Patrick Levallois

Laval University, Quebec City, Quebec, Canada

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Publications (98)356.9 Total impact

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    ABSTRACT: Introduction: Past research have shown that people living in deprived areas are more frequently exposed to higher levels of environmental pollution. Additionally, few studies have shown that inequalities in exposure to drinking water pollutants could also occur. The project aims to explore the issue of social inequalities in exposure to three common drinking water contaminants in rural areas of Québec, Canada. Methods: Data from 593 rural municipalities over the period 2004-2008 were considered. An ecological composite Canadian material deprivation index was used as a proxy of socioeconomic status for each municipality. Total trihalomethanes (TTHMs), lead and nitrates, which presence in water could be potentially harmful for human health, were chosen as indicators of drinking water quality. Poisson regression and multilevel linear models with random effects were conducted to estimate the associations between drinking water contaminants and material deprivation. Results: Deprived municipalities uses simpler treatment techniques (chlorination only) than the wealthiest ones (advanced treatment). The proportion of municipalities with lead >5µg/L and TTHMs >80µg/L in water is the highest in the most deprived ones. Moreover, most deprived municipalities have an higher risk of having elevated tap lead levels (RR=1.33, 95%CI: 1.30-1.36). Conversely, most deprived municipalities have a lower risk of having high TTHMs levels (RR=0.78, 95%CI: 0.69-0.86) and nitrates levels (RR=0.83, 95%CI: 0.80-0.87). Discussion: Exposure to drinking water contaminants could vary according to socioeconomic status in rural areas of Québec, Canada. These findings suggest an environmental inequality in drinking water contaminants distribution and support the promotion of policies aiming to reduce exposure to chemical contaminants in water of rural municipalities. Further research should focus on the analysis of different levels of rurality and on drinking water exposure inequalities in urban areas.
    No preview · Conference Paper · Sep 2015
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    ABSTRACT: Few studies have assessed social inequalities in exposure to drinking water contaminants. This study explores this issue in 593 rural municipalities of Québec, Canada. Quartiles of an ecological composite deprivation index were used as a proxy of socioeconomic status. Total trihalomethanes (TTHMs) and lead were chosen as proxies of chemical drinking water quality. The results show that the majority of deprived rural municipalities apply no treatment to their water (26%) or use a basic treatment (51%), whereas a relative majority of the wealthiest municipalities (40%) use advanced treatment. The proportion of municipalities having important lead (>5µg/L) levels is highest in most deprived municipalities. Moreover, most deprived municipalities have a higher risk of high tap lead levels (RR=1.33; 95%CI: 1.30, 1.36). Conversely, most deprived municipalities have a lower risk of high TTHMs levels (RR=0.78; 95%CI: 0.69, 0.86). These findings suggest an environmental inequality in drinking water contaminants distribution in rural municipalities.
    Full-text · Article · Aug 2015 · Environmental Pollution
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    ABSTRACT: 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. To estimate the relation between a cumulative water Pb exposure index (CWLEI) and blood Pb levels (BPb) in children aged 1 to 5 years. Between September 10, 2009 and March 27, 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 June 22, 2011 and September 6, 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. 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 bw) 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. In children aged 1 to 5 years, 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.
    No preview · Article · Jun 2015 · Environmental Health Perspectives
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    ABSTRACT: Inorganic arsenic and its metabolites are considered dangerous to human health. Although several studies have reported associations between low-level arsenic exposure and diabetes mellitus in the United States and Mexico, this association has not been studied in the Canadian population. We evaluated the association between arsenic exposure, as measured by total arsenic concentration in urine, and the prevalence of type 2 diabetes (T2D) in 3151 adult participants in Cycle 1 (2007-2009) of the Canadian Health Measures Survey (CHMS). All participants were tested to determine blood glucose and glycated hemoglobin. Urine analysis was also performed to measure total arsenic. In addition, participants answered a detailed questionnaire about their lifestyle and medical history. We assessed the association between urinary arsenic levels and T2D and prediabetes using multivariate logistic regression while adjusting for potential confounders. Total urinary arsenic concentration was positively associated with the prevalence of T2D and prediabetes: adjusted odds ratios were 1.81 (95% CI: 1.12-2.95) and 2.04 (95% CI: 1.03-4.05), respectively, when comparing the highest (fourth) urinary arsenic concentration quartile with the lowest (first) quartile. Total urinary arsenic was also associated with glycated hemoglobin levels in people with untreated diabetes. We found significant associations between arsenic exposure and the prevalence of T2D and prediabetes in the Canadian population. Causal inference is limited due to the cross-sectional design of the study and the absence of long-term exposure assessment.
