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Findings from a NIOSH IEQ investigation.
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana. Fairfax, VA: American Industrial Hygiene Association, 2001 Jun; :66
Background: In March 2000, NIOSH conducted an indoor environmental quality (IEQ) evaluation in a two-story office building located in South Carolina. Workers were concerned about exposure to carbon monoxide (CO), as well as mold in the building. Their symptoms included headache, sinus problems, and upper respiratory problems. Methods: Measurements of carbon dioxide (CO2), CO, temperature, and relative humidity (RH) were made and the ventilation systems were visually examined. Dust samples were collected by micro-vacuuming sections of carpet and "sticky" tape samples were collected using the adhesive side of the tape to pull spore structures and hyphae from the growth surface. Areas suspected of water damage were probed with a moisture meter. Twelve of the 115 employees volunteered for informal interviews. Results: The highest CO2 concentrations ranged from 1030 to 1190 parts per million (ppm), suggesting that parts of the building was receiving insufficient outside air (OA). Temperature and RH levels ranged from 69 to 75 degrees F, and 35 to 53%, respectively, within the thermal comfort parameters recommended by the American Society of Heating, Refrigerating, and Air Conditioning Engineers. CO concentrations ranged up to 2 ppm. Micro vacuum samples did not reveal high fungal concentrations, however bacterial levels ranged up to 5.9 x 10 6 colony forming units per gram of collected dust, mainly Gram negative species. Tape samples of suspect fungal colonies revealed Cladosporium, Ulocladium, and trace levels of Stachybotrys chartarum. The highest moisture readings were beneath exterior windows while carpeted areas were predominantly dry. Of the 12 employees interviewed, most reported respiratory problems, congestion, fatigue, and headache. Conclusions: There was inadequate amounts of OA provided to some offices. Localized microbial reservoirs existed and there were numerous ongoing moisture incursion conditions. It was unclear, however, how these related to the health complaints described by the interviewed employees. Recommendations were provided to further improve ventilation and eliminate the wet conditions conducive to microbial growth.
Indoor-environmental-quality; Exposure-levels; Carbonates; Molds; Respiration; Respiratory-system-disorders; Pulmonary-system; Pulmonary-function; Pulmonary-system-disorders; Temperature-measurement; Humidity; Ventilation-systems; Dusts; Air-conditioning; Fungi; Workers; Work-environment; Work-areas; Indoor-air-pollution
American Industrial Hygiene Conference and Exposition, June 2-7, 2001, New Orleans, Louisiana
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division