United States        EPA 400-R-92-012
Environmental Protection   March 1993
Air And Radiation (6203J)
Indoor Air Pollution
EPA's Approach And

              ost people are aware that outdoor air pollution can damage their
health but may not know that indoor air pollution can also have significant
harmful effects.  U. S. Environmental Protection Agency (EPA) studies of
human exposure to air pollutants indicate that indoor levels of many pollutants
may be 2-5 times, and occasionally more than 100 times, higher than outdoor
levels. These  levels of indoor air pollutants are of particular concern because
it is estimated that most people spend as much as 90% of their time indoors.
       'ver the past several decades, our exposure to indoor air pollutants is
believed to have increased due to a variety of factors, including the construction
of more tightly sealed buildings, reduced ventilation rates to save energy, the use
of synthetic building materials and furnishings, and the use of chemically-
formulated personal care products, pesticides and household cleaners.
      In recent years,  comparative risk studies performed by EPA and its
Science Advisory Board have consistently ranked indoor air pollution among
the top five environmental risks to public health. EPA, in close cooperation
with other Federal agencies and the private sector, has begun a concerted effort
to better understand indoor air pollution and to reduce peoples' exposure to air
pollutants in offices, homes, schools and other indoor environments where
people live, work and play.

Indoor Air Pollution and Health
Awareness of indoor air pollution as an
environmental issue is relatively new.
Indoor air pollutants can cause long
and short term health effects, especially
when concentrations build up. One
challenge for researchers today is to in-
crease our understanding of the possi-
ble health impacts of being exposed to
mixtures of indoor air pollutants at low
levels for long periods of time.

Long-Term Health Effects
Some health effects may show up years
after exposure has occurred or only
after long or repeated periods of expo-
sure and thus can be characterized as
long-term health effects. These effects,
which include respiratory diseases and
cancer, can be severely debilitating or
fatal.  Long-term health effects are
associated with indoor air pollutants
such as radon, asbestos, and environ-
mental tobacco smoke.

Immediate Health Effects
Immediate effects, which may appear
after a single, high-dose exposure or
repeated exposures, include irritation
of the eyes, nose, and throat, head-
aches,  dizziness, and fatigue.  These
immediate effects are usually short-
term and treatable.  Sometimes the
treatment is simply eliminating the
person's exposure to the source of the
pollution, if it can be identified.
Symptoms of certain diseases, includ-
ing asthma, hypersensitivity
pneumonitis, and humidifier fever, can
appear soon after exposure to some
indoor air pollutants. When symptoms
of diagnosable illness can be attributed
directly to airborne building contami-
nants,  they are referred to as building'
related  illness.
   In contrast, there are situations in
which  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, referred to by some as
sick building syndrome, is often tempo-
rary, but some buildings have  long-
 term problems. Frequently, problems
 result when a building is operated or
 maintained in a manner that is incon-
 sistent with its original design or
 prescribed operating procedures.
   Occupants may complain of one or
 more of the following symptoms: dry 01
 burning mucous membranes in the
 nose, eyes, and throat, sneezing, stuffy
 or runny nose, fatigue or lethargy,
 headache, dizziness, nausea, irritability.
 and forgetfulness. Contributing factors
 may include inadequate ventilation;
Biological pollutants, such as pollen (shown
above) and mold and mildew, are a major
cause of health complaints and illness.

chemical and biological contamina-
tion from indoor or outdoor sources;
and other non-pollutant stressors such
as temperature, humidity, lighting,
ergonomic problems and job-related
psychosocial issues.

Indoor Air Pollution Costs
Initial efforts by EPA to assess the
costs of indoor air pollution (see
Report to Congress on Indoor Air Qual-
ity, August 1989) concluded that it
was reasonable to estimate that the
costs of indoor air pollution were in
the tens of billions of dollars per year.
The major types of economic costs
associated with indoor air pollution
are direct medical costs for people
whose health is affected by poor
indoor air quality and  who receive
treatment; lost productivity from
absence due to illness; decreased
efficiency on the job; and materials
and equipment damages due to expo-
sure to indoor  air  pollutants.

