The highlight outcomes have quantified the total number of inpatient hospitalizations due to short-term exposure to O3 pollution up to 440.39 (95% CI: - 0.03 - 872.72) cases calculated according to the 8-hour average threshold of QCVN 05: 2013/BTNMT and 1, 556.94 (95% CI: - 1.20 - 3, 047.94) cases calculated according to the Interim target threshold 2 of WHO guidance in 2021.