世界卫生组织在2021年将建议的年平均PM2.5浓度水平降低至5μg/m3。以前,该指南针对环境空气污染，现在它明确适用于室内空气污染。然而,归因于不同室内排放源的疾病负担被忽视了，特别是在城市地区。我们的目标是估计中国城市地区室内PM2.5的死亡率。我们的模型估计了2019年中国城市PM2.5造成的711万（584-823）死亡和2.75万亿（2.26-3.19）人民币经济损失，其中室内来源造成了394万（323-457）死亡和1.53万亿（1.25-1.77）人民币损失。当室外PM2.5为5μg/m3时，每年仍将有53.6万（427-638）的PM2.5死亡和2.07万亿（1.65-2.47）人民币损失，其中485万（386-578）的死亡和1.87万亿（1.49-2.23）人民币归因于室内来源。尽管室外空气更清洁，没有使用固体燃料，相当大的健康危害和经济损失可归因于室内PM2.5。需要采取措施减少室内和室外来源的人类PM2.5暴露，以大幅减少死亡人数。
The World Health Organization reduced the recommended level of annual mean PM2.5 concentrations to 5 μg/m3 in 2021. Previously, the
guideline was geared toward ambient air pollution, and now it explicitly applies to indoor air pollution. However, the disease burden attributed to different indoor emission sources has been overlooked, particularly in urban areas. Our objective was to estimate the mortality attributable to indoor PM2.5 in urban areas in China. Our model estimated 711 thousand (584-823) deaths and 2.75 trillion (2.26-3.19) CNY economic losses attributable to PM2.5 in urban China in 2019, in which indoor sources contributed 394 thousand (323-457) deaths and 1.53 trillion (1.25-1.77) CNY losses. There would still be 536 thousand (427-638) PM2.5-attributable deaths and 2.07 trillion (1.65-2.47) CNY losses each year when the outdoor PM2.5 is 5 μg/m3, of which 485 thousand (386-578) deaths and 1.87 trillion (1.49-2.23) CNY are attributable to indoor sources. Despite cleaner outdoor air and no solid fuels being used, considerable health hazards and economic losses are attributable to indoor PM2.5. Measures to reduce PM2.5 exposure in humans from both indoor and outdoor sources are required to achieve a substantial reduction in deaths.
