The Medical Effects of Mold Exposure

Exposure to mold can cause illness in humans, including asthma, allergic rhinitis, allergic bronchopulmonary aspergillosis, sinusitis, and hypersensitivity pneumonitis. This is well documented. Now, researchers are suggesting that many new mold-related illnesses may exist even though more studies need to be conducted.

Molds cause adverse human health effects through 3 defined mechanisms: toxic-irritant effects from mold byproducts, direct infection by the organism, and triggering a harmful immune response. Each of these mechanisms has scientifically documented mold-related human diseases. However, there may be many more mold-related illnesses. Litigation has pushed the possibility into the public sphere with assertions that exposure to indoor mold causes an array of poorly defined illnesses. Scientists are typically quick to point out the lack of evidence supporting these assertions.

Let’s take a further look at what is and what is not supported by scientific evidence.

The relationship between mold and asthma

Some estimates suggest that around 10% of the general population has IgE antibodies to common inhalant molds. Around 50% of those individuals have or will have allergic reactions after exposure to mold (fungal allergens). While exposure to indoor mold happens, exposure to outdoor fungal allergens is more relevant to sensitization and symptoms of disease. Sensitization to fungi, particularly Alternaria alternata, has been linked to the occurrence and severity of asthma. Exposure to atmospheric fungal spores outdoors has been linked to asthma symptoms and medication use in children with asthma.

The links between asthma and exposure to indoor mold is less clearly established. However, a review of the available literature suggests that children living in damp homes with visible mold were more likely to have lower respiratory tract symptoms like coughing and wheezing when compared to children living in drier, mold-free homes.