Correlation Analysis Between Acute Bronchial Asthma Attacks And Air Quality In Children

Objective:In this study,the general and clinical data of hospitalized children with acute asthma attacks in Lanzhou City,and the changes of air pollutant concentration in urban areas were statistically analyzed.To explore the correlation between the changes of air pollutant concentration and the number of hospitalized children with acute asthma attacks and lung function indexes.Method:In this study,children hospitalized for acute asthma attacks from 01/01/2014 to12/31/2021 in Gansu Provincial Maternal and Child Health Hospital,aged between 6-14 years old,were selected,including gender,age,ethnicity,home address,length of hospitalization,personal history of allergy,family history of allergy,blood count,respiratory pathogens,sputum culture,chest imaging,and pulmonary function,and other indicators The air quality monitoring platform is used to analyze the pattern.The concentrations of six major air pollutants(PM_2.5,PM₁₀,SO₂,CO,NO₂,O₃)were obtained from the Chinese air quality online monitoring platform in the same period.The effects of changes in air pollutant concentrations on the number of children hospitalized for acute asthma attacks were analyzed by two-by-two correlation and multiple regression methods,and the effects of changes in air pollutant concentrations on the lung function of children hospitalized for acute asthma attacks were also analyzed by linear regression methods.Result:（1）A total of 404 hospitalized children were included in this study,with 286（70.8%）boys and 118（29.2%）girls by age,and the ratio of boys to girls was about 2.4:1.93.6%（378/404）were Han Chinese,followed by 3.7%（15/404）of Hui,and 2.7%（11/404）of the rest by ethnicity.By age,84.7%（342/404）of children aged 6-12 years old and 15.3%（62/404）of children aged 12-14 years old were classified by home address,and the top three were Chengguan District,Qilihe District and Anning District,accounting for 31.7%（128/404）,29.7%（120/404）and 16.1%（65/404）,respectively.（2）Statistical analysis of 404 hospitalized children for their personal allergy history,family allergy history,whether or not they had a coexisting respiratory infection,and length of stay showed no statistical difference in the number of boys and girls for personal and family allergy history（P>0.05）.Analysis of the number of asthma attacks alone and asthma attacks with respiratory tract infections showed no statistical difference between boys and girls（P>0.05）.Analysis of the length of stay in hospital for boys and girls revealed a statistical difference in the length of stay for boys and girls（P<0.05）.（3）The number of hospitalizations for acute asthma exacerbations in children showed a yearly increasing trend from 2014-2016 and a yearly decreasing trend from 2016-2019,with a brief peak in 2016 and again a significant increase in 2020-2021.The lowest number of hospitalizations was 27（6.4%）in 2014 and the highest number of hospitalizations was 96（23.8%）in 2021.The peak of the disease occurred in March,July,and September of each year with 7.9%（32/404）,9.7%（39/404）,and 23.3%（94/404）,respectively,with the highest 23.3%（94/404）in September and the lowest 2.4%（10/404）in February.The fall season was the peak of acute attack hospitalizations with 43.3%（175/404）,followed by summer with 30.0%（121/404）and winter with the least with 8.9%（36/404）.（4）Pulmonary function indices FVC（87.21±16.60）L,FEV1（79.60±17.48）L,FVC/FEV1（90.81±10.67）in children hospitalized for acute asthma attacks in Lanzhou.No statistical differences were found in the pulmonary function indexes FVC,FEV1,and FVC/FEV1 in male and female children（P>0.05）.（5）The annual average detection value of PM_2.5 in Lanzhou City from 2014-2018showed a decreasing trend year by year,with the annual average detection value<35μg/m³ in2018 and>35μg/m³ in the rest of the years.The annual average detection value of PM₁₀ from2014-2021 was>70μg/m³,with a decreasing trend year by year from 2016-2018.The fluctuation range of annual average concentration of SO₂ from 2014 to 2021 is 15-27μg/m³.The annual average concentration of CO decreases year by year from 2014 to 2021.The average concentration of NO₂ is higher than 40μg/m³ from 2014 to 2021 and peaks in 2017.The monthly average concentration of PM_2.5 in Lanzhou urban area occurs in December and the lowest in August from 2014 to 2021.The highest and lowest monthly average concentrations of SO₂,NO₂ occur in December and June,respectively.The peak values of SO₂,NO₂,PM_2.5,PM₁₀ and CO in different seasons are concentrated in winter and the valley values are concentrated in summer.peak values of O₃in different seasons are concentrated in summer and the valley values are seen in winter.（6）Bivariate analysis revealed that the trends of daily average concentrations of air pollutants PM_2.5,PM₁₀,and NO₂ in Lanzhou city were consistent with the number of acute exacerbations in children with asthma,and all were positively correlated,with correlation coefficients of PM_2.5（P<0.01,r=0.227）,PM₁₀（P<0.01,r=0.395）,and NO₂（P<0.01,r=0.143）,respectively.The study showed that daily concentrations of PM_2.5,PM₁₀,and NO₂were strongly correlated with the number of acute exacerbation cases in children with asthma,and daily concentrations of SO₂,O₃,and CO were not correlated with acute asthma exacerbation hospitalization in children（P>0.05）.The results of multiple regression analysis showed that PM₁₀ and NO₂ were correlated with acute asthma attacks in children,with PM₁₀being strongly correlated with acute asthma attacks in children,and PM_2.5,SO₂,CO,and O₃were not correlated with acute asthma attack hospitalization in children.（7）The regression results based on gender stratification showed that there was an association between the lung function indicators FVC and FEV1 and the change in daily mean PM_2.5 and PM₁₀ concentrations in girls.Girls’lung function indexes FEV1/FVC were only influenced by the daily average PM_2.5 concentration.In boys,the lung function indicators FVC and FEV1 were associated with changes in the daily average concentrations of PM₁₀,PM_2.5,and NO₂,and changes in PM_2.5 concentrations had an effect on the lung function indicators FEV1/FVC in hospitalized boys.Conclusion:（1）The hospitalization rate of boys was greater than that of girls among children aged 6-14 years old hospitalized for acute asthma attacks in Lanzhou City from 2014to 2021.The number of hospitalizations for acute asthma attacks was the highest in 2021.September was the most predominant month for acute attacks in children with asthma in Lanzhou City.（2）The daily average detection values of PM_2.5,PM₁₀ and NO₂ were closely related to the number of acute attacks of children with asthma,and the results of multiple regression analysis showed that PM₁₀ and NO₂ were correlated with acute attacks of children with asthma.（3）The average daily concentrations of PM2.5 and PM10 had an effect on the pulmonary function indexes FVC and FEV1 in hospitalized girls,and the average daily concentrations of PM10,PM2.5 and NO2 had an effect on the pulmonary function indexes FVC and FEV1 in boys with acute asthma attack.（4）Air pollution is an important factor affecting the hospitalization of children with acute asthma attack in Lanzhou City,and also the lung function index of children hospitalized with acute asthma attack.Therefore,environmental management should be advocated to reduce the consumption of medical resources and economic burden.