People whose jobs involve regular pesticide exposure may be more prone to Parkinson's disease, finds a new study.
A team led by Dr. Caroline M. Tanner, of the Parkinson's Institute, Sunnyvale, California, observed 519 individuals with Parkinson's disease, and 511 controls of the same age and sex, living in the same area.
Participants were questioned about their employment and job history, their contact and exposure to toxins, including solvents and pesticides.
A research article describing the study, published in the September issue of Archives of Neurology, says that almost 44 Parkinson's affected individuals admitted pesticide exposure, compared to 27 people of controls, which suggest occupational proximity and exposure to pesticide may increase risk of Parkinson's.
The authors write: "Growing evidence suggests a causal association between pesticide use and parkinsonism. However, the term 'pesticide' is broad and includes chemicals with varied mechanisms.... Because few investigations have identified specific pesticides, we studied eight pesticides with high neurotoxic plausibility based on laboratory findings. Use of these pesticides was associated with higher risk of parkinsonism, more than double that in those not exposed."
The researchers add: "This convergence of epidemiologic and laboratory data from experimental models of Parkinson's disease lends credence to a causative role of certain pesticides in the neurodegenerative process."
The scientists say that their findings are only based on occupational pesticide users.
They write: "Other pesticide exposures such as hobby gardening, residential exposure, wearing treated garments or dietary intake were not assessed. Because these exposures may affect many more subjects, future attention is warranted."