The Inside Story, A Guide To Indoor Air Quality

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A Guide To Indoor Air Quality


Air Pollution Sources in the Home

Indoor Air Quality in Your Home
What If You Live in an Apartment?
Improving the Air Quality in Your Home
A Look at Source-Specific Controls
Environmental Tobacco Smoke
Biological Contaminants
Stoves, Heaters, Fireplaces, and Chimneys
Household Products
Reference Guide to Major Indoor Air Pollutants in the Home
When Building a New Home
Do You Suspect Your Office Has an Indoor Air Problem?
Where to Go for Additional Information


1. Moisture
2. Pressed Wood Furniture
3. Humidifier
4. Moth Repellents
5. Dry-Cleaned Goods
6. House Dust Mites
7. Personal Care Products
8. Air Freshener
9. Stored Fuels
10. Car Exhaust
11. Paint Supplies
12. Panelling
13. Wood Stove
14. Tobacco Smoke
15. Carpets
16. Pressed Wood Sub flooring
17. Drapes
18. Fireplace
19. Household Chemicals
20. Asbestos Floor Tiles
21. Pressed Wood Cabinets
22. Unvented Gas Stove
23. Asbestos Pipe Wrap
24. Radon
25. Unvented Clothes Dryer
26. Pesticides
27. Stored Hobby Products
28. Lead-Based Paint


All of us face a variety of risks to our health as we go about our day
to day lives. Driving in cars, flying in planes, engaging in recreational
activities, and being exposed to environmental pollutants all pose varying
degrees of risk. Some risks are simply unavoidable. Some we choose to accept
because to do otherwise would restrict our ability to lead our lives the way
we want. And some are risks we might decide to avoid if we had the
opportunity to make informed choices. Indoor air pollution is one risk that
you can do something about.

In the last several years, a growing body of scientific evidence has
indicated that the air within homes and other buildings can be more seriously
polluted than the outdoor air in even the largest and most industrialised
cities. Other research indicates that people spend approximately 90 percent
of their time indoors. Thus, for many people, the risks to health may be
greater due to exposure to air pollution indoors than outdoors.

In addition, people who may be exposed to indoor air pollutants for the
longest periods of time are often those most susceptible to the effects of
indoor air pollution. Such groups include the young, the elderly, and the chronically
ill, especially those suffering from respiratory or cardiovascular disease.


While pollutant levels from individual sources may not pose a
significant health risk by themselves, most homes have more than one source
that contributes to indoor air pollution. There can be a serious risk from
the cumulative effects of these sources. Fortunately, there are steps that
most people can take both to reduce the risk from existing sources and to
prevent new problems from occurring.

This booklet was prepared by the U.S. Environmental Protection Agency
(EPA) and the U.S. Consumer Product Safety Commission (CPSC) to help you
decide whether to take actions that can reduce the level of indoor air
pollution in your own home.

Because so many Americans spend a lot of time in offices with
mechanical heating, cooling, and ventilation systems, there is also a short
section on the causes of poor air quality in offices and what you can do if
you suspect that your office may have a problem. A glossary and a list of
organisations where you can get additional information are listed at the back
of this booklet.


Indoor pollution sources that release gases or particles into the air
are the primary cause of indoor air quality problems in homes. Inadequate
ventilation can increase indoor pollutant levels by not bringing in enough
outdoor air to dilute emissions from indoor sources and by not carrying
indoor air pollutants out of the home. High temperature and humidity levels
can also increase concentrations of some pollutants.

Pollutant Sources
There are many sources of indoor air pollution in any home. These include
combustion sources such as oil, gas, kerosene, coal, wood, and tobacco
products; building materials and furnishings as diverse as deteriorated,
asbestos containing insulation, wet or damp carpet, and cabinetry or
furniture made of certain pressed wood products; products for household
cleaning and maintenance, personal care, or hobbies; central heating and cooling
systems and humidification devices; and outdoor sources such as radon,
pesticides, and outdoor air pollution.

The relative importance of any single source depends on how much of a
given pollutant it emits and how hazardous those emissions are. In some
cases, factors such as how old the source is and whether it is properly
maintained are significant. For example, an improperly adjusted gas stove can
emit significantly more carbon monoxide than one that is properly adjusted.
Some sources, such as building materials, furnishings, and household products
like air fresheners, release pollutants more or less continuously.

Other sources, related to activities carried out in the home, release
pollutants intermittently. These include smoking, the use of unvented or
malfunctioning stoves, furnaces, or space heaters, the use of solvents in
cleaning and hobby activities, the use of paint strippers in redecorating
activities, and the use of cleaning products and pesticides in housekeeping.
High pollutant concentrations can remain in the air for long periods after
some of these activities.

Amount of Ventilation
If too little outdoor air enters a home, pollutants can accumulate o levels
that can pose health and comfort problems. Unless they are built with special
mechanical means of ventilation, homes that are designed and constructed to
minimise the amount of outdoor air that can leak into and out of the home may
have higher pollutant levels than other homes. However, because some weather
conditions can drastically reduce the amount of outdoor air that enters a
home, pollutants can build up even in homes that are normally considered


Outdoor air enters and leaves a house by: infiltration, natural
ventilation, and mechanical ventilation. In a process known as infiltration,
outdoor air flows into the house through openings, joints, and cracks in
walls, floors, and ceilings, and around windows and doors. In natural
ventilation, air moves through opened windows and doors. Air movement
associated with infiltration and natural ventilation is caused by air
temperature differences between indoors and outdoors and by wind.

Finally, there are a number of mechanical ventilation devices, from
outdoor vented fans that intermittently remove air from a single room, such
as bathrooms and kitchen, to air handling systems that use fans and duct work
to continuously remove indoor air and distribute filtered and conditioned
outdoor air to strategic points throughout the house. The rate at which outdoor
air replaces indoor air is described as the air exchange rate. When there is
little infiltration, natural ventilation, or mechanical ventilation, the air
exchange rate is low and pollutant levels can increase.


Apartments can have the same indoor air problems as single family homes
because many of the pollution sources, such as the interior building
materials, furnishings, and household products, are similar. Indoor air
problems similar to those in offices are caused by such sources as
contaminated ventilation systems, improperly placed outdoor air intakes, or
maintenance activities.

Solutions to air quality problems in apartments, as in homes and
offices, involve such actions as: eliminating or controlling the sources of
pollution, increasing ventilation, and installing air cleaning devices. Often
a resident can take the appropriate action to improve the indoor air quality
by removing a source, altering an activity, unblocking an air supply vent, or
opening a window to temporarily increase the ventilation; in other cases,
however, only the building owner or manager is in a position to remedy the

(See the section What to Do If You Suspect a Problem on page 30.) You
can encourage building management to follow guidance in EPA and NIOSH s
Building Air Quality: A Guide for Building Owners and Facility Managers. It
is available for $24 from the

Superintendent of Documents,
P.O. Box 371954,
PA 152507954;
stock # 055000003904.


Health effects from indoor air pollutants may be experienced soon after
exposure or, possibly, years later.

Immediate effects may show up after a single exposure or repeated
exposures. These include irritation of the eyes, nose, and throat, headaches,
dizziness, and fatigue. Such immediate effects are usually short term and
treatable. Sometimes the treatment is simply eliminating the persons exposure
to the source of the pollution, if it can be identified. Symptoms of some
diseases, including asthma, hypersensitivity pneumonitis, and humidifier
fever, may also show up soon after exposure to some indoor air pollutants.

The likelihood of immediate reactions to indoor air pollutants depends
on several factors. Age and pre existing medical conditions are two important
influences. In other cases, whether a person reacts to a pollutant depends on
individual sensitivity, which varies tremendously from person to person. Some
people can become sensitised to biological pollutants after repeated exposures,
and it appears that some people can become sensitised to chemical pollutants
as well.

Certain immediate effects are similar to those from colds or other
viral diseases, so it is often difficult to determine if the symptoms are a
result of exposure to indoor air pollution. For this reason, it is important
to pay attention to the time and place the symptoms occur. If the symptoms
fade or go away when a person is away from the home and return when the
person returns, an effort should be made to identify indoor air sources that
may be possible causes. Some effects may be made worse by an inadequate
supply of outdoor air or from the heating, cooling, or humidity conditions
prevalent in the home.

Other health effects may show up either years after exposure has
occurred or only after long or repeated periods of exposure. These effects,
which include some respiratory diseases, heart disease, and cancer, can be
severely debilitating or fatal. It is prudent to try to improve the indoor
air quality in your home even if symptoms are not noticeable. More
information on potential health effects from particular indoor air pollutants
is provided in the section, A Look at Source Specific Controls.

