Short-term Effects Of Ambient Air Pollution On Daily Outpatient Visits For Urticaria In Beijing, China

Objective To investigate the short-term association between ambient air pollutants exposure and daily dermatological department visits for urticaria in Beijing, China. It is to evaluate quantitatively the correlation between each pollutant and daily outpatient urticaria and establish initially exposure-response relationship evaluation model. And then the results can provide clinical epidemiological evidence for the study of the effect of ambient air pollution on the skin and lay the foundation for further vitro and in vivo researches.Methods 1. Subjects who visited the dermatological department of the General Hospital of Air Force for urticaria from 2012.4.1 to 2014. 4.30 were included in the study. Air pollution parameters, including the daily 24-h average concentration of PM2.5, PM10,nitrogen dioxide(NO2), sulfur dioxide(SO2), daily average temperature and relative humidity in the same period were collected. We used generalized additive models(GAM),the distributed lag non-linear model(DLNM) and Spearman rank correlation test to analyze the number of dermatology outpatient for urticaria and pollutants, the risk was expressed as an odds ratio(OR) per 1 standard deviation of PM2.5 and a RR and its corresponding 95% confidence interval(95%CI) by1μg/m3 augment of each pollutant.Results 1. In a single-air pollutant mode, RR and 95%CI by every 1μg/m3 increase in PM2.5,PM10,NO2 and SO2 were 1.0001(95%CI 0.9997,1.0004),1.0002(95%CI 0.9999,1.0004), 1.0020(95%CI1.0028,1.0011) and1.0011(95%CI1.0002, 1.0021) respectively. when multi-pollutant models included SO2, PM10, PM2.5, the correlation of NO2 and daily outpatient urticaria was enhancement; when the models included PM2.5, PM10 respectively, the strength of association SO2 and daily outpatient visits for urticaria enhanced. In the group aged from35 to 65,RR and 95%CI by every1μg/m3 increase in SO2, NO2 were 1.0016(95% CI 1.0001,1.0031), 1.0029(95% CI 1.0015,1.0043). 2. After adjusting for all the confounding factors by DLNM, we see the maximum risk was observed in the distributed lag0-20 model(The largest cumulative effect of PM2.5, OR, 1.22; 95%confidence interval, 1.03–1.46), the relationship between PM2.5 and the daily counts of visits for urticaria were statistically significant. The concentrations of PM2.5 were negatively correlated with daily average temperature but positively correlated with daily relative humidity(P < 0.05). Daily average temperature and relative humidity were positively related to the daily counts of outpatient for urticaria(P < 0.05).Conclusion SO2 and NO2 are positively associated with daily dermatological department visits for urticaria in Beijing;After adjustment for other possible biological confounding factors and other atmospheric factors, PM2.5 was positively correlated with daily dermatological department visits for urticaria and there is an obvious lag effect on urticaria outpatient. People aged of 35 to 60 year-olds are more sensitive to environmental air pollution.