Short-term effects of air pollutants on hospital admissions for acute bronchitis in children:a multi-city time-series study in Southwest China

Background Few studies have investigated the effects of air pollutants on children with acute bronchitis.This study aimed to explore the acute effects of four air pollutants[fine particulate matter(PM_(2.5)),inhalable particulate matter(PM10),sulfur dioxide(SO_(2)),and nitrogen dioxide(NO_(2))]on the daily number of children admitted to the hospital for acute bronchitis in Sichuan Province,China.Methods The 49,975 records of hospitalized children with acute bronchitis from medical institutions in nine cities/prefectures,Sichuan Province,China,as well as the simultaneous meteorological data and air pollution data from 183 monitoring sites,were collected from 1 January 2017 to 31 December 2018.A generalized additive model was adopted to analyze the exposure–response and lag effects of hospitalizations of children with acute bronchitis to air pollutants.Stratified analyses were conducted based on sex,age,and season.Results The single-pollutant model showed that a 10µg/m3 increase at lag07 of PM_(2.5),PM10,SO_(2),and NO_(2) corresponded to an increase of 1.23%[95%confidence interval(CI)0.21–2.26%],1.33%(95%CI 0.62–2.05%),23.52%(95%CI 11.52–36.81%),and 12.47%(95%CI 8.46–16.64%)in daily hospitalizations for children with acute bronchitis,respectively.Children aged 0–2 were more prone to PM_(2.5)(P<0.05).Interestingly,the effects were stronger in the warm season than in transition seasons and the cool season for PM_(2.5) and PM10(P<0.05).Conclusion The higher daily average concentrations of four pollutants in Sichuan Province can result in an increased number of children hospitalized for acute bronchitis.