six sections include case studies,
professional advisories, and technical
analyses of the life cycle of building
materials. AEERL is involved with: 1)
development of the materials analysis
section; 2) development of a data
gathering/data analysis methodology (i.e.,
modified Life Cycle Assessment); and 3)
establishment of acceptable quality
assurance and peer review procedures.

The ERG's goal is to meet the public's
need for informed decision making in
support of sustainable environments. It
also provides public outreach for two of
EPA's highest priorities; IAQ and
pollution prevention. The ERG
subscription service currently reaches
more than 2000. For subscription
information, contact Nancy Solomon at
AIA (202-626-7463). EPA Contact:

James B. White (919-541-1189).

The Indoor Air Quality Data Station:
An Integrated Sensing and Logging
Platform - This portable IAQ data
logging system monitors HVAC influ-
ences on IAQ in schools and other |:

buildings. Temperature, relative humi
ity, carbon dioxide, radon, and differ-
ential pressure data can be retrieved via
modem. Source: 1992 Toxics Measure-
ment Symposium.* Author & EPA

Mailing List for Inside IAQ

If you would like to be added to or deleted from the Inside IAQ mailing list,
please mail or fax (919-541-2157) your name and address to:

Inside IAQ, Attn: Kelly Leovie
U.S. EPA/AEERL MD-54
Research Triangle Park, NC 27711

¥CU.S. GOVERNMENT PRINTING OFFICE: 1994 - $80-067/H0143

Contact: Bruce Harris (919-541-7807).
ai

IAQ Information Clearinghouse

Additional information on indoor air is available through the Indoor Air
Quality Information Clearinghouse maintained by EPA's Indoor Air Division.

‘The Clearinghouse can be contacted by phone at 1-800-438-4318 or 301-585-
9020, or by fx at 301-588-3408.

Page 14

2)


Pollution Prevention Research

IRL is researching various pollution prevention techniques

4. -¢-, equipment or technology changes, process or procedure

ification, reformulation or redesign of products) in order to

reduce indoor air pollution through the development of low-

emitting or low-impact materials. AEERL has initiated

cooperative agreements in ‘four different project areas for this

research: aerosol consumer products, composite wood products,
office equipment and products, and textiles.

Aerosol Consumer Products - The three objectives of this
research project are to: 1) characterize emissions from aerosol
consumer products as a function of time; 2) develop methods and
models to measure and predict emissions and personal exposures;
and 3) develop pollution prevention techniques and guidelines for
the manufacture and use of these products. The research is
being performed by Georgia Tech Research Institute, the
University of Illinois, and Purdue ‘University. (EPA Contact:
Kelly Leovic, AEERL, 919-541-7717)

Composite Wood Products - This’ project focuses on the
development of low emitting/low impact composite wood
products. A product list will be developed and screened to
determine emission characteristics and pollution prevention
opportunities. Products offering opportunities for pollution
prevention will then be selected for further research. Studies of
manufacturing processes then will be implemented, and

yosecommendations for lower emitting products will be made. The

\Aearch will be conducted by Research Triangle Institute. (EPA
Contact: Betsy Shaver, AEERL, 919-541-7915)

Office Equipment and Products - The objectives of this
research project are to collect emissions data from office
equipment and products, to identify the sources of these
emissions, and to develop pollution prevention approaches to
reduce or eliminate emissions from selected equipment/products.
The research will be conducted by Research Triangle Institute
and Underwriters Laboratories. (EPA Contact: Kelly Leovic,
AEERL, 919-541-7717)

Textile Products - Five research projects are underway at the
College of Textiles at North Carolina State University: 1) VOC
emissions (e.g., formaldehyde) from finishes used on fabrics -
A number of fabric and finish combinations have been surveyed
and five have been selected for further study; 2) Fiber-based
alternatives for plywood and particleboard - Initial research has
resulted in several potential products, and these products will be
tested for structural characteristics and VOC emissions; 3)
Fusion bonding equipment - Emissions will be characterized for
the most common fusion bonding materials, and research will
determine process changes to reduce emissions; 4) and 5) Effects
of physical and chemical structure on adsorption and

issioncharacteristics of textiles - Selected materials will be

‘ted and a model will be developed. (EPA Contact: James

ite, AEERL, 919-541-1189)

Solutions
Evaluation of In-Duct Particulate Air Cleaners

AEERL has conducted an extensive evaluation of in-duct air
cleaners. The evaluation included determining efficiency as a
function of particle diameter for both clean and dirty air
cleaners. The differential pressure across the filters was also
evaluated because of its effect on energy consumption and the
quantity of air moved through the filter. Commonly used air
cleaners were included in the study: electrostatic precipitators
(ESPs), high efficiency filters, common furnace filters, industrial
American Society of Heating, Refrigerating, and Air
Conditioning Engineers (ASHRAE) rated filters, and
electrostatically augmented filters.

The ESP air cleaners offered the highest particle collection
efficiency for all particle diameters and the lowest pressure drop.
The performance of the ESPs was not affected by dust loading.
The ESPs did, however, generate a few parts per billion of
ozone. The ozone can be controlled by carbon filters located
after the air cleaner. The filters would require occasional (i-e.,
annual) changing.

The high efficiency filters provided high particle collection
efficiency but had much higher pressure drops than the ESPs.
Commonly used furnace filters and the industrial ASHRAE rated
filters had low particle collection efficiency, especially in the 0.2
to 2 um diameter range.

The electrostatically augmented air cleaner based on electret
technology provided improved performance compared to a
furnace filter when clean. However, the performance of the
filter was significantly reduced when the filter was dirty. The
other type of electrostatically augmented filters tested did not
show any significant improvement compared to a furnace filter.
In addition, the pressure drops across the filter increased as the
filter became dirty.

100 —

80

Collection efficiency (%)
8

Boroo2 0.050102 05 1 2 5 1
Particte diameter (um)

Performance of Various In-Duct Particulate Air Cleaners.

Page 5


Detailed suggestions from each of the seven workgroups are
summarized below. The suggestions are not meant as a
comprehensive listing or ranking of AEERL research priorities,
but only as summaries of the topics discussed by Workshop
participants.

The following pollution prevention options were suggested for
adhesives and caulks/sealants: material substitution; material
elimination (e.g., eliminating unnecessary chemicals); innovative
technologies (e.g., producing a carpet with an attached stick-on
pad, producing adhesives without solvents); process substitution;
and packaging reduction.

The biocontaminants workgroup concluded that research should
concentrate on: improvement of biocontaminant measurement
techniques; development of building codes to prevent places in
buildings that encourage biocontaminant growth; development of
effective building cleaning schedules; and public education.

The building materials workgroup discussed vinyl and fabric wall
coverings; HVAC systems; interior panels; ceiling tiles; and
electrical wire jacketing. General suggestions included research
on the source characteristics of a material and the potential sink
characteristics; coating or sealing exposed surfaces to prevent
VOC release; easy-to-clean designs; and consideration of total
surface area of material used, the toxicity of emitted compounds,
and the emission mechanisms (e.g., physical, chemical).

Pollution prevention suggestions for consumer products included:
packaging, delivery, storage, and disposal issues; consumer-
based performance standards development; total cost benefit
assessment; labeling; consumer education on proper product use;
source characterization; and test method development.

The following products were suggested for potential research by
the furniture workgroup: finish coatings, upholstery, institutional
and residential furniture, and cushioning. Research should
identify all emitters and emission rates, then the critical
emissions and products. The next step is to identify
manufacturing changes that will reduce emissions.

