Neurotoxic effects of organic solvents in exposed workers: an occupational, neuropsychological, and neurological investigation.

Ninety-eight workers, 65 exposed to organic solvents and 33 unexposed, were examined in order to assess possible neurotoxic signs and symptoms related to solvent exposure. The study group, who were selected according to the type of exposure in a given work process, had been exposed to various types of solvents. The groups were comparable in regard to age, the history of brain traumas and other neurological diseases, and alcohol consumption. The exposed workers had more symptoms of intellectual impairment, poorer performances in psychological tests, and more often signs of cerebral asthenopia. Symptoms and signs of peripheral neuropathy were not significantly increased. Solvent exposure and neurotoxic signs and symptoms were mildly correlated in the study group. Such dose-effect correlations have previously been proved only in a few epidemiological studies. This warrants reevaluation of the risk of developing toxic encephalopathy during prolonged occupational exposure to solvents.