    No preview · Article · Jun 2015
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    ABSTRACT: The presence of chemical compounds formed as disinfection by-products (DBPs) is widespread in developed countries, and virtually whole populations are exposed to these chemicals through ingestion, inhalation, or dermal absorption from drinking water and swimming pools. Epidemiological evidence has shown a consistent association between long-term exposure to trihalomethanes and the risk of bladder cancer, although the causal nature of the association is not conclusive. Evidence concerning other cancer sites is insufficient or mixed. Numerous studies have evaluated reproductive implications, including sperm quality, time to pregnancy, menstrual cycle, and pregnancy outcomes such as fetal loss, fetal growth, preterm delivery, and congenital malformation. The body of evidence suggests only minor effects from high exposure during pregnancy on fetal growth indices such as small for gestational age (SGA) at birth. Populations highly exposed to swimming pools such as pool workers and professional swimmers show a higher prevalence of respiratory symptoms and asthma, respectively, although the direction of the association, and thus causality, is not clear among professional swimmers. The risk of asthma, wheezing, eczema, and other respiratory outcomes among children attending swimming pools has been the object of extensive research. Early studies suggested a positive association, while subsequent larger studies found no correlations or showed a protective association. Future research should develop methods to evaluate the effects of the DBP mixture and the interaction with personal characteristics (e.g., genetics, lifestyle), clarify the association between swimming pools and respiratory health, evaluate the occurrence of DBPs in low- and middle-income countries, and evaluate outcomes suggested by animal studies that have not been considered in epidemiological investigations
    No preview · Article · Jan 2015
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    ABSTRACT: Past studies have examined the effects of maternal exposure to water chlorination disinfection by-products (DBPs), such as trihalomethanes (THMs) and haloacetic acids (HAAs) during pregnancy. However, no human-based study has yet evaluated the effect of emerging DBPs, such as haloacetaldehydes (HAs) and haloacetonitriles (HANs) on small-for-gestational-age (SGA) status in newborns. This study aims to assess the association between maternal multiroute exposure to HAs and HANs during the third trimester of pregnancy and SGA status at birth, among neonates delivered by women residing in the Quebec City area (Province of Quebec, Canada). We also evaluated the interaction between exposure to these emerging unregulated by-products and regulated DBPs also found in drinking water (THMs and HAAs), for which a positive association with adverse reproductive outcomes has been suggested in previous studies. We conducted a population-based case-control study in the Quebec City area. SGA newborns (n=330) were compared to 1100 controls, with matching based on calendar week of birth. HA and HAN concentrations in drinking water at participant's tap were estimated using spatio-temporal strategy based on bimonthly measurements carried out at several locations in the participant's distribution system. A computer-assisted telephone interview was completed to collect information on individual habits of water consumption and water related activities in order to determine individual multiroute exposure. This enabled us to estimate the dose of HAs and HANs absorbed daily by each participant. Associations between total HA, HAN concentrations in drinking water and SGA were analyzed. Associations between the daily-absorbed doses of these emerging DBPs and SGA were also analyzed. Odds ratios (ORs) comparing the 4th quartile of exposure to the reference group (the first three quartiles) were obtained by means of conditional logistic regression, and controlling for potential confounders. Globally, no evidence of increased risk of SGA was found with total HA and HAN concentrations in tap water when participants in the 4th quartile of exposure were compared to the first three quartiles (OR=1.0; 95% CI [0.7-1.5] and OR=0.8; 95% CI [0.6-1.2], respectively). Similarly, no association was found with the daily-absorbed doses of total HAs or HANs (OR=0.9; 95% CI [0.6-1.3] and OR=1.1; 95% CI [0.7-1.6], respectively). However, a small non statistically significant association was found between the dose of brominated HA and SGA (OR=1.4; 95% CI [0.9-2.1]). Also, in spite of the lack of interaction between other DBP classes, an unexpected negative interaction was observed between concentration of chloral hydrate (CH) (which represents the main HA species), and regulated DBPs (P=0.006). In this population, exposure to low levels of HAs and HANs during the third trimester of pregnancy through drinking water was not associated to SGA status in newborns. Nonetheless, more research is needed to clarify possible effect of brominated compounds and interaction between different DBPs. Copyright © 2015 Elsevier Inc. All rights reserved.
