The risk assessment of factors influencing health of school children according to a large-scale longitudinal study

从1991年到2000年，对大阪府所有公立小学儿童进行了5次主观症状问卷调查。利用这些调查数据，我们研究了这十年来学校建筑的新建或翻新是否影响了儿童的健康。首先，我们通过对每次调查的logistic回归分析来评估儿童主观症状患病率与环境因素之间的关系。教室的新建筑或翻新与儿童的任何症状之间没有显著的联系。接下来，研究了教室建设或翻新期间患病率的变化。总体而言，这些学校的患病率变化与全州的平均患病率变化没有什么不同。另一方面，在2001年暑假期间，四所小学新建或翻新了一些教室。我们在工程建成后的两年内测量了5次室内空气污染物浓度。装修后普通教室的甲醛浓度与未装修教室相同。虽然装修后的甲苯和二甲苯浓度超出了室内浓度标准，但装修后一个月就下降了。然而，一间电脑室的甲醛浓度在两年后的夏季仍然超过了标准。一间图书馆和一间音乐室的甲醛浓度甚至在两年后仍接近指导标准。

A questionnaire survey on subjective symptoms on all the public primary school children in Osaka Prefecture had been carried out 5 times from 1991 to 2000. Using these survey data, we examined whether new constructions or renovations of school buildings in these ten years influenced children's health. First, we assessed relationships between the prevalence rates of subjective symptoms among children and environmental factors by the logistic regression analysis on each survey. There was no significant association between the new construction or renovation of the classrooms and any symptom of children. Next, the changes in the prevalence rates over the construction or renovation of classrooms were examined. Generally, the changes of the prevalence in these schools were not different from those in the average prevalence of the Prefecture.On the other hand, new constructions or renovations of some classrooms were conducted at four primary schools during the summer vacation in 2001. We measured indoor concentrations of air pollutants 5 times during two years starting just after the constructions. Formaldehyde concentrations in ordinary classrooms just after the renovations were at the same levels obtained at the nonrenovated classroom. Although toluene and xylene concentrations just after the renovation were beyond the levels of indoor concentration guidelines, they had declined one month after the renovation. In a computer room, however, formaldehyde concentrations still exceeded the level of guideline in summer season after two years. Formaldehyde concentrations in a library and a music room were observed to be close to the guideline level even two years later.