oEPA
United States
Environmental Protection
Agency
United States
Public Health
Service
National
Environmental
Health Association
July 1991
Office of Air and Radiation (6607J)
Introduction to
Indoor Air Quality
A Reference Manual
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EPA/400/3-91/003
Introduction to
Indoor Air Quality
A Reference Manual
United States United States National
Environmental Protection Public Health Environmental
Agency Service Health Association
July 1i91
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Reference Manual
Table of Contents
TABLE OF CONTENTS
INDOOR AIR QUALITY REFERENCE
MANUAL
ACKNOWLEDGEMENTS ix
SECTION 1. OVERVIEW OF THE
REFERENCE MANUAL
SECTION 2. FACTORS AFFECTING INDOOR
AIR QUALITY 3
Section 2.1. Indoor Air Quality Modeling 4
Section 4.4 Biological Contaminants
102
Section 2.2. Sources of Indoor Air
Contaminants
20
SECTION 3. DEFINING HEALTH EFFECTS
AND RISK ASSESSMENT 29
Section 3.1. Defining Adverse Health Effects 30
Section 3-2. The Respiratory Tract 31
Section 3.3. Risk Assessment 36
Section 3.4. EPA Cancer Risk Assessments
for Indoor Air Contaminants 43
SECTION 4. SOURCES AND HEALTH
EFFECTS OF SELECTED
CONTAMINANTS 47
Section 4.1. Combustion Contaminants 49
Section 4.2. Pesticides 66
Section 4.3. Formaldehyde and Other
Volatile Organic Compounds 85
SECTION 5. CONTROL OF INDOOR AIR
CONTAMINANTS 115
Section 5.1. Residential Heating Systems
and Moisture Control 116
Section 5.2. Evaluation of Air Cleaners 131
Section 5.3. Public and Private Sector
Organizations Involved In
Indoor Air Quality Activities 135
SECTION 6. INDOOR AIR QUALITY
MEASUREMENTS 141
Section 6.1. Indoor Air Quality Sampling
Methods 143
Section 6.2. Accuracy, Precision, and
Related Terms 168
Section 6.3. Representative Sampling 170
Section 6.4. Calibration 172
Section 6.5. Passive Samplers 180
Section 6.6. Air Exchange Rates 181
SECTION 7. STANDARDS AND GUIDELINES
FOR VENTILATION AND
HEALTH EFFECTS 185
SECTION 8. INVESTIGATION
TECHNIQUES
203
Section 8.1. General Investigation
Techniques for Residences 205
Section 8.2. Investigation Techniques for
Combustion Sources 217
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Section 8.3. Investigation Techniques for
Pesticides 242
Section 8.4. Investigation Techniques for
Formaldehyde and Other
Volatile Organic Compounds 258
Section 8.5 Investigation Techniques for
Biological Contaminants 277
LIST OF EXHIBITS
SECTION 2. FACTORS AFFECTING INDOOR
AIR QUALITY 3
Exhibit 2-1.. Major sources of infiltration
measured during weatherization
studies. 10
Exhibit 2-2 Effective leakage area of building
components (0.016 inches
water). 11
Exhibit 2-3. Values for wind coefficient. 12
Exhibit 2-4. Source emission rates for
selected contaminants. 13
Exhibit 2-5. Decay rates for selected
contaminants. 17
Exhibit 2-6. Deposition velocities for selected
contaminants on various surfaces
and indoor areas. 18
Exhibit 2-7.
Sources of indoor air
contaminants.
21
SECTION 3. DEFINING HEALTH EFFECTS
AND RISK ASSESSMENT 29
Exhibit 3-1. Structure of the respiratory tract. 35
Exhibit 3-2. Commonly used ventilatory
measurements.
36
Exhibit 3-3 EPA cancer risk assessments.
44
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"Reference Manual
Table of Contents
SECTION 4. SOURCES AND HEALTH
EFFECTS OF SELECTED
CONTAMINANTS
47
Exhibit 4-la. Relationship between carbon
monoxide (CO) concentrations
and carboxyhemoglobin
(COHb) levels in blood. 54
Exhibit 4-lb. Carboxyhemoglobin levels and
related health effects. 55
Exhibit 4-2. Controlled studies of the effects
of human exposure to nitrogen
dioxide. 56
Exhibit 4-3. Effects of exposure to nitrogen
dioxide plus other gas stove
combustion products in the
home on the incidence of
acute respiratory disease in
epidemiology studies involving
gas stoves. 59
Exhibit 4-4. Selected studies of human
exposure to carbon dioxide. 61
Exhibit 4-5. Selected studies of asthmatic
subjects exposed to sulfur
dioxide. 62
Exhibit 4-6. Composition of mainstream
and sidestream smoke. 63
Exhibit 4-7. Summary of health effects,
products, and uses of 50
active ingredients in household
pesticides. 69
Exhibit 4-8. Selected weighted summary
statistics for indoor air
concentrations of pesticides in
Jacksonville and
Springfield/Chicopee (ng/m3). 75
Exhibit 4-9.
Exhibit 4-10.
Measurements of pesticides in
buildings. 79
Potential sources of
formaldehyde indoors.
91
Exhibit 4-11. Measurements of formaldehyde
concentrations in different
types of buildings. 92
Exhibit 4-12. Health effects and sources of
selected volatile organic
compounds. 94
Exhibit 4-13. Examples of volatile organic
compound measurements in
indoor air. 96
Exhibit 4-l4a. Examples of selected volatile
organic compound emission
rates for materials and typical
household products indoors. 99
Exhibit 4-l4b. Additional examples of volatile
organic compound emission
rates for selected materials
found indoors. 100
Exhibit 4-15. Molds identified in 68 homes
in southern California. 110
Exhibit 4-16. Fungi reported as allergenic. Ill
SECTION 5. CONTROL OF INDOOR AIR
CONTAMINANTS 115
Exhibit 5-1. Oil furnace installation. 118
Exhibit 5-2. Gas-fired forced-air furnace
configurations. 119
Exhibit 5-3. Forced-air distribution systems. 120
Exhibit 5-4. Installation of a vapor retarder
in the attic.
125
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Exhibit 5-5. Installation of a vapor retarder
in the crawl space or floor. 126
Exhibit 5-6. Installation of a continuous
vapor retarder. 128
Exhibit 5-7. Attic ventilation strategies. 129
Exhibit 5-8. Sizing factors for different vent
coverings. 130
Exhibit 5-9- Comparative performance of
viscous impingement and
dry media filters. 132
Exhibit 5-10. Estimated percentage of
particle removal for portable
air cleaners by CADR and by
room size. 134
Exhibit 5-11. Minutes to achieve 90%
removal of airborne particles. 135
Exhibit 5-12. Public interest organization
indoor air activities. 136
Exhibit 5-13. Professional and trade
association indoor air activities. 137
SECTION 6. INDOOR AIR QUALITY
MEASUREMENTS
141
Exhibit 6-1. Collection and analytical
methods for quantitative
monitoring of some
contaminants. 146
Exhibit 6-2a. Commercially available indoor
air monitoring equipment. 147
Exhibit 6-2b. Identification codes for
methods in Exhibit 6-2a. 155
Exhibit 6-2c. Identification codes for
manufacturers in Exhibit 6-2a. 156
Exhibit 6-3.
Exhibit 6-4'.
Exhibit 6-5.
Exhibit 6-6.
Exhibit 6-7.
Battery-powered personal air
samplers. 159
Properties of filters used in
particulate sampling. 160
Some storage properties of gases
in plastic bags. 163
Limitations of selected solid
adsorbents. 164
Sources for testing and
calibration procedures
applicable to indoor air
quality sampling.
Exhibit 6-8.
Exhibit 6-9.
Exhibit 6-10.
National Institute of
Standards and Technology
(NIST) Standard Reference
Materials (SRMs) for the
calibration of instruments and
procedures utilized in air
quality analysis.
Precision and accuracy.
Exhibit 6-11.
Exhibit 6-12.
Exhibit 6-13-
Calibration using the
soap-bubble meter.
165
166
169
Example calibration or audit
form for a direct reading
carbon monoxide or carbon
dioxide monitor. 176
Different types of airflow
meters. 177
Sample rotameter calibration
form. 178
179
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SECTION 7.
Exhibit 7-1.
Exhibit 7-2.
STANDARDS AND GUIDE-
LINES FOR VENTILATION
AND HEALTH EFFECTS 185
Air quality standards and
guidelines for selected
contaminants.
186
Exhibit 7-3.
Outdoor air requirements for
ventilation of commercial
facilities (offices, stores, shops,
hotels, sports facilities). 1 95
Outdoor air requirements for
ventilation of residential
facilities (private dwellings,
single, multiple). 1 99
Exhibit 7-4.
Exhibit 7-5.
Uniform Building Code
ventilation requirements.
Acceptable ranges of
temperature and humidity
during summer and winter.
SECTION 8. INVESTIGATION
TECHNIQUES
Exhibit 8-1. Indoor air quality health
effects form.
Exhibit 8-2. Indoor air quality residential
inspection form.
Exhibit 8-3. Location and operation of
typical backdraft diverter.
Exhibit 8-4. CABO Building Code
combustion air requirements
for residential fuel-burning
equipment.
Exhibit 8-5. Separation guidelines to
prevent downdrafts into
chimneys.
200
202
203
206
211
232
233
234
Exhibit 8-6.
Exhibit 8-7.
Exhibit 8-8.
Exhibit 8-9-
Examples of chimney caps. 235
Potential consequences when
more than one appliance
is connected to the same flue. 236
Combustion inspection form. 237
238
Features of proper stove
installation.
Exhibit 8-10. Suggested chimney sizes for
residential wood-burning
equipment. 239
Exhibit 8-11. Safety guidelines for unvented
gas-fired heaters. 240
Exhibit 8-12, Safety guidelines for unvented
kerosene heaters. 240
Exhibit 8-13- Sources of termiticide
contamination and mitigation
methods. 249
Exhibit 8-14. Pesticides that can be
measured using low volume
PUF sampling with GC/ECD. 250
Exhibit 8-15. Useful sources of information
on pesticides. ' 251
Exhibit 8-16. Guidelines for using pesticides
safely. 252
Exhibit 8-17. First aid guidelines for pesticide
poisonings. 255
Exhibit 8-18. Guidelines for cleaning
pesticide spills and residues. 256
Exhibit 8-19- Examples of biological control
of pesticides. 257
Exhibit 8-20. Selected passive formaldehyde
measurement methods. 270
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Exhibit 8-21. A dose-effect relationship
between formaldehyde (HCHO)
exposure and selected health
effects in mobile and
conventional homes. 271
Exhibit 8-22. Effect of temperature and
relative humidity on formal-
dehyde (HCHO) levels in a
mobile home under controlled
conditions. 272
Exhibit 8-23. Advantages and disadvantages
of nonspecific and specific
detector systems for VOC and
SVOC analysis.
Exhibit 8-24. Commercially available
portable VOC detection
instruments.
Exhibit 8-25. Characteristics of sorption
collection methods.
Exhibit 8-26. Environmental survey form
for evaluating the presence
of potential sources of
allergens.
273
274
275
290
Exhibit 8-27. Commonly used samplers for
collecting indoor bioaerosols. 295
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Reference Manual
Acknowledgements
ACKNOWLEDGEMENTS
JL he Indoor Air Quality Learning Module and
the Indoor Air Quality Reference Manual were devel-
oped under a cooperative arrangement between the
National Environmental Health Association, the
Bureau of Health Professions of the U.S. Public
Health Service, and the Indoor Air Division of the
Environmental Protection Agency.
The documents were written by:
IngridRitchie, Ph.D., Associate Professor
School of Public and Environmental Affairs
Indiana University
The following persons are gratefully acknowledged
for their contributions:
Barry Stern had the foresight to recognize the
importance of indoor air quality issues and the need
to strengthen the competency of practicing environ-
mental health professionals in this atea, His
initiative in developing this project, his support,
and his patience have been fundamental to the
success of this work.
David Mudarri was the principal technical advisor
for this project. He provided expert technical
guidance and made extensive and invaluable
editorial contributions. His insight and thoughtful
assistance provided the framework for both docu-
ments, and his tireless effort and encouragement
helped steer the project through many difficult
times.
Edward Culver (Bureau Administrator, Bureau of
Environmental Health, Health and Hospital
Corporation of Marion County, Indianapolis,
Indiana) contributed Lesson 9 of the Learning
Module, "Establishing an Indoor Air Quality
Program."
Geraldine Straensee spent many hours typing
complex tables and initially formatting the docu-
ments. Her forbearance through innumerable
revisions is sincerely appreciated.
Reviewing Organizations
Individuals from the following organizations
reviewed and commented on all or part of the two
documents.
Federal Agencies
Bonneville Power Administration,
Department of Energy
Consumer Product Safety Commission
Department of Health and Human Services
National Institute of Environmental Health
Sciences
National Institute for Occupational Safety
and Health
Department of Housing and Urban Development
Office of Policy Development and Research
Environmental Protection Agency
Office of Air and Radiation
Office of Pesticides and Toxic Substances
Office of Research and Development
Office of Water
General Services Administration
Public Buildings Services
State and Local Government Agencies
Association of Local Air Pollution Control Officials,
Washington, DC
Central District Health Department, Boise, ID '
Clark County Health Department, Las Vegas, NV
Connecticut Department of Health Services,
Hartford, CT
Division of Environmental Services, Toledo, OH
Forsyth County Environment Affairs Department,
Winston-Salem, NC
Health and Hospital Corporation of Marion County,
Indianapolis, IN
Illinois Department of Public Health,
Springfield, IL
Lincoln-Lancaster County Air Pollution Control
Agency, Lincoln, NE
Mansfield Health Department, Mansfield, MA
Maryland Department of Education, Baltimore, MD
(continued next page)
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Acknowledgements
Reference Manual
Minneapolis Department of Environmental Health,
Minneapolis, MN
Montgomery County Public Schools, Rockville, MD
Piano Health Department, Piano, TX
Southeastern Health District, Pocatello, ID
State College Health Department, State College, PA
Other Organizations
Department of Environmental Health, East Carolina
University, Greenville, NC
Indoor Air Quality and Safety Research,
Gas Research Institute, Chicago, IL
Sponsoring Organizations
National Environmental Health Association
Executive Director: Nelson Fabian
Project Coordinators: Terry Johnson
Larry Marcum
Grants Assistant: Geraldine Struenesee
U.S. Department of Health and Human Services
Project Officer: Barry Stern, M.P.H., R.S.
Bureau of Health Professions
Health Resources and Services
Administration
U.S. Public Health Service
U.S. Environmental Protection Agency
Project Officer. David H. Mudarri, Ph.D.
Indoor Air Division
Office of Air and Radiation
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is
SECTION 1.
OVERVIEW OF THE
REFERENCE MANUAL
JLhe Indoor Air Quality Reference Manual i
the companion document to the Indoor Air Quality
Learning Module, The purpose of the Reference
Manual is to provide an opportunity for continuing
education plus useful reference material on selected
indoor air quality topics.
The Reference Manual is divided into 8 sections
corresponding to the first eight lessons of the
Learning Module. Section 1 provides an overview of
the Reference Manual and suggests ways that the
Reference Manual can best be used as an adjunct to
the Learning Module. Sections 2-8 contain informa-
tion that supplements the corresponding lessons in
the Learning Module. For example, Lesson 2 of the
Learning Module describes the factors that affect
indoor air quality, while Section 2 of the Reference
Manual shows how those factors are combined in
indoor air quality modeling to simulate indoor
environments; Section 2 also provides specific
information and data on individual factors.
Sections 3 and 4 of the Reference Manual correspond-
to Lessons 3 and 4 of the Learning Module and
contain information on the nature of human re-
sponses as well as health effects from specific
contaminants. Section 5 contains information about
air cleaning devices and residential heating and air
mover systems.
The Reference Manual also contains information and
exhibits which can be directly used in field investi-
gations. For example, Section 4 contains tables
which relate symptoms, contaminants, and sources
in a way that could assist in diagnosing indoor air
quality problems; Section 6 provides information on
specific measurement techniques and equipment,
including availability of equipment from various
manufacturers; Section 7 provides a listing of public
health and occupational standards which can be
useful in interpreting measured data; and Section 8
includes specific forms and questionnaires which can
be used to collect data during field investigations.
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SECTION 2.
FACTORS AFFECTING
INDOOR AIR QUALITY
Section 2.1 discusses the general mass
balance equation and its use in indoor
air quality modeling. Exhibits 2-1
through 2-6 provide some examples
of empirical data for parameters
which are used in the model. Section
2.2 contains Exhibit 2-7 which is a
detailed listing of sources and con-
taminants potentially released by
those sources.
Table of Contents
Section 2.1. Indoor Air Quality Modeling 4
Section 2.2. Sources of Indoor Air Contaminants 20
list of Exhibits
Exhibit 2-1. Major sources of infiltration measured
during weatherization studies. 10
Exhibit 2-2. Effective leakage area of building components
(0.016 inches water). 11
Exhibit 2-3. Values for wind coefficient. 12
Exhibit 2-4. Source emission rates for selected
contaminants. 13
Exhibit 2-5. Decay rates for selected contaminants. 17
Exhibit 2-6. Deposition velocities for selected
contaminants on various surfaces and
indoor areas. 18
Exhibit 2-7. Sources of indoor air contaminants. 21
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Section 2
1AQ Reference Manual
2.1. INDOOR AIR QUAIITY MODELING
.Indoor ait quality models describe the
transport and dispersion of air contaminants
throughout a structure and the variation of indoor
ait contaminant concentrations as a function of
source strengths, air-exchange rates, removal
mechanisms, and other parameters.
Most models are based on either the principles of
conservation of energy or the conservation of mass in
a compartment or zone. Some models are based on
empirical methods in which test data are evaluated
statistically and fitted using regression analysis.
These empirical models may better reflect the
specific circumstances for which they are calibrated,
but they do not have the wide applicability of the
models which are based on first principles.
In a mass or energy balance model, the term
compartment or zone refers to a region in which
spatial variations in contaminant concentration can
be ignored over the time period of interest. A
single room, a floor, or a house that is well-mixed is
usually treated as a single zone. Houses with central
forced-air heating systems can be considered to be
well-mixed when the circulation fan is operating.
Houses with other types of heating systems caa also
be considered to be well-mixed providing interior
doors remain open and a sufficiently long time
period is allowed for mixing. For steady-state
conditions (when generation of contaminants equals
removal), these models reduce to simple algebraic
equations. The basic mass balance equation for a
single zone model is presented below.
The accuracy of the single zone model depends on
the degree of mixing, the time period of concern,
and the extent to which the parameters have been
characterized. Model performance can be measured
by comparing predicted data with actual measured
values. After the model has been calibrated, it
should be evaluated against other data. It is
important to note that the data set which is used for
calibrating the model should not be used to evaluate
the model's general predictive capability.
Single zone models may not be adequate when
sources and sinks are not uniformly distributed
throughout the area or when stratification of
contaminants occurs, and in these cases multi-zone
models may be needed. These models may be
adequate, for example, to describe contaminant
concentrations when a kerosene heater is operating
in one room of a house (zone 1) that is separated
from the remainder of the house (zone 2) by closed
doors.
Multi-zone models might also be used when
predicting contaminant concentrations in a building
with multiple floors. These models include separate
mass balance equations for each zone, and they are
more complex than single zone models.
In general, indoor air quality models are useful tools
that can be used: 1) to understand how the factors
that affect indoor air quality relate to one another,
2) to predict concentrations of contaminants for
places and conditions that cannot be measured, and
3) to determine required accuracy and precision for
monitoring studies.
Available Indoor Air Quality Models
Numerous models have been developed to estimate
concentrations of contaminants in indoor air, and
some of these also estimate inhalation exposures.
The Air and Energy Engineering Research Labora-
tory (AEBRL) at EPA has developed a multi-zone
indoor air quality model (Sparks, 1988) which can
be used on an IBM-PC or compatible computer.
The AEERL model treats each room as a well-mixed
chamber that can contain both sources and sinks.
Source terms which can be included are random on/
off sources (for example, cigarettes), sources that are
on for specific periods of time (for example, kerosene
heaters), steady-state sources (for example, moth
crystals), and sources with high initial emission
rates followed by a low steady-state rate of emission
(for example, floor wax). The model also allows the
impact of heating, ventilating, and air-conditioning
(HVAC) systems, air cleaners, and interroom air
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IAQ Reference Manual
Section 2
flows on indoor air quality to be evaluated. The
model has been verified to a limited extent with
experimental data from EPA's indoor air quality test
house.
The AEERL model is user friendly and has a menu-
driven user interface. Output from the model can
be displayed if a graphics adapter and monitor are
available. Additional information on the model and
user's manual can be obtained by contacting the Air
and Energy Engineering Research Laboratory, U.S.
EPA, Research Triangle Park, NC 27711.
Further discussion on single zone, multi-zone, and
exposure models can be found in NAS (1981);
Wadden and Scheff (1983); Nagda, Rector, and
Koontz (1987); McNall et al. (1985); Sexton and
Ryan (1988); Sexton and Hay ward (1987); Axley
(1987); and Repace (1987).
Mass Balance Equation
The primary source for the following discussion is
Nagda et al. 1987; other useful sources include
NRC (1981) and Wadden and Scheff(1983).
The generation and removal of contaminants in
indoor environments can be described mathemati-
cally based on the conservation of mass:
rate of accumulation =
rate of [input + generation - output -sinks],
(1)
or
VdC. _ rate of change
dt in mass due to
K infiltration \ /generation\
of outdoor air/ \indoors /
(exfiltration \ /indoor removal \ T ,~>
of indoor air/ \ of contaminants / J
where,
V = the indoor volume,
C. = the indoor concentration, and
t = time
Parameters in the mass balance equation must be
evaluated independently. Some parameters, such as
volumes and surface areas, can be measured directly
or can be easily obtained from blueprints. Others
such as ventilation rates and source emission/
removal rates are more difficult to obtain.
Infiltration and exfiltration
The infiltration of contaminants from the outdoors
depends on the product of the outdoor contaminant
concentrations (Co) and the volume rate of air
exchange ( W), where v is the air exchange rate in
air changes per hour (ach).
Not all outdoor air contaminants that move into a
structure reach the inside; some fraction of contami-
nants, Fb, is intercepted by the cracks and crevices in
the building envelope which decreases the amount
that actually reaches the indoor air. The overall
relationship for the change in indoor contaminant
concentrations due to infiltration from outdoor air
is, therefore, given by:
VdC...... = (l-FJi/VCdt.
i(mfil) x b' o
Removal of contaminants due to the exfiltration of
indoor air is the product of the volume rate of air
exchange (vV) and the concentration of air leaving
the structure, Ce. In cases of good mixing, Ce is the
same as C. and the exfiltration term over a period of
time is given by:
= -WCdt.
Generation and removal
of contaminants
The generation of contaminants indoors (source
term) over a period of time can be expressed as Sdt,
where S is the contaminant emission rate,
VdC, . =Sdt.
i(gen)
The removal of indoor contaminants is due to
chemical reactions, adsorption of contaminants on
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Section 2
IAQ Reference Manual
indoor surfaces, and removal by mechanical means
through air cleaning devices. The rate of decay due
to chemical reactions and/or adsorption over a
period of time is given by Xdt, where X is the
overall decay rate of the contaminant.
Removal by air cleaning devices depends on the
volume flowrate of air handled by the device, q, and
on the efficiency of the device, F (that is, the
proportion of contaminants removed). Removal by
air cleaning devices can be expressed as qFC.dt.
The expression for total removal over a period of
time is then given by:
VdCi(rem)=-Xdt-qFC;dt.
Effective Volume
The concentration of contaminants indoors also
depends on the indoor volume. The actual volume
that is available for contaminant dispersal depends
on the degree of air circulation, and it is known as
the effective volume (kV), where k is a dimension-
less factor. The value of k becomes 1 when the
entire indoor air volume is available for contaminant
dispersal. The value of k is less than 1 when there is
no forced mixing and the degree of circulation
depends on thermal gradients indoors.
Generalized Mass Balance Equation
Equation 2 can be written as a generalized mass
balance equation for predicting indoor concentra-
tions. Assuming uniformly mixed conditions and
an effective volume, kV, rather than the total indoor
volume, V, equation 2 becomes:
kVdq = (1 - Fb)vkVCdt + Sdt - vkVC.dt- (3)
Xdt - qFCdt ,
or
dt
= (l-Fb)vC
+ S - vC - \ - qFC.
kV kV kv'
(4)
where,
C.= indoor concentration (mass/
volume);
Fb= fraction of outdoor concentration
intercepted by the building envelope
(dimensionless fraction);
v = air exchange rate (I/time);
CQ = outdoor concentration (mass/volume)
S = indoor source generation rate (mass/
time);
kV = effective indoor volume where k is a
dimensionless fraction;
X = decay rate (mass/time);
q = flow rate through air cleaning device
(volume/time); and
F = efficiency of the air cleaning device
(dimensionless fraction).
Mixing factor: Because the extent of air mixing in
the interior varies, a mixing factor, m, may be
introduced which modifies the air exchange to yield
an effective air exchange rate for exfiltration of a
contaminant. The mixing factor is the ratio of the
concentration of the exiting air to the concentration
of the indoor air. When the two concentrations are
the same, the air is said to be completely mixed, and
m equals one. When contaminants are exhausted
directly from their source, m will be >1. However,
the more usual case is for m to be < 1 because
mixing is not complete.
The value of m has been estimated to be in the
range of 0.33 - 1.0 (Wadden and Scheff, 1983). In
general, mixing between rooms in residential
structures is usually complete in less than 1 hour;
therefore, the complete mixing assumption is often
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IAQ Reference Manual
Section 2
used to estimate average concentrations over time
periods greater than 1 hour.
The effective air exfiltration rate for a given con-
taminant is the product of the mixing factor, m, and
the air exchange rate, v, and it is given by mv.
Therefore, equation 4 becomes:
dC. = (1 - Fb)vCo + _S_ - mvC - _\_ - qFC. (5)
dt' kV kV W'
Use of the Mass Balance Equation
The basic mass balance equation can be used for
many applications, and the solutions to the equation
will vary depending on initial assumptions. Some
examples of applications include using the equation
to predict the buildup of contaminants as a result of
the infiltration of contaminated outdoor air or from
using an indoor source for varying time periods; to
evaluate the effectiveness of mechanical ventilation;
or to determine the effect of air exchange rates and
other variables on indoor contaminant concentra-
tions.
Equilibrium Concentrations
One application of the model is to compute the
equilibrium (steady-state) concentrations that would
be achieved under a variety of conditions. The
simplest case assumes a nonreactive contaminant, no
indoor sources (S = 0), no cleaning devices (F = 0),
no capture of outdoor contaminants by the indoor
air (Ffc = 0), and uniform mixing (m = 1). Under
these conditions, equation 5 reduces to:
dC. = v(C - C.) .
1 x o r
dt
(6)
Thus, in this simple case, when equilibrium is
reached (that is, when the indoor air concentration
is constant), dC./dt = 0, and the indoor concentra-
tion equals the outdoor concentration.
Effect of Indoor Sources: If we now introduce an
indoor source of contaminants, equation 6 becomes:
dC = v(Co - C.) +_S_ ,
dt kV
and the equilibrium concentration (when dC./dt = 0)
would be given by:
C. = C + S .
kvV
Other terms can be introduced in a similar way.
Effect of Time: Another application is to deter-
mine under a given set of conditions how much
time is required to reach equilibrium or what
concentration will result after a given period of
time. Using the simple case in equation 6 where we
assume an initial indoor concentration, C.o, and a
final indoor concentration equal to a constant
outdoor concentration, Co, then the indoor concen-
tration at any time, t, is given by:
C. =C
I,t O
(7)
For example, we can calculate the indoor concentra-
tion of carbon monoxide (CO) after 2 hours in a
100 m3 space assuming that the outdoor concentra-
tion is 9 ppm; the initial CO indoors is 3 ppm;
there are no indoor sources or cleaning devices; the
air exchange rate is 0.3 ach; and uniform mixing of
the indoor air occurs. The solution is:
C2hr = 9 ppm + (3 ppm - 9 ppm) (0.55)
= 5.7 ppm.
After 2 hours the indoor concentration under the
stated conditions equals 5.7 ppm or about 60% of
outdoor concentration.
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Section 2
IAQ Reference Manual
Quantifying Parameters
Values for the input parameters which are needed
either to make simple computations or to use
available indoor air quality models are derived by
direct measurements or by combining special
knowledge of specific conditions with values derived
from the literature or specific research. The follow-
ing discussion provides some basis for assisting the
user in defining values for specific applications.
Infiltration and exfiltration: The infiltration rate
of a given building can vary considerably depending
on the weather conditions, occupant activities, and
the operation of appliances and HVAC equipment.
Weatherization studies on houses in the United
States have shown that major sources of air leakage
are walls and floors, ceilings, heating systems,
windows and doors, and fireplaces. Air leaks
through vents and diffusion through walls are minor
sources. The importance of these individual sources
will vary depending on the region of the country
and construction techniques. Exhibit 2-1 identifies
specific sources of air leakage and ranges of infiltra-
tion that have been measured for each.
Air exchange rates: Air exchange rates for input
into models can be obtained in one of three ways.
The type of air exchange rate data which are needed
will depend on the particular situation which is
being investigated.
One approach is to use an average number of air
exchanges per hour that have been developed for
different types of structures and conditions. This
method provides only ballpark estimates, since air
exchange rates cannot be reliably estimated from a
visual inspection of the building, its age, or con-
struction. Air exchange rates can also be deter-
mined using empirical models which are statistical
fits to measurements over a long period of time at
specific sites. These models incorporate tempera-
ture differentials between indoors and outdoors and
wind speed with empirically derived regression
constants to obtain air exchange rates. The accuracy
of empirical models is about 40%, but individual
predictions can vary by 100% (ASHRAE, 1989).
The best way to obtain air exchange rates is to
measure them directly using tracer gas methods. If
direct measurements are not possible, air exchange
rates can also be determined indirectly by measur-
ing or calculating air leakage rates and converting
these rates to air exchange rates.
A model developed by the Lawrence Berkeley
Laboratory (Sherman and Grimsrud, 1989) has been
widely used as the basis for indirect calculations and
it is summarized below. The accuracy of these
calculations will depend on the accuracy of the
required inputs. The method of calculating the air
exchange rates from leakage rate data in residences
is as follows (ASHRAE, 1989):
1) Use Exhibit 2^2 to determine the
effective air leakage area from each
possible source. For example, the
leakage area of 100 ft of uncaulked sills
is: 100 ft x 0.19 in2/ft = 27.0 in2.
2) Add the individual leakage areas to
obtain a total effective leakage area.
The total effective leakage area can also
be measured using fan pressurization.
3) Using the effective leakage area,
calculate the airflow rate due to
infiltration:
Q = L(AAt + B|i2)0-5
where,
Q = airflow rate, cfm;
L = effective leakage area, in2;
At = average indoor-outdoor temperature
difference for the time interval of
the calculation, °F;
A = stack coefficient, cfm2 in"4°F"';
-------
IAQ Reference Manual
Section 2
The stack coefficient for residences is a
function of the number of stories:
A = 0.0156 for one story;
A = 0.0313 for two stories;
A = 0.0471 for three stories.
*
B = wind coefficient, cfm2 in"4 mph"2>;
The wind coefficient depends on the
number of stories and the degree of shield-
ing around the house, and it can be ob-
tained from Exhibit 2-3.
H = average wind speed measured for the
time interval of interest, mph.
4) Calculate the infiltration rate by divid-
ing Q by the building volume.
Example Calculation:
Estimate the infiltration over the heating season in a
one-story house with a volume of 10,000 ft3 and a
leakage area of 50 in2. The average indoor tempera-
ture during the heating season is 75°F and the
average outdoor temperature is 32°F. The house is
located on a lot that has a thick hedge on one side
and single story houses on the other sides (heavy
shielding). The average wind speed during the
heating season is 5 mph.
First, calculate the airflow rate due to infiltration:
Q = 50 [(0.0156 x 43) + (0.0039 x 52)}0-5
= 43.8 cfm
= 2630 ft3/hr.
Next, calculate the ach:
= (2630 ft3/hr)/10,000 ft3
= 0.26 ach.
Source and removal terms; A wide range of
sources and source combinations are possible in
indoor environments. Some sources may start and
stop in a random fashion (tobacco products), some
emit for limited and specified periods of time (gas
heaters), some emit at rates that are high initially
but reduced over short or long periods of time
(waxes, formaldehyde), and others may emit at a
more uniform rate over a period of time (moth
balls). Different types of sources and source combi-
nations can be modeled, but the equations may
become more complex. Also, a given source can have
different emissions at different times depending on
the conditions of the measurements. For example,
the rate of emissions from a kerosene heater that
uses a wick will depend on the burner setting, age
of the wick, type of fuel used, age of the heater, and
other factors. In addition, it should be noted that
different methodologies for the measurement of the
emission rate can yield different .results. Exhibit 2-
4 gives examples of some emission rates for selected
sources and contaminants.
The removal term, R, is often unknown, and for
some contaminants it may depend on the physical
and chemical characteristics of the interior space.
The removal term may be incorporated into the
source term to give a net source term, or it can be
evaluated as a function of the decay rate (X) or
deposition velocity (v,e); Exhibits 2-5 and 2-6
provide examples of decay rates and deposition
velocities for selected contaminants. The caveats for
the source term also apply to the removal term.
Removal expressed as a function of the decay rate
and the contaminant mass (VC.) is given by:
R = XVC.
Removal expressed as deposition is given by:
R =
aC.
where,
(continued next page)
-------
Section 2 IAQ Reference Manual
v& = deposition velocity, length time"1 and
a = area of contact, length2.
The relationship between X and vdc is then:
%-AV.
a
Exhibit 2-1. Major sources of infiltration measured during weatherization studies.
SOURCE
walls
ceiling details
heating system
windows and doors
fireplaces
vents in conditioned spaces
diffusion through walls
RELATIVE
RANGE (%)
18-50
3-30
3-28
6-22
0-30
2-12
AMOUNT OF LEAKAGE
AVERAGE (%)
35
18
15
15
12
5
<1
SOURCE: ASHRAEU985)
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1AQ Reference Manual
Section 2
Exhibit 2-2. Effective leakage area of building components (0.016 inches water).
COMPONENT
SELL FOUNDATION-WAIL
Caulked,inJ/ft of perimeter
Not caulked, iti2/fc of perimeter
BEST
EST.
0.04
0.19
MAX MIN
0,06 0.02
0.19 0.05
COMPONENT
DOMESTIC HOT WATER SYSTEMS
Gas Water Heater (only if in
conditioned space), in2 per unit
BEST
EST.