    No preview · Article · Jan 2015 · Environmental Research

  • No preview · Chapter · Jan 2015
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    Gerard Ngueta · Catherine Gonthier · Patrick Levallois
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    ABSTRACT: Objective To estimate the extent of changes in mean BLLs from colder to warmer months, in children aged 1 to 5 years with different status of lead in colder months. Methodology We performed a systematic review using an in-house algorithm developed in MEDLINE, EMBASE, Web of Science, and CINHAL. Search was performed between November, 2012 and July, 2013, and data evaluation and extraction were subsequently conducted. The mean BLLs observed in the warmer months was divided by the one observed in the colder months to obtain the warmer-to-colder ratio (WCR). Study-specific WCRs were pooled using the fixed-effects method of Mantel-Haenszel to estimate the combined WCR. Results From 4,040 papers initially identified, eight cohort studies were considered relevant for inclusion. The combined WCR was inversely related to the BLLs observed during colder months. The values were 1.25 (95% CI: 0.90–1.60), 1.06 (95% CI: 0.92–1.19), and 0.95 (95% CI: 0.51–1.39) for children showing baseline BLLs of < 10 μg dl−1, 10–20 μg dl−1and ≥ 20 μg dl−1, respectively. The combined WCR was influenced neither by children's age nor place/date of study. Conclusion The extent of the summer increase in BLLs depends on the BLLs in the colder months.
    Full-text · Article · Dec 2014 · Journal of Trace Elements in Medicine and Biology
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    G Ngueta · M Prévost · E Deshommes · B Abdous · D Gauvin · P Levallois
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    ABSTRACT: Drinking water represents a potential source of lead exposure. The purpose of the present study was to estimate the magnitude of winter-to-summer changes in household water lead levels (WLLs), and to predict the impact of these variations on BLLs in young children. A study was conducted from September, 2009 to March, 2010 in 305 homes, with a follow-up survey carried out from June to September 2011 in a subsample of 100 homes randomly selected. The first 1-L sample was drawn after 5min of flushing, followed by a further 4 consecutive 1-L samples after 30min of stagnation. Non-linear regression and general linear mixed models were used for modelling seasonal effects on WLL. The batchrun mode of Integrated Exposure Uptake Biokinetic (IEUBK) model was used to predict the impact of changes in WLL on children's blood lead levels (BLLs). The magnitude of winter-to-summer changes in average concentrations of lead corresponded to 6.55μg/L in homes served by lead service lines (LSL+ homes) and merely 0.30μg/L in homes without lead service lines. For stagnant samples, the value reached 10.55μg/L in 'LSL+ homes' and remained very low (0.36μg/L) in 'LSL- homes'. The change in the probability of BLLs ≥5μg/dL due to winter-to-summer changes in WLL was increased from <5% (in winter) to about 20% (in summer) in children aged 0.5-2years. The likelihood of having BLLs ≥5μg/dL in young children during warm months was reduced by at least 40% by flushing tap-water.
    Full-text · Article · Jul 2014 · Environment International
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    ABSTRACT: Background: Hypertension is the leading risk factor for cardiovascular disease, but its cause is not always known. Interest is increasing in the potential role of environmental chemicals, including lead. Data and methods: Data are from the first two cycles of the Canadian Health Measures Survey. Lead in whole blood (PbB), and systolic (SBP) and diastolic (DBP) blood pressure were measured and hypertension status was derived for 4,550 respondents aged 40 to 79. Linear regression estimated associations between PbB and SBP and DBP. Logistic regression estimated associations between PbB and hypertension. Adjusted least squares geometric means of PbB were estimated for hypertensive versus non-hypertensive individuals. Results: Compared with non-hypertensive individuals, those with hypertension had higher average PbB levels, were older, more likely to be male, and more likely to have other hypertension risk factors (diabetes, family history of high blood pressure). In adjusted regression models, a modest association emerged between PbB levels and SBP among 40- to 54-year-olds, and between PbB levels and DBP for the overall population. No association emerged between PbB levels and hypertension prevalence. Interpretation: A modest association was observed between blood lead levels and blood pressure, but not with hypertension, in Canadian adults aged 40 to 79.
