Assessing the impact of air pollutants on clinical visits for childhood allergic respiratory disease induced by house dust mite in Shanghai, China

Abstract

Abstract Background The prevalence of allergic respiratory disease (ARD) is increasing worldwide during the last few decades, causing a great disease burden especially for children. Air pollution has been increasingly considered as a potential contributor to this trend, but its role in ARD induced by house dust mite (HDM-ARD) remains unclear, especially in time-series study. Methods A positive reporting of respiratory allergy to named allergens was included by serum specific IgE testing. A time series Quasi-Poisson regression with distributed lag non-linear model, combined with generalized linear model was used to examine the effects of air pollutants on ARD, HDM-ARD and ARD induced by non-house dust mite (NHDM-ARD). Results A total of 16,249 cases of ARD, including 8,719 HDM-ARD and 8,070 NHDM-ARD from 1 Jan 2013 to 31 Dec 2017 were involved in this study. Air pollutants were significantly associated with clinical visits for childhood ARD and HDM-ARD. Exposure to higher O3 and interquartile range (IQR) increment in O3 (40.6 µg/m3) increased the risks of clinical visits for childhood HDM-ARD (RRlag0-5 for the 95th percentile of O3: 1.26, 95% confidence interval (CI): 1.03, 1.55; RRlag0-5 for IQR increment (40.6 µg/m3): 1.09, 95% CI: 1.01, 1.17) and ARD (RRlag0-5 for the 95th percentile of O3: 1.19, 95% CI: 1.03, 1.38; RRlag0-5 for IQR increment (40.6 µg/m3): 1.06, 95% CI: 1.01, 1.12). In addition, higher O3 was associated with increased RR of boys with ARD (RRlag0-5 for the 95th percentile: 1.26, 95% CI: 1.05, 1.51; RRlag0-5 for IQR increment (40.6 µg/m3): 1.09, 95% CI: 1.02, 1.16) and HDM-ARD (RRlag0-5 for the 95th percentile: 1.36, 95% CI: 1.06, 1.75; RRlag0-5 for IQR increment (40.6 µg/m3): 1.11, 95% CI: 1.02, 1.22), but not in girls. Conclusions Exposure to O3 appeared to be a trigger of clinical visits for childhood ARD, especially for HDM-ARD and boys. These findings provide novel evidence on the impact of air pollution on HDM-ARD, which may have significant implications for designing effective intervention programs to control and prevent childhood ARD, especially HDM-ARD, in China and other similar developing countries.