance.
2018: The US Department of Health and Human Services (DHHS) National Toxicology Program released a protocol for the review of the link between Paraquat exposure and development of Parkinson’s disease. As part of this protocol, DHHS acknowledged hundreds of studies that investigated the link and found it to be real. The purpose of the review was to lay out the evidence of the link in order to inform the EPA further as it makes decisions related to Paraquat.
