United States
Environmental Protection
Agency
& EPA
Office of Research
and Development
Research Triangle Park, NC 27711
EPA/600/N-95/004, Spring/Summer 1995
Inside I A Q
EPA's Indoor Air Quality Research Update
Inside IAQ is distributed twice a year and
highlights indoor air quality (IAQ) research
conducted by EPA. If you would like to be added
to or removed from the mailing list, please mail,
fax, or e-mail your name, address, and phone
number to:
Inside IAQ, Attn. Kelly Leovic (MD-54)
U.S. EPA/APPCD
Research Triangle Park, NC 27711
Fax: 919-541-2157
E-mail: kleovic@engineer.aeerl.epa.gov
In This Issue
Page
Research Project Highlights 2
X Evaluation of Emissions from Latex
Paint 2
X Carpet Freshener Study 3
X EPA Compares Large Chamber
Design With International Chambers . . 3
X Development of a Medium for
Recovering Aerosolized Bacteria 4
X Irritation of the Nasal Septum 5
X EPA Researches Office Equipment ... 6
X Evaluation of Fungal Growth
On Ceiling Tiles 8
X Influence of Climatic Factors on
House Dust Mites 8
X Ventilation Research Program 9
^ EPA Begins Air Duct Cleaning
Research 10
X Cost Analysis of IAQ Control
Techniques 11
Summaries of Recent Publications 13
Glossary of Acronyms 16
Engineering Solutions to Indoor Air Quality Problems
July 24-26, 1995
Sheraton Imperial Hotel and Conference Center
Research Triangle Park, NC
Register now to attend this international symposium cosponsored by the Air
& Waste Management Association (A&WMA) and the U.S. Environmental
Protection Agency's (EPA) Air Pollution Prevention and Control Division.
The symposium will include oral presentations, a poster session, continuing
education courses, and an exhibition.
For registration information and a copy of the program, contact the A&WMA
Registrar at 412-232-3444, ext. 3142; fax 412-232-3450. For information on
the exhibition, contact Roy Neulicht at 919-677-0249, ext. 5126; fax 919-
677-0065.
Symposium Program
Monday, July 24 - Source Characterization
Source Management & Pollution Prevention
Reception and Poster Viewing in Exhibition Area
Tuesday, July 25 - Ventilation & Modeling - Air Cleaning
Wednesday, July 26 - Biocontaminant Control
Who's Who in EPA's Office of Research and Development (ORD)?
ORD is reorganizing into four national laboratories. The organizational changes
that affect IAQ research are:
New Organization Former Organization
National Risk Management Research Laboratory
(NRMRL)/ Air Pollution Prevention and Control
Division (APPCD)
Air and Energy Engineering
Research Laboratory (AEERL)
National Exposure Research Laboratory (NERL)/
&
HumanExposure Research Division (HERD)
Environmental Monitoring
Sampling Laboratory (EMSL)
National Health and Environmental Effects
Research Laboratory (NHEERL)
Health Effects Research
Laboratory (HERL)
NERL/Human Exposure and Field Research
Division (HEFRD)
Atmospheric Research and
Exposure Assessment
Laboratory (AREAL)
National Center for Environmental Assessment
(NCEA)
Environmental Criteria and
Assessment Office (ECAO)
-------
Research Project Highlights
Source Characterization Research
Evaluation of Emissions From Latex Paint
This three-part study was initiated in 1994. Part 1 (Initial
Assessment) has been completed and was summarized in the
Fall/Winter 1994 issue of Inside IAQ. Results from Part 2
(Chamber Testing) are covered in this article. Part 3 (Test House
Studies) will be completed by the end of 1995 and will be
presented in a future issue.
The Initial Assessment was designed to determine the most
appropriate techniques for conducting the study, including: a)
selection of a test paint; b) analysis of volatile organic
compounds (VOCs) and water content using American Society
for Testing and Materials (ASTM) methods; c) determination of
major organic compounds; d) development of optimal sampling
and analysis methods for organic paint emissions; and e)
evaluation of paint application methods.
The purpose of the Chamber Testing is to: a) select the test
substrate; b) determine emission rates for Total Volatile Organic
Compounds (TVOCs) as well as for individual compounds; c)
determine the effect of previous coats on emissions; d) determine
short- and long-term emission rates; and e) evaluate and develop
source emission models, including mass transfer models.
(Modeling results will be discussed in a future issue of Inside
IAQ.)
Environmental test chamber methods used for this study have
been developed for evaluating emissions from indoor materials
and products. The flow-through, dynamic chambers have a
volume of 53 liters and are constructed with electropolished
stainless steel interior surfaces to minimize adsorption of VOCs.
Small fans are used to enhance mixing and provide a velocity
near the test surface of 5 - 10 cm/s, which is typical of indoor
environments. Emissions testing is conducted by placing a freshly
painted (2-3 minutes) substrate (16.3 x 16.3 cm) in the chamber,
painted side up. The chamber is then closed, and clean air, <
5ug/m3 TVOCs, flow is started through the chamber. A flow rate
of 0.44 1/min, equivalent to 0.5 air change per hour, is used.
Sufficient samples of the chamber outlet are collected to describe
the change in emissions over time. Testing is conducted at 23 °C
with an inlet relative humidity (RH) of 50%.
VOC emissions from painted gypsumboard and painted stainless
steel were evaluated in the dynamic chamber. As shown in Figure
1, TVOC emissions from painted gypsumboard are quite different
than those from painted stainless steel. Significant amounts of
VOCs are adsorbed by the gypsumboard, thus reducing the short-
term emissions. Gypsumboard was subsequently selected as the
test substrate for this study.
140
120
iT'lOO
|> BD
cT 60
H 40
20
0
New Gypsumboard Stainless Steel
100
Time (h)
150
Figure 1 Emissions of TVOCs from Painted Gypsumboard and
Painted Stainless Steel
The chamber samples were also analyzed to determine the
emissions of individual latexpaint components, namely: ethylene
glycol, propylene glycol, diethylene glycol, butoxyethoxyethanol
(BEE), and Texanol® (2,2,4-trimethyl-1,3 -pentanediol mono 2-
methylpropanoate). As shown in Figure 2, emissions of Texanol®
and ethylene glycol are the highest, with Texanol® emissions
predominating for the first 50 hours and ethylene glycol
emissions being the primary VOC emitted thereafter.
20
c
(U
o
c.
o
O
O
f
\\
\ \
;
\ - • . . .
P. Glycol E. Glycol BEE Texanol
••-..
"•-•>~^:.. -
50
100
Time (h)
150
P. Glycol = Propylene Glycol
E. Glycol = Ethylene Glycol
BEE= Butoxyethoxyethanol
Figure 2 Emissions of Latex Paint VOCs from Painted
Gypsumboard
Testing was then conducted to determine if paint applied to
previously painted gypsumboard affects the emission profile. Two
previously coated boards were used: 1) a piece of gypsumboard
cut from a wall of EPA's IAQ test house that had not been
repainted for over 8 years, and 2) a gypsumboard sample painted
5 weeks previously. These two samples had emission profiles
essentially the same as for the first coat on new gypsumboard.
Many wet, evaporative sources emit for only a short time (e.g.,
several days). Most of the testing done in this evaluation program
occurred over a 7-day (168 hour) period. One test has been
continued in order to observe the emissions from latex paint over
Inside IAQ, Spring/Summer 1995
Page 2
-------
the long term. Figure 3 shows the emissions of VOCs over a
period of almost 6 months. Note that the emissions of ethylene
glycol are much higher than the other compounds. Also note that,
at the last sampling period, the concentrations of
butoxyethoxyethanol and Texanol® were near the quantification
limit of the sampling and analysis system.
