- 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.
- 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.
http://www.mold-kill.com
Mold in My Home: What Do I Do?
This is an update of
our March 1998 info sheet to provide basic information to people who have
experienced water damage to their home. It describes health concerns related
to mold exposure, and it also provides general guidelines on prevention,
mold detection, as well as cleanup of mold -contaminated materials.
Additional resources and documents are referenced.
ABOUT MOLD
What are Molds?
Molds are simple,
microscopic organisms, present virtually everywhere, indoors and outdoors.
Molds, along with mushrooms and yeasts, are fungi and are needed to break
down dead material and recycle nutrients in the environment. For molds to
grow and reproduce, they need only a food source – any organic material,
such as leaves, wood, paper, or dirt— and moisture. Because molds grow by
digesting the organic material, they gradually destroy whatever they grow
on. Sometimes, new molds grow on old mold colonies. Mold growth on
surfaces can often be seen in the form of discoloration, frequently green,
gray, brown, or black but also white and other colors. Molds release
countless tiny, lightweight spores, which travel through the air.
How am I exposed to
indoor molds?
Everyone is exposed
to some mold on a daily basis without evident harm. It is common to find
mold spores in the air inside homes, and most of the airborne spores found
indoors come from outdoor sources. Mold spores primarily cause health
problems when they are present in large numbers and people inhale many of
them. This occurs primarily when there is active mold growth within home,
office or school where people live or work. People can also be exposed to
mold by touching contaminated materials and by eating contaminated foods.
Can mold become a
problem in my home?
Molds will grow and
multiply whenever conditions are right— sufficient moisture is available
and organic material is present. Be on the lookout in your home for common
sources of indoor moisture that may lead to mold problems:
- Flooding
- Leaky roofs
- Sprinkler spray
hitting the house
- Plumbing leaks
- Overflow from
sinks or sewers
- Damp basement or
crawl space
- Steam from shower
or cooking
- Humidifiers
- Wet clothes
drying indoors or clothes dryers exhausting indoors
Warping floors and
discoloration of walls and ceilings can be indications of moisture
problems. Condensation on windows or walls is also an important
indication, but it can sometimes be caused by an indoor combustion
problem! Have fuel-burning appliances routinely inspected by your local
utility or a professional heating contractor.
Should I be
concerned about mold in my home?
Yes, if indoor mold
contamination is extensive, it can cause very high and persistent airborne
spore exposures. Persons exposed to high spore levels can become
sensitized and develop allergies to the mold or other health problems.
Mold growth can damage your furnishings, such as carpets, sofas and
cabinets. Clothes and shoes in damp closets can become soiled. In time,
unchecked mold growth can cause serious damage to the structural elements
in your home.
HEALTH EFFECTS
What symptoms are
commonly seen with mold exposure?
Molds produce health
effects through inflammation, allergy, or infection. Allergic reactions
(often referred to as hay fever) are most common following mold exposure.
Typical symptoms that mold-exposed persons report (alone or in
combination) include:
- Respiratory
problems, such as wheezing, difficulty breathing, and shortness of
breath
- Nasal and sinus
congestion
- Eye irritation
(burning, watery, or reddened eyes)
- Dry, hacking
cough
- Nose or throat
irritation
- Skin rashes or
irritation
Headaches, memory
problems, mood swings, nosebleeds, body aches and pains, and fevers are
occasionally reported in mold cases, but their cause is not understood.
How much mold can
make me sick?
It depends. For some
people, a relatively small number of mold spores can trigger an asthma
attack or lead to other health problems. For other persons, symptoms may
occur only when exposure levels are much higher. Nonetheless, indoor mold
growth is unsanitary and undesirable. Basically, if you can see or smell
mold inside your home, take steps to identify and eliminate the excess
moisture and to cleanup and remove the mold.
Are some molds more
hazardous than others?
