High blood lead levels are associated with lead concentrations in households and day care centers attended by Brazilian preschool children.

ABSTRACT

BACKGROUND: A previous study observed high blood lead levels (BLL) in preschool children attending 50 day care centers (DCC) in São Paulo, Brazil. OBJECTIVE: To identify whether lead levels found in both homes and DCC environments are associated with high blood lead levels. METHODS: Children attending 4 DCCs, quoted here as NR, VA, PS and PF, were divided into two groups according to BLL high exposure (HE ≥13.9 µg/dL; 97.5 percentile of the 2013 year sample) and low exposure (LE <5 µg/dL). For in situ lead measurements (lead paint mode mg/cm2 and ROHS mode µg/g) in the children's households and in the DCC environments, a field portable X-ray-fluorescence analyzer was used. Multiple logistic regressions were performed to control for confounding factors. Odds ratios were adjusted for age, sex, day care center's measured lead, and tobacco. RESULTS: In an NR DCC building, 33.8% of the measurements had lead levels >600 µg/g, whereas such levels were observed in 77.1% of NR playground measurements. In VA DCC, 22% and 23% of the measurements in the building and in the playgrounds had levels higher than 600 µg/g, respectively. The percentage of high lead levels in the children's houses of the LE group was 5.9% (95% CI 4.3-7.6%) and 13.2 (95% CI 8.3-18.0%) in the HE group. Moreover, a significant association was found between high BLLs and lead levels found both in households and DCCs (p < 0.001). Most of the high lead measurements were found in tiles and playground equipment. CONCLUSIONS: Lead exposure estimated from the DCCs, where children spend about 10 h/day, can be as relevant as their household exposure. Therefore, public authorities should render efforts to provide a rigorous surveillance for lead-free painting supplies and for all objects offered to children.