Policy-driven Changes in the Health Risk of PM and O Exposure in China During 2013-2018

China issued a series of control measures to mitigate PM pollution, including long-term (i.e., Air Pollution Prevention and Control Action Plan, APPCAP) and short-term (emergency measures in autumn and winter) acts. However, the O concentration increased significantly as PM levels sharply decreased when these measures were implemented. Therefore, the policy-driven positive/negative health effects of PM/O need to be comprehensively estimated. The health impact function (HIF) is applied to evaluate the health burden attributable to long- and short-term PM and O exposure. The results show that the PM concentration decreased by 42.95% in 74 cities, whereas O pollution is increased by 17.56% from 2013 to 2018. Compared with 2013, the number of premature deaths attributable to long- and short-term PM exposure decreased by almost 5.31 × 10 (95% confidence interval [CI]: 2.87 × 10-4.71 × 10) (10.13%) and 3.00 × 10 (95% CI: 1.66 × 10-4.39 × 10) (72.49%), respectively, in 2018. In contrast, O-attributable deaths, increased by 1.98 × 10 (95% CI: 0.31 × 10-3.59 × 10) (130.57%) and 0.91 × 10 (95% CI: 0.50 × 10-1.33 × 10) (76.16%) for long- and short-term exposure, respectively. The number of avoidable deaths attributed to PM reduction is larger than the level of premature deaths related to increasing O. Although annual mean PM concentrations have fallen rapidly, the benefits of reducing long-term exposure are limited, whereas the deaths associated with acute exposure decrease more significantly due to the reduction of heavy-pollution days by implementing emergency measures. The results show appreciable effectiveness in protecting human health and illustrate that synchronous control of PM and O pollution should be emphasized.