United States Office of Research

Environmental Protection and Development

Agency Research Triangle Park, NC 27711

EPA/600/N-95/007 Fall/Winter 1995

 EPA Inside IAQ EPA's Indoor Air Quality Research Update

We Apologize for the delay. . .

Due to the printing and distribution

moratorium imposed while EPA was

operating under continuing resolutions, we were unable to distribute

this Fall/Winter 1995 issue as

originally scheduled.

In This Issue Page

Evaluation of an IAQ Source Management

 Strategy for a Large Building .......... 1

EPA Examines Indoor Emissions

 from Conversion Varnishes ........... 2

Review of Concentration Standards and

 Guidelines for Fungi in Indoor Air ....... 4

Two Case Studies Evaluating HVAC

 Systems as Sources of Bioaerosols ...... 4

Effect of Ventilation on Radon Levels

 in a Municipal Office Building ......... 6

Indoor Air Bibliographic Database ....... 7

Using Animal Models to Understand

 Human Susceptibility to Indoor Air ..... 8

Reducing Indoor Air Emissions from

 Aerosol Consumer Products .......... 10

Summaries of Recent Publications ....... 12

Summaries of “Engineering Solutions

 to IAQ Problems” Symposium Papers . . 13

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

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 of e-mail your name and address to:

 Inside IAQ, Att. Kelly Leovic (MD-54)

 U.S. EPA/APPCD

 Research triangle Park, NC 27711

 Fax: 919-541-2157

 E-mail: kleovic@engineer.aeerl.epa.gov

EVALUATION OF AN IAQ SOURCE MANAGEMENT

STRATEGY FOR A LARGE BUILDING

EPA’s Air Pollution Prevention and Control Division (APPCD) developed

an approach to IAQ management in buildings that is based upon the

assumption that exposure to indoor air pollutants can be minimized given

sufficient knowledge and control of sources, sinks, and building ventilation.

This assumption implies that the source emissions and building ventilation

data are available in a form that can be used to predict exposure using

computer simulation models. Although the approach is simple in concept,

successful application may depend upon the quality and quantity of source

and ventilation data available as well as the efficacy of the models that

relate source emission and ventilation characteristics to exposure.

In a pioneering effort, the State of Washington implemented a proactive IAQ

program to ensure healthful work environments in four planned new office

buildings. Key components of the program were designed to minimize

occupant exposure to indoor air pollutants in the newly constructed buildings

by ensuring adequate ventilation, utilization of low emitting products in

construction and furnishing, staged loading to minimize cross contamination

of fleecy surfaces during construction and use of a 90-day 100% outdoor air

(OA) flush-out prior to occupancy.

In 1992, APPCD conducted a pilot investigation of the source management

and control program as implemented in design and construction of one of the

buildings: the Natural Resources Building (NRB). The NRB is a six-story

mixed use office building with over 320,000 square feet (97,536 m2) of

occupiable space. Our goals were to collect a broad spectrum of data in the

NRB that would enable us to develop a focussed study to evaluate the IAQ

and cost effectiveness of the product selection, building flush-out, and

ventilation strategies used in design and construction of the next building 

(Continued on Page 2)

Radon Mitigation Research Update

APPCD’s annual publication, the Radon Mitigation Research Update, will

no longer be published. Updates on EPA’s radon research will now be

included in Inside IAQ. If you were on the mailing list for the Radon

Mitigation Research Update and would like to receive Inside IAQ, please

send your name and address to the location listed at the left.
Inside IAQ, Fall/Winter 1995 Page 2

30 60 90 120 266 0

0.5

1

1.5

2

2.5

Sampling Period (days)

1st floor 4th floor 6th floor Outdoors

TVOC Concentration (mg/m3)

end

flush

preflush

0 30 60 90 120 266 0

0.2

0.4

0.6

0.8

1

Elapsed Time (days)

1st floor 4th floor 6th floor

Ratio

(Continued from Page 1)

to be constructed by the State under the IAQ program. Though we

were unable to conduct the follow-on study, we did collect a great

deal of information that is instructive for design and application of

this type of proactive IAQ program.

Product source emissions characterization data that were

generated to demonstrate compliance with the State’s

maximum acceptable concentrations per product were

collected from private laboratories that conducted emissions

tests and from other sources in custody of the data. The data

consisted of small- and large-chamber emissions test results,

material safety data sheets (MSDS), and/or compliance

certifications for 78 products that were proposed and/or used

in the NRB. Product categories included adhesives and

sealants, business machines, ceiling materials, floor coverings,

fireproofing, furniture, wall coverings, heating, ventilation, and

air-conditioning (HVAC) system components, paints and

coatings, and wall systems. Product loading data (number of

products or surface area per floor) were obtained for 15

products including work stations, ceiling materials, floor

coverings, seating, and tables.

Measurement of IAQ

Building air quality data were collected at sites within the

building and outdoors at completion of construction, during the

flush out, and after occupancy. The sites were selected to

investigate air quality differences between and within floors as

well as those within and outside the building. Over 200

different individual volatile organic compounds (VOCs) were

tentatively identified in the indoor air samples over the course

of the study. As is seen in Figure 1, total volatile organic

compounds (TVOCs) concentrations remained relatively

Figure 1. TVOC concentrations in the NRB

constant during the flush-out. Three compounds, tetradecane,

pentadecane, and hexadecane, dominated the indoor air VOC

concentrations at the sites where sampling stations were

located. The sum of the three compounds averaged 36 ± 4%,

77 ± 6%, and 61 ± 12% of TVOCs on the first, fourth, and

sixth floors, respectively, over the first 120 days of the study

(Figure 2). The ratio of the sum of these three compounds to

TVOCs dropped by a factor of 10 by day 266.

Figure 2. Ratio of the sum of the C14- C16n-alkanes

 to TVOCs.

The known dominant source of these compounds, a carpet tile,

was installed on the second, third, fourth, and fifth floors. At

day 120, the characteristic carpet tile emissions constituted

80% of the TVOCs on the fourth floor where TVOC

concentrations were greater than 1.5 mg/m3. Thus, a single

source may be responsible for TVOC emissions that exceed

the State’s target that no product contribute more than 0.5

mg/m3 to TVOC loading in the building 30 days after

installation. Between days 120 and 266, the ratio of the carpet

tile hydrocarbons to TVOC drops from 0.8 to below 0.05 at

the fourth floor site, indicating a significant decrease in source

strength. Small chamber emissions tests of carpet tile

submitted for compliance testing and a quality control sample

removed from the building suggest significant sample to

sample variability and demonstrate the predominance and slow

emissions decay pattern of the C14 - C16 hydrocarbons.

Attempts to predict indoor VOC concentrations from source

emissions and building ventilation data were unsuccessful.

Emissions data derived from compliance statements, MSDS

sheets, and single-point 24 hour emissions tests did not provide

sufficient data for modeling. Longer term testing (96 hour) of

carpet tile samples was indicative of the slow emissions decay

rates as well as variability among samples.
Inside IAQ, Fall/Winter 1995 Page 3

We were unable to determine the value of the 90-day flush-out

from the data collected in the pilot study. The limited data

available suggest that the OA flush rate was 12 to 45% lower

than the target 100% OA intake rate. Given the apparently

slow emissions decay rates for the product apparently

responsible for a significant portion of the elevated building

VOC concentrations, it appears that the primary value of the

flush-out period was to shorten the period of time that

occupants were exposed to the elevated VOC concentrations

related to the source of these emissions. From the source and

building VOC data, it cannot be determined whether the

elevated concentrations in the building are due to direct

emissions from the carpet tiles or some other product that has

not been tested but was installed in the building.