While pollutants commonly found in indoor air are responsible for many
harmful effects, there is considerable uncertainty about what concentrations
or periods of exposure are necessary to produce specific health problems.
People also react very differently to exposure to indoor air pollutants.
Further research is needed to better understand which health effects occur
after exposure to the average pollutant concentrations found in homes and
which occur from the higher concentrations that occur for short periods of

The health effects associated with some indoor air pollutants are
summarised in the chart in the middle of this booklet titled Reference Guide
to Major Indoor Air Pollutants in the Home.


Some health effects can be useful indicators of an indoor air quality
problem, especially if they appear after a person moves to a new residence,
remodels or re furnishes a home, or treats a home with pesticides. If you
think that you have symptoms that may be related to your home environment,
discuss the with your doctor or your local health department to see if they
could be caused by indoor air pollution. You may also want to consult a board
certified allergist or an occupational medicine specialist for answers to
your questions.

Another way to judge whether your home has or could develop indoor air
problems is to identify potential sources of indoor air pollution. Although
the presence of such sources (see illustration at the beginning of this
booklet) does not necessarily mean that you have an indoor air quality
problem, being aware of the type and number of potential sources is an
important step toward assessing the air quality in your home.

A third way to decide whether your home may have poor indoor air
quality is to look at your lifestyle and activities. Human activities can be
significant sources of indoor air pollution. Finally, look for signs of
problems with the ventilation in your home. Signs that can indicate your home
may not have enough ventilation include moisture condensation on windows or
walls, smelly or stuffy air, dirty central heating and air cooling equipment,
and areas where books, shoes, or other items become mouldy. To detect odours
in your home, step outside for a few minutes, and then upon re entering your
home, note whether odours are noticeable.


The federal government recommends that you measure the level of radon
in your home. Without measurements there is no way to tell whether radon is
present because it is a colourless, odourless, radioactive gas. Inexpensive
devices are available for measuring radon. EPA provides guidance as to risks
associated with different levels of exposure and when the public should
consider corrective action. There are specific mitigation techniques that
have proven effective in reducing levels of radon in the home. (See Radon
section on p. 11 of this booklet for additional information about testing and
controlling radon in homes.)

For pollutants other than radon, measurements are most appropriate when
there are either health symptoms or signs of poor ventilation and specific
sources or pollutants have been identified as possible causes of indoor air
quality problems. Testing for many pollutants can be expensive. Before
monitoring your home for pollutants besides radon, consult your state or
local health department or professionals who have experience in solving
indoor air quality problems in non industrial buildings.


The federal government recommends that homes be weatherized in order to
reduce the amount of energy needed for heating and cooling. While
weatherization is underway, however, steps should also be taken to minimise
pollution from sources inside the home. (See Improving the Air Quality in
Your Home for recommended actions.) In addition, residents should be alert to
the emergence of signs of inadequate ventilation, such as stuffy air,
moisture condensation on cold surfaces, or mould and mildew growth.
Additional weatherization measures should not be undertaken until these
problems have been corrected.

Weatherization generally does not cause indoor air problems by adding
new pollutants to the air. (There are a few exceptions, such as caulking,
that can sometimes emit pollutants.) However, measures such as installing
storm windows, weather stripping, caulking, and blown in wall insulation can
reduce the amount of outdoor air infiltrating into a home. Consequently,
after weatherization, concentrations of indoor air pollutants from sources
inside the home can increase.


Source Control

Usually the most effective way to improve indoor air quality is to
eliminate individual sources of pollution or to reduce their emissions. Some
sources, like those that contain asbestos, can be sealed or enclosed; others,
like gas stoves, can be adjusted to decrease the amount of emissions. In many
cases, source control is also a more cost efficient approach to protecting
indoor air quality than increasing ventilation because increasing ventilation
can increase energy costs. Specific sources of indoor air pollution in your
home are listed later in this section.

Ventilation Improvements

Another approach to lowering the concentrations of indoor air
pollutants in your home is to increase the amount of outdoor air coming
indoors. Most home heating and cooling systems, including forced air heating
systems, do not mechanically bring fresh air into the house. Opening windows
and doors, operating window or attic fans, when the weather permits, or
running a window air conditioner with the vent control open increases the
outdoor ventilation rate. Local bathroom or kitchen fans that exhaust
outdoors remove contaminants directly from the room where the fan is located
and also increase the outdoor air ventilation rate.

It is particularly important to take as many of these steps as possible
while you are involved in short-term activities that can generate high levels
of pollutants for example, painting, paint stripping, heating with kerosene
heaters, cooking, or engaging in maintenance and hobby activities such as
welding, soldering, or sanding. You might also choose to do some of these
activities outdoors, if you can and if weather permits.

Advanced designs of new homes are starting to feature mechanical
systems that bring outdoor air into the home. Some of these designs include
energy efficient heat recovery ventilators (also known as air-to-air heat
exchangers). For more information about air-to-air heat exchangers, contact

Conservation and Renewable Energy Inquiry and Referral Service
(CAREIRS), PO Box 3048,
Merrifield, VA 22116;
(800) 5232929.

Air Cleaners

There are many types and sizes of air cleaners on the market, ranging
from relatively inexpensive tabletop models to sophisticated and expensive
whole house systems. Some air cleaners are highly effective at particle
removal, while others, including most tabletop models, are much less so. Air
cleaners are generally not designed to remove gaseous pollutants.

The effectiveness of an air cleaner depends on how well it collects
pollutants from indoor air (expressed as a percentage efficiency rate) and
how much air it draws through the cleaning or filtering element (expressed in
cubic feet per minute). A very efficient collector with a low air circulation
rate will not be effective, nor will a cleaner with a high air circulation
rate but a less efficient collector. The long term performance of any air
cleaner depends on maintaining it according to the manufacturer s directions.

Another important factor in determining the effectiveness of an air
cleaner is the strength of the pollutant source. Tabletop air cleaners, in
particular, may not remove satisfactory amounts of pollutants from strong
nearby sources. People with a sensitivity to particular sources may find that
air cleaners are helpful only in conjunction with concerted efforts to remove
the source.

Over the past few years, there has been some publicity suggesting that
house plants have been shown to reduce levels of some chemicals in laboratory
experiments. There is currently no evidence, however, that a reasonable
number of house plants remove significant quantities of pollutants in homes
and offices. Indoor house plants should not be over watered because overly
damp soil may promote the growth of micro organisms which can affect allergic

At present, EPA does not recommend using air cleaners to reduce levels
of radon and its decay products. The effectiveness of these devices is
uncertain because they only partially remove the radon decay products and do
not diminish the amount of radon entering the home. EPA plans to do
additional research on whether air cleaners are, or could become, a reliable
means of reducing the health risk from radon. EPA s booklet, Residential Air
Cleaning Devices, provides further information on air cleaning devices to
reduce indoor air pollutants

For most indoor air quality problems in the home, source control is the
most effective solution. This section takes a source by source look at the
most common indoor air pollutants, their potential health effects, and ways
to reduce levels in the home. (For a summary of the points made in this
section, see the chart in the middle of this booklet titled Reference Guide
to Major Indoor Air Pollutants in the Home. )


The most common source of indoor radon is uranium in the soil or rock
on which homes are built. As uranium naturally breaks down, it releases radon
gas which is a colourless, odourless, radioactive gas. Radon gas enters homes
through dirt floors, cracks in concrete walls and floors, floor drains, and
sumps. When radon become strapped in buildings and concentrations build up
indoors, exposure to radon becomes a concern.

Any home may have a radon problem. This means new and old homes, well
sealed and drafty homes, and homes with or without basements.

Sometimes radon enters the home through well water. In a small number
of homes, the building materials can give off radon, too. However, building
materials rarely cause radon problems by themselves.

Health Effects of Radon

The predominant health effect associated with exposure to elevated
levels of radon is lung cancer. Research suggests that swallowing water with
high radon levels may pose risks, too, although these are believed to be much
lower than those from breathing air containing radon. Major health
organisations (like the Centres for Disease Control and Prevention, the
American Lung Association (ALA), and the American Medical Association) agree
with estimates that radon causes thousands of preventable lung cancer deaths
each year. EPA estimates that radon causes about 14,000 deaths per year in
the United States however, this number could range from 7,000 to 30,000
deaths per year. If you smoke and your home has high radon levels, your risk
of lung cancer is especially high.

Reducing Exposure to Radon in Homes

Measure levels of radon in your home.

You can t see radon, but it s not hard to find out if you have a radon
problem in your home. Testing is easy and should only take a little of your

There are many kinds of inexpensive, do-it-yourself radon test kits you
can get through the mail and in hardware stores and other retail outlets.
Make sure you buy a test kit that has passed EPA s testing program or is
state certified. These kits will usually display the phrase Meets EPA Requirements.
If you prefer, or if you are buying or selling a home, you can hire a trained
contractor to do the testing for you.

