Program Needs for
Indoor Environments Research (PNIER)
March 2005
www.epa.gov/iaq/pdfs/pnier.pdf
-------
U.S. EPA, 402-B-05-001, March 2005
-------
U.S. Environmental Protection Agency
Program Needs for Indoor Environments Research (PNIER)
INTRODUCTION
Overview:
All across our nation, people live, work, and learn in indoor environments. On average, people
spend approximately 90% of their time indoors, where many pollutant levels are often two to five
times higher than outdoors. The EPA and its Science Advisory Board have ranked indoor air
pollution among the top five environmental risks to public health (U.S. EPA, 1987;
U.S. EPA, 1990).
The Indoor Environments Division (IED), located within the Office of Radiation and Indoor Air
(ORIA) under the Office of Air and Radiation (OAR), is the lead U.S. EPA program office for
issues relating to indoor environmental quality. The Indoor Environments Division focuses on
several priority areas including: indoor air toxics, asthma, radon, schools, and environmental
tobacco smoke. Additionally, there are several other offices within the EPA that have significant
responsibilities related to the indoor environment within their programs. These offices include,
but are not limited to, EPA Regional Offices, the Office of Research and Development (ORD),
the Office of Children's Health Protection, the Office of Pollution Prevention and Toxic
Substances, the Office of Solid Waste and Emergency Response, and the ORIA laboratories.
This document, Program Needs for Indoor Environments Research (PNIER), is a strategic
document outlining EPA's research needs for the indoor environment. The PNIER concept was
initiated within the Indoor Environments Division, and the document developed into its present
form through strong collaboration with other EPA offices. PNIER is considered a 'living
document' that can evolve to reflect the changing needs of EPA program offices and researchers
through periodic updates and revisions.
PNIER is intended to be a document that captures the indoor environments research needs for all
EPA offices with program responsibilities related to indoor environmental quality. It is
envisioned that PNIER will be a valuable document that can serve several purposes, including:
• articulating EPA's indoor environments research needs, for both internal and external uses;
• identifying where knowledge gaps exist;
• helping to establish a more well-defined presence for an indoor environments research
program at EPA;
• facilitating collaboration between EPA program offices and research offices when developing
research agendas and awarding research grants;
• fulfilling EPA's Healthy Buildings, Healthy People (HBHP) initiative, which calls for the
development of a high-level, cross-Agency indoor environments research strategy. PNIER
could serve as EPA's foundation towards this larger cross-agency research strategy, and could
influence research performed by other agencies and organizations (U.S. EPA, 2001).
U.S. EPA, 402-B-05-001, March 2005
-------
PNIER is limited to the EPA's indoor environments research needs, and is not intended to be a
'global' document for all possible indoor environments research. While PNIER is intended to
describe EPA's indoor environments research needs, it is not envisioned that all research
contained within PNIER be performed directly by EPA's research community. In some cases, it
may be appropriate for the research to be performed by other government agencies, private
industry, non-profit organizations, or other outside parties. It is also important to note that
while PNIER describes research needs, it does not attempt to prioritize the research needs
or catalog any ongoing research efforts that may support PNIER.
PNIER Development History:
The PNIER development process included close coordination with a wide range of EPA offices
and staff. The following PNIER development and review sequence was performed:
• The initial PNIER concept was presented, with requests for input and comment, to EPA's
Indoor Environments Division staff and EPA Regional staff working on indoor air and
radon-related issues in a series of meetings held during the spring of 2001. The initial PNIER
concept was also presented to the EPA's ORD staff, and staff from other EPA offices, at an
Indoor Environments Scientist-to-Scientist meeting in May 2001.
• Members of the IED Scientific Analysis Team outlined and drafted preliminary sections for
the PNIER programmatic and technical areas shown in the content outline on page 4. Outlines
and preliminary drafts were discussed and revised by the IED Scientific Analysis Team during
regular meetings dedicated to PNIER (June 2001-February 2002).
• The IED Scientific Analysis Team conducted an internal team-based review of the initial
compiled draft of PNIER, and developed a revised draft (March 2002 - May 2002).
• PNIER was reviewed by the IED Division Director and IED staff. Comments were resolved,
resulting in a version of PNIER that was considered a suitable starting point for soliciting
input and comments from other EPA offices (June 2002 - November 2002).
• The initial PNIER draft developed by the Indoor Environments Division was distributed to the
following EPA organizations for review and comment in January 2003:
- Office of Research & Development (ORD)
- Office of Children's Health Protection (OCHP)
- Office of Prevention, Pesticides and Toxic Substances (OPPTS)
- Office of Solid Waste and Emergency Response (OSWER)
- Office of Air and Radiation, Office of Air Quality Planning and Standards (OAR/OAQPS)
- Office of Air and Radiation, Office of Atmospheric Programs (OAR/OAP)
- Office of Air and Radiation, Office of Transportation Air Quality (OAR/OTAQ)
- EPA Regional Offices (Regional Program Managers for indoor environments)
- Radiation & Indoor Environments National Laboratory / Las Vegas (RIENL)
• Comments were received from reviewers between late January and late April 2003. IED staff
considered the review comments and developed a revised version of PNIER that was
redistributed to EPA reviewers (April-July 2003).
• Indoor environments research needs, primarily within the context of PNIER, were discussed
during an. Indoor Environments Scientist-to-Scientist meeting on September 3-4, 2003, that
included staff from several EPA offices. Follow-up actions planned from that meeting include
2 U.S. EPA, 402-B-05-001, March 2005
-------
ORD developing an indoor environments 'research framework' for presentation to ORD's
upper management, modifying the EPA's multi-year research plans to incorporate indoor
environments research needs, and evaluating ORD's capabilities and identifying research that
may be accomplished through organizations external to the EPA.
Indoor Environments Research Criteria:
The following criteria were established for assessing the suitability of research items to be
included in PNIER:
1. Research must be consistent with the EPA's authorization under Title IV of the Superfund
Amendments and Reauthorization Act of 1986 (SARA), which gives the EPA broad
authority to conduct research on indoor air quality (IAQ) issues, develop and disseminate
information on IAQ, and coordinate IAQ efforts at the federal, State and local levels.
2. Research should be for indoor environmental health risks predominantly due to inhalation
exposure, and health risks predominantly associated with indoor sources, or which maybe
managed by controlling indoor exposures. This also includes managing outdoor sources that
impact the indoor environment.
3. Research should focus on indoor environments that the general public frequently accesses
(e.g., residences, schools, offices, public buildings, vehicle passenger compartments, etc.).
Research should not address specialized indoor environments with established regulations
(e.g., industrial work sites, hospitals, and other specialized occupational settings).
4. Research should address perceived high risk areas where there is apractical likelihood to
implement corrective actions. Research is expected to provide a reasonable return-on-
investment.
5. Research that motivates public action, industry development, and real-world implementation
of indoor environmental improvements should be included.
6. Research that builds on the existing knowledge base and that supports current EPA activities
and priorities for the indoor environment should be included.
7. Research should be accepted and endorsed by organizations outside the EPA
(peer acceptance of the research).
8. Research should focus on areas that are not currently addressed by mature programs
(e.g., asbestos, lead).
9. Research should be for efforts that could be initiated within the next five years, and
completed within the next ten years. Research may include efforts that are already underway
or represent an expansion of those efforts.
10. When research is intended to develop methods to mitigate indoor air problems, an analysis of
the efficacy of the methods should be done.
U.S. EPA, 402-B-05-001, March 2005
-------
PNIER Content Outline:
Indoor environmental quality is an extremely broad subject, and there are many possible options
for presenting research categories. The following content outline was developed as an attempt to
meld categories useful for organizing basic research with those that support EPA's program
needs. Detailed indoor environments research needs for these outline topics are presented in the
following sections, starting on page 5.
A. POLLUTANTS, SOURCES AND HEALTH EFFECTS
A. 1. Chemicals (Including Indoor Air Toxics)
A.2. Biological Contaminants
A.3. Sensitization, Allergy and Irritation Health Effects
A.4. Particulate Matter
B. HUMAN PERFORMANCE
C. IAQ MEASURES AND INDICES
C. 1. Building IAQ Indices
C.2. Development of Public Health Measures for IAQ
D. BUILDING DESIGN AND OPERATION
D.I. Building Characterization and Intervention
D.2. Ventilation Systems
D.3. Radon Control
D.4. Building Design and Implementation
E. HOMELAND SECURITY
F. PRODUCT AND TECHNOLOGY VERIFICATION
References for Introduction:
U.S. Environmental Protection Agency (U.S. EPA). 1987. Unfinished Business: A Comparative
Assessment of Environmental Problems. Washington DC: U.S. Environmental Protection
Agency.
U.S. Environmental Protection Agency (U.S. EPA). 1990. Reducing Risk: Setting Priorities and
Strategies for Environmental Protection. Washington DC: U.S. Environmental Protection
Agency. EPA-SAB-EC-90-021.
U.S. Environmental Protection Agency (U.S. EPA). 2001. Healthy Buildings, Healthy People:
A Vision for the 21st Century. Washington DC: U.S. Environmental Protection Agency.
EPA 402-K-01-003.
U.S. EPA, 402-B-05-001, March 2005
-------
A. POLLUTANTS AND SOURCES
A.l. CHEMICALS (INCLUDING INDOOR AIR TOXICS)
Background Information:
In the early 1980's, the relatively high exposures and potential risks from toxic chemicals in the
indoor environment became recognized through the EPA Total Exposure Assessment
Methodology (TEAM) studies (Wallace, 1987). Since that time, the potential exposures and
risks from toxic chemicals in indoor air have been confirmed by a number of studies, both within
and outside EPA (U.S. EPA, 1998). However, with the exception of joint programs between
ORIA and OPPT in the late 1980's and early 1990's to address emissions from carpet products
and wall paint, little effort has been directed at research to evaluate and manage these exposures
and risks, in part because there have been no regulatory drivers that require EPA to do so.
Since the enactment of the Clean Air Act Amendments of 1990, work on reducing toxic
chemicals in ambient (outdoor) air from stationary emissions sources has focused mainly on
developing standards based on technology [i.e., maximum achievable control technology
(MACT) and generally available control technology (GACT) standards]. The Agency is now
required to address the "residual risk" remaining after promulgation of these standards and,
therefore, is moving into a "risk-based" assessment process which requires new and improved
assessment tools. In addition, the Agency's mobile source program is required to study the need
for, and feasibility of, controlling emissions of toxic air pollutants associated with motor vehicles
and fuels, and to set technology-based standards to reduce exposures from these sources. While
the Agency is mandated to address toxic air pollutants from outdoor sources only, in some cases
indoor exposures to these substances may be greater than those from outdoors. Currently, the
Agency does not know enough about the relative exposures and risks resulting from indoor and
outdoor sources to fully understand the relative importance of these sources.
In the past few years, the outdoor and indoor air toxics programs have become much more
integrated and have started to address the close connections between indoor and outdoor
environments and each environment's impact on the other. Although research is needed to
address indoor, stationary, and mobile sources of toxic air pollutants, in general, research has
focused on outdoor air toxics.
While some research on chemicals and mixtures is useful for determining risks from both indoor
and outdoor pollutants (e.g., dose-response assessments, time-activity studies), certain types of
unique research activities are needed to address indoor risks. For example, the methods used to
determine emissions characteristics, to model the flow of pollutants, to study the fate and
transport of pollutants, and to manage risks are substantially different for indoor and outdoor
environments. Therefore, in these areas, research directed at studying outdoor pollutants cannot
substitute for indoor air research.
The long-term program goals for research on chemicals and their sources are to: (1) develop and
refine systems that can be used on an ongoing basis to prioritize and select those chemicals and
mixtures, in addition to radon and environmental tobacco smoke, that are of concern in indoor
U.S. EPA, 402-B-05-001, March 2005 5
-------
environments, (2) further develop methods to determine how the selected pollutants and mixtures
of concern interact with the indoor environment, with each other, and with other chemicals
(e.g., ozone), (3) examine the determinants of exposure for, and the potential risks posed by, the
chemicals and mixtures of concern, and (4) develop methods and practices that can be used to
mitigate any substantial risks of the selected chemicals and mixtures.
Program Needs for Chemicals (Including Indoor Air Toxics) Research:
A.I.a. Determine chemicals and mixtures found in indoor environments.
A.l.a.l. Perform additional baseline analyses to determine the typical levels of
chemicals in indoor environments.
EPA recently completed the sampling portion of the Building Assessment,
Survey, and Evaluation (BASE) study to determine the typical concentration
distributions of a number of chemicals found in a representative sample of U.S.
office buildings and to correlate these pollutant levels with building parameters
and occupant activities and symptoms. However, similar studies have not been
completed in other types of buildings (e.g., homes, schools, day care facilities,
retail establishments, etc.) and the number and types of pollutants monitored in
the BASE study was not comprehensive (i.e., chemicals to be monitored were
selected based on past studies and ease of sampling and analysis). Studies such as
BASE need to be expanded to a larger set of building environments and a broader
spectrum of pollutants (see section D.I.a. for additional discussion). In addition,
the data (existing BASE data and future data collected) need to be analyzed to
assist in determining the potential sources of the chemicals indoors.
A.l.a.l. Analyze formulation and emissions data for products and materials used
indoors to determine likely chemical exposures indoors.
Another source of information on chemicals that may lead to exposures indoors is
formulation and emissions databases for products and materials used indoors.
Some data are available on product formulations through voluntary industry
disclosure and, in rare cases, have been obtained through required industry
disclosure under the ambient air program of the Clean Air Act (CAA). However,
most of the available data on product formulations were obtained prior to 1990,
which limits their usefulness. Data for some chemical exposures may also be
obtained through current programs such as the EPA Voluntary Children's
Chemical Evaluation Program (65 FR 81700), which provides data on exposures
to 23 chemicals to enable the public to better understand the potential health risks
to children, or through work with the Organization of Economic Cooperative
Development (OECD) to develop emissions scenario documents for products.
Another source of product formulation data is Material Safety Data Sheets
(MSDSs); however, these data sheets may not list all the potential chemicals of
concern in a product or material used indoors. For a more limited number of
products and materials, emissions data are available in the literature through
6 U.S. EPA, 402-B-05-001, March 2005
-------
chamber or field studies. Formulation and emissions databases for products and
materials are particularly useful where the data have been used in indoor air
quality models to assess potential concentrations, and related exposures, indoors.
A.l.a.3. Evaluate levels of pollutants that may result from particular exposure
scenarios of concern.
Studies such as BASE, which evaluate the typical concentrations of chemicals and
mixtures indoors, do not effectively address the high level exposures that may
occur under special circumstances. For example, high level exposures may occur
during the use or storage of specific products or materials within the indoor
environment; in some cases, these may come from areas external to the living area
(e.g., from attached garages or parking areas, or from commercial facilities located
within a building). In addition, exposures from external sources may be of
concern, including emissions from stationary or mobile sources, particularly those
in close proximity to a building, or penetration of chemicals through soil.
