Air pollution and climate change drive health inequities across China's provinces (2000–2023)

Achieving health equity is a key mission of the United Nations Sustainable Development Goals (SDGs). This study integrated epidemiological models for both acute and chronic health outcomes with climate, demographic, and cause-specific mortality data. It assessed province-level health inequalities and their drivers across China (2000–2023), focusing on short- and long-term exposures to air pollution (PM_2.5, ozone) and climate-related events (heatwaves, cold spells). The results show that China's clean air initiatives have significantly reduced PM_2.5 levels, improving short-term exposure risks and narrowing ozone-related health inequalities. However, densely populated and aging regions in northern and central China continue to bear disproportionate health burdens. A hidden inequality also emerges in the west, where low mortality counts mask high mortality rates. Approximately 80% of the health benefits accrue to just 13.5%–19.0% of the population, while older adults – only 10% of the population—bear over 70% of the health burden. The analysis identifies three key drivers contributing to health inequality: accelerated population aging, inequities in healthcare access, and heightened vulnerability to climate change. The multi-risk factor analysis reveals persistent significant inequalities in health risks and benefits across regions and demographic groups.