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Benmarhnia, T, Kaufman JS.  In Press.  When evidence of heat-related vulnerability depends on the contrast measure. International Journal of Biometeorology .
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Benmarhnia, T, Deguen S, Kaufman JS, Smargiassi A.  2015.  Vulnerability to heat-related mortality a systematic review, meta-analysis, and meta-regression analysis. Epidemiology. 26:781-793.   10.1097/EDE.0000000000000375   AbstractWebsite

Background: Addressing vulnerability to heat-related mortality is a necessary step in the development of policies dictated by heat action plans. We aimed to provide a systematic assessment of the epidemiologic evidence regarding vulnerability to heat-related mortality.Methods: Studies assessing the association between high ambient temperature or heat waves and mortality among different subgroups and published between January 1980 and August 2014 were selected. Estimates of association for all the included subgroups were extracted. We assessed the presence of heterogeneous effects between subgroups conducting Cochran Q tests. We conducted random effect meta-analyses of ratios of relative risks (RRR) for high ambient temperature studies. We performed random effects meta-regression analyses to investigate factors associated with the magnitude of the RRR.Results: Sixty-one studies were included. Using the Cochran Q test, we consistently found evidence of vulnerability for the elderly ages >85 years. We found a pooled RRR of 0.99 (95% confidence interval [CI] = 0.97, 1.01) for male sex, 1.02 (95% CI = 1.01, 1.03) for age >65 years, 1.04 (95% CI = 1.02, 1.07) for ages >75 years, 1.03 (95% CI = 1.01, 1.05) for low individual socioeconomic status (SES), and 1.01 (95% CI = 0.99, 1.02) for low ecologic SES.Conclusions: We found strongest evidence of heat-related vulnerability for the elderly ages >65 and >75 years and low SES groups (at the individual level). Studies are needed to clarify if other subgroups (e.g., children, people living alone) are also vulnerable to heat to inform public health programs.

Benmarhnia, T, Sottile MF, Plante C, Brand A, Casati B, Fournier M, Smargiassi A.  2014.  Variability in Temperature-Related Mortality Projections under Climate Change. Environmental Health Perspectives. 122:1293-1298.   10.1289/ehp.1306954   AbstractWebsite

Background: Most studies that have assessed impacts on mortality of future temperature increases have relied on a small number of simulations and have not addressed the variability and sources of uncertainty in their mortality projections.Objectives: We assessed the variability of temperature projections and dependent future mortality distributions, using a large panel of temperature simulations based on different climate models and emission scenarios.Methods: We used historical data from 1990 through 2007 for Montreal, Quebec, Canada, and Poisson regression models to estimate relative risks (RR) for daily nonaccidental mortality in association with three different daily temperature metrics (mean, minimum, and maximum temperature) during June through August. To estimate future numbers of deaths attributable to ambient temperatures and the uncertainty of the estimates, we used 32 different simulations of daily temperatures for June-August 2020-2037 derived from three global climate models (GCMs) and a Canadian regional climate model with three sets of RRs (one based on the observed historical data, and two on bootstrap samples that generated the 95% CI of the attributable number (AN) of deaths). We then used analysis of covariance to evaluate the influence of the simulation, the projected year, and the sets of RRs used to derive the attributable numbers of deaths.Results: We found that < 1% of the variability in the distributions of simulated temperature for June-August of 2020-2037 was explained by differences among the simulations. Estimated ANs for 2020-2037 ranged from 34 to 174 per summer (i.e., June-August). Most of the variability in mortality projections (38%) was related to the temperature-mortality RR used to estimate the ANs.Conclusions: The choice of the RR estimate for the association between temperature and mortality may be important to reduce uncertainty in mortality projections.

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Heo, S, Nori-Sarma A, Lee K, Benmarhnia T, Dominici F, Bell ML.  2019.  The use of a quasi-experimental study on the mortality effect of a heat wave warning system in Korea. International Journal of Environmental Research and Public Health. 16   10.3390/ijerph16122245   AbstractWebsite

Many cities and countries have implemented heat wave warning systems to combat the health effects of extreme heat. Little is known about whether these systems actually reduce heat-related morbidity and mortality. We examined the effectiveness of heat wave alerts and health plans in reducing the mortality risk of heat waves in Korea by utilizing the discrepancy between the alerts and the monitored temperature. A difference-in-differences analysis combined with propensity score weighting was used. Mortality, weather monitoring, and heat wave alert announcement data were collected for 7 major cities during 2009-2014. Results showed evidence of risk reduction among people aged 19-64 without education (-0.144 deaths/1,000,000 people, 95% CI: -0.227, -0.061) and children aged 0-19 (-0.555 deaths/1,000,000 people, 95% CI: -0.993, -0.117). Decreased cardiovascular and respiratory mortality was found in several subgroups including single persons, widowed people, blue-collar workers, people with no education or the highest level of education (university or higher). No evidence was found for decreased all-cause mortality in the population (1.687 deaths/1,000,000 people per day; 95% CI: 1.118, 2.255). In conclusion, heat wave alerts may reduce mortality for several causes and subpopulations of age and socio-economic status. Further work needs to examine the pathways through which the alerts impact subpopulations differently.

