Study On The Correlation Between Air Pollution,Meteorological Factors,and Outpatient Visits For Allergic Rhinitis In Changchun

Objective:Through analyzing the changes in the outpatient visits for allergic rhinitis（AR）,to evaluate the impact of air pollution and meteorological factors on AR onset,and to explore the effects of air pollution on AR under different temperature and humidity conditions.The aim is to provide a basis for formulating precise prevention and control measures for AR in the Changchun area.Methods:From 2018 to 2020,the air pollutant and meteorological data of Changchun and the AR outpatient data of the Second Hospital of Jilin University were collected.The Spearman rank correlation method was used to analyze the correlation between air pollutants and meteorological factors.The generalized additive model and distributed lag nonlinear model were used to examine the relationship between air pollution,meteorological factors,and AR outpatient visits after controlling for the long-term trends,day-of-week effects,and other confounding factors.Further stratified by gender and age,the effects of air pollution and extreme meteorological factors on different AR populations were analyzed.After stratifying air temperature and relative humidity,the effect of air pollution on AR under different meteorological conditions was analyzed.Results:1.Basic information:From 2018 to 2020,a total of 15536 patients AR patients visited the outpatient department of the Second Hospital of Jilin University.From2018 to 2020,the main pollutants exceeding standards in Changchun were PM_2.5and PM₁₀,followed by NO₂,O₃,and SO₂,whose daily average concentrations and ranges were 37.66μg/m³（3-410μg/m³）,63.86μg/m³（5-394μg/m3）,33.25μg/m³（8-96μg/m³）,54.13μg/m³（9-173μg/m³）,12.19μg/m³（2-64μg/m³）.The changes in pollutant concentration exhibit seasonal trends,with the peak concentrations of PM_2.5,PM₁₀,and SO₂occurring during winter and spring,while the peak concentration of O₃occurs during spring and summer.The daily average value and range of temperature,relative humidity,pressure,and average wind speed in Changchun from 2018 to 2020were 7.69°C（-20.0-29.9°C）,60.9%（15-100%）,986.89h Pa（965.8-1011.2h Pa）,and2.70m/s（0.3-6.5m/s）respectively,reflecting the characteristics that Changchun belongs to the north temperate continental monsoon climate.2.The effect of air pollution on AR outpatient visits:There was a lag effect of air pollution on the number of AR outpatient visits.When the single-day effect was at its maximum,as the daily average concentration of PM_2.5,PM₁₀,NO₂,SO₂,and O₃increased by 10μg/m³,AR outpatient visits increased by 1.60%（95%CI:0.48%～2.74%）,1.18%（95%CI:0.31%～2.07%）,5.42%（95%CI:2.83%～8.07%）,11.39%（95%CI:1.15%～22.68%）,and-1.36%（95%CI:-2.15%～0.57%）,respectively.When the cumulative lag effect was at its maximum,as the daily average concentration of PM_2.5,PM₁₀,NO₂,SO₂,and O₃increased by 10μg/m³,AR outpatient visits increased by 3.21%（95%CI:1.36%～5.09%）,1.92%（95%CI:0.41%～3.44%）,11.09%（95%CI:6.12%～16.30%）,36.44%（95%CI:8.68%～71.28%）,and-6.18%（95%CI:-9.77%～-2.45%）,respectively.Every 10μg/m³increase in the daily average concentration of PM_2.5,PM₁₀,NO₂,and SO₂had a statistically significant effect on the overall population,male and female AR outpatient visits（P<0.05）,and the relative risk（RR）value of AR outpatient visits were>1.The effects of NO₂and SO₂on males were slightly higher than those on females;PM_2.5,PM₁₀,and NO₂had statistically significant effects on AR outpatient visits in people aged<15 years and 15-64years（P<0.05）,and SO₂had the same effects on AR outpatient visits in people aged15-64 years,and each RR value was>1.3.The effect of meteorological factors on AR outpatient visits:There was a non-linear correlation between meteorological factors and AR outpatient volume.Lower temperatures,lower relative humidity,and a lower average wind speed had a more significant impact on AR outpatient visits,the RR value for the effect of temperature on AR outpatient visits was greatest when the temperature was-7.0°C.Among the extreme meteorological factors,low temperature（<-12.0°C）,high temperature（<-24.2°C）,and low relative humidity（33%）had a statistically significant hazard effect on the overall population（P<0.05）,while low average wind speed（<1.4m/s）had a statistically significant protective effect on the overall population（P<0.05）.The hazard effects of extreme meteorological factors on males and<15 years old were stronger.Males were more sensitive to high temperature and low relative humidity,while those<15 years old were more sensitive to low temperature,high relative humidity,and low average wind speed.4.The effect of air pollution on AR outpatient visits under different temperature and humidity conditions:In the stratification of temperature and relative humidity,under the condition of low temperature（<0.7°C）,PM_2.5,PM₁₀,and NO₂had a greater impact on the onset of AR,and for every 10μg/m³increase in their daily average concentration,the RR values of AR outpatient visits were 1.02（95%CI:1.00～1.04）,1.02（95%CI:1.00～1.04）,and 1.13（95%CI:1.07～1.19）,respectively.Under the condition of low relative humidity（<52%）,PM_2.5,PM₁₀,and NO₂had a greater impact on the onset of AR,and for every 10μg/m³increase in their daily average concentration,the RR values of AR outpatient visits were 1.02（95%CI:1.00～1.03）,1.01（95%CI:1.00～1.02）,and 1.05（95%CI:1.00～1.10）,respectively.Conclusion:1.The main pollutants that exceeded the standard in Changchun from 2018 to2020 were PM_2.5and PM₁₀.2.Air pollutants could affect the number of AR outpatient visits.An increase in the concentration of PM_2.5,PM₁₀,SO₂,and NO₂could significantly increase the number of AR outpatient visits,and the effect of air pollutants on AR had a significant lag and cumulative effect.Air pollution had a greater impact on males and children.3.There was a non-linear correlation between meteorological factors and AR outpatient volume.Extreme low temperature and low relative humidity had a hazard effect on AR in the overall population,while low average wind speeds have a protective effect.The hazard effect of extreme meteorological factors was stronger for males and children.When the winter temperature in Changchun is lower than-12℃,the risk of AR increases.The increased risk of AR in Changchun from December to January may be due to the influence of temperature factors.4.The cold and dry climate of Changchun could enhance the effect of air pollution(PM_2.5,PM₁₀,and NO₂)on the onset of AR.