What is mold and where is it found?
Mold (fungi) is present everywhere indoors and outdoors. There are
more than 100,000 species of mold. At least 1,000 species of mold
are common in the U.S. Some of the most commonly found are species
of Cladosporium, Penicillium, and Aspergillus. Mold is most likely
to grow where there is water or dampness such as in bathrooms and
How can mold affect your health?
Most types of mold routinely encountered are not hazardous to
healthy individuals. However, too much exposure to mold may cause or
worsen conditions such as asthma, hay fever, or other allergies. The
most common symptoms of overexposure are cough, congestion, runny
nose, eye irritation, and aggravation of asthma. Depending on the
amount of exposure and a person's individual vulnerability, more
serious health effects such as fevers and breathing problems can
occur but are unusual.
How can you be exposed to mold?
When moldy material becomes damaged or disturbed, spores
(reproductive bodies similar to seeds) can be released into the air.
Exposure can occur if people inhale the spores, directly handle
moldy materials, or accidentally ingest it. Also, mold can sometimes
produce chemicals called mycotoxins. Mycotoxins may cause illness in
people who are sensitive to them or if they are exposed to large
amounts in the air. Large exposures are typically associated with
certain occupations (e.g., agricultural work).
How does mold grow?
All molds need water to grow. Mold can grow almost anywhere there is
water damage, high humidity, or dampness. Most often molds are
confined to areas near the source of water. Removing the source of
moisture such as through repairs or dehumidification is critical
to preventing mold growth.
What is Stachybotrys chartarum?
Stachybotrys chartarum (also known as Stachybotrys atra) is a type
of mold that has been associated with health effects in people. It
is a greenish-black mold that can grow on materials with a high
cellulose content such as drywall sheetrock, dropped ceiling
tiles, and wood that become chronically moist or water-damaged,
due to excessive humidity, water leaks, condensation, or flooding.
How can you tell if Stachybotrys chartarum is present in your
Many molds are black in appearance but are not Stachybotrys. For
example, the black mold commonly found between bathroom tiles is not
Stachybotrys. Stachybotrys can be positively identified only by
specially trained professionals (e.g., mycologists) through a
How can Stachybotrys chartarum affect your health?
Typically, indoor air levels of Stachybotrys are low; however, as
with other types of mold, at higher levels health effects can occur.
These include allergic rhinitis (cold-like symptoms), dermatitis
(rashes), sinusitis, conjunctivitis, and aggravation of asthma. Some
related symptoms are more general such as inability to concentrate
and fatigue. Usually, symptoms disappear after the contamination is
There has been some evidence linking Stachybotrys with pulmonary
hemosiderosis in infants who are generally less than six months old.
Pulmonary hemosiderosis is an uncommon condition that results from
bleeding in the lungs. In studied cases of pulmonary hemosiderosis,
the exposure to Stachybotrys came from highly contaminated
dwellings, where the infants were continually exposed over a long
period of time.
What should you do if mold is present in your home or apartment?
Although any visible mold can be sampled by an environmental
consultant and/or analyzed by a laboratory specializing in
microbiology, these tests can be very expensive from hundreds to
thousands of dollars. There is no simple and cheap way to sample the
air in your home to find out what types of mold are present and
whether they are airborne. Even if you have your home tested, it is
difficult to say at what levels health effects would occur.
Therefore, it is more important get rid of the mold rather than find
out more about it. The most effective way to treat mold is to
correct underlying water damage and clean the affected area.
How should mold be cleaned?
Mold should be cleaned as soon as it appears. Persons cleaning mold
should be free of symptoms and allergies. Small areas of mold should
be cleaned using a detergent/soapy solution or an appropriate
household cleaner. Gloves should be worn during cleaning. The
cleaned area should then be thoroughly dried. Dispose of any sponges
or rags used to clean mold.
If the mold returns quickly or spreads, it may indicate an
underlying problem such as a leak. Any underlying water problems
must be fixed to successfully eliminate mold problems. If mold
contamination is extensive, a professional abatement company may
need to be consulted.
Will my health or my child's health be affected, and should we
see a physician?
If you believe that you or your children have symptoms that you
suspect are caused by exposure to mold, you should see a physician.
Keep in mind that many symptoms associated with mold exposure may
also be caused by many other illnesses. You should tell your
physician about the symptoms and about when, how, and for how long
you think you or your children were exposed.
Who can I call if I suspect I have a mold problem or if I want more
For more information about the health effects of mold exposure and
information on the safe removal of mold, please call the Cambridge
Public Health Department's Environmental Health Unit at