Objective To determine the relationship between air pollutants [SO2,NO2,8 hours average concentration of ozone(O38h)] and outpatient visits for acne in Lanzhou,China. Methods Data of daily outpatient visits for acne and concentrations of air pollutants(SO2,NO2,and O38h)from January 2013 to December 2017 were collected.With the control of long-term trend and day-of-week effect,a distributed lag nonlinear model was used to analyze the lag and cumulative effects of air pollutants on the outpatient visits.The model was established based on the different groups of gender and age. Results During the study period,the average daily outpatient visits were 34.94±15.27,and the average concentrations of SO2,NO2,and O38h were 24.09,43.77,and 82.94 μg/m3,respectively.The Spearman's correlation analysis showed that the daily outpatient visits for acne were positively correlated with NO2 concentration while negatively correlated with O38h concentration;SO2 concentration was negatively correlated with O38h concentration;NO2 concentration was positively correlated with SO2 and O38h concentrations.A 10 μg/m3 increase in daily concentrations of NO2 and SO2 was respectively associated with 2.61%(95% CI=0.98%-4.27%)and 1.71%(95% CI=0.54%-2.89%)increase in the outpatient visits for acne.A 10 μg/m3 increase in O38h concentration was associated with -0.62%(95% CI=-1.12%--0.11%)increase in the outpatient visits.Multipollutant models indicated that air pollutant concentrations were significantly associated with the daily outpatient visits for acne. Conclusions SO2 and NO2 are positively associated with daily dermatological department visits for acne in Lanzhou,while O38h concentration has a negative correlation with the visits.The sensitivity of acne daily outpatient visits to changes in SO2,NO2,and O38h varies among patients of different genders and at different ages.
Keywords: NO2; O3; SO2; acne; air pollutants; distributed lag nonlinear model.