Airborne fungi and bacteria - Background levels in office buildings

Few data have been published on normal background levels of airborne fungi and bacteria in office spaces. The need is growing for baseline data that can be used in complaint investigations, remediation monitoring, and evaluation of building design, operation, and maintenance. Recovery from a major earthquake centered near California State University at Northridge presented an opportunity to study a variety of office structures and to compare bioaerosols and their degree of temporal and spatial variability. Airborne concentrations were observed to be low. Variation within structures and throughout the year was also relatively small. The potential value of these observations is discussed. Higher concentrations of bioaerosols in one of the temporary structures, which was the site of worker complaints, provided a case study in data interpretation and a caution to environmental health professionals investigating indoor air quality complaints.