Damp, moldy buildings can make asthma worse and cause coughing, wheezing and other breathing problems in healthy people, but there is no good evidence that it can cause other illnesses, the National Academy of Sciences concluded in a 2004 study. But they also said that more research would be done to investigate possible links to health problems and ways to build dryer structures.
“Because excessive dampness is prevalent in buildings and is associated with a range of respiratory symptoms, it constitutes a public health problem,” said Noreen Clark, dean of the School of Public Health at the University of Michigan at Ann Arbor. Clark chaired a nine-member committee that reviewed the issue for the academy’s Institute of Medicine. “Even though the available evidence does not link mold or other factors associated with building moisture to all the serious health problems that some attribute to them, excessive indoor dampness is a widespread problem that warrants action,” she said.
Molds are a normal part of the natural environment. They play a large role in nature by breaking down dead organic matter (fallen leaves and dead trees) outdoors. But molds should be avoided inside homes and other buildings because they can be harmful to our respiratory system.
All molds reproduce by tiny spores that are invisible to the naked eye. These lightweight spores float easily through the air and grow when they land on surfaces that are wet, whether it is inside a building or outdoors. When molds are present in large numbers, they can cause allergic symptoms similar to those caused by plant pollen. There are many different types of mold, none of which can grow without water.
New Orleans after Hurricane Katrina was a prime example of what can occur when water covers indoor and outdoor surfaces and the cleanup process has to be delayed. Mold spores covered homes and buildings around New Orleans and grew to become such a significant health problem that whole buildings had to be torn down or stripped of everything. Even without the health problems associated with molds, they gradually will destroy everything they grow on.
Recent floods in the United States will continue to affect all involved for quite some time. In addition to structural and internal damage, residents must check for “new residents” and mold. New mold growth often looks like spots and can be many colors — white, orange, green or black — and it usually smells musty.
Molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, toxic molds, such as Stachybotrys and Aspergillus, produce toxins called mycotoxins. Exposure to mycotoxins can cause more serious illness.
Inhaling or touching mold or mold spores can cause allergic reactions in sensitive individuals. Allergic responses include hay fever-type symptoms, such as sneezing, runny nose, red eyes and skin rash (dermatitis).
Allergic reactions to mold are common. They can be immediate or delayed.
Molds also can cause asthma attacks in people with asthma who are allergic to mold. In addition, mold exposure can irritate the eyes, skin, nose, throat and lungs of both mold-allergic and non-allergic people. Symptoms other than the allergic and irritant types are not commonly reported as a result of inhaling mold.
It is very important to completely dry water-damaged areas and items within 24-48 hours to prevent mold growth. If mold is a problem in your home, clean up the mold and get rid of the excess water or moisture. Fix leaky plumbing or other sources of water. Wash mold off hard surfaces with detergent and water and dry completely. Absorbent materials (such as ceiling tiles and carpet) that become moldy probably should be replaced.
The Centers for Disease Control and Prevention recommend that buildings be inspected for evidence of water damage and visible mold as part of routine building maintenance. Conditions causing mold (including condensation) should be corrected to prevent mold from growing. Use the following guidelines:
• Keep humidity levels in homes and buildings between 40-60 percent.
• Use an air-conditioner or a dehumidifier during humid months.
• Be sure that buildings have adequate ventilation, including exhaust fans in kitchens and bathrooms.
• Use mold inhibitors, which can be added to paints.
• Clean bathrooms with mold-killing products.
• Do not carpet bathrooms.
• Remove and replace flooded carpets.
In addition to mold, there are many other sources of pollutants in the home. Obvious ones are chemicals, cleaning products and pesticides. Less obvious are pollutants caused by such simple tasks as cooking, bathing or heating the home.
Over the years, buildings have been made more airtight to conserve energy. A variety of methods have been employed to keep the hot or cool air from escaping. Installing storm windows and insulation, applying caulk and weather-stripping to seal cracks and other openings not only trap in hot or cool air, they also trap in pollutants and sometimes even help generate more.
Most indoor air pollutants cannot be seen or smelled and the symptoms they produce are sometimes vague or similar to other illnesses, making it hard to attribute them to a specific cause. Some symptoms may not even show up until years later, making it even harder to discover the cause. Common symptoms of exposure to indoor air pollutants include headaches, tiredness, dizziness, nausea, itchy nose, and scratchy throat. More serious effects are asthma and other breathing disorders.
EPA studies have found that pollutant levels inside can be two to five times higher than outdoors. After some activities, indoor air pollution levels can be more than 100 times higher than outdoors.
By controlling biological contaminants such as dust mites and cat allergens, asthma cases could be reduced by 55 to 60 percent.
Ventilation issues arise from the presence of people in a room or a building and the need to remove the carbon monoxide, odors and other contaminants that they generate and are affected by.
Signs that can indicate your home may not have enough ventilation include moisture condensation on windows or walls, smelly or stuffy air, dirty central heating and air-cooling equipment and areas where books, shoes or other items become moldy.
Ratcliffe is a consultant to the Coastal Health District. You can call her at 876-6399.