No abstract

No abstract

Lead is neurotoxic at very low dose and there is a need to better characterize the impact of domestic sources of lead on the biological exposure of young children. A cross-sectional survey evaluated the contribution of drinking water, house dust and paint to blood lead levels (BLLs) of young children living in old boroughs of Montréal (Canada). Three hundred and six children aged 1 to 5 years and currently drinking tap water participated in the study. For each participant, residential lead was measured in kitchen tap water, floor dust, windowsill dust and house paint and a venous blood sample was analyzed. Multivariate logistic regression was used to evaluate the association between elevated BLL in the children (≥ 75th percentile) and indoor lead contamination by means of odds ratios (OR) using 95% confidence intervals (CI). There was an association between BLL ≥75th percentile (1.78 μg/dL) and water lead when the mean water concentration was >3.3 μg/L: adjusted OR=4.7 (95% CI: 2.1–10.2). Windowsill dust loading >14.1 μg/ft2 was also associated with BLL ≥1.78 μg/dL: adjusted OR=3.2 (95% CI: 1.3–7.8). Despite relatively low BLLs, tap water and house dust lead contribute to an increase of BLLs in exposed young children.

The impact of lead on neurodevelopmental effects in children even at low levels of exposure is well established. Population and toxicokinetic modeling studies have found a clear relationship between water lead levels and blood lead levels in children at low levels of lead in drinking water. Various mitigation strategies can lower lead levels in water. The importance of drinking water as a contributor to total lead exposure depends on water lead levels and the amount consumed, as well as the relative contribution of other sources. Efforts should be made to reduce lead exposure for all sources, including drinking water, considering that no threshold level of exposure exists for the neurodevelopmental effects of lead in children.

No abstract