|By Ivan Raconteur, Editor
Recent heavy rains have caused flooding in some local areas, and even after floodwaters receded, they left behind a serious health concern: mold.
However, flooding is not the only cause of indoor mold problems. Leaks, humidity, and condensation can also lead to mold growth.
Mold is a type of fungus that is present in the natural environment. Mold spores can be found almost everywhere, and are even found in dust.
The key to preventing the growth of mold is controlling moisture.
Health effects from exposure to mold can vary depending on the person and the amount of mold present.
People with severely weakened immune systems who are exposed to mold may develop serious fungal respiratory infections. The Minnesota Department of Health (MDH) recommends people consult a medical professional if they are concerned about the effects of a moldy environment on their health.
According to the MDH, those most likely to be affected by mold include infants and children; elderly people; individuals with respiratory conditions, allergies, or asthma; and people with severely weakened immune systems (such as people with HIV infection, chemotherapy patients, and organ transplant recipients).
Although some people are more likely to be affected than others, long term exposure to moldy environments may eventually become unhealthy for anyone.
Many types of mold can produce potentially harmful substances, so indoor mold growth should be removed promptly.
According to the US Environmental Protection Agency (EPA), molds are usually not a problem indoors, unless they come into contact with moisture and begin growing. When this happens, molds have the potential to produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins).
The best way to determine if a mold problem exists, according to the MDH, is to look for mold growth and investigate the source of earthy, musty odors.
Mold may appear cottony, velvety, granular, or leathery. It may be white, gray, brown, black, yellow, or green. Mold often appears as discoloration, staining, or fuzzy growth on building materials or furnishings.
The MDH does not recommend testing for mold. Instead, the agency recommends people assume there is a problem if they see mold or smell mold odors.
According to the EPA, it is not possible to get rid of all mold and mold spores indoors, but mold growth can and should be prevented by controlling moisture.
The EPA suggests small areas of water damage can probably be cleaned by a homeowner, but in cases where there has been a lot of water damage or mold growth covers more than 10 square feet, it may be advisable to hire a professional who has experience in mold remediation.
Mold clean up and removal
The most important step is to fix the moisture source that created the problem. Sources may include flooding, condensation, roof and plumbing leaks, and humidity.
The MDH recommends keeping the indoor relative humidity from 20 to 40 percent in the winter, and less than 60 percent the rest of the year.
Devices to measure relative humidity may be purchased at hardware or home supply stores. These are typically small, and cost $10 to $50, according to the EPA.
To prevent moisture problems in crawl spaces, a plastic cover can be placed over the dirt to keep moisture from entering from the ground. Crawl spaces should also be well ventilated.
Plumbing leaks or seepage should be fixed immediately.
Using exhaust fans that are vented to the outdoors in kitchens and bathrooms can help reduce indoor moisture. Clothes dryers should also be vented to the outdoors.
Materials should be dried as soon as possible after they become wet. This can be done by using fans and dehumidifiers, and by moving wet items away from walls and floors.
The next step is to remove and dispose of mold-contaminated materials, especially porous materials. Non-porous and semi-porous materials with surface mold growth may be saved if they are structurally sound.
Because the amount of mold particles in the air increases when mold is disturbed, the MDH recommends using protective equipment when handling or working around mold-contaminated materials.
Rubber gloves, goggles, outer clothing, and respirators may be used.
The MDH recommends at least an N95 or N100 type disposable respirator. Options that provide greater protection include half-face negative-air respirators with a HEPA filter such as N100 or P100.
In order to minimize the amount of dust generated, moldy materials should be enclosed in plastic bags or sheets before they are carried through a residence. Vents in the work area may be covered, and plastic sheeting may be hung to protect the rest of the residence.
The next step is to clean the area to remove surface mold from non-porous or semi-porous surfaces such as hard plastic, concrete, glass, metal, and solid wood.
It is important to remove all mold contamination.
The MDH recommends thoroughly scrubbing all contaminated surfaces using a stiff brush, hot water, and a non-ammonia soap/detergent, or a commercial cleaner. The area should then be rinsed with clean water.
After cleaning has removed all visible mold, a disinfectant may be used to kill any remaining mold.
Disinfecting may be accomplished by mixing one quarter to one half cup of bleach per gallon of water, and applying the solution to surfaces where mold growth was visible.
Any runoff solution should be collected and removed, but the treated surfaces should not be rinsed or wiped. The bleach solution should be allowed to dry on the surface.
The EPA notes that if individuals choose to use disinfectants, such as chlorine bleach, they should ventilate the area and exhaust the air to the outdoors.
Chlorine bleach should never be mixed with other cleaning products that contain ammonia, because doing so could produce toxic fumes.
The MDH recommends that people continue to be alert for signs of moisture problems or mold growth in areas where problems have been experienced.
Health experts do not recommend the use of ozone air cleaners to address mold or any other indoor air problems.
More information is available at the following sites: