Estimating Infant and Adult Mortality Burden Attributable to Fine Particulate Matter in China from 2013 to 2023: An Environmental Justice Perspective

China’s clean air actions have substantially improved air quality and reduced PM 2.5 -attributable mortality, but their equity impacts across life stages remain unclear. Here, we assessed spatiotemporal changes in PM 2.5 -attributable mortality among infants and adults in China from 2013 to 2023 using high-resolution PM 2.5 data, gridded population data sets, and exposure–response functions from the Global Exposure Mortality Model (GEMM) and previous meta-analysis. Socioeconomic inequality was evaluated using gridded gross domestic product data and quantified by the concentration index (CI), which is a classical metric of socioeconomic inequality and has been applied to assess the health impacts from air pollution exposure. From 2013 to 2023, population-weighted PM 2.5 exposure declined substantially in both groups, accompanied by marked reductions in attributable mortality. PM 2.5 -attributable infant deaths declined from 89.2 thousand (95% uncertainty interval: 36.3–110.8) in 2013 to 14.0 thousand (95% UI: 5.0–20.6) in 2023, representing an 84% reduction, compared with a 39% reduction among adults. Despite these overall improvements, PM 2.5 -attributable infant deaths were disproportionately concentrated in economically disadvantaged regions, with the concentration index worsening from −0.071 in 2013 to −0.096 in 2023, whereas inequality among adults narrowed toward zero. To reduce environmental inequality, increased focus on reducing air pollution exposure in economically disadvantaged regions is warranted.