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AN SAB REPORT
REVIEW OF THE
INDOOR AIR
ENGINEERING
REVIEW OF THE OFFICE OF
RESEARCH AND DEVELOPMENT
INDOOR AIR ENGINEERING
RESEARCH AND DEVELOPMENT
PROGRAM
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UNIT10 STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON, D.C. 20460
iPA-SAB-BBC-03-009
OmCEOFTHEAOMINtSTRATOfi
SCCNCE ADVISORY BCARD
April 15, 1993
Honorable Carol M. Browner
EPA-Administrator
U.S. Environmental Protection Agency
401 M Street, SW
Washington, D.C. 20460
Subject; Science Advisory Board Report on Eeview of OED*a
Draft "Indoor Air Engineering R&D Program"
Dear Ms. Browner;
The Science Advisory Board (SAB) has completed its review the Air and
Energy Engineering Research Laboratory's (AEERL) air engineering research and
development (R&D) program and is pleased to submit this report summarizing our
findings. On July 20 and 21, 1992, the Indoor Air Engineering Research
Subcommittee (IAERS), consisting of members and consultants of the SAB's
Environmental Engineering Committee (EEC) and the Indoor Air Quality and
Total Human Exposure Committee (IAQTKEC), reviewed a very weE prepared
briefing document, received detailed briefings from the program managers, engaged
in dialogue with this group, and offered advice to the AEERL research team
regarding this • topic.
In accordance with the "charge to the committee," the IAERS review focused
on source characterization and source-exposure modeling (well established research
programs); microbial contaminant control/bioresponse testing and new strategic
directions (emerging research areas). The IAERS recognized that the current in-
house research program resources, supplemented by judicious use of contractor
support and cooperative agreements, and leveraging other projects are achieving
positive and impressive results.. This report offers comment and recommendations
in six different categories which are briefly described below.
1) The AEEEL's source characterization effort is a mature program with
strong in-house capabilities. The productivity of the program is
reflected in many ways, including the leadership role that the AEERL
Q,
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has established both in this country and abroad, the successful effort
to develop many publications in peer*reviewed journals and staff
participation and sponsorship of targeted specialty conferences. It is
also observed by the Subcommittee that the future direction of the
program, while appropriate, is ambitious, given the present levels of
funding. The IAERS endorses this ambitious research program, but
stresses that the resources available to carry out the research
program are not adequate, nor do the expenditures reflect the high
level of societal concern regarding indoor air issues.
2) Current mathematical modeling efforts are noteworthy. They could
be improved by integrating other related Agency efforts into the
Indoor Air Quality (IAQ) model. Refinements in the mathematical
representation of mixing and transport processes, to the extent that
they would have practical value in managing risks from indoor air
exposures, and further sensitivity studies would also help provide an
improved understanding of the uncertainty in the analysis.
3) Research on microbial contaminants in indoor environments should
continue to emphasize preventive approaches to control conditions
leading tq the presence and growth of these organisms over methods
to control them through the use of biocides and other non-preventive
remedies. Research design should be bolstered in the selection of
indicator species and certain other research parameters (e.g., eye
irritations, coughing, allergic reactions, and headaches).
4) Bioresponse-based testing is proposed as a reasonable extension of
current airborne chemical testing. Collaboration with established
research efforts already in progress, including the activities of the
Health and Environmental Research Laboratory (HERL) is necessary
to move forward in this area. Establishing correlations between the
biological and chemical data should be considered a priority for all
these research efforts. While this review focused on the engineering
research area and the health-based assessment was not reviewed in
detail, priority should be given to establishing correlations between
engineering issues and health-based testing and coordination.
5) The strategic directions thrust addresses AEERL's future R&D
program. Emphasis on pollution prevention and cost-effectiveness
modeling is important to maintain. Improvements in the
dissemination ("diffusion", that is dissemination is a form that enable
the recipients to use) of this and all the other information gained in
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r
—
guarantee a qualify program.
SAB * offe« a
your
ppr^iate *. opportunit, to «-*-«, J
totific •**• traMEutted "e
«- .00, forward to
ottd~e. Loenr, Cnak
Executive Committee
Science Advisory Board
Sincerely,
Mr. Richard A, Conway, CUalr
Environmental Engineering Committee
Science Advisory Board
Dr. Robert B. Pojaiek, Cnait
Indoor Air Engineering Research
Subcommittee
Environmental Engineering Committee
Science Adviiory Board
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I
NOTICE
Smert assessment of scientific matters related to problems faemg Jfce A^nQr.
^
recommendation for use.
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^ ABSTHACT
The Indoor Air Engineering Eeseareh Subcommittee (IAE1S) of the
Environmental Engineering Committee (EEC) of the EPA Science Advisory Board
(SAB) IMS prepared a report on the Agency's Office of H^ea^ ^d Dejelopmeat
(OED)t Air and Energy Engineering Seseareh Laboratory's (ABEBL) indoor air
engineering research and development (HAD) program. The IAEBS met on July
20 and 21, 19S2.
The review focused on four specific program areas: two of the areas
(emission measurement! and source-exposure modeling) are well ertablished; the
other two areas (microbial contaminant control and new stratepc directions) are
emerging research areas. The KERB found the AEE1L approach to indoor air
research to be appropriate and the program very successful in terms of peer-
reviewed publications and participation in professional organizations as well as
focused specialty conferences related to indoor air engineering research issues, and
the research program's overall impact on the research field. These
accomplishments are particularly noteworthy, especially considering the modest
budget and in-house personnel resources devoted to this activity.
The IAB1S encouraged the AEERL staff to explore how their research
should rely on and interact with other government and private research programs
The IAEBS also recommended that a unified conceptual model should he developed
to effectively inventory sources and sinks. A number of broad-ranging
recommendations were made, with focus on improving an excellent easting
research program, to address prevention of microbial contaminants and to improve
technical outreach to particular target groups, such as allergy specialists, budding
designers, building operators and managers, homeowners, indoor air quality model
users, and university researchers.