    No preview · Article · Jul 2014 · Health reports / Statistics Canada, Canadian Centre for Health Information = Rapports sur la santé / Statistique Canada, Centre canadien d'information sur la santé
  • N Savard · P Levallois · L P Rivest · S Gingras
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    ABSTRACT: We evaluated associations between ecological variables and the risk of very small for gestational age (VSGA) birth in Quebec in 2000-2008. Ecological variables came from the Canadian Community Health Survey, the Canadian census and Quebec's birth registry; individual variables also came from Quebec's birth registry. Odds ratios (ORs) adjusted for mother's age, academic qualification, parity, marital status and country of birth were estimated using multilevel logistic regression (generalized estimating equations method). Births in neighbourhoods with a high proportion of people leading a sedentary lifestyle (OR: 1.07, 95% confidence interval [CI]: 1.01-1.11) and those with a high/middle proportion of residents with food insecurity (OR: 1.09, 95% CI: 1.05-1.15; OR: 1.05, 95% CI: 1.01-1.11) had higher odds of VSGA birth. Those with middle proportion of married residents had lower odds of VSGA birth (OR: 0.94, 95% CI: 0.90-0.98).
    No preview · Article · Feb 2014 · Chronic Diseases and Injuries in Canada
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    ABSTRACT: Drinking water intake of arsenic (As) from private wells may represent a significant exposure pathway and induce oxidative DNA damage. We measured total As concentrations in hair and nails, and concentrations of the different species of As and its metabolites as well as 8-OHdG in urine of 110 non-smoking adults living in a rural region of the Province of Quebec, Canada. Significant differences in exposure biomarker levels were observed between individuals consuming drinking water with As levels of≤1.0,>1.0 -≤10 and>10 μg/l. Multivariate linear regression analysis also showed a significant relationship between estimated daily drinking water intakes of As and biomarker levels. Conversely, 8-OHdG levels were not significantly related to daily drinking water intakes of As or to hair, nail or urinary exposure biomarker levels, according to multivariate linear regression analysis. Even at the relatively low levels of As found in well water of our participants, water consumption significantly increases their body load of As, as confirmed by multiple matrix measurements, which reflected exposure over different time frames. However, this increased internal As dose was not associated with higher oxidative damage to DNA as reflected by urinary 8-OHdG levels.Journal of Exposure Science and Environmental Epidemiology advance online publication, 6 November 2013; doi:10.1038/jes.2013.80.
    Full-text · Article · Nov 2013 · Journal of Exposure Science and Environmental Epidemiology
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    ABSTRACT: Childhood nonviral gastroenteritis is a priority for various public health authorities. Given that waterborne transmission is sometimes incriminated during investigation of gastroenteritis outbreaks, the authors hypothesized that watershed characteristics may influence the occurrence of this disease and could contribute additional insights for better prevention and control. The study described here aimed to investigate watershed characteristics in relation to nonviral gastroenteritis and specifically three bacterial and parasitic forms of childhood gastroenteritis to assess their relative importance in the province of Quebec, Canada. Information on children aged 0-4 years with bacterial or parasitic enteric infections reported through ongoing surveillance between 1999 and 2006 in the province of Quebec was collected. Factors measured at the municipal and watershed levels were analyzed using multilevel models with a Poisson distribution and log link function. Childhood nonviral gastroenteritis, giardiasis, and campylobacteriosis were positively associated with small ruminants and cattle density. Childhood salmonellosis was positively associated with cattle density. Also, childhood campylobacteriosis incidence was positively associated with larger watershed agricultural surface. In addition to local agroenvironmental factors, this analysis revealed an important watershed effect.
    No preview · Article · Oct 2013 · Journal of environmental health
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    ABSTRACT: Diverse fecal and nonfecal bacterial contamination and nutrient sources (e.g. agriculture, human activities and wildlife) represent a considerable non-point source load entering natural recreational waters which may adversely affect water quality. Monitoring of natural recreational water microbial quality is most often based mainly on testing a set of microbiological indicators. The cost and labour involved in testing numerous water samples may be significant when a large number of sites must be monitored repetitively over time. In addition to water testing, ongoing monitoring of key environmental factors known to influence microbial contamination may be carried out as an additional component. Monitoring of environmental factors can now be performed using remote sensing technology which represents an increasingly recognized source of rigorous and recurrent data, especially when monitoring over a large or difficult to access territory is needed. To determine whether this technology could be useful in the context of recreational water monitoring, we evaluated a set of agroenvironmental determinants associated with fecal contamination of recreational waters through a multivariable logistic regression model built with data extracted from satellite imagery. We found that variables describing the proportions of land with agricultural and impervious surfaces, as derived from remote sensing observations, were statistically associated (odds ratio, OR = 11 and 5.2, respectively) with a higher level of fecal coliforms in lake waters in the southwestern region of Quebec, Canada. From a technical perspective, remote sensing may provide important added-value in the monitoring of microbial risk from recreational waters and further applications of this technology should be investigated to support public health risk assessments and environmental monitoring programs relating to water quality.