The EPA Radon Measurement Proficiency (RMP) Program evaluates testing
contractors. A contractor who has met EPA s requirements will carry a special
RMP identification card. EPA provides a list of companies and individual
contractors to state radon offices. You can call your state radon office to
obtain a list of qualified contractors in your area (call 800-SOS-RADON for a
list of state radon offices).

Refer to the EPA guidelines on how to test and interpret your test

You can learn more about radon through EPA s publications, A Citizen s
Guide to Radon: The Guide to Protecting Yourself and Your Family From Radon
and Home Buyer s and Seller s Guide to Radon, which are available from state
radon offices.

Learn about radon reduction methods.

Ways to reduce radon in your home are discussed in EPA s Consumer s
Guide to Radon Reduction. You can get a copy from your state radon office.
There are simple solutions to radon problems in homes. Thousands of
homeowners have already fixed radon problems. Lowering high radon levels
requires technical knowledge and special skills. You should use a contractor
who is trained to fix radon problems.

The EPA Radon Contractor Proficiency (RCP) Program tests these
contractors. EPA provides a list of RCP contractors to state radon offices. A
contractor who is listed by EPA will carry a special RCP identification card.
A trained RCP contractor can study the problem in your home and help you pick
the correct treatment method. Check with your state radon office for names of
qualified or state certified radon reduction contractors in your area.

Stop smoking and discourage smoking in your home.

Scientific evidence indicates that smoking combined with radon is an
especially serious health risk. Stop smoking and lower your radon level to
reduce lung cancer risk.

Treat radon contaminated well water.

While radon in water is not a problem in homes served by most public
water supplies, it has been found in well water. If you've tested the air in
your home and found a radon problem, and you have a well, contact a lab
certified to measure radiation in water to have your water tested. Radon
problems in water can be readily fixed. Call your state radon office or the
EPA Drinking Water Hot line (8004264791) for more information.


Environmental tobacco smoke (ETS) is the mixture of smoke that comes
from the burning end of a cigarette, pipe, or cigar, and smoke exhaled by the
smoker. It is a complex mixture of over 4,000 compounds, more than 40 of
which are known to cause cancer in humans or animals and many of which are
strong irritants. ETS is often referred to as second hand smoke and exposure
to ETS is often called passive smoking.

Health Effects of Environmental Tobacco Smoke

In 1992, EPA completed a major assessment of the respiratory health
risks of ETS (Respiratory Health Effects of Passive Smoking: Lung Cancer and
Other Disorders EPA/600/690/006F). The report concludes that exposure to ETS
is responsible for approximately 3,000 lung cancer deaths each year in
non-smoking adults and impairs the respiratory health of hundreds of
thousands of children.

Infants and young children whose parents smoke in their presence are at
increased risk of lower respiratory tract infections (pneumonia and
bronchitis) and are more likely to have symptoms of respiratory irritation
like cough, excess phlegm, and wheeze. EPA estimates that passive smoking
annually causes between 150,000 and 300,000 lower respiratory tract
infections in infants and children under 18 months of age, resulting in
between 7,500 and 15,000 hospitalisations each year. These children may also
have a build up of fluid in the middle ear, which can lead to ear infections.
Older children who have been exposed to second hand smoke may have slightly
reduced lung function.

Asthmatic children are especially at risk. EPA estimates that exposure
to second hand smoke increases the number of episodes and severity of
symptoms in hundreds of thousands of asthmatic children, and may cause
thousands of non-asthmatic children to develop the disease each year. EPA
estimates that between 200,000 and 1,000,000 asthmatic children have their
condition made worse by exposure to second hand smoke each year.

Exposure to second hand smoke causes eye, nose, and throat irritation.
It may affect the cardiovascular system and some studies have linked exposure
to second hand smoke with the onset of chest pain. For publications about
ETS, contact EPA s Indoor Air Quality Information Clearinghouse (IAQ-INFO),

Reducing Exposure to Environmental Tobacco Smoke

Don t smoke at home or permit others to do so. Ask smokers to smoke

The 1986 Surgeon General s report concluded that physical separation of
smokers and non smokers in a common air space, such as different rooms within
the same house, may reduce but will not eliminate non smokers exposure to
environmental tobacco smoke.

If smoking indoors cannot be avoided, increase ventilation in the area
where smoking takes place.

Open windows or use exhaust fans. Ventilation, a common method of
reducing exposure to indoor air pollutants, also will reduce but not eliminate
exposure to environmental tobacco smoke. Because smoking produces such large
amounts of pollutants, natural or mechanical ventilation techniques do not
remove them from the air in your home as quickly as they build up. In
addition, the large increases in ventilation it takes to significantly reduce
exposure to environmental tobacco smoke can also increase energy costs
substantially. Consequently, the most effective way to reduce exposure to
environmental tobacco smoke in the home is to eliminate smoking there.

Do not smoke if children are present, particularly infants and

Children are particularly susceptible to the effects of passive
smoking. Do not allow baby sitters or others who work in your home to smoke
indoors. Discourage others from smoking around children. Find out about the
smoking policies of the day care centre providers, schools, and other care
givers for your children. The policy should protect children from exposure to


Biological contaminants include bacteria, moulds, mildew, viruses,
animal dander and cat saliva, house dust mites, cockroaches, and pollen.
There are many sources of these pollutants. Pollens originate from plants;
viruses are transmitted by people and animals; bacteria are carried by people,
animals, and soil and plant debris; and household pets are sources of saliva
and animal dander. The protein in urine from rats and mice is a potent
allergen. When it dries, it can become airborne. Contaminated central air
handling systems can become breeding grounds for mould, mildew, and other
sources of biological contaminants and can then distribute these contaminants
through the home.

By controlling the relative humidity level in a home, the growth of
some sources of biologicals can be minimised. A relative humidity of 3050
percent is generally recommended for homes. Standing water, water-damaged
materials, or wet surfaces also serve as a breeding ground for moulds,
mildews, bacteria, and insects. House dust mites, the source of one of the
most powerful biological allergens, grow in damp, warm environments.

Health Effects From Biological Contaminants

Some biological contaminants trigger allergic reactions, including
hypersensitivity pneumonitis, allergic rhinitis, and some types of asthma.
Infectious illnesses, such as influenza, measles, and chicken pox are
transmitted through the air. Moulds and mildews release disease causing
toxins. Symptoms of health problems caused by biological pollutants include
sneezing, watery eyes, coughing, shortness of breath, dizziness, lethargy,
fever, and digestive problems.

Allergic reactions occur only after repeated exposure to a specific
biological allergen. However, that reaction may occur immediately upon
re-exposure or after multiple exposures over time. As a result, people who
have noticed only mild allergic reactions, or no reactions at all, may
suddenly find themselves very sensitive to particular allergens.

Some diseases, like humidifier fever, are associated with exposure to
toxins from micro organisms that can grow in large building ventilation
systems. However, these diseases can also be traced to micro organisms that
grow in home heating and cooling systems and humidifiers. Children, elderly
people, and people with breathing problems, allergies, and lung diseases are
particularly susceptible to disease causing biological agents in the indoor

Reducing Exposure to Biological Contaminants

Install and use exhaust fans that are vented to the outdoors in
kitchens and bathrooms and vent clothes dryers outdoors.

These actions can eliminate much of the moisture that builds up from
everyday activities. There are exhaust fans on the market that produce little
noise, an important consideration for some people. Another benefit to using
kitchen and bathroom exhaust fans is that they can reduce levels of organic
pollutants that vaporise from hot water used in showers and dishwashers.

Ventilate the attic and crawl spaces to prevent moisture build up.

Keeping humidity levels in these areas below 50 percent can prevent
water condensation on building materials.

If using cool mist or ultrasonic humidifiers, clean appliances
according to manufacturer s instructions and refill with fresh water daily.

Because these humidifiers can become breeding grounds for biological
contaminants, they have the potential for causing diseases such as
hypersensitivity pneumonitis and humidifier fever. Evaporation trays in air
conditioners, dehumidifiers, and refrigerators should also be cleaned

Thoroughly clean and dry water-damaged carpets and building materials
(within 24 hours if possible) or consider removal and replacement.

Water-damaged carpets and building materials can harbour mould and
bacteria. It is very difficult to completely rid such materials of biological

Keep the house clean. House dust mites, pollens, animal dander, and
other allergy causing agents can be reduced, although not eliminated, through
regular cleaning.

People who are allergic to these pollutants should use allergen proof
mattress encasements, wash bedding in hot (130 F) water, and avoid room
furnishings that accumulate dust, especially if they cannot be washed in hot
water. Allergic individuals should also leave the house while it is being
vacuumed because vacuuming can actually increase airborne levels of mite
allergens and other biological contaminants. Using central vacuum systems
that are vented to the outdoors or vacuums with high efficiency filters may
also be of help.

