EPA/600/9-85/021
June 1985
Comprehensive
Indoor Air Quality
Research Strategy
January 1, 1985
Interagency
Committee on
Indoor Air Quality
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EPA/600/9-85/021
June 1985
COMPREHENSIVE INDOOR AIR QUALITY RESEARCH STRATEGY
January 1, 1985
INTERAGENCY COMMITTEE ON INDOOR AIR QUALITY
Environmental Protection Agency, Co-chair
Department of Energy, Co-chair
Department of Health and Human Services, Co-chair
Consumer Product Safety Commission, Co-chair
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NOTICE
This document has been reviewed in accordance with
U.S. Lnvironmental Protection Agency policy and
approved for publication. Mention of trade names
or commercial products does not constitute endorse-
ment or recommendation for use.
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Preface
The strategy which follows, to the maximum extent possible, reflects
and is consistent with the programs that are ongoing in various federal
departments and agencies. The administration strongly supports the
coordination and technical assistance the CIAQ provides to its members
and to the public and private sector. However, submission of this report
should not be construed as support for a specific long-term separately
funded research program. Therefore, no funding levels and timeframes are
appropriate and included.
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Table of Contents
INTRODUCTION
CURRENT FEDERAL RESEARCH
TASK #1: DETERMINATION OF INDOOR AIR POLLUTANT SOURCES AND
FACTORS AFFECTING HUMAN EXPOSURE
TASK #2: CHARACTERIZATION OF INDOOR AIR QUALITY IN THE
UNITED STATES 7
TASK #3: DETERMINATION OF THE RELATIONSHIP BETWEEN ENERGY
CONSERVATION AND INDOOR AIR QUALITY 9
TASK #4: DETERMINATION OF HEALTH EFFECTS OF INDOOR AIR
POLLUTION 11
TASK #5: DEVELOPMENT OF EFFECTIVE CONTROL AND MITIGATION
TECHNIQUES 12
TASK #6: NATIONAL MULTIPOLLUTANT FIELD SURVEY 13
COMPREHENSIVE INDOOR AIR QUALITY RESEARCH STRATEGY 15
APPENDIX: CASE STUDIES: RADON AND FORMALDEHYDE 19
REFERENCES 27
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INDOOR AIR QUALITY RESEARCH STRATEGY
INTRODUCTION
The effects of air pollution on human health and welfare have been a
major concern in this country for decades. Major emphasis has been placed
on outdoor sources, outdoor contaminant concentrations, and industrial
indoor environments. However, individuals spend as much as 90 percent of
their time in indoor environments such as residences, buildings, and various
modes of transportation. Studies have established that indoor concen-
trations of many pollutants can attain levels that exceed outdoor ambient
standards, some reaching potentially hazardous levels (1-3). It is becoming
increasingly evident that exposure to pollutants indoors may be of considerably
greater importance than exposure to pollutants outdoors. In addition,
energy conservation measures such as reduction in building ventilation and
infiltration rates and use of supplementary heating sources may further
elevate concentrations of pollutants indoors.
Many organizations have expressed concerns about indoor air quality
including the World Health Organization (WHO) (4), the National Academy of
Sciences (NAS) (5), the American Society of Heating, Refrigeration and Air
Conditioning Engineers (ASHRAE) (6), the Office of Technology Assessment (7)
and the Consumer Federation of America (8).
In response to the concerns of these groups and Congress (9), sixteen
Federal agencies (see Table 1) formed the Interagency Committee on Indoor
Air Quality (CIAQ) in December, 1983. One of the first actions of the CIAQ
was to form seven workgroups (see Table 2). These workgroups have identified
current programs and future needs in indoor air quality research in reports
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Table 1: Interagency Committee on Indoor Air Quality (CIAQ) Members
Environmental Protection Agency (EPA)a
Department of Energy (DOE)a
Department of Health and Human Services (HHS)a
Consumer Product Safety Commission (CPSC)a
Bonneville Power Administration (BPA)
Department of Defense (DOD)
Federal Trade Commission (FTC)
General Services Administration (GSA)
Department of Housing and Urban Development (HUD)
Department of Justice (DOJ)
National Aeronautics and Space Administration (NASA)
National Bureau of Standards (NBS)
Occupational Safety and Health Administration (OSHA)
Tennessee Valley Authority (TVA)
Department of Transportation (DOT)
U.S. Small Business Administration (SBA)
a Co-chair of CIAQ
Table 2: CIAQ Workgroups
Allergens/Pathogens--chaired by NIOSH Organics--chaired by CPSC and EPA
Combustion Sources--chaired by CPSC Radon--chaired by DOE and EPA
Field Studies--chaired by NIOSH Structural Characteristics--chaired by DOE
Formaldehyde--chaired by CPSC and EPA
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submitted in June, 1984. These reports are being updated, and will be
distributed through the CIAQ by April, 1985.
