Sampling for Airborne Microorganisms

Microbiologists have confronted the challenges of sampling and analysis of airborne microorganisms since the early 20th century. Today, the concentration and composition of airborne microorganisms are of interest in various areas such as agricultural and industrial settings, hospitals, home and office environments, and military installations. In all of these applications, the term "bioaerosol" is used to refer to airborne biological particles, such as bacterial cells, fungal spores, viruses, and pollen grains, and to their fragments and by-products. A wide variety of bioaerosol sampling and analysis methods have been used, and new methods are being developed. However, no single sampling method is suitable for the collection and analysis of all types of bioaerosols and no standardized protocols are currently available. Therefore, data from different studies are often difficult to compare because of differences in sampler designs, collection times, airflow rates, collection media and analysis methods. In addition, human exposure limits have not been established for bioaerosols because of the lack of exposure, dose, and response data. The purpose of this chapter is to present various bioaerosol sampling and analysis methods that would allow facilitating an intelligent selection of instrumentation and techniques. The principles of bioaerosol sampling are presented, followed by a review of traditional and emerging sampling methods and techniques, including the results of performance evaluations of the various sampler types. Equipment calibration and air sampling considerations such as collection times and the number of samples are discussed. The advantages and disadvantages of surface sampling methods are also described.