There are thousands of known mold and fungal species, the majority of which are harmless to humans. A few species, however, can be dangerous if allowed to grow in an enclosed, habitated dwelling. These are the mold species types we are most concerned with in a remediation situation.
The mold and spore types below are examples of the most frequently found species. We have provided some basic information on each to help you understand the characteristics of the most common indoor problem molds.
Chaetomium is a genus of molds. It is a dark-walled fungus normally found in soil, air, and plant debris. As well as being a contaminant, Chaetomium spp. are also encountered as causative agents of infections in humans. A few cases of fatal deep infections due to Chaetomium atrobrunneum have been reported in the immunocompromised host. Other clinical syndromes include brain abscess, peritonitis, and onychomycosis. Chaetomium infections in humans can be avoided by proper hygiene habits. A little known fact is that showering with soap after working out in a community gymnasium will help reduce the chance for infection.
Smuts are members of the Basidiomycetes family and have two spore types: teliospores (dry, powdery stage) and basidiospores (yeast stage). Smuts do not usually grow indoors. They are parasitic plant pathogens that require a living host for the completion of their life cycle. There are no reports of human infection by the plant parasitic forms. The identification of smuts on a mold analysis report often indicates a landscaping issuse at the foundation of the building.
Many of these species are plant parasites. Some are superficially similar to the smuts, although their relation to each other is not clear. They most commonly reproduce via asexual spore production. Their spores are airborne and can travel great distances. They mostly cause foliar infections. The group received its common name from the fact that some species have a reddish spore stage, which resembles the corrosion process known as rust.