Effect of Health

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Effect of Health


    Health Effects of Mold

    Molds do not generally affect healthy individuals, however those with allergies or asthma may be more sensitive and develop reactions to mold. Sensitive people (and those with prolonged mold exposure) may experience hay-fever type symptoms including: coughing, skin rash, running nose, red eyes, nasal congestion, aggravation of asthma or difficulty breathing. Also, individuals with immune system suppression, lung diseases, are at increased risk for infection from molds.1

    Health Effects of Indoor Mold

    Exposure to mold can occur when airborne mold particles, mostly spores and fragments, are inhaled. We breathe in mold spores and fragments every day, indoors and out. Usually these exposures do not present a health risk. However,  health problems may result when people are exposed to large amounts of mold, particularly indoors.  Inhaling excessive quantities of airborne mold particles, fragments or spores may lead to allergic illness, trigger asthma, cause respiratory infections, or may bring about toxic effects from certain chemicals in the mold cells. Following are descriptions of health problems that can be caused by exposure to mold.

    Allergic Illness

    When mold cells are inhaled and land in the respiratory tract, the body's immune system's response to those invading cells can cause allergic illness. The immune system tries to destroy the mold as it would an agent, like a flu virus, that might cause infection. In about 10 percent of people in the U.S., the immune system overreacts and causes the allergic response resulting in symptoms such as runny nose, scratchy throat and sneezing. Most of us know this allergic illness as "hay fever" or "allergic rhinitis."


    Asthma is a disease that affects the lungs and with symptoms such as wheezing, breathlessness, chest tightness, and coughing.  Asthma attacks often at night or early in the morning, but can also occur at any time.   During an asthma attack the airways partially close causing breathing difficulties ranging from mild (such as a dry cough) to life-threatening (inability to breathe).

    In an asthma attack, the airways that carry air in and out of the lungs become inflamed.   Often inflammation is the result from inhaling allergens or irritants.  The inflammation causes the muscles around airways to tighten, narrowing the airways and creating less flow in and out of the lungs.  Inflamed cells in the airways make more mucus than usual further restricting air flow.

     According to the Centers for Disease Control and Prevention (CDC), one in 12 adults and one in 11 children in the United States have asthma. More than half of asthmatics have respiratory allergies, often to mold. Molds can trigger asthma episodes in sensitive asthmatics. 

    Respiratory Infection

    Some mold species can cause respiratory infection when the live mold invades the tissues of the lungs or respiratory tract. Generally, infections are not a significant risk for healthy people, but can be dangerous for individuals with severely weakened immune systems. Two infections, Histoplasmosis and Cocidicimycosis can be a risk for healthy people.  These diseases occur when people are exposed to enormous numbers of mold spores during activities such as cleanup of bird or bat roosts and other activities that disturb reservoirs where large numbers of mold spores reside.

    Toxic Effects

    Very large doses of certain molds, when inhaled or ingested, can result in poisoning caused by toxins, called mycotoxins, in the mold cells. The evidence on whether an individual can inhale enough toxins from inhaling spores or fragments from indoor mold growth is inconclusive or unavailable.

    One particular type of mold that has been highlighted in the media is Stachybotrys chartarum (also known as Stachybotrys atra), commonly referred to as "black mold". Stachybotrys is a greenish-black mold that grows on materials with high cellulose content (drywall, wood, paper, ceiling tiles) that are chronically wet or moist. It is one of several molds that can produce mycotoxins under certain environmental conditions. The health effects of breathing mycotoxins are not well understood, but we do know that most molds can present some health risks, such as allergic reactions. Therefore, any mold growth in a building should be cleaned up, regardless of the type of mold.


    Moisture and Mold Prevention Control Tips

    Controlling, and preventing moisture will prevent the growth, and spread of Mold.

    • Stop water leaks, repair leaky roofs and plumbing. Keep water away from concrete slabs and basement walls.
    • Open windows and doors to increase air flow in your home, especially along the inside of exterior walls. Use a fan if there are no windows available.
    • Clean and dry water damaged carpets, clothing, bedding, and upholstered furniture within 24 to 48 hours, or consider removing and replacing damaged furnishings.
    • In the office, consider using leather-covered rather than fabric-covered office furniture. Fabric-covered cushions allow dust and moisture to build up in the cushioning, supporting the growth of dust mites
    • Make sure that warm air flows into all areas of the home. Move large objects a few inches away from the inside of exterior walls to increase air circulation.
    • Install and use exhaust fans in bathrooms, kitchens, and laundry rooms.
    • Vacuum and clean your home regularly to remove mold spores.
    • To determine if a vinyl product such as an insect screen is offgassing an irritating smell, remove the item and ventilate the room to see if the odor goes away.

    Mold Testing, Mold Analysis

    In most cases, if visible mold growth is present, sampling is unnecessary. Since no EPA or other federal limits have been set for mold or mold spores, sampling cannot be used to check a building’s compliance with federal mold standards. Surface sampling may be useful to determine if an area has been adequately cleaned or remediated.

    Sampling for mold should be conducted by professionals who have specific experience in designing mold sampling protocols, sampling methods, and interpreting results.

    Sample analysis should follow analytical methods recommended by the American Industrial Hygiene Association (AIHA), the American Conference of Governmental Industrial Hygienists (ACGIH), or other professional organizations.3

    Mold Cleanup

    In all instances it is important to Act fast, as mold damages your home as it grows. Remember that unless the source of the moisture, or cause of water leak is rectified, the mold will regrow, and continue to cause damage and health concerns.

    1. A Brief Guide to Mold, Moisture and Your Home, US Environmental Protection Agency Office of Air & Radiation, USA, viewed 15 August 2008, <http://www.epa.gov/mold/moldguide.html>
    2. Got Mold? Frequently Asked Questions About Mold, Washington Department of Health, USA, viewed 20 August 2008, <http://www.doh.wa.gov/ehp/ts/IAQ/GOT_Mold.html>.
    3. Guide to Mold, Moisture and Your Home, Testing or Sampling for Mold, US Environmental Protection Agency Office of Air & Radiation, USA, viewed 15 August 2008, <http://www.epa.gov/mold/preventionandcontrol.html