Indoor Air A Report on EPA's Indoor Air Research Program 1986-1990 Annual Report


             United States
             Environmental Protection
             Agency
Office of Research and
Development
Washington, DC 20460
July i, 1990
Annual Report
                                                     (V
             Research And Development
EPA
              Indoor Air
                                  V

              A Report on EPA's
              Indoor Air Research
              Program 1986 -1990
              Annual
              Report
                               '~  \\
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   A REPORT ON EPA'S INDOOR AIR RESEARCH
                  PROGRAM 1986 -1990
O> '; : -•
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er> 1%,
                         July 1, 1990
              Office of Research and Development

             U. S, Environmental Protection Agency
                              By
                      Michael A. Berry, Ph.D.
         Deputy Director, Environmental Criteria and Assessment Office
               Matrix Manager, Indoor Air Research Program
                               . ,  ',.,,* ,w»p p< ."J ;
         This document is intended for EPA review and comment only and
         not for outside distribution.

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          A REPORT ON EPA'S INDOOR AIR RESEARCH

                         PROGRAM 1986 - 1990


                                CONTENTS



                    EPA INDOOR AIR RESEARCH PROGRAM

Sara Title IV: Indoor Air Research Requirements

Research Activities, Organization, and Objectives

EPA Recommendations to Congress

Research Accomplishments

     Health Impact and Risk Assessment

     Source Characterization and Mitigation
                                             • >
     Building Studies and Methods Development

     Health Effects
     Biocontamination Assessment
                                APPENDICES
Appendix A: Indoor Air:  ORD IAQ Research and Extramural Activities

Appendix B: Indoor Air Research Program Publications and Presentations

Appendix C: Indoor Air Research Five-Year Plan (FY90-94)

Appendix D: EPA Indoor Air Research Program for Fiscal Year 1990

Appendix E: EPA Indoor Air Research Program for Fiscal Year 1991
Page



  1

  1

  2

  6

  6

  7


 10.

 12

 15

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                                TABLES



Indoor Air Research Program Resource Summary



                                FIGURES



EPA Moor Air Research Program Framework
Page





 4
                                    11

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 EPA INDOOR AIR RESEARCH PROGRAM STEERING COMMITTEE MEMBERS
Norman Childs
Environmental Criteria and
 Assessment Office
Research Triangle Park, NC

Da Cote
Health Effects Research Laboratory
Research Triangle Park, NC

Alfred Dufour
Environmental Monitoring
 Systems Laboratory
Cincinnati, OH

Ross Highsmith
Atmospheric Research and Exposure
 Assessment Laboratory
Research Triangle Park, NC   ..

W. Gene Tucker
Air and Energy Engineering
 Research Laboratory
Research Triangle Park, NC
In addition, there were several Agency scientists who also contributed to this report.  Of specific
note were the contributions of:  Bruce A. Tichenor,  Air and Energy Engineering Research
Laboratory; Ronald Rogers, Health Effects Research Laboratory; and William Ewald and Beverly
Comfort, Environmental Criteria and Assessment Office.

Technical Assistance

Project Management, editing, production and word processing from NSI, Inc., under contract
to the Environmental Criteria and Assessment Office, Office of Health and Environmental
Assessment:  Miriam Gattis, Lynette Davis, Phil Gagne, Derrick Stout and Jorja Followill.
                                        ill

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                     EPA INDOOR AIR RESEARCH PROGRAM
SARA TITLE IV: INDOOR AIR RESEARCH REQUIREMENTS
In October 1986, Congress passed the Superfund Amendments and Reauthorization Act (SARA,
PL 99-499). The Act included the Radon Gas and Indoor Air Quality Research Act (Title IV),
which for the first time mandated a federal indoor air research program. Under this legislation,
EPA is directed to undertake a comprehensive effort of research and development, including the
coordination of government and private efforts.  The ultimate goal of this activity is to
characterize indoor air nationwide, predict health consequences, and disseminate information to
the public regarding indoor air control techniques and mitigation measures.
                          i
Research program requirements under SARA include:  identifying and assessing the sources and
levels of indoor air pollution; developing instruments for indoor air quality data collection; and
studying complaint buildings.  The statute also requires research directed at identifying effects
of indoor air pollution on human health.  In the area of mitigation and control the following are
required: developing mitigation measures to  prevent or abate indoor air pollution; developing
methods to reduce or eliminate indoor air pollution; developing methods to assess the potential
for contamination presented by new construction; and examining design measures to improve
indoor air quality.

