Molds are microscopic forms
of fungi that grow into visible colonies under the right conditions. They are
found everywhere – both indoors and outdoors year-round. Outdoors, molds live
in the soil, on plants and on dead or decaying matter. Another common term for
mold is mildew. Mold growth is encouraged by warm and humid conditions,
although it can grow during cold weather also. There are many thousands of
species of mold and they can be in any color, including white, orange, green,
brown or black. Many times, mold can be detected by a musty odor. Most fungi,
including molds, produce microscopic cells called “spores” that spread easily
through the air. Live spores act like seeds, forming new mold growths
(colonies) when they find the right conditions. All of us are exposed to fungal
spores daily in the air we breathe, both outside and inside. This and the
following information is from
Maryland Department of Health's Mold Fact Sheet.
Most, if not all, of the mold found
indoors comes from outdoor sources. Indoors it seems to grow and become a
problem only where there is water damage, high humidity or dampness. All molds
need moisture to grow. Common sources of indoor moisture that can cause mold
problems include flooding, roof and plumbing leaks, damp basements or crawl
spaces. Any place where moist air condenses on cold surfaces may be a source of
are we concerned about mold?
Small amounts of mold growth in
workplaces or homes are not a major concern. When molds are present in large
quantities, they may cause nuisance odors and health problems for some people.
do molds affect people?
Most people will have no reaction at
all when exposed to molds. Allergic reactions, similar to common pollen or
animal allergies, including runny nose, eye irritation and skin rash, are the
most common health effects for individuals sensitive to molds. Flu-like
symptoms, such as cough, congestion, headache and fatigue may occur. Molds may
also aggravate asthma. Fungal infections from building-associated molds may
occur in people with serious immune disease, but this is very rare. Most
symptoms are temporary and eliminated by correcting the mold problem.
is affected by exposure to mold?
For those who are affected by mold
exposure, there can be a wide variation in how they react. Some individuals are
more sensitive than others. Some general groups that tend to be more sensitive
Those with special health concerns
should consult their doctor if they are concerned about mold exposure. The
symptoms that may seem to occur from mold exposure can also be due to other
causes, such as bacterial or viral infections or other allergies.
mold be toxic?
Some molds can produce toxic substances
called mycotoxins. Airborne mycotoxins have not been shown to cause health
problems to occupants in residential or commercial buildings. The health
effects of breathing mycotoxins are not well understood and are currently under
is “black mold”?
The news media sometimes refer to
“black mold” or “toxic black mold.” It has usually been associated with the
mold Stachybotrys chartarum, a type of greenish-black mold commonly associated
with heavy water damage. Known health effects are similar to other common
molds. Early reports of severe effects have been put in doubt by later
should I do if I see or smell mold?
An important and very practical step in
solving a mold problem is to identify and fix the moisture sources that caused
the mold growth. For small mold problems, detergent and water can be used to
wash mold off hard surfaces. Bleach solution kills mold. Porous or absorbent
materials (such as ceiling tiles, wallboard and carpeting) that become moldy
should be replaced.
about testing the building for mold?
Mold and moldy odors seldom require
testing. The first step should be to inspect for water damage and any visible
mold growth. The next step would be to get rid of any visible mold and to solve
any moisture problem causing a moldy condition. There are no standards for “acceptable”
or “unacceptable” levels of mold in buildings. Any testing should be done by a
can people decrease mold exposure?
Keep humidity levels as low as you
can—no higher than 50%–all day long. An air conditioner or dehumidifier will
help you keep the level low. Bear in mind that humidity levels change over the
course of a day with changes in the moisture in the air and the air
temperature, so you will need to check the humidity levels more than once a
The Howard County Health Department does not have a program to evaluate mold concerns or provide assistance for addressing mold-related problems. However, additional general information about mold and mold cleanup can be accessed through these links.
Environmental Protection Agency - Mold
Environmental Protection Agency Guide to Mold, Moisture, and Your Home
Una Breve Guía para el Moho, la Humedad y su Hogar está disponible en el formato PDF
Centers for Disease Control and Prevention - Mold
Cleaning Mold and Mildew