Breast Milk Lead Concentrations of Mothers Living Near Tin Smelters

We compared Pb concentration in human milk from 37 mothers living in a neighborhood of tin-ore smelters to that from 45 mothers living in a fishing community. The median breast-milk-Pb (BM-Pb) concentration was significantly (p = 0.0000001) higher (11.3 μg L(-1); ≤0.96-29.4 μg L(-1)) in mothers living in the vicinity of smelters than that of rural mothers (1.9 μg L(-1); ≤0.96-20.0 μg L(-1)). These mothers also showed a statistically significant correlation between length of residence and BM-Pb concentration (Spearman r = 0.6864; p0.0001). The estimated median exposure (for infants6 months) was 3.0 μg kg(-1) b.w. for rural infants compared to 7.5 μg kg(-1) b.w. for infants in the vicinity of metal smelters. Overall, most BM-Pb concentrations (79 %) in the metal smelter area were above the critical limit of 5.0 μg L(-1) set by the WHO.