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ABOUT MOLD
by Minnesota Dept. of Health Services
What
is it?
Molds are
simple, microscopic organisms, found virtually everywhere, indoors and
outdoors. Molds can be found on plants, foods, dry leaves, and other
organic material. Molds are needed for breaking down dead material. Mold
spores are very tiny and lightweight, and this allows them to travel
through the air. Mold growths can often be seen in the form of
discoloration, ranging from white to orange and from green to brown and
black. When molds are present in large quantities, they can cause
allergic symptoms similar to those caused by plant pollen.
Should I be concerned about mold in my home?
Yes, if the contamination is extensive. When airborne
mold spores are present in large numbers, they can cause allergic
reactions, asthma episodes, infections, and other respiratory problems for
people. Exposure to high spore levels can cause the development of an
allergy to the mold. Mold can also cause structural damage to your home.
Similarly, when wood goes through a period of wetting, then drying, it can
eventually warp and cause walls to crack or become structurally weak.
What does mold need
to grow?
For mold to grow, it needs:
-
food sources - such as leaves, wood, paper, or dirt
-
a source of
moisture
-
a place to grow
Can mold become a problem in my home?
Yes, if there is moisture available to allow mold to
thrive and multiply. The following are sources of indoor moisture that may
cause problems:
-
flooding
-
backed-up
sewers
-
leaky
roofs
-
humidifiers
-
mud
or ice dams
-
damp
basement or crawl spaces
-
constant
plumbing leaks
-
house
plants -- watering can generate large amounts of moisture
-
steam
from cooking
-
shower/bath
steam and leaks
-
wet
clothes on indoor drying lines
-
clothes
dryers vented indoors
-
combustion
appliances (e.g. stoves) not exhausted to the outdoors
CAUTION:
If
you see moisture condensation on the windows or walls, it is
also possible that you have a combustion problem in your home.
It is important to have sufficient fresh air available for
fuel burning appliances, such as the furnace, water heater,
stove/range, clothes dryer, as well as a fireplace. A shortage
of air for these appliances can result in back drafting
of dangerous gases such as carbon monoxide into the home. To
prevent back drafting of air, you need either open vents or a
ventilation system that brings fresh air into the home to
replace air that is exhausted out. Have your local utility
company or a professional heating contractor inspect your
fuel-burning appliances annually.
HEALTH EFFECTS
How am I exposed to indoor molds?
Mold is found everywhere, indoors and outdoors. It is
common to find mold spores in the air of homes and growing on damp
surfaces. Much of the mold found indoors comes from outdoor sources.
Therefore, everyone is exposed to some mold on a daily basis without
evident harm. Mold spores primarily cause health problems when they enter
the air and are inhaled in large number. People can also be exposed to
mold through skin contact and eating.
How much mold can make me sick?
It depends. For some people, a relatively small number
of mold spores can cause health problems. For other people, it may take
many more. The basic rule is, if you can see or smell it, take steps to
eliminate the excess moisture, and to cleanup and remove the mold.
Who is at greater risk when exposed to mold?
Exposure to mold is not healthy for anyone inside
buildings. It is important to quickly identify and correct any moisture
sources before health problems develop. The following individuals appear
to be at higher risk for adverse health effects of molds:
-
Infants and children
-
elderly
-
immune compromised patients (people with HIV
infection, cancer chemotherapy, liver disease, etc.)
-
pregnant women
-
individuals with existing respiratory conditions,
such as allergies, multiple
What
symptoms are common?
Allergic reactions may be the most common health problem of mold exposure.
Typical symptoms reported (alone or in combination) include:
-
respiratory
problems, such as wheezing, and difficulty in breathing
-
nasal
and sinus congestion
-
eyes-burning,
watery, reddened, blurry vision, light sensitivity
-
dry,
hacking cough
-
sore
throat
-
nose
and throat irritation
-
shortness
of breath
-
skin
irritation
-
central
nervous system problems (constant headaches, memory problems, and mood
changes)
-
aches
and pains
-
possible
fever
Are some molds more hazardous than others?
Allergic persons vary in their sensitivities to mold,
both as to amount and type needed to cause reactions. In addition, certain
types of molds can produce toxins, called mycotoxins, that the mold
uses to inhibit or prevent the growth of other organisms. Mycotoxins are
found in both living and dead mold spores. Materials permeated with
mold need to be removed, even after they are disinfected with cleaning
solutions. Allergic and toxic effects can remain in dead spores.
Exposure to mycotoxins may present a greater hazard than that of
allergenic or irritative molds. Mycotoxins have been found in homes,
agricultural settings, food, and office buildings.
DETECTION
OF MOLD
How
can I tell if I have mold in my house?
If
you can see mold, or if there is an earthy or musty odor, you can assume
you have a mold problem. Allergic individuals may experience the symptoms
listed above. Look for previous water damage. Visible mold growth is found
underneath materials where water has damaged surfaces, or behind walls.
Look for discoloration and leaching from plaster.
Should I test my home for mold?
The California Department of Health Services does not
recommend testing as the first step to determine if you have a mold
problem. Reliable sampling for mold can be
expensive, and requires equipment not available to the general public.