RESEARCH ACTIVITIES. ORGANIZATION. AND OBJECTIVES

In October  1986,  EPA's Office  of Research and Development (ORD) established a matrix-
managed research  program  that  emphasizes  risk  assessments  for indoor environments,
development of sampling devices for use indoors, indoor air quality models, materials testing
methods, research test house experiments, and investigations of special complaint buildings.  In
conducting  indoor air research, the Office of Research and Development  has integrated the
research efforts of the  Health Effects  Research Laboratory, the Atmospheric Research and
Exposure Assessment Laboratory, the Air and  Energy Engineering Research Laboratory, and the
Environmental Criteria and Assessment Office all located at Research  Triangle Park, NC, and
more recently, the Environmental Monitoring Systems Laboratory in Cincinnati, OH. A research
steering committee has been  formed  consisting of a  senior research  manager from  each
laboratory.  The committee advises the  matrix manager on specific research projects, resource
requirements and  allocation, and assists in coordinating multidisciplinary  research projects.
Appendix A lists all the major indoor air research activities in the  Office of Research and
Development and the individuals responsible for each activity.

The Office of Research and Development's Indoor Air Research Program has strived to support
the needs of EPA's emerging Indoor Air Division, Office of Air and Radiation (OAR), as well
as the technical needs of state and local  government agencies and private sector

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organizations.  EPA's researchers have taken the lead in working with other Federal agencies to
identify the most important indoor air quality concerns. The Agency's 1989 Report to Congress
outlines the most important research needs of government and the private sector. EPA's Indoor
Air Research Program is addressing twenty-four of the thirty-three priority research needs
identified in the report to Congress.

Subsequent to the submission of the Agency's report to Congress, EPA designed a long term
program and strategy that will play a major role in addressing indoor air needs. Appendix C
outlines ORD's 5-year plan for  indoor air research.  That plan, along with individual project
descriptions of indoor air research projects, was presented to other Federal agencies in indoor air
research through the interagency Committee for Indoor  Air Quality (CIAQ) in January 1990.
Also, since January 1990, the Indoor Air Research Program has conducted a survey of ongoing
indoor air research throughout the United States.  The results of that survey will appear in a
separate report that will be presented to the CIAQ and the EPA Science Advisory Board in the
near future.  In the 1989 Report to Congress, EPA made six recommendations intended to
develop the necessary information required by Title IV of SARA. These recommendations are
listed below. They represent the primary  objective, activity, and support areas of the Indoor Air
Research Program.

EPA RECOMMENDATIONS TO CONGRESS

      1.    Research to better'Characterize exposure  and  health  effects  of chemical
           contaminants and pollutant  mixtures  commonly  found indoors  should  be .
           significantly expanded.

     2.    A  research program to characterize and develop mitigation  strategies for
           biological contaminants in indoor air should be developed.

     3.    Research to identify and characterize significant indoor air pollution sources and
           to evaluate appropriate mitigation strategies should be significantly expanded.

     4.    A program is needed to develop and promote, in conjunction with appropriate
           private sector organizations,  guidelines covering ventilation, as well as other
           building design, operation, and maintenance  practices for ensuring that indoor
           air quality is protective of public health.

     5.    A program of technical assistance and information dissemination, similar in
           scope to the Agency's radon program, is needed to inform the public about
           risks and mitigation strategies, and to assist state and local governments and the
           private sector in solving indoor air quality problems. Such a program should
           include an indoor air quality clearinghouse.

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     6.    The Federal government should undertake an effort to characterize the nature
           and pervasiveness of the health  impacts associated with indoor air quality
           problems in commercial and public buildings, schools, health care facilities,
           and residences, and  develop and  promote  recommended  guidelines for
           diagnosing and controlling such problems.
These recommendations are based on identified potential indoor air hazards throughout the
Nation as well as the need to inform the public of effective control measures and mitigation
procedures.  Along with radon, the health impact from exposure to biological pollutants and
environmental tobacco smote (ETS) is quite substantial.  There is enormous public concern
over, exposure to and the effects of many of the gas phase organic compounds found indoors.
This has led to a growing demand to study the phenomenon of "chemical sensitivity" in humans.
Previously, little research has been directed towards identifying the cause of complaints in
buildings.  To date,  no advances  have been  made in explaining the  differences between
noncomplaint and complaint buildings.

