In This Issue Page

Research Project Highlights ............. 2

 ' Evaluation of Emissions from Latex

 Paint ........................... 2

 ' Carpet Freshener Study ............ 3

 ' EPA Compares Large Chamber

 Design With International Chambers . . 3

 ' Development of a Medium for 

 Recovering Aerosolized Bacteria ..... 4

 ' Irritation of the Nasal Septum ........ 5

 ' EPA Researches Office Equipment ... 6

 ' Evaluation of Fungal Growth

 On Ceiling Tiles .................. 8

 ' Influence of Climatic Factors on

 House Dust Mites ................. 8

 ' Ventilation Research Program ....... 9

 ' EPA Begins Air Duct Cleaning

 Research ....................... 10

 ' Cost Analysis of IAQ Control

 Techniques ..................... 11

Summaries of Recent Publications ....... 13

Glossary of Acronyms ................ 16

United States Office of Research

Environmental Protection and Development

Agency Research Triangle Park, NC 27711

EPA/600/N-95/004, Spring/Summer 1995

 EPA Inside IAQ 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

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 Air and Energy Engineering

(NRMRL)/Air Pollution Prevention and Control Research Laboratory (AEERL)

Division (APPCD)

National Exposure Research Laboratory (NERL)/ Environmental Monitoring

&

Human Exposure Research Division (HERD) Sampling Laboratory (EMSL)

National Health and Environmental Effects Health Effects Research

Research Laboratory (NHEERL) Laboratory (HERL)

NERL/Human Exposure and Field Research Atmospheric Research and

Division (HEFRD) Exposure Assessment

Laboratory (AREAL)

National Center for Environmental Assessment Environmental Criteria and

(NCEA) Assessment Office (ECAO)
Inside IAQ, Spring/Summer 1995 Page 2

P. Glycol = Propylene Glycol

E. Glycol = Ethylene Glycol

BEE= Butoxyethoxyethanol

0 50 100 150

0

5

10

15

20

Time (h)

Concentration (mg/m3)

P. Glycol E. Glycol BEE Texanol

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, <

5μg/m3 TVOCs, flow is started through the chamber. A flow rate

of 0.44 l/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 23EC

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 shortterm emissions. Gypsumboard was subsequently selected as the

test substrate for this study.

Figure 1 Emissions of TVOCs from Painted Gypsumboard and

Painted Stainless Steel

The chamber samples were also analyzed to determine the

emissions of individual latex paint 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.

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 3

0 1,000 2,000 3,000 4,000

0.001

0.01

0.1

1

1 0

100

T ime (h)

Concentration (mg/m3)

P. Glycol E. Glycol BEE Texanol

1 2 3 4

0

5

10

15

20

25

30

Test Number

Percentage of Particulates Under 0.35 μm

1. Carpet Vacuumed

2. Freshener Applied

3. Carpet Revacuumed

4. 24 Hours Later

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.

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 μm 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)

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 4

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 air flow 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

