A little mildew around your tub or shower is no reason for alarm. But if you smell a musty odor or see visible signs of water damage in your home, it could be serious. Perhaps you don’t see or smell anything but are experiencing unexplained hay fever symptoms — or worse.
Even if only part of your family is experiencing symptoms, there could be a mold problem. Mold affects everyone differently depending on factors such as your immune system, allergies, age, the type of mold, and more.
Is It Mold or Mildew?
Mold and mildew are both fungi that thrive in warm, moist environments. While it can be confusing, mildew refers to certain types of fungus, including some types of mold. The main difference between mold and mildew is in their appearance and potential health risks.
- Mold is often thicker and black, green, red, or blue in color. It often grows on foods, walls, and other organic and building materials.
- Mildew is usually a thin, powdery growth of fungus, gray or white in color. It often grows in showers, on paper, and on fabrics.
What Mold Needs To Survive
Although there are at least 1,000 species of mold common in the U.S., the most common types of mold found in homes include Cladosporium, Penicillium, Aspergillus, and Alternaria. Mold overgrowth in your home is a serious issue that must be addressed immediately since mold has the potential to cause health problems and even make a home uninhabitable.
It is essential to fix any and all water leaks right away since mold begins to grow within the first 24 to 48 hours. Mold cannot live without moisture; it’s one of the four basic elements mold needs to survive:
- Moisture (from leaks, high humidity, condensation)
- Food (any organic material including wood, drywall, paper, and even soap residue)
- Temperature between 40 and 110 degrees Fahrenheit
Allergic Reactions to Mold
Mold allergies are common. According to the Centers for Disease Control and Prevention, “An estimated 6%–10% of the general population and 15%–50% of those who are genetically susceptible are sensitized to mold allergens.” There are thousands of molds, but only a few dozen cause allergic reactions. Symptoms of a mold allergy might include:
- Itchy nose, mouth, and lips
- Asthma attacks in those with asthma
- Throat irritation
- Itchy, watery eyes
- Runny nose
- Nasal congestion
- Skin rash (dermatitis)
Mold exposure can irritate the eyes, skin, nose, throat, and lungs in both mold-allergic and non-allergic people. Mold can also trigger asthma symptoms such as wheezing, shortness of breath, or chest tightness.
Some molds are volatile and release compounds directly into the air, known as microbial volatile organic compounds (MVOCS). Of greater concern, though, are molds that produce mycotoxins, which may cause a toxic response in humans and animals. More than 200 mycotoxins have been identified from common molds.
These so-called “toxic molds” that produce mycotoxins include Aspergillus versicolor, which can cause pulmonary infections, and Stachybotrys chartarum, often referred to as “black mold.” The mycotoxins produced by Stachybotrys chartarum can cause serious breathing difficulties, bleeding of the lungs, damage to internal organs, mental impairment, cancer, and even death in some cases. Both of these molds produce Trichothecenes, a mycotoxin that can be absorbed by your intestinal lining, airways, and skin.
Dead mold may still cause allergic reactions in some people, so killing it isn’t enough; it’s important to remove the mold. Note that the EPA does not recommend using bleach to kill mold (bleach is a respiratory irritant). If the mold problem is over 10 square feet in size, you should hire a professional to clean up the mold.
Mold Prevention Tips
Here are my recommendations to help prevent mold in your home.
- Use an air purifier with a HEPA filter to capture airborne mold spores.
- Keep humidity between 40-60%; preferably about 35%.
- Reduce moisture in the bathroom and kitchen by turning on an exhaust fan or opening a window during and after bathing or cooking.
- If you reside in a humid climate, use an air conditioner or a dehumidifier to keep the humidity levels low.
- Fix all leaks immediately and dry any water-damaged areas within 24 to 48 hours; the sooner, the better.
- Clean sinks and tubs with a nontoxic solution to keep mold and mildew at bay.
- Change your HVAC filters regularly (every 3 months according to Energy Star). I recommend a high-performance electrostatically charged filter. The fibers in these filters act like tiny magnets to attract and capture small particles, removing even small, lung-damaging particles from your home’s air.
For additional mold guidance, check out Home Remedies: Removing Mold
Feature image courtesy of Emily May. Originally published on June 9, 2015, this article was updated in October 2022.