Mold Information
Introduction to Molds
Molds produce tiny spores to reproduce. Mold
spores waft through the indoor and outdoor air continually. When mold spores
land on a damp spot indoors, they may begin growing and digesting whatever
they are growing on in order to survive. There are molds that can grow on
wood, paper, carpet, and foods. When excessive moisture or water accumulates
indoors, mold growth will often occur, particularly if the moisture problem
remains undiscovered or un-addressed. There is no practical way to eliminate
all mold and mold spores in the indoor environment; the way to control
indoor mold growth is to control moisture.
Basic Mold Cleanup
The key to mold control is moisture control. It
is important to dry water damaged areas and items within 24-48 hours to
prevent mold growth. If mold is a problem in your home, clean up the mold
and get rid of the excess water or moisture. Fix leaky plumbing or other
sources of water. Wash mold off hard surfaces with detergent and water, and
dry completely. Absorbent materials (such as ceiling tiles & carpet) that
become moldy may have to be replaced.
Things You Should Know About Mold
- Fix the source of the water
problem or leak to prevent mold growth.
- Reduce indoor humidity (to
30-60% ) to decrease mold growth by: venting bathrooms, dryers, and
other moisture-generating sources to the outside; using air conditioners
and de-humidifiers; increasing ventilation; and using exhaust fans
whenever cooking, dishwashing, and cleaning.
- Clean and dry any damp or wet
building materials and furnishings within 24-48 hours to prevent mold
growth.
- Clean mold off hard surfaces
with water and detergent, and dry completely. Absorbent materials such
as ceiling tiles, that are moldy, may need to be replaced.
- Prevent condensation: Reduce
the potential for condensation on cold surfaces (i.e., windows, piping,
exterior walls, roof, or floors) by adding insulation.
- In areas where there is a
perpetual moisture problem, do not install carpeting (i.e., by drinking
fountains, by classroom sinks, or on concrete floors with leaks or
frequent condensation).
- Molds can be found almost
anywhere; they can grow on virtually any substance, providing moisture
is present. There are molds that can grow on wood, paper, carpet, and
foods.
- Potential health effects and
symptoms associated with mold exposures include allergic reactions,
asthma, and other respiratory complaints.
- There is no practical way to
eliminate all mold and mold spores in the indoor environment; the way to
control indoor mold growth is to control moisture.
- If mold is a problem in your
home or school, you must clean up the mold and eliminate sources of
moisture.
- In many bathrooms and
adjoining rooms mold can be managed by using Clorox, in a spray bottle
of 24 ounce, fill with 1 ounce of Clorox or Purex and approximately 16
ounce of water. Be careful not to get this spray mixture on colored
curtains, clothing or towels. The area where fungus is visible, simply
spray the area with 2 or 3 squirts of the Clorox mixture. Do this
maintenance daily for about a week and the mold will disappear, then
perform every other day or after a while maybe once a week will prevent
it from coming back. Most mold in restrooms are a result of poor
ventilation, keeping the exaust fan on when bathing or showering may
also help reduce mold in this area. In small apartments this mold can
also grow on glass, mirrors and windows in other rooms too. Again with
a little maintenance and good ventilation, it is controllable.
Asthma and Mold
Molds can trigger asthma episodes in sensitive
individuals with asthma. People with asthma should avoid contact with or
exposure to molds.
EPA's
Asthma
web site
EPA's
Asthma Brochure
EPA's
Mold page
from Asthma web site
- Allergy & Asthma
Network/Mothers of Asthmatics (AAN/MA): (800) 878-4403;
www.aanma.org
- American Academy of Allergy,
Asthma & Immunology (AAAAI):
www.aaaai.org
- American Lung Association:
1-800-LUNG-USA (1-800-586-4872);
www.lungusa.org
- Asthma & Allergy Foundation of
America: (800) 7ASTHMA;
www.aafa.org
- Canada Mortgage & Housing
Corporation fact sheets on mold -
www.cmhc-schl.gc.ca/en/burema/gesein/abhose/abhose_50.cfm
- National Institute of Allergy
and Infectious Diseases:
www.niaid.nih.gov
- National Jewish Medical and
Research Center: (800) 222-LUNG (5864);
www.njc.org
Health and Mold
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.
EPA's publication,
Indoor Air Pollution: An Introduction for Health Professionals
, assists health professionals (especially the primary care physician)
in diagnosis of patient symptoms that could be related to an indoor air
pollution problem.
Allergic Reactions - excerpted from
Indoor Air Pollution: An Introduction for Health
Professionals section on: Animal Dander, Molds, Dust Mites, Other
Biologicals .
Consult the
Centers for Disease
Control (CDC) website
Homes and Molds
The EPA publication, "A Brief Guide to
Mold, Moisture, and Your Home" , is available here in
HTML
and
PDF formats. This Guide provides information and guidance for
homeowners and renters on how to clean up residential mold problems and how
to prevent mold growth. A printed version will be available soon.
Moisture Control
Water in your home can come from many sources.
