Neurobehavioral toxicity of long-term exposure to tetrachloroethylene.

One hundred and one employees of dry cleaning shops exposed to tetrachloroethylene (time weighted average 205 mg/m3) and 84 employees of departmental stores and hotels were compared from the results of a psychological examination. Age, gender, the daily consumption of alcohol and the intellectual level were taken into consideration analysing the effects of tetrachloroethylene. Perceptual speed, digit reproduction as a memory test, the digit symbol test as a substitution task and variables of a choice reaction test as well as a cancellation test differed significantly between the controls on one hand, and the groups of low and high exposure on the other. But, the differences between the exposure groups were not significant. There was no effect of alcohol on the exposure-related group differences. By means of discriminant analyses the diagnostic effectiveness of the biochemical, neurological and psychological methods were compared to classify the subjects into exposure groups. The highest rate of correct classifications was performed by the multidisciplinary combination of approaches.