Congressional interest over the quality of indoor air has been expressed
in hearings before the Committee on Science and Technology, U.S. House of
Representatives, and in the language of appropriation committee reports in
both Houses of Congress requiring coordination between Federal agencies.
The most recent examples are the May 23, 1984, Department of Housing and
Urban Development-Independent Agencies Appropriation Bill, 1985 Report
and the June 28, 1984, Department of the Interior and Related Agencies
Appropriation Bill 1985 Report. These reports directed the Environmental
Protection Agency to:
"... expand current planning efforts for indoor air research into
a long-term, comprehensive strategy to identify future research
needs and priorities. To assure effective coordination with other
involved Federal agencies, this strategy should be developed and
coordinated through the Interagency Committee on Indoor Air
Quality, which EPA chairs. The strategy should be submitted to
the Congress by January 1, 1985, and indicate the division of
responsibilities among the primary agencies."
and the Department of Energy to:
"... establish a joint review of the indoor air quality program with
(the Environmental Protection Agency and the Consumer Product Safety
Commission) to assure a well planned, well coordinated total
government effort."
In response to these Congressional concerns, the CIAQ has sought to
develop a comprehensive research strategy on indoor air quality. The
strategy draws on the varied expertise existing within the public and private
sectors to accomplish two aims:
1. To develop an understanding of the magnitude of the risk to
human health from exposures to indoor air pollutants and the
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contribution of various energy conservation measures, introduction
of new building materials and consumer products.
2. To provide technical information and guidance, including cost-
effective mitigation measures, to state and local governments,
the private sector and the general public.
To accomplish these aims, the following six tasks were identified as critical
elements of the strategy. These tasks form the basis of this research
strategy, and are interactive. In addition, they are consistent with the
recommendations expressed by WHO, NAS, ASHRAE, and others. Accomplishment
of these tasks requires an integrated effort by Federal, state, local and
private sector researchers.
1. Identification of indoor air pollutant sources and factors
affecting human exposure.
2. Characterization of indoor air quality.
3. Determination of the relationship between energy conservation
and indoor air quality.
4. Determination of the health effects of indoor air pollution.
5. Determination of optimal control and mitigation techniques.
6. Development and conduct of national multipollutant field studies.
We acknowledge that both the private sector and academics are conducting
indoor air quality research. The following discussion describes current
Federal research efforts addressing each of these six tasks. This discussion
is followed by a section which outlines a comprehensive indoor air quality
research strategy. In addition, to determine how the six research tasks
integrate into the research strategy, two case studies, for radon and
formaldehyde, have been included in an Appendix.
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CURRENT FEDERAL RESEARCH
TASK #1: IDENTIFICATION OF INDOOR AIR POLLUTANT SOURCES AND FACTORS
AFFECTING HUMAN EXPOSURE
The identification of significant sources of indoor air pollutants
(Table 3), their migration pathways and environmental factors that influence
human exposure provides the basis for the interpretation of monitoring
data and the development of cost-effective control technology. To date, a
high priority has been placed on programs that delineate the basic phenomena
that affect human exposure primarily for radon, formaldehyde and other
organics, and combustion pollutants.
Efforts to determine the sources and dynamics of indoor radon are
di rected to:
1. Determine the contributions of soil, water, and building materials
to the indoor radon source term;
2. Develop models that relate indoor radon concentrations to the
various sources, migration pathways, driving forces, and air
infiltration rates;
3. Determine environmental factors, such as, building construction,
particulate concentrations, temperature, pressure, humidity, and
human activity patterns, that influence human exposure to radon
and its decay products; and
4. Determine radiation dose to the critical cells of the respiratory
tract from the inhalation of radon decay products.