The office equipment workgroup suggested researching:
blueprint machines; dry printers and copiers; toner emissions,
increasing toner transfer efficiencies, and the secondary toner
market; equipment bakeouts; propellants and other dispensing
agents; and paper proliferation in the office. Emissions research
should include: emission characterization, chemical
transformations and interactions with emissions from other
sources, and product aging. The workgroup also recommended
designing products so that they are easily remanufactured;
studying the relationship between equipment miniaturization and
emissions; and understanding cross media and energy impacts,
toxicity, and flammability issues.

The textiles workgroup suggested the following research:
measure primary emissions from textiles and create a database;
investigate source/sink behavior; understand exposures and
health effects; conduct life-cycle analyses considering use

patterns and exposures, consumer and end-use issues, aging,
maintenance, and raw materials; finishes (e.g., formaldehyde,
fire retardants), and the use of mechanical rather than chemical
finishes; process changes (e.g., pressure drying rather than
atmospheric drying); and process design changes (e.g., ue)
optimally designed machines so that fabric does not need to be
sized for different uses).

Proceedings from the Workshop (EPA-600/R-93/198; NTIS
PB94-114782) are available from the National Technical
Information Service (NTIS). (See address on page 11.)

Ventilation and IAQ Workshop

AEERL co-sponsored a Workshop on Ventilation and IAQ with
the University of Illinois Bioenvironmental Engineering Research
Laboratory (BERL). The Workshop was held September 14-16,
1993, in Raleigh, NC.

Over 80 IAQ researchers, HVAC industry representatives,
engineers and architects, and buildings science and
environmental professionals attended. The objective was to
review an analysis of ventilation technology systems prepared for
AEERL by BERL.

The analysis summarized emerging trends and technologies and
identified research and development activities in these HVAC
areas: system selection and application; design; construction and
installation; commissioning and testing, adjusting, and balancing,

and operations and maintenance. Non-industrial ventilation)
systems were the primary target of the document.

Workgroups focused on the impact of ventilation systems on
IAQ related to buildings and ventilation. The Workshop
identified several areas of needed research:

TM Development of an acceptable definition of IAQ for industry
use. It is important to define IAQ in terms of health risk, lost
productivity, and associated costs.

| Design of more flexible HVAC systems to accommodate
building use changes and renovations. For example, designs to
allow supply and return air to be properly installed and balanced
to match space alterations and expanded system capacity needs.

= Emphasis on life cycle costing to discourage least cost
engineering. Installing the least expensive system can often lead
to IAQ problems. In addition, these systems are typically harder
to commission because of the lack of proper balancing and
distribution components, and they are often more difficult and
costlier to maintain.

= Development of improved field measurement techniques,
instrumentation, and IAQ sensors. The industry needs tools and
diagnostic procedures that are less costly, more reliable, an
have greater accuracy than current techniques.

Page 10



make informed decisions to protect public
health. This strategy emphasizes the
quantitative evaluation of indoor
qovm, EXPOSUTES and associated health effects as
Cite basis for relative risk assessment of

both pollutants and pollutant mixtures.
For pollutants for which the potential
risks are relatively well characterized
(e.g., asbestos, radon, environmental
tobacco smoke, and formaldehyde),
research efforts focus on developing
approaches to prevent or reduce indoor
exposures. Lead Author, Ken Sexton.
EPA Contact: Kevin Teichman (202-260-
5900).

s Ch sate

Assessment of Fungal Growth on
Ceiling Tiles Under Environmentally
Characterized Conditions (NTIS PB93-
222024) - Static chambers with defined
relative humidity, temperature, and light
conditions are being used to study the
effect of building environment on
microbial growth. Four types of ceiling
tile (one aged, two mineral
fiber/crystalline silica, and one fire
resistant) were placed in the chambers,

, to equilibrate, and inoculated

‘ith either Penicillium glabrum or
Aspergillus versicolor. The critical bulk
moisture content for organism growth
varied depending upon tile type and test
mold, Lead Author, K. Foade. EPA
Contact: John C.S. Chang (919-541-
3747).

Bioresponse Testing of Sources of
Indoor Air Contaminants (NTIS PB93-
222032) - This paper reviews the concept
of “"bioresponse" testing of emissions
from sources of indoor air contaminants.
Examples of bioresponse methods that
measure human, animal, or in vitro
biological responses to emissions are
briefly described. The potential value of
bioresponse methods for evaluating health
and sensory comfort in relation to indoor
sources is discussed and related to
product testing. Lead Author & EPA
Contact: W. Gene Tucker (919-541 -
2746).

Fundamental Mass Transfer Models for
Cher Air Pollution Sources (NTIS
)3-221992) - A simple model based on

Fick's Law of Diffusion has been
developed for wet solvent-based sources.
In this model, the mass transfer rate is
assumed to be gas-phase limited and
controlled by the boundary layer mass
transfer coefficient, the saturation vapor
Pressure of the material emitted, and the
mass of volatile material remaining.
Results of static and dynamic chamber
, as well as test house studies, are
prencated Lead Author & EPA Contact:
Bruce A. Tichenor (919-541-2991).

on the Determination of VOCs Emitted
From Indoor Materials Using Small
Test Chambers (NTIS PB93-222073) -
An interlaboratory comparison used small
test chambers to assess the agreement
among laboratories for characterizing
VOCs emitted from indoor materials and
Products. Results from this paper are
highlighted under Research Project
Highlights on pages 1 and 2 (International
Comparison of Small Chambers). Lead
Author, Angelo Colombo. EPA Contact:
Bruce A. Tichenor (919-541 -2991).

Modeling of Alkane Emissions from a
Wood Stain - The effects of organic
emissions from wood stain were
evaluated in a test house. Concentrations
of three alkane species - nonane, decane,
and undecane - were measured as a
function of time. Results showed that the
test house concentrations can be simulated
by an integrated IAQ model taking into
consideration source, sink, and ventilation
effects. Sink effects in the test house
were significant, and an _ inverse
relationship between the test house sink
strength and the volatility of the three
alkane species was found. Lead Author &
EPA Contact: John C.S. Chang (919-541-
3747).

Exposure Assessment

A New House Dust Collection System
and its Use in a Study of Asthma in
Dust Mite Sensitive Children in
Raleigh, North Carolina - A prototype
dust collection system, the House Dust
Vacuum One, was designed for use in a
study to investigate the relationship
between house dust mite antigen levels

Page 7

and the presence of wheeze in dust mite
sensitive children. No _ significant
differences in mean micro-environmental
dust mite antigen levels were observed
between samples from the homes of
wheezers and nonwheezers. The new unit
was determined to be well suited for
surface dust and dust mite antigen
collection studies. Lead Author,
Frederick W. Henderson. EPA Contact:
Andrew B. Lindstrom (919 541-4866).

Assessing Potential Exposures from
Routine Use of VOC-Contaminated
Groundwater - Residential measurements
were made to assess potential exposures
from the routine household use of VOC-
contaminated groundwater. Measurements
were based on a single 20-minute shower
using groundwater containing 185-367
pg/L benzene. Personal doses estimated
over the 6-hour experiment for occupants
of the bathroom and living room were
<135 pg and <80 yg benzene,
respectively. The 20-minute shower
resulted in an estimated total dose of 281
ug benzene (113 pg for inhalation and
168 yg for dermal). Lead Author and
EPA Contact: V. Ross Highsmith (919-
541-7828).

