Aerobiologic sampling

Regardless of placement of an aerobiological sampler in a laminar airflow work zone, it can at best measure the effect of the process at some point downstream from the product. For example, the mouth of a flask may be situated in first air issuing from the HEPA filter, while air impinging on the surface of a plate adjacent to it will be affected by disruptions of the airstream caused by the flask. Contamination found on the plate then results from a different set of conditions than those to which the product is subjected and does not exactly parallel the product contamination mechanism. Only a media-fill process simulation can fulfill this function. Aerobiologic sampling immediately downstream of the critical orifice can, however, detect downward shifts in the overall cleanliness of the critical process air, which in turn may indicate increased contamination potential near the product. 

A Aerobiologic samples B Flat surface samples C Irregular surface samples P Proprietary media system S Standard Commercially-available system. 

The different characteristics and operating principles of aerobiological samplers do not facilitate direct and simple comparisons. The user should, therefore, carefully evaluate the numerous advantages and disadvantages of each method in selecting a sampler for the intended application (Tables 2A and Two studies that provide basic comparisons of aerobiological sampling systems may offer useful information ... 

Buttner M.P. and Stetzenbach L.D. (1991) Evaluation of four aerobiological sampling methods for the retrieval of aerosolized Pseudomonas syrin)>ae. Appl. Environ. Microbiol., 57. 1268-1270. 

Although inventive, these samplers were cumbersome, as a result extensive sampling was impractical. The renaissance of aerobiology was essentially the mid 20th century when samplers were developed that made repeat observations feasible. The two chief samplers developed at this time were the Hirst spore trap and the Andersen culture impactor [2, 3]. The half-century since their development has seen aerobiology greatly expand and support fields such as plant... 

Aerobiology can be a valuable tool for estimating bioaerosol exposure however, it is essential that volumetric sampling be used. 

Benbough, J.E. and Hambleton, P. (1973). Structural, organisational and functional changes associated with envelopes of bacteria sampled from aerosols. In Fourth International Symposium on Aerobiology. J.F.Ph. Hers and K.C. Winkler (eds). Oosthoeck Ultrecht, The Netherlands, pp. 135-137. 

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