Biological Pollutants in
Your Home
Prepared by: The Consumer
Product Safety Commission (CPSC),
and The American Lung
Association, The
Christmas Seal People
This guidance will help you
understand:
-
what indoor biological
pollution is;
-
whether your home or
lifestyle promotes its
development; and,
-
how to control its
growth and buildup.
Outdoor air pollution in
cities is a major health
problem. Much effort and
money continues to be spent
cleaning up pollution in the
outdoor air. But air
pollution can be a problem
where you least expect it,
in the place you may have
thought was safest--your
home. Many ordinary
activities such as cooking,
heating, cooling, cleaning,
and redecorating can cause
the release and spread of
indoor pollutants at home.
Studies have shown that the
air in our homes can be even
more polluted than outdoor
air.
Many Americans spend up to
90 percent of their time
indoors, often at home.
Therefore, breathing clean
indoor air can have an
important impact on health.
People who are inside a
great deal may be at greater
risk of developing health
problems, or having problems
made worse by indoor air
pollutants. These people
include infants, young
children, the elderly, and
those with chronic
illnesses.
Biological pollutants are or
were living organisms. They
promote poor indoor air
quality and may be a major
cause of days lost from work
or school, and of doctor and
hospital visits. Some can
even damage surfaces inside
and outside your house.
Biological pollutants can
travel through the air and
are often invisible.
Some common indoor
biological pollutants are:
-
Animal Dander (minute
scales from hair,
feathers, or skin)
-
Dust Mite and Cockroach
parts
-
Fungi (Molds)
-
Infectious agents
(bacteria or viruses)
-
Pollen
Some of these substances are
in every home. It is
impossible to get rid of
them all. Even a spotless
home may permit the growth
of biological pollutants.
Two conditions are essential
to support biological
growth: nutrients and
moisture. These conditions
can be found in many
locations, such as
bathrooms, damp or flooded
basements, wet appliances
(such as humidifiers or air
conditioners), and even some
carpets and furniture.
Modern materials and
construction techniques may
reduce the amount of outside
air brought into buildings
which may result in high
moisture levels inside.
Using humidifiers, unvented
heaters, and air
conditioners in our homes
has increased the chances of
moisture forming on interior
surfaces. This encourages
the growth of certain
biological pollutants.
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Most information about
sources and health effects
of biological pollutants is
based on studies of large
office buildings and two
surveys of homes in northern
U.S. and Canada. These
surveys show that 30% to 50%
of all structures have damp
conditions which may
encourage the growth and
buildup of biological
pollutants. This percentage
is likely to be higher in
warm, moist climates.
Some diseases or illnesses
have been linked with
biological pollutants in the
indoor environment. However,
many of them also have
causes unrelated to the
indoor environment.
Therefore, we do not know
how many health problems
relate only to poor indoor
air.
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All of us are exposed to
biological pollutants.
However, the effects on our
health depend upon the type
and amount of biological
pollution and the individual
person. Some people do not
experience health reactions
from certain biological
pollutants, while others may
experience one or more of
the following reactions:
-
Allergic
-
Infectious
-
Toxic
Except for the spread of
infections indoors,
ALLERGIC REACTIONS may
be the most common health
problem with indoor air
quality in homes. They are
often connected with animal
dander (mostly from cats and
dogs), with house dust mites
(microscopic animals living
in household dust), and with
pollen. Allergic reactions
can range from mildly
uncomfortable to
life-threatening, as in a
severe asthma attack. Some
common signs and symptoms
are:
-
Watery eyes
-
Runny nose and sneezing
-
Nasal congestion
-
Itching
-
Coughing
-
Wheezing and difficulty
breathing
-
Headache
-
Fatigue
Health experts are
especially concerned about
people with
asthma. These people
have very sensitive airways
that can react to various
irritants, making breathing
difficult. The number of
people who have asthma has
greatly increased in recent
years. The number of people
with asthma has gone up by
59 percent since 1970, to a
total of 9.6 million people.
