Association of blood lead with calcium, iron, zinc and hemoglobin in children aged 0-7 years: a large population-based study.

Lead exposure in children has received increasing attention from scientists and public health institutions worldwide. Deficiencies of nutritional essential metals can increase the hazard from lead exposure by enhancing absorption and toxicity of dietary lead. Lead, as a ubiquitous toxicity metal, may interact metabolically with nutritional essential metals. A large population-based study was conducted to investigate blood lead, calcium, iron, zinc and hemoglobin levels in healthy children aged 0-7 years. Based on the records, 158 (3.57 %) of 4,429 children had a blood lead levels (BLLs) ≥ 10 μg/dl, and 1,324 (30.30 %) children had a BLL ≥ 7 μg/dl. BLLs in children aged less than 3 years was lower than those in older children. BLLs had a negative correlation with blood calcium and iron level (r = -0.357 and r = -0.070, P < 0.01). Multiple logistic regression analysis also showed that BLLs had a negative correlation with blood calcium and iron. BLLs can be influenced by the status of some essential trace metals in children. Supplement of nutritional elements may help reduce lead absorption. Children with elevated BLLs (≥ 10 μg/dl) were controlled well in recent years in Chengdu. But the burden of reducing BLLs remains extremely arduous, which requires the joint efforts of both government agencies and the public.