Mold Allergy

Molds are microscopic organisms called fungi, found virtually everywhere, indoors and out. Molds reproduce through spores spread by water, insects or air, so tiny and lightweight they can float through the air like pollen. When inhaled, molds typically cause symptoms such as nasal and sinus congestion, sore throat, sneezing, watery or burning eyes, dry cough, shortness of breath, and irritation of the nose, throat or even skin.

What makes mold spores so dangerous for people with asthma remains mostly a mystery. Some experts theorize that mold spores’ small size permits them to pass more easily into the lower airways, where they can trigger an asthma attack. Others contend mold spores may also interact with other allergens and environmental air pollution, thus increasing the asthma risk from those substances. In addition to allergic reactions, people also can have an irritant response to some of the volatile chemicals that molds put out.

Indoor molds lurk in damp areas such as basements, attics, under-sink cabinets, refrigerators, garbage containers, clothes dryers, upholstery and house plants. Dusty and musty old books, magazines and newspapers are also breeding grounds that many people overlook. Other common hiding places include damp window moldings and sills, shower stalls and shower curtains.

Where Mold Lives and How to Avoid Exposure

To reduce mold inside your home, eliminate the conditions they need to grow: moisture, darkness and poor ventilation.

Remove visible mold and mildew with a bleach solution or non-toxic mix of 1T baking soda, 2T white vinegar and 1 qt water.

Outdoors, mold grows on leaves, trees, and rotting wood. While ridding the outdoors of mold isn’t possible, you can reduce your exposure by keeping windows closed and limiting outdoor activities when mold levels are high. Many local weather reports list mold counts along with pollution levels. Airborne molds often reach peak levels on dry, windy days when breezes kick up spores growing in moist areas.

Helpful links

Excerpts from CDC Hurricane 2017 Key Messages (

o   Recognizing Mold

  • You may recognize mold by:
  • Sight. Are the walls and ceiling discolored, or do they show signs of mold growth or water damage?
  • Smell. Do you smell a bad odor, such as a musty, earthy smell or a foul stench?

o   Safely Preventing Mold Growth

  • Clean up and dry out the building as quickly as you can.
  • Open doors and windows.
  • Use fans to dry out the building. Position fans to blow air out doors or windows.
  • When in doubt, take it out! Remove all porous items that have been wet for more than 48 hours and that cannot be thoroughly cleaned and dried. These items can remain a source of mold growth and should be removed from the home. Porous, non-cleanable items include carpeting and carpet padding, upholstery, wallpaper, drywall, floor and ceiling tiles, insulation material, some clothing, leather, paper, wood, and food.
  • Removal and cleaning are important because even dead mold may cause allergic reactions in some people.

o   Cleaning Up Mold

  • To remove mold growth from hard surfaces use commercial products, soap and water, or a bleach solution of no more than 1 cup of household laundry bleach in 1 gallon of water. Follow the manufacturers’ instructions for use (see product label). Use a stiff brush on rough surface materials such as concrete.

o   When removing mold:

  • Never mix bleach with ammonia or other household cleaners. Mixing bleach with ammonia or other cleaning products will produce dangerous, toxic fumes.
  • Open windows and doors to provide fresh air.
  • Wear rubber boots, rubber gloves, and goggles during cleanup of affected area.
  • Protect your nose and mouth against breathing in mold: Before you enter a building with mold damage, wear at least a NIOSH-approved N-95 respirator, which you can buy at a home supply store. If you plan to spend a lot of time removing moldy belongings or doing work like ripping out moldy drywall, wear a half-face or full-face respirator. Make certain that you follow instructions on the package for fitting the mask respirator tightly to your face. N-95 respirators are only approved for filtering out dust in the air (for example, from sweeping, sawing, and mold removal). This type of respirator will not protect you against chemicals or gases in the air, such as cleaning products or carbon monoxide.
  • Employers, workers and volunteers can find additional resources on this topic in the NIOSH Key Messages document also available at
  • Excerpts from the Homeowner’s and Renter’s Guide to Mold Cleanup After Disasters that might be relevant:
    • “Sampling for mold is not usually recommended.”
    • “This job may be too difficult or dangerous for you. It may be best to get help from experienced and qualified professionals if you can.  Hire a mold inspection or remediation professional affiliated  with or certified by the National Environmental Health Association (NEHA), the American Industrial Hygiene Association (AIHA), the Institute of Inspection, Cleaning and Restoration Certification (IICRC), or American Council for Accredited Certification (ACAC) to inspect, repair, and restore the damaged parts of your home. Your state also may regulate mold remediation.”


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