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Cartier, Y, Benmarhnia T, Brousselle A.  2015.  Tool for assessing health and equity impacts of interventions modifying air quality in urban environments. Evaluation and Program Planning. 53:1-9.   10.1016/j.evalprogplan.2015.07.004   AbstractWebsite

Background: Urban outdoor air pollution (AP) is a major public health concern but the mechanisms by which interventions impact health and social inequities are rarely assessed. Health and equity impacts of policies and interventions are questioned, but managers and policy agents in various institutional contexts have very few practical tools to help them better orient interventions in sectors other than the health sector. Our objective was to create such a tool to facilitate the assessment of health impacts of urban outdoor AP interventions by non-public health experts.Methods: An iterative process of reviewing the academic literature, brainstorming, and consultation with experts was used to identify the chain of effects of urban outdoor AP and the major modifying factors. To test its applicability, the tool was applied to two interventions, the London Low Emission Zone and the Montreal BIXI public bicycle-sharing program.Results: We identify the chain of effects, six categories of modifying factors: those controlling the source of emissions, the quantity of emissions, concentrations of emitted pollutants, their spatial distribution, personal exposure, and individual vulnerability. Modifiable and non-modifiable factors are also identified. Results are presented in the text but also graphically, as we wanted it to be a practical tool, from pollution sources to emission, exposure, and finally, health effects.Conclusion: The tool represents a practical first step to assessing AP-related interventions for health and equity impacts. Understanding how different factors affect health and equity through air pollution can provide insight to city policymakers pursuing Health in All Policies. (C) 2015 The Authors. Published by Elsevier Ltd.

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Juneau, C, Benmarhnia T, Poulin A, Cote S, Potvin L.  2015.  Socioeconomic position during childhood and physical activity during adulthood: a systematic review. International Journal of Public Health. 60:799-813.   10.1007/s00038-015-0710-y   AbstractWebsite

A growing body of evidence links socioeconomic position early in life and physical activity during adulthood. This systematic review aimed to summarize this evidence.Medline and EMBASE were searched for studies that assessed socioeconomic position before age 18 years and physical activity at age a parts per thousand yen18 years. Studies were rated according to three key methodological quality criteria: (1) was childhood socioeconomic position assessed prospectively? (2) Was socioeconomic position during adulthood included in the statistical analysis? (3) Was a validated instrument used to measure of physical activity?Forty-two publications were included. Twenty-six (61.9 %) found a significant association between socioeconomic position early in life and physical activity during adulthood. Twenty-one studies met at least two methodological quality criteria. Among those, the proportion was higher: 15/21 (71.4 %). Associations were of weak to moderate strength, positive for physical activity during leisure time, and negative for transports and work.The bulk of the evidence supports the notion that there is a life course association between socioeconomic position early in life and physical activity during adulthood. Studies using more rigorous methodology supported this conclusion more consistently.

Schwarz, L, Benmarhnia T, Laurian L.  2015.  Social Inequalities Related to Hazardous Incinerator Emissions: An Additional Level of Environmental Injustice. Environmental Justice. 8:213-219.   10.1089/env.2015.0022   AbstractWebsite

Environmental justice (EJ) research focuses on disproportionate population exposures to multiple point and non-point pollution sources. The hazardous pollutants released by waste incinerators can contribute to uneven (or unjust) spatial and social distributions of environmental risks. The EJ literature has already revealed that the geographical distribution of incinerators generates distinct social inequalities. In the French context, these inequalities are evident when considering the proportion of unemployed people, the proportion of recent immigrants and the proportion of persons born abroad (each increases the likelihood that a town hosts an incinerator). In this article, we seek to determine whether additional social injustices occur due to disproportionate quantities of incinerator emissions. We collected annual nitrogen oxide (NOx) emissions from all incinerators in France for 2009-2010. We found that incinerators in French municipalities with higher unemployment and higher proportions of immigrants and persons born abroad have higher NOx emission levels, even when controlling for population size and broader regional social and environmental deprivation indices. This indicates that incinerators in France generate higher social inequalities than initially thought, both due to their spatial distribution and to the amount of emissions they release. We recommend that unequal social impacts should be considered in waste management planning, facility siting decisions, and decisions affecting emission controls for existing and possible future incinerators in France.