To accomplish the research objectives identified in the report to Congress, ORD has organized
and grouped projects and activities in the following areas:                        _

       •   Indoor Air Program Management and Technology Transfer

       •   Indoor Air Health Impact and Risk Assessment
       •   Indoor Air Source Characterization and Mitigation

       •   Indoor Air Building Studies and Methods Development
       •   Indoor Air Health Effects

       •   Biocontamination Assessment

The general goals and direction of each of these research areas are presented in the five year plan
shown in Appendix C.  The specific projects carried out and planned under these areas for FY90
and FY91 are shown in Appendices D and E, respectively.  Table 1 presents the funding history
of the research program since FY87.

The Indoor Air Research Program addresses a complex environmental problem requiring the
successful  integration  of  different  disciplines  and  technical  activities  (risk  assessment,
engineering, methods development, health effects research, field studies, and microbiology).
Figure 1 illustrates the major research project areas of the Research Program. In relation to each
other, these information gathering activities form the  research program framework.  Their
ultimate purpose is to provide the public with technical information

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TABLE 1. INDOOR AIR RESEARCH PROGRAM RESOURCE SUMMARY
Research Area

IA Assessment
Building Studies
Health Effects
Source Assessment and Control
Biocontamination Research
TOTAL

IA Assessment
Building Studies
Health Effects
Source Assessment and Control
TOTAL
»
IA Assessment
Building Studies
Health Effects
Source Assessment and Control
TOTAL

IA Assessment
Building Studies
Health Effects
Source Assessment and Control
TOTAL
IA Assessment
Building Studies
Health Effects
Source Assessment and Control
TOTAL
FTE
FY91
3.0
3.0
5.0
7.0
JLQ
17.0
FY90
3.0
3.0
1.0
_AQ
15.0
FY89
3.0
3.0
1.0
8.0
15.0
FY88
3.0
3.0
1.0
8.0
15.0
2.0
3.0
1.7
6.0
12.7
S&E
(SK)

308.0
299.4
310.0
881.7
•_•—
1551.1

174.4
226.1
60.2
904.3
1365.0

180.0
181.5
61.1
538.4
961.1

180.0
174.0
100.0
398.0
852.0
0
210.0
100.0
320.4
630.4
R&D
($K)

467.0
1313.5
841.6
1579.8
200.0
4401.9

238.6
564.4
949.1
823.8
2575.9

249.0
616.0
960.0
921.2
2746.2

299.0
533.0
625.0
840.0
2297.0
178.0
767.0
550.0
725.0
2220.0
Total
<$K)

775.0
1612.9
1151.6
2461.5
200.0
6201.0

413.0
790.5
1009.3
1728.1
3940.9

' 429.0
797.5
1021.1
1459.6
3707.2

479.0
707.0
725.0
1238.0
3149.0
178.0
977.0
650.0
1045.4
2850.4

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on the. health risks of poor indoor air quality and at the same time give guidance for the
attainment and maintenance of healthy indoor air.

During the FY86-89 period, ORD's research strategy for indoor air was to develop the necessary
equipment and experience by which to assess indoor air quality. The program emphasized the
development of source assessment and testing methods, indoor air models, monitoring methods,
test house procedures, and risk assessment methodologies. Since then the program has begun to
demonstrate a capability to measure human response in a clinical research setting and to conduct
large building studies, such as in the Library of Congress and EPA's headquarters building
studies in Washington.

In addition, the research program is developing animal test capabilities to assess multiple
pollutants from indoor sources, enlarging the building studies program, planning a mitigation
guidance component of the program, and it is beginning preliminary testing on a limited number
of air cleaning devices. The risk assessment component of the program has begun to develop
methods for assessing multiple pollutants and noncancer endpoints. A biocontaminant assessment
component of the Research Program will be initiated in FY91.

RESEARCH ACCOMPLISHMENTS

Appendix B presents the numerous publications of and presentations by EPA's indoor air
researchers. These efforts have clearly contributed to a better understanding of indoor air quality
and its impact on public health. Several researchers have been recognized as national experts
in their specialty areas and many of them continue to perform as leaders in both national and
international research activities. The major accomplishments of EPA's Indoor Air Research
Program and its on-going research are summarized below. These accomplishments are reflected
in the several manuals and fact sheets either in preparation or already released to the public
through OAR's Indoor Air Division.

Health Impact and Risk Assessment

• An information assessment identifying the hazards of indoor environments was completed
in 1987 and submitted to Congress as part of EPA's Indoor Air Quality Implementation
Plan. The document serves as the first step in the process of risk assessment in that it
provides a preliminary hazard identification of indoor pollutants. The assessment also
discusses the known monitoring methods and mitigation techniques.

