Microbes and Moisture Content of Materials from Damaged Building

Meklin T., M.Sc., Haatainen S., B.Sc, Kauriinvaha E. M.Sc, Kettunen A-V. M.Sc, Haverinen U., M.Sc., Vahteristo M. M.Sc., Viljanen M. Prof., Nevalainen A Ph.D. National Public Health Institute, Kuopio, Finland, e-mail Teija.Meklin@ktl.fi

The aim of the study was to characterize the microbial flora of the envelope of a school building and the correlation of the microbial concentrations and the moisture content of materials was estimated. Material samples (n=95) were taken from different structures before the dismantling of the school. In all, 40 sample pairs were taken from which both concentrations of microbes and moisture contents (% by weight) were determined. The range of the total concentration of fungi was <45 - 8 600 000 cfu/g for all the analyzed material samples. The growth of microbes in a building is mostly regulated by the moisture of the materials and often the elevated concentrations of mesophilic fungi (>10 000 cfu/g) were associated with elevated moisture content of the material. However, the microbial concentrations did not fully correlate with the moisture contents of the material.