Volume 22, Number 4
1998

Review

Bioaerosols. Harriet Burge, editor. ACGIH Pubn. # 9612. ISBN: 0-87371-724-4. 1995. 331 pages. $94 from ACGIH, Kemper Woods Center, 1330 Kemper Meadow Dr., Cincinnati, OH 45240-1634 (513/742-2020, fax 742-3355, e-mail pubs@acgih.org, web http://www.acgih.org).

This is a reference text on biological contaminants, including mold. Chapters include Bioaerosol Investigations, Airborne Contagious Disease, Endotoxin, Mammalian Aeroallergens, Bioaerosol-Induced Hypersensitivity Diseases, and Sampling and Analysis of Biological VOC's (volatile organic compounds).

The editor, who attended the September Bioaerosols Conference in Saratoga Springs, emphasized that no threshold limit values could be set for mold exposure because there is still so much that is unknown. We don't know much about how the spore carries toxins, she said, or about biological decay. There is no human data for cellular responses, for malaise, or weight loss; or on dose-response relationship for humans or animals. We don't know why whole spores make rats lose weight, while extracted spores don't. (An attendee at that conference suggested that the toxins could be produced by the mycelia, and the spores might merely be contaminated by them--but this idea was not followed up.)

This AICGH publication was one of six published guidelines cited by Phil Morey, one of the 31 "faculty" members at the interdisciplinary conference. The earliest guideline, a passage from Leviticus, does not mention mold, but does describe the process of cleaning up a house after a leper has lived in it: basically, this involved tearing out the contaminated parts and hauling them away.

The other published cleanup guides were a book by Samson (Robert A. Samson?) et al., 1994; the New York City guide for cleanup of Stachybotrys Chartarum (probably "Guidelines on Assessment and Remediation of Stachybotrys Atra in Indoor Environments," currently under revision); the Health Canada Guide, 1995; and the guidelines from the International Society for Indoor Air Quality, 1996. (These references were taken from personal notes at the conference, and may not be entirely accurate.) All these guidelines say, according to Morey:

Building people can do the minimal level cleanup (i.e. small areas of involvement, say under 2 or 3 square feet).

Physically remove the growth.

Contain the dust in the cleanup area with plastic sheeting tightly taped at the edges.

Use protective clothing.

Remove the dust.

Discard porous materials.

Physically clean the area. Tap water and detergent is enough. ("A biocide should be the last thing you think of," Phil Morey says.)

In the discussion period following his presentation, he was asked how to persuade administrators that containment is worth the cost, and he answered, "The information about lawsuits and consequences is out there." Someone asked how you can tell when your remediation is complete; he said, "When [the mold] is physically gone; and when the air inside is the same as that outside." Someone who hadn't been listening asked which biocide he recommended, and he answered, "I don't."