TPS 681: Short-term health effects of air pollutants 1, Exhibition Hall, Ground floor, August 26, 2019, 3:00 PM - 4:30 PM
Background/Aim: Previous studies showed that short-term associations between ambient particulate air pollution (PM) and mortality are heterogeneous across populations in different areas of the world. However, little is known about the factors responsible for these inter-regional differences. In this contribution, we used data from a multi-country multi-city study to identify contextual factors that modify short-term mortality risks of PM.
Methods: We collected daily series of mortality counts and air pollution data (PM10, PM2.5) for 327 cities in 25 countries in the period 1985-2015. City-level standardized measures of demographic, socioeconomic, and environmental indicators were derived from the OECD Regional/Metropolitan Database, in addition to climatological variables from the weather series. We applied a two-stage time-series design. First, for each city we modelled the linear associations of two-day moving average PM10, and PM2.5 with total mortality using quasi-Poisson regression and distributed lag nonlinear models. Second, we used meta-regression models to evaluate the effect modification of each indicator.
Results: In preliminary analyses, the pooled percent mortality change for a 10 μg/m3 increase in PM10 and PM2.5 concentrations were 0.20% 95%CI(0.14%; 0.25%), and 0.31% 95%CI(0.21%; 0.41%) respectively. For PM10, significant changes of the figures above, for an IQR increase in each factor, were found for Gini index (0.12% to 0.29%, p=0.015), average temperature (0.13% to 0.27%, p=0.001), and Sprawl index (0.14% to 0.26%, p=0.033). For PM2.5, a tendency to increase the mortality risk was found for GDP (0.24% to 0.38%, p=0.073), while cities with an extended green area have a lower percent mortality change (0.41% to 0.20%, p=0.054).
Conclusion: This represents the largest study assessing effect modification of ambient particulate air pollution and mortality relationships, performed by comparing different populations across the world. Preliminary findings suggest larger PM-mortality risks, in urban communities characterised by a higher level of inequalities, warmer climate, and less green area.