Conclusions

The State’s IAQ program was successful in raising the

awareness of product manufacturers to emissions from their

products. Results of the pilot study demonstrate that intraproduct sample variability and long term emissions data may

be required in order to manage indoor VOC levels by source

selection. A strategy to ensure that installed products are

representative of products tested for compliance also may be

necessary for implementation of this type of program. A

thorough evaluation of this approach to IAQ management

would require more accurate, longer term source characterization data, more frequent building pollutant characterization,

and building ventilation system data. Finally, information

characterizing adsorption and desorption of VOCs emitted

from sources is required to evaluate the impact of sinks on

VOC contaminant levels. (EPA Contact: Mark Mason, 919-

541-4835, mmason@engineer.aeerl.epa.gov)

EPA EXAMINES INDOOR EMISSIONS FROM

CONVERSION VARNISHES

Conversion varnishes are clear varnishes commonly used as

coatings on wooden cabinets and, less frequently, on furniture.

They do not cure by drying, as do many coatings, but rather by

a chemical reaction, creating a durable water- and chemicalresistant coating that protects the wood during its use.

Preliminary results from two studies indicate the potential of

these varnishes to emit formaldehyde and other VOCs into the

indoor environment.

The first study, being conducted by the Research Triangle

Institute under cooperative agreement with EPA, is examining

the emissions from engineered wood products into the indoor

environment and ways to prevent them. Several different

engineered wood products used to make kitchen cabinets were

tested. Preliminary results show significantly higher emissions

of both formaldehyde and volatile organics from the cabinet

components that were finished with conversion varnishes

(formaldehyde emission rates ranged from 2,000 to 5,800

μg/m2h, organics from 4,600 to 11,00 μg/m2h) than from

engineered wood components laminated with vinyl or

melamine (formaldehyde emission gates ranged from 50 to 90

μg/m2h, organics from 400 to 1,400 μg/m2h). The remainder of

this project will focus on evaluating alternatives to standard

conversion varnishes that have lower VOC emissions.

The second study, being conducted in-house at APPCD,

involves small chamber testing of conversion varnishes during

curing and aging. In a preliminary test conducted on one

commercially available varnish, the total mass of formaldehyde emitted was 1% of the mass of varnish applied. The

formaldehyde emission profile fit the second order decay

model:

E(t) = E0/(1 + ktE0)

where:

 E(t) = the emission factor as a function of time;

 E0 = 29.0 μg/m2h is the initial emission factor;

 k = 0.00361 m2/mg is the second-order decay rate

 constant; and

 t = time after the beginning of the test.

The total mass of VOCs emitted during the test period (250

hours) was 44% of the mass of varnish applied, calculated as

toluene. The predominant VOC compounds were xylene at

34% and isobutanol at 5% of the mass of varnish applied.

Additional tests will be conducted on other commercially used

varnishes and to determine the effect on emissions of multiple

coats and coating different substrates. (EPA Contact: Betsy

Howard, 919-541-7915, bhoward@engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 4

REVIEW OF CONCENTRATION STANDARDS &

GUIDELINES FOR FUNGI IN INDOOR AIR

Exposure to fungal aerosols clearly causes human disease.

However, methods for assessing exposure remain poorly

understood, and guidelines for interpreting data are often

contradictory. APPCD, together with the Harvard School of

Public Health, is reviewing and comparing existing guidelines

for indoor airborne fungi, discussing limitations of existing

guidelines, and identifying research needs that should

contribute to the development of realistic and useful guidelines.

Existing guidelines are exclusively based on baseline data

(rather than health effects data), and are absolute (listing

numbers), relative (comparing indoors to outdoors), or a

combination of the two. Regulations controlling fungal

aerosols have been published only by the Russian Federation.

The U.S. Occupational Safety and Health Administration

(OSHA) has proposed a standard that is under review. Other

guidelines have been proposed or sponsored by North

American and European government agencies. Finally, some

of the most often quoted guidelines have been proposed by

individuals based on either prospective sampling studies or

personal experience. Guidelines range from less than 100

colony forming units (CFU)/m3 to more than 1000 CFU/m3

(total fungi) as the upper limit for non-contaminated indoor

environments.

Some major problems with existing guidelines lie in the lack

of connection to human dose/response data, reliance on shortterm grab samples analyzed only for culture, and absence of

standardized protocols for data collection, analysis, and

interpretation. Research needs include the study of human

responses to specific fungal agents, development and

widespread use of standard protocols using available sampling

methodologies, and the development of long-term, time

discriminating personal samplers that are inexpensive, easy to

use, and amenable to straightforward, relevant analysis. (EPA

Contact: John Chang, 919-541-3747, jchang@engineer.aeerl.

epa.gov)

TWO CASE STUDIES EVALUATING HVAC

SYSTEMS AS SOURCES OF BIOAEROSOLS

An overall goal of the APPCD Ventilation Research Program

is to increase our understanding of how HVAC systems can act

as sources of indoor air pollution and to develop appropriate

design, operation, and maintenance practices to reduce human

exposure. For the past 2 years, EPA, in conjunction with the

American Society of Heating, Refrigerating and

Air-Conditioning Engineers, Inc. (ASHRAE), has been

identifying and quantifying emission sources from HVAC

systems.

In the last issue of Inside IAQ (EPA/600/N-95/004,

Spring/Summer 1995, pp. 9-10, 15), a report was discussed

(EPA-600/R-95-014; NTIS PB95-178596) that showed all

currently identifiable emission sources from HVAC systems

that have been reported and published. These included

intrinsic emission sources such as fibers and products from

metal degradation; emission sources resulting from

contamination including dust, cleaning compounds, biocides,

and microbial growth; and system design/operation such as

entrainment/reentrainment, transport, and improper building

pressurization.

Microbial contamination has been an important area of this

research. Studies show that fungi, bacteria, and other microorganisms from indoor and outdoor sources may accumulate

inside HVAC systems. With an appropriate substrate and

sufficient moisture, these microorganisms may survive and

multiply, and bioaerosols may be distributed throughout the

building by the HVAC system. Bioaerosols are airborne

microbial contaminants, including viruses, bacteria, fungi, algae,

and protozoa plus the reproductive units, metabolites, and

particulate material associated with these microorganisms.

Two case studies were performed to evaluate whether HVAC

systems contain microbial sources that affect bioaerosol

concentrations in occupied spaces and to compare sampling

approaches that might be used in IAQ investigations.

The first was a three-story office building constructed in 1988.

It is 29,200 ft2 (2717 m2) and has a typical variable-airvolume

(VAV) medium pressure HVAC system that is well

maintained. The second, also three-story, was constructed in

1966. It is 23,700 ft2 (2200 m 2) and is served by a low

pressure perimeter induction system and interior multizone

system that is not as well maintained.

Bioaerosol emissions in the HVAC systems were examined by

making both upstream and downstream measurements at major

components, including OA intakes, air handling units (AHUs),

duct liners, mixing plenums, fans, supply and return ducts,

filter banks, diffusers, heat exchangers, condensate drains, and

perimeter induction units.
Inside IAQ, Fall/Winter 1995 Page 5

For the first building, visual inspections showed that surfaces

of ducts and other HVAC components in contact with the air

stream were relatively clean with little dust accumulation.

There were no signs of water or microbial contamination.