3.1
MAX MIN
3.9 2.325
JOINTS BETWEEN CEILING AND WALLS
Joints, inVft of wall 0.07 0.12 . 0.02
(only if not taped or plastered
and no vapor barrier)
WINDOWS
Casement
Weatherstripped, in2/ft2 of window 0.011 0.017 .0.0,0,6
Not weatherstripped, ItfffMwindow 0.023 0.034 0,011
Awning
Weatherstripped, ina/fi2 of window 0.011 0.017 OiflOS
Not weatherstripped, in'/fW window 0.023 0.034 iO.OJl
Single Hung
Weatherstripped, in2/ft2 of window 0.032 0,042 0,02£
Not weatherstripped, hvVft2 of window 0.063 0.083 0.052
Double Hung
Weatherstripped, in2/ft2 of window 0.043 0,063 0,023
Not weatherstripped, in2/ft2of window 0.086 0.126 0,046
Single Slider
Weatherstripped, in2/ft2 of window 0.026 0.039 0.013
Not weatherstripped, in2/ft2 of window 0.052 0.077 0.026
Double Slider
Weatherstripped, in2/ft2 of window 0.037 0.054 0.02
Not weatherstripped, in2/ft2 of window 0.074 0.11 0,04
DOORS
Single Door
Weatherstripped, in%2 of door 0.114 0.215 ,0.043
Not weatherstripped, in2/ft2 of door 0.157 0.243 0,086
Double Door
Weatherstripped, ina/ft2 of door 0.114 0,215 O.Q43
Not weatherstripped, inVft2 of door 0.16 0.32 0,1
Access to Attic ot Ctawl space
Weatherstripped, in2/ft2 per access 2.8 2.8 1.2
Not weatherstrijjped, in2/ft2 per access 4.6 4.6 .1.6-
WALL-WINDOW FRAME
Wood frame Wall
Caulked, in2/ft2 of window
No caulking, inVft2 of window
Masonry Wall
Caulked, in2/ft2 of window
No caulking, in2/ft2 of window
WALL-DOOR FRAME
Wood Frame Wall
Caulked, in2/ft2 of window
No caulking, Jn2/ft2 of window
Masonry Wall
Caulked, in2/fi2 of window
No caulking, in2/ft2 of window
0.004 0.007 0.004
0.024 0.039 Q.,022
0.019 0.03 .Q.01,6
0.093 0,15 0.082
0.004 0,004 0.001
0.024 0.024 0,,009
0.0143 0.0143 0.004
0.072 0,072 0.024
ELECTRIC OUTLETS AND LIGHT FIXTURES
Electric Outlets and Switches
Gasketed, in2 per outlet and switch 0 00
Not gasketed, in2 pee outlet and switch 0.076 0.16 0
Recessed Light Fixtures, in2 per fixture 1.6 3.10 1.6
-PIPE AND DUCT PENETRATIONS THROUGH ENVELOPE
Pipes
Caulked or sealed, in2 per pipe 0.155 0.31 0
Not caulked of sealed, in2 per pipe 9.30 1.55 0.31
Ducts
Sealed or with continuous
vapor barrier, in2 per duct 0,25 0,25 0
Unsealed and without vapor barrier,
in2 per duct 3.7 3.7 2.2
FIREPLACE
Without Insert
Damper closed, in2 per unit
Damper open, in2 per unit
With Insert
Damper closed, in2 per unit 5.6 7.1 4.03
Damper open or absent, in2 per unit 10.0 14.0 6.2
10.7 13.0 8.4
S4.0 59.0 50.0
EXHAUST FANS
Kitchen Fan
Damper closed, in2 per fan
Damper open, in2 per fan
Bathroom Fan
Damper closed, in2 per fen
Damper open, in2 per fan
Dryer Vent
Damper closed, in2 per fen
0.775 1.1 0.47
6.0 6,5 5.6
1.7
3.1
FURNACE—FORCED AIR SYSTEMS
(only if in conditioned space)
Sealed combustion furnace, per unit
Retention head burner furnace,
in2 per unit
Retention head plus stack damper,
in2 per unit
Furnace with stack damper,
in2 per unit
AIR CONDITIONER
Wall or window unit, in2 per unit
3.7
1.9 14
3.4 2.8
0.47 0.9
0
HEATING DUCTWORK-FORCED AIR SYSTEMS
(only in unconditioned space)
Joints taped or caulked, in2 per house 11 11 5
Joints not taped/caulked, In2 per house 22 22 11
0 00
5 6.2 3.1
3.7 4.6 2.8
4.6 6.2 3.1
5.6 0
SOURCE: Reprinted with permission from the 1985 ASHRAE Handbook—Fundamentals published by the American Society of Heating, Refrigerating
and Air-Conditioning Engineers, Inc.
-------
Section 2
IAQ Reference Manual
Exhibit 2-3. Values for wind coefficient.
SHIELDING CLASS
HOUSE HEIGHT (STORIES)
ONE TWO THREE
1— no obstructions or local
shielding
2— light local shielding;
few obstructions,
a few trees or small shed
3— moderate local shielding;
some obstructions within
two house heights, thick hedge,
solid fence^ or one
neighboring house
4— heavy shielding; obstructions
around most of the perimeter,
buildings of trees within 30ft
in most directions; typical
suburban shielding
5— very heavy shielding;
large obstructions
surrounding perimeter
within two house heights;
typical downtown shielding
0.0119
0.0092
0.0065
0.0039
0.0012
0.0157
0.0121
0.0086
0.0051
0.0016
0.0184
0.0143
0.0101
0.0060
0.0018
SOURCE: ASHRAE(1989)
-------
IAQ Reference Manual
Section 2
Exhibit 2-4. Source emission rates for selected contaminants.
CONTAMINANT AND
MATERIAL
SOURCE EMISSION RATE
REFERENCE
Formaldehyde
medium density fiberboard"
particle board
textiles, resilient flooring
carpeting, ceiling tiles,
carpet pad
. fibrous glass insulation,
softwood plywood
hardwood paneling
particleboard underlayment
industrial particleboard
medium density fiberboard
UFFI simulated wall panel
gas burner, gas oven
kerosene heater, convective
kerosene heater, radiant
cigarettes
ovenb
top burner5
Percbloroethylenff1
50% polyester, 50% rayon
rayon
polyester knit
acetate
acrylic knit
wool blend
cotton
linen
65% polyester, 35% cotton
80% rayon, 15% flax
1.5 mg/m2/hr
0.560 mg/m2/hr initally
0.1 - 0.2 mg/m2/hr after 6 to 27
months
<.0.01 mg/m2/hr
0.01 mg/mz/hr
0.02 mg/m2/hr
0.11-0.28 mg/m2/hr
0.30 mg/mz/hr
0.31 mg/m2/hr
1.5 mg/m2/hr
0.23 mg/m2/hr
0.67 mg/hr
0.33 mg/hr
1.3 mg/hr
0.5 mg/hr
11.4(9.9-14.2) pg/kcal(n=5)
5.2(2.0-12.0) ug/kcal(n=5)
220 ug/m2/hr
55 ng/rn2/hr
430 ug/m2/hr
6700 ug/m2/hr
56 ng/m2/hr
990 ug/m2/hr; 1200 ug/m2/yr
440 ng/m2/hr
570 Mg/m2/Jtir
350 ng/m2/hr
180 ug/m2/hr
CPSC,1985
Matthews etal. 1984
Tray nor et al., 1979
Tkhenor and Sparks, 1988'
(continued next page)
-------
Section 2
IAQ Reference Manual
Exhibit 2*4. Source •mission rates for selected contaminants Continued).
CONTAMINANT AND
MATERIAL
SOURCE EMISSION RATE
REFERENCE
Para-dichlorobenzene
Carbon Monoxide
gas stove'
oven
stove, top burner
kerosene heater, blue flame
reduced fuel consumptionf
kerosene heater, white flame
reduced fuel consumptlonr
kerosene heater, convective
kerosene heater, radiant
wood stove, airtight
wood stove, not airtight
Carbon Dioxide
oven
stove, top burner
kerosene heater, convective
kerosene heater, radiant
Nitrogen Dioxide
gas stoves
oven
stove, top burner
kerosene heater, blue flame
reduced fuel consumption'
1.44mg/cm2/hr
61.7 ± 3.58 ug/kj (n=192)
950 (650-1600) ug/kcal (n=6)
890 (720-1090) ug/kcal (n=4)
125-9 Mg/kJ
1.40
23.9
3.00 ng/kj
1.26 ± 0.49 10"6 ft'5/Btu/hr
1.164,0.48 10-fi ft3/Btu/hr
10-140 cm3/hr (n=7)
220-1800 cms/hr(n=4)
200,000 Mg/kcal
(195,000-250,000) (jg/kcal (n=6)
205,000 Mg/kcal
(196,000-217,000) pg/kcal (n=3)
1376 ±200 10-6 ft3/Btu/hr
1379 ±240 lO'6 fWBtu/hr
10.5 ± 1.43 ng/kj(n=192)
62 (44-74) Mg/kcal (n=ll)
85(69-100)ug/kcai(n=4)
4.7 pg/kj
1-15 Mg/kJ
Clayton and Stephenson, 1988
Borrazzo et at., 1987
Traynor et al,, 1979
Porter, 1984
Ritchie and Arnold, 1984
Traynor etal, 1987
Traynor etaL, 1979
Ritchie and Arnold, 1984
Bonaa.zoet.al. ,1987
Traynor et. al. , 1979
Porter, 1984
-------
IAQ Reference Manual
Section 2
Exhibit 2-4, Source emission rates for selected contaminants (tontinuod).
CONTAMINANT
MATERIAL
SOURCE EMISSION RATE
REFERENCE
Nitrogen Dioxide (continued)
kerosene heater, white flame
reduced fuel consumptionf
kerosene heater, convective
kerosene heater, radiant
Nitric Oxide
gas stoves
oven
stove, top burner
kerosene heater, blue flame
reduced fuel consumptionf
kerosene heater, white flarne
reduced fuel consumptionf
kerosene heater, convective
kerosene heater, radiant
Sulfur Dioxide
oven
stove, top burner
kerosene heater, convective
kerosene heater, radiant
Hydrogen Cyanide
oven
stove, top burner
7.2 ng/kj
1.61 pg/kj
0.211 +. 0.042 10-fi fWBtu/hr
0.025 ± 0.008 ID"* ftVBm/hr
16.8 ± 1.37 Mg/kJ(n=192)
29 (14-50) ug/kcal (n= 1 1)
31(21-47).ug/kcal(n=4)
14.4 ug/kj
0.52 ug/kj
0.41 1 ± 0.105 10-6 fts/Btu/hr
0.014 + 0.008 10-* ft'Btu/hr
0.8(0.5-1.0) ug/kcal (n=ll)
0.8 (0.6-0.9) ug/kcal (n=4)
0.078 ± 0.010 lO'6 ft3/Btu/hr
0.079 ±.0.017 10-6 fP/Btu/hr
1.8 (1.6-2.3) pg/kcal (n=3)
0.07 ug/kcal
Ritchie and Arnold, 1984
!/,, 1987
Traynor et al., 1979
Porter, 1984
Ritchie and Arnold, 1984
Traynor etal, 1979
Ritchie and Arnold, 1984
Traynor et al., 1979
(continued next page)
-------
Section 2
IAQ Reference Manual
Exhibit 2-4. Source emission rates for selected contaminants Uonf/nued).
CONTAMINANT AND
MATERIAL
SOURCE EMISSION RATE
REFERENCE
Total Suspended Partzculates
wood stove, airtight
wood stove, not airtight
no stove, background
Bettzo(a)pyrenet .
wood stove, airtight
wood stove, airtight
no stove, background
2.5-8.7 mg/hr(n=7)
16-230 mg/hr(n=4)
1.1,1.6mg/hr(n=2)
0.02-0.76 ng/hr (n=7)
2.2-57 ug/hr (n=4)
-------
IAQ Reference Manual
Section 2
Exhibit 2-5. Decoy rates lor selected contaminants.
CONTAMINANT AND MATERIAL
DECAY RATE
REFERENCE
Nitrogen Dioxide
based on steel chamber studies
* highest removal
unpainted plaster board
cement block
wool carpet
« high removal
used bricks
masonite
polyurethane foam
• moderate removal
cotton/polyester bedspread
painted plasterboard
plywood (1/4 in)
acrylic fiber or nylon
carpet
ceiling tile (wood fiber)
all viayl wallcovering
with proper backing
• low removal
particleboard
ceramic tile
cotton terrycloth
wool (80%)/polyester (20%) fabric
window glass
galvanized metal duct
formica countertop
vinyl or asphalt tile
Formaldehyde
based on concentration measurements
based on "fast" chamber studies
particleboard underlayment
paneling
medium density fiberboard
based on concentration data for Houston
Particles <1 micron diameter
Radon
Billick and Nagda, 1987
> 8.4/hr
8.4/hr
6.0/hr
4.2/hr
4,1/hr
3.7/hr
2,7/hr
2.6/hr
2.6/hr
1.9 - 2.0/hr
1.9/hr
1.9/br
0.7/hr
0.7/hr
0.3/hr
0.3/hr
<0.1/hr
0
0
0
-0.0182 to-0.0231/mo
(ave = -0.0195)
-0,078/mo (ave)
-0.093/mo (ave)
-0.05 3/mo (ave)
-0.0013 to -0.0028/mo (ave)
0.05/hr
1.258 x lO^/min
Versar, 1985
U.S. CPSC, 1985
Stock and Sixto,
Dockery and
~K.vsvda.etaL, 1980
-------
Section 2
IAQ Reference Manual
Exhibit 2-6. Deposition velocities for
indoor ureas.
CONTAMINANT AND MATERIAL
Sulfur Dioxide
carpet
pink tufted (pH = 4.1)
pile
backing
orange (pH = 3.5)
pile
backing
green (pH = 6,7)
pile
backing
white (pH = 9.2)
pile
backing
mustard (pH = 4.8)
pile
backing
dark green (unused) (pH = 4.3)
pile
backing
dark green (used) (pH - 4.5)
pile
backing
embossed vinyl
wallpaper
paint
gloss
emulsion
selected contaminants on various
DEPOSITION VELOCITY
0.031 cm/sec
0.006 cm/sec
0.053 cm/sec
0.014 cm/sec
0.074 cm/sec
0.016 cm/sec
0.072. cm/sec
0.012 cm/sec
0.022 cm/sec
0.017 cm/sec
0.020 cm/sec
0.0 11 cm/sec
0.029 cm/sec
0.014 cm/sec
0.096 cm/sec
0.007 cm/sec
0.033 cni/sec
0.128 cm/sec
surfaces and
REFERENCES
Walsh eta/., 1977
Walsh eta/., 1977
Walsh etal., 1977
Nitrogen Dioxide
flooring materials
carpet
0.55 to 3.46 m/hr (n = 5)
Miyasaki, 1984
-------
IAQ Reference Manual
Section 2
Exhibit 2-6. Deposition velocities for selected contaminants on various surfaces and
indoor areas (tttntinued).
CONTAMINANT AND MATERIAL
DEPOSITION VELOCITY
REFERENCES
Nitrogen Dioxide (continued)
tatami facing
floor sheet
plastic tile
ceramic tile
bath mat
needle punch
wall materials21
wall paper
printed plywood
ceiling materials"
insulation board
painted insulation board
plaster board
wooden cement board
asbestos cement board
Nitric Oxide
flooring materials3
carpet 1
tatami facing
floor sheet 1
needle punch
ceiling materials
insulation board
painted insulation board
plaster board
wooden cement board
0.46 m/hr
0.04 to 0.09 m/hr (n = 3)
0.12 m/hr
0.15 m/hr
1.97 m/hr
0.47 m/hr
0.06, 0.08 m/hr (n=2)
0.05 m/hr.
4.31 m/hr
2.13 m/hr
0.66 m/hr
1.17 m/hr
1.47 m/hr
0.01 m/hr
0.01 m/hr
0.00 m/hr
0.03 m/hr.
0.00 m/hr
0.04 m/hr
0.11 m/hr
0.12 m/hr
Miyazaki, 1984
Miyazaki, 1984
Miyazaki, 1984
Ozone
fabrics
cotton muslin
lamb's wool
nylon
linen
0.88 - 6.52 cm/min
0.24 - 6.34 cm/min
0.03 - 1.92 cm/min
0.33 - 0.56 cm/min
Saberskytf*/., 1973
(continued next page)
-------
Section 2
IAQ Reference Manual
Exhibit 2-6. Deposition velocities for selected contaminants on various surfaces and
indoor areas (tontinued).
CONTAMINANT AND MATERIAL
DEPOSITION VELOCITY
REFERENCES
Ozone (continued)
building materials
neoprene
plywood (1 side varnished)
polyethylene sheet
lucite
aluminum
plate glass
0.91 -5.79cm/min
0.30 - 1.83 cm/min
0.61 - 1.46 cm/min
0.03 - 0.37 cm/min
0.03 - 0.06 cm/min
0.03 - 0.06 cm/min
Sabersky et al, 1973
* average values from the results of experiments at 20-26°C, 40-60% RH
2.2. SOURCES OF INDOOR AIR
CONTAMINANTS
Exhibit 2-7 provides a more detailed
tabulation of sources and contaminants. Product
categories and examples of products are identified
for major source categories including consumer and
commercial sources, building sources, personal
sources, and outdoor sources. Examples of contami-
nants which have been identified for the product
categories are also given.
Specific compounds are grouped according to
general categories of contaminants (for example,
vinyl chloride is a VOC which has been measured
from building materials). Examples of building
materials are included (pressed wood products,
construction adhesive, insulating materials, plastic
piping, and vinyl or plastic wall coverings). The
reader should not attempt to match specific contaminants
•with specific products.
-------
IAQ Reference Manual
Section 2
Exhibit 2-7. Sources of indoor air contaminants.
SOURCES
CONTAMINANTS
CONSUMER AND COMMERCIAL PRODUCTS
Cleaners and waxes
aerosol bathroom cleaner
unpressurized aerosol window cleaner
liquid all purpose cleaner
powdered abrasive cleaner
dishwashing detergent
concentrated spot remover
liquid floor wax
aerosol furniture wax
aerosol and solid room deodorants
paste furniture wax
oven cleaners
Particulates
• nonmetals (phosphates, other inert powders)
VOCs
• aromatic hydrocarbons (toluene,
p-dkhlorobenzene)
« halogenated hydrocarbons (perchloroethylene;
methylene chloride; 1,1,1-trichloroethane)
» alcohols
» ketones (acetone, methyl ethyl ketone)
* aldehydes (formaldehyde)
• esters (alkyl ethoxylate)
• ethers
Paints and Associated Supplies
paints (oil, urethane, acrylic)
varnishes and shellac
wood stains
paint thinners
paint brush cleaners
paint removers
Pesticides
termite treatment of homes
aerosol all-purpose household pesticides
roach killer (powder, liquid, spray)
flea killer (powder, liquid dip, aerosol)
mold and mildew inhibitors
houseplant insecticides
moth repellents
rodenticides (rat or mouse killer)
Particulates
• metals (lead, mercury, chromium)
VOCs
» aromatic hydrocarbons (toluene)
• aliphatic hydrocarbons (n-hexane, heptane)
« halogenated hydrocarbons (methylene chloride,
propylene dichloride)
• alchohols
• ketones (methyl ethyl ketone, methyl isobutyl
ketone)
• ester (ethylacetate)
• ethers (methyl ether, ethyl ether, butyl ether)
Particulates
• nonmetals (sulfur, lime)
VOCs
• aliphatic hydrocarbons (kerosene)
• aromatic hydrocarbons (xylene)
• halogenated hydrocarbons (chlordane, p-
dichlorobenzene, heptachlor, chloropyrifos,
diazinon)
(continued next page)
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Section 2
IAQ Reference Manual
Inhibit 2-7. Sources of indoor air contaminants (tontinued).
SOURCES
CONTAMINANTS
CONSUMER AND COMMERCIAL PRODUCTS (continued)
Pesticides (continued)
fungicides (household disinfectants)
Adhesives
rubber cement
plastic model glue
floor tile adhesive
ceramic adhesive
carpet adhesive
all-purpose adhesives
Cosmetic/Personal Care Products
perfume
personal deodorants (aerosols, solids)
body powder (talc)
shampoo and body soaps
rubbing alcohol
hair sprays
Automotive Products
hydraulic fluids
motor oils
gasoline
automotive cleaners
automotive waxes
Hobby Supplies
photographic chemicals
specialty adhesives
clay dust
VOCs (continued)
* ketones (methyl isobutyl ketone)
• organic sulfur/phosphorous compounds
(malathion)
VOCs
* aliphatic hydrocarbons (hexane, heptane)
» aromatic hydrocarbons
» halogenated hydrocarbons
* alcohols
• organic nitrogen compounds (amines)
• ketones (acetone, methyl ethyl ketone)
• esters (vinyl acetate)'
• ethers
VOCs
» alcohols (propylene glycol, ethyl alcohol,
isopropyl alcohol)
* ketones (acetone)
• aldehydes (formaldehyde, acetaldehyde)
* esters
• ethers (methyl ether, ethyl ether, butyl ether)
VOCs
• aliphatic hydrocarbons (kerosene, mineral
spirits)
• aromatic hydrocarbons (benzene, toluene,
xylene)
* halogenated hydrocarbons (perchloroethylene)
» alcohols (ethylene glycol, isopropyl alcohol)
* ketones (methyl ethyl ketone)
• amines (triethanolamine, isopropanolamine)
Particulates
« nonmetals (fibers, smoke)
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IAQ Reference Manual
Section 2
Exhibit 2-7. Sources of indoor air contaminants (tontinued).
SOURCES
CONTAMINANTS
CONSUMER AND COMMERCIAL PRODUCTS (continued)
Hobby Supplies (continued)
wood fillers
Furnishings and Clothing
carpets
upholstered furniture
plastic furniture
shower curtains
draperies
blankets
mattresses
VOCs
• aliphatic hydrocarbons (kerosene, hexane,
heptane)
• aromatic hydrocarbons (toluene, xylene, benzene)
• halogenated hydrocarbons (methylene chloride,
ethylene chloride)
« alcohols (benzyl alcohol, ethanol, methanol,
isopropyl alcohol)
• aldehydes (formaldehyde, acetaldehyde)
• ketones (methyl isobutyl ketone, acetone)
« esters [di-(2-ethylhexyl) phthalate} (DEHP)
• ethers (ethylene glycol ether)
• amines (ethylene diamine)
VOCs
• aromatic hydrocarbons (styrene, brominated
aromatics)
• halogenated hydrocarbons (vinyl chloride)
• aldehydes (formaldehyde)
• ethers
• esters (DEHP)
BUILDING SOURCES
Building Materials
pressed wood products
construction adhesive
insulating materials
plastic piping
vinyl or plastic wall coverings
Particulates
• fibers (fiberglass, asbestos)
VOCs
• aliphatic hydrocarbons (n-decane, n-dodecane)
• aromatic hydrocarbons (toluene, styrene,
ethylbenzene)
• halogenated hydrocarbons (vinyl chloride)
• aldehydes (formaldehyde)
• ketones (2-propanone, 2-butanone)
• ethers
• esters (urethane, ethylacetate, DEHP)
(continued next page)
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Section 2
IAQ Reference Manual
Exhibit 2-7. Sources of indoor air contaminants Continued).
SOURCES
CONTAMINANTS
BUILDING SOURCES (continued)
Building Materials (continued)
Heating, Ventilating, and Air-Conditioning
Systems
furnaces (carbon-based fuels)
air conditioner reservoirs
Garages
vehicular exhaust
stored chemicals (pesticides, paints, solvents,
gasoline)
Combustion Appliances
unvented heaters (kerosene, gas)
gas cooking stoves
woodburning stoves and fireplaces
Radioactive Contaminants
• radon gas
Inorganic Gases
• sulfur dioxide, nitrogen oxides, carbon
monoxide, carbon dioxide
Particulates
• nonmetals (fiberglass, molds, smoke)
VOCs
• aliphatic hydrocarbons (methane)
Polynuclear Aromatic Hydrocarbons
• benzo(a)pyrene
Inorganic Gases
• sulfur dioxide, nitrogen oxides, carbon
monoxide
Particulates
• metals (lead, nickel, platinum, palladium)
VOCs
• aromatic hydrocarbons (benzene)
• chlorinated hydrocarbons, other substituted
hydrocarbons
Polynuclear Aromatic Hydrocarbons
• benzo(a)pyrene
Inorganic Gases
• sulfur dioxide, nitrogen oxides, carbon
monoxide, carbon dioxide
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IAQ Reference Manual Section 2
Exhibit 2-7. Sources of Indoor air contaminants (tontinued).
SOURCES CONTAMINANTS
BUILDING SOURC1S (continued)
Combustion AppMances (continued) VOCs
» aliphatic hydrocarbons (propane, butane,
isobutane)
Polytiucleat Aromatic Hydrocarbons
• ben2o(a)pyrene
Radioactive Contaminants
« radon
Aldehydes
* acetaldehyde, acrolein
PERSONAL SOURCES
Tobacco Smoke Over 3800 Compounds Including:
Inorganic Gases
Metals
Particulates
Radioactive Contaminants
VOCs
Organic Nitrogen Compounds
Ketones
Polynuclear Aromatic Hydrocarbons
Human and Biological Origin Inorganic Gases
animal feces * ammonia
pets
indoor plants (spores, pollen) Particulates
metabolic products • nonmetals (dander, feces)
pathogens
VOCs
• * aliphatic hydrocarbons (methane)
« aromatic hydrocarbons (toluene)
* aldehydes (acetaldehyde)
(continued next page)
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Section 2
IAQ Reference Manual
Exhibit 2*7. Sources off Indoor air contaminants faontinved).
SOURCES
CONTAMINANTS
OUTDOOR SOURCES
Soils and Rocks
Outdoor Air
industrial emissions
contaminated groundwater
vehicular exhaust
Potable Water
volatilization of VOCs during showering,
bathing, other uses of potable water
Humidifiers
Contaminated Groundwater
seepage into basements
Radioactive Contaminants
» radon gas
Inorganic gases
* carbon monoxide, sulfur dioxide, nitrogen
dioxide, ozone
Particulates
« metals (lead, other metals of respirable size
•range)
* nonmetals (fibers)
VOCs
* aliphatic hydrocarbons
• aromatic hydrocarbons
* halogenated hydrocarbons
• aldehydes and ketones
» alcohols
« esters
» ethers
• organic nitrogen compounds
» organic sulfur/phosphorous compounds
Radioactive Contaminants
« radon gas
YOCs
* halogenated hydrocarbons (1,1,1-
trichloroethane, chloroform, tricMoroetbylene,
tetrachloroethylene)
Particulates
• aerosolized asbestos and minerals, biological
contaminants
Radioactive contaminants
VOCs
SOURCE: Adapted from U.S. BPA. (198?)
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IAQ Reference Manual
Section 2
REFERENCES
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers (ASHRAE), 1985. "Natural ventilation and
infiltration." Chap. 22. 1985 ASHRAE Handbook. Fundamen-
tals. ASHRAE: Atlanta, GA.
American Society of Hearing, Refrigerating, and Air-Condi-
• tioning Engineers (ASHRAE). 1989. 1989 ASHRAB
Handbook: fundamentals. I-P edition. ASHRAE: Atlanta, GA.
AxIey.J.W. 1987. "The NBS multi-zone model." Presented
at the 1987 Annual Meeting of Pacific Northwest International
Section of the Air Pollution Control Association." November
8-10. Seattle, WA.
Billick, I.H. and N.L. Nagda. 1987. "Reaction decay of
nitrogen dioxide." Indoor Air '87 VoL 1, Volatile Organic
Compounds, Combustion Gases, Particles and Fibers, Microbiological
Agents, Oraniendruck GmbH: Berlin, Germany, pp. 311-
315.
Borrazzo, J.E., C.I. Davidson, and C.T. Hendrickson. 1987.
"A statistical analysis of published gas stove emission factors for
CO, NO, andNO2." Indoor Air'87, "Vol. 1 Volatile Organic
Compounds, Combustion Gases, Particles ami Piters, Microbiological
Agents, Oraniendruck GmbH: Berlin, W. Germany, pp.
316-320.
Clayton, R. and E. Stepheoson. 1988. Indoor Air Quality Test
House Mothcake Testing. IABReport88-5. U.S. Environmen-
tal Protection Agency: Research Triangle Park, NC.
Dockery, D.W. andJ.D. Spengler. 1981. "Indoor-outdoor
relationships of respirable sulfates and particles." Atmos,
Environ. 15: 335-343.
Kusuda, T., S. Silberstein, and P.E. McNall, Jr. 1980.
"Modeling of radon and its daughter concentrations in
ventilated spaces." J, Air Poll, Control Assoc. 30: 1201-1207.
Matthews, T.G., T.J. Reed, B.J. Tromberg, C.R. Daffron, and
A.R. Hawthorne. 1984. "Formaldehyde emissions from
consumer and construction products: potential impact on
indoor formaldehyde concentrations." Indoor Air, Vol. 3,
Sensory and Hypernactivity Reaction to Sick Buildings. Swedish
Council for Building Research: Stockholm, Sweden, pp. 115-
120.
McNall, P., G. Walton, S. Silberstein, J. Axley, K, Ishiguro,
P. Grot, and T. Kusuda. 1985. Indoor Air Quality Modeling,
Phase 1 Report, framework for Development of General Models.
NBSIR 85-3265. U.S. Department.of Commerce, National
Bureau of Standards: Gaithersburg, MD.
Miyazaki, T. 1984. "Adsorption characteristics of NOs by
several kinds of interior materials," Indoor Air, VoL 4.
Chemical Characterization and Personal Exposure, Swedish Council
for Building Research: Stockholm, Sweden, pp. 103-110.
Nagda, N.L., H.B. Rector, and M.D. Koontz. 1987. Guidelines
for Monitoring Indoor Air Quality. Hemisphere Publishing Corp.:
New York.
National Research Council (NRC). 1981. Indoor Pollutants.
National Academy Press: Washington, DC.
Porter, W.K, 1984. "Pollutant emissions from kerosene
heaters and unvented gas space heaters." Indoor Air, Vol. 4-
Chemical Characterization and Persona/ Exposure, Swedish Council
for Building Research: Stockholm, Sweden, pp. 265-270.
Repace, J.L. 1987. "Indoor concentrations of environmental
tobacco smoke: models dealing with effects of ventilation and
room size." Chapt. 3. Environmental Carcinogens, Methods of
Analysis and Exposure Assessment, VoL 9—Passim Smoking. I.K.
O'Neill, K.D. Brunnemann, B. Dodet, and D. Hoffman (eds).
IARC Scientific Publications No. 81. World Health Organiza-
tion, International Agency for Research on Cancer: Lyon,
France, pp. 25-41.
Ritchie, I.M. and F.C. Arnold. 1984. "Characterization of
residential air pollution from unvented kerosene heaters."
Indoor Air, Vol. 4- Chemical Characterization and Personal
Exposures. Swedish Council for Building Research: Stockholm,
Sweden, pp. 253-258.
Sabersky, R. H., D.A. Sinema, and F.H. Shair. 1973.
"Concentrations, decay rates and removal of ozone and their
relation to establishing clean indoor air," Envirtn, Sci. Technol,
7: 347-353.
Sexton, K. and S.B. Hayward. 1987. "Source apportionment of
indoor air pollution." Atm. Environ. 21(2): 407-418.
Sexton, K. and P.B. Ryan, 1988. "Assessment of human
exposure to air pollution: Methods, Measurements, and
Models," Air Pollution, the Automobile and Public Health. A.
Watson, R.R. Bates, and D. Kennedy (eds). National Academy
Press: Washington, DC. pp. 207-238.
Sherman, M.H. and D.T. Grimsrud. 1980. "Infiltration-
pressurization correlation: Simplified physical modeling."
ASHRAE Transactions. 86(3): 778-807.
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Section 2
IAQ Reference Manual
Sparks, 1,1. 1988. Indoor Air Quality Model Version 1,0, EPA-
600/8-88-097a. U.S. Environmental Protection Agency, Air
and Energy Engineering Research Laboratory: Eesearch
Triangle Park, NC
Stock, T.H. and R.M. Sixto. 1985. "A survey of typical
exposures to formaldehyde in Houston area residences." Amer.
lnd.Hyg.Assoc.J, 46; 313-317.
Traynor, G.W., D.W. Anthon, and C.D. Hollowell. 1979.
Indoor Air Quality: Gas Stove Emissions, Lawrence Berkeley
Laboratory: Berkeley, CA. As cited in National Research
Council (NRC), 1981. Indoor Pollutants. National Academy
Press: Washington, DC.
Traynor, G.W., M.G. Apte, A.R. Carruthets, J.F. Dillworth,
D.T, Grimsrud, and L.A. Gundel. 1985. "Indoor air pollution
due to emissions from wood-burning stores." LBL-17854.
Lawrence Berkeley Laboratory, Building Ventilation and Indoor
Air Quality Program: Berkeley, CA,
Tichenor, B.A., L.E. Sparks. 1988. Evaluation ofperchlmetbyl-
ern emissions from dry cleanedfabrics. EPA-600/2-88-061. U.S.
Environmental Protection Agency: Washington, DC.
U.S. Consumer Product Safety Commission (CPSC). 1985.
"Pressed wood products exposure assessment report." U.S.
CPSC: Washington, DC.
U.S. Environmental Protection Agency (EPA). 1987. Draft
Report. Indoor Air Pollution, The Magnitude and Anatomy of
Problems and Solutions, U.S. EPA, Office of Air and Radiation
Programs: Washington, DC,
Versar, Inc. 1985. "Formaldehyde exposure in residential
settings: sources, levels and effectiveness of control options,"
Draft Final Report. As cited in U.S. Consumer Product Safety
Commission (CPSC). 1985. "Pressed wood products exposure
assessment program," U.S. CPSC: Washington, DC.
Walsh, M., A. Black, A. Morgan, and G.H. Crawshaw, 1977.
"Sotption of SO2 by typical indoor surfaces, including wool
carpets, wallpaper and paint." Atm. Environ. 11: 1107-1111.
Wadden, R. A. and P.A. SchefF, 1983. Indoor Air Pollution.
John Wiley & Sons: New York, NY.
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SiCTION 3.
DEFINING HEALTH
EFFECTS AND RISK
ASSESSMENT
Section 3-1 contains a discussion of
what constitutes an adverse health
effect from the perspective of different
public health organi2ations; Section
3.2 provides an overview of the
structure and function of the respira-
tory tract and its defense mechanisms;
Section 3.3 provides an overview of
the process of risk assessment; and
Section 3.4 provides a summary of
EPA cancer risk assessments for
specific indoor air contaminants.
Table of Contents
Section 3.1. Defining Adverse Health Effects
Section 3.2. The Respiratory Tract
Section 3.3. Risk Assessment
Section 3.4. EPA Cancer Risk Assessments for
Indoor Air Contaminants
30
31
36
43
list of Exhibits
Exhibit 3-1. Structure of the respiratory tract. 35
Exhibit 3-2. Commonly used ventilatory measurements. 36
Exhibit 3-3- EPA cancer risk assessments. 44
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Section
1AQ Reference Manual
3.1, DEFINING ADVERSE HEALTH EFFECTS
i here is a range of effects that can occur
from exposure to indoor air contaminants. Some
exposures result in body burdens which do not
produce physiologic changes or morbidity. Others
can produce mild discomfort at one extreme, and
mortality at the other. Because of these broad
ranges of effects and variability in susceptibility, it
is useful to review different approaches to the
question of whether or not an exposure has resulted
or can result in adverse health effects.
The American Thoracic Society (Andrews, et al,t
1985) has developed guidelines which define
adverse respiratory effects. These guidelines were
developed within the context of the Clean Air Act
as it applies to protection of the public agajnst
adverse health effects from outdoor air contami-
nants. In this context, the Society's Scientific
Assembly on Environmental and Occupational
Health defines adverse effects as "medically signifi-
cant physiologic or pathologic changes" that
interfere with normal activity, cause episodic
respiratory illness, incapacitating illness, permanent
respiratory injury, and/or progressive respiratory
dysfunction.
Recognizing that the determination of adverse
health effects is not entirely medical, but also a
subjective societal decision, the Assembly listed
potential health effects in a hierarchy of severity and
did not demarcate between adverse and nonadverse
effects. Thus, the definition of "medically signifi-
cant" is broadly interpreted and includes:
asthmatic attacks;
reports of chronic respiratory symptoms;
the need to take pulmonary medication;
decreased pulmonary function;
increased prevalence of wheezing;
chest tightness;
cough/phlegm;
acute upper respiratory infections;
eye, nose, and throat irritation; and
odors.
This listing provides guidance that recognizes that
irritation and odor effects can be interpreted as
adverse health effects.
The American Society of Hearing, Refrigerat-
ing, and Air-Conditioning Engineers
{ASHRAE), in ASHRAE Standard 62-1989,
defines acceptable air quality as "air in which there
are no known contaminants at harmful concentra-
tions as determined by cognizant authorities and
with which a substantial majority (80% or more) of
the people exposed do not express dissatisfaction."
ASHRAE also explicitly identifies discomfort effects
as unacceptable.
ASHRAE Standard 62-1989 reflects a concern for
the growing number of sick building syndrome
complaints by building occupants. This definition
also reflects the Society's traditional interest in
occupant satisfaction with the building's thermal
environment. Thus, the ASHRAE definition and
the background information to the procedures
section of the Standard provide considerable latitude
in determining whether or not adverse effects occur.
The American Public Health Association's
Model Housing Code (Mood, 1986) also provides
latitude in addressing adverse health effects. The
term "cognizant authority" used by ASHRAE is also
used in APHA's Model Housing Code, In APHA'S
model code, the term usually refers to the local
health officer who has the responsibility of deter-
mining whether or not the presence of a contami-
nant is harmful.
The World Health Organization's Working
Group on Indoor Air Quality (WHO, 1983) did not
explicitly define adverse health effects, but identi-
fied the following effects as adverse: odor, irrita-
tion, airway effects, carcinogenic effects, systemic
effects, and respiratory disease.
Based on these sources, an adverse health effect
could be interpreted broadly to include effects
which are medically significant, physiologic or
pathologic changes which do not result in the
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IAQ Reference Manual
Section 3
expression of symptoms and/or frank disease, and
discomfort effects, including odors. Decreases in
productivity should also be added to this list.
