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What
is Mold?
Molds are fungi. Molds grow throughout the natural and built
environment. Tiny particles of mold are present in indoor
and outdoor air. In nature, molds help break down dead
materials and can be found growing on soil, foods, plant
matter, and other items. Molds produce microscopic cells
called "spores" which are very tiny and spread easily
through the air. Live spores act like seeds, forming new
mold growths (colonies) when they find the right conditions.
What does mold need to grow?
Mold only needs a few simple things to grow and
multiply:
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Moisture
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Nutrients
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Suitable place to grow
Of these, controlling excess moisture is the key to
preventing and stopping indoor mold growth.
Should I be concerned about mold in my home?
Mold should not be permitted to grow and multiply indoors.
When this happens, health problems can occur and building
materials, goods and furnishings may be damaged.
Health Effects
Can mold make me and my family sick?
Mold can affect the health of people who are exposed to it.
People are mainly exposed to mold by breathing spores or
other tiny fragments. People can also be exposed through
skin contact with mold contaminants (for example, by
touching moldy surfaces) and by swallowing it.
The type and severity of health effects that mold may
produce are usually difficult to predict. The risks can vary
greatly from one location to another, over time, and from
person to person.
What symptoms might I see?
The most common health problems caused by indoor
mold are allergy symptoms. Although other and more serious
problems can occur, people exposed to mold commonly report
problems such as:
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Nasal and sinus congestion
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Cough
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Wheeze/breathing difficulties
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Sore throat
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Skin and eye irritation
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Upper respiratory infections (including sinus)
Are the risks greater for some people?
There is wide variability in how different people
are affected by indoor mold. However, the long term presence
of indoor mold growth may eventually become unhealthy for
anyone. The following types of people may be affected more
severely and sooner than others:
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Infants and children
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Elderly people
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Individuals with respiratory conditions or
sensitivities such as allergies and asthma
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Persons having weakened immune systems (for example,
people with HIV infection, chemotherapy patients, organ
transplant recipients)
Those with special health concerns should consult a
medical professional if they feel their health is affected
by indoor mold. Are some molds more hazardous than
others?
Some types of mold can produce chemical compounds (called
mycotoxins) although they do not always do so. Molds that
are able to produce toxins are common. In some
circumstances, the toxins produced by indoor mold may cause
health problems. However, all indoor mold growth is
potentially harmful and should be removed promptly, no
matter what types of mold is present or whether it can
produce toxins.
Home Investigation
How do I tell if I have a mold problem?
Investigate, don't test. The most practical way to find a
mold problem is by using your eyes to look for mold growth
and by using your nose to locate the source of a suspicious
odor. If you see mold or if there is an earthy or musty
smell, you should assume a mold problem exists. Other clues
are signs of excess moisture or the worsening of
allergy-like symptoms.
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Look for visible mold growth (may appear cottony,
velvety, granular, or leathery and have varied colors of
white, gray, brown, black, yellow, green). Mold often
appears as discoloration, staining, or fuzzy growth on
the surface of building materials or furnishings. When
mold is visible, testing is not recommended.
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Search areas with noticeable mold odors.
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Look for signs of excess moisture or water damage.
Look for water leaks, standing water, water stains,
condensation problems. For example, do you see any
watermarks or discoloration on walls, ceilings, carpet,
woodwork or other building materials?
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Search behind and underneath materials (carpet and
pad, wallpaper, vinyl flooring, sink cabinets),
furniture, or stored items (especially things placed
near outside walls or on cold floors). Sometimes
destructive techniques may be needed to inspect and
clean enclosed spaces where mold and moisture are
hidden; for example, opening up a wall cavity.
Should I test for mold?
We do not recommend testing for mold yourself.
Instead, you should simply assume there is a problem
whenever you see mold or smell mold odors. Testing should
never take the place of visual inspection and it should
never use up resources that are needed to correct moisture
problems and remove all visible growth.
Sometimes, mold growth is hidden and difficult to locate.
In such cases, a combination of air (outdoor and indoor air
samples) and bulk (material) samples may help determine the
extent of contamination and where cleaning is needed.
However, mold testing is rarely useful for trying to answer
questions about health concerns.
Mold Clean-up and Removal
To clean up and remove indoor mold growth, follow steps
1-6 as they apply to your home.