EPA's Program for Dealing with Indoor Air Pollution
Because of the potentially serious
impacts on the health of individuals
who may experience indoor air quality
problems  as well as the dollar costs
to society if indoor air pollution is not
addressed  EPA has developed a
comprehensive program to better
understand the indoor air pollution
problem and to take decisive steps to
reduce people's exposures to indoor air
contaminants of all types.
  Even in the absence of complete
scientific understanding of indoor air
pollution, prudent public policy dic-
tates that reasonable efforts be under-
taken to reduce people's exposure to
potentially harmful levels of indoor air
pollutants, using the authorities avail-
able to the Federal government under
current laws.
Backdrafting of pollutants from combustion
appliances can result in dangerous, and even
fatal, levels of carbon monoxide.  A trained
professional should inspect, clean, and tune-
up the central heating system (furnaces,
flues, and chimneys) annually.

  Pollution prevention  and effi-
cient resolution of indoor air quality
problems of all types  must become
a routine aspect of the design, con-
struction, maintenance, and operation
of public and commercial buildings,
homes, health and day care  facilities,
educational institutions and other
special use buildings.
  An effective research and develop-
ment program must  be conducted to
achieve a more complete understand-
ing of the factors affecting indoor air
quality, exposure patterns, health
effects, and control techniques for
improving indoor air quality.
   EPA is implementing this program
using non-regulatory as well as regula-
tory tools available under a number of
Federal laws to provide information
and incentives for action to product
manufacturers, architects, engineers,
builders, building owners and manag-
ers, and building occupants.
 Awareness of indoor air pollution
 as an environmental issue is rela-
 tively new.  Indoor air pollutants
   can cause long and short term
   health effects especially when
   concentrations build up.  One
 challenge for researchers today is
 to increase our understanding of
   the possible health impacts of
  being exposed to mixtures of in'
  door air pollutants at low levels
      for long periods of time.
The primary objectives of EPA's
program are to:
  Establish effective partnerships
with organizations representing the
range of target audiences for indoor air
quality information to communicate
specific guidance and information and
promote timely action on indoor air
quality issues;
  Forge constructive alliances with
other Federal agencies to leverage
resources and ensure that existing
statutory authorities are used most
  Develop practical guidance on
indoor air quality issues utilizing a
broad-based consensus approach
which includes representatives from
industry and public interest groups to
ensure that information provided is
accurate and practical;
  Design market-based incentives for
industries to lower chemical emissions
from their products and provide
consumers and other decision-makers
with information needed to make
informed purchasing decisions;
   Sharpen the focus of the chemical
screening and  risk management
program under the Toxic Substances
Control Act (TSCA) and the Federal
Insecticide, Fungicide, and Rodenti-
cide Act (FIFRA) to ensure that
chemicals that pose unreasonable risks
indoors are identified and addressed;
 Biological pollutants can thrive on damp
 surfaces. Moisture on the interior surfaces of
 buildings can be controlled either by reducing
 the humidity levels indoors or by adding
 insulation to exterior walls (shown above).

  Identify and fill research gaps in
order to provide information to
address outstanding indoor air quality
policy issues;

  Select appropriate environmental
indicators to measure progress in
reducing population exposure to
indoor air quality problems as the
program matures;
  Enhance  scientific understanding
and public awareness of the complex
factors affecting indoor air quality; and
  Bring about substantial reductions
in human exposure to the entire range
of indoor air pollutants.