This interpretation reflects an emerging interna-
tional consensus of individuals and organizations
involved with indoor air quality. Woods (1986)
aptly distills the criteria for judging building
performance based on presentations and discussions
from Indoor Air 84, the Third International Confer-
ence on Indoor Air Quality and Climate. As
summarized by Woods, these criteria include the
ability of the building to provide for the health,
safety, comfort, acceptability, well-being, and
productivity of occupants.
3.2. THE RESPIRATORY TRACT
Every person breathes in 10,000 to 20,000
liters of air each day that contain several million
particles and gas molecules. It is one of nature's
wonders that the respiratory tract is able to cleanse
much of this contaminated air by the time the air
reaches the region of the lungs where gas exchange
takes place.
The respiratory tract is protected from injury by
many interrelated defense mechanisms including
mechanical defenses, fluids that line the airways,
airway reflexes, and antimicrobial, inflammatory
and immune defenses. If one or more of these is
impaired, respiratory damage and disease can result.
An understanding of the structure and defense
mechanisms of the respiratory tract is a useful first
step toward understanding many of the respiratory
related health effects associated with indoor air
• contaminants.
Structure of the Respiratory Trait
The respiratory ttact can be divided into three
regions: the nasopharyngeal region, the tracheo-
bronchial region, and the pulmonary region (Ex-
hibit 3-1).
Nasopharyngeal Region
The nasopharyngeal region is the upper portion of
the respiratory tract, and it consists of the nose,
mouth, pharynx, and larynx, A primary function of
this region is to condition the temperature and
humidity of the air in the nose.
As air enters the nose, nasal hairs trap some of the
larger particles. Another important defense mecha-
nism is the turbulent flow of air in this region. The
airflow is turbulent because of turbinates and the
small cross-sectional area in the nasopharynx.
Larger particles (>8-10 urn) are removed by inertial
impaction, and there is a tapid drop in the deposi-
tion rate of particles having a mass median diameter
of less than 1 micron.
Other defense mechanisms include the presence of
nasal secretions and mucociliaty clearance. Highly
soluble or reactive gases such as sulfur dioxide and
formaldehyde are effectively absorbed by or interact
with nasal secretions, which decreases the concentra-
tion of these contaminants that reach the lower
airways,
TracheobroocMal Region
The tracheobtoochlal region includes the trachea
and bronchi. The trachea, a tube about 4.5 inches
long and 1 inch in diameter, extends from the
bottom of the larynx through the neck and into the
chest. At the lower end, it divides into two tubes,
the right and left bronchi. These conducting
airways are lined with ciliated epithelium and
coated with & thin layer of mucus which is secreted
by goblet cells and rnucus-secreting cells. The
airway secretions are about 95% water, and the
remainder consists of carbohydrates, proteins,
inorganic materials, and small amounts of antimi-
crobial substances.
The nasopharyngeal and tracheobronchial regions
also have "irritant" receptors which are located in
the epithelium. Inhaled gases or particles can
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Section 3
IAQ Reference Manual
activate the irritant receptors and initiate
bronchoconstriction, mucus hypersecretion, and
rapid breathing. Bronchoconstriction is a reaction
in which the smooth muscles of the airways con-
strict, causing the airways to narrow.
Contaminants in this region are removed by impac-
tion onto the airway secretions and removal by the
action of the cilia. The cilia are hairlike filaments
that wave back and forth at about 12 times per
second. They are abundant in the respiratory tract
from the nose to the terminal bronchioles. Their
role is to propel mucus that contains contaminants
from the airways to the upper respiratory tract
(called mucociliary transport mechanism or
mucociliary escalator) where the mucus may be
swallowed or expelled by sneezing or coughing.
If the cilia become damaged (for example, by
tobacco smoke), they cannot propel the mucus. It
remains in the airways until it is coughed up and
expectorated or- swallowed. (Heavy smokers typi-
cally have to cough up mucus in the mornings when
they arise because of a buildup of mucus during the
night—as a result of cilia which are not able to
remove mucus efficiently.)
Within each lung, the bronchi divide and subdi-
vide, becoming smaller and smaller. The branches
at the farthermost reaches of the lung (pulmonary
region) are very small and are called bronchioles.
This division or bifurcation can be visualized by
thinking of the trachea as the trunk of an upside
down tree, and the bronchi and bronchioles as the
branches which become smaller and smaller,
The bronchioles do not contain as many ciliated
cells as the larger airways; they have almost no
mucus producing cells and a very thin layer of
airway secretions that line airways. The bronchioles
appear to be particularly susceptible to injury from
contaminants, particularly cigarette smoke and
ozone.
Pulmonary Region
The pulmonary region is the area where gas ex-
change occurs. The bronchioles lead into several
ducts (alveolar ducts), each of which ends in a
cluster of air sacs. Each cluster (alveolar sac)
resembles a tiny bunch of grapes and ends in tiny air
sacs called alveoli. The walls of the alveoli are thin
membranes only one to two cells thick through
which oxygen and other gases can pass freely.
From top to bottom, the respiratory tract branches
from the trachea into 25 to 100 million branches,
and these branches end in about 300 million alveoli.
These alveoli have a combined cross sectional area of
about 8,6 ft2 (an amazingly large area considering
that the cross sectional area of the trachea is only
about .31 in2) COlishifski and Benjamin, 1988].
Gas exchange in the alveolar region is based on the
principle that gases diffuse rapidly from areas of
higher concentration to areas of lower concentration.
In the body, the concentration of oxygen (and any
contaminants) is higher in the alveolae air than it is
in the blood coming from the body's tissues. At the
same time the pulmonary artery brings oxygen
deficient blood from the body tissues back to the
capillaries which are in contact with the alveoli,
Oxygen from the lungs diffuses from the alveoli to
the body via the pulmonary vein, which carries the
blood to the heart. Some of the oxygen is carried in
solution in the plasma, and the remaining is
combined with hemoglobin in the red blood cells to
form oxyhemoglobin. The oxygen is then released
by the hemoglobin whenever the oxygen tension of
the plasma decreases. As the oxygen diffuses from
the plasma into the tissue capillaries, it is continu-
ally replenished by more oxygen' from the oxyhemo-
globin.
The diffusion of carbon dioxide follows the same
principle, but the concentration of carbon dioxide is
higher in the body tissues than in the incoming air.
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IAQ Reference Manual
Section 3
Contaminants that reach the air-exchange surfaces of
the terminal alveoli are intercepted, ingested, and
processed by alveolar macrophages or polymorpho-
nuclear leucocytes. Once these cells have completed
their work, they exit the lung via the mucociliary
escalator or via the lymphatic system.
Those contaminants (such as carbon monoxide) that
are not removed by the lung's defense mechanisms
can enter the blood and lymph systems, resulting in
the transport of contaminants to the organs where
adverse effects can occur.
The bronchioles and the alveoli appear to be
particularly susceptible to injury from inhaled
toxicants. This may occur because under normal
conditions the bronchioles contain fewer ciliated
cells than larger airways, almost no mucus-produc-
ing cells, and the clearance mechanism of this
region is relatively slow.
Modes off Action (Oases, Particles)
The mode of action of contaminants in the respira-
tory system depends on the characteristics of the
gases and particles and on the individual's rate and
type of breathing (oral, nasal, or combination).
Particles and gases that reach the conducting
airways first interact with liquids that line the
respiratory tract. Reactions with these liquids can
potentially increase the susceptibility of the under-
lying airway epithelium to injury. Acute effects
include inflammation and pulmonary edema;
chronic effects include bronchitis, bronchiolitis,
fibrosis, emphysema, alveolitis, and cancer.
Gases
Important characteristics of gases which determine
how they behave in the respiratory tract include
solubility, reactivity, and concentration. Soluble
gases are absorbed in the upper airways, where they
may be buffered, detoxified, diffuse into the sys-
temic circulation, or exert a pathologic effect.
Extremely water soluble gases such as ammonia and
sulfur dioxide most often cause upper airway
irritation and injury. Sulfur dioxide is highly
soluble, and about 90% of all sulfur dioxide that is
inhaled is absorbed in the upper respiratory passages
with only slight penetration to the lower respiratory
tract.
Ozone is several hundredfold less soluble than sulfur
dioxide, and less of it will be absorbed in the upper
respiratory tract. If the breathing rate is increased
or if breathing switches from nose to mouth, less of
each contaminant is removed in the upper respira-
tory tract and more will reach the middle and lower
portion of the lungs. Nitrogen dioxide is less
soluble and less reactive than ozone. Therefore, it
could penetrate more deeply into the lungs.
Insoluble gases such as carbon monoxide, which are
not reactive with airway secretions or cells, can
reach the lower lung and diffuse into the blood-
stream in- the same concentrations as they were
inspired.
. Particulates
The action of particulates depends on size, shape,
density, and reactivity of the particulates. Particles
will be deposited in one of the' three regions of the
lung depending on the velocity of the airstream and
the size of the particles (Task Group on Lung
Dynamics, 1966).
Larger particles are deposited primarily in the
nasopharyngeal region. As particles are inhaled,
some are deposited as the airstream passes through'
the nose and pharynx. In this region, the changing
path of the airstteam causes larger particles to be
removed by impaction on the airway walls because
they cannot negotiate the turbinates. Particles
greater than about 10 microns in diameter are
effectively trapped by the nasopharyngeal defense
mechanisms. About 60-80% of particles in the size
range 5 to 10 microns in diameter are trapped in
this zone. Small particles (less than 5 microns in
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diameter) are not effectively trapped in this zone—
only 5% are trapped and the remainder can travel to
the lower regions of the lung (Task Group on Lung
Dynamics, 1966),
In the tracheobronchial region, airflow is slower and
particles are deposited by sedimentation and
impaction. This region has minimal deposition of
particles except for very small particles which are
deposited by diffusion. About 10% of the particles
in the size range 1 to 10 microns in diameter and
30% of particles 2 to 5 microns in diameter are
deposited in this zone (Task Group on Lung
Dynamics, 1966).
In the pulmonary region, particles ate deposited by
diffusion, and one method of removal occurs by
macrophages. In this region there is a maximum
efficiency of deposition at a size around 0.1 microns
in diameter or less and between about 1 and 2
microns in diameter (about 30?6 deposition), and
there is a minimum efficiency for particles about 0.5
microns in diameter (Task Group on Lung Dynam-
ics, 1966).
The air sac linings are coated with a fluid film that
serves the same cleansing function as the fluid in the
breathing tubes. Deposited particles or dissolved
panicles and gases may be removed by the fluid
which flows upward in the air sacs. The macro-
phages, in turn, can migrate to the small bronchi-
oles where they are removed by the mucociliary
escalator, or they may pass through the alveolar
membrane into the lymph system. Macrophages
can also be destroyed and release particles into the
alveolar sac. If particles are not removed by these
means, they may form a deposit in the air sac which
may or may not result in health effects,
The rate of clearance of particles is important in
determining the responses to contaminants, espe-
cially slow acting toxicants such as carcinogens.
The residence time of particles ranges from minutes
to hours in the upper respiratory tracts hours to days
in the tracheobronchial region, and days to months
in the pulmonary region.
Pattern of Breathing
The type and rate of breathing also affect the
deposition of particles and gases. During mouth
breathing, larger particles will get deeper into the
lung if the breathing is slow, deep, and with large
lung volumes. Mouth breathing bypasses the
defense mechanisms in the nasopharyngeal region.
Pulmonary Function Tests
In many scientific studies pulmonary function tests
are performed to determine if contaminants can
adversely affect the respiratory tract, and physicians
also use pulmonary function tests to determine if
lung function has been impaired. Large decreases in
pulmonary function provide evidence of an adverse
respiratory effect, but small changes may or may not
be significant.
The American Thoracic Society's Scientific Assem-
bly on Environmental and Occupational Health
views pulmonary function tests which to reflect
inflammatory changes of the small airways equivo-
cally. The Assembly observes that preliminary
results indicate that these tests may predict suscep-
tibility' to respiratory disease or increased respon-
siveness, but concludes the results should not be
used as indicators of adverse health effects in
individuals. The Assembly's ambiguity reflects the
current scientific data base in this area,
The ventilatory capacity of the lungs can be mea-
sured by a spirometer. The spirometer is an instru-
ment which measures volumes of air and relates
them to time (Exhibit 3-2 summarizes some of the
commonly used terms of pulmonary function tests),
Small, portable spirometers which can be used in
field work can be purchased. These instruments can
provide basic ventilatory measurements. More
sophisticated tests require laboratory spirometry
equipment.
Lung function testing is probably most useful in the
evaluation of lung function after occupational
exposures or as a component of research, but there
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may be some instances when it may be an appropri-
ate component of an indoor air quality investiga-
tion. The investigator should know that lung
function tests have limitations. The results of these
tests vary considerably among normal people of the
Exhibit 3-1. Structure of the respiratory trail.
same sex, age, and height. Whenever these tests are
conducted as part of an indoor air quality assess-
ment, a physician or other knowledgeable person
should conduct and interpret results.
Frontal Sinus
Maxlory Sinus
/
Adenoids
Sphenoids! Sinus
Pharynx
Epiglottis
Esophagus
Lymph Node
Nasal Cavity
Oral Cavity
Tongue
Right Main Bronchus
Upper Lobe of Right Lung
Middle Lobe
lower lobe
Diaphragm
Alveolui(AirSac)
Pulmonary Vein
Capillaries
Pulmonary Artery
Upper Lobe of bft king
lower Lobe
Pleura! Space
Bronchial Cilia
Mucous
Cells
SOURCE: Reprinted with permission of the American Lung Association.
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Exhibit 3-2. Commonly used ventilatory measurements.
TERM
SYMBOL
DESCRIPTION
vital capacity
forced vital capacity
one-second forced
expiratory volume
one-second forced
expiratory volume
expressed as a
percentage of BVC
maximal voluntary
ventilation
VC
FVC
p
PEV^xlOQ
FVC
MW
The largest exhaled volume of air measured after a
maximal inspiration followed by a maximal expira-
tion without forced or rapid effort,
The vital capacity performed with expiration as
forceful and rapid as possible.
Volume of air exhaled during the first second of
a forced vital capacity; normally, the FEVj is about
80% of the FVC.
The observed FEVt expressed as a percentage of the
observed FVC. The ratio is typically normal or
increased in restrictive diseases and reduced in
obstructive deseases.
Volume of air which a subject can breathe with
voluntary maximal effort for a given time (10-15
sec., if possible, equated to 1 min.).
SOURCE; West (1980), Olishififci and Benjamin (1988)
3.3. RISK ASSESSMENT
JKisk assessment is a tool that has been
used increasingly in the fields of environmental
science and health to identify the probability of
injury, disease, or death from exposure to agents
(chemical, physical or biological) under specific
circumstances. Risk assessments attempt to answer,
either qualitatively or quantitatively, basic ques-
tions such as: Is the water, food, or air safe? Will
acute or chronic effects result? If there is an effect,
will it occur in months, years, or decades? How
many people are likely to be affected by exposure to
the agent?
Risk assessment can also be used to evaluate the net
risk and costs associated with a particular policy.
For example, before water was chlorinated, many
deaths occurred from infectious disease outbreaks
such as typhoid and cholera. More recently, the use
of chlorine to disinfect water is known to increase
the rate of formation of halogenated hydrocarbons.
Risk analysis can be used to compare the risk (and
therefore cost) of illness associated with not chlori-
nating water to the increased risk of cancer from
chlorination byproducts,
The process of risk assessment is not infallible.
Caution must be used in making assumptions and
selecting input data for the assessments. When risk
assessments are used, the uncertainty associated
with them must always be acknowledged.
Useful references for additional information on risk
assessment include several articles on cancer risk
assessment (Calabrese, 1987; Menzel, 1987; Sielken,
1987; Severn, 1987; Wilkinson, 1987) and guide-
lines published by EPA for conducting exposure
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assessments and assessing risks from carcinogens,
mutagens, teratogens and chemical mixtures (U.S.
EPA, 1986 a-e). EPA's risk assessment methodolo-
gies are currently under review and revised guide-
lines are anticipated.
Assessment vs Management of Risk
Once the risk associated with exposure to an agent
has been defined, a policy can be developed to
manage that risk. In the environmental and health
fields, risk assessments are generally performed by
scientists and engineers, and the management of
risk is usually a decision made by a governmental
agency,
Risk management is a socio-political decision on
whether or how much to control future exposure to
the contaminant or activity under consideration.
The risk assessment portion of the decision-making
process should be carried out independently from
considerations of the consequences of risk manage-
ment. The risk management decision depends in
part on the risk assessment, but also on the consid-
eration of social, economic, and political factors.
Measures of Risk
Risk assessments are used to measure the likelihood
of a specific effect, such as death from acute hazards
(in early deaths/year), cancer (in early deaths/year),
and various types of chronic conditions (in cases/
year).
Risk can be measured for a population or an indi-
vidual, A population risk is the number of occur-
rences of a hazard per year within a given popula-
tion. For example, assume there were 15 million
automobile accidents in the U.S. in 1988; of these,
assume that about 1 in 300 resulted in the death of
an individual. The population risk-is 1/300 x 15
million, or 50,000 deaths/year.
The individual risk is the probability of a single
occurrence affecting an individual during a year,
For the automobile accident example, the individual
risk of dying as a result of an automobile accident is
about 50,000 deaths/year/250 million people. This
means that an individual has a 2 in 10,000 chance
(or 1 in 5000) chance of dying as a result of an
automobile accident.
The above examples are quantitative estimates of
risk, but risk can also be expressed in qualitative
terms using categories such as "low," "medium,1* or
"high."
Perception of Risk
There is a difference between the measure of risk
and the perception of risk. The measurement of risk
is based upon an estimated likelihood or frequency
of an effect. The perception of risk is based upon a
societal-political or personal interpretation and
acceptance of the hazard posed by a situation or
chemical exposure. For example, people who drive
cars, but do not wear seatbelts, may perceive their
risk to be less than the actual risk of driving
without wearing seatbelts. On the other hand, the
perceived risk of flying may be considerably higher
than the actual risk for those people who are afraid
to fly.
Risks can be voluntary or involuntary and may
result from natural or synthetic substances. In
general, people are willing to accept higher risks
from voluntary exposure to agents (for example,
smoking) than from involuntary exposure (for
example, pesticide residues in food). Also, people
might be willing to accept a cancer risk of 1/10,000
or 1/100,000 as a result of eating peanut butter
containing low levels of naturally occurring afla-
toxin, but they might reject having a synthetic
chemical with a cancer risk of 1/100,000 in their
water supply,
The Risk Assessment Process
EPA has published guidelines for performing risk
assessments of carcinogens, mutagens, chemical
mixtures, and developmental toxicants (U.S. EPA
1986 a-e). The basic elements of risk assessment
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which are identified in the guidelines include one or
more of the following: hazard identification, dose-
effect evaluation, exposure assessment, and risk
characterization. Examples used in the discussion of
these elements below ate taken predominantly from
carcinogenic risk assessment, not because it is more
important, but because this area is the most devel-
oped.
Hazard Identification
Hazard identification is the process of determining
whether or not exposure to an agent can cause an
increase in the incidence of a health condition. This
involves a review and analysis of available scientific
information to determine whether or not an agent
poses a particular risk.
Information which is used to identify hazards is
obtained from cellular and tissue studies, animal
studies, controlled human exposure studies, case
studies of humans exposed in accidents or in the
workplace, and epidemiologic studies,
Carcinogen risk assessment: A hazard identifica-
tion to determine whether or not a contaminant
poses a carcinogenic risk should include information
on the nature of contaminants, degradation prod-
ucts, and metabolites. The available scientific
literature should be reviewed for the following key
elements;
» physical and chemical properties which
affect the distribution and decay of the
chemical in the body;
• routes and patterns of exposure;
» structural or activity properties of the
chemical or its metabolites that support or
argue against the prediction of potential
carcinogenicity;
» metabolic and pharmacokinetic properties
of the chemical which determine how the
chemical is distributed, metabolized, and
excreted in the animal or human;
• toxicologic effects other than carcinogenic-
ity, interactions with other chemicals or
agents and with lifestyle factors, and other
factors relating to toxicologic effects;
• short-term predictive tests which detect
chemical interactions with DNA and assess
mutagenic activity;
» long-term animal studies which identify
the tumorigenic or carcinogenic potential of
the chemical; and
« human epidemiologic studies which
examine the association between the
chemical and the incidence of cancer.
Of these elements, animal and human epidem-
iologic studies have been the most widely used
sources of data to evaluate hazards, but they do have
limitations.
Animal studies are used because it is assumed that
effects in humans can be inferred from effects in
animals. This assumption is generally accepted
because-all the chemicals that have been demon-
strated to be carcinogenic in humans (except
possibly arsenic) have been shown to be carcinogenic
in some, but not all, animal species. Even so,
caution must be used when animal studies are
interpreted because there are potential differences in
the way different species metabolize, distribute, and
excrete chemicals.
The overall confidence that an ageot which is
carcinogenic in animals will be carcinogenic in
humans increases with the following types of
evidence:
» an increase in the number of animal species
and strains showing an effect, and with
both sexes showing an effect;
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an increase in. the number of tissue sites
affected by the agent;
the presence of a clear-cut dose-effect
relationship;
a high level of statistical significance of the
increased tumor incidence in treated
compared to control groups;
a dose-related shortening of the time for
tumors to form or death to occur as a result
of tumors; and
a dose-related increase in the proportion of
tumors which become malignant.
Humaua epidemiologic studies which are properly
designed and conducted provide the most direct
information about the toxicity of a particular
contaminant. These studies, however, are not
available for most chemicals because of the complex-
ity and cost associated with gathering these data.
Epidemiologic studies require large sample si2es for
statistical reasons, and long time periods are needed
to observe effects such as cancer. It is also difficult
to quantify exposures because confounding variables
such as socioeconomic effects, personal habits such
as smoking and drinking, and other risk factors may
not be known or cannot be adjusted for in the
calculations.
Because of the problems associated with epidemio-
logic studies, animal studies and the other types of
evidence listed above are usually used to derive
estimates of cancer risk in humans.
The weight of evidence is reviewed carefully for
technical adequacy and then given an overall
classification for human carcinogenicity. The 'EPA
classification system includes 5 groups in descend-
ing order of overall weight of the evidence:
Group A (Carcinogenic to Humans): Used when
there is sufficient evidence from epidemiologic studies
to support a finding that a causal relationship exists
between exposure to the agent and cancer;
Group B (Probably Carcinogenic to Humans):
Used when there is enough evidence of carcinoge-
nicity based on animal studies and limited epide-
miological evidence (Group Bl) or inadequate or no
human data (Group B2);
Group C (Possibly Carcinogenic to Humans):
Used when there is limited evidence for carcinoge-
nicity in animals and inadequate or no human data;
Group D (Not Classifiable as to Human Carcino-
genicity): Used when there is inadequate animal
evidence of carcinogenicity and inadequate or no
human data; and
Group E (Evidence of Noncarcinogenicity in
Humans): Used when there is no evidence for
carcinogenicity in at least two adequate animal tests
in different species or in both adequate epidemio-
logic and animal studies.
Dose-Effect Assessment
Dose-effect assessment is a critical part of the overall
risk assessment process. It attempts to quantify the
relationship between the dose and adverse effects
expected in humans. Ideally, human epidemiologic
data should be used to develop the dose-effect
relationship for carcinogenic and noncarcinogenic
effects. In practice, however, these data are usually
not available, and data from animal studies are used.
There are three problems associated with the use of
animal data which must be considered in the dose-
effect assessment. First, animals are usually exposed
at high doses, which means that effects at low doses
must be extrapolated. Second, animals and humans
differ in susceptibility. Third, there are some
individuals in the population who may be more
susceptible to effects than the average person.
The extrapolation of effects at high doses to those at
low doses usually involves one of two assumptions:
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1) biological effects occur after a threshold dose has
been reached, or 2) there is a linear relationship
between the dose and the effect. Effects which
involve the alteration of genetic material (genotoxic
effects), including the initiation of cancer, are
assumed to be nonthreshold effects; that is, the
effect is proportional to the dose, and there will
always be an effect unless the dose is zero. A
threshold dose is assumed for effects which are not
genotoxic.
These assumptions, however, may need to be revised
for some substances as new methods of assessing
dose-effect relationships are developed. One of these
new methods is the use of physiological pharmaco-
kinetic modeling, which compares the sensitivity of
animal and human cells and then relates these via
dosimetry models to human and animal species
sensitivity (Menzel, 1987). Whenever these new
models appropriately simulate real effects, they may
be preferable to the traditional threshold versus
nonthreshold models.
Regardless of the assessment methodology, numeri-
cal estimates of the dose-effect relationship should
not stand alone—assumptions and uncertainties
should be included. The risk characterization
should include a discussion and interpretation of the
numerical estimates that provide the risk manager
some insight into the degree to which the estimates
are likely to reflect the true magnitude of the risk to
humans.
Nonearciaogen dose-effect assessment: For
noncarcinogens, the threshold dose in animal
studies is approximated by the no-observed-adverse-
effect level, NOAEL (expressed in mg/kg/day). The
NOAEL is selected in the context of the entire data
set. Uncertainties in the NOAEL are compensated
by dividing the NOAEL by an uncertainty factor
(previously called the safety factor) which may be 10
(or less), 100, 1000, or 10,000. The uncertainty
factor dates to the early days of food additive
legislation when it became clear that there was no
universally accepted quantitative method of ex-
trapolating from animal data to humans. The
selection of the uncertainty factor is a professional
judgment that depends on the nature and quality of
the data, the seriousness of the effect, the type of
effect, and the population to be protected.
The NOAEL can be used to derive the reference
dose (RfD) for humans. The reference dose, which
was formerly called the acceptable daily intake
(ADI), can be expressed as an oral reference dose
(mg/kg/day) or inhalation reference concentration
(mg/m3). The RfD is a dose (from contaminants in
food, water, and air) that is anticipated to be without
risk to humans over a lifetime of exposure. The
RfD is derived by dividing the NOAEL for the
toxic effect appearing at the lowest dose by the
uncertainty factor. An additional modifying factor
which comments on the quality of the data may also
be included. The RfD is an estimate of risk (with
uncertainty that spans perhaps an order of magni-
tude). It is not a guarantee of absolute safety, and it
may overestimate the risk in some instances,
In those instances when the NOAEL cannot be
identified, the RfD might be calculated with the
lowest observed-adverse-effect level (LOAEL),
The assessment should be accompanied by a confi-
dence statement that comments on the quality of
the study that drives the assessment, the underlying
data base and the degree to which the selected study
agrees with the data base, and the overall adequacy
of the assessment.
Carcinogen dose-effect assessment: There are three
main components to the dose-effect assessment for
carcinogens:
1) the appropriate data base is selected based
on the quality of the data, its relevance to
human modes of exposure, and other
factors;
2) mathematical models are used to extrapo-
late from high to low doses of exposure; and
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3) appropriate scaling factors are used to
extrapolate from animal studies to human
exposure.
In the absence of human data, data are typically
used from a species that responds most like humans
or has in the long-term studies shown the greatest
sensitivity.
Several mathematical models (linearized multistage
model, one-hit model, gamma multi-hit model,
log-probit model, and other time-to-response
models such as the Weibull model) have been used
to extrapolate the risks from high doses to those at
low doses. No single model is recognized as most
appropriate for all carcinogens (U.S. EPA, 1986a).
The selection of a specific model depends on the
underlying mechanism that results in the develop-
ment of cancer, and if such data are available, the
selected model should be consistent with these data.
Unfortunately, the way in which cancer develops is
not understood for most carcinogens. In the absence
of these data, EPA recommends the use of the
multistage model, which assumes that cancer
originates in a single cell as a result of an irrevers-
ible and self-replicating process that involves a
number of different random biological events.
EPA uses a linearized modification of the multistage
model which assumes that the time rate of occur-
rence of each event is in strict linear proportion to
the dose. This model, the linearized multistage
model, is considered to be the strongest of the
available models (U.S. EPA, 1988). The selection of
the model for extrapolation is important because at
low doses the predicted values from the models
diverge significantly. For example, for a given dose
there may be a factor of 10* or 108 difference in the
estimation of lifetime cancer risk at a given concen-
tration by the most conservative and least conserva-
tive models. This is an uncertainty equivalent to
not knowing if one has enough money to buy a cup
of coffee or pay off the national debt (Cothern, et al.
1986). Even so, it is highly likely that the projec-
tions of the more protective models will not under-
estimate risk and they may strongly overestimate it
(U.S. EPA, 1988).
The risk estimates at low doses derived from animal
studies must also be adjusted for the differences
between the human and the animal test species.
Some of these differences include body size, genetic
variability, population homogeneity, health status,
life span, pharmacokinetic effects such as metabo-
lism and excretion patterns, and the exposure
regimen,
The most common approach for making these
adjustments is to use standardized scaling factors
which are related to the type of exposure pathway
and sensitivity of the target organs. Scaling factors
include mg per kg body weight per day, ppm in the
diet or water, mg per m2 body surface per day, and
mg per kg body weight per lifetime. Because
detailed toxicological, physiological, metabolic, and
pharmacokinetic data may be limited for a specific
agent, EPA considers a scaling factor based on
surface area (mg per m2 body surface area per day) to
be appropriate because certain pharmacological
effects scale according to surface area (U.S. EPA,
1986a).
Carcinogenic risk assessments must be accompanied
by a weight-of-evidence statement that is a profes-
sional judgment of the quality of the assessment.
The system for classifying the evidence is given
under the Hazard Identification section.
Exposure Assessment
The exposure assessment estimates the exposures to
which the population of interest is likely to be
subjected. It must be combined with the dose-
effect assessment in order to obtain a quantitative
estimate of the risk.
At the present time there is no single approach to
exposure assessment that applies to every case.
Rather, the method that is used must match the
individual case based on the available data. As in all
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IAQ Reference Manual
phases of the risk assessment process, the assump-
tions, approximations, and assertions made for the
exposure assessment should be stated.
The major elements of the exposure assessment
which are outlined by EPA include identification
and characterization of the following areas:
• Sources. The production, distribution,
uses, disposal, and environmental releases of
the chemical should be assessed.
» Exposure pathways and environmental
fate. The transport, transformation,
principle pathways of exposure, and
predicted environmental distribution
should be evaluated.
* Measured or estimated concentrations,
The concentrations available for exposure
should be evaluated using measurement,
mathematical models, or a combination of
the two.
• Exposed populations. Populations and
subpopulations at potentially high exposure
should be identified, and subpopulations of
high sensitivity may be studied separately.
• Integrated exposure analysis. An expo-
sure profile is developed from the estima-
tion of environmental concentrations and
the description of the exposed population.
This profile should include the size of the
exposed population; duration, frequency,
and intensity of exposure; and routes of
exposure.
EPA currently assumes that receiving a high dose of
a carcinogen over a short time period is equivalent
to receiving a low dose over a lifetime. This
assumption is used to calculate a lifetime average
daily exposure (LADE) that is incorporated into the
risk characterization.
Risk Characterization
The final step in the risk assessment process is the
characterization of risk. In this step, numerical
estimates of risk are presented along with a frame-
work for evaluating those risks. The risk character-
ization section should summarize the hazard
identification, exposure assessment, and the dose-
effect assessment, and the public health risk esti-
mates. Major assumptions, scientific judgments,
and to the extent possible, uncertainties should be
included.
Noncarcinogen Risk Characterization: The risk
for noncarcinogens may be characterized by a
margin of safety (MOS) approach that is estimated
by dividing the reference dose (oral or inhalation) by
the estimated daily human dose (U.S. EPA, 1988).
The MOS quantifies the ratio between potential
exposures and a presumed safe level; it is not an
absolute statement of risk, but a surrogate for risk.
The larger the MOS, the smaller the risk. The MOS
that is needed to protect human health will vary
depending on the agent, and its selection is similar
to the process used to select the uncertainty factors
for the reference dose calculation.
Carcinogen Risk Characterization: The numerical
estimates for carcinogenic risks can be calculated in
one of three ways. The unit cancer risk, under an
assumption of low-dose linearity, is the excess
lifetime risk due to a continuous constant lifetime
exposure of one unit of carcinogen concentration.
Typical exposure units include ppm or ppb in food
or water, or ppm or }Jg/m3 in air. When the dose,
expressed as mg/kg/day is used rather than the
concentration, the term slope factor is used and
represents the risk per unit dose. One can convert a
slope factor to unit risk by multiplying the slope
factor by the inhalation rate (20 ms/day) and
dividing by body weight (70kg). The dose corre-
sponding to a given level of risk can be used in some
instances—for example, when using nonlinear
extrapolation models where the unit risk would
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differ at different dose levels. Finally, risks can, be
characterized either in terms of individual risks,
population risks, or both.
Individual risks provide an estimate of the addi-
tional lifetime risk for individuals exposed to
average and maximum levels of an agent. Indi-
vidual risks can be obtained by multiplying the
incremental unit risk (from the dose effect assess-
ment) by the lifetime average daily exposure of that
person {U.S. EPA, 1989).
Population risk estimates provide a measure of the
possible total expected excess number of cancers in a
population during a lifetime of exposure to a given
agent. The population risk is derived by multiply-
ing the individual risk by the total exposed popula-
tion over some selected time period (U.S. EPA,
1989).
The usefulness of these estimates must be balanced
with the likelihood that the agent is a human
carcinogen. The likelihood is reflected by the
letters A, B2, BI( C where "A" is the most certain
risk and "C" is only a possible human carcinogen.
The availability of a unit risk estimate does not
modify the uncertainty associated with "B" or "C"
designations aor are risks for A carcinogens neces-
sarily more accurate than risks for "B" and "C"
agents.
3.4. EPA CANCER RISK ASSESSMENTS POR
INDOOR AIR CONTAMINANTS
iiPA maintains an online data base,
Integrated Risk Information System (IRIS), that is a
primary source of EPA health hazard assessments
and related information on chemicals of environ-
mental concern. IRIS is intended for users with
some knowledge of health sciences, but extensive
training in toxicology is not needed. IRIS is
maintained by the Environmental Criteria and
Assessment Office, U.S. EPA, Cincinnati, OH. This
data base, which includes over 400 chemicals, can
be accessed by groups outside of EPA through
diskettes which are updated quarterly or through
online sources which are updated monthly. The
user fees are about $130 per quarter for the dis-
kettes, and the online service has a $25 per month
fee which is applied to a user fee of $25 per hour
plus an additional charge for each computer screen
accessed.
The online data base includes the following infor-
mation: oral reference dose assessments, inhalation
reference dose assessments, carcinogenicity assess-
ments (slope factors/unit risk factors), drinking
water health advisories, EPA regulatory actions, and
supplementary data.
Exhibit 3-3 provides a summary of cancer risk
estimates for selected indoor air contaminants. All
of the estimates, except radon, are unit risk esti-
mates, which provide an upper bound estimate of
risk that may occur from continuous lifetime
exposure per unit of air concentration of the con-
taminant (U.S. EPA, 1989). These numbers can be
used to compare or prioritize hazards in a relative
sense, and in some special circumstances may be
useful for evaluating the highest likely cancer
impact on an exposed population.
The risk estimate for radon includes an estimate of
the annual population cancer risk resulting from
exposure to radon indoors. Estimates of the annual
population cancer risk resulting from exposure to
other contaminants are not available at this time.
-------
Section 5
IAQ Reference Manual
Exhibit 3-3. EPA (timer risk assessments.1
CONTAMINANT
Radon
VOCs
Benzene
Methylene chloride
Chloroform
Carbon tetraefaloride
1,2-Dichloroethane
Trichloroechylene
Tetrachloroethylene
Formaldehyde
PAHs
Benz(a)-anthracene
Ben2o(a)-pyrene (BaP)
Dibe0zo(a,h)-anthracene
3-Methylchol-anthrene
Pesticides
Alarm
Chlordane
Dieldrln
HeptacMor
Lindane
UNIT RISK23
(CLASSIFICATION)
3-6 x 10 -
8,3xlO-6/pg/m}(A)
4,7 x 10-7/ pg/mj (B2)
2.3 x lO'5/ pg/m» (B2)
1.5xlO-'/J%/mJ(B2)
2,6 x ID'5/ JJg/m5
4.6 x 10-3/ pg/m}
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IAQ Reference Manual Section 3
Exhibit 3-3. EPA caiuer risk assessments1 (tontinuod).
ESTIMATED
UNIT RISK2-3 ANNUAL EXCESS
CONTAMINANT (CLASSIFICATION) CANCER CASES
Asbestos 1.6 x 10"4 to
2.3 x 10-3/
0.01 fibers/ml<5A7) (A)
1.8xlO-3to
2.7 x ID'3/
0.01 fibers/ml(7'8> (A)
^SOURCE: U.S. EPA (1989a)
2Unit risk of the contaminant is an upper bound estimate of the lifetime risk of contracting cancer per unit exposure. Upper bound
means that the true risk which can't be defined is not likely to be higher than the upper bound value and may be lower.
