Several times each year I get a patient concerned about mold in their home, or so-called “black mold”, noted behind a wall while doing some renovation. The concerns usually center on a complaint of shortness of breath or cough, and sometimes secondary gain is at work when the home or apartment is rented.

Mold grows in a warm humid environment. Every environment has some mold, and moisture control is the way to control mold growth. The term “mold” really refers to fungus and the types can be many and varied. Most people will not develop any pulmonary infection due to fungus exposure for at least two reasons: first, patients with fungal infections usually have some type of problem with their immune system related to disease or age; and second, for lung disease to occur, the exposure must be substantial with large amounts of fungal particles aerosolized, which usually occurs in industrial settings such as grain silo cleaning.

Fungi can produce toxins (called mycotoxins) but these must be eaten or ingested in some form to cause disease. Lastly, we will occasionally see patients who may have developed a hypersensitivity to fungus exposure. Once again, this is usually in a workplace where heavy daily exposure is occurring such as in the lumber industry. There are no Federal standards for acceptable levels of fungal spores in the environment and the work-up for patients who are concerned about home exposure is often difficult and unsatisfying. Air quality studies do not always correlate with objective evidence of disease.