Research on organic pollutants is directed toward determining the
contribution of various building materials as chronic sources of airborne
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Table 3: Typical Sources of Indoor Air Pollutants
Sources
Ambient Ai r
Soil
Water
Combustion Engines
Building Materials
Concrete, Stone, Brick
Pressed wood products
Insulations
Adhesives, Paints and Solvents
Air Conditioners, Humidifiers
Combustion Appliances
(gas, wood, coal, oil and kerosene)
Furnishings
Office Machines and Supplies
Cleaners and Polishes
Human
Metabolic
Smoking
Cooking
Hobbies
Hygiene
Animals and Pests
Plants, Microbial Contamination
Pollutants
Sulfur Dioxide (S02), Nitrogen Oxides
(NOX), Ozone, Carbon Monoxide (CO),
Particulates, Organics, Metals
Radon
Radon, Volatile Organics
NOX, CO, Carbon Dioxide (C02), Organics,
Particulates, Metals
Radon
Formaldehyde, Other Volatile Organics
Formaldehyde, Fibers, Asbestosl
Volatile Organics
Bacteria, Fungi, Protozoa
NOX, CO, C02, Water Vapor, Organics, S02,
Particulates
Formaldehyde, Other Volatile Organics,
Fibers
Organics, Particulates
Ammonia, Volatile Organics, Particulates
C02, Odors, Hater Vapor, Bacteria
CO, C02, Nitrogen Dioxide (N02),
Organics, Particulates
Organics, Odor, Water Vapor
Organics, Microorganisms
Organics, Odor
Microorganisms, Mites, Allergens,
(animal dander, insect parts and feces)
Spores, Pollen, Allergens
1 Asbestos research is not discussed in this strategy, because Federal
research and regulatory action are coordinated through the Federal
Asbestos Task Force independent of the CIAQ.
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pollutants including formaldehyde. The relationships between pollutant
emissions from building materials and building-related factors such as
construction techniques, ventilation, temperature, humidity and age of the
material are being studied. Consumer product and structural sources of
various organic compounds identified indoors are also being evaluated.
Studies are in progress to determine the emission properties and major
pollutants of combustion sources such as unvented kerosene and gas heaters
and coal/wood stoves. The influences of appliance design, ventilation and
use patterns are included in this research.
TASK #2: CHARACTERIZATION OF INDOOR AIR QUALITY
The range and frequency distribution of indoor air pollutant concentra-
tions on a nationwide basis are needed to ascertain the health risks associ-
ated with current exposures. Concentrations need to be correlated with many
factors including sources, structural characteristics, infiltration and
ventilation rates, geography and climate. This information will be used
to determine the efficacy of control measures and the impact of energy
conservation practices.
Earlier studies which characterized indoor air pollutants were limited
in scope because they used small sample sizes, measured only single or few
pollutants, studied a single source, were conducted in a limited geographic
area or used different methodologies. Though valuable in their context,
these data do not provide a unified national picture of indoor air pollution.
Therefore, a national multi-pollutant field survey would provide the data
base required to develop hypotheses to further test and determine dose-
response response relationships. However, before conducting such a study,
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there must be an effort to:
1. Develop instruments to monitor pollutants and gather other relevant
data;
2. Field test these instruments for efficacy, reliability, and cost-
effectiveness;
3. Develop analytical tools and models; and
4. Centralize this information where interested parties can have
access to it.
Current Federal research which supports these efforts is described below.
Methods Development
Research to develop passive samplers for carbon monoxide (CO), nitrogen
dioxide (N02), carbon dioxide (C02), volatile organics, water vapor and air
exchange rates is in progress. Simple cost-effective active sampling
techniques for CO, NO?, formaldehyde, and organic vapors are being evaluated.
Questionnaires to identify pollutant sources and to characterize structural
characteristics, weatherization conditions and consumer product usage are
being developed. In addition, coordinated efforts are underway to prepare
a standard survey design protocol.
Field Monitoring Studies
Both existing and new methodologies are being tested for appropriate-
ness and cost-effectiveness in pilot studies.
Analytical Methods and Models
Mathematical models are being developed to relate indoor pollutant
concentrations to pollutant sources, removal mechanisms, thermal comfort
parameters, and air exchange rates. These models will be used to predict
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indoor air quality and associated health effects in indoor environments,
to simulate the effects of proposed mitigation efforts, and to perform
cost-benefit analyses. The models will be validated and verified by field
data.
IAQ Data Bases
To maximize analysis and distribution of information to interested
Federal and local agencies and the private sector, uniform data are needed.
Results from past field studies are being compiled for entry into a single
data base. Results from current and future field studies will also be
entered into this data base.
TASK #3: DETERMINATION OF THE RELATIONSHIP BETWEEN ENERGY CONSERVATION
AND INDOOR AIR QUALITY
Potentially adverse indoor contaminant levels are further elevated by
efforts to conserve energy. These efforts include reduction of building
infiltration and ventilation rates, use of supplemental heating appliances,
and introduction of certain building materials. Energy conservation and
indoor air quality requirements will have important ramifications on the
cost, design and operation of comfort conditioning systems, energy use
patterns and peak energy usage.
