Assessment of the changing trends of air quality health index in Anyang City over the past five years

Using the Air Quality Health Index (AQHI) methodology based on the results of environmental epidemiological research in Hong Kong, the trend and site-specific characteristics of excess health risk (%ER) in Anyang City from 2019 to 2023 were calculated amid worsening atmospheric compound pollution. The results indicated that due to reduced pollution source activities during the COVID-19 pandemic, the 80th percentile of %ER showed a year-on-year decline from 2019 to 2022. However, as the compound pollution intensified in 2023, %ER rebounded at the 80th percentile. Under the influence of climate change, the earlier onset of high-temperature days in spring led to more pronounced co-pollution from particulate matter and ozone, with %ER exhibiting an upward trend in spring. The contribution of specific pollutants was closely related to nearby pollution sources, resulting in significant differences in %ER across monitoring sites. A comparison of different air quality assessment methods revealed that the Air Quality Index (AQI) and composite indices tended to underestimate the health effects of ozone from March to July and in September. The AQHI method provides a more accurate assessment of health risks associated with compound pollution and offers the public more precise health risk advisories related to air pollution.