Allergic persons
vary in their sensitivities to mold, both as to the amount and the types
to which they react. In addition to their allergic properties, certain
types of molds, such as Stachybotris chartarum, may produce compounds that
have toxic properties, which are called mycotoxins. Mycotoxins are not
always produced, and whether a mold produces mycotoxins while growing in a
building depends on what the mold is growing on, conditions such as
temperature, pH, humidity or other unknown factors. When mycotoxins are
present, they occur in both living and dead mold spores and may be present
in materials that have become contaminated with molds. While Stachybotrys
is growing, a wet slime layer covers its spores, preventing them from
becoming airborne. However, when the mold dies and dries up, air currents
or physical handling can cause spores to become airborne. At present there
is no environmental test to determine whether Stachybotrys growth found in
buildings is producing toxins. There is also no blood or urine test that
can establish if an individual has been exposed to Stachybotrys chartarum
spores or its toxins.
Who is at greater
risk when exposed to mold?
Exposure to mold is
not healthy for anyone inside buildings. Therefore, it is always best to
identify and correct high moisture conditions quickly before mold grows
and health problems develop. Some people may have more severe symptoms or
become ill more rapidly than others:
- Individuals with
existing respiratory conditions, such as allergies, chemical
sensitivities, or asthma.
- Persons with
weakened immune systems (such as people with HIV infection, cancer
chemotherapy patients, and so forth)
- Infants and young
children
- The elderly
Anyone with health
problems they believe due to molds should consult a medical professional.
Additional fact sheets on Mold and Health Effects are available from CDHS:
- Health Effects of
Toxin -Producing Molds in California
- Stachybotrys
charta rum (atra) — a mold that may be found in water-damaged homes
- Fungi and Indoor
Air Quality
- Misinterpretation
of Stachybotrys Serology
These documents are
available from the Environmental Health Investigation Branch, (510)
622-4500, or on the web at
www.dhs.ca.gov/ehib/.
DETECTION OF MOLD
How can I tell if I
have mold in my house?
You may suspect that
you have mold if you see discolored patches or cottony or speckled growth
on walls or furniture or if you smell an earthy or musty odor. You also
may suspect mold contamination if mold-allergic individuals experience
some of the symptoms listed above when in the house. Evidence of past or
ongoing water damage should also trigger more thorough inspection. You may
find mold growth underneath water-damaged surfaces or behind walls, floors
or ceilings.
Should I test my
home for mold?
The California
Department of Health Services does not recommend testing as a first step to
determine if you have a mold problem. Reliable air sampling for mold can be
expensive and requires expertise and equipment that is not available to the
general public. Owners of individual private homes and apartment generally
will need to pay a contractor to carry out such sampling, because insurance
companies and public health agencies seldom provide this service. Mold
inspection and cleanup is usually considered a housekeeping task that is the
responsibility of homeowner or landlord, as are roof and plumbing repairs,
house cleaning, and yard maintenance. Another reason the health department
does not recommend testing for mold contamination is that there are few
available standards for judging what is an acceptable quantity of mold. In
all locations, there is some level of airborne mold outdoors. If sampling is
carried out in a home, an outdoor air sample also must be collected at the
same time as the indoor samples, to provide a baseline measurement. Because
individual susceptibility varies so greatly, sampling is at best a general
guide.
The simplest way to
deal with a suspicion of mold contamination is: If you can see or smell
mold, you likely have a problem and should take the steps outlined below.
Mold growth is likely to recur unless the source of moisture that is
allowing mold to grow is removed and the contaminated area is cleaned.
GENERAL CLEAN-UP PROCEDURES
The following is
intended as an overview for homeowners or apartment dwellers. We recommend
that you consult one of several more thorough documents currently
available as guidance, listed in the USEFUL PUBLICATIONS
section below.
Elements of the
Clean-up Procedures:
- Identify and
eliminate sources of moisture
- Identify and
assess the magnitude and area of mold contamination
- Clean and dry
moldy areas – use containment of affected areas
- Bag and dispose
of all material that may have moldy residues, such as rags, paper,
leaves, and debris.
Assessing the Size
of a Mold Contamination Problem
There will be a
significant difference in the approach used for a small mold problem –
total area affected is less than 10 ft– and a large contamination problem
– more than 100 ft. In the case of a relatively small area, the clean-up
can be handled by the homeowner or maintenance staff, using personal
protective equipment (see below). However, for cases of much larger areas,
it is advisable that an experienced, professional contractor be used. For
in-between sized cases, the type of containment and personal protection
equipment to be used will be a matter of judgment.
