For not the first time, a study suggests a link between Parkinson’s disease and pesticide exposure. Parkinson’s disease is a progressive, degenerative central nervous system disorder that typically affects motor skills and speech, among other functions and, while not fatal, complications can be deadly. The cause is unknown and there is no cure.
A new study has found that ongoing exposure to pesticides, weed killers, and solvents, may raise risks for developing Parkinson’s disease, according to HealthDay News. The researchers looked at more than 100 studies and determined that exposure to these elements increased Parkinson’s disease risk by 33 – 80 percent, according to their report in the May 28 issue of the journal Neurology.
“Due to this association, there was also a link between farming or country living and developing Parkinson’s in some of the studies,” study leader Dr. Emanuele Cereda, of the IRCCS University Hospital San Matteo Foundation in Pavia, stated in a journal news release.
Some of the studies the team reviewed looked specifically at how home or work environment affected the risk of disease risk and some looked at from where water was obtained, according to HealthDay News. The researchers found that exposure to either paraquat, a weed killer, or maneb and mancozeb, fungicides, seemed to double risks for developing Parkinson’s disease.
“We didn’t study whether the type of exposure, such as whether the compound was inhaled or absorbed through the skin, and the method of application, such as spraying or mixing, affected Parkinson’s risk,” Cereda said. “However, our study suggests that the risk increases in a dose response manner as the length of exposure to these chemicals increases,” according to HealthDay News, which noted that the research did find links between certain chemicals and Parkinson’s disease, the research did not prove that the chemicals caused the disorder.
We previously wrote that increased risks for Parkinson’s disease were linked to some solvents. In that study, published in the Annals of Neurology, researchers found that exposure to trichloroethylene (TCE) was associated with a significantly increased risk of Parkinson’s disease and saw a trend for significance for exposure to the chemicals perchloroethylene (PERC) and carbon tetrachloride (CCl4). “Although the present work focused on occupational exposures, solvents are ubiquitous in the environment, and this is particularly true for those implicated in this study—TCE, PERC, and CCl4,” the authors wrote. “Our findings require replication in other populations with well-characterized exposures, but the potential public health implications are considerable,” the team authored.
We’ve also written that over the past several years, the agricultural pesticide paraquat has been linked to Parkinson’s, posing a risk to agricultural workers who toil in fields where the pesticide is sprayed, as well as to people living near the fields. Other research revealed that people exposed at their workplaces to ziram, maneb, and paraquat tripled their risk of Parkinson’s; workplace exposure to both ziram and paraquat nearly doubled Parkinson’s risk; and people who worked with either paraquat or the pesticide rotenone were 2.5 times likelier to develop Parkinson’s disease.
Another study found that some medications, notably the amphetamines Benzedrine or Dexedrine, used to treat attention deficit hyperactivity disorder (ADHD) could also place those patients at risk for Parkinson’s disease.
Yet another study found an association with glyphosate, the active ingredient in Monsato’s Roundup, and Parkinson’s disease and Parkinson’s-related brain disorders. According to a report from the Organic Authority, Roundup is the best-selling pesticide in the world and is the companion chemical application to many of the company’s genetically modified seeds including corn, soy, canola, and cotton. A 2011 report published in the journal Parkinsonism Related Disorders, detailed the case of a 44-year-old woman with Parkinson’s-like symptoms after sustaining long-term chemical exposure to glyphosate for three years as a worker in a chemical factory.