P. Glycol E. Glycol BEE Texanol
1,000
2,000
Time (h)
3,000
4,000
Figure 3 Long Term Emissions of Latex Paint VOCs from
Painted Gypsumboard
This study should result in the following information: a) emission
rate data for VOCs from latex paint on gypsumboard for specific
test parameters; b) validated source emissions models for latex
paint, including mass transfer models; c) test house data showing
the concentrations of VOCs from latex paint; and d) a draft
ASTM "Standard Practice for Determining Emissions from
Interior Latex Paints." If a mass transfer model can be used to
successfully predict emissions, a test method based on ASTM
VOC content and equilibrium data from static headspace should
be possible. Thus, the dynamic chamber test method would be
replaced by a simpler and less expensive technique. Other latex
paints need to be evaluated to provide data for generalizing these
test methods. (EPA Contact: Bruce A. Tichenor, APPCD, 919-
541-2991)
Source Characterization Research
Carpet Freshener Study
Carpet fresheners are typically intended to be used as a cover for
household odors. They consist of a fine powder with a fragrance
added. The powder is applied broadcast to a carpet and then the
carpet is vacuumed to remove the excess and volatilize the
fragrance. Given the concerns about the impact of breathable
fine particulates on lungs, EPA conducted a series of tests on
carpet fresheners.
The study was done in APPCD's test house, and two carpet
fresheners were examined. Each product uses a different
substrate as the powder. The immediate impact after application
and long-term buildup due to periodic reapplication were
evaluated. The effect of vacuuming was also examined since the
average vacuum cleaner redistributes a third or more of all the
fine particulates collected.
Figure 4 shows a typical result from this study where the
breathable fines (defined as 0.35 um and smaller) increased from
16.9% of the total to 29.1% following application of the carpet
freshner. While vacuuming reduces this increase in breathable
fines, background concentrations continue to remain high for an
additional 8 to 24 hours. However, to put this in perspective,
similar if not greater increases can be caused by random activities
in any busy household.
The long-term buildup of airborne particulates due to repeated
applications of carpet freshener (60 days and 3 applications) was
masked by normal day-to-day fluctuations in background
particulate concentration. Therefore, it would appear that in most
cases the impact of applying carpet freshener is limited to the
application phase and immediately afterwards. (EPA Contact:
Ray Steiber, APPCD, 919-541-2288)
el-
's
30
25
20
15
10
5
0
—
; •;
s p
91
1 . Carpet Vacuumed
2. Freshener Applied
3. Carpet Revacuumed
4. 24 Hours Later
/ >
71
1234
Test Number
Figure 4 Increase in Breathable Fine Particulates Following
Application of Carpet Freshener
Source Characterization Research
EPA Compares Large Chamber Design With International
Chambers
Large (room-sized) environmental test chambers are being
constructed by three different governments for use in
characterizing sources of indoor air pollution. Participating
government organizations include: EPA's APPCD, the National
Research Council Canada, and Australia's Institute of Minerals,
Energy and Construction. These "large" chambers are intended
to supplement existing indoor air emission source
characterization facilities by providing adequate size facilities to
contain and characterize emissions from large assemblages, such
as furniture; equipment operation, such as photocopying; and
activities, such as painting or cleaning. These large chambers
will also be helpful in studying the usefulness of computer
Inside IAQ, Spring/Summer 1995
Page 3
-------
modeling for scaling up emissions data from small environmental
chambers to a controlled room-like environment. This study
should improve the ability of each of the laboratories to develop
test methods which give reliable results when run on chambers of
different construction.
The three large chambers, while intended for similar purposes,
have been designed and constructed to different specifications.
The organizations involved will conduct a study to compare the
design and performance of these chambers in order to develop a
better understanding of how they can be best used. The first
phase of this interlaboratory comparison study will consist of a
comparison of the design specifications and construction. Later
phases will address such topics as airflow patterns, ability of the
systems to hold temperature and humidity setpoints, airtightness
and cleanliness of the chamber systems, analytical measurements,
and measured emission rates from a standard source. (EPA
Contact: Betsy Howard, APPCD, 919-541-7915)
Exposure Assessment Research
Development of a Medium for Recovering Aerosolized Bacteria
Researchers at NERL/HERD and at the Maryland Biotechnology
Institute are conducting cooperative research to develop the best
medium or set of media for recovery of the diverse types of bacteria
found in indoor air. Recoveries on various media are being
compared with those on Trypticase Soy Agar (TSA), a nutritionally
complex medium known to recover injured bacteria and frequently
used in indoor air investigations. Media selected for the study are
those employed by other investigators in aerobiology and, in
addition, media designed for growth of a wide range of bacterial
species.
Twelve species of bacteria are being tested. An important finding
was that aerosolization of bacteria resulted in decreased colony
forming ability. From the data gathered in this study, it is concluded
that, for the media tested, there are large differences in recovery,
with recovery success a function of the time bacteria remained in the
air, as well as the type of medium employed for recovery.
A total of 120 media or media combinations have been evaluated.
Results of recovery experiments performed with Staphylococcus
aureus and Serratia marcescens are shown in Tables 1 and 2,
respectively. The data illustrate that (i) recoveries on the reference
medium, TSA, are low compared with those on several media
formulations not typically used in indoor air investigations; (ii) the
best recovery medium varies with the microorganism that is being
recovered; and (iii) only a small proportion of the total bacteria
observed in microscopic counts, Acridine Orange Direct Counts, are
being resuscitated and recovered as viable colony forming units
(CPUs). Thus far, Brain Heart Infusion Agar (with or without
serum), TSA combined with Trehalose or serum, and Mueller
Hinton Agar have yielded the best recoveries of aerosolized
cultures.
Table 1
Recovery of Staphylococcus Aureus on Selected Media
MEDIA
TSA
TSA+10%FBS
MUELLER HINTON+5% FBS
BRAIN HEART+5% EBS
GC+1%BSA
BEEF EXTRACT AGAR
BHI AGAR
CAMPYLOBACTER+5%FBS
BEEF EXTRACT +5% FBS
LAB-LEMCO+5% Blood
GC+0.5% TSOVITALEX
TSA+5%FBS
SCHAEDLER+5% BLOOD
GC+l%BSA+5% BLOOD
CTA
EUGON AGAR
EUGON+5% BLOOD
GC+5% BLOOD
CHAPMAN STONE AGAR
SHAEDLER AGAR
CFU/Total
0.189
0.4207
0.4055
0.3694
0.3194
0.2991
0.2926
0.288
0.2829
0.2827
0.282
0.2802
0.2782
0.278
0.2734
0.2687
0.2687
0.2668
0.2643
0.2635
Standard
Error
0.0117
0.07152
0.07948
0.046
0.076
0.026
0.051
0.046
0.027
0.067
0.067
0.037
0.052
0.06
0.011
0.071
0.051
0.053
0.064
0.067
Table 2
Recovery of Serratia Marcescens on Selected Media
MEDIA
TSA
>/2TSA+6% TREHALOSE
YEAST+0.04% CYSTEINE
TSA+0.04% CYSTEINE
TSA+2mM BETAINE
>/2TSA
YEAST+2mM Betaine+0.04% CS
TSA+50mMINOSITOL
1/2TSA+2mM BETAINE
!/2TSA+0.04% CYSTEINE
>/2TSA+8% TREHALOSE
YEAST EXTRACT AGAR
YEAST+2mM BETAINE
MSA+0.04% CYSTEINE
MSA+50mM INOSITOL
>/2TSA+4% TREHALOSE
MSA+2mM BETAINE
CTSA
>/2TSA+2% TREHALSOE
CFU/Total
0.01405
0.07167
0.07117
0.06789
0.06789
0.04036
0.03875
0.026
0.02944
0.01761
0.01761
0.01639
0.01577
0.01503
0.01445
0.01417
0.01411
0.01358
0.01307
Standard
Error
0.0028
0.01112
0.05621
0.01766
0.02295
0.01835
0.01612
0.00271
0.01066
0.00874
0.01116
0.00557
0.00665
0.00171
0.00377
0.00566
0.00162
0.0471
0.051
Additional media which can recover a broader spectrum of airborne
bacteria are being developed and tested. (EPA Contact: Gerard
Stelma, HERD, 513-569-7384)
Inside IAQ, Spring/Summer 1995
Page 4
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Health Effects Research
Irritation of the Nasal Septum
Many indoor air pollutants affect the body by entering the blood
stream and impairing the normal function of organs (a systemic
mechanism). Many indoor air pollutants are also irritating to the
nose and eyes. A person's ability to perform tasks can be affected by
both a systemic mechanism and by sensory irritation (a peripheral
mechanism). Usually, a study of a pollutant's effects on task perfor-
mance involves both systemic and peripheral mechanisms.