Benmarhnia, T, Kihal-Talantikite W, Ragettli MS, Deguen S.  2017.  Small-area spatiotemporal analysis of heatwave impacts on elderly mortality in Paris: A cluster analysis approach. Science of the Total Environment. 592:288-294.   10.1016/j.scitotenv.2017.03.102   AbstractWebsite

Background: Heat-waves have a substantial public health burden. Understanding spatial heterogeneity at a fine spatial scale in relation to heat and related mortality is central to target interventions towards vulnerable communities. Objectives: To determine the spatial variability of heat-wave-related mortality risk among elderly in Paris, France at the census block level. We also aimed to assess area-level social and environmental determinants of high mortality risk within Paris. Methods: We used daily mortality data from 2004 to 2009 among people aged >65 at the French census block level within Paris. We used two heat wave days' definitions that were compared to non-heat wave days. A Bernoulli cluster analysis method was applied to identify high risk clusters of mortality during heat waves. We performed random effects meta-regression analyses to investigate factors associated with the magnitude of the mortality risk. Results: The spatial approach revealed a spatial aggregation of death cases during heat wave days. We found that small scale chronic PM10 exposure was associated with a 0.02 (95% CI: 0.001; 0.045) increase of the risk of dying during a heat wave episode. We also found a positive association with the percentage of foreigners and the percentage of labor force, while the proportion of elderly people living in the neighborhoodwas negatively associated. We also found that green space density had a protective effect and inversely that the density of constructed feature increased the risk of dying during a heat wave episode. Conclusion: We showed that a spatial variation in terms of heat-related vulnerability exists within Paris and that it can be explained by some contextual factors. This study can be useful for designing interventions targeting more vulnerable areas and reduce the burden of heat waves. (C) 2017 Elsevier B.V. All rights reserved.

Wang, Q, Benmarhnia T, Li CC, Knibbs LD, Bao JZ, Ren M, Zhang HH, Wang SH, Zhang YW, Zhao QG, Huang CR.  2019.  Seasonal analyses of the association between prenatal ambient air pollution exposure and birth weight for gestational age in Guangzhou, China. Science of the Total Environment. 649:526-534.   10.1016/j.scitotenv.2018.08.303   AbstractWebsite

Ambient air pollution has been linked to small for gestational age (SGA); however, the relationship with large for gestational age (ILA) is unclear and very few studies have investigated seasonal effects on the association between air pollution and SGA or LGA. Using birth registry data of 506,000 singleton live births from 11 districts in Guangzhou, China between January 2015 and July 2017, we examined associations between ambient air pollutants (PM2.5, PM10, NO2, SO2, and O-3) and SGA/LGA, and further assessed the modification effect of season. Daily concentrations of air pollutants from 11 monitoring stations were used to estimate district-specific exposures for each participant based on their district of residence during pregnancy. Two-level binary logistic regression models were used to evaluate associations between air pollution and SGA/LGA. Stratified analyses by season and a Cochran Q test were performed to assess the modification of season. Exposure to PM2.5, NO2, SO2, and O-3 was significantly associated with increased risk of SGA, especially for exposure during the second and trimester. For an interquartile range (IQR) increase in PM2.5(6.5 mu g/m(3)), NO2 (12.7 mu g/m(3)), SO2 (2.8 mu g/m(3)) and O-3 (20.8 mu g/m(3)) during the entire pregnancy, SGA risk increased by 2% (OR - 1.02, 95% CI: 1.00-1.04), 8% (OR = 1.08, 95% CI: 1.04-1.12), 2% (OR - 1.02, 95% CI: 1.01-1.03), and 14% (1.14, 1.11-1.17), respectively. A decreased risk of WA was found for PM2.5, PM10, SO2, and O-3 during the first trimester or entire pregnancy. When examined by season, significant associations between air pollutants and SGA were observed for women who conceived during summer or fall, and the patterns were consistent for all pollutants. Our study suggests that conception during different seasons might modify the association between ambient air pollution and SGA. (C) 2018 Elsevier B.V. All rights reserved.