Key Words: Indoor Air, Indoor Air Engineering, Indoor Air Engineering Research,
Indoor Air Eesearch
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INDOOR MR ENGWEERIMi BESEA1CH SUBOOiPinTEl
EIWIBONliEMTAL ENGINEERING COMMITTEE
of the
SCIENCE ADVISORY BOARD
Dr. lobcrt B. Pojaaefc, Corporate Vice President, Environmental Programs, GEI
Consultants, Inc., Winchester, MA
MfMBERS Aflp CONSULTANTS
Ms. Christine Ervin, Director,, Oregon Department of Energy, Salem, OE
Dr. Timothy V. Larson, Research Associate, Department of Civil Engineering,
University of Washington, Seattle, WA
Dr Morton lippmann* Professor of Environmental Medicine, New York University
Medical Center, Institute of Environmental Medicine, Tuxedo, N.Y.
Dr. John F. McCarthy, President, Environmental Health & Engineering, Inc.,
Newton, MA
Dr. Win. Randal Seeker, Senior Vte« President, Energy and Environmental
Research Corp., Irvine, CA
Dr. Waiter M. Shank, President, The Corporation on Resource Recovery and the
Environment (CORRE), Silver Spring, MD
Dr. Mitchell J, Small, Professor, Departments of CM Engineenngmd
Engineering & Public Policy, Carnegie Melon University, Pittsburgh, FA
Dr James E. Woods, Professor of Building Construction, CoEege of : ArcMtecture
and Urban Studies, Virginia Polytechnic Institute and State University,
Blactehurg, VA
Sejence ^dviairy Board Staff
Dr IL Jack Kboyoomjian, Designated Federal Official, U.S. EP4 , Science Advisory
Board (M01-F), 401 M Street, SW., Washington, D.C. 204SO
Mra. Diana L. Pozun, Staff Secretary
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TABLE OF CONTENTS
1. EXECUTIVE SUMMARY . v 1
1.1, Source Characterization 1
1.2 Modtling . • * 2
1.3 Microbial Contaminants 3
1.4 Bioresponse-Based Testing „ . . . . 4
1.5 Strategic Direction i
1.6 Additional Considerations . 6
2. INTRODUCTION 1
3, SOURCE CHARACTERIZATION 9
4. MODELING • • • • • ' • U
5. MICROBIAL CONTAMINANTS 15
6. BIQRESPONSE-BASED TESTING 18
7. STRATEGIC DIRECTION 20
8. ADDITIONAL CONSIDERATIONS 23
8.1 Resource Allocation - 23
APPENDS A - REFERENCES CITED A-l
APPENDS B - GLOSSARY OF TERMS AND ACRONYMS B-l
IV
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1. BXECU'ITOE SUMMARY
This report presents the Science Advisory' Board's (SAB) review of the
Office of Research and Development's (ORD), Air and Energy' Engineering
Research Laboratory1! (AEEBli) "Indoor Air Engineering Beseareh and
Development (R&D) Program," (June 1991 document. See Appendk A - reference
1), On July 20 and 21, 1992, the Indoor Air Engineering Besearch Subcommittee
(IAEHS) of the SAB's Environmental Engineering Committee (EEC), in
cooperation with the SAB's Indoor Air Quality Total Human Exposure Committee
(IAQTHEC) reviewed the document, received detailed briefings from researchers
and research managers who developed the document, discussed the approaches,
technical rationale, and merits of the research and offered technical advice on this
important research area. Additional review occurred in mail correspondence with
the IAEBS and the 'EEC. The EEC conducted a public review on this draft report
at its October 28 and 29, 1992 meeting. Throughout the process, the IABHS
offered additional commentary to refine the recommendations contained herein.
The 'findings and recommendations are aimed at improving the current
indoor air engineering R&D program (hereafter referred to as "the E&D program",
or "the document" supporting this program). The following highlights key findings
and recommendations:
LI Source Characterization
The productivity of the AEEEL staff is reflected in many ways, including its
leadership role in the United States and abroad, the sizeable number of peer-
reviewed articles in technical journals, and in their participation and sponsorship
of targeted specially conferences.
a) The IAEBS finds that the AEEKL's approach to source characterization
is appropriate, and has strong in-house capabilities,
b) The focus of the AEEEL research program has logically evolved from
small chamber studies to field studies, and represents a good balance
between small chamber testing, modeling, and test-house studies. However,
the IAEBS believes that, because nonresidential facilities have different
ventilation characteristics as well as different sources and sinks of indoor
air contaminants, it is important to have a large-scale test facility for non-
residential environments, and recommends that the AEEEL obtain such a
test facility. It will also be desirable to have more interaction with field
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monitoring programs of other groups to reinforce the practicality of the
data, •»
c) The present emphasis on high vapor pressure compounds has been
adequately justified; however, it may be appropriate now to include new
information from the literature regarding lower vapor pressure organic
compounds as possible indoor air pollutants.
d) A unifying conceptual model should be developed to effectively inventory
sources and sinks. An analogy exists in the Underground Storage Tank
(UST) research program which utilizes a conceptual model with 13 loci for
physicochemical interactions in the subsurface environment,
e) Other specific recommendations on improving source characterization
research are offered, such as the need to systematically characterize criteria
used for selecting sources and source strengths for analysis, the need to
emphasize pragmatic applications of the research to realize reduced risks in
IAQ, and the need to obtain more input from engineers and architects to
ensure effective transfer of data and technology.
f) It is recommended that a formal plan for technical outreach be developed
for effectively providing information to the EPA program office for public
distribution,
1J Modeling
While the current research program has been very successful, the IAERS
suggests refinements to the current directions and focus for the research which it
believes will lead to continued and increased quality and positive impacts.
