Types of Mold

There are many types of mold. In fact there are over 10,000 known species. Some of these molds are toxic and others are not. In addition, some cause allergies. Understanding the type of mold and the quantity in the air in your home is essential to create a proper mold removal protocol. Each case is different and therefore an understanding of the effects of each type of fungi is imperative.

Below is a list of the most popular or typical types of mold found in building structures along with an explanation of their possible effects on humans.

Aspergillus: Approximately 200 Known Species

Toxins:
A. flavus: aflatoxin B1 & B2, cyclopiazonic acid, kojic acid.
A. fumigatus: ergot alkaloids, fumigaclavines, gliotoxin, fumigatoxin, fumigillin, fumitremorgens, helvolic acid, tryptoquivaline tremorgens, verruculogen.
A. niger: malformin C, oxalic acid.
A. ustus: austocystins.
A. versicolor: aspercolorin, averufin, cyclopiazonic acid, sterigmatocystin, versicolorin.

There are approximately 200 different species of Aspergillus which cannot be easily differentiated by their morphology. Some species of Aspergillus are considered serious, sixteen of which have been documented as etiological agents of human disease. The diseases caused by these species rarely occur in individuals with normally functioning immune systems. Toxin production is dependent on the species or the strain within a species and on the food source. These fungi are found in soil, compost piles, plant debris and stored grain, as well as on water-damaged building materials. This type of mold is considered one of the most potent known.

Penicillium: Approximately 200 Known Species

Toxins:  Various toxins by different species: penicillic acid, peptide nephrotoxin, viomellein, xanthomegin, xanthocillin X, mycophenolic acid, roquefortine C & D, citrinin, penicillin, cyclopiazonic acid, isofumigaclavine A penitrem A, decumbin, patulin, citreoviridin, griseofulvin, verruculogen, ochratoxin, chrysogine, meleagrin.

Description: A wide number of organisms have been placed in this genus, therefore, identification to a species is sometimes difficult. It is commonly found in aerosol samples, carpet, wallpaper, and interior fiberglass duct insulation. Many species of Penicillium are common contaminants on various substrates and are known as potential mycotoxin producers. Human pathogenic species P. Marneffei is known to cause disease in immune compromised individuals.

Chaetomium: Approximately 80 known Species

Toxins: Chaetomin.Chaetomium globosum produces chaetoglobosins.

Description: Chaetomium is a large ascomycetous fungus easily identified by its large “lemon-shaped” ascospores and large, round, oval or flask shaped perithecia with straight and/or wavy filamentous appendages. It is allergenic and occasionally causes systemic or cutaneous phaeophyohomycosis. It readily digests cellulose and is frequently isolated from decomposing plant materials, especially woody or straw-like materials. In water damaged buildings it is frequently found on sheetrock and paper products.

Cladosporium: Approximately 500 Known Species

Toxins:Some Species: Cladosporin, emodin, e acid.

Description: Cladosporium is the most frequently found fungus in outdoor air. Indoors, it usually occurs at low concentrations in damp or humid areas, but may be found in high concentrations in water-damaged building materials. Its ability to sporulate heavily and to get airborne makes it an important fungal allergen. This type of mold has been found to be occasionally associated with disease in humans; one species can cause chronic subcutaneous infection. Cladosporium can rapidly invade many different niches, and is therefore considered ubiquitously problematic. It is known to be a common cause of asthma in the Western Hemisphere.

Stachybotrys: Approximately 15 Known Species

Toxins:Macrocyclin trichothecenes: verrucarin J, roridin E, satratoxin F, G, & H, sporidesmin G, trichoverrol, cyclosporins, stachybotryolactone.

Description: Stachybotrys is a dark colored fungi that thrives on water damaged cellulose rich materials such as sheetrock, paper, ceiling tiles, cellulose containing insulation backing and wallpaper. The presence of this fungus in buildings is significant because of the mold’s ability to produce extremely toxic (potent) mycotoxins. Exposure to these toxins can occur through inhalation, ingestion or dermal exposure and can include the following symptoms: dermatitis, cough, rhinitis, nose bleeds, a burning sensation in the mouth and nasal passages, cold and flu symptoms, headache, general malaise, and fever. Inhalation of conidia may also induce pathological changes pneumomycotoxicoses). Satratoxin has been reported to be easily absorbed in animals and in high doses or chronic low doses it can be lethal. Considerable recent media attention has been focused on the fungi Stachybotrys chartarum (atra) due to infant deaths in Cleveland, Ohio from pulmonary hemosiderosis, which may be associated with contamination of residences with this fungus.