• A comprehensive bibliographic data base (Reference Bibliography) for indoor air pollution
has been established. The citations of all indoor air research publications known to EPA
are published yearly. The Reference Bibliography is an ongoing project that is intended to
be a complete list of all published information pertaining to indoor air pollution. Health
effects, monitoring methods, exposure levels, mitigation techniques, office building, and
specific individual pollutants are some of the key word categories that can be searched in

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the bibliographic data base. This project is useful to Federal, state, and local agencies,
researchers, and private companies who are interested in determining what information has
been published in a specific area of indoor air pollution. The bibliographic data base is
available in both computerized and published versions.

• A risk assessment methodology is being developed and tested for its effectiveness in
representing the risk from exposure to multiple pollutants from products such as carpet,
tobacco and unvented kerosene heaters.

• Several reports have been completed under an especially established Indoor Air Research
Report Series to highlight the results of the Indoor Air Program. These reports are
undergoing Office of Health and Environmental Assessment (OHEA) review and include:
Development of a Risk Characterization Framework, A\Review of Indoor Air Quality Risk
Characterization Studies, Methods of Analysis for Environmental Carcinogens, Indoor
Concentration of Environmental Carcinogens, Use of Benzene Measurement Data in Risk
Characterization Estimate: A Preliminary Approach.

• Other reports are being prepared that address subjects such as the health impact associated
with the stress and annoyance of odorous compounds and the health consequence of cleaning
and maintenance practices in the indoor environment.

Source Characterization and Mitigation

• Laboratory studies of the emissions from unvented kerosene space heaters identified many
vapor- and particulate-phase organic compounds, plus acid aerosols, that are of potential
health concern. (The subsequent section on health effects contains further information of
the results of these studies.) Testing results are being summarized and factors important
in kerosene heater selection and use are being reported as input to EPA guidance.

* Testing procedures for evaluating the emission characteristics of building materials and
consumer products have been developed. Small test chambers are used to determine the
emission rate and composition of vapor phase organics emitted from indoor sources.
Research is conducted to evaluate the effect of temperature, relative humidity, air exchange
rate, and product loading on the emission rates. A variety of sources have been tested
including polyurethane coatings, wood wax, architectural coatings, moth repellant (para-
dichlorobenzene), dry cleaned fabrics (tetrachloroethylene), air fresheners, carpet, and
office partitions.

» An international interlaboratory comparison study is underway to develop statistics on the
comparability of chamber test data. The study is being jointly undertaken by EPA and the
University of Aarhus (Denmark) and includes participants from the United States, Denmark,
Sweden, West Germany, and Italy.

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EPA has drafted a Standard Guide for small chamber testings for acceptance and publication
by the American Society for Testing and Material (ASTM). The Guide has passed
subcommittee balloting and is being voted on by the Society's full committee. It is
anticipated that balloting by the full Society will occur later this year. A version of the
Guide has been published as an EPA report (EPA 600/8-89/074) and has been widely
distributed for use by both IAQ researchers and private sector manufacturers of indoor
materials and products.

Through its program to characterize sources of indoor air pollutants, EPA has introduced
the concept of controlling low-emitting indoor materials and products as an important
approach to pollution prevention and indoor air quality control. Several major
manufacturers are now using procedures developed under EPA's indoor air research
program to test emissions and predict indoor exposures from their products. This is a
significant step toward private-sector involvement in improving indoor air quality.

Fundamental research on the behavior of indoor sinks has been initiated. Rates of
adsorption to and desorption from carpet, drywall, ceiling tile, upholstery, and glass have
been determined for ethylbenzene and tetrachloroethylene via small test chamber studies.
Indoor air research test house studies have shown that reemissions (desorption) from sinks
have a major impact on the long-term exposure to pollutants from indoor sources. The new
data on sinks will greatly increase our ability to predict indoor pollutant concentrations
through modeling, and may help explain occupant complaints in buildings with no^apparent
sources-of pollutants. . • '

Exposure to emissions from indoor sources can be controlled by appropriate source
management and proper ventilation. ORD has applied these concepts to several indoor
sources of concern to EPA Program Offices by using data obtained in small chamber and
test house studies. "Airing out" freshly dry cleaned clothes as a means to reduce indoor
exposure to tetrachloroethylene was shown to be ineffective, due to the slow decay of
tetrachloroethylene emissions (study conducted for Office of Toxic Substances and OAR).
Appropriate conditioning of carpet for 30 days prior to installation can reduce indoor
concentrations of 4-phenylcyclohexane (4-PC) to below 1 ppb (study conducted for the
Office of Administration). Recommendations were made for the time between application
of an architectural coating and an adhesive in an office and the return of the occupants
(study conducted for Project 1992 and the Environmental Health and Safety Division, Office
of Administration).

