Umbilical cord blood or serum concentrations of mercury, lead, selenium and copper were measured with inductively coupled plasma mass spectrometry in a population of 300 infants born in Baltimore, Maryland. Geometric mean values were 1.37 ìg/L (95% confidence interval: 1.27, 1.48) for mercury; 0.66 ìg/dL (95% CI: 0.61, 0.71) for lead; and 38.62 ìg/dL (95% CI: 36.73, 40.61) for copper. Mean selenium was 70.10 ìg/L (95% CI: 68.69, 70.52). Mercury, selenium and copper levels were within exposure ranges reported among similar populations, whereas the distribution of lead levels was lower than prior reports; only one infant had a cord blood lead above 10 ìg/dL. Levels of selenium were significantly correlated with concentrations of lead (Spearman's ñ=0.20) and copper (Spearman's ñ=0.51). Multivariable analyses identified a number of factors associated with one of more of these exposures. These included: increase in maternal age (increased lead); Asian mothers (increased mercury and lead, decreased selenium and copper); higher umbilical cord serum n-3 fatty acids (increased mercury, selenium and copper), mothers using Medicaid (increased lead); increasing gestational age (increased copper); increasing birthweight (increased selenium); older neighborhood housing stock (increased lead and selenium); and maternal smoking (increased lead). This work provides additional information about contemporary prenatal element exposures and can help identify groups at risk of atypical exposures.
Adolescent Adult