    No preview · Article · Apr 2013 · Water Science & Technology
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    ABSTRACT: The spatiotemporal presence of eight N-nitrosamines in the water of seven supply systems in Quebec considered to be susceptible to these emerging disinfection by-products was evaluated. This is the first study on the presence of N-nitrosamines in drinking water utilities in Quebec. Seven sampling campaigns were carried out at several sampling points in each of the systems over a period of 1 year. The results show that N-nitrosamines, primarily N-nitrosodimethylamine (NDMA), were not commonly detected in the water of the facilities under study (10 % of samples). The concentrations measured were lower than those reported in recent North American studies. None of the 195 samples taken exceeded the Ontario standard of 9 ng/L for NDMA (maximum value observed of 3.3 ng/L). N-nitrosomethylethylamine and N-nitrosopiperidine were detected once, with concentrations of 3.7 and 6.0 ng/L, respectively. Chloramination was identified as being the main risk factor regarding the presence of N-nitrosamines, but water quality and some operating parameters, in particular disinfectant residual, also seem to be related to their presence. NDMA concentrations at the end of the distribution systems were generally higher than water leaving the plant. No seasonal trends were observed for the formation of N-nitrosamines in the investigated supply systems. Finally, an association between the presence of N-nitrosamines and the levels of trihalomethanes and haloacetic acids was observed in some facilities.
    No preview · Article · Feb 2013 · Environmental Monitoring and Assessment
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    ABSTRACT: Dwellings with/without a lead service line [LSL] were sampled for lead in tap water in Montreal, during different seasons. Short-term simulations using these results and the batchrun mode of the Integrated Exposure Uptake Biokinetic (IEUBK) model showed that children's exposure to lead at the tap in the presence of an LSL varies seasonally, and according to the type of dwelling. From July to March, for single-family homes, the estimated geometric mean [GM] blood lead level [BLL] decreased from 2.3-3.6 μg/dL to 1.5-2.5 μg/dL, depending on the children's age. The wide seasonal variations in lead exposure result in a minimal fraction (0-6%) of children with a predicted BLL >5 μg/dL in winter, as opposed to a significant proportion (5-25%) in summer. These estimations are in close agreement with the BLLs measured in Montreal children in fall and winter, and simulations using summer water lead levels illustrate the importance of measuring BLLs during the summer. Finally, simulations for wartime residences with long LSLs confirm the need to prioritize the control of this lead exposure from tap water.
    No preview · Article · Feb 2013 · Water Research
  • P Levallois · P Chevalier · S Gingras · P Déry · P Payment · P Michel · M Rodriguez
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    ABSTRACT: This study was designed to evaluate the epidemiology of severe gastroenteritis in children living in Québec rural areas with intensive livestock activities. From September 2005 through June 2007, 165 cases of gastroenteritis in children aged from 6 months to 5 years, hospitalized or notified to the public health department were enrolled, and 326 eligible controls participated. The parents of cases and controls were asked questions about different gastroenteritis risk factors. The quality of the drinking water used by the participants was investigated for microbial indicators as well as for four zoonotic bacterial pathogens (Campylobacter spp, Escherichia coli, Salmonella spp and Yersinia spp) and two enteric parasites (Cryptosporidium spp and Giardia spp). From 134 stool specimen analysed, viruses were detected in 82 cases (61%), while 28 (21%) were found with at least one of the bacteria investigated, and five cases were infected by parasites. Campylobacteriosis was the main bacterial infection (n = 15), followed by Salmonella sp (n = 7) and E. coli O157:H7 (n = 5) among cases with bacterial gastroenteritis. No significant difference was found between cases and controls regarding the quality of water consumed; the frequency of faecal contamination of private wells was also similar between cases and controls. Considering the total cases (including those with a virus), no link was found between severe gastroenteritis and either being in contact with animals or living in a municipality with the highest animal density (4th quartile). However, when considering only cases with a bacterial or parasite infection (n = 32), there was a weak association with pig density that was not statistically significant after adjusting for potential confounders. Contact with domestic, zoo or farm animals were the only environmental factor associated with the disease.
