23
May
New Study Spotlights Ten Pesticides Implicated in Development of Parkinson’s
(Beyond Pesticides, May 23 2023) New research is zeroing in on the role of 10 commonly used pesticides in the development of Parkinson’s. Published in the journal Nature Communications by a team of scientists lead by researchers at the University of California, Los Angeles, the study focused on the toxicity of these pesticides to neurons that have been found to lead to the presentation of the disease. Research is increasingly focusing on environmental exposures, and pesticides in particular, as a major factor in the development of Parkinson’s. This study adds further evidence that this line of research is a valid and worthwhile undertaking for the nearly one million people in the United States struggling with this incurable disease. [The authors note that the herbicide paraquat’s strong connection to Parkinson’s is not addressed in this study, but is the focus of a separate manuscript.]
Scientists sought to further focus on which pesticides were most likely to be playing a role in Parkinson’s development. Records from California’s vast pesticide use database aided the search. From a comprehensive pesticide-wide association study, 53 of 288 pesticides screened were found to be linked to Parkinson’s. Scientists then took these 53 pesticides and conducted live-cell imaging screening, exposing dopaminergic neurons (groups of brain cells that play a role in heart, kidney, hormone, and central nervous system functioning) to the chemicals. Through this process, researchers homed in on 10 pesticides “directly toxic” to these neurons, as the study indicates.
Those pesticides included: copper sulfate, copper sulfate pentahydrate, dicofol, diquat dibromide, endosulfan, endothall, folpet, naled, propargite, and trufluralin. The most toxic of the ten was propargite, an organosulphite insecticide already associated with cancer and reproductive impacts. Diquat dibromide, naled, and folpet also recorded significant toxicity to neurons.
Despite clear toxicity, a press release for the study published by UCLA notes, “Aside from their toxicity in dopaminergic neurons, there is little that unifies these pesticides. They have a range of use types, are structurally distinct, and do not share a prior toxicity classification.”
“We were able to implicate individual agents more than any other study has before, and it was done in a completely agnostic manner,” said Kimberly Paul, PhD, lead author and assistant neurology professor at UCLA Dr. Paul said. “When you bring together this type of agnostic screening with a field-to-bench paradigm, you can pinpoint pesticides that look like they’re quite important in the disease.”
Those closely tracking the connection between pesticides and Parkinson’s may be wondering whether paraquat, an herbicide currently the subject of a major lawsuit against its primary manufacturer for its connection to Parkinson’s, was reviewed as part of this study. It was part of the 288 pesticides screened, however the authors indicated the following: “Due to special considerations for paraquat dichloride, specifically strong experimental support for the hypothesis and the interest in estimating the effects of duration and intensity of exposure, we present results from these analyses in a separate manuscript.” In other words, stay tuned for more specific information on the hazards of paraquat from this research team.
It is critical to emphasize that these harmful effects are only being investigated by independent scientific researchers. As far as regulators are concerned, that data has little significance over studies submitted by pesticide industry manufacturers, which the U.S. Environmental Protection Agency uses as a basis to register toxic chemicals. The agency has done little to nothing to attempt to rein in use when emerging science points to a potential public health crisis. In fact, the Biden EPA took action in 2021 to reapprove paraquat, despite mounting evidence of it as a causal source behind Parkinson’s, with even weaker protections than those considered by the Trump administration.
The Biden EPA in this sense is in need of significant reforms, so that emerging independent data becomes incorporated in real time into assessments over a chemical’s registration and ongoing use. There must be more flexibility within the regulatory process to suspend or cancel chemicals that present widespread public health threats. Join Beyond Pesticides in urging the Biden administration, EPA, and Congress to adopt a new direction for pesticide regulation.
I do not have a website. My father had Parkinson’s disease, and I assisted with his care , but the whole story was horrible. It began in 1950. He lived about 25 years more. If I can learn enough about computers, I might be able to write letters for your group .
May 25th, 2023 at 1:21 pm