Metal exposures in an inner-city neonatal population

Objectives: We measured concentrations of lead (Pb), manganese (Mn), chromium (Cr), and copper (Cu) in umbilical cord whole blood and examined sources of environmental Pb exposures in a predominantly African-American population. Methods: Between April and July 2006, we collected reproductive histories, questionnaires, and blood samples from 102 women, aged 16-45. years, who delivered at a Memphis, TN hospital. Results: The prevalence of preeclampsia and low birth weight infancy in the study population was 11% and 10%, respectively. Twenty-eight percent of mothers reported living near a potential Pb-contaminated area, while 43% lived in a residence built before 1978. Geometric mean (GM) concentrations for umbilical cord blood in the study population were 1.3, 3.5, 9.0, and 52.0μg/dL for Pb, Mn, Cr, and Cu, respectively. Six neonates had cord blood Pb (CBL) concentrations above 10μg/dL, while 20 had CBL concentrations ≥ 2μg/dL. GM umbilical CBL levels were higher in neonates born to women living near a potential Pb-contaminated area (2.2 vs. 1.1μg/dL) and those with friends, family or household members exposed to lead products (1.6 vs. 1.1μg/dL). Some evidence of an exposure-response relationship was also detected between all four metal concentrations and an increasing number of maternal lead exposures. After adjustment for confounding, proximity to a Pb-contaminated area was the strongest environmental determinant of CBL levels among neonates with CBL concentrations of ≥ 2μg/dL (odds ratio. =5.1; 95% CI. =1.6, 16.7). Conclusions: Metal concentrations were elevated in this population, and CBL levels were associated with proximity to Pb-contaminated areas.