Cadmium-induced renal tubular dysfunction in a group of welders

Aims To evaluate the body burden of cadmium and cadmium-induced proteinuria in a group of Chinese welders. Methods Cadmium concentrations in the breathing zone and in urine were measured by atomic absorption spectrometry. beta(2)-Microglobulin (beta(2)-MG) in urine as a marker of renal tubular function was measured using an ELISA kit. All urinary parameters were adjusted by urinary creatinine (Cr). Results A total of 103 welders participated. The concentration of airborne cadmium in the welders' breathing zones ranged from 5 to 86 mu g/m(3), and 17% of samples exceeded the threshold limit value. Six welders' urinary cadmium levels exceeded the Chinese recommended reference value. Urinary beta(2)-MG levels increased significantly with increasing urinary cadmium levels and in two welders, the values were close to the level for chronic cadmium poisoning in China. Conclusions Environmental and urinary cadmium levels were raised in this group of welders and were associated with raised markers of renal tubular dysfunction. The exact source of the cadmium warrants further assessment.