Infiltration of OA occurred during HVAC system night

shutdown due to stack effect, exhaust fan operation, and

improper damper positions. These energy losses may increase

the chances of condensation that could act to deposit spores

and other bioaerosols in the ductwork.

For fungi, the concentration in bulk samples averaged 11

CFU/mg with the highest concentrations in the return air duct

linings and in the dust at filters. Concentrations at HVAC

components downstream of the filters were lower, indicating

that the filter was helpful. A total of 22 fungal taxa were

identified in the bulk samples. Cladosporiun, Penicillium,

Alternaria, and non-sporulating fungi were the most common.

Cladosporium was the dominant taxa found in HVAC system

particulate matter collected. Proportions of Aspergillus,

Penicillium, Alternaria, and non-sporulating fungi were fairly

constant throughout the HVAC system.

For bacteria, the concentrations averaged 24 CFU/mg with the

greatest concentrations (11,420 CFU/mg) found on the supply

fan housing. The next highest concentrations were found on

the central return air duct.

Airborne sampling for fungi averaged 48 CFU/m3 in the

HVAC systems, 43 CFU/m3 in the indoor air, and 17 CFU/m3

outdoors.Cladosporium was the dominant taxon in the HVAC

samples, and Penicillium and non-sporulating fungi in the

indoor air. These concentrations are generally low compared

to other studies. Airborne bacteria averaged 226 CFU/m3 in

the HVAC system, 252 CFU/m3 in the indoor air, and 87

CFU/m3 in the outdoor air. The highest concentrations (848

CFU/m3) were found in the central return at the return air fan.

This is consistent with findings at return air grilles throughout

the building. Bacteria concentrations are more uniform

throughout the building than fungi since the occupants are a

major contributor.

In the second building, HVAC system conditions did not

appear as clean as the first building. There was accumulation

of dust and debris in and around the mechanical room and on

the exterior surfaces of the HVAC systems. Ductwork had

some open drill holes where negative air pressure could draw

in air from the mechanical equipment room. There were oil

slicks on the concrete floor and condensate ran from the AHU

to a floor drain. Visual inspection of the interior system

components showed that dust accumulation was generally low;

however, a damp musty odor was evident when the AHU was

off. No moisture damage was visible.

Fungi concentrations in bulk samples averaged 5 CFU/mg.

This is much lower than comparative measurements in the first

building. The researchers suspect that concentrations were

lower due to the accumulation of inorganic debris.

Concentrations at all sites were low. Researchers identified 20

total fungal taxa with Cladosporium being dominant in HVAC

bulk samples.

Bacteria concentrations were highest in the OA duct and the

perimeter induction units. Low concentrations were found in

the supply air duct. Intermediate levels were found in the

return air duct.

Air samples showed very little contribution to bioaerosol levels

as fungi concentrations in the HVAC were generally low (58

CFU/m3). Office spaces had similar levels (44 CFU/m3).

However, when the fan section was manually disturbed, the

fungi levels were very high (greater than 8,075 CFU/m3) as

was the case with the bacteria concentrations (86,000

CFU/m3).

Conclusions

A number of comparisons can be made between the two

buildings. Typically the bulk samples yielded two to four

times as many fungi taxa as air samples, but the majority of

fungal taxa were identified using both types of sampling

techniques. However, proportions of species or taxa varied

considerably. These differences are significant and seem to

suggest that building sampling may be indicative of higher

numbers of actual taxa or species available as a source of

bioaerosols and air sampling.

Bulk sampling appears sufficient to identify microbial

reservoirs in HVAC systems, and air sampling of disturbed

reservoirs can confirm actual or potential releases. However,

due to spatial variability in settling, deposition, moisture, etc.,

multiple sites in HVAC ducts and AHUs should be sampled to

obtain representative concentrations in surface and bulk

measurements.

The quantification of bioaerosol emissions based on impaction

measurements taken upstream and downstream of HVAC

components may not be effective since short sampling periods

are not representative of the temporal variability commonly

found in emissions. Additionally, it is also difficult to capture

any existing HVAC spatial variability; component access is

typically difficult; and the need for low velocity (fan shut off)

alters the flow regime and thus the entraimment and

suspension of potential bioaerosols. Measurements taken at

terminal units, however, are easily obtained and may indicate

whether the HVAC system is discharging bioaerosols (EPA

Contact: Russell N. Kulp, 919-541-7980, rkulp@

engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 6

EFFECT OF VENTILATION ON RADON

LEVELS IN A MUNICIPAL OFFICE BUILDING

APPCD, together with the Florida Department of Community

Affairs and Southern Research Institute, is conducting research

to help assess the impact of building design, construction, and

operating features (e.g., mechanical systems) on radon and

other indoor air pollutants. The research will help APPCD

better understand the effects of various building features on

IAQ and will also provide information to support the Florida

Standard for Radon Resistant Construction in Large Footprint

Structures.

Building Description

An extensive characterization and parametric assessment study

was conducted in a typical Florida multistory commercial

building. Indoor radon levels were above the EPA guideline of

4 pCi/L and ranged from 4 to 15 pCi/L. The building has

149,000 ft2 (45,415 m 2) of floor space distributed over five

stories with an atrium that extends from the ground floor up to

a glass skylight. Each of the first fours opens out into a

balcony around the atrium. The atrium opening is enclosed

completely on the fifth floor. The building foundation is slabon-grade with supporting pilings under the slab and grade

beams in some locations. The slab thickness is 6 in. (15.2 cm)

with pilings that penetrate the sub-surface soil to an

undetermined depth. The building has 11 AHUs, with 2 each

on floors two through five and 3 on the first floor.

First, the HVAC system was inspected thoroughly, and a

certified test and balance contractor measured actual flow

distribution in the mechanical subsystems. Based on the

inspection of the HVAC system and continuous monitoring,

several deficiencies were noted which would be expected to

adversely affect radon levels, other IAQ factors, or energy

consumption. Specifically, OA air flow rates were far below

design values on the first and fourth floors; maximum supply

air flow rates are below design values on all but the fifth floor;

the building generally operates under negative pressure; and

there is an excessive pressure imbalance between zones,

especially on the first floor.

Measurement of IAQ Parameters

A series of measurements were made during several cycles of

building operation between May and August 1994. For

continuous measurements, IAQ data stations were used to

monitor radon, differential pressures, room temperatures,

relative humidities, and carbon dioxide (CO2) concentrations

in each of 13 zones. The 13 data stations were distributed 2

per floor on the top four floors, with 5 stations distributed in

several zones on the first floor. Ten additional continuous

radon monitors were located on the first floor.

As shown in Table 1, baseline radon concentrations in the

building averaged approximately 8.1 pCi/L on the first floor

and 3.1 pCi/L on the upper floors, with a building average of

4.1 pCi/L. The data in Table 1 also show that radon

concentrations were essentially unaffected by varying the OA

damper from minimum to maximum (columns two and three).

Measurements of the building air change rate over this period

ranged from 0.15 to 0.25 hr-1, indicating that varying the OA

damper settings also has little effect on the building ventilation

rate. This suggests that ventilation in this building is primarily

by direct leakage across openings in the building shell and is

driven by local pressure differentials between specific indoor

zones and the outdoors. The observed magnitude of HVACinduced pressure imbalance among the first floor zones is

enough to expect that a significant portion of the observed

infiltration/exfiltration is derived from this source. Based on

these measurements, researchers concluded that too little

induced OA was coming into the building to significantly

affect ventilation in comparison to the gains and losses of air

through the building shell induced by depressurization and

pressure imbalance.