To understand the observed effects of an indoor air pollutant, it
would be desirable to know the relative contribution of each
mechanism. It is possible, for instance, that the peripheral
mechanism would produce effects on one class of tasks and the
systemic mechanism would affect another class. Similarly, low
exposure could involve mainly one, while high exposure could
involve mainly the other, or both, mechanisms. It is also possible that
a peripheral and systemic mechanism could produce opposing
effects. An EPA research project is studying the effects of purely
sensory irritation, without concomitant systemic effects.
The study is addressing nasal irritation, as opposed to eye only or
both. To produce a nasal irritation usually involves injection of an
irritant chemical into the nose, a process that is difficult to control
and quantify as well as mechanically cumbersome. A new method of
electrical stimulation of the nerve endings which are responsible for
sensory irritation is being developed to avoid the problems with
chemical stimulation. Small (0.5 cm) metal disks are placed on each
side of the nasal septum and held in place by a weak spring clip.
Small alternating electrical currents are delivered via the disks with
the goal of producing a burning or irritating sensation, but at an
intensity so low that tissue damage does not result. One of the other
effects of electrical stimulation of body tissues is to produce
involuntary muscle twitch or tremor. Muscle tremor would be
undesirable because it would not well simulate chemical stimulation.
Human subjects were required to press a button when they first
noticed either irritation or muscle tremor while electrical stimulation
was presented. Figure 5 gives the observed relative electrical current
strengths needed for each in the nasal septum.
80 —
70 —
60—
50 —
a:
3 30—1
20-
10 —
IRRITATION
\^
10
50
I
100
\ \
500 1000
20 50 100 200
FREQUENCY OF STIMULUS CURRENT (Hz)
Figure 5 Relative Electrical Current Strength Required to
Produce Irritation or Tremor in the Nasal Septum
as a Function of Frequency or Electrical Current
Note that stimulation below 6 - 10 Hz produces irritation at
relatively low intensities whereas production of muscle tremor
requires much more current. At higher frequencies the thresholds for
each phenomenon were not found to be so widely separated.
Electrical currents of 4 Hz are to be used for future work.
Magnitude and similarity estimates are also planned comparing
electrical stimulation with more traditional chemical stimulation.
One of the major effects of irritation is expected to be distraction
from task performance Such distraction could interfere with
attention, memory, and cognition. Experiments are being conducted
in which distractions (noises) are being presented to people in a
effort to produce disruption. Such parameters as probability of signal
presentation and various task instructions are being tested to find
ways of making tasks more sensitive to disruption. When task
standardization is complete, the tasks will be used to test the effect
of various intensities of irritation as produced by electrical
stimulation of the nasal septum. (EPA Contact: Vernon A. Benignus,
NHEERL, 919-966-6242)
Inside IAQ, Spring/Summer 1995
Page 5
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Solutions Research
EPA Researches Office Equipment
EPA, Research Triangle Institute, and Underwriters Laboratories are
working together with industry to identify and evaluate pollution
prevention opportunities to reduce indoor air emissions from office
equipment. The project includes:
! conducting a literature review on indoor air emissions from
office equipment,
! developing standard test guidance to characterize indoor air
emissions from office equipment,
! measuring indoor air emissions from selected types of office
equipment, and
! identifying and evaluating pollution prevention approaches for
reducing indoor air emissions from office equipment.
The literature review has been completed, and a standard test
method is being developed. Currently, indoor air emissions from
dry-process photocopy machines are being evaluated. The
remainder of this article discusses project progress to date.
Literature Review-The literature review, Office Equipment: Design,
Indoor Air Emissions, and Pollution Prevention Opportunities
(EPA-600/R-95-045, NTIS PB95-191375, March 1995),
summarizes information on office equipment design; indoor air
emissions of organics, ozone, and particulates from office
equipment; and potential pollution prevention approaches for
reducing these emissions.
The report covers 1) dry and wet process photoimaging machines
(copiers, printers, and faxes); 2) spirit duplicators; 3) mimeograph
machines; 4) digital duplicators; 5) diazo (blueprint) machines; 6)
computers; 7) impact matrix printers; and 8) other equipment types.
Photoimaging machines are emphasized in the report because of
their prevalence and potential opportunities for pollution prevention.
Emissions from office equipment result from operation, offgassing
from components, or episodic releases related to catastrophic failure
of a unit. For equipment that does not use supplies (e.g., video
display terminals, VDTs), emissions are primarily from offgassing
of residual organics. The source can be either construction materials
(e.g., plastic casings) or components (e.g., circuit boards). Emissions
from offgassing decrease with time. For VDTs, over 300 hours of
"on time" is normally required before emissions reach a negligible
level.
Equipment that uses supplies (e.g., toner, ink, and paper) has
emissions from both offgassing and operation. Emissions from
offgassing will decrease with time; however, emissions from
operation will either remain fairly constant or may even increase
between routine maintenance and as the equipment ages. For
example, ozone emissions from five tested photocopiers ranged from
16 to 131 ug/copy before routine maintenance and were reduced to
less than 1 to 4 ug/copy after maintenance.
Published data on emissions from office equipment are limited.
However, increased levels of ozone, TVOCs, and particulates have
been observed in the presence of operating office equipment. One
researcher measured increased levels of ozone, formaldehyde,
TVOC, and particulates in a chamber evaluation (three personal
computers, one photocopier, and one laser printer). Thirty human
subjects participating in the experiment had a significantly increased
perception of headache, mucous membrane irritation, and dryness in
the eyes, nose, and throat as well as dry and tight facial skin when
exposed to the operating equipment in the chamber. Other
researchers have also reported that emissions associated with normal
operation of office equipment can contribute to increased indoor air
pollutant concentrations and complaints by exposed workers.
Table 3 summarizes published emission rates, IAQ impacts, and
potential pollution prevention solutions associated with some of the
equipment types discussed in the literature review.
Development of Standard Test Guidance-In cooperation with
industry, a guidance document for measuring indoor air emissions
from office equipment is being developed. The test method is
designed to be analytically sensitive and generally applicable to
all types of office equipment. It is intended to characterize
emissions, to support identification of potential pollution
prevention strategies, and to promote uniform testing.
Flow-through dynamic test chambers have been selected because
they are generally applicable to all types of equipment and provide
the most versatile data. A technical paper detailing the test guidance
will be presented at, and included in the proceedings of, the
upcoming symposium, Engineering Solutions to Indoor Air Quality
Problems.