Accomplishments of the modeling effort are particularly noteworthy, especially
given the modest budget and limited in-house personnel resources devoted to this
activity,
a) The IAERS concludes that the Indoor Air Quality (IAQ) modeling
component of the AEERL research program is important, appropriate,
rigorous, and well directed.
b) The IAERS believes that perceived barriers of responsibility within the
Agency may be limiting broader interactions. For instance, the AEERL
research program has been unnecessarily constrained by focusing on organic
air toxics. Other critical issues in the Agency, such as asbestos and lead
exposure, would greatly benefit from the type of integrated IAQ model
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developed by the' ABERL staff. These problems require similar
consideration^ the benefits of source control versus alternative measures
for exposure reduction.
e) Further sensitivity studies on models are needed to examine the effects
of environmental factors such as temperature (T) and relative humidity
(EH), and to examine the behavior of the model at low concentrations
where sink processes are likely to dominate initial source effects, so that
appropriate desorption mechanisms can be identified.
d) The IAE1S believes that the Heating, Ventilation and Air Conditioning
(HVAC) Industry needs more information- on mitigation of indoor air
pollution-oritnted issues, rather than a single focus on energy conservation.
The IAERS believes that the real -utility of the model for exposure
assessment will come when it is interfaced with realistic, flexible models for
air exchange, ventilation, human activities, and the interaction between
these factors. The IAEES recommends research focused to evaluate non-
ideal mixing and transport, as well as research in large chamber and field
studies by including multiple sample points in chambers or rooms with
source emissions.
e) The IAEBS believes that an important part of the IAQ modeling
program is the development and transfer of the model and its capabilities to
the user community. Specifically, the IABKS recommends expanding tbJs
technology transfer, with focus on particular target groups, such as model
users, building designers and managers, university researchers and students.
1,3 Microbial Contaminants
- The IAEBS commends the AEEEL staff for undertaking this new and
challenging research program and believes that an expanded and long-term
sustained effort needs to be incorporated into EPA's overall research agenda.
Given the emerging nature of this research program, the IAEBS recommends
several actions to target limited resources, as well as to bolster funding for this
important research area.
a) The IAERS concurs with the AEBEL's research priorities to generate
scientific date and develop standard test methods to incorporate engineering
solutions into biocontaminant programs. The IABHS concurs with the
AEEEL that emphasis should be given to preventive approaches to control
conditions leading to biologic contamination over methods to control
organisms through bioddes and' other non-preventive remedies.
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b) It may be" useful to select indicator microbial species that are hardest to
control, on th£ theory that those methods which control these would capture
many other species simultaneously. Use of an expert panel would help
identify criteria for selecting such priority biocontaminants. Likewise, the
IAERS believes that additional in-house resources and expertise are needed
to critique and take full advantage of feedback from outside specialists.
c) The IAERS encourages the AEERL staff to re-evaluate the basis for
selecting ceiling tiles as the primary substrate in the dynamic chamber tests.
There is a need to expand emphasis on dynamic chamber tests in the nejct
phases of research as well as the need to test lower RH values, based on the
state-of-the-art practices for drying out buildings.
d) The IAERS encourages the AEERL staff to explore how'their research
should rely on and interact with other government and private research
programs, noting particularly the need to interact with the American
Institute of Architects (AIA), American Society of Heating, Refrigeration and
Air Conditioning Engineers (ASHEAE), American Society for Testing and
Materials (ASTM), Centers for Disease Control (CDC) and its National
Institute for Occupational Safety and Health (NIOSH), Interagency
Committee on Indoor Air Quality (CIAQ), Consumer Product Safety
Commission (CPSC), National Institutes of Health (NIH), various
universities and others,
e) While the AEERL's current target audiences emphasize academic
institutions and technical organizations, there may be a need to reach out to
a more diverse set of interests, such as allergy specialists, homeowners,
commercial building operators/owners, and consultants specializing in indoor
air issues.
1.4 Bioresponse-Based Testing
The IAERS agrees that bioresponse-based testing of emissions is a
reasonable extension of chemical-based testing. The IAERS further notes that this
is potentially a very important research area that, in conjunction with chemical
measurements, could provide an integrated approach to assessing the impacts of
emissions to the indoor environment. The IAERS also notes that, by analogy, the
EPA already has established the concept of bioresponse-based testing and toxicity
reduction evaluation (TRE) within its water effluent guidelines program.
a) The IAERS commends the AEERL staff for the Ml use of cooperative
agreements, and encourages further cooperation with the Agency's Health
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and Environmental Research Laboratory (HEEL) and the solicitation of
competitive av^grds and other mechanisms to encourage broader
participation within this research area.
b) The IAERS recommends that priority be given to establishing
correlations between biological response and the chemical composition of air
emissions, so that subsequent research efforts can be properly focused,
c) The IAERS raises concerns regarding the issues of time-dependence of
exposures, the rationale for relating the frequency of respiration hi animal
assays to the immediate response measures proposed, and the question of
odor perception in "control" or clean ah- atmospheres.
d) The IAERS recognizes that the overall expenditures in this program are
modest relative to the size of the problem, but encourages more proactive
development of specific budget and resource estimates along with
recommendations for joint cooperation with the HERL*
1.5 Strategic Direction
The IAERS recognizes that the future strategic direction of the AEERL
R&D program, while considered ambitious and appropriate, is important and
commendable.
a) The IAERS recommends that the AEERL look at a number of
management options, inclusive of pollution prevention, and utilize cost-
effectiveness (CE) modeling. The IAERS recognizes that not all avoided
risks can be assigned a monetary value, but to the maximum extent
practicable, those that can should be explicitly identified.
b) The AEERL R&D program should continue to stress comparative
studies, focusing on the complementary roles of prevention and control
strategies to develop practical guidance for building and product designers.
c) The IAERS recommends that the AEERL emphasize pollution prevention
over other control strategies.
d) The developers of models need to be sensitive to site-specific
applications, such as in the development and utilization of studies where
building designer and operator involvement are sought.