Association of Personal and Workplace
Characteristics with Reported Health
Symptoms of 6771 Government
Employees in Washington, DC - An
IAQ questionnaire was completed by
6771 government employees. Regression
analyses on 12 clusters of health
symptoms indicated that both personal
and workplace characteristics were
associated with symptoms. The variables
associated with the largest number of
symptoms at the two agencies studied
were dry air/dusty office, chemical/paint
odors, hot stuffy air, and sensitivity to
chemicals. Other variables that were
often significantly associated with
symptoms were glare, carpet/drape odor,
dust/mold allergy, career frustration, and
job pressure/conflict. Lead Author &
Contact: Lance Wallace (703-341-7509).

EPA Base Program--Collecting Baseline
Information on Indoor Air Quality -
EPA's Office of Radiation and Indoor Air
and AREAL have begun a major study of


The major conclusions from the evaluation are:

= ESPs and high efficiency filters are the only air cleaners that
provide high (>90%) collection efficiency for particles in
the 0.2 to 2 um diameter range.

© High efficiency filters significantly increase the pressure
drop in the heating, ventilating, and air-conditioning
(HVAC) system which increases fan motor amperage draw
and reduces total air flow. The ESPs do not.

© Electrostatically augmented air cleaners do not appear to
provide significant performance benefits compared to
common filters, especially when they become dirty.

= Particle collection efficiency of all filters, except the electret
filter and ESP, increased as the filters became dirty.

The test methods developed during this study will form the basis
for an air cleaner evaluation test method recommended to the
private sector. (EPA Contact: Leslie Sparks, AEERL, 919-
541-2458)

Solutions
Catalog of Materials as Potential Sources of Indoor Air
Emissions

A variety of research efforts, both in the U.S. and
internationally, have focused on materials as potential sources of
indoor air emissions. These research efforts typically do not
concentrate on any one group of products or standard sampling
and analytical methods. In addition, there is little consistency in
the terminology used to describe the products tested. This lack
of consistency in test methods and terminology makes the data
difficult to compare.

Asa result, AEERL published the

Potential Sources of Indoor Air Pollution (EPA-600/8-90-074;
NTIS PB91-125708) in 1990. This report presented a
classification of building materials, fixtures and furnishings, and.
consumer products used or found in homes or offices, regarilese)
of their potential to emit.

Materials and products considered to be potential sources of
indoor air emissions were then selected for further study. The
objective then was to: 1) generate a useful scheme for
presenting the variety of material sources in homes and offices;
and 2) present available usage, constituent, and emissions data
for these material sources. The results of this second study are
to be presented in Volumes I and II of the Catalog of Materials
as Sources of Indoor Air Emissions. Volume I of the catalog
(EPA-600/R-93-108a; NTIS PB93-212041) was published in
June 1993, and contains sections on: insulation products, wall
coverings, resilient floor covering, carpet, adhesives, caulks and
sealants, and pesticide products. Volume II of the Catalog, to
be published early in 1994, will contain sections on: wood
products, paints and coatings, foam products, fabricated rubber
products, and mineral products.

Each section presents a classification scheme for the product
category, sales and usage volume data, qualitative data on
product composition, and quantitative and qualitative data on
emission rates. Emissions information is presented only for
VOCs as these are the compounds most likely to be emitted from
materials found in homes and office buildings. Data tables
summarizing available emissions and constituent data ”
provided and are organized according to a product classificati
scheme. (EPA Contact: James White, AEERL, 919-541-1189)

Summaries of ORD Papers in Indoor Air '93 Proceedings

Indoor Air Quality: Exploring Policy
Options to Reduce Human Exposures -

Establishing Priorities in the U.S.
EPA's Indoor Air Engineering
Research Program (NTIS PB93-221984)
- AEERL consulted researchers within
government, industry, and academia to
help identify and rank priority program
areas for IAQ engineering research.
Specific program elements include
chemical source characterization,
bioresponse testing, air cleaning,
ventilation, biocontamination, cost/IAQ
modeling, and pollution prevention.
Recommendations included expansion of
AEERL biocontaminant _prevention/
control research. Lead Author & EPA
Contact: Michael C. Osborne (919-541-
4113).

Page 6

This plenary paper presents factors
policymakers must consider in
establishing IAQ policies and the role
researchers can play in ensuring policies
are based on the best available science.
Examples cited are environmental tobacco
smoke, radon, problem buildings, and
ventilation standards. Lead Author &
EPA Contact: Kevin Teichman (202-260-
71669).

Indoor Air Quality: The U.S.
Environmental Protection Agency's
Research Strategy - EPA's IAQ research
strategy is to identify, characterize, and
compare the health risks associated wi,
exposures to indoor air pollutants so
Tisk assessors and risk managers can


Neurobehavioral and Subjective
Reactions of Young Men and Women
to a Complex Mixture of Volatile
Organic Compounds - The neuro-
sehavioral and subjective reactions of 26
“male and 15 female subjects to 4-hour
controlled exposure to clean air and 25
mg/m’ of VOCs were compared. Subjects
reported greater odor intensity and
unpleasantness; increased eye, nose and
throat irritation; and reduced IAQ during
VOC exposure. Neurobehavioral
performance was not affected by VOCs.
Contrary to previous reports, women did
not express more sick building syndrome
type complaints than men during VOC

exposure. Lead Author & EPA Contact:
D. Otto (919-541-6226).

Pulmonary, Respiratory, and Irritant
Effects of Exposure to a Mixture of
VOCs at Three Concentrations in
Young Men - The objective of this study
was to determine if the frequency of
human respiration is affected by exposure
to a mixture of VOCs (0, 12, 24 ppm).
Twenty subjects were exposed to the mix
for 4 hours during which respiration rate
was collected continuously and

-~-questionnaire data were obtained hourly.

\w.wResults indicate no effect on respiratory

frequency. However, there was a linear
increase in respiratory eyeblink frequency
with time in the chamber. Eyeblink
frequency was elevated by exposure.
Increased eye irritation, odor strength,
and degradation of IAQ were reported in
comparison to control exposures. Lead
Author & EPA Contact: J.D. Prah (919-
541-6244).

Time Course of Odor and Irritation
Effects in Humans Exposed to a
Mixture of 22 Volatile Organic
Compounds - Ratings of IAQ, odor and
irritation intensity, and other variables
were obtained before and during 4 hour
exposures to clean air and three
concentrations of a mixture of VOCs.
Perceived odor intensity decreased, and
irritation intensity increased gradually
during VOC exposure in a dose-related
fashion. Odor and irritation appear to be
primary determinants of perceived IAQ.
Lead Author & EPA Contact: H. Ken
Hudnell (919-541-7866).

Solutions

Evaluation of Ventilation Performance
for Indoor Space (NTIS PB93-212751) -
Ventilation performance depends on

room geometry, ventilation method, and
operating conditions, as well as location,
source strength, and types of
contaminants, A menu-driven ventilation
model was developed that is capable of
determining the turbulent flow field and
time-dependent/steady-state contaminant
concentration distributions _ within
isothermal indoor space. Lead Author,
Toshiaki Yamamoto EPA Contact: Leslie
E. Sparks (919-541-2458).

Status of ASHRAE Standard 62 -
Ventilation for Acceptable Indoor Air
Quality (NTIS PB93-222040) - This
paper describes the purpose, history, and
major features of ASHRAE Standard 62.
The status of the review and revision
process as of January 1993 and the
current working outline of the revised
standard are discussed. The
complementary roles of ventilation,
source management, and air cleaning are
emphasized. Extending the standard
beyond ventilation system design to
include operation and maintenance of
buildings and ventilation systems is also
projected. EPA Contact: W. Gene Tucker
(919-541-2746).

