The construction and validity analysis of AQHI based on mortality risk: A case study in Guangzhou, China

The current air quality indices have been criticized for not capturing combined health effects of multiple air pollutants. We proposed an Air Quality Health Index (AQHI) based on the air pollution-mortality associations for communicating health risks of air pollution. Time-series studies were conducted to estimate the associations between air pollutants including sulfur dioxide (SO₂), nitrogen dioxide (NO₂), ozone (O₃), suspended particulate matter smaller than 2.5 μm in aerodynamic diameter (PM_2.5) and mortality in Guangzhou from 2012 to 2015. The sum of excess mortality risk was calculated to construct the AQHI, which was then adjusted to an arbitrary scale. We then assessed the validity of AQHI. An interquartile increase (IQR) of AQHI was associated with 3.61% [95% confidence interval (95% CI), 2.85%-4.37%], 3.73% (95%CI, 2.18%-5.27%) and 4.19% (95%CI, 2.87%-5.52%) increase of mortality, respiratory and cardiovascular hospital admissions, respectively. Compared with the currently used Air Quality Index (AQI), AQHI had higher effects on mortality and morbidity. Our study suggests that AQHI might comprehensively capture the combined effects of air pollution, which make it be a more valid communication tool of air pollution-related health risk.