    No preview · Article · Feb 2013 · Zoonoses and Public Health
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    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/ft(2) 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.Journal of Exposure Science and Environmental Epidemiology advance online publication, 30 January 2013; doi:10.1038/jes.2012.129.
    Full-text · Article · Jan 2013 · Journal of Exposure Science and Environmental Epidemiology
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    ABSTRACT: Safe drinking water is essential for wellbeing. Although microbiological contamination remains the largest cause of water-related morbidity and mortality globally, chemicals in water supplies may also cause disease, and evidence of the human health consequences is limited or lacking for many of them. We aimed to summarize the state of knowledge, identify gaps in understanding, and provide recommendations for epidemiological research relating to chemicals occurring in drinking water. The assessment of exposure and the health consequences of chemicals in drinking water is challenging. Exposures are typically at low concentrations, measurements in water are frequently insufficient, chemicals are present in mixtures, exposure periods are usually long, multiple exposure routes may be involved, and valid biomarkers reflecting the relevant exposure period are scarce. In addition, the magnitude of the relative risks tends to be small. Research should include well designed epidemiological studies covering regions with contrasting contaminant levels and sufficient sample size; comprehensive evaluation of contaminant occurrence in combination with bioassays integrating the effect of complex mixtures; sufficient numbers of measurements in water to evaluate geographical and temporal variability; detailed information on personal habits resulting in exposure (e.g., ingestion, showering, swimming, diet); collection of biological samples to measure relevant biomarkers; and advanced statistical models to estimate exposure and relative risks, considering methods to address measurement error. Lastly, the incorporation of molecular markers of early biological effects and genetic susceptibility is essential to understand the mechanisms of action. There is a particular knowledge gap and need to evaluate human exposure and risks of a wide range of emerging contaminants.
    Preview · Article · Jan 2013 · Environmental Health Perspectives
  • Marc Rhainds · Patrick Levallois
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    ABSTRACT: The purposes of this study were to determine the umbilical cord blood lead levels in a nonindustrialized city and the effect of place of residence on the blood lead levels of newborns. During spring 1990, we conducted a survey of umbilical cord blood lead levels from 823 live newborns in two hospitals from the Québec City area. The geometric mean of cord blood lead levels was 0.094 mumol/l (95% confidence interval [95% CI] = 0.088-0.099). Less than 1% (95% CI = 0.2-1.7) of the babies had cord blood lead levels at 0.48 mumol/l or greater. We estimate that each year in the Québec City area between 150 and 200 newborns are at risk for developing psychoneurological problems during their first years of life. Frequency distribution of cord blood lead level did not differ significantly among urban, suburban, and rural areas; however, a higher proportion of cord blood lead levels greater than 0.25 mumol/l was observed in the urban area (9.4%), compared with suburban (2.6%) and rural (3.1%) areas. The proximity of potential environmental lead sources (highway, industry, city center) located within 1/2 mile (.8 km) of the mother's residence was associated with a high cord blood lead level. Cord blood lead levels were also elevated for newborns whose mothers lived in newer (< or = 5 y) and older buildings (> or = 50 y). We concluded that the environmental characteristics of the mother's residence are a better indicator of environmental lead exposure than the place of residence.(ABSTRACT TRUNCATED AT 250 WORDS)
    No preview · Article · Dec 2012 · Archives of Environmental Health An International Journal

Publication Stats

2k Citations
356.90 Total Impact Points


  • 1995-2015
    • Laval University
      • • Department of Social and Preventive Medicine
      • • Department of Medicine
      Quebec City, Quebec, Canada
    • Institut National de Santé Publique du Québec (INSPQ)
      Quebec City, Quebec, Canada
  • 2014
    • CHU de Québec
      Quebec City, Quebec, Canada
  • 2006
    • Université de Montréal
      Montréal, Quebec, Canada
    • Health Canada
      Ottawa, Ontario, Canada
  • 1998-2005
    • Université du Québec
      Québec, Quebec, Canada
  • 1998-2004
    • Centre Hospitalier Universitaire de Québec (CHUQ)
      Quebec City, Quebec, Canada
  • 2003
    • Environment Canada
      Montréal, Quebec, Canada
  • 1997
    • Pacific Northwest National Laboratory
      Ричленд, Washington, United States
  • 1994
    • Centre Hospitalier de Laval
      Лаваль, Pays de la Loire, France