Mold in the Home

"Mold is Gold" proclaims attorneys across the United States. It is speculated that mold related lawsuits may dwarf tobacco and asbestos lawsuits combined.
 
Television segments explore the "Sick House Syndrome". Newspaper headlines entice their readers with stories of homeowners being forced to leave their homes, and juries in courtrooms awarding multi-million dollar judgements against homebuilders and insurance companies.
 
How much of the mold headlines and hysteria in the media is hype, and actual health risk?
 
Let’s take a look at the types of mold, it’s causes, and who is most at risk from mold exposure.

What is Mold?

Mold has been around since the days of Noah. Mold is a microscopic organism found virtually everywhere, including the home. Mold grows on plants, foods, leaves, and other organic matter. It can be found indoors and outdoors. There are hundreds of varieties of mold, some beneficial, some toxic.

How does Mold grow?

For many people, they first learned about mold in an elementary school science class.
 
Students placed a piece of bread in a glass jar, added a few drops of water, sealed the lid, and stored the jar in a dark location. Over the next few days and weeks, a growth began, and eventually covered the entire piece of bread.
 
From this experiment, we learn that Mold requires three things to grow:
  1. Moisture.
  2. A Food Source: Organic materials such as wood.
  3. A Physical Space with poor ventilation.

Mold in the Home

Based on the three requirements needed for mold to grow and thrive, let’s take a look at areas and conditions in a residential home that may be susceptible to mold growth.
 
Mold is commonly found growing in damp areas, such as in crawl spaces and basements. Improper grading and a lack of gutters, allow water to drain towards the home, and into the crawl space or basement. The moisture intrusion, combined with a food source, the wood floor joist and sub-flooring, combined with poor ventilation, produces an excellent environment for mold growth.
 
Areas of the home that have moisture related problems might be conducive to mold growth. Sources of moisture that may be contributing to mold growth include roof and plumbing leaks. Mold growth is likely when there is moisture intrusion into the wall cavity, which is common on homes clad with synthetic stucco (EIFS), or brick veneer homes without properly installed and functioning weep holes.
 
Residential homes of today may be more vulnerable to mold growth than homes built 30 years ago or older due to a lower level of ventilation in the home. As architects and builders design and build homes with higher insulation values and less ventilation, it creates one of the three requirements for mold growth: a physical space with poor ventilation.

Mold and Your Health

Once mold is growing in the home, spores can be released and inhaled. The Center for Disease Control (CDC) in Atlanta, Georgia has not defined what level of mold is considered safe, and what level would be considered a health risk. The people most at risk to mold related health problems are infants, and children, the elderly, and those affected by other health related issues and with low immune systems.
 
Out of hundreds of different types of mold, the following types are most related to health concerns:
  1. Stachybotrys: possible association with pulmonary hemorrhage among infants; causes suppressed immune functions; some species are carcinogens.
  2. Penicillium: common mold found in homes; effects respiratory system, some species are toxic.
  3. Aspergillus: common mold found in homes; has 150 species that are all allergenic, some toxic and carcinogenic; related to asthma problems.
  4. Fusarium: highly studied mold; correlates with suppressed immune system and the common cold, flu and congestion, may be toxic.

Mold Testing

If mold is observed in the home, it may be desirable to have the area tested to determine the type of mold, and whether it is toxic or non-toxic. A qualified professional trained to do mold testing should only perform mold testing. Qualified mold professionals include mycologist, industrial l hygienists, and indoor air quality specialists.

There are a number of mold testing methods.

  • Swab testing involves taking a culture of the mold using a sterile swab, and submitting the sample to a laboratory for analysis.
  • Air Sampling utilizes a cassette to collect mold spores from the air and carpet, which is then submitted to a laboratory for analysis. Air sampling is more thorough than swab testing.

Mold Abatement:

Once the type of mold is identified, removal (known as abatement) can be performed.
 
If the mold is toxic (Mycotoxic or Pathogenic), abatement should only be performed by a qualified professional, such as an Industrial Hygienist. Homeowners should not attempt to remediate any types of toxic mold.
 
If the mold is non-toxic (Allergenic), the first course of action will be to make necessary repairs and improvements to help eliminate the moisture source. Once repairs have been made, the affected area should be thoroughly cleaned using a non-ammonia soap with a stiff brush. Always wear gloves for protection, and a special repirator mask when handling moldy surfaces. After cleaning, the area should be disinfected using a solution of 10% bleach (1 1/2 cups bleach per gallon of water). Let the affected area dry overnight to allow the bleach to kill the mold. Be careful with bleach fumes as they can irritate the eyes, nose and throat. Never mix bleach and ammonia, as the fumes are toxic.

Reducing Mold in the Home

Proper control of moisture and the level of ventilation can reduce the risk of mold, and help in creating a healthy and happy home. Homeowners can be proactive in reducing the risk of mold by:
  • Any types of leaks in the home should be properly repaired.
  • The level of ventilation in the attic and crawl space should be evaluated, and improved as needed.
  • A moisture/vapor barrier should be installed on the floor of the crawl space to reduce moisture in the crawl space.
  • The exterior grading of the lot should be evaluated to determine if improvements are needed to help control lot drainage away from the home. The gutters should be kept clean, and downspout extension tubes or splash blocks should be installed to help discharge roof rainwater at least 4 to 6 feet away from the home.
*Information above provided by homeinspections-usa.com
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