Monitoring studies, or source characterization studies (see section A.l.d), are
needed to more fully address the both the acute and chronic exposures that may
result from particular exposure scenarios of concern.
A.l.a.4. Further develop and refine personal monitoring techniques and equipment
for use indoors.
Stationary monitors set up at fixed sites in a building may not accurately represent
the actual exposures that occur to individuals in the building. For example, a
person using a consumer product in a bedroom may receive a much higher
exposure to the product than would be indicated by a monitor set up on the other
side of the bedroom or in the kitchen. For this reason, personal monitors have
been designed to be worn or carried by individuals to more accurately record the
their exposures. The development of improved personal monitors that are less
cumbersome for users to wear and that can accurately sample for a broader range
of chemicals is needed. In addition, the research is needed to develop and
establish recommended sampling methods for these devices.
A.l.b. Determine hazards and dose-response indices for chemicals and mixtures found in
indoor environments.
Even if we knew the levels of chemicals and mixtures that occur indoors under a broad
range of exposure scenarios, we would be at a loss to determine their impact without
knowledge of the hazards of the chemicals and mixtures and the doses that may result in
health impacts. For several years, concerns about carcinogenicity have dominated
discussions about the risks posed by toxic substances. However, the noncarcinogenic
effects on organs and organ systems may pose an equal or greater threat to public health.
Some of the targets of these effects to consider include the respiratory system,
cardiovascular and cardiopulmonary systems, the reproductive system, and the nervous
system. Developmental effects may also be of concern. In particular, there is a need to
U.S. EPA, 402-B-05-001, March 2005 7
-------
develop toxicity data for chemicals and mixtures that may be relevant to potentially
susceptible life stages including pregnant women, infants and children, and the elderly.
Dose-response data are not available for many of the volatile organic chemicals and
mixtures found in the indoor environment, although some steps have been taken in recent
years to obtain such data through programs like EPA's High Production Volume (HPV)
Initiative Program (65 FR 81686), a program to obtain basic screening-level hazard data
for chemicals produced or imported in quantities exceeding 1 million pounds per year,
and the VCCEP. Even when data are available, they are generally based on a less than
comprehensive review of the health effects of the chemicals and mixtures. To help in
prioritizing the health effects data needed, an analysis of the available monitoring data
should be performed to help target chemicals for evaluation in laboratory or
epidemiological studies (e.g., chemicals that are unlikely to be highly toxic, based on
structure-activity relationships, and that are found at very low levels indoors would be
given lower preference for further toxicological testing).
Several inorganic compounds are not adequately characterized from a health effects
perspective including combustion byproducts such as nitrogen dioxide (NO2) and carbon
monoxide (CO). A thorough analysis of the current literature, as well as additional
research, is needed to fully assess the respiratory effects of NO2 at levels expected to
occur in the indoor environment and also the potential association between respiratory
illnesses and symptoms and elevated NO2 levels. These respiratory illnesses and
symptoms include chronic obstructive pulmonary disease in adults; asthma, the increased
occurrence of respiratory infections, and the increased sensitivity to inhaled allergens,
particularly in children; and the potential for the development of diarrhea and other non-
respiratory symptoms in infants. In addition, more research is needed on the potential
morbidity associated with low-level CO exposures, the potential mechanisms of CO
toxicity unrelated to hemoglobin binding, and the impact and mechanisms of CO
exposure on potential highly-susceptible populations (e.g., the elderly, infants, and
persons with heart, lung, or blood disorders).
Further research is also needed to determine if chemical allergens, irritants, fragrances, or
odors can potentially cause or trigger asthma.
A.l.c. Prioritize chemicals and mixtures of concern and select a small number for further
study.
The purpose of the prioritization should be to select a handful of chemicals or classes of
chemicals that will undergo a more extensive analysis, as detailed under sections A. 1 .d
through A. 1 .h. For some chemicals, the research sequence described by sections A. 1 .d
through A. 1 .h. may not fully apply, as the initial chemical assessments may reveal that
certain steps may be bypassed due to the availability of existing information.
EPA already has programs to address two high-risk components of indoor air, radon and
environmental tobacco smoke (ETS). EPA needs to develop a generally acceptable
system for prioritization of chemicals of concern, other than radon and ETS. Although the
8 U.S. EPA, 402-B-05-001, March 2005
-------
prioritization will focus on potential relative risks of chemicals and mixtures in indoor
air, the prioritization scheme may be expanded to include dermal exposures as well as
inhalation exposures. One approach is to look at monitored levels of the chemicals in
indoor environments. Another approach is to consider the development of prioritization
systems based on the formulations or emissions of products and materials used in the
indoor environment, in conjunction with modeling to determine potential concentrations.
We may also use biomonitoring data to assist in prioritizing chemicals or mixtures of
concern. However, although biomonitoring data are useful in determining those
chemicals and mixtures that are a concern from the standpoint of cumulative exposures,
additional analyses would be needed to determine the contributions to these cumulative
exposures occurring through the indoor environment. Biomonitoring data may help us,
however, to narrow the list of chemicals and mixtures of concern. EPA must also
continue to evaluate and compare the exposures and risks that may occur due to specific
scenarios of concern (e.g., 'hot spots' with untypically high exposures), so that we do not
neglect high-exposure scenarios of concern and other known risks.
Based on this prioritization, specific chemicals or mixtures would be selected for further
study.
A.l.d. Characterize the sources of the chemicals and mixtures selected in A.l.c.
A.l.d.l. Determine potential sources of selected chemicals and mixtures.
Specific research to determine the sources of the chemicals and mixtures selected
will vary. For example, if a chemical is chosen based on product formulations or
emissions or on specific scenarios of concern, the source(s) of the chemical or
mixture will already be known. However, further source characterization studies
may be needed to more accurately determine emissions factors for these sources
under differing conditions.
If chemicals and mixtures are chosen from a prioritization scheme using
monitoring data (Section A.l.c) or because of health concerns at levels in the
indoor environment, data needed will depend on the properties of the chemical or
mixture. For chemicals that are unlikely to be produced through natural processes
or through breakdown of products or materials indoors (e.g., methylene chloride),
source information can be obtained through (1) a market analysis of products and
materials formulated using that chemical or mixture, (2) a search of databases
containing product formulation data, (3) a search of data from indoor air source
characterization studies, etc. For chemicals that may have natural sources or that
may be formed by the breakdown of products or materials, combustion processes,
or chemical interactions (e.g., formaldehyde), source characterization is more
complex, and will rely upon both the information sources mentioned above and a
further literature review of potential mechanisms of increased indoor
concentrations.
U.S. EPA, 402-B-05-001, March 2005
-------
A.l.d.2. Develop quantitative emissions factors by source.
In many cases, the data available will provide only an indication of potential
sources of exposure; they will not provide the quantitative data on emissions
factors that are needed to do an exposure assessment. Therefore, research will be
needed using chamber or test house studies, or through the development of
emissions models (e.g., based on chemical formulations), to determine emissions
factors for exposure scenarios of concern.
A.l.d.3. Determine cumulative exposures.
In addition to the characterization of indoor sources of the chemicals and
mixtures, research is also needed to determine the amount of the chemicals and
mixtures found indoors that may be from ambient air, track-in from outdoors,
food, water, soil, and other potential sources.
A.l.e. Study the indoor fate of the chemicals and mixtures selected in A.l.c.
Research on the fate of the chemicals and mixtures of concern will be highly dependent
on the substances themselves (i.e., their likelihood of penetrating the building envelope;
of being adsorbed to, and re-emitted from, materials indoors; and of interacting with other
chemicals or mixtures in the indoor environment). Research is also needed to better
understand the impact of reactive contaminants on the indoor environment. Reactive
contaminants have the potential to react with other components of the indoor
environment to form 'new' pollutants (usually chemicals or particulate matter) (Weschler
and Shields, 1997, 1999). For example, several reports have shown that low levels of
ozone react with some volatile organic compounds in the environment to produce
chemical pollutants and particulates that are associated with health impacts including
respiratory system irritation. Some highly-used chemicals and products are of particular
concern because of the reactive nature of the resulting compound produced when ozone
reacts with these substances (e.g., limonene or other terpenes, decomposition products of
printer/copier toner powder, and building materials that contain an unsaturated carbon-
carbon structure). The chemical structures of all the potentially formed species and their
impact on health are not yet known and should be evaluated under research needs
described in sections A.l.b. and A.l.g.
Although understanding the fate of chemicals in the indoor environment maybe
important in determining the actual exposures that may occur from chemicals and
mixtures indoors, these data are difficult and time-consuming to obtain. It may be
necessary, in the short term, to estimate the effects of these processes indoors while we
await the results of this research. Therefore, this research should have secondary
importance to the research in sections A. 1 .a through A. 1 .d, and sections
A.l.fthroughA.l.h.
10 U.S. EPA, 402-B-05-001, March 2005
-------
A.l.f. Perform exposure assessments for the chemicals and mixtures selected in A.l.c.
A.l.f.l. Determine and compare cumulative exposures.
Research will be needed to determine the exposures that may occur with the
chemicals and mixtures of concern. If there appear to be scenarios where high
levels of the chemical or mixture may occur over short time periods, acute
exposures should be assessed, as well as chronic exposures. If not, analyses of
chronic exposures alone may be sufficient. Data on sources, estimated
concentrations, and time-activity patterns should be combined to estimate these
exposures. Where concentration data are not directly available through
monitoring, modeling can be used to estimate exposure concentrations if data are
available on emissions factors for the chemicals and mixtures. Although the focus
of the exposure assessments will be on indoor air exposures, the relative
exposures from other media (ambient air, track-in from outdoors, food, water,
soil, etc.) should also be estimated; if exposures from other media account for a
disproportionate exposure as compared to those from indoor sources, further
assessment of exposures from indoor sources may not be required.
The initial exposure assessments will be less detailed, and will be refined as the
key pollutant sources and routes of exposure are determined. More detailed,
follow-on exposure assessments will only be required if the risks estimated based
on the initial exposure assessments warrant further study (see section A.l.g.) and
should focus on scenarios that appear to result in the greatest exposures based on
the initial assessments.
A.l.f.l. Develop more refined assessments of exposure variations by population.
Although there have been a number of studies looking at time-activity patterns for
the general population (Klepeis, Tsang, and Behar, 1996), less is currently known
about demographic or geographic variations in product use (e.g., differences in
product use by certain cultures or occupations or differences in pesticide use
across the country) or variations in product use across building types
(e.g., differences in the cleaning products used, or differences in pressed wood
use, in homes versus office buildings). Further research on variations in both acute
and chronic exposures are needed in these areas. The evaluation of any possible
increased exposures, both demographically/geographically and by building type,
for particular susceptible populations (e.g., infants and children, pregnant women,
the elderly, those with asthma, etc.) is also an area of needed research. In some
cases, EPA may be able to work with industry to obtain such information on a
voluntary basis; in other cases, it may be necessary to survey for this information.
Depending on the chemicals and mixtures selected, their sources, and the level of
detail needed in the assessments, evaluation of these factors maybe more or less
important.
U.S. EPA, 402-B-05-001, March 2005 11
-------
A.l.f.3. Further develop and refine exposure modeling tools and assessments.
This exposure assessment work may also require further development and
refinement of exposure modeling tools such as indoor air quality models.
In addition, the results of these assessments should be transferred, as appropriate,
to inform other exposure modeling efforts within the Agency (e.g., the Hazardous
Air Pollutant Exposure Model [HAPEM] being used for the National Scale
Assessment, and community-based modeling assessments).
A.l.g. Assess risks for the chemicals and mixtures selected in A.l.c.
Risk assessments should be performed by combining data on exposures (section A.l.f.)
and dose-response indices (section A.l.b.) for the selected chemicals and mixtures. As
with the exposure assessments, initial risk assessments should be less detailed; more
detailed assessments should be performed, as warranted, for any significant risk
scenarios. In addition, the relative risks from exposures in various media should be
assessed; if management of risks due to exposures from other media (ambient air, track-in
from outdoors, food, water, soil, etc.) is more effective in reducing risk, further
assessment of risks from indoor sources may not be required. When possible, the risks to
certain susceptible populations, such as pregnant women, infants and children, and the
elderly, should be assessed.
A.l.h. Perform research on methods to manage risks for the chemicals and mixtures
selected in A.l.c.
A.l.h.l. Determine the need for development of risk management methods.
This research will be dependent on results from section A. 1 .g. In many cases,
further research will be needed to determine the most efficient and cost-effective
methods to reduce risk, however, if the risks from a chemical or mixture found
indoors do not appear to be significant or if the risks occur in large part through
another mode of exposure (e.g., ambient air or pesticide track-in), research efforts
may be better spent elsewhere. Even if the risks from an indoor source(s) are
substantial, further research on methods to manage risks may not be warranted
(e.g., there are obvious things that can be done to substantially reduce exposures
and risks). In addition, for the case in which the chemical or mixture of concern is
a HAP, the potential reductions in exposure due to regulatory actions should be
taken into account before determining the need for additional voluntary risk
management research.
A.l.h.l. Perform research to determine the most effective methods for voluntary
reduction of risks.
If research to manage risks appears warranted, initial research efforts should focus
on voluntary actions that might be taken to reduce risks. Risk management
research will be dependent on the sources of concern, and may include the
12 U.S. EPA, 402-B-05-001, March 2005
-------
following options, among others: (1) assessments of risk reductions through
voluntary reformulations of products by industry or the use of alternative products
which are judged as "safer," (2) evaluations of the effects of changes in industrial
processes on emissions and the related risk reduction, (3) analyses of the
effectiveness of the use of "best practices" to reduce risks, (4) analyses of the
effectiveness of increasing ventilation or affecting building pressure differentials;
(5) voluntary actions taken by consumers and businesses to alter behavior or
practices, (6) assessments of the economic benefits of risk management options,
(7) evaluations of the effectiveness of market incentive programs, and
(8) assessments of the impact of educational and outreach programs, including
programs such as "Read the Label." Efforts should be made to set up formal
voluntary programs with industry, both to obtain needed data to develop
appropriate risk management options and to assist us in achieving risk reductions.
Also, although source modification or substitution may be the "best" option for
reducing risks, it may take several years to implement. Therefore, quick and
inexpensive options should be investigated in the interim
Program Applications for Chemicals Research:
Fundamental to reducing risks from exposures to chemicals and mixtures in any environment is
the identification of pollutants of concern and the assessment of sources, fate, exposures, and
risks. Many EPA program offices are involved in projects to collect data on, and to assess the
exposures, risks, and risk management options for chemicals and mixtures that may be emitted
from products and materials indoors or that may infiltrate the indoor environment from outdoors.