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e) The IAEHS recommends that the AEERL staff examine the recent
literature whiflji relates the inter-relationship between CE and pollution
prevention areas to ensure consistency of approach. The IAERS further
recommends that model development should be conducted with building
designers and architects so that the model results are consistent with their
existing cost and evaluation methods,
0 The IAERS encourages the AEERL to remain sensitive to the impact of
IAQ strategies on fire protection, particularly with regard to the effect of
stairwell and entrance-exit design for safe egress of occupants and fire
fighters and other emergency response personnel, especially during a fire
emergency, and especially for high-rise structures.
1.6 Additional Considerations
The IAERS recognizes that the current in-house research program
resources, supplemented by judicious use of contractor support, cooperative
agreements, and leveraging with other projects, are achieving positive and
impressive results. The IAERS further notes that:
a) The AEERL should add appropriate staff necessary to lead the
prioritized projects to develop a well-qualified and well-rounded
multidisciplinary research team to deal with an expanded charge, and
b) An overall plan should be presented and either funds be allocated to
more adequately reflect the stated mission of the program, or that the
mission be modified to focus more on exposure control strategies,
bioresponse measures and cost-effectiveness studies. If needed, justification
• for additional funding and resource allocations should be prepared.
This is the end of the Executive Summary. The body of the report follows
on the subsequent text.
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2. INTEODUCTION
The EPA ORD, Indoor Air Branch of the Air and Energy Engineering
Research Laboratory (AEEEL) at Research Triangle Park, North Carolina
prepared a document entitled "Indoor Air Engineering R&D Program," (hereafter
referred to as the document, or the R&D program. See Appendix A - reference 2).
The Indoor Air Engineering Research Subcommittee (IAERS) of the Environmental
Engineering Committee (EEC), with assistance from the Indoor Air Quality Total
Human Exposure Committee (IAQTHEC) of the EPA Science Advisory Board
(SAB), reviewed the document, dated June 1992, at a meeting on July 20 and 21,
1992. On those dates, the IAERS received detailed briefings from researchers and
research managers who developed the document (See Appendix A * reference 3 for
presentation materials), discussed the approaches, technical rationale, and merits
of the research and offered technical advice on this important research area.
The basic topics covered in this review of the indoor air engineering E&D
program included source characterization, source-exposure modeling, microbial
contaminant control, and strategic directions for the research. Additional review
occurred in mail correspondence with the IAEHS and the EEC. The EEC
conducted a public review for closure on this draft report at its October 28 and 29,
1992 meeting. Throughout the process, the IAEES offered additional commentary
to refine the recommendations contained herein.
The IAERS was given the following charge which focused on the existing
research and directions for future research. The original charge was transmitted,
along with the document to be reviewed, to Dr. K. Jack Kooyoomjian, Designated
Federal Official to the SAB's IAEBS in a July 19, 1992 memo from Mr. Frank T.
Princiotta, Director of the AEBRL (See Appendix A - reference 4). The charge
was subsequently modified at the July 20 and 21, 1992 review meeting (See
Appendk A - reference 3, and see note below)1. The revised charge to the
Subcommittee as presented at the meeting follows:
a) Is the EPA/ORD approach to source characterization - with its focus on
developing methods for characterizing emissions, sink effects, and exposures
-a rational and scientifically sound approach?
1 The IAERS recognizes the modification of the charge made at the meeting and
concurs with the emphasis on exposure. See Section 4, Modeling, page 11 for further
discussion on this point.
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b) Is the EPA/OBD approach to indoor air quality (IAQ) modeling for
evaluation of source-related exposures and IAQ control options sufficiently
rigorous and appropriately practical?
c) Are the EPA/OBD projects and plans for developing guidance on control
of mierobial contaminants reasonable and scientifically sound?
d) Is bioresponse-based testing of emissions from sources a reasonable
extension of chemically-based testing? Is it likely to improve EPA'a ability
to assess the health and comfort risks of indoor sources?
e) Is there any aspect of the strategic direction of the indoor air
engineering research program that should be re-evaluated?
The Subcommittee findings and recommendations respond directly to the
charge, and address other issues raised as a result of the review. The charge was
expanded by the IAERS to address the adequacy of fiscal and personnel resources
and the adequacy of technology transfer to practitioners and to educational
institutions as they relate to the above topic. The IAERS also wishes to note the
earlier findings of the SAB in its Reducing Risk report (See Appendix A -
reference 6) where indoor air issues were rated as a significant problem area. The
findings and recommendations of the IAERS are derived primarily from the
dialogue which occurred at the July 20 and 21, 1992 meeting, and from
subsequent deliberations on the topic by the IAERS, its parent committee, the
EEC, as well as the IAQTHEC as the coordinating committee.
This report is organized directly with each section addressing the charge, as
well as the IAERS offering wider-ranging guidance to strengthen the
implementation aspects of this important R&D program.
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3. SOUECE GHAHACTERBAHON
Is the EPA/OED approach to source characterization - with its fictts on
developing methods for characterizing emission*, sink effects, and exposures ~ a
rational ami scientifically sound approach?
This is a mature program with strong in-house capabilities. The good ^
productivity of the program Is reflected in many ways, including the leadership
role that the AEEEL has taken, both in this country and abroad, the successful
effort to develop many publications in peer-reviewed journals and the staff
participation and sponsorship of targeted specialty conferences. For instance, the
scientific validity of the approach developed for the small chamber studies is
reconfirmed by its adoption as an ASTM method.
The Subcommittee believes that the AEEEL's approach to source
characterization is appropriate, and that the development of methods that aid-in
understanding the fundamental interaction of emissions and sink effects on
individual exposures is important. The approach of using fundamental transport
models should certainly help in relating emissions to other physical and chemical
factors, as well as improve the ability to generalize this research. The focus of the
program has logically evolved from small chambers to field studies. There is a
good balance between small chamber testing, modeling and test-house studies,
However, the Subcommittee believes that it is important to have a large-scale test
facility for non-residential environments, and recommends that the AEBBL obtain
such a test facility. This could be a relatively modest-sized space (ie., 2000 square
feet) with a well controlled independent HVAC system. It would also be desirable
to have more interaction with field monitoring programs of other groups to
reinforce the practicality of the data.
