With more than 100,000 species in the world, it is no wonder molds can be found everywhere. Neither animal nor plant, molds are microscopic organisms that produce enzymes to digest organic matter and spores to reproduce. These organisms are part of the fungi kingdom, a realm shared with mushrooms, yeast, and mildews. In nature, mold plays a key role in the decomposition of leaves, wood, and other plant debris. Without mold, we would find ourselves wading neck-deep in dead plant matter. And we wouldn't have great foods and medicines, such as cheese and penicillin. However, problems arise when mold starts digesting organic materials we don't want them to, like our homes.

Once mold spores settle in your home, they need moisture to begin growing and digesting whatever they are growing on. There are molds that can grow on wood, ceiling tiles, wallpaper, paints, carpet, sheet rock, and insulation. When excess moisture or water builds up in your home from say, a leaky roof, high humidity, or flooding, conditions are often ideal for molds. Longstanding moisture or high humidity conditions and mold growth go together. There is no practical way to eliminate all molds and mold spores in the indoor environment; the way to control indoor mold growth is to control moisture.

There are a lot of home test kits on the market, like spore traps, that are not adequate. There are always mold spores in the air and these types of tests rely on a spore landing in the dish and growing. This will not tell you much if anything about your problem, the amount of spores, or anything about how to take care of it. It will tell you that there is mold in the air, which is to be expected.

Most laboratories can do a test on a sample you get either from the spore traps, or a surface test using a swab or tape. This can be useful for finding out what kind of mold you have, but unless you buy sterile testing equipment, the tests can easily be contaminated, and again, it will not tell you how much mold spores you are being exposed to or how to take care of the problem.

Even an experienced mold inspector can be wrong using only a visual examination. Surface sampling is important to identify molds, but only if it is complimented with a series of air quality tests as well. An outside air quality test must be done with any inside tests as a comparison. These tests are only effective if done after a complete home mold inspection to find areas of concern. By using the results of the visual inspection, a professional can determine where to run the tests and how to interpret the results. Without a visual home inspection, it is impossible to accurately locate the source of the mold.