Relationship of lead and essential elements in whole blood from school-age children in Nanning, China.

OBJECTIVES: The aim of this study was to investigate blood lead level and its relationship to essential elements (zinc, copper, iron, calcium and magnesium) in school-age children from Nanning, China. METHODS: A total of 2457 children aged from 6 to 14 years were enrolled in Nanning, China. The levels of lead (Pb), zinc (Zn), copper (Cu), iron (Fe), calcium (Ca) and magnesium (Mg) were determined by an atomic absorption spectrometer. RESULTS: The mean blood lead level (BLL) was 57.21±35.00µg/L. 188 (7.65%) asymptomatic children had toxic lead level higher than 100µg/L. The school-age boys had similar lead level among different age groups, while the elder girls had less BLL. The blood Zn and Fe were found to be increased in the boys with elevated BLL, but similar trends were not observed in the girls. Positive correlations between Pb and Fe or Mg (r=0.112, 0.062, respectively, p<0.01) and a negative correlation between Pb and Ca (r=-0.047, p<0.05) were further established in the studied children. CONCLUSIONS: Lead exposure in school-age children was still prevalent in Nanning. The boys and girls differed in blood levels of lead and other metallic elements. Lead exposure may induce metabolic disorder of other metallic elements in body.