The growing trend in new construction is substantially reduced infil-
tration. The state of the art is such that typical levels of about 0.7-1.0
air changes per hour may be reduced to 0.2 air changes per hour. When
infiltration is reduced to this extent, elevated levels of indoor pollutants
may be found. More research is required to relate ventilation rates to
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indoor air pollutant concentrations and to provide for the establishment
of energy efficient ventilation guidelines which maintain acceptable indoor
ai r quality.
Infiltration and Ventilation
Research efforts devoted to infiltration and ventilation studies in
residential buildings have contributed significantly to the development of
infiltration measurement techniques, air leakage characterization of
buildings, and infiltration modeling to assess the impact of reduced
infiltration rates on energy requirements and indoor air quality. Current
research includes:
1. Extending single chamber, residential infiltration models to
include all forms of ventilation (both natural and mechanical);
2. Developing and validating low cost methods of measuring
infiltration and leakage, e.g., perfluorocarbon tracer gases
and acoustic AC pressurization;
3. Testing a multi-chamber infiltration model suitable for multi-family
residential buildings and multizone single-family buildings; and
4. Participating in national and international efforts to develop
ventilation, leakage, infiltration, and construction quality
guideli nes.
Only very limited information exists on infiltration and ventilation
in commercial and institutional buildings. Research is required to develop
and validate techniques to measure ventilation rates and air distribution
patterns. Prototype systems are being developed which utilize multiple
tracer gases, both actively and passively. Research efforts will test and
validate these systems. Data on ventilation rates and efficiencies are
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being collected in a number of commercial buildings and will be used to
extend the multichamber infiltration model described above.
Combustion Appliances and Building Materials
Research on supplemental heating appliances has included field studies,
laboratory chamber studies of pollutant emission rates, consumer use surveys
and limited exposure modeling. Current efforts concentrate on development
of certification test methods and voluntary guidelines for these appliances.
Formaldehyde emissions from urea-formaldehyde foam insulation, pressed
wood products and fibrous glass insulation have been characterized and
evaluated. This information has been provided to manufacturers and to
consumers for their consideration in development of voluntary guidelines.
In addition, volatile organic emissions from building materials, such as
sealants and caulking compounds, are now an area of investigation.
TASK #4: DETERMINATION OF HEALTH EFFECTS OF INDOOR AIR POLLUTION
The causal relationship between indoor pollution exposures and adverse
health effects is critical to the understanding of population risk. This
relationship is needed to evaluate the impact of energy conservation and
mitigation strategies. Occupational and residential studies of most indoor
pollutants have not produced adequate data to determine specific health effects
and exposure-response relationships for pollutants found in indoor air.
Only limited data are available to define the acute and chronic health effects
from low level exposure to essentially all of the indoor air pollutants.
Generally, such effects are extrapolated either from occupational exposure
studies or from animal toxicity studies. Animal toxicology studies are in
progress on some indoor air pollutants e.g., perchloroethylene, dichlor-
omethane, formaldehyde, and nitrogen dioxide.
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Controlled human exposure studies have been initiated to obtain exposure-
response relationships for specific acute health effects from exposure to
pollutants. Such studies include responses of sensitive individuals
(e.g., asthmatics) to exposure to irritant gases such as nitrogen dioxide,
formaldehyde, and sulfur dioxide. Additional studies have been initiated
to develop biochemical markers of exposure to specific pollutants and
pollutant sources. These markers may prove useful in future epidemiological
studies.
Health hazard evaluations are documenting exposures to low levels of
numerous air contaminants, such as volatile organics. Incidents of
adverse health effects are also being reported in commercial and institu-
tional buildings from exposure to volatile organics, sidestream tobacco
smoke, fibers, biologically active aerosols, and allergens. Occupational
exposure studies have provided some evidence for human health effects from
pollutants such as radon and formaldehyde. Additional studies in progress
may provide further information on such associations.
Discussions are underway with the National Center for Health Statistics
(NCHS) on utilizing the National Health and Nutrition Evaluation Survey III
(NHANES III) to determine adverse health effects associated with exposure
to indoor air pollutants.
TASK #5: DEVELOPMENT OF EFFECTIVE CONTROL AND MITIGATION TECHNIQUES
As in the case of outdoor pollution, the identification of indoor
pollution sources and the development of source control and mitigation
strategies will reduce exposures to elevated indoor pollutant concentrations.
Control strategies include source control, ventilation, air purification,
and architectural and materials applications.
