Effects of combined exposure to PM, O, and NO on health risks of different disease populations in the Beijing-Tianjin-Hebei region.

Air pollution adversely affects people's health. Under the current background of compound air pollution in China, the emission reduction potential of air pollution control has significantly decreased, and there are few studies on multi-pollutant emission reduction and synergistic effects. PM, O, and NO have caused the enormous disease burden and health risks. This study evaluated the single and combined health effects of pollutants in the Beijing-Tianjin-Hebei region, and discussed the differences in susceptibility among disease populations. Identified the interactions of multiple pollutants and evaluated current environmental policies. This study provided evidence of the interactive effect of combined PM, O, and NO exposure on the health risks of different disease populations. Among them, the interaction between PM and O posed the most significant health risks (Odds Ratio of 3.026) and had the greatest impact on the health of people with cardiovascular diseases (Odds Ratio of 3.136). The excess deaths affected by combined exposure exceeded 40 % of the total excess deaths. The assessment of environmental policies indicated that compliance with the AQG 2021 guideline values would reduce ambient air pollution-related deaths in the Beijing-Tianjin-Hebei region alone by about 30,000 per year. Our national standards were still far from the benchmarks given by the World Health Organization, especially for NO. In the future, attentions should also be paid to the control of NO and other reaction precursors while coordinating the control of PM and O.