Surface Ozone Trends and Health Impacts in the Yangtze River Delta Region During 2015–2019

The steady escalation of surface-level ozone (O3) concentrations has become a major atmospheric pollution issue in China, with considerable implications for public health. This research systematically examines the spatial and temporal patterns of O3 levels within the Yangtze River Delta region, spanning 2015–2019. Additionally, it evaluates how both prolonged and brief periods of O3 exposure influence mortality risks—including all-cause deaths as well as fatalities linked to cardiovascular and respiratory conditions. The results indicate that: (1) From 2015 to 2019, surface O3 levels in the YRD showed a steady upward trend. The yearly average AVGDMA8 concentration climbed from 76.6 ± 17.5 μg/m3 to 89.7 ± 6.3 μg/m3, while the 4DMA8 values jumped from 171.4 ± 33.9 μg/m3 to 187.6 ± 17.6 μg/m3, with an average annual increase of 2.9 ± 3.5 μg/m3. (2) Between 2015 and 2019, long-term exposure to AVGDMA8 O3 concentrations was linked to an estimated 35,806 (95% CI: 18,130–69,540) all-cause deaths, 22,058 (95% CI: 7580–42,270) cardiovascular deaths, and 6656 (95% CI: 0–14,000) respiratory deaths across cities in the YRD. In addition, short-term exposure to 4DMA8 O3 led to 30,075 (95% CI: 16,550–43,600) all-cause premature deaths, 14,137 (95% CI: 5330–22,710) cardiovascular deaths, and 5448 (95% CI: 2840–8129) respiratory deaths. These results offer support for evaluating the impacts of O3 pollution policy and refining health intervention approaches in the YRD.