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Benmarhnia, T, Auger N, Stanislas V, Lo E, Kaufman JS.  2015.  The relationship between apparent temperature and daily number of live births in Montreal. Maternal and Child Health Journal. 19:2548-2551.   10.1007/s10995-015-1794-y   AbstractWebsite

Temperature is a hypothesized determinant of early delivery, but seasonal and long term trends, delayed effects of temperature, and the influence of extreme cold temperatures have not yet been addressed. We aim to study the influence of apparent temperature on daily number of births, considering lag structures, seasonality and long term trends.We used daily number of births in conjunction with apparent outdoor temperatures between 1981 and 2010 in Montreal. We used Poisson regression combined with a distributed lag nonlinear model to consider non-linear relationships between temperature and daily number of births across specific lag periods.We found that apparent temperature was associated with the daily number of births in Montreal, with a 1-day delay. We found an increase in births on hot days, and decrease on cold days, both offset by a harvesting effect after 4 and 5 days.This study suggests that the number of births is affected by extreme temperatures. Obstetric and perinatal service providers should be prepared for spikes in the number of births caused by extreme temperatures.

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Benmarhnia, T, Grenier P, Brand A, Fournier M, Deguen S, Smargiassi A.  2015.  Quantifying Vulnerability to Extreme Heat in Time Series Analyses: A Novel Approach Applied to Neighborhood Social Disparities under Climate Change. International Journal of Environmental Research and Public Health. 12:11869-11879.   10.3390/ijerph120911869   AbstractWebsite

Objectives: We propose a novel approach to examine vulnerability in the relationship between heat and years of life lost and apply to neighborhood social disparities in Montreal and Paris. Methods: We used historical data from the summers of 1990 through 2007 for Montreal and from 2004 through 2009 for Paris to estimate daily years of life lost social disparities (DYLLD), summarizing social inequalities across groups. We used Generalized Linear Models to separately estimate relative risks (RR) for DYLLD in association with daily mean temperatures in both cities. We used 30 climate scenarios of daily mean temperature to estimate future temperature distributions (2021-2050). We performed random effect meta-analyses to assess the impact of climate change by climate scenario for each city and compared the impact of climate change for the two cities using a meta-regression analysis. Results: We show that an increase in ambient temperature leads to an increase in social disparities in daily years of life lost. The impact of climate change on DYLLD attributable to temperature was of 2.06 (95% CI: 1.90, 2.25) in Montreal and 1.77 (95% CI: 1.61, 1.94) in Paris. The city explained a difference of 0.31 (95% CI: 0.14, 0.49) on the impact of climate change. Conclusion: We propose a new analytical approach for estimating vulnerability in the relationship between heat and health. Our results suggest that in Paris and Montreal, health disparities related to heat impacts exist today and will increase in the future.

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Bailey, J, Gerasopoulos E, Rojas-Rueda D, Benmarhnia T.  2019.  Potential health and equity co-benefits related to the mitigation policies reducing air pollution from residential wood burning in Athens, Greece. Journal of Environmental Science and Health Part a-Toxic/Hazardous Substances & Environmental Engineering.   10.1080/10934529.2019.1629211   AbstractWebsite

Athens, Greece has been in economic and social crises after the 2008 global recession, resulting in an increase in wood burning as a cheaper method of residential heating in the winter. Reducing wood burning emissions is a source-specific method to address air quality degradation, and indirectly climate change, through instituting policies aimed at human health co-benefits. In this work, we investigate and quantify the potential health co-benefits from policies reducing outdoor particulate matter (PM) pollution from residential wood burning by assessing the pollution conditions during the 2015 calendar year in Athens, Greece, emphasizing vulnerable populations. We conducted a systematic literature search to extract data regarding effective improvements to outdoor PM due to wood burning interventions, and get a range of potential ambient PM reduction estimates regarding realistic benefits from different interventions. We applied a health impact assessment methodology and used existing Athens specific data to calculate the preventable daily average non-accidental deaths associated with reducing PM, additionally considering low and high socioeconomic status (SES) groups. We found that the reduction in outdoor PM concentration showed the potential to benefit lower SES groups as much as 13.5 times more than the high SES group, representing an opportunity for policies to improve not only the health of the total population but also improve environmental equity and health disparities.

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Deguen, S, Petit C, Delbarre A, Kihal W, Padilla C, Benmarhnia T, Lapostolle A, Chauvin P, Zmirou-Navier D.  2015.  Neighbourhood characteristics and long-term air pollution levels modify the association between the short-term nitrogen dioxide concentrations and all-cause mortality in Paris. Plos One. 10   ARTN e013146310.1371/journal.pone.0131463   AbstractWebsite

