High prevalence of parkinsonism after occupational exposure to lead-sulfate batteries.

Seven of nine postal workers exposed to lead-sulfate batteries over a period of up to 30 years developed parkinsonian symptoms. One of the remaining two showed left-hand bradykinesia and one was not available for examination. The high prevalence and cause of parkinsonism in these patients remains unexplained. Lead intoxication may play a role in the occurrence of parkinsonian symptoms, but involvement of sulfate and other sulfur compounds must also be considered.