Measurement of Emissions-Research Triangle Institute, in
cooperation with several equipment manufacturers and private
testing companies, will be conducting a round-robin validation of the
test method this summer. Emissions from three different dry-process
photocopy machines will be measured with two primary objectives:
1) to evaluate the test method so that it can be readily adapted for use
by industry, and 2) to identify the root causes of indoor air emissions
from dry-process photocopy machines and to develop pollution
prevention solutions to reduce these emissions. Dry-process
photocopy machines were selected for this initial evaluation because
they are prevalent in most office environments and are a known
source of ozone (up to 158 ug/sheet or 1350 ug/min), particulate,
and VOCs (up to 16 ug/sheet) emissions. (EPA Contact: Kelly
Leovic, APPCD, 919-541-7717)
Inside IAQ, Spring/Summer 1995
Page 6
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Table 3 Summary of Office Equipment Emissions From Literature Review
Type of
Equipment
Dry-process
photocopying
machines
Laser printers
Computer terminals
Wet-process
photocopying
machines
Ink/bubble jet
printers
Spirit duplicators
Mimeograph
machines
Fax machines
Digital duplicators
Blueprint machines
(dyeline)
Emissions
Hydrocarbons, respirable
suspended particulates
(toner powder), and ozone
Hydrocarbons, respirable
particulates, and ozone
Ozone and off-gassing
VOCs
Aliphatic hydrocarbons
and ozone
Hydrocarbons and ozone
Methanol
Hydrotreated heavy and
light naphthenic distillates
Ozone and VOCs
VOCs-petroleum solvent
and ethylene glycol
Ammonia, carbon
monoxide, methanol,
ethanol, trinitrofluorene,
and trichloroethane
Emission Rates
(from various studies)
O 3: Average 40 /^g/copy; peak production
131 ^g/copy;
0-1350 ^g/copy, average - 259 ^g/min;
48-158 /^g/copy;
<4-54 ^g/copy
Paniculate: 0.001 we/in3 room
concentration of black carbon;
90-460 Mg/m3 in exhaust air
TVOC: 0.5-16.4 wg/sheet from paper
O^: 100-4,000 Mg/m3 room concentration;
average 438 ^g/min
100 Mg/min (w/filter)
Particulate: 60 we/in3
TVOC: 2.0-6.5 wg/sheet from paper
Limited published data,
TVOC: Maximum of 175 we/hour from
VDT drops quickly within 300 hours of on
time
TVOC: 25 g/h, 0.241 g/copv observed.
high room concentration of 64 mg/m3,
4,150 mg/m3 in exhaust air
No published emission rate or IAQ data
Breathing zone concentrations of 40-635
ppm; 195-3,000 ppm with no ventilation,
80-1,300 ppm with ventilation, and 9-135
ppm with enclosure and ventilation
Heavy naphthenic distillate, 30 mg/page,
10 mg/page light naphthenic distillate
No published emissions rate or IAQ data
Combined VOCs: 20 mg/page
1-40 ppm ammonia in breathing zone of
operator, average - 8.2 ppm
Potential Pollution Prevention
Solutions
Lower voltage to reduce ozone,
toner reformulation, improved
transfer efficiency, low
maintenance machines, lower fuser
temperature, changes in toner
particle size, low-emitting
components.
Same as for dry-process
photocopying machines
Low-emitting materials and/or
lower voltage, low-emitting
materials for cards used in
integrated circuit boards
Solvent reformulation, pressure
fusing, decrease voltage, low-
emitting components
Solvent reformulation, low-emitting
components
Mineral spirits or replacement with
photocopiers
Ink reformulation, replacement with
photocopiers or other technologies
Same as for dry-process
photocopying machines
Lower VOC inks, replacement with
photocopiers
Computer Aided Design/alternative
technologies, improved maintenance
* (Source: Office Equipment: Design, Indoor Air Emissions, and Pollution Prevention Opportunities,
EPA-600/R-95-045, NTIS PB95-191375, March 1995)
Inside IAQ, Spring/Summer 1995
Page 7
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Solutions Research
Evaluation of Fungal Growth on Celling Tiles
Fungal growth on ceiling tiles is one of the major causes of IAQ
problems. Suspended ceiling tiles have been extensively used in
offices, schools, hospitals, and commercial buildings, and after
installation, there is often no cleaning or maintenance. The ceiling
tiles are subject to dust accumulation and water intrusion from
plumbing leaks and from condensation. This frequently leads to
microbial (fungi and bacteria) growth on the tiles. The fungal growth
can result in destruction of the tiles and in indoor air contamination
by emitting spores and VOCs.
APPCD evaluated the potential for fungal growth on four different
types of ceiling tiles using static chambers. Two of the predominant
genera of allergenic fungi found in indoor problem environments are
Penicittium and Aspergillus. Three species, P. glabrum, P.
chrysogenum, and A. niger, representative of these two genera, were
selected as test microorganisms. All ceiling tiles were purchased as
30.5 x 61 cm boards and cut into 3.8 cm squares. The pieces of tiles
were sterilized by autoclaving before inoculation. After being
inoculated with the test microorganisms, the ceiling tile samples were
placed in the chamber at the desired RH and temperature.
Figure 6 shows the static chamber test results for new Class A tiles
inoculated with P. glabrum. No growth of P. glabrum was obtained
in chambers with an equilibrium RH of 85% or less. Significant
growth of P. glabrum was obtained in chambers with equilibrium
RH at 90% or greater. Therefore, the minimum equilibrium RH at
which growth of P. glabrum was initiated was between 85 and 90%.
Other ceiling tiles and test microorganisms were also evaluated by
the same procedures.
It was found that even new ceiling tiles could support fungal growth
under favorable conditions. Used ceiling tiles appeared to be more
susceptible to fungal growth than the new ones. It was suspected that
better nutrient supply from the dust accumulated on the used tiles
facilitated the fungal growth. The minimum equilibrium RH at which
growth occurred for these materials and organisms was always
above the currently recommended 60% from the American Society
of Heating, Refrigerating and Air-Conditioning Engineers
(ASHRAE) Standard 55-92 for indoor environments. Therefore,
maintaining a building at below 60% RH can help prevent the
growth of the molds tested provided no other sources of water (i.e.,
from condensation or leaks) are available. However, when there is
a water source to wet the ceiling tiles, even if the RH is below 85%,
fungi could still proliferate as long as the moisture content in the
ceiling tiles was adequate. Episodes of fungal growth could be
avoided if the wetted ceiling tiles were dried quickly and thoroughly.
(EPA Contact: John Chang, APPCD, 919-541-3747)
u_
O
D)
O
54% RH 70% RH 85% RH 90% RH 94% RH 97% RH
Figure 6
7 14 21 28
day
Penicillium Glabrum Growth on Chamber-
Conditioned New Class A Ceiling Tiles
Solutions Research
Influence of Climatic Factors on House Dust Mites
House dust mites cause perennial allergies in dust-sensitive
individuals, hi the U.S., the dust mites most commonly found in
homes areDermatophagoidesfarinae (D¥),D.pteronyssinus (DP),
andEuroglyphus maynei (EM). DF and DP are cosmopolitan, while
EM is limited to the southern U.S. Most homes are co-inhabited by
both DF and DP or by DF, DP, and EM, but some homes in a
geographical area may contain only DF or DP. hi co-inhabited
homes, one species is predominant and usually makes up greater than
75% of the total dust mite population. The dominant or only species
present varies between homes within a geographical area. In a given
geographical area, some homes contain large mite densities, while
others contain low or no mite densities.
It is not clear what factors contribute to the development of large
mite populations in a home or what factors favor one species over
the others. As a result, a research project has been initiated to: 1)
identify climatic factors that favor development of a large population
of each species or one mite species over another, 2) determine the
role temperature and RH play on the fecundity, development, and
population dynamics of dust mites, and 3) identify key factors that
can be manipulated to control mite and allergen levels in homes and
thus manage these allergies. (EPA Contact: John Chang, APPCD,
919-541-3747)
Inside IAQ, Spring/Summer 1995
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Solutions Research
Ventilation Research Program
Heating, ventilating, and air-conditioning (HVAC) systems play a
major role in determining the quality of the indoor environment. The
lack of proper thermal comfort can often result in the perception of
poor IAQ by the occupants. A typical complaint is that the air is too
"stuffy." Sore and irritated throats and eyes are often a result of
insufficient RH control. Inadequate levels of outdoor air are most
often blamed for poor IAQ. The literature is filled with studies that
document the many problems associated with HVAC systems that
result in unacceptable IAQ: poor design and construction practices,
insufficient ventilation rates, lack of proper operational and
maintenance procedures, and others. Many of these problems can be
avoided by combining good engineering practice with appropriate
indoor source management. EPA is currently conducting research
into ventilation systems. Its focus is to increase our understanding of
how HVAC system design and application can be combined with
source management strategies to reduce exposure.
