Correlation Of Air Pollution And Meteorological Factors With The Number Of Stroke Admissions In Shenyang

Objective:In recent years,the morbidity and mortality of stroke has increased year by year and has become a major factor in the global burden of disease.Recent epidemiological studies have shown that air pollution and meteorological factors are also environmental risk factors for stroke morbidity and mortality that cannot be ignored.As Shenyang is the largest city in northeast China,with large temperature differences between the four seasons,cold and long-lasting winters,coal-fired heating in winter and straw burning in spring and autumn further aggravate air pollution,the purpose of this study was to analyze the effects of air pollutants and meteorological factors on the number of stroke admissions in Shenyang and to provide a basis for exploring the risk factors associated with stroke.Methods:A total of 8661 cases of stroke admissions from January 1,2018,to December31,2019,in Shenyang were selected for this study.The correlation between air pollution and the number of stroke admissions was analyzed using a generalized summation model with Poisson-like distribution and Bayesian model,after adjusting for confounding factors such as long-term trends,week effects,holidays,and meteorological factors in the regression model.Stratification according to sex,age,and temperature was performed in the subgroup analysis.The stability of the model under co-exposure to multiple pollutants was analyzed by building a two-pollutant model and transforming degrees of freedom,and finally the exposure-response relationship between air pollution and the number of stroke admissions was analyzed using a penalized spline function.Results:A total of 8661 patients with stroke were included in this study after screening according to the International Classification of Diseases,with an average daily admission of 12.Among them,4520 were female and 4141 were male,4432 were<65 years old and4229 were≥65 years old.The total number of admissions during the cold season was 4649and the total number of admissions during the warm season was 4012.The mean concentrations of PM_2.5,PM₁₀,SO₂,NO₂,CO and O₃ during the study period were 40.27,74.08,21.75,35.18,946.48,and 58.60μg/m³,and the mean temperature and relative humidity were 9.36°C and 58.41%,respectively.After adjusting for long-term trends,meteorological factors,week effects,and holidays,PM_2.5 had a significant effect on the number of stroke admissions on day 3（lag3）,day 4（lag4）,and day 5（lag5）after exposure and had the greatest effect on stroke on day 3 of exposure with RR of 1.011（95%CI:1.001～1.021）,1.008（95%CI:1.001～1.014）,1.007（95%CI:1.000～1.013）,the effect of PM₁₀ on stroke admissions was significant at lag5 and lag6.The RR value for stroke was1.031（95%CI:1.006～1.056）for each 10μg/m³ increase in SO₂ concentration in lag3.The effect of CO on stroke admissions was significant in both lag4 and lag5 and the RR value was 1.001（95%CI:1.000～1.002）for both days.A cumulative effect of PM_2.5,SO₂ and CO on stroke was also found.Conclusion:1.Air pollutant exposure in Shenyang is associated with increased risk of stroke admissions,and pollutants have acute and cumulative effects on stroke admissions.2.Males and people over 65 years of age are more sensitive to pollutants,the effect of air pollutants on stroke admissions is more significant in the cold season.3.During the cold season when the concentration of each air pollutant was fixed at the respective 55th and60th percentile,there was a positive combined effect of six air pollutants and stroke admissions;when temperature,relative humidity,wind speed,and air pressure were at the35th-45th percentile,there was a positive combined effect of meteorological factors on stroke admissions.