Global health risk attributable to PM_2.5 pollution in relation to wealth inequality

Ambient fine particulate matter (PM_2.5) pollution causes the largest environmental health risk globally, yet exposure levels and the resulting health risks vary across countries with different income levels. Global wealth inequality has intensified in recent years, yet the relationship between wealth inequality and health risks related to PM_2.5 pollution remains poorly understood. In this study, we evaluated the global mortality and health cost attributable to PM_2.5 exposure from 2017 to 2021, and analyzed the relationship between wealth inequality, PM_2.5 pollution, and the associated health risks across regions with varying economic levels. We found a consistent decline in mortalities and health costs attributable to PM_2.5 exposure from 2017 to 2020, followed by a rebound after 2020, driven primarily by the resurgence of PM_2.5 concentrations and a deceleration in the reduction of baseline mortality rates. We also found that the average PM_2.5 concentration and associated risks decrease as domestic wealth inequality decreases and national income level increases. However, regions with extremely high levels of wealth inequality consistently show lower national average PM_2.5 concentrations and health risks. These findings highlight the need to consider healthcare security during emergencies, as well as policy fairness across economic regions, in the formulation of global PM_2.5 pollution control measures to promote sustainable, more equitable economic growth and coordinated air pollution management.