Summaries of Recent EPA Indoor Air Workshops

Indoor Air Quality/Pollution Prevention Workshop

To assist AEERL in identifying potential areas of research for
applying pollution prevention to IAQ, a 2-day workshop was
held March 9-10, 1993. The 64 Workshop attendees included
scientists and engineers with experience in IAQ, pollution
prevention, and/or industrial processes.

The Workshop covered background information on IAQ,
pollution prevention, and AEERL's strategy to combine the two.
Participants were then placed into one of six workgroups to
focus on pollution prevention research in the following topic
areas: adhesives and sealants, building materials, consumer
products, furniture, office equipment, and textiles. On the
second day, an ad hoc workgroup on biocontaminants was added
because of participants' interest.

At the Workshop, a number of materials/products were identified
as potential research options for applying pollution prevention
techniques to improve IAQ. A ranking or prioritization of the
aaterials/products suggested was not included as part of the
Workshop.

AEERL will use the suggestions from the Workshop as input for
both IAQ/pollution prevention strategic planning and for
determining specific program direction and prioritization of
future research projects.

In summary, the major themes from the Workshop were:

| There is a desire for EPA to identify the major IAQ
problems. Many discussions focussed on the relative
importance of different IAQ sources.

| = Making the link between IAQ and pollution prevention was
difficult. More specific examples or case studies would be
helpful.

TM The workgroups consistently identified a need for more
emissions testing, methods development, modelling,
consumer education, and source ranking.

© The issue of proprietary information must be considered in
developing a pollution prevention research strategy for
indoor materials and products.

= Participants felt that research on preventing biocontaminant
growth is important.

@ The Workshop served to initiate interaction between IAQ,
pollution prevention, and industry researchers.

Page 9


EPA's Indoor Air Quality Research Update EPA/600/N-93-021
Office of Research and Development Fall/Winter 1993

This issue of Inside IAQ is the second in a series of reports on EPA's Office of Research and
Development's (ORD's) indoor air research. Inside IAQ covers indoor air research conducted by
EPA's four ORD components located in Research Triangle Park, NC: the Air and Energy
Engineering Research Laboratory (AEERL), the Atmospheric Research and Exposure Assessment
Laboratory (AREAL), the Environmental Criteria and Assessment Office (ECAO), and the Health
Effects Research Laboratory (HERL). Indoor air research conducted by ORD‘s Environmental
Monitoring Systems Laboratory (EMSL), located in Cincinnati, OH, is also included.

The primary goals of Inside IAQ are to communicate EPA's indoor air research results in a timely
manner and to provide sources of more detailed technical information. Inside IAQ is distributed
twice a year. If you would like to be added to the mailing list, please refer to the last page.

EPA's Indoor Air Research Program

lh

The goals of EPA's Indoor Air Research Program are to: 1) improve the scientific understanding
of indoor air pollution health risks and techniques to reduce these risks, 2) provide critical
scientific information to EPA program offices and regions in support of developing, implementing,
and evaluating risk management options, and 3) promote private sector involvement in identifying,
understanding, and addressing important indoor air pollution problems.

The Program covers five multidisciplinary areas:

@ Source Characterization ABER ary .
bY Exposure Assessmen t 28H. MARTIN LUTHER KiNG
: CINCINNATI, OHIO 45;
@ Risk Assessment x 268
@ Solutions

Research Project Highlights

The following sections provide information on 11 ORD indoor air research projects. The research topics included in this issue are:
International Comparison of Smal] Chambers ® Methods for Characterization of Biocontaminant Sources ® Development of Gene
Probes for Identification of Fungi § Development of Methods for Recovery of Aerosolized Fungi ® Development and Testing of a
Personal Whole Air Sampler ® Results of EPA Carpet Emissions Tests TM Health Effects Research on Exposure to NO, ® Use of a
High-Volume Small Surface Sampler for the Microbiological Evaluation of Dust ® Pollution Prevention Research ® Evaluation of
In-Duct Particulate Air Cleaners ® Catalog of Materials as Potential Sources of Indoor Air Emissions

wre Characterizati
International Comparison of Small Chambers

EPA recently participated in an international study that compared The experiment was conducted using three materials, The first
small chamber measurements of volatile organic compound material tested was a source that emitted n-dodecane at a known
““OC) emissions. The purpose of the comparison was twofold: rate. The objectives of this test were to check for sinks and
‘) to obtain experimental validation of the various small chamber _ possible problems with the chambers and to determine the
measurement guidelines used internationally, and 2) to assess the accuracy of the analytical procedure.

comparability of the results obtained by 20 different laboratories.
&& Printed on recycled paper.


Exposure Assessment

Comparison of Transfer of Surface
Chlorpyrifos Residues From Carpet by
Three Dislodgeable Residue Methods -
The Dow drag sled, the California cloth
roller, and the Southwest Research
Institute polyurethane foam roller, three
sampling methods developed to estimate
the transfer of a chemical from a
contaminated surface to the skin, were
evaluated. The cloth roller was found to
be less suitable than the other methods
because its transfers exhibited greater
variability and were altered by orientation
of the roll relative to the lay of the carpet
fibers. The effect of moistening the
sampling media on transfer by the drag
sled and the polyurethane foam roller are

discussed. Source: 1992 Toxics
Measurement Symposium.* Lead
Author, D. E. Camann. EPA Contact:

Robert G. Lewis (919-541-3065).

Methodology for Determination of
Polycyclic Aromatic Hydrocarbons and
Other Semi-Volatile Organic
Compounds in House Dust - Analytical
methods were validated to determine
polycyclic aromatic hydrocarbons (PAH)
and other semi-volatile organic
compounds (SVOC) in house dust. The
storage stability of three potential markers
(solanesol, nicotine, and cotinine) for
particulate-phase ETS in house dust was
also examined. Results suggest that
cotinine is a better marker for ETS
particles in house dust than nicotine and
solanesol is not a suitable marker.
Results from a small field study that
evaluated the effect of smokers in the
house on PAH, cotinine, and nicotine
concentrations in house dust are included.
Source: 1992 Toxics Measurement
Symposium.* Lead Author, Jane C.
Chuang. EPA Contact: Nancy K. Wilson
(919-541-4723).

Sampling, Supercritical Fluid
Extraction and GC/MS Analyses of
Indoor Air Semi-Volatile Toxic
Organics - A method has been developed
to sample indoor airborne semi-volatile
toxic organics followed by supercritical
fluid extraction and GC/MS analyses.
The sampling module, parameters used in

the wet chemistry preparation, typical
quality assurance/quality control data, and
preliminary results from several
categories of homes (e.g., electric and
gas heating/cooking systems,
smoking/non-smoking) are discussed.
Source: 1992 Toxics Measurement
Symposium.* Lead Author, V. M.
Kanagasabapathy. EPA Contact: Robert
Chapman (919-541-6219).

The Mutagenicity of Outdoor and
Indoor Air Samples Taken in Roanoke
During Wintertime - The mutagenicity
of wintertime ambient air samples in
Boise, ID, and Roanoke, VA, was
examined using the Salmonella
mutagenicity assay. Twenty homes were
sampled in 10 matched pairs. Each pair
included one home with a combustion
heat source (an oil heater, a woodstove,
or a fireplace), and the other home
without. Both the extractable organic
matter and SVOC samples were
mutagenic, and the level of mutagenicity
could be associated with the known
sources. Source: 1992 Toxics
Measurement Symposium.* Lead Author
& EPA Contact: Larry D. Claxton (919-
541-2329).

