Correlation between environmental factors in Nanchong in spring and the symptoms of allergic rhinitis

Pan Chen; Zhu Qi; Luo Guangcheng; Huang Yongqin; Li Wanning; Tian Hongchan; Yu Wangbo

doi:10.11986/j.issn.1673-873X.2025.08.13

Abstract：Objective To explore the effects of spring airborne pollen concentration,meteorological factors,and air quality on the symptoms of allergic rhinitis(AR)patients in Nanchong and clarify the relationship between environmental factors and AR symptoms.Methods A total of 1,169 AR patients who visited the outpatient service of the Department of Otorhinolar-yngology & Head and Neck Surgery at the Affiliated Hospital of North Sichuan Medical College during the months of Feb-ruary to April in each of the years 2022,2023,and 2024 were selected as the research participants.The AR symptoms were quantitatively assessed using the four-point symptom score scale,and the environmental data of the same period were col-lected.The correlation between AR symptoms and environmental factors was analyzed.Results The average daily tempera-ture in Nanchong during spring ranged from 7.19 to 27.27℃,the average daily air pressure was 973.79 hPa,the average daily relative humidity was 73.00％RH,the average daily maximum wind speed was 7.20 m/s,the average PM2.5 concen-tration was 33.00 μg/m3,the average O3 concentration was 90.00 μg/m3,and the average airborne pollen concentration was 344.00 particles/1,000 mm2.Stepwise regression analysis showed that airborne pollen concentration had a positive effect on the total nasal symptom score(TNSS)of patients(Beta=0.089,P=0.003),while the daily maximum wind speed had a negative effect on TNSS(Beta=-0.068,P=0.022).The daily minimum temperature(Beta=-0.216,P＜0.001)and the daily average relative humidity(Beta=—0.122,P＜0.001)had negative effects on the total ocular symp-tom score(TOSS)of patients.Multi-factor logistic regression analysis found that environmental factors exerted influence on nasal symptoms in AR patients in two ways.First,the effect on nasal congestion symptoms:Increased daily relative humid-ity was a risk factor for moderate-to-severe nasal congestion(OR=1.018 930,95％CI:1.002 498-1.035 632,P=0.024);increased PM2.5 levels were a risk factor for moderate-to-severe nasal congestion(OR=1.010 691,95％CI:1.001 288-1.020 181,P=0.026);increased airborne pollen concentration was a risk factor for moderate-to-severe nasal congestion(OR=1.000 080,95％CI:1.000 009-1.000 151,P=0.028);increased O3 concentration was a risk factor for moderate-to-severe nasal congestion(OR=1.009 158,95％CI:1.002 721-1.015 635,P=0.005).Second,the effect on nasal itching symptoms:Increased daily relative humidity was a risk factor for moderate-to-severe nasal itching(OR=1.013 965,95％CI:1.000 590-1.027 519,P=0.041);increased PM2.5 levels were a risk factor for moderate-to-severe nasal itching(OR=1.010 234,95％CI:1.002 640-1.017 886,P=0.008);increased airborne pollen concentration was a risk factor for moderate-to-severe nasal itching(OR=1.000 216,95％CI:1.000 125-1.000 307,P＜0.001).Meanwhile,environ-mental factors showed an impact on ocular symptoms in AR patients in two aspects.First,the effect on eye itching symp-toms:Increased daily temperature was a protective factor for moderate-to-severe eye itching,with an OR(95％CI)of 0.914 394(0.872 503-0.958 296);increased PM2.5 levels were a risk factor for moderate-to-severe eye itching,with an OR(95％CI)of 1.016 980(1.009 132-1.024 888).Second,increased daily temperature,daily air pressure,daily relative humidity,and airborne pollen concentration were protective factors for moderate-to-severe tearing,with OR(95％CI)values of 0.894 713(0.806 918-0.992 059),0.944 451(0.893 213-0.998 628),0.895 795(0.864 778-0.927 925),and 0.999 283(0.998 837-0.999 729),respectively.Conclusion In Nanchong,during the spring season,airborne pollen concentration,PM2.5 levels,and meteorological factors(such as daily temperature and relative humidity)significantly affect the symptoms of AR patients.Increased pollen concentration and PM2.5 are important triggers for AR symptom exacerbation,while mete-orological factors indirectly affect AR symptoms by influencing the spread of pollen.This study highlights the substantial role of environmental factors in the onset of AR and provides scientific evidence for the prevention and treatment of AR.