You cannot avoid mold. In fact, mold spores are everywhere. The reason that you do not see piles of dead plant material and other organic material accumulating outside is because of mold. Mold has a purpose in our eco-system, to feed on dead organic matter. However, mold becomes a serious problem when it begins growing indoors. When this happens, the indoor spore counts increase to unhealthy levels and this is what leads to sickness. Unfortunately, most homes are filled with food that mold loves to eat and provided with sufficient moisture, mold can live off many materials found in homes, such as paper, wood, cellulose in the paper backing on drywall, insulation, glue used to bond carpet to its backing wallpaper, carpet, ceiling tiles, and everyday dust, people and pet dander and dirt. The other ingredient that mold needs to thrive is the right temperature ranging from 41 degrees to 100.4 degrees Fahrenheit, common in most U.S. states.
Mold Prevention is Based on Moisture Prevention
The final and most important ingredient mold needs is moisture. Mold can not grow without moisture. One of the most common signs that you may have mold could be a “musty” or “mildewy” odor. In addition, your home may provide you with visual clues that you have mold which could include buckled floorboards, carpet that is discolored, water stains on ceilings or walls, and of course visual growth. Keep in mind, not all mold is black, but can be various colors.
One of the biggest challenge for homeowners is keeping moisture down because of the high humidity levels caused by high temperatures. Humidity control is essential to mold control. Other common moisture sources include rain leaks (e.g., on roofs and wall joints); surface and groundwater leaks (e.g., poorly designed or clogged rain gutters and footing drains, basement leaks); plumbing leaks; and stagnant water in appliances (e.g., dehumidifiers, dishwashers, refrigerator drip pans, and condensing coils and drip pans in HVAC systems).
Moisture problems can also be due to water vapor migration and condensation problems, including uneven indoor temperatures, poor air circulation, soil air entry into basements, contact of humid unconditioned air with cooled interior surfaces, and poor insulation on indoor chilled surfaces (e.g., chilled water lines). Problems can also be caused by the production of excess moisture within homes from humidifiers, unvented clothes dryers, overcrowding, etc. Finished basements are particularly susceptible to mold problems caused by the combination of poorly controlled moisture and mold-supporting materials.
There is some evidence that mold spores from damp or wet crawl spaces can be transported through air currents into the upper living quarters. Older, substandard housing low income families can be particularly prone to mold problems because of inadequate maintenance (e.g., inoperable gutters, basement and roof leaks), overcrowding, inadequate insulation, lack of air conditioning, and poor heating. Low interior temperatures (e.g., when one or two rooms are left unheated) result in an increase in the relative humidity, increasing the potential for water to condense on cold surfaces.
Indoor Mold Exposure
In the last several years, a growing body of scientific evidence has indicated that the air within homes and other buildings can be more seriously polluted than the outdoor air in even the largest and most industrialized cities. Research indicates that people spend approximately 90% of their time indoors, so the risks to health from exposure to indoor air pollution may be greater than risks from outdoor pollution. In addition, people exposed to indoor air pollutants for the longest periods are often those most susceptible, including the young, the elderly, and the chronically ill, especially those suffering from respiratory or cardiovascular disease (CDC).
People are routinely exposed to more than 200 species of fungi indoors and outdoors . These include moldlike fungi, as well as other fungi such as yeasts and mushrooms. The terms “mold” and “mildew” are nontechnical names commonly used to refer to any fungus that is growing in the indoor environment. Mold colonies may appear cottony, velvety, granular, or leathery, and may be white, gray, black, brown, yellow, greenish, or other colors. Many reproduce via the production and dispersion of spores.
A recent Institute of Medicine (IOM) review of the scientific literature found sufficient evidence for an association between exposure to mold or other agents in damp indoor environments and the following conditions: upper respiratory tract symptoms, cough, wheeze, hypersensitivity pneumonia in susceptible persons, and asthma symptoms in sensitized persons. Certain molds can cause a variety of adverse human health effects, including allergic reactions and immune responses (e.g., asthma), infectious disease (e.g., histoplasmosis), and toxic effects (e.g., aflatoxin-induced liver cancer from exposure to this mold-produced toxin in food).