Risk Assessment

Use of a High-Volume Small Surface
Sampler for the Microbiological
Evaluation of Dust From Carpeted and
Non-Carpeted Surfaces - This paper
discusses a building cleaning effectiveness
study being conducted by ECAO. This
study is discussed under Research Project
Highlights on page 4 (Use of a High-
Volume Small Surface Sampler for the
Microbial Evaluation of Dust). Source:
1992 Toxics Measurement Symposium.*
Lead Author, K. E. Leese. EPA
Contact: M. A. Berry (919- 541-4172).

Solutions

An Analytical Solution to Describe the
Pressure/ Flow Relationship in EPA's
Soil-Gas Chamber - An analytical model
has been developed to describe the
relationship between pressure differential
and flow rate in AEERL's soil gas

Page 12

chamber. The classic method of images is
applied to simulate the boundary
conditions imposed by the finite
dimensions of the chamber. The resulting
influence on constant pressure contours \
and the streamlines is shown. Source:
1992 Toxics Measurement Symposium.*
Author & EPA Contact: Ronald B.
Mosley (919-541-7865).

Case Studies of Radon Reduction
Research in 13 School Buildings -This
report details AEERL radon mitigation
research in 13 school buildings located in
Colorado, Maine, Minnesota, Ohio,
South Dakota, Tennessee, and
Washington state. The objectives of the
research were to better understand the
conditions under which HVAC systems
can be used for effective radon reduction
and to compare the performance of
HVAC system control of radon with
active subslab depressurization control in
the same building. Source: EPA Report
(EPA-600/R-93-225). Lead Author,
Bobby E. Pyle. EPA Contact: Kelly
Leovic (919-541-7717).

Case Studies of Radon Reduction
Research in Maryland, New Jersey,
and Virginia Schools - One school in
each of these states was selected for this
radon research project. In two of the
schools the objective was to evaluate the
potential for modification of the school
HVAC system to control radon
concentrations. The third school was
recently constructed with radon resistant
features, and the objective was to
evaluate the effectiveness of those
features. Source: EPA Report (EPA-600/
R-93-211; NTIS PB94-117363). Lead
Author, David W. Saum. EPA Contact:
Kelly Leovic (919- 541-7717).

Characteristics of School Buildings in
the U.S. - To guide AEERL's radon
mitigation research in schools,
information on the physical characteristics
of 100 randomly selected schools was
collected. The results show: most school
structures are of slab-on-grade
construction; gravel was used as subslab
fill material in approximately half of the
structures; approximately 80% of the,
schools have either central HVAC or unit
ventilators capable of delivering


® Encouragement of building owners and operators to provide
continuous building commissioning and preventive maintenance.
Building owners and operators need to understand that
. commissioning of a facility does not end when occupancy begins.

«... Many studies prove that continued good IAQ is dependent on
continued preventive maintenance.

TM Increased technology transfer and communications among
researchers and industry professionals. Researchers need to
realize that the ultimate end user of IAQ research is an engineer,
architect, or building owner and that economics, profit margin,
and practicality are driving forces.

Areas of emerging trends and technological advances discussed
at the workshop included development of:

= Computer-based automated contro! and analysis system for
continuous monitoring and evaluation of IAQ.

= Alternative ventilation strategies include displacement
ventilation, under-floor supply distribution, and dedicated
occupant environmental control systems for improved ventilation.

§S Advanced/enhanced filtration (particle, gas, and microbial)
technology to reduce outdoor air and energy requirements.

TM Continued use of experimental computational fluid
dynamics models to assist ventilation effectiveness research.

For additional information on the Workshop, contact Russell N.
Kulp at (919) 541-7980.

Symposium on Measurement of Toxic
and Related Air Pollutants

This international symposium will be held
May 2-6, 1994, at the Omni Hotel and
Convention Center in Durham, North
Carolina. The symposium is sponsored
by AREAL and the Air & Waste
Management Association (AWMA) and

_..Will include oral presentations and
exhibits. Indoor air pollutant

“measurements are included in the
program. For information, contact Bruce
W. Gay, Jr., U.S. EPA, MD-80,
Research Triangle Park, NC 27711 (919-
541-2830).

Upcoming ORD Meetings

Symposium on Characterizing Indoor
Sources and Sinks

ASTM Subcommittee D22.05 on Indoor
Air will be holding a Symposium on
Characterizing Indoor Sources and Sinks.
The Symposium will be held September
25-28, 1994, in Washington, DC, and
will be chaired by Bruce Tichenor of
AEERL. Topics will include: chamber
design, characterization, and
performance; operation; data
interpretation and application; and other
topics related to emissions testing. For
information, contact ASTM (215-299
5413) or Bruce Tichenor (919-541-2991).

Biocontaminant Workshop

AEERL, EMSL, and AREAL are
sponsoring a Biocontaminant Workshop
in March 1994. The objectives of the
Workshop are to assist EPA in planning
both short-term and long-term (beyond 3
years) research in the areas of
biocontaminant measurement and control.
Attendance at the workshop will be
limited. For information, contact John
Chang (919-541-3747).

Summaries of Recent Publications

(*) Summaries listing "1992 Toxics
Measurement Symposium" as a source
abbreviates “Proceedings of the
AWMA/EPA International Symposium on
Measurement of Toxic and Related Air
Pollutants, Durham, N.C., May 3-8,
1992, EPA-600/R-92-131."

s ct «ati

Fundamental Mass Transfer Model for
Indoor Air Emissions from Surface
Coatings - A simple model based on the
boundary layer theory was developed to
determine emissions from freshly applied

Page 11

paints and coatings. The model provides
a better fit to chamber-derived emissions
data than an empirical first-order decay
model, especially over the decaying
portion of the concentration versus time
curve, In this model, the mass transfer
rate is assumed to be controlled by the
boundary layer mass transfer coefficient,
the saturation vapor pressure of the
material being emitted, and the mass of
volatile material remaining in the source.
Static and dynamic chamber tests and test
house data indicate that the model can be
applied to different products with similar
solvents. Source: Indoor Air (accepted for
publication). EPA contact: Bruce
Tichenor, AEERL (919-541-2991).


IAQ and occupant perceptions in public
and commercial office buildings. A set of
core measurements will be made for this
Building Assessment Survey and
Evaluation (BASE). The cross-sectional
study will include approximately 200
buildings over the next three to five
years. Measurements include
environmental conditions in a
representative sampling space in each
building, an occupant questionnaire, and
characterization of the building and the
HVAC system. The information collected
will be coded for confidentiality and
included in a publicly accessible database.
Lead Author, Susan E. Wonble. EPA
Contact: Ross Highsmith (919-541-7828).

Evaluation of "Before" and "After,"
Occupant, IAQ, and HVAC
Parameters in a Building Remediated
Because of Unacceptable IAQ - An
Augusta, Maine, office building with 810
occupants has undergone many
IAQ/HVAC diagnostic evaluations during
the past ten years. In 1992, the owner
upgraded the building's HVAC system.
To assess conditions in the building
before remediation, an HVAC evaluation,
an occupant questionnaire, and
measurement of VOCs, microbial levels,
inhalable particles, and work station
thermal comfort were conducted. After
remediation in 1993, the evaluations will
be repeated and results compared. Lead
Author, Frederick T. McKnight. EPA
Contact: Ross Highsmith (919-541-7828).

