Cadmium, mercury, and lead in kidney cortex of the general Swedish population: a study of biopsies from living kidney donors

Abstract

Cadmium, mercury, and lead concentrations were detennined in deep-frozen kidney cortex biop- sies taken from 36 living, healthy Swedish kidney donors (18 males and 18 females), who were 30-71 (mean 53) years of age. Information about occupation, smoking, the presence of dental amalgam, and fish consumption could be obtained for 27 ofthe donors. The samples (median dry weight 0.74 mg) were analyzed using inductively coupled plasma mass spectrometry, and the results were transformed to wet-weight concentrations. The median kidney Cd was 17 pdgg (95% confidence interal, 14-23 pg/g), which was similar in males and females. In 10 active smokers, the median kidney Cd was 24 p/g, and in 12 who never smoked, it was 17 pg/g. The median kidney Hg was 0.29 pglg, with higher levels in females (median 0.54 plgg) than in males (median 0.16 pg/g). Subjects with amalgam fillings had higher kidney Hg (median 0.47 pg/g, n = 20) than those without dental amalgam (median 0.15 pgig, n= 6), but kidney Hg was below the detection limit in some samples. Nearly half of the samples had kidney Pb below the detection limit. The median kidney Pb was estimated as 0.14 pg/g. This is the first study of heavy metals in kidney cortex of living, healthy subjects, and the results are relatively similar to those of a few previous autopsy studies, indicating that results from autopsy cases are not seriously biased in relation to kidney metal concentrations in the general population. Cd concentrations in those who never smoked were relatively high, indicating considerable Cd intake from the diet in Sweden. The effect of dental amalgam on kidney Hg was as expected, although the reason for the difference in Hg levels between males and females is unclear.