[Urinary lead concentration as a risk factor during mixed exposure to lead, zinc and cadmium].

Six groups of subjects with different exposure to lead, zinc and cadmium, selected from among workers of zinc works, were studied. The concentration of the metals in the air was in the range: 0.04--0.70 mg Pb/m3; 0.16--1.84 mg ZnO/m3 and below 0.020 mg CdO/m3. Urine specimens were taken several times from the same subjects in mid -- week between the 3rd and 5th work hour. The concentration of the metals in urine was determined by the atomic absorption spectrophotometric method. The exposure to the metals was based on the relation between their concentrations in the air and urine. Statistical analysis indicated that under the conditions of mixed exposure to lead, zinc and cadmium, lead concentration in urine -- with prevailing toxic effects of lead -- may be used to evaluate occupational exposure.