Mould Health Concerns

Disclaimer: Diagnosis of a particular health effect should be left to a medical professional. Health effects in general are not well studied, and dosage, exposure, and sensitivity thresholds are not well known and can potentially vary tremendously depending on various conditions and on the particular individuals. Effects will also vary from species to species within a particular mould genus. Additionally, many ill effects of mould that have been observed recently are the result of modern building design and its lack of adequate ventilation, which can vary from room to room, let alone building to building.

A person’s exposure to moulds is primarily through inhalation of airborne spores. For most people, short-term exposure to mould does not result in any significant health effects. Most of the health complaints reported are upper respiratory in nature, such as coughing, itchy eyes, stuffy nose, sneezing, and sore throat.

For a person who has a compromised or sensitive immune system, health effects can be severe. Some moulds are infectious (pathogenic) and others produce chemical by-products or mycotoxins (toxigenic agents). For individuals with compromised or sensitive immune systems, exposure to pathogenic moulds or their toxic by-products may be associated with a variety of adverse health effects, including allergic reactions, asthma, pneumonitis with flu-like symptoms, infections of the upper airways, sinusitis, or lung diseases.

Mould health concerns can be broken down into three different types: allergy, toxin, and infection.

Allergy is the most common effect and can range from hay fever and asthma all the way to very particular reactions and diseases in certain organs or tissues. Hay fever like symptoms are probably the most common health effect attributed to mould in indoor environments.

Toxin effects can manifest themselves in a very wide variety of ways. Most research up to now has been directed at effects that have to do with ingestion (such as by eating contaminated grain), and comparatively little has been studied about inhaled effects. A particular species of Stachybotrys (S. chartarum) produces a toxin that has been linked to bleeding lung deaths of ten infants in Cleveland. A host of other severe health effects has since been attributed to this toxin, and currently this and very similar toxins produced by other moulds (Memnoniella and Trichoderma) is where much interest has been directed in terms of inhaled toxins.

Infections are potentially the most dangerous and deadly of mould health effects, but mould in general has an inherently difficult time infecting an uncompromised immune system. Many moulds won’t even grow at normal body temperature. While these infections are rare, infections in compromised individuals are much more common and can be very dangerous and problematic due to the lack of treatment options. Compromised individuals include those whose immune systems are weakened such as (but not limited to) those with AIDS, certain cancers, the very old, the very young, and those undergoing certain drug therapies.

Major infectious indoor moulds: Aspergillus, Fusarium, Zygomycetes (includes Mucor / Rhizpous)