Atmospheric particulate matter and hospital admission due to lower respiratory tract infection: A case-cross study in Shijiazhuang, China / 解放军医学杂志

ABSTRACT

Objective To explore the association between atmospheric particulate matter (PM10/PM2.5) levels and hospital admissions due to lower respiratory tract infection in Shijiazhuang. Methods Data of air pollution, meteorologic data, and the data of patients admitted to hospital due to lower respiratory tract infection were retrospectively analyzed. Pearson's correlation coefficients were calculated to analyze correlations between atmospheric particulate matter and meteorologic factors. Data of hospital admission due to lower respiratory tract infection and of atmospheric air pollution levels in Shijiazhuang were obtained, a bidirectional case-crossover design was used to investigate the association between hospital admissions due to lower respiratory tract infection and levels of atmospheric particles. Stratified analyses of exposure based on age, gender, complications and season were performed to evaluate the effect. Results Pearson's correlation analysis showed positive correlations among PM2.5, PM10, SO2, NO2 and CO. The concentration of all these five pollutants were negatively correlated with O3 and daily mean temperature, while a positive correlation was found between concentrations of the 5 pollutants and daily average temperature and O3. In single-pollutant model, every 10μg/m3 increase in PM2.5 and PM10 at lag5 brought the corresponding OR values (95%CI) up to 1.010(1.005-1.015) and 1.006(1.003-1.009) respectively. In the multi-pollutant models, the observed effects of PM2.5 remained significant. Stratified analysis based on gender, age, season and comorbidities showed that the effect of PM2.5 exposure on lower respiratory tract infection admissions was stronger in males, persons younger than 60 years of age and persons without comorbidities, and even more stronger in cold season. The effect of PM10 exposure on lower respiratory tract infection admissions was stronger in females, persons older than 60 years of age and persons with comorbidities, and even more stronger in cold season. Conclusion Our study demonstrates that higher levels of atmospheric particulate matter (PM10/PM2.5) may increase the risk of hospital admissions due to lower respiratory tract infection.