The four heavy metal concentrations (Cd, Pb, Cu and Zn) in the 216 urine samples from the residents of three Cd-polluted and matched control areas were determined. And the differences of these metal distributions as well as the estimation of possible mechanisms of the heavy metal excretion in the urine in relation to the dietary intake were statistically analyzed.
Urinary Cd in the polluted area residents was higher than that of the control area residents, however, the ratio of urinary excretion of Cd among the polluted area residents to the control area residents was smaller than the ratio of fecal Cd excretion in the two area residents. This may suggest the more accumulation and retention of Cd among the Cd-polluted area residents, resulting in the appearance of less Cd concentration in the urine.
The urinary Pb concentration in the polluted area residents also showed higher than those of the control area residents; this tendency was consistent with the results from the dietary and fecal Pb analyses. The essential metals in the urine, Cu and Zn, showed the different tendency that urinary Zn con-centration did not differ by area, whereas that urinary Cu did differ by area. These were not consistent with the results from the fecal analysis, suggesting the different metabolism of the essential metals in the human body.
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