Types of Mold Found in Homes

Updated July 19, 2017

Molds grow anywhere there is oxygen, moisture, and an organic food source. Indoor moulds can appear in basements, refrigerators, or bathrooms. Some moulds produce mycotoxins, airborne toxins, which can be dangerous for people and animals to breathe in. Prolonged exposure to fungal spores can cause irreversible neurological damage and immune system damage.

Health Implications

There are many serious symptoms that are caused by mould toxins. Breathing difficulties and allergies are most common, along with immune diseases like rheumatoid arthritis, lupus, and fibromyalgia. According to, some cancers, heart conditions, and mental deficiencies are attributable to mould inhalation as well. Always clear and remove water damaged areas thoroughly to prevent the fungi from growing.


Of the 35+ types of known mould strains; Chaetomium can have the most impact on health. Mycotoxins from this mould can cause permanent brain and immune damage. A hardy class of mycotoxins produced by the chaetomium mould is called trichothecenes. These have been explored as a possible toxin that could be used in chemical warfare as they can make a person quite ill but do not show up in an autopsy. Chaetomium is one of the top three most dangerous moulds known to humans and animals.

Stachybotrys Chartarum

Stachbotrys produce mycotoxins and appear usually appear after water damage. It lives in humid and damp conditions, mostly on building materials such as drywall and wood. Unfortunately, its presence is not always notices as it grows behind walls and other out of sight places. This mould is the culprit behind the "sick building" epidemic where employees in older buildings complain of cold or flu like symptoms while working but are fine when not in the building. The strain is not easy to remove and can withstand fire in excess of 260 degrees Celsius.


Because fungi contains no chlorophyll, they must find an external food source. The most common fungi that is found indoors is associated with decaying refrigerated foods. This mould causes hay fever and asthma in people with an allergic susceptibility.


If removed from the contaminated environment quickly you may be treated with medication and diet changes to help alleviate symptoms. A positive attitude and a treatment plan from a fungi specialist is advised.

Do It Yourself Mold Testing Kits

Testing the air quality in your home or business can be done with a do it yourself mould testing kit. These kits can be found in any big box hardware store for under $15. Most allow you to use a "lift" test, sticky tape is applied directly to visible mould, and an air sample test from your home's duct work if available. The results will be clear in 48 hours and you can send your sample to the maker's lab for an additional fee.

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About the Author

Based in Rhode Island, Cindy Dixon has been writing since 1995. Her articles appear in “Weeder's Weekly” magazine and design journals. Dixon previously served as an editor for a international parenting site and was a copywriter for a Fortune 500 company. She holds a Bachelor of Arts in graphic design from Rhode Island College.