Parkinson’s disease linked to pesticide exposure

26 Dec 2007

Parkinson’s disease is associated with the degeneration of dopaminergic neurons in the substantia nigra region of the brain. It is the second commonest neurodegenerative disease after alzheimer’s disease.

Many case-control studies have investigated the association between parkinsonism and pesticide exposure and some of these have found an association. Use of well water, rural living and agricultural employment have also been implicated in Parkinson’s.

Although many studies have associated parkinsonism with pesticide exposure, many of them are also relatively insensitive. The Geoparkinson study, initiated in 2000, was initiated to address some of these outstanding questions.

The study found that increased exposure to pesticides increased the likelihood of Parkinson’s disease with those most highly exposed experiencing a 40% increase in the probability of developing the disease.

It is known that chemical exposure to 1-methyl-4-phenyl tetrahydropyridine and rotenone induce parkinsonism in rat model systems and that the pesticides Maneb and Paraquat have been associated with Parkinson’s disease in a number of studies. These results reinforce previous concerns that pesticides are likely to be significant contributors to the prevalence of this disease.

Environmental risk factors for Parkinson’s disease and parkinsonism: the Geoparkinson study. Dick, F.D. et al (2007) Occupational and Environmental Medicine 64: 666-672