APPLICATION OF CULTURABLE SAMPLING METHODS FOR THE ASSESSMENT OF WORKPLACE CONCENTRATIONS OF BIOAEROSOLS

Case studies are presented demonstrating the utility of culturable air sampling methods as exposure assessment tools. These investigations i ncluded (1) plants that manufacture enzymes, (2) a paper mill, and (3) a large office building with a ventilation system contaminated with P enicillium. In the first case study, a comparison of total bacterial c ounts (in combination with identification and quantification of the pr oduction strain) from unit processes to background locations identifie d exposure sites. Additionally, a comparison of the sampling results a cross the three manufacturing plants (among similar processes) identif ied effective control strategies based on the containment capabilities of the various technologies. This evaluative framework was also succe ssfully applied in the second and third case studies. In combination w ith the identification and quantification of suspect microorganisms, e mission patterns were identified to known immunologically active agent s. In the second case study, elevated levels of Thermoactinomyces spec ies were documented in the transfer tower and the biomass storage buil ding. In the third case study, Penicillium from a contaminated ventila tion system was identified as the predominant fungus in the indoor air . Current sampling methodologies for microbiological agents in ambient air are limited in their ability to comprehensively characterize pers onal exposures. However, these air sampling methods provide informatio n that can be used to propose theories concerning agent dissemination and effectiveness of exposure control methods. In addition, when combi ned with medical and epidemiologic evidence, the collected data can he lp to establish causal relationships between exposures and symptoms.