Environmental studies in moldy office buildings: biological agents, sources and preventive measures.
Morey PR; Hodgson MJ; Sorenson WG; Kullman GJ; Rhodes WW; Visvesvara GS
Ann Am Conf Gov Ind Hyg 1984 Jan; 10:21-35
Health hazards resulting in hypersensitivity pneumonitis and other respiratory diseases were studied in five large office buildings during a 5 year evaluation conducted by NIOSH. Tests were primarily aimed at identifying the possible sources of microbial agents contributing to the etiology of pneumonitis related disorders. Occupied spaces, and heating, ventilation, and air conditioning (HVAC) systems of each building were studied. Samplers were used to collect airborne fungi, bacteria, and amoebae, while respirable dusts were collected using cyclone samplers. Air velocity through open outside air intake valves was determined by means of anemometers or velometers. Short term colorimetric indicator tubes were used to test for the presence of contaminant gases in occupied spaces; other air contaminants were collected in a large charcoal tube. Airborne fibrous glass was sampled by the fiber count method. Moisture incursion into occupied spaces and HVAC systems was found to be a common trait of office buildings reporting outbreaks of disease. The high incidence of respiratory disorders observed among workers in such buildings was attributed to extant microorganism concentrations. The authors recommend: moisture control occupied spaces and HVAC system components; stagnant water and slime removal from building mechanical systems; the use of steam as a humidifier moisture source; water spray elimination in office building HVAC system components; a relative humidity of less than 70 percent; use of filters with a 50 to 70 percent rated efficiency; and a strict maintenance program for HVAC system air handling units, and fan coil units to reduce the rate of respiratory illness among workers in moldy office buildings.
Respiratory-hypersensitivity; Work-environment; Airborne-particles; Microorganisms; Quantitative-analysis; Air-quality-measurement; Trace-analysis; Occupational-respiratory-disease; Air-contamination; Air-purification; Medical-research
Annals of the American Conference of Governmental Industrial Hygienists