(CFUs). 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 CFU/Total Standard

Error

TSA 0.189 0.0117

TSA+10%FBS 0.4207 0.07152

MUELLER HINTON+5% FBS 0.4055 0.07948

BRAIN HEART+5% FBS 0.3694 0.046

GC+1%BSA 0.3194 0.076

BEEF EXTRACT AGAR 0.2991 0.026

BHI AGAR 0.2926 0.051

CAMPYLOBACTER+5%FBS 0.288 0.046

BEEF EXTRACT +5% FBS 0.2829 0.027

LAB-LEMCO+5% Blood 0.2827 0.067

GC+0.5% TSOVITALEX 0.282 0.067

TSA+5%FBS 0.2802 0.037

SCHAEDLER+5% BLOOD 0.2782 0.052

GC+1%BSA+5% BLOOD 0.278 0.06

CTA 0.2734 0.011

EUGON AGAR 0.2687 0.071

EUGON+5% BLOOD 0.2687 0.051

GC+5% BLOOD 0.2668 0.053

CHAPMAN STONE AGAR 0.2643 0.064

SHAEDLER AGAR 0.2635 0.067

Table 2

Recovery of Serratia Marcescens on Selected Media

MEDIA CFU/Total Standard

Error

TSA 0.01405 0.0028

1⁄2TSA+6% TREHALOSE 0.07167 0.01112

YEAST+0.04% CYSTEINE 0.07117 0.05621

TSA+0.04% CYSTEINE 0.06789 0.01766

TSA+2mM BETAINE 0.06789 0.02295

1⁄2TSA 0.04036 0.01835

YEAST+2mM Betaine+0.04% CS 0.03875 0.01612

TSA+50mM INOSITOL 0.026 0.00271

1⁄2TSA+2mM BETAINE 0.02944 0.01066

1⁄2TSA+0.04% CYSTEINE 0.01761 0.00874

1⁄2TSA+8% TREHALOSE 0.01761 0.01116

YEAST EXTRACT AGAR 0.01639 0.00557

YEAST+2mM BETAINE 0.01577 0.00665

MSA+0.04% CYSTEINE 0.01503 0.00171

MSA+50mM INOSITOL 0.01445 0.00377

1⁄2TSA+4% TREHALOSE 0.01417 0.00566

MSA+2mM BETAINE 0.01411 0.00162

cTSA 0.01358 0.0471

1⁄2TSA+2% TREHALSOE 0.01307 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 5

80

70

4

60

0

20

30

40

50

6 10 20 50 100 200 500 1000

10

FREQUENCY OF STIMULUS CURRENT (Hz)

RELATIVE CURRENT INTENSITY

IRRITATION

TREMOR

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 performance 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. 

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 6

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 μg/copy before routine maintenance and were reduced to

less than 1 to 4 μg/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 μg/sheet or 1350 μg/min), particulate,

and VOCs (up to 16 μg/sheet) emissions. (EPA Contact: Kelly

Leovic, APPCD, 919-541-7717)
Inside IAQ, Spring/Summer 1995 Page 7

Table 3 Summary of Office Equipment Emissions From Literature Review *

Type of

Equipment Emissions

Emission Rates

(from various studies)

Potential Pollution Prevention

Solutions

Dry-process

photocopying

machines

Hydrocarbons, respirable

suspended particulates

(toner powder), and ozone

O 3

: Average 40 Fg/copy; peak production

131 Fg/copy;

0-1350 Fg/copy, average - 259 Fg/min;

48-158 Fg/copy;

<4-54 Fg/copy

Particulate: 0.001 Fg/m3room

concentration of black carbon;

90-460 Fg/m3in exhaust air

TVOC: 0.5-16.4 Fg/sheet from paper

Lower voltage to reduce ozone,

toner reformulation, improved

transfer efficiency, low

maintenance machines, lower fuser

temperature, changes in toner

particle size, low-emitting

components.

Laser printers Hydrocarbons, respirable

particulates, and ozone

O3

: 100-4,000 Fg/m3room concentration;

average 438 Fg/min

100 Fg/min (w/filter)

Particulate: 60 Fg/m3

TVOC: 2.0-6.5 Fg/sheet from paper

Same as for dry-process

photocopying machines

Computer terminals Ozone and off-gassing

VOCs

Limited published data,

TVOC: Maximum of 175 Fg/hour from

VDT drops quickly within 300 hours of on

time

Low-emitting materials and/or

lower voltage, low-emitting

materials for cards used in

integrated circuit boards

Wet-process

photocopying

machines

Aliphatic hydrocarbons

and ozone

TVOC: 25 g/h, 0.241 g/copy observed,

high room concentration of 64 mg/m3,

4,150 mg/m3in exhaust air

Solvent reformulation, pressure

fusing, decrease voltage, lowemitting components

Ink/bubble jet

printers

Hydrocarbons and ozone No published emission rate or IAQ data Solvent reformulation, low-emitting

components

Spirit duplicators Methanol 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

Mineral spirits or replacement with

photocopiers

Mimeograph

machines

Hydrotreated heavy and

light naphthenic distillates

Heavy naphthenic distillate, 30 mg/page,

10 mg/page light naphthenic distillate

Ink reformulation, replacement with

photocopiers or other technologies

Fax machines Ozone and VOCs No published emissions rate or IAQ data Same as for dry-process

photocopying machines

Digital duplicators VOCs–petroleum solvent

and ethylene glycol

Combined VOCs: 20 mg/page Lower VOC inks, replacement with

photocopiers

Blueprint machines

(dyeline)

Ammonia, carbon

monoxide, methanol,

ethanol, trinitrofluorene,

and trichloroethane

1-40 ppm ammonia in breathing zone of

operator, average – 8.2 ppm

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 8

1 3 7 14 21 28

2

3

4

5

6

7

54% RH 70% RH 85% RH 90% RH 94% RH 97% RH

day

log CFU/ tile

Solutions Research

Evaluation of Fungal Growth on Ceiling 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

Penicillium 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)

Figure 6 Penicillium Glabrum Growth on ChamberConditioned 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. In the U.S., the dust mites most commonly found in

homes are Dermatophagoides farinae (DF), D. pteronyssinus (DP),

and Euroglyphus 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. In 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 Page 9

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.