The present emphasis on high vapor pressure compounds has been
adequately justified. However, with new information appearing in the ^literature
regarding semi-volatile organic compounds as possible IAQ pollutants, it may be
appropriate to include them in the continuing work It is also observed by the
Subcommittee that the future direction of the program, while appropriate, is overly
ambitious given the present level of funding.
There are several recommendations that would help the laboratory prioritize
its efforts. These include:
a) A unifying, conceptual model should be developed to effectively inventory
sources and sinks. This would link into the cataloging effort currently _
underway. One recommendation is to use the format of the loci (also listed
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as LOCI) model developed by RREL-Edison (EPA/600/2-91/053) (See
Appendix A - reference 5) as an example, as well as Appendix B - Glossary
of Terms and Acronyms.
b) The AEERL needs to systematically characterize criteria used for
selecting sources and sizes for analysis.
c) There is a need to examine the process by which certain environmental
parameters (e.g., T, RH) are being considered in the dynamic chamber tests.
d) Consideration should be made of emissions from processes and people.
e) More feedback from engineers and architects should be obtained to
ensure an effective transfer of data and dialogue with, this audience,
D A formal plan for technical outreach should be derived for effectively
providing information to the EPA program office for public distribution.
g) Some consideration should be made to emphasize pragmatic applications
of this research to realize reduced risks.
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4. MODELING
Is the EPAJORD approach to indoor air qualify (tAQ) modeling jbr
evaluation of source-related exposures and IAQ control options sufficiently rigorous
and appropriately practical?
The inclusion of an IAQ modeling component in the AEERL research
program is appropriate and important. The AEERL staff properly recognizes the
role of modeling as both a predictive tool for particular evaluations and
assessments, and as a means of integrating the various components of the research
program. This is evident in the role that modeling has played in identifying the
need for more mechanistic source representations, and the importance of sink
processes in IAQ assessments. It is also evident in the planned role for modeling
in evaluating the results of current and future research on source control,
ventilation and air cleaning options. The AEERL modeling program has properly
emphasized the importance of field validation studies, consistent with the general
guidelines provided to the Agency by the SAB (See Appendix A - reference 1 -
The Modeling Resolution). As such the overall approach to modeling taken by
AEERL is judged to be appropriately directed and rigorous.
The excellent quality of the IAQ modeling effort is evident by the number
and quality of peer-reviewed journal publications, conference presentations and
organization, development of useful working tools, and the general impact on the
direction and progress of the research community. Accomplishments of the
modeling effort are particularly noteworthy, given the modest budget and in-house
personnel resources devoted to this activity. The IAERS does, however, have
suggestions on refinements to the current directions and focus for the research
which we believe will lead to continued and increased quality and positive impacts.
These include areas of technical focus, as well as mechanisms for dissemination of
results, and are discussed below.
a) Further sensitivity studies of the model are needed to examine the
effects of environmental factors such as temperature (T) and relative
humidity (RH), and to examine the behavior of the model at low
concentrations where sink processes are likely to dominate initial source
effects, so that appropriate models for desorption can be identified.
b) The IAERS notes the importance of mixing and transport processes for
exposure evaluations. While development of a model for predicting exposure
to intimate sources is included in the proposed research plan, the
importance of localized gradients and channeling effects for personal
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exposure is such that broadened and greater emphasis is recommended.
Non-ideal trantport models will be especially important when evaluating
bioeontamination, where particle processes must be considered in addition to
the gas phase transport. Evaluation of non-ideal mixing and transport, to
the extent that it would have practical value in managing risks from indoor
air exposures, should be included as a regular part of experimental
evaluations in large chamber and field studies by including multiple
sampling points in chambers or rooms with source emissions.
The importance of modeling and validation of personal exposure estimates
was noted by the IAERS, There was some concern that initial emphasis on source
characterization may have limited utility of the IAQ model for exposure
characterization. Some of the confusion was because the initial charge to the
IAERS did not mention "exposure" prediction as an objective of the modeling
program, nevertheless, the IAEES recognizes the modification of the charge made
at the meeting and concurs with the emphasis on exposure.
The model can be appropriately used for exposure assessment, so long as
realistic building and human activity descriptions are selected. However, there
does not appear to be sufficient emphasis on determining these for the IAQ model.
The reason given for this is that the ABERL responsibility is constrained to
providing a tool for individual exposure, as 'Opposed to population exposure, which
is the responsibility of the Health and Environmental Research Laboratory
(HERL). The IAEES believes that this constraint is too limiting, and that the real
utility of the model for exposure assessment will come when it is interfaced with
realistic, flexible models for air exchange, ventilation, human activities, and the
interaction between these factors (Le, certain activities involve the initiation of
sources, or the changing of air flow patterns by opening doors, windows, etc.).
The division of responsibility between AEERL and HERL appears to be artificial,
and may be slowing the needed progress. Collaboration on joint model
development should occur; additional resources (if they are needed) should be
provided to facilitate this collaboration. This effort should include increased
emphasis on field studies and methods for validating exposure predictions.
The IAERS believes that artificial barriers of responsibility within the
Agency may be limiting broader applications, and greater interaction with other
programs is encouraged. For instance, another area where the limited focus of the
AEERL research program has, until now, been appropriate to promote quality
progress with limited resources, but where future impact may be unnecessarily
constrained, involves the sole focus of the research program on organic air toxics.
Other critical issues to the Agency, including asbestos and lead exposure, would
greatly benefit from the type of integrated IAQ model developed by the AEEEL
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staff. Similar issues arise as to the benefits of source control versus alternative
measures for exposu|e reduction (for example, in remodeling old homes with lead-
based paint), and the model could provide useful insights for these issues.