In consultation with the building owners, a temporary system

that consisted of three in-line fans was installed in the first

floor AHUs. The purpose was to determine if forced

ventilation could increase the air exchange rate and decrease

radon entry on the first floor.

As shown in the final three columns of Table 1, first floor radon

concentrations were progressively reduced with addition of

increased amounts of forced OA for ventilation. With the greatest

supply of OA (1900 cfm), the first floor radon levels dropped to

4.8 pCi/L, approximately 60% of the baseline concentration.

Radon reductions on upper floors, where additional OA was not

supplied, were not as dramatic as the first floor. Other measures

of building ventilation rate effects, such as peak excess CO2, also

show a net dilution effect on both first and upper floors, indicative

of increased ventilation during the “fan on” periods. These

measurements are consistent with the fan operation adding

roughly 1200 cfm (14-22%) to the previous 5500-8500 cfm of

infiltration/exfiltration.

Conclusions from Case Study

This study demonstrates control of indoor radon levels by

introducing additional OA on the first floor only of a large,

relatively open, multistory building. The results indicate that the

greatest relative reductions in radon levels were on the first floor

where baseline radon levels were the highest. This study thus

demonstrates the potential for a targeted dilution strategy in which

OA is delivered to only one portion of a relatively open building

while interzonal floor-to-floor effects are contained or minimized.

(EPA Contact: Marc Y. Menetrez, 919-541-7081,

mmenetrez@engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 7

Table 1. Average radon levels under various operational modes (pCi L-1)

Location Baseline Max OA Min OA

2 OA Fans

(700 cfm)

3 OA Fans

(1000 cfm)

3 OA Fans

(1900 cfm)

1st Floor 8.1 7.4 7.9 6.6 5.6 4.8

Floors 2-5 3.1 3.2 3.4 3.4 3.1 2.8

Building 4.1 4.0 4.3 4.0 3.6 3.2

INDOOR AIR BIBLIOGRAPHIC DATA BASE

The National Center for Environmental Assessment (NCEA)

published a revised version of the Indoor Air - Bibliographic

Data Base in 1994. The bibliographic data base is an

extensive bibliography of reference materials on IAQ. The

data base is organized by key word, lead author, and citations.

A more current copy of the bibliographic data base

is available on computer diskette through EPA. The hard copy

version of the data base is available through the NRMRL’s

Technology Transfer and support Division (513-569-7562)

and the National Technical Information Service (NTIS) (703-

487-4650). (EPA Contact: Beverly Comfort, 919-541-4165,

comfort.beverly@epamail.epa.gov)

Organizational Changes

OFFICE OF RESEARCH AND DEVELOPMENT (ORD)

CURRENT ORGANIZATIONAL TITLES Formerly

National Risk Management Research Laboratory/ Air pollution Prevention and

Control Division/ Indoor Environment Management Branch (Mike Osborne,

919-541-4113)

Air and Energy Engineering Research

Laboratory/Radon Mitigation Branch

and Indoor Air Branch

National Exposure Research Laboratory/ Human Exposure Research Division

(Gerald Stelma, 513-569-7384)

Environmental Monitoring and

Sampling Laboratory

National Health and Environmental Effects Research Laboratory

(Sue McMaster, 919-541-3844)

Health Effects Research Laboratory

National Exposure Research Laboratory/ Human Exposure and Field Research

Division (Miriam Rodon-Naveira, 919-541-3075)

Atmospheric Research and Exposure

Assessment Laboratory

National Center for Environmental Assessment

(Beverly Comfort, 919-541-4165)

Environmental Criteria and

Assessment Office

National Risk Management Research Laboratory/ Technical Transfer and

Support Division (513-569-7562)

Center for Environmental Research

Information
Inside IAQ, Fall/Winter 1995 Page 8

USING ANIMAL MODELS TO UNDERSTAND

HUMAN SUSCEPTIBILITY TO INDOOR AIR

Often, the signs and symptoms of exposure to indoor air

contaminants appear in only a few of the many exposed

individuals, even though exposure levels appear to be similar.

This suggests that differences in individual susceptibility play

an important role in determining responses to exposure.

Historically, the development of animal models has greatly

facilitated the study of a variety of biological and toxicological

problems. Many of the common signs and symptoms of indoor

air exposure apparently involve direct effects on the nervous

system or are mediated directly or indirectly by the nervous

system. These considerations prompted EPA’s National Health

and Environmental Effects Research Laboratory (NHEERL)

to hold a workshop on animal models of nervous system

susceptibility to indoor air contaminants. The workshop was

held in October 1994 in Chapel Hill, North Carolina, and

included a number of national and international scientific

experts.

The purpose of the workshop was to provide scientific input

into EPA’s research planning process with regard to the

development of animal models to determine susceptibility to

indoor air pollutants. The workshop included: 1) human

clinical and epidemiological evidence regarding exposures and

outcomes; 2) possible experimental designs and modeling; 3)

determining differences in susceptibility; and 4) proposed

experiments and modeling for testing hypotheses.

Clinical and Epidemiological Evidence

The human clinical conditions discussed were multiple

chemical sensitivity (MCS), sick building syndrome (SBS),

and building-related illness (BRI). BRI is the best defined and

involves building contaminants of known identity which

produce definitive health outcomes. One example of BRI is

legionnaires’ disease. SBS, less well defined, involves experienced illness which is alleviated upon leaving the building.

Often the causes of SBS are unknown. The health problems

reported in SBS vary, but often include a number of

subjectively experienced symptoms. MCS is least well

specified. In MCS, a diffuse array of symptoms are reportedly

triggered by exposure to a variety of different chemicals, and

are not necessarily restricted to any particular location or class

of compounds. As with SBS, the health outcomes in MCS are

based on reports of subjective discomfort or illness for which

there are few or no corresponding clinical signs of illness or

dysfunction. There is no consensus in the medical community

about the existence of MCS, and the lack of objective evidence

of impairment represents a major impediment in the

development of animal models of such conditions in a

traditional sense.

One conclusion from the workshop was that better characterizations of the human conditions are needed. However, many

workshop participants stated that the enigmatic nature of the

human clinical conditions did not preclude the development of

animal models, because valid test methods and corresponding

animal models currently exist for many relevant outcomes.

These methods and models could be used to test a variety of

hypotheses. regarding susceptibility to indoor air contaminants.

Possible Experimental Designs and Models

Traditional experimental approaches tend to emphasize

measures of central tendency, and minimize the influence of

individual subjects deviating far from population norms. One

approach proposed to identify susceptible individuals was to

examine those subjects already at the extremes of the normal

distribution of test scores, and to determine whether they might

be most susceptible to exposure.

Another experimental approach addressed the goal of

identifying genetic contributions to susceptibility. This

approach involved the study of genetically defined inbred

strains of laboratory animals, which could be ranked for

sensitivity to exposure. This would provide a repeatable supply

of individuals with a predetermined susceptibility, thus

facilitating the identification of genetic factors that influence

susceptibility.

Quantitatively, it was suggested that variability in response

outcome be considered as the focus of, rather than a detractor

from, the research effort. Sources of individual variability

include differences in uptake of chemicals, pharmacokinetic

distribution to target sites, and response to the agents.

Variability can be both a within-subject, as well as a betweensubjects, consideration because the susceptibility of an

individual may vary substantially over time. It is important to

establish dose-response relationships for definitive outcomes

in order to establish legitimate cause-and-effect relationships.