Currently the research activities are devoted to the following areas:
large buildings studies, air duct cleaning, HVAC pollution sources,
gas-phase filtration, and energy and IAQ studies. A brief
description of each follows.
! Field studies in large buildings are an important aspect of the
research program. In order for designers to fully understand the
implications of providing acceptable indoor environments, a good
understanding of HVAC performance characteristics and the impact
on IAQ is essential. Field studies are currently being performed in
various large buildings located in different geographical areas of the
U.S. to fully understand and demonstrate accepted ventilation
standards, such as ASHRAE Standard 62-1989, Ventilation for
Acceptable Indoor Air Quality.
! Air duct cleaning is a new area of research for EPA.
Working with industry representatives, the APPCD is investigating
the effect that cleaning has on IAQ and energy consumption.
Additional concerns are cleaning technologies and techniques. A
test facility is being designed and constructed to provide information
to the public and the industry. A field study of residential cleaning
procedures and techniques will also be carried out. (See related
article on page 10.)
! Traditionally, HVAC systems have always been considered
to be a part of the solution to poor IAQ since one of its primary
functions is to introduce outdoor air for dilution and odor control.
Recent studies have indicated that in many cases the HVAC system
can be a part of the problem. Table 4 shows emissions sources and
typical problems associated with HVAC systems. Many HVAC
system components can act as direct or indirect sources of particles
and/or VOCs. Most prominent is the occurrence of biological
growth and bioaerosol generation in the presence of moisture
provided by air washers and other recirculating water systems,
inadequate humidity control, poorly designed humidifying systems,
insufficient cooling coil maintenance, and condensate drain pans.
EPA is currently conducting research into these areas to identify and
quantify sources of indoor pollution from HVAC systems. Most of
this work is being done cooperatively with ASHRAE.
! The proper use of gas-phase filtration equipment to provide
good IAQ is an area of increasing interest by IAQ practitioners.
How to field test the effectiveness of these devices is an obstacle to
their application. Working with ASHRAE, research into field test
methods is currently being performed. The objectives are to provide
design engineers with information on proper design and application
of gas-phase filtration for IAQ.
! An important consideration in the Ventilation Research
Program is the energy costs to implement ventilation standards. This
is especially important in geographical areas that are subject to hot
and humid conditions and where operating and energy costs can
increase due to increased outdoor air usage. Research into these
costs is currently being performed in a large building in Florida. The
objective is to determine the incremental costs associated with
varying the quantity of outdoor air. Variations in outdoor air range
from 5 to 20 cfm/person (0.142 to 0.566 mVm/person). Computer
simulations and field verification are utilized to understand the
energy impacts.
Acceptable IAQ is a rising expectation by the general public. It is
the overall goal of the Ventilation Research Program to utilize its
resources and expertise to reduce indoor human exposure by
providing improved HVAC systems that are energy conserving and
that provide healthful productive environments (EPA Contact:
Russell N. Kulp, APPCD, 919-541-7980)
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 800-438-4318 or 301-585-9020, or by fax
at 301-588-3408.
Inside IAQ, Spring/Summer 1995
Page 9
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Table 4 Emission Sources and Problems Identified in HVAC Systems
SOURCES and PROBLEMS
TYPICAL EXAMPLES
Intrinsic emission sources
Seals, Caulks, Adhesives
Fibers
Metal degradation products
Lubricating oils, etc.
Ozone
Offgassing of VOCs, deterioration
Asbestos, fiber shedding
Deterioration and entrainment of coatings, platings, metal surfaces
Fans, motors in the air stream
Release by electrostatic air cleaners
Emission sources resulting from
contaminations
Dust
Other organic debris
Growth of microoganisms
VOC sinks
Cleaning compounds and Biocides
Boiler steam
Construction material, skin cells, etc., with accumulation possibly leading to
microbial contamination, VOC sorption-desorption, and low flows
Leaves, bird droppings
Growth and aerosolization of bioaerosols and VOCs from microorganisms at
sites including: cooling coils, drain pans, drains, traps, sumps, filters,
insulation, duct surfaces, plenums, humidifiers, evaporative coolers, cooling
towers
Filters, sound absorbers, insulation materials, deposited dust
Biocides, disinfectants, deodorizers
Anticorrosives, biocides, slimicides, oxygen-scavenging or filming chemicals,
anti-corrosives, pH control neutralizes
Design/operational effects on IAQ
Entrainment and Re-entrainment
Rotary heat exchangers
Building pressurization
Transport
Climate control
Ventilation and Air exchange
Cleaning procedures
Leaks, polluted outdoor air, building exhaust
Sorption-desorption of VOCs
Intake of polluted outdoor air
Odor, VOC and particle migration
High humidity
Inadequate dilution of internal sources, inadequate outdoor air
Inadequate filter maintenance, clogged condensate drains and traps, open
traps, inadequate access to air handling units
Solutions Research
EPA Begins Air Duct Cleaning Research
Can air duct cleaning improve IAQ? Can cleaning the HVAC
system reduce operating costs? When should an HVAC system be
cleaned? How effective is air duct cleaning? These are some of the
questions that EPA will be investigating as part of a new research
effort into IAQ and air duct cleaning (ADC). Working with
representatives from the air duct cleaning industry and a number of
insulation manufacturing companies, EPA is embarking on an initial
2-year ADC research program. The program will concentrate
primarily on residential systems. Determining the impacts on IAQ
and energy is the primary goal.
This research was prompted by a growing concern that consumers
are sometimes led to believe that cleaning the home
heating and air-conditioning (HAC) system can provide many
benefits such as improved IAQ, increased energy efficiency, and
prolonged system life. Currently there is little scientific data to
support these claims.
To lay out this research plan, EPA held a workshop in December
1994. The workshop was attended by several industry groups,
including: the National Air Duct Cleaning Association (NADCA),
the Association of Specialists for Cleaning and Restoration,
International (ASCR), and the North American Insulation
Manufacturers Association (NAIMA). The primary focus of the
workshop was to develop a plan for the EPA-funded ADC research.
hi the first year of research, EPA plans to design and construct a full
scale residential system test facility, complete with air handling unit,
supply and return air ductwork, registers and diflusers, and controls.
Inside IAQ, Spring/Summer 1995
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Using the test facility, EPA plans to test the effectiveness and impact
of the three most commonly used cleaning technologies currently
applied to non-porous and insulated surfaces: 1) contact vacuuming,
2) air washing, and 3) power brushing. Contact vacuuming
generally involves the use of a portable vacuum cleaner that is hand-
operated with direct contact between the brush head and the interior
duct surfaces to dislodge and remove dirt and debris. Air washing
introduces compressed air directly on the surface or component to
loosen the dirt and debris. Power brushing uses rotating bristle
brushes to directly loosen dirt and debris from the duct surface, hi
all of these methods, the duct section(s) being cleaned is subjected to
negative pressure with a "negative air system." This allows the
efficient collection and removal of all dislodged contaminants.
The test facility will include a commercially available residential
HAC system. Early design discussions suggest the need for a 1.5 to
2 ton (18,000 to 24,000 Btuh) HAC system operating
approximately at 400 to 600 cfm (11.3 to 17.0 nrVm). The
distribution system (ductwork and terminal units) will be designed
with "slip-in, slip-out" features to allow different interior surfaces
and configurations to be tested.