Asthma in children under 15
years of age has increased
41 percent in the same
period, to a total of 2.6
million children. The number
of deaths from asthma is up
by 68 percent since 1979, to
a total of almost 4,400
deaths per year.
INFECTIOUS DISEASES
caused by bacteria and
viruses, such as flu,
measles, chicken pox, and
tuberculosis, may be spread
indoors. Most infectious
diseases pass from person to
person through physical
contact. Crowded conditions
with poor air circulation
can promote this spread.
Some bacteria and viruses
thrive in buildings and
circulate through indoor
ventilation systems. For
example, the bacterium
causing Legionnaire's
disease, a serious and
sometimes lethal infection,
and Pontiac Fever, a
flu-like illness, have
circulated in some large
buildings.
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Are you concerned about the
effects on your health that
may be related to biological
pollutants in your home?
Before you discuss your
concerns with your doctor,
you should know the answers
to the following questions.
This information can help
the doctor determine whether
your health problems may be
related to biological
pollution.
-
Does anyone in the
family have frequent
headaches, fevers, itchy
watery eyes, a stuffy
nose, dry throat, or a
cough? Does anyone
complain of feeling
tired or dizzy all the
time? Is anyone wheezing
or having difficulties
breathing on a regular
basis?
-
Did these symptoms
appear after you moved
to a new or different
home?
-
Do the symptoms
disappear when you go to
school or the office or
go away on a trip, and
return when you come
back?
-
Have you recently
remodeled your home or
done any energy
conservation work, such
as installing
insulation, storm
windows, or weather
stripping? Did your
symptoms occur during or
after these activities?
-
Does your home feel
humid? Can you see
moisture on the windows
or on other surfaces,
such as walls and
ceilings?
-
What is the usual
temperature in your
home? Is it very hot or
cold?
-
Have you recently had
water damage?
-
Is your basement wet or
damp?
-
Is there any obvious
mold or mildew?
-
Does any part of your
home have a musty or
moldy odor?
-
Is the air stale?
-
Do you have pets?
-
Do your house plants
show signs of mold?
-
Do you have air
conditioners or
humidifiers that have
not been properly
cleaned?
-
Does your home have
cockroaches or rodents?
TOXIC REACTIONS are
the least studied and
understood health problem
caused by some biological
air pollutants in the home.
Toxins can damage a variety
of organs and tissues in the
body, including the liver,
the central nervous system,
the digestive tract, and the
immune system.
There is no simple and
cheap way to sample the
air in your home to
determine the level of
all biological
pollutants. Experts
suggest that sampling
for biological
pollutants is not a
useful problem-solving
tool. Even if you had
your home tested, it is
almost impossible to
know which biological
pollutant(s) cause
various symptoms or
health problems. The
amount of most
biological substances
required to cause
disease is unknown and
varies from one person
to the next.
Does this make the
problem sound hopeless?
On the contrary, you can
take several simple,
practical actions to
help remove sources of
biological pollutants,
to help get rid of
pollutants, and to
prevent their return.
Begin by touring your
household. Follow your
nose, and use your eyes.
Two major factors help
create conditions for
biological pollutants to
grow: nutrients and
constant moisture with
poor air circulation.
-
Dust and
construction
materials, such as
wood, wallboard, and
insulation, contain
nutrients that allow
biological
pollutants to grow.
Firewood also is a
source of moisture,
fungi, and bugs.
-
Appliances such as
humidifiers,
kerosene and gas
heaters, and gas
stoves add moisture
to the air.
-
A musty odor,
moisture on hard
surfaces, or even
water stains, may be
caused by:
- Air-conditioning
units
- Basements, attics,
and crawlspaces
- Bathrooms
- Carpets
- Heating and
air-conditioning
ducts
-
Humidifiers and
dehumidifiers
- Refrigerator drip
pans
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Before you give away the
family pet or move, there
are less drastic steps that
can be taken to reduce
potential problems. Properly
cleaning and maintaining
your home can help reduce
the problem and may avoid
interrupting your normal
routine. People who have
health problems such as
asthma, or are allergic, may
need to do this and more.
Discuss this with your
doctor.
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.
