The short-term association between air pollution and childhood asthma hospital admissions in urban areas of Hefei City in China: A time-series study

Background: The impacts of air pollution on asthma attacks have become a hotspot. Previous studies mainly focused on the developed countries or cities. There have been very limited studies in less-developed region to quantify the effects of air pollutants on asthma admissions in children. This study aims to assess the short-term impact of air pollutants on asthma hospital admissions for children in Hefei, China. Methods: Poisson generalized linear regression combined with distributed lag non-linear model (DLNM) were applied to investigate the effects of air pollutants on daily childhood hospital admissions of asthma from 2015 to 2016, controlling for meteorological factors. Subgroup analyses by sex and age were performed. Results: There were a total of 17,227 asthma admissions during 2015-2016. We found positive correlations between childhood asthma hospital visits and concentrations of NO2, O-3, PM10 and PM2.5. Significantly, NO2 exhibited robust positive correlations with cumulative effects 1.551 (95% CI: 1.306-1.841, lag0-3 days) in single-pollutant model and 1.580 (95% CI: 1.315-1.899, lag0-3 days) in multiple-pollutant model. Conclusions: Air pollutants had adverse effects on childhood asthma. NO2 presented the greatest effect, followed by PM2.5. Results will be important for health authority and guardians to realize the severity of air pollution on the increased risk of asthma, so as to develop relevant strategies and health interventions to meet the challenges of childhood asthma and reduce air pollution.