Mortality burden attributable to long-term ambient PM2.5 exposure in China: using novel exposure-response functions with multiple exposure windows.

Exposure to ambient fine particulate matter (PM 2.5) increases the mortality burden. Exposure windows and exposure-response functions (ERFs) are two critical components of accurate mortality burden estimation. We explored the potential heterogeneity of exposure windows and reassessed the PM 2.5 -attributable mortality burden in China with novel ERFs. Based on 1 km × 1 km satellite-retrieved PM 2.5 and population data, provincial-level age structure, and mortality data, we applied the recent Global Exposure Mortality Model (GEMM) with multiple exposure windows (1-year to 6-year during 2010–2015) to estimate age-specific PM 2.5 -attributable mortality burden in China in 2015. Then, the Global Burden of Disease (GBD) 2017 Integrated Exposure-Response (IER) and Log-Linear (LL) models were exercised for comparative analysis. The PM 2.5 -attributable mortality was the highest with a 3-year average exposure window (2013–2015). The GEMM-based total premature deaths were 133.2% [95% confidence interval (95% CI): 93.6%–226.4%] and 14.2% (95% CI: 13.9%–16.8%) higher than the values obtained from the GBD2017 IER model and LL model, respectively. The national mortality burden attributable to PM 2.5 was 1.94 (95% CI: 1.63–2.23) million, of which IHD and stroke were the leading causes, accounting for 27.3% and 23.0% of the total burden respectively. The mortality burden for the people over 80 years old was 0.62 (95%CI: 0.52–0.71) million, accounting for 31.9% (95%CI: 31.8%–32.0%) of the total burden. This study demonstrates the potential heterogeneity of PM 2.5 -attributable mortality burden associated with different exposure windows, especially when there are spatial-temporal variations in PM 2.5 concentrations. The model comparison results suggest that the health impacts attributed to long-term PM 2.5 exposure in China may be much higher than previously estimated. The population over 80 years old has the highest PM 2.5 -attributable mortality burden. These findings have important policy implications for addressing air pollution at the provincial and national level in China. • First explore the potential heterogeneity of exposure windows on mortality burden. • The PM 2.5 -related mortality burden in China was reassessed using the novel GEMM. • Mortality burden from PM 2.5 was estimated as 1.94 million in China in 2015. • GEMM-based excess deaths were 133.2% and 14.2% higher than that of IER and LL. • The population over 80 years old has the most serious mortality burden. [ABSTRACT FROM AUTHOR]