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 (PM_2.5) 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 PM_2.5 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 PM_2.5 from 2000 to 2012 (51.8%) and the subsequent decrease from 2012 to 2020 (47.6%). Currently, industrial sources remain the largest contributor to PM_2.5 (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 PM_2.5 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 PM_2.5, 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.