Temporal changes in blood lead levels of children in east Germany

This analysis investigates the temporal changes in blood lead levels (BLL) in repeated cross-sectional surveys of 5-7 year old children conducted in 1992-93, 1995-96 and 1998-99 and in a prospective cohort from a smelter town and an agricultural control region in east Germany. The region of Hettstedt has a long history of mining and smelting resulting in high levels of heavy metal pollution whereas the region of Zerbst has no known industrial sources of heavy metals. In the region of Hettstedt lead content in ambient dust fall declined since the early 1990s due to the closure of many factories, whilst in Zerbst lead in ambient dust fall was constantly low in the 1990s. Blood lead levels decreased during the observation period both in children from the smelter town and in children from the agricultural control region. From 1992-93 to 1998-99 the mean BLLs of school entrants fell by 20% (41.6 to 33.3 micrograms/l) in Hettstedt and by 30% (34.2 to 23.8 micrograms/l) in Zerbst. In the same observation period mean BLLs of cohort children declined by 35% (41.9 to 27.3 micrograms/l) in Hettstedt and by 39% (32.3 to 19.8 micrograms/l) in Zerbst. At the beginning of the observation period cohort children were 5-7 years of age and were followed up to the age of 11-14. Adjustment for sociodemographic factors, city area and environmental uptake of lead did not influence the percentage changes in BLL of school-entrants. It seems that the decline in ambient lead fall had an impact on the body burden of lead, but the overall decrease in BLL in these two regions is caused by the overall decrease of lead in gasoline and thus in food.