Neighbourhood Characteristics and Long-Term Air Pollution Levels Modify the Association between the Short-Term Nitrogen Dioxide Concentrations and All-Cause Mortality in Paris

Abstract

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=[1.41-4.90], p<0.001). Among these deprived census blocks, excess risk was even higher where long-term average NO2 concentrations were above 55.8 μg/m3 (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.

Tobacco‐attributable burden of cancer according to socioeconomic position in France

“…As these exposures are disproportionately concentrated in male occupations, this could partly account for the sex difference observed in our data. Other risk factors may also partly account for the higher incidence of cancers linked to tobacco smoking among the low socioeconomic groups because they are more prevalent in these groups (e.g., poor diet or physical inactivity) and/or because, the same level of exposure may be more harmful in these groups (e.g., air pollution) . These risk factors may also interact, leading to larger cancer risk in the low socioeconomic groups.…”

Socioeconomic status and health outcomes: cystic fibrosis as a model

“…Although exposure to industrial air toxins has decreased over the past few decades, it remains highly correlated with social class [68]. People in poor neighborhoods have higher exposure to long-term air pollution and short-term nitrogen dioxide concentrations than people in affluent neighborhoods [69]. Such exposure compromises lung growth in children [70] and leads to increased mortality in adults [69,71].…”

“…People in poor neighborhoods have higher exposure to long-term air pollution and short-term nitrogen dioxide concentrations than people in affluent neighborhoods [69]. Such exposure compromises lung growth in children [70] and leads to increased mortality in adults [69,71]. A significant correlation has been reported between ambient concentrations of particulate matter, nitrogen dioxide, and ozone, on the one hand, and prescriptions of IV antibiotics for pulmonary exacerbations, on the other [72].…”

Cumulative Risk and Impact Modeling on Environmental Chemical and Social Stressors

“…As shown in Table 1, among the 31 articles identified [35–70], 10 studies [37, 42, 43, 46, 52, 55, 61, 66, 68, 69] used multivariable linear/non-linear regression models to evaluate the combined effects of multiple chemical and non-chemical stressors, and 7 studies [36, 38, 40, 45, 47, 59, 68] used logistic regression models. In addition, we found 5 studies [49, 56, 57, 63, 67] that used hierarchical/multilevel regression models.…”

“…All studies used supervised techniques, specifically regression models, but several of them also used unsupervised methods such as hierarchical cluster analysis, factor analysis and principal component analysis (PCA), in addition to regression models. Air pollutants were the environmental chemical exposure most often modeled: 20 out of the 31 studies evaluated air pollutants [35, 38, 40, 42, 43, 45, 49–53, 56, 58, 60–64, 66, 69], especially the criteria pollutants such as particulate matter (PM) and nitrogen dioxide (NO 2 ). For instance, the joint effects of exposure to PM 2.5 and O 3 and socioeconomic status measures upon pregnancy outcomes including low birth weight, preterm birth and small for gestational age were evaluated based on a linear or logistic mixed regression model [49].…”