Suitable cross-program strategies for research on chemicals and mixtures in the indoor
environment are needed to address a wide array of program interests. For example, ORIA has the
general need to respond to public inquiries, and to provide information and training to numerous
audiences, about the potential impacts of chemicals and mixtures in the indoor environment and
methods that can be used to reduce exposures and risks. In addition, as implementation of the air
toxics sections of the Clean Air Act moves towards a more risk-based process, it is important that
ORIA works with OAQPS and OTAQ so that indoor sources and exposures are appropriately
combined with those outdoors in an integrated strategy. This research would provide information
about indoor exposures and risks that are needed to integrate indoor and outdoor air toxics
strategies, and design those strategies to minimize total human exposures from both
environments. Other offices with a need for research on chemicals and mixtures indoors include
OPPTS, which is working to develop guidance for Federal facilities on the selection of products
and materials for use indoors; OSWER, which is concerned with the infiltration of hazardous
chemicals into buildings through soil; and OCHP, which is concerned with exposures to infants,
children, pregnant women, and the elderly in the indoor environment.
U.S. EPA, 402-B-05-001, March 2005 13
-------
References for Chemicals Research:
Kepleis NE, Tsang AM, and Behar JV. 1996. Analysis of the National Human Activity Pattern
Survey (NHAPS) Respondents From the Standpoint of Exposure Assessment: Percentage of
Time Spent, Duration, and Frequency of Occurrence for Selected Microenvironments by
Gender, Age, Time-of-Day, Day-of-Week, Season, and U.S. Census Region. Final Report.
Washington, DC: Office of Research and Development, U.S. Environmental Protection
Agency. EPA/600/R-96/074.
U.S. Environmental Protection Agency (U.S. EPA). 1998. A comparison of indoor and outdoor
concentrations of hazardous air pollutants. Inside EPA, Spring/Summer 1998. Research
Triangle Park, NC: Office of Research and Development, U.S. Environmental Protection
Agency. EPA/600/N-98/002.
Wallace LA. 1987. The Total Exposure Assessment Methodology (TEAM) Study: Summary and
Analysis: Volume I. Washington DC: Office of Acid Deposition, Environmental
Monitoring and Quality Assurance, Office of Research and Development, U.S.
Environmental Protection Agency.
Weschler CJ, and Shields, HC. 1999. Indoor ozone/terpene reactions as a source of indoor
particles. Atmospheric Environment. Vol. 33, pp 2301-2312.
Weschler CJ, and Shields, HC. 1997. Potential reactions among indoor air pollutants.
Atmospheric Environment. Vol. 31 (21), pp 3487-3495.
14 U.S. EPA, 402-B-05-001, March 2005
-------
A.2. BIOLOGICAL CONTAMINANTS
Background Information:
Indoor biological contaminants can have adverse impacts on human health. Bacteria, viruses,
fungi/ molds, pets, rodents, cockroaches, and dust mites may all contribute to the contamination
of indoor environments. In many cases, the presence of these contaminants is associated with a
transient or long standing moisture problem, which supports the growth of fungi, dust mites, and
certain bacteria, or they may result from the presence of a pet or pest infestation. To a limited
extent, biocontaminants may be blown in from outdoors, or carried in on people's hair or
clothing. In addition, biocontaminants may be purposely introduced into a building as an act of
terrorism, an issue which has recently emerged as a national priority.
Biocontaminants can cause a variety of allergic or infectious diseases. Fungi also produce
irritants and in some cases potentially toxic substances (mycotoxins). Pets, rodents, cockroaches,
mold, and dust mites are known to be asthma triggers. Some of the most serious and potentially
fatal building related illnesses are caused from exposure to indoor biological contaminants.
These include Legionnaires disease, hypersensitivity pneumonitis, and allergic asthma. The
extent to which exposure to these contaminants indoors can be or should be reduced, and under
what circumstances, has great consequences for public health.
Over the past few decades, we have seen an unprecedented rise in asthma, allergic rhinitis, and
other allergic diseases. However, the reasons or causes for this rise are unknown. Millions of
dollars are spent yearly on medications, devices, and doctors appointments to address indoor
allergy issues. It is estimated that more than 50 million Americans have allergic diseases
(AAAAI, 1996-2001) and that in 1996 chronic sinusitis affected more that 38 million Americans
(CDC, 2002). In fact, allergic diseases are the 6th leading cause of chronic disease in the U.S.
and allergies cost health care systems more thanlS billion dollars per year (AAAAI, 1996-2001).
Economic costs for allergic rhinitis alone, estimated for 1993, were 3.4 billion dollars (Storms,
Meltzer, Nathan et al, 1997).
In addition, buildings have changed over the years - with the advent of new construction
techniques, new building materials, tighter building envelopes, and reduced outside air
ventilation, the incubation and transmission of infectious diseases through the indoor
environment is of growing concern. This is of particular concern in buildings with high occupant
density such as schools.
Unfortunately, our knowledge of the relationships between building conditions, occupant
exposures, and health consequences is limited, as is our knowledge of viable means to effectively
mitigate exposures and health impacts. Nevertheless, because of the public health impact of
biocontaminants, there is considerable interest in producing information and guidelines to the
public, the building industry, and to public health authorities. In response, the EPA has provided
some limited guidance, mostly under the premise that reducing exposure is an appropriate
response. But while there are little hard data and the true efficacy of such an approach is not
known, organizations such as the National Academy of Sciences recommend proceeding with
exposure reduction measures for indoor asthma triggers rather than waiting until all desirable
U.S. EPA, 402-B-05-001, March 2005 15
-------
research is performed (NAS, 2000). Asthma and allergy sensitization and exposure reduction
measures are discussed in additional detail in section A.3.
Program Needs for Biological Contaminants Research:
A.2.a. Conduct research for specific biocontaminants.
A.l.a.l. Conduct studies on mold allergens and mycotoxins.
Mold allergens
Mold allergens are important asthma and allergy triggers. Research is needed to
obtain more information on the characteristics and health-related issues associated
with mold allergens. Research should identify the specific fungal proteins that
cause allergic response. Standardized and quantitative methods to assess mold
exposure are important efforts, which should include studies to establish
biomarkers of exposure to mold in humans (or surrogate biomarkers) in order to
assist researchers and medical personnel in assessing mold exposures. Research
should identify patterns of cross-reactivity among fungal allergens and the relative
potency of different antigens.
Mycotoxins
Research is needed to obtain more information on the characteristics and health-
related issues associated with mycotoxins, including work which directly
correlates mycotoxin exposure by the inhalation route with human health effects.
The health effects resulting from inhalation exposure to mycotoxins are largely
unknown; ongoing research on these health effects is important, and should
continue.
A.2.a.2. Conduct studies on allergens from rodents and rabbits.
Research is needed to develop a better understanding of biological contaminants
that originate from rodents (e.g., rats and mice) and rabbits. Studies should assess
the degree to which rodent/rabbit exposures in the home exacerbate and/or cause
asthma in sensitized asthmatics.
A.2.b. Assess the effects of early-life exposures on the development of the immune system.
One theory regarding the development of asthma from an environmental exposure
involves the developing immune system. During early life, an environmental exposure (or
exposures) may push the immune system to develop in such a way that the risk of
developing asthma is increased. Some studies, however, indicate that early childhood
exposure to some contaminants (e.g., allergens, microbes, and their products such as
endotoxin) can be protective, and may reduce the chances of developing asthma.
It is theoretically possible that EPA's guidance for reducing exposure to biological
contaminants, particularly during infancy/early childhood while the immune system is
16 U.S. EPA, 402-B-05-001, March 2005
-------
developing, could be counterproductive for some indoor biological pollutants. More
information is needed regarding the effects of early-life exposures on the immune system
and the potential that the lack of exposure during infancy can increase atopy in some
individuals. This is especially critical because it may help explain the rapid rise in allergic
diseases, and it has the potential to strongly influence the EPA's outreach messages
related to asthma and other allergic diseases. The role of breast milk in this process
should also be considered.
A.l.b.l. Conduct early-life exposure studies for endotoxin.
Endotoxin comes from the outer membrane of gram-negative bacteria. Endotoxin
can be found in household dust in both urban and rural settings. People are
exposed to low levels of endotoxin on a continuing basis since gram-negative
bacteria are ubiquitous. Endotoxin is apotent stimulant of the immune system,
and it is possible that endotoxin exposure has both positive and negative effects,
depending upon age of exposure and other factors. Some studies suggest that early
exposure to endotoxin can be protective against asthma, but that later life
exposure can exacerbate existing asthma. In the case of dust mite exposure, early
life exposure can clearly cause asthma, but for other biological pollutants such as
endotoxin, we do not have enough information to make a determination on the
effects of early exposure. Studies are needed to determine what effects, if any,
that early-life exposure to endotoxin has on the developing immune system.
A.2.b.2. Conduct early-life exposure studies for other environmental factors.
Other exposures which may affect a developing immune system during early-life
include infectious diseases, parasites, and other biological contaminants such as
dog/cat allergens. Research should include single pollutants as well as mixtures of
chemical and biological contaminants. A first step in this research area could be to
convene an expert panel to identify and prioritize the environmental factors and
contaminants that should be considered, followed by appropriate research to
evaluate the potential health impacts such as allergic and asthma-like conditions.
Program Applications for Biological Contaminants Research:
The rapid rise in the incidence of asthma and other allergic diseases is yet unexplained.
We know that some common allergens are biological, and that exposure to some of these
allergens occurs primarily indoors. This makes allergic diseases both medical and indoor
environmental problems. On the specific issue of mold, there is some epidemiological evidence
that the existence of mold and/or dampness in the home increases the risk of respiratory
symptoms - this ongoing research is important and should continue. The balance between
humidification and dehumidification of indoor environments needs to be assessed in conjunction
with appropriate control of mold growth (see section D, "Building Design and Operation).
The ability to understand the relationship between mold exposure and health is a foundational
issue and requires that techniques to reliably and accurately assess mold exposure be developed.
U.S. EPA, 402-B-05-001, March 2005 17
-------
References for Biological Contaminants Research:
American Academy of Allergy, Asthma and Immunology (AAAAI). 1996-2001. The Allergy
Report: Science Based Findings on the Diagnosis and Treatment of Allergic Disorders.
Centers for Disease Control (CDC). 2002. Fast Stats A-Z, Vital and Health Statistics, Series 10,
No. 200, Table 57. 1996 as cited inNIAID (National Institute of Allergy and Infectious
Diseases). January 2002. Allergy Statistics, Fact Sheet.
National Academy of Sciences (NAS), Institute of Medicine. 2000. Clearing the Air, Asthma and
Indoor Air Exposures. Washington DC: National Academy Press.
Storms W, Meltzer E, Nathan R, and Seiner J. 1997. The Economic Impact of Allergic Rhinitis.
Journal of Allergy and Clinical Immunology. 99:8820-4.
18 U.S. EPA, 402-B-05-001, March 2005
-------
A.3. SENSITIZATION, ALLERGY AND IRRITATION HEALTH EFFECTS
Background Information:
Exposure to certain levels of specific pollutants may cause an individual to become increasingly
susceptible to respiratory reactions upon further exposure to those or other pollutants.
This applies to a broad spectrum of pollutants, including chemicals (see also A.I),
biocontaminants (see also A.2) and particulate matter (see also A.4). This enhanced
susceptibility is referred to as sensitization and may be reported as a positive allergen test
response. For example, most studies have shown an association between exposure to dust mite
and cockroach allergens above certain levels and an increased prevalence of sensitization. Some
studies have reported this association for cat and dog allergens, whereas others have not found an
association for these allergens. Several studies have reported clear dose-response relationships
between the allergen levels and sensitization. Atopy or genetic disposition has also been strongly
associated with sensitization potential. In contrast to sensitization, there is a "hygiene
hypothesis" or "dirt hypothesis" that suggests that the human immune system development is
affected by reduced exposure at birth and in early life to certain contaminants (see A.2.b).
There is a large and ever growing body of current literature related to the influence of indoor
pollutants such as dust mites, pet dander, molds, cockroaches, and environmental tobacco smoke
on asthma or allergy symptoms. The association between these indoor contaminants and the
exacerbation of allergies and asthma is well-established. For dust mites and environmental
tobacco smoke, there is also strong data to support an association between exposure to the
contaminant and initiation of asthma or allergy symptoms. Several primarily outdoor air
pollutants have also been linked to asthma and other adverse respiratory conditions, including
sulfur dioxide, nitrogen dioxide, ozone and particulate matter including acid aerosols. Although
there is a large body of current data on the impact of environmental exposures on asthma and
allergies, the results of many of the studies are limited by problems with inconsistencies in
disease diagnosis, design of study, or inappropriate consideration of confounders. In addition,
there are potentially several different variations (phenotypes) of asthma and allergies, and
different treatments or mitigation methods may be required.
Several contaminants found in the indoor environment can directly or indirectly induce allergic
respiratory reactions, while other contaminants cause respiratory symptoms through non-allergic
mechanisms such as irritation. Most allergens stimulate production of immunoglobulin E (IgE)
antibodies that can result in various hypersensitivity reactions. There also appear to be chemical
compounds with a capacity to trigger inflammation without involving IgE.
Program Needs for Sensitization, Allergy and Irritation Health Effects Research:
A.3.a. Investigate relationships for pollutant exposure levels and sensitization.
Although there is strong support for a relationship between some pollutant exposures
above certain levels and sensitization in particular populations, research is needed to
more fully assess the exact relationships between exposure, sensitization, asthma, and/or
other respiratory morbidity variables. The sensitization process, as well as the thresholds
U.S. EPA, 402-B-05-001, March 2005 19
-------
of exposure and other potentiating conditions that can trigger a response, exacerbate an
existing disease, or induce a new or unidentified disease state are of critical interest.
Research should also investigate whether combinations of allergens affect sensitization.
A.3.a.l. Characterize exposure thresholds that sensitize individuals and those that
trigger allergic reactions to pet and cockroach allergens.
Pet allergens and cockroach allergens are difficult to control because of their
adhesive and aerodynamic properties. In addition, pet allergens tend to be
ubiquitous and travel readily between environments on people's clothing, and
cockroaches can infest a dwelling from an adjacent dwelling or building. Thus,
significant exposure reduction for these allergens is difficult to achieve.
Knowledge of the thresholds for sensitization and for triggering responses would
help determine the degree of avoidance and mitigation that is critical so that
proper guidelines can be established.
A.3.b. Conduct characterization studies of allergens and chemical irritants.
Although the literature concerning allergic reactions and allergens has greatly advanced in
recent years, research is needed to address data gaps with regard to the mechanisms of
action of various allergens on the respiratory system. Research is also needed to address
limitations and gaps in available information regarding specific actions of irritants on the
respiratory system. Some of the major data gaps in the available literature for both
allergens and irritants involve the specific characteristics of inflammatory processes;
the exact mechanism of action of contaminants on the respiratory system; the long-term
role of continued exposure to contaminants on persistent lung conditions; the possibility
of differential impacts of exposure on potentially sensitive populations such as children
and the elderly; efficacy and effectiveness of mitigation methods; and, the role of
avoidance or mitigation to symptom or disease improvement. Research is also needed to
further investigate the concept of total allergic burden, and whether exposure to low-
levels of multiple allergens simultaneously (or within a short time period) affect health
endpoints.