To perform these various cleaning experiments, the facility must first
be "loaded" with a representative contaminant. To accomplish this,
EPA has obtained actual duct dust from local ADC companies
which will be used to load the system to predetermined levels. Once
the system is loaded, tests can be performed to evaluate cleaning
technologies on selected non-porous and insulated ductwork
sections, or on selected system components such as heating and
cooling coils.
hi addition, energy consumption analyses will be performed to get a
clearer idea of the level of energy savings. The workshop attendees
were interested in performing microbiological mitigation tests and
suggested introducing a selected microbiological contaminant into a
section of ductwork or system component and performing evaluations
of mitigating capabilities of the three cleaning technologies (biocides
will not be tested). Most of what is done in the test facility will have
to relate to the research planned for the second year, hi the second
year, EPA will perform a field study using nine actual homes. The
purpose is to confirm and validate the test facility findings with field
generated data. The homes that will be used in the field study will be
selected using criteria developed by EPA and coordinated with
industry. Some of the criteria that need to be considered are: 1)
smoking or non-smoking, 2) pets or no pets, 3) HAC system type
and configuration, and 4) age of the home, hi addition, EPA has
proposed using a local ADC company that is a NADCA member for
the field study.
After the field study, industry has suggested looking at how
commercial HVAC systems are cleaned and the IAQ and energy
impacts. EPA agrees with this assessment and plans to continue to
work with industry to assess and meet the research needs of the
consumer and industry. (EPA Contact: Russell N. Kulp, APPCD,
919-541-7980)
Solutions Research
Cost Analysis of IAQ Control Techniques
This new project is developing practical guidance to help evaluate
the cost-effectiveness of IAQ control techniques under different
conditions. The guidance will provide criteria to help the user:
! select between IAQ control options (e.g., ventilation, air
cleaning, and source management); or
! select the preferred design and operating characteristics within
a given control option.
General guidance will be the near-term product of this cost
analysis. Site-specific analysis will be required by the user in any
particular application. For example, this guidance would address
the following type of design question: for a given type of new
office building, what is the general cost-effectiveness of the
following alternative steps for reducing exposure to VOCs during
initial degassing, or during VOC spills or other episodes?
! Alternative 1: Design the HVAC system for increased
ventilation.
! Alternative 2: Incorporate provisions for VOC air cleaning.
! Alternative 3: Implement source management into the building
design (e.g., source elimination, source substitution, or localized
exhaust ventilation).
For this study, cost-effectiveness is defined as the incremental
unit increase in life cycle cost per unit reduction in exposure,
expressed as a function of the absolute reduction achieved in
exposure.
The initial approach for this study will be to conduct a series of well-
defined case studies addressing alternative building types. For each
building type, a sensitivity analysis will be carried out, estimating the
cost-effectiveness of the alternative IAQ control approaches as the
following variables are systematically varied:
Inside IAQ, Spring/Summer 1995
Page 11
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! building (e.g., floor plan, interior partitions);
! nature and location of sources (e.g., initial source term and
decay rate);
! HVAC system (e.g., in existing systems, available excess coil
and fan capacity, or space for incorporation of additional filter
banks); and
! IAQ control system (e.g., the amount of additional ventilation to
be provided, the capacity of the air cleaner, or the exact nature
of the source management step).
The initial effort will include two components: 1) development of
the preliminary methodology for the cost analysis; and 2) testing
of this preliminary methodology, applying it to a specific case, to
determine whether refinements to the methodology are necessary.
A number of tasks will be addressed in developing the preliminary
methodology:
! Listing of the alternative classes of building types to be
addressed, and their associated types of HVAC systems.
! Definition of the specific scenarios to be addressed during the
study.
! Determination of the criteria for determining "effectiveness"
(e.g., how exposure will be calculated, or what measures of
exposure will be used).
! Determination of how the cost-effectiveness results and
guidelines can best be presented.
The scenario for the initial case study to test this methodology will
be a new small office building where ventilation, air cleaning, and
source management are being weighed for VOC control during the
building design.
The methodology development effort has begun with an initial effort
to list the categories of commercial and institutional buildings to be
considered. (Residential and industrial buildings are expected to be
addressed in a later phase.) An initial listing of building categories
is shown in Table 5. (EPA Contact: Bruce Henschel, APPCD, 919-
541-4112)
Table 5 Categories of Commercial and Institutional Buildings Under Consideration for IAQ Cost Analysis Study
Building Category
Key Features
Building Category
Key Features
Commercial Office Space
Single Office
Multiple Office
Office Complex
Office Tower
Educational
Secondary School (Multiple
Building)
Secondary School (Enclosed)
College Building (Liberal
Arts)
College Building (Science)
Retail Sales and Service
Specialty Store
Restaurant
Auto Service Center
General Merchandise
Department Store
Strip Shopping Mall
Enclosed Shopping Mall
1 story
2 to 3 stories
4 to 7 stories
10+ stories
1 to 2 story, detached buildings
1 to 2 story, single building
4 to 7 story classroom bldg. with
no special HVAC requirements
4 to 7 story building with
laboratories
1 story with no special HVAC
requirements
1 story, kitchen
1 story building
1 story building
2+ stories
Medical Services
Single Medical Office
Multiple Medical Offices
Community Hospital
Medical Center
Extended Medical Care
Facility
Nursing Care Retirement
Facility
Entertainment/Recreation
Sports Recreation Facility
Theater/Auditorium
Arena
Lodging
Motel
Hotel
Transportation
Rail/Bus Terminal
Airport Terminal
Enclosed Parking Garage
Correctional Facilities
Prison
1 story
2 to 4 stories
1 to 3 stories <100 beds
4 to 10 stories >100 beds
1 to 10 stories, patients needing
minimal care
1 floor, daily nursing care
1 or 2 story, health club
1 story, seating 200+
Seating 10,000+
1 to 2 story, detached buildings
Multi-story single building
Inside IAQ, Spring/Summer 1995
Page 12
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Summaries of Recent Publications
This section provides summaries of recent
publications by EPA's Indoor Air Research
Program. The summaries are organized into
the following sections: Source Character-
ization and Solutions. The source of the
publication is listed with each summary.
Publications with NTIS numbers are
available (prepaid) from the National
Technical Information Service at: 5285 Port
RoyalRoad, Springfield VA22161,703-487-
4650 or 800-553-6847.
Source Characterization
Comparing the Field and Laboratory
Emission Cell (FLEC) with Traditional
Emissions Testing Chambers - Perform-
ance of the FLEC was evaluated as applied
to emissions from floor wax and latex paint.
Tests included validation of the repeatability
of the test method, evaluation of the effect of
different air velocities on source emissions,
and a comparison of FLEC versus small
chamber characterization of emissions.
Source: Proceedings of ASTM Symposium
"Methods for Characterizing Indoor Sources
and Sinks," Sept. 25-28,1994, Washington,
D.C. (Lead Author: Nancy F. Roache, EPA
Contact: Bruce A. Tichenor, 919-541-2991)
Considerations on Revisions of
Emissions Testing Protocols - The ASTM
Standard Guide for Small-Scale
Environmental Chamber Determinations of
Organic Emissions from Indoor
Materials/Products (D 5116) was first
published in 1990 and is due for review and
revision in 1995. This paper addresses
several issues that should be considered in
the revision: the effect of air velocity on
emissions; the "edge effect" (e.g., substrate
size can affect
emission rate); emission factor estimation
(e.g., to include a wider range of models and
different methods by which the model
parameters are determined); and loss of
volatile components from the source during
sample preparation. Source: Proceedings of
ASTM Symposium "Methods for
Characterizing Indoor Sources and Sinks,"
Sept. 25-28,1994, Washington, D.C. (Lead
Author: Zhishi Guo, EPA Contact: Bruce A.
