Blood lead levels of contemporary Japanese children.

ABSTRACT

OBJECTIVES: Lead concentrations in whole blood (BPb) of Japanese children were measured to obtain insight into the sources of variation and to estimate health risk. METHODS: Blood samples were taken from 352 children (aged 1-14 years) at pediatric clinics/hospitals in 3 regions of Japan (Tokyo, Shizuoka, and Osaka) during 2005-2006 (Shizuoka only) and 2008-2010 (3 regions), and BPb was measured by inductively coupled plasma mass spectrometry after acid digestion. RESULTS: Geometric mean BPb of the 352 children was 1.07 µg/dL, among the lowest in the world. Based on this result, the probability of exceeding BPb 10 µg/dL, the action level proposed by the US Centers for Disease Control and Prevention, in general Japanese children was estimated to be negligible. There was a significant negative correlation between BPb and age, while sex difference was not significant. BPb was significantly lower in subjects in Tokyo than in the other two regions. Age-adjusted mean BPb was significantly higher in children with a family member who smoked in their presence than in those who did not have such a family member, indicating that passive smoking had a significant effect on BPb. CONCLUSIONS: Health risk of lead exposure is minimal in Japanese children. To lower the exposure level further, reduction of passive smoking is suggested as one of the effective measures.