Increasingly,
we are talking about specific kinds of mold, not just old mold. Is this a new
problem or just one that our technology is now allowing us to detect more
effectively?
Are we
overreacting or should we be concerned? If we should be concerned, what
products or actions are most effective? Unfortunately, there is not a simple
answer. We do have better technology that allows us to understand and analyze
more of the world around us. Some of the air quality issue is simply because we
know more about it.
However, it
is also true that we are building homes and buildings that are more vulnerable
to conditions that promote the growth of mold. It is also true that mold is one
of the most common causes of frequently reported respiratory problems. The
following is intended to provide an overview of what we know about mold and
what we can do about it. Before you take any action in your own home or
building, however, you should consult a local specialist: a building inspection
engineer.
The problem
of mold is one that no building owner or manager can afford to ignore. Mold has
been suggested as one possible factor in so-called Sick Building Syndrome. The
unusual weather conditions in many parts of the United States in recent years
have provided good conditions for the growth of toxigenic fungi and increased
the potential for human exposure. Throughout the country, deaths of children
from pulmonary hemosiderosis (bleeding lung disease) have been attributed to
inhalation of toxins produced by the fungus Stachybotrys chartarum.
The U.S.
Department of Housing and Urban Development awarded $3.1 million to the city of
Cleveland to remediate mold and moisture problems in houses and apartments.
Mold problems in the Martin County Courthouse in Florida apparently caused by a
leaky EIFS (exterior insulation finish system) facade cost $26 million to
remediate. The building cost $13 million to construct a few years earlier. An
old school building in Canada, infested with toxigenic fungi, had to be burned.
Mold is a problem.
What is
mold?
The words
mold and mildew are sometimes used interchangeably. If there is a difference in
the two terms, it is that mildew generally refers to a fungus-caused
discoloration of an underlying, porous material, whereas mold refers to a
fungus growth on a porous, often rotting material. Essentially, mold is the
growth produced by several types of fungi as they feed on organic matter. Mold
typically reproduces asexually by means of airborne spores. These spores are
always present in the air. There are thousands of types of fungi (mold).
Many fungi
are helpful. Some good types of fungi are those used to produce Camembert and
Roquefort cheeses. The wonder drug penicillin is a by-product of the fungus
Penicillium notatum.
What does it
need from us?
Like all
living things, mold spores need certain conditions to reproduce and grow. Mold
needs water, food, and the right temperature range. Mold grows better in a dark
environment, and with an organic, porous material to grow on. Such material
often provides a source of both food and water.
Unfortunately,
buildings provide an almost ideal environment to support the growth of mold.
The typical temperatures are right, and there are plenty of dark places and
organic substances. Just add water, and you’ve created a perfect mold breeding
ground.
Dry rot, a
common condition in older homes, is bacterial activity similar to mold and
needs the same combination of conditions for ideal growth. If you have dry rot,
you probably have mold. The reverse is true as well.
Why should
we be concerned?
Mold can
feed on and destroy most of the organic materials found in buildings such as
wood, paper, carpet, and glue. However, almost any surface can support the
growth of mold. Although mold can be found anywhere, it typically grows in
dark, moist places such as behind walls or in HVAC ducting.
Mold can
cause harmful health effects in humans. Although the species Stachybotrys
chartarum (sometimes referred to as stacky for short) has received most of the
recent press, many other types of fungi are potentially harmful to humans as
well. For this reason, Stachybotrys chartarum is not treated as a unique case.
One bit of
good news: although Stachybotrys chartarum is considered one of the more
hazardous forms of mold, its spores are wet and slimy. That makes it a bit
easier to visually identify and much less likely to become airborne.
Stachybotrys chartarum is usually transferred by contact with insects or
rodents or by water.
Exposure to
fungus can cause organic dust toxic syndrome (ODTS) or hypersensitivity
pneumonitis (HP). ODTS may occur following a single exposure to high
concentrations of dust contaminated by fungus, such as might be encountered
during remediation or renovation work. The symptoms are flu-like. HP occurs as
a result of prolonged exposure and can lead to permanent lung damage.
Exposure to
fungus can also cause allergic reactions: typically a runny nose, sneezing, eye
irritation, cough, or aggravation of asthma.
What should
I look for?
Mold is not
only a problem in itself but also a symptom of a water problem. The first step
in any investigation for the presence of mold in buildings is to follow the
water.
Look for
evidence of high humidity, condensation, or visual evidence of water staining.
Mold grows in dark, hidden places, such as behind walls, and may not always be
visible. Other clues, such as musty odors or reported physical symptoms in
occupants, should be noted.
How do I
know if I have a mold problem?
If you see
mold or evidence of moisture accumulation, test the suspect material. Testing,
in order to identify the particular species of mold, can be performed by a
number of laboratories. The EPA has recently developed a DNA-based testing
procedure that dramatically reduces the time it takes to identify which of the
100 or so most common mold species may be present. Using this technology, tests
that used to take days or weeks can now be performed in a matter of hours.
Information on the EPA testing method is available at http://www.epa.gov.
Consultants
and laboratories are listed under environmental laboratories or industrial
hygienists in the yellow pages. Such firms can usually help with mitigation as
well, should that be necessary.
How can I
minimize the risk of mold?
Because mold
likes the same temperature as humans, changing the ambient temperature as a
method of control is not usually an option.
