Mitigation of Visible Fungal Contamination in Buildings: Experience From 1993 - 1998

Philip r. Morey, P.H.d., Daryl Sawyer, B.s. AQS Services, Inc,. 2235 Baltimore Pike, Gettysburg, PA

Experience in the early 1990ís led to the recommendation that removal of visible fungal growth from interior surfaces in buildings be performed in a manner that minimized the dispersion of particles (dusts) in indoor air. Several documents beginning with the 1994 New York City Guidelines on Assessment and Remediation of Stachybotrys atra in Indoor Environments provided practitioners with procedures that can be used to remove visible fungal growth from building interiors. All fungal remediation guidelines recommend that sustained and extensive fungal growth on interior surfaces should be physically removed and that people performing remediation work should use appropriate personal protective equipment. In addition, all guidelines published in 1993-1998 recommend that moisture problems in building infrastructure be fixed in order to prevent new fungal growth. Fungal remediation guidelines specify a certain surface area of visible fungal growth (generally 3 to 10m2) that requires containment barriers similar to those used when hazardous chemical or physical materials are removed from buildings. Misunderstanding of 1993-1998 guidelines has resulted in both overly conservative approaches to clean-up as well as to dispersion of fungal spores throughout a building because of poor dust control. Unlike guidelines on removal of hazardous chemical and physical agents where rigid inspection protocols and specific numerical guidelines are appropriate, the removal of mycobiota is a variable process depending on many factors including the biology of the fungal taxa. Factors such as the following should be considered during the remediation process: (a) the location, extent, and kind of fungal growth in building systems, (b) the susceptibility of building materials to biodeterioration, (c) the porosity of building materials, (d) the susceptibility of occupants to bioaerosol exposure, and (e) sampling and monitoring protocols appropriate for the fungal contaminants. Fungal remediation in buildings continues to require a considerable degree of professional judgement with regard to procedures appropriate for containment of dusts and for control of the contaminant mycobiota.