Denis Bard

Traffic-Related Air Pollution and Socioeconomic Status : A Spatial Autocorrelation Study to Assess Environmental Equity on a Small-Area Scale

Background: Most ecologic studies of environmental equity show that groups with lower socioeconomic status (SES) are more likely to be exposed to higher air pollution levels than groups of higher SES. However, these studies rarely consider spatial autocorrelation in the data. We investigated the associations between traffic-related air pollution and SES on a small-area level in Strasbourg (France) and assessed the impact of spatial autocorrelation on the results. Methods: We used a deprivation index, constructed from census data, to estimate SES at the block level. Average ambient nitrogen dioxide (NO2) levels during year 2000, modeled at the block level by a dispersion model, served as a marker of traffic exhaust. We estimated the association between exposure to NO2 and the deprivation index by using an ordinary least squares model and a simultaneous autoregressive model that controls for the spatial autocorrelation of data. Results: The association between the deprivation index and NO2 levels was positive and nonlinear with both regression models; the midlevel deprivation areas were the most exposed. Control of spatial autocorrelation strongly reduced the strength of the association but clearly improved the models goodness-of-fit; the most pronounced reduction was observed for the midlevel deprivation areas (regression coefficients decreased by 67%). Conclusions: This study confirms the need to take spatial autocorrelation into account in ecologic studies and shows that failure to do so may lead to biased and unreliable estimates and thus to erroneous conclusions. This may be especially important in studying the role of air pollution on social inequalities in health.

Effect of socioeconomic status on the relationship between atmospheric pollution and mortality

Current knowledge about potential interactions between socioeconomic status and the short- and long-term effects of air pollution on mortality was reviewed. A systematic search of the Medline database through April 2006 extracted detailed information about exposure measures, socioeconomic indicators, subjects’ characteristics and principal results. Fifteen articles (time series, case-crossover, cohort) examined short-term effects. The variety of socioeconomic indicators studied made formal comparisons difficult. One striking fact emerged: studies using socioeconomic characteristics measured at coarser geographic resolutions (city- or county-wide) found no effect modification, but those using finer geographic resolutions found mixed results, and five of six studies using individually-measured socioeconomic characteristics found that pollution affected disadvantaged subjects more. This finding was echoed by the six studies of long-term effects (cohorts) identified; these had substantial methodological differences, which we discuss extensively. Current evidence does not yet justify a definitive conclusion that socioeconomic characteristics modify the effects of air pollution on mortality. Nevertheless, existing results, most tending to show greater effects among the more deprived, emphasise the importance of continuing to investigate this topic.

A small-area ecologic study of myocardial infarction, neighborhood deprivation, and sex: a bayesian modeling approach.

Background: Socioeconomic inequalities in the risk of coronary heart disease (CHD) are well documented for men and women. CHD incidence is greater for men but its association with socioeconomic status is usually found to be stronger among women. We explored the sex-specific association between neighborhood deprivation level and the risk of myocardial infarction (MI) at a small-area scale. Methods: We studied 1193 myocardial infarction events in people aged 35–74 years in the Strasbourg metropolitan area, France (2000–2003). We used a deprivation index to assess the neighborhood deprivation level. To take into account spatial dependence and the variability of MI rates due to the small number of events, we used a hierarchical Bayesian modeling approach. We fitted hierarchical Bayesian models to estimate sex-specific relative and absolute MI risks across deprivation categories. We tested departure from additive joint effects of deprivation and sex. Results: The risk of MI increased with the deprivation level for both sexes, but was higher for men for all deprivation classes. Relative rates increased along the deprivation scale more steadily for women and followed a different pattern: linear for men and nonlinear for women. Our data provide evidence of effect modification, with departure from an additive joint effect of deprivation and sex. Conclusions: We document sex differences in the socioeconomic gradient of MI risk in Strasbourg. Women appear more susceptible at levels of extreme deprivation; this result is not a chance finding, given the large difference in event rates between men and women.

Exploring the joint effect of atmospheric pollution and socioeconomic status on selected health outcomes: an overview of the PAISARC project

Health socioeconomic gradients are well documented in developed countries, but incompletely explained. A portion of these health inequalities may be explained by environmental exposures. The objective of PAISARC is to explore the relations between socioeconomic status, air pollution exposure and two selected health outcomes?asthma exacerbations and myocardial infarction?at the level of a small area. The study design is ecological, using data available from the national census, with the residential block (French IRIS, 2000 people on average, National Institute of Statistics?INSEE) as the statistical unit. The setting is the Greater Strasbourg metropolitan area (450?000 inhabitants) in eastern France. We first constructed a socioeconomic status index, using 1999 national census data and principal component analysis at the resolution of these census blocks. Air pollution data were then modeled at the same resolution on an hourly basis for the entire study period (2000?2005). Health data were obtained from various sources (local emergency networks, the local population-based coronary heart disease registry, health insurance funds) according to the health outcome. We present here the initial results and discuss the methodological approaches best suited for the forthcoming steps of our project.

Signal émergent, alerte et prise de décision en santé et environnement

La loi relative a « l’independance de l’expertise en matiere de sante et d’environnement et a la protection des lanceurs d’alerte » votee en avril 2013 (loi n° 2013-316 du 16 avril 2013) est en attente de ses arretes d’application. Ce texte porte largement sur la creation d’une Commission nationale de la deontologie et des alertes (CNDA) en matiere de sante publique et d’environnement, chargee de veiller aux regles deontologiques s’appliquant a l’expertise [...]

Création de la Société française de santé et environnement

Auteur(s) : Denis Bard, Pierre-Andre Cabanes, Alain Grimfeld, Francelyne Marano, Severine Kirchner Institutionnalisee par la creation d’une agence nationale (l’Afsse, devenue l’Afsset1) en 2001, la sante environnementale est aujourd’hui un champ d’expertise reconnu pour lequel des formations universitaires initiales existent. De nombreuses autres agences ou institutions (Afssa, InVS, Ineris, CSTB, INRS, IRSN2 et d’autres encore) contribuent a des degres divers a ce champ d’expertise, [...]