THURSDAY, Feb. 17 (HealthDay News) -- People who use the pesticides rotenone and paraquat have a 2.5 times increased risk of developing Parkinson's disease, a new study finds.

U.S. researchers compared 110 people with Parkinson's disease and 358 people without the nervous system disorder. All of the participants were enrolled in the Farming and Movement Evaluation Study involving licensed pesticide applicators and their spouses.

"Rotenone directly inhibits the function of the mitochondria, the structure responsible for making energy in the cell," study co-author Freya Kamel, a researcher at the National Institute of Environmental Health Sciences, said in an institute news release.

"Paraquat increases production of certain oxygen derivatives that may harm cellular structures," she added. "People who used these pesticides or others with a similar mechanism of action were more likely to develop Parkinson's disease."

The study was recently published online in the journal Environmental Health Perspectives.

"These findings help us to understand the biologic changes underlying Parkinson's disease. This may have important implications for the treatment and ultimately the prevention of Parkinson's disease," lead author Dr. Caroline Tanner, clinical research director of the Parkinson's Institute and Clinical Center in Sunnyvale, Calif., said in the news release.

The two pesticides are not approved for home or garden use in the United States. Paraquat use is restricted to certified applicators, and rotenone's only approved use is to kill invasive fish, according to the news release.

More information

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