Interaction Between Atmospheric Pollutants And Meteorological Factors On Hospitalization Risk Of Hemorrhagic Stroke In Ningxia

Objective To analyze the independent influence of atmospheric pollutants and meteorological factors on hospitalization risk of hemorrhagic stroke,explore the interaction of atmospheric pollutants and meteorological factors on hospitalization risk of hemorrhagic stroke,and identify sensitive groups according to age and gender groups.Methods（1）Data of hospitalized hemorrhagic stroke cases,meteorological data and atmospheric pollutant data were collected in Ningxia from January 1,2015 to December 31,2019.（2）The change trend of daily hospitalized cases,meteorological factors and atmospheric pollutants was observed by time series graph,and the correlation between meteorological factors and atmospheric pollutants was analyzed by Spearman rank correlation.（3）Generalized additive model and distributed lag non-linear model were used to analyze the independent effects of atmospheric pollutants and meteorological factors on hospitalization risk of hemorrhagic stroke.（4）Bivariate response surface model and stratified analysis were used to evaluate the interaction between atmospheric pollutants and meteorological factors on hospitalization risk of hemorrhagic stroke.Results（1）Basic information:A total of 16905 hospitalized cases of hemorrhagic stroke were included in this study.The adult patients were more than elderly patients,and male patients were more than female patients.The average number of hospitalized cases per day was9,showing an overall trend of increasing in winter and spring and decreasing in summer and autumn.The average daily temperature,average daily relative humidity and average daily pressure were 10.39℃,49.20%and 868.99 h Pa from 2015 to 2019.The daily mean concentrations of PM_2.5,PM₁₀,SO₂ and NO₂ are 41.41,100.85,30.72 and 28.832)/8)³,respectively;the daily maximum eight-hour mean concentration of O₃ is 94.992)/8)³,and the daily mean concentration of CO is 0.878)2)/8)³.The concentration of PM_2.5,PM₁₀,SO₂,NO₂and CO showed a trend of high in winter and low in summer,and the concentration of O₃showed a trend of high in summer and low in winter.（2）Effects of atmospheric pollutants on hospitalization risk of hemorrhagic stroke:short-term exposure to PM_2.5,PM₁₀,NO₂ and CO increased the risk of hospitalization for hemorrhagic stroke in the total population,and the effect values were the largest on Lag04,Lag04,Lag05 and Lag07,respectively.For every 102)/8)³ increased in the concentration of PM_2.5,PM₁₀and NO₂,the risk of hospitalization for hemorrhagic stroke increased by 2.027%（ER=2.027,95%CI:0.560～3.515）,0.496%（ER=0.496,95%CI:0.056～0.937）and 4.995%（ER=4.995,95%CI:1.069～9.073）.For every0.18)2)/8)³ increased in the concentration of CO,the risk of hospitalization for hemorrhagic stroke increased by 2.066%（ER=2.066,95%CI:0.312～3.850）.Increased O₃concentration was associated with decreased risk of hospitalization for hemorrhagic stroke in the total population,and no effect of SO₂ was found on hospitalization risk for hemorrhagic stroke in the total population.In the age subgroup,NO₂ is more harmful to the adult population,while PM_2.5,PM₁₀ and CO are more harmful to the old population.In the gender subgroup,PM_2.5,SO₂,NO₂and CO are more harmful to the male population,while PM₁₀ is more harmful to the female population.（3）The influence of meteorological factors on hospitalization risk of hemorrhagic stroke:short-term exposure to low temperature and high relative humidity increased the hospitalization risk of hemorrhagic stroke in the total population,and the effect value was the largest on Lag07（RR=1.453,95%CI:1.066～1.981;RR=1.715,95%CI:1.129～2.605）;No effect of barometric pressure on hospitalization risk of hemorrhagic stroke was found in the total population.In the age subgroup,low temperature,low pressure and high pressure were more harmful to the adult population,while high relative humidity was more harmful to the old population.In the gender subgroup,low temperature and high relative humidity are more harmful to the male population,and high pressure is more harmful to the female population.（4）Interaction of atmospheric pollutants and meteorological factors on hospitalization risk of hemorrhagic stroke:low temperature,high relative humidity and high pressure have synergistic effects with atmospheric pollutants on hospitalization risk of hemorrhagic stroke in the total population,respectively.In the age subgroup,the adult population were more sensitive to the synergistic effect of high temperature,low relative humidity,high pressure and atmospheric pollutants.The old population is more sensitive to the synergistic effect of low temperature,high relative humidity and atmospheric pollutants.In the gender subgroup,the male population was more sensitive to the synergistic effect of high relative humidity,high pressure and pollutants.The female population is more sensitive to the synergistic effects of high temperature,low relative humidity and high pressure with pollutants.Conclusion（1）According to the Level 2 concentration limit of China’s Ambient Air Quality Standards,the overall air quality in Ningxia is great.（2）Short-term exposure to PM_2.5,PM₁₀,SO₂,NO₂,CO,low temperature and high relative humidity can increase the hospitalization risk of hemorrhagic stroke.（3）Atmospheric pollutants and meteorological factors have interaction effects on hospitalization risk of hemorrhagic stroke.（4）There are age and gender differences in the effects of atmospheric pollutants,meteorological factors and their interactions on hospitalization risk of hemorrhagic stroke,and attention should be paid to protecting susceptible populations under specific climatic conditions.