Yes. Some of these fungi produce toxic metabolites (mycotoxins), and almost all molds that grow in the built environment can produce triple helical glucan, both of which are toxic to lung cells. Many studies in appropriate laboratory animals have demonstrated that very low exposures of these compounds can result in inflammation. The health effects of breathing mycotoxins indoors are not well understood and they continue to be studied. This research is done to better understand why epidemiological studies consistently show increased asthma among occupants of damp buildings not associated with atopy.
Some studies have shown that in agricultural settings, occupational exposure to fungi that produce mycotoxins on grain may result in significant exposures to their toxins. However, it is important to not relate human exposures to mycotoxins in agricultural settings with those exposures that can occur in the built environment (homes and offices). Exposures to mycotoxins in agricultural environments can be at much higher airborne concentrations, and these levels can result in systemic exposure. These agricultural exposures tend to be fungi that do not generally occur in buildings, such as Aspergillus flavus (aflatoxin) and Fusarium graminearum (deoxynivalenol).
The news media and some contractors often refer to “black mold” or “toxic black mold.” It is usually associated with Stachybotrys chartarum, a type of greenish‐black mold commonly associated with heavy water damage. Not all molds that appear to be black are Stachybotrys. The known health effects from exposure to Stachybotrys are similar to those caused by other common molds, and again in high exposure situations (as in agriculture), are known to be associated with severe health effects in some people. Such exposures seldom, if ever, occur in buildings except during remediation activities by people not taking appropriate precautions.