A.3.b.l. Investigate allergy and irritancy issues for occupational contaminants in
other indoor environments.
Several allergens and chemicals that have been shown to cause allergy or asthma
in occupational settings have not been well-studied in other typical indoor
environments (e.g., residences and schools). For example, mouse allergen is a
well-defined cause of IgE-mediated hypersensitivity in occupational settings, but
although it is known that mouse allergen is widely distributed in inner-city homes
where allergy and asthma prevalence is high, little information is available on the
impact of the level of mouse allergen found in homes on the respiratory system of
susceptible individuals. Further study is needed to assess the clinical importance
of this potentially significant and under-recognized indoor allergen. Similarly, rat
and rabbit allergens are known to cause allergies and asthma in occupational
20 U.S. EPA, 402-B-05-001, March 2005
-------
environments, but further research is needed to assess these contaminants in other
indoor environments.
A.3.C. Determine the efficacy of exposure reduction measures recommended in existing
EPA guidance.
The EPA currently recommends reducing or eliminating exposure to indoor asthma
triggers to reduce the likelihood of asthma symptoms indoors. There is insufficient data
to support the effectiveness of this approach. Research is needed to fill this data gap, and
to assess critical issues such as whether reducing exposure to indoor contaminants
reduces the potential for sensitization, and whether occupant age or other population
characteristics are significant factors. One example of research that could be performed
in this area includes assessing whether the removal of a dog or cat from a home results in
a sufficient decrease in overall allergen exposure to decrease allergic symptoms in
sensitized individuals. Similar research could be performed for other exposure reduction
measures.
A.3.d. Conduct studies to determine the most effective mitigation techniques to achieve
sub-threshold levels for allergens and irritants.
Studies are needed to evaluate potential mitigation strategies for reducing exposures to
allergens and irritants. For each strategy, research should evaluate the effectiveness in
reducing exposure, the net improvement in health conditions, cost-effectiveness, ease-of-
implementation, and applicability to various indoor environments. Given the variable
nature of human immune systems, occupants will likely have varied responses to indoor
allergens and irritants, and a sufficiently 'clean' or 'mitigated' room may not be the same
for all occupants. Studies would need to determine whether there are practical ways of
reducing exposures in various contaminated environments below the required thresholds,
or whether a complete change in environment may be necessary.
Program Applications for Sensitization, Allergy and Irritation Health Effects Research:
The EPA seeks to educate health care providers and the public about the importance of having a
balanced approach to asthma management involving both medication and environmental controls
(trigger avoidance). Many of the trigger avoidance strategies currently used are based on the
concept that exposure reduction will alter symptoms, even though additional scientific evidence
as to the efficacy of such strategies is needed. Furthermore, the National Academy of Sciences
recommended that, although more research is needed, these exposure reduction measures should
be implemented rather than waiting until all desirable research is performed (NAS, 2000).
In addition, a troubling question is the issue of whether some exposures may be needed to
prevent sensitization and allergic response. And for those exposures for which it truly is
advisable to mitigate, how much mitigation is necessary or feasible are open questions.
Knowledge as to how exposure to certain allergens affects human responses, and what threshold
levels must be achieved to avoid an allergic response is of critical concern. The proposed
research is designed to provide information needed to identify and promote effective
environmental control strategies.
U.S. EPA, 402-B-05-001, March 2005 21
-------
References for Sensitization, Allergy and Irritation Health Effects Research:
National Academy of Sciences (NAS), Institute of Medicine. 2000. Clearing the Air, Asthma and
Indoor Air Exposures. Washington DC: National Academy Press.
22 U.S. EPA, 402-B-05-001, March 2005
-------
A.4. PARTICULATE MATTER
Background Information:
Airborne particulate matter (PM) refers to a large group of materials of diverse sizes and
chemical characteristics which share the ability to be transported in the air as discrete solid
particles or liquid droplets. These particles originate from a number of natural processes as well
as from some human activities, both indoors and outdoors. A large number of inorganic and
organic materials may be contained within these particles, including biological contaminants.
Epidemiological studies document a number of associations linking outdoor particulate matter
concentrations to adverse health effects such as decreased lung function, exacerbation of
respiratory diseases, and premature death. Studies on indoor air have also shown that particulate
matter is a significant indoor pollutant (e.g., EPA's Particle TEAM study, and EPA's Building
Assessment and Survey Evaluation [BASE] study). Indoor exposures to particulate matter can be
significant, and there is inadequate information as to whether indoor particles originate outdoors,
thus reflecting the epidemiological results above, or whether there is a substantial component
from indoor sources that would add to the health impacts from particle exposure. Of particular
concern are the growth of biological contaminants indoors, particulate matter from indoor
combustion appliances, and other potential indoor sources including printers and copiers.
Furthermore, there is little known about the particle dynamics that could affect particulate matter
exposure. For example, there is believed to be a 'personal cloud' in which an individual's
exposure to particles is not influenced solely by ambient contaminant levels, but also by particles
that become airborne due to one's own physical activity. Information on these issues is needed
for the EPA to develop an effective program to mitigate exposure and risks from indoor
particulate matter.
An EPA program has been established to conduct particulate matter research, primarily from an
outdoor air perspective, to support review and implementation of EPA's National Ambient Air
Quality Standards (NAAQS) for PM. Congress directed the EPA to arrange for an independent
study by the National Research Council (NRC). This study was intended to identify the most
important research priorities, develop a conceptual plan for particulate matter research, and
monitor and evaluate the research progress. NRC established the Committee on Research
Priorities for Airborne Particulate Matter in January 1998. This committee identified ten high
priority research topics and developed a 13-year integrated strategic plan (from 1998 to 2010) of
recommended research.
While some of the indoor environments research needs for particulate matter maybe addressed
by the NRC plan and EPA's existing program for outdoor particulate matter research, there are
several key areas that require research specifically for advancing the EPA's indoor environments
program.
U.S. EPA, 402-B-05-001, March 2005 23
-------
Program Needs for Indoor Particulate Matter Research:
A.4.a. Conduct research for particulate matter measurement techniques.
Particulate matter concentrations can be measured using different techniques and
measurement units. For example, one approach is to measure the particulate matter
concentration in particle counts per unit volume, while another approach entails
measuring the particle mass. Research may be needed to reconcile different methods to
ensure proper interpretation of data and inter-comparison of results. Some measurement
research is being conducted under the outdoor air particulate matter research program.
Specific research is needed to develop appropriate measurement techniques for indoor
environments, which may have unique measurement error and other technical
considerations. Research is needed to determine the factors for the conversion from
particle number to mass for uncharacterized indoor aerosols. Specific research is also
needed on the development and verification of improved personal monitoring devices.
A.4.b. Develop particulate matter cumulative exposure models derived from specific
indoor particle source parameters, indoor transport mechanisms, indoor
contributions of outdoor sources, outdoor exposures, and human activity.
Outdoor air quality particulate matter exposure models are being developed, however
these models typically fail to account for indoor sources of particulate matter and many of
the issues identified in subsequent sections A.4.C.1 through A.4.C.3. Efforts are needed to
develop improved exposure models that accurately predict cumulative particulate matter
exposure by integrating outdoor exposures with indoor exposures, i.e., indoor exposures
that are based on both outdoor and indoor sources of particulate matter within the indoor
environment. Research could investigate linking/adapting existing indoor and outdoor
exposure models. There may be existing indoor air quality exposure models, such as the
CONTAM model developed by the National Institute for Standards and Technology
(NIST), which may be adapted or modified for particulate matter exposure modeling.
A.4.c. Identify major indoor particulate sources for different indoor environments.
There is a need to understand the major indoor sources of particulate matter for homes,
schools and offices, and to identify other critical indoor environments where particulate
matter requires further investigation. A comprehensive study is needed of how sources
impact each other.
A.4.C.I. Quantify the contribution of indoor sources and outdoor sources to
particulate matter found indoors.
Particulate matter in the indoor environment can result from indoor sources, and
outdoor sources from which the particles are able to migrate indoors. Where
possible, this research should identify and characterize the predominant indoor
and outdoor sources of particulate matter, determine how sources impact each
other, and assess the relative contribution of the indoor and outdoor sources to
24 U.S. EPA, 402-B-05-001, March 2005
-------
total PM exposure, as well as to total indoor PM exposure and total outdoor PM
exposure. Research should also identify reactive contaminants, mechanisms, and
devices (such as ozone generators) that lead to the existence of secondary particles
in the indoor environment. The resulting compounds and their toxicities need to
be fully characterized.
A.4.C.2. Investigate the 'personal dust cloud' phenomena.
The implications of the 'personal dust cloud' phenomena are largely unknown.
Research is needed to evaluate how much an individual's particulate matter
exposure is affected by localized personal activities that may either generate
particulate matter or increase particulate matter exposure by re-entrainment of
settled-out particulate matter, and evaluate the impact of other
individuals"personal dust clouds' on exposure. Research is also needed to assess
the impact of the 'personal dust cloud' on health and to identify/develop low cost
ways to mitigate any such effect.
A.4.C.3. Investigate the chemical composition and size distribution of indoor
particulate matter.
In order to adequately assess particulate matter health risks and mitigation
techniques of indoor particles from both indoor and outdoor sources, information
is needed regarding the chemical composition and how it relates to particle size
and particle source. This research should differentiate between coarse, fine, and
ultra-fine particles. The differentiation between fine particles (less than 2.Sum)
and ultra-fine particles (less than 0.1 um) is required to infer the aerodynamic
properties of the particles in the distribution and ascertain the appropriate
effective disposition rate constant.
A.4.d. Determine the health effects and risks of indoor particulate matter.
Many studies have associated particulate air pollution with asthma exacerbations,
increased respiratory symptoms, decreased lung function, increased medication use, and
increased respiratory-related hospital admissions, among other health endpoints.
Although there is a strong association between particulate matter exposure and respiratory
symptoms, there are several areas that have not been fully evaluated, including the
mechanisms of action (i.e., direct impact of the particulate on respiratory tissues,
transport of allergen or irritant to tissues where it causes an effect, or receptor modulation
causing an inflammatory response), composition of particles or particle complexes,
concentrations of concern, and impacts of co-pollutants. Particulate matter has also been
strongly been associated with excess cardiopulmonary death; however, mechanisms of
action for this effect are debated in literature. Further information on these mechanisms
of action and the biological basis of these adverse health effects may help establish levels
of concern and health-based risk management options, especially for sensitive
populations. In addition, the populations that have been reported to be at increased risk
(e.g., the elderly, persons with pneumonia, heart diseases, and respiratory diseases) may
U.S. EPA, 402-B-05-001, March 2005 25
-------
spend greater amounts of time indoors and may have an even larger component of their
total particulate matter exposure due to indoor particulate sources.
The majority of available health effects information on particulate matter exposure is
based on studies of outdoor air. While considerable particulate matter health effects
research is being conducted under the auspices of the outdoor air particulate matter
research program, this research will likely need to be expanded to consider the particulate
matter that is determined to be most-characteristic of the indoor environment, particularly
from indoor sources (see sections A.4.C.I. and A.4.C.3). Additional research items
include:
1. identifying the most-toxic indoor particulate matter contaminants;
2. investigating indoor particulate matter health effects for the general population
and for susceptible sub-populations;
3. investigating the deposition and late of particles in the respiratory tract,
particularly for indoor biological contaminants (e.g., cockroach parts);
4. evaluating the health effects when particulate matter is combined with other
indoor pollutants.
A.4.e. Assess particulate matter mitigation strategies.
Recommended mitigation strategies will likely be dependent on the particulate matter sources
(physical characteristics and health impacts), the building design and operating characteristics,
and the occupants. For example, ventilation with outdoor air may be considered a mitigation
strategy for indoor particulate matter; however, there may be many situations where the indoor
particulate matter results predominantly from outdoor sources or where the outdoor ambient air
may require filtration or other treatment.
There ultimately needs to be simple and cost-effective actions that the EPA can recommend for
the general population, and for sensitive and susceptible individuals, to reduce particulate matter
exposure in the indoor environment. In evaluating particulate matter mitigation strategies, the
research should consider the effectiveness in reducing particulate matter exposure, the net
improvement in health conditions, cost-effectiveness, ease-of-implementation, and applicability
to other indoor environments. Existing mitigation techniques that should be investigated can be
divided into strategies which are continuous (such as building design, building construction
features that limit the entry of outdoor particles, air filtration, and ventilation), intermittent
activities primarily involved with clean-up (such as high-efficiency vacuum cleaners, wet
mopping, hazardous particle removal, and changes in cleaning and maintenance practices), and
lifestyle changes (such as eliminating indoor smoking or getting rid of house pets). Additional
particulate matter mitigation strategies should also be investigated after the research described in
sections A.4.C.1 through A.4.C.3 yields information regarding specific indoor particulate matter
sources and exposure routes.
26 U.S. EPA, 402-B-05-001, March 2005
-------
Program Applications for Indoor Particulate Matter Research:
Particles are ubiquitous contaminants, but unlike chemical contaminants, outdoor and indoor
particles vary in size, shape, and chemical make-up. As a result, conclusions reached relative to
particles outdoors do not necessarily apply to particles indoors. In addition to the outdoors,
indoor sources of particles include material sources, biological sources, combustion sources, and
activity sources, such as vacuuming. While particles are a known health hazard, the extent of
that hazard indoors, or the types or sources of indoor particles creating that hazard remain
unknown. This research will enable EPA to provide substantive and detailed guidance for
controlling indoor particle exposures in ways that are effective in reducing risk. Research to
investigate particulate matter from indoor combustion appliances would directly support EPA's
role in the international Partnership for Clean Indoor Air, particularly if the assessments include
exposures from indoor cooking fires, biomass stoves, kerosene, and liquefied propane gas.
U.S. EPA, 402-B-05-001, March 2005 27
-------
B. HUMAN PERFORMANCE
Background Information:
Human performance refers to our ability to perform various generic mental and physical
functions such as reading/comprehending, calculating, remembering, typing, or driving.
These tasks are inherent to how well we perform life's functions at home, at school or at work.
They have important social and economic value, and understanding how the quality of the indoor
environment enhances or inhibits curability to perform life's tasks is the subject of this
programmatic research need.