Determining Differences in Susceptibility

Several hypotheses were discussed concerning how

susceptibility to exposure may be acquired or altered in

otherwise normal individuals. One potential mechanism

involves classical conditioning, in which the temporal pairing

of a previously neutral stimulus (conditioned stimulus) with a

biologically active stimulus (unconditioned stimulus) results in

a learned association. The previously neutral stimulus alone

then elicits the biological response. Once the association is

established, a biological response could be triggered by

exposure to levels of stimuli which previously had no effect.

The responses to classically conditioned stimuli, however,

typically diminish rather quickly without continued pairingsof

the conditioned and unconditioned stimuli, which is not
Inside IAQ, Fall/Winter 1995 Page 9

obviously present in MCS. Another type of learning, operant

conditioning, involves the elicitation of responses which are

followed by either positive or negative consequences.

Responses that are “reinforced” in this fashion may be much

longer lived. A number of experiments have shown that

susceptibility to chemical treatment can be altered

substantially by operant conditioning.

Stress may also influence the susceptibility to a chemical

treatment through the consequences of activation of a complex

neuroendocrine system. Personal and social factors may alter

the response to stress, and the resultant health consequences

can involve multiple bodily sites and disorders.

Neural plasticity, defined as modifications in the functional

properties of a neurological system as a result of experience,

may also serve as a source of increased sensitivity to chemical

exposure.

Finally, a phenomenon know as time-dependent sensitization,

which involves progressive and enduring enhancement of

behavioral and biochemical responsiveness to chemical

treatment, could also underlie augmented susceptibility.

Testing of Hypotheses

Many symptoms reported following exposure to indoor air

contaminants involve sensory complaints (odor or irritation),

cognitive or behavioral changes including frank avoidance of

odors or environments, and inflammation. Specific

experimental models of these topics were discussed. The

function of the trigeminal and olfactory systems could be

investigated both electrophysiologically and behaviorally. The

 measurement of respiratory depression following exposure can

be used to test hypotheses regarding the irritancy of inhaled

substances.

The perception of odor varies greatly among individuals, and

can be influenced by psychological factors such as expectancy

and learning. The concentrations which animals will terminate

exposure vary both between and within animals as a function

of exposure history. Neuro-immune interactions are also

important to consider, and might be profitably studied using

immuno-deficient mice or other well-characterized models.

It was demonstrated that several hypotheses of the

development of susceptibility could be profitably examined

experimentally using existing animal models. One important

point was that animal models need not replicate every aspect

of the human condition, but are of value if they focus on a

single facet for study. The importance of selecting speciesappropriate endpoints in animal models was emphasized.

Animal models that specifically address issues related to IAQ

include the sensory aspect of odor and irritation perception,

behavioral avoidance of contaminated atmospheres, and

neurogenic inflammation. A research program based on animal

models would augment and complement continued efforts to

better characterize the human conditions. These research

efforts would likely improve the ability to assess the risks of

exposure of susceptible individuals to indoor air environments,

as well as in other exposure situations of concern to EPA.

Source: EPA Report, MS-95-264-USEPA, 1995. (EPA

Contact, Ken Hudnell, 919-541-7866 ,

hudnell@am.herl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 10

REDUCING INDOOR AIR EMISSIONS FROM

AEROSOL CONSUMER PRODUCTS

Because aerosol consumer products, such as those used for

personal care, pest control, and cleaning, are commonly used

in the indoor environment, APPCD is supporting research to 1)

better understand personal exposures to aerosol consumer

products, and 2) to develop pollution prevention techniques to

reduce exposures. A group of Industry Partners is actively

involved in the research to ensure that the results will be

practical for industry.

Developing Measurement Methods and Models

Georgia Tech and the University of Illinois are working

together to develop measurement methods and models for

manufacturers to use to develop a better understanding of

aerosol behavior. This improved understanding can then be

used by manufacturers to develop and produce more

efficacious and less toxic aerosol consumer products.

Georgia Tech is developing a Mass Spectrometer (MS)/MS

system for the chemical characterization of representative

aerosol products. They are also measuring particle sizes for

various spray patterns using a Malvern Analyzer and are

developing an electron mobility analyzer for future work on

particle sizing in conjunction with the MS system. The MS/MS

system eliminates the need for collection and concentration

techniques and chromatographic separations, and is

particularly sensitive to polar compounds. As a result, the

system is well suited for real-time, direct analysis of aerosol

consumer products. The University of Illinois is developing

techniques and instrumentation capabilities to measure aerosol

transport and distribution in rooms. A model is also being

developed to predict aerosol behavior in rooms. Researchers at

the University of Illinois are currently analyzing the spray

patters of representative aerosol products using particle image

velocimetry (PIV) techniques. Figure 3 illustrates PIV data

showing aerosol particle concentrations at various distances

from the spray nozzle.

The ultimate outputs from this project include: 1) indoor air

characterization data on emissions from representative aerosol

consumer products as a function of time; 2) methods,

technology, and models to measure and predict emissions and

personal exposures from use of aerosol products indoors; and

3) pollution prevention techniques and guidelines for the

manufacture and use of these products.

Innovative Spray Nozzle Design

In another project, Purdue University has developed and

demonstrated an innovative spray nozzle design for use with

precharged aerosol containers. This design is similar to one

previously developed and demonstrated at Purdue for pumpand trigger-dispensed aerosol products.

The new dispenser design (Figure 4) allows manufacturers to

reformulate selected aerosol consumer products (e.g., personal

care, hair care, degreasers, and hard surface cleaners) using

water and air in place of VOC solvents and hydrocarbon

propellants in precharged systems, while still maintaining

acceptable product delivery characteristics.

Laser diffraction measurements made at Purdue indicate that

the new dispenser design produces product droplets in the

desired size range. Data demonstrate that Sauter Mean

Diameters (SMDs) are within experimental error of 70 Fm for

air to liquid ratios (ALRs) as low as 70%. Reducing the ALR

below 0.75% results in a rapid increase in the mean drop size.

The data also indicate little sensitivity of mean drop size to

viscosity over the range considered in this study (0.020 to

0.080 kg/m-s, or 20 to 80 cP).

Data also show that air consumption is below target values and

supply pressures are acceptable. Dispenser performance is

relatively insensitive to product formulation, as described by

its viscosity and surface tension. This simplifies manufacturing

since a single dispenser design can then be used with a wide

array of products.

Current research at Purdue is addressing three questions

necessary to provide rational design guidelines to industry.

First, when the product exits the dispenser, how does it break

up into ligaments and drops? Second, to what extent does the

spray entrain surrounding air? Third, what challenges must be

met during intermittent nozzle operation? Pulsed holography

and PIV are being used to acquire the necessary data to answer

these questions. (EPA Contact: Kelly Leovic, 919-541-7717.)
Inside IAQ, Fall/Winter 1995 Page 11

Porous Insert

Air

Injection

Holes

Brass

Aerator

Tube

Liquid Liquid

Acrylic

Exit

Orifice

Acrylic

Containment

Tube

Brass Top

Plate

Air

Figure 3. Time averaged concentration contour plots of

aerosol particles (1 in. = 2.54 cm).

Figure 4. Prototype of new dispenser developed by

Purdue University

THE INDOOR AIR QUALITY

INFORMATION CLEARING HOUSE

(IAQ INFO)

IAQ INFO is an easily accessible, central source of

information on indoor air quality. It is supported by EPA’s

Office of Air and Radiation’s Indoor Environment Division.

