Estimation of Ambient PM <sub>2.5</sub>-Related Disease Burden in China by 2030 Under Climate and Population Change Scenarios: A Modelling Study

Abstract

Background: Fine particulate matter (PM2.5) pollution is one of the most critical environmental and public health problems in China, which has caused enormous disease burden, especially long-term PM2.5 exposure. Global climate change is another environmental challenge in the coming decades, which is also an essential factor affecting PM2.5 pollution. Moreover, China is embracing an aging population. However, little evidence exists evaluating the potential impact of climate change and population ageing on long-term PM2.5 exposure-related disease burden. This study aims to quantify the impact of climate and population changes on changes in the disease burden attributed to long-term PM2.5 exposure from 2015 to 2030 in mainland China. Methods: This modeling study investigated long-term PM2.5 exposure-related mortality across China based on PM2.5 projections under Intergovernmental Panel on Climate Change Representative Concentration Pathways (RCPs) and population scenarios from the Shared Socioeconomic Pathways (SSPs). Three types of population projections in 2030 relative to 2015 were set up as follow: (i) population remained the same from 2015; (ii) the population size changed under SSPs but age structure remained same; (iii) both population size and age structure changed under SSPs. Global Exposure Mortality Model was adopted to estimate PM2.5-related premature deaths. Findings: Ambient PM2.5 concentrations showed a decrease from 2015 to 2030 under two climate and emission scenarios. Estimates of related premature mortality in 2030 declined compared with 2015 due to lower PM2.5 concentrations (RCP4.5: -16.8%; RCP8.5: -16.4%). If the age structure of population remained no change and the population size changed under SSPs, the premature mortality also showed a decrease ranging from -18.6% to -14.9%. When both population size and age structure changed under SSPs, the premature mortality would sharply increase by 35.7%-52.3% (with net increase of 666-977 thousand) in 2030. Interpretations: The PM2.5 pollution in 2030 under both RCP4.5 and RCP8.5 would slightly improve. However, the modest decrease due to air pollution improvement would be offset by population ageing. Funding Statement: None. Declaration of Interests: The authors declare that they have no conflicts of interests.