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Mitigation and control research is being developed for commercialization
of energy efficient techniques to control indoor pollutant concentrations.
Current efforts include evaluating techniques to reduce pollutant strengths
and block migration pathways, examining pollutant-specific removal mechanisms,
and studying ventilation processes in indoor environments.
Ventilation strategies, with and without heat recovery, air purifi-
cation devices, and architectural and material applications are appropriate
in some situations, especially when source control is impractical. The
effectiveness of these mitigation measures is being laboratory tested,
evaluated, and mathematically modeled.
Pilot mitigation programs are being developed to test a range of
approaches for reducing excessive concentrations. The objective of these
studies is to assure the effectiveness of mitigation measures in wide-scale
mitigation programs. Mitigation measures are beiny studied as a function of
building characteristics, appliances used, and occupant use patterns.
The results of control and mitigation research efforts will be used to
develop consensus testing protocols, guidelines, and information for developing
voluntary standards, primarily by industry itself. Pilot mitigation program
results will be made available in reports to state and local agencies,
utilities, and other groups interested in mitigation.
TASK #6: NATIONAL MULTIPOLLUTANT FIELD SURVEY
A large national multipollutant field survey of indoor air pollution
will be a key component in the CIAQ research program. The National Multi-
pollutant Field Survey will provide the data base required to develop
hypotheses to determine dose-response relationships. The survey will draw
upon the results of the previous research tasks, and the survey results
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will focus future research in these ongoing efforts. The survey will
provide an estimate of the range and distribution of indoor exposures to
indoor air pollutants, and identify those factors which influence their
concentrations. The impact of energy conservation practices, including
reduced ventilation rates and use of supplementary heating sources, and the
effectiveness of mitigation techniques will be studied. A National Multi-
pollutant Field Survey is necessary to identify and focus indoor air quality
research efforts, to control indoor air pollution and to assess the impact
of future energy conservation.
The best approach to obtain health effects data related to indoor air
quality is being explored. Information on health effects may be obtained
from health studies of specific pollutants, including groups with high
exposures to indoor air pollutants. Selected health effects information
could be collected as part of the national survey. One approach to obtaining
health effects data is to conduct an indoor exposure study in conjunction
with another health study such as the NHANES study planned for Fiscal Year
1988 by NCHS.
The CIAQ has directed its Field Studies Workgroup to direct the planning,
development and execution of this national survey. Over the next year,
this Workgroup will coordinate the development of sample design options
for a national survey, taking into account the research on factors affecting
exposure levels of specific indoor air pollutants (e.g., climate, pollutant
sources, ventilation). The Workgroup will also evaluate and coordinate
the CIAQ agencies' research efforts in field testing and participation in
regional indoor air quality studies. These coordination efforts will help
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ensure that this Federal research effort will provide the necessary basis
for conducting a national field survey.
In a similar fashion, the Field Studies Workgroup will review current
health studies, and recommend various options for obtaining health effects
information, including a possible joint survey in conjunction with the
NCHS NHANES III study.
By the end of FY 1985, the Workgroup will present various options
for a national indoor air field survey to the full CIAQ for review and
implementation.
COMPREHENSIVE INDOOR AIR QUALITY RESEARCH STRATEGY
Current Federally sponsored research is addressing, in a limited way,
each of the six previously identified tasks. Because of the nature of the
indoor air pollution problem, a much more comprehensive program is required
by both the public and private sectors. The following strategy is directed
at overall program needs, with the CIAQ and its workgroups providing a
central coordinating function in the development process. Federal agencies
will collaborate in the development and accomplishment of this program
according to their missions, expertise, and budgetary capacity.
Each of the six research tasks discussed previously is essential to
the definition of current and future trends in indoor pollutant exposure,
the consequent risk, and the most effective mitigation techniques. In
addition to the current research tasks described in the previous sections,
the following research needs must also be pursued.