Reducing Pollutant Levels Indoors
The Building System Approach
EPA has set a high priority on improv-
ing the way in which buildings are
designed and operated, having
concluded that people's exposure to
indoor air pollutants can be reduced
significantly by implementing current
knowledge about sound building
operation and maintenance practices.
Some of the major actions to  date

  Issuance, in cooperation with the
National Institute for Occupational
Safety and Health,  of comprehensive
guidance, entitled Building Air Quality:
A Guide for Building Owners and
Facility Managers, on how to prevent
and resolve the full range of indoor air
quality problems in public and
commercial buildings.
  Publication of The Inside Story: A
Guide to Indoor Air Quality, to help
people identify and correct potential
indoor air quality problems in their
own homes.
A good on-site investigation of a building is
often more helpful in identifying and
resolving indoor air quality problems than
measuring individual pollutant concentra-
tion levels.
In addition, EPA is developing
guidance for school facility managers,
new home builders, and architects and
design engineers to acquaint them
with the most current information on
how to prevent indoor air quality
problems from occurring or resolve
them quickly if they do occur.
The Pollutant-Specific Approach
This emphasis on a "buildings
approach" holds the most promise for
addressing all of the factors 
including those related to the ventila-
tion system as well as sources of
individual pollutants  that affect
indoor air quality. However, the
Agency also strongly believes that it
must aggressively utilize its combined
statutory authorities to identify
specific pollutants that present direct
health risks in the indoor environ-
ment,  and to use a variety of means to
reduce their levels indoors. The
indoor air pollutants that are currently
receiving significant Agency attention

The Indoor Radon Abatement Act of
1988 (Title III of TSCA) established
a national goal of achieving indoor
levels  of radon which are no greater
than outdoor levels. EPA has
undertaken a range of activities
directed toward this goal, including
revising public information materials,
providing financial  and rechnical
assistance to States, developing and
encouraging the adoption of radon-
resistant building practices, establish-
ing training centers, operating
industry proficiency programs,
conducting studies in schools and
Federal buildings, and performing
mitigation research in different
building types.

Environmental Tobacco Smoke
EPA has recently completed a major
report  on the respiratory health effects
associated with environmental
tobacco smoke. The report, entitled
Respiratory Health Effects of Passive
Smoking: Lung Cancer and Other
Disorders, concludes that  each year
secondhand smoke is responsible for
about 3,000 lung cancer deaths in
non-smokers and causes respiratory
health problems for hundreds of
thousands of young children. EPA is
developing an education and outreach
program to inform the public about
the risks of passive smoking.

Title II of TSCA, the Asbestos Hazard
Emergency Response Act (AHERA),
passed in 1987, required EPA to
establish a regulatory framework for
addressing asbestos in schools.  The
Agency has set standards for state
accreditation of personnel involved in
asbestos management or abatement in
                                                                               Radon and volatile organic compounds can
                                                                               enter buildings through cracks and openings
                                                                               such as the sump hole shown above.
                                                                               Keeping basements under positive pressure,
                                                                               or sump holes under negative pressure, will
                                                                               prevent these gases from entering buildings.
school buildings and will extend
accreditation requirements to those
who inspect or abate asbestos in public
and commercial buildings. EPA is also
involved in a range of outreach, grant,
and technical assistance activities.
Major recent accomplishments include
publication, with the Consumer
Product Safety Commission and the
American Lung Association, of a
homeowners' guide to Asbestos In Your
Home; completion of a public dialogue
on asbestos in buildings with industry,
real estate interests, unions and the
public sector; and publication of a
building owner's guide, Managing
Asbestos in Place.

 Toxic Substances
 TSCA grants EPA broad authority to
 control chemical substances and
 mixtures that present an unreasonable
 risk of injury to health and the
 environment.  EPA has authority to
 require testing of chemical substances
 and mixtures; regulate hazardous
 chemical substances and mixtures by
 prohibiting or restricting their manu-
 facture, processing, distribution, and
 Sometimes professional assistance is needed
 to deal with particularly hazardous indoor air

 disposal; review new chemicals and
 their intended uses; and impose
 labeling or notification requirements.
 TSCA has been used to regulate
 asbestos, and the Agency is now
 evaluating groups of chemicals in
 selected use categories for their effect
 on people in indoor environments.

