A study was conducted during March and July of 1987 of a multistory office building which had a long history of specific and nonspecific complaints. The building, Columbia Plaza, Washington, DC, was occupied by several government agencies. Two of the floors selected for study had many complaints, and one had few complaints. The building was contaminated with fungus growth and had a history of flooding and excessive humidity. Questionnaires were used to obtain information on symptoms in workers. Bioaerosol samples were collected three times a day for 2 days at four sites on each of three floors studied. In March, Thermoactinomyces levels were higher than those outdoors at all building sites. In July, Sporobolomyces were abundant at several sites. Both organisms had been implicated in building related hypersensitivity pneumonitis. Fungi found contaminating surfaces in the building were not elevated in ambient air, but levels did increase with agitation of contaminated materials. The authors conclude that the building is sporadically contaminated with molds and thermophilic actinomycetes. Primary factors in the biological contamination were lack of relative humidity control and lack of proper building maintenance. The health risks posed by the biological contamination are not clear. The authors recommend that proper maintenance of central air handling units be conducted and that humidity should be kept below 60%. Fan coil units and ducts should be cleaned, and filters should be changed frequently.
Division of Respiratory Disease Studies, NIOSH, U.S. Department of Health and Human Services, Morgantown, West Virginia