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Mold: The Invisible and Pervasive Invader

by Mary Shackelton, MPH, ND

With the recent flooding in Colorado, mold is on everyone’s mind. And, rightly so. It is dangerous, and nothing to mess around with.

Flooding and Mold

If your drywall was saturated with water, your risk of having mold increases greatly. If your carpet and carpet pad were soaked…get them out of your house! This is the perfect breeding ground for mold. Mold is something that you may not be able to see, or sometimes even smell, and can be there for a very long time. Many Colorado residents will say that they can’t have mold issues because our climate is so dry, but this is not true. A leaky faucet behind a bathroom wall, a leaking pipe in a basement, water coming into the house from outside pooling in your roof or under the foundation of your house are all possibilities for the growth of mold.  Within 48 hours of water damage, mold can begin to grow. With the recent floods and saturation of materials in the home, it is important to gain an understanding of mold contamination, and it’s possible effects on human health.

 Black MoldThe CDC investigated the resulting mold growth after hurricanes Rita and Katrina on August 29 and September 25, 2005. They found that 46% of homes (>100,000) had some mold and 17% (40,000) had heavy mold exposures. “Although molds can be found almost anywhere, they need moisture and nutrients to grow. The exact specifications for optimal mold growth vary by the species of mold. However, mold grows best in damp, warm environments. The availability of nutrients in indoor environments rarely limits mold growth because wood, wallboard, wallpaper, upholstery, and dust can be nutrient sources. Similarly, the temperature of indoor environments, above freezing and below the temperature for denaturing proteins, can support mold growth, even if the actual temperature is not optimal” — (Doll SC. Determination of limiting factors for fungal growth in the built environment. Cambridge, MA: Harvard University School of Public Health; 2002). That means the mold can grow almost anywhere there is water. 

Mold can cause every kind of symptom with any kind of severity. The result of mold exposure is variable among different locations, from person to person and over time.  The main route of exposure to mold is via the respiratory tract and the most common symptoms people experience from exposure to mold is: 

  • nasal congestion
  • sore throats
  • asthma
  • difficulty with breathing
  • chest tightness
  • upper respiratory infections
  • recurrent infections
  • headaches
  • itchy eyes
  • runny nose

The onset of these symptoms can be subtle and difficult to pinpoint. Small children, elderly, immunocompromised, and people, who already experience asthma and respiratory conditions are most at risk of the above symptoms when exposed to mold.

Below is a direct excerpt from the June 2006 CDC report on Mold Prevention Strategies and Possible Health Effects in the Aftermath of Hurricanes and Major Floods. 

Public Health Strategies and Recommendations for Mold Prevention

In the aftermath of major hurricanes and floods, buildings or materials soaked for >48 hours are contaminated with mold unless proven otherwise by inspection or adequate environmental sampling or cleaned according to the EPAs recommendations. Recommendations from CDC are for protecting and monitoring the health and safety of workers and residents who enter, repair, or destroy flooded buildings. The recommendations are focused on limiting human exposure to mold and other microbial agents and preventing any adverse health effects related to such exposure.

Note: I think it is important for everyone affected by the recent floods to read the following: 

  • Workers and residents might be exposed to high levels of mold-related contaminants.
  • Sufficient evidence exists of an association between adverse health outcomes and exposure to damp indoor environments or materials contaminated with fungal growth.
  • Insufficient evidence exists for establishing health-related guidelines on the basis of concentrations of mold (quantitative measure) or species of mold (qualitative measure) in either indoor or outdoor environments.
  • Allergen testing to determine the presence of IgE to specific fungi might be a useful component in the complete clinical evaluation and diagnosis of mold-related allergies and in the decision to avoid exposure to fungal allergens that might be causing allergic symptoms. However, testing for IgE sensitization to molds has important limitations. Allergens used in these tests are often poorly standardized and the tests often have unclear sensitivity and specificity. In addition, allergen testing is not relevant to diseases that are not mediated by IgE.
  • Clear, concise, and practical recommendations and actions are necessary to limit exposure to mold and to prevent mold-related health outcomes where possible.

For further information, please go to: http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5508a1.htm for a detailed list of mold prevention strategies and a full understanding of how to address mold contamination.