BackgroundWhile a great number of papers have been published on the short-term effects of air pollution on mortality, few have tried to assess whether this association varies according to the neighbourhood socioeconomic level and long-term ambient air concentrations measured at the place of residence. We explored the effect modification of 1) socioeconomic status, 2) long-term NO2 ambient air concentrations, and 3) both combined, on the association between short-term exposure to NO2 and all-cause mortality in Paris (France).MethodsA time-stratified case-crossover analysis was performed to evaluate the effect of short-term NO2 variations on mortality, based on 79,107 deaths having occurred among subjects aged over 35 years, from 2004 to 2009, in the city of Paris. Simple and double interactions were statistically tested in order to analyse effect modification by neighbourhood characteristics on the association between mortality and short-term NO2 exposure. The data was estimated at the census block scale (n=866).ResultsThe mean of the NO2 concentrations during the five days prior to deaths were associated with an increased risk of all-cause mortality: overall Excess Risk (ER) was 0.94% (95% CI=[0.08;1.80]. A higher risk was revealed for subjects living in the most deprived census blocks in comparison with higher socioeconomic level areas (ER=3.14% (95% CI=[1.4-14.90], p<0.001). Among these deprived census blocks, excess risk was even higher where long-term average NO2 concentrations were above 55.8 mu g/m(3) (the top tercile of distribution): ER=4.84%(95% CI=[1.56;8.24], p for interaction= 0.02).ConclusionOur results show that people living in census blocks characterized by low socioeconomic status are more vulnerable to air pollution episodes. There is also an indication that people living in these disadvantaged census blocks might experience even higher risk following short-term air pollution episodes, when they are also chronically exposed to higher NO2 levels.

Perchoux, C, Nazare JA, Benmarhnia T, Salze P, Feuillet T, Hercberg S, Hess F, Menai M, Weber C, Charreire H, Enaux C, Oppert JM, Simon C.  2017.  Neighborhood educational disparities in active commuting among women: the effect of distance between the place of residence and the place of work/study (an ACTI-Cites study). Bmc Public Health. 17   10.1186/s12889-017-4464-8   AbstractWebsite

Background: Active transportation has been associated with favorable health outcomes. Previous research highlighted the influence of neighborhood educational level on active transportation. However, little is known regarding the effect of commuting distance on social disparities in active commuting. In this regard, women have been poorly studied. The objective of this paper was to evaluate the relationship between neighborhood educational level and active commuting, and to assess whether the commuting distance modifies this relationship in adult women. Methods: This cross-sectional study is based on a subsample of women from the Nutrinet-Sante web-cohort (N = 1169). Binomial, log-binomial and negative binomial regressions were used to assess the associations between neighborhood education level and (i) the likelihood of reporting any active commuting time, and (ii) the share of commuting time made by active transportation modes. Potential effect measure modification of distance to work on the previous associations was assessed both on the additive and the multiplicative scales. Results: Neighborhood education level was positively associated with the probability of reporting any active commuting time (relative risk = 1.774; p < 0.05) and the share of commuting time spent active (relative risk = 1.423; p < 0.05). The impact of neighborhood education was greater at long distances to work for both outcomes. Conclusions: Our results suggest that neighborhood educational disparities in active commuting tend to increase with commuting distance among women. Further research is needed to provide geographically driven guidance for health promotion intervention aiming at reducing disparities in active transportation among socioeconomic groups.

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Schinasi, LH, Benmarhnia T, De Roos AJ.  2018.  Modification of the association between high ambient temperature and health by urban microclimate indicators: A systematic review and meta-analysis. Environmental Research. 161:168-180.   10.1016/j.envres.2017.11.004   AbstractWebsite

Background: Landscape characteristics, including vegetation and impervious surfaces, influence urban micro climates and may lead to within-city differences in the adverse health effects of high ambient temperatures. Objective: Our objective was to quantitatively summarize the epidemiologic literature that assessed microclimate indicators as effect measure modifiers (EMM) of the association between ambient temperature and mortality or morbidity. Methods: We systematically identified papers and abstracted relative risk estimates for hot and cool micro climate indicator strata. We calculated the ratio of the relative risks (RRR) and 95% confidence intervals (95% CI) to assess differences in health effects across strata, and pooled the RRR estimates using random effects meta analyses. Results: Eleven papers were retained. In the pooled analyses, people living in hotter areas within cities (based on land surface temperature or modeled estimates of air temperature) had 6% higher risk of mortality/morbidity compared to those in cooler areas (95% CI: 1.03-1.09). Those living in less vegetated areas had 5% higher risk compared to those living in more vegetated areas (95% CI: 1.00-1.11). Discussion: There is epidemiologic evidence that those living in hotter, and less vegetated areas of cities have higher risk of morbidity or mortality from higher ambient temperature. Further research with improved assessment of landscape characteristics and investigation of the joint effects of physiologic adaptation and landscape will advance the current understanding. Conclusion: This review provides quantitative evidence that intra-urban differences in landscape characteristics and micro-urban heat islands contribute to within-city variability in the health effects of high ambient temperatures.

