Measurement and distribution of zinc, cadmium, and mercury in human kidney tissue.

Simultaneous analyses of human kidney cortex tissues for zinc, cadmium, and mercury were made by neutron activation combined with either radiochemical separation prior to counting or direct germanium detector gamma spectrometry. For some samples from adults and infants, analyses were made on successive tissue slices from the outer cortex to the inner medulla. Zinc and cadmium show a concentration gradient, with the highest concentrations at the outer medulla. Mercury was preferentially concentrated deeper in the cortex. All three metals, and especially cadmium, are found in higher concentrations in adult than in infant kidneys. A mechanism for the rapid increase in renal cadmium is proposed. The heterogeneous renal distribution of the elements indicates that careful sampling is necessary in any comparative study of their occurrence in human kidney tissue.