Take steps to minimise biological pollutants in basements.

Clean and disinfect the basement floor drain regularly. Do not finish a
basement below ground level unless all water leaks are patched and outdoor
ventilation and adequate heat to prevent condensation are provided. Operate a
dehumidifier in the basement if needed to keep relative humidity levels
between 30 50 percent.

To learn more about biological pollutants, read Biological Pollutants
in Your Home issued by the U.S. Consumer Product Safety Commission and the
American Lung Association. For contact information, see the section, Where to
Go For Additional Information.


In addition to environmental tobacco smoke, other sources of combustion
products are unvented kerosene and gas space heaters, wood stoves,
fireplaces, and gas stoves. The major pollutants released are carbon
monoxide, nitrogen dioxide, and particles. Unvented kerosene heaters may also
generate acid aerosols.

Combustion gases and particles also come from chimneys and flues that
are improperly installed or maintained and cracked furnace heat exchangers.
Pollutants from fireplaces and wood stoves with no dedicated outdoor air
supply can be back drafted from the chimney into the living space, particularly
in weatherized homes.

Health Effects of Combustion Products

Carbon monoxide is a colourless, odourless gas that interferes with the
delivery of oxygen throughout the body. At high concentrations it can cause
unconsciousness and death. Lower concentrations can cause a range of symptoms
from headaches, dizziness, weakness, nausea, confusion, and disorientation,
to fatigue in healthy people and episodes of increased chest pain in people
with chronic heart disease. The symptoms of carbon monoxide poisoning are
sometimes confused with the flu or food poisoning. Foetuses, infants, elderly
people, and people with anaemia or with a history of heart or respiratory
disease can be especially sensitive to carbon monoxide exposures.

Nitrogen dioxide is a colourless, odourless gas that irritates the
mucous membranes in the eye, nose, and throat and causes shortness of breath
after exposure to high concentrations. There is evidence that high
concentrations or continued exposure to low levels of nitrogen dioxide increases
the risk of respiratory infection; there is also evidence from animal studies
that repeated exposures to elevated nitrogen dioxide levels may lead, or
contribute, to the development of lung disease such as emphysema. People at
particular risk from exposure to nitrogen dioxide include children and
individuals with asthma and other respiratory diseases.

Particles, released when fuels are incompletely burned, can lodge in
the lungs and irritate or damage lung tissue. A number of pollutants,
including radon and benzo(a)pyrene, both of which can cause cancer, attach to
small particles that are inhaled and then carried deep into the lung.

Reducing Exposure to Combustion Products in Homes

Take special precautions when operating fuel burning unvented space

Consider potential effects of indoor air pollution if you use an
unvented kerosene or gas space heater. Follow the manufacturer s directions,
especially instructions on the proper fuel and keeping the heater properly
adjusted. A persistent yellow tipped flame is generally an indicator of
maladjustment and increased pollutant emissions. While a space heater is in
use, open a door from the room where the heater is located to the rest of the
house and open a window slightly.

Install and use exhaust fans over gas cooking stoves and ranges and
keep the burners properly adjusted.

Using a stove hood with a fan vented to the outdoors greatly reduces
exposure to pollutants during cooking. Improper adjustment, often indicated
by a persistent yellow tipped flame, causes increased pollutant emissions.
Ask your gas company to adjust the burner so that the flame tip is blue. If
you purchase a new gas stove or range, consider buying one with pilot less
ignition because it does not have a pilot light that burns continuously.
Never use a gas stove to heat your home. Always make certain the flue in your
gas fireplace is open when the fireplace is in use.

Keep wood stove emissions to a minimum. Choose properly sized new
stoves that are certified as meeting EPA emission standards.

Make certain that doors in old wood stoves are tight fitting. Use aged
or cured (dried) wood only and follow the manufacturer s directions for
starting, stoking, and putting out the fire in wood stoves. Chemicals are
used to pressure treat wood; such wood should never be burned indoors.
(Because some old gaskets in wood stove doors contain asbestos, when
replacing gaskets refer to the instructions in the CPSC, ALA, and EPA
booklet, Asbestos in Your Home, to avoid creating an asbestos problem. New
gaskets are made of Fibreglass.)

Have central air handling systems, including furnaces, flues, and
chimneys, inspected annually and promptly repair cracks or damaged parts.

Blocked, leaking, or damaged chimneys or flues release harmful
combustion gases and particles and even fatal concentrations of carbon
monoxide. Strictly follow all service and maintenance procedures recommended
by the manufacturer, including those that tell you how frequently to change
the filter. If manufacturer s instructions are not readily available, change
filters once every month or two during periods of use. Proper maintenance is
important even for new furnaces because they can also corrode and leak
combustion gases, including carbon monoxide. Read the booklet What You Should
Know About Combustion Appliances and Indoor Air Pollution to learn more about
combustion pollutants. The booklet is available by contacting CPSC, EPA s IAQ
INFO Clearinghouse, or your local ALA. (See Where to Go for Additional
Information for contact information.)


Organic chemicals are widely used as ingredients in household products.
Paints, varnishes, and wax all contain organic solvents, as do many cleaning,
disinfecting, cosmetic, decreasing, and hobby products. Fuels are made up of
organic chemicals. All of these products can release organic compounds while
you are using them, and, to some degree, when they are stored.

EPA s Total Exposure Assessment Methodology (TEAM) studies found levels
of about a dozen common organic pollutants to be 2 to 5 times higher inside
homes than outside, regardless of whether the homes were located in rural or
highly industrial areas. Additional TEAM studies indicate that while people
are using products containing organic chemicals, they can expose themselves
and others to very high pollutant levels, and elevated concentrations can
persist in the air long after the activity is completed.

Health Effects of Household Chemicals

The ability of organic chemicals to cause health effects varies greatly
from those that are highly toxic, to those with no known health effect. As
with other pollutants, the extent and nature of the health effect will depend
on many factors including level of exposure and length of time exposed. Eye
and respiratory tract irritation, headaches, dizziness, visual disorders, and
memory impairment are among the immediate symptoms that some people have
experienced soon after exposure to some organics. At present, not much is
known about what health effects occur from the levels of organics usually
found in homes. Many organic compounds are known to cause cancer in animals;
some are suspected of causing, or are known to cause, cancer in humans.

Reducing Exposure to Household Chemicals

Follow label instructions carefully.

Potentially hazardous products often have warnings aimed at reducing
exposure of the user. For example, if a label says to use the product in a
well ventilated area, go outdoors or in areas equipped with an exhaust fan to
use it. Otherwise, open up windows to provide the maximum amount of outdoor
air possible.

Throw away partially full containers of old or unneeded chemicals

Because gases can leak even from closed containers, this single step
could help lower concentrations of organic chemicals in your home. (Be sure
that materials you decide to keep are stored not only in a well ventilated
area but are also safely out of reach of children.) Do not simply toss these
unwanted products in the garbage can. Find out if your local government or
any organisation in your community sponsors special days for the collection
of toxic household wastes. If such days are available, use them to dispose of
the unwanted containers safely. If no such collection days are available,
think about organising one.

Buy limited quantities.

If you use products only occasionally or seasonally, such as paints,
paint strippers, and kerosene for space heaters or gasoline for lawn mowers,
buy only as much as you will use right away.

Keep exposure to emissions from products containing methylene chloride
to a minimum.

Consumer products that contain methylene chloride include paint
strippers, adhesive removers, and aerosol spray paints. Methylene chloride is
known to cause cancer in animals. Also, methylene chloride is converted to
carbon monoxide in the body and can cause symptoms associated with exposure
to carbon monoxide. Carefully read the labels containing health hazard
information and cautions on the proper use of these products. Use products
that contain methylene chloride outdoors when possible; use indoors only if
the area is well ventilated.

Keep exposure to benzene to a minimum.

Benzene is a known human carcinogen. The main indoor sources of this
chemical are environmental tobacco smoke, stored fuels and paint supplies,
and automobile emissions in attached garages. Actions that will reduce
benzene exposure include eliminating smoking within the home, providing for
maximum ventilation during painting, and discarding paint supplies and
special fuels that will not be used immediately.

Keep exposure to perchloroethylene emissions from newly dry cleaned
materials to a minimum.