-
Have major
appliances, such as
furnaces, heat pumps
and central air
conditioners,
inspected and
cleaned regularly by
a professional,
especially before
seasonal use. Change
filters on heating
and cooling systems
according to
manufacturer's
directions. (In
general, change
filters monthly
during use.) When
first turning on the
heating or air
conditioning at the
start of the season,
consider leaving
your home until it
airs out.
-
Have window or wall
air-conditioning
units cleaned and
serviced regularly
by a professional,
especially before
the cooling season.
Air conditioners can
help reduce the
entry of
allergy-causing
pollen. But they may
also become a source
of biological
pollutants if not
properly maintained.
Clean the coils and
incline the drain
pans according to
manufacturer's
instructions, so
water cannot collect
in pools.
-
Have
furnace-attached
humidifiers cleaned
and serviced
regularly by a
professional,
especially before
the heating season.
-
Follow
manufacturer's
instructions when
using any type of
humidifier. Experts
differ on the
benefits of using
humidifiers. If you
do use a portable
humidifier
(approximately 1 to
2 gallon tanks), be
sure to empty its
tank every day and
refill with
distilled or
demineralized water,
or even fresh tap
water if the other
types of water are
unavailable. For
larger portable
humidifiers, change
the water as
recommended by the
manufacturer. Unplug
the appliance before
cleaning. Every
third day, clean all
surfaces coming in
contact with water
with a 3% solution
of hydrogen
peroxide, using a
brush to loosen
deposits. Some
manufacturers
recommend using
diluted household
bleach for cleaning
and maintenance,
generally in a
solution of one-half
cup bleach to one
gallon water. When
using any household
chemical, rinse well
to remove all traces
of chemical before
refilling
humidifier.
-
Empty dehumidifiers
daily and clean
often. If possible,
have the appliance
drip directly into a
drain. Follow
manufacturer's
instructions for
cleaning and
maintenance. Always
disconnect the
appliance before
cleaning.
-
Clean refrigerator
drip pans regularly
according to
manufacturer's
instructions. If
refrigerator and
freezer doors don't
seal properly,
moisture may build
up and mold can
grow. Remove any
mold on door gaskets
and replace faulty
gaskets.
-
Clean mold surfaces,
such as showers and
kitchen counters.
-
Remove mold from
walls, ceilings,
floors, and
paneling. Do not
simply cover mold
with paint, stain,
varnish, or a
moisture-proof
sealer, as it may
resurface.
-
Replace moldy shower
curtains, or remove
them and scrub well
with a household
cleaner and rinse
before re-hanging
them.
Controlling dust is very
important for people who
are allergic to animal
dander and mites. You
cannot see mites, but
you can either remove
their favorite breeding
grounds or keep these
areas dry and clean.
Dust mites can thrive in
sofas, stuffed chairs,
carpets, and bedding.
Open shelves, fabric
wallpaper, knickknacks,
and venetian blinds are
also sources of dust
mites. Dust mites live
deep in the carpet and
are not removed by
vacuuming. Many doctors
suggest that their
mite-allergic patients
use washable area rugs
rather than wall-to-wall
carpet.
-
Always wash bedding
in hot water (at
least 130° F "one
hundred degrees
Fahrenheit") to kill
dust mites. Cold
water won't do the
job. Launder bedding
at least every 7 to
10 days.
-
Use synthetic or
foam rubber mattress
pads and pillows,
and plastic mattress
covers if you are
allergic. Do not use
fuzzy wool blankets,
feather or
wool-stuffed
comforters, and
feather pillows.
-
Clean rooms and
closets well; dust
and vacuum often to
remove surface dust.
Vacuuming and other
cleaning may not
remove all animal
dander, dust mite
material, and other
biological
pollutants. Some
particles are so
small they can pass
through vacuum bags
and remain in the
air. If you are
allergic to dust,
wear a mask when
vacuuming or
dusting. People who
are highly
allergy-prone should
not perform these
tasks. They may even
need to leave the
house when someone
else is cleaning.