It is hard
to eliminate the molds food source entirely, because it feeds on a wide range
of materials commonly used in building construction and interior finishes.
However, because mold can feed on dirt, cleanliness can go a long way toward
control.
The easiest
way to minimize mold growth is to eliminate sources of water. Moisture in a
building can exist in two forms, as humidity and as free water. Moisture may
come from inside the building through condensation, plumbing leaks, cooking,
showers, or the HVAC system. Water may enter the building from the outside
through leaks in the roof, the facade, or the basement. Water also may be
introduced into the building through the use of wet building materials such as
roofing materials, insulation, and drywall.
If you
identify any of these sources of water or moisture, you should take immediate
steps to eliminate them. This may require modifications to the structure,
improved ventilation, improved environmental controls (HVAC), improved surface
drainage, or any one of many other possibilities. You should consult a
qualified building inspection engineer for advice.
How can I
remediate an existing problem?
Any plan to
remediate mold must first address solving the water problem. The source of the
moisture must be identified and the condition rectified. Only then should the
process of remediation begin.
Remediation
consists of either cleaning the affected materials in place or the removal and
replacement of these materials. The decision of whether to clean or replace is
largely an economic one, based on the size of the areas affected, the ease of
access, and whether or not the building components have been damaged by either
mold or water.
If the
buildings structural components are not damaged, small areas can usually be
remediated by homeowners or maintenance staff. Trained contractors, however,
should handle larger areas. Dealing with extensive areas of mold is like
handling any other hazardous material and requires specific training. The New
York City Department of Health publishes a useful guide titled Guidelines on
Assessment and Remediation of Fungi in Indoor Environments. It is available on
line at http://www.ci.nyc.ny.us/html/doh/html/epi/moldrpt1.html
Other ways
of dealing with large infestations are being tested. At least one company
treats moldy houses by enclosing them and raising the interior temperature in a
controlled manner to about 160 degrees F. This effectively bakes the mold and
kills it.
Most air
cleaners (purifiers, ionizers, etc.) are not effective in dealing with a mold
problem. At best, such equipment deals with the symptom rather than the cause.
Summary
For help
with mold problems or suspected mold problems, the first step is to contact an
engineer who is qualified to perform the diagnostics necessary to determine the
root cause of the problem. Determining the cause of the problem, whether that
is a leaky roof, facade issues, excess humidity, or a malfunctioning HVAC
system, is often a complex process of detective work. There are often false
leads, and inexperienced people often mistake effect for cause, leading to a
misdiagnosis.
Breathing is
essential to life. It is not an option. Breathing contaminated air can lead to
respiratory irritations and, for some, can be life threatening. It is time well
spent to inspect the buildings in which you live and work to determine if there
are any suspect conditions that might lead to a mold infestation. If there are,
testing, source identification, and remediation should follow quickly.
For the
office nearest you, call 1-800-242-1969.
Facts and Myths about Household Mold
Without question, mold is one of the most misunderstood
threats to homes. Lawsuits related to mold have been brought against developers
or even association boards over health issues and construction problems in
communities. These incidents have brought to focus the confusion over mold –
what is it exactly, and how much is too much? Mold can almost always be found
in the air that we breathe and the buildings we live in. But if mold is as old
as the earth, why all the concern now?
Mold has come into the spotlight due to several factors, one
of the most prominent being the increasingly modern lifestyle that associations
and their residents lead. The latest luxuries and conveniences such as indoor
swimming pools and central A/C can place additional sources of moisture in the
residences and clubhouses – which is the number one reason for indoor mold.
There is no way to eliminate all molds and mold spores; the only way to control
indoor mold is to control moisture.
To restore some sanity to the discussion, let’s bust the two
biggest myths about mold.
MYTH:
It is possible to live in a community completely free of mold.
Fact:
Every building and thereby every community has some amount of measurable mold –
no matter how small. Mold is everywhere, both in and outside your homes. The
number one step that associations can take to reduce the levels of problematic
mold is by using the building’s ventilation systems, or installing proper ones
to get rid of excess moisture.
Venting homeowner’s bathrooms and dryers to the outside of
the building, using air conditioners in the summer, and immediately fixing any
signs and the source of a water leak will go a long way in preventing mold
growth. Mold may always be present, but it doesn’t always have to be harmful.
Since HVAC systems and/or the building frames are often a common element in
garden-style condominiums, these communities can take an active step in to
control moisture.
MYTH: There
are national standards in place on how to test for mold, and how much mold is
“allowed” inside a home.
Fact: There
are no national standards or protocols on how to test for mold or analyze its
impact. However, when a problem is suspected, an industrial hygienist should
investigate the property and give a professional assessment of the mold levels.
The only way they can really perform this assessment is by testing the outside
level of mold and comparing it to the inside level.
Be wary of any ‘mold inspectors’ who require you to pay high
fees for a test and then when mold is found, as it will be, recommend very
drastic and expensive measures to get rid of it. There are a few extreme
situations where this remediation may be necessary, but these cases generally
involve large sections of the building with discoloration, damp walls and
floors, and a strong musty smell.
There could be hidden mold in your community's homes, and
since some types of mold are more hazardous than others, it’s wise to
investigate if you suspect a problem. Mold remediation can often be a simple
process, as long as you stay vigilant and aware of the interior moisture
levels. The trick is to catch mold before it eats away at your community’s
homes—and wallet.