'The risk estimates for radon, asbestos, and benzene are based on epidemiological data. The risk estimates for the organic contami-
nants, except benzene, are based on animal bioassay data and represent the "upper-bound" estimate of the risk. The alpha designation
i.e A, B2, B , C, is the weight-of-evidence classification which indicates the certainty that the agent is a human carcinogen.
4U.S. Environmental Protection Agency (EPA). 1986. Risk Assessment Methodology Environmental Impact Statement: NESHAPsfor
Radionuclides. Background Information Document. Vol. I. U.S. EPA, Office of Radiation Programs: Washington, DC.
'Fibers as measured by phase contrast microscopy.
*Lung cancer in male and female smokers and nonsmokers.
'U.S. Environmental Protection Agency (EPA). 1985. Airborne Asbestos Health Update. EPA-600/8-84-003F. U.S. EPA Office of
Health and Environmental Assessment: Research Triangle Park, NC.
8Mesothelioma in male and female smokers and nonsmokers.
'Future downward revision to approximately 16,000 annual excess cancer cases is likely.
REFERENCES
American Society of Heating, Refrigerating, and Air-Condi- Calabrese, E.J. 1987. "Animal extrapolation. A look inside
tioning Engineers (ASHRAE). 1989. ASHRAE Standard 62- the toxicologist's black box." Environ. Set. Technol. 21(7):
7989. Ventilation for acceptable indoor air quality. ASHRAE, Inc: 618-623.
Atlanta, GA.
Cothern, C.R., W.A. Coniglio, and W. L. Marcus. 1986.
Andrews, C., S. Buist, E.G. Ferris, Jr., J. Hackney, W. Rom, J. "Estimating risk to human health." Environ. Set. Technol. 20(2):
Samet, M. Schenker, C. Shy, and D. Strieder. 1985. "American 111-116
Thoracic Society guidelines as to what constitutes an adverse
respiratory health effect, with special reference to epidemiologic Deisler, P.P., Jr. 1988. "The risk management—risk
studies of air pollution." Am. Rev. Resp. Dis. 131(4): 666-668. . , „ „ . „ . _ , , ,,_,,,. ,c ,n
r e assessment interface. Environ. Set. Technol. 22(1): 15-19-
-------
Section 3
IAQ Reference Manual
Menzel, D.B. 1987. "Physiological pharmacokinetic model-
ing." Environ. Set. Techno!. 21(10): 944-950:
Mood, B. (ed). 1986. APHA-CDC Recommended Minimum
Homing Standards, American Public Health Association,
Committee on Housing and Health: Washington, DC.
Olishifski,J.B. and G.S. Benjamin. 1988. "The Lungs," Chap.
2. Fundamentals of Industrial Hygiene. 3rd edition. B.A. Plog
(ed). National Safety Council: Chicago, IL.
Severn, D.J. 1987. "Exposure assessment." Environ. Set.
Technol. 21(12): 1159-1163.
Sielken, R.L. 1987. "Cancer dose-response extrapolations."
Environ. Sci. Tethnol. 21(11): 1033-1039.
Task Group on Lung Dynamics. 1966. "Deposition and
retention models for internal dosimetry of the human respira-
tory tract." Health Physics. 12(2): 173-207.
U.S. Environmental Protection Agency (EPA). 1985. Airborne
Asbestos Health Update. EPA-600/8-84-003F. U.S. EPA, Office
of Health and Environmental Assessment: Research Triangle
Park, NC.
U.S. Environmental Protection Agency (EPA). 1986a.
"Guidelines for carcinogen risk assessment." Federal Register.
51(185): 33991-34003. September 24.
U.S. Environmental Protection Agency (EPA). 1986b.
"Guidelines for mutagenicity risk assessment." Federal Register.
51(185): 34005-34025. September 24.
U.S. Environmental Protection Agency (EPA). 1986c.
"Guidelines for the health risk assessment of chemical mix-
tures." Federal Register. 51(185): 34013-34025. September
24.
U.S. Environmental Protection Agency (EPA). 1986d.
"Guidelines for the health assessment of suspect developmental
toxicants." Federal Register. 51(185): 34028-34040. Septem-
ber 24.
U.S. Environmental Protection Agency (EPA). 1986e.
"Guidelines for exposure assessment." Federal Register.
51(185): 34041-34054. September 24.
U.S. Environmental Protection Agency (EPA). 1988. Principles
of Risk Assessment. A Nontechnical Review. (165.6). U.S. EPA:
Washington, DC.
U.S. Environmental Protection Agency (EPA). 1989a. Report to
Congress on Indoor Air Quality. Vol. II: Assessment and Control of
Indoor Air Pollution. EPA 400/1-89 001C. U.S. EPA, Office of
Air and Radiation: Washington, DC.
U.S. Environmental Protection Agency (EPA). 1986b. Risk
Assessment Methodology Environmental Impact Statement: NESHAPs
for Radionuclides. Background Information Document. Vol.1. U.S.
EPA, Office of Radiation Programs: Washington, DC.
West,J.B. 1980. Respiratory Physiology - The Essentials. 2nd
edition. Williams & Williams: Baltimore, MD.
Wilkinson, C.F. 1987. "Being more realistic about chemical
carcinogenesis." Environ. Set. Technol. 21(9): 843- 847.
Woods, J. , Jr. 1986. "Building performance assessment."
Indoor Air. Vol.6. Evaluations and Conclusions for Health Sciences
and Technology. Swedish Council for Building Research:
Stockholm, Sweden.
Working Group on Assessment and Monitoring of Exposure to
Indoor Pollutants. 1983. Indoor Air Pollutants: Exposure and
Health Effects. EURO Reports and Studies 78. World Health
Organization: Copenhagen, Denmark.
-------
SECTION 4.
SOURCES AND HEALTH
EFFECTS OF SELECTED
CONTAMINANTS
Section 4 provides a discussion of the
sources and health effects of combus-
tion contaminants, pesticides, micro-
biological contaminants, formalde-
hyde, and other volatile organic
compounds. Each of the sections
contains exhibits which summarize
health effects data. In addition,
Section 4.2 also discusses the regula-
tory framework for pesticides.
Table off Contents
Section 4.1. Combustion Contaminants 49
Section 4.2, Pesticides 66
Section 4.3. Formaldehyde and Other Volatile
Organic Compounds 85
Section 4.4. Biological Contaminants 102
List of Exhibits
Exhibit 4-la. Relationship between carbon monoxide
(CO) concentrations and carboxyhemo-
globin (COHb) levels in blood. 54
Exhibit 4-lb. Carboxyhemoglobin levels and related
heath effects. 55
Exhibit 4-2. Controlled studies of the effects
of human exposure to nitrogen dioxide. 56
Exhibit 4-3. Effects of exposure to nitrogen dioxide
plus other gas stove combustion products
in the home on the incidence of acute
respiratory disease in epidemiology studies
involving gas stoves. 59
Exhibit 4-4. Selected studies of human exposure to
carbon dioxide. 61
Exhibit 4-5. Selected studies of asthmatic subjects
exposed to sulfur dioxide. 62
Exhibit 4-6. Composition of mainstream and sidestream
smoke. 63
Exhibit 4-7. Summary of health effects, products, and
uses of 50 active ingredients in household
pesticides. 69
(continued next page)
-------
Section 4 IAQ Reference Manual
Exhibit 4-8. Selected weighted summary statistics for
indoor air concentrations of pesticides in
Jacksonville and Springfield/Chicopee
(ng/m3). 75
Exhibit 4-9- Measurements of pesticides in buildings. 79
Exhibit 4-10. Potential sources of formaldehyde indoors. 91
Exhibit 4-11. Measurements of formaldehyde
concentrations in different types of
buildings. 92
Exhibit 4-12. Health effects and sources of selected volatile
organic compounds. 94
Exhibit 4-13. Examples of volatile organic compounds
measurements in indoor air. 96
Exhibit 4-l4a. Examples of selected volatile organic
compound emission rates for materials
and typical household products found
indoors. 99
Exhibit 4-l4b. Additional examples of volatile organic
compound emission rates for selected
materials found indoors. 100
Exhibit 4-15. Molds identified in 68 homes in southern
California. 110
Exhibit 4-16. Fungi reported as allergenic. Ill
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IAQ Reference Manual
Section 4
4.1. COMBUSTION CONTAMINANTS
L here are many possible sources of com-
bustion contaminants in residential and commercial
buildings. These sources can release contaminants
which can result in health effects ranging from
headaches and respiratory tract irritation to death.
This section provides an overview of health effects
that have been related to contaminants from
combustion sources.
Sources of Combustion Contaminants
Residential Buildings
An important concern associated with the use of
vented and unvented combustion sources is safety
hazards including fires, burns from contact with hot
metal surfaces, and poisonings from the accidental
ingestion of fuel. Fires are also'a concern with the
use of tobacco products, hobby, and craft activities.
A second concern is the release of indoor air con-
taminants from all fuel-burning unvented appli-
ances and from vented appliances which are improp-
erly installed, poorly maintained, or improperly
operated. Safety hazards will not be discussed
further in this section, but potential health effects
from specific combustion contaminants are summa-
rized below.
The primary fuel sources for vented and unvented
household appliances include natural gas, fuel oil,
wood, coal, kerosene, and LP gas. Charcoal, news-
print, and other potentially hazardous fuels should
not be burned indoors.
Large combustion appliances such as gas, wood, or
oil-fired central heating systems are used mainly in
those areas where winter temperatures fall below
68°F. Smaller appliances such as gas water heaters,
ranges, and clothes dryers are used all year. Under
normal conditions the byproducts of these appli-
ances are exhausted outside of the dwelling through
a flue or chimney. Contaminants can be released
indoors if there is a blockage in the flue or chimney
or if the appliance is not vented properly.
When a combustible fuel burns, heat and light are
given off along with a broad range of contaminants
including asphyxiants, irritants, carcinogens,
teratogens, and mutagens. Carbon monoxide,
carbon dioxide, water vapor, and the nitrogen oxides
are the primary contaminants from the combustion
of natural gas. The combustion of kerosene adds
sulfur dioxide and inhalable particulates, including
polycyclic aromatic hydrocarbons to the inventory.
Tobacco combustion and improperly vented wood
and coal combustion sources increase the list of
potential contaminants, and they can release
aldehydes, a variety of polycyclic aromatic com-
pounds, and other contaminants to the indoor air.
Tobacco smoke, combustion-related hobby and craft
activities, and unvented kerosene and gas space
heaters pose special problems because they release
contaminants directly into the living space. To-
bacco smoke is of particular concern because of the
many carcinogenic, teratogenic, and mutagenic
chemicals in the smoke.
Another potential problem is the release of moisture
from the combustion of fuel by unvented sources. It
is possible for water vapor from combustion to
condense onto window frames and sills and to wet
surfaces such as wood and insulation which are not
directly visible. In addition to structural damage
which can be caused by excessive moisture, these
wetted materials can provide an excellent substrate
for microbial growth which can produce a variety of
effects in sensitive individuals (Section 4.4).
Commercial Buildings
In commercial buildings, important sources of
combustion contaminants include tobacco smoking,
garages which are attached to working spaces, and
improperly located air intake vents. Air intake
vents which are located at ground level or adjacent
to vehicles or other combustion sources can signifi-
cantly elevate indoor contaminant levels by trans-
porting contaminants to all areas served by the air
handling system.
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Section 4
IAQ Reference Manual
Health Effects of Combustion Contaminants
Symptoms of exposure to combustion contaminants
can include headaches, decreased alertness, flu-like
symptoms, nausea, fatigue, rapid breathing, chest
pain, confusion, impaired judgment, and others.
Concentrations at which these symptoms will occur
depend on health status and individual variations in
sensitivity, so that specific responses at a given
concentration of a contaminant will vary among
individuals.
Each year there are unnecessary deaths due to carbon
monoxide poisoning from faulty furnaces and other
combustion sources. When an investigator receives
a call and the client reports headaches, drowsiness,
and nausea, especially during the heating season, the
inspector should be aware of potential problems
with furnaces or unvented combustion appliances.
Carbon Monoxide
Carbon monoxide (CO) is a colorless, odorless, and
tasteless gas which is produced from the incomplete
combustion of any carbon-containing fuel. It is a
chemical asphyxiant that prevents oxygen from
reaching the body's tissues. Normally, oxygen is
carried to the body's tissues by hemoglobin in the
form of oxyhemoglobin (OHb). When CO is
present, it also combines with hemoglobin to form
carboxyhemoglobin (COHb). In fact, CO is about
200 times as effective as oxygen (O2) in combining
with hemoglobin. This means that when both O2
and CO are present, hemoglobin will not be avail-
able to carry O2 to the tissues. Once inside the
body, CO has a half-life of about 5 hrs.
The health effects of CO exposure are generally
discussed in terms of the % COHb in the blood
(Exhibit 4-la,b). The level of COHb is directly
related to the CO concentration in the air, the
duration of the exposure, and the activity level of
the individual. For a given CO dose, the COHb
level will reach an equilibrium over some period of
time. As the CO concentration increases or de-
creases from this point, the COHb level will follow.
Normally, metabolic processes in the body will
result in a COHb level of 0.5% to 1.0%. Average
COHb levels among nonsmokers are 1.2% - 1.5%.
In cigarette smokers this level is about 3% - 4% on
average, but it may be as high as 10% in heavy
smokers (WHO, 1987).
Continuous exposure to 30 ppm CO leads to an
equilibrium COHb level of 5%; about 80% of this
value occurs in 4 hours and the remaining 20% over
the next 8 hours. Continuous exposure to 20 ppm
CO leads to COHb levels of 3.7% and exposure to
10 ppm leads to COHb levels of 2%. The time for
equilibrium to be established is usually 8 hours, but
this time can be shorter if a person is physically
active (Douttetal., 1980).
Carbon monoxide can have detrimental effects on
the heart, lungs, and nervous system. At COHb
levels of 10% or less, the major effects are cardiovas-
cular and neurobehavioral. Levels of 2.5% have
been shown to aggravate symptoms in angina
pectoris'patients. No adverse health effects have
been reported below 2.0% COHb; and findings in
the range of 2.0 to 2.9% are inconclusive (WHO,
1987). A level of 2.5% COHb can result from
exposure to air with 50 ppm CO for 90 minutes or
15 ppm for 10 hours (Turiel, 1985).
Nitrogen Oxides
There are many chemical species of the oxides of
nitrogen (NOx), but nitrogen dioxide (NO2) and
nitric oxide (NO) are of greatest concern as indoor
air contaminants. Nitrogen oxides are produced
when fossil fuels are burned, and most of the
emissions occur as NO which can be converted to
N02.
Nitric oxide is a colorless, odorless, and tasteless gas
that is only slightly soluble in water. The toxico-
logical and health effects data base for NO is
somewhat limited. There is some evidence of
inflammatory changes at the cellular level at 2 ppm
(U.S. EPA, 1982). The formation of methemoglo-
bin (met-Hb), which intereferes with the transport
-------
1AQ Reference Manual
Section 4
of oxygen, has been attributed to the action of
nitrite ion generated by either NO or NO2 in
solution. Background levels of met-Hb in the blood
are in the range of 0.2 and 0.796 in the absence of
high NOx levels. Case et a/, (1979) provide evidence
to show that met-Hb in whole blood can result from
the direct uptake of NO by hemoglobin in the
blood. Case et al, suggest that exposure to NO at 3
ppm may be physiologically comparable to exposure
to CO concentrations of 10 ppm to 15 ppm.
Nitrogen dioxide is a corrosive and highly oxidiz-
ing gas with a characteristic pungent odor which
has been described as stinging, suffocating, and
irritating. The odor threshold has been placed
between 0.11 ppm and 0.22 ppm by different
investigators (WHO, 1987). NO2 has a pungent
odor that is described as stinging, suffocating, and
irritating. The odor threshold has been placed
between 0.11 ppm and 0.22 ppm by different
investigators (WHO, 1987).
NO2 is a deep lung irritant which has been shown to
result in biochemical alterations and histologically
demonstrable lung damage in laboratory animals as
a result of both acute and chronic exposures. In
laboratory animals, biochemical changes occur at
concentrations as low as 0.2 ppm for 30 minutes
(WHO, 1987). Long-term animal studies have
resulted in emphysema-like structural changes and
increased susceptibility to bacterial lung infections
(WHO, 1987). Changes at the cellular level occur
at the time of exposure, but biological effects are
delayed, which complicates the understanding" of
long term effects.
In humans, 80% to 90% of NO2 can be absorbed
upon inhalation. Controlled clinical studies have
been conducted on susceptible subjects at concentra-
tions in the range of 0.1 ppm to 5.0 ppm. Most
studies show that substantial changes in pulmonary
function can be demonstrated in normal, healthy
adults at or above concentrations of 2 ppm (WHO,
1987). The evidence at lower concentrations is not
as clear. Asthmatics appear to be responsive at
about 0.5 ppm, and subjective complaints have been
reported at that level (WHO, 1987). Below 0,5
ppm, small but statistically significant, decrements
in pulmonary function have been reported in
asthmatics (WHO, 1987). Kagawa and Tsuru
(1979) reported decrements in the lung function of
asthmatics at concentrations as low as 0.15 ppm,
but others have not substantiated these findings.
Exhibit 4-2 summarizes some of the human expo-
sure studies that have been conducted.
Epidemiologic studies suggest that children who are
exposed to combustion contaminants from gas
stoves have higher rates of respiratory symptoms and
illness than other children. Nitrogen dioxide
concentrations in these studies ranged from a low of
0.005 ppm to about 0.3 ppm (U.S. EPA, 1982;
WHO, 1987). In general, these results have not
been supported in studies of adults. Exhibit 4-3
summarizes some of the studies which have been
conducted.
Carbon Dioxide
Carbon dioxide is a colorless, odorless gas. It is a
simple asphyxiant, but it can also act as a respiratory
stimulant. At concentrations above 1.5% respira-
tion is affected, and breathing becomes faster and
more difficult. Concentrations above 3% can cause
headaches, dizziness, and nausea. Above concentra-
tions of 6% - 8% stupor and death can result (NRC,
1981).
The lowest level at which effects have been observed
in both human and animal studies is about 1%
(U.S. CPSC, 1983). Structural changes in the lungs
of guinea pigs have been observed along with
calcification of the kidneys. In humans, effects
include increases in respiration, changes in blood
pH and pCO2, and decreases in the ability to
perform strenuous exercise. The significance of
these effects is not clear, but a potential increase in
respiratory and gastrointestinal illness has been
postulated because these effects were observed in
submarine crews at concentrations of 0.5% - 1%
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Section 4
IAQ Reference Manual
(NRC, 1981). Exhibit 4-4 summarizes the results
of some studies which have been conducted.
Sulfur Dioxide
Sulfur dioxide (SO2) is a colorless gas with a strong,
pungent odor which can be detected at about 0.5
ppm (NEC, 1981). SO2 is very soluble in water and
exerts its irritant effects primarily on the upper
respiratory tract, but its site of action depends on
the presence of particulates, and the rate, depth, and
type of breathing.
There is considerable variability in the response to
SO2 among both normal, healthy subjects and
asthmatics, and this makes it difficult to define a
no-adverse-effect level. It has been estimated that
about 5% of the population may be sensitive to SO2
(WHO, 1987).
There is good agreement that healthy adults
experience adverse effects at concentrations of 0.75
ppm to 1.0 ppm, and that asthmatics experience
increased airway resistance at exposures of about 0.4
ppm for 10 minutes, both during exercise and at
rest (WHO, 1987). Discernable effects have been
reported below that level, but WHO concludes that
the consequences of those effects are not clear.
Increased airway resistance has been reported at
concentrations of 0.1 ppm among mild asthmatics
who were exercising (Sheppard, 198la). There is
also some evidence that sulfur dioxide at levels of
0.15 ppm appears to act synergistically with ozone
at levels of 0.15 ppm (Kagawa and Tsuru, 1979a).
Exhibit 4-5 summarizes some of the human expo-
sure studies which have been conducted on asth-
matic subjects.
Particulates
In addition to the compounds listed above, other
gases and particulates can be released from indoor
combustion sources. In homes where wood is
burned, respirable particulates which include
polynuclear (or polycyclic) aromatic hydrocarbons
(PAH) compounds, trace metals, nitrates, and
sulfates have been measured. PAH compounds and
chromium (Tu and Hinchliffe, 1983) have also been
measured from kerosene heaters.
PAHs are of particular concern because of their
carcinogenic potential. PAH compounds include a
large number of organic compounds which contain
two or more benzene rings in their structure. These
compounds are produced as the result of incomplete
combustion. They are only very slightly soluble in
water, but they are very soluble in fat. Although fat
soluble, these compounds are metabolized rapidly in
the body and do not tend to bioaccumulate in the
fatty tissues. It is thought that the metabolites of
PAH compounds in the body (diol-epoxides) are
ultimately the carcinogens (WHO, 1987).
Once PAH compounds enter the air, they can be
adsorbed onto respirable-sized particles and inhaled
into the lungs. PAH compounds are also present in
foods (smoked, broiled, refined) and water; in fact,
the oral intake of PAH compounds may be much
higher than the inhaled amount in the general
population (WHO, 1987).
PAH compounds have been shown to be carcino-
genic in animal tests and mutagenic in short-term
laboratory tests. Evidence for carcinogenicity is
supported by epidemiologicai studies of coke-oven
workers, coal-gas workers, and workers in alumi-
num production plants (WHO, 1987).
Environmental Tobacco Smoke
Environmental tobacco smoke (ETS) is a term which
describes the contaminants released into the air
when tobacco products burn or when smokers
exhale. The hazards of inhaling mainstream smoke
(inhaled by the smoker) and sidestream smoke
(produced at the burning end of the tobacco prod-
uct) are well documented. The inhalation of ETS is
known as "involuntary smoking" or "passive
smoking."
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IAQ Reference Manual
Section 4
Studies have shown that cigarette smoke contains
over 3800 chemical compounds (NRC, 1981); some
of these compounds are shown in Exhibit 4-6.
Many of these gaseous and particulate contaminants
are irritants, and others are carcinogens (43 identi-
fied compounds), mutagens, and teratogens.
Particles in tobacco smoke are especially hazardous
because they are inhalable (0.1 Jim to 1.0 {Jrn),
remain airborne for hours after smoking stops, and
attract radon decay products. Exhibit 4-6 shows
that concentrations of contaminants in sidestream
smoke can be several times higher than those in
mainstream smoke.
In 1986 two major reports reached similar conclu-
sions about the hazards of passive smoking; these
"were Environmental Tobacco Smoke. Measuring Expo-
sures and Assessing Health Effects, which was prepared
by the National Academy of Sciences (NRC, 1986)
for the Environmental Protection Agency and the
Department of Health and Human Services, and The
Health Consequences of Involuntary Smoking, which was
prepared for the Office of the Surgeon General (U.S.
DHHS, 1986).
Both reports concluded that passive smoking
significantly increases the risk of lung cancer in
adults. The NAS Report (NRC, 1986) estimates
that the risk of lung cancer is about 30% higher for
nonsmoking spouses of smokers than for nonsmok-
ing spouses of nonsmokers, and that as many as
20% of lung cancers in nonsmokers may stem from
exposure to tobacco smoke. The Surgeon General's
Report (U.S. DHHS, 1986) concludes that simply
separating nonsmokers from smokers in work
environments is not sufficient to protect nonsmok-
ers. Although the available studies did not specifi-
cally include workplace environments, tobacco
smoke poses similar risks, regardless of the environ-
ment.
There was also agreement that passive smoking
substantially increases respiratory illness in children.
Children who live in households where there are
smokers are more likely to have respiratory infec-
tions (including bronchitis and pneumonia) than
children in nonsmoking households. Additional
effects in children include increases in coughing,
wheezing, sputum production, slower lung function
growth, and low birthweight babies in mothers who
are nonsmokers but are exposed to ETS. The
prevalence of these effects has been found to increase
with the number of smokers in the home,
The evidence for these effects was so strong that the
National Research Council's Committee on Passive
Smoking voted to recommend eliminating tobacco
smoke from any area where there are small children
or infants.
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Section 4
IAQ Reference Manual
Exhibit 4-la. Relationship between
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IAQ Reference Manual
Section 4
Exhibit 4-1 b. Carboxyhemoglobin levels and related health effects.
% COHb EFFECTS ASSOCIATED WITH
IN BLOOD THIS COHb LEVEL
80
60
40
30
7-20
5-17
5-5.5
Below 5
2.9-45
2.3-4.3
Death1
Loss of consciousness; death if exposure continuesa
Confusion; collapse on exercise*
Headache; fatigue; impaired judgement*
Statistically significant decreased maximal oxygen consumption during strenuous
exercise in healthy young men'3
Statistically significant diminution of visual perception, manual dexterity, ability to
learn, or performance in complex sensorimotor tasks (such as driving)*3
Statistically significant decreased maximal oxygen consumption and exercise time
during strenuous exercise in young healthy men*3
No statistically significant vigilance decrements after exposure to COb
Statistically significant decreased exercise capacity (i.e., shortened duration of exercise
before onset of pain) in.patients with angina pectoris and increased duration of
angina attacks'5
Statistically significant decreased (about 3-7%) work time to exhaustion in exercising
healthy menb
SOURCE: aU.S. EPA (1979); bU.S. EPA (1985)
-------
Exhibit
4-2. Controlled studies of the effects of human
POLLUTANT CONCENTRATION DURATION OF
EXPOSURE NUMBERS TYPE
Hg/m» ppm AND ACTIVITY OF SUBJECTS
9400
9400
7520
4700
1880
1880
940-9400
940
5 14 hours 8, normal
J 2 hours * 11, normal
intermittent
light excercise
4 75 minutes 25, normal
including light 23, asthmatic
and heavy
exercise
2.5 2 hours 8, normal
1 2 hoars 16, normal
1 2 hours 8, normal
0.5-5 3-60 minutes 63, chronic bronchitic
25, chronic bronchitic
0.5 2 hours 10, normal
7, chronic bronchitic
13, asthmatic
exposure to nitrogen dioxide.0
PULMONARY EFFECTS
Increase of Raw during the first
30 minutes of ejqxsure, with decrease
during the following 4 hours. Increase
of Rate after 6.8 and 14 hours of ex-
posure. Reactivity to acetylcholine
increased.
Increase of Raw and decrease in AaDOy
no farther increase when combined with
200 |% O3 per m3 and 1 5.0 mg SO2 per rn3
No effect on SRatv, heart rate or skin
conductance
Increase of &H#, no change in Pa02
or PaC02
Small changes in PVC
No increase in Roto
Increase of Raw at 3.0 mg/m3
Decrease of Pa02 at 7.5 mg/m5;
no change at 3.8 mg/m3
None
SYMPTOMS
Not described
Not described
Systolic blood
pressure different.
No Symptoms
Not described
5 subjects
complained of chest
tightness
Not described
Not described
Not described
7 out of 13
asthmatic subjects
suffered from symptoms
such as chest tightness
REFERENCE
Beil & Ulmer
(1976)
Von Nieding
aal, (1977)
"Llnnetal.
(1985)
Beil & Ulmer
(1976)
Hackney
#<*£(! 978)
Beil & Ulmer
(1976)
Von Nieding
aal. (1971)
Von Nieding
*-«1973)
Kerr at al.
(1979)
*•**
•NN
(O
g)
lr
8
ft1
&
a
-------
Exhibit
4*2. Controlled studies of the effects of human
exposure to nitrogen dioxide" (tontinved).
POLLUTANT CONCENTRATION DURATION OF
tlg/m3
560
560
560
2000
380
280
290
230
460
910
EXPOSURE NUMBERS TYPE
ppm AND ACTIVITY OF SUBJECTS
0.3 20 minutes at 10, asthmatic
rest, followed by
10 minutes of
moderate
exercise (oral
exposure,
mouthpiece)
0.3 20 minutes at 13, asthmatic
rest, followed by
three 10 minute cycles
of moderate exercise
(chamber exposure)
0.3 1 hour 8, normal
1.06
0.2 2 hours 31, asthmatic
intermittent
light exercise
0.15 NO2 2 hours 6, normal
0,15 O3 intermittent
0. 1 5 light exercise
N02 + 03
0.12 20 minutes 8, normal
0.24 attest 8, asthmatic
0.48
PULMONARY EFFECTS
NO2 plus exercise decrease in
FEV, and partial expiratory flow
rates at 6O% TLC, After exposure
at rest, no significant change
in function
11% decrease in FEV,;
stastically significant
Small increase in mean SRaw at
560 (%/rn3; no change at 2000 JJg/m3
No effect on forced expiratory
function or total respiratory
resistance observed with NO2
alone. Small exacerbation by
NO2 of metacholine-induced
bronchoconstriction in 17 of 21
subjects tested
Decrease in SGate/Vtg with O3
foe 5 of 6 subjects, and all 6 for
combined O3 + NO2; very
small (<59B) decrease in
SGawlVtg with NO2 alone in 3 of
6 subjects
Normal: small increase in SRate
at 460 JJg/m3; decrease in SRssv at
910 |Jg/m3; no change in reactivity
to histamine. Asthmatic: no effects in
SRaw; increase in reactivity to
histamine at 910 Jlg/m3
SYMPTOMS
None
Fewer symptoms
during NO2 exposure
compared to air
Cough with O3
andOj + NO2,
but not NO2
alone
REFERENCE
Bauer el al.
(1984)
Roger
. ttal, (1990)
Rehnrfa/,
(1982)
Kleinman
ttal. (1983)
Kagawa &
Tsuru(1979)
Byline* al.
(1985)
(continued next page)
£
to
i*_.j
£
«h
Ǥ
1
1
»••
SP
1.
i
-h.
-------
Exhibit 4-2. Controlled studies of the effects of human exposure to nitrogen dioxide0 Continued).
POLLUTANT CONCENTRATION DURATION OF
EXPOSURE NUMBER &TYPB
AND ACTIVITY OF SUBJECTS
PULMONARY EFFECTS
SYMPTOMS
REFERENCE
1
190
190
190
190
190
0.1
0.1
0,1
0.1
0.1
1 hour at rest
1 hour at rest
1 hour at rest
1 hour at test
1 hout at test
20, asthmatic
20, normal
9, asthmatic,
hypersensitive
to ragweed
15, normal
1}, asthmatic (atopies)
7, asthmatic
20, asthmatic
No effect on baseline SGatti, FEV, or None
V.yj, increased reactivity to car-
bachol in normal subjects and in
asthmatics
No effect on baseline SGaw, FEV, None
and V, or reactivity to ragweed
No change in SRate for either group; None
no change in sensitivity to
methacholine
No change in response to grass pollen
after exposure to NO2
No effect on SRav>; incteased
sensitivity to carbachol in
some subjects
Ahmed etal,
(1982)
Ahmed** al,
(1983)
Hazueha
a al, (1983)
Orehek
etal, (1981)
Orehek
etal. (1976)
a Indication of change only described if statistically significant. Abbreviations ate as follow: SRatv, specific airway resistance; Saw, airway resistance; SGatv, specific airway conductance, the
reciprocal of SRaur, FEV,, forced expiratory volume at 1 second; TLC, total lung capacity; Vtg, total gas volume; V^ flow volume; ft(02 and PaC02, arterial partial pressure of oxygen and carbon
dioxide; AaD02, difference in partial pressure of oxygen in the alveoli as against the arterial blood; FVC, forced vital capacity.
SOURCE: Air Quality Guidelines for Eitnft, Copenhagen, WHO Regional Office for Europe, 1987 (WHO Regional Publications, European Series, No. 23). Used with permission.
JO
-------
Exhibit 4-3. Effects of exposure to nitrogen dioxide plus other gas stove combustion
incidence of acute respiratory disease in epidemiology studies involving
NO2 CONCENTRATION
(%/m5 (ppm)
STUDY POPULATION
EFFECTS
products in the home on the
gas stoves.
REFERENCE
Studies of Children
NO2 concentration not
measured at time of study
NO2 concentration not
measured in same homes
studied
Kitchens:
9-596 (gas)
(0.005-0,317)
11-353 (electric)
(0.006-0.188)
Bedrooms:
7.5-318 (gas)
(0.004-0.169)
6-70 (electric)
(0.003-0.037)
(by triethanolamine
diffusion samplers)
Sample of households 24 hr
average: gas (0.005-0.11);
electric (0-0.06); outdoors
(0,015-0.05); monitoring
location not reported; 24 hr
averages by modified sodium
arsenite; peaks by
chemiluminescence
Sample of same households
as reported above but no
new monitoring reporting
2554 children from homes
using gas to cook compared
co 3204 children from homes
using electricity; ages 6-11
4827 children, ages 5-10
808 6-and-7«year-olds
128 children, ages 0-5
346 children, ages 6-10
421 children, ages 11-15
174 children under 12
Bronchitis, day or night cough, morn-
ing cough, cold going to chest, wheeze,
and asthma increased in children in
homes with gas stoves
Higher incidence of respiratory symp-
toms and disease associated with gas
stoves after controlling for confounding
factors
Higher incidence of respiratory illness
Melkrfa/. (1977)
Meliarfa/, (1979)
Floteys/a/. (1979)
in gas-stove homes. No apparent statis- Companion paper co
tical relationship between lung func-
tion tests and exposure to NO2 levels
in kitchen or bedroom
No significant difference in reported
respiratory illness between homes with
gas and electric stoves in children from
birth to 12 years
No evidence that cooking mode is
associated with the incidence of acute
respiratory illness
Meliarftf/. (1979);
Goldstein**/. (1979)
Mitchell *«/, (1974);
See also Keller* al.
(1979 a,b)
Keller et al. (1979h)
•• (continued next tiaee)
1AQ Reference 1M
&
re5
!•
i
-------
Exftibif 4-3. Effects of exposure to nitrogen dioxide plus other gas stove combustion products in the home on the
incidence of acute respiratory disease in epidemiology studies involving gas stoves Continued).
NO, CONCENTRATION
(Ig/m* (ppm)
STUDY POPULATION
EFFECTS
Sec
n 4
REFERBNCE
95 perceotile of 24 hr indoor
average; 39-116 (%/m*
(0.02-0.06) (gas) vs
17.6-95.2 Hg/m' (0,01-
0.05) (electric); frequent
peaks (gas) > 1100 jJg/in3
(O.fi ppm)] 24 hr by modi-
fied sodium arsenite; peaks
by chemiluminescence
Preliminary measurements
peak hourly 470-940 JJg/m5;
max 1880 Hg/ms(lppm)
See Mitchell a al. (1974) for
monitoring
8120 children ages 6-10 in 6 dif-
ferent communities; data
collected on lung function and
on history of illness
before the age of 2
Adults cooking with gas
stoves, compared to those
cooking with electric stoves
Adults cooking with gas
stoves, compared to those
cooking with electric stoves,
146 households
Significant association between history
of serious respiratory illness before age
2 and use of gas stoves. Small but
statistically significant decrements in
lung function tests between lower
FVC,, FVC levels from gas
stove homes compared with children
from homes with electric stoves
Studies of Adults
No consistent statistically significant
increases in respiratory illness
associated with gas stove usage
No evidence that cooking with gas is
associated with an increase in
respiratory disease
Spe!zer#<»/. (1980)
Spengler,?/.*/. (1979)
U.S. EPA (1976)
Keller itol.
(19798, b)
See Mitchell tf«£ (1974) for
monitoring
See Mitchell it al. (1974) for
monitoring
Members of 441 households
Members of 120 households
(subsample of 441 households
above)
No significant difference in reported
respiratory illness among adults in gas
vs electric cooking homes
No significant difference among adults
in acute respiratory disease incidence in
gas vs electric cooking homes
Mitchell <*<»/. (1974);
See also Keller etal.
(1979a,b)
Keller ttal.
(1979a,b)
a Forced expiratory volume at 1 sec.
" Forced vital capacity
SOURCE: U.S. EPA (1982)
-------
ixhibit 4-4. Selected studies of human exposure to carbon dioxide.
