A few months ago we took a look at the life cycles of mold and applied it to the growth of mold in an HVAC system. In this article we used the word mold with the assumption that the reader had an idea of what mold is. While most people would probably be able to identify mold if they saw it growing it helps to know what exactly you’re up against, which is why we are going to look into the secret lives of mold and expose our foe for the soggy scoundrel that he is.
To begin it must be understood that all mold is fungi but not all fungi is mold. It is possible for fungi to grow as a single cell but mold by its very existence grows in the form of multicellular filaments, called hyphe. This mean that mold consist of more than one cell and have differentiate cells that perform specialized functions in the organism. If you’re exploring around the home, mold is a fuzzy growth on moist organic matter by several types of fungi. Mildew is mold growing on fabric. While mold growing within an HVAC unit is a quick way to spread it around, it is not the only way. And, while some molds cause disease or food spoilage, others are useful for their role in biodegradation or in the production of various foods, beverages, antibiotics and enzymes. For the purpose of this article we will only be looking at mold that is harmful and furthermore mold that is easily found in the home.
There are four kinds of health problems that come from exposure to mold; allergic reactions, irritation of tissues, infections and toxic effects due to mycotoxins. When mold grows indoors in moist organic materials, building occupants may begin to notice odors and suffer a variety of health problems associated with mold exposure. People with weak immune systems (i.e., immune-compromised or immune-suppressed individuals) are more vulnerable to infections by molds (as well as more vulnerable than healthy persons to mold toxins). Aspergillus fumigatus, for example, has been known to cause aspergillosis in the lungs of immune-compromised individuals. These individuals inhale the mold spores which then start growing in their lungs. Trichoderma has also been known to infect immune-compromised children. Healthy individuals are usually not vulnerable to opportunistic infections from airborne mold exposure. However, molds can cause common skin diseases, such as athlete’s foot, as well as other infections such as yeast infections.
Mold spores are hardened containers, which possess all the DNA instructions needed to create new mold creatures, aerial eggs as it were. If they bump into dry walls they just rebound and go back to floating, but when they bump into wet walls they stick. Out of the broken open shell a single creature’s body appears, then a groping arm grows from that body, a leathery hypha, albino and clear, and then from that hypha grows another, and another, and then many, many others more. These hyphae are used by molds to obtain nourishment. For some species it is the sulfur grains in concrete that are sought, in others it’s the metals in paint, or the glue in wallpaper, or even, for one especially abundant species, found at some time in almost every house in northern temperate climates, it will be the actual antibiotic poisons that the wood they land on produces which they slurp up and use as food. The hyphae excrete enzymes that break down complex organic materials. All over your house these freshly appearing mold creatures will plug into the walls via their hyphae. If enough moisture is available for the mold to emerge from hibernation, they are very likely to start growing on your walls. Most of the mold spores you get were probably produced locally, and any especially damp building in the neighborhood will act as a fertile nursery. Other mold spores come from further away, and the British meteorological service’s sampling aircraft have detected them arriving in Britain across the sea from all sides, with buoyant flights across the North Sea from Denmark taking only two day or so with a fair wind. In the U.S. they can be blown from Texas to Minnesota within a week. The spores can last up to forty years before hatching.
While not everyone is especially sensitive to the mold that seems to be all around us at all times, keeping homes and businesses healthy should be a priority. Next month we will outline different ways to deal with the mold that is or wants to be living with you.
Katie Long
Power Vac America, Inc.
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