Mold spores: Another Ubiquitous Asthma Trigger

John Bottrell Health Pro
  • One of the more common asthma triggers is mold. And, like tree and grass pollen, mold is something that is next to impossible to avoid. It grows pretty much anywhere there's moisture, which basically means mold is ubiquitous -- it's everywhere.

    Mold is known to be a trigger of asthma symptoms, but some evidence suggests it also may cause asthma, which I wrote about here.

    According to the Environmental Protection Agency (, mold is microscopic fungi that live on plant and animal matter. It’s not necessarily the mold itself that triggers asthma, but tiny spores the mold creates to reproduce. These spores get into the air and are easily inhaled. For most people, they don't cause any harm.

    Add This Infographic to Your Website or Blog With This Code:

    But for those of us allergic to mold, our immune systems develop an "abnormal" reaction to the spores. The first time you're exposed to mold, your body generates mold spore IgE, which is basically an antibody designed to recognize mold spores. Your body becomes sensitized to mold spores.

    Each subsequent time you're exposed to the spores, your immune system treats them as an enemy combatant. And that results in cells releasing mediators of inflammation, such as histamine and leukotrienes.

    These mediators cause the tissues lining your eyes and respiratory tract to become inflamed, and that’s what causes your common allergy and asthma symptoms: itchy, red and watery eyes, stuffy nose, sneezing, wheezing, etc.  

    According to the Asthma and Allergy Foundation of America (, outdoor mold allergies are most prevalent at the end of July to late summer, although peak mold times can be dependent on the type of mold. The spores generally are spread by the wind.  

    Mold can grow pretty much anywhere, such as any of the following:

    •   Rotting logs
    •   Fallen leaves
    •   Compost piles
    •   Gardens
    •   Anywhere there's stale water

    There's really not much you can do about outdoor molds. However, some can be avoided. For example, it’s highly recommended that you leave work in areas that might have mold to others. At the very least, you should wear a protective mask so you don't inhale the spores.

    Mold, unlike pollen, doesn't die off during the winter months. In fact, mold pretty much stays dormant during the winter, and then grows on vegetation killed by the cold.

    There are also other things you can do to protect yourself. One is to track outdoor mold spore counts just as you would track outdoor pollen counts if you're allergic to pollen. One good source is the National Allergy Bureau.

    Mold spores in your home, meanwhile, can be more easily treated. The EPA offers the following recommendations:

    • Clean up mold and get rid of the source of moisture.
    • Mold on surfaces can be cleaned up with soap and water. The area should be  allowed to dry completely.
    • Make sure you run an exhaust fan during and after taking a shower to prevent water and mold buildup in the bathroom.
    • Use an exhaust fan when boiling water or washing dishes in the kitchen to prevent mold buildup.
    • Fix water leaks as soon as possible to prevent moisture buildup and mold growth.
    •  Maintain a low indoor humidity, preferably between 30 and 50 percent (Humidity control is also recommended to prevent humidity from triggering asthma as I wrote here)

    To learn more check out A Brief Guide to Mold, Moisture, and Your Home, compliments of the website. In the meantime, good luck battling your mold allergy. 

Published On: June 26, 2012