Gas chromatography-mass spectrometry was used to determine the microbial contents of building materials subjected to water damage in a laboratory experiment and of materials collected from houses affected by water during the flood in Klodzko in south-western Poland, July 1997. The samples were examined for 3-hydroxy fatty acids, markers of bacterial endotoxin, and ergosterol, marker of fungal biomass. The amounts of both 3-hydroxy fatty acids and ergosterol were higher in materials that had been exposed to water than in unexposed ones. All markers were stable in the building materials for at least 6 weeks at room temperature and could thus be used to reveal microbial contamination even when cultivation results for bacteria and fungi were negative. Direct measurement of 3-hydroxy fatty acids and ergosterol in human environments could be a useful method, e.g. in monitoring indoor air as regards presence of potentially harmful microorganisms and microbial constituents.

• fungi: assessment, sampling and analysis : by markers, ergosterol as marker of fungal biomass
• measurement and instrumentation : gas chromatography-mass spectrometry
• measurement: GC-MS

1. Airborne environmental endotoxin: a cross-validation of sampling and analysis techniques
2. Determination of ergosterol in organic dust by gas chromatography-mass spectrometry
3. Determination of microbial chemical markers by gas chromatography-mass spectrometry - potential for diagnosis and studies on metabolism in situ
4. Quantification of ergosterol and 3-hydroxy fatty acids in settled house dust by gas chromatography-mass spectrometry: Comparison with fungal culture and determination of endotoxin by a Limulus amebocyte lysate assay
5. Use of gas chromatography-mass spectrometry/solid phase microextraction for the identification of MVOCs from moldy building materials