An important part of the IAQ modeling program is the transfer of the
model and the modeling capability to the user community. To date, this has been
very successful within the IAQ research community.
Additional efforts to expand this technology transfer, with focus on
particular target groups, is recommended. These include:
a) M9de* users: Actively solicit comments by providing a brief
questionnaire when the ioftwmre is distributed. Since the software is
distributed without charge, the request that these questionnaires be
completed and returned to EPA should be viewed as a necessary and
reasonable requirement of users.
b) Buildiftg designers, manage and operators: Efforts to interface with
and serve the needs of this group can lead to widespread, practical
application of the methodology, with a potentially great impact on IAQ. To
accomplish this, there will be a need to expand the capabilities of the model
to deal with larger, more complex buildings (the current emphasis has been
on residential and small commercial buildings), and to readily allow for
summary representations of model output (Le.» total exposure, peak
concentration, etc.) comparable in detail to other design criteria used by
building professionals. The plan to incorporate a cost component to the
model provides the opportunity for closer interaction with the building
design and management community. An important issue that requires
further consideration is whether to preset the model with default values for
particular design scenarios, so that the model will be easy to use, even for
novice architects and engineers, or to require individualized input so that a
high level of user expertise is mandated.
C) University re^^herg and studentsi The internal focus of the research
program has been successful, however, it is time to encourage broader
participation. The AEERL program is in the forefront of IAQ model
development, and more indoor air researchers and specialists can benefit
from the expertise, leadership, and experience of the AEERL in-house staff.
Research projects on individual sources, sinks, and transport factors should
be encouraged. The model itself would be very useful as a classroom
educational tool, for both architects and engineers. This type of model
transfer would lead to future designers, builders and managers becoming
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more aware of the need for considering indoor air environmental quality in
their activities.
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5. MICRQBIAL CONTAMINANTS
Am the EPA/ORD jwtyeels and plans for developing guidance on control of
microbial contaminants reofonoWe and scientifically mund?
The IAEES commends the AEBRL staff for undertaking this new and
challenging research program and believes that an expanded and long-term,
sustained effort needs to be incorporated in EPA's overall research agenda. This
emerging research program is responding to heightened public concerns over
biological contamination in buildings and numerous private ventures attempting to
respond to those concerns. Clearly, there is a prevalence of conjecture and
anecdotal evidence in this area with little scientific data available to design
appropriate prevention and control programs. In particular, the Subcommittee
concurs with the following research priorities:
a) To generate scientific data and standard test methods which can be used
by EPA and other organizations for biocontaminant programs.
b) To incorporate engineering solutions into biocontaminant programs.
c) To emphasize preventive approaches to control the conditions leading to
biologic contamination over methods to control organisms through biocides
and other non-preventive remedies,
Given the emerging nature of this research program, the Subcommittee
believes that very basic questions need to be addressed by the research and makes
the following recommendations which recognize the need to both target limited
resources, as well as to bolster funding for this important research area:
i
a) In general, the plan needs better specification of the research problem
including enunciation of research hypotheses. The plan should retain the
preventive approaches to control the conditions leading to biologic
contamination over methods to control organisms through biocides and
other remedies.
b) Indicator species are used in most every EPA media program, such as E«
coli for drinking water. This allows inexpensive screening tests in place of
very expensive tests for specific chemicals or agents. While not without its
problems, it may be useful to select indicator species in the indoor air
research program that are hardest to control, on the theory that those
methods which are effective for those indicator species would control many
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other species simultaneously. Use of an expert panel would help identify
such criteria f§r selecting priority biocontaminants,
c) Funding and manpower constraints underscore the need to clearly
understand and specify criteria for selecting various research- parameters--
partieularly the organism! for analysis. While the choice of penieillium
fungi may be practical and reasonable, further specification of desirable
testing characteristics is warranted to justify that choice. For example,
some species are particularly sensitive to temperature (T) and relative
humidity (RH); others are viable under a wide range of environmental
conditions.
d) The IAERS believes that additional in-house resources and expertise are
needed to critique and take full advantage of feedback from outside
specialists. Such complementary expertise is common practice for EPA's
chemical research programs, but wholly absent from this project.
Specialized training in microbiology could be secured for existing staff to
develop greater expertise within EPA, Likewise, an interageney transfer
from the CDC could be brought in to oversee the program,
e) The IAERS raises specific questions concerning the basis for selecting
ceiling tiles as the primary substrate; the need to simulate more realistic
types of surface contamination versus use of sterilized surfaces in tests; the
need to expand emphasis on dynamic chamber tests in the next research
phases; and the use of lower EH values based on state-of-the-art practices
for drying out buildings (i.e., less than 20% HH versus 33% RH).
f) It is critical for the AEERL staff to explore how this effort should rely
on and interact with other government research programs in EPA, NIH,
CDC, and its NIOSH and elsewhere. This interaction will build on existing
successful efforts to obtain support from widely-recognized private and
public institutions (e.g., various universities, ASTM, ASHRAE, CPSC, AIA).
Clearly, significant progress cannot be made in the area of biologic
contamination without additional resources and expertise. As such, it may
be advisable to ask the CIAQ to devise a programmatic and budgetary
strategy for conducting research in this area.
g) Preliminary results from the first-phase static chamber tests with
penicillium already have yielded results which could greatly improve the
effectiveness of current prevention strategies. This points to the need for
EPA to devise an education and outreach strategy for the microbial
contaminant program. While the AEERL's current target audience
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emphasizes academic institutions and technical organizations such as ASTM,
EPA program offices should reach out to cither audiences including allergy
specialists, homeowners and building operators, building managers, and
popular magazines.
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6. BIORESPQNSE-EASED TESTING
Is biormponse-based testing of emissions from sources a reasonable extension of
chemically-based testing? Is it likely to improve EPA's ability to assess the health,
and comfort risks of indoor sources?
