In many parts of the country, summertime means high temperatures and high humidity - a combination that can breed large amounts of
allergens. In particular, dust mite allergen and mold spores thrive in hot, moist environments. In this article, we will focus on mold - what it is,
how it grows, the health problems it can cause, and what you can do to prevent mold from gaining a foothold in your home.
General Information About Mold
Mold is a naturally occurring fungus that is both necessary and useful - outdoors. It decays matter such as dead leaves and
fallen trees. But indoors, as we all know, it should be avoided. Mold reproduces through invisible spores, which are tiny and light,
which makes them an airborne threat. If a mold spore lands on a damp surface that provides it with moisture and nourishment, it will grow and
reproduce to form colonies. That's when problems start!
Adverse Health Effects of Indoor Mold
While most individuals aren't affected by a little bit of accidental mold growth, on some overripe fruit for instance,
others can experience the following reactions especially when mold growth is prolific:
- Allergies - Inhaling or touching mold spores may cause allergic responses. Symptoms can include a runny nose, red eyes, and
skin rashes (dermatitis). Allergic reactions can be immediate upon exposure or delayed until allergens build up in the body.
- Asthma - Mold can trigger asthma symptoms including wheezing, shortness of breath, and coughing.
- Multiple Chemical Sensitivities (MCS) flare-ups - Molds can produce volatile organic compounds (VOCs), which typically include
aldehydes, alcohols, keytones, and hydrocarbons according to information presented by American Air and Water. Individuals who are sensitive
to VOCs may experience MCS symptoms including dizziness, nausea, memory problems, breathing difficulties, flu-like symptoms, rashes, and hives.
- Respiratory problems - The Centers for Disease Control (CDC) reports that "In 2004 the Institute of Medicine (IOM) found there
was sufficient evidence to link indoor exposure to mold with upper respiratory tract symptoms, coughing, and wheezing in otherwise healthy
people. The IOM also found limited or suggestive evidence linking indoor mold exposure and respiratory illness in otherwise healthy
Long-term Effects of Mold Exposure
Short-term effects of mold, while serious, are at least relatively easy to spot. Long-term effects of mold exposure on the other hand,
may not present obviously as mold-related. As John Martyny, PhD, an industrial hygienist with the National Jewish Health Center in Denver puts
it in WebMD, "Very often, people don't really know what the problem is. They have an allergic reaction, lots of sinus drainage, lots of
upper respiratory problems, and it doesn't last for just a month or two. This goes on 12 months, a year. It is not a minimal problem - it
can really change your life."
Furthermore, mold exposure can cause serious respiratory problems with symptoms like chest tightness and difficulty
breathing. Dr. Martyny goes on, "Some people who are exposed to high levels of any mold for a long time develop lung hypersensitivity - which
leads to scar tissue in the lungs. Some people recover when the mold source is removed. But if they've been exposed for a long time, they
may never recover."
Though yet to be definitively proven, according to the CDC and other reputable sources, it's likely that certain
toxic molds present a serious health threat if they take hold and multiply within your home. The mold can send dangerous spores called
mycotoxins into your living environment. Official names of these mycotoxins include: trichothecenes, beta glucans, nitric oxides, aflatoxins,
stachybotrys mold (commonly called "black mold"), penicillium, and aspergillus. These mycotoxins can interfere with cell and DNA
function, cause respiratory illness, skin rashes, memory problems, and brain damage, among other serious health problems.
Ways to Prevent Mold Formation
The best way to reduce your chance of exposure to dangerous mold is to keep it from forming in your home. Here is a
checklist from the Environmental Protection Agency (EPA) about how to prevent mold formation:
Moisture and Mold Prevention and Control Tips
- When water leaks or spills occur indoors - ACT QUICKLY. If wet or damp areas are dried 24-48 hours after a
leak or spill happens in most cases mold will not grow.
- Clean and repair roof gutters regularly.
- Make sure the ground slopes away from the building foundation, so that water does not enter or collect around the foundation.
- Keep air conditioning drip pans clean and the drain lines unobstructed and flowing properly.
- Keep indoor humidity low. If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative
humidity. Relative humidity can be measured with a moisture or humidity meter.
- If you see condensation or moisture collecting on windows, walls or pipes ACT QUICKLY to dry the wet surface and reduce
the moisture / water source. Condensation can be a sign of high humidity.
Actions that will help to reduce humidity
- Vent appliances that produce moisture, such as clothes dryers, stoves, and kerosene heaters to the outside whenever
possible. (Combustion appliances such as stoves and kerosene heaters produce water vapor and will increase the humidity
unless vented to the outside.)
- Use air conditioners and dehumidifiers when needed.
- Run the bathroom fan or open the window when showering. Use exhaust fans or open windows whenever cooking, running the dishwasher, etc.
Actions that will help prevent condensation
For more information on controlling indoor humidity in your home, visit our
Home Humidity Control page.
- Reduce the humidity.
- Increase ventilation or air movement by opening doors and/or windows, when practical. Use fans as needed.
- Cover cold surfaces, such as cold water pipes, with insulation.
Cleaning Up Mold Safely
Mold cleanup can be a dangerous undertaking, exposing the person doing the cleaning to excess amounts of the substance as it gets
disturbed. In general, according to the EPA's Mold Cleanup guidelines, if the moldy area is less than about 10 feet square, you can
attempt to do the job yourself; otherwise, you should consult a mold remediation professional.
When cleaning up any amount of mold, it's important to take the proper precautions:
For more a more detailed explanation of cleaning up after water damage and safely restoring areas affected by excess moisture or flood waters,
check out our Restoring Water Damage section of our website.
- Wear goggles to avoid getting mold spores into your eyes.
- Prevent mold spore inhalation by using an N95 respirator.
- Wear gloves to avoid contact with mold.
- Also remember to keep the room or area you are cleaning well-ventilated to avoid over-exposure to fumes from cleaning products.
When humidity is high, making every effort to control moisture and humidity in your home helps protect your family from the
dangerous impact mold can have on your health.