Perchloroethylene is the chemical most widely used in dry cleaning. In
laboratory studies, it has been shown to cause cancer in animals. Recent
studies indicate that people breathe low levels of this chemical both in
homes where dry cleaned goods are stored and as they wear dry cleaned
clothing. Dry cleaners recapture the perchloroethylene during the dry
cleaning process so they can save money by re using it, and they remove more
of the chemical during the pressing and finishing processes. Some dry
cleaners, however, do not remove as much perchloroethylene as possible all of
the time. Taking steps to minimise your exposure to this chemical is prudent.
If dry cleaned goods have a strong chemical odour when you pick them up, do
not accept them until they have been properly dried. If goods with a chemical
odour are returned to you on subsequent visits, try a different dry cleaner.


Formaldehyde is an important chemical used widely by industry to
manufacture building materials and numerous household products. It is also a
by product of combustion and certain other natural processes. Thus, it may be
present in substantial concentrations both indoors and outdoors.

Sources of formaldehyde in the home include building materials,
smoking, household products, and the use of unvented, fuel burning
appliances, like gas stoves or kerosene space heaters. Formaldehyde, by
itself or in combination with other chemicals, serves a number of purposes in
manufactured products. For example, it is used to add permanent press
qualities to clothing and draperies, as a component of glues and adhesives,
and as a preservative in some paints and coating products.

In homes, the most significant sources of formaldehyde are likely to be
pressed wood products made using adhesives that contain urea formaldehyde
(UF) resins. Pressed wood products made for indoor use include: particle
board (used as sub flooring and shelving and in cabinetry and furniture);
hardwood plywood panelling (used for decorative wall covering and used in
cabinets and furniture); and medium density fibreboard (used for drawer
fronts, cabinets, and furniture tops). Medium density fibreboard contains a
higher resin to wood ratio than any other UF pressed wood product and is
generally recognised as being the highest formaldehyde emitting pressed wood

Other pressed wood products, such as softwood plywood and flake or
oriented strand board, are produced for exterior construction use and contain
the dark, or red/black coloured phenol formaldehyde (PF) resin. Although
formaldehyde is present in both types of resins, pressed woods that contain
PF resin generally emit formaldehyde at considerably lower rates than those
containing UF resin.

Since 1985, the Department of Housing and Urban Development (HUD) has
permitted only the use of plywood and particle board that conform to
specified formaldehyde emission limits in the construction of prefabricated
and mobile homes. In the past, some of these homes had elevated levels of
formaldehyde because of the large amount of high emitting pressed wood
products used in their construction and because of their relatively small
interior space.

The rate at which products like pressed wood or textiles release
formaldehyde can change. Formaldehyde emissions will generally decrease as
products age. When the products are new, high indoor temperatures or humidity
can cause increased release of formaldehyde from these products.

During the 1970s, many homeowners had urea formaldehyde foam insulation
(UFFI) installed in the wall cavities of their homes as an energy
conservation measure. However, many of these homes were found to have
relatively high indoor concentrations of formaldehyde soon after the UFFI
installation. Few homes are now being insulated with this product. Studies
show that formaldehyde emissions from UFFI decline with time; therefore,
homes in which UFFI was installed many years ago are unlikely to have high
levels of formaldehyde now.

Health Effects of Formaldehyde

Formaldehyde, a colourless, pungent smelling gas, can cause watery
eyes, burning sensations in the eyes and throat, nausea, and difficulty in
breathing in some humans exposed at elevated levels (above 0.1 parts per
million). High concentrations may trigger attacks in people with asthma.
There is evidence that some people can develop a sensitivity to formaldehyde.
It has also been shown to cause cancer in animals and may cause cancer in

Reducing Exposure to Formaldehyde in Homes

Ask about the formaldehyde content of pressed wood products, including
building materials, cabinetry, and furniture before you purchase them.

If you experience adverse reactions to formaldehyde, you may want to
avoid the use of pressed wood products and other formaldehyde emitting goods.
Even if you do not experience such reactions, you may wish to reduce your
exposure as much as possible by purchasing exterior grade products, which
emit less formaldehyde. For further information on formaldehyde and consumer
products, call the EPA Toxic Substance Control Act (TSCA) assistance line

Some studies suggest that coating pressed wood products with
polyurethane may reduce formaldehyde emissions for some period of time. To be
effective, any such coating must cover all surfaces and edges and remain
intact. Increase the ventilation and carefully follow the manufacturer s
instructions while applying these coatings. (If you are sensitive to
formaldehyde, check the label contents before purchasing coating products to
avoid buying products that contain formaldehyde, as they will emit the
chemical for a short time after application.)

Maintain moderate temperature and humidity levels and provide adequate

The rate at which formaldehyde is released is accelerated by heat and
may also depend somewhat on the humidity level. Therefore, the use of
dehumidifiers and air conditioning to control humidity and to maintain a
moderate temperature can help reduce formaldehyde emissions. (Drain and clean
dehumidifier collection trays frequently so that they do not become a
breeding ground for micro organisms.) Increasing the rate of ventilation in
your home will also help in reducing formaldehyde levels.


According to a recent survey, 75 percent of U.S. households used at
least one pesticide product indoors during the past year. Products used most
often are insecticides and disinfectants. Another study suggests that 80 90
percent of most people s exposure to pesticides occurs indoors and that
measurable levels of up to a dozen pesticides have been found in the air
inside homes.

The amount of pesticides found in homes appears to be greater than can
be explained by recent pesticide use in those households; other possible sources
include contaminated soil or dust that floats or is tracked in from outside,
stored pesticide containers, and household surfaces that collect and then
release the pesticides. Pesticides used in and around the home include
products to control insects (insecticides), termites (termiticides), rodents
(rodenticides), fungi (fungicides), and microbes (disinfectants). They are
sold as sprays, liquids, sticks, powders, crystals, balls, and foggers.

In 1990, the American Association of Poison Control Centres reported
that some 79,000 children were involved in common household pesticide
poisoning or exposures. In households with children under five years old,
almost one half stored at least one pesticide product within reach of

EPA registers pesticides for use and requires manufacturers to put
information on the label about when and how to use the pesticide. It is
important to remember that the "cide" in pesticides means to kill.
These products can be dangerous if not used properly.

In addition to the active ingredient, pesticides are also made up of
ingredients that are used to carry the active agent. These carrier agents are
called "inerts" in pesticides because they are not toxic to the
targeted pest; nevertheless, some inerts are capable of causing health

Health Effects From Pesticides

Both the active and inert ingredients in pesticides can be organic
compounds; therefore, both could add to the levels of airborne organics
inside homes. Both types of ingredients can case the effects discussed in
this booklet under Household Products. However, as with other household
products, there is insufficient understanding at present about what pesticide
concentrations are necessary to produce these effects.

Exposure to high levels of cyclodiene pesticides, commonly associated
with misapplication, has produced various symptoms, including headaches,
dizziness, muscle twitching, weakness, tingling sensations, and nausea. In
addition, EPA is concerned that cyclodienes might cause long term damage to the
liver and the central nervous system, as well as an increased risk of cancer.

There is no further sale or commercial use permitted for the following
cyclodiene or related pesticides: chlordane, aldrin, dieldrin, and
heptachlor. The only exception is the use of heptachlor by utility companies
to control fire ants in underground cable boxes.

Reducing Exposure to Pesticides in Homes

Read the label and follow the directions. It is illegal to use any
pesticide in any manner inconsistent with the directions on its label.

Unless you have had special training and are certified, never use a
pesticide that is restricted to use by state certified pest control
operators. Such pesticides are simply too dangerous for application by a non
certified person. Use only the pesticides approved for use by the general
public and then only in recommended amounts; increasing the amount does not
offer more protection against pests and can be harmful to you and your plants
and pets.

Ventilate the area well after pesticide use.

Mix or dilute pesticides outdoors or in a well ventilated area and only
in the amounts that will be immediately needed. If possible, take plants and
pets outside when applying pesticides to them.

Use non chemical methods of pest control when possible.

Since pesticides can be found far from the site of their original
application, it is prudent to reduce the use of chemical pesticides outdoors
as well as indoors. Depending on the site and pest to be controlled, one or
more of the following steps can be effective: use of biological pesticides,
such as Bacillus thuringiensis, for the control of gypsy moths; selection of
disease resistant plants; and frequent washing of indoor plants and pets.
Termite damage can be reduced or prevented by making certain that wooden
building materials do not come into direct contact with the soil and by
storing firewood away from the home. By appropriately fertilising, watering,
and aerating lawns, the need for chemical pesticide treatments of lawns can
be dramatically reduced.

If you decide to use a pest control company, choose one carefully.

Ask for an inspection of your home and get a written control program
for evaluation before you sign a contract. The control program should list
specific names of pests to be controlled and chemicals to be used; it should
also reflect any of your safety concerns. Insist on a proven record of
competence and customer satisfaction.

Dispose of unwanted pesticides safely.

If you have unused or partially used pesticide containers you want to
get rid of, dispose of them according to the directions on the label or on
special household hazardous waste collection days. If there are no such
collection days in your community, work with others to organise them.