IAQ INFOcan provide information on many aspects of indoor

air quality:

ó Indoor air pollutants and their sources

ó Health effects of indoor air pollution

ó Testing and measuring indoor air pollutants

ó Constructing and maintaining homes and buildings to

minimize IAQ problems

ó Existing standards and guidelines related to IAQ

ó General information on Federal and State Legislation

IAQ INFO contains:

ó Citations and abstracts on more than 2,000 books, reports,

newsletters, and journal articles

ó An inventory of publications prepared by the Federal

government, including fact sheets, pamphlets, directories,

training materials, and reports

ó Information on more than 150 government research,

public interest, and privte sector organizations in the IAQ

field

You may call a toll-free number to speak to an information

specialist, Monday through Friday, 9:00 a.m. to 5:00 p.m.

EST. After hours, you may leave a voice message, or you may

inquire by fax or mail anytime.

IAQ INFO

P.O. Box 37133

Washington, DC 20013-7133

1-800-438-4318

202-484-1307

Fax: 202-484-1510
Inside IAQ, Fall/Winter 1995 Page 12

SUMMARIES OF RECENT PUBLICATIONS

This section provides summaries of recent

publications on EPA’s indoor air

research. The source of the publication is

listed after 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. EPA papers

presented at the Engineering Solutions to

Indoor Air Quality Problems symposium

held in July 1995 are summarized

beginning on page 13.

Laboratory Assessment of the Permeability

and Diffusion Characteristics of Florida

Concretes: Phase II. Field Samples and

Analyses-The report summarizes a study

that establishes the capability to measure

concrete’s permeability and diffusivity and

to correlate the physical parameters of the

concrete to the measured diffusion and

permeability coefficients. For both

permeability and diffusivity, the amount of

water added to the mix at the site was

directly and positively related and identified

as a possible major factor. The total amount

of sand and stone in the mix was possibly

correlated to the permeability. A third

possible correlation involved the amount of

fly ash or the cement to fly ash ratio.

Source: EPA Report, EPA/600/R-95/103

(NTIS PB95-243168), July 1995. (Lead

Author: R. Snoddy; EPA Contact: David

C. Sanchez, 919-541-2979, dsanchez@

engineer.aeerl.epa.gov)

Statewide Mapping of Florida Soil Radon

Potentials, Vol. 1, Technical Report, Vol. 2,

Appendices A-P-The report gives results of

statewide mapping of Florida soil radon

potentials. The maps provide scientific

estimates of regional radon potentials that

can serve as a basis for implementing

radon-protective residential building

standards. Source: EPA Report, EPA-600-

R-95-142a & 142b (NTIS PB96-104351 &

-104369), September 1995. Lead Author:

Kirk K. Nielson; EPA Contact: David C.

Sanchez, 919-541-2979, dsanchez@

engineer.aeerl.epa.gov)

Ozone Generators in Indoor Air

Settings-This report addresses typical

questions posed by both consumers and

professionals about the effects of ozone as

an IAQ ameliorative. Source: EPA Report,

EPA-600/R-95-154. (NTIS PB 96-

100201), October 1995, (Lead Author and

EPA Contact: Ray Steiber, 919-541-2288,

rsteiber@engineer.aeerl.epa.gov)

Lumped-parameter Model Analyses of

Data from the 1992 New House Evaluation Project–Florida Radon Research

Program-The report documents analyses of

Phase 2 data from the Florida Radon

Research Program’s (FRRP’s) New House

Evaluation Project that were performed

using a lumped-parameter model. The

analyses focused primarily on empirically

characterizing the radon resistance of the

house/soil interface for different foundation

designs. The analyses were also aimed at

comparing the effectiveness of active and

passive radon protection features. Source:

EPA Report, EPA/600/ R-95/090 (NTIS

PB95- 243077), July 1995. (Lead Author:

Kirk K. Nielson; EPA Contact: David C.

Sanchez, 919-541-2979 ,

dsanchez@engineer.aeerl.epa.gov)

Design and Testing of Sub-slab Depressurization for Radon Mitigation in North

Florida Houses, Part I-Performance and

Durability; Vol. 1, Technical Report; Vol.

2, Data Appendices-The objectives of this

study were to develop and test the use of a

soil depressurization computer model as a

design tool, to optimize the sub-slab soil

depressurization design for North Florida

houses, and to observe system performance

and durability. Radon concentrations,

originally on the order of 10-30 pCi l-1 were

reduced to below 4 pCi L -1 in all nine

houses studied. The systems retained

effectiveness during the 3-18 month

durability observations. Source: EPA

Report, EPA-600/R-95-149a & 149b(NTIS

PB96-103585 & -103593), September

1995. (Lead Author: C. E. Roessler; EPA

Contact: David C. Sanchez, 919-541-2979,

dsanchez@ engineer.aeerl.epa.gov)

Relative Sensitivity of the Ocular

Trigeminal, Nasal Trigeminal and

Olfactory Systems to Airborne Chemicals-Thresholds for eye irritation and odor

resulting from exposure to ketones and

alkylbenzenes are discussed. Eye irritation

thresholds are well above odor thresholds,

and both sensory thresholds declined with

carbon chain length. Also, eye irritation

thresholds were remarkably close to nasal

pungency thresholds obtained previously in

persons lacking olfaction (i.e., anosmics)

Source: Chemical Senses, Vol. 20, No. 2,

pp. 191-198, 1995. (Lead Author: J.

Enrique Cometto-Muñiz; EPA Contact:

Ken Hudnell, 919-541-7866, hudnell@

am.herl.epa.gov)

Evaluation of Building Design,

Construction, and Performance for the

Control of Radon in Florida Houses:

Evaluation of Radon Resistant Construction Techniques in Eight Houses-The eight

houses in this study were built following

Florida’s radon resistant construction

standard. The study shows that operation of

well designed and constructed HVAC

systems does not significantly affect indoor

radon, regardless of the pressures induced

between interior air zones. Source: EPA

Report, EPA-600/R-95-114 (NTIS PB95-

253910), July 1995. (Lead Author: D. E.

Hintenlang, Univ. of Florida; EPA Contact:

David C. Sanchez, 919-541-2979,

dsanchez@engineer.aeerl.epa.gov)

Soil and Fill Laboratory Support–1992,

Radiological Analyses, Florida Radon

Research Program-Analyses performed

on soil and fill samples included moisture,

radium-226, and radon emanation

coefficient determinations for 164

samples representing 21 sites. Central

Florida (Polk County) sites were characterized by elevated radioactivity fill over

a wide rand of substrate concentrations.

Source: EPA Report, EPA-600-R-95-

145, September 1995. (Lead Author: C.E.

Roessler; EPA Contact: David C.

Sanchez, 919-541-2979, dsanchez@

engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 13

ENGINEERING SOLUTIONS TO INDOOR AIR QUALITY PROBLEMS SYMPOSIUM

An international symposium, Engineering Solutions to Indoor Air Quality Problems, was held July 24-26, 1995, in Research

Triangle Park, North Carolina. The symposium was cosponsored by APPCD and the Air & Waste Management Association

(A&WMA). Topics included: source characterization, source management and pollution prevention, ventilation and modeling, air

cleaning, and biocontaminant control. There were over 200 attendees from around the world, including researchers from the

government, private sector, industry, and academia. Summaries of APPCD-sponsored papers presented at the Symposium are below.

Proceedings from the symposium will be published by the A&WMA and EPA in late 1995. To obtain a copy of the proceedings,

contact the A&WMA at 412-232-3444 or NTIS at 703-487-4650. The next symposium will be held in 1997 in Research Triangle

Park. An announcement and call for papers will be sent to everyone on the Inside IAQ mailing list.