EXPOSURE
CONCENTRATION
AND DURATION
4%, 2 wks exposure
bracketed by two 2-wk
control periods
EXPOSURE
METHOD
Chamber, 24
subjects
EFFECTS
No psychomotor impairment; no decrement in
complex task performance by healthy young
subjects
REFEBINCE
Storm and
Giannetta(1974)
4.2%, 5 days and 11 days;
3%, 30 days; exposures
bracketed by two 3-5 day
control periods
3%, 5 days bracketed by
two 5-day control periods
1.5%, 42 days
0.7-5%, 50-60 days
I%aad2%, 30 days
to
f
«
1
Chamber, 12
subjects total;
4 in each of 3 groups
Space Cabin
Simulator; 7
subjects
Chamber*;
Submarines (13
Polaris patrols)
Chamber, 2 subjects
in each of 2 exposures
Increased arterial and cerebrospinal fluid bicar-
bonate; decreased pH; occasional mild headaches and
awareness of increased ventilation during first 24-hrs of
exposure; some ectopic foci noted during excercise but
small sample size hampered interpretation; decreased
tolerance to excercise noted
No changes in ammonia or titratable acidity; ao
changes in serum electrolytes, blood sugar, serum
creatinine, or liver function; no significant changes
in exercise or psychomotor studies
Increases in respiratory minute volume, tidal
volume, physiological dead space; decrease in
vital capacity; respiratory acidosis, increase in
pCO}, decrease in pH; decrease of plasma chloride,
red cell sodium increase, potassium decrease; decrease
in plasma calcium metabolism, urine calcium, urine
magnesium, increase in red cell calcium. In the
submarine study a decrease in respiratory and
gastrointestinal disease was noted with decreasing
CO2 (and other pollutants).
At 2% significant increases in pC02 in blood and
alveolar air, decrease in ability to perform strenuous
excercise; decrease in blood pH, increase in pulmonary
ventiliation; changes at 1% were not considered to be "
significant; authors conclude that prolonged CO
exposure causes acidosis, hypodynamia, and fatigue
but effects are reversible
Sinclair etal. (1969)
*Similar effects were noted in subjects in both the chamber exposure and submarine exposure.
SOURCE: Adapted from U.S. CPSC (1984)
Glatte etfti (1967)
Schaefer(1979)
Zharov «*(*/. (1963)
05
I.
-------
Exhibit 4-5. Selected studies of asthmatic
SULFUR DIOXIDE
CONCENTRATION a
Cppm)
1,3,5
1.0
0.1, 0.25, 0.5
0.50
0.5
0.25,0.5
0.30
DURATION NUMBER AND
OF EXPOSURE TYPE OF
(min) SUBJECT
10 7, normal
7, atopk
7, asthmatic
5 6, asthmatic
10 7, asthmatic
180 40, asthmatic
10 5, asthmatic
60 24, asthmatic
120 19, asthmatic
^^^^^^^^^^^^^^^^^^^^^^^^^1 O*1 ^^^^^^1
^^^^^^^^^^^^^^^^H lsd ^^^^1
subjects exposed to sulfur dioxide.
TYPE OF TYPE OF
EXPOSURE ACTIVITY EFH3CTSb
Mouthpiece Rest SRaui increased significantly at all
concentrations for asthmatic subjects,
only at 5 ppm for normal and atopic
subjects. Some asthmatics exhibited
marked dyspnea requiring
bronehodilation therapy
Mouthpiece Exercise SRaw significantly increased in the
asthmatic group at 0.5 and 0.25 ppm of
sulfur dioxide and at 0,1 ppm in the two
most responsive jubject. At 0.5 pprn
three asthmatic subjects developed
wheezing and shortness of breath
Oral chamber Rest MMFR significantly decreased 2.7%;
Nose clips recovery within 30 minutes
Mouthpiece Exercise SRitw increases were observed over
exercise baseline rates for 80% of
the subjects.
Chamber Exercise No statistically significant changes in
FVCotSttaw
Chamber Exercise No pulmonary effects seen with 0.3 ppm
of sulfur dioxide and 0.5 ppm of nitrogen
REFERENCE
Sheppard
etal. (1981«)
Sheppatd
etal.
'(1980, 1981b)
Jaeger
etal. (1979)
Linn et al.
(1982)
Linn et al.
(1982)
Linn etal.
(1980)
>
dioxide exposure compared to exercise
baselin
a0.1 ppm of sulfur dioxide •» 262 Hg/m*; 0.05 ppm «* 1310 Hg/m3; 1.0 ppm =• 2620 |Jg/m5; 5.0 ppm ~ 13,100 (Ig/m3; 10 pptn 26,200 Hg/m'; 50 ppm *> 131,000 Hg/rn3.
Significant increase or decrease noted here refers to "statistically significant" effects, independent of whether the observed effects are "medically significant" or not. Abbreviations are as follows:
', specific air way resistance; MMFR, maximum mid-expiratory flow rate; FVC, forced vita! capacity.
SOURCE: World Health Organization (WHO) 1987. Air Quality Guidelines for Bumfs, Copenhagen, WHO Regional Office for Europe, 1987 (WHO Regional Publications, European Series,
No. 23). Used with permission.
-------
IAQ Reference Manual
Section 4
Exhibit 4-6. Composition of mainstream and sidestream smoke.
CHARACTIRISTIC
OE COMPOUND
General characteristics:
Dilation of smoke
production, s
Tobacco burned
Particles, no. per cigarette
Particles:
Tar (chloroform extract)
Nicotine
Benzo [a} pyretic
Pyrene
Fluotanthene
Benzo [aj fluorene
Benzo Cb/c] fluorene
Chrysene, benz {a] anthracene
Benzo Cb/k/J] fluoranthrene
Benzo [e3 pytene
Perylene
Dibenz ta, j] anthracene
Dibenz [a, hj anthracene,
ideno-(2, 3-ed] pyrene
Betizo {ghi} perylene
Anthanthrene
Phenols (total)
Cadmium
Gases and vapors:
Water
Carbon monoxide
Ammonia
Carbon dioxide
NO»
Hydrogen cyanide
Actoiein
Formaldehyde
Toluene
Acetone
PoI0ntani-21Q, pCi
CONCENTRATION,
MAINSTREAM
SMOKE (1)
20
347
1,05 x 1Q12
20.8
10.2b
0.92
0,46b
3.5 x 10-'
4.4x10-*
13 x 10-4
2.70 x 10-4
2.72 x ID"4
1.84 x W*
6.9 x ID'5
1.91 * ID"4
4.9 x 10'5
2.5 x 10-5
9,0 x 10-*
1.1 x ID'5
3.1 x 10-*
3.9 x 10'5
2.2 x 10'5
0.228
1.25 x W4
' ?.5C
18.3
—
0.16
63.5
0.014
0.24
0.084
—
—
0.108
0.578
0.04-0.10
mg/CIGARETra*
SIDESTREAM
SMOICB (2)
550
411
3.5 x 10"
44.1
34.5b
1.69
, 1.27b
1.35X10-4
1.99 x ICr4
3.9 x 10-4
1.011 x 10'3
1.255 x WJ
7.51 x 10-4
2.51 x 10-4
1.224 x 10-}
2,60 x 10-4
1.35 x 10-4
3.9 x ID'5
4.1 x 10-'
1.04 x 1
-------
Section 4
1AQ Reference Mamtal
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Ahmed, T., I. Dama, RJL Dougherty, R, Schreck, and M.A.
Sackner, 1983. "Effect of NO2 (O.I ppm) on specific bronchial
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Beit, M, and W.T, Ulmer. 1976. "Wirkung von NO2 im
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Imer. Arch. Oceup. Eminn. Hhb. 38; 31-44.
Bylin, G., T. Lindvmll, T. Rehn, B. Sundin. 1985, "Effects of
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-------
IAQ Reference Manual
Section 4
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-------
Section 4
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Muysers, 1971. "Minimum concenttwions of NO2 causing
acute effects on the respiratory gas exchange and airway
resistance in patients with cnroaic bronchitis," Internatioiulet
Artbivfiir Arbeitimaiizitt, 27: 338-348.
von Nieding, G., Lollgen, and H. Kreckeier, R. Fuchs, M.
Wagner, and K. Koppenhagen. 1973. "Studies of the acute
effects of NOj on lung function: Influence on diffusion,
perfusion and ventilation in the lungs." Internationales Arehiv
far Arbtittmtditin. 31: 61-72.
von Nieding, G., M. Wagner, H. lollgen, and H. Krekeler.
1977. " Zur afcuten Wirkung von Ozon auf die Lungenfonk-
tion des Mensehen." (Acute effects of ozone on human lung
function.) VDl-Bmchtt. 270: 123-129.
World Health Organization (WHO). 1987. Air Quality
GtiMinesfor Europe, European Series No. 23. WHO;
Copenhagen, Denmark.
Zhtrov, 8.G., Y.A, ll'ln, Y.A. Kovalenko, LR. KaUoichencko,
LI. Kttpova, N.S. Mikerova, M.M, Osipova, and Y.Y.
Simonov. 1963. "Effect on man of prolonged exposure to
atmosphere with a high CO2 content." Aviation and Space Med,
Mama. pp. 155-158.
4.2. PESTICIDES
Irestieides are chemicals which are used to
kill or control pests. A pest is any organism that is
not wanted ia a particular location (for example, in
the home or garden). Termites, cockroaches, fleas,
rodents, ants, moths, caterpillars, dandelions and
other weeds, fungi, bacteria, and molds in buildings
are examples of pests. Pesticides can be categorized
into insecticides, herbicides, fungicides, rodenti-
cides, disinfectants or antimicrobial agents, and
plant growth regulators.
Because most pesticides are inherently toxic, proper
use and storage are needed to minimize the poten-
tial adverse effects from exposure. Unfortunately,
consumers tend to be casual about pesticides,
perhaps assuming they are innocuous since they can
be purchased in grocery stores, drug stores, and
hardware stores, and because these products can be
used without a license or special protective clothing.
As a result, each yeac there ace cases of poisonings
by these products which could have been prevented
through proper use of the products or through the
application of alternative methods of pest control,
The use of pesticides is widespread. In 1985
agricultural uses in the U.S. accounted for 77% of
the total usage (over 1 billion pounds), and farmers
spent about $4.6 billion on pesticides (U.S. EPA,
1987). Nonagricultural uses of pesticides are also
significant. During 1984, almost 230 million
pounds of herbicides, insecticides, fungicides, and
rodenticides were used for nonagricultural purposes
(U.S. GAO, 1986). Of this total, about 28.7% was
used in homes and gardens, and the remainder was
used by industry, government, and commerce',
According to 1988 estimates, lawn care pesticides in
the U.S. account for about 67 million pounds of
active ingredients (about B% of the total active
ingredients applied for agricultural purposes), and
sales have increased to over |700 million annually
(U.S. GAO, 1990). It is estimated that about 11%
of single family households use commercial applica-
tors for lawn care. Diazinon and 2,4-D have been
determined to be the most widely used lawn care
-------
IAQ Reference Manual
Section "4
pesticides; about 6 million pounds of diazinon and 4
million pounds of 2,4-D are used on residential
kwns each year (U.S. GAG, 1990).
Exhibit 4-7 summarizes some general statements of
the health effects, products, and uses of 50 active
ingredients in pesticides used in.and around resi-
dences. The actual risks of any of these pesticides
will depend on a variety of factors including the
application method, protective measures, and
ventilation.
Measured Concentrations in Homes
A nationwide survey conducted by EPA during
1976 and 1977 of household pesticide use found
that about 91% of households use pesticides (U.S.
EPA, 1987). In the home, pesticides are used to kill
pests on kwns, trees, shrubs, flowers, and veg-
etables. Pesticides are almost universally used to
control termite infestations either before or after
construction. Pesticides are applied to living spaces
to rid them of unwanted pests. And, people use
these products on themselves or their pets to
prevent the bites of mosqukos, chiggers, flies, ticks,
fleas, and other pests,-
In 1985, EPA extended its earlier work by develop-
ing a, methodology for determining pesticide
exposures in the general population of the U.S. (U.S.
EPA, 1990). The methodology used in this study,
which is known as the Non-occupational Pesticides
•Exposure Study (NOPES), was designed as a means
of developing estimates of exposure to some of the
most commonly used household insecticides via air,
drinking water, food, and dermal contact. In the
two cities which were studied (Jacksonville, Florida
and Springfield/Chicopee, Massachusetts), the
average number of pesticides in the home was 4.2
for Jacksonville and 5.3 in Springfield/Chicopee.
Exhibit 4-8 summarizes some of the data (indoor
concentrations only) from the study. For the
majority of the 33 target compounds which were
studied, indoor air concentrations were substantially
higher than outdoor air concentrations, and personal
air concentrations were usually similar to indoor air
concentrations. Another finding of this study was
that seasonal variations existed for many of the
compounds. This effect appears to be compound
specific and complex, and it probably reflects the
interaction of many variables including tempera-
ture, patterns of pesticide usage, use of heating and
cooling systems, and occupant activities.
The study also attempted to assess the relative
contributions of air, food, water, and dermal
exposure in the two tested cities. Based on limited
data it appears that exposure from water ingestion
was negligible. Food appeared to be a dominant
contributor for some compounds, while air domi-
nated for others. Limited data were collected for
dermal exposures, and the importance of this
pathway needs further study.
Exhibit 4-9 summarizes some additional measure-
ments of pesticides in buildings under different
conditions. These and other data suggest some
pesticides which are sprayed will persist for long
periods at varying concentrations. It is also possible
for these chemicals, particularly termiticides, to
migrate up and down through cracks and crevices in
the building and by air currents.
Hazards
Most pesticides are inherently toxic, and the
potential hazards posed by these chemicals are
magnified by improper use and storage. During the
1976 and 1977 nationwide survey, EPA found that
less than 50% of the people who participated in the
survey read pesticide labels for application.proce-
dures. About B5% of the people used pesticide
products without reservation, and only 9% used
these products with caution (as cited in U.S.
1PA, 1987).
In addition to direct exposures as a result of im-
proper use, secondary exposure can also occur when
people are unknowingly exposed as a result of some
other activity. For example, pesticides sprayed onto
fields can drift into homes, schools, or other build-
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Section 4
IAQ Reference Manual
Ings, Or, if an office area, public building, or home
is catered before an applied pesticide has cleared,
people and animals can be exposed to potentially
haaardous levels,
Pesticide formulations that have resulted in higher
concentrations indoors include bug bombs or home
foggers which are packaged in pressurized contain-
ers. These formulations contain pesticides such as
DDVP (2,2-dichlorovinyl dimethyl phosphate)
which have a relatively high volatility (vapor
pressure of 1,2 x 10~5mm Hg). If homes are reen-
tered too soon after application, acute health
problems can occur because initial concentrations
are high (in the range of rng/m3),
A widely used product of concern is the pest strip.
These products contain DDVP as the main ingredi-
ent. DDVP, which is an organophosphate pesticide,
may also be listed in the product literature as
dichlorvos or Vapona. DDVP is a concern because it
is classified as a possible human carcinogen, and it
also causes liver and nerve damage in animals.
Pesticides from these strips vaporize into the
surrounding air, and prolonged exposure is likely to
increase health risks.
Another concern is the use of use of pest repellents
which are applied to the skin and clothing as sprays,
lotions, or sticks. Many of these products contain
DEBT (diethykoluamide) which may also be listed
in the product description as detamide, metalde-
phene, MGK, or OFF. Regardless of the formula-
tion, DEBT is rapidly absorbed by the skin and into
the blood system. There have been reports of acute
neurotoxicity in children exposed to DEET-contain-
ing products, both through heavy normal use and
accidental ingestion (CU, 1987). Headaches, skin
irritation, contact dermatitis, and behavioral
disorders can also result from exposure to DEBT
(Morgan, 1989). Because of these potential effects,
the use of DIET, especially in children should be
minimized.
The application of pesticides to control subterranean
termites is also of concern. Prior to 1987, it was
thought that when cyclodiene termiticides such as
chiordane were applied correctly for subterranean
termite control, the residents of treated homes
would not be exposed to the pesticide. However,
studies in 1987 demonstrated that pesticides used
for subterranean termite control can be found at low
levels in the air of properly treated homes. As a
result, EPA has taken a series of actions which have
led to the withdrawal of cyelodiene termiticides
from the market.
Pesticide Formulations
Pesticides are packaged in a variety of forms includ-
ing baits, dusts, "bombs," slow-release insecticide
strips, flea collars, mothballs, dry powders, aerosols
sprays, solutions, and wettable powders which
readily mix with water.
Pesticide products contain both active and inert
ingredients. Active ingredients are biologically
active (the pest killer). Inert ingredients are added
to the formulation to affect its characteristics in
some way. The term "inert" is misleading because
it is a legal term, not a chemical term. It does not
mean that the compound cannot adversely affect
humans or animals.
Typically, a pesticide formulation is mostly inert
ingredients. There are about 1200 inert ingredients
which can be used to dissolve the pesticide, provide
a surface on which solids can adsorb, stabilize the
product, improve handling and application, or
intensify the killing power of the pesticide.
Many insecticides are lipophilic (soluble in fat).
Insecticides are commonly dissolved in petroleum
distillates which are mixtures of low molecular
weight aliphatic and aromatic hydrocarbons.
Toluene or xyiene are added to some formulations to
stabilize the insecticide or make it more emulsifi-
able. Alcohols, glycols, ethers, or chlorinated
solvents are used as carriers (also called vehicles) for
insecticides which are not strongly lipophilic.
These carriers also make the insecticide more likely
to be absorbed through the skin.
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IAQ Reference Manual
Section 4
Classification of Inert Ingredients
Inert ingredients may be more toxic than some
active ingredients. However, inert ingredients are
considered to be proprietary, and generally are not
required to be identified by the product label. An
exception are inerts which EPA classifies as being of
"immediate lexicological concern" (a list of chemi-
cals including carbon tetrachloride, formaldehyde,
methylene chloride, and others). Pesticides with
these chemicals must either be reformulated or have
a label which states: "This product contains the
toxic inert ingredient ....*'
In 1985, EPA established a classification system to
allow inert ingredients to be regulated according to
the risks these chemicals pose. List 1 are those
inerts of immediate toxkoiogical concern; 28 of
these chemicals are suspected carcinogens. List 2
includes those which ate classified as potentially
toxic (62 chemicals). List 3 contains those inerts for
which there is insufficient data for classification
(over 800 chemicals), and list 4 includes inerts
which pose a minimal risk (273 chemicals).
Most of the inert ingredients have not been tested
for long term effects. Unfortunately, there is
insufficient information to classify the toxicity of
about 2/j of the inert ingredients, and it is also
possible for a chemical that has been banned as an
active ingredient in pesticides to be used as an inert
ingredient.
Exhibit 4-7. Summary of health effects, products, and uses of SO active ingredients in
household pesticides.
PESTICIDE COMMON NAME
(SOME, NOT ALL,
CONSUMER PRODUCTS)
USIS
COMMEHTS
INSBCTIC1DES
OrganopAefp&ates
Acephate (Ottho Otthene Systemic
Insect Control; Ortho ISOMX
Insect Killer
Chtorpynfos (Onto Hea-B-Gon;
d-Con Home Pest Control Killer
Johnston's No-Roach, Raid Home
Insect Killer—prof nl strength)
Diazinon (Spectracide products,
Johnston's No-Roach, Real-Kill
Ant & Roach)
Dkhlorvos 2% formulations require
certified applicator
(continued next page)
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Section 4
IAQ Reference Manual
Exhibit 4*7. Summary of health effects, products, ami uses of SO active ingredients ii
household pesticides (tontlnued).
PESTICIDE COMMON NAME
(SOME, NOT ALL,
CONSUMER PRODUCTS)
USES
COMMENTS
MaJathion (Bonide Rose Spray; Ortho
Orchard Spray; Johnston's No-
Roach Spray; Gro-Wdl Fruit Tree
Spsmy; Sergeant's Flea & Tick Dip
for Dogs)
Mated (Bawect Flea & Tick Collars;
Sergeant's Hea & Tiek Collars)
fyretbroitb
AUeehrin (d-Con Home Pest
Comtol; Gro-Wcll Ant mad Roach
Spray; Sergeant's Indoor Fogger;
Sergeant's Sklp-Hea Shampoo;
Raid Yarf-Guard Outdoor Fogger)
Petmethrin (Black Hag Roach Endet;
Said Fumigator Cake; Sudbury Hea
& Tick Dip)
Phenothrin (Ortho Home & Garden
Insect Killer! Combat Hying
Insect Fbgg«! d-Con Eica & Tick
Killer Bt( Raid Yard Gu«d Outdoor
FoggetHI)
Resnicthrin et:
products
same as. above
same as above
same as above
same as above
fituit & vegetable gatdeas, pet products,
human lice & chigger dusts, fish poison
low tosicity cholinesterase inhibitor;
cancer studies ate not adequate and
will be redone; widely used in home products;
one of GAO's top 10 home chemicals; also used
in mosquito control programs; banned by Horida in 1986
for community mosquito control
metabolizes to dtchlotvos
synthetic pytethrin of low toxicitjr;
widely used by consumers and
professionals to control household pests;
also used by professionals as a termiticide
synthetic pyrethrin; possible human carcinogen
synthetic pyrethrin
synthetic pyrefhzin
synthetic pyrethrin; possible humsn carcinogen
human exposure has not been measured; widely used;
viewed as comparatively safe, but not folly tested;
natural botanical derivative
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IAQ Reference Manual
Section 4
Exhibit 4-7. Summary of health effects, products, and uses of 50 active ingredients in
household pesticides (tontinued).
PESTICIDE COMMON NAME
(SOME, NOT ALL,
CONSUMER PRODUCTS)
USIS
COMMENTS
INSECTICIDES (continued)
Pyrethrins
(Raid Hying Insect Killer; Black
Flag Triple Action; Raid House 8c
Garden; Hot Shot Fly & Mosquito;
Hartz 2 in 1 Flea & Tick Dip for
Dogs/Cats; A-200 Pyrinate Anti-
Lice Shampoo)
house & garden products, pet products,
anti-lice shampoos
viewed as comparatively safe, but not fully tested;
natural botanical derivative
Bendiocarb (TAT Ant Traps; Raid
Traps)
Carbaryl (Spectracide Sevin Liquid,
Ortho Sevin Garden Dust, Sergeant's
Flea and Tick Powder for Dogs,
Bonide Rose Spray)
Prqpoxur (Black Flag Ant & Roach
Killer; Combat Ant & Roach Instant
Killer; Ortho Hornet & Wasp Killer;
Sergeant's Flea & Tick Spray; Daltek
Flea & Tick Collars)
Chlordane
Dicofol (Bonide Rose Spray;
Ortho Isotox Insect Killer;
Pratt Noculate Insect Spray)
Lindane (HCH, BHC) (Kwell shampoo;
Roxo Borerkili; Gro-Well Borer
Killer; Ortho Lindane Borer and
Leaf Miner Spray)
Methoxychlor (Black Flag Insect
Spray; Ortho Tomato & Vegetable
Dust; Sergeant's Cat Flea Powder;
Gro-Well Fruit Tree Spray)
ant, roach, and flea control indoors;
ornamentals; insecticide-impregnated
shelfpaper; turf
fruit & vegetable gardens; turf,
pet products—flea collars and
dusts; ornamentals; indoor use
indoor use; ant Sc roach killers;
pet products; mosquito foggers
termite control
vegetable gardens, indoor
insect & mite control
house It garden use; shelf
paper; anti-lice shampoos;
pet products; termite control
house & garden use; pet
products
cholinesterase inhibitor; widely used by professionals for
control of indoor pests; applied as a dust or wettable
powder; consumer exposure occurs almost entirely from
home uses; EPA recommends application of ready-to-use
products by professional only
low toxicity cholinesterase inhibitor; commonly used
insecticide for control of pests indoors and outdoors;
applied to leaf surfaces as wettable powder and dust;
should not be used on pregnant dogs because it may cause
birch defects in dogs
probable human carcinogen; cholinesterase inhibitor;
toxic residue for weeks after application; infants crawling
on treated surfaces may be exposed dermally; widely used
probable human carcinogen; cancelled in 1988; product
may still be stored because shelf supplies were allowed to
be depleted; most widely used termiticide before
withdrawal; applied as a liquid poured or injected into
the soil around the building foundation
possible human carcinogen; home use is not large;
DDT & related compounds may be present as
contaminants
possible/probable human carcinogen; use against termites
(house) is restricted to unoccupied buildings; exposure
from Kwell shampoo can be high if used too often or
left on skin too long
many toxicology data gaps; formula used to control
pantry pests; primarily applied as a liquid spray, widely
used for mosquito and fly control outdoors
(continued next page)
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Section 4
IAQ Reference Manual
Exhibit 4*7. Summary of health effects, products, and uses of SO active ingredients in
household pesticides Continued).
PESTICIDS COMMON NAME
(SOME, NOT ALL,
CONSUMER PRODUCTS)
USES
COMMENTS
INSECTICIDES (continued)
Metboprene
(Dexol Red Spider & Mite Killer;
Eterol White Fly & Mealy Bug
Spray; Spectracide Professional
Flea Control; Rtid Flea Killer Pita)
Synergists
MGK 264 (Blackjack Ant & Roach
Killer; d-Con Flea & Tick Killer;
Hartz 2 in 1 Flea & Tick Dip for
Dogs/Cats; Ortho High Power Indo
Fogger; Eaid Fogger)
Piperonyl butoxide (Raid House &
Garden, Formula II; Ortho Tomato &
Vegetable Insect Spray; Ham 2 in
1 Rid Flea Shampoo for Dogs)
cockroach, mosquito, and flea
control; control of mealy bugs
Se spider mites on house plants
house use; pet products
house & garden use; pet
products
considered to be quite safe; chtonic data gaps
inhalation & contact exposure could be significant; widely
used
widely used; direct inhalation is an important
exposure route
FUNGICIDES
Benomyl (DuPont Tersan 1991; Gro-
Weil Benomyl Systemic Fungicide)
Cnpt.in (Onho Tomato & Vegetable
Dust; Ortho Orthocide Garden
Fungicide; Bonide Rose Spray;
Gro-Well Fruit Tree Spray)
Chlorothalonil (Ortho Liquid Lawn
Disease Control; Ortho Multi-Purpose
Fungicide; Ortho Vegetable Disease
Control)
Folper (Ortho Phaltan Rose & Garden
Fungicide)
vegetables & ornamentals;
lawn & turf
fruit, vegetables, ornamentals;
turf; house plants; paints; materials;
(pets, human anti-fungal shampoos;
cosmetics)*
ornamentals, turf, lawns; fruits,
vegetables; paint & grout additive;
wood preservative
paints; plastics
possible human carcinogen; accounts for 5596 of fungi-
cides worldwide; many fiingi are resistant to it
probable human carcinogen; EPA estimates shampoos
may pose cancer risk of 1 in 10,000; registration
cancelled for many commercial food crops bur home
pesticide use is permitted; widely used by consumers
and professionals; usually applied as a wettable powder
probable human carcinogen; insufficient data on home use
probable human carcinogen; cancelled on ornamentals
and in wood preservatives; >20% formulations cannot be
sold to consumers; protective clothing required
Maneb (Deseol Maneb Garden Fungicide; ornamentals & vegetable
Security Maneb Spray) gardens
ethylthiourea, a metabolite, is a probable human
carcinogen, teratogen, antithyroid agent, and possibly, a
mutagen
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IAQ Reference Manual
Section 4
Exhibit 4-7. Summary of health effects, products, and uses of 50 active Ingredients in
household pesticides (tontinued).
PESTICIDE COMMON NAME
(SOME, NOT ALL,
CONSUMER PRODUCTS)
USES
COMMENTS
FUNGICIDES (continued)
Sulfur and Lime Sulfur (Pic Sulfur
Candle, fumigant; Ortho Orrhorix
Spray Fungicide; Safer Garden
Fungicide and Mitkide)
TBTO (Cuprinol Stain & Wood
Preservative; Cabot's Wood-
Preserving Stain)
Triforine (Ortho Funginex Rose
Disease Control; Ortho Orthenex
Insect & Disease Control)
Zineb (Security Zineb Spray)
bedbug control, fumigants; insect
& mildew control on ornamentals
and food plants
anti-fbuling agent in marine paints;
wood preservatives
ornamentals & vegetables
ornamentals, fruits, vegetables
low toxicity, but may cause irritation
limited data; skin absorption may be significant
complete data base
limited data
OTHEE INGREDIENTS
Deet (Offl; Muskol Spray; Cutter
Stick and Cutter Cream; Blockade
flea products)
toxicology
Metaldenyde (Snarol Snail & Slug
Killer Pellets; Ortho Bug-Geta & Bug-
Geta Plus; Deadline Slug & Snail Bait)
Methiocarb (Ortho Slug-Geta)
insect repellent; pet flea repellent
slug &, snail baits
rapid skin penetration Sc blood absorption; acute
neutotoxkity possible in children; widely used,
but long-terna toxicity is nor known; additional
data being generated
inhalation & skin absorption not a concern
complete data base
HERBICIDES
Ammonium Sulfamate (Ortho Brush
Killer A; Science Ammate Weed &
Brush Killer)
Benefm (Greenview Crabicide;
Eockland Balan Crabgrass Preventer)
2,4-D (Orcho Weed-B-Gon; Scott's
Spot Dandelion Control; hundreds
of others)
brush control
crabgrass control
weed killer; lawns & gardens
DCPA (Gro-Well Garden Weeder; Ortho lawn & garden crabgtass Si
Garden Weed Preventer; Gro-Well weed control
Pre-Vent Weed Control)
many data gaps
widespread use in lawn care; limited data; new .data
being generated
commonly used lawn herbicide for the control of
broadleaf weeds and dandelions; primary application is
in granular lawn fertilizers; professionals commonly
apply as a spray; cancer and epidemiology studies are
being developed and reviewed
widespread use in lawn care; considered to be low in
toxicity; some data gaps
(continued next page)
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Section 4
IAQ Reference Manual
ixhibil 4-7. Summary of health efforts, products, and uses of 50 aitivo ingredients in
household pesticides (tontinved).
PESTICIDE COMMON NAME
(SOME, NOT ALL,
CONSUMER PHODUCTS)
USES
COMMENTS
HERBICIDES (continued)
Dicamba (Spectraeide lawn Weed
Killer; Scott's Spot Dandelion
Control)
Fluazifop (Fluazifop-butyl)
(Ortho Gr»ss-B-Gon-Grass Killer)
Glyphosztc (Ortho Kleenup Spot Weed
& Grass Killer; Roundup I, & G Lawn
& Garden Formulation; Ortho Fence &
Grass Edger I!)
Mecoprop (MCPP) {Ortho Weed-B-Gon;
Spectracide lawn Weed Killer; Gro-
Well Dandelion & Broadleaf Weed
Killer; Dexol Spot Weeder)
Met hancarsonates (Gra-Well Crabgrass
Killer; Ortho Crabgrass & Dandelion
Killer, Ortho Crabgnss Killer,
Formula II)
Pendimcth.ilin (Scott's Lawn Pro
Step I Crabgrass Preventer Plus
Fertilizer)
Prometon (Gro-Well No-Gro Weed &
Grass Killer; Ortho Triox Vegetation
Killer)
Simmzine (1-Z Clot; Algi-Kleer)
lawns & turf
lack cancer study in second species; relatively low toxichy
grass control along walks & in gardens minimal data gaps
lawn & garden weed control
broadleaf control in lawns
lawn & aid; crabgrass control
grass & weed control in lawns
& gardens
grass & weed control in lawns
& gardens
algae control in fish ponds, aquaria;
orchard & berry-patch weed control
dermal Sc eye exposure a concern during
application & mixing; protective clothing requited
for agricultural uses but not home use; home-use
data is limited
widely used; many data gaps
inhalation & dermal exposure is a concern;
limited data
considered to have low toxicity; limited
home-use data
limited data
potential exposure in treated pools; limited data
Triclopyr (Ortho Brush-B-Gon; Ortho
Poison Ivy and Poison Oak Killer)
Trifluraun (Ortho 3-Way Rose &
Flower Care; Gteenview Preen)
brush & poison ivy/oak control
control of grasses & broadleaf weeds
in lawns, turf, flower, & orchards
limited data
possible nitrosamine contaminant;
manufacturers are required to guarantee
minimal levels of contaminant
* Use of fungicides on humans and pets is regulated by FDA;
these uses are not under the purview of FIFRA.
SOURCE: Format adapted from Consumers Union (1987); health effects information revised by the U,S, EPA Office of Pesticide Programs (1990),
-------
Exhibit 4-8.
PESTICIDE
Gamma-BHC
Chlorothalonil
Heptachlor
Rotwel
Dichlorvos
AIpha-BHC
Hexachlotobenzene
Chlorpyrifes
Aldrin
Dacthal
Selected weighted summary statistics
Springf ield/Chicopee (ng/m3).0
mean
max
mean
made
mean
max
mean
max
mean
max
mean
max
mean
max
mean
max
mean
max
mean
max
SUMMER
20.2
245.0
53
264.0
163.4
1600.0
0.2
20.0
134.5
2280.0
1.2
32.0
1.3
21.0
366.0
2170.0
31.3
1840.0
0.2
12.0
for indoor air concentrations
SPRING
Jacksonville
13.4
1530.0
2.2
51.0
153.9
2370.0
0.0
0.0
86.2
2910.0
1.2
28.0
0.4
7.7
205.4
4350.0
6.8
320.0
0.0
0.0
WINTER
6.0
75.0
6.7
523,0
72.2
684.0
0.0
0.0
24.5
1090,0
1.1
32.0
03
5,3
120.3
1043.3
6,9
106.0
0.3
3.2
off pesticides
SUMMER
*
*
*
*
*
*
*
*
*
*
in Jacksonville
SPRING
and
WINTER
Spriagfield/Chicapee
0.5
5.0
0.1
35.0
31.3
253-0
0.2
8,8
4.3
324.0
0.2
8.0
0,0
0.0
9.8
252.0
0.0
0.0
1.6
32.0
9.5
118.0
0.1
9.2
3.6
152.0
0.0
4.8
1.5
158.0
0,0
0.0
0.1
5.7
5.1
291.0
0.3
3.9
0.3
15.0
(continued next page)
IAQ Reference Manual
I
^
-------
Exhibit 4-8.
PESTICIDE
Selected weighted summary statistics for Moor
Springfield/Chieopee (ng/m3)0 (tontinued).
HeptmcMor Ipoxide mean
Oxychlosjane
Captan
Folpet
2,4-D
DieHrin
Methoxychlor
Dicofol
Cis-Peanethrin
Ttans-Peanethtin
max
mean
max
mean
max
mean
max
mean
max
mean
max
mean
wax
mean
max
mean
max
mean
max
SUMMER
0.5
11.0
0.1
5.2
1.9
44.0
0.5
23,0
1.8
48,0
14.7
177.0
0.2
17.0
0.0
0.0
0.5
53.0
0,4
31.0
SPRING
Jacksonville
0.8
160.0
0.0
0.0
2.2
254.0
0.7
65,0
0,0
0.0
8.3
61.0
0,3
55.0
11,0
581.0
1.9
153,0
1.1
56.0
air concentrations of
WINTER
0.8
30.0
0.0
6.5
0.1
21.0
0.6
24.0
2,5
58,0
7.2
57.0
0.2
7.0
0.0
0.0
1.3
62.0
0.8
37.0
pesticides in Jacksonville and
SUMMER SPRING
Springfield/Chieopee
* 0.0
0.0
* 0.0
0.0
* 0.1
22.0
* 0.7
36.0
* 2.1
104.0
* 1.0
8.8
* 0.0
0.0
*• o.o
0,0
* 0.0
0.0
* 0.0
0.0
WINTER
0.0
0.0
0.0
0.0
0.0
6.4
0,0
0.0
0,0
0,0
4.2
40.0
0.0
0.0
0,0
0.0
0.0
0.0
0.0
0.0
Section 4
•«.
fe
5
i
i
-------
Exhibit 4-8.
PESTICIDE
Chlordane
4,4'-DDT
4,4'-DDD
4,4'-DDB
Selected weighted summary statistics for indoor
Springfield/Chicopee (ng/m3)0 Continued).
mean
max
mean
max
mean
max
mean
max
Ortho-phenyiphenol mean
Propoxur
Bendiocarb
Atrazine
Diazinon
max
mean
max
mean
max
mean
max
mean
max
SUMMER
324.0
3020.0
**
**
**
96.0
1040.0
528.5
7920.0
85.7
1500.0
0.0
0.0
420.7
13700
SPRING
Jacksonville
245.6
4380,0
1.0
13.0
0.0
0.0
0.6
15.0
70.4
1240.0
222.3
2030.0
5.5
89.0
0.0
0.0
109.2
2370.0
air conientrations off pesticides
WINTER SUMMER
220.3 *
2050.0
0.5 *
11.0
0.0 *
0.0
0.2 *
8.8
59.0 *
1440.0
162.5 *
1370.0
3.4 *
68.0
0.0 *
0.0
85.7 *
1080.0
in Jacksonville
SPRING
and
WINTER
Springfield/Chicopee
199.4
1700.0
0.0
6.3
0.0
0.0
0.9
8.4
44.5
560.0
. 26.7
505.0
0.2
10.0
0.0
0.0
48.4
1810.0
34.8
735.0
0.6
15.0
0,0
0.8
0.6
3.5
22.8
286.0
17.0
669.0
0.4
38.0
0.0
0.0
2.5
27.0
(continued next page)
lAQ Reference Manual
I
•h,
-------
Exhibit 4*8. Selected weighted summary statistics for indoor air concentrations of pesticides in Jacksonville and
Spring!ield/Chicopee (ng/m3)0 (tontinued).
