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An outbreak of allergic respiratory disease occurred in a new building that was characterized from initial occupancy by the presence of extensive visible mold (especially Aspergillus versicolor) on interior surfaces. Epidemiological study of the occupants of both the affected building and a comparison neighboring structure indicated high rates of respiratory and other symptoms among persons working in the affected building. Subsequent clinical evaluations of some persons occupying the building for up to five years identified several cases of building-related allergic respiratory disease, including asthma and hypersensitivity pneumonitis. Based on these findings, the building was evacuated before remediation began. The mycological goal of the three-year building restoration project was to reduce concentration of non-phylloplane fungi such as A. versicolor to the lowest feasible level. All visibly colonized materials in the building were discarded and all fine dust on interior surfaces was removed by vacuuming and/or damp wiping. A medical surveillance program utilizing serial self-reported questionnaires and readily available clinical evaluations was designed to monitor the health of building occupants after re-entry. Symptom rates just prior to building reentry were substantially lower than those found before evacuation and have remained unchanged after re-occupancy was completed. No new or recrudescent cases of illness are known to have occurred after building re-entry.

Personal exposure to fungi, bacteria, endotoxin, and (1-->3)-beta-D-glucan was determined at different woodworking sites--logging sites, sawmills, woodchipping sites, and joineries. Exposure levels to fungi at logging sites and sawmills were in the range of 10(3)-10(4) cfu/m3, at the woodchipping mill, 10(3)-10(5) cfu/m3, and at joineries, 10(2)-10(4) cfu/m3. Although mean endotoxin levels were lower than the suggested threshold value of 20 ng/m3, some personal exposures at sawmills and a joinery exceeded the standard. The geometric mean personal (1-->3)-beta-D-glucan exposure level at the woodchipping mill was 2.32 ng/m3, at sawmills, 1.37 ng/m3, at logging sites, 2.02 ng/m3, and at joineries, 0.43 ng/m3. Highly significant associations were found between mean personal inhalable endotoxin exposures and Gram-negative bacteria levels (p < 0.0001), and mean personal inhalable (1-->3)-beta-D-glucan exposures and fungi levels (p = 0.0003). The prevalence of cough, phlegm, chronic bronchitis, nasal symptoms, frequent headaches, and eye and throat irritations was significantly higher among woodworkers than controls. Dose-response relationships were found between personal exposures and work-related symptoms among joinery workers and sawmill and chip mill workers.