Peripheral nerve conduction velocity in workers occupational exposed to lead.

ABSTRACT

The peripheral nerve conduction velocity between the wrist and elbow of the right upper limb and the relationship between this parameter and biochemical parameters for workers occupationally exposed to lead were studied. The results showed that nerve conduction velocity could be altered by lead exposure. The nerve conduction velocity was decreased when the exposure level was 0.0652 mg/m3 (time-weighed average), and it slowed further in proportion to increasing exposure levels. There was a negative correlation between the nerve conduction velocity and the length of exposure. A decrease in the nerve conduction velocity was noted after less than three years of exposure to lead. There was a close relationship between the nerve conduction velocity and the level of lead in the blood; the nerve conduction velocity decreased proportionally with increasing blood lead levels. The blood lead level associated with a change in the nerve conduction velocity was less than 40 micrograms/100 ml (less than 1.9 mumol/l). No correlation between the nerve conduction velocity and the amount of metabolites of porphyrin was found. The measurement of nerve conduction velocity can be used as one of the sensitive criteria for the early detection of the toxic effects of lead.