Comprehensive neurophysiological evaluation of lead exposed workers

A survey of the neurotoxic effects of lead in battery workers was carried out, based on the evaluationof multiple neurophysiological parameters. Thirty-one battery qorkers and thirty-seven controls were examined. Exposure levels in both groups were evaluated by determination of blood lead levels and zincprotopophyrin. The neurophysiological tests included Visual Evoked Response -VER, motor conduction velocity of median, ulnar, deep peroneal and tibial nerves; sensory conduction velocity of the median nerve, recording of the smooth pursuit eye movements. Since 1979 the battery workers had undergone periodic medical surveillance, based on PbB and ZPP. Current maximal and time-weighted average PbB values were taken into account as indicators of exposure. No significant difference was detected between the two groups for the parameters under evaluation, and no consistent dose-effect relantioship was found. In our experience, no single neurophysiological parameter seems to be useful in the medical surveillance of low level lead exposed subjects working in small plants.