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Benmarhnia, T, Huang J, Jones C.  In Press.  Lost in Translation: Considering the representation of uncertainty in the presentation of empirical findings in WHO policy statements. International Journal of Health Policy and Management.
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Beck, F, Richard JB, Deutsch A, Benmarhnia T, Pirard P, Roudier C, Peretti-Watel P.  2013.  Knowledge about radon and its associated risk perception in France. Cancer Radiotherapie. 17:744-749.   10.1016/j.canrad.2013.06.044   AbstractWebsite

Purpose. - Radon exposure is a major environmental risk in health. It remains badly known by the general population. It is the second cause of lung cancer, after tobacco smoking. The aim of this cross-sectional general population survey was to describe radon exposure risk knowledge and the socioeconomic factors related to this knowledge.Materials and methods. - The Cancer Barometer survey 2010 questioned the French population about its knowledge of radon as such and as health risk factor. This survey was a two-stage random sampling with computer-assisted telephone interview that was performed from April 3, 2010 to August 7, 2010 on a sample of 3,359 people aged 15 to 75 years old.Results. - Among people aged 15 to 75 years old, only one in five knows that radon is a natural gas coming from the ground. This knowledge is more frequent among people living in an area that is directly concerned by radon, among men and increases with age, with the level of education and the level of income. Radon risk remains still widely underestimated by the general public, including in areas concerned by this risk. When people were confronted with radon exposure, few intended to remedy by improving their home.Conclusion. - The success of prevention initiatives implies the support and the collaboration of various national and local actors. To improve their impact for the prevention of lung cancers, it could be more effective to couple these actions with prevention messages on tobacco. (C) 2013 Societe francaise de radiotherapie oncologique (SFRO). Published by Elsevier Masson SAS. All rights reserved.

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Delpla, I, Benmarhnia T, Lebel A, Levallois P, Rodriguez MJ.  2015.  Investigating social inequalities in exposure to drinking water contaminants in rural areas. Environmental Pollution. 207:88-96.   10.1016/j.envpol.2015.08.046   AbstractWebsite

Few studies have assessed social inequalities in exposure to drinking water contaminants. This study explores this issue in 593 rural municipalities of Quebec, 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 (>5 mu g/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% Cl: 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. (C) 2015 Elsevier Ltd. All rights reserved.

Vijayaraghavan, M, Benmarnhia T, Pierce JP, White MM, Kempster J, Shi YY, Trinidad DR, Messer K.  2018.  Income disparities in smoking cessation and the diffusion of smoke-free homes among US smokers: Results from two longitudinal surveys. Plos One. 13   10.1371/journal.pone.0201467   AbstractWebsite

Background Lower rates of successful quitting among low-income populations in the United States may be from slower dissemination of smoke-free homes, a predictor of cessation. Objectives To explore the role of smoke-free homes in cessation behavior across income levels. Participants Current smokers who were >= 18 years and who participated in the longitudinal 2002-2003 (n = 2801) or 2010-2011 (n = 2723) Tobacco Use Supplements to the Current Population Survey. Measurements We categorized income as multiples of the federal poverty level (FPL) (<300% FPL versus >= 300% FPL). We examined the association of smoke-free homes with 1+day quit attempts and 30+days abstinence at 1-year follow-up. We then conducted a mediation analysis to examine the extent that smoke-free homes contributed to income disparities in 30+days abstinence. Results Between the two surveys, heavy smoking (>= 1 pack/day) declined by 17%, and smoking prevalence declined by 15% among those with higher-incomes (>300%FPL). Although similar in 2002, the prevalence of smoke-free homes was 33% lower among individuals living <300% FPL than those living >= 300% FPL. Although the quit attempt rate was similar, the 30 +days abstinence rate was higher in the 2010-11 cohort than in 2002-3 cohort (20.6% versus 15.5%, p<0.008). Whereas smoking >= 1 pack/ day was associated with lower odds of 30 +days abstinence (Adjusted odds ratio [AOR] 0.7; 95% CI 0.5-0.9), having a higher income (AOR 1.9, 95% CI 1.4-2.6) and a smoke-free home (AOR 1.6, 95% CI 1.2-2.1) were associated with greater odds of 30+day abstinence. Differential changes in smoke-free homes across income groups between the two surveys contributed to 36% (95% CI 35.7-36.3) of the observed income disparity in 30+days abstinence. Conclusions Increasing the diffusion of smoke-free homes among low-income populations may attenuate at least a third of the income disparities in smoking cessation, highlighting the need for interventions to increase adoption of smoke-free homes among low-income households.