Residents of individual private homes must pay a contractor to carry out
such sampling, as it is not usually done by public health agencies. Mold
cleanup is usually considered one of the housekeeping tasks of the private
citizen, along with roof and plumbing repairs, sweeping and house
cleaning.
Another problem is that there are few available
standards for judging what is an acceptable quantity of mold. In
all locations, there is some outdoor levels of molds. If sampling is
carried out, an outdoor air sample needs to be taken at the same time as
the sample indoors, to provide a baseline measurement. Since the
susceptibility of individuals varies so greatly, sampling is at best a
general guide. The simplest approach is: if you can see or smell mold,
you have a problem. Once you know the problem exists, follow the
procedure given next.
Unless the source of moisture is removed and the
contaminated area is cleaned and disinfected, mold growth is likely to
reoccur.
GENERAL CLEAN-UP
PROCEDURES
-
Identify and correct the moisture source
-
Clean, disinfect, and dry the moldy area
-
Bag and dispose any material that has moldy
residues, such as rags, paper, leaves, or debris.
What can I save? What should I toss?
Substances that are porous and can trap molds, such as
paper, rags, wallboard, and rotten wood should be decontaminated and
thrown out. Harder materials such as glass, plastic, or metal can be kept
after they are cleaned and disinfected.
Ultimately, it is critical to remove the source of
moisture first, before beginning remedial action, since mold growth will
return shortly if an effected area becomes re-wetted.
Removal of Moldy Materials
After fixing the moisture source and removing excess
moisture, the cleanup can begin:
-
Wear gloves when handling moldy materials
-
Remove porous materials (examples: ceiling tiles,
sheetrock, carpeting, wood products)
-
Carpeting can be a difficult problem -- drying does
not remove the dead spores. If there is heavy mold, disposal of the
carpet should be considered
-
Bag and discard the moldy substances
-
Allow the area to dry 2 or 3 days
-
If flooded, remove all sheetrock to at least 12
inches above the high water mark. Visually inspect the wall interior
and remove any other intrusive molds. (This step may have to be
carried out by a licensed contractor).
CAUTION: Spores are easily released when moldy material
is dried out.
Soap Cleanup
-
Before disinfecting contaminated areas, clean the
areas to remove as much of the mold (and food it is growing on) as
possible.
-
Wear gloves when doing this cleanup
-
Use a non-ammonia soap or detergent, or a
commercial cleaner, in hot water, and scrub the entire area affected
by the mold
-
Use a stiff brush or cleaning pad on block walls
or uneven surfaces
-
Rinse clean with water. A wet/dry vacuum is handy
for this.
Disinfect Surfaces
-
Wear gloves when using
disinfectants
-
After thorough cleaning and rinsing, disinfect the
area with a solution of 10% household bleach (e.g., 1½ cup bleach per
gallon of water). Using bleach straight from the bottle will not be more
effective
Never mix bleach with Ammonia-the fumes are toxic
-
For spraying exterior large areas, a garden hose and
nozzle can be used
-
When disinfecting a large structure, make sure the
entire surface is wetted (floors, joists, and posts)
-
Avoid excessive amounts of runoff or standing bleach
-
Let disinfecting areas dry naturally overnight --
this extended time is important to kill all the mold.
CAUTION: Bleach fumes can irritate the eyes, nose, and
throat, and damage clothing and shoes. Make sure the working area is
ventilated well.
Can cleaning up mold be hazardous to my health?
Yes. Exposure to mold can occur during the cleaning
stage. Mold counts are typically 10 to 1000 times higher than background
levels during the cleaning of mold damaged materials. Take steps to
protect your health during cleanup:
-
When handling or cleaning moldy materials, consider
using a mask or respirator to protect you from breathing airborne
spores. Respirators can be purchased from hardware stores; select one
for particle removal (sometimes referred to as a N95 or TC-21C
particulate respirator). Respirators are not as effective removing
bleach fumes, so minimize your exposure when using bleach or other
disinfectants.
-
Wear protective clothing that is easily cleaned or
discarded
-
Use rubber gloves
-
Try cleaning a small test patch of mold first. If
you feel that this adversely affected your health, you should consider
paying a licensed contractor or professional to carry out the work
-
Ask family members or bystanders to leave areas
when being cleaned.
-
Work over short time spans and rest in a fresh air
location.
-
Air your house out well during after the work
CAUTION: Never use a gasoline engine indoors (e.g.
pressure washer, generator) -- you could expose yourself and your family
to carbon monoxide.
Can Air Duct Systems become
Contaminated with Mold?
Yes. Air duct systems can become contaminated with
mold. Duct systems can be constructed of bare sheet metal, sheet metal
with an exterior fibrous glass insulation, sheet metal with an internal
fibrous glass liner, or made entirely of fibrous glass. If your home’s
air duct system has had water damage, first identify the type of air duct
construction that you have. Bare sheet metal systems, or sheet metal with
exterior fibrous glass insulation, can be cleaned and disinfected.