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 m3/m/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)
Inside IAQ, Spring/Summer 1995 Page 10

Table 4 Emission Sources and Problems Identified in HVAC Systems

SOURCES and PROBLEMS TYPICAL EXAMPLES

Intrinsic emission sources

 Seals, Caulks, Adhesives Offgassing of VOCs, deterioration

 Fibers Asbestos, fiber shedding

 Metal degradation products Deterioration and entrainment of coatings, platings, metal surfaces

 Lubricating oils, etc. Fans, motors in the air stream

 Ozone Release by electrostatic air cleaners

Emission sources resulting from

contaminations

 Dust Construction material, skin cells, etc., with accumulation possibly leading to

microbial contamination, VOC sorption-desorption, and low flows

 Other organic debris Leaves, bird droppings

 Growth of microoganisms 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

 VOC sinks Filters, sound absorbers, insulation materials, deposited dust

 Cleaning compounds and Biocides Biocides, disinfectants, deodorizers

 Boiler steam Anticorrosives, biocides, slimicides, oxygen-scavenging or filming chemicals,

anti-corrosives, pH control neutralizers

Design/operational effects on IAQ

 Entrainment and Re-entrainment Leaks, polluted outdoor air, building exhaust

 Rotary heat exchangers Sorption-desorption of VOCs

 Building pressurization Intake of polluted outdoor air

 Transport Odor, VOC and particle migration

 Climate control High humidity

 Ventilation and Air exchange Inadequate dilution of internal sources, inadequate outdoor air

 Cleaning procedures 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.

 In 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 diffusers, and controls.
Inside IAQ, Spring/Summer 1995 Page 11

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 handoperated 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. In

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 m3/m). 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.

In 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. In 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. In 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 welldefined 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 12

 ! 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 Medical Services

Single Office 1 story Single Medical Office 1 story

Multiple Office 2 to 3 stories Multiple Medical Offices 2 to 4 stories

Office Complex 4 to 7 stories Community Hospital 1 to 3 stories <100 beds

Office Tower 10+ stories Medical Center 4 to 10 stories >100 beds

Educational

Extended Medical Care

 Facility

1 to 10 stories, patients needing

 minimal care

Secondary School (Multiple

 Building)

1 to 2 story, detached buildings Nursing Care Retirement

 Facility

1 floor, daily nursing care

Secondary School (Enclosed) 1 to 2 story, single building Entertainment/Recreation

College Building (Liberal

 Arts)

4 to 7 story classroom bldg. with

 no special HVAC requirements

Sports Recreation Facility 1 or 2 story, health club

College Building (Science) 4 to 7 story building with

 laboratories

Theater/Auditorium 1 story, seating 200+

Retail Sales and Service Arena Seating 10,000+

Specialty Store 1 story with no special HVAC

 requirements Lodging

Restaurant 1 story, kitchen Motel 1 to 2 story, detached buildings

Auto Service Center 1 story building Hotel Multi-story single building

General Merchandise 1 story building Transportation

Department Store 2+ stories Rail/Bus Terminal

Strip Shopping Mall Airport Terminal

Enclosed Shopping Mall Enclosed Parking Garage

Correctional Facilities

Prison
Inside IAQ, Spring/Summer 1995 Page 13

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 Characterization 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

Royal Road, Springfield VA 22161, 703-487-

4650 or 800-553-6847.

Source Characterization

Comparing the Field and Laboratory

Emission Cell (FLEC) with Traditional

Emissions Testing Chambers - Performance 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 Lowand 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 Characterization 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 14

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

of Penicillium 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, lumpedparameter model to characterize indoor

radon concentrations from data that are more

readily available than those required for

existing mathematical models. The lumpedparameter model was developed from

numerous sensitivity analyses with the more

detailed RAdon Emanation and TRAnsport

into Dwellings (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/R94/201 (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

(Penicillium 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,

Penicillium 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: In 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 housesoil 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, EPA600/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 Page 15

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 biological 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/R95-045 (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 characterized 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 radoncontrol 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 NorthCentral 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) 
FIRST CLASS MAIL

POSTAGE AND FEES PAID

EPA

PERMIT No. G-35

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

IAQ-Indoor Air Quality

NADCA-National Air Duct Cleaning Association

NAIMA-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