biostudies-literatureHuang WMedical Research CouncilWellcome Trust101488https://www.ebi.ac.uk/biostudies/studies/S-EPMC7618329biostudies-literatureUnknown8(11)Ambient air pollutants are leading contributors to global mortality. Despite the well-established risks, most studies have relied on single-pollutant models in limited regions, leaving the combined effects and individual contributions of pollutants unclear, particularly across countries. Here, we integrate daily mortality and air pollutant (nitrogen dioxide [NO₂], ozone [O₃], fine particulate matter, and sulfur dioxide) data from 482 cities in 12 countries/territories from 1998 to 2021 to assess the joint mortality risks and identify the main contributing pollutant through an air quality health index of multi-pollutant constrained groupwise additive models (AQHI-Multi). AQHI-Multi outperformed commonly used air quality indices in capturing the overall mortality risks. O₃ and NO₂ were the leading contributors (accounting for over 70% across countries/territories), with O₃'s share increasing slightly to moderately in most countries/territories. These findings highlight the need for developing air quality indices using advanced multi-pollutant models and the emerging global significance of targeted control of O₃ and NO₂.One earth (Cambridge, Mass.)Improved global air quality health index reveals ozone and nitrogen dioxide as main drivers of air-pollution-related acute mortality.PMC7618329MR/V034162/1Zhang JGuo YYu PMasselot PSun QMadureira JYu WSera FTong SBell MLHashizume MXu RZhou SGaio VGasparrini AKan HYang ZBreitner SMCC Collaborative Research NetworkLi SLi TLavigne EHuang WZhang YGuo YLfalseImproved global air quality health index reveals ozone and nitrogen dioxide as main drivers of air-pollution-related acute mortality.Ambient air pollutants are leading contributors to global mortality. Despite the well-established risks, most studies have relied on single-pollutant models in limited regions, leaving the combined effects and individual contributions of pollutants unclear, particularly across countries. Here, we integrate daily mortality and air pollutant (nitrogen dioxide [NO₂], ozone [O₃], fine particulate matter, and sulfur dioxide) data from 482 cities in 12 countries/territories from 1998 to 2021 to assess the joint mortality risks and identify the main contributing pollutant through an air quality health index of multi-pollutant constrained groupwise additive models (AQHI-Multi). AQHI-Multi outperformed commonly used air quality indices in capturing the overall mortality risks. O₃ and NO₂ were the leading contributors (accounting for over 70% across countries/territories), with O₃'s share increasing slightly to moderately in most countries/territories. These findings highlight the need for developing air quality indices using advanced multi-pollutant models and the emerging global significance of targeted control of O₃ and NO₂.2025-01-01T00:00:00Z2025 Nov2026-06-06T13:58:02.531Z2026-05-31T03:10:15.102ZS-EPMC76183294136241610.1016/j.oneear.2025.101488