Spatiotemporal evolution characteristics of PM2.5 pollution and health burden in mega-urban agglomerations of China
With rapid economic development and urbanization over the past decades,China has suffered a severe PM2.5 pollution.The analysis of the characteristics and spatiotemporal trends of PM2.5 pollution and its health effects in typical urban agglomerations is vital for evaluating and optimizing pollution control policies.Based on multi-source high-resolution air pollution,population data,and health assessment methods,this study analyzed and compared PM2.5 pollution and its health burden in four mega-urban agglomerations Beijing-Tianjin-Hebei(BTH),Yangtze River Delta(YRD),Pearl River Delta(PRD),and Chengdu-Chongqing(CC)urban agglomerations during 2000-2020.The results showed that the PM2.5 pollution in BTH was the most serious,followed by the YRD and CC,and the PM2.5 pollution in PRD was the least polluted.The four urban agglomerations all experienced a"rise first and then fall"process of PM2.5 pollution,with annual average PM2.5 concentrations decreasing by 35.6%,43.9%,34.6%,and 49.7%during 2000-2020,respectively.In 2020,the PM2.5 attributable deaths in BTH,YRD,PRD,and CC were 128000,140000,52000,and 90000,respectively.Population growth and aging mainly contributed to the increase in the PM2.5 health burden,which contributed most to the PRD.The reduction of PM2.5 pollution was the main driving force to decrease the PM2.5 attributable health burden,suggesting that air pollution controls in urban agglomerations have achieved significant health benefits.In the future,it is necessary to strengthen the control measures of PM2.5 pollution in urban agglomerations from the perspective of population health,with special attention to the health risks of the elderly population.