Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. 
Clinical Pharmacist and Master’s student in Clinical Pharmacy with research interests in pharmacovigilance, behavioral interventions in mental health, and AI applications in clinical decision support. Experience includes digital health research with Bloomsbury Health (London) and pharmacovigilance practice in patient support programs. Published work covers drug awareness among healthcare providers, postpartum depression management, and patient safety reporting. What was studied?
This original research article investigated the impact of lead exposure from domestic sources, specifically drinking water, indoor dust, and paint, on blood lead levels (BLLs) in young children aged 1–5 years in Montréal, Québec, Canada. The focus keyphrase, “impact of drinking water, indoor dust and paint on blood lead levels,” is central to this study. The research aimed to quantify the contribution of each source to children’s BLLs in homes with potential lead service lines and older construction, where such exposures are plausible. By conducting a cross-sectional survey, the researchers simultaneously evaluated BLLs and environmental lead contamination in the home, using rigorous sampling and laboratory analysis protocols for water, dust, and paint. Multivariate logistic regression was employed to assess the association between elevated BLLs (≥75th percentile; 1.78 µg/dL) and environmental lead levels, adjusting for confounders like age, ethnicity, parental education, season, and behaviors relevant to lead exposure.
Who was studied?
The study population consisted of 306 children, aged 1 to 5 years, living in four selected boroughs of Montréal. Families were randomly chosen from a health database, targeting homes likely to have lead service lines and older infrastructure. Only one child per family participated, and eligibility required that the child regularly consumed tap water, was born in Canada, lived in the current dwelling for at least one year, and did not spend significant time outside the home. Exclusion criteria included use of water filtration devices, residence in large multi-unit buildings, or severe illness. The sample reflected a majority of Caucasian children, with high rates of parental university education and home ownership. Data were collected during the fall and winter seasons, and parents completed detailed interviews on risk factors and child behaviors, such as pica and daycare attendance.
Most important findings
| Critical Points | Details |
|---|---|
| Drinking Water Impact | Children exposed to mean kitchen tap water lead concentrations >3.27 µg/L had significantly higher odds (adjusted OR 4.66; 95% CI: 2.12–10.24) of elevated BLLs (≥1.78 µg/dL), even though most water samples were below local regulatory limits. The association was robust across different sampling protocols and seasons, highlighting the persistent influence of low-level water lead contamination on child BLLs. |
| Indoor Dust Impact | Elevated windowsill dust lead loadings (>14.14 µg/ft²) were also associated with increased odds (adjusted OR 3.22; 95% CI: 1.33–7.79) of BLLs ≥1.78 µg/dL. Floor dust showed a weaker, non-significant association after adjusting for other sources, indicating windowsill dust as a more critical contributor. |
| Paint Impact | While high lead concentrations in paint chips (>5,000 mg/kg) initially appeared associated with elevated BLLs, this relationship lost statistical significance after adjusting for water and dust exposures, probably due to interrelated contamination pathways (e.g., leaded paint contributing to dust). Nonetheless, leaded paint remains a potential risk, particularly in older homes. |
| Low Overall BLLs | The geometric mean BLL among participants was 1.35 µg/dL, with only one case exceeding Québec’s notification level (10 µg/dL). Despite generally low BLLs, measurable increases were linked to domestic exposures, underscoring that no safe threshold for lead exists. |
| Sociodemographic Effects | Children from visible minority groups and those whose parents lacked a university degree had higher BLLs. Seasonal differences were observed, with higher BLLs in the fall compared to winter. These factors must be considered in risk assessments and interventions. |
Key implications
This study demonstrates that even low-level lead contamination in drinking water and indoor windowsill dust measurably increases blood lead levels in young children. For heavy metal certification programs, the findings highlight the necessity of rigorous testing and control for all potential household sources, including water in older homes with lead service lines, to protect sensitive populations.
Citation
Levallois, P., St-Laurent, J., Gauvin, D., Courteau, M., Prévost, M., Campagna, C., Lemieux, F., Nour, S., D’Amour, M., & Rasmussen, P. E. (2014). The impact of drinking water, indoor dust and paint on blood lead levels of children aged 1–5 years in Montréal (Québec, Canada).Journal of Exposure Science and Environmental Epidemiology, 24(2), 185–191. https://doi.org/10.1038/jes.2012.129
