DETERMINANTS OF LEAD CONCENTRATIONS IN UMBILICAL-CORD BLOOD OF A COHORT OF 9189 NEWBORNS IN THE DISTRICT OF BRAUNSCHWEIG, FRG

From September 1985 until August 1986 the possibility of lead concentr ation determination in umbilical cord blood was offered to all neonate s in the district of Braunschweig by the Ministry of Social Affairs of Lower Saxony. A geometric mean concentration of 3.76 +/- 1.69-mu-g Pb /dl was found in 9189 neonates, being 64% of the total birth cohort. T he median an concentration was 3.59-mu-g/dl. 4.7% of the children show ed concentrations of above 10-mu-g/dl. Lead concentrations of twins sh owed a strong linear correlation (r = + 0.94). They were higher than t hose of singleton births (p = 0.02). Lead concentrations in neonates w ere significantly associated with the age of the mother and with the b irthweight of the newborn. Seasonal differentials were significant wit h higher values in summer (4.39 +/- 1.8-mu-g Pb/dl) compared to winter (3.25 +/- 1.5-mu-g/dl). Duration of daily participation in road traff ic was independent of blood lead concentrations. Potential occupationa l lead exposure of a member of the household was also no significant r isk factor for higher lead concentration in the newborn. Familiy homes constructed before 1955 and those with lead water pipes were associat ed with significant increases of lead concentrations in neonates. Neig hborhood was also significantly associated, with higher values in thos e living by main roads. In the southern part of the district lead conc entrations were about 10% higher than in the northern part. Concentrat ions in neonates coming from cities were the same as in those coming f rom rural areas. Newborns from old lead mining and processing areas in the Harz mountains, in particular those coming from Oker-Harlingerode , had low lead concentrations in umbilical cord blood.