Researchers Link Another Pesticide to Parkinson’s Disease

California researchers who previously linked two commonly used pesticides with Parkinson’s disease have identified a third. And their study found that even people who only work near farms where the chemicals are sprayed  — meaning nonfarmworkers such as firefighters and teachers — face a significant risk of developing the motor system disorder.

The chemical now being linked to Parkinson’s is ziram, a fungicide. Like the two other pesticides the researchers previously associated with Parkinson’s, maneb and paraquat, it appears to harm brain cells related to Parkinson’s, although in different ways.

People exposed to all three pesticides by virtue of working near areas that are sprayed face a threefold greater risk of developing Parkinson’s than those with less exposure, according to the study, which was published in European Journal of Epidemiology. The results suggest that the pesticides “may act together to increase the risk of PD considerably,” Dr. Beate Ritz, senior author of the study and a UCLA  epidemiology professor, said in a news release.

The study evaluated 703 people, including 362 with Parkinson’s, who lived in California’s heavily agricultural Central Valley from 1974 to 1999. After assessing information about the study participants’ work and residential histories, the researchers estimated their level of exposure to the pesticides, and then calculated how that correlated to the incidence of Parkinson’s.

As the Los Angeles Times reports, previous animal studies found that ziram destroyed neurons that use the transmitter chemical dopamine to send messages in the brain. The damage occurs in cells operating in regions of the brain that govern motor function, causing the tremors, unsteady gait and difficulty initiating movement that are the hallmarks of Parkinson’s.

In the latest research, the California scientists broke new ground in determing how ziram and the other pesticides affect humans by using sophisticated tools to determine how much exposure people have had to the chemicals.

The result was that they were able to show that even people who don’t work in the sprayed fields can be harmed by the pesticides. “This stuff drifts,” Ritz said. “It’s borne by the wind and can wind up on plants and animals, float into open doorways or kitchen windows — up to several hundred meters from the fields.”

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One comment to “Researchers Link Another Pesticide to Parkinson’s Disease”

  1. Diane Newman

    My late husband, agronomist Professor Robert C. Newman, University of Wisconsin-Madison Horticulture Dept., spent his 30+ working years researching herbicides for several companies (pre-marketed pesticides — he didn’t always know what they were, as code numbers were used). I remember Monsanto, Hoechst, Bayer, two or three more. He retired in 1991, in 1999 was diagnosed with Parkinson’s, and he died of it in 2009. It was generally assumed by neurologists in Madison and in St Louis (where we lived since 2006), that pesticides caused his illness.
    I write to mention that a fellow researcher, R. Gordon Harvey (UW Agronomy Dept.) was diagnosed with ALS in the 90s, and died after about 3 years. Another researcher, Charles Koval (UW Entolmology Dept.) recently died of multiple myeloma following 10+ years of that illness. These men also worked heavily with pesticides, A USDA researcher at Wisconsin also died of a cancer, I think his name was Robert Havey, bujt could verify if you have any interest..
    Would it be worthwhile to research Ag schools in the US to see if a preponderance of faculty or any other field workers have suffered fatal neurological or blood disorders? My husband was aware that he was handling dangerous stuff, so did most of the field agronomic work himself.
    Just a bit of information for you. Thanks for your time.

    Diane Newman
    6533 Winnebago St.
    St. Louis MO 63109
    314 647 1219

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