Keep exposure to moth repellents to a minimum.

One pesticide often found in the home is paradichlorobenzene, a
commonly used active ingredient in moth repellents. This chemical is known to
cause cancer in animals, but substantial scientific uncertainty exists over
the effects, if any, of long term human exposure to paradichlorobenzene. EPA
requires that products containing paradichlorobenzene bear warnings such as
avoid breathing vapours to warn users of potential short term toxic effects.

Where possible, paradichlorobenzene, and items to be protected against
moths, should be placed in trunks or other containers that can be stored in
areas that are separately ventilated from the home, such as attics and
detached garages. Paradichlorobenzene is also the key active ingredient in
many air fresheners (in fact, some labels for moth repellents recommend that
these same products be used as air fresheners or deodorants). Proper
ventilation and basic household cleanliness will go a long way toward
preventing unpleasant odours.

Call the National Pesticide Telecommunications Network (NPTN).

EPA sponsors the NPTN (800-858-PEST) to answer your questions about
pesticides and to provide selected EPA publications on pesticides.


Asbestos is a mineral fibre that has been used commonly in a variety of
building construction materials for insulation and as a fire retardant. EPA
and CPSC have banned several asbestos products. Manufacturers have also
voluntarily limited uses of asbestos. Today, asbestos is most commonly found
in older homes, in pipe and furnace insulation materials, asbestos shingles,
mill board, textured paints and other coating materials, and floor tiles.

Elevated concentrations of airborne asbestos can occur after asbestos
containing materials are disturbed by cutting, sanding or other remodelling
activities. Improper attempts to remove these materials can release asbestos
fibres into the air in homes, increasing asbestos levels and endangering
people living in those homes.

Health Effects of Asbestos

The most dangerous asbestos fibres are too small to be visible. After
they are inhaled, they can remain and accumulate in the lungs. Asbestos can
cause lung cancer, mesothelioma (a cancer of the chest and abdominal
linings), and asbestosis (irreversible lung scarring that can be fatal).
Symptoms of these diseases do not show up until many years after exposure
began. Most people with asbestos related diseases were exposed to elevated
concentrations on the job; some developed disease from exposure to clothing
and equipment brought home from job sites.

Reducing Exposure to Asbestos in Homes

Learn how asbestos problems are created in homes. Read the booklet,
Asbestos in Your Home, issued by CPSC, the ALA, and EPA.

To contact these organisations, see the section, Where to Go For More

If you think your home may have asbestos, don t panic!

Usually it is best to leave asbestos material that is in good condition
alone. Generally, material in good condition will not release asbestos fibre.
There is no danger unless fibres are released and inhaled into the lungs.

Do not cut, rip, or sand asbestos containing materials.

Leave undamaged materials alone and, to the extent possible, prevent
them from being damaged, disturbed, or touched. Periodically inspect for
damage or deterioration. Discard damaged or worn asbestos gloves, stove top
pads, or ironing board covers. Check with local health, environmental, or
other appropriate officials to find out about proper handling and disposal

If asbestos material is more than slightly damaged, or if you are going
to make changes in your home that might disturb it, repair or removal by a
professional is needed. Before you have your house remodelled, find out
whether asbestos materials are present.

When you need to remove or clean up asbestos, use a professionally
trained contractor.

Select a contractor only after careful discussion of the problems in
your home and the steps the contractor will take to clean up or remove them.
Consider the option of sealing off the materials instead of removing them.

Call EPA s TSCA assistance line (2025541404) to find out whether your
state has a training and certification program for asbestos removal
contractors and for information on EPA s asbestos programs.


Lead has long been recognised as a harmful environmental pollutant. In
late 1991, the Secretary of the Department of Health and Human Services
called lead the number one environmental threat to the health of children in
the United States. There are many ways in which humans are exposed to lead:
through air, drinking water, food, contaminated soil, deteriorating paint,
and dust.

Airborne lead enters the body when an individual breathes or swallows
lead particles or dust once it has settled. Before it was known how harmful
lead could be, it was used in paint, gasoline, water pipes, and many other

Old lead based paint is the most significant source of lead exposure in
the U.S. today. Harmful exposures to lead can be created when lead based
paint is improperly removed from surfaces by dry scraping, sanding, or open
flame burning. High concentrations of airborne lead particles in homes can
also result from lead dust from outdoor sources, including contaminated soil
tracked inside, and use of lead in certain indoor activities such as
soldering and stained glass making.

Health Effects of Exposure to Lead

Lead affects practically all systems within the body. At high levels it
can cause convulsions, coma, and even death. Lower levels of lead can
adversely affect the brain, central nervous system, blood cells, and kidneys.

The effects of lead exposure on foetuses and young children can be
severe. They include delays in physical and mental development, lower IQ
levels, shortened attention spans, and increased behavioural problems.
Foetuses, infants, and children are more vulnerable to lead exposure than
adults since lead is more easily absorbed into growing bodies, and the
tissues of small children are more sensitive to the damaging effects of lead.
Children may have higher exposures since they are more likely to get lead
dust on their hands and then put their fingers or other lead contaminated
objects into their mouths.

Get your child tested for lead exposure. To find out where to do this,
call your doctor or local health clinic. For more information on health
effects, get a copy of the Centres for Disease Control s, Preventing Lead
Poisoning in Young Children (October 1991).

Ways to Reduce Exposure to Lead

Keep areas where children play as dust free and clean as possible.

Mop floors and wipe window ledges and chewable surfaces such as cribs
with a solution of powdered automatic dishwasher detergent in warm water.
(Dishwasher detergents are recommended because of their high content of
phosphate.) Most multipurpose cleaners will not remove lead in ordinary dust.
Wash toys and stuffed animals regularly. Make sure that children wash their
hands before meals, nap time, and bedtime.

Reduce the risk from lead based paint.

Most homes built before 1960 contain heavily leaded paint. Some homes
built as recently as 1978 may also contain lead paint. This paint could be on
window frames, walls, the outside of homes, or other surfaces. Do not burn
painted wood since it may contain lead.

Leave lead based paint undisturbed if it is in good condition do not
sand or burn off paint that may contain lead.

Lead paint in good condition is usually not a problem except in places
where painted surfaces rub against each other and create dust (for example,
opening a window).

Do not remove lead paint yourself.

Individuals have been poisoned by scraping or sanding lead paint
because these activities generate large amounts of lead dust. Consult your
state health or housing department for suggestions on which private
laboratories or public agencies may be able to help test your home for lead
in paint. Home test kits cannot detect small amounts of lead under some
conditions. Hire a person with special training for correcting lead paint
problems to remove lead based paint. Occupants, especially children and
pregnant women, should leave the building until all work is finished and
cleanup is done.

For additional information dealing with lead based paint abatement
contact the Department of Housing and Urban Development for the following two
documents: Comprehensive and Workable Plan for the Abatement of Lead Based
Paint in Privately Owned Housing: Report to Congress (December 7, 1990) and
Lead Based Paint: Interim Guidelines for Hazard Identification and Abatement
in Public and Indian Housing (September 1990).

Do not bring lead dust into the home.

If you work in construction, demolition, painting, with batteries, in a
radiator repair shop or lead factory, or your hobby involves lead, you may
unknowingly bring lead into your home on your hands or clothes. You may also
be tracking in lead from soil around your home. Soil very close to homes may
be contaminated from lead paint on the outside of the building. Soil by roads
and highways may be contaminated from years of exhaust fumes from cars and
trucks that used leaded gas.

Use door mats to wipe your feet before entering the home. If you work
with lead in your job or a hobby, change your clothes before you go home and
wash these clothes separately. Encourage your children to play in sand and
grassy areas instead of dirt which sticks to fingers and toys. Try to keep
your children from eating dirt, and make sure they wash their hands when they
come inside.

Find out about lead in drinking water.

Most well and city water does not usually contain lead. Water usually
picks up lead inside the home from household plumbing that is made with lead
materials. The only way to know if there is lead in drinking water is to have
it tested. Contact the local health department or the water supplier to find
out how to get the water tested. Send for the EPA pamphlet, Lead and Your
Drinking Water, for more information about what you can do if you have lead
in your drinking water. Call EPA s Safe Drinking Water Hot line (8004264791)
for more information.

Eat right.

A child who gets enough iron and calcium will absorb less lead. Foods
rich in iron include eggs, red meats, and beans. Dairy products are high in
calcium. Do not store food or liquid in lead crystal glassware or imported or
old pottery. If you reuse old plastic bags to store or carry food, keep the
printing on the outside of the bag.

You can get a brochure, Lead Poisoning and Your Children, and more
information by calling the National Lead Information Centre, 800-LEAD-FYI.


