Health risk assessment of air pollution in Xinjiang, Northwest China

Air pollution disrupts ecological stability, threatens public health, and increases the risk of associated diseases. This study analyzed the spatiotemporal variations of six criteria pollutants from 2015 to 2024 in Xinjiang and their associated health risks using air quality index (AQI), aggregate air quality index (AAQI) and health risk indices (equivalent health risk-based index (EHAQI) and excess risk (ER)). The study was divided into two periods for comparative analysis: period one (2015-2019) and period two (2020-2024). Results showed that PM₁₀ dominated as the primary pollutant, particularly in Southern Xinjiang. Single-pollutant metrics underestimated combined health impacts of the six pollutants. Environmental policies and lockdowns significantly reduced SO₂ (47.9%), CO (41.7%), PM₂.₅ (19.9%), NO₂ (16.4%), and PM₁₀ (12.0%) compared with Period one. The O₃ growth rate in Northern Xinjiang exceeded that in Southern Xinjiang by 3.7%. Health risk assessments revealed that PM₁₀-driven excess risk (ER) accounted for 80% of the total health burdens in Southern Xinjiang. While in Northern Xinjiang, NO₂ dominated ER, surpassing PM₁₀. Spring and winter saw peak EHAQI values, and 36.0% of residents were exposed to "severe" pollution in spring. These findings could provide scientific evidence for PM reduction policies in Southern Xinjiang and pollution-related disease prevention.