Up-to-date information on the health effects of mold exposure. Can mold be more than an allergen?
The risks of indoor mold growth once again are grabbing headlines in the wake of hurricanes Rita and Katrina. It is important to understand what is known about the health effects of mold.
First, is there such a thing as a “killer” mold? The answer is complex. Some molds and mold byproducts can be very dangerous to some people. However, exposure does not mean that people will get sick and die. For example, Aspergillius sp. can cause a rare, serious lung condition called aspergilliosis, which can be deadly. Those people most at risk have severely compromised immune systems such as those undergoing chemotherapy, those with HIV/AIDS or those who have had bone marrow or organ transplants.
Secondly, various molds can produce mycotoxins. Individuals can experience health problems if they are exposed to high levels of these compounds but this is rare in most indoor environments. Health effects include eye, nose and throat irritations, headache, dizziness, dermatitis, diarrhea and impaired or altered immune function. While we know that ingesting mycotoxins can cause problems, researchers are just starting to study how these substances may affect health.
Thirdly, inhaling large concentrations of dust with mold spores may cause lung irritation and in some instances a serious lung condition called hypersensitivity pneumonitis. This condition is generally an occupational hazard in agriculture. However, there have been some cases reported in individuals in residences and among mold remediators working without proper protection.
By far the most common health impacts from mold are those associated with allergies and asthma. Researchers estimate that about 10 percent of the US population is allergic to mold spores. Symptoms can range from watery eyes, throat irritation, coughing and sneezing to more serious conditions such as sinusitis and asthma.
One of the most important avenues of research with indoor mold focuses on damp buildings. Two excellent studies (Jaakkola et al. 2005 and Cox-Gasner et al. 2005) provide the first solid evidence that damp buildings and exposure to resultant indoor mold growth are risk factors for developing asthma and not just in making asthma symptoms worse. The results from these studies indicate that the risk for developing asthma appears higher, but is not limited to, people who are sensitive to mold allergens or those who have parents with asthma. Children are at a greater risk than adults. These studies emphasize the importance of cleaning up and preventing indoor mold growth by eliminating moisture intrusion and reducing indoor humidity to reduce the number of people who develop asthma and the frequency and severity of attacks for those who do have asthma.