The Association Between Indoor Environment As Well As Lifestyle With Respiratory Diseases And Lung Function Of Children In Urban Areas Of Chongqing

Objective:To investigate the prevalence of respiratory diseases and the status of lung function among primary school children in two main urban districts of Chongqing,and to explore the factors that may affect respiratory diseases and lung function in the indoor environment of the target children’s house,and to analyze the relationship between lifestyle（diet and exercise）and lung function of children.Methods:One primary school was selected in each of the two main urban districts of Chongqing by purposive sampling,and all children and their parents with informed consent in each primary school were taken as study subjects.A self-designed parent questionnaire was used to investigate the parents of informed consents and 2126 valid questionnaires were obtained;A random sample of 771 children participating in the parent questionnaire was selected for lifestyle（diet and exercise）questionnaire survey as well as height and weight measurements and lung function test.Chi-square test and multivariate logistic regression were used to analyze the relationship between indoor environment and children’s respiratory diseases;The effects of indoor environment and lifestyle on lung function FVC,FEV₁,PEF,FEF_25-75 and FEV₃ values were analyzed by t-test,variance analysis,simple and multiple linear regression methods.Results:（1）The results of the parents’questionnaire showed that the proportions of children diagnosed by doctors with asthma,bronchitis,pneumonia and allergic rhinitis were 3.6%,23.5%,9.2%and 13.2%,respectively.After adjusting the potential influencing factors,multivariate logistic regression analysis showed that indoor ventilation and air circulation were important influencing factors for children’s respiratory health,which were shown as follows:the use of air conditioning for more than 8 hours a day in summer was a risk factor for developing asthma,bronchitis,pneumonia and allergic rhinitis in children and ventilation for less than 12hours per day during the summer was a risk factor for developing allergic rhinitis.The risk of developing pneumonia and allergic rhinitis increased by1.53 and 1.51times in children from opened kitchens than closed kitchen families,respectively;In addition,indoor damp and mildew was a risk factor closely related to childhood asthma,bronchitis and allergic rhinitis.The frequent use of sanitary incense and mosquito coil incense in summer also increased the risk of developing asthma（OR=2.58）and bronchitis（OR=1.42）in children.（2）The results of lung function test showed that FVC,FEV₁,PEF,FEF_25-75 and FEV₃ were significantly higher in older children than those of younger children.Boys have significantly higher lung function test results than girls in FVC,FEV₁ and FEV₃.The abnormal rates of FVC in boys and girls were 13.6%and 13.1%,respectively.In terms of the effect of indoor environment on children’s lung function,after adjusting for potential influencing factors,multiple linear regression results showed that frequent use of air fresheners significantly reduced children’s PEF and FEF_25-75 values.In terms of the effects of lifestyle on children’s lung function,multiple linear regression results indicated that increased frequency of vegetables and dairy products consumption significantly increased the FVC and FEV₃ test values,increased frequency of fruit consumption significantly increased FVC,FEV₁and FEV₃ test values in children,and daily exercise time of more than one hour in and out of school significantly improved the FVC and FEV₃ test values.Conclusion:Poor indoor ventilation,the presence of damp and mildew,and the frequent use of sanitary incense and mosquito coil incense are risk factors for respiratory diseases among primary school children in the two main urban areas of Chongqing.Frequent use of air fresheners may be a risk factor for reducing lung function in children.High frequency consumption of vegetables,fruits and dairy products as well as daily physical exercise for more than one hour in and out of school have positive effects on the development of lung function in children.