Tichenor, 919-541-2991)
Evaluation of Emissions from Latex
Paint - This paper discusses EPA research
on the evaluation of indoor air emissions
from latex paint. (See related article
"Evaluation of Emissions from Latex Paint,"
on page 2.) Source: Proceedings of Low-
and No-VOC Coating Technologies 2nd
Biennial International Conference, March
13-15,1995, Durham, NC. (Lead Author &
EPA Contact: Bruce A. Tichenor, 919-541-
2991)
Indoor Air Research: Characterizing
Air Emissions from Indoor Sources -
This brochure provides an overview of
EPA's indoor air source characterization
research. Source: EPA Publication
EPA/600/F-95/005, February 1995. (Lead
Author & EPA Contact: Kelly Leovic, 919-
541-7717)
Overview of Source/Sink Characteriz-
ation Methods - Methods and models for
characterizing indoor sources and sinks are
discussed in this paper. Source: Proceedings
of ASTM Symposium "Methods for
Characterizing Indoor Sources and Sinks,"
Sept. 25-28,1994, Washington, D.C. (Lead
Author & EPA Contact: Bruce A. Tichenor,
919-541-2991)
Design and Characterization of a Small
Chamber for Chemical and Biological
Evaluation of Sources of Indoor Air
Contamination - A 34 L source emissions
chamber that can be used in determining
chemical emissions and biological response
to product emissions was evaluated. The
chamber, which mates directly to the 2.3 L
mouse exposure chamber specified by
ASTM E981-84, was found to be without
significant leaks and background emissions
that have been noted in experiments using
aquariums as chambers. Source:
Proceedings of ASTM Symposium
"Methods for Characterizing Indoor Sources
and Sinks," Sept. 25-28,1994, Washington,
D.C. (Lead Author & EPA Contact: Mark
A. Mason, 919-541-4835)
Source Testing and Data Analysis for
Exposure and Risk Assessment of Indoor
Pollutant Sources-Ideally, experiments to
determine source emissions should run long
enough to capture all of the emissions from
the source. Unfortunately, such testing is not
practical for many types of sources such as
pressed wood products and many other
building materials. In these cases, the source
emission models and consequent risk
assessment must be based on incomplete
knowledge of the total source emissions.
Source: Proceedings of ASTM Symposium
"Methods for Characterizing Indoor Sources
and Sinks," Sept. 25-28,1994, Washington,
D.C. (Lead Author & EPA Contact: Leslie
E. Sparks, 919-541-2458)
Inside IAQ, Spring/Summer 1995
Page 13
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Solutions
Air Infiltration Measurements Using
Tracer Gases: A Literature Review -
This is a literature review of air infiltration
measurements using tracer gases, including
sulfur hexafluoride, hydrogen, carbon
monoxide, carbon dioxide, nitrous oxide,
and radioactive argon and krypton. Sulfur
hexafluoride is the most common tracer gas,
primarily because its presence may be
accurately measured in the ppb range, while
most of the other gases used may be
accurately measured in the ppm range. The
report also describes a computer-controlled
injection system. Source: EPA Report,
EPA/600/R-95/013 (NTIS PB95-173225),
January 1995. (Lead Author, Max M.
Samfield; EPA Contact: David Sanchez,
919-541-2979)
Characterization of Environmental
Chambers for Evaluating Microbial
Growth on Building Materials - This
chapter discusses the development of
prevention and control strategies for
biocontaminants in indoor air using static
chambers with characterized environmental
conditions of RH, temperature, and light to
study the ability of fungi to grow on a
variety of building materials. Duplicate
chambers were prepared for each RH: 33%,
54%, 70%, 85%, and 97%, and the growth
ofPenicillium glabrum on aged ceiling tile
removed from offices was studied. The
second series of tests used wetted block,
representing ceiling tiles involved in
flooding or other events, under two sets of
conditions. In the first condition, the air
inside the chambers was quiescent, while the
second condition involved slight air
movement. Additional tests using the static
chambers should identify limiting
environmental factors for multiple
microorganisms and a variety of building
materials. Source: Health Implications of
Fungi in Indoor Environments, Air Quality
Monographs-Vol. 2, Elsevier, 1994. (Lead
Author: K. K. Foarde; EPA Contact: John
C. S. Chang, 919-541-3747)
Design and Operation of a Dynamic Test
Chamber for Measurement of
Biocontaminant Pollutant Emission and
Control - A room-size dynamic test
chamber has been constructed to study the
conditions and factors that influence
biocontaminant emissions and dissemination.
The chamber was designed to conduct three
types of microbiological experiments: 1)
growth on various building materials, 2)
emission and deposition experiments, and 3)
both room-type and in-duct tests of air
cleaners. Protocols for aerosol dispersion,
uniformity evaluation, and flow and air
exchange characterization are discussed
along with a microbiological
decontamination protocol. Source:
Proceedings of ASTM Symposium
"Methods for Characterizing Indoor Sources
and Sinks," Sept. 25-28,1994, Washington,
D.C. (Lead Author: Douglas W. VanOsdell;
EPA Contact: John C. S. Chang, 919-541-
3747)
Development of a Lumped-Parameter
Model of Indoor Radon Concentrations -
The report describes a simplified, lumped-
parameter model to characterize indoor
radon concentrations from data that are more
readily available than those required for
existing mathematical models. The lumped-
parameter model was developed from
numerous sensitivity analyses with the more
detailed RAdon Emanation and 77t4nsport
into ZHvellings (RAETRAD) model and
from analyses of trends from empirical data
sets. The model analyses established radon
dependence on soil parameters, house size,
floor cracks and openings, and indoor air
pressures. Source: EPA Report, EPA/600/R-
94/201 (NTIS PB95-142048), November
1994. (Lead Author: Kirk K. Nielson; EPA
Contact: David Sanchez, 919-541-2979)
EPA Radon Mitigation Research Update
- This publication highlights EPA's research
on radon mitigation. It provides the radon
mitigation community with timely and useful
information in five research areas:
Innovative and Supporting Research,
Existing Houses, New House Construction,
Schools and Other Large Buildings, and
Ventilation. Source: EPA Publication,
EPA/600/N-94/011, August 1994. (Lead
Author & EPA Contact: Kelly Leovic, 919-
541-7717)
Evaluation of Fungal Growth
(Penicittium Glabrum) on a Ceiling Tile -
Laboratory research employing static
chambers is studying the impact of different
equilibrium RHs and moisture conditions on
the ability of a new ceiling tile to support
fungal growth. Amplification of the mold,
Penicittium glabrum, occurred at RHs
above 85 to 90%. Conversely, at lower
RHs, decreases were detected. The issue of
survival vs.die-off may be important in the
control of fungal contamination in building
materials. Source: hi Proceedings of "Indoor
Air: An Integrated Approach," Gold Coast,
Australia, Nov. 27-Dec. 1, 1994 (Lead
Author & EPA Contact: John C. S. Chang,
919-541-3747)
Feasibility of Characterizing Concealed
Openings in the House-Soil Interface for
Modeling Radon Gas Entry - This report
examines the feasibility of characterizing the
total effective size of openings in the house-
soil interface that permit indoor radon entry.
Since many of these foundation openings are
concealed by the building structure or
consist of porous regions, they are
characterized indirectly by their radon
permeability rather than by direct
observation. A lumped parameter model,
based on the detailed RAETRAD model for
radon entry, is the basis of the feasibility
study. Sensitivity analyses conducted with
the lumped-parameter model demonstrate a
characteristic pattern of increasing indoor
radon concentrations with increasingly
negative indoor air pressures. With
sensitivity analyses, the lumped-parameter
model indicates that the dominant
parameters affecting indoor radon levels are
the size of the foundation openings, the
pressure-driven radon entry velocity, and the
ventilation parameters for the house
superstructure. Source: EPA Report, EPA-
600/R-95-020 (NTIS PB95-178414),
February 1995. (Lead Author: Kirk K.
