Spatial Patterns of Satellite-Retrieved PM 2.5 and Long-Term Exposure Assessment of China from 1998 to 2016.

Previous studies have shown that particulate matter with an aerodynamic diameter of less than 2.5 micrometers (PM) is tightly associated with adverse effects on human health, i.e., morbidity and mortality. Based on long-term satellite-derived PM datasets, this study analyzed the spatial patterns and temporal trends of PM concentrations in China from 1998 to 2016 using standard deviational ellipse and statistical analyses. A long-term assessment of exposure and health impacts due to PM was undertaken by the Environmental Benefits Mapping and Analysis Program-Community Edition (BenMAP-CE) model. The results show that concentrations of PM increased nonlinearly in most areas of China from 1998 to 2016. Higher concentrations were found in eastern China and western Tarim Basin, and most areas exceeded the World Health Organization's (WHO) annual PM standards. The median center of average PM concentration of the country shifted to the southeast and then returned during the examined time period. The proportion of the population exposed to equal PM concentrations increased at first, then trended downward. The proportion of the population exposed to PM over WHO Interim Target-1 (35 µg/m³) increased 20.6%, which was the largest growth compared with other WHO standard levels. The extent of health risk in China increased and expanded from 1998 to 2016, especially in the Beijing-Tianjin-Hebei region, the Yangtze River Delta, and the Pearl River Delta, which are China's top three urban areas. The implementation of the Air Pollution Prevention and Control Action Plan has gradually paid off. If the government can achieve long-term adherence to its plan, great economic and health benefits will be gotten through the BenMAP-CE model analysis.