Indoor Concentration Modeling of
Aerosol Strong Acidity - A model,
developed for estimating indoor
concentrations of acid aerosol in a semi-
rural community in PA, was applied to
estimate indoor concentrations of aerosol
strong acidity (H*) in suburban NJ. The
purpose was to assess the applicability of
the model for predicting H* exposures in
a suburban environment and to evaluate
the model's performance for daytime and
nighttime periods. The model applied to
the site in NJ did not predict the indoor
H* concentrations as well as it did for the
experiment for which it was developed.
Lead Author & EPA Contact: Michael
Zelenka (919-541-1326).

Indoor, Outdoor, and Personal Air
Exposures to Particles, Elements, and
Nicotine for 178 Southern California
Residents - Personal, indoor, and
outdoor concentrations of inhalable
particles, associated elements, and
nicotine were measured for a sample of
178 persons representing nonsmoking
residents of Riverside, CA. Newly
designed personal monitors were
employed. Personal exposures often
exceeded concurrent indoor and outdoor
concentrations, both for particles and for
14 elements. The increase is due in part
to personal activities such as cooking and
sharing a home with a smoker. Personal
and indoor nicotine levels were elevated
for persons reporting exposure to
environmental tobacco smoke (ETS) and
living in homes with smokers. EPA
Contact: Lance Wallace (703-341-7509).

Sources and Factors Influencing
Personal and Indoor Exposures to
Particles, Elements and Nicotine:
Findings from the Particle Team Pilot
Study - During the fall of 1990, a large-
scale field monitoring program to
characterize personal exposures to
inhalable particles with aerodynamic
diameter less than 10 um was conducted
in Riverside, CA. Results show that
personal exposures to nicotine are
strongly related to percent time spent
indoors in the presence of a smoker.
Modeling results also indicated that air
exchange rate, amount of dusting,
vacuuming and cooking affect indoor
particle concentrations. Lead Author,
Halk Ozkaynak. EPA Contact: Lance
Wallace (703-341-7509).

Health Effects

Cotinine Elimination Following ETS
Exposure in Young Children as a
Function of Age, Sex, and Race - The
determination of the elimination half-life
(t,,) of cotinine from urinary excretion
data is useful in correlating urinary
cotinine concentrations to estimate ETS
exposure. Currently, quantitative
relationships between urinary cotinine
excretion and ETS exposure in children
have not been determined. This research
determined the cotinine t,,. in children up
to three years of age using urinary

Page 8

cotinine excretion data. Lead Author,
Albert M. Collier. EPA Contact: George
M. Goldstein (919-541-6204).

Electronically Enhanced Measures ce)
Eye Irritation for Use in Studying
Subjects Exposed to VOCs - Simple,
rapid, and objective methods of
measuring tear-film break-up time and
quantitating eye irritation are needed in
order to study the health effects in
individuals that complain of ocular
irritation following exposure to VOCs.
The described method uses miniaturized,
closed circuit television to non-invasively
measure tear film break-up time. A
procedure that uses computer
enhancement of eye photographs to
objectively score changes in eye redness
is also described. Lead Author & EPA
Contact: George M. Goldstein (919-541-
6204).

Evidence for Mild Inflammation and
Change in Alveolar Macrophage
Function in Humans Exposed to 2 PPM
NO, - In this study, 10 healthy volunteers
were exposed to either 2.0 ppm NO, or
filtered air for 4 hours while undergoing
intermittent moderate exercise. Thi;
project is highlighted under Re
Project Highlights beginning on page 3
(Health Effects Research on Exposure to
NO,). Lead Author, Susanne Becker.
EPA Contact: Robert Devlin (919-541-
6255).

Mite Antigen Concentrations in House
Dust and the Occurrence of Wheezing
in Children with Dust Mite Allergy -
This study examined the relationship
between dust mite antigen concentrations
in house dust samples and the occurrence
and frequency of wheezing in 58 children
with dust mite allergy. Dust samples were
obtained from six sites in each home: the
child's mattress, blanket, _ pillow,
bedroom floor, and the recreation room
couch and floor. Differences in the
degree of home environmental contamin-
ation with mite antigen did not account
for differences in the occurrence or
frequency of wheezing, bronchial hyper-
activity, or lung function among children
with dust mite allergy. Lead Author,
Frederick W. Henderson. EPA Cont
Andrew B. Lindstrom (919-541-4866).


The objective of this study by HERL was to investigate whether
inflammation is induced by exposure to 2.0 ppm of NO, and
whether alveolar macrophage host defense functions are altered.

In this study, 10 healthy adults (males and females, 22-35 years
old) were exposed to either 2.0 ppm of NO, or filtered air for 4
hours while undergoing intermittent moderate exercise. Changes
in a number of cellular and biochemical parameters, in both the
airways and alveolar region of the lung, were measured.

Cells and fluid lining the lung passages of the volunteers were
removed by bronchoalveolar lavage 16 hours after the exposure
to NO,. The lavage was divided into two parts: one which
samples primarily the large airways of the lung (bronchial
fraction) and one which samples the gas exchange region
(alveolar fraction). Subjects exposed to NO, had a 3-fold
increase in inflammatory cells (neutrophils), and a 1.5-fold
increase in 0-1 antitrypsin, an anti-inflammatory protein, in the
lungs. There were no other changes in cells or biochemical
mediators found in the bronchial fraction, and no significant
changes found in neutrophils or biochemical mediators in the
alveolar fraction, However, alveolar macrophages, the body's
first line of defense against inhaled microorganisms, showed a
decrease in ability to engulf yeast particles as well as a decrease
in production of superoxide anion, a compound involved in
killing microorganisms.

The results of this study showed evidence of mild inflammation
in the large airways but not the alveoli of humans exposed to
NO,. In addition, NO, exposure resulted in a decrease in ability
of alveolar macrophages to engulf and kill microorganisms.

A complete copy of this paper is available in the Indoor Air '93
Proceedings. (EPA Contact: Robert Devlin, HERL, 919-966-
6255)

Risk Assessment Research
Use of a High-Volume Small Surface Sampler for the
Microbiological Evaluation of Dust

Research Triangle Institute and ECAO have adapted a high
volume small surface sampler for collection of microbials in
surface dust. The sampler was previously developed by AREAL
for the collection of residential carpeted and non-carpeted surface
dust for pesticide and lead analysis. The major adaptations
involve disinfecting the unit, using sterile polypropylene bottles
to collect samples, and special bags on the exhaust of the unit.

Results show that the sampler can be used to collect surface
dusts for the analysis of viable molds, yeasts, bacteria,
endotoxins, and dust mite guanine on both carpeted and non-
carpeted surfaces. Protocols for using the sampler are being
developed. In addition, bioaerosol monitoring will allow the
relationship between surface and airborne microbial
concentrations to be evaluated.

