Association between air pollution and the number of outpatient visits for dermatitis in a hospital in Beijing city / 中华皮肤科杂志

ABSTRACT

Objective To investigate the association between air pollution and the daily number of outpatient visits for dermatitis in Beijing city, and to evaluate the sensitivity to air pollution in populations of different gender and age. Methods Time-series data on daily outpatient visits for dermatitis between April 2012 and April 2014 were collected from Air Force General Hospital of PLA. The daily average concentrations of sulfur dioxide (SO2), nitrogen dioxide(NO2), and particulate matters(PM2.5, PM10)were obtained from Beijing Municipal Environmental Monitoring Center, and routine meteorological data (including daily mean temperature, relative humidity and wind speed)were collected from the China Meteorological Data Sharing Service System. A generalized additive model was used to analyze the association between daily average concentrations of air pollutants and the number of daily outpatient visits for dermatitis. Results In single-pollutant models, an increase of 10 μg/m3 in daily concentrations of PM2.5, PM10, SO2, and NO2 was associated with the number of outpatient visits for dermatitis with the relative risk being 1.003 1 (95% CI, 1.001 6 - 1.004 5), 1.0025 (95% CI, 1.001 4 - 1.003 7), 1.0057 (95% CI, 1.001 5 - 1.009 9)and 1.009 7 (95% CI, 1.005 6 - 1.013 8)respectively. Similarly, multipollutant models showed that air pollutant concentrations were significantly associated with the daily number of outpatient visits for dermatitis. Distributed lag models showed that the effects of PM2.5, PM10 and NO2 on daily outpatient visits for dermatitis were mainly observed on the day of exposure, while the effect of SO2 increased along with the increment of lag days. Stratification analysis showed that people aged less than 60 years and females were relatively more sensitive to particulate matters (PM2.5, PM10), while NO2 affected all groups of people at the same degree, and SO2 mainly affected people aged 35 - 60 years. Conclusion Air pollutants PM2.5, PM10, SO2 and NO2 may all increase the risk of dermatitis in Beijing area.