The Science Behind Scent Detection

There are no health-based standards for mold or other biological agents in indoor air. We do not recommend routine air sampling for mold with building air quality evaluations.

In many cases, very short-term sampling for mold spores is performed. However, the results, especially negative findings of mold, may not represent actual exposures.

Spore counts and culture results (colony forming units) are often included in indoor air quality reports. These do not capture the full range of exposures. Therefore, measured mold concentrations in spore counts or colony forming units with short-term air samples cannot be interpreted in relation to health risks.

Microorganisms grow frequently in hidden places, e.g., behind wall linings, in floors, or behind installations. They are often not visible from the outside. Often, health complaints occur even after the moisture damage has dried, sometimes even only then. In these cases, moisture measurements are not suitable to localize the microorganisms.

Besides spores and other particles, microorganisms emit gaseous substances (microbial volatile organic compounds = MVOC). The MVOCs are still emitted from the contaminated material long after the microorganism has died.

Dogs can be trained to search for microbial odor and to detect the source. This is a very successful method for locating hidden microbial damage. The mold dog, however, must be correctly trained, led, and interpreted. In some cases, it is the only applicable method to find spots damaged by microorganisms.

During a building inspection, the dog is accompanied by a professional dog handler and an experienced consultant. At places where the dog marks a microbial odor, samples must be taken for microbiogical analysis. By this well directed procedure, destruction of material is unneccessary and additional costs can be avoided.