NATIONAL SURVEY ON HOME DAMPNESS AND CHILDREN ALLERGIC SYMPTOMS DURING CONSECUTIVE SURVEY PERIODS IN JAPAN
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- ジュウタク ノ ダンプネス ノ ケイ ネンヘンカ ガ ショウニ ・ ジドウ ノ アレルギーセイ ショウジョウ ニ オヨボス エイキョウ ニ カンスル ゼンコク チョウサ
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Meta-analysis has revealed that building dampness and mouldy indoor environments are associated with a 30%–50% increase in respiratory and asthma-related health issues (Fisk, 2007). The Institute of Medicine (IOM) published an authoritative source of information on damp indoor spaces and health in 2004 (IOM, 2004). Proper architectural methods and optimal occupant behaviour in indoor environments are needed to minimize building dampness. Authors have already proposed a method to estimate indoor dampness from self-reported information by occupants and verified its validation. In this paper, results of an internet survey conducted over two consecutive years were analyzed for an association between indoor dampness based on proposed estimation method and allergic symptoms among children.<br> A prospective cohort survey of children under twelve years old was conducted via the internet. Questionnaires were distributed on the web to 5,071 houses in all prefectures of Japan in February 2014, and 3,262 completed questionnaires were returned within 5 days. The response rate was 64.3%. These houses had already participated in a questionnaire survey during the same month of the previous year. Therefore, we could estimate changes in the indoor environment and children's allergic symptoms over two consecutive years.<br> A method to estimate indoor dampness using occupants' self-reported answers to questions about visible vapor condensation, mould growth, perception of mouldy odor and other factors during the winter season was proposed. This dampness index ranges from 0 to 24, and its values are classified into four ranks based on the quartiles. Rank 4 represents houses with the most serious problems related to indoor dampness. The questionnaires also included items regarding the following health-related symptoms among children: ocular symptoms, nasal symptoms, respiratory symptoms, dermal symptoms and mental symptoms. The results showed that the prevalence of each symptom except for mental symptom was from about 2.0 to 11.5% at second survey period, and that the prevalence of symptom onset within 3 months was included after exposing indoor dampness during winter. The dampness index revealed an association between indoor dampness and health-related symptoms.<br> We further assessed the association between four kinds of health-related symptoms onset one year later from first survey period and factors that influenced indoor dampness. Adjusted odds ratios (ORs) were calculated using a multivariable logistic regression model adjusted for gender, age and parents health conditions. Adjusted ORs for ocular symptoms (OR = 4.94, p < 0.001) were statistically significant in Rank 4 of the dampness index. Based on this analysis, an increased risk of ocular symptoms due to a change in indoor dampness was estimated. Moreover, adjusted ORs for nasal and respiratory symptoms were statistically significant when the dampness index remained at Rank 3 and Rank 4 during surveyed period of two years. It is revealed that exposed indoor dampness affects onset of both the nasal and respiratory symptoms among children.
- Journal of Environmental Engineering (Transactions of AIJ)
Journal of Environmental Engineering (Transactions of AIJ) 83 (754), 1025-1032, 2018
Architectural Institute of Japan