Implicated again

Pesticides cause Parkinson's disease

Published: Wednesday 15 January 2003

For the first time, a study has linked human exposure to pesticides with Parkinson's disease (PD).

The actual cause of PD remains a mystery till date, despite intense research about the same. Over the years, the disease has become widespread in many countries, with its symptoms ranging from stiff movements to muscle spasm.

Experiments conducted on rats using the pesticide rotenone show that if the animals are given repeated doses of rotenone, they display symptoms of PD. High levels of organochlorine compound dieldrin have also been found in the brains of PD patients.

The study was conducted on sugarcane and pineapple plantation workers of Hawaii by Helen Petrovitch and her colleagues from the Honolulu-based Pacific Health Research Institute. The cases of PD were identified through a review of Hawaiian death certificates and records of PD cases available with local neurologists. In all, 7,986 plantation workers were studied, out of which 116 were found to suffer from PD.

The incidence of PD was found to rise with increasing years of exposure to pesticides, especially chlorane and DDT, which were frequently used in the plantations. Men who had worked for more than 20 years in the plantations were found to have double the risk of PD when compared with those who had never worked on a plantation.

Poison in plantations
Duration of work
(in years)
Total number of plantation workers Number of workers suffering from Parkinson’s disease
0 5363 73
1-10 1843 24
11-20 315 7
More than 20 465 12
Source:Arch Neurol, Vol 59, November 2002

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