Effects of occupational exposure to mercury vapour at low concentrations on urinary excretion of protein and NAG activity

摘要

Aim: The detection of early subclinical signs of nephrotoxicity of mercury vapour was the purpose of the present study. Subjects and methods: Exposed subjects were male and female workers engaged in mercury battery production. In every October from 1986 to 1999, total mercury (T-Hg) concentrations in urine, blood and hair were determined. Urinary NAG activity and protein concentration were also determined. Control subjects were workers in the same factory without occupational exposure to mercury vapour. In July 2000, urinary concentrations of T-Hg and protein and NAG activity were determined in the control subjects. Results: Significant positive correlations were observed in exposed subjects in every year from 1986 to 1999, but not in control subjects. No significant differences were observed between control and exposed subjects in T-Hg concentration, NAG activity, and protein concentration in urine. In the exposed subjects, urinary T-Hg had not increased since the start of mercury work. The personal exposure levels of exposed subjects were between 0.001 to 0.008 mg Hg/m~3. Conclusion: Positive correlation between urinary protein and NAG activity might be one of more sensitive indicators of proceeding renal tubular injury than urinary T-Hg and/or NAG acitivity themselves.