Mold |
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Molds in the Environment |
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What are molds?
Molds are fungi that
can be found both indoors and outdoors. No one knows how many species of
fungi exist but estimates range from tens of thousands to perhaps three
hundred thousand or more. Molds grow best in warm, damp, and humid
conditions, and spread and reproduce by making spores. Mold spores can
survive harsh environmental conditions, such as dry conditions, that do
not support normal mold growth.
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What are some of the
common indoor molds?
- Cladosporium
- Penicillium
- Alternaria
- Aspergillus
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How do molds affect
people?
Some people are
sensitive to molds. For these people, exposure to molds can cause
symptoms such as nasal stuffiness, eye irritation, wheezing, or skin
irritation. Some people, such as those with serious allergies to molds,
may have more severe reactions. Severe reactions may occur among workers
exposed to large amounts of molds in occupational settings, such as
farmers working around moldy hay. Severe reactions may include fever and
shortness of breath. Some people with chronic lung illnesses, such as
obstructive lung disease, may develop mold infections in their lungs.
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Where are molds
found?
Molds are found in
virtually every environment and can be detected, both indoors and
outdoors, year round. Mold growth is encouraged by warm and humid
conditions. Outdoors they can be found in shady, damp areas or places
where leaves or other vegetation is decomposing. Indoors they can be
found where humidity levels are high, such as basements or showers.
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How can people
decrease mold exposure?
Sensitive individuals
should avoid areas that are likely to have mold, such as compost piles,
cut grass, and wooded areas. Inside homes, mold growth can be slowed by
keeping humidity levels between 40% and 60%, and ventilating showers and
cooking areas. If there is mold growth in your home, you should clean up
the mold and fix the water problem. Mold growth can be removed from hard
surfaces with commercial products, soap and water, or a weak bleach
solution (1 cup of bleach in 1 gallon of water).
Specific
Recommendations:
- Keep the humidity
level in the house between 40% and 60%.
- Use an air
conditioner or a dehumidifier during humid months.
- Be sure the home
has adequate ventilation, including exhaust fans.
- Add mold
inhibitors to paints before application.
- Clean bathrooms
with mold killing products.
- Do not carpet
bathrooms and basements.
- Remove or replace
previously soaked carpets and upholstery.
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What areas have high
mold exposures?
- Antique shops
- Greenhouses
- Saunas
- Farms
- Mills
- Construction areas
- Flower shops
- Summer cottages
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I found mold growing in
my home, how do I test the mold?
Generally, it is not
necessary to identify the species of mold growing in a residence, and
CDC does not recommend routine sampling for molds. Current evidence
indicates that allergies are the type of diseases most often associated
with molds. Since the susceptibility of individuals can vary greatly
either because of the amount or type of mold, sampling and culturing are
not reliable in determining your health risk. If you are susceptible to
mold and mold is seen or smelled, there is a potential health risk;
therefore, no matter what type of mold is present, you should arrange
for its removal. Furthermore, reliable sampling for mold can be
expensive, and standards for judging what is and what is not an
acceptable or tolerable quantity of mold have not been established.
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A qualified
environmental lab took samples of the mold in my home and gave me the
results. Can CDC interpret these results?
Standards for judging
what is an acceptable, tolerable, or normal quantity of mold have not
been established. If you do decide to pay for environmental sampling for
molds, before the work starts, you should ask the consultants who will
do the work to establish criteria for interpreting the test results.
They should tell you in advance what they will do or what
recommendations they will make based on the sampling results. The
results of samples taken in your unique situation cannot be interpreted
without physical inspection of the contaminated area or without
considering the building’s characteristics and the factors that led to
the present condition.
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