Dr. Clive Brown, a medical epidemiologist with the Center for Disease Control (CDC), participated in the 2005 Surgeon General’s Workshop on Healthy Indoor Environments, and he recently sat down with the achoo! Review staff to discuss the importance of humidity control in maintaining a healthy home.

Dr. Brown has been studying dampness and mold at the CDC for the past six years. Approximately 60-80 of the 100 calls received per month by the Air Pollution and Respiratory Health Branch of the CDC involve dampness-related issues. Over 80% of people with respiratory allergy symptoms are sensitive to fungi, and these sensitive individuals may experience congestion, wheezing, irritated eyes, irritated skin, and difficulty breathing in the presence of mold.

“Mold is associated with many chronic sinusitis symptoms,” says Dr. Brown, referring to a 1999 Mayo Clinic study which found that allergic fungal sinusitis (AFS) was diagnosed in 93% of cases of chronic rhinosinusitis (CRS), a condition that affects an estimated 37 million Americans.

The main problem facing people with mold allergy is that mold can be found everywhere. “Mold is ubiquitous,” says Dr. Brown. “It’s always in the air. If you go anywhere and do a sample for mold, the spores will always be there.”

“There’s so much mold out there, and you are constantly breathing in and out,” he says. According to the CDC website, mold spores are so tiny that as many as 250,000 can fit on a pin head, and a person can inhale as many as 750,000 spores a minute!

Another major problem facing people who are allergic to mold is that mold spores (their fungal reproductive cells) can withstand extremely harsh conditions and seemingly last forever!

Dr. Brown explains, “You can easily kill and remove the mold itself, but molds reproduce by producing what we call spores, and these spores really can exist, as far as we knowit looks like forever.”

“Even if you create a sterile environment,” Dr. Brown continues, “mold spores are going to come in through open doors, on pets, on your clothes when you come in, and other sourcesand those spores can resist harsh conditions. When the situation changes and the spores find an ideal growth environmentthat is an environment where there is a lot of moisturethen they can grow.”

So, mold spores are everywhere, and they seem to last forever. Bad news for mold allergy sufferers! But there’s also good news: Like Dr. Brown said, mold is easily killed and removed. You can clean mold with diluted bleach (but you should never mix bleach with ammonia because this will produce toxic fumes). If you decide to clean mold with diluted bleach, open windows for ventilation and wear gloves and protective goggles. You can also clean up visible mold growth with the versatile, odorless M-1 House Wash or Vital Oxide and prevent future mold growth with the M-1 Sure Cote sealant.

However, as Dr. Brown points out, “Prevention is the best medicine.”

Dr. Brown offers this advice to mold allergy sufferers: “Step back from the mold and do not focus on the mold so much because mold cannot grow unless there’s moisture. The most important thing is to try to maintain conditions in your home that do not lead to the accumulation of moisture.”

Humidity is the amount of water vapor in the air, and humidity control is one of the most important steps you should take in creating a healthy indoor environment. Humidity control is not only effective in preventing mold growth, but it’s also effective in curbing the dust mite population in your homebecause dust mites also require a certain level of moisture for survival. Dust mites and molds are the two most common household allergens.

“The issue is: ‘Can you get the humidity in the house within the level that’s recommended?'” says Dr Brown. “We recommend a humidity range somewhere between 40-60% as the ideal range.”

You should control the humidity in your home with a dehumidifier, which removes excess moisture from the air, and monitor the humidity in your home with a hygrometer.

“You’ve got to make sure that you keep the dehumidifier clean,” cautions Dr. Brown, “because the water which accumulates can be a source of mold and bacteria itself.”

Other than using a dehumidifier, Dr. Brown offers the following tips: “Your washing machine may burst, etc., but aside from those issues, you should try to make sure that you have a properly ventilated home, that your AC is at the right capacity for your home, and make sure you don’t have leaks and that the landscaping is adequate around your home so you don’t have water seeping into your home. So, do all the things that reduce the accumulation of moisture, especially if you live in a very humid environment like some of the Southern cities and states. When things do happen like that washing machine leak, clean it up promptly and dry it out quicklywithin 48 hours.”

Besides causing allergic reactions, mold can also cause infectionsthat is, the mold actually invades the pulmonary system and grows in the mucus within the lungs. People who have chronic lung conditions and compromised immune systems are more susceptible to mold infection.

Mold growth in your home not only threatens your health, but it also threatens the structural integrity of your home. Mold grows on and breaks down dead plant material like wood. In nature, Dr. Brown explains, “One of their roles is a scavenger to get rid of organic materials.”

Excess moisture in your home can also lead to other problems, such as accelerated emissions of toxic chemicals from carpets, construction materials, and furniture. Dr. Brown points out, “In general, water is a good medium for chemical reactions. If you leave wood in water, for example, that wood will rot. Wherever you have moisture, that moisture then facilitates breakdown of materials.”

In conclusion, Dr. Brown reminds us: “Mold is not one species. You’re dealing with many, many different species of mold, and chances are, if you are an allergic type of person, it is very likely you are allergic to one of the types of mold out there.”

While people are typically allergic to only a few types of mold, there are thousands of species of moldand there’s a good chance that many more species of mold will be discovered in the future.