PESTICIDE
SUMMER
SPRING
WINTER.
SUMMER
SPRING
WINTER
Jacksonville
Springfield/Chfcopee
Carbatyl
Malathion
mean
max
mean
max
68.1
3190.0
20.8
1890,0
0.4
97.0
15.0
240.0
0.0
0,0
20.4
1660.0
0.3
16,0
5.0
275.0
0.0
0.0
0.0
0.0
Resmethrin
mean
max
0.1
19.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
* ng/m3; nanograms pet cubic meter (1000 ng = l(Jg)
*These pesticides were not sampled during the summet in Springfield/CMcopee,
**These pesticides were not sampled during the summer in Jacksonville.
SOURCE: U.S. EPA (1990)
JO
I
-------
IAQ Reference Manual
Section 4
Exhibit 4-9. Measurements of pestUides in buildings.
PESTICIDE
CONCENTRATION
RANGE, Mg/m3
COMMENTS
REFERENCES
Diazinon (emulsion)
Bendiocarb (0.5% wettable powder)
Carbaryl (5% dust)
Acephate (1% suspension)
Diazinon (1% suspension)
Chlorpyrifos (0.5% suspension)
Fenitrothion (1.0% suspension)
Propoxur
38.4
9.7
7.1
0.9
1.0
0.4, 0.5
0.6, 0.4
7.7
ND*
1.3
0.2
0.01
1.3
2.9
0.3
1.6
0.6
0.4
1.1
1.1
0.3
3.3
1.1
0.5
15.4
2.7
0.7
Dormitory Leidyetal. (1982)
treatment room, day of treatment
treatment room, 7 days later
treatment room, 21 days later
adjacent room, day of treatment
adjacent room, 21 days later
rooms above and below treatment
room; day of treatment
rooms above and below; 21 days later
Dormitory Wright et al. (1981)
day of treatment
3 days later
day of treatment
1 day later
3 days later
day of treatment
1 day later
3 days later
day of treatment
1 day later
3 days later
day of treatment
1 day later
3 days later
day of treatment
1 day later
3 days later
day of treatment
1 day kter
3 days later
(continued next page)
-------
Section 4
IAQ Reference Manual
Exhibit 4-9. Measurements of pesticides in buildings ( NAS guideline
0 > NAS guideline
0.02% > NAS guideline
no NAS guideline
Olds (1987)
-------
IAQ Reference Manual
Section 4
Exhibit 4-9. Measurements of pesticides in buildings Continued).
PESTICIDE
CONCENTRATION
RANGE, Hg/m3
COMMENTS
REFERENCES
Chlordane
NDL**
• slab (ducts in slab)
• crawl space
• slab (ducts in attic)
5038 Houses
% of houses with identical level
(time between treatment
and sampling not given)
Lillie & Barnes
(1987)
Time of Treatment
preconstr. postconstr.
77%
5%
NDL to <2
• slab (ducts in slab)
• crawl space
• slab (ducts in attic)
>2 to <.5
• slab (ducts in slab)
• crawl space
• slab (ducts in attic)
>5
• slab (ducts in slab)
• crawl space
• slab (ducts in attic)
17%
11%
53%
5%
4%
0
1%
0
18%
28%
0
19%
0
* ND - not detected
** NDL - nondetectable level
HEALTH EFFECTS OF PESTICIDES
Poisonings
During 1987, 57,430 cases of pesticide
exposure were reported to poison control centers,
and 98% of these were due to accidental exposures.
Insecticides accounted for about 66% of the total
cases, followed by rodenticides (17%), moth
repellents (7.7%), herbicides (7.2%), and fungicides
(2.3%). About 60% of the cases involved children
less than 6 years of age. (Blondell, 1989)
During the period 1980 to 1985, at least 46.5% of
the accidental pesticide related deaths in the U.S.
occurred in the home (40.9% of the locations were
not specified). Organophosphate insecticides were
responsible for about 32% of the deaths. Seventeen
percent of the victims were under the age of 5;
29-6% were between 25 and 44 years of age; 23.9%
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Section 4
IAQ Reference Manual
were between 45 and 64 years of age; and 22% were
over the age of 65 (Blondell, 1989).
Pesticide poisonings are the second most common
source of childhood poisonings. A new trend to
develop products with less offensive odors makes
poisonings more likely. Consumers should know
that the availability of these products is increasing
in the marketplace, and the absence of this warning
signal may lull users into a false sense of security.
Prevention of poisoning through proper selection,
storage, and use of pesticides is the key to reducing
adverse health effects. Although medical treatments
can counteract the pesticide poisoning, they apply
to acute exposures and many treatments pose risks
to the health of patients.
Symptoms of Acute and Chronic Exposures
Many pesticides (for example, organophosphates and
organochlorines) affect more than one organ system
and produce a variety of symptoms which can
progress rapidly from mild to fatal. Some pesticides
produce reactions almost immediately while others
result in delayed reactions. The specific symptoms
that will result from a given exposure situation
depend on the pesticide and its site of action, the
dose received, and the sensitivity of the exposed
individual. It should be noted that some individu-
als may be more sensitive to pesticides and other
chemicals than the general population.
Irritation of the skin, eyes, and respiratory tract are
common effects of pesticides. Skin exposure can
result in itching, redness, swelling, blistering or an
acne-like condition. The mucous membranes and
the lining of the respiratory tract are especially
sensitive, and inhaled pesticides can produce
stinging, swelling, difficulty breathing, and in-
creased mucous production. Flu-like symptoms are
common.
Gastrointestinal tract symptoms include salivation,
nausea, vomiting, abdominal cramps, and diarrhea.
Nervous system effects include fatigue, headache,
diz2iness, weakness, behavioral and mood distur-
bances, decreased or blurred vision, tingling and
numbness of the extremities, tremors, pinpoint and
nonreactive pupils, paralysis, coma, and death.
Shock, hypertension, and arrhythmias of the heart
can result when the cardiovascular system is
affected. The kidneys and blood can also be damaged.
Some pesticides are sensitizers, and they result in
more severe and potentially life-threatening reac-
tions with subsequent exposures to small amounts.
Chronic exposure to some pesticides can result in
damage to the liver, kidneys, and nervous system.
Typical clinical findings include muscular weakness,
and numbness and tingling of the extremities
(peripheral neuropathy).
A history of recent pesticide use and the presence of
these types of symptoms should suggest the possi-
bility of pesticide poisoning.
Health Iffects Data
There are significant gaps and uncertainties in the
health effects data base. For example, the lowest
dose that results in acute effects is not known with
certainty for most pesticides. In addition, the
effects of chronic exposures and the doses at which
these effects occur are not'well documented.
Deficiencies in the data base for long-term health
effects are also important because of the potential
exposure to pesticides in schools, parks, retail stores,
mass transit vehicles, or other public areas; and
nonoccupational exposures, in general, are poorly
characterized.
Of particular concern are the carcinogenic, muta-
genic, and teratogenic potential of pesticides. The
data base for assessing these effects is inadequate to
support definitive conclusions, but some animal and
short-term tests suggest that many pesticides may
be carcinogenic or genotoxic (Borzsonyi et a/., 1984;
U.S. GAO, 1986; AMA Council on Scientific
Affairs, 1988).
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IAQ Reference Manual
Section 4
In addition to the animal and cell studies, there are
epidemiologic studies of occupationally exposed
workers which suggest that subacute poisoning does
occur as a result of continuous low-level exposure
(Sharp eta/,, 1986; Xue, 1987; Stokes and Brace,
1988). Also, a study by Lowengart et al. (1987)
underscores the concern for health effects in children
resulting from of home pesticide use. Although this
study was not designed to evaluate the relationship
between household chemicals and cancer, the data in
the study showed an association between pesticide
exposure in children and infants and childhood
leukemia. However, other studies confirming this
work are needed.
REGULATORY FRAMEWORK
Federal
liPA regulates pesticide formulations
under the Federal Insecticide, Fungicide and
Rodentkide Act (FIFRA) of 1947 and its amend-.
ments. All pesticides must be registered with EPA
before the products can be sold or distributed. Each
product must have a label which identifies the EPA
registration number, ingredients, proper use, health
effects, warnings, and cautions.
Registration is based on an overall risk/benefit
standard which requires the EPA to consider the
economic, environmental, and social costs and
benefits of pesticide use. Pesticides can be regis-
tered if the pesticide performs its stated function
when used according to label instructions, without
posing an unreasonable risk of adverse effects on
human health or the environment. EPA has a
Science Advisory Panel of outside experts which
reviews major pesticide decisions or regulations.
The toxicological data that are required for register-
ing pesticides used in and around the home depends
on the nature, magnitude, and duration of expected
exposures if the pesticide labels are reasonably
followed. Some basic data such as acute toxicity
studies for labeling the pesticide formulation are
required routinely. Longer term studies such as
reproduction carried over 2 generations of breeding
and cancer studies in rats and mice are required only
for nonfood uses which could result in high expo-
sures over a significant period of a person's lifetime.
Pesticides used on food crops have been tested in all
types of studies including long-term chronic and
cancer testing.
An important provision of FIFRA requires EPA to
review "old" pesticides (previously registered) to
ensure that these products meet current scientific
and regulatory standards. Pesticides which were
considered to be "reasonably safe" were to be
reregistered, and those which were considered to be
"unreasonably unsafe" were to be cancelled. Prior to
1988, EPA was able to evaluate 185 active ingredi-
ents of about 600 previously registered pesticide
active ingredients. The 1988 amendments acceler-
ate and expedite the reregistration process which
should enable EPA to evalute the remaining
chemicals more quickly.
EPA can also place a pesticide into "Special Review"
if it believes the chemical poses a serious potential
health or environmental risk. Special Review is an
intensive investigation of the pesticide's risks and
benefits.
EPA can limit the use of a chemical in some
applications, but may decide its use is safe in others.
For example, diazinon is one of the most widely
used ingredients in consumer pesticide products. In
1988 EPA banned the use of diazinon on sod farms
and golf courses because of-its toxicity to certain
birds and other nontarget species, Diazinon can
still be applied to lawns because lawns are not the
usual habitat for the waterfowl that are at risk.
If a pesticide is considered to be a significant health
hazard, EPA or other appropriate agency can take
one of the following actions: 1) cancel the registra-
tion; 2) cancel the registration and withdraw the
product; 3) place restrictions on use or application
of the compound; 4) suspend the registration
pending resolution of the hazard or receipt of data;
5) set tolerance limits for pesticide residues on
-------
Section 4
IAQ Reference Manual
foodstuffs; or 6) establish maximum permissible
limits for the pesticide in drinking water.
As EPA evaluates pesticides, it publishes fact sheets
which identify the manufacturer, date of registra-
tion, uses, toxicity, and regulatory action. These
fact sheets and registration information for indi-
vidual pesticides are a useful source of information.
Warning Labels
EPA requires pesticides to be labeled according to
one of four toxicity categories based on a series of
tests which relate to acute effects such as eye or skin
irritation and other harmful effects that result
shortly after the pesticide exposure occurs.
Depending on the health effects evaluation, prod-
ucts may be labeled DANGER (highly poisonous),
WARNING (moderately poisonous), or CAU-
TION (least hazardous). Unfortunately, based on
EPA's 1987 survey, it seems highly likely that
many consumers do not discriminate among these
different labels.
Registration and labeling, however, have limita-
tions. In 1986 the GAO noted, "The public is not
told about the uncertainties surrounding chronic
health risks." (U.S. GAO, 1986). In 1988 the
California Senate Office of Research echoed the
GAO's concerns when it concluded that "labeled
precautions for consumers may often provide only a
minimal, and in certain instances inadequate, basis
for avoiding hazards, especially infants and chil-
dren" (Jennings, 1988).
EPA does require some pesticide products to
contain warnings about potential chronic effects,
but the labeling regulations do not require disclo-
sure of chronic health hazards or the lack of full
assessments of chemicals.
local Authority
Regulation of lawn chemicals is one area in which
state and local jurisdictions have attempted to
inform the public about pesticide use. Some states
such as Rhode Island, Massachusetts, Maryland,
Minnesota, and Iowa have enacted laws which
require the posting of warnings for the application
of lawn chemicals. These regulations require
notifications of pesticide applications, listing of the
pesticides to be applied, and the disclosure of health
and environmental effects.
REFERENCES
AMA Council on Scientific Affairs. 1988. "Cancer risk of
pesticides in agricultural workers." JAMA. 260 (7): 959-966.
Blondell, J. 1989. Personal Communication: U.S. Environ-
mental Protection Agency, Health Effects Division: Washing-
ton, DC.
Borzsonyi, M., G. Torok, A. Pinter, and A. Surjan. 1984.
"Agriculturally-related carcinogenic risk." IARC (Interna-
tional Agency for Research on Cancer) Scientific Publication
Series. Vol. 56.: M. Borzsonyi, N.E. Day, K. Lapis, and H.
Yamasaki (eds). World Health Organization: Geneva,
Switzerland.
Consumers Union. 1987. "What EPA knows about the risks of
home use products containing 50 common active ingredients."
Consumers Union: Mt. Vernon, NY.
Dobbs, A.J. and N. Williams. 1983. "Indoor air pollution from
pesticides used in wood remedial treatments." Environ.
Poll.(Series B). 6: 271-296.
Jennings, B.H. 1988. "Issue Brief. Pesticides at home:
Uncertain risks and inadequate regulations." California Senate
Office of Research: Sacramento , CA. 27 pp.
Leidy, R.B., C.G. Wright, and H.E. Dupree, Jr. 1982.
"Concentration and movement of diazinon in air." J. Environ.
Sci. Health. B17(4): 311-319-
Lillie, T.H. and E.S. Barnes. 1987. "Airborne termiticide
levels in houses on United States Air Force installations." Indoor
Air'87. Vol.1. Volatile organic compounds, combustion gases,
particles and fibers, microbiological agents. Oraniendruck GmBH:
Berlin, W. Germany.
Lowengart, R.A., J.M. Peters, C. Cicioni, J. Buckley, L.
Bernstein, S.. Preston-Martin, and E. Rappaport. 1987.
"Childhood leukemia and parents occupational and home
exposures." J.N.C.I. 79(1): 39-46.
-------
IAQ Reference Manual
Section 4
Morgan, D.P, 1989. Recognition and Mitititgeaitnt ofPmtieitie
Poiiomngf. 4th edition, EPA-540/9-88-001, U,S. Environ-
mental Protection Agency, Office of Pesticide Programs:
Washington, DC,
National Research Council (NRC). 1981. Indoor Pollutants.
National Academy Press: Washington, DC.
Olds, KX. 1987. "Indoor airborne concentrations of
termiticides in Department of the Army family bowsing,"
IrtJoar Air '87, Vol.1. Volatile organic eamjxnmdt, combustion gases,
particles andflbtfs, micmbit/logieal agtnts, Oraniendrack GmBH:
Berlin, W. Germany.
Rosenberg, M.J., P.J. Feldblum, and E.G. Marshall. 1987.
"Occupational influences on reproduction: A review of recent
literature," /. Occ. Med, 29 <7): 584-591.
Sharp, D.S., B. Eskenazi, R, Harrison, P, Callas, and A.M.
Smith. 1986, "Delayed health hazards of pesticide exposure,"
Am. Rev. Public Health, 7; 441-471.
Stokes, C. S. and K, D. Brace. 1988, "Agricultural chemical
we and cancer mortality ifl selected rural counties in the
U.S.A," J. Rural Studies. 40): 239-247.
U,S, Environmental Protection Agency (EPA). 1987. A
Consumer's Gaidt to Safer Pesticidt Use. OPA 87-013. U.S. EPA,
Office of Public Afiate: Washington, DC.
U.S. Environmental Protection Agency (IPA). 1990.
Nentccupationalpesticide exposure study (NOPES). EPA/600/3-90/
003. U.S. EPA, Atmospheric Research and Exposure .Assess-
ment laboratory: Research Triangle Park, NC.
U.S. General Accounting Office (GAO). 1986. Nasagricteltaral
pesticides. Riifa and mgti/ations, GAO/RCED-86-97, U.S.
GAO: Washington, DC.
U.S. General Accounting Office (GAO). 1990, lawu Care
Pesticides. Risks Remain Uncertain While Prohibited Safety Claims
Continue, GAO/RCBD-90-134. U.S. GAO: Washington, DC.
Wright, CO., R.B. Leidy, and HUB. Dupree, Jr. 1981,
"Insecticides in the ambient air of rooms following their
application for control of pests." Bull, Mnvimnm. Cantata.
Tvxicel, 26: 548-553.
Wright, C.G. and R.B. Leidy. 1982. "Chlordane and
heptachlor in the ambient air of houses treated for termites."
Ball. Em/iro»m. Contam. Toximl, 28: 617-623.
Xue, S. 1987, "Health effects of pesticides: A review of
epidemiologic research from the perspective of developing
nations," Am,J. Iwtust, Ate/, 12: 269-279.
4.3 FORMALDEHYDE AND OTHER VOLATILE
ORGANIC COMPOUNDS
Sources of Formaldehyde
Residential Buildings
Formaldehyde (HCHO) is a flammable, colorless gas
with a characteristic odor. The odor threshold for
HCHO is about 1 ppm, but it can be detected at
levels as low as 0.05 ppm by some people (NRC,
1981). It is one of the most widely used chemicals
in the United States. About' half of the HCHO
produced annually (6 billion pounds in 1983) is
used to make urea- and phenol-HCHO resins
which, in turn, are used to produce adhesives,
bonding and laminating agents, foam insulation,
fabrics, coatings, and paper (U.S. HUD, 1984).
Phenol-HCHO based resins, which are less suscep-
tible to moisture degradation, are used to make
interior and exterior grade products (softwood
plywood, waferboard, and oriented strand board).
Urea-HCHO resins are used only on interior grade
products because they are susceptible to moisture
deterioration.
HCHO can be released from a variety of products
(Exhibit 4-10), but the primary residential'sources
are hardwood plywood, particleboard, medium-
density fiberboard (MDF), and other pressed wood
products. All of these pressed wood products are
produced by combining wood pieces or chips with
an adhesive and other chemicals (including urea-
HCHO resins) and pressing them together in hot
hydraulic presses. The potential for HCHO emis-
sions is the greatest for MDF, followed by particle-
board and hardwood plywood,
Hardwood plywood is used to make decorative wall
paneling, furniture, cabinets, doors, and flooring.
Softwood plywood also has a variety of applications,
but it does not contain HCHO. Particleboard is
used primarily as underlayment, mobile home
decking, and to make industrial board which, in
turn, is used to make many products including
furniture and kitchen cabinets. MDF is used
-------
Section 4
1AQ Reference Manual
primarily in furniture and cabinets as a cost effective
alternative to solid wood.
During the last several years, manufacturers of
particleboard, hardwood plywood, and MDF have
taken measures to reduce the amount of HCHO
that is used to make the board, MDF, however, as
of 1986 was considered to be a relatively higher
emitter of HCHO than the other two products
(U.S. CPSC, 1986).
Another important use of urea-HCHO resin is in
the production of urea-HCHO foam insulation
(UFFI) which is foamed-in-place. Between 1975
and 1981 about 435,000 homes were insulated with
UFFI (U.S. CPSC, 1982). Because of concerns about
UFFI, the CPSC banned the the installation of UFFI
in homes and schools as of August 10, 1982. This
ban, which was intended to prevent the risk of
injury from cancer as well as the occurrence of acute
illness, was contested by the industry and over-
turned by the Fifth Circuit Court of Appeals in
1983.
Commercial Buildings
Any commercial building that is newly constructed
or recently renovated can be a potential source of
HCHO emissions. Important potential sources of
HCHO in commercial buildings include any
materials made of MDF, particleboard, and hard-
wood plywood. These materials include flooring
materials, paneling, and furniture. In addition, any
fabrics or other fibers that have been treated to be
permanent press, soil and wrinkle resistant, and
water repellent may be additional sources. Confined
areas where smoking is permitted could have
elevated levels of HCHO and other aldehydes
because of the buildup of these combustion
byproducts.
Measured Concentrations of HCHO
Formaldehyde is perhaps one of the most widely
characterized indoor air contaminants. Exhibit 4-11
summarizes some of the measurements which have
been made in mobile homes, conventional homes,
offices, and a variety of public buildings.
These and other studies have shown that manufac-
tured housing could be expected to have higher
average concentrations of HCHO than conventional
housing, probably because of the greater number of
sources and higher surface to volume ratio. It
should be noted that construction techniques have
changed for manufactured housing and average
concentrations in these homes may be lower than in
the past.
HCHO concentrations in conventional houses
insulated with UFFI are generally higher than in
houses with other types of insulation. Measure-
ments of HCHO concentrations in nonresidential
buildings have generally demonstrated lower
concentrations than in conventional or mobile
homes.
Although general trends have been noted, the
reported data also show that a wide range of concen-
trations can exist in any type of construction
depending on the age of the structure, season, time
of day, climatic factors, and presence of sources.
Health Effects of Formaldehyde
Concerns about exposure to HCHO have resulted in
thousands of complaints to agencies such as the
CPSC and in numerous lawsuits. These complaints
have related primarily to effects resulting from acute
exposures, but increasingly consumers are concerned
about health effects resulting from chronic expo-
sures and the potential carcinogenicity of HCHO.
HCHO is a known irritant and sensitizer. The
frequency and severity of irritant effects from
HCHO has been shown to increase with concentra-
tion and length of exposure. Symptoms of upper-
airway irritation include a tingling sensation in the
nose, dry throat, and sore throat. These symptoms
usual coexist with tearing, burning, stinging, and
pain in the eyes (NRC, 1981). These effects can
occur within a few minutes after exposure to HCHO
-------
IAQ Reference Manual
-Section 4
depending on the exposure concentration and the
sensitivity of the individual. At higher levels,
inhalation of HCHO produces lower airway irrita-
tion and pulmonary effects which are characterized
by coughing, chest tightness, and wheezing,
Skin contact with HCHO has been reported to
result in irritation, allergic contact dermatitis, and
urticaria. These effects may be caused by direct
contact with HCHO or formalin (HCHO in
solution with methauol), or by HCHO-releasing
agents (cosmetics, germicides, iacornpletly cured
resins) and the decomposition of HCHO-containing
resins (textiles). Repeated contact with low concen-
trations of HCHO can result in setisitization
reactions.
Additional reported effects of HCHO exposure
include nosebleeds and runny noses, persistent
swelling of nasal turbinates, headaches, fatigue,
memory and concentration problems, nausea,
dizziness, and breathlessness (U.S. EPA, 1987a).
HCHO has also been reported to be associated with
altered reproductive function in women and
fetotoxic effects, but additional work is needed to
validate these findings. It has been shown to be
mutagenic in a variety of test systems, including
humans (U.S. EPA, 1987a).
Irritant effects have been associated with concentra-
tions in the range of 0.1 to 3 ppm, and concentra-
tions as low as 0.03 ppm have been reported to
cause effects in sensitive individuals. It has been
estimated that 10% to 12% of the U.S. population
may have hyperreactive airways which may make
them more susceptible to the irritant effects of
HCHO; this estimate includes asthmatics (NRC,
1981).
The Committee on Toxicology of the National
Academy of Sciences (NEC, 1980) evaluated data
available in 1980, and it concluded that there is.oo
population threshold effect level for the irritant
effects of HCHO in humans. Based on its review,
the Committee concluded that less than 20% of the
population would experience slight to mild irrita-
tion and discomfort when exposed to less than
0.25 ppm HCHO. More recently, CPSC also
concluded that there may not be a threshold limit
concentration for HCHO (U.S. CPSC, 1986). The
WHO Working Group on Assessment and Moni-
toring of Exposure to Indoor Air Pollutants (1983)
concluded that indoor HCHO concentrations of less
than 0.05 ppm were of limited or no concern and
concentrations greater than 0.10 ppm were of
sufficient concern to call for corrective action.
The most controversial health effect from exposure
to HCHO is its carcinogenic potential in humans.
The debate surrounding the role of HCHO as a
carcinogen began with a study sponsored by the
Chemical Industry Institute of Toxicology (CUT) in
1980 in which it was reported that nasal cancer
developed ia 103 of 240 laboratory rats exposed to
14.3 ppm HCHO and in two rats exposed to 5,6
ppm HCHO. Nasal cancer also developed in 2 of
240 mice exposed to 143 ppm HCHO (Kerns et al,
1983).
Since the results of the CIIT study were made
available, there have been other animal and human
epidemiologic studies which suggest that HCHO
should be presumed to pose a carcinogenic risk to
humans. The Federal Panel on Formaldehyde (FPF,
1982), the International Agency for Research on
Cancer (IARC, 1982), the CPSC (1986), and the
U.S. EPA (1987a) have concluded that HCHO
poses a carcinogenic risk to humans.
In 1987 the U.S. EPA classified HCHO as a
"Probable Human Carcinogen" (Group Bl) based on
sufficient animal and limited human evidence and
other supporting data (U.S. EPA, 1987). In 1989
EPA, in consultation with EPA's Science Advisory-
Board, undertook efforts to update the 1987
assessment in light of new hazard data and recent
advances in risk assessment methodology. The new
methodology incorporates pharmacokinetic data
which provides a closer approximation to a delivered
dose and uses monkey DNA binding data as the
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Section 4
IAQ Reference Manual
basis for human dosimetty. This update effort will
likely significantly reduce the 1987 cancer risk
estimates.
Sources of Other Volatile Organic
Compounds
Sources
Organic compounds can be divided into three •
categories based on volatility. Volatile organic
compounds (VOCs) exist entirely in the vapor phase
at ambient temperature and have vapor pressures
greater than about 1 mm Hg. Semi-volatile organic
compounds (SVOCs) have vapor pressures in the
range of 10"7 to 1 mm Hg and are present both in
the vapor and particle-bound state. Nonvolatile
organic compounds are those that are present only as
paraeuktes and have vapor pressures less than W"1
mm Hg (Riggin and Petersen, 1985).
Over 230 different organic compounds have beea
measured in indoor air at levels greater than 1 ppb
(Sterling, 1985), and over 900 volatile organic
compounds have been identified in indoor air (U.S.
EPA, 1989). These compounds are incorporated
into almost all materials and products that are used
in construction materials, consumer products,
furnishings, pesticides, and fuels. Drinking water
(typically well water) that is contaminated with
VOCs can also be an indoor air source when con-
taminated water is used for showering, bathing,
cooking, and other uses that potentially result in the
release of VOCs, Some examples of VOCs and the
products which contain them are given in Exhibit
4-12. Exhibit 4-13 contains examples of some
emission rates for selected VOC-containing
products,
A national survey conducted by EPA (1987b) on the
usage of household solvents has provided insight
into the sources of six solvents contained in con-
sumer products and the usage of those products by
consumers. The solvents which were studied
include methylene chloride and five potential
substitute chemicals: 1,1,1-trichloroethane,
trichloroethylene, tetrachloroethylene, carbon
tetrachloride, and 1,1,2-tricMorotrifluoroethane.
EPA examined a total of 1026 brands of household
products, which were grouped into 67 product
categories, and the use patterns of 5000 adults.
These studies demonstrated that exposure to VOCs
is widespread through the use of consumer products,
but the significance of these exposures is not known.
Almost half of the brands surveyed contained at
least one of the six target chlorocarbons. Methylene
chloride and 1,1,1-trichloroethane were the pre-
dominant chemicals—34% of the brands tested
positive for methylene chloride and 1498 for 1,1,1-
trichloroethane. Methylene chloride was found in
78% of the paint removers/strippers and 60% of the
aerosol spray paints tested, 1,1,1-Trichloroethane
was found in most of the typewriter correction
fluids, suede protectors, and brake quieters/cleaners
tested,
Less than 4% of the brands tested were positive for
any of the four remaining chlorocarboos. Trichloro-
ethylene was found in 78% of the typewriter
correction fluids tested, Tetrachloroethylene was
found in 58% of the brake quieters/cleaners tested.
Carbon tetrachloride was not found at the 1 % level
in any of the products tested.
In addition to the findings of specific concentrations
of chemicals in household solvent products, the
study found that concentrations of chlorocarbons
varied considerably between brands of the same
product type, and in a few brands, concentrations
differed by geographic regions of the country. One
of the most important findings of this study was
that product labels are often inadequate; only 56%
of the brands with chlorocarbons were kbeled as
containing these chemicals.
Extent of Use
The EPA household solvent products survey (U.S.
EPA, 1987b) showed that on average people had
used slightly fewer than 7 products during their
lifetime. During a 12-month period prior to the
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IAQ Reference Manual
Section 4
survey, participants reported that they used almost
5 products on average,
Products were ranked according to the incidence of
"ever used." The most frequently used products
were contact cements/super glues/spray adhesives
(60.6% of the population), latex paint (55.2%), and
wood stains/varnishes/finishes (42.9%). The lowest
incidence of ever used products (less than 3%) was
for automotive products (transmission cleaners,
brake quieters/cleaners, and gasket removers).
The 5 most frequently used products during the
previous-12-month period were typewriter correc-
tion fluid, solvent cleaners, spot removers, special-
ized electronic cleaners, and tire/hubcap cleaners.
These products were also used for the shortest
amounts of time (from 7.5 minutes for typewriter
correction fluid to 29-5 minutes for solvent clean-
ers), latex paint, oil paint, paint removers/strppers,
adhesive removers, and wood stains/varnishes/
finishes.were the 5 products which were used less
frequently, but for the longest periods of time (from
117 minutes for wood stains/vamishes/fmisrtes to
295 minutes for latex paint).
The survey also showed that respondents were
somewhat aware of the potential adverse effects of
using these products. Over 70% of the respondents
reported that they kept a door or window open to
the outside when using nonautomotive primers,
latex paint, outdoor water repellents, and paint
removers and strippers.
Measured Coocentrations
The data base for VOCs and other organic com-
pounds includes studies of healthy and sick build-
ings. Some examples of VOCs measurements in
residential and nonresidential buildings are given in
Exhibit 4-14.
These data along with the consumer use surveys
conducted by EPA show that exposure to VOCs is
widespread and highly variable. In general, VOCs
can be expected to be higher in buildings immedi-
ately after construction or renovation compared to
older buildings. The use of consumer products can
be expected to predominate VOC emissions after
building-related VOCs decrease in concentration.
The Team Studies conducted by Wallace and others
(Wallace, 1987) have provided important informa-
tion about actual exposures to VOCs. These studies
showed that:
» Indoor personal exposures were greater than
mean outdoor concentrations for each of 11
target VOCs.
« Breath levels correlated significantly with "
personal air exposures but not with outdoor
a.ir levels for nearly all the chemicals.
• Inhalation accounted for more than 99% of
the exposure for all contaminants studied,
except foe the trihalomethanes.
« Specific sources of exposure were identified
and included smoking (aromatics such as
benzene, styrene, ethylbenzene, and m,p-
xylene in breath); passive smoking (same
chemicals in indoor air); visiting dry
cleaners (tetrachloroethylene in breath);
pumping gas or being exposed to auto
exhaust (benzene in breath); various
occupations such as chemicals, plastics,
wood processing, scientific laboratories,
garage or repair work, metal work, printing
(aromatic chemicals in daytime personal
air).
* Other sources which were hypothesized
included room air fresheners, toilet bowl
deodorizers, or moth crystals (p-dichloro-
benzene in indoor air); and use of hot water
in the home (chloroform in indoor air).
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Section 4
IAQ Reference Manual
Health if fads of Other Volatile Organic
Compounds
Exposure to VOCs can result in both acute and
chronic health effects. Exhibit 4-12 summarizes
some health effects for selected contaminants. Most
of the available health effects data have been
developed from animal studies or occupational
studies. In general, the health effects data base for
VQCSj especially, low-level or intermittent expo-
sures, is not complete.
Many of the YOCs are potent narcotics and result in
the depression of the central nervous system, VOCs
can also result in irritation of the eyes and respira-
tory trace and sensitization reactions which involve
the eyes, skin, respiratory tract, and heart. At
higher concentrations, many of these chemicals have
been shown to result in liver and kidney damage.
Symptoms of VQC exposure (depending on the
dose) could include fatigue, headache, drowsiness,
dizziness, weakness, joint pains, peripheral numb-
ness or tingling, euphoria, tightness in the chest,
unsteadiness, blurred vision, skin irritation, irrita-
tion of the eyes and respiratory tract, and cardiac
arrhythmias (Rosenberg, 1990).
The term "solvent eneephalopathy" is used to
describe a group of symptoms (major symptoms—
headache, irritability, difficulty concentrating, and
fine-motor deficits) attributed to VOC exposures. A
dose-effect relationship has not been described, but
effects occur at levels well below the threshold limit
values for individual solvents, and there appears to
be a relationship between duration of exposure and
the time required to resolve symptoms after expo-
sure stops. YOCs are present in office environments
at concentrations that have been associated with
solvent eneephalopathy (Hodgson, 1988).
Many of the VOCs which have been measured
indoors are known human carcinogens (benzene) or
animal carcinogens (carbon tetrachloride, chloro-
form, trichlorosehylene, tetrachloroethylene, and
p-dichlorobenzene). VOCs such as 1,1,1-trichlo-
roethane, styrene, and a-pinene are mutagens and
possible carcinogens. Other VOCs such as octane,
decane, and undecane are possible co-carcinogens.
Estimates,* Cancer risk estimates
developed by EPA for exposure to some VOCs are
given in Exhibit 3-2, Section 3 of the Reference
Manual, Other investigators have also estimated the
cancer risk from VOCs. Wallace (1986) estimated
that six VOCs (benzene and the other 5 animal
carcinogens listed above) contribute 1000 to 5000
excess cancer cases per year nationwide. Tancrede et
al, (1987) estimated the cancer risk of 9 VOCs
which had previously been measured In New Jersey
(Bayonne and Elizabeth), 19 VOCs in California
(Los Angeles), and 44 VOCs in Dutch houses. The
estimated mean individual risk (the sum of the
mean individual risks for each of the VOCs) was
0,019-0.03 for the residents of New Jersey and
0.002 for the residents of California. The estimated
mean risk for the contaminants based on the Dutch
data was 0.001-0,002, The unit risk estimates were
computed using human and animal data, by atialogy
with other chemicals, and other methods.
When the risks were computed based only on those
chemicals for which there was either animal bioassay
data or human epidemiologkal data, the estimated
risk was 0.003 for New Jersey, 0.001 for California,
and 0.0002-0,001 for The Netherlands. Estimated
risks for radon (0.0520), passive smoking (0.002-
0,008), and formaldehyde (0.034) were also shown
for comparison. Tancrede et aL concluded that even
though their estimates were conservative, the
calculations suggested exposure to VOCs through
indoor air were important. Although there are few
risk assessments available for VOCs in indoor air,
VOCs appear likely to pose a significant cancer risk
(U.S. EPA, 1989).
Sick "Building Syndrome and Multiple Chemical
Sensitivity: There is some evidence VOCs can
provoke some of the symptoms typical of sick
building syndrome. M01have observed increased
mucous irritation and impaired memory in healthy
subjects (who previously demonstrated symptoms of
-------
IAQ Reference Manual
Section 4
sick building syndrome) who were exposed to 22
VOCs at total VOC concentrations of 5 mg/m3 and
25 mg/m? (M0ihave #<*/., 1987).
Kjaergaard etal. (198?) also demonstrated a dose-
dependent response in 63 randomly selected healthy
subjects who were exposed to n-decane in the range
of 0 to 100 ppm. Exposed subjects experienced
mucous membrane irritation, decreased tear film
stability, and sensation of increased odor intensity
and reduced air quality. The authors concluded that
these results support the hypothesis that VOCs can
provoke some of the symptoms of sick building
syndrome.
Individuals who appear to demonstrate multiple
chemical sensitivity report severe reactions to
a variety of VOCs and other organic compounds
which are released by building materials and various
consumer products including cosmetics, soaps,
perfumes, tobacco, plastics, dyes, and other prod-
ucts. Many of the chemicals contained in these
products are potent sensitizers.
These reactions can occur after exposure to a single
sensitizing dose or sequence of doses, after which
time, a far lower dose can provoke symptoms.
Reactions can also be provoked as a result of chronic
exposure to low doses. Ashford and Miller (1989)
summarize some of the studies that have been
conducted that attempt to link multiple chemical
sensitivity to exposure to VOCs and other organic
compounds.
ixhibit 4-10. Potential sources of formaldehyde indoors.
