Impacts of apparent temperature and air pollutants on daily pneumonia hospitalizations and their interaction in rural areas of Western China

This study investigated the impacts and interactive effects of apparent temperature and air pollutants on rural pneumonia hospitalizations in Jiuquan, China (2015–2020), utilizing NRCMS surveillance data, distributed lag non-linear models (DLNM), and stratified analyses. The findings revealed an inverted U-shaped relationship between apparent temperature and pneumonia hospitalizations, peaking at a relative risk (RR) of 1.50 (95% CI: 1.41–1.60). Per interquartile range (IQR) increases in CO, SO2, O3, NO2, PM2.5, and PM10 were associated with RR values of 1.11 (95% CI: 1.01–1.21), 1.04 (95% CI: 0.97–1.12), 1.08 (95% CI: 0.93–1.24), 1.02 (95% CI: 0.93–1.12), 1.04 (95% CI: 0.97–1.12), and 1.05 (95% CI: 1.00–1.12), respectively. Furthermore, synergistic interactive effects occurred between low apparent temperature and high air pollution, and among distinct air pollutants. Subgroup analyses showed higher risks for children under 7 years old, minimal gender disparities, and more pronounced risks during autumn and winter. The study underscores the critical need for targeted interventions in rural areas during concurrent periods of low apparent temperature and high air pollution to reduce public health risks.