The indoor air research test house has been used for the study of pollutant sources, sinks,
and transport of pollutants under scenarios that would be expected to be encountered in
homes. Several products from which organic emissions have been studied include: moth
crystals, (invented kerosene space heaters, solvent emissions from dry cleaning of clothing,

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aerosol spray products and other products that are applied wet and then allowed to dry on
site, oil wood stain, varnishes, and floor waxes. Several studies on air movement in a
house provided information on how pollutants move and how changes can be made to
modify these movements. For example, the fan of the heating/cooling system of a home
completely overcomes any effect of area fans, such as bathroom and/or kitchen fans.
However, if the heating/cooling fan is turned off, the small fans can reduce pollutant levels
in the closed rooms they are ventilating. Future work in the test house will explore: 1) the
effects of pressure and temperature on the movement of pollutants; 2) other organic
emissions from consumer products; and 3) changes in products and uses that can reduce
exposure to inhabitants.
i
Analytical methods developed by EPA for indoor air research that are appropriate for
general use are being rewritten in ASTM format for publication in the ASTM Books of
Standard Methods. The canister collection method for volatile organic compounds is in the
process now.

Research on indoor air control methods has examined the effectiveness of activated carbon
for control of low concentrations of vapor-phase organics. These studies show that
activated carbon devices are ineffective in removing the vapor-phase organic compounds.
Alternative mechanisms for removing low concentrations of vapor-phase organics are being
evaluated on a theoretical basis.

The emission of ozone from electrostatic precipitator air cleaners has been evaluated. The
study show that large in-duct electrostatic precipitator air cleaners can generate ozone.
Additional experiments are planned to determine the destruction of ozone in ductwork and
in normal indoor environments. Experiments will also be conducted to determine the
effectiveness of carbon beds and catalytic beds in preventing ozone from entering the living
spaces.

Preliminary experiments on the effectiveness of particulate air cleaners have been
completed. These experiments demonstrate the need for particle size-based testing of air
cleaners because, with existing methods, filters with high ratings were less that SO percent
efficient in removing particles in the size range of environmental tobacco smoke. An
improved test method is being developed and evaluated in FY90. Work to assist private
standard setting bodies such as ASHRAE in developing standard methods for evaluating air
cleaners based on this research is underway.

Cooperative research with ASHRAE to determine definitions of and methods for evaluating
ventilation effectiveness is underway. A workshop to develop ventilation effectiveness
definitions, methods, and research needs was held in the fall of 1989. This meeting brought
together the leading researchers and practitioners in the ventilation field. The output of the
workshop will assist private organizations such as EPRI and ASHRAE as well as
government organizations conducting research in ventilation.

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• A preliminary test method for evaluating the particulate emissions from vacuum cleaners
has been developed. The preliminary tests show that vacuum cleaning may be a significant
source of respirable particles in indoor air, at least for short periods of time. Several
private companies have expressed interest in the results of this work and in working with
EPA to develop a standard test method.

* The indoor air quality model has been verified in several experiments conducted in the EPA
indoor air test house. The model makes it possible to use the source emission rate data
collected in chamber studies to predict the impact of various sources on indoor air quality.
The model shows the impact of reemitting sinks and has proven valuable in evaluating
indoor air quality control options. The model has been revised to make it easier for the
less-expert user to use. Additional research is revising the model to predict personal
exposure to pollutants from indoor sources. Work is also underway to better define room-
to-room air flows, infiltration of outdoor air, and imperfect mixing on indoor air quality.
The model has already proved to be a valuable tool for people involved in indoor air
research and practice. Over 200 copies of the model have been distributed.

