Potential Litigation Over the Link Between Paraquat and Parkinson’s Disease

Paraquat is a chemical herbicide sold in Canada to kill weeds in orchards and crops such as potatoes.[1] Syngenta and their corporate predecessors have sold, and continue to sell, paraquat in Canada under the brand name Gramoxone since 1963. In 1998, a modified form of the herbicide was also marketed as a competitor to glyphosate-resistant products such as Roundup®.[2]

Paraquat is the third most widely used herbicide in the world, although its use may be starting to drop worldwide as it is banned in an ever-increasing number of countries because of health risks.[3] Usage in Canada, however, continues despite mounting evidence of harm.

Scientific studies have linked exposure to paraquat to Parkinson’s disease since 2002.[4] Parkinson’s disease is a chronic and progressive neurodegenerative disease that is caused by a loss of neurons and the dopamine neurotransmitter they produce. There is currently no therapy to slow, stop, or reverse the progression of Parkinson’s disease. More than 100,000 Canadians currently live with Parkinson’s disease, with 25 more diagnosed each day.[5]

In response to every increasing data supporting the link between paraquat and Parkinson’s disease, the United States National Institute of Health launched a study in 2011 of farm workers exposed to the herbicide (the FAME study).[6] The study found that the exposed individuals received Parkinson’s disease diagnoses at a rate of 2.5 times that of those who were not exposed to paraquat. Multiple other studies have also found similar linkages between occurrences of Parkinson’s disease and paraquat exposure.

In response to these troubling scientific findings, and the already known acute toxic effect of paraquat resulting in poisonings, over 40 countries have banned its use.[7] Paraquat is even banned from both use since 1989 and export since 2020 from Switzerland, Syngenta’s home country.[8]

Allegations have been made that companies, including Syngenta, did not disclose the risk of Parkinson’s disease and other harms during regulatory approval processes. In the 2007 decision from the European Union Court of First Instance banning the use of paraquat in the European Union, the Court found that:

“although there are studies on the link between paraquat and Parkinson’s disease, that issue was never referred to by the notifier. Moreover, the Commission’s reports did not contain any assessment of the literature relating to possible links between paraquat and Parkinson’s disease.” [9]

Paraquat is still used in Canada, although the government did increase regulations around its sale and use to reduce potential ecological risks and protect public health.[10] But, the government can only properly regulate harmful substances if harms are properly disclosed by the companies making and selling the products. As found by the European court, Syngenta and their corporate predecessors may have misrepresented the safety and failed to notify regulators of potential risks associated with the use of products containing paraquat in Canada as well.

Despite these increased regulations, paraquat is still entering our environment and food supply chains in Canada. As the science strengthens and diagnoses of Parkinson’s disease are further linked with paraquat, we may see growing class action litigation in Canada to address these harms.

If you are interested in discussing this with Wagners, please don’t hesitate to contact us at 902-425-7330 or toll-free at 1-800-465-8794 or by email at [email protected] .


[1] https://www.canada.ca/en/health-canada/services/consumer-product-safety/pesticides-pest-management/public/consultations/re-evaluation-note/2015/special-review-paraquat/document.html#a2

[2] https://www.producer.com/news/potent-popular-herbicide-now-available-in-canada/

[3] www.publiceye.ch/fileadmin/doc/Pestizide/2017_PublicEye_Adverse_Health_Effects_Paraquat_Bibliography.pdf

[4] McCormack, AL. “Environmental Risk Factors and Parkinson’s Disease: Selective Degeneration of Nigral Dopaminergic Neurons Caused by the Herbicide Paraquat.” Neurobiology of Disease., vol. 10, no. 2, Blackwell Science, 2002, pp. 119–27, doi:10.1006/nbdi.2002.0507.

[5] https://www.parkinson.ca/about-parkinsons/

[6] https://www.nih.gov/news-events/news-releases/nih-study-finds-two-pesticides-associated-parkinsons-disease; Caroline Tanner, et al, “Rotenone, Paraquat, and Parkinson’s Disease” (2011) 1196 Environ Health Perspect 886.

[7] www.publiceye.ch/fileadmin/doc/Pestizide/2017_PublicEye_Adverse_Health_Effects_Paraquat_Bibliography.pdf

[8] https://www.swissinfo.ch/eng/swiss-ban-export-of-highly-dangerous-pesticides/46099090

[9] https://curia.europa.eu/en/actu/communiques/cp07/aff/cp070045en.pdf

[10] https://www.canada.ca/en/health-canada/services/consumer-product-safety/reports-publications/pesticides-pest-management/fact-sheets-other-resources/paraquat.html.

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