By Joel Loving
We seem to be hearing more and more about molds – specifically toxic molds – and their potential for causing health problems. Most of us have heard or read about
the Texas couple who lost their home, a husband's career, and nearly a 3-year-old child from a blackish-green mold known as
Stachybotrys. Molds have always been present in our environment so what has changed to create so much concern today?
Mold 101 – An Overview Molds, or mildew as they are sometimes called, are types of fungi. They are not plants or animals, but are a separate kingdom of their own. Molds are very common in nature, and are always
present in both indoor and outdoor air. They feed on dead organic matter, and play an important ecological role by decomposing dead leaves, grass, and other plant material. They reproduce through the release of microscopic spores into the air, much like a dandelion's seed, which can then grow into mold somewhere else, given the right conditions. Mold growth can range from powdery to woolly, and anywhere from white and pink to green, brown and black in color.
To grow, molds need a food source with high organic content, such as wood, paper, cotton, or other plant-derived materials. They also need moisture, which can come from leaks, floods, condensation, steam, or even
just high humidity. If mold is found on a surface, then it either currently has, or in the past had, access to moisture.
The Mold "Epidemic"
So what's behind this sudden mold epidemic – are new homes moldier? Modern home design and materials, like fake stucco (a favorite mold food when wet), the way insulation can trap moisture behind walls, and the fact that homes are now more air tight, all tend to expose families for extended periods. This increases their chances of being impacted by mold. Stories like that of the Texas family who were driven out of their home by mold and subsequently awarded a multimillion-dollar settlement create media attention and in some cases, even hysteria. All this awareness feeds the epidemic and keeps this relatively new concept of toxic mold possibly "living in our homes" on our minds.
Health Concerns The most common health problems associated with exposure to mold spores are simply allergic reactions.
Allergies to molds usually have the same effects as allergies to hay or pollen, and include symptoms like headaches, sinus problems, sore
throats, or coughing. When outdoor levels of molds are highest, such as during the fall leaf mold season, many people experience allergic reactions.
Exposures to certain molds now commonly thought of as "toxic
molds", can bring about more serious health effects and these cases attract most of the attention. As it turns out, it isn't the molds that are toxic, but rather chemicals that are produced by the molds. These
chemicals, known as mycotoxins, are associated with
the mold's growth, digestion, and self defense processes. Mycotoxins, like the sting of a bee, are toxic to other organisms.
The greatest factor affecting the development of health problems though, is individual
sensitivity. Certain people are naturally more sensitive than others to molds and the related mycotoxins. Those who are more susceptible usually include children, the elderly, and immune-compromised individuals, such as
patients undergoing chemotherapy.
Mold Investigations and Testing
An investigation for possible mold infestation begins with an inspection for visible mold growth. Whether or not such growth is noticeable, an inspection for signs of water damage, or areas with potential moisture sources is the next step.
Relative humidity levels higher than 60% indoors can also encourage mold growth. If the indoor relative humidity is much higher than that measured outside, this may indicate that too much moisture is being trapped
inside the house.
Whether there is visible mold growing in a home, or just signs of water damage, or unusually high humidity levels, these are all problems requiring immediate attention.
Once the moisture source
is eliminated, and the mold growth properly removed, the problem is usually solved; however, if for medical or legal reasons for instance, there is a need to know what species of molds are growing or releasing spores,
and in what concentrations, then mold sampling and analysis may be necessary. Although homeowner test kits are becoming more available, they are still somewhat limited in what they can do. Trained and experienced
professionals most accurately perform mold sampling, and microbiologists in accredited laboratories best do the analyses.
When performing any mold remediation, it is first necessary to find and eliminate the moisture source. If the moisture problem is not resolved, the mold growth will return. So unless you are capable of fixing this primary problem, the first professional you should hire, whether it is a plumber, roofer, or perhaps even a landscaper, is one that gets rid of the moisture source, and ensures it will not return.
Usually, the homeowner can safely manage small areas of non-toxic mold growth. Cleanup of extensive contamination, particularly if the HVAC system or large areas of the home are involved, should be remediated by
personnel with training and experience in handling environmentally contaminated materials. Mold levels can increase up to 100,000 times background levels during mold cleanup, possibly resulting in acute exposures.
Mold is Everywhere
Although mold is indeed, everywhere, the potential impact of indoor mold growth is substantial. Exposure to certain toxic molds can result in serious health problems, some of which can be long term.
detection and elimination of water infiltration problems are the key elements in the prevention of mold growth in a home. If the presence of excessive moisture is not recognized, but the typical symptoms of mold
exposure are, the homeowner may benefit from the assistance of a qualified physician, home inspector, indoor air quality consultant, or a combination thereof. Provided the moisture and related mold problems are
identified and permanently remediated, the effected homeowners may once again take control over their indoor environment. Molds can then be left to do what we like to have them do – break down dead leaves and make great
Joel Loving is an Indoor Air Quality Consultant, Certified Mold Inspector, President of Environmental
Health Consultants, Inc., and a member of the general faculty at the University of Virginia Office of Environmental Health and Safety. He can be reached at 434-977-1409, or