Pressed-wood products
Insulation
Combustion sources
Paper products
StifTeners, wrinkle
resisters, and water repellents
Other sources
hardwood plywood, particle board, medium-density fiberboard (MDF),
decorative paneling
urea-formaldehyde foam insulation (UFFI), fiberglass made with
HCHO binders
natural gas, kerosene, tobacco, automobile exhaust
grocery bags, waxed paper, facial tissues, paper towels, disposable
sanitary products
floor coverings (rugs, linoleum, varnishes, plastics), carpet backings,
adhesive binders, fire retardants, permanent press textiles
plastics, cosmetics, deodorants, shampoos, disinfectants, starch-based
glues, adhesives, laminates, paints, fabric dyes, inks, fertilizers,
fungicides
SOURCE: Adapted from NEC (1981)
-------
Section 4
IAQ Reference Manual
Exhibit 4-11. Measurements of formaldehyde tomentrations In different types of
buildings.
CONCENTRATION (ppm)
TYPE OF
BUILDING
Conventional homes with chipboard
(n-23)
Conventional homes
(n»8Q)
All homes
(n»WO)
U-F foamed conventional homes
(n-14)
U-F wood products conventional homes
(n-13)
Mobile homes
(n-65)
Mobile home day cate centeis
(n-7)
Permanent day care centers
(n-2)
Mobile homes
Conventional homes
(n-489)
Mobile homes
(n-137)
Conventional homes
Inergy efficient homes
(n«7)
Apartments
(n-19)
Condominiums
-------
IAQ Reference Manual
Section 4
Exhibit 4-11. Measurements of formaldehyde concentrations in different types of
buildings (tontinued).
TYPE OF
BUILDING
CONCENTRATION (ppm)
MINIMUM MAXIMUM MIAN
REFERENCE
Energy efficient condomtoioms
(n=3>
Nonmanufacrared homes
(n=48)
Mobile homes - all
Cn=633)
Pre-1981 mobile homw
(n=266)
Post-1981 mobile homes
(o=391)"
New buildings
(n=3)
Old buildings
(n=3)
Office buildings
0,15
0.2
<0,010
<0,010
0,012
0,025
0,464
0.38fi
0.464
0.192
0,103
0,039
0.18
0.41
0,072
0,061
0.080
Sexton et al (1986)
Sheldenff^/, (1987)
0.031
Bayer & Black (1988)
, Draeger tubes
OfiRce, nursing home, hospital
Office, office/school, nursing home
-------
Exhibit 4-12. Health effects and sources of selected volatile organic compounds.
COMPOUND
HEALTH EFFECTS"'
SOURCES AND USES
Formaldehyde
Benzene
Xylenes
Toluene
Styreoe
Tolueoe dissocyanate (TDI)
Trichloroethylene
Ethyl benzene
Methylene chloride
(Dichloromethane)
probable human carcinogen; eye and respiratory
tract irritant; a variety of low-level symptoms
carcinogen; respiratory tract irritant
narcotic; irritant; affects heart, liver,
kidney and nervous system
narcotic; may cause anemia
narcotic; affects central nervous system;
possible human carcinogen
sensitizer; probable human carcinogen
animal carcinogen; affects central nervous system
severe irritatioa to eyes and respiratory tract;
affects central nervous system
narcotic; affects central nervous system;
probable human carcinogen
listed ia Exhibit 4-10
plastic and rubber solvents; cigarette
smoking; paints, stains, varnishes, filler,
other finishes; inhalation of gasoline vapor
adhesives, joint compound, wallpaper,
caulking compounds, floor coveting, floor
lacquer, grease deaners,shoe dye, tobacco
smoke, kerosene heaters, varnish, solvent
for resins, enamels; used in non-lead
auromobik fuels, pesticides, dyes,
Pharmaceuticals
solvents, solvent-based adhesives, water- .
based adhesives, edge-sealing, moulding
rape, wallpaper, joint compound,
calcium silicate sheet, vinyl floor covering,
vinyl coated wall paper, caulking
compounds, paint, chipboard, kerosene
heaters, tobacco smoke
plastics, paints, synthetic rubber, and resins
polyurethane foam aerosols
solvent for paints, varnishes, oil and wax,
cleaning compounds, degreasing produce,
dry-cleaning
solvents, in styrene-rekted products
paint removers, aerosol finishers; acoustical
office partitions
I
I
-------
Exhibit 4*12. Health effects and sources of selected volatile organic compounds Continued).
COMPOUND HEALTH EFFECTS SOURCES AND USES
Para-dicMorobenzene narcotic; eye and respiratory tract irritant; moth crystals, room deodorizers
affects liver, kidney, and central nervous system
Benzyl chloride, central nervous system irritants and • vinyl tiles pjasticized with butyl benzyl
Benzal chloride • • deptessants; affects liver and kidney; phthalate
eye and respiratory tract irritant
2-butanone . irritant; central nervous system depressant floor/wall covering, calcium silicate sheet,
' (MEK) fiberboard, caulking compounds,
particleboard, tobacco smoke
• Petroleum distillates central nervous system depressant; affects • cleaning products, solvents, paint thinnets
iiver-and kidney
4-pfaenylcyclohexene eye and respiratory tract irritant; centra! • byproduct of sytrene butadiene latex, an
nervous system effects • adhesive used in most synthetic fibers
carpets
'For many indoor pollutants, there is insufficient data to determine the levels arwhich the specific effects listed would actually occur and the extent to
which these levels are experienced in non-industrial indoor environments.
SOURCE; Tucker (1988), Dreisbach (1980), Turiel (1985)
I-
K
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Section 4
IAQ Reference Manual
Exhibit 4*13. Examples of volatile organic compound measurements in indoor air.
CONCENTRATION (pg/m*)
CONTAMINANT
MINIMUM
MAXIMUM
MEAN
RBFI81NCE
Benzene
Kitchens (n = 15)
Other rooms (n « 15)
Outdoors, next to dwellings (n = 5)
Toluene
Kitchens
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IAQ Reference Manual
Section 4
Exhibit 4-13. Examples of volatile organic compound measurements in indoor air ((ontinved).
CONTAMINANT
Total VOCsC d
Aromatic Hydrocarbons
Aliphatic Hydrocarbons r
Chlorinated Hyfocatbons
Oxygenated Hydrocarbons
Total VOCsC ,
Aromatic Hydrocarbons
Aliphatic Hydrocarbons ,.
Chlorinated Hytocarbons
Oxygenated Hydrocarbons
Total VCCs
1,1,1-Trichlotoethane
Benzene
Ethylbenzene
o-Xylene
Toluene
3-Methylpentane
Hexane
1, 2, 3-Trimethylbenzene
Heptane
1, 4-Dioxane
Acetone
4-Metfayl- 1-pentanone
Butylacetate
Total VCCs
1 , 1,1-Trichloroethane
m, p-Dichlorobenzene
m, p-Xylene
Tetrachloroethylene
Benzene
Ethylbenzene
o-Xylene
Trichloroethylene
Chloroform
Styrene
Carboa Tetrachloride
CONCENTRATION (pg/m*)
MINIMUM MAXIMUM MEAN
New buildings, (office, nursing home, hospital)
21-1100
11-270
4.7-810
3.9-56
ND-9.6
Older buildings, (office, office/school,
nursing home)
18-130
12-74
1.9-18
47-46
ND-4.3
3 Nonresidential buildings
237-1090
14,8-214
12.9-43-2
1.16-17.2
. 3.66-16.8
7.84-98.7
1,42-37,6
4.7-68.7
<0.02-0.522
1,24-38.9
<0,02-20.1
11.1-62,7
0.343-27.9
10.6-48.3
Homes in 2 cities over the course
of 3 sampling periods in 3 years
200-338
45-94
45-71
36-52
11,45
NC*-28
9.2-19
12-16
4.6-13
4.0-8.0
2,1,8.9
NDJ-9.3
REFERENCE
Sheldon
«*«/.(198S)
Sheldon,
etaL (1988)
Bayer and
Black (1988)
Wallace (1987)
{continued next page t
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Section 4
1AQ Reference Manual
Exhibit 4-13. Examples of volatile organic compound measurements in indoor air (continued).
CONCENTRATION
CONTAMINANT
MINIMUM
MAXIMUM
MIAN
REFERENCE
n-Ocwme
n-Decane
n-Undecane
n-Dodecuie
a-PJnene
o-DicMotobenzene
1,1, 1-Tiichloroethane
m- and p-Xytene
m» and p-Diehlorobenzetie
Tetnchloroethylene
o-Xylene
Ethylbeozene
Trichlofoethyfcne
Styrene
Chloroform
Carbon Tettachloride
1,2-Dichlorobenzene
p-Dloxane
Homes in 1 city over the course
of 3 samplings periods in 1 year
Wallace (1987)
23-5.8
2.0-5,8
2.7-5.2
2.1-2.5
2.1-6.5
0.3-0.6
16-96
11-28
5.5-18
5.6-16
4.4-13
3.7-11
3.8-7.8
1-3.6
0.6-1,9
0.8-1.3-
0.1-0.5
0.2-1.8
not included in the calculation of the mean
overnight air samples, Elizabeih-Bayonne, NJ; additional measurements are given in Wallace (1987) and
TEAM publications
specific levels of individual contaminants ate given la Shelden tt at, (1988)
benzene; o- and m-xylene; styrene; ethylbenzene; isopropylbenEene; n-ptopylbenzeme; o- and m-toiuene;
1,2,3-trtaechylbenzene; 1,2,4-ttimethylbenzene; l,3>5-trimethylbenzene
a-pmenc, n-decs«e, n-und«rane, n-dodecane
1,2-diehloroethane; 1,1,1-ctkhlocoethane; tricfaloroethylene; p-dichlorobenzene
(V
n-butylacetate; 2-ethoxyethylacetate
Atlanta, GA; spring season; additional VOCs ate given in Bayet and Black (1988)
not calculated-high background contamination
not detected in most samples
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IAQ Reference Manual
Section 4
Exhibit 4-14a. Examples off selected volatile organic compound emission rales for
materials and typical household products found indoors.
EMISSION RATES OF SELECTED MATERIALS (|lg/g)a
Compound Name Adheslves Coati0g Fabric Foam Lubricant Paint
Rubber
Limonene — — — — —
Methyl Chloroform 0,40 0.20 0,07 1.00 0.50
Styrene 0,17 5.20 — 0.02 12.54
Tetrachloroethylene 0.60 — 0.30 65.00 0.60
Trichloroethylene 0.30 0.09 0.03 0.10 0,10
Sample Size (n) 98 22 30 68 23
33.50
0.10
0.15
0.20
0.07
90
Tape
1 ,2-DicMoroethane
Benzene
Carbon Tetrachloride
Chloroform
Ethylfaeazene
0.80 —
0.9 0.6
1.00 —
0.15 —
,„„„
— 0.75 —
— 0.7 0.20
— 0.18 —
0.10 0,04 0,20
,
__ —
0.90 0.10
— 4.20
— 0.90
527.8 —
3.25
0.69
0.75
0.05
0.20
0,10
0.10
0.08
0.09
66
EMISSION RATE OF SELECTED HOUSEHOLD PRODUCTS (Mg/g)b
Health
Compound Deodo- & Beauty Elect. Misc. Ink& Photo Photo
Name Cosmetics rants Aids Equip. Hotisewares Pen Paper Equip. Film
1,2 ,-Dicfaloroethane
Benzene
Carbon
Tetrachloride
Chloroform
Ethylbenzene
Limonene
Methyl Chloroform 0.20
Styrene 1.10
TetracMoroethyleae 0.70
Trichloroethylene 1.90
Sample Size (n) 5
— 1.85
— 0,40
0.15
1.00
0.01
0.17
0.11
23
0.06
0.02
0.00
0.23
0.80
0.03
0.05
0.05
0.01
71
1.10
0.04
4.85
1.80
0.19
0.02
0.06
23
0.40 0,03
0.20 —
10.00 • 0.10
0.10
0.30
2.00
0.07
25
0.26
0.42
0.10
12
1.51 0.04
2,50
2.50
10.50
0.08
0.04
0.03
35
0.10
0.13
1.90
0.10
0.13
26
SOURCE: «Ozkaynafc#*£(1987>
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Section 4
IAQ Reference Manual
Exhibit 4-14B. Additional examples off volatile organic compound emission rates for
selected materials found indoors.
MATERIAL3
latex caulk
latex paint (Glidden)
Carpet adhesive
Vinyl cove molding
Linoleum tile
large diameter
telephone cable
Black rubber molding
Small diameter
telephone cable
Carpet
Vinyl edge molding
Particle board
Polystyrene foam
insulation
Tar paper
Primer/adhesive
Latex paint (Bruning)
Water rejpellant
mineral board
Cement block
PVCpipe
Duct insulation
Treated metal roofing
tJrethane sealant
Fiberglass insulation
Exterior mineral board
Interior mineral board
Ceiling tile
Red clay brick
Plastic laminate
Plastic outlet cover
Joint compound
Linoleum tile cement
ALIPHATIC
OXYGENATED
ALIPHATIC
HYDROCARBONS
252
111
136
31
6.0
14
24
33
27
18
27
0.19
3.2
3.6
-
1.1
-
-
0,13
•
_
-
-
-
-
-
-
-
-
-
EMISSION
AROMATIC
HYDROCARBONS
380
52
98
26
14
35
78
26
9.4
12
1.1
20
3.1
2.5
3-2
0.43
0,39
0,53
0.15
0.19
0.13
0.08
0.03
-
-
-
-
-
.
-
RATE ^gim2/hv)
HALOGENATED
COMPOUND
5.2
86
b
1.4
0.62
40
0.88
1.4
-
0.41
0,14
1.4
-
-
-
.
0.15
.
-
0.06
-
.
. -
-
-
-
-
-
.
ALL TARGET
HYDROCARBONS
637
249
234
60
46
45
103
60
36
30
28
22
6.3
6,1
3,2
1.5
0.54
0.53
0.28
0,25
0.13
0.80
0.03
-
-
-
-
-
-
-
* emission rates for cove adhesive are not reported; sample was overloaded. It is estimated that cove adhesive is one of the
emitters of VOCs with emissions of target compounds >4700 jJg/nrT.
no detectable emissions
SOURCE; Sheldon et al (1988)
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IAQ Reference Manual
Section 4
REFERENCES
Andersen, I., G.R. Lundqvist, and L. M01have. 1975- "Indoor
air pollution due to chipboard used as a construction material."
Atm, Environ. 9:1121-1127.
Ashford, N.A. and C.S. Miller. 1989. Chemical Sensitivity, A
Report to the New Jersey State Department of Health. December.
Bayer, C.W. and M.S Black. 1988. "Indoor air quality
evaluations of three office buildings." IAQ 88, Engineering
Solutions ts Indoor Air Problems. American Society of Heating,
Refrigerating, and Air-Conditioning Engineers (ASHRAE):
Atlanta, GA. pp. 284-293.
Black, M.S. and C.W. Bayer. 1988. "Pollutant measurement
methods used in IAQ evaluations of three office buildings." IAQ
88, Engineering Solutions to Indoor Air Problems, American
Society of Heating, Refrigerating, and Air-Conditioning
Engineers (ASHRAE): Atlanta, GA. pp. 317-353.
Dally, K.A., L.P. Hanrahan, M.A. Woodbury, and M.S.
Kanahek. 1981. "Formaldehyde exposure in nonoccupational
environments." Arch, Environ, H, 36(6); 277-284.
Dreisbach, R.H. 1980. Handbook of Poisoning. 10th edition.
Lange Medical Publications: Los Altos, CA.
"Federal Panel on Formaldehyde Report." 1982. Environ, H.
Persp, 43: 139-168.
Hanrahan, L.P., H.A. Anderson, K.A. Dally, A.D. Eckmann,
and M.S, Kanarek. 1985. "Formaldehyde concentrations in
Wisconsin mobile homes." JAPCA. 35(11): 1164-1167.
Hodgson, M.A. 1988. "Health risks of indoor pollutants."
IAQ 88. Engineering Solutions to Indoor Air Problems. American
Society of Heating, Refrigerating, and Air-Conditioning
Engineers (ASHRAE): Atlanta, GA. pp. 284-293.
International Agency for Research on. Cancer {IARC). 1982.
"Formaldehyde." IARC Monographs an the Evaluation of the
Carcinogenic Risk of Chemicals to Humans. Vol. 29: Some Industrial
Chemicals and Dyestuffs. Lyon, France. World Health Organiza-
tion: Geneva, Switzerland, pp. 345-389-
Kerns, W.D., K.L. Pavkov, D.J. Donofrio, EJ. Gralla, and J.A.
Swenberg. 1983. "Carcinogenicity of formaldehyde in rats and
mice after long-term inhalation exposure." Cancer Research. 43:
4382-4392.
Kjaergaard, S., L, M01have, and O.F. Pedersen. 1987. "Human
reactions to indoor air pollution: n-decane," Indoor Air '87.
Vol. 1. Volatile Organic Compounds, Combustion Gases, Particles and
Fibres, Microbiological Agents. Oraniendruck GmbH: Berlin,
Germany, pp. 97r101.
M0lhsve, L., B, Bach, and O.F. Pedersen; 1987. "Human
reactions to low concentrations of volatile organic compounds."
Env. Intl. 8: 117-127.
National Research Council (NRC). 1980. Formaldehyde—an
assessment of its health effects; Report to the U.S. Consumer Product
Safety Commission, National Academy Press: Washington, DC.
National Research Council (NRQ. 1981. Inefar Pollutants.
National Academy Press: Washington, DC.
Olsen, J.H. and M. D0ssing. 1982. "Formaldehyde induced
symptoms in day-care centers." Am, Ind, Hyg. Assoc, J, 43:
366-370.
Ozkaynak, H., P.B. Ryan, LA. Wallace, W.C. Nelson, and J.V.
Behar. 1987. "Sources and emission rates of organic chemical
vapors in homes and buildings." Indoor Aif '87. Vol. 1. "Volatile
Organic Compounds, Combustion Gates, Particles and Fibres,
Microbiological Agents. Oraniendruck GmbH: Berlin, Germany.
pp. 3-7.
Riggin, R.M. and B.A. Petersen. 1985. "Sampling and
analysis methodology for semivolatile and nonvolatile organic
compounds in air." Indoor Air and Human Health, R.B.
Gammage, S.B. Kaye, and Y.A. Jacobs (eds). Lewis Publishers,:
Chelsea, MI. pp. 351-358.
Ritchie, I.M. and R.G. Lehnen. 1985. "An. analysis of
formaldehyde concentrations in mobile and conventional
homes," J. Environ. H. 47(6): 300-305..
Rosenberg, J. 1990. "Solvents." Chap. 27. Occupational
Medicine, J, LaDou (ed). Appleton & Lange: Norwalk, CT.
Sardinas, A.V., R.S. Most, M.A. Giulietti, and P.Honchar.
1979- "Health effects associated with urea-formaldehyde foam
insulation for Connecticut." J. Environ. H. 41(5): 270-272.
Seifert, B. and H.J. Abraham. 1982. "Indoor air concentrations
of benzene and some other aromatic hydrocarbons." Ecotox,
Environ. Safety. 6: 190-192.
Sexton, K., K. Liu, and M.X. Petreas. 1986. "Formaldehyde
concentrations inside private residences: A mail-out approach
to indoor air monitoring." JAPCA. 36(6): 698-704,
Sheldon, L., H. Zelon, J. Sickles, C. Eaton, and T. Hartwell.
1988. Indoor Air Quality in Public Buildings. Vol. II. U.S.
Environmental Protection Agency, Environmental Monitoring
Systems Laboratory, Office of Research and Development:
Research Triangle Park, NC,
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Section 4
IAQ Reference Manual
Steeling, D.A. 1985. "Volatile organic compounds in indoor
air: An overview of sources, concentrations, and health effects."
Indoor Air and Human Health. R.B. Gammage, S.B. Kaye, and
V.A. Jacobs (eds). lewis Publishers: Chelsea, MI. pp. 387-
402.
Stock, T.H. and S.R. Mendez. 1985. "A survey of typical
exposures to formaldehyde io Houston area residences." Am.
lad Hyg. Asset. J. 46(6): 313-317.
Tancrede, M., R. Wilson, L. Zeise, and E.A.C. Crouch. 1987.
"The carcinogenic risk of some organic vapors: A theoretical
survey." Aim. Environ. 21(10): 2187-2205.
Tucker, W.G. 1988. "Emissions of air pollutants from indoor
materials; An emerging design consideration." 5tb Canadian
Building & Construction Congress. Montreal, Canada. November
27-29.
Turlel, I. 1985. InJoor Air Quality and Human Health. Stanford
University Press: Stanford, CA,
U.S, Consumer Product Safety Commission (CPSC). 1982.
"Part IV: Ban of urea-formaldehyde foam insulation, with-
drawal of proposed information labeling rule, and denial of
petition to issue a standard." Federal Register. 47(<54): 14366-
14421.
U.S, Consumer Product Safety Commission (CPSC), 1986.
Briefing Package on formaldehyde Emissions from Urea-formaldehyde
Pressed Wood Products, U.S. CPSC: Washington, DC.
U.S. Department of Housing and Urban Development (HUD).
1984. "Manufactured home construction and safety standards;
final rule." Federal Register, 49<155): 31995-32013.
U.S, Environmental Protection Agency (EPA). 1987a.
Assessment of Health Risks to Garment Workers and Certain Home
Residents from Exposure to Formaldehyde. U.S. EPA, Office of
Pesticides and Toxic Substances: Washington, DC.
U.S. Environmental Protection Agency (EPA). 1987b.
Hmtbtild Solvent Products: A National Usage Survey. Final
Report, U.S. EPA, Office of Pesticides and Toxic Substances:
Washington, DC.
U.S. Environmental Protection Agency (EPA). 1989. Report to
Congress on Indoor Air Quality. Vol. II. Assessmtnt and Control of
Indoor Air Pollution. EPA 40071-89-001C. U.S. EPA:
Washington, DC.
van dec Wai, J.F., A. M.M. Moons, and R. Steenlage. 1987.
"Thermal insulation as a source of air pollution." Indoor Air '87.
Vol. 2. Volatile Organic Compounds, Combustion Gases, Particles
and Fibres, Microbiological Agents, Oraniendruck GmbH: Berlin,
Germany, pp. 79-83.
Wallace, LA., E. Pellizzari, T. Hartwell, C. Sparacino, and H,
Zelon. 1983. "Personal exposures to volatile organic and other
compounds indoors and outdoors—The TEAM Study."
Presented at the 79th Annual Conference of the Air Pollution
Control Association. Atlanta, GA. Paper #83.912.
Wallace, L.A. 1986. "Cancer risks from organic chemicals in
the home." Environmental Risk Management: Is Analysis Useful?
Proceedings. Air Pollution Control Association: Chicago, IL.
Publication #50-55.
Wallace, L.A. 1987. The Total Exposure Assessment Methodology
(TEAM) Study: Summary and Analysis: Vol. 1. EP A/600/6-87 -
002a. U.S, Environmental Protection Agency, Office of
Research and Development; Washington, DC.
World Health Organization (WHO). 1983. Indoor air
pollutants: Exposure and health effects. WHO Working Group on
Assessment and Monitoring of Exposure to Indoor Pollutants:
Copenhagen, Denmark.
4.4. BIOLOGICAL CONTAMINANTS
JL he home and workplace can harbor a
variety of airborne allergens and pathogens. About
50% to 60% of all community acquired illness is
due to respiratory infections and most of these are
caused by viruses (Feeley, 1985); but, bacterial
diseases and allergic reactions caused by biological
sources can pose significant problems in homes and
public facilities such as day care centers, hospitals,
hotels, nursings homes, schools, and office buildings
(Feeley, 1985).
Pathogens and Illness
Biogenic agents (those produced by living organ-
isms) in the indoor environment generally have
limited direct toxicity, and more often, result in
infection or allergic responses. The term bioaerosol
refers to biogenic agents that are airborne.
Most viral and bacterial diseases are spread by direct
person to person contact (kissing, hugging, touch-
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IAQ Reference Manual
Section 4
ing) or indirectly as a result of droplets in air which
are produced by talking, sneezing, and coughing.
In addition to these modes of transmission, some
evidence suggests that these diseases can be trans-
mitted through building-related airborne pathways
(such as the heating, ventilating, and air-condition-
ing system). For example, an epidemic of measles
(28 cases after an incubation period of about 10
days) in an elementary school near Rochester, New
York was traced to a student in the second grade
and a ventilation system that served fourteen
classrooms. The ventilation system recirculated air
from room to room before being exhausted outside.
The investigators concluded that the ventilation
system was responsible for the outbreak since the
student did not occupy the same room as the other
children who became infected (Riley etaL, 1978).
In a more recent study, Brundage et al. (1988)
demonstrated that army trainees who were housed
in new energy-efficient barracks with mechanical
ventilation had acute febrile respiratory disease rates
that wete 51% higher, on average, than trainees
who were housed in older barracks.' These results
support the hypothesis that risks of respiratory
infection are increased among susceptible popula-
tions in buildings that have tightly sealed envelopes
and closed ventilation systems.
Infectious agents can also enter the indoor environ-
ment from the outside air. Once inside, they can be
incubated, amplified, and disseminated by humidi-
fiers, air conditioners, and other building compo-
nents.
Legionella
Legionelfa is a major cause of respiratory illness
worldwide and accounts for 1-13% of all
pneumonias seen in hospitals in the United States,
Canada, England, and Germany (Feeley, 1985). The
bacteria are ubiquitous and can survive in water for
long periods of time—up ro a year under certain
conditions (Skaliy and Mclachern, 1979),
Epidemics caused by "Legionetta occur most com-
monly during the summer and early fall while
sporadic cases of disease occur throughout most of
the year. The characteristics and causes of some of
these epidemics are discussed in Imperato (1981)
and Band etal. (1981).
Sources ofLegionel/a in residences and office build-
ings include contaminated forced-air heating
systems, humidifiers, water flooding, hot water
systems, hot tubs, vaporizers, nebulizers, and
external sources, primarily cooling towers and
evaporative condensers but also dusts from construc-
tion and landscaping activities. Legionella has also
been isolated from potable drinking water.
Two important bacterial diseases which are both
caused by Legionella pneutnophila are Legionnaires'
disease and Pontiac fever. These two diseases, which
are referred to as legionellosis, are not spread via
petson-to-person contact. Rather, they can be
spread both indoors and outdoors through the soil/
air or water/air link.
Legionnaires' disease: One of the most dramatic
and frightening cases of indoor airborne bacterial
infections is the mysterious illness that affected .
veterans attending the American Legion Convention
in Philadelphia in 1976. A pneumonia-like illness
was contracted by 182 persons who were either in or
near the Bellevue Stratford Hotel. Twenty-nine
people died (Fraser et a/., 1977). The organism that
caused the disease, a grain negative bacillus named
Legionella, pneumophila was first isolated in 1977 at
the Centers for Disease Control. The illness, named
after the group that was most aiFected in 1976, has
come to be known as Legionnaires' disease.
Legionnaires' disease is a form of legionellosis that is
a very severe multi-systemic illness that can affect
the lungs, gastrointestinal tract, central nervous
system, and kidneys. It is characterized by a low
attack rate (2-3%), long incubation period (4-10
days), and severe pneumonia. Hospitalization is
required and about 2-3% of cases are fatal even with
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Section 4
IAQ Reference Manual
proper treatment. It has been estimated that in the
U.S., Legionella species account for 8% to 10%, or
50,000 to 60,000 cases of community-acquired
pneumonias (Fang, 1988).
Pontiac fever: Pontiac fever was first recognized in
19
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IAQ Reference Manual
Section 4
Several important conditions are caused by airborne
allergens including allergic rhinitis, allergic asthma,
allergic bronchopulmonary aspergillosis, hypersensi-
tivity pneumonitis, and humidifier fever.
Allergic rhinitis: Allergic rhinitis is an acute
condition that resolves readily when the source is
removed. It is commonly called "hay fever" when it
is related to pollens produced by the change of
seasons, and it affects about 15% of the population.
It is characterized by dilation and edema of the nasal
mucosa and mucus secretion; typical symptoms
include sneezing, itching, excessive mucus secretion,
and obstruction of nasal passages. Conjunctivitis
(irritation, itching, and reddening of the eyes) may
also be associated with allergic rhinitis. Secondary
bacterial infections may result from blocked sinuses
and eustachian tubes.
Allergic asthma: Allergic asthma affects about 3%
to 5% of the population in the U.S. (Reed, 1981).
It is characterized by bronchospasm, edema of the
bronchial mucosa, accumulation of bronchial
mucus, or any combination of these conditions. The
narrowing of the airways and production of mucus
can block the airways. Typical symptoms include
wheezing, shortness of breath, sneezing, itching of
the nose, and rhinorrhea. Repeated attacks can lead
to a narrowing of the airways which is reversible
over short periods of time (spontaneously or with
treatment).
Allergic asthma can be caused by a variety of viable
and nonviable biological agents. Factors related to
indoor air quality such as cigarette smoke, sulfur
dioxide, and other particles and gases can precipitate
attacks. Emotional stress and exposure to cold have
also been shown to result in asthmatic attacks.
Allergic bronchopulmonary aspergillosis (ABPA):
ABPA is an uncommon, progressive disease that is
caused by an allergic reaction to the inhalation of a
widely distributed soil fungus, Aspergillus fumigatus.
Spores are about 3 microns in diameter and grow at
body temperatures. Episodes of ABPA most
frequently occur during the winter when the counts
of Aspergillus fumigatus are highest.
Other species of Aspergillus can also result in a
variety of syndromes. ABPA is characterized by
recurrent episodes of pulmonary eosinophilia,
usually associated with asthmatic attacks. As the
disease progresses, bronchiectasis (dilation of the
bronchial tubes associated with significant mucus
production), irreversible airway narrowing, and
pulmonary fibrosis may occur in the upper lobes of
the lung. Typical symptoms include coughing,
wheezing, difficulty breathing, and low-grade fever.
Hypersensitivity pneumonitis: Hypersensitivity
pneumonitis (also called extrinsic allergic alveolitis)
is primarily an occupational disease of agricultural
and industrial workers who are exposed to sensitiz-
ing agents in organic (especially fungal spores) and
inorganic dusts. However, it can and does occur as a
result of exposures to sensitizing agents in residen-
tial and office environments. Some examples of
hypersensitivity pneumonitis include pigeon-
breeder's or bird-fancier's lung which is caused by
the inhalation of serum proteins in the droppings of
pigeons and parakeets. The attack rate has been
estimated to be between 0.1% and 21% in pigeon
breeders (Parkes, 1982). The inhalation of thermo-
philic actinomycetes (a group of filamentous
bacteria that superficially resemble fungi) growing
in moldy hay can produce farmer's lung. Exposure
to inorganic compounds such as toluene diisocyante
(isocyanate lung) and copper sulfate (vineyard
sprayer's lung) can also produce pneumonitis.
Expsoure to thermophilic actinomycetes in residen-
tial or office ventilation systems can result in
ventilation pneumonitis. Fungi which have been
implicated in ventilation pneumonitis include
Aspergillus, Pendllum, Alternaria, Rbizopus,
Paedlomyces, and Aureobasidium. Regardless of the
agent, estimated rates of pneumonitis in office
workers range from 1.2% (Arnow et al., 1974) to
4% (Gamble #.*/., 1986).
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Section 4
IAQ Reference Manual
Hypersensitivity pneumonitis can result from
intermittent exposure to high concentrations of
allergens or continuous exposure to low concentra-
tions of allergens. The symptoms and progression
of the disease are the same, regardless of the agent
causing the disease (NRC, 1981). Continuous
exposure to low concentrations of allergens often
does not result in the appearance of overt symptoms,
but at a later time, less reversible stages of the
disease can develop.
Sensitization causes an inflammatory reaction in the
alveolar walls and peripheral bronchioles due to an
allergic reaction between the agent and circulating
antibodies and sensitized lymphocytes. The diagno-
sis of hypersensitivity pneumonitis is made by the
physician based on the patient's history and results
of some tests. These include restrictive pulmonary
function tests, decreased exercise tolerance, granulo-
mas and interstitial fibrosis on lung biopsy, repro-
duction of symptoms upon bronchial challenge with
the suspected agent, and response to corticosteriod
medications (Kreiss, 1989).
An acute attack causes symptoms which are similar
to the flu: chills, fever, dry cough, shortness of
breath, tightness in the chest, and fatigue. Symp-
toms typically occur within 4 to 6 hours after
exposure, and may persist for 12 hours to 10 days.
Changes in lung function can return to normal over
a period of about a month after the condition
develops. Between attacks, the individual may be
symptom free and feel fine. Over a period of time,
the lung gradually develops fibrous scar tissue.
Irreversible pulmonary fibrosis, followed by pulmo-
nary failure, and death can occur in severe cases.
Humidifier fever is a type of pneumonitis that is
probably due to allergic reactions of the alveolar
wall. It has been related to amoebae, bacteria, and
fungi. Bacillus subtilis (Parrot and Blyth, 1980),
amoebae including A. polyphaga and N. gruberi
(Edwards, 1980), and bacterial endotoxin (Rylander
etal, 1978, 1984) are specific agents which have
been implicated in this condition. Sources of the
these agents include humidifier reservoirs, air
coolers, air conditioners, spas, and aquaria.
The disease is characterized by episodes of flu-like
symptoms (chills, muscle aches, malaise) and fever
without prominent pulmonary symptoms and signs.
Symptoms develop 4 to 8 hours after exposure and
resolve spontaneously, usually within 24 hours
without long-term effects. Lung function changes
may include a restrictive ventilatory defect with a
decrease in gas transfer that improves over a period
of days. Pulmonary fibrosis does not occur and
chest x-rays do not show abnormalities (NRC,
1981).
Chronic humidifier fever has been reported from
residential humidifiers (Kreiss and Hodgson, 1984),
but the prevalence of the disease (acute and chronic
forms) in the home environment has not been
evaluated. In Great Britain, an attack rate of 2% to
3% has been estimated in office buildings with
mechanical ventilation based on reports of symp-
toms (Finnegan et al. 1984). Epidemics in the
workplace are rare, but when they do occur, attack
rates are high (30% to 75%).
An additional potential problem associated with the
use of some types of humidifiers is the formation of
fine particles during the operation of the humidifier.
Highsmith et al. (1988) measured fine particle
concentrations greater than 590 |Jg/m3 when an
ultrasonic humidifier was operated in a kitchen
using tap water containing 303 mg/1 total dissolved
solids. Using distilled water does reduce, but not
eliminate, the formation of fine particulates. Even
when the ultrasonic humidifier was operated using
purchased distilled water, whole house fine particu-
late concentrations greater than 40 |Jg/m3 were
measured. Fine particle concentrations greater than
6300 )Jg/m3 were measured when the ultrasonic
humidifier was operated in a closed room situation.
Even when distilled water was used by the manufac-
turer, fine particles were generated. Impeller units
generated less than one-third of the aerosol mass
compared to the ultrasonic units, and steam units
generated no measurable increase in fine particles.
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IAQ Reference Manual
Section 4
The health consequences of these participates have
not been evaluated.
Allergenic Agents
House Dust Mite
One important agent that has been implicated in
allergenic conditions such as allergic rhinitis or
allergic asthma is the house dust mite. It is not the
actual house dust mite that causes disease, but
allergens which are probably present in the excreta
of the mite, some of which is of inhalable size
(Tovey et al. 1981). The highest levels of allergens
from house dust mites that occur indoors have been
shown to be associated with respirable particles in
the size range 0.8 to 1.4 microns (Reed and
Swanson, 1984).
The house dust mite, which is an arachnid, is about
300 microns long, and it can be found in almost
every home. Mites are translucent and cannot be
seen with the naked eye. The most commonly
found mites include Dermatophagoides pteronyssinus (in
Europe) and D. farinae (in North America) (NRC,
1981).
Mite populations vary depending on atmospheric
moisture and food sources. Growth is favored by a
temperature of 25 °C and a relative humidity greater
than 45%. Below 45% RH at 20 °C to 22 °C,
almost no house dust mites are able to survive
(Korsgaard, 1982).
House dust mites are important causes of allergic
rhinitis and asthma in climates with humid, mild
conditions (NRC, 1981). In North America, the
mite population is at a maximum during the
summer when windows are open and ventilation is
good; levels drop in winter when the heating season
begins and the relative humidity drops to 10% to
Dust mites feed on the skin scales of humans and
other animals. The mites, however, cannot feed on
new skin; rather, they require skin scales that have
been defatted. This explains why these mites are
found in mattresses, bedclothes, and heavily used
upholstered furniture. High concentrations of other
specialized mites that cause allergic conditions can
also be found in interior spaces that are used to store
or process agricultural products.