Water can enter your home by leaking or by seeping through basement floors.
Showers or even cooking can add moisture to the air in your home. The amount
of moisture that the air in your home can hold depends on the temperature of
the air. As the temperature goes down, the air is able to hold less
moisture. This is why, in cold weather, moisture condenses on cold surfaces
(for example, drops of water form on the inside of a window). This moisture
can encourage biological pollutants to grow.
There are many ways to control moisture in your
home:
- Fix leaks and seepage. If
water is entering the house from the outside, your options range from
simple landscaping to extensive excavation and waterproofing. (The
ground should slope away from the house.) Water in the basement can
result from the lack of gutters or a water flow toward the house. Water
leaks in pipes or around tubs and sinks can provide a place for
biological pollutants to grow.
- Put a plastic cover over dirt
in crawlspaces to prevent moisture from coming in from the ground. Be
sure crawlspaces are well-ventilated.
- Use exhaust fans in bathrooms
and kitchens to remove moisture to the outside (not into the attic).
Vent your clothes dryer to the outside.
- Turn off certain appliances
(such as humidifiers or kerosene heaters) if you notice moisture on
windows and other surfaces.
- Use dehumidifiers and air
conditioners, especially in hot, humid climates, to reduce moisture in
the air, but be sure that the appliances themselves don't become sources
of biological pollutants.
- Raise the temperature of cold
surfaces where moisture condenses. Use insulation or storm windows. (A
storm window installed on the inside works better than one installed on
the outside.) Open doors between rooms (especially doors to closets
which may be colder than the rooms) to increase circulation. Circulation
carries heat to the cold surfaces. Increase air circulation by using
fans and by moving furniture from wall corners to promote air and heat
circulation. Be sure that your house has a source of fresh air and can
expel excessive moisture from the home.
- Pay special attention to
carpet on concrete floors. Carpet can absorb moisture and serve as a
place for biological pollutants to grow. Use area rugs which can be
taken up and washed often. In certain climates, if carpet is to be
installed over a concrete floor, it may be necessary to use a vapor
barrier (plastic sheeting) over the concrete and cover that with
sub-flooring (insulation covered with plywood) to prevent a moisture
problem.
- Moisture problems and their
solutions differ from one climate to another. The Northeast is cold and
wet; the Southwest is hot and dry; the South is hot and wet; and the
Western Mountain states are cold and dry. All of these regions can have
moisture problems. For example, evaporative coolers used in the
Southwest can encourage the growth of biological pollutants. In other
hot regions, the use of air conditioners which cool the air too quickly
may prevent the air conditioners from running long enough to remove
excess moisture from the air. The types of construction and
weatherization for the different climates can lead to different problems
and solutions.
Moisture On Windows
Your humidistat is set too high if excessive
moisture collects on windows and other cold surfaces. Excess humidity for a
prolonged time can damage walls especially when outdoor air temperatures are
very low. Excess moisture condenses on window glass because the glass is
cold. Other sources of excess moisture besides overuse of a humidifier may
be long showers, running water for other uses, boiling or steaming in
cooking, plants, and drying clothes indoors. A tight, energy efficient house
holds more moisture inside; you may need to run a kitchen or bath
ventilating fan sometimes, or open a window briefly. Storm windows and
caulking around windows keep the interior glass warmer and reduce
condensation of moisture there.
Humidifiers are not recommended for use in
buildings without proper vapor barriers because of potential damage from
moisture buildup. Consult a building contractor to determine the adequacy of
the vapor barrier in your house. Use a humidity indicator to measure the
relative humidity in your house. The American Society of Heating and Air
Conditioning Engineers (ASHRAE) recommends these maximum indoor humidity
levels.
Outdoor Recommended Indoor Temperature Relative
Humidity
+20 F. 35%
+10 F. 30%
0 F. 25%
-10 F. 20%
-20 F. 15%
Anne Field, Extension Specialist, Emeritus,
with reference from the Association for Home Appliance Manufacturers (
www.aham.org
).
Should You Have the Air Ducts in Your Home Cleaned?
- excerpt on duct cleaning and mold
follows, please review the entire document for additional information on
duct cleaning and mold.
You should consider having the air ducts in
your home cleaned if:
There is substantial visible mold growth inside
hard surface (e.g., sheet metal) ducts or on other components of your
heating and cooling system. There are several important points to understand
concerning mold detection in heating and cooling systems:
- Many sections of your heating
and cooling system may not be accessible for a visible inspection, so
ask the service provider to show you any mold they say exists.
- You should be aware that
although a substance may look like mold, a positive determination of
whether it is mold or not can be made only by an expert and may require
laboratory analysis for final confirmation. For about $50, some
microbiology laboratories can tell you whether a sample sent to them on
a clear strip of sticky household tape is mold or simply a substance
that resembles it.
- If you have insulated air
ducts and the insulation gets wet or moldy it cannot be effectively
cleaned and should be removed and replaced.
- If the conditions causing the
mold growth in the first place are not corrected, mold growth will
recur.