This mold species is extremely widespread.

Outdoors it may be isolated from samples of soil, seeds, and plants, and is quite common.  Indoors, it is often found in carpets, textiles, and on horizontal surfaces in building interiors like window frames.

The species Alternaria alternata is capable of producing tenuazonic acid and other mycotoxins (toxic substances created by molds) associated with several diseases in humans and animals.   Pneumonitis, sinusitis, deratomycosis (tinea and candidiasis), onychomycosis (nail fungus), subcutaneous phaeohyphomycosis (deep skin infections), and invasive infections may be caused by this species.  Acute symptoms may include edema and bronchiospasms, and chronic exposure may cause pulmonary emphysema.

This is a very common outdoor mold, but is also found indoors. It is a common allergen.

Indoors, Cladosporium is commonly found on the surface of fiberglass duct liners in the interior of supply ducts. It may also be found on paint and textiles.

It can cause mycosis and asthma. Acute symptoms include edema and bronchiospasms, and chronic cases may develop pulmonary emphysema.

Epicoccum species can be found in food, textiles, and paper products indoors. It causes allergic responses in people, and may exacerbate asthma symptoms.

Epicoccum has not been linked to any human or animal infection, and is not generally considered a human pathogen.

Penicillium encompasses a wide number of species. Identification of specific species is often difficult.

This type of mold is quite commonly found in soil, food, and cellulose. It is also found in carpet, wallpaper, interior fiberglass duct insulation, paint, and compost piles.

Penicillium may cause pneumonitis and allergic alveolitis in susceptible individuals. It is reported to be allergenic. It can also cause asthma, and acute exposure can cause edema and bronchiospasms. Chronic exposure can cause pulmonary emphysema.

Some species can produce mycotoxins.

Aspergillus is a mold genus containing approximately 150 different species.

It is found in decaying vegetation, soil, stored food, and animal feed. Some species are parasitic on insects, plants and animals, including man.

All of the species contained in this genus should be considered allergenic. Two species, Aspergillus fumigates and Aspergillus flavus, are the most common ones causing illness in humans. They can cause asthma attacks, and acute exposure can cause edema, bronchiospasms, and pulmonary emphysema.  Other members of this genus are also reported to cause a variety of opportunistic infections of the ears and eyes.

Many species produce mycotoxins which may be associated with disease in humans and other animals.  Toxin production is dependent on the species or a strain within a species and on the food source for the fungus. Some of the toxins this genus produces are considered to be human carcinogens.

Not all molds that are black are the infamous “black mold.”  Stachybotrys is the one that people should be most concerned about.

Several strains produce a trichothecene mycotoxin — Satratoxin H — which is poisonous by inhalation. The toxin is present in the mold spores.

Fortunately, this is a slow growing mold and it does not compete well with other rapidly growing molds. It grows on building material with high cellulose, low nitrogen content, such as wood, paper, and some ceiling tiles. Areas with relative humidity above 55% that are also subject to temperature fluctuations are ideal for Stachybotrys to grow in and produce toxins.  Individuals with chronic exposure to Satratoxin H report cold and flu-like symptoms, sore throats, diarrhea, headaches, fatigue, dermatitis, intermittent local hair loss, and generalized malaise.

Satratoxin H will suppress the immune system affecting the lymphoid tissue and the bone marrow. Animals injected with the toxin from this fungus exhibited the following symptoms: necrosis and hemorrhage within the brain, thymus, spleen, intestine, lung, heart, lymph node, liver, and kidney. Satratoxin H is also reported to be a liver and kidney carcinogen. Effects of absorption of the toxin in the human lung are known as pneumomycosis.

Stachybotrys is rarely found in outdoor samples. It is usually difficult to find in indoor air samples unless it is physically disturbed. The spores are in a gelatinous mass and will die readily after release. That said, even dead spores are still toxic and can cause an allergic response. Percutaneous absorption has caused mild symptoms.

Chaetomium species are rarely associated with human infections. That said, there are reports of infections involving individuals with weak immune system. Chaetomium globosum, which is the most commonly found of the Chaetomium species, is known to produce 2 toxins in moisture damaged buildings, chaetoglobosins A and C. These toxins have the potential to cause illness to building occupants.

Curvularia is a potential allergen. Some people may experience hay fever, asthma and or allergic fungal sinusitis. In severely immunocompromised individuals, Curvularia may cause corneal infections, mycetoma, onychomycosis, ocular keratitis, sinusitis, mycetoma, pneumonia, endocarditis, cerebral abscess, and disseminated infection.