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Protect yourself by
inspecting your
potential new home. If
you identify problems,
have the landlord or
seller correct them
before you move in, or
even consider moving
elsewhere.
-
Have professionals
check the heating
and cooling system,
including
humidifiers and
vents. Have duct
lining and
insulation checked
for growth.
-
Check for exhaust
fans in bathrooms
and kitchens. If
there are no vents,
do the kitchen and
bathrooms have at
least one window
apiece? Does the
cooktop have a hood
vented outside? Does
the clothes dryer
vent outside? Are
all vents to the
outside of the
building, not into
attics or
crawlspaces?
-
Look for obvious
mold growth
throughout the
house, including
attics, basements,
and crawlspaces, and
around the
foundation. See if
there are many
plants close to the
house, particularly
if they are damp and
rotting. They are a
potential source of
biological
pollutants.
Downspouts from roof
gutters should route
water away from the
building.
-
Look for stains on
the walls, floor or
carpet (including
any carpet over
concrete floors) as
evidence of previous
flooding or moisture
problems. Is there
moisture on windows
and surfaces? Are
there signs of leaks
or seepage in the
basement?
-
Look for rotted
building materials
which may suggest
moisture or water
damage.
-
If you or anyone
else in the family
has a pet allergy,
ask if any pets have
lived in the home.
-
Examine the design
of the building.
Remember that in
cold climates,
overhanging areas,
rooms over unheated
garages, and closets
on outside walls may
be prone to problems
with biological
pollutants.
-
Look for signs of
cockroaches.
-
Dirty air conditioners
-
Dirty humidifiers and/or
dehumidifiers
-
Bathroom without vents
or windows
-
Kitchen without vents or
windows
-
Dirty refrigerator drip
pans
-
Laundry room with
unvented dryer
-
Unventilated attic
-
Carpet on damp basement
floor
-
Bedding
-
Closet on outside wall
-
Dirty heating/air
conditioning system
-
dogs or cats
-
Water damage (around
windows, the roof, or
the basement)
Warning! Carefully read
instructions for use and any
cautionary labeling on
cleaning products before
beginning cleaning
procedures.
-
Do not mix any chemical
products. Especially,
never mix cleaners
containing bleach with
any product (such as
ammonia) which does not
have instructions for
such mixing. When
chemicals are combined,
a dangerous gas can
sometimes be formed.
-
Household chemicals may
cause burning or
irritation to skin and
eyes.
-
Household chemicals may
be harmful if swallowed,
or inhaled.
-
Avoid contact with skin,
eyes, mucous membranes
and clothing.
-
Avoid breathing vapor.
Open all windows and
doors and use an exhaust
fan that sends the air
outside.
-
Keep household chemicals
out of reach of
children.
-
Rinse treated surface
areas well to remove all
traces of chemicals.
What if damage is already
done? Follow these
guidelines for correcting
water damage:
-
Throw out mattresses,
wicker furniture, straw
baskets and the like
that have been water
damaged or contain mold.
These cannot be
recovered.
-
Discard any
water-damaged
furnishings such as
carpets, drapes, stuffed
toys, upholstered
furniture and ceiling
tiles, unless they can
be recovered by steam
cleaning or hot water
washing and thorough
drying.
-
Remove and replace wet
insulation to prevent
conditions where
biological pollutants
can grow.
Contact your local
American Lung
Association for
copies of: Indoor Air
Pollution Fact Sheets,
Air Pollution in Your
Home? and other
publications on indoor
air pollution.
Contact the
U.S. Consumer Product
Safety Commission,
Washington, D.C. 20207,
for copies of
Humidifier Safety Alert.
To report an unsafe
consumer product or
product-related health
problem, consumers may
call the U.S. Consumer
Product Safety
Commission at
1-800-638-2772. A
teletypewriter for the
hearing impaired is
available at
1-800-638-8270; the
Maryland TTY number is
1-800-492-8104.
You may also contact
EPA's IAQ INFO
Clearinghouse at
1-800-438-4318 (or (703)
356-4020) for more
information on indoor
air quality and to order
publications from the
list of
IAQ publications.
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