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Identify and Fix the Moisture Problem
- the most important step in solving a mold problem is
to identify and correct the moisture sources that
allowed the growth in the first place. Common indoor
moisture sources include:
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Flooding
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Condensation (caused by indoor humidity that is
too high or surfaces that are too cold)
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Movement through basement walls and slab
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Roof leaks
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Plumbing leaks
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Overflow from tubs, sinks, or toilets
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Firewood stored indoors
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Humidifier use
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Inadequate venting of kitchen and bath humidity
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Improper venting of combustion appliances
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Failure to vent clothes dryer exhaust outdoors
(including electric dryers)
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Line drying laundry indoors
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House plants - watering them can generate large
amounts of moisture
To keep indoor surfaces as dry as possible, try to
maintain the home's relative humidity between 20-40
percent in the winter and less than 60 percent the rest
of the year. You can purchase devices to measure
relative humidity at some home supply stores.
Ventilation, air circulation near cold surfaces,
dehumidification, and efforts to minimize the production
of moisture in the home are all very important in
controlling high humidity that frequently causes mold
growth in our cold climate.
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Begin Drying All Wet Materials - as
soon as possible, begin drying any materials that are
wet. For severe moisture problems, use fans and
dehumidifiers and move wet items away from walls and off
floors. Check with equipment rental companies or
restoration firms to see if you can rent fans and
dehumidifiers.
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Remove and Dispose of Mold Contaminated
Materials - items which have absorbed moisture
(porous materials) and which have mold growing on them
need to be removed, bagged and thrown out. Such
materials may include sheet rock, insulation, plaster,
carpet/carpet pad, ceiling tiles, wood products (other
than solid wood), and paper products. Likewise, any such
porous materials that have contacted sewage should also
be bagged and thrown away. Non-porous materials with
surface mold growth may be saved if they are cleaned
well and kept dry (see step 4).
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Take Steps to Protect Yourself - the amount of
mold particles in air can increase greatly when mold
is disturbed. Consider using protective equipment
when handling or working around mold contaminated
materials. The following equipment can help minimize
exposure to mold:
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Rubber gloves
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Eye goggles
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Outer clothing (long sleeves and long pants)
that can be easily removed in the work area and
laundered or discarded
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Medium-efficiency or high-efficiency filter
dust mask (these can be found at safety
equipment suppliers, hardware stores, or some
other large stores that sell home repair
supplies) -- at a minimum, use an N-95 or
equivalent dust mask
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Take Steps to Protect Others - plan and perform
all work to minimize the amount of dust generated.
The following actions can help minimize the spread
of mold spores:
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Enclose all moldy materials in plastic (bags
or sheets) before carrying through the home
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Hang plastic sheeting to separate the work
area from the rest of the home
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Remove outer layer of work clothing in the
work area and wash separately or bag
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Damp clean the entire work area to pick up
settled contaminants in dust
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Clean Surfaces - surface mold
growing on non-porous materials such as hard plastic,
concrete, glass, metal, and solid wood can usually be
cleaned. Cleaning must remove and capture the mold
contamination, because dead spores and mold particles
still cause health problems if they are left in place.
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Thoroughly scrub all contaminated surfaces using
a stiff brush, hot water and a non-ammonia
soap/detergent or commercial cleaner
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Collect excess cleaning liquid with a wet/dry
vacuum, mop or sponge
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Rinse area with clean water and collect excess
rinse water
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Disinfect Surfaces (if desired) -
after cleaning has removed all visible mold and other
soiling from contaminated surfaces, a disinfectant may
be used to kill mold missed by the cleaning. In the case
of sewage contamination, disinfection must be performed.
Contact your home inspector for advice.
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Mix 1/4 to 1/2 cup bleach per gallon of water
and apply to surfaces where mold growth was visible
before cleaning. The solution can be applied with a
spray bottle, garden sprayer, it can be sponged on,
or applied by other methods.
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Collect any run-off of bleach solution with a
wet/ dry vacuum, sponge or mop. However, do not
rinse or wipe the bleach solution off the areas
being treated -- allow it to dry on the surface.
Always handle bleach with caution. Never mix bleach with
ammonia -- toxic chlorine gas may result. Bleach can
irritate the eyes, nose, throat, and skin. Provide fresh
air (for example, open a window or door). Protect skin
and eyes from contact with bleach. Test solution on a
small area before treatment, since bleach is very
corrosive and may damage some materials.
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Remain on Mold Alert - Continue
looking for signs of moisture problems or return of mold
growth. Be particularly alert to moisture in areas of
past growth. If mold returns, repeat cleaning steps and
consider using a stronger solution to disinfect the area
again. Re-growth may signal that the material should be
removed or that moisture is not yet controlled.
When can we rebuild?
Rebuilding and refurnishing must wait until all affected
materials have dried completely. Be patient it takes time to
dry out wet building materials. |