Effects of Air Pollutants on Outpatient Visits for Atopic Dermatitis in Lanzhou

Objective To quantitatively evaluate the associations of PM2.5,PM10,NO2,and SO2 concentrations with the outpatient visits for atopic dermatitis in Lanzhou. Methods The data of outpatient visits,together with meteorological data and air pollutant data,from January 2013 to December 2017 were collected.The generalized additive model based on Poisson distribution was employed to study the lag effects of PM2.5,PM10,NO2,and SO2 concentrations on the visits of outpatients,with the seasonal and long-term trends and day-of-the-week effect controlled. Results The results of the single pollutant model showed that PM2.5 and PM10 had the most obvious while still insignificant impact on the outpatient visits for atopic dermatitis on the current day(lag0).NO2 also had the most obvious impact in the case of lag0 and showed a lag effect.For each 10 μg/m3 increase in NO2 concentration,the excess risk(ER)of outpatient visits for atopic dermatitis was 1.95%(95% CI=1.09%-2.82%,P=0.01).SO2 had the most significant effect on lag6,and the outpatient visits increased by 1.55%(95% CI=0.48%-2.54%)for every 10 μg/m3 rise in SO2 concentration(P=0.02).Females were more sensitive to PM10 and SO2 than males.For every 10 μg/m3 increase in PM10 and SO2,the female outpatient visits increased by 0.02% and 2.47%,respectively.Males were sensitive to PM2.5 and NO2,and the every 10 μg/m3 rise in PM2.5 and NO2 increased male outpatient visits by 0.47% and 1.78%,respectively.Gaseous pollutants(NO2 and SO2)had more significant effect on people ≤2 years old than on those of other ages.Every 10 μg/m3 rise in NO2 and SO2 would increase the ≤2-year-old outpatient visits by 2.35% and 1.57%,respectively(P=0.02).People of 13-59 years old were sensitive to NO2 concentration,and every 10 μg/m3 rise in NO2 concentration increased their visits by 1.39%.NO2 affected the outpatient visits during the cold and warm seasons,with the ER values of 2.35% and 1.89%,respectively(P=0.01).Particulate matter(PM2.5 and PM10)had the most obvious yet insignificant association with the outpatient visits in winter.The interactions between PM2.5 and NO2,between PM10 and NO2,and between SO2 and NO2 affected the total outpatient visits for atopic dermatitis.The results of double pollutant model showed that in the presence of PM2.5,PM10,or SO2,the effect of NO2 on the outpatient visits for atopic dermatitis enhanced compared with that predicted by single pollutant model(P=0.01). Conclusion The air pollutants(PM2.5,PM10,NO2,and SO2)in Lanzhou were closely related to the outpatient visits for atopic dermatitis,and the increased concentrations of NO2 and SO2 was more likely to increase the risk of atopic dermatitis.