Evidence is accumulating that indoor air quality can have a measurable impact on human
performance. Early studies using survey data in which respondents estimate the effect of indoor
air on their productivity suggest that current conditions reduce productivity by 3%-4% on
average, or that personal controls of ventilation and temperature could improve productivity by
up to 6% and 10% respectively (U.S. EPA, 1989; Raw, Roys and Leaman, 1990). More recent
controlled field studies measuring performance of specific tasks suggest that increased pollution
sources or reduced ventilation can reduce human performance measures by 2%-6% (Wargocki,
Wyon, Baik et al, 1999). Further, a major cross sectional study of offices of a large U.S.
corporation found that 35% of short term sick absences could be attributed to low ventilation
conditions. The economic value of losses in human performance has been estimated to be in the
"tens of billions" of dollars (U.S. EPA, 1989) or $20 to $160 billion dollars per year (Fisk and
Rosenfeld, 1997).
While the potential value for improved human performance from improved indoor air quality
appears to be substantial, many methodological uncertainties make research in this field difficult.
First, it is important to determine if the impact on human performance is biologically dependent
or independent of other health symptoms such as headaches or lethargy (i.e., is it the headache or
other health condition that causes performance to be effected?). Second, there is no generally
accepted method of measuring human performance in ways that are appropriate to different
indoor environments. Self assessed productivity through surveys is a convenient measure, but
there is only scant evidence that such measures accurate lyre fleet true productivity. Various test
methods have been used to measure different aspects of mental and physical acuity (e.g., typing
test, memory test, arithmetic test), but without standardization, and it is difficult to compare
results across studies or to relate how such measures represent human performance in real world
conditions of different indoor environments. Research on the attributes of indoor air quality
parameters that impact human performance is needed before prescriptive guidance can be
formulated.
The long term program goals for research in human performance are to (1) understand the
biological mechanism by which indoor air quality affects human performance, and the
relationship (or lack thereof) between indoor air quality health symptoms and human
performance; (2) develop a general consensus on the metrics for measuring human performance
in various settings, and develop continuing research to improve those metrics over time;
(3) develop a database of information sufficient for statistically reliable inferences to support
28 U.S. EPA, 402-B-05-001, March 2005
-------
guidelines or standards affecting indoor environmental parameters in homes, schools, offices,
hospitals, and other environments.
Program Needs for Human Performance Research:
B.I.a. Evaluate methods and define research agenda for measuring human performance.
Knowledge on the relationship between indoor environment parameters and human
performance are hindered by the lack of standardized measures. Establish a panel of
renowned scientists with expertise in the field of human performance measurements,
convened under the auspices of the National Academy of Sciences, the World Health
Organization, or similar body. The panel should review current theory and practice in the
measurement of human performance, recommend specific protocols for measuring
human performance in a variety of settings (e.g., short term memory, motor ability,
cognitive abilities), and recommend a research agenda using these protocols.
B.l.b. Develop dose-effect relationships for key contaminants on human performance
measures.
Ethical considerations inhibit experiments in which human subjects are exposed to
harmful contaminants, while animal studies that shows definitive performance
decrements in rats due to exposure to specific contaminants only provide indirect
evidence. However, some research suggests promising methods for extrapolation of
dose-effect relationships in animals to estimate the corresponding relationships in humans
(e.g., Benignus, 2001). The ability for cross-species extrapolation would greatly enhance
our ability to document and quantify the decrements in human performance associated
with indoor air pollution.
B.l.c. Quantify the relationship between health symptoms and human performance.
There are many studies relating occupant symptoms to building or air quality attributes
and this literature has been critically reviewed (Mendell, 1993; Seppanen, Fisk and
Mendell, 1999). However, there is little information about the relationship between health
symptoms and human performance, though there is some suggestion that decreases in
human performance do not take place until certain health symptoms such as headache
become evident (Wargocki, Wyon, Baik et al, 1999). This suggests that information on
the relationship between health symptoms and human performance combined with
available data on the relationship between building attributes and health symptoms could
be used to estimate human performance effects of building attributes. Quantifying the
relationship between building performance and health would provide a missing link in
our ability to quantify how building or air quality attributes affect human performance.
U.S. EPA, 402-B-05-001, March 2005 29
-------
B.l.d. Quantify the relationship between building attributes and human performance
using both laboratory and field studies.
B.l.d.l. Conduct cross sectional studies to identify possible indoor parameters that
affect human performance.
Conduct cross sectional studies in which data from many buildings are
systematically compared in an attempt to derive statistical relationships between
IAQ relevant building parameters and performance/productivity variables. Such
studies would suggest relevant variables that could be more rigorously tested
through controlled studies.
B.l.d.l. Conduct controlled studies to determine key indoor parameters that affect
human performance.
Conduct controlled studies in laboratories and in actual environments in which
building or air quality parameters are systematically changed and human
performance measured to identify specific indoor air quality parameters that affect
human performance. Attempt to derive cause-effect relationships and
dose-response functions. Parameters of interest would include such things as
variations in specific source emissions, type and rate of ventilation air, personal
controls of their microenvironment, air cleaning, intensity of housekeeping,
humidity/moisture controls, and thermal controls. Light (including daylight), noise
and ergonomic effects could also be studied.
B.l.d.3. Conduct studies to determine the efficacy of using self assessed performance
as a true measure of actual performance.
Since data on subjective measures are easier and more feasible to obtain,
knowledge of the relationship between subjective and objective measures can
greatly facilitate the use and interpretation of available data for guidance
development and decision-making.
B.l.e. Conduct research to examine the potential for improving productivity in schools
and offices through actions designed to improve human performance
B.l.e.l Quantify the relationship between measures of human performance and
productivity in real world environments.
Human activity in the office or in school involve a complex combination of
mental and physical functions and tasks (e.g., reading, writing, calculating,
interpreting, reacting, communicating, typing), each of which may or may not be
affected by indoor air quality. Thus, while research on the relationship between
indoor air quality and specific elements of human performance (e.g., reading
comprehension) is important, it does not, in itself, capture the economic or social
value of performance changes in various indoor settings. Rather, the value of
30 U.S. EPA, 402-B-05-001, March 2005
-------
performance changes is reflected through its impact on productivity. For example,
how much is productivity improved by a 10% decrease in typing errors in an
office setting, or how does a 10% improvement in short-term memory affect a
student's performance in school? A set of experiments would be undertaken to
establish the relationships between changes in human performance and changes in
productivity in office, school, and home environments.
B.l.e.2 Conduct intervention and cross sectional studies to measure productivity
changes in schools and offices
The EPA and other organizations provide and promote guidance on good indoor
air quality practices that are expected to improve occupant health and
performance. This research would test the hypothesis that following good IAQ
practices in schools or office buildings will result in measurably higher
productivity, taking into account the need to reduce exposures from both indoor
and outdoor sources.
Program Applications for Human Performance Research:
The indoor air quality program is a non-regulatory program that depends on its ability to motivate
people to take actions that improve indoor air quality in their environments. Currently, however,
motivational messages must be related to improvements in health because this is where data are.
This is very limiting. The general public maybe sensitive to health issues related to their homes,
but for other audiences such as office building managers, corporate executives, or school
administrators, improved health may be only a secondary concern to human performance and
productivity. To businesses, improved performance and productivity implies increased profits or
growth. To schools, student performance is a measure of educational system success. Thus,
developing information on how indoor air quality impacts human performance in offices,
schools, and other environments greatly expands the potential for indoor air quality programs to
effectively motivate the public to take action. The information from this research could
substantially energize the motivational potential of program material in virtually every program
area.
References for Human Performance Research:
Benignus, VA. 2001. Quantitative cross-species extrapolation in noncancer risk assessment.
Regul ToxicolPharmacol. 34(l):62-8.
Fisk, WJ and Rosenfeld AJ. 1997. Estimates of Improved Productivity and Health From Better
Indoor Environments. Indoor Air: International Journal of Indoor Air Quality and Climate.
7: 158-172.
Mendell, MJ. 1993. Non-Specific Symptoms in Office Workers: A Review and Summary of the
Epidemiologic Literature. Indoor Air: International Journal of Indoor Air Quality and
Climate. 3:227-236.
U.S. EPA, 402-B-05-001, March 2005 31
-------
Raw GJ, Roys MS, and Leaman A. 1990. Further Findings from the Office Environment Survey:
Productivity, Proceedings of the Fifth International Conference on Indoor Air Quality and
Climate - Indoor Air 90. Vol 1. pp 231 -236.
Seppanen OA, Fisk WJ, Mendell MJ. 1999. Association of ventilation rates and CO2
concentrations with health and other responses in commercial and institutional buildings.
Indoor Air: InternationalJournal of Indoor Air Quality and Climate. 4::226-52.
U.S. Environmental Protection Agency (U.S. EPA). 1989. Report To Congress on Indoor Air
Quality, Volume II: Assessment and Control of Indoor Air Pollution. Office of Air and
Radiation. EPA/400/1-89/001C.
Wargocki, P, Wyon DP, Baik YK, Clausen G, and Fanger PO. 1999. Perceived Air Quality,
SBS-Symptoms and Productivity in an Office at Two Pollution Loads, Proceedings of the
Eighth International Conference on Indoor Air Quality and Climate - Indoor Air '99. Vol 2.
pp 131-136.
32 U.S. EPA, 402-B-05-001, March 2005
-------
C. IAQ MEASURES AND INDICES
C.I. BUILDING IAQ INDICES
Background Information:
Current market forces and legal incentives for improving IAQ are absent largely because of our
inability to define IAQ by a simple measuring system, similar to the way energy can be
measured. In the absence of a convenient measure for IAQ, buildings can not be labeled or
categorized by their IAQ performance. IAQ is not easily marketed by owners, nor can tenants
conveniently negotiate for an IAQ upgrade during lease negotiations. In addition, insurers can
not conveniently adjust the insurance rates or mortgage companies adjust their finance rates on
the basis of IAQ. Nor does the research community have a convenient measure of IAQ that can
be related to health, property value, or productivity. For any market or program transaction to
incorporate IAQ, a convenient measure or measures are needed. This was recognized by the
Healthy Buildings Healthy People (HBHP) project that called for the development of an IAQ
index.
The pollution standards index (PSI) for outdoor air, or the UV index for sunlight are examples of
indices that greatly facilitate the valuation of risk conditions so that they may be easily
incorporated into decision and transactions. A variety of methods for constructing an index are
available and they vary from a simply linear weighting of input variables to more complex
structures.
A building IAQ index can be designed to incorporate readily available information on IAQ
related building parameters such as ventilation, the presence of sources, and thermal parameters.
An index may require some measures of air contaminants, though comprehensive sampling for
all buildings to be indexed may prove impractical. In addition, an IAQ index could incorporate
measures of the ability of building management to maintain good IAQ conditions over time, and
thus incorporate ratings operations and maintenance protocols along with ratings of IAQ
management practices. Separate specific indices may ultimately be needed for homes, schools,
offices, and other indoor environments.
The long term goals for this program initiative are to (1) develop a generally accepted set of
indices that would reasonably represent indoor air quality in buildings, (2) provide for the quick
development of trial indices based on current knowledge, with index structures that can
accommodate easy refinement and expansion over time, (3) energize markets and other
institutional mechanisms to incorporate IAQ into decision-making based on its measurability
through such indices, and (4) establish an active area of research interest in the IAQ community
and the building community for continuous refinement of the indices.
U.S. EPA, 402-B-05-001, March 2005 33
-------
Program Needs for Building IAQ Index Development Research:
C.l.a. Review and evaluate indexing methodologies.
Establish a panel of renowned scientists with expertise in the field of index development
in the health or environmental sciences convened under the auspices of the National
Academy of Sciences, the World Health Organization, or similar body. The panel will
review current theory and practice in the development of indices to measure
environmental conditions, and make recommendations as to (1) the criteria that should be
used as the basis for the indices (2) the methods that would be useful for constructing one
or more building indoor air quality indices, and (3) the databases that are available or
could easily be developed for use in these indices.
C.l.b. Construct and characterize different indices.
Identify several individuals or organization, each of which will develop one or more IAQ
indices for buildings, and will characterize the indices (e.g., how does the index of IAQ
building parameters track occupant symptoms, or how does the index change as building
conditions change) using available data such as that from comprehensive building surveys
(e.g. BASE), as well as individual buildings, and hypothetical buildings designed to
evaluate the indices.
C.l.c. Evaluate different indices and provide recommendations for selection.
Convene one or more workshops or similar forums in which the indices developed are
presented and critiqued and recommendations made for further development or selection.
Program Applications for Building IAQ Index Development Research:
With the development of IAQ indices, IAQ would become more quantifiable, enabling a host of
new program initiatives. Measurable indices would make it possible to integrate IAQ into
normal market transactions for buildings, rental space, liability insurance, health insurance, and
finance. Once institutionalized in these markets, good IAQ practices could become important in
the marketplace. Initially, the program office would promote the adoption of building IAQ
indices by appropriate national and international standard setting organizations, and then help
institutionalize these indices through cooperative programs with public and private institutions.
34 U.S. EPA, 402-B-05-001, March 2005
-------
C.2. DEVELOPMENT OF PUBLIC HEALTH MEASURES FOR IAQ
Background Information:
Poor or inadequate indoor air quality in the nation's building stock may increase the prevalence
of many diseases such as lung cancer and asthma, as well as the spread of infectious diseases.
Yet, to date, there are no mechanisms to establish the proportion of these diseases that are
directly or indirectly attributable to poor IAQ. Research is needed to establish the attributable
risk of selected health endpoints to indoor air parameters that can be measured and tracked over
time as a means to measure health gains or losses from changes in the indoor air quality of the
nation's building stock. Such a need was recognized by the EPA's Healthy Buildings Healthy
People (HBHP) project.
By way of example, consider recent research that estimates the incidence of asthma, otitis media,
bronchitis, and pneumonia in children attributable environmental tobacco smoke (ETS)
exposure. The estimates are based on a review of the literature that report on the relative risk or
odds ratios of these diseases associated with ETS exposures (DiFranza and Lew, 1996), from
which attributable risk is then calculated. From information on attributable risk, the proportion of
the national incidence of each of these diseases attributable to ETS exposure has been estimated,
along with national medical expenditures for physicians, emergency care, hospitalizations, and
medications (Cunningham, Houle and Mudarri, 2002). From this information, estimates of the
reductions in the national incidence in these diseases, and the reductions in associated national
medical expenditures resulting from programs to reduce exposure of children to ETS can also be
made. Similar efforts could be initiated for other exposures, and other building conditions, and
other health endpoints. This type of data would provide a significant opportunity to establish
health-based goals under the Government Performance Results Act (GPRA), and then track
progress overtime in achieving those goals.
One should harbor no illusions that a small amount of research in a short period of time will
provide comprehensive data on all the diseases attributable to indoor air that may be of interest.
But a case can be made for providing estimates for those diseases based on existing research that
have reported relative risks or odds ratios, and then starting on a long term path to provide a
comprehensive database. The research should tie into and complement CDC's National Report(s)
on Human Exposure to Environmental Chemicals. Considering all potential health outcomes,
the long term goals of this program need for research are to: (a) develop estimates of the
incidence of all diseases attributable to poor indoor air quality; and (b) relate progress made in
improving indoor air to the improvement in public health through the quantifiable reduction in
disease incidence.