Task #1: SOURCES AND ENVIRONMENTAL FACTORS AFFECTING HUMAN EXPOSURE
- Initiate research efforts to identify and quantify sources
of indoor allergens and organic compounds
- Expand efforts to quantify sources and pathways of combustion
products, radon, and formaldehyde
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- Investigate environmental factors (e.g., air exchange rates,
structural characteristics) affecting occupant exposures
to indoor air pollutants
Task #2: CHARACTERIZATION OF INDOOR AIR QUALITY
- Methods Development and Field Testing
Develop monitoring instrumentation, both active and passive,
for volatile organic pollutants, allergens, microorganisms,
particulates, and N02
Refine, field test, and transfer to the commercial market
instrumentation for CO and all of the above
Develop survey questionnaires and protocols
- Quality Assurance
Develop quality assurance programs similar to that in place
for radon for the important chemical and biological pollu-
tants, to assure that exposure measurements made by various
laboratories in the United States and elsewhere are
comparable
- Analytical Methods and Modeling
Develop standardized techniques for data analysis that
assure validity and accuracy
Improve and validate existing multipollutant indoor air
quality models
- Data Base
Expand data bases to include measurement technologies and
health effect surveys
Task #3: IMPACT OF ENERGY CONSERVATION
- Develop predictive models for determining the effects of
building design and energy conservation practices on
future indoor pollution exposures
- Refine passive samplers for multi-zonal infiltration and
ventilation studies
- Develop techniques to perform air infiltration, ventilation,
and ventilation efficiency measurements in commercial and
institutional buildings
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Task #4: HEALTH EFFECTS
- Conduct chronic toxicity studies in laboratory animals
- Study populations particularly sensitive to chemical or
microbial indoor air pollutants
- Develop biochemical markers for exposure to pollutants
e.g., urinary cotinine for passive tobacco smoke and
urinary hydroxylproline for
Evaluate the toxicity of low level exposure to particulates
and other chemicals both individually and in combinations
Develop and conduct appropriate epidemiological studies
for indoor pollutants, e.g., radon and formaldehyde
Utilize more sophisticated approaches to study the health
effects of pollutants such as N02, CO and formaldehyde
Evaluate the use of Cf>2 in large buildings to predict
complaints of tight building/sick building syndrome
Task #5: POLLUTANT CONTROL
Develop and evaluate source control and mitigation measures
for risk reduction and cost effectiveness for a broad range
of indoor environments and pollutants
Validate minimum ventilation requirements to support consensus
guidelines designed to provide acceptable health and comfort
levels in indoor environments
Task #6: NATIONAL MULTIPOLLUTANT SURVEY
- Develop and conduct a multipollutant field survey to determine
the national distribution of indoor exposures and associated
health effects
- Utilize survey results to design and conduct specific studies
to obtain additional information about health effects, energy
conservation, pollutant sources and control options
In summary, a major national effort is needed to implement this compre-
hensive indoor air quality research strategy. Action is needed by both the
public and private sectors. The CIAQ's role in addressing this problem will
be to coordinate Federal research efforts, and to develop new mechanisms for
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interacting with state and local governments and the public and private sectors.
Through the CIAQ workgroups, research conducted in other programs, such as the
National Toxicity Program, will be used to augment indoor air quality efforts.
The CIAQ will also periodically evaluate research results to reassess health
risks associated with indoor air pollution. Finally, the CIAQ will make a
concerted effort to assure technology transfer through dissemination of
research results and participation in symposia, public meetings, and work-
shops.
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Appendix A
Case Studies: Radon and Formaldehyde
The case studies which follow demonstrate how these six tasks delineated
in the strategy are being pursued for both radon and formaldehyde.
Radon:
The inhalation of the decay products of radon is likely to be one of the
most significant sources of risk to human health from indoor air pollution,
contributing to approximately 5,000 to 15,000 lung cancer cases per year (10).
Expertise in radon research has been developed in DOE, EPA, and HHS programs
in response to recognized problems in uranium, phosphate and radium industrial
activities. In recent years, increased attention has been given by DOE,
EPA, HUD, NBS, TVA, and BPA to the overall problems associated with environ-
mental radon exposure, both outdoor and indoor. Coordination of these
research efforts has been achieved through the ad-hoc Interagency Research
Group on Indoor Air Quality and, since 1983, the Radon Working Group of the
Committee on Indoor Air Quality. As a consequence of this work, the capability
of assessing the health risks associated with current and possible future
exposures of the U.S. population to radon is more advanced than for any
other indoor air pollutant.
The research progress to date can be related to the six tasks of this
strategy document in the following way:
Task #1 Sources and Influence of Environmental Factors
This identification of sources of indoor radon and the influence of
environmental factors on radon concentrations has been a main thrust of
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Federally sponsored research. DOE, EPA, and TVA sponsored research programs
have established the existence and relative importance of soil, water and
building materials as radon sources. In the United States, soil is usually
the dominant source. DOE research has identified pressure differentials
and convective processes as the mechanisms for driving most of the radon into
structures. EPA and DOE research groups are cooperatively developing models
of environmental and structural factors influencing radon and decay product
exposures.
