Loss of life expectancy from PM2.5 in Brazil: A national study from 2010 to 2018.

Abstract

Long-term exposure to PM2.5 is proved to be linked with mortality. However, limited studies have estimated the PM2.5 related loss of life expectancy (LLE) and its changing trends. How much life expectancy would be improved if PM2.5 pollution is reduced to the new WHO air quality guideline (AQG) level is unclear. Data on deaths from all-causes, cancer, cardiovascular and respiratory diseases were collected from 5,565 Brazilian municipalities during 2010-2018. A difference-in-differences approach with quasi-Poisson regression was applied to examine the PM2.5-years of life lost (YLL) associations and PM2.5 associated LLE. The annual PM2.5 concentration in each municipality from 2010 to 2018 was 7.7µg/m3 in Brazil. Nationally, with each 10μg/m3 increase in five-year-average (current and previous four years) concentrations of PM2.5, the relative risks (RRs) were 1.18 (95% CI: 1.15-1.21) for YLL from all-causes, 1.22 (1.16-1.28) from cancer, 1.12 (1.08-1.17) from cardiovascular and 1.17 (1.10-1.25) from respiratory diseases. Life expectancy could be improved by 1.09 (95% CI: 0.92-1.25) years by limiting PM2.5 concentration to the national lowest level (2.9µg/m3), specifically, 0.20 (0.15-0.24) years for cancer, 0.16 (0.11-0.22) years for cardiovascular and 0.09 (0.05-0.13) years for respiratory diseases, with significant disparities across regions and municipalities. Life expectancy would be improved by 0.78 (0.66-0.90) years by setting the new WHO AQG PM2.5 concentration level of 5μg/m3 as an acceptable threshold. Using nationwide death records in Brazil, we found that long-term exposure to PM2.5 was associated with reduced life expectancy from all-causes, cancer, cardiovascular and respiratory diseases with regional inequalities and different trends. PM2.5 pollution abatement to below the WHO AQG level would improve this loss of life expectancy in Brazil.