LOS ANGELES — A widely used agricultural pesticide may pose a far greater threat to brain health than previously understood, according to new research from UCLA Health that links long-term exposure to the chemical chlorpyrifos with a sharply elevated risk of developing Parkinson's disease, while also identifying a specific biological mechanism that may explain why.

The study, published in the journal Molecular Neurodegeneration, found that people with long-term residential exposure to chlorpyrifos had more than 2.5 times the risk of developing Parkinson's disease compared with those who were not exposed. The research combined human population data with laboratory experiments in mice and zebrafish, providing both an epidemiological link and biological evidence to support it.

Researchers analyzed data from 829 people diagnosed with Parkinson's disease and 824 individuals without the condition, all enrolled in UCLA's long-running Parkinson's Environment and Genes study. The cohort was drawn from three agricultural counties in central California — Kern, Fresno and Tulare — with participants recruited in two waves, one from 2000 to 2007 and a second from 2009 to 2015. To estimate each participant's cumulative exposure to chlorpyrifos, the research team combined California's Pesticide Use Report database, which has tracked agricultural chemical use in the state since 1972, with detailed residential and workplace address histories spanning decades.

Dr. Jeff Bronstein, a professor of Neurology at UCLA Health and the study's senior author, said the findings move beyond general associations between pesticides and Parkinson's to implicate one chemical specifically.

"This study establishes chlorpyrifos as a specific environmental risk factor for Parkinson's disease," Bronstein said, adding that the work does not simply lump pesticides together as a broad category but isolates this compound's distinct........

© International Business Times