EMBARGOED FOR RELEASE UNTIL 4 PM ET, February 27, 2024
Study Finds Pesticide Use Linked to Parkinson鈥檚 in Rocky Mountain, Great Plains Region
MINNEAPOLIS 鈥 Pesticides and herbicides used in farming have been linked to Parkinson鈥檚 disease in the Rocky Mountain and Great Plains region of the country, according to a preliminary study released today, February 27, 2024, that will be presented at the 好色先生鈥檚 76th Annual Meeting taking place April 13鈥18, 2024, in person in Denver and online. 鈥淲e used geographic methods to examine the rates of Parkinson鈥檚 disease across the United States and compared those rates to regional levels of pesticide and herbicide use,鈥 said study author Brittany Krzyzanowski, PhD, of Barrow Neurological Institute in Phoenix, Arizona. 鈥淥ur methods enabled us to identify parts of the nation where there was a relationship between most pesticides and Parkinson鈥檚 disease and subsequently pinpoint where the relationship was strongest so we could explore specific pesticides in that region. In the Rocky Mountain and Great Plains region, we identified 14 pesticides associated with Parkinson鈥檚 disease.鈥 Krzyzanowski said the region included parts of Colorado, Idaho, Kansas, Montana, Nebraska, Nevada, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah and Wyoming. The study involved review of records from the 21.5 million people enrolled in Medicare in 2009 to determine the rate of Parkinson鈥檚 disease for various regions across the country. The researchers then looked for a possible relationship between these rates of Parkinson鈥檚 and the use of 65 pesticides. They found that the pesticides and herbicides simazine, atrazine and lindane had the strongest relationship with Parkinson鈥檚 disease. When researchers divided counties into 10 groups based on exposure to pesticides, people living in the counties with the highest amount of application of the herbicide simazine were 36% more likely to have Parkinson鈥檚 disease than people living in the counties with the lowest amount of exposure. In the counties with the highest exposure to simazine, 411 new Parkinson鈥檚 disease cases developed per every 100,000 people compared to 380 cases in the counties with the lowest exposure. For the herbicide atrazine, those exposed to the highest amount were 31% more likely to have Parkinson鈥檚 disease than those with the lowest exposure. For the insecticide lindane, those with the most exposure were 25% more likely to have the disease. In the counties with the highest exposure to atrazine, 475 new Parkinson鈥檚 disease cases developed per every 100,000 people compared to 398 cases in the counties with the lowest exposure. In the counties with the highest exposure to lindane, 386 new Parkinson鈥檚 disease cases developed per every 100,000 people compared to 349 cases in the counties with the lowest exposure. The results remained the same when researchers adjusted for other factors that could affect the risk of Parkinson鈥檚 disease, such as air pollution exposure. 鈥淚t鈥檚 concerning that previous studies have identified other pesticides and herbicides as potential risk factors for Parkinson鈥檚, and there are hundreds of pesticides that have not yet been studied for any relationship to the disease,鈥 Krzyzanowski said. 鈥淢uch more research is needed to determine these relationships and hopefully to inspire others to take steps to lower the risk of disease by reducing the levels of these pesticides." A limitation of the study was that it relied on the use of county-level estimates since person-level information on pesticide exposure was not available for the study population. The study was supported by the Michael J. Fox Foundation for Parkinson鈥檚 Research. Learn more about Parkinson鈥檚 disease at , home of the 好色先生鈥檚 free patient and caregiver magazine focused on the intersection of neurologic disease and brain health. Follow Brain & Life庐 on , and . When posting to social media channels about this research, we encourage you to use the hashtags #Neurology and #AANscience.