Green, H, Bailey J, Schwarz L, Vanos J, Ebi K, Benmarhnia T.  2019.  Impact of heat on mortality and morbidity in low and middle income countries: A review of the epidemiological evidence and considerations for future research. Environmental Research. 171:80-91.   10.1016/j.envres.2019.01.010   AbstractWebsite

Heat waves and high air temperature are associated with increased morbidity and mortality. However, the majority of research conducted on this topic is focused on high income areas of the world. Although heat waves have the most severe impacts on vulnerable populations, relatively few studies have studied their impacts in low and middle income countries (LMICs). The aim of this paper is to review the existing evidence in the literature on the impact of heat on human health in LMICs. We identified peer-reviewed epidemiologic studies published in English between January 1980 and August 2018 investigating potential associations between high ambient temperature or heat waves and mortality or morbidity. We selected studies according to the following criteria: quantitative studies that used primary and/or secondary data and report effect estimates where ambient temperature or heat waves are the main exposure of interest in relation to human morbidity or mortality within LMICs. Of the total 146 studies selected, eighty-two were conducted in China, nine in other countries of East Asia and the Pacific, twelve in South Asia, ten in Sub-Saharan Africa, eight in the Middle East and North Africa, and seven in each of Latin America and Europe. The majority of studies (92.9%) found positive associations between heat and human morbidity/mortality. Additionally, while outcome variables and study design differed greatly, most utilized a time-series study design and examined overall heath related morbidity/mortality impacts in an entire population, although it is notable that the selected studies generally found that the elderly, women, and individuals within the low socioeconomic brackets were the most vulnerable to the effects of high temperature. By highlighting the existing evidence on the impact of extreme heat on health in LMICs, we hope to determine data needs and help direct future studies in addressing this knowledge gap. The focus on LMICs is justified by the lack of studies and data studying the health burden of higher temperatures in these regions even though LMICs have a lower capacity to adapt to high temperatures and thus an increased risk.

Wang, Q, Benmarhnia T, Zhang HH, Knibbs LD, Sheridan P, Li CC, Bao JZ, Ren M, Wang SH, He YL, Zhang YW, Zhao QG, Huang CR.  2018.  Identifying windows of susceptibility for maternal exposure to ambient air pollution and preterm birth. Environment International. 121:317-324.   10.1016/j.envint.2018.09.021   AbstractWebsite

Maternal exposure to ambient air pollution has been associated with preterm birth (PTB), however, entire pregnancy or trimester-specific associations were generally reported, which may not sufficiently identify windows of susceptibility. Using birth registry data from Guangzhou, a megacity of southern China (population -14.5 million), including 469,975 singleton live births between January 2015 and July 2017, we assessed the association between weekly air pollution exposure and PTB in a retrospective cohort study. Daily average concentrations of PM2.5, PM10, NO2, SO2, and O-3 from 11 monitoring stations were used to estimate district-specific exposures for each participant based on their district residency during pregnancy. Distributed lag models (DLMs) incorporating Cox proportional hazard models were applied to estimate the association between weekly maternal exposure to air pollutant and PTB risk (as a time-to-event outcome), after controlling for temperature, seasonally, and individual-level covariates. We also considered moderate PTB (32-36 gestational weeks) and very PTB (28-31 gestational weeks) as outcomes of interest. Hazard ratios (HRs) and 95% confidential intervals (95% CIs) were calculated for an interquartile range (IQR) increase in air pollutants during the study period. An IQR increase in PM2.5 exposure during the 20th to 28th gestational weeks (27.0 mu g/m(3)) was significantly associated with PTB risk, with the strongest effect in the 25th week (HR = 1.034, 95% CI:1.010-1.059). The significant exposure windows were the 19th-28th weeks for PM10, the 18th-31st weeks for NO2, and the 23rd-31A weeks for O-3, respectively. The strongest associations were observed in the 25th week for PM10 (IQR = 37.0 mu g/m(3); HR = 1.048, 95% CI:1.034-1.062), the 26th week for NO2 (IQR = 29.0 mu g/m(3); HR = 1.060, 95% CI:1.028-1.094), and in the 28th week for O-3 (IQR = 90.0 mu g/m(3); HR = 1.063, 95% CI:1.046-1.081). Similar patterns were observed for moderate PTB (32-36 gestational weeks) and very PTB (28-31 gestational weeks) for PM2.5, PM10, NO2 exposure, but the effects were greater for very PTB. We did not observe any association between pregnancy SO2 exposure and the risk of PTB. Our results suggest that middle to late pregnancy is the most susceptible air pollution exposure window for air pollution and PTB among women in Guangzhou, China.