• A Database of Indoor Air Pollutant Sources (DIAPS) has been developed and there have
been many requests for the data base from both foreign and domestic researchers. The data
base is being distributed on a limited basis to get user response. The basic structure of
DIAPS has been changed to reflect user concerns on speed and to make user update easier.
•
Building Studies and Methods Development

* A compendium of methods for measuring indoor air pollutants and a technical assistance
document have been compiled to provide standard operational procedures and technical
assistance to agencies and individuals responsible for sampling and assessing indoor air
quality. This methods compendium contains technically-reviewed sampling and analysis
procedures in a standardized format for measurements of selected indoor pollutants of
primary importance. The ten chapters of the compendium cover determination of volatile
organic compounds (VOCs), nicotine, carbon monoxide, carbon dioxide, nitrogen dioxide,
formaldehyde, benzo(a)pyrene and other polynuclear aromatic hydrocarbons, acid gases
and aerosols, particulate matter, pesticides, and air exchange rates. Each chapter contains
one or more active or passive sampling procedures along with one or more appropriate
analytical procedures. Abbreviated versions of each method are also being developed for
use by field operators and laboratory analysts.

• Passive samplers and personal monitoring devices have been developed for VOCs,
formaldehyde, ozone, and nitrogen dioxide. Research is underway to develop passive and
personal devices for carbon monoxide and ozone. Passive samplers are important because
they are of low cost, can be worn on a person's clothing, and can be used as a screening
10

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tool to indicate areas with highest pollutant concentrations. Passive personal devices or
badges are important because they are low cost, unobtrusive, and require minimal resources.
They also nay provide a better estimate of personal exposures. Passive badges do have a
shortfall in monitoring and analytical sensitivity and accuracy when compared to the routine
active sampling techniques. However, the are good screening tools to determine locations
for additional monitoring or compliance. Changes in pollutant levels can be measured by
personal monitoring devices as the wearer moves into and out of a room containing a
combustion appliance or humidifier in use. Measurements can also be gathered from small
microenvironments such as within a car, parking garage, or dry cleaning establishment.
Exposures can be examined during personal activities, such as cleaning, stripping furniture,
or after new furnishings have been installed in a home or office. These samplers are used
to more accurately predict exposure scenarios where high pollutant levels may be present.

Research has been initiated to develop sampling and analytical methods for VOCs,
semivolatile organic compounds (SVOCs), and aldehydes. Multiple species from these
classes of compounds are routinely observed in varying concentrations indoors. Sources
for the compounds include furnishings, combustion appliance emissions, glues, paints,
solvents, and other products for indoor use. Particular emphasis is being placed on the
collection and analysis of polar VOCs/SVOCs, as these compounds are commonly
associated with health implications, including cancer and neurotoxic effects.

A sampling method has been developed to measure peak exposure of VOCs that may result
from personal activities. Initial studies examined the effects of cleaning and painting,
combustion sources, water off-gassing, and automobile exhaust emissions. This research
is important because other sampling methods are unable to delineate the peak pollutant
levels that may have serious health consequences.

The EPA, in collaboration with DOE and NIST, has supported the development of an
advanced mathematical model to predict indoor air pollution concentrations in multiroom
buildings. A user-friendly interface, entitled CONTAM87, is being designed for use with
the model. CONTAM87 is a general purpose contaminant dispersal model for predicting
concentration levels within a multizone complex. The model requires as input specification
of the mass flow rates between the zones.

Development of an indoor air quality model has also been undertaken by EPA engineers.
The first version of a model designed to simulate pollutant interactions in the indoor
environment has been published. Experiments in the indoor air test home have confirmed
the model predictions for a limited range of conditions. This model will be an invaluable
tool for understanding indoor air quality problems especially in smaller buildings and
residences. The effects of sources, sinks, inter-room air flow, and HVAC systems can be
examined through the model. It will help researchers evaluate indoor air quality problems
and solutions and aid in building design.
11

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Research is evaluating portable home humidifiers and examining the processes and
mechanisms that result in the aerosolization into indoor air of impurities in the charging
water. The research is designed to characterize the chemical and physical characteristics
of the humidifier-generated aerosol and assess the health implications resulting from typical
exposures.

EPA, along with DOE and NIOSH, is investigating complaints of indoor air pollution in
the Library of Congress. EPA will conduct air monitoring analysis in that building and
work with health scientists of other agencies to explain health effects associated with
pollution concentrations.

EPA researchers have responded to the immediate needs of their own agency in the
investigation of complaints in EPA Headquarters, Washington, DC. Extensive air samples
have been taken, materials (carpet) have been evaluated, and a report on sampling results
has been submitted to EPA management.

Technical guidance documents are being developed for sick building syndrome (SBS)
investigators. Step-by-step procedures are being established to allow investigations to
follow a logical progression and to enable comparison between studies.

