Interaction between PM_2.5 and air temperature on daily hospital visits of children due to respiratory disease in Changping district, Beijing

ObjectiveTo understand the interaction between fine particulate matter with aerodynamic diameter ＜2.5 μm （PM_2.5） and air temperature on the daily hospital visits of children due to respiratory disease in Changping district of Beijing.

MethodsThe data of daily hospital visits of children were collected from a hospital in Changping, and the relevant meteorological data and air pollution data, including PM_2.5, SO₂ and NO₂ concentrations, in Changping from 1^st of January 2014 to 31^st of December 2017 were also collected. Based on the distributed lag non-linear model （DLNM） with quasi-Poisson link, response surface model and stratified model were used to investigate the potential interactions between air pollution and air temperature on daily hospital visits of children due to respiratory disease.

ResultsAt low, moderate, and high temperature layers stratified by the mean temperatures of 25th and 75th percentiles, a 10 μg/m³ increase of PM_2.5 concentration resulted in the relative risks of 1.003 （0.994–1.011）, 1.015 （1.007–1.023） and 1.039 （1.021–1.057）, respectively, for total hospital visits due to respiratory disease in children on lag 0–14 days. The adverse effect of PM_2.5 increased obviously under higher air temperature （P＜0.05）.

ConclusionThere was an obvious interaction between PM_2.5 and high temperature on hospital visits due to respiratory disease in children, the adverse effect of PM_2.5 on hospital visits due to respiratory disease in children were more obvious when air temperature was high.