[Biological indicators of the renal involvement in workers with previous exposure to cadmium: a 5-year follow up].

Six welders who had been exposed to high cadmium concentrations were monitored for 5 years after cessation of exposure. Indicators of exposure and effect had shown marked alterations during exposure, with 3 subjects showing low molecular weight proteinuria (beta 2-microglobinuria), one of whom with total proteinuria as well. During the follow-up period, beta 2-microglobinuria increased up to a maximum in 2 subjects; in another subject, after a temporary increase, beta 2-microglobinuria returned to normal levels after 5 years. Urinary enzyme excretion had exceeded normal values during exposure; during the follow-up, brush border enzyme excretion was persistently high (only angiotensin converting enzyme activity showed a progressive reduction), whereas cytoplasmatic enzyme values returned to normal one year after cessation of exposure.