Low blood lead levels and hemoglobin concentrations in preschool children in China.

It is well known that lead (Pb) produces reduced haemoglobin (Hb) levels and risk of anemia when blood lead levels (BPb) are greater than 20 µg dL^-1. Two recent studies reported an increased risk of anemia in children with BPb between 10-20 µg dL^-1, but few studies examined the association between Hb levels or risk of anemia and BPb under 10 µg dL^-1. In the present study this association was examined using data of 140 preschool children from a larger prospective cohort study in China. Data showed that compared to children with BPb <5 µg dL^-1, children with BPb between 7.5-10 µg dL^-1 had significantly lower Hb levels, but there were no marked differences for other groups. A linear regression model showed a negative relationship between BPb and Hb levels after controlling for age, gender, height, weight, and iron (Fe) deficiency. This finding, although limited by a small sample size, suggests it may be important to examine Pb-induced hemosynthesis effect at concentrations less than 10 µg dL^-1.