Aerosol Filtration Efficiency of In-Duct

Air Cleaners-A test method has been

developed for measuring the fractional

aerosol filtration efficiency of air

cleaners. The method provides a reliable

and accurate means of measuring air

cleaner fractional efficiencies over the

particle diameter size range of 0.01 to 10

Fm. The fractional efficiency of several

common air cleaners was evaluated:

fiberglass furnace filters, paper-media

filters, and several types of electronic air

cleaners. Results show that filtration

efficiency is highly particle size

dependent over the 0.01-10 Fm size

range. Filtration efficiency was also seen

to be dependent upon flow rate and the

dust load condition of the air cleaner.

(Lead Author: James T. Hanley; EPA

Contact: Leslie E. Sparks, 919-541-2458,

lsparks@engineer.aeerl.epa.gov)

Air Exchange Measurements in an IAQ

Test House-Air exchange rates in an

IAQ test house have been determined by

using tracer gas techniques. It was found

that, with all windows and outside doors

closed, the variation of air exchange rate

covered a six-fold range: from as low as

0.18 per hour to as high as 1.1 per hour.

The major factors that affect air exchange

include: weather conditions, operation of

the heating and air conditioning system,

closing or opening interior doors, and

changes in house structure. (Lead Author:

Zhishi Guo; EPA Contact: Leslie Sparks,

919-541-2458 ,

lsparks@engineer.aeerl.epa.gov)

Characterization of Aerosol Consumer

Products-This paper discusses the development of a mass spectrometer (MS)

interface that will allow for the real-time

characterization of both the particulate

and gaseous phases of an aerosol

consumer product. An electron mobility

analyzer is being designed to define to

particle size of the aerosol droplets. This

is being interfaced with an atmospheric

triple quadrupole MS for the gaseous

characterization. Preliminary data on

particle size of the aerosol products and

on gaseous characterization are included.

See article on page 10. (Lead Author:

Charlene W. Bayer; EPA Contact: Kelly

Leovic, 919-541-7717, kleovic@

engineer.aeerl.epa.gov)

Characterization of the Usefulness of

the Field and Laboratory Emission Cell

(FLEC) for the Evaluation of

Emissions from Engineered Wood

Products-A series of tests was designed

to evaluate the performance of the FLEC

as applied to the testing of emissions from

engineered wood products. The objective

was to determine appropriate parameters

for testing the emissions of formaldehyde

and other possible aldehydes, ketones,

and VOCs. Commercially available

household products (e.g., kitchen

cabinets) constructed from different types

of engineered wood with various

laminates and coatings were tested. (Lead

Author: Nancy F. Roach; EPA Contact:

Elizabeth M. Howard, 919-541-7915,

bhoward@engineer,aeerl.epa.gov)

A Comparison of Design Specifications

for Three Large Environmental

Chambers-Large (room-sized) environmental test chambers are currently being

constructed by three government organizations (U.S. EPA, National Research

Council Canada, and Australia’s Institute of

Minerals, Energy, and Construction) to

characterize sources of indoor air pollution.

The chambers, while intended for similar

purposes, have been designed and

constructed to different specifications. A

study will compare the design and

performance of these chambers in order to

develop a better understanding of how they

can be best used for IAQ measurements.

(Lead Author & EPA Contact: Betsy M.

Howard, 919-541-7915 ,

bhoward@engineer.aeerl.epa.gov)

Developing Guidance for Considering

Cost-Effectiveness when Selecting and

Designing IAQ Control ApproachesAPPCD is undertaking a program to

develop a practical methodology that will

facilitate cost-effectiveness considerations

in selecting among alternative IAQ control

options. This paper describes an initial

effort where the methodology will be tested

by using it to conduct a sensitivity analysis

for a 4-story office building. The costeffectiveness of ventilation, air cleaning,

and source management will be compared

as key variables associated with the

building, the HVAC system, and the IAQ

control system are systematically varied.

Lead Author & EPA Contact: D.B.

Henschel, 919-541-4112, bhenschel@

engineer.aeerl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 14

The Effect of Relative Humidity on

Gaseous Air Cleaner Media Performance: Toluene Adsorption by Activated

Carbon-Performance characteristics of

activated carbon as a gas-phase air

cleaner media were examined. Toluene

breakthrough curves at relative humidities

(RHs) from below 5 to 80% were

obtained. RH appears to have negligible

influence on the adsorption of toluene

below 50%. By 75% RH, the adsorption

of the toluene is decreased. The linearity

of the log-log relationship between the

concentration and the 10% breakthrough

time for lower concentration challenges

indicates that high concentration

breakthrough data can be used to predict

breakthrough time for lower

concentration challenges. (Lead Author:

M. K. Owen; EPA Contact: Leslie

Sparks, 919-541-2458, lsparks@

engineer.aeerl.epa.gov)

Effects of Altered Ventilation on Radon

and IAQ Variables in a Five-Story

Municipal Office Building-This paper

summarizes a study of a multistory office

building where radon and other air

quality parameters were monitored as the

HVAC systems were modified. See

article on page 6. (Lead Author: Ashley

D. Williamson; EPA Contact: Marc Y.

Memetrez, 919-541-7981, mmenetrez@

engineer. aeerl. epa. gov)

Effervescent Atomization at Low Air/

Liquid Ratios-A new type of consumer

product aerosol dispenser that uses water

instead of VOC solvents and air in place

of hydocarbon propellants is described.

The primary feature of this dispenser is

the elimination of VOC carrier liquids

and hydrocarbon propellants from a

variety of consumer products. The aerosol

dispenser is insensitive to product fluid

physical properties (surface tension and

viscosity) which in turn allows a single

design to be employed for a wide variety

of products. See article on page 10. (Lead

Author: J. Sutherland; EPA Contact:

Kelly Leovic, 919-541-7717,

kleovic@engineer.aeerl. epa.gov)

Energy Impacts of Compliance with

ASHRAE Standard 62-1989 in a Hot &

Humid Climate-The main objectives of

this study were to ascertain the energy

impacts associated with increasing OA

for compliance with ASHRAE Standard

62-1989 and to investigate the relative

energy efficiencies of the building

systems and operations and maintenance

procedures. Manual computations and

computer simulations were made to

calculate energy consumption. (Lead

Author: Pete Rojeski; EPA Contact: Russ

N. Kulp, 919-541-7980, rkulp@

engineer.aeerl.epa.gov)

Evaluation of an Indoor Air Quality

Source Management Strategy for Large

Building Construction-In conjunction

with the State of Washington, a pilot

study was conducted to evaluate the air

quality, building performance, and

loading data that influence the ability to

predict IAQ from product emissions

testing and building operation data. See

article on page 1. (Lead Author & EPA

Contact: Mark Mason, 919-541-4853,

mmason@ engineer.aeerl.epa.gov)

Increases in Levels of Breathable Fine

Particles Due to the Application of

Carpet Fresheners in a Suburban

Home-The paper details the results of a

study in which two carpet fresheners were

applied to the carpet of a suburban home.