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Chyderiotis, S, Beck F, Andler R, Hitchman SC, Benmarhnia T.  2019.  How to reduce biases coming from a before and after design: the impact of the 2007-08 French smoking ban policy. European Journal of Public Health. 29:372-377.   10.1093/eurpub/cky160   AbstractWebsite

Background: Smoke-free laws aim at protecting against second-hand smoke and at contributing to change smoking behaviors. Impact evaluation studies can help understand to what extent they reach their goals. Simple before and after designs are often used but cannot isolate the effect of the policy of interest. Methods: The short-term impact of the French smoking ban (2007-08) on smoking behavior outcomes was evaluated among smokers with data from the ITC project. We first conducted a before and after design on the French sample. Second, we added the UK (excluding Scotland) as a control group and finally used external pre-policy data from national surveys to control for bias arising from pre-policy trends. Results: After one year post-implementation, the smoking ban led to a decrease in seeing people smoking in bars, restaurants and workplaces [estimated risk ratios (RR) of 8.81 IC95% (5.34-14.71), 2.02 (1.79-2.31) and 1.24 (1.16-1.33), respectively], as well as an increase in support for the smoke-free policy, but only in bars and restaurants [RR of 1.35 (1.15-1.61) and 1.25 (1.16-1.35)], respectively. No impact was found on smoking behaviors and on having a strict no smoking policy at home. The simple before and after design systematically overestimated the smoking ban's impact [e.g. RR of 29.9 (20.06-44.56) for observed smoking in bar, compared to 13.21 (7.78-22.42) with the control group, and 8.81 (5.34-14.71) with the correction from external data]. Conclusion: When data are lacking to conduct quasi-experimental designs for impact evaluation, the use of external data could help understand and correct pre-policy trends.

Benmarhnia, T, Dionna PA, Tchouaket E, Fansi A, Brousselle A.  In Press.  How effective does a Healthy Lifestyle Habits Promotion Strategy need to be to make it cost-neutral. IJPH.
Benmarhnia, T, Alexander S, Price K, Smargiassi A, King N, Kaufman JS.  2018.  The heterogeneity of vulnerability in public health: a heat wave action plan as a case study. Critical Public Health. 28:619-625.   10.1080/09581596.2017.1322176   AbstractWebsite

The concept of vulnerability is frequently used in public health policies to develop tailored interventions or dedicate proportionately more resources to certain sub-populations. However, once segments of the population are identified as vulnerable, they are rarely consulted regarding whether this label is acceptable before instituting interventions. Instead, it is implicitly assumed that the targeted individuals identify themselves as vulnerable and experience an unambiguous and consistent need for public health assistance. In this paper, using public health interventions during heat waves as a case study, we question such assumptions. A qualitative study was conducted in Montreal, Canada involving two focus groups among populations specifically targeted by the heat action plan as vulnerable: one composed of individuals diagnosed with schizophrenia, and one composed of individuals who have alcohol or drug addictions. Findings revealed significant heterogeneity in the definition and experience of vulnerability as it is used in the context of a heat action plan in Montreal. We found differences between the two focus groups in several areas including sources of information they had access to within the heat action plan measures and their perspectives regarding the appropriateness of specific measures in the heat action plan. We then observed differences within each of the focus groups in several areas including their social networks relationships. The concept of vulnerability is often used in public health policies. Yet, while this concept may be convenient for shaping policies to reduce inequalities in health, the heterogeneity of populations defined as vulnerable should not be underestimated.

Benmarhnia, T, Delpla I, Schwarz L, Rodriguez MJ, Levallois P.  2018.  Heterogeneity in the relationship between disinfection by-products in drinking water and cancer: A systematic review. International Journal of Environmental Research and Public Health. 15   10.3390/ijerph15050979   AbstractWebsite

The epidemiological evidence demonstrating the effect of disinfection by-products (DBPs) from drinking water on colon and rectal cancers is well documented. However, no systematic assessment has been conducted to assess the potential effect measure modification (EMM) in the relationship between DBPs and cancer. The objective of this paper is to conduct a systematic literature review to determine the extent to which EMM has been assessed in the relationship between DBPs in drinking water in past epidemiological studies. Selected articles (n = 19) were reviewed, and effect estimates and covariates that could have been used in an EMM assessment were gathered. Approximately half of the studies assess EMM (n = 10), but the majority of studies only estimate it relative to sex subgroups (n = 6 for bladder cancer and n = 2 both for rectal and colon cancers). Although EMM is rarely assessed, several variables that could have a potential modification effect are routinely collected in these studies, such as socioeconomic status or age. The role of environmental exposures through drinking water can play an important role and contribute to cancer disparities. We encourage a systematic use of subgroup analysis to understand which populations or territories are more vulnerable to the health impacts of DBPs.