Researchers have found that exposure to pesticides among French farm workers makes them more prone to Parkinson's disease (PD).
The researchers observed that the risk was more pronounced in case of professional exposure towards organochlorine insecticides.
The study, led by Dr. Alexis Elbaz, of Inserm, the national French institute for health research in Paris, involved individuals affiliated with the French health insurance organization for agricultural workers who were frequently exposed to pesticides in the course of their work.
For the study, occupational health physicians interviewed participants, visited farms, and collected a large amount of data on pesticide exposure to construct a detailed lifetime exposure history to pesticides.
The data included farm size, type of crops, animal breeding, which pesticides were used, time period of use, frequency and duration of exposure per year, and spraying method.
It was found that PD patients had been exposed to pesticides through their work more frequently and for a greater number of years/hours than those without PD.
Also, among the three main classes of pesticides (insecticides, herbicides, fungicides), they found that men who had used insecticides had a two-fold increase in the risk of PD.
"Our findings support the hypothesis that environmental risk factors such as professional pesticide exposure may lead to neurodegeneration," noted Elbaz.
The study underlined the need to educate workers applying pesticides as to how these products should be used and the importance of promoting and encouraging the use of protective devices.
The study also raises the question about the role of lower-level environmental exposure through air, water and food, and additional studies are needed to address this question.
The study has been published in Annals of Neurology, the official journal of the American Neurological Association.