The data show that there is a measurable

increase in breathable fines after each

application, but that the increase is

transitory, lasting no more than 8 to 24

hours. (Lead Author & EPA Contact:

Raymond W. Steiber, 919-541-2288,

rsteiber@engineer. aeerl.epa.gov)

Measurement of Indoor Air Emissions

from Office Equipment-EPA, Research

Triangle Institute, and a group of office

equipment manufacturers have developed a

test method for measuring indoor air

emissions from office equipment. The

method is intended to characterize emissions from office equipment and to support

identification of potential pollution

prevention strategies. The paper describes

the test method including: chamber

construction, clean air supply, operational

and control systems, sample collection and

analysis equipment, standards generation

and calibration systems, and performance

characteristics. Preliminary test results from

two dry-process photocopy machines are

also included. (Lead Author & EPA

Contact: Kelly W. Leovic, 919-541-7717,

kleovic@ engineer.aeerl.epa.gov)

Microbiological Screening of the Indoor

Air Quality in a Large Building-A

microbiological screening study of a noncompliant five-story office building in

Florida was conducted to generate baseline

measurements that could be used to study

the impact of ventilation systems design and

operation on microbiological

contamination. This paper presents the

results from that microbiological screening

study. See article on page 4. (Lead Author:

D. W. Van Osdell; EPA Contact: Russ N.

Kulp, 919-541-7980, rkulp@engineer.

aeerl.epa.gov)

A Novel, Full-Scale, Whole-Field,

Optical Diagnostic Technique for

Improvement of Indoor Air Quality-A

novel, full-scale, whole-field, optical

diagnostic technique and instrumentation

have been developed to study aerosol

transport in the indoor environment. The

purpose is to better understand aerosol

consumer products and to develop pollution

prevention strategies to reduce exposure.

Both instantaneous structures and statistical

properties of air flow have been calculated

to determine quantitatively the

characteristics of indoor air flow. See

article on page 10. (Lead Author: Michael

M. Cui; EPA Contact: Kelly W. Leovic,

191-541-7717, kleovic@engieering.

aeerl.epa.gov)
Inside IAQ, Fall/Winter 1995 Page 15

Ongoing Evaluation of Sources and

Factors affecting Emissions from

Engineered Wood Products-This project

is characterizing indoor air emissions

from engineered wood products and

identifying and evaluating pollution

prevention approaches for reducing

indoor air emissions from these products.

The research is being conducted in five

phases: (1) evaluate existing data and

testing methodologies; (2) convene a

research planning meeting; (3) select

high-priority emissions sources; (4)

evaluate high-priority emission sources;

and (5) develop and demonstrate pollution

prevention approaches for reducing

indoor air emissions from selected highpriority sources. This paper presents the

results of Phases 1 through 3. (Lead

Author: Sonji L. Turner; EPA Contact:

Betsy Howard, 919-541-7915,

bhoward@engineer.aeerl.

epa.gov)

VOC Removal at Low Contaminant

Concentrations Using Granular

Activated Carbon-Beds of granular

activated carbon are the most commonly

used air cleaning technology for VOCs.

However, design and operating data at the

low concentrations encountered indoors

are scarce, and extrapolation to those

concentrations has not been

demonstrated. Small-scale carbon beds

have been challenged with single

contaminants at concentrations ranging

from 4 0 4000 mg/m3. Results suggest

that higher concentration, single

component breakthrough tests, which are

short and easily obtained, may be

extrapolated to low concentrations. (Lead

Author: D. W. VanOsdell; EPA Contact:

Leslie E. Sparks, 919-541-2458,

lsparks@engineer. aeerl.epa.gov)

A Study of the Structures of Spray

Cones Utilizing Digital Particle Image

Velocimetry-This paper discusses the

dynamic physical properties of a spray

cone using PIV techniques. The dynamic

structures of aerosol size, concentration,

and velocity are included. The results can

be used to improve the efficiency of

aerosol products, to understand the

characteristics of the transport

mechanism, and to develop pollution

prevention strategies. See article on page

10. (Lead Author: Michael M. Cui; EPA

Contact: Kelly W. Leovic, 919-541-

7717, kleovic@engineerl.aeerl. epa.gov)

Susceptibility of Fiberglass Duct Lining

to Fungal (Penicillium Chrysogenum)

Growth-A series of experiments, each

lasting 6 weeks, was conducted in static

environmental chambers to evaluate the

conditions that support the growth of a

fungus, penicillium chrysogenum, on

fiberglass duct lining. Two different

fiberglass duct liners and one fiberboard

duct, all newly purchased, were evaluated

following inoculation with P.

chrysogenum. The studies demonstrated

that the xerophilic mold, P. chrysogenum,

amplified under conditions of high RH

even on newly purchased duct lining, and

that either wetting or dirtying increased

material susceptibility. To prevent the

growth of P. chrysogenum, dust

accumulation and/or RH needs to be

properly controlled in the HVAC duct.

(Lead Author: K. K. Foard; EPA Contact:

John C. W. Chang, 919-541-3747,

jchang@engineer.aeerl.epa.gov)

Sampling and Analysis of VOCs for

Indoor Air Source CharacterizationThis paper discusses a number of issues

related to sampling and analysis of VOCs

that need to be addressed in the design

and performance of source characterization testing for small chambers, large

chambers, test houses, and in the field.

(Lead Author: Roy Fortmann; EPA

Contact: Mark Mason, 919-541-4835,

mmason@engineer. aeerl.epa.gov)

Short and Long Term VOC Emissions

from Latex Paint-Latex paint (interior,

water-based) is being evaluated in order

to develop methods for predicting

emissions of VOCs over time. Painted

gypsum board is placed in dynamic flowthrough test chambers. Results show that

most of the Texanol® emissions occur

within the first few days, and emissions of

ethylene glycol occur over several

months. This behavior indicates that

evaporative mass transfer processes

dominate the short term emissions, while

long term emissions are limited by

diffusion processes within the gypsum

board. (Lead Author: Kenneth Krebs;

EPA Contact: Bruce A. Tichenor, 919-

541-2991, btichenor@engineer.aeerl.epa.

gov)

Review of Concentration Standards,

Guidelines, and Proposals for Indoor

Fungi-This paper provides a complete

review of current standards, guidelines,

and proposals for levels of indoor fungi.

See article on page 4. (Lead Author:

Carol Y. Rao; EPA Contact: John C. W.

Chang, 919-541-3747, jchang@

engineer. aeerl. epa.gov)
Inside IAQ, Fall/Winter 1995 Page 16

Glossary of Acronyms

AHU-Air Handling Unit

ALR-Air to Liquid Ratio

APPCD-Air Pollution Prevention and Control Division

ASHRAE-American Society of Heating, Refrigerating

and Air-Conditioning Engineers, Inc.

A&WMA-Air and Waste Management Association

BRI-Building-related Illness

CFU-Colony Forming Units

EPA-U.S. Environmental Protection Agency

FLEC-Field and Laboratory Emissions Cell

FRRP-Florida Radon Research Program

HVAC-Heating, Ventilating, and Air-Conditioning

IAQ-Indoor Air Quality

MCS-Multiple Chemical Sensitivity

MS-Mass Spectrometer

MSDS-Material Safety Data Sheets

NHEERL-National Health and Environmental Effects

Research Laboratory

NRB-Natural Resources Building

NRMRL-National Risk Management Research Laboratory

NTIS-National Technical Information Service

OA-Outdoor Air

ORD-Office of Research and Development

OSHA-Occupational Safety and Health Administration

PIV-Particle Image Velocimetry

RH-Relative Humidity

SBS-Sick Building Syndrome

SMD-Saunter Mean Diameter

TVOC-Total Volatile Organic Compound

VAV-Variable Air Volume

VOC-Volatile Organic Compound

United States

Environmental Protection Agency

Air Pollution Prevention and Control Division

MD-54

Research Triangle Park, NC 27711

Official Business

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