PARKINSONS-DISEASE AND BRAIN LEVELS OF ORGANOCHLORINE PESTICIDES

Epidemiological studies have suggested an etiologic relationship betwe en pesticide exposure and Parkinson's disease (PD). Organochlorine pes ticides were assayed in postmortem brain samples from 20 PD, 7 Alzheim er's disease (AD), and 14 nonneurological control cases. The three gro ups were similar in age at death, sex, and demographic variables. Only two of 16 pesticide residues screened were detected. A long-lasting r esidue of DDT (pp-DDE) was found in the majority of cases of PD and AD , as well as in all the control cases; pp-DDT was significantly more l ikely to be found in AD controls than the PD cases (Fisher's exact two -tailed, P = 0.04). Dieldrin was detected in 6 of 20 PD brains, 1 of 7 AD, and in none of 14 control samples. Despite the relatively small n umber of brains assayed, the association between Dieldrin and the diag nosis of PD was highly significant (P = 0.03). Dieldrin, a lipid-solub le, long-lasting mitochondrial poison, should be investigated as a pot ential etiological agent of Parkinsonism.