Anthropogenic emissions shape long-term changes in PM2.5 concentrations and health risks in China.

China has experienced an initial increase and a subsequent decrease in fine particulate matter (PM2.5) concentrations since the early 21st century, with substantial heterogeneity across different source contributions. This study developed a source-oriented CMAQ model to construct a source-resolved PM2.5 concentration database for China during 2000-2020. Subsequently, source-specific health risks and the contributions of key driving factors were systematically evaluated using the piling-up decomposition method. The results indicate that anthropogenic emissions, particularly from industrial sources, were the primary drivers of both the increase in PM2.5 from 2000 to 2012 (51.8%) and the subsequent decrease from 2012 to 2020 (47.6%). Currently, industrial sources remain the largest contributor to PM2.5 (about 32%), followed by residential (about 22%) and transportation sources (about 13%). Implementation of two-phase air pollution control measures led to a 20.4% reduction in national premature mortality attributable to PM2.5 from 2012 to 2020, although 10.6% of this benefit was offset by changes in population and baseline mortality rates. Throughout 2000-2020, health risks associated with anthropogenic sources consistently exceeded their proportional contribution to PM2.5, primarily because these emissions are concentrated in densely populated areas. These findings underscore that, in addition to implementing region-specific emission reduction policies, maintaining stringent controls on anthropogenic emissions, particularly from industrial and transportation sources, is crucial to maximizing future health benefits.