 FIFRA authorizes EPA to control
 pesticide exposures by requiring that
 any pesticide be registered with EPA
 before it may be sold, distributed, or
 used in this country.  EPA is evaluat-
 ing the health impacts of indoor
 products including insecticide sprays,
 termiticides, and wood preservatives.
 Major accomplishments include the
 withdrawal from the market of
 chlordane as a termiticide in homes
 and mercury used as a mildewcide in
 many indoor paints.
 Even in the absence of complete
    scientific understanding of
   indoor air pollution, prudent
    public policy dictates that
  intensive efforts be undertaken
 to minimize people's exposure to
   the entire range of indoor air
Exposure to dust from lead-based paint
can pose a serious health threat in
homes or apartments where remodel-
ing is taking place.  Toddlers and
young children are at particular risk
because they are more likely to
swallow lead dust and the impact on
their bodies is more severe. EPA,
along with other key Federal agencies,
is working to develop a comprehensive
strategy to address lead exposures and
to develop effective lead testing and
abatement procedures.

Indoor Air Pollutants from
Drinking Water
The Safe Drinking Water Act
(SDWA) authorizes EPA to set and
enforce standards for contaminants in
public water systems to protect against
both health and welfare effects. EPA
sets standards for volatile organic
compounds  (VOCs) that can enter
the air through volatilization from
water used in a residence or other
building. Eighteen such standards
have been issued to date and three
more are planned. EPA is also
developing a standard for radon in
drinking water.

The Carpet Policy Dialogue:
An Innovative Approach To Reduce
Pollutant Emissions
The Agency recently completed a
year long "dialogue" with carpet floor
covering industries, unions, public
interest groups, and other Federal
agencies to explore ways of reducing
the emission of VOCs from new
carpet and related installation
materials, such as carpet cushion and
adhesives. As a result of this volun-
tary process, the carpet industry
agreed to test new carpet floor
covering materials for total VOC
emissions and is exploring ways of
lowering emissions of VOCs from
carpet products. Most  importantly, the
industry has undertaken an extensive
consumer education program in
cooperation with other dialogue
participants, designed  to provide the
public with information on the role
that carpet products play in indoor air
quality and ways that consumers can
make informed purchase decisions.
EPA expects to conduct similar
discussions with other industry groups
to determine whether  additional
reductions in indoor pollutant
emissions can be achieved through
voluntary actions.
The carpet industry has agreed to provide
information on carpets and indoor air quality
to consumers and is developing its own
testing and certification program.

 Increasing Access to Indoor Air Information
Information Dissemination
In addition to publishing a wide range
of information materials on indoor air
quality, EPA is also developing addi-
tional strategies for disseminating
information to key audiences. To
ensure that a full range of information
about indoor air quality problems and
solutions is readily available to both
the technical and non-technical
public, the Indoor Air Quality Infor-
mation Clearinghouse (IAQ INFO)
opened in 1992. IAQ INFO is
equipped with toll-free, operator-
assisted telephone access, and is able
to provide written information in-
cluding fact sheets and brochures,
perform literature searches, and make
referrals to appropriate Federal, State
and Regional resources.

Training Key Indoor Air Audiences
Because concern about indoor air
problems is a relatively recent phe-
nomenon, many of the people who
are in the best position to prevent
problems or resolve them when they
do occur are not sufficiently informed
about the issue.
   Many  indoor air quality problems
can be avoided through sound build-
ing operation practices, or resolved by
knowledgeable building personnel
without the need for potentially
costly outside assistance. EPA has
developed a training course for build-
ing owners to acquaint them with the
guidance  contained in Building Air
Quality: A Guide for Building Owners
and Facility Managers (December
1991). Because many indoor air qual-
ity problems are best resolved by re-
sponsible government agencies at the
State and local level, EPA has devel-
oped both a live instructional course
on indoor air quality issues, entitled
Orientation to Indoor Air Quality, and a
self-paced learning module entitled
Introduction to Indoor Air Quality
(April 1991) for these audiences.
Advancing the Science of
Indoor Air Quality
EPA is conducting studies to assess
indoor air conditions in the nation's
existing building stock. Special em-
phasis is being given to identifying
those factors that exert the greatest
influence on overall indoor air quality
(IAQ) and on occupant health symp-
toms. The information gained will be
used to improve IAQ diagnostic pro-
Because concern about indoor air

