Background: Drinking water is recognized as a source of lead (Pb) exposure. However, questions remain about the impact of chronic exposure to lead-contaminated water on internal dose.

Objective: Our goal was to estimate the relation between a cumulative water Pb exposure index (CWLEI) and blood Pb levels (BPb) in children 1–5 years of ages.

Methods: Between 10 September 2009 and 27 March 2010, individual characteristics and water consumption data were obtained from 298 children. Venous blood samples were collected (one per child) and a total of five 1-L samples of water per home were drawn from the kitchen tap. A second round of water collection was performed between 22 June 2011 and 6 September 2011 on a subsample of houses. Pb analyses used inductively coupled plasma mass spectroscopy. Multiple linear regressions were used to estimate the association between CWLEI and BPb.

Results: Each 1-unit increase in CWLEI multiplies the expected value of BPb by 1.10 (95% CI: 1.06, 1.15) after adjustment for confounders. Mean BPb was significantly higher in children in the upper third and fourth quartiles of CWLEI (0.7–1.9 and ≥ 1.9 μg/kg of body weight) compared with the first (< 0.2 μg/kg) after adjusting for confounders (19%; 95% CI: 0, 42% and 39%; 95% CI: 15, 67%, respectively). The trends analysis yielded a p -value < 0.0001 after adjusting for confounders suggesting a dose–response relationship between percentiles of CWLEI and BPb.

Conclusions: In children 1–5 years of age, BPb was significantly associated with water lead concentration with an increase starting at a cumulative lead exposure of ≥ 0.7 μg Pb/kg of body weight. In this age group, an increase of 1 μg/L in water lead would result in an increase of 35% of BPb after 150 days of exposure.

Citation: Ngueta G, Abdous B, Tardif R, St-Laurent J, Levallois P. 2016. Use of a cumulative exposure index to estimate the impact of tap water lead concentration on blood lead levels in 1- to 5-year-old children (Montreal, Canada). Environ Health Perspect 124:388–395; http://dx.doi.org/10.1289/ehp.1409144

Address correspondence to P. Levallois, Institut National de Santé Publique de Québec, 945, Rue Wolfe, Québec, Qc. Canada, G1V 5B3. Telephone: 1 (418) 650-5115, ext. 5216. E-mail address: Patrick.Levallois@msp.ulaval.ca

We thank M. Prévost, A. Trudelle, D. Gauvin, C. Campagna, S. Nour, F. Lemieux, and M. D’Amour for their contribution to the study and for their useful comments on previous versions of the paper.

The initial study was funded by the Canadian Water Network (CWN), Health Canada, and the Ministère de la santé et des services sociaux du Québec (Quebec, Canada). The water follow-up study was funded by the Ministère du Développement durable, de l’Environnement et de la Lutte contre les changements climatiques (Quebec, Canada).

The authors declare they have no actual or potential competing financial interests.

Received: 28 August 2014 Accepted: 12 June 2015 Advance Publication: 16 June 2015 Final Publication: 1 March 2016

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