Neurotoxic effects in mercury-exposed workers.

Mercury levels in blood and urine and several nerve conduction velocities (CV) were measured in two groups of workers exposed to mercury (Hg) and in a reference group. Furthermore neuropsychiatric examination and psychological tests were performed. There was a significant mild degree of slowing of sensory CV, but no dose-effect relationship was evaluated on a group basis. The individual assessment showed in some cases hints of abnormal CV caused by mercury exposure. Significant correlations were found between duration of exposure and decrease of short-term memory. However there was no relationship in the case of the other psychological tests. In conclusion, results indicate that there are no disorders of central and/or peripheral nervous system function if the valid Biological Threshold Limit Values in FRG (50 micrograms Hg/l blood and/or 200 micrograms Hg/l urine) are not exceeded.