The sampler has been tested on surfaces in two buildings
(designated as A and B). Building A has routinely maintained
carpeted and tiled floors. The carpeted floor surface of Building
B did not appear to be routinely maintained and was noticeably
soiled. Results from the sampling are shown in Figures 1, 2, an)
3 for surface dust loading, fungi, and endotoxins, respectively.
The microbiological composition of the surface dusts from the
buildings was found to be similar to that of ordinary outdoor
dirt. Microbial concentrations were higher in the carpet floor
dust than in tile dust in both buildings. Dusts in building A had
insignificant levels of endotoxin; however, Building B levels are
elevated. Dust mite guanine was not detected in any of the dust
samples. (EPA Contact: Mike A. Berry, ECAO, 919-541-4172)

7
er
st
at
at
af
af
| 7
Biig A Brag A Big B
Carpet Tile Carpet
Figure 1. Surface Dust Loading (g/m?)
1.00E+7
1.00E+6 7]
1.00E+5 |
1.00E+4 7]
1.00E+3 1

Bldg A Big A Bhig B
Carpet Tile Carpet

Figure 2. Fungi Concentrations (CFU/g of dust)

1000
100}
0]
q
or
Bidg A Bldg A Bldg B
Lowest Highest Carpet

Figure 3. Endotoxin in Surface Dust (ug/g of dust)

Page 4


—


Exposure Assessment Research
Development and Testing of a Personal Whole Air Sampler

Research Triangle Institute and AREAL have developed and
juated a small, lightweight personal whole air sampler. The
ler can be wom to monitor personal exposures to VOCs and

is suitable for large-scale population-based exposure studies.

The prototype sampler is 25.5 cm high, 22.5 cm wide, and 7.5
cm deep. With a 1-L SUMMA sample canister in place, the unit
weighs 3.35 kg. The unit uses rechargeable batteries that
operate for approximately 16 hours. The batteries, electronics
module, and flow controller are enclosed in a plastic case. The
sampler can be placed in a laptop computer carrying case or
carried over the shoulder. The unit could also be used as a
compact microenvironmental sampler.

Laboratory testing of the unit demonstrated that the sample flow
rate was not affected by temperature or the activity of the person
wearing the sampler. Recoveries of methylene chloride,
chloroform, 1,1,1-trichloroethane, benzene, n-octane, o-xylene,
n-decane, and p-dichlorobenzene averaged 89% or higher for
three final prototype samplers. Recoveries were slightly lower
for vinyl chloride (74%) and n-dodecane (82%). The precision
for the three prototype samplers was excellent during laboratory
tests. Further evaluation of the sampler is required to fully
validate its performance under field conditions. (EPA Contact:
Andy Lindstrom, AREAL, 919-541-4866)

mma-
Canister (1 liter)

+r

22.5.em |

Nee Personal Whole Air Sampler.

Health Effects Research
Results of EPA Carpet Emissions Tests

In 1992 Anderson Laboratories, a private testing company,
reported that the off-gassing of certain “complaint” carpets
caused sensory and pulmonary irritation, neurobehavioral effects
and, in the most extreme cases, death, in exposed mice. Based
on these test results, HERL and AEERL initiated a study to
replicate the Anderson results.

Results from the EPA tests showed that, based on the assessment
of respiratory irritation, neurobehavioral effects, measures from
a general toxicity screen, and evaluation of carpet contaminants
and emissions, there was no indication that exposure to emissions
from the two carpets tested posed a serious health risk.

In the HERL and AEERL study, two standard test methods using
laboratory mice, one for estimating sensory irritancy and the
other for evaluating the neurotoxic potential of chemicals, were
coupled with a postmortem assessment. The postmortem
evaluation included measurements of hemoglobin, serum clinical
chemistries, blood and lung lavage white cell counts, organ
weights, and a gross necropsy with a microscopic evaluation of
all major organs.

Three tests were run: two with preheated carpet emission
exposures and one with a preheated control exposure. No toxic
effects were observed from exposure to the two tested carpets.
However, clinical chemistry and histopathological alterations
were observed with exposure to both the control air and the
carpet emissions when compared to the non-exposed,
unrestrained control mice. These results indicate that the
alterations were caused by the exposure procedure rather than
the carpet emissions.

A detailed chemical and microbial evaluation of the carpets and
their emissions was also performed. Pesticide residues,
microbiological flora, and over 200 VOCs were present, but at
insufficient quantities to result in acute toxicity.

A technical paper, detailing the EPA study, has been submitted
to the Journal of the American Industrial Hygiene Association
and should be published in 1994. To assist in better
understanding the varying results between the EPA and the
Anderson tests, the next step for EPA researchers will include
discussions with physicians with experience in treating patients
that associate health problems with carpet exposure. (EPA
Contact: Robert Dyer, HERL, 919-541-2760)

Health Effects Research
Health Effects Research on Exposure to NO,

Nitrogen dioxide (NO.) is a common indoor air pollutant,
especially in homes with unvented combustion appliances.
Epidemiological studies suggest that children living in homes
with elevated levels of NO, are more prone to respiratory
infections than children living in homes with lower levels of
NO,.

Page 3



The second material tested was polyvinyl chloride flooring
material. The laboratories were asked to determine the emission
rate for four compounds (phenol, 1,2,4-trimethylbenzene, n-
decane, and n-undecane) and for total volatile organic
compounds (TVOCs) at 48 and 72 hours.

Water-based floor wax was the third material tested. The
participants were requested to use an average wax layer
thickness of 0.05 mm. Sampling was carried out at 10 different
times in order to determine the concentration/time curve for four
compounds (6-pinene, linalool, geraniol, and 0.-cedrene) and for
TVOCs.

No method was prescribed for VOC sampling and analysis, and
each investigator was free to use his/her usual procedure.
However, it was requested that TVOC concentrations be
reported as toluene equivalents.

Results from the 20 participating laboratories showed that
chambers of different materials (5 glass and 18 stainless steel)
and of widely different capacities (0.035 to 1475L) appeared
equally suitable. The repeatability of duplicate measurements
(including sampling) within each laboratory was good.

The analysis for n-dodecane showed, for most laboratories, an
unexpected and yet unexplained discrepancies. Hypotheses which
might explain these discrepancies include irreversible or very
slowly reversible sinks in the chambers, error in the flowrate
determination, error in the analytical system, error in weight loss
measurement, and inadequate chamber mixing.

The interlaboratory agreement appeared reasonable (coefficient
of variation 26 - 42%) with the tile, but the scatter was very
high for the wax. At least three kinds of difficulties seem to have
occurred with the wax test: 1) chamber difficulties such as
chamber sink effects or highly scattered data; 2) analytical
difficulties; and 3) curve fitting difficulties. (EPA Contact: Bruce
A. Tichenor, AEERL, 919-541-2991)

Souree Ct ization R
Methods for Characterization of Biocontaminant Sources

AEERL and Research Triangle Institute are developing two
methods for evaluating indoor biocontaminant sources. The first
method uses static chambers (32 x 39 x 51 cm) and saturated salt
solutions. This method can be used to assess the ability of indoor
materials to support the growth of microbials such as fungi,
bacteria, and dust mites. Both qualitative and quantitative
analyses are used to characterize the microbial growth. Four
types of ceiling tiles and two duct lining materials have been
tested in these static chambers to validate the methodology. A
standard guide for the static chamber test method is currently
under review by the American Society of Testing and Materials
(ASTM) Subcommittee D22.05.06.

