Prevalence and predictors of exposure to multiple metals in preschool children from Montevideo, Uruguay

The extent of children's exposure to multiple toxic metals is not well described in many developing countries. We examined metal exposures in young children (6-37. months) from Montevideo, Uruguay and their mothers (15-47. years) participating in a community-based study. Hair samples collected from 180 children and their mothers were analyzed for: lead (Pb), cadmium (Cd), manganese (Mn), and arsenic (As) concentration using inductively coupled plasma-mass spectrometry (ICP-MS). Median metal levels (μg/g) were: Pb 13.69, Mn 1.45, Cd 0.17, and As 0.09 for children and Pb 4.27, Mn 1.42, Cd 0.08, and As 0.02 for mothers. Of the child and maternal samples, 1.7% and 2.9% were below the limit of detection (LOD) for Cd, and 21.3% and 38.5% were below the LOD for As, respectively. Correlations between maternal and child levels ranged 0.38-0.55 (p<0.01). Maternal hair metal levels were the strongest predictors of metal concentrations in children's hair. Girls had significantly lower As levels than boys (p<0.01) but did not differ on other metals. In addition, in bivariate logistic regressions predicting the likelihood that the child would be exposed to multiple metals, hemoglobin <10.5. g/dL (OR=2.12, p<0.05), blood lead (OR=1.17, p<0.01), and the mother being exposed to two or more metals (OR=3.34, p<0.01) were identified as significant predictors of increased likelihood of multiple metal exposure. Older child age (OR=0.96, p<0.05), higher maternal education (OR=0.35, p<0.01), and higher number of household possessions (OR=0.83, p<0.01) were significantly associated with decreased likelihood of multiple metal exposure. Preschool children in Uruguay are exposed to multiple metals at levels that in other studies have been associated with cognitive and behavioral deficits. Sources of exposure, as well as cognitive and behavioral consequences of multiple metal exposure, should be investigated in this population.