“Revolutionary Screening Approach by Researchers Could Simplify Identification of Pesticides Linked to Diseases”

10 Pesticides Linked to Parkinson’s Disease: Evidence of Environmental Toxins

Recent research conducted by UCLA Health and Harvard has successfully identified ten pesticides that may significantly damage neurons relating to Parkinson’s disease. A new understanding of the complexities surrounding the disease is shining light on environmental toxins’ involvement in its development.

Pesticide Exposure Link to Parkinson’s

The link between pesticide exposure and Parkinson’s disease has long been established. In California, the largest agricultural producer and exporter in the United States, there are over 14,000 pesticide products registered for use, featuring more than 1,000 active ingredients. However, it has been challenging to pinpoint which pesticides may increase the risk of developing the neurodegenerative disorder, Parkinson’s.

New Research Success

In a recent study published in the scientific journal Nature Communications, researchers from UCLA Health examined the exposure history of 288 pesticides in Central Valley Parkinson’s disease patients. The researchers were able to determine long-term exposure for each person and, using a pesticide-wide association analysis, tested each pesticide individually for association with Parkinson’s.

Through a novel pairing of epidemiology and toxicity screening that leveraged California’s extensive pesticide use database, UCLA and Harvard researchers were able to identify 10 pesticides that were directly toxic to dopaminergic neurons. The neurons play a key role in voluntary movement, and the death of these neurons is a hallmark of Parkinson’s.

Results

The 10 pesticides identified as directly toxic to these neurons included four insecticides (dicofol, endosulfan, naled, propargite), three herbicides (diquat, endothall, trifluralin), and three fungicides (copper sulfate [basic and pentahydrate] and folpet).
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.

Co-exposure of cotton-farming pesticides that are typically used in combinations produced more toxicity than any single pesticide in the same group.

Further Study

Researchers are also interested in the toxicity of multiple pesticides commonly applied in cotton fields to explore the biological pathways disrupted by pesticide exposure and which biologic pathways are disrupted among Parkinson’s patients.

Kimberly Paul, a lead author and assistant professor of neurology at UCLA, said the study demonstrated an approach that could broadly screen for pesticides implicated in Parkinson’s to find the ones responsible for damage to the neurons.

The researchers are focusing on distinct effects on dopamine neurons and cortical neurons, respectively important for the movement and cognitive symptoms of Parkinson’s patients. The lab research also expands to non-neuronal cells in the brain, the glia, to better understand how pesticides influence the function of these critical cells.

Conclusion

The UCLA Health and Harvard research presents a significant step towards understanding the role of exposure to pesticides in Parkinson’s disease development. The scientific breakthrough contributed to spotting a link by approaching subjects in a completely unbiased manner. Research that is presently being conducted will undoubtedly lead to the identification of more targeted pesticides linked to Parkinson’s disease and increase understanding of the disease itself.