Building a new home provides the opportunity for preventing indoor air
problems. However, it can result in exposure to higher levels of indoor air
contaminants if careful attention is not given to potential pollution sources
and the air exchange rate.

Express your concerns about indoor air quality to your architect or
builder and enlist his or her cooperation in taking measures to provide good
indoor air quality. Talk both about purchasing building materials and
furnishings that are low emitting and about providing an adequate amount of

The American Society of Heating, Refrigerating, and Air Conditioning
Engineers recommends a ventilation rate of 0.35 ach (air changes per hour)
for new homes, and some new homes are built to even tighter specifications.
Particular care should be given in such homes to preventing the build up of
indoor air pollutants to high levels.

Here are a few important actions that can make a difference:

Use radon resistant construction techniques.

Obtain a copy of the EPA booklet, Radon Resistant Construction
Techniques for Residential Construction, from your state radon office or
health agency, your state home builders association, or your EPA regional

Choose building materials and furnishings that will keep indoor air
pollution to a minimum.

There are many actions a homeowner can take to select products that
will prevent indoor air problems from occurring a couple of them are
mentioned here. First, use exterior grade pressed wood products made with phenol
formaldehyde resin in floors, cabinetry, and wall surfaces. Or, as an
alternative, consider using solid wood products. Secondly, if you plan to
install wall to wall carpet on concrete in contact with the ground,
especially concrete in basements, make sure that an effective moisture
barrier is installed prior to installing the carpet. Do not permanently
adhere carpet to concrete with adhesives so that the carpet can be removed if
it becomes wet.

Provide proper drainage and seal foundations in new construction.

Air that enters the home through the foundation can contain more
moisture than is generated from all occupant activities.

Become familiar with mechanical ventilation systems and consider
installing one.

Advanced designs of new homes are starting to feature mechanical
systems that bring outdoor air into the home. Some of these designs include
energy efficient heat recovery ventilators (also known as air to air heat

Ensure that combustion appliances, including furnaces, fireplaces, wood
stoves, and heaters, are properly vented and receive enough supply air.

Combustion gases, including carbon monoxide, and particles can be back
drafted from the chimney or flue into the living space if the combustion
appliance is not properly vented or does not receive enough supply air. Back
drafting can be a particular problem in weatherized or tightly constructed
homes. Installing a dedicated outdoor air supply for the combustion appliance
can help prevent back drafting.

Indoor air quality problems are not limited to homes. In fact, many
office buildings have significant air pollution sources. Some of these
buildings may be inadequately ventilated. For example, mechanical ventilation
systems may not be designed or operated to provide adequate amounts of
outdoor air. Finally, people generally have less control over the indoor
environment in their offices than they do in their homes. As a result, there
has been an increase in the incidence of reported health problems.


A number of well identified illnesses, such as Legionnaire s disease,
asthma, hypersensitivity pneumonitis, and humidifier fever, have been
directly traced to specific building problems. These are called building
related illnesses. Most of these diseases can be treated nevertheless, some
pose serious risks.

Sometimes, however, building occupants experience symptoms that do not
fit the pattern of any particular illness and are difficult to trace to any
specific source. This phenomenon has been labelled sick building syndrome.
People may complain of one or more of the following symptoms: dry or burning
mucous membranes in the nose, eyes, and throat; sneezing; stuffy or runny
nose; fatigue or lethargy; headache; dizziness; nausea; irritability an
forgetfulness. Poor lighting, noise, vibration, thermal discomfort, and
psychological stress may also cause, or contribute to, these symptoms.

There is no single manner in which these health problems appear. In
some cases, problems begin as workers enter their offices and diminish as
workers leave; other times, symptoms continue until the illness is treated.
Sometimes there are outbreaks of illness among many workers in a single
building; in other cases, health symptoms show up only in individual workers.

In the opinion of some World Health Organisation experts, up to 30
percent of new or remodelled commercial buildings may have unusually high
rates of health and comfort complaints from occupants that may potentially be
related to indoor air quality.


Three major reasons for poor indoor air quality in office buildings are
the presence of indoor air pollution sources; poorly designed, maintained, or
operated ventilation systems; and uses of the building that were
unanticipated or poorly planned for when the building was designed or

Sources of Office Air Pollution

As with homes, the most important factor influencing indoor air quality
is the presence of pollutant sources. Commonly found office pollutants and
their sources include environmental tobacco smoke; asbestos from insulating
and fire retardant building supplies; formaldehyde from pressed wood
products; other organics from building materials, carpet, and other office
furnishings, cleaning materials and activities, rest room air fresheners,
paints, adhesives, copying machines, and photography and print shops;
biological contaminants from dirty ventilation systems or water damaged
walls, ceilings, and carpets; and pesticides from pest management practices.

Ventilation Systems

Mechanical ventilation systems in large buildings are designed and
operated not only to heat and cool the air, but also to draw in and circulate
outdoor air. If they are poorly designed, operated, or maintained, however,
ventilation systems can contribute to indoor air problems in several ways.

For example, problems arise when, in an effort to save energy,
ventilation systems are not used to bring in adequate amounts of outdoor air.
Inadequate ventilation also occurs if the air supply and return vents within
each room are blocked or placed in such a way that outdoor air does not
actually reach the breathing zone of building occupants. Improperly located
outdoor air intake vents can also bring in air contaminated with automobile
and truck exhaust, boiler emissions, fumes from dumpsters, or air vented from
rest rooms. Finally, ventilation systems can be a source of indoor pollution
themselves by spreading biological contaminants that have multiplied in
cooling towers, humidifiers, dehumidifiers, air conditioners, or the inside
surfaces of ventilation duct work.

Use of the Building

Indoor air pollutants can be circulated from portions of the building
used for specialised purposes, such as restaurants, print shops, and dry
cleaning stores, into offices in the same building. Carbon monoxide and other
components of automobile exhaust can be drawn from underground parking
garages through stairwells and elevator shafts into office spaces.

In addition, buildings originally designed for one purpose may end up
being converted to use as office space. If not properly modified during
building renovations, the room partitions and ventilation system can
contribute to indoor air quality problems by restricting air re circulation
or by providing an inadequate supply of outdoor air.


If you or others at your office are experiencing health or comfort
problems that you suspect may be caused by indoor air pollution, you can do
the following:

Talk with other workers, your supervisor, and union representatives to
see if the problems are being experienced by others and urge that a record of
reported health complaints be kept by management, if one has not already been

Talk with your own physician and report your problems to the company
physician, nurse, or health and safety officer.

Call your state or local health department or air pollution control
agency to talk over the symptoms and possible causes.

Encourage building management to obtain a copy of Building Air Quality:
A Guide for Building Owners and Facility Managers. Building Air Quality (BAQ)
is simply written, yet provides comprehensive information for identifying,
correcting, and preventing indoor air quality problems. BAQ also provides
supporting information such as when and how to select outside technical
assistance, how to communicate with others regarding indoor air issues, and
where to find additional sources of information. BAQ is available for $24
from U.S. GPO,

Superintendent of Documents,
P.O. Box 371954,
Pittsburgh, PA
stock #055000003904.

Frequently, indoor air quality problems in large commercial buildings
cannot be effectively identified or remedied without a comprehensive building
investigation. These investigations may start with written questionnaires and
telephone consultations in which building investigators assess the history of
occupant symptoms and building operation procedures. In some cases, these
inquiries may quickly uncover the problem and on site visits are unnecessary.

More often, however, investigators will need to come to the building to
conduct personal interviews with occupants, to look for possible sources of
the problems, and to inspect the design and operation of the ventilation
system and other building features. Because taking measurements of pollutants
at the very low levels often found in office buildings is expensive and may
not yield information readily useful in identifying problem sources,
investigators may not take many measurements. The process of solving indoor
air quality problems that result in health and comfort complaints can be a
slow one, involving several trial solutions before successful remedial
actions are identified.

If a professional company is hired to conduct a building investigation,
select a company on the basis of its experience in identifying and solving
indoor air quality problems in non industrial buildings.

Work with others to establish a smoking policy that eliminates
involuntary non smoker exposure to environmental tobacco smoke.

Call the National Institute for Occupational Safety and Health (NIOSH)
for information on obtaining a health hazard evaluation of your office
(800-35-N-EACH), or contact the Occupational Safety and Health
Administration, (202) 2198151.

Federal Information Services

Federal agencies with indoor air quality information may be contacted
as follows:

U.S. Environmental Protection Agency (EPA)
Public Information Centre
401 M St., SW
Washington, DC 20460
(202) 260-7751

Indoor Air Quality Information Clearinghouse (IAQ INFO)
P.O. Box 37133
Washington, DC 200137133
(800) 438-4318
(301) 585-9020

Operates Monday to Friday from 9 to 5 Eastern Standard Time (EST).
Distributes EPA publications, answers questions on the phone, and makes
referrals to other non profit and governmental organisations.

