Friday, December 16, 2005

Vapor Phase Mold Emission

Environmental Health Perspectives Volume 113, Number 12, December 2005
Acute Effects of a Fungal Volatile Compound

Robert Wålinder,1 Lena Ernstgård,2 Gunnar Johanson,2 Dan Norbäck,1 Per Venge,3 and Gunilla Wieslander1

1Department of Medical Sciences/Occupational and Environmental Medicine, University Hospital, Uppsala, Sweden; 2Division of Work Environment Toxicology, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden; 3Department of Medical Sciences/Clinical Chemistry and Asthma Research Center, University Hospital, Uppsala, Sweden

Objective: 3-Methylfuran (3-MF) is a common fungal volatile product with active biologic properties, and previous studies have indicated a contribution to airway disease. The aim of the present study was to assess the acute health effects of this compound in humans.
Design: Acute effects were assessed via chamber exposure to (1 mg/m3) 3-MF.
Participants and measurements: Twenty-nine volunteers provided symptom reports, ocular electromyograms, measurement of eye tear film break-up time,vital staining of the eye, nasal lavage, acoustic rhinometry, transfer tests, and dynamic spirometry.
Results: No subjective ratings were significantly increased during exposure. Blinking frequency and the lavage biomarkers myeloperoxidase and lysozyme were significantly increased, and forced vital capacity was significantly decreased during exposure to 3-MF compared with air control.
Conclusions and relevance to clinical practice: Acute effects in the eyes, nose, and airways were detected and might be the result of the biologically active properties of 3-MF. Thus, 3-MF may contribute to building-related illness.

BrooklynDodger comments: Important here are effects of a vapor phase effluent of mold. To protect against this you would need an organic vapor as well as a particulate respirator.

The report documents effects of a one or two hour exposure at about 1 mg/m3, measured in a group of 30 against whatever the background rate of variation in the biomarkers and lung function. What would be the reference level?

[The Dodger was lazy in draft. For those not afflicted with IH, the conversion from mg/m3 to ppm is MW/24.45 at room temperature. 3-MF would be C5H9O, or MW 85. So 1 mg/m3 is about 0.3 ppm]. Based on 10 fold extrapolation for acute to chronic, and another 10 fold for population variability, and another 10 for not having achieved a NOAEL, and no extrapolation for animal to human, we get a reference level of 0.003 ppm.

To the Dodger's surprise, this compound would appear unreactive and of no particular concern based on structure. So would be diacetyl, found in butter flavorings.

At a minimum, this demands that respiratory protection for mold remediation include organic vapor protection as well as particles.

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