Can cleaning up
mold be hazardous to my health?
Yes. During the
cleaning process, you may be exposed to mold, strong detergents, and
disinfectants. Spore counts may be 10 to 1000 times higher than background
levels when mold-contaminated materials are disturbed. Take steps to
protect you and your family’s health during cleanup:
- When handling or
cleaning moldy materials, it is important to use a respirator to protect
yourself from inhaling airborne spores.
Respirators can be
purchased from hardware stores; select one that is effective for particle
removal (sometimes referred to as an N-95 particulate respirator).
However, respirators that remove particles will not protect you from fumes
(such as bleach). Minimize exposure when using bleach or other
disinfectants by ensuring good ventilation of the area.
- Wear protective
clothing that is easily cleaned or discarded.
- Use rubber
gloves.
- Try cleaning a
test area first. If you feel that this activity adversely affected your
health, you should consider paying a licensed contractor or other
experienced professional to carry out the work.
- Ask family
members or bystanders to leave areas that are being cleaned.
- Work for short
time periods and rest in a location with fresh air.
- Air out your
house well during and after the work.
- Never use a
gasoline engine indoors (e.g., water pump, pressure washer or
generator), as you could expose your family to toxic carbon monoxide.
Removal of Moldy
Materials
Clean up should
begin after the moisture source is fixed and excess water has been
removed. Wear gloves when handling moldy materials.
- Discard porous
materials (for example, ceiling tiles, sheetrock, carpeting, and wood
products).
- Bag and discard
moldy items; if properly enclosed, items can be disposed with household
trash.
- Dry affected
areas for 2 or 3 days.
Spores are more
easily released when moldy materials dry out, hence it is advisable to
remove moldy items as soon as possible.
If there was
flooding, sheetrock should be removed to a level above the high-water
mark. Visually inspect the wall interior and remove any mold-contaminated
materials.
What can I save?
What should I toss?
You should discard
moldy items that are porous and from which it will be difficult to remove
mold completely: paper, rags, wallboard, rotten wood, carpet, drapes, and
upholstered furniture. Contaminated carpet is often difficult to
thoroughly clean, especially when the backing and/or padding can become
moldy. Solid materials – glass, plastic, and metal – can generally be kept
after they are thoroughly cleaned.
Clean-up
When attempting to
clean less porous items (i.e., solid items such as floors, cabinets, solid
furniture), the first step is to remove as much mold as possible. A
cleaning detergent is effective for this purpose. Wear gloves, mask and
eye protection when doing this cleanup.
- Use non-ammonia
soap or detergent, or a commercial cleaner, in hot water, and scrub the
entire area that is affected by the mold.
- Use a stiff brush
or cleaning pad on cement-block walls or other uneven surfaces.
- Rinse cleaned
items with water and dry thoroughly. A wet/dry vacuum cleaner is helpful
for removing water and cleaning items.
Disinfection of
Contaminated Materials
Disinfecting agents
can be toxic for humans, not just molds. They should be used only when
necessary and should be handled with caution.
Disinfectants are
intended to be applied to thoroughly cleaned materials and are used to
ensure that most microorganisms have been killed. Therefore, do not use
disinfectants instead of, or before, cleaning materials with soap or
detergent. Removal of mold growth from nonporous materials usually is
sufficient. Wear gloves, mask and eye protection when using disinfectants
- After thoroughly
cleaning and rinsing contaminated materials, a solution of 10% household
bleach (for example, 1½ cup household bleach per gallon of water) can be
used as a disinfectant.
- Using bleach
straight from the bottle is actually LESS effective than diluted bleach.
- Keep the
disinfectant on the treated material for the time prescribed time before
rinsing or drying, typically 10 minutes is recommended for a bleach
solution
- Bleach fumes can
irritate the eyes, nose, and throat, and damage clothing and shoes. Make
sure working areas are well ventilated.
- When disinfecting
a large structure, make sure that the entire surface is wetted (for
example, the floors, joists, and posts).