U.S. EPA, 402-B-05-001, March 2005 35
-------
Program Needs for Research on Public Health Measures for IAQ:
C.2.a. Select target diseases and indoor air parameters.
C.l.a.l. Establish candidate diseases associated with specific indoor air quality
attributes.
Conduct a comprehensive literature review and evaluation of diseases (or other
health effects) for which national statistics are collected and for which studies are
available that provide estimates of relative risk/odds ratio, dose-response, or
similar statistical association to indoor air quality attributes. Identify candidate
diseases and attributes for further investigation.
C.2.a.2. Identify available data and data needs to determine population exposures to
candidate indoor air quality attributes.
Conduct a comprehensive review of available data and/or data collection efforts
needed to establish the proportion of the population exposed to the indoor air
quality attributes identified in C.2.a.l.
C.2.a.3. Select two or three diseases and associated indoor air quality attributes for
development of national impact estimates.
Based on C.2.a.l and C.2.a.2, select two or three candidate diseases and their
associated indoor air quality attributes for a concerted effort to estimate the
attributable risk and national incidence of the selected disease attributable to
indoor air quality. An important criteria for choice should be the availability of
data for appropriate estimates of attributable risk.
C.2.b. Estimate the proportion of selected diseases attributable to indoor air quality.
Data gaps on the national incidence of the selected diseases and the attributable risk
associated with indoor air quality attributes for those diseases will have to be assessed,
and, if necessary, additional studies and data collection efforts instituted. Once the data
are established, estimates of the attributable risk and the national incidence of the selected
diseases attributable to indoor air quality should be made.
C.2.c. Publish estimates of attributable risk and national incidence of selected diseases
attributable to indoor air quality.
These estimates should be thoroughly peer reviewed and published. Solicitation of
interest from a wider research community to continue these studies, selecting other
disease endpoints would be part of an overall strategy to elevate indoor air quality as a
public health concern.
36 U.S. EPA, 402-B-05-001, March 2005
-------
Program Applications for Research on Public Health Measures for IAQ:
The health research budget in the United States is substantial, much of it is focused on research
directly related to specific diseases. Developing estimates of attributable risk to indoor air may
provide an avenue by which indoor air could be promoted as a more significant topic of interest
to the health research community. Further, these studies would allow EPA to develop
quantitative health-based GPRA goals for indoor air, establish a data collection program to track
the critical indoor air and building attributes over time, and thereby report on progress in
reducing disease incidence through improved indoor air quality.
References for Research on Public Health Measures for IAQ:
Cunningham K, Houle C, and Mudarri D. 2002. Medical Cost of Childhood Illnesses
Attributable to Environmental Tobacco Smoke: Total National Costs and Costs to Managed
Care Organizations. Draft Contractor Report prepared for the Indoor Environments Division.
U.S. Environmental Protection Agency, Washington, D.C.
DiFranza J and Lew R. 1996. Morbidity and Mortality in Children Associated with the Use of
Tobacco Products by Other People. Pediatrics. 97(4): 560-568.
U.S. EPA, 402-B-05-001, March 2005 37
-------
D. BUILDING DESIGN AND OPERATION
Background Information:
Building design and operation play an important role in maintaining a healthy and productive
indoor environment. There are several factors driving building professionals to review current
products and practices, and to search for practical and effective alternatives, associated with
building design and operation. Examples of these driving forces include the green building
movement, the progression towards more energy-efficient buildings, and growing concerns over
liability due to poor indoor air quality. Other motivations include reduced costs from medical
expenses and lost work performance due to illnesses, allergies, and irritations arising from poor
indoor air quality. Although much is known or suspected regarding health risks and performance
impacts in the indoor environment, a comprehensive, integrated effort to conduct research on the
effects of building design and operation is needed.
While the potential value for improved building design and operation appears to be substantial,
significant gaps still exist in the current state of knowledge. Building professionals are generally
unaware or lack sufficient data to know what they can do to reduce the risk of asthma, cancer,
and other serious diseases caused by indoor pollutant exposure. Best practices and products will
vary according to the diverse types, locations, and planned uses of buildings.
It is in the proper application of best practices and products that the benefits of a healthy indoor
environment that enhances human performance can be realized. The overall program goal for
research in building design and operation is to collect and develop data that can be used to create
guidelines for building professionals to use in selecting best practices and products based on
quantifiable bottom-line costs, as well as health, performance, and other related environmental
impacts (e.g., climate change, sustainable building practices, contributing to outdoor air
toxics, etc.).
Program Needs for Building Design and Operation Research:
D.I. BUILDING CHARACTERIZATION AND INTERVENTION
D.I.a. Characterize the IAQ of US building stock.
During the 1990's, the EPA conducted the Building Survey and Assessment Evaluation
(BASE) program for office buildings, which characterized the baseline levels of indoor
environmental parameters, occupant symptoms, and responses within 100 randomly
selected office buildings (Burton, Baker, Hanson et a/., 2000; Girman, Baker and Burton,
2002). The BASE study results are being used by the EPA to assist with the development
of national policy related to office building design and operation. A logical continuation
would be to characterize the IAQ of other building types, such as schools, homes, and
elderly care facilities. These studies would likely be structured differently from the
BASE study, and would be more limited in scope and complexity.
38 U.S. EPA, 402-B-05-001, March 2005
-------
This research would identify and prioritize the building types to be investigated. A major
outcome of the studies would be the correlation of occupant symptoms and responses to
building parameters including indoor and outdoor pollutant sources, outdoor air
ventilation rates, humidity control systems, and operation and maintenance practices.
This research would also include efforts to: (1) establish panels of national experts to
develop the study protocols for each building type; (2) develop and test appropriate
sampling and measurement techniques, as needed; and (3) collect, analyze, and report on
the data.
Pilot studies may prove to be useful in developing and refining the protocols and
measurement techniques. The data review and analysis could include fUrther
consideration of the existing BASE data, and new data that are collected for other
building types. Data obtained from the studies of various building types should then be
combined to assess the relative contributions of these different indoor environments to
total indoor exposure. Improved exposure models could then be developed and validated.
An example would be a study on the impacts of sources in attached garages emanating
into adjacent living spaces.
D.l.b. Conduct intervention studies of cost, health, and performance benefits resulting
from best practices in building operation and design, and other best practices for
voluntary risk reduction activities.
This research includes conducting intervention studies to determine whether the benefits
resulting from application of building design and operation guidelines (best practices)
outweigh the cost of implementing those guidelines. The research would initially be
targeted to office buildings, schools, and residences. Given that the resources for
applying the full range of building design and operation guidelines are often limited, the
data from the field studies could be collected and reported in a manner that would assist
building professionals in deciding which specific best practices provide the highest return
on investment. Best practices for which there is the potential for significant application
costs as well as substantial quantifiable benefits include:
- control of pollutant sources;
- moisture control;
- biocontamination prevention, clean-up and remediation;
- quantity and quality of outdoor ventilation air,
- operation, maintenance, and housekeeping practices;
- design, construction, and commissioning practices; and
- other recommendations in EPA's Tools for Schools kit and EPA's Design Tools for
Schools website
This research could also include intervention studies to determine the benefits resulting
from EPA's indoor air quality programs, specifically actions specified to reduce risk from
indoor air toxics (e.g., the actions specified by the ETS and radon programs).
Additionally, research is needed to determine the most effective voluntary risk reduction
methods for chemicals that are known health hazards.
U.S. EPA, 402-B-05-001, March 2005 39
-------
D.2. VENTILATION SYSTEMS
D.2.a. Analyze advanced ventilation system approaches.
Ventilation plays a major role in the health, comfort, and performance of building
occupants, and in the initial cost, operating costs, and liability costs of buildings.
Research should be performed to determine the value of the following promising
ventilation technologies:
• Vertical displacement ventilation systems: This is an approach often used in
European commercial buildings and schools to save energy and improve indoor
air quality (Seppanen, Fisk, Eto et al, 1989). The principle behind vertical
displacement ventilation is a laminar flow of low pressure air that originates at the
floor level and exhausts at the ceiling level, which 'lifts' pollutants away from
occupants and reduces the transport and mixing of pollutants within the occupant
breathing zone. There have been only a few demonstrations of this technology in
the U.S. (Belida, Turner, Martel et al., 1997). Research is needed to evaluate the
European and U.S. results, assess the differences between European and U.S.
applications (e.g., climatic variations, HVAC system influences, and energy
prices), and identify the most appropriate applications of this technology in
the U.S.
• Decoupled ventilation approaches: This approach involves separating the outdoor
ventilation air from the air flow that is provided for space heating and cooling.
The potential advantages of this approach include better control of indoor
humidity, reduced capital costs, reduced energy costs and easier maintenance
(Harriman, Brundrett and Kittler, 2001). Research should focus on how this
technology could apply in different climatic regions, and how it would interface
with commonly-used HVAC system designs.
• Automation of Heating, Ventilating and Air Conditioning (HVAC) controls:
The primary purposes of HVAC controls are thermal comfort, energy-efficiency,
and regulation of outdoor ventilation air flow into the building.
Currently-available HVAC control systems often fail to perform as intended due
to improper installation, adjustment and operation. Research is needed to
prioritize equipment malfunctions and indoor contaminant levels that have the
potential to affect indoor air quality, and to determine the value that improved
controls, including new sensor technologies, would provide though
self-diagnostics and automated corrective actions.
• Residential ventilation: Traditional heating and cooling systems in U.S. homes
have not addressed the fresh air ventilation needs for home occupants. Homes
experience inadequate ventilation because they rely on infiltration and natural
ventilation with outdoor air rather than controlled mechanical ventilation systems.
Energy-efficient home construction often results in 'tight' buildings with very low
leakage (infiltration).
40 U.S. EPA, 402-B-05-001, March 2005
-------
Over the past two decades, materials and techniques available to home builders
have resulted in typical new homes having natural ventilation rates less than what
is specified by the American Society of Heating, Refrigerating and
Air-conditioning Engineers (ASHRAE) for residences, a minimum of 0.35 air
changes per hour (Howard, 2000; FSEC, undated). The result is stale air,
moisture problems, and elevated pollutant levels indoors.
Positive mechanical ventilation with clean outdoor air is needed to dilute indoor
contaminants. Mechanical ventilation is a relatively new practice for new home
construction, and research is needed to determine the most practical and
appropriate approaches which may, in fact, be climate-dependent. Research
should include a survey to investigate the natural ventilation rate in homes via
blower door testing; and studies intended to evaluate and improve the
cost-effectiveness of controlled mechanical ventilation so that these systems are
more-readily accepted by builders and homeowners.
Many Americans have residences in apartment buildings, with designs that range
from small buildings with a few apartments to large, multistory buildings with
hundreds of apartments units. Research is also needed to assess current
ventilation approaches for apartment buildings, and to develop recommendations
for advanced ventilation approaches that promote good indoor air quality.
• Air filter efficiency: Every type of building requires some degree of air filtration.
Filtration is needed for several reasons, including protection of equipment,
energy-efficient operation, and protection of occupant health and performance.
The selection of an appropriate filtration system depends on several factors
including the HVAC system design, the building design characteristics, occupancy
requirements, and financial considerations (including life cycle costs and impacts
on performance and productivity). A study is needed to determine the appropriate
filtration approach for various building types and applications for these design
parameters.
D.2.b. Develop recommendations for improving existing building ventilation systems.
Given that the proper quantity and quality of ventilation is a critical component of good
IAQ, utilize a literature survey, field surveys, and field studies to identify the typical
failure modes and operating problems for ventilation systems. Typical failure modes
result from design and construction errors (such as selection of noisy equipment that is
turned off by occupants, variable-air-volume (VAV) systems with fixed outdoor air
dampers and/or no minimum settings to ensure adequate ventilation at reduced load);
operation and maintenance errors (such as neglect, turning off ventilation systems due to
noise or comfort, not performing a periodic check to measure the outdoor air flow rate);
and simple deterioration of equipment. Based on this data, develop maintenance and
operation procedures, and practical upgrades for existing ventilation systems, to help
ensure a proper supply of outdoor air in existing buildings; and to stimulate the
U.S. EPA, 402-B-05-001, March 2005 41
-------
production of better ventilation equipment. Examples of potential research areas include
optimizing the performance of unit ventilators in existing school classrooms, assessing
and recommending ventilation approaches for multi-family (apartment) dwellings, and
developing ventilation recommendations for urban areas with potentially large sources of
outdoor pollution.
D.2.c. Characterize the impact of ventilation systems and occupant density on the rate of
transmission of infectious diseases in indoor environments.
There is suggestive evidence that low outdoor air ventilation rates and high occupant
density increase the transmission of common respiratory diseases such as the common
cold and the flu virus (Wheeler, 1997). However, it is not clear the extent to which this
occurs, and the extent to which increased ventilation rates mitigate the impacts of
occupant density. In addition, vertical displacement ventilation systems may serve to
reduce disease transmission from infected individuals by virtue of the air flow patterns
that are established. Since respiratory disease impacts have a significant public health
implication, and since sick absences are a significant cost factor to the economy,
quantitative data on the impacts would go a long way to resolving the controversy
surrounding the rate of ventilation that is considered adequate, and for identifying
superior ventilation designs. Initial studies should be performed for high-occupant
density environments, such as classrooms or auditoriums, to determine if there is a
measurable effect and whether further investigations are warranted.
D.3. CONTROL OF RADON AND OTHER SOIL GASES
D.3.a. Conduct studies on potential humidity control benefits of radon mitigation systems.
The most commonly used approach for reducing radon levels in residential applications
involves active soil depressurization (ASD). Radon mitigation systems based on this
approach typically use one or more vent pipes with a fan to remove soil gases from
beneath a home's foundation and vent the soil gases to a location away from the home's
living space (U.S. EPA, 1993; ASTM, 2001). It is estimated that approximately 500,000
homes in the United States have had elevated radon levels reduced using ASD radon
mitigation systems over the last 15 years (Jalbert and Gregory, 2002). There have been
anecdotal reports that homeowners often perceive additional improvements in the IAQ in
their homes after an ASD radon mitigation system has been installed. Common
perceptions are that the home feels drier, there are fewer problems related to high indoor
humidity, and musty odors in basements are reduced. Research is needed to investigate
whether ASD radon mitigation provides additional IAQ benefits, particularly with respect
to reducing indoor moisture and humidity problems, and which also could result in
reduced indoor mold and mildew. Pending the results for ASD radon mitigation systems,
follow-on investigations may be appropriate for passive radon control systems (passive
systems do not incorporate a fan) that are commonly used in new home construction.
Information to support this research need may be provided by ongoing programs such as
that described in section D.3.C. for evaluating methods to control migration of volatile
contaminants in soil gases into the indoor environment. Research should also investigate
42 U.S. EPA, 402-B-05-001, March 2005
-------
the effectiveness of radon mitigation systems over time (in reducing radon levels and
potentially providing humidity control benefits).