The second method for evaluating biocontaminant sources uses
a dynamic chamber (2.44 x 2.44 x 2.44 m). Continuous air flow
through the chamber is provided to simulate a typical room, and
the air mixing pattern in the chamber is controlled by 2 ceili
fan. Aerolized spores can be injected into the chamber, and
growth of biocontaminants on various sources can be monitored
through observation windows. The chamber can also be used to
evaluate in-room air cleaners (EPA Contact: John C.S. Chang,
AEERL, 919-541-3747)

Exposure Assessment Research
Development of Gene Probes for Identification of Fungi

Current methods for identifying fungi in air samples are
dependent on culturing the organisms, followed by detailed
morphological examinations, both of which are time consuming
and difficult methods. As a result, EMSL is researching the
feasibility of developing molecular-based detection methods using
polymerase chain reaction (PCR) amplification of small subunit
ribosomal RNA genes. These genes were chosen because: they
are present in all organisms; they contain highly conserved
sequence regions which can serve as priming sites for PCR
amplification; and they contain variable sequence regions which
can serve as target sites for genus or species specific DNA
probes.

The first phase of this project is to establish a data base of small
subunit ribosomal RNA gene sequences from fungal species
identified as being common to indoor environments and/or
having potential adverse health effects. Data, thus far, indi
sufficient sequence diversity to allow the construction of species-
specific probes. (EPA Contact: Gerard N. Stelma, Jr., EMSL,
513-569-7384)

Exposure Assessment Research
Development of Methods for Recovery of Aerosolized Fungi

EMSL and researchers at Georgia State University have been
evaluating a variety of commercial and experimental growth
media. The goal is to develop a standardized method for
collecting the broadest possible spectrum of indoor fungi.

The media were first tested for their ability to quantitatively
recover aerosolized fungi commonly found in indoor air. The
best media are now being evaluated in the field to determine
which recover the broadest spectrum of fungi.

Field tests conducted in a number of buildings in the Southeast
U.S. are nearly complete. The results indicate that a set of three
media used concurrently allows the best recovery of the widest
variety of fungal species. This set of media will be evaluated in
a second independent laboratory in 1994. (EPA Contact: Gerard
N. Stelma, Jr., EMSL, 513-569-7384) 5

Page 2



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conditioned outdoor air; and about 25%
of the schools have subslab footings
extending both beneath the classroom
walls and along the corridors, thus
_- Omplicating the installation of a subslab
ion system. Source: EPA
Report (EPA-600/R-93-218) Lead
Author, Harry Chmelynski. EPA
Contact: Kelly Leovic (919-541-7717).

Comparison of Measurement
Techniques for Soil Permeability in
EPA's Soil-Gas Chamber - Initial soil
permeability measurements in AEERL's
soil chamber yield relatively good
agreement between two methods. One
method uses a set of 23 point probes
located in a vertical plane and is similar
to the standard practice of measuring in
situ soil permeabilities. The other method
uses an arrangement designed to ensure
ideal geometric flow patterns and yields
a better approximation of the effective
bulk permeability. The permeability
measurements are then compared to the
predictions of a widely used empirical
model. Source: 1992 Toxics
Measurement Symposium.* Author &
EPA Contact: Ronald B. Mosley (919-
» $41-7865).

Nie

Designs for New Residential HAC
Systems to Achieve Radon and Other
Soil Gas Reduction - Residential heating
and cooling (HAC) systems can
significantly impact the pressure-driven
entry of soil gas into houses. Entry of
soil gas is of concern because it can
contain contaminants such as radon,
VOCs, pesticides, and biocontaminants.
HAC configurations that have lowered
radon entry rate in new construction, and
which could be applied to reduce the
entry of other soil gas contaminants, are
presented. Source: Proceedings of the
1993 International Radon Conference,
Denver, CO., September 20-23, 1993.
Lead Author & EPA Contact: Timothy
M. Dyess (919-541-2802).

EPA's Indoor Air Quality/Pollution
Prevention Workshop - To assist
AEERL in prioritizing areas of
AQ/pollution prevention research, a
workshop was held March 9-10, 1993.
the workshop is discussed on page 9.
"Source: EPA Report (EPA-600/R-93/198;

NTIS PB94-114782) and the Proceedings
of the Annual AWMA Meeting, June 13-
18, 1993. EPA Contact: Kelly Leovic
(919-541-7717).

Evaluation of Radon Movement
Through Soil and Foundation
Substructures - A 2x2x4m chamber
filled with radium containing soil is being
used to study convective and diffusive
soil gas movement through soil and
foundation substructures. A perforated
pipe vacuum line draws air (or tracer gas)
through the soil under varying moisture
conditions to simulate convective flow
conditions. Data from the chamber will
be used to model soil permeability
properties and radon entry conditions
imperative to site characterization for soil
gas source potential. Source: 1992
Toxics Measurement Symposium.* Lead
Author, Marc Y. Memetrez. EPA
Contact: Ron Mosley (919-541-7865).

Follow-up Radon Measurements in 14
Mitigated Schools - To determine the
long-term performance of radon
mitigation systems, radon measurements
were made between February and April
1992 in 14 schools that had been
mitigated between 1988 and 1991.
Results show that active soil
depressurization systems have been very
effective in maintaining low long-term
radon levels in these 14 schools. Source:
EPA Report (EPA-600/R-93/197). Lead
Author, Jean-Claude Dehmel. EPA
Contact: Kelly Leovic (919-541-7717).

Measurements of Soil Permeability and
Pressure Fields in EPA's Soil-Gas
Chamber - An analytic solution for
advective flow in AEERL's soil-gas
chamber is presented. The solution
includes the effects of moisture dependent
variations of permeability with position.
Relatively good agreement between the
measurements and model is obtained
except in the region near the water level
where the boundary conditions are not
Tigorously satisfied. Source: Proceedings
of the 1993 International Radon
Conference, Denver, CO, September 20-
23, 1993 EPA Contact: Ron B. Mosley
(919-541-7865).

Page 13

Measurement of the Surface
Permeability of Basement Concretes -
This report details the development and
test results of a portable permeameter
used for surface permeability
measurements of concrete. Surface
permeability of concrete determines the
performance of seals between concrete
sections, an important passive technique
for preventing radon entry into new
buildings. EPA Report (EPA-600/R-93-
169; NTIS PB93-232114). Lead Author,
Arthur Scott. EPA Contact: Timothy M.
Dyess (919-541-2802).

Radon in Florida Large Building Study
- This project is examining how IAQ is
affected by ventilation, mixing, and
leakage rates in two research buildings.
Measurements include: radon, carbon
dioxide, temperature, humidity,
differential pressures, outdoor air intake
flow rates, and tracer gas methods. The
outdoor air intake is adjusted from no
outdoor air to recommended ASHRAE
ventilation standards. Source: 1992
Toxics Measurement Symposium.*
Author & EPA Contact: Mare Y.
Menetrez (919-541-7981).

Removal Efficiencies in Terms of
Particle Size and Concentration of
Console Air Cleaners in a Suburban
Home - Removal efficiency data and
cost/benefits for two commercial console
air cleaners are presented. One is
equipped with a high efficiency filter and
the other with an ESP. Data show that
both units are highly efficient at removing
particles 1.0 yum and greater, the size
range of spores and pollens, but less
efficient at removing submicron particles.
Source: Proceedings of the Annual
AWMA meeting, June 13-18, 1993
(EPA-600/A-93-183, NTIS PB93-
222016). Lead Author & EPA Contact:
Raymond S. Steiber (919-541- 2288).

The Environmental Resource Guide
(ERG) - The ERG is a comprehensive
reference resource being developed
cooperatively between AEERL and the
American Institute of Architects (AIA).
The ERG aids architects and other design
professionals in evaluating environmental
impacts of design decisions. The ERG's


United States

Environmental Protection Agency

Air and Energy Engineering Research
Laboratory

Research Triangle Park, NC 27711

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