If your system has sheet metal with an internal fibrous
glass liner, or are made entirely of fibrous glass, the ductwork normally
will need to be removed and discarded. Ductwork in difficult locations may
have to be abandoned. If you have other questions, contact an air duct
cleaning professional, or licensed contractor.
After I’ve cleaned everything as thoroughly as
possible, can I still have mold odors?
Yes. It is possible that odors may persist. Continue to
dry out the area and search for any hidden areas of mold. If the area
continues to smell musty, you may have to re-clean the area again (follow
the cleaning steps given in this sheet). Continue to dry and ventilate the
area. Don’t replace flooring or begin rebuilding until the area has
dried completely.
How can further damage to my home be prevented?
Check regularly for the following:
-
moisture condensation on windows
-
cracking of plasterboard
-
drywall tape loosening
-
wood warping
-
musty odor
If you see any of the above, seek out and take steps to
eliminate the source of water penetration, as quickly as possible.
Can Ozone air cleaners help remove indoor mold, or
reduce odor or pollution levels?
Some air cleaners are designed to produce ozone. Ozone
is a strong oxidizing agent used as a disinfectant in water and sometimes
to eliminate odors. However, ozone is a known lung irritant. Symptoms
associated with exposure include cough, chest pain, and eye, nose, and
throat irritation. Ozone generators have been shown to generate indoor
levels above the safe limit. Furthermore, it has been demonstrated that
ozone is not effective in controlling molds and fungi, even at high
concentrations far above safe health levels. Also, ozone may damage
materials in the home. For these reasons, the California Department of
Health Services strongly recommends that you do not use an ozone air
cleaner in any occupied residential space. Refer to the CDHS IAQ Info
Sheet: Health Hazards of Ozone-generating Air Cleaning Devices (January
1998).
USEFUL PUBLICATIONS
Biological Pollutants in Your Home,
1990. Available
from local ALA or U.S. EPA’s IAQINFO. Concise booklet aimed at
concerned or affected homeowner
Mold, Moisture & Indoor Air Quality: A Guide to
Designers, Builders, and Building Owners, 1994. Available from
Building Science Corp. 617-323-6552.
Moisture, Mold and Mildew
in Building Air
Quality (Appendix C), 1991. Available from U.S. EPA’s IAQINFO. Illustrative
and useful resource guide.
Repairing Your Flooded Home. Available from
American Red Cross and FEMA offices. Excellent resource with details on
technical & logistical issues.
Clean-up Procedures for Mold in Houses.
Available
from Canada Mortgage & Housing Corp. 800-668-2642. Effective,
hands-on information for affected homeowner.
NIOSH Warns of Hazards of Flood Cleanup Work.
National Institute of Occupational Safety and Health (NIOSH) Update. Aimed
at flood emergency workers. 800-356-4674.
Factsheet on Stachybotrys atra (chartarum).
CDHS
Environmental Health Investigations Branch, April 1997. Summarizes
information on S.A. and includes NYC recommendations for evaluating and
remediating microbial contamination.
REFERRALS TO OCCUPATIONAL
& ENVIRONMENTAL
CLINICS
Association of Occupational & Environmental
Clinics. 202-347-4976; http://gilligan.mc.duke.edu/oem/aoec.htm
American College of Occupational & Environmental
Medicine. 847-228-6850;
http://www.acoem.org.
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How
Common Are
Household Molds?
How
common are household molds? A 1994 Harvard University School of Public
Health study of 10,000 homes in the United States and Canada found half
had "conditions of water damage and mold associated with a 50 to
100% increase in respiratory symptoms."
When
molds grow, it's usually in damp places, behind walls and under floors,
above ceiling tiles or behind shower walls -- wherever there are wet
cellulose materials they can feed on, such as wood, ceiling tiles,
plasterboard, or accumulations of organic material inside
air-conditioning and heating systems. Water is the key. Without it,
molds can't get started, much less spread. But when water is left to sit
for even 24 hours, common molds can take hold. If water continues to sit
and areas become completely saturated, that's when a more lethal mold,
such as Stachybotrys, can move in.
The
top ten symptoms that you or a family member may be suffering from
allergy to mold, animal dander, or dust
(listed in alphabetical order: note that
you may suffer one or several of these symptoms)---
a memory loss or
memory difficulties/Alzheimers-like symptoms
a
learning difficulties or mental functioning problems
a feeling lost or "disconnected" from
what's happening around you
a
headaches
a seizures
a
runny nose (rhinitis)
a clear,
thin, watery mucus from your nose may appear suddenly
a sinus congestion and sinus problems
a thick, green slime coming out of nose (from
sinus cavities)
a
coughing and resulting sore lungs/chest from excessive coughing
a coughing up blood
a bleeding lungs
a
difficulty breathing
a
hives
a
itching of the nose, mouth, eyes, throat, skin, or any area
a
redness of the sclera (white of your eyes)
a
skin rashes
a
skin redness
a open skin sores and lacerations
a
sneezing
a sneezing fits (more than three
sneezes in a row, happening often)
a vomiting
a
diarrhea
a
chronic, excessive, or continued fatigue
a chronic dandruff problems that don't go
away despite use of shampoo like "Head & Shoulders" and "Pantene Pro-V" |