Evaluation of the health risk of air pollution in major Chinese cities using a risk-based, multi-pollutant air quality health index during 2014-2018

Combined air pollution in eastern China is becoming increasingly pronounced, and the air quality index (AQI), which represents the condition of the primary pollutant, can no longer sufficiently evaluate the health risk of air pollutants to humans. In this study, the temporal and spatial distributions of the health risk values (percentage of excess risk, %ER) of four principal air pollutants in six representative cities in China (Beijing, Shanghai, Guangzhou, Chengdu, Shenyang, and Xi'an) from 2014 to 2018 are calculated using an air quality health index (AQHI) that is based on environmental epidemiological research results developed by Hong Kong. The results show that the 90th percentile of the corresponding annual average %ER in these cities decreased by varying degrees. The health risk attributed to air pollution was lower in cities of southern China than those of northern China. The average contributions of PM10 and O-3 exceeded 25% and 30%, respectively, which indicates that the combined pollution was severe in the six cities. However, the AQI evaluation method usually underestimates the health risk of air pollution in spring and summer because this method only considers one primary pollutant. In the early spring period (March-May) of Beijing, AQI fell by -24%, but %ER rose by 4% while considering the combined pollution. This substantial difference suggests an urgent demand for corporations and data sharing between the Chinese environmental protection administration and medical authorities to establish and develop a more accurate, scientific, and localized air quality evaluation system. The system developed by China can better assess the health risk caused by combined pollution, which is more adapted to different regions, and provide the public with more accurate advice regarding health risks from air pollution.