Risk Assessment Of Indoor Environment On Child’s Asthma At Residences

Recently, with high prevalence of child’s asthma, the effect of indoor environment on child’s health is becoming more significant. This doctoral dissertation focus on the relationship between indoor environment and child’s asthma, using questionnaire and animal experiment, analyzing the risk of child’s asthma from indoor environment with statistical analysis technique and mining association rule, evaluating quantitively the influence of formaldehyde on pathological indexes of asthma, and modeling the health risk assessment of indoor environment.First, referring to the foreign mature research methods of indoor environment and health and considering domestic social economic background and environmental pollution feature, this dissertation designed questionnaire for domestic research and established systematic questionnaire research technique. In questionnaire survey, this study adopted graded sampling, verified the implementation plan with pre-investigation, ensured the quality of questionnaire with quality control measures, and finally got 5299 valid questionnaires that was the first-hand data in domestic filed of indoor environment and child’s asthma. In this study, 2917 children who have lived in the surveyed home from birth were selected in this analysis, and with confounding factors the risk factors of indoor environment were found by chi-square test and logistic regression model. With literature review, the possible pollution parameters in indoor environment were identified.Then, the mining association rule was used in the evaluation of influence of multi-factor of indoor environment on child’s asthma. This study took traditional support-confidence framework to observe the associations between indoor environment and child’s asthma, screened the association rules with subjective measure and objective evaluation, such as Lift, PS value and Match, verified the statistical and practical significance of the final association rules, and found the combination of two factors and three factors of indoor environment that were strongly associated with wheezing, cough and doctor-diagnosed asthma.Next, based on the risk factors or factorial combination of indoor environment and taking(Lift- 1) as the risk level of child’s asthma, this study set up a relational model for indoor environmental factors and health risk levels. With the relational model as core part, this study established health risk assessment model of indoor environment at residences, using evaluation questionnaire to collect the data by self-report of indoor environmental factor and subjective perception of odor, taking the relational model as assessment criteria to identify the risk factors or factorial combination of indoor environmental. This study also verified the effectiveness and predictive accuracy by case analysis, and found this model had good guiding significance and high practical value in the research field of indoor environment at the present stage.Next, in the identified indoor environmental pollution parameters, formaldehyde was selected to quantitively evaluate its facilitation effect in the process of asthma. This study adopted animal model of asthma, comparing the concentration of chronic allergic inflammation, bronchial hyperresponsiveness and pathology change of lung tissue in different exposure level of formaldehyde, and found that the concentration of chronic allergic inflammation in 60minFA+OVA group, 90minFA+OVA group and 120minFA+OVA group was significantly different from that in the OVA-control group, and the analytical results of bronchial hyperresponsiveness and pathology change of lung tissue were consistent. Then, referring to foreign assessment method of indoor environment, this study proposed minimal risk level of formaldehyde for child’s asthma that was 0.00094mg/m3.With analysis of existing problems in this field of indoor environment and child’s asthma, this study qualitatively identified and quantitively evaluated the risk of child’s asthma from indoor environment, established questionnaire research method and assessment model for indoor environment and proposed minimal risk level of formaldehyde, providing reliable theoretical guidance and technical basis in this field.