Abstract：Objective To explore the effect of PM2.5 on the bronchitis outpatient visits of children in Jinhua.Methods The data of bronchitis outpatient visits of children from 2015 to 2016 were collected from Jinhua municipal central hospital and Jinhua maternity and child healthcare hospital. The PM2.5 and the meteorological factors monitoring data in the same study period were also collected. Generalized additive model（GAM）based on the Poisson regression was conducted to analyze the correlation between PM2.5 and the bronchitis outpatient visits of children and the lag effects.Results The daily average mass concentration of PM2.5 from 2015 to 2016 was（50.5±28.3）μg/m3 in Jinhua. The mass concentration of PM2.5 in winter was higher,with average of（70.1±36.3）μg/m3. There were totally 94 795 bronchitis outpatient visits of children and with average of 130 visits per day. The peak seasons of outpatient visits were winter and spring. There was a positive correlation between daily bronchitis outpatient visits for children and mass concentration of PM2.5（rs=0.40,P<0.01）. After controlling meteorological factors,there was a lag effect on the influence of mass concentration of PM2.5 on the bronchitis outpatient visits of children,which reached the strongest effect on the second day（RR=1.002 433,95%CI：1.002 193-1.002 673）. An increase in mass concentration of PM2.5 by 10 μg/m3 increased the bronchitis outpatient visits by 0.243 3%.Conclusion The higher mass concentration of PM2.5 may increase the bronchitis outpatient visits of children in Jinhua. There was a lag effect on the influence of mass concentration of PM2.5 on the bronchitis outpatient visits of children,and the hysteresis effect on second day was the strongest.