Task #2 Characterization of Exposure
Major efforts have been made to develop and evaluate techniques for the
measurement of radon and its decay products. Methods are now available, many
commercially, for both active and passive measurements. DOE, EPA, Bureau of
Mines (BOM), NBS, state agencies, academia, and the private sector have
cooperated in the conduct of intercomparisons of measurement instruments
and techniques. The DOE Environmental Measurements Laboratory and the BOM
Denver Research Center are two of the four reference laboratories in an
international intercalibration program being sponsored by the Organization
of Economic Cooperation and Development (OECD) Nuclear Energy Agency.
Exposure data obtained in limited Federally sponsored field studies
constitute a significant fraction of the overall data base on indoor radon
exposure in the United States. The available data are currently being used
to initially assess the frequency distribution of radon exposure. They
suggest that the inhabitants of perhaps a million homes in the United States
are exposed to radon levels in excess of the current recommendation for
remedial action of the National Council on Radiation Protection and
Measurements (11).
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Task #3 Energy Conservation
The effect of energy conservation practices on radon exposure is related
primarily to those conservation measures which reduce air exchange rates.
DOE, BPA, and TVA have conducted field studies of radon exposure which have
included investigations of exposure before and after retrofitting and in
energy-efficient structures.
Task #4 Health Effects
Extensive studies of radon exposure and accompanying health effects in
selected populations of mine workers have been sponsored by HHS, BOM, EPA,
and DOE, and groups in other countries. These studies have established a
clear association of radon exposure with the incidence of lung cancer in
miners. Models have been developed which extrapolate these results to
individuals in normal environmental situations. These developments form
the basis for the non-occupational risk estimates used by the various
Federal agencies. Case-control epidemiological studies in the environmental
situation must be conducted to reduce the uncertainties in these risk
estimates. For example, an important element of future studies would be
establishing the possible relationship between radon exposure and smoking
in the induction and promotion of lung cancer.
Task #5 Control and Mitigation
Radon source control and mitigation research is being conducted to
develop both retrofit techniques for existing structures and improvements
in construction practices for new housing. Mitigation methods, such as air-
to-heat exchangers, use of sealants, and mechanical ventilation of substructure
spaces, are being evaluated. New EPA and DOE research initiatives are
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being directed at controlling radon sources. Practical retrofit techniques
are likely to be available in the near future. Future studies will emphasize
the control of radon entry through revised building design and construction
practices.
Task #6 National Multipollutant Survey
The National Multipollutant Survey now being considered will include a
radon component. In addition, the CIAQ is also considering a separate
national radon survey which could be started and completed much sooner,
since radon sampling protocols are currently available. The product of
these survey efforts will be the national frequency distribution of radon
exposure and information on factors that influence this distribution. This
information is of interest to agencies such as EPA and HUD as means to
identify structures that have, or are likely to have, unusually high radon
levels. This distribution is also valuable to DOE, TVA and BPA in the
assessment of future trends in exposure due to the introduction of advanced
conservation technology. These Federal agency interests are considered in
decisions to assist state and local agencies with their indoor pollutant
field studies.
The CIAQ Radon Working Group will provide a mechanism for updating the
inventory of Federal radon research and evaluating research priorities,
thereby determining the role of the various agencies in Federal radon
research.
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Formaldehyde:
Formaldehyde is a highly irritating gas which has caused cancer in
animals. Indoor concentrations are generally much higher than outdoors.
Low level acute exposures as encountered in indoor air have resulted in
eye, nose and throat irritation, while long-term exposures have been
associated with health problems such as headaches, dizziness, nausea,
coughing, recurring infections of upper respiratory tract and menstrual
irregularities. Formaldehyde is also a sensitizer at least via the
dermal route. There are human studies that suggest that formaldehyde
exposures may be associated with genotoxic changes in the blood and cancers
of skin, brain, blood (leukemia), pharynx, larynx, and lung.
The major sources of formaldehyde indoors are generally pressed wood
products, insulations and combustion. Other sources include textiles,
furnishings, and consumer products. CPSC, EPA, HUD, DOE, industrial
organizations, and academia have developed expertise and are working to
define the overall problems associated with formaldehyde exposure.
Coordination of research efforts have been carried out through the Interagency
Regulatory Liaison Group (IRLG), Ad-hoc Interagency Research Group on Indoor
Air Quality, CPSC liaison with government agencies and industry, and more
recently thorugh the formaldehyde workgroups of the CIAQ and the Interagency
Risk Management Council (IRMC). As a result, the capability of assessing
risks from formaldehyde exposure is more advanced than any other chemical
indoor pollutant.
