While the fungal exposure assessment was based on the determination of fungal propagules for a long time, recent progress has led to the development of methodology for other fungal agents, e.g. the fungal cell wall components, metabolites, and allergens, that may be responsible for health effects caused by fungal exposure. This review includes a summary of the sampling techniques and analytical methods that are currently used or are in progress for the fungal exposure assessment. Prospects for the future trends are also discussed. In the future, the development will focus on sampling techniques that allow longer sampling times, a higher sampling efficiency for relevant particle sizes, and better possibilities for a wide range of analyses. In addition, new or modified methodology based on chemical, immunochemical, and molecular biological techniques to measure fungal agents related to health effects will improve the understanding of biological responses caused by fungal exposure.

This study's database comprised results of volatile organic compound (VOC) measurements from 176 office buildings. In 23 of the 176 buildings, formaldehyde measurements were also conducted. It was suspected that the buildings had indoor air problems, but a walk-through inspection did not reveal any clear, abnormal contaminant sources. The 50 most abundant VOCs and their concentrations in 520 air samples were analyzed. The irritation potency was estimated for 33 out of the 50 common VOCs and their mixtures, as well as for formaldehyde. This information was used to calculate the recommended indoor air levels (RILs) for the VOCs. The RILs were considerably higher than the measured mean indoor air concentrations in the buildings. However, the RIL for formaldehyde was exceeded in most of the 23 buildings studied. According to the evaluation of irritation potency, formaldehyde was a more likely cause of sensory irritation than the mixture of common nonreactive VOCs at the concentrations that occurred in the buildings without abnormal indoor sources. Furthermore, environmental symptoms of office workers were characterized in 20 office buildings (including the database of 176 office buildings) with the aid of an indoor air questionnaire. The most frequent symptoms related to the indoor environment were involved the upper respiratory tract. However, no relationship could be shown between the reported symptoms and the occurrence of VOC and formaldehyde concentrations in these buildings. Generally, the study results indicated that formaldehyde was the more likely agent causing sensory irritation than the mixture of the common nonreactive VOCs at the concentrations occurring in the buildings without abnormal indoor sources.

Hanhela R, Louhelainen K, Pasanen A-L. Prevalence of microfungi in Finnish cow barns and some aspects of the occurrence of Wallemia sebi and Fusaria. Scand J Work Environ Health 1995;21:223--8. Objectives The occurrence of microfungi in the air and in feeding and bedding materials was studied on 32 Finnish dairy farms. Methods Air samples for determining viable and total spore concentrations were collected on membrane filters and with a cascade impactor. Genera of mesophilic, xerophilic, and thermophilic fungi were identified in four culture media. Total spore counts were done with the aid of an epifluorescence microscope. To identify fungal flora in agricultural materials, feeding and bedding material samples were also taken from the farms. Results The airborne spore concentrations varied for viable mesophilic, xerophilic, and ther mophilic fungi from 10' to lo7 colony-forming units per cubic meter, and for total spores from lo5 to lo7 spores per cubic meter. Asl~ergillus, Perzicilliur?z, Cladosporiunz, Absidia species, Wclllenzin sebi and yeasts were the predominant fungi in the air, as well as in the material samples. C O~C~U S~O~S In general, the airborne spore concentrations were high although the variation in the concentrations of different fungal groups was large between the farms. Along with using new growth media, two fungi whose prevalence was earlier poorly known in Finland were detected. W sebi proved to be the most abundant xerophilic fungi in the air and hay samples, while Fusariunz spp were very common in grain and straw but rare in air.