Objectives In this study, the prevalence of typical fungal species in modern, nonmoisture-damaged offices was compared with the prevalence of fungi in moisture- and mold-damaged office buildings.

Methods The study included 34 mold-damaged and 43 nondamaged office buildings in southern Finland. Most of the buildings had a concrete structure and several floors. A mechanical ventilation system was in use in 86% of the buildings. Wintertime samples of indoor air, settled dust, and building material were collected from the buildings.

Results Penicillium was the most prevalent fungi in the environmental samples studied. Still, the prevalence of Penicillium and Aspergillus versicolor gave the strongest indication of mold damage in the buildings studied (P-value <0.001 or <0.01), although all the fungi examined were identified in both the damaged and nondamaged buildings. Other predominant fungi in the office buildings were yeasts, sterile fungi, and Cladosporium. Some indicator value for mold damage was associated with the prevalence of Aspergillus fumigatus, Aspergillus niger, Aspergillus ochraceus, Aspergillus glaucus, Acremonium, Paecilomyces variotii, Rhizopus stolonifer, and Stachybotrys chartarum.

Conclusions This study shows that workers are more exposed to Penicillium species than to other species in office environments regardless of whether mold damage is present or not. It also shows that moisture indicators are not absolutely specific.

Key terms Finland; fungal species; fungus; mold damage; nondamage; office building; office environment