What cannot be seen by the naked eye can be detected through the process of air sampling. Air samples are important for more than one reason. Once the samples have been analyzed, the types of mold present can be determined, severity of the problem can be assessed, and plans for correction can be made. Once mold removal has taken place, the air can once again be sampled in order to determine if the removal was a success.
Some home inspectors are qualified to test for mold. The most common devices used to collect mold air samples include:
- Impaction sampler: Uses air to trap spores directly on slides
- Cassette sampler: Works in the same manner as the impaction sampler, but is disposable
- Particle collector: Collects airborne mold and places it on a culture dish
When To Sample For Mold
Any home in which water damage has occurred is a candidate for air sampling. Homes in which mold is visible, or a musty odor is noticed are also prime candidates. Home buyers and owners may also choose to have testing done even if there are no signs of mold. Home inspectors may recommend that sampling be done if they feel the home is at risk. Note that air sampling will include testing the outdoor levels as well. This is done so that an accurate comparison can be made between the indoor and outdoor air. If higher concentrations of molds are found indoors, or if the type, genus or species of mold found indoors differs significantly from the outdoor air, then you may have a mold problem.
The Air Sampling Process
Air samples will be taken in rooms in which mold is present, or rooms in which it is suspected to be present based on many factors such as elevated moisture content in the floors, walls or ceiling. Collection devices are placed a few feet off the floor and allowed to run for approximately ten minutes. To ensure reliable results, the home will need to be completely closed, with all windows and doors shut. Heating and cooling systems will need to be turned off during the collection process. Sampling is typically not done during adverse weather, as windy conditions or changes in the barometric pressure can affect results.
Air Sampling Facts
- Air sampling alone cannot confirm or deny that a problem exists. Visual home inspection and the collection of surface samples will also be recommended
- Indoor spore levels will vary based on certain conditions. This makes it important to have the samples taken by someone that is well trained and knows when and where to collect
- Spores can be damaged during the collection process. Should they be, identifying specific mold types may be impossible
- Serious mold problems are often indicated when long spore chains are present in testing. Spore chains in lower level mold conditions will break apart once they become airborne
Though air sampling may not be the only testing that needs to be done, it does have value. When mold is suspected or seen by a home inspector, air sampling will likely be recommended as the first step. Not all types of mold present a health hazard, but those that do will need to be removed from the home as soon as possible.
