The combined effect of air pollution and non-optimal temperature on mortality in Shandong Province, China: establishment of air health index

Purpose The air health index (AHI) captures the combined effects of air pollution and non-optimal temperatures and helps assess the atmospheric environment’s overall health risk. Shandong Province is a crucial industrial base in China, and the health effects of air pollution and non-optimal temperature cannot be ignored. To construct an AHI for Shandong Province and assess the district-level mortality burden due to AHI in the study area. Methods Daily district-specific mortality, meteorological, and air pollution data over 2013–2018 were collected in Shandong Province, China. The AHI construction eventually incorporated PM 2.5 and NO 2 , O 3 , and non-optimal temperatures. Attributable fraction (AF) and attributable number (AN) were used to estimate the district-specific mortality burden attributable to AHI. Results The average AHI value observed in Shandong Province was 6. Our research revealed a positive association between the total AHI and total mortality, with an overall trend of a slow increase followed by a rapid increase. The exposure–response curves, when stratified by gender, age, and cause of death, were approximately consistent with the overall trend. The provincial attributable fraction (AF) was 5.31% (95% CI 4.58%, 5.91%), and the attributable number (AN) was 188,246 (95% CI 162,396, 209,533). Overall, higher ANs mainly appeared in the southwestern area, while higher values of AF were observed in the central-eastern and central-northern areas. Conclusions The air health index performs well in predicting death burden and can convey health risks related to exposure to the ambient environment to the public.