Urinary excretion of platinum from platinum industry workers.

OBJECTIVES Assessment of level of exposure to platinum and platinum concentration in urine from platinum industry workers to evaluate internal exposures and excretion kinetics. METHODS Platinum concentrations in urine samples from 34 workers were measured by adsorptive voltammetry after UV-photolysis. Morning and evening samples were taken two to six times during six months. Individual exposures were assessed by personal air sampling. Also, two male volunteers were exposed to platinum dust for four hours at a typical platinum refinery workplace. RESULTS Urinary platinum excretion after a shift in platinum industry workers was found to be up to 6270 ng/g creatinine--that is, 1000 times above the median value of unexposed people. Urinary excretion reached the maximum nearly 10 hours after inhalative exposure to dust containing platinum. Elimination corresponded to a first half life of about 50 (95% confidence interval (95% CI) 36 to 66) hours, but there were indications that a part of the incorporated platinum is stored longer. The amount of urinary platinum excretion showed a close correlation with the exposure level monitored by personal air sampling. CONCLUSIONS A newly developed analytical method enabled the detection of even natural background concentrations of platinum. Thus, increased urinary platinum concentrations could be detected early, which is important to avoid damaging health of exposed workers.