The IAERS agrees that the bioresponse-based testing of emissions is a
reasonable extension of chemical-based testing. This is potentially a very
important research area that, in conjunction with chemical measurements, could
provide an integrated approach to assessing the impacts of emissions to the indoor
environment. By analogy, the EPA already has established the concept of
bioresponse-based testing and toxicity reduction evaluation (THE) within its water
effluent guidelines program. Lessons already learned from the other media
programs may be useful. The IAERS offers the following suggestions and
observations;
a) The AEERL has unique skills and strengths to contribute to an overall
program of bioresponse-based testing. Specifically, the Subcommittee noted
the available in-house and extramural skills with regard to the generation
and characterization of relevant complex mixtures representative of potential
indoor exposures to specific sources, and the opportunity to couple this
capability with objective biological endpoints.
b) The Subcommittee commends the AEERL staff for the establishment of
cooperative agreements both with Dr. Leaderer and his colleagues at the
J.B. Pierce Laboratory at Yale University and with Dr. Molhave and
colleagues at Arhus University in Denmark that seek to establish objective
measures of response. These are two of the leading research groups
studying the effects of low level VOC exposure. In addition, IAERS
encourages further cooperation with the Agency's HERL, and, as time and
resources permit, solicitation of competitive awards and cooperative
agreements, as well as other mechanisms to encourage broader participation
within this research area. Priority should be given to engineering issues
and health-based testing and coordination, such as establishing correlations
between biological response and the chemical composition of air emissions,
so that subsequent control efforts can be properly focused. Continued
collaboration and linkage between AEERL and HERL on the engineering
and health effects to examine the biological aspects is encouraged,
c) Specific concerns raised by the IAERS include the issues of the time-
dependence of these exposures, the rationale for relating frequency of
respiration in animal assays to the immediate response measures proposed,
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and the question of odor perception in "control", or clean air atmospheres.
Some questions that need to be addressed by the research include: (1) How
are time-varying exposure concentrations considered within the traditional
dose-response framework? (2) What are the underlying biological
mechanisms relevant to the analogy between respiratory frequency and odor
or other immediate irritant effects? (3) How is the co-variate of odor
perception controlled for in the design of objective response studies?
d) The IAERS recognizes that the overall expenditures are modest relative
to the size of the problem, but encourages more proactive development of
specific budget and resource estimates within this sub-program, including
explicit details of joint cooperation with the HERL.
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7. STRATEGIC DIRECTION
Is there any Aspect of the strategic direction on the indoor air engineering research
program that should be re-evaluated?
The future proposed directions of the AEERL R&D program, while considered
ambitious, are appropriate, important and commendable. The IAERS recommends
that:
a) With regard to IAQ, common sense dictates that if pollution is not
produced, it will not pose harm to the environment or to building occupants.
However, when indoor air pollutants are generated, avoidance of indoor air
pollutant sources may not be altogether practical in some instances.
Therefore, alternative management options or some combination of options
inclusive of pollution prevention may have to be considered (e.g., air
cleaning or venting). These management options can be investigated
utilizing cost-effectiveness (CE) modeling.
b) The AEERL R&D program should continue to stress comparative
studies, focusing on the relative roles of prevention and control strategies.
Building and product designers need such practical guidance that evolves
from this R&D activity,
c) The IAERS agrees with the AEERL staff that it will be necessary in the
R&D program to consider CE as an important, and perhaps critical, tool in
the area of IAQ pollution prevention: CE must be included in the context of
the proposed program. It will be important to have such tools that enable
recognition of the CE activities which encompass pollution prevention
objectives related directly to improving IAQ. Additional emphasis upon CE
model development is warranted,
d) Less quantifiable and longer-term costs associated with control options
that lead to the Agency's waste management hierarchy, as it relates to
pollution prevention must be recognized. At a minimum, the CE model
should specify "routine" cost factors and identify other increments associated
with pollution prevention objectives. Not all avoided risks can be expressed
in monetary terms, but to the maximum extent practicable, these should be
explicitly identified,
e) The AEERL program should be undertaken with a clear recognition of
objectives. For instance, one question that should be asked: Is the model to
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be developed, intended for design purposes, or alternatively, to support a
more far-reaching context, such as a regulatory development or interest?
f) Models can easily be "misapplied." Moreover, the developers of models
should be sensitive to site-specific applications, such as in the development
and utilization of scenarios where building designer and operator
involvement should be sought. In addition, the similarity between
"effectiveness" and "productivity" models should be considered in the context
of their ultimate utility to the target audience.
g) It will be important to clearly define the target audience. Moreover, the
desired impact (e.g., pollution prevention) upon the targeted audience should
be determined. Some guidance needs to be provided as to trade-offs which
address alternative management strategies, (Le, combinations of pollution
prevention, air cleaning and venting).
h) It should prove worthwhile, early in the exercise of developing CE
models to consider what models already exist, and how they might relate to
the proposed effort.
i) The AEERL program must account for current initiatives reported in the
literature. In particular, recent literature which relates to the inter-
relationship between CE and pollution prevention areas of investigation
should be examined to identify the applicability of current knowledge in this
area.
j) It is recommended that CE model development be conducted in
collaboration with building designers and architects so that the model
results are consistent with their existing cost and evaluation methods. The
01 model results should easily interface with these methods, to encourage
its use for various indoor air applications. Interaction with and review by
an economist will be needed to ensure that life cycle costs are appropriately
calculated. Peak concentrations and ambient emissions should be added to
the measures of effectiveness which may be considered for particular
applications.
k) In addition, EPA has cost manuals directed at small vent VQC control
technologies for emissions to the ambient environment. These might be
considered in the cost analysis.
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1) It is considered advisable to provide the highest level of disaggregation of
the costs in development of any of the computer models, in order to provide
the most flexible cost models for a wide variety of users.
m) It ii to be stressed that reduction of exposure to air contaminants must
not simply be at the cost of increased export of contaminants to the outside
environment. It would be inappropriate to vent contaminants to the outside
air. CE analysis must be sensitive to this issue.
n) The IABRS encourages the AfiERL to remain sensitive to the impacts of
IAQ strategies on fire protection, particularly with regard to the effect of
stairwell and entrance-exit design for safe egress of occupants and fire
fighters and other emergency response personnel, especially during a fire
emergency, and especially for high rise structures.
