| Popis: |
So-calledsick house syndrome was broken out in a newly built church and we have surveyed it's indoor air chemicals. Concentrations of formaldehyde (133?269μg/m3) in the church exceeded the guideline value (100/μg/m3) by the Ministry of Health, Labour and Welfare of Japan. We searched for the emission sources of formaldehyde, and relatively high concentrations were found in the wall and floor of the sanctuary. Moreover, a ventilation rate of the sanctuary was considerably reduced because of using staffed insect prevention net. After cleaning the insect prevention net, installation of new air inlets, and changing a mechanical extraction ventilation to a mechanical supply ventilation, concentrations of formaldehyde decreased to the level less than the guideline value. In the mean time, by the administration of church and the building designer, some chemical agents regarded as formaldehyde scavengers were applied to reduce the formaldehyde concentration. However, in the second summer from the construction, concentrations of formaldehyde increased and exceeded the guideline value again, though the concentrations were lower than those of last summer. It is necessary to find out emission sources of formaldehyde in more detail, and to reduce the formaldehyde concentrations of air in the church. |
