Role of socio-economic status in the relationship between air pollution and health

Abstract

OPS 60: Social factors and environmental health across the world, Room 210, Floor 2, August 27, 2019, 1:30 PM - 3:00 PM Background/aims: Inequalities in air pollution exposure and relative health impacts are a relevant aspect in epidemiological research and policy. Aim of the study was to investigate the role of deprivation in the association between air pollution and mortality in a large Italian cohort. Methods: The Supersito project analyzed the effects of aerosols on health in an Italian cohort (aged 30+) of residents in a highly polluted area of Northern Italy. Three years daily measurements (2012-2014) of PM2.5 and its components were made in 4 sites. Monitoring and modeling approach were used to assign a spatio-temporal exposure to each subject’s home address. Natural and cause-specific mortality were analyzed in relation to PM2.5 in the period 2009-2013, using Cox regression models (age of subjects as temporal axis), adjusting for education, citizenship, sex and residence area (urban, coastal, rural), and stratifying for a Deprivation Index (DI) calculated at census-block level and categorzed by quintiles of population at a regional level. Results: 6,011,667 person-years were observed. Total mortality shows an increasing trend in the crude rate related to DI quintiles. The cohort characteristics (gender, age, level of exposure to PM2.5) are homogeneous in the 5 sub-groups, with a prevalence of residence in urban area for less deprived and coastal area for most deprived. Natural mortality reported a 7% increase in risk for increases of 10 □g/m3 of PM2.5 on the whole cohort, but the increase was much higher in most compared to the least deprived [HR=1.014 (95%CI:0.93-1.10), 1.0015 (95%CI:0.93-1.10), 1.022 (95%CI:0.93-1.11), 1.08 (95%CI:1.00-1.16), 1.18 (95%CI:1.11-1.25), respectively]. Conclusions: Stratified analysis revealed increasing associations between PM2.5 and mortality for those living in most deprived small areas. Both PM2.5 and deprivation have been measured at residence, therefore we cannot disentangle if deprivation acts at the individual or context level in increasing the effect of air pollution on mortality.