  problems is a relatively recent

phenomenon, many of the people

  who are in the best position to

prevent problems or resolve them

when they do occur are not suffi-

 ciently informed about the issue.
cedures as well as to provide a basis
for evaluating the effectiveness of our
pollution reduction strategies over
time.  Another set of studies now
underway  is designed to quantify the
costs of key indoor  air pollution
control options for  typical building
  EPA's Office of Research and De-
velopment conducts a multi-disciplin-
ary research program on indoor air
quality which encompasses studies of
the health effects associated with
indoor air pollution exposure; assess-
ments of indoor air pollution sources
and control approaches; building
studies and investigation methods;
risk assessments of indoor air pollut-
ants; and a recently initiated program
on biocontaminants.

Working with Other
Federal Agencies
More than 20 different Federal agen-
cies have responsibilities associated
with indoor air quality, either through
their own statutory responsibilities or
because they are major property man-
agers. The activities of these agencies
are  coordinated through a variety of
mechanisms, including an interagency
Committee on Indoor Air Quality
(CIAQ) which meets on a quarterly
basis to exchange information on
indoor air issues. Five Federal agen-
cies  EPA, the Consumer Product
Safety Commission, the Department
of Energy, the National Institute for
Occupational Safety and Health, and
the  Occupational Safety and Health
Administration  are CIAQ co-chair
agencies. In addition, EPA works
closely with other agencies on regula-
tory and information development
efforts and jointly sponsors many of its
guidance and public information
documents with these other agencies
to help ensure that Federal actions are
Recent EPA publications are designed to increase the awareness of key audiences about indoor air
pollution problems and solutions.

Other Federal Sources of IAQ Information
U.S. Environmental Protection Agency

Indoor Air Quality
Information Clearinghouse
P.O. Box 37133
Washington, DC 20013-7133
Fax: 301-588-3408
National Pesticides
Telecommunications Network
Provides information on pesticides.

TSCA Hotline Service
Provides information on asbestos,
PCB, VOCs, and other toxic

U.S. Department of Energy

Office of Conservation and
Renewable Energy
1000 Independence Ave., SW, CE-43
Washington, DC 20585
Quantifies the relationship among
reduced infiltration, adequate ventila-
tion, and acceptable indoor air quality.
National Institute for Occupational
Safety and Health

Requests for information:
Conducts research, recommends
standards to the U.S. Department of
Labor, and conducts training on
various issues including indoor air
quality to promote safe and healthful
workplaces. Undertakes investiga-
tions at request of employees, employ-
ers, other Federal agencies, and state
and local agencies to identify and
mitigate workplace problems.

Consumer Product Safety

For a copy of CPSC's booklets about
combustion appliances, asbestos,
biological pollutants, lead, methylene
chloride, humidifiers, and formalde-
hyde in your home, write to:

U.S. Consumer Product Safety
Washington D.C. 20207
To report an unsafe consumer product
or a product-related injury, call:
Occupational Safety and Health

Promulgates safety and health
standards, facilitates training and
consultation, and enforces regulations
to ensure that workers are provided
with safe and healthful working
conditions. For further information
contact OSHA Regional Offices in
Seattle, San Francisco, Denver,
Kansas City, MO, Dallas, Chicago,
Atlanta, Philadelphia, New York, and

Cover Photos (from top to bottom)
Levels of some pollutants are higher indoors
than outdoors in even the most heavily
industrialized cities.
Environmental tobacco smoke is one of the
most widespread indoor air pollutants.
House dust mites are a leading cause of
asthmatic episodes among children and young
Improperly placed outdoor air supply vents
can pull truck and automobile exhaust fumes
into buildings.
   Printed on paper that contains at least 50% recycled fiber