Asymptomatic sensorimotor polyneuropathy in workers exposed to elemental mercury

Area of Science:

• Occupational Health
• Neurotoxicology
• Environmental Medicine

Background:

• Chlor-alkali plants utilize inorganic mercury, posing potential exposure risks to workers.
• Chronic exposure to mercury vapor can lead to various health issues, particularly affecting the nervous system.

Purpose of the Study:

• To investigate the association between chronic inorganic mercury vapor exposure and neurologic impairment in chlor-alkali plant workers.
• To determine if mercury exposure levels correlate with the severity of observed neurologic deficits.

Main Methods:

• Evaluated 138 chlor-alkali plant workers using neurologic and electrodiagnostic assessments.
• Measured urine mercury levels to quantify exposure.
• Compared findings between exposed subjects with polyneuropathy and a control group.

Main Results:

• Eighteen workers exhibited mild polyneuropathy.
• These subjects had significantly elevated urine mercury levels (p < 0.05).
• Polyneuropathy was associated with reduced sensation, prolonged distal latencies, reduced sensory evoked response amplitudes, and abnormal electromyography.

Conclusions:

• Elemental mercury exposure is associated with an axonal type of sensorimotor polyneuropathy.
• The severity of neurologic impairment appears directly related to the magnitude of mercury exposure.