The influence of chronic occupational exposure to lead on peripheral nerves conduction.

Abstract

Background: The impact of lead on the peripheral nervous system (PNS) remains inadequately explored. Despite the absence of classic lead neuropathy resulting from uncontrolled exposure to high metal doses in workers under biomonitoring, the focus shifts to chronic exposure at lower doses. This study aims to evaluate the influence of occupational lead exposure on peripheral nerve conduction in chronically exposed individuals.

Material and methods: The study comprised 58 workers, divided based on an 8-year mean serum lead concentration into lower exposure (blood lead [PbB] level ≤40 μg/dl) and higher exposure (PbB level >40 μg/dl) subgroups. Conduction tests and laboratory assessments, including oxidative stress parameters, were conducted.

Results: In the higher lead exposure group, average amplitudes of motor fiber-evoked potentials and sensory fiber conduction velocity were 8% and 3% lower, respectively, compared to the lower exposure group. Correlation analysis revealed positive correlations between sensory fiber-evoked potential amplitudes and blood serum sulfhydryl groups, and catalase activity. Motor fiber-evoked potential amplitudes negatively correlated with lipofuscin concentration. Lipofuscin concentration also negatively correlated with sensory fiber-evoked potential amplitudes. Zinc protoporphyrin concentration negatively correlated with sensory fiber-evoked potential amplitudes and conduction velocity.

Conclusions: Chronic lead exposure disrupts peripheral nerve conduction, evident in reduced motor fiber-evoked potential amplitudes and slower sensory fiber conduction velocity. The toxic impact on the PNS may be attributed to oxidative stress and heme biosynthesis disorders. Med Pr Work Health Saf. 2025;76(2).