SOURCE TESTER FOR FUNGI AEROSOLIZED IN INDOOR ENVIRONMENTS: DEVELOPMENT AND EVALUATION OF THE NEW CONCEPT

摘要

Microbial contamination of indoor environments has gained special attention because of adverse health effects associated with bioaerosols. The health effects associated with indoor mold include allergies and asthma. It has been widely recognized that a reliable method is needed to directly assess the sources of indoor fungi that can be aerosolized and cause health effects. The airborne fungal spore concentration measured with bioaerosol samplers during specific time intervals may not be representative of indoor air quality because of the sporadic nature of the spore release. Due to the irregularity of fungal spore emission and the variations in physical conditions indoors, fungal spores may not be well mixed in the environment, and therefore, short term air sampling data do not always adequately represent human exposure. To evaluate the health effects associated with airborne spores, it is important to be able to measure the source strength, i.e., the spore aerosolization potential. The spore release from growth surfaces is driven by the energy provided by external sources and by the environmental factors. Spore release by air currents seems to be the most prevalent mechanism for indoor fungi (Gregory, 1973; Madelin, 1994). The amount of fungal spores released from agar (Pasanen et al., 1991) and fiberglass duct material (Foarde et al., 1999) was found to be proportional to the air velocity and inversely proportional to the air humidity. In order to estimate the "worst case" scenario of air contamination with spores aerosolized from indoor surfaces, it is important to assess the fungal source under the conditions most favorable for aerosolization. We have developed a new method for assessing the potential for fungal sources to aerosolize spores, and have evaluated this method using different contaminated materials.