Research is being conducted to develop a standardized building diagnostic and assessment
protocol. Studies are being planned to collect baseline data from noncomplaint and
complaint buildings that can be used by indoor air quality investigators to assess the indoor
air quality in large buildings. The indoor air quality in selected office buildings will be
monitored to evaluate temporal and spatial distributions of indoor air contaminants and to
relate the indoor air quality to worker discomfort symptoms.
Health Effects
Public interest in indoor air pollution and complaints of sick building syndrome have
increased rapidly during the past few years. VOCs have been identified as major
constituents of indoor air pollution and the health effects of exposure to these chemicals are
of considerable concern. Danish studies suggest that human exposure to a complex mixture
of VOCs (25 mg/m3), representative of chemicals and concentrations found in new homes,
produces sensory irritation and impairment of short-term memory. EPA research has
confirmed that exposure to the Danish mixture produces sensory irritation in normal, health
young adult males (a subset of the general population least likely to show such effects), but
no evidence of memory deficit or other behavioral impairments was found. Further studies
of chemically sensitive individuals are planned to clarify these findings. Studies using VOC
mixtures more representative of American buildings are also planned.
12

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In a second study, nasal lavage was performed to assess inflammatory response in the upper
airways using the same mixture and concentration. Evidence of an inflammatory response
(increased numbers of polymorphonuclear leukocytes  (PMNs)) was  found following
exposure to VOCs compared to clean air. This rinding is very important as it suggests that
PMNs may provide a useful biochemical marker to identify chemically sensitive individuals
and to characterize sick building syndrome.
                    i
Additional studies, using animal and in vitro systems, are being initiated to assess the
potential  health  impact of VOC mixtures  on selected organ systems, e.g.,  immune,
respiratory, nervous, and/or reproductive, as well as the potential mutagenicity. Results
will be compared to information collected in human studies in order to develop models for
animal-to-human extrapolation and also to help guide additional human studies.  Based on
existing evidence of respiratory tract inflammation following controlled VOC exposure, and
complaints of increased respiratory disease as a component of the Sick Building Syndrome,
initial research will focus on the evaluation of immunotoxic effects and assessment of
respiratory initancy following controlled VOC exposures in inhalation chambers. Elevated
ambient levels of inhaled air pollutants have been associated with an increased susceptibility
to respiratory  viral  infections, particularly  in children.  The socioeconomic impact of
influenza viral disease is estimated at  3-5 billion dollars per year in the United States.
Furthermore, viral upper respiratory tract infection has been implicated as an important
contributor to the etiology of asthma, the incidence and mortality of which is increasing in
the United States.  Studies will be performed to determine whether indoor air pollutant
mixtures  affect the susceptibility or  severity of airway hyperreactivity  in the influenza-
induced model for asthma. A new animal inhalation facility, which is nearing completion,
will be used  to  fulfill experimental  designs that address simple and complex exposure
toxicology as well as aim at dissecting  questions of additivity or interaction of VOCs in a
conceptual framework to  develop generic approaches to further mixture study.  Also, in
collaboration  with AEERL, offgas VOC initancy and mutagenicity can be assessed to
determine acute effects of exposure on  breathing patterns as a bioassay system for relative
potency as well as potential carcinogenicity of these gases or combinations.

Environmental tobacco smoke (ETS) is the largest source of indoor air pollution and is also
the major combustion source  contributing  to total human exposure to  mutagens and
carcinogens.   ORD  studies provide  specific data on human exposure  to ETS using
biochemical and  mutagenesis bioassay  measures as well as physical chemical markers of
exposure. Controlled laboratory chamber  studies determined ETS emission factors for
mutagenic activity using  Salmonella mutation assays.  The emission factors for alkenes
(e.g., 1,  3-butadiene) and  aldehydes (e.g., formaldehyde), which are either known or
potential carcinogens, are also being investigated for the first time in these studies. Human
exposure concentrations and dosimetry are  assessed and compared under both controlled
chamber and actual indoor environmental conditions. Levels of nicotine and its major
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metabolite, cotinine, have been found to be useful quantitative and semiquantitative
measures of human exposure and dosimetry. The relationship between nicotine exposure
and urinary cotinine excretion has been studied in preschool children exposed in their homes
and in adults exposed on commercial airline flights. Air monitoring studies in residences
and public indoor areas using both nicotine and mutagenic activity have demonstrated that
separation of smokers into separate areas does not achieve an ETS-free or genuine
nonsmoking area unless there is both physical separation and separate ventilation. The data
from these studies provide information needed in developing policy and guidance
information that will be provided to the public, local, state, and national governmental
agencies and other specific groups (e.g., ventilation engineers, etc.) on how to improve
indoor air quality.

