Sociodemographic Disparities in Global Compound Event Exposure for Cold Spells and PM_2.5 Pollutions

Cold spells and PM_2.5 pollution frequently cooccur, intensifying health and economic impacts. However, the spatiotemporal trends and disparities of these compound events remain unclear. In this study, we defined a compound event as a day on which both a cold spell and a PM_2.5 pollution event occurred and assessed its spatiotemporal characteristics and disparities at the grid scale. Our findings indicated an increase in global compound exposure, accompanied by significant regional disparities. From 2000 to 2023, 86% of Europeans experienced at least one compound event per year, 20 times the population more than in North America. More than 70% of countries with rising event days and population exposure were located in Asia and Africa. Total exposure increased from 64.5 to 91.3 million person-days, with the highest levels observed in high-income countries, where young adults, males, and urban populations were most affected. Our research provides a new perspective on understanding the inequities in compound exposure, particularly with respect to economic and regional disparities.