Parkinson's disease (PD) is an idiopathic, progressive and degenerative disorder of the central nervous system, characterized by slow and reduced movement, muscular rigidity, tremor and postural abnormality. It is second most common neurodegenerative disorder with the prevalence of 1–2 percent after the age of 50 years. PD is a multi-factorial disease, caused by the combination of age, genetic and environmental factors. Environmental exposures to pesticides, herbicides and heavy metals play a critical role in the onset and progression of PD. The susceptibility of individuals for PD depends on the metabolic enzymes involved in the detoxification of selected environmental chemicals and toxicants. Inherited differences in metabolic enzymes are mainly responsible for the neuronal degeneration. Genetic polymorphisms in the toxicant responsive genes greatly alter the susceptibility of chemically induced PD. Evidences obtained from genome wide analysis and biochemical, molecular and epidemiological studies have concluded the significant contribution of environmental factors in the onset of PD. In this article, an update on the role of environmental factors in the onset and progression of Parkinson's disease has been discussed.

doi: 10.5214/ans.0972.7531.2005.120404