The Association Between Indoor Environmental Exposure And Allergic Symptoms Such As Asthma Among Preschool Children

With the change of human life style,the time of living and working in the indoor environment of people can be up to 80% ~ 90%.Children spend most of their time in school or at home,and they are in the period of growth with lower resisitance and immunity.It has been found that there are positive associations between indoor mold exposure and the prevalence of respiratory diseases,as well as indoor crowdness and dry cough at night among preschool children.Therefore,it is important to study the correlation between indoor environmental factors and children's symptoms such as asthma,rhinitis and eczema.Ten kindergartens were randomly selected in Taiyuan city.Children's health symptoms,the information of family and classroom environmental factors were collected through questionnaire survey.Dust samples were collected by vacuum cleaners and petri dishes.Polymerase Chain Reaction method and Enzyme Linked Immunosorbent Assay method were performed to analyse the concentration of fungal DNAs and allergens.Correlation between indoor carbon dioxide,temperature and humidity and indoor microbial exposure was analyzed by Kendal Tau Beta test.The association between indoor environmental exposures and children's health were analyzed by two-level logistic regression.The results showed that:(1)The prevalence of ever rhinitis,ever rhinitis in 12 months,ever pneumonia and ever wheezing was higher than other symptoms,and there was no significant difference between boys and girls.(2)Moldy floor/wall/ceiling,damp floor/wall/ceiling,water damage,damp clothes/bedding,condensation of water from windows in winter,a moldy smell and a sense of moisture in the air were positively associated with asthma related symptoms.New furniture,renovations,the presence of cockroaches and mice were risk factors for the symptom of asthma,rhinitis,pneumonia and eczema,while daily cleaning had a protective effect on the prevalence of asthma and pneumonia.The presence of flies and mosquitoes had a protective effect on eczema but had a adverse effect on asthma.(3)Total fungal DNA,Aspergillus spp and Penicillium spp(Asp/Pen)DNA,Aspergillus versicolor DNA,Stachybotrys chartarum(S.chartarum)DNA in the settled dust and cat allergen were negatively correlated with ever wheezing.Airborne Asp/Pen DNA and Aspergillus versicolor DNA were negatively related with ever pneumonia.Dog allergen was positively associated with ever rhinitis and rhinitis in 12 months.Fungal DNA and allergens were significantly correlated with indoor temperature,relative humidity,carbon dioxide and crowdness.(4)Compared to cement reinforced,wall material of brick had a protective effect on ever eczema in 12 months.Tiles used in flooring materials can increase the prevalence of ever pneumonia.Terrazzo flooring has been shown to protect against ever pneumonia,ever rhinitis and rhinitis in 12 months.There was a negative correlation between ever wheezing and window opening area,whether the door was opened and cleaning frequency was 3 times a day.Wheezing in 12 months was negatively related with whether the door was opened and cleaning frequency was 3 times a day.There was a negative association between ever rhinitis and rhinitis in 12 months and cleaning frequency was more than 3 times a day.Ever eczema in 12 months was negatively related with cleaning frequency was 3 times a day,while was positively associated with cleaning frequency was more than 3 times a day.In conclusion,people should develop good habits of opening windows or doors for ventilation and cleaning regularly,in order to prevent the moisture problems and the appearance of cockroaches,rats and so on.This study provides some scientific knowledge for protecting preschool children's health and improving indoor environment quality.