Lead and cadmium levels in daily foods, blood and urine in children and their mothers in Korea

Objectives: The present study was initiated to examine the dietary intake, blood level and urinary concentration of lead (Pb) and cadmium (Cd) among children in Korea, in comparison with the findings in their mothers. Methods: Peripheral blood, spot urine and 24-h food duplicate samples were collected in Busan, Korea, from 38 pairs of children (4-10 years of age) and their mothers (28-46 years, non-smoking, mostly housewives), who provided informed consent. Samples were wet-ashed by being heated in the presence of mineral acids, and Pb and Cd in the wet-ashed samples were analyzed by graphite furnace atomic absorption spectrometry. Pb and Cd in food (Pb-F, Cd-F), blood (Pb-B, Cd-B) and urine [observed value (Pb-Uob, Cd-Uob), and values corrected for creatinine (Pb-Ucr, Cd-Ucr) or a specific gravity (1.016; Pb-Usg, Cd-Usg)] were presented in terms of geometric mean (GM) and geometric standard deviation (GSD). Results: Pb-F and Cd-F in the children were 0.337 mug Pb and 0.457 mug Cd/kg body weight per day as GM, respectively. Pb-B and Cd-B were 38.0 mug Pb and 1.51 mug Cd/l, and Pb-U and Cd-Uob were 5.44 mug Pb/l and 1.33 mug Cd/l, respectively. Pb-F and Pb-B for children were not significantly different from the values for their mothers. In contrast, Cd-F and Cd-B were significantly different between children and their mothers. Cd-F for children correlated with Cd-F for mothers, but no significant correlation was observed in Cd-B, Cd-U, Pb-F, Pb-B or Pb-U between children and their mothers. The dietary intake of Pb in total Pb intake (i.e., respiratory and dietary intake) accounted for 51.7 and 64.8% in children and their mothers, respectively, whereas the corresponding proportions were 97.8 and 98.2%, respectively, for Cd. Conclusion: Cd intake was exclusively from food, both in. children and mothers. Dietary Cd intake of children significantly correlated with that of their mothers. Dietary Pb intake in children, however, did not correlate with that of their mothers. Pb uptake from ambient air tended to be higher in children than in their mothers.