ABSTRACT
Objective To investigate the current status of lead(Pb) poisoning in children and correlations between Pb levels and calcium(Ca), iron(Fe), zinc(Zn) and environmental factors. Methods ①Questionnaire survey was conducted among 3160 parents in Qingdao area, regarding factors that might have effects on the levels of Pb. ②Levels of blood Pb, Ca, Fe and Zn were determined by graphite furnace atomic absorption (GFAA) spectrometry for 3160 children, who were divided into three groups: mildly increased Pb levels, moderately increased Pb levels and severely increased Pb levels, and the effects of Ca, Fe and Zn on children's blood Pb levels were analyzed by multiple linear regressions.③Children having mildly Pb increase were divided into four groups and received Ca, Fe or Zn preparations or placebo. Results ① Children living with smokers, in new houses, in houses or kindergartens located in industrial areas or main traffic roads, consuming preserved eggs or canned drinks regularly were more easily poisoned.②Percentages of children with increased levels who had insufficient blood Ca, Fe and Zn : 53.31% (306/574), 46.17% (265/574) and 68.47% (393/574), respectively, in the group of children with mildly increased Pb levels; 57.68% (263/456), 49.34% (225/456) and 77.41% (353/456), respectively, in the group of children with moderately increased Pb levels; 64.71% (11/17), 58.82% (10/17) and 82.35%(14/17), respectively, in the group of children with severely increased Pb levels. In contrast, the percentages of children in the control group who had low blood Ca, Fe and Zn were 19.78%(418/2113), 5.21% (110/2113) and 14.62%(309/2113), respectively. ③The levels of Ca, Fe and Zn had a negative correlations with blood levels of Pb(coefficient of regression were-0.870,-0.430,-0.565, respectively). ④When given Ca, Fe and Zn, the children had the blood Pb levels decreased by 78.32% (112/143), 66.43% (95/143) and 67.83% (97/143), respectively. Conclusions ①Children's increased levels of Pb have adverse effects on the absorption of Ca, Fe and Zn. ②Intaking Ca, Fe and Zn preparations can reduce blood Pb level.