D.3.b. Conduct studies to evaluate radon-resistant construction techniques for new homes.
Radon-resistant new construction (RRNC) techniques reduce indoor concentrations of
radon by blocking radon entry points through the use of sealing techniques, and by using
the natural upward thermal draft in a passive vent pipe to slightly depressurize the area
under the home's foundation (U.S. EPA, 1994). The passive vent pipe is typically run
through the conditioned portion of the home (usually hidden in an interior wall or pipe
chase), and relies on the natural upward draft of gases in the pipe caused by the difference
between indoor and outdoor temperatures. Research is needed in the following areas to
support the EPA's Radon Program:
• Effectiveness of RRNC for reducing radon levels: Research conducted to date
shows that RRNC techniques typically reduce radon levels by approximately 50%,
on average, however there is a range in the reported results (NAHB Research
Center, 1994; NAHB Research Center, 1996; LaFollette and Dickey, 2001).
More research is needed to further investigate the effectiveness of RRNC
techniques, which includes assessing the effect of builder installation techniques
and quality control, and the effects of seasonal weather variations. Research
should also investigate the effectiveness of RRNC over time. Research could also
investigate the potential energy benefits and the Integrated Pest Management
(IPM) benefits that may result from the improved home sealing associated with
RRNC.
• Installation costs of RRNC: An often significant barrier towards getting builders
to incorporate RRNC techniques into new homes is the incremental added cost for
the features. Some studies were conducted in the early 1990s (ICF, Inc. &
Camroden Associates, Inc., 1992), however research is needed to assess the
current RRNC installation costs experienced by home builders. The research
should consider situations where some of RRNC techniques are already
implemented as part of the normal home building process (e.g., gravel layer,
polyethylene sheeting, weatherization). The research should also investigate the
additional costs associated with activating passive RRNC systems, which is
accomplished by installing a fan and system operating indicator.
D.3.C. Conduct studies to evaluate methods to control migration of volatile contaminants in
soil gases.
Another source of toxic contaminants indoors relates to contaminated soil gas resulting
from contaminated ground water, leaking storage tanks, toxic dumps, and landfills.
There are tens of thousands of Superfund and RCRA sites that are known and probably
many that are still unknown. Volatile contaminants in soil gas can enter buildings in a
manner similar to radon. Consequently, mitigation methods similar to those effective
with radon may be used. However, current health-based risk reductions often requires
U.S. EPA, 402-B-05-001, March 2005 43
-------
much higher performance of the mitigation methods (such as sub-surface
depressurization) than is required by the corresponding radon action level. Additional
research and development maybe required to optimize the performance of these systems.
The government currently has an emphasis on the development of Brownfields, many of
which have contaminated ground water and vadose zones. Buildings constructed over
these areas will be prone to indoor air toxic problems. This is a circumstance in which
the methods for radon reduction in new construction should be revisited to ascertain their
applicability to control these new soil gas contaminants. While many of the construction
methods will be directly applicable to other toxic soil gases, some research issues exist.
First of all, the required level of protection may be significantly higher than in the
corresponding case for radon. Consequently, the level of performance of the proposed
construction methods must be tested and demonstrated to provide adequate protection by
reducing the risk levels appropriately.
There maybe some implications for both active (fan-driven) and passive (natural draft)
mitigation strategies for the toxic gases associated with volatile contaminants in the soil
and groundwater. These gases may diffuse through concrete slabs more effectively than
radon. Consequently, prevention of advective transport into buildings may not result in
sufficient protection of the indoor environment. In the case of radon, it was observed that
reversing the direction of air flow through the building foundation from inward to
outward almost always reduced the indoor radon concentrations below the action level.
This appeared to be true even when the sub-slab concentration of radon was only
nominally reduced. This result agreed with measurements of diffusion rates through
concrete slabs. If the effective diffusion rates through the slab are significantly higher for
these other gaseous contaminants, then there may be potential for elevated indoor
contaminant levels even when a negative pressure is maintained beneath the slab.
Effective mitigation methods may be required, not only to reverse the direction of
advective flow through the building foundation, but also to reduce the sub-slab
concentration to quite low values. Some new research and development work maybe
required to extend the capabilities of current radon reduction methods to be effective
against these new soil gas contaminants. Research should also investigate the
effectiveness of these systems over time (in reducing radon levels and indoor
concentrations of volatile contaminants from the soil and ground water). Research could
also investigate the potential impacts of contractor qualifications and installation
techniques on the effectiveness and durability of these systems.
D.3.C.I. Conduct studies to investigate relationships between subsurface
concentrations and indoor concentrations of volatile contaminants.
A vapor intrusion-focused research topic that has recently been initiated by the
EPA's Office of Solid Waste & Emergency Response (OSWER) and Office of
Research & Development (ORD) involves efforts to collect evidence from
investigations of vapor intrusion cases from across the United States for
incorporation into the Indoor Air Vapor Intrusion (IAVI) database. This research
effort is initially focusing on defensible evidence of the relationship between the
44 U.S. EPA, 402-B-05-001, March 2005
-------
subsurface concentrations and the associated indoor air concentrations
(i.e., amount of attenuation in vapor concentrations), see: http://iavi.rti.org.
Anticipated future efforts include working to identify the site-specific
characteristics that influence the observed attenuation factors. This information
could be used to help improve the accuracy of predictions and prevent the over-
and/or under-regulation of these exposures.
D.4. BUILDING DESIGN AND IMPLEMENTATION
D.4.a. Conduct research to support building materials selection and installation
procedures.
D.4.a.l. Compare and evaluate product emission methods and standards.
As part of the green building movement, a number of organizations have
established mechanisms for evaluating or rating products with respect to their
impact on indoor pollution and health. For example, Green Seal, a non-profit
institution, provides product standards based on product formulations, while
Green Guard, another non-profit organization uses an emission measurement
method along with a set of health criteria. As the Green Building movement is
rapidly expanding, and includes the encouragement and support of EPA, a host of
institutions are using these or similar standards. However, there is a growing
concern that many of these standards are not protective of health and may have
little scientific foundation. The State of California has developed emission-based
standards using California's acute and chronic exposure levels as it's health basis
and appears to be the most scientifically supportable, but it has not received
independent scrutiny or wide public acceptance. EPA is developing green
building guidance for federal facilities but has yet to address the indoor pollution
issues involved in the selection of products. Research is needed to provide a
systematic comparison and evaluation of the major methodologies and standards
used for evaluating products based on the extent to which they limit indoor air
pollution and protect public health. Such research would inform the green
building community and guide EPA as it develops and refines its guidelines.
D.4.a.2. Develop a building materials selection and installation protocol.
The materials, finishes, furnishings, maintenance supplies, and housekeeping
supplies that go into new or existing buildings can have a major impact of the
quality of the indoor air. Building professionals responsible for the materials
acquisition are becoming more aware that proper selection is important to the
health and performance of occupants. Comprehensive yet easy to follow
guidelines on how to best select products are urgently needed, yet the
development of such guidelines is not possible without emissions and health
effects data on key building sources and products. Research should identify the
sources and products with the greatest impact on IAQ, and characterize their
emissions and health effects. This research interrelates with the Chemicals and
U.S. EPA, 402-B-05-001, March 2005 45
-------
Sources program needs in this document, which describe developing quantitative
emissions factors for various sources (section A.I.d.2).
With this information, a set of quick and easy materials selection guidelines,
providing objective criteria to building designers, could be developed. Criteria
could then be developed for determining what constitutes 'best' materials,
including effects on occupant health and performance (as information is
available), initial capital costs, operating costs, materials performance, life-cycle
costs, outdoor environmental impacts, and other impacts on indoor quality
through activities such as materials maintenance and replacement.
In addition to materials selection, it is also important to determine appropriate
recommendations for installation, for example, scheduling sequence and minimal
use of problematic emitting materials.
D.4.b. Conduct studies on the relationship between IAQ, energy efficiency, and moisture
management.
Current market trends include designing and constructing energy-efficient buildings,
which often results in practices that can adversely affect the quality of the indoor
environment. Energy-efficiency and IAQ are strongly interdependent. Proper
implementation of energy-efficiency measures requires a thorough consideration of IAQ
impacts. Similarly, IAQ measures must be implemented in a manner that is consistent
with energy-efficiency goals. For example, there is often a perceived conflict between
ventilating with an adequate quantity of outdoor air and the need to minimize energy
costs. Research is needed to investigate energy-efficient heating, cooling and ventilation
techniques which promote good IAQ.
Energy-efficient buildings can have IAQ problems when moisture management is not
properly addressed during the design and construction. Moisture management is often a
climate-specific issue. Improperly designed and constructed buildings and mechanical
systems can cause indoor moisture problems due to air-flow-induced moisture transfer
through the building shell, condensation, outdoor air ventilation, and improper surface
water drainage. Research is needed to develop design guidelines that will minimize the
potential for mold and comfort problems resulting from excessive indoor moisture.
D.4.c. Evaluate current and popular building practices.
Several practices in building design and operation can have a substantial impact on
indoor air quality, thus affecting health and performance. Many of these practices result
from current trends in 'green building' and sustainable development. Following are
examples of building practices that should be evaluated for indoor air quality, economic,
and performance impacts:
46 U.S. EPA, 402-B-05-001, March 2005
-------
• Use of recycled content materials in new and existing buildings;
• Siting new buildings on brownfields, landfills, and other contaminated sites
(e.g., evaluating soil gas intrusion and its contribution to indoor contaminant
levels, and evaluating the effectiveness of mitigation techniques such as sub-slab
depressurization);
• Siting new buildings in areas with high moisture load potentials, such as filled-in
wetlands and flood zones;
• Use of air purification such as germicidal ultraviolet lights, carbon air filters, and
ion and ozone generators (see also sections F.I and F.2);
• Use of biocides in building materials, maintenance supplies, and air filters
(see also section F.I);
• Duct cleaning (determining whether it is needed, what methods are most effective,
and the relative value of duct cleaning versus air handling unit cleaning);
• Floor type and materials selection;
• Floor care focused on particle control via high-efficiency vacuums, central
vacuums, entry mats, floor maintenance materials and procedures;
• Sloped roofs as an alternative to the flat roof systems that are typically used in
non-residential buildings, to provide better moisture management;
• Attached garages (e.g., evaluating contaminant levels and exposures in adjacent
occupied spaces, assessing building design impacts and mitigation strategies);
• Building and HVAC system commissioning and periodic re-commissioning
(commissioning is a formal process intended to verify and document that a
building and/or HVAC system is constructed, adjusted, and performing in a
manner consistent with its intended design);
• Building flush out to remove built-up contaminants prior to occupancy.
Program Applications for Building Design and Operation Research:
Historically, risk evaluations of environmental exposures have focused on long term exposures
leading to chronic diseases such as cancer. Exposures are often modeled based on limited field
data. With the development of the Building Assessment Survey and Evaluation Study (BASE),
the EPA is making data available, specific for commercial office buildings, for rigorous
assessments of both chronic and short term exposures and risks. With BASE data, researchers are
now beginning to examine exposures leading to other health endpoints such as respiratory
diseases, as well as health symptoms such as headache and mucous membrane irritation.
Examination of the building conditions and practices that lead to these health effects can also be
examined. The proposed research for the development of similar data on other building types,
using compatible data collection protocols, would lead to a broad set of analyses to identify the
full impact of indoor air on health, comfort, and productivity of occupants; the attributable risk
associated with specific building contaminants, sources, and practices; and the mitigation steps
required to minimize risk.
New ventilation technologies and systems, such as displacement ventilation, decoupled
ventilation, as well as energy recovery ventilation systems have the potential to greatly improve
indoor air quality at significantly reduced energy costs. In addition, new controls and automation
U.S. EPA, 402-B-05-001, March 2005 47
-------
systems stand to greatly improve system efficiencies. The proposed research is designed to
accelerate the demonstration and adoption of these technologies.
In addition, the EPA has provided the most comprehensive and up to date IAQ guidance for
commercial buildings, schools, and radon in residences. However, while the guidance is
comprehensive, it is generic, and not necessarily tailored to the actual building stock. The next
steps in the evolution of this guidance await further research. The proposed research would
evaluate the effectiveness of mitigation practices that are recommended, identify and assess the
most common failures of building systems and controls that lead to indoor air quality risks, and
evaluate new technologies and products that could improve or degrade progress toward improved
indoor environments.
Further, the proposed research is designed to provide information needed to guide ever-growing
constituencies for indoor air, such as those constituencies dealing with energy efficiency, green
building design and construction, and homeland security.
References for Building Design and Operation Research:
ASTM. 2001. ASTME-2121, Standard Practice for Installing Radon Mitigation Systems in
Existing Low-Rise Residential Buildings. West Conshohocken PA: American Society for
Testing and Materials.
Belida, LM, Turner WA, Martel SM, et al. 1997. The Advantage Classroom; Sustainable
Design For Achieving Indoor Air Quality, Comfort, and an Improved Learning Environment,
Proceedings of the Healthy Buildings/IAQ '97 Conference - Global Issues and Regional
Solutions, Vol 1, pp 123-128. Washington DC: Healthy Buildings/IAQ '97.
Burton LE, Baker BJ, Hanson D, et al. 2000. Baseline Information on 100 Randomly Selected
Office Buildings in the United States (BASE): Gross Building Characteristics, Proceedings
of Healthy Buildings 2000, Vol 1, pp 151-155. Helsinki: Healthy Buildings 2000.
FSEC, undated. Priorities for Building a New Florida Home. Florida Solar Energy Center Web
Site: www.fsec.ucf.edu/Bldg/FYH/PRIORITY/Index.htm
Girman JR, Baker BJ, and Burton LE. 2002. Prevalence of Potential Sources of Indoor Air
Pollution in U.S. Office Buildings, Proceedings of the 9th International Conference on Indoor
Air Quality and Climate - Indoor Air 2002, Vol 4, pp 438-443. Santa Cruz: Indoor Air 2002.
Harriman LG, Brundrett GW, and Kittler R. 2001. Humidity Control Design Guide For
Commercial and Institutional Buildings. Atlanta: American Society of Heating,
Refrigerating, and Air Conditioning Engineers, Inc.
Howard B, 2000. Accounting for Air Infiltration. Home Energy Magazine Online
November/December 2000. Web site: http://hem.dis.anl.gov/eehem/00/001103.html.
48 U.S. EPA, 402-B-05-001, March 2005
-------
ICF, Inc. and Camroden Associates, Inc. 1992. Analysis of Options for EPA's Model Standards
for Controlling Radon in New Homes. Draft Contractor Report prepared for the EPA Radon
Division. U.S. Environmental Protection Agency, Washington, D.C.
Jalbert P and Gregory B. 2002. National Radon Results: 1985 to 2003. Published on EPA web
site: www.epa.gov/radon/pdfs/natl_radon_results_update.pdf
LaFollette S and Dickey T. 2001. Demonstrating Effectiveness of Passive Radon-Resistant New
Construction. Journal of the Air & Waste Management Association. Volume 51:102-108.
