Longitudinal Impacts of PM2.5 Constituents on Adult Mortality in China

Limited evidence exists for long-term effects of PM2.5constituents on mortality. Hence, we aimed to assess associationsbetween all-cause mortality and long-term exposure to PM2.5constituents in China. We designed a nationwide cohort study of30524 adults from 162 prefectural areas across mainland China withfollow-ups through years 2010-2017. Cox proportional hazardsmodels with time-varying exposures were employed to quantifyassociations between all-cause mortality and long-term exposure toPM2.5and constituents. A total of 1210 deaths occurred during172297.7 person-years. A multiadjusted Cox model estimated anhazard ratio (HR) of 1.125 (95% confidence interval: 1.058-1.197)for all-cause mortality, associated with an interquartile range (IQR =26.7 mu g/m3) rise in exposure to PM2.5. Comparable or strongerassociations were found among PM2.5constituents with the mortality risk increased by 11.3-14.1% per IQR increase in exposureconcentrations. After adjustment for the collinearity between total PM2.5and constituents, effect estimates for nitrate, ammonium,and sulfate remained significant and became larger. Urban residents, alcohol drinkers, smokers, and men were more susceptible tochronic impacts from ambient PM2.5constituents. This cohort study added the novel longitudinal evidence for elevated mortalitylinked with long-term exposure to PM2.5constituents among Chinese adults