County Courthouse - HHE

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Construction Health Hazard Evaluation

MARTIN COUNTY COURTHOUSE

AND CONSTITUTIONAL OFFICE BUILDING

STUART, FLORIDA

HETA 93-1110-2575

May 1996

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Summary

On September 9, 1993, the National Institute for Occupational Safety and

Health (NIOSH) received a request for a Health Hazard Evaluation (HHE) from

the County Board of County Commissioners in Stuart Florida. NIOSH was

asked to evaluate potential worker exposures to toxigenic fungi during

renovation of the microbiological-contaminated areas of the County

Courthouse Complex. The courthouse complex was severely contaminated with

predominantly Aspergillus, Penicillium, and Stachybotrys. The Courthouse

complex had been unoccupied since December 1992, due to occupant health

complaints.

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In September 1993, NIOSH investigators conducted an initial environmental

assessment at the Courthouse complex before remediation activities began.

Follow-up site visits were conducted in October and November 1993, during

remediation activities of the County Courthouse (MCC) and the

Constitutional Office Building (COB). A final site visit was conducted in

June 1994, after the completion of the remediations. Environmental

monitoring included air sampling for culturable (viable) fungi, total fungal

spores, total particulates, and ergosterol (the major constituent of the

cell walls of fungi). Viable microorganisms in bulk samples were also

identified.

Remediation activities were performed in asbestos abatement-type containment

areas with dedicated supply and exhaust ventilation systems equipped with

high efficiency particulate air (HEPA) filters. Initial air sampling using

culturable sampling techniques resulted in unquantifiable concentrations of

fungi due to overgrowth; therefore, filtration sampling techniques were

utilized. Personal breathing zone (PBZ) and general area air samples were

collected during remediation activities with polycarbonate filters which

were subsequently analyzed for (1) total spore counts via microscopic

analysis and (2) total fungal biomass which involved the determination of

ergosterol (the major sterol constituent of most fungi).

PBZ sampling was conducted inside containment areas, immediately outside

containment, and in distant parts of the building. While containment areas

appeared to reduce the dissemination of spores, potentially toxigenic fungal

spores were identified on 56% of all filter samples collected outside

containment areas. The escape of these spores most likely occurred during

the removal of contaminated building materials from the containment areas.

Workers removing microbiologically-contaminated building materials were

exposed to a potential health hazard. While the containment in this study

appeared to reduce the dissemination of spores, potentially toxigenic fungal

spores were identified on 56% of all filter samples collected outside

containment areas. The escape of these spores most likely occurred during

the removal of contaminated building materials from the containment areas.

The application of both viable and non-viable sampling methods in this study

proved to be extremely useful in monitoring potential fungal exposures. The

results of this study indicate that construction workers or building

maintenance staff performing renovations or remediations may unknowingly put

themselves and other occupants at risk of exposures to toxigenic fungi.

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Keywords: SIC 9211 (Courts), indoor environmental quality, bioaerosols,

fungi, Stachybotrys, microbial contamination, IEQ, IAQ.

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To request a full text copy of this HHE, contact NIOSH Publications at

(1-800-356-4674)