January 2001.
NAHB Research Center. 1994. The New Home Evaluation Program. Final report provided for
EPA Grant No. X819586-01-0. Upper Marlboro MD: NAHB Research Center.
NAHB Research Center. 1996. Seasonal Performance of Passive Radon-Resistant Features in
New Single-Family Homes. Final report provided for EPA Grant No. X 819586-01-5,
Task 2. Upper Marlboro MD: NAHB Research Center.
Seppanen OA, Fisk WJ, Eto J, et al. 1989. Comparison of Conventional Mixing and
Displacement Air-Conditioning and Ventilating Systems in U.S. Commercial Buildings.
ASHRAE Transactions. V. 95, Pt 2. VA-89-19-3.
U.S. Environmental Protection Agency (U.S. EPA). 1993. Radon Mitigation Standards. Office
of Air and Radiation. EPA 402-R-93-078. Revised edition republished in April 1994.
U.S. Environmental Protection Agency (U.S. EPA). 1994. Model Standards and Techniques for
Control of Radon in New Residential Buildings. Office of Air and Radiation.
EPA 402-R-94-009.
Wheeler AE. 1997. The V in Classroom HVAC. ASHRAE Journal. October 1997, pp 48-55.
U.S. EPA, 402-B-05-001, March 2005 49
-------
E. HOMELAND SECURITY
Background Information:
Recent events and the increased threat of terrorist activities in the U.S. have heightened the need
for measures to prevent and clean-up potential releases of chemical, biological, and radiological
warfare agents into buildings. There are also instances when remedial measures are needed to
address accidental and unintentional releases of toxic substances and other potentially hazardous
conditions within the indoor environment. This section presents a simple overview of potential
research initiatives in these program areas, which are rapidly emerging. The EPA will likely be
receiving major funding increases in FY03 and outyears for research initiatives related to
homeland security, planned for execution within several offices including the Office of Research
& Development (ORD); the Office of Solid Waste & Emergency Response (OSWER); the Office
of Water (OW); the Office of Prevention, Pesticides and Toxics (OPPT); and the Office of Air
and Radiation (OAR).
Because this is a rapidly emerging area, the present version ofPNIER does not attempt to capture
all of the detailed indoor environments research initiatives that can and should be pursued by the
EPA for homeland security. The broad research initiatives identified in this section ofPNIER
will be further developed, shaped and refined as the larger EPA initiatives and programs become
established. In September 2002, the EPA published a high-level strategy for homeland security
(U.S. EPA, 2002), and efforts will be made to ensure that the indoor environments research
needs contained in PNIER are consistent with that strategy. The EPA's Office of Research &
Development has established a National Homeland Security Research Center (NHSRC), and a
Safe Buildings research program for addressing detection/sampling and analysis; containment;
decontamination; and disposal. All homeland security research outlined in this document will be
closely coordinated across these Agency programs.
There are several chemical agents (e.g., nerve agents, blister agents, choking agents) and
biological agents (e.g., anthrax, botulinum toxin, ebola, ricin, etc.) which could be employed
under terrorist or wartime activities because of their direct toxic effects. Although there are
several thousand poisonous agents known, only a limited number are generally considered
suitable for warfare due to their nature and ability for storage and resistance to climate.
While some treatments and antidotes are known for a portion of these agents, there is a great deal
of research that needs to be done. However, due to the varied nature of the agents and the
multitude of ways to expose a population (i.e., in the water supply, as a plume in the outside air,
through the ventilation system in a building, or as a direct contaminant release inside a building),
it is not reasonable to expect that the most effective immediate reaction to these threats will or
should be medical in nature. Therefore, it is important to establish ways to limit the ability of
these agents to reach the population at large, particularly in the indoor environment.
Any products or technologies developed for homeland security should be objectively evaluated,
with thorough performance verification.
50 U.S. EPA, 402-B-05-001, March 2005
-------
Program Needs for Homeland Security Research:
E.I. Conduct simulation modeling studies of contaminant releases to determine critical
pathways and control variables.
Releases of chemical, biological, and radiological agents should be simulated under a
variety of conditions and assumptions of survival potential, using available building air
flow models (research may reveal that modifications are needed for existing models).
Studies are needed to characterize the fate and transport of chemical, biological, and
radiological agents in indoor environments under a variety of conditions, including:
outdoor releases, indoor releases, and point sources which could include individuals.
The information obtained during this research will serve as a foundation for prevention,
mitigation and clean-up guidelines for the indoor environment.
E.2. Conduct research to support the development of EPA guidance to ensure emergency
preparedness in building types through operation and maintenance practices.
In its role as the lead government agency for building emergency preparedness, the EPA
needs to develop credible and practical guidance for building owners and operators to
ensure adequate protection in the event of a chemical, biological or radiological
contamination incident. Research is needed to develop, demonstrate, and verify building
operation and maintenance practices which help prevent indoor air contamination, and
ensure suitable building emergency preparedness. This should include development of
building ventilation system operation and maintenance recommendations, considering
both outdoor and indoor sources of the contaminants, and identifying the key variables
that can be controlled to prevent and mitigate contaminant transmission. Once developed,
these recommendations could be added to existing educational and support materials
used by building operators (e.g., maintenance and operation checklists).
E.3. Conduct research to support the development of EPA guidance to ensure emergency
preparedness in building types through new technologies and materials.
Research is needed to identify and develop suitable detection methods for chemical,
biological, and radiological contaminants. Special considerations should be given to the
development of practical sensor and control system technologies that will allow
immediate identification and automated building response to a potential threat. Other
technologies that warrant research include improved air filtration and cleaning system
designs, and alternative air distribution system designs. New technologies and materials
must have the capability to be applied cost-effectively to abroad range of contaminants
and building types.
E.4. Conduct research to support building clean-up and re-occupancy.
After emergency response, the issue of clean-up after a chemical, biological, or
radiological warfare incident or an accidental toxic release is a matter of continued
concern. There is insufficient information available to support the use of existing
U.S. EPA, 402-B-05-001, March 2005 51
-------
building clean-up protocols with a high degree of confidence. Highly-controlled
laboratory studies should be conducted to establish with confidence appropriate cleaning
agents and processes to ensure that clean-up is successful, and that workers are
sufficiently protected. Information from these studies will be used to establish guidelines
for EPA and other public health entities engaged in clean-up efforts. Specific research
areas include:
• reviewing currently available threat analyses (including NHSRC's efforts)
• developing lists of contaminants of concern (e.g., from terrorism, criminal activities, or
accidental incidents),
• conducting baseline contamination and decontamination studies,
• developing standards for appropriate levels of clean-up, which could be dependent on
the specific contaminant(s) and other building-related factors. This would be closely
coordinated with NHSRC's Rapid Risk Assessment Program
E.5. Verify the performance of products and technologies developed to address
homeland security.
Verification is needed to validate claims for products and technologies that have been and
are being developed to address homeland security concerns. For example, in response to
recent terrorist incidents there is an increasing number of products being developed and
marketed to address issues such as biological warfare (e.g., the release of anthrax from
intentionally contaminated mail in office buildings), and exposure and clean-up after
terrorist incidents. The protection of the American citizens is of utmost concern, and
there needs to be objective research performed to ensure that only safe, credible and
reliable products are introduced into the public marketplace. These research efforts will
be closely coordinated with the NHSRC's Environmental Technology Verification (ETV)
efforts.
An example would be to investigate the effectiveness of sheltering-in-place actions for
schools, office buildings, and other public facilities. This has already been demonstrated
for residential applications under the Chemical Stockpile Emergency Preparedness
Program (Sorensen and Vogt, 2001).
Program Applications for Homeland Security Research:
The vulnerability of building occupants to a chemical or biological attack depends on the
location of the release, characteristics of a building that affect air flow patterns, the location of
occupants, and the preparedness of the building management to recognize an attack, and to
subsequently be able to isolate and contain the contaminants. The proposed research would
provide the basis for the EPA to develop guidelines for building and governmental officials to
prepare for and react appropriately to an attack. In addition, further proposed research is needed
to prepare for effective clean up of the attack agents and other related contaminants after the
attack, so that buildings can be re-occupied.
52 U.S. EPA, 402-B-05-001, March 2005
-------
References for Homeland Security Research:
Sorensen J and Vogt B. 2001. Will Duct Tape and Plastic Really Work? Issues Related to
Expedient Shelter-In-Place. Oak Ridge National Laboratory Report ONRL/TM-2001/154.
Date published - August 2001.
U.S. Environmental Protection Agency (U.S. EPA). 2002. Strategic Plan for Homeland Security.
September 2002. Published on EPA web site:
www.epa.gov/epahome/downloads/epa homeland security strategic plan.pdf
U.S. EPA, 402-B-05-001, March 2005 53
-------
F. PRODUCT AND TECHNOLOGY VERIFICATION
Background Information:
There are several products and technologies available in the public and commercial marketplaces
that are promoted for their contribution to a healthy indoor environment. In many cases, the
effectiveness and net health impacts of these products and technologies have not been fully
evaluated. The research needs described in this section are intended to address some of these
information gaps, however it is expected that the scope of the research will likely exceed what is
captured in this document as new products and technologies evolve.
Program Needs for Product and Technology Verification Research:
F.I. Conduct research on source control products and technologies.
Often the most effective approach to reducing indoor air contaminant exposure is source
control. Source control involves both removal and control of contaminant levels.
There are several products and appliances marketed for use on surfaces and in ventilation
systems (e.g., anti-microbial cleaners and sealants, air fresheners, vacuum cleaners, etc.)
which are marketed for this purpose. Many of these products have not been fully
assessed for their net effectiveness in improving indoor air quality, and some of these
products can themselves be sources of indoor air pollution. In addition, the impact on
human health especially from inhalation exposure to these products or by-products
produced during use of some of these products has not been fully investigated. One major
concern from a health standpoint is the increased incorporation of anti-microbial agents
and fragrances in some of these products. There are also concerns expressed in literature
about the potential impact of high-level use of these products on human immune system
development and biological organism resistance as well as the unknown potential for
health impacts from long-term, low-level exposures, which have not been investigated.
Further research is needed on each of these issues and data gaps.
F.2. Investigate the performance of air treatment systems.
The performance of air cleaning systems (e.g., ionizers, electrostatic precipitators,
ultraviolet germicidal lights, photocatalytic cleaners, activated carbon filters, and alumina
coated filters), and filter efficiencies need to be investigated to compare the results with
vendor claims. These devices are widely advertised as effective methods for cleaning up
the air and providing symptomatic relief for individuals with indoor air health and
comfort concerns. However, air cleaning devices and air filters are not generally
sufficient by themselves to reduce indoor air contaminant exposures especially when
there are large pollutant sources, or the pollutants themselves settle-out on surfaces.
In general, the health benefits of air filters and air cleaning devices are not objectively
clear and most claims are based on the very limited scientific evidence. In addition, there
are several questions about the potential for adverse impacts on respiratory tissues and
chronic or latent health effects due to contaminants (e.g., ozone, hydroxyl radicals and
other oxidizing agents, ionized particles, formaldehyde, etc.) emitted by some air cleaning
54 U.S. EPA, 402-B-05-001, March 2005
-------
devices that have not been thoroughly investigated. As part of this work there is a need to
assess and input into the test standards presently used by the industry for various
categories of equipment.
F.3. Investigate risk management controls for indoor fuel-fired heating and cooking
devices.
Billions of people around the world are exposed to high levels of combustion byproducts
from indoor use of propane, methane, kerosene, natural gas, traditional biomass
(e.g., wood, dung, and crop residues), and other fuels during heating and cooking.
The specific pollutants of concern and the potential health risks from these indoor
exposures are dependent on several factors including fuel types, appliance designs,
building factors (i.e., ventilation levels, building design, room dimensions, etc.), use
patterns, and individual susceptibilities and vulnerabilities with potentially greater impact
on highly vulnerable populations such as the elderly, women, children, the chronically ill,
and the economically disadvantaged. In addition, the choice of appliance and fuel-type is
often associated with societal and cultural issues or beliefs. Biomass burning is
associated with 1.6 million deaths per year, adverse pregnancy outcomes, and increased
risk of serious respiratory infections worldwide (WHO 2002).
In the United States and several other industrialized countries, there is a body of literature
and research on the performance of indoor fuel-fired heating and cooking devices,
potential levels of indoor contaminants resulting from these devices, potential health
impacts of these contaminants at higher levels, and performance certification programs
for some appliances and fuel types. A large portion of the global population is exposed to
high levels of contaminants from a wide variety of device designs, particularly in
non-industrialized nations. There are also several unknowns related to the specific health
impacts of exposure to lower levels of contaminants and exposures experienced by
certain susceptible populations, use patterns, and risk reducing technology modifications
that need to be addressed (see also A. 1 .b and A. 1 .h.2). Several studies in developing
countries have documents the health impacts of burning traditional biomass and coal fuels
indoors for home cooking and heating. Assistance is needed with evaluating risk control
options that are being employed and building local/regional capacity for monitoring
indoor air pollution in homes with improved technologies.
Research is needed to investigate and develop self-sustaining and viable risk control and
risk management options. Research should consider social, cultural, and economic
barriers related to the use of fuel-fired heating and cooking devices and fuel choices in a
variety of industrialized and non-industrialized settings. These investigations should
include consideration of new risk reduction technologies and development of design
guidance or standards. Specifically, research is needed to investigate the performance of
improved cook stoves, as more information is needed on the emissions, efficiency and
reliability of improved technologies and fuels that are being developed and promoted.
Research is also needed to investigate the performance of new personal monitoring
devices that have been developed to measure PM and CO, and to develop and establish
recommended sampling methods for these devices.
U.S. EPA, 402-B-05-001, March 2005 55
-------
Program Applications for Product and Technology Verification Research:
As good indoor air quality becomes more widely appreciated and desired by consumers, a host of
products are being increasingly developed and marketed to solve or protect against indoor air
quality problems. These products include new air cleaning technologies, anti-microbial agents,
air fresheners, and air quality sensors. With this increased presence in the marketplace there
have been increased inquiries concerning the efficacy, effectiveness, and benefits of these
products. However, whether many of these products work, how they work, and what possible
secondary contaminants or health effects maybe created or enhanced from use of some of these
products is often unknown and is of utmost concern to the indoor air quality community.
The research proposed in this section addresses the need for further evaluation of the
performance, effectiveness, and potential positive and/or negative impacts on indoor air quality
and human health from these types of products. This information will help EPA and other
concerned federal, state and local organizations to subsequently issue information reports and
guidelines to potential users.
References for Product and Technology Verification Research:
World Health Organization (WHO). 2002. Reducing Risks, Promoting Healthy Life. Geneva,
Switzerland: World Health Organization.
56 U.S. EPA, 402-B-05-001, March 2005
------- |