National Radon Hot line
Information recording operates 24 hours a day.

National Lead Information Centre
(800) LEAD-FYI

Operates 24 hours a day, seven days a week. Callers may order an
information package. To speak to an information specialist, call
Operates Monday to Friday from 8:30 to 5 EST.

National Pesticides Telecommunications Network
National toll free number: (800) 858-PEST
In Texas: (806) 7433091

Operates Monday to Friday from 8 to 6 Central Standard Time. Provides
information about pesticides to the general public and the medical,
veterinary, and professional communities.

RCRA/Super fund Hot line
National toll free number: (800) 4249346
In Washington, DC area: (703) 4129810

Operates Monday to Friday from 8:30 to 7:30 EST. Provides information
on regulations under both the Resources Conservation and Recovery Act
(including solid and hazardous waste issues) and the Super fund law.

Safe Drinking Water Hot line
(800) 4264791

Operates Monday to Friday from 8:30 to 5 EST. Provides information on
regulations under the Safe Drinking Water Act, lead and radon in drinking
water, filter information, and a list of state drinking water offices.

TSCA Assistance Information Service
(202) 5541404

Operates Monday to Friday from 8:30 to 5 EST. Provides information on
regulations under the Toxic Substances Control Act and on EPA's asbestos

U.S. Consumer Product Safety Commission (CPSC)
Washington, DC 202070001
Product Safety Hot line: (800) 638-CPSC

Teletypewriter for the hearing impaired (outside Maryland): (800)
638-8270; Maryland only: (800) 492-8104. Recorded information is available 24
hours a day when calling from a touch tone phone. Operators are on duty
Monday to Friday from 10:30 to 4 EST to take complaints about unsafe consumer

U.S. Department of Housing and Urban Development
Office of Energy and the Environment
Washington, DC 20410
HUD USER National toll free number: (800) 245-2691
In Washington, DC area: (301) 251-5154.

U.S. Department of Energy
Office of Conservation and Renewable Energy
1000 Independence Ave., SW
Washington, DC 20585

Conservation and Renewable Energy Inquiry and Referral Service
PO Box 3048,
Merrifield, VA 22116;
(800) 523-2929.

Operates Monday to Friday from 9 to 5 EST. Provides consumer
information on conservation and renewable energy in residences.

U.S. Public Health Service
Division of Federal Occupational Health
Office of Environmental Hygiene, Region III, Room 1310
3535 Market St., Philadelphia, PA 19104
(215) 596-1888; fax: 215-596-5024

Provides indoor air quality consultative services to federal agency

Centres for Disease Control and Prevention
Lead Poisoning Prevention Branch
4770 Buford Highway, NE (F42), Atlanta, GA 30341-3724
(800) 488-7330

Office on Smoking and Health Centres for Disease Control and Prevention
U.S. Department of Health and Human Services

4770 Buford Highway, NE (K50), Atlanta, GA 30341-3724
(404) 488-5701

Occupational Safety and Health Administration
Office of Information and Consumer Affairs
Room N-3647
200 Constitution Avenue, NW, Washington, DC 20210
(202) 219-8151

Bonneville Power Administration
Portland, OR 97208

General Services Administration
18th and F Streets, NW, Washington, DC 20405

Tennesee Valley Authority
Industrial Hygiene Branch
Multipurpose Building (1B), Muscle Shoals, AL 35660

State and Local Organisations

Your questions or concerns about indoor air problems can frequently be
answered by the government agencies in your state or local government.
Responsibilities or indoor air quality issues are usually divided among many
different agencies. Calling or writing the agencies responsible for health or
air quality control is the best way to start getting information from your
state or local government. To obtain state agency contacts, write or call EPA
s IAQ Information Clearinghouse, (800) 4384318.


Eastern Regional Centre
6 World Trade Centre
Vesey Street, 3rd Floor Room 350
New York, NY 10048-0950
(212) 466-1612

Central Regional Centre
230 South Dearborn Street Room 2944
Chicago, IL 60604-1601
(312) 353-8260

Western Regional Centre
600 Harrison Street Room 245
San Francisco, CA 94107
(415) 744-2966

States in Region
Connecticut, District of Columbia, Delaware, Florida,
Massachusetts, Maryland, Maine, North Carolina, New Hampshire, New York,
Pennsylvania, South Carolina, Rhode Island, Virginia, Vermont, West Virginia

Alabama, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky, Michigan,
Minnesota, Missouri, Mississippi, North Dakota, Nebraska, Ohio, South Dakota,
Tennessee, Wisconsin

Alaska, Arkansas, Arizona, California, Colorado, Hawaii, Idaho,
Louisiana, Montana, New Mexico, Nevada, Oklahoma, Oregon, Texas, Utah,
Washington, Wyoming


Address inquiries to the Indoor Air Coordinators in the EPA regional
offices at the following addresses:

Region 1
John F. Kennedy Federal Building
Boston, MA 02203

Region 2
26 Federal Plaza
New York, NY 10278

Region 3
841 Chestnut Building
Philadelphia, PA 19107
215-597-4084 (radon)

Region 4
345 Courtland Street NE
Atlanta, GA 30365

Region 5
77 W. Jackson Blvd.
Chicago, IL 60604

Region 6
First Interstate Bank Tower
1445 Ross Avenue
Dallas, TX 75202

Region 7
726 Minnesota Avenue
Kansas City, KS 66101

Region 8
EPA 999 18th Street, Suite 500
Denver, CO 80202-2466

The following organisations have information discussed in this booklet.
EPA s IAQ Information Clearinghouse, (800)438-4318, can provide the names of
a variety of organisations that have information on all of the issues
discussed in this publication.

American Association of Poison Control Centres
3800 Reservoir Rd., NW
Washington, DC 20007

American Society of Heating, Refrigerating, and Air-Conditioning
1791 Tullie Circle NE
Atlanta, GA 30329

World Health Organisation
Publications Centre
49 Sheridan Avenue
Albany, NY 12210

Your local American Lung Association (ALA)
1740 Broadway
New York, NY 10019
(800) LUNG-USA


Acid aerosol

Acidic liquid or solid particles that are small enough to become airborne.
High concentrations of acid aerosols can be irritating to the lungs and have
been associated with some respiratory diseases, such as asthma.

Animal dander

Tiny scales of animal skin.


A substance capable of causing an allergic reaction because of an individual
s sensitivity to that substance.

Allergic rhinitis

Inflammation of the mucous membranes in the nose that is caused by an
allergic reaction.

Building-related illness

A discrete, identifiable disease or illness that can be traced to a specific
pollutant or source within a building. (Contrast with Sick building syndrome

Chemical sensitisation

Evidence suggests that some people may develop health problems characterised
by effects such as dizziness, eye and throat irritation, chest tightness, and
nasal congestion that appear whenever they are exposed to certain chemicals. People
may react to even trace amounts of chemicals to which they have become

Environmental tobacco smoke

Mixture of smoke from the burning end of a cigarette, pipe, or cigar
and smoke exhaled by the smoker (also second hand smoke or passive smoking).


Any of a group of parasitic lower plants that lack chlorophyll,
including moulds and mildews.

Humidifier fever

A respiratory illness caused by exposure to toxins from micro organisms
found in wet or moist areas in humidifiers and air conditioners. Also called
air conditioner or ventilation fever.

Hypersensitivity pneumonitis

A group of respiratory diseases that cause inflammation of the lung
(specifically granulomatous cells). Most forms of hypersensitivity
pneumon-itis are caused by the inhalation of organic dusts, including moulds.

Organic compounds

Chemicals that contain carbon. Volatile organic compounds vaporise at
room temperature and pressure. They are found in many indoor sources,
including many common household products and building materials.


A unit for measuring radioactivity, often expressed as picocuries per
litre of air.

Pressed wood products

A group of materials used in building and furniture construction that
are made from wood veneers, particles, or fibres bonded together with an
adhesive under heat and pressure.

Radon and radon decay products

Radon is a radioactive gas formed in the decay of uranium. The radon
decay products (also called radon daughters or progeny) can be breathed into
the lung where they continue to release radiation as they further decay.

Sick building syndrome

Term that refers to a set of symptoms that affect some number of
building occupants during the time they spend in the building and diminish or
go away during periods when they leave the building. Cannot be traced to
specific pollutants or sources within the building. (Contrast with Building
related illness ).

Ventilation rate

The rate at which indoor air enters and leaves a building. Expressed in
one of two ways: the number of changes of outdoor air per unit of time (air
changes per hour, or ach ) or the rate at which a volume of outdoor air
enters per unit of time (cubic feet per minute, or cfm )

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