The goal of biological sampling is to help determine whether the biological particles present in a particular environment are affecting or causing irritation in certain individuals. Sampling is also used to locate the source of indoor micro-organisms and find an effective remediation. While we are typically surrounded by a wide variety of different micro-organisms every day, sampling provides us with a method to establish in a scientific way whether the environment in question contains more organisms than would normally be present. There are numerous techniques that may be used to evaluate the level of indoor micro-organisms. We believe, however, that scientific comparisons are only possible when volumes of air measured are sampled and when results of surveys are expressed in terms of volumetric measurement. Currently, there are no widely accepted protocols or regulations regarding biological air sampling. In the absence of standard, we believe that common sense should prevail. However, the New York City Department of Health, Bureau of Environmental & Occupational Disease Epidemiology has established guidelines on Assessment and Remediation of Fungi in Indoor Environments. We know that some bacteria and fungal spores can cause disease only when they are alive (viable,) while others are capable of producing allergies or irritation even when no longer living. Also, while cultures may permit greater accuracy in speciating some fungal organisms present, spores vary widely in their ability to grow and compete on laboratory media. This may result in an inaccurate characterization of the area sampled. Therefore, a complete sampling protocol for the biological flora in any environment uses both a culturable and non-culturable sampling method. Yet often, due to time and budget constraints, this is not always possible. In these cases, we currently believe that non-culturable spore trap samples provide a more accurate 'snap shot' of the air and are the best choice when only one sampling method may be used.

There are other simple sampling methods that may be used to supplement volumetric air sampling. Surface samples are taken by tape life imprints, by swabbing the suspect surface with a culturette swab, or by submitting a bulk sample of the suspect surface. We typically recommend having a direct microscopic examination performed on surface samples. While culturing a surface sample may help resolve a specific identification problem, used alone, such a culture may result in an inaccurate characterization of the area sampled. A direct microscopic examination of a surface shows exactly what is there, without being affected by an organism's ability to compete and grow on sampling media.
Clean Air Testing Labs, Inc. 1111 Steele Blvd, Baldwin, New York 11510 - Tel: 516-546-2640 Fax: 516-546-8811A