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To the naked eye, molds are invisible. But the nose will likely know it is there. In fact, you may smell these members of the fungi kingdom before you ever see them! These organisms survive in damp, moist conditions and feed on organic materials. Outdoors, these fungi combine with bacteria to serve a crucial function in nature as a recycling system, responsible for the decay and decomposition of organic materials. Inside our homes and workplaces, however, the airborne particles and gases that molds produce can cause musty odors and may lead to illness or allergic reactions in susceptible individuals. The American Conference of Governmental Industrial Hygenists states “bio-aerosols (which include mold and bacteria) cause infections and hypersensitivity diseases and that bio-aerosols in indoor environments may cause toxic effects.”

Molds make their way inside through windows, doors, ventilation, structural openings, and cracks, as well as during times of construction. When given the proper environmental conditions and food sources, fungi—with its special ability to decay material— may begin to discolor and deteriorate our homes, furnishings, and building materials. Molds, like all living creatures, require food and water to survive. Water sources for mold may include: leaking pipes, damp basements, high humidity, and flooding. In an indoor environment, food sources for mold usually exist in the form of paper, wood, drywall, insulation, and cellulose material. Temperature and light can also contribute to the kind of mold species that may grow.

Controlling water or humidity is an important variable in deterring mold growth. Research shows when there is high humidity at the surface of or standing water adjacent to a growth site for more than 48 hours, mold colony formation will begin. The longer the periods of dampness or high humidity, the more types of mold species can be expected to grow. Dormant mold colonies will reactivate in an even shorter period of time.

According to the Indoor Air Quality Association (IAQA), “studies indicate that levels for fungal bio-aerosols indoors should be below a total of 300 colony forming units (CFUs) per cubic meter … and no individual organism should really contribute more than 50 CFUs to the total.” To deter mold growth and encourage a healthy indoor environment, the IAQA recommends an indoor air temperature of 73 to 79 degrees in the summer and 68 to 74.5 degrees in the winter. Try to maintain a relative indoor humidity level of 30 to 50 percent.

It is important to have mold levels monitored regularly, testing a home at least once every two years is recommended. This is particularly helpful for patients who suffer from allergies, asthma, or chemical sensitivities. If you notice common visible mold growth in your bathroom or kitchen, it may be cleaned with a disinfectant designed and labeled to treat mold. If you believe a more serious condition exists, however, you might consider the services of a general contractor. Make sure that all remediation efforts are performed by a licensed and insured professional with training in proper safety and clean up methods that
comply with OSHA standards. If mold growth spreads up to 10 square feet and cannot be cleaned, remediation guidelines recommend removal followed by cleaning of the affected area. If the area is larger than 10 square feet, seek the advice of a Certified Mold Remediator to survey the conditions. An overgrowth indicated by a musty odor or an allergic reaction without visible mold growth may be managed by ultraviolet (UV) lights and dehumidifiers. Germicidal UV light has been used since the 1950s in food preparation and medical applications to improve indoor air quality. Now, with heating, ventilating, and air conditioning equipment, as well as our designs to better secure our enclosed spaces, we are further compromising air quality and harboring more fungi (mold and spores), airborne viruses, and bacteria. Due to equipment advances, there are now various germicidal UV light fixtures to protect against airborne microbe contamination. UV air duct disinfection units can be used for two types of applications in HVAC equipment to treat the:

1) air-stream or
2) surfaces within the air-handler.

With the proper system design and installation, moving air can be disinfected with germicidal UV light, diminishing mold spores.

In conjunction with UV light, dehumidifiers are recommended to remove humidity, thus deter mold. To remove moisture and prevent fungal growth, the humidity levels in a structure must be aggressively lowered and maintained. Proper humidity level is to be determined by the coldest surface area in the structure. The air in the structure must be dehumidified to a dew point (or saturation temperature) lower than these coldest spots. Unfortunately, most residential dehumidifiers cannot provide the humidity removal necessary to achieve or maintain these levels. In these cases, a high quality dehumidifier is well worth the expense! Air conditioning does remove some humidity, but unless the system contains re-heat features, maintaining these levels will be extremely difficult.

Preventing mold is a collaborative effort that requires testing, removal of water and moisture sources, possible remediation, and the use of state-ofthe- art indoor air technology. If you feel overwhelmed, be sure to contact a healthy home expert who can help you with the process and insure that all the appropriate criteria are met. All of these steps will help to deter mold growth and help you create a healthier living space.

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ABOUT THE AUTHOR
Caroline Blazovsky is a national healthy home expert, certified mold remediator, indoor air quality specialist, member of the ACGIH and IAQA and president of My
Healthy Home, LLC. She is available for consultations. For more information, visit
www.myhealthyhome.info.