Collaborative control of fine particles and ozone required in China for health benefit

PM 2.5 concentration declined significantly nationwide, while O 3 concentration increased in most regions in China in 2013–2020. Recent evidences proved that peak season O 3 is related to increased death risk from non-accidental and respiratory diseases. Based on these new evidences, we estimate excess deaths associated with long-term exposure to ambient PM 2.5 and O 3 in China following the counterfactual analytic framework from Global Burden Disease. Excess deaths from non-accidental diseases associated with long-term exposure to ambient O 3 in China reaches to 579 (95% confidential interval (CI): 93, 990) thousand in 2020, which has been significantly underestimated in previous studies. In addition, the increased excess deaths associated with long-term O 3 exposure (234 (95% CI: 177, 282) thousand) in 2013–2020 offset three quarters of the avoided excess deaths (302 (95% CI: 244, 366) thousand) mainly due to PM 2.5 exposure reduction. In key regions (the North China Plain, the Yangtze River Delta and the Fen-Wei Plain), the former is even larger than the latter, particularly in 2017–2020. Health benefit of PM 2.5 concentration reduction offsets the adverse effects of population growth and aging on excess deaths attributed to PM 2.5 exposure. Increase of excess deaths associated with O 3 exposure is mainly due to the strong increase of O 3 concentration, followed by population aging. Considering the faster population aging process in the future, collaborative control, and faster reduction of PM 2.5 and O 3 are needed to reduce the associated excess deaths.