Combustion sources are significant sources of pollutants in homes. Since 1983, ORD has
investigated the health effects of indoor combustion emissions on human health in support
of the Clean Air Act. A major component of this ORD effort has been the investigation
of lung cancer and indoor air pollution from (invented coal and wood combustion in homes
in a rural county, Xuan Wei, in China under a China-U.S. Protocol for Scientific and
Technical Cooperation in the Field of Environmental Protection. This Xuan Wei Project
has been described as a landmark and EPA's single most important joint research project
with China. ORD scientists and Chinese scientists jointly investigated the etiology of lung
cancer, using an interdisciplinary, approach to link air monitoring, chemical, physical and
lexicological data to human epidemiological data. This study showed a strong association
between indoor air pollution and lung cancer, and also identified the classes of compounds
associated with incidence of lung cancer. This study represents a major contribution to the
understanding of nontobacco-related environmental causes of lung cancer in man, and
demonstrated the difference in cancer risk that results from variations of the type of coal
and wood combustion emissions. It also provided a unique opportunity to use a human
population with high exposures and health effects to apply and validate the biomarkers,
which had been developed in the laboratory. Further, sampling needs for this study led to
the development of a medium volume sampler to collect PM10 and semivolatile organics.
Since its development, it has been widely used on other EPA programs, including the IACP
and indoor air projects on kerosene heaters and environmental tobacco smoke.

An estimated 15-17 million unvented kerosene heaters have been sold in the United States.
Many of them were sold to the residents of mobile homes and multi-dwellings. The
pollutants emitted from kerosene heaters can accumulate in homes with small air volume
and low ventilation. Studies were conducted both in a chamber and in mobile homes to
characterize the kerosene heater emissions for mutagenicity and chemical constituents and
to assess the human exposure in a real home environment. Both the chamber and the
mobile home studies show that kerosene heaters emit fine respirable particles that contain
mutagenic organic pollutants, including carcinogenic polycyclic aromatic
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hydrocarbons (PAH) and nitro-PAH. High mutagenic activity was found during the start-
up stage. High emissions of SVOCs from kerosene heaters were found in both the chamber
and the home studies. Limited health effects information is available on the SVOCs and
further work is characterizing them. The home study also shows that, as a result of
kerosene heater usage in homes, the PM10 and CO concentrations in three homes (out of
a total of eight homes monitored) exceeded the United States National Ambient Air Quality
Standards, including two homes that exceeded the PM10 24-hour standard and one home
•• mat exceeded the CO 1-hour peak and 8-hour average standards. These data suggest that
\ the emissions from unvented kerosene heaters impact air quality in homes and can be
; potentially carcinogenic.

Bibcontamination Assessment

• Recently it has become obvious that exposure to biological pollutants, i.e., mold, mold
spores, mildew, bacteria, viruses, and insect and animal parts and excreta, poses an adverse
effect on human health in the indoor environment. A preliminary report on the potential
health impact of the pollutants is being prepared, and is scheduled to be completed within
the next few months. This report will also summarize the occurrence and sources of
biological contaminants in the indoor environment. The health effects to be studied include
the pathogenicity, allergenic potential, and toxicity of the biological pollutants. This report
will also discuss the sampling methods available to date, and will review the research
needed to gain an adequate understanding of the impact of biological pollutants. When
possible, the allergenic, immunogenic, and immunotoxic potential of these pollutants will
also be quantified so that a correlation can be made between concentration and disease
potential. A more comprehensive report on biological contaminants in the indoor
environment is expected to be completed in FY91.

• A major problem in identifying and characterizing effects from exposure to biological
contaminants in the indoor environment is the lack of standardized detection and
identification methods. To this end, the Environmental Monitoring Systems Laboratory-
Cincinnati is developing methods to greatly improve the standard sampling and measurement
methods for pathogens and allergens indoors. The laboratory will also work to characterize
sources of indoor microbial contamination and define the relationship between indoor air
quality, infections, and allergies. The program will initially focus on the development of
optimum detection methods for bacteria and fungi. Concurrently, the collection fluid for
impinger type samplers will be modified to minimize the holding time after impingement.
Methods for critical factors, such as, virulence and allergy determinants, will be developed.
Critical factors are specific characteristics of microbes that confer on them the ability to be
pathogenic or allergenic. Fungi associated with indoor air environments are difficult to
identify because identification usually is based on morphological characteristics that require
the skills of a highly trained mycologist. This process will be simplified by
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