- Properly collect
and dispose extra disinfectant and runoff.
- Never mix bleach
with ammonia; toxic fumes may be produced.
Can air ducts
become contaminated with mold?
Yes. Air duct
systems can become contaminated with mold. Duct systems may be constructed
of bare sheet metal, sheet metal with fibrous glass insulation on the
exterior, or sheet metal with an internal fibrous glass liner, or they may
be made entirely of fibrous glass. Bare sheet metal systems and sheet
metal with exterior fibrous glass insulation can be cleaned and
disinfected. If water damaged, ductwork made of sheet metal with an
internal fibrous glass liner or made entirely of fibrous glass will often
need to be removed and discarded. Ductwork in difficult-to-reach locations
may have to be abandoned. If you have other questions, contact an air duct
cleaning professional or licensed contractor.
Can ozone air
cleaners help remove indoor mold or reduce odors?
Sometimes air
cleaners are promoted to remove indoor mold or associated odors, and some
of these are designed to produce ozone. Ozone is a strong oxidizing agent
that is used as a disinfectant in water and sometimes to eliminate odors.
However, ozone is a known lung irritant. Ozone generators have been shown
to sometimes produce indoor levels above the safe limit. Furthermore, it
has been shown that ozone is not effective in controlling molds and other
microbial contamination, even at concentrations far above safe health
levels. Also, ozone may damage materials in the home, for example, cause
rubber items to become brittle. For these reasons, the California
Department of Health Services strongly recommends that you NOT use an
ozone air cleaner in any occupied space. Refer to the CDHS IAQ Info Sheet:
Health Hazards of Ozone-generating Air Cleaning Devices (January 1998),
available on the CDHS-IAQS web site.
How can I prevent
indoor mold problems in my home?
Inspect your home
regularly for the indications and sources of indoor moisture and mold
listed above. Take steps to eliminate sources of water as quickly as
possible. If a leak or flooding occurs, it is essential to act quickly :
- Stop the source
of leak or flooding.
- Remove excess
water with mops or wet vacuum.
- Whenever
possible, move wet items to a dry and well ventilated area or outside to
expedite drying. Move rugs and pull up areas of wet carpet as soon as
possible.
- Open closet and
cabinet doors and move furniture away from walls to increase
circulation.
- Run portable fans
to increase air circulation. Do NOT use the home’s central blower if
flooding has occurred in it or in any of the ducts. Do NOT use fans if
mold may have already started to grow -- more than 48 h since flooding.
- Run dehumidifiers
and window air conditioners to lower humidity.
- Do NOT turn up
the heat or use heaters in confined areas, as higher temperatures
increase the rate of mold growth.
- If water has
soaked inside the walls, it may be necessary to open wall cavities,
remove baseboards, and/or pry open wall paneling.
USEFUL PUBLICATIONS
Links to the following
documents can be found at
www.cal-iaq.org/MOLD/.
General Information
- Molds, Toxic Molds,
and Indoor Air Quality. Detailed overview for the legislature by the
California Research Bureau.
- Mold in Workplace –
CDHS-HESIS Infosheet. Useful overview with specific resources for workers.
- Biological
Pollutants in Your Home. Concise booklet by U.S. EPA and ALA aimed at
affected homeowner.
- Mold and Moisture.
Appendix H in the U.S. EPA IAQ Tools for Schools
Clean-up Guidance
- Repairing Your
Flooded Home. Excellent resource by the American Red Cross and FEMA, with
details on technical & logistical issues.
- Guidelines on
Assessment and Remediation of Fungi in Indoor Environments. Widely
referenced guidelines developed by the New York City Department of Health.
- Mold Remediation in
Schools and Commercial Buildings. Valuable, new guidance by U.S. EPA, also
applicable to residences.
- Consultants,
Laboratories & Clinics CDHS Listing of Consultants Offering IAQ Services
in California. Self -reported database of contractors.
- CDHS List of
Laboratories for Bioaerosol (Mold) Testing. Identifies labs providing
bioaerosol testing.
- Association of
Occupational & Environmental Clinics.
www.aoec.org.
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