Microbial problembuildings -: The effect on IAQ of different remediation methods

In Scandinavia a large proportion of problem buildings are caused by damp conditions. These conditions lead to microbial growth and/or chemical degradation of building materials. The microbial emissions are commonly perceived as moldy odor, while the chemical products may be perceived plastic smell. Both microbial and chemical emissions are commonly stored deep in the concrete. The proper remediation technique is to remove these sources of contamination. However, some of the building materials cannot be removed, such as concrete. These materials usually carry a large sink capability. In order to remove sources from different sinks, the use of different ventilation systems aimed to "ventilate at the source" can be of value. The use of ventilated floors or "baking out" concrete show good results. The "baking out" method need short treatment periods of 10 to 20 days, whereas ventilated floors needed more than a year to achieve equal results. The combination of parallel sampling of indoor air and exhaust from the ventilated floors on Anasorb 747, allowed for analyzing and screening the indoor air and the construction air for stored microbial and chemically produced volatile organic compounds. The sampled air was then analyzed using GC-MS technique. The results of the air samples were later verified through microbial and chemical analysis of the building material. The health effect of these remediation methods was studied through questionnaires and interviews before and after the remediation.