During the last two decades, researchers have found a clear link between the development of Parkinson’s disease and exposure to paraquat dichloride. This is a significant driver behind many other countries banning the herbicide, including the European Union. Studies that outline these findings include:
- 2011: In 2011, the National Institute of Health conducted a study called the Farming and Movement Evaluation Report that used the Agricultural Health Study data. The study found that paraquat users were 2.5 times more likely to develop Parkinson’s disease than those not exposed. The study also linked paraquat dichloride exposure with oxidative stress, which can result in the loss of dopaminergic neurons.
- 2014: A study on environmental toxins and Parkinson’s disease in 2014 found that study participants sprayed with the chemical were twice as likely to develop Parkinson’s disease compared to the public.
- 2017: Another study conducted in 2017 found a link between Parkinson’s disease and paraquat exposure in people who possessed certain genetic traits. The study showed that exposure to the weed killer resulted in DNA damage and weak mitochondrial respiration.
The Center for Biological Diversity and Californians for Pesticide Reform recently sent a letter to California’s Department of Pesticide Registration, urging the department to ban paraquat, noting that multiple scientific studies have linked the herbicide with Parkinson’s disease.