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8. ADDITIONAL CONSIDERATIONS
The IAERS was mindful of resource constraints. The ORD research staff
have made an earnest effort to implement Total Quality Management (TQM)
principles in all its activities. The IAERS expects that the ORD staff should
expect to seek continuous improvement to its research program, and to make
incremental changes, within their resource constraints, to try to achieve their goals
over some period of time which is likely to be longer than several fiscal years.
The IAERS could not come to a consensus on a prioritization of
recommendations, because we tended to favor research areas that each member
was familiar with. However, each member was comfortable with th« continuous
improvement observed within the research program. Instead of ranking the
recommendations and having only the top three of four addressed fully, the IAERS
asked that all the recommendations be addressed incrementally over time to better
improve a research program that is already quite good.
The IABRS, during their review, identified two other points of concern, and
considered them as a sixth charge. These two points are as follows:
a) The adequacy of fiscal and personnel resources to accomplish the R&D
mission; and
b) The adequacy of information transfer to practitioners and to educational
institutions.
8.1 Resource Allocation
With regard to resource allocations, two concerns were identified;
a) The allocation of resources should reflect the mission and objectives of
indoor air engineering R&D; and
b) The research projects should be prioritized to match the available or
anticipated resources.
The IAERS notes that $1,150K of the total budget of $2250K has been
allocated to air cleaner testing and evaluation ($650K) to ventilation ($350K) and
bioresponse ($250K, with a $175K Congressional add-on), and that no funds have
been allocated to CE studies. We recommend that the funds be allocated to more
adequately reflect the stated mission of the program or that the mission be
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modified to focus more on exposure control strategic! (i.e., ventilation and air
cleaning), bioresponse measures and CE studies. We have been advised by the
Agency ORD/RTP staff that $461K has been spent in prior years in cooperative
agreements, but much of that funding was not spent directly on bioresponse
research (mostly kerosene heater emissions).
The IAERS recognizes that the current in-house research program
resources, supplemented by judicious use of contractor support and cooperative
agreements, and leveraging other projects are achieving positive and impressive
results. However, the IAERS also encourages the AEERL to add appropriate staff
(e.g., architect, HVAC engineer, bioengineer, engineering economist) to lead the
prioritized projects, so that an intrinsically thorough understanding of the
procedures and outcomes can be developed by a well-qualified and weE-rounded
multidisciplinary research team to deal with an expanded charge.
Finally, the IAEES recommends that an overall plan be developed and
presented that prioritizes all of the current and proposed B&D projects within
available resources, and that, if needed, justification for additional funding and
resource allocations be prepared.
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APPENDIX A - EEFERENCiS CITED
1) U.S. EPA^T'^solution on U~
Rugulmtory Assessment and decision-Making,"
January 13, 1989
2> US EPA/ORD/AEERL, "Indoor Air Engineering R&D Program,".
^ TT Q FPA/ORD/AEEEL, "Indoor Air Engineering B&D Program: Source
3> S2iSiEsSSi.&PO-» Modeling, ***U(££>«£*^
ATwi Strateaic Dirsctions" Presentation Materiala Submitted to toe J^fi s
k— r eh ?^™Ti±^ t±^°°r
Branch, Air and Energy Engineering Research Laboratory, Eesearch
Triangle Park, N.C., July 20, 1992
A) IT S EPA/OED/AEEEL, memorandum entitled "Report on Indoor Air
Triangle Park, N.C,» dated «My 19, 1992
« TT Q FPA/ORD/SREL "Assessing UST Corrective Action Technology; A
51
September 1991
*\ TT cj FPA«AR "Reducing Risk: Setting Priorities and Strategies for
6) The Report of the %»*££%
Relative Risk .Reduction Strategies Committee. (EPA-SAB-EC-90-
September 25, 1990.
A-l
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APPENDIX B - GLOSSARY OF TERMS AND ACRONYMS
AEERL Air and Energy Engineering Research Laboratory
AIA American Institute of Architects
AREAL Atmospheric Research and Exposure Assessment
Laboratory
ASHRAE American Society of Heating, Refrigeration and Air Conditioning
Engineers
ASTM American Society for Testing and Materials
CDC U.S. Centers for Disease Control (Atlanta,
Georgia)
CE Cost-Effectiveness
CIAQ Interagency Committee on Indoor Air Quality
CQRRE Corporation on Resource Recovery and the
Environment
CPSC U.S. Consumer Product Safety Commission
EPA U,S. Environmental Protection Agency (U.S. EPA, or "The Agency")
EEC Environmental Engineering Committee (SAB/EPA)
FY Fiscal Year
HERL Health and Environmental Research Laboratory
(U.S. EPA/ORD)
HQ Headquarters
HVAC Heating, Ventilation and Air Conditioning
IAERS Indoor Air Engineering Research Subcommittee
IAQ Indoor Air Quality
IAQTHEC Indoor Air Quality and Total Human Exposure Committee
K Thousand (dollars)
LOCI Underground Storage Tank Conceptual Model
Developed by the U.S. EPA/ORD Risk Reduction
Engineering Laboratory (REEL)
NC North Carolina
NIH National Institutes of Health
NIOSH National Institute for Occupational Safely and Health (NIOSH)
ORD Office of Research and Development (U.S. EPA)
GTS Office of Toxic Substances (U,S. EPA)
R&D Research and Development
RH Relative Humidity
RREL Risk Reduction Engineering Laboratory (U.S.
EPA/ORD)
RTF Research Triangle Park
SAB Science Advisory Board (U.S. EPA)
T Temperature
TQM Total Quality Management
TRE Toxicity Reduction Evaluation
US United States
VOC Volatile Organic Compound
B-l
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