The research progress to date can be related to the six tasks of this
strategy document in the following way:
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Task #1 Sources and Influence of Environmental Factors
CPSC, DOE, EPA, HUD, TVA, and industrial groups have identified the
importance of source strength, emission rates, background concentrations,
decay rates and environmental factors on indoor formaldehyde levels.
Task #2 Characterization of Exposure
The efforts of CPSC, DOE, EPA and the private sector have resulted in
development of commercially available active and passive formaldehyde
monitors. Limited intercomparisons of instruments and techniques have
been conducted by CPSC, DOE, EPA and the private sector. More studies are
in progress. The multiple factors influencing indoor formaldehyde levels
are being incorporated into predictive models. The CPSC, DOE, EPA, TVA,
various State Departments of Health, and the private sector have conducted
small scale field studies to obtain exposure data. The results from these
studies, even though obtained with differing methodologies, constitute the
major portion of available exposure data, and indicate a significant portion
of the U.S. population may be exposed to elevated levels of formaldehyde.
Task #3 Energy Conservation
The effects of reduced ventilation rates and use of supplementary
heating sources on indoor formaldehyde emission rates and concentrations
have not been extensively investigated. Limited data suggest that formaldehyde
concentrations may not be inversely proportional to changes in air exchange
rates.
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Task #4 Health Effects
Health effects data on formaldehyde were generated and compiled through
the efforts of CPSC, EPA, NIOSH, National Cancer Institute, academia,
industry, and similar institutions in Europe. A consensus regarding the
adverse health effects from low-level exposure to formaldehyde was agreed
to at a conference sponsored by the White House Office of Science and
Technology Policy (OSTP) (12). The use of data and models for estimation of
cancer risk from exposure to formaldehyde is being coordinated through the
Interagency Risk Management Council (IRMC). The Formaldehyde Workgroup
of the CIAQ will continue to inventory, evaluate, and distribute the results
of health-related research.
Task #5 Control and Mitigation
Early steps toward defining the appropriate control and mitigation
techniques were taken by CPSC, Canadian Department of Consumer Protection
and the private sector. However, more extensive efforts await the
understanding of sources and factors that influence indoor concentrations.
Task #6 National Multipollutant Survey
The National Multipollutant Survey now being planned will include a
formaldehyde monitoring component. Once an inter-laboratory comparison of
commercially available methods is completed, the CIAQ may consider a separate
national radon and formaldehyde survey. The national frequency distribution
of formaldehyde exposure coupled with probable sources and building structural
characteristics is necessary to identify populations at risk, define control
and mitigation measures, and assess the impact of future trends in energy
conservation.
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Th e Formaldehyde Workgroup of the CIAQ will continue to provide a
mechanism for compiling formaldehyde research, evaluating overall research
priorities, and performing peer reviews of a) proposed projects, b) data from
completed studies, and c) documents generated by Federal agencies. As a
consequence, the workgroup will define for the CIAQ the role of various
agencies in Federal formaldehyde research.
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REFERENCES
1. Government Accounting Office, Indoor Pollution: An Emerging Public Health
Problem (Government Printing Office, Washington, D.C., 1980).
2. "Symposium on health aspects of indoor air pollution," Bull. N.Y. Acad.
Med. 57 (1981)
3. "Proceedings of the 3rd International Conference on Indoor Air Quality and
Climate," (Swedish Council for Building Research, Stockholm, Sweden, 1984).
4. Health Aspects Related to Indoor Air Quality (World Health Organization,
Geneva, 1979).
5. Committee on Indoor Pollutants, National Research Council, Indoor Pollutants
(National Academy Press, Washington, D.C., 1981).
6. The American Society of Heating, Refrigeration, and Air Conditioning
Engineers, Inc., "Position statement on indoor air quality," approved by
the ASHRAE board of directors on July 1, 1981.
7. Office of Technology and Assessment, Residential Energy Conservation
(Government Printing Office, Washington, D.C., 1979).
8. Consumer Federation of America, "Policy Resolutions 1985", in preparation.
9. House of Representatives, 90th Congress, 1st Session, H.R. 2899, Report
No. 98-212, Part I, referred to the Committee on Appropriations on
May 16, 1983.
10. National Council on Radiation Protection, Evaluation of Occupational and
Environmental Exposures to Radon and Radon Daughters in the United States,
Report No. 78, May 31, 1984.
11. A.V.J. Nero, Lawrence Berkely Laboratory Publication, LBL-10525 (August
1981).
12. Office of Science and Technology Policy, Report on the Consensus Workshop
on Formaldehyde (Little Rock, Ar., October 3-6, 1983).
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