Dustborne and airborne fungal propagules represent a different spectrum of fungi with differing relations to home characteristics.
BACKGROUND
Exposure to fungi is often assessed by culturing floor dust or air samples. Our objective was to evaluate the relationships between dustborne and airborne fungi and to identify factors that modify these relationships.


METHODS
From November 1994 to September 1996 sequential duplicate 45-l air samples were collected in bedrooms of 496 homes in the Boston area, using a Burkard culture plate sampler. After air sampling, bedroom floors were sampled with a vacuum cleaner that was modified to collect dust in a cellulose extraction thimble. Dust was sieved, and the fine dust was dilution-plated onto DG-18 media.


RESULTS
Concentrations of total culturable fungi per gram of bedroom-floor dust were correlated weakly, but significantly, with those of indoor air (r = 0.13, P < 0.05). Concentrations of some individual taxa in the dust and indoor air were also weakly associated. Adjusting for the concentrations of fungi in outdoor air, dustborne fungal concentrations were positively associated with those in indoor air for the taxa Cladosporium and Penicillium, but not for total fungi. The indoor air fungal levels were often predicted by different covariates to those predicting fungal levels in dust. The type of housing (house or apartment) and the presence of carpeting were often predictive factors for dust fungi. In contrast, outdoor fungal levels were often predictive of the indoor air fungal levels.


CONCLUSIONS
Because our data do not indicate a strong overall relationship between culturable fungi in dust and indoor air, the results from these two methods (dust and air sampling) likely represent different types of potential fungal exposures to residents. It may be essential to collect both air and dust samples, as well as information on housing characteristics, as indicators for fungal exposure.
Chew
G L
GL
Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, New York, NY 10032, USA.
Rogers
C
C
Burge
H A
HA
Muilenberg
M L
ML
Gold
D R
DR
D000393:Air Pollutants / Q000032:analysis* / Q000145:classification*; D016902:Air Pollution, Indoor / Q000032:analysis*; D000818:Animals; D001900:Boston; D015331:Cohort Studies; D004285:Dogs; D004391:Dust / Q000032:analysis*; D005430:Floors and Floorcoverings / Q000145:classification; D005500:Follow-Up Studies; D005658:Fungi / Q000145:classification*; D006801:Humans; D006813:Humidity; D015588:Observer Variation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D012621:Seasons; D013223:Statistics as Topic
D000393:Air Pollutants; D004391:Dust