Chronic cadmium intoxication and renal injury among workers of a small-scale silver soldering company

Abstract Background Cadmium exposure may induce chronic intoxication with renal damage. Silver soldering may be a source of cadmium exposure. Methods We analyzed working environment measurement data and periodic health screening data from a small silver soldering company with ten workers. Concentrations of cadmium in air from working environment measurement data were obtained. Concentrations of blood and urinary cadmium, urine protein and urine β2-microglobulin (B2M) were obtained. Generalized linear model was used to identify the association between blood and urine cadmium and urine B2M. Clinical features of chronic cadmium intoxication focused with toxicological renal effects were described. Results Mean duration of work was 8.5 years (standard deviation [SD] 6.9, range from 3 to 20 years). Cadmium concentrations in air were ranged from 0.006 to 0.015 mg/m3. Blood cadmium was elevated in all ten workers with highest level of 34.6 μg/L (mean 21.288 μg/L, SD 11.304, range from 9.641 to 34.630 μg/L). Urinary cadmium was elevated in nine workers with highest level of 62.9 μg/g Cr (mean 22.151 μg/g creatinine, SD 19.889, range from 3.228 to 62.971 μg/g creatinine). Urine B2M was elevated in three workers. Urinary cadmium was positively associated with urine protein (beta coefficient 10.27, 95% confidence interval [4.36, 16.18]). Other clinical parameters were compatible with renal tubular damage. Conclusion Cadmium intoxication may occur at quite low air concentrations. Exposure limit may be needed to be lowered.