Short-term health impacts related to ozone in China before and after implementation of policy measures: A systematic review and meta-analysis

This paper presents a meta-analysis of the impacts of short-term exposure to ozone (O3) on three health endpoints: all-cause, cardiovascular, and respiratory mortality in China. All relevant studies from January 1990 to December 2021 were searched from four databases. After screening, 30 studies were included for the meta-analysis. The results showed that a significant rise of 0.41 % (95 % confidence interval (CI): 0.35 %–0.48 %) in all-cause, 0.60 % (95 % CI: 0.51 %–0.68 %) in cardiovascular and 0.45 % (95 % CI: 0.28 %–0.62 %) in respiratory mortality for each 10 μg m−3 increase in the maximum daily 8 h average O3 concentration (MDA8 O3). Moreover, results stratified by heterogeneous time periods before and after implementing a policy measure in 2013, showed that the pooled effects for all-cause and respiratory mortality before were greater than those after, while the pooled effects for cardiovascular mortality before 2013 were slightly smaller than those after. The finding that short-term exposure to O3 was positively related to the three health endpoints was validated by means of a sensitivity analysis. Furthermore, we did not observe any publication bias. Our results present an updated and better understanding of the relationship between short-term exposure to O3 and the three health endpoints, while providing a reference for further assessment of the impact of short-term O3 exposure on human health. [Display omitted] •Short-term O3 exposure has significant positive impact on and three health endpoints.•The pooled estimates for China differ from those in other countries.•There was different estimated risk before and after the implementation of policy.•Further studies about the impact of O3 on health in China are warranted.