Nielson; EPA Contact: David Sanchez, 919-
541-2979)
Inside IAQ, Spring/Summer 1995
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HVAC Systems as Emission Sources
Affecting Indoor Air Quality: A Critical
Review - A critique of the literature reveals
that few studies are well-controlled,
comprehensive, and quantitative. Significant
gaps in the data are highlighted and
procedures are suggested to improve the
characterization of bioaerosol and VOC
emissions sources. Based on the available
literature, several HVAC components are
cited fairly frequently as emission sources,
and there is broad agreement regarding their
significance. The components include bio-
logical growth and bioaerosol generation in
the presence of moisture provided by air
washers and other recirculating water
systems, poor humidity control, poorly
designed humidifying systems, and poorly
maintained cooling coils and drip pans. IAQ
problems appear to be exacerbated by dust
accumulation and by the presence of fibrous
insulation. The importance of good design
and operation of HVAC systems, including
the appropriate placement and maintenance
of air intakes, building pressurization, and
local exhaust in source areas, is also well
accepted. More limited data implicate dust
(resulting from inadequate filtration
maintenance of filters) as a sink and
secondary source for VOCs. Source: EPA
Report, EPA-600/R-95-014 (NTIS PB95-
178596), February 1995. (Lead Author
Stuart Batterman. EPA Contact: Russell N.
Kulp, 919-541-7980)
Office Equipment: Design, Indoor Air
Emissions, and Pollution Prevention
Opportunities - The report summarizes
available information in the literature on
office equipment design; indoor air
emissions of organics, ozone, and
particulates from office equipment; and
pollution prevention approaches for
reducing these emissions. Dry and wet
process photoimaging machines (copiers,
printers, and faxes), spirit duplicators,
mimeograph machines, digital duplicators,
diazo (blueprint) machines, computers and
computer terminals, and impact matrix
printers are covered. (See related article,
"EPA Researches Office Equipment" on
page 6.) Source: EPA Report, EPA-600/R-
95-045 (NTIS PB95-191375), March 1995.
(Lead Author: Bob Hetes; EPA Contact:
Kelly Leovic, 919-541-7717)
Radon Generation and Transport in
Aged Concrete - This report gives results
of a characterization of radon generation and
transport in Florida concretes sampled from
12- to 45-year-old residential slabs. It also
compares measurements from the aged
concrete samples to previous measurements
on newly poured Florida residential
concretes. Radon generation in the aged
slabs is characterized in terms of concrete
radium concentrations and radon emanation
coefficients, and radon transport is charac-
terized by radon diffusion coefficients and
air permeability coefficients. Source: EPA
Report, EPA-600/R-95-032 (NTIS PB95-
181590), February 1995. (Lead Author:
Vern C. Rogers; EPA Contact: David
Sanchez, 919-541-2979)
Radon Generation and Transport
Through Concrete Foundations - The
Florida Radon Research Program (FRRP),
sponsored by EPA and the Florida
Department of Community Affairs, is
developing the technical basis for a radon-
control construction standard. Results of the
research conducted under the FRRP are
presented in several technical reports. This
report summarizes a project that examined
radon generation and transport through
Florida residential concretes. The concretes
are characterized by radium concentrations,
radon emanation coefficients, radon
diffusion coefficients, and permeability
coefficients. Source: EPA Report,
EPA/600/R-94/175 (NTIS PB95-101218),
September 1994. (Lead Author: Vern C.
Rogers; EPA Contact: David Sanchez, 919-
541-2979)
Radon Mitigation Research: Improved
Technology for Environmental
Protection - This brochure summarizes the
impact of EPA's research on radon
mitigation in the U.S. It also includes
background information on radon and radon
mitigation. Source: EPA Report,
EPA/600/F-94/035. (Lead Author and EPA
Contact, Kelly Leovic, APPCD, 919-541-
7717)
The RAETRAD Model of Radon Gas
Generation, Transport, and Indoor
Entry - The report describes the theoretical
basis, implementation, and validation of the
RAETRAD model, a conceptual and
mathematical approach for simulating radon
(222Rn) gas generation and transport from
soils and building foundations to the indoor
environment. It has been implemented in a
computer code of the same name to provide
a relatively simple, inexpensive means of
estimating indoor radon entry rates and
concentrations. Source: EPA Report,
EPA/600/R-94/198 (NTIS PB95-142030),
November 1994. (Lead Author: K K
Nielson; EPA Contact: David Sanchez, 919-
541-2979)
RAETRAD Version 3.1 User Manual -
This report is a user's manual for the
RAETRAD computer code. RAETRAD is
a two-dimensional numerical model to
simulate radon entry and accumulation in
houses from its calculated generation in
soils, floor slabs, and footings and its
movement by diffusion and advection
through soil and concrete pores and
openings. User input defines nominal house
size and foundation parameters, concrete
properties, and soil properties, including
their distributions of radium, moisture, and
related properties. Source: EPA Report,
EPA/600/R-94/195 (NTIS PB95-139689),
November 1994. (Lead Author: Kirk K.
Nielson; EPA Contact: David Sanchez, 919-
541-2979)
Soil Radon Potential Mapping of Twelve
Counties in North-Central Florida - This
report describes the approach, methods, and
detailed data used to prepare soil radon
potential maps of 12 counties in North-
Central Florida. The maps were developed
under the FRRP to provide a scientific basis
for implementing radon-protective building
construction standards in areas of elevated
risk and avoiding unnecessary regulations in
areas of low radon risk. Source: EPA
Report, EPA/600/R-94/218 (NTIS PB95-
159869), December 1994. (Lead Author:
Kirk K. Nielson; EPA Contact: David
Sanchez, 919-541-2979)
Inside IAQ, Spring/Summer 1995
Page 15
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Glossary of Acronyms
ADC-Air Duct Cleaning
AEERL-Air and Energy Engineering Research Laboratory
(now APPCD)
AHU-Air Handling Unit
APPCD-Air Pollution Prevention and Control Division
AREAL-Atmospheric Research & Exposure Assessment
Laboratory (now HEFRD)
ASCR-Association of Specialists for Cleaning, Restoration,
International
ASHRAE-American Society of Heating, Refrigerating
and Air-Conditioning Engineers, Inc.
ASTM-American Society for Testing & Materials
A&WMA-Air and Waste Management Association
BEE-Butoxyethoxyethanol
CFU-Colony Forming Unit
DF-Dermatophagoides farinae
DP-D. pteronyssinus
ECAO-Environmental Criteria and Assessment Office
(now NCEA)
EM-Euroglyphus maynei
EMSL-Environmental Monitoring Systems Laboratory
(now HERD)
EPA-U.S. Environmental Protection Agency
FLEC-Field and Laboratory Emissions Cell
FRRP-Florida Radon Research Program
HAC- Heating and Air-Conditioning
HEFRD-Human Exposure and Field Research Division
HERD-Human Exposure Research Division
HERL-Health Effects Research Laboratory (now NHEERL)
HVAC-Heating, Ventilating, and Air-Conditioning
lAQ-Indoor Air Quality
NADCA-National Air Duct Cleaning Association
NADVIA-North American Insulation Manufacturers
Association
NCEA-National Center for Environmental Assessment
NERL-National Exposure Research Laboratory
NHEERL-National Health and Environmental Effects
Research Laboratory
NRMRL-National Risk Management Research Laboratory
NTIS-National Technical Information Service
ORD-Office of Research and Development
RAETRAD-Radon Emanation and Transport into
Dwellings
RH-Relative Humidity
TSA-Trypticase Soy Agar
TVOC-Total Volatile Organic Compound
VDT-Video Display Terminal
VOC-Volatile Organic Compound
United States
Environmental Protection Agency
Air Pollution Prevention and Control Division
MD-54
Research Triangle Park, NC 27711
Official Business
Penalty for Private Use
$300
EPA/600/N-95/004, Spring/Summer 1995
An Equal Opportunity Employer
FIRST CLASS MAIL
POSTAGE AND FEES PAID
EPA
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