The effect of lead in tap water on blood lead in children in a smelter town.

Hettstedt, a city in eastern Germany with a long history of mining and smelting of non-ferrous ores, has multiple lead waste deposits and the remains of a former lead smelter and a copper-silver smelter. As part of a cross-sectional study, an analysis of lead concentrations in drinking water and in blood was undertaken to determine the impact of lead in drinking water on the internal burden of lead in children. The geometric mean of blood lead levels among children 5-14 years old was 35.0 micrograms/l with a 95% confidence interval (C.I.) of 33.4-36.7. The geometric mean of lead in the random tap water samples was 0.5 microgram/l (95% C.I., 0.5-0.6) and 0.7 microgram/l (95% C.I., 0.6-0.8) in the stagnant tap water samples. Blood lead levels were somewhat correlated with the random water measures but not the stagnant water measures (random sample: r = 0.12, P = 0.012; stagnant sample: r = 0.04, P = 0.396). After adjustment for relevant confounders, lead in drinking water (random sample) was not significantly associated with blood lead levels. Factors that were significantly associated with blood lead included gender, the city area of residence, lead in house dust, regular contact with dogs and dirtiness of the child after playing outdoors. Based on this study, lead in domestic tap water contributed little to the lead exposure of children in the lead contaminated region of Hettstedt.