Fungi
Fungi are a major group (over 100,000 species) of
chlorophyll-less eukaryotic organisms which are
formed by hyphae with chitinous or cellulosic rigid cell
walls. Most fungi are saprophytic (live off dead organic
matter for food), and some fungi require specific
substrates for growth and reproduction (dung and
wood-rotting fungi, for example). Many can use any
nonliving organic matter, providing temperature and
moisture conditions are met.
Fungi reproduce either by specialized cells (spores)
that are produced on fruiting branches or by
fragmentation of the fungus body (mycelium).
Fungi have both sexual and asexual stages which can
result in allergenic effects, and there may be more
than one spore type for each stage. The identifica-
tion of fungi and spores can be difficult. Many
fungi cannot be identified without fruiting struc-
tures. Another complicating factor is that fungal
names have undergone changes, and the names for
the various life cycle stages may be different because
they were described at different times (Burge,
1985).
Major fungi classes of interest include Zygomycetes,
Ascomycetes (powdery mildews), Basidiomycetes
(rusts, smuts, mushrooms), and a fourth class
Deuteromycetes or Fungi Imperfecti, which is an
artificial grouping of asexual fungus stages (Burge,
1985). The imperfect fungi are perhaps the most
important class from an indoor air quality perspec-
tive because this class includes Aspergillus,
Cladosporium, Alternaria, Penicillium, and other
saprophytes which are commonly found indoors.
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Section
1AQ Reference Manual
Any organic material that is wet can support the
growth of fungi. In the outdoor environment fungi
can utilize soil, animal and bird droppings, dead
leaves, grass, tree bark, dead wood, and fallen fruits.
Indoors, any damp, nonliving organic surface can be
colonized by fungi; these surfaces include carpet,
upholstery fabric and fillers, wood, concrete, painted
surfaces, wall coverings, soap scum on tiles and
porcelain surfaces. Humidifiers and air conditioners
can also serve as reservoirs for fungi. Some fungi
have even become adapted to growth in dry house
dust environments (Rijckaert, 1981) and carpeting
that is not water damaged (Gravesen etal., 1986).
Measured concentrations: The most abundant
spore types ate produced continuously outdoors
during the growing season at concentrations
ranging from 103 to 105/m3; these fungi can reach
levels of 10° to 104/m3 indoors. In the outdoor
environment, airborne spore concentrations are
reduced in areas with snow cover (dispersion of
spores is prevented) and where temperatures fall
below freezing (spore production is decreased).
Spore counts are usually highest in late summer and
autumn, although Aspergillus fumigatus is more
common in autumn and winter (NRC, 1981).
Spores may be introduced into the home from the
outside or result from unrestrained growth inside if
conditions are favorable. Exhibit 4-15 identifies
some fangi which have been isolated indoors.
In the ambient air, concentrations of Aspergillus
fttmigatm rarely exceed 150 spores/m3, but concen-
trations in specific sources such as compost piles can
exceed several million spores/m3. The concentration
in clean interiors is also low, ranging from 0 to 200
spores/m3 (NRC, 1981). Recoveries of thermo-
philic actinomycetes (filamentous bacteria) in
domestic air are generally less than 3000 counts/m3
while occupational exposures can be 10 times higher
(Burgee/*/., 1980).
Factors such as shading of homes*and organic debris
outdoors have been found to be significantly
associated with higher spore concentrations indoors
(Kozak et al., 1985). Indoors, there is a direct
relationship between mold growth and airborne
spore levels and humidity levels between 25% and
70% (Burge, 1985). Mold growth is suppressed
below 25% RH, and humidities above 70% are
optimal for growth.
Kozak et al. (1985) reported on sources of fungi
problems in 186 homes that were surveyed using
rotorod and Anderson samplers over a period of 4
years in southern California. Of the 80 homes
sampled with both types of sampling devices, 63
had a history of water damage and were suspected of
having an endogenous mold problem. Forty-nine
percent of these homes had more than one problem
area.
The most likely areas with mold problems were the
bathroom (31% of cases), living room (18.4%),
family room/den (16.5%), and a bedroom (11.7%).
The most likely materials were jute-backed carpet-
ing and baseboards (53.5% of problems), wicker
straw baskets (17.5%) and walls, ceilings, and
window frames (13.6%). The most frequent causes
were chronic water spills (35% of problems),
followed by recurrent water leaks from plumbing
(20.4%) and one-time disasters such as roof leaks
and structural defects (10%). Exhibit 4-15 provides
a list of molds identified in 68 California homes.
Disease-producing fungi: Alternaria, Cladosporium,
Aspergillus and Memlius lachrymans have been
identified as important causes of allergic asthma and
rhinitis. Other spores which may colonize the
airways include Candida, Scedosporium, Scopulariopsis,
Geotrichium, and Paecilomyces Q$JLC, 1981). Exhibit
4-16 includes a list of fungi that have been reported
as allergenic. Contact with the respiratory tract
may be brief, followed by clearance out of the
airways, or it may be prolonged and followed by
colonization of the airways.
Elimination of fungal growth is necessary for spore-
sensitive individuals, but there is no consensus on
dose-response relationships. Holmberg (1987)
found that airborne levels greater than 50 CFU/m3
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IAQ Reference Manual
Section 4
of thermotolerant Aspergillus spp. were a significant
risk factor for irritation of the eyes and respiratory
symptoms.
Some clinicians caution allergic patients against
keeping living plants or processed plant materials in
their homes because they have been implicated as
substrates for saprophytic fungi which are allergens.
However, Surge efal. (1982), in a study of 10
homes and 3 greenhouses in Michigan, concluded
that healthy undisturbed houses are not a major
exposure source for airborne fungus spores. Samples
were collected before and after watering and also
while plant foliage was disturbed by a small fan.
This study, however, was done in a colder climate
and the limited results may not apply to continu-
ously warm and/or humid environments.
Other AUergenie Agents
Insect excretions are strong sensitizers that can
result in allergic responses. Roach fecal pellets are
important sensitizers, but carpet beetles, houseflies,
and bedbugs may also be implicated.
Domestic animals, particularly cats, but also dogs,
rabbits, guinea pigs, birds, and horses can be
important causes of allergic rhinitis and asthmatic
attacks. It is generally accepted that the source of
the allergen is animal dander, small scales of
feathers or hair, or saliva (cat). Animal danders are
very strong sensitizers, and highly sensitive people
may develop allergic eczema or urticaria (hives) as a
result of direct contact with the allergen. The feces
of birds (parakeets and pigeons) can also result in
allergic rhinitis, asthma, and hypersensitivity
pneumooitis; the original source of the allergen is
serum proteins which are secreted in the gut (Reed
and Swanson, 1984).
Some individuals may also be allergic to compo-
nents in tobacco smoke, chemical cleaners, dyes in
carpeting, hair sprays, evergreen Christmas trees,
and other chemical agents.
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Section 4
IAQ Reference Manual
Exhibit 4-1 5. Molds
MOLD GENERA
ClaJotparium
Penicillium species
Nensporulatiag mycelia?
Altemaria
Streptamyca
Epicoecam
Atpergilliu species
AureobaiiJiHm
Dreckslera (Helminthasporium)
Gtphalosporium
Atremonlum
Fmarium
Batrytis
Aspergilltts niger
Rbizepus
Rbodotorula
Btauvera
Chuetomium
Unkmnvn
Scopulariopsis
Mucor
Cttn-'utaria
Rhinocladiella
Verticilliutn
Plenozythia
Pithomyca
Zygospsrium
Paeciltmyces
Stachybottys
Alpergillaj fumigatus
Nigraspora
Stysanus
Pleospora
Batryasporium
TruheJerma
Cbrysosporiam
Phama
Sptmbalemyces
Tr'ulwtbtcium
Ulocladittm
Yeast
Gtotrithum
identified in 68 homes
PERCENT OF HOMES
IN WHICH
GENERA ISOLATED
100.0
91-2
89.7
87.0
58.8
52.9
48.5
44.1
38.2
36.7
35.3
25.0
23.5
19-1
13.2
11.8
10.3
8.8
8.8
8.8
7.4
7.4
4.4
4.4
4.4
2.9
2.9
2.9
2.9
2.9
2.9
2.9
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
1.5
in southern California.
RANGE OF
SPORES/m}
12 - 4,637
0 - 4,737
0-494
0-282
0-212
0-153
0-306
0-294
0-94
0-59
0-188
0-47
0-54
0-59
0-24
0-29
0- 12
0-47
0-34
0-25
0-41
0-12
0- 12
0-12
0-6
0-25
0- 18
0-12
0-12
0-5
0-5
0-6
0-18
0-12
0-12
0-6
0-6
0-6
0-6
0-5
0-5
0-3
MEAN OF
SPOEES/m}
437.7
168.9
44.3
30.7
28.1
9.6
15.0
8.0
6.9
5.3
3.6
4.5
2.9
2.9
1.4
1.5
0.7
1.2
1.2
0.9
1.4
1.1
0.5
0.4
0.3
0.4
0.4
0.3
0.3
0.2
0.1
0,1
0.3
0.2
0.2
0.1
0.1
0.1
0.1
0.1
0.1
0.04
8 Subcultures of nonsporulating mycelia from one home (grown on Meyer's multiple media) subsequently produced Torula herbarium
colonies.
SOURCE: Kozak P.P., J. Gallup, L,H. Cummins, and S. A. Gillrnan, "Factors of importance in determining the prevalence of indoor
molds." Annals of Allergy. 1979; 43: 88-94. Copyright ©, The American College of Allergists. Used with permission.
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IAQ Reference Manual
Section 4
Exhibit 4-16. fungi reported as allergenic.
Myxomycetes
Fuligo
Stemonitis
Lycogala
Deuteromycetes
Alternaria
Cladosporium
Aspergillus
Sporobolomyes
Penitillum
Epicocatm
Fusarium
Candida
Rhodotontla
Tilletiopm
Phoma
Botrytis
Helminthospormm
Momlia
Paealomyces
Sporotricbttm
Stemphylium
Tricbothecium
Cepbalosporium
Gliocladittm
Aureobasidium
Tricboderma
Coniosporwm
Dieoccum
Ntgrospora
Torula
Spondylocladium
Curvularia
Epidermophyton
Trichopbyton
Zygomycetes
Mucor
Absidia
Rhimpus
Ascomycete - sexual stages
Xylaria
Eurotium
Erysiphe
Daldinia
Chaetomium
Claviceps
Microsphaera
Saccharomyces
Basidiomycetes
Heterobasidiomycetes
Pucdnia
Ustilago
Tilhtia
Urocytis
Dacrymyces
Holobasidiomycetes
Chlompbyllum
Podaxis
Agarictu
Armillaria
Coprinm
Hypholoma.
Ganaderma
Merulius
Polypoms
Stereum
Pleurotus
Cantbanllus
SOURCE: Adapted from Surge, H. A. 1985. "Fungus Allergens." Clin. Rev. Allergy, 3: 319-329. Used with permission.
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Section 4
IAQ Reference Manual
REFERENCES
Arlian, L.G., IX. Berstein, and J.J.Gallagher. 1982. "The
prevalence of house dust mites, Dertaatopbadoides spp, and
associated environmental conditions in homes in Ohio."
J, Allergy Clin. Immunol. 69: 527,
Atnow, P.M., J.N. Fink, D.P, Schlueter, J.J. Barboriak, G.
Mallison, S.I. Said, S. Martin, G.F. Unger, G.T. Scanlon, and
V.P. Kurup. 1974. "Early detection of hypersensitivity
pneumonias in office workers." Am,J. M.ed. 64: 236-242.
Band, J.D., M. LaVenture, J.P. Davis, G.F. Mallison, P. Skaliy,
P.S. Hayes, W.L. Schell, H. Weiss, D.J. Greenberg, and D.W.
Fraser. 1981, "Epidemic Legionnaires'Disease." JAMA. 245
(23): 2404-2407,
Surge, H.A. 1985. "Fungus allergens." Clin. Rev, Allergy. 3:
319-329.
Burge, H.A. 1988. "Environmental Allergy: Definition,
Causes, Control." IAQ 88. Engineering Solutions ta Indoor Air
Problems, ASHRAE: Washington, DC.
Surge, H.A., W.R. Solomon, and MX. Muilenberg. 1982.
"Evaluation of indoor plantings as allergen exposure sources."
J. Allergy Clin, Immuml. 70(2): 101-108.
Burge, H.A..W.R, Solomon, and J.R, Boise. 1980. "Microbial
prevalence in domestic humidifiers." Appl. Environ. Mierobiol.
39<4): 840-844.
Brundagc, J.F., R. Scott, W.M. Lednar, D.W. Smith, and R.N.
Miller. 1988. "Building-associated risk of febrile acute
respiratory diseases in army trainees." JAMA, 259 (14):
2108-2112.
Ed wards, J.H. 1980. "Microbial and Immunological investiga-
tions and remedial action after an outbreak of humidifier fever.
Br.J. Ind. Med. 37: 55-62.
Fang, G.D., M.J. Fine, JJ. Orloff, VJL Yu, J.T. Grayston, S.P.
Wang, R.B. Kohler, D, Arisumi, R.R, Muder, and W. Kapoor.
1988. (abstract) "A prospective multi-center study of 359
eases of community-acquired pneumonia." American Society of
In feet low Diseases.
Feeley, J.C. 1985. "Impact of indoor air pathogens on human
health." Chapter 12. Indoor Air and Human Health. R.B.
Gammage and S.V. Kaye (eds). Lewis Publishers: Chelsea, MI.
FInnegan, M.J., C.A.C. Pickering, and P.S. Burge. 1984. "The
sick building syndrome: prevalence studies." Br,Med.J, 289:
1573-1575.
Fraser, D.W., T.R. Tsai, W. Orenstein, W.E. Parkin, H.J.
Beecham, R.G. Sharrar, J. Harris, G.F. Mallison, S.M. Martin,
J.E. McDade, C.C. Shepard, and P.S. Brachman. 1977.
"Legionnaires' disease. Description of an epidemic of pneumo-
nia." N. Eng/.J, Med, 297: 1189-1203.
Gamble, J., P. Morey, T. Richards, M. Petersen, and R.M.
Castellan. 1986. "Building-related respiratory symptoms:
problems in identification." IAQ 86. Managing Indoor Air for
Health and Energy Conservation. ASHRAE: Atlanta, GA. pp.
16-30.
Glick, T.H., M.B. Gregg, B. Herman, G.W. Mallison, W.W.
Rhodes, I. Kasanoff. 1978. "Pontiac fever: An epidemic of
unknown etiology in a health department. I. Clinical and
epidemiologic aspects." Amer.J. Epidemiol, 107: 149-160.
Gravesen, S., L. Larsen, F. Gyntelberg, and P. Skov. 1986.
"Demonstration of microorganisms and dust in schools and
offices." Allergy. 41: 520-525.
Highsmith, V.R., CD. Rodes, and R.J. Hardy. 1988. "Indoor
particle concentrations associated with the use of tap water in
portable humidifiers." Environ. Set, Technol. 22(9): 1109-1112.
Holmberg, K. 1987. "Indoor mould exposure and health
effects." Indoor Air'87. Vat, 1. Volatile Organic Compounds,
Combustion Gases, Particles and Fibers, Microbiological Agents.
Oraniendruck GmbH: Berlin, W. Germany, pp. 637-645.
Imperato, P.J. 1981. "Legionellosis and the indoor environ-
ment." Bull. N.Y. Acad. Med, 57 (10): 922-935.
Korsgaard, J. 1982. "Preventive measures in house-dust
allergy." Anter. Rev, Resp. Dis. 125: 80-84.
Kozak, P.P., J. Gallup, L.H. Cummins, and S.A. Gillman.
1979- "Factors of importance in determining the prevalence of
indoor molds." Ann. Allergy. 43: 88-94.
Kozak, P.P., J. Gallup, L.H. Cummins, and S.A. Gillman.
1985. "Endogenous mold exposure; Environmental risk to
atopic and nonatopic patients." Indoor Air and Human Health.
R.B. Gammage and S.V, Kaye (eds). Lewis Publishers:
Chelsea, MI.
Kreiss, K. 1989. "The epidemiology of building-related
complaints and illness." Occupational Medicine: State of the Art
Reviews. 4(4): 575-592.
National Research Council (NRC). 1981. Indoor Pollutants,
National Academy Press: Washington, DC.
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IAQ Reference Manual
Section 4
Parkes, W.R. 1982. Occupational Lung Disorders. 2nd edition.
Butterworths: London, England.
Parrott, W.F. and W. Blyth. 1980. "Another causal factor in
the production of humidifer fever." J. Soc. Occup. Med. 30:
63-68.
Reed, C.F. 1981. "Allergicagents." Bull. N.Y. Acad. Med. 57
(10): 897-906.
Reed, C.E. and M.C. Swanson. 1984. "Indoor allergens:
identification and quantification." Indoor Air. Vol.1. Recent
Advances in the Health Sciences and Technology. Swedish Council
for Building Research: Stockholm, Sweden, pp. 99-108.
Riley, E.G., G. Murphy, and R.L. Riley. 1978. "Airborne
spread of measles in a suburban elementary school." Amer.J.
Epidemiol. 107: 421-432.
Rijckaert, G. 1981. "Exposure to fungi in modern homes."
Allergy. 36: 277-279-
Rylander, R., P. Haglind, M. Lundholm, I. Mattsby, and K.
Stenqvist. 1978. "Humidifier fever and endotoxin exposure."
Clin. Allergy. 8: 511-516. -
Rylander, R. and P. Haglind. 1984. "Airborne endotoxins and
humidifier disease." Clin. Allergy. 14: 109-112.
Rylander, R., P. Haglind, M. Lundholm, I. Mattsby, and K.
Sarsfield. 1974. "Mite-sensitive asthma of childhood: Trial of
avoidance measures." Arch, Dis. Childhood, 49: 716-721.
Skaliy, P. and H.V. McEachern. 1979. "Survival of Legion-
naires' disease bacterium in water." Ann. Intern. Med. 90: 662-
663.
Tovey, E.R., M.D. Chapman, and T.A.E. Platts-Mills. 1981.
"Mite faeces are a major source of house dust allergens." Nature.
289: 592-593.
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Page Intentionally Blank
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SECTION 5.
CONTROL OF INDOOR AIR
CONTAMINANTS
This section supplements Lesson 5 of
the Learning Module, which covers
various options for controlling indoor
air quality, and Section 8 of the
Reference Manual, which provides
inspection techniques for specific
contaminants. Section 5.1 contains
an overview of heating and distribu-
tion systems, and a general discussion
of moisture control in residences.
Section 5.2 describes types of air
cleaners and methods for testing their
efficiency. It provides a summary of
the ASHRAE (Standard 52-1976) and
ANSI/AHAM (Standard AC-1-1988)
methods for evaluating air cleaners.
Section 5.3 consists of Exhibits 5-12
and 5-13, which are referenced in the
Learning Module, and which provide
listings of public interest, profes-
sionals and trade associations that are
involved in controlling indoor air
contaminants.
Table off Contents
Section 5.1.
Section 5.2.
Section 5.3.
Residential Heating Systems and Moisture
Control 116
Evaluation of Air Cleaners
131
Public and Private Sector Organizations
Involved In Indoor Air Quality Activities 135
Lists of Exhibits
Exhibit 5-1. Oil furnace installation. 118
Exhibit 5-2. Gas-fired forced-air furnace configurations. 119
Exhibit 5-3- Forced-air distribution systems. 120
Exhibit 5-4. Installation of a vapor retarder in the attic. 125
Exhibit 5-5. Installation of a vapor retarder in the
crawl space or floor. 126
Exhibit 5-6. Installation of a continuous vapor retarder. 128
Exhibit 5-7. Attic ventilation strategies. 129
Exhibit 5-8. Sizing factors for different vent coverings. 130
Exhibit 5-9. Comparative performance of viscous
impingement and dry media filters. 132
Exhibit 5-10. Estimated percentage of particle removal
for portable air cleaners by CADR and by
room size. 134
Exhibit 5-11. Minutes to achieve 90% removal of
airborne particles. 135
Exhibit 5-12. Public interest organization indoor air
activities. 136
Exhibit 5-13. Professional and trade association indoor
air activities. 137
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Section 5
IAQ Reference Manual
5.1. RESIDENTIAL HEATING SYSTEMS AND
MOISTURE CONTROL
RESIDENTIAL HEATING SYSTEMS
Types of Healing Systems
JLhe purpose of heating and cooling
systems is to provide sufficient warmth during the
winter and adequate cooling during the summer
without discomfort to the occupants. There are
many potential heating and cooling system configu-
rations for residential use. These include conven-
tional gas or oil furnaces, continuous condensing
furnaces, electric furnaces and heaters, heat pumps,
fireplaces and woodstoves, coal furnaces, and
hydronic (hot water) heating systems.
Older homes (more than 50 years old) are likely to
have a gravity furnace, hot water, or steam system.
Homes built during the last few decades are likely
to have forced-air systems, but some may have
hydronic systems in which water is pumped
through pipes and radiators. Hydronic systems
were used after World War II in houses built on
concrete slabs. Newer houses may have heat pumps
or continuous condensing furnaces. And houses of
all types and ages could have fireplaces and/or wood
stoves for primary or supplementary heating,
Hot Air Systems
Gravity systems: Gravity-air systems consist of a
furnace that heats air which is circulated through a
ducting system. The gravity-air system has a
furnace (often called an octopus) that occupies a
large portion of a basement with large "arms"
(delivery and return ducts) that extend from the
furnace. The furnace is basically a metal box inside
a larger one. As fuel burns, air in the larger box is
heated and flows through individual ducts to the
heat registers in different rooms. As the air cools, it
sinks and travels back through the return air ducts
to the furnace where the air is heated again. Com-
bustion gases are exhausted through a chimney.
Since there are no moving parts, this system is very
quiet. Humidifiers can be attached, but this system
cannot accommodate other air cleaning equipment.
Cold spots typically result along outer walls during
cold days in houses that are not well insulated.
Forced-air systems: The forced-air system is similar
to the gravity system, but it has a blower driven by
an electric motor which pulls the cold air into the
return ducts, blows it through the heat exchanger in
the furnace, and back into the hot air ducting.
Another difference is that the cold air ducts run to a
main return duct from each room return rather than
to the individual ducts as in a gravity system.
Forced-air systems are more efficient than gravity
systems; the furnace does not need to be centrally
located, and smaller furnaces can be used. The
furnace can be located in a basement, attic, garage,
or first floor of the house. Humidifiers and air-
cleaning equipment can be accommodated. Forced-
air systems are generally more comfortable because
heat stratification is reduced.
Hot Water (Hydronie) Systems
Gravity systems: Hydronic gravity systems (hot
water or steam) work on the same principle as the
gravity-air system. Hot water (or steam) rises up
though a boiler into pipes that connect to radiators.
Water flows through the radiators and back to the
boiler where it is heated again. These systems
provide even heat, but they may be slow to respond
to demands for more heat.
Pump driven systems: The hydronic pump driven
system is the hot water equivalent of a forced-air
system. This system is more efficient than the hot
water gravity system and the boiler and pipes can be
smaller. The boiler can be installed anywhere.
Water can be carried through the radiators by a
series loop, one-pipe, or two-pipe systems.
Electric Baseboard Heating Systems
Electrical baseboard heating systems can be installed
for whole house heating or localized heat. The
-------
IAQ Reference Manual
Section 5
system usually has one or more baseboards in each
room, and each unit in a room can be individually
controlled. This system does not require flues or
chimneys. Baseboard units are typically resistance
coils or antifreeze units.
Gas/Oil Furnaces
Conventional gas and oil furnaces are similar except
that the burners (and fuel) are different. Most gas
furnaces have a burner with a number of jets; some
have a single large jet in which the flame is spread
by a deflector plate. Both types commonly have a
pilot light which heats a thermocouple that holds
open an electrical valve that supplies gas to the
furnace. Oil furnaces have a combustion chamber
into which oil is pumped through a spray nozzle
and mixed with air which is blown into the cham-
ber. The oil burner does not have a pilot light;
instead, it is ignited by a high-voltage spark across a
pair of electrodes positioned directly in the stream
of oil and air. Exhibit 5-1 shows typical installa-
tions for oil furnaces in older homes.
In conventional natural-draft furnaces, the gas is
supplied to the burner at low pressure and mixed
with the required amount of air for combustion.
The hot gases pass through a heat exchanger where
air (or water) is heated, and the waste gases are then
vented through a chimney to the outside. These
systems are inefficient (flue gas temperatures are
300T to 500°F) and large quantities of hot air can
escape up the chimney even when the chimney is
not operating because the draft hood and combus-
tion chamber are open to the flue.
Mechanical (also called powered) combustion
furnaces utilize a small electric fan to move the
combustion gases; they do not need a chimney or
draft hood, which increases efficiency. Combustion
gases exit through a small vent, usually to an
outside wall. If the blower is located upstream of
the heat exchanger, the system is called a forced-
draft system. If the blower is located downstream,
the system is called an induced-draft system. Either
of these furnaces can be configured as a direct-vent
furnace in which combustion air is obtained from
outside the structure.
Continuous condensing furnaces are very efficient
(up to 95%) because they have two or more heat
exchangers that capture most of the heat that
normally goes up the flue. The first heat exchanger
operates in the same way as a conventional furnace;
the additional exchangers condense the water vapor
in the flue gases to extract the latent heat, and
condensate is drained to a house sewer. The tem-
perature of flue gases is lower (100 to 180°F) and
the gases are exhausted through a small flue (often
PVC pipe) by an induced draft fan. Standard
features include spark ignition and a direct outside
air feed to the combustion chamber.
All furnace's (gas, oil, or water) need safety devices
which switch off the gas o.r power to the pump/
blower motor in case the air or water reaches a
temperature that exceeds the design temperature.
Exhibit 5-2 illustrates different configurations of
gas-fired, forced-air furnaces that may be encoun-
tered in residential heating systems.
Forced-Air Delivery Systems
Forced-air delivery systems include extended
plenum and graduated trunk systems for basements,
radial and crawl space plenum systems for crawl
spaces, and slab-on-grade forced-air systems (Ex-
hibit 5-3). Basement forced-air systems typically
use an extended plenum duct system or a graduated
trunk system. Crawl space systems include a radial
system in which supply ducts radiate out from a
supply plenum. Slab-on-grade forced-air systems
consist of a down-flow furnace connected to radial
supply ducts which are set in place before the
concrete is poured.
Regardless of the type of system used, warm air
supply registers should be located against outside
walls, preferably beneath windows so that rising
warm air counteracts the falling cold air. Cold air
return grills should be located in or near inside
-------
Section 5
IAQ Reference Manual
Exhibit 5-1. Oil furnace installation.
To
Nofe: Enouj
furnace roon
for each gall
Pipin
lh air for combustion must<
i. Provide 15-square-irtch o
on of oil burned per hour.
To Wiring
Stac
Floe
Draff
Regulator
.»
< Relay
-i
A>.W».. «,",*.; .r^,st .•*•:.
-^
g Hook-up for Bui
inter
aening
— Furnace May
Be Located
Here
led
(K
r
Antisiphon Valve
(Underwriter Listed)
. "X.
Furnace ,
M
m
1 MnBi
A
s Oil Burner
W OD Soft Copper Tubing
Pipe 3" Below Floor
Piping Hook-up for Insii
Dr
Regu
i
1
,ft *
ator '
1 Stack R
fl rf
..
s^~Rp
To Flue ^
t>.4s
^ote: Enough airfor combustion must enter
wnace room. Provide 15-square-inch opening
or each gallon of oil burned per hour,
slay
I ' ' v
V****'*^^*.^ -V>
Furnace
/
V-Hj jn
^ _, 7'0"Mii
x Burner
"--Pump"
i'S*
V «
%•'•.
s
1
''.*"
.«"•
•',-»:'
'•:'f
'if
"I1*,
%-f
."
-------
IAQ Reference Manual
Section 5
Exhibit 5-2. Gas-fired forced-air furnace configurations.
Circulating
Air Blower
Heat Exchange
Gas Burner
Circulating
Air Plenum
Vent Pipe
- Draff Diverter
Relief Air
Control
Compartment
Combustion Air
Gas Supply Manifold
Filter t
Circulating Air
Upf low Forced-Warm-Air Furnace
Circulating Air Plenum
Filter
Heat
Exchanger-
Circulating
Air Blower-
T
i
O
Combustion
Products
T
^ Vent Pipe
-Draft Diverter
- Relief Air
-Control
Compartment
— Combustion
\Air
Gas Burner Gas Supply Manifold
Basement (Low-Boy) Forced-Warm-Air Furnace
Filter
"x
Circulating
Air —*
Vent Pipe
Circulating - \
Air Blower Draft Diverter r
\ \
\
o
Combustion
Products
E
Gas Burner
Combustion
""•Air
Heat Exchange
Horizontal Forced-Warm-Air Furnace
Circulating Air
Circulating
Air Blower
HeatExchange
Gas Burner
Circulating Air Plenum
Vent Pipe
Draft Diverter
— Relief Air
Control
Compartment
*" Combustion Air
\
Gas Supply Manifold
Downflow (Counter-flow)
Forced-Warm-Air Furnace
SOURCE: Reprinted with permission of the American Society of Heating, Refrigerating, and Air-Conditioning Engineers from the
1988 ASHRAE Handbook—Equipmmt,
-------
Section
IAQ Reference Manual
Exhibit 5-3. (Forced-air distribution systems
."Take-Off" Ducts to Rooms
Furnace
Heated Air
to Rooms
Extended Plenum Duct System
Extended Plenum System
» This system is typically installed in base-
ments where headroom is important,
and is one of the commonly used systems,
• It is a relatively simple but flexible
system, although generally limited to
small- and medium-sized installations.
* A rectangular plenum, usually located
alongside the main supporting beam,
is extended from one or both sides of the
furnace.
• Individual room" takeoff ducts" extend
at right angles the plenum and can often
be hidden in the space between floor
joists for an unrestricted headroom.
• Either a single floor-level central cold-air
return or a matching extended plenum
return air duct with several pickups can
Graduated Trunk System
• This is similar to the extended plenum
system but has a main supply trunk that is
graduated in size to help balance
delivery pressure after each takeoff,
• This is an ideal but expensive system and'
is generally used only for larger or more
complex installations.
• Reducer
Heated Air to Rooms
Graduated Trunk Duct System
SOURCE'. Peter A, Mann, P. A. 1989. Illustrated Residential and Commercial Construction. ©1989, Figures 14-11, 14-12, 14-13.
Reprinted by permission of Prentice Hall, Inc. Bnglewood Cliffs, NJ 07632.
-------
IAQ Reference Manual
Section 5
Exhibit 5-3. forced-air distribution systems Continued).
First Floor Structure
Sealed and Insulated
Crawl Space
Radial Duct System
Down-Flow Furnace
Cold-Air Return 1
Radial System
* This system requires a" down-flow" type
of furnace that blows warm airdownward
to a distribution plenum beneath the floor.
* Individual room supply ducts radiate out
from the supply plenum, as shown at the
left, and are positioned below the floor
joists.
• This system is generally used only in
crawl space or slab-on-grade
construction, where headroom below
the supply ducts is of no concern,
* The cold-air return is usually through a
single grille on or near the furnace head.
»In an unheated crawl space the supply
ducts must be sealed and well insulated.
Floor Registers
Floor Joists
Heated-Air Discharged
Into Crawl Space
Crawl Space Plenum System
Crawl Space Plenum System
«In this system the crawl space itself is used as a plenum to distribute the warm air to the individual rooms.
* A down-flow furnace is located on the first floor and discharges warm air into the crawl space, where a positive pressure is created. The
warmed air then flows upward through the open floor registers into the first-floor rooms. In addition to the connection effect, the floor is
warm and rdiates heat. This increases the mean radiant temperature and raises comfort levels.
« Variations in crawl space depth have little effect on the system's overall efficiency, and any type of foundation construction can be used.
• The foundations and crawl space floor must be treated as a fully heated basement and insulated to suit. The crawl space must be made
airtight using a continuous and sealed air/vapor barrier.
• System costs are relatively low since no supply ducts are required and overall system efficiency tends to be quite high.
SOURCE; Peter A. Mann, P.A. 1989. Illustrated Residential and Commercial Construction. ©1989, Figures 14-11,14-12,14-13.
Reprinted by permission of Prentice Hall, Inc. Englewood Cliffs, NJ 07632.
(continued next page)
-------
Section 5
IAQ Reference Manual
Exhibit 5-3. Forced-air distribution systems Continued).
Perimeter Loop System
Perimeter Loop System
This is similar to the radial system shown opposite wifh the addition of a perimeter loop connected to the radial supply ducts,
* Supply registers are located in the outer loop at suitable room positions,
»Fewer radial.feeder ducts are needed, and the slab perimeter is kept relatively warm provided that the perimeter bop is not insulated,
• The feeders and loop are set in place before the concrete floor slab is poured. Ensure that the ducts are sloped downward toward the
supply plenum for the collection of any water that may accumulate in me system.
The radial system can also be used in slab-on-grade construction but tends to result in cold floor areas at the slab perimeter.
SOURCE: Peter A. Mann, P.A. 1989. Illustrated Residential and Commercial Construction. ©1989, Figures 14-11, 14-12, 14-13,
Reprinted by permission of Prentice Hall, Inc. Bnglewood Cliffs, NJ 07632.
-------
IAQ Reference Manual
Section J
partition walls. Ducts should not be located in cold
spaces such as outside walls.
A crawl space plenum system could also be used in
which air from the furnace discharges into the crawl
space. This creates a positive pressure and warm air
flows upward through open floor registers. The
foundation and crawl space floor must be insulated
and the crawl space must be made airtight using a
continuous and sealed air/vapor retarder. These
systems may be susceptible to microbial or soil gas
contamination of the ventilation air.
MOISTURE CONTROL
This section provides an. overview of
sources and solutions to moisture problems; the
basis of this discussion is Moisture and Home Energy
Conservation (NCAT, 1983). This document is a
useful reference, and it is available at minimal cost
from the National Center for Appropriate Technol-
ogy. In addition, books on the construction of
energy efficient homes or retrofits of existing homes
will also be helpful.
Moisture problems can occur in any part of the U.S.
as a result of improper construction and control
methods, but some areas, such as the coastal states
or areas where winter temperatures average 35°F or
less, have special problems. Moisture problems
result from a combination of these climatic factors
and many activities and situations inside and
outside the home.
Sources inside the home can result in significant
releases of water vapor (humidity). For example, the
water vapor produced by a humidifier could be
about 48 pounds in 24 hours; gas appliances
produce about 88 pounds for each 1000 ft5 of gas
burned; washing and rinsing an 8 ft x 10 ft room
produces about 2.5 pounds; drying 10 pounds of
clothes produces about 10 pounds; and 4 occupants
in the home produce about 3 pounds of water vapor
each day (Hedden, 1982);
As moisture is produced it can be present as a vapor
(gas), liquid, or solid. Water vapor travels through
the home by air movement and diffusion, and liquid
water travels by capillary action. This movement is
largely controlled by differences between pressure
inside of the house and outside of the house and the
movement of water vapor from an area of higher
pressure to an area of lower pressure,
Capillary action refers to the movement of liquid
water from a source through a porous material such
as soil. Capillary action can be an important route
of water vapor entry through basements and crawl
spaces. Diffusion is the direct movement of water
vapor through the building materials; it occurs as
interior sources contribute to the buildup of water
vapor and the interior pressure increases. Water
vapor is primarily transferred through air movement
caused by wind or temperature and pressure differ-
ences between the interior and exterior of the
structure.
During the winter, warm interior air may pass to
the outside through cracks and openings in the
building. If the warm, moist air comes into contact
with cooler surfaces, the water vapor will condense
onto the cooler surfaces (condensation). During the
summer when the outside air is warmer and moister
than inside air, the air flows into the house carrying
moisture with it. Wind can also cause pressure
differentials, and the downwind side of a house may
show more signs of moisture because water vapor is
being forced through this side.
The movement of moisture in, around, and through
the envelope of the house is a prime consideration in
the design and construction of the house. This is an
area that is especially important in the design of
energy efficient homes because of the relatively low
air exchange rates in these homes. If water vapor is
not controlled, many problems can result.
Too much water vapor can cause window sweating
when warm, moist air contacts cold surfaces. Warm
air holds more water vapor than cold air, and the
-------
Section 5
1AQ Reference Manual
water in the warm air will condense on the cold
surface as the air comes in contact with the window.
Even if a storm sash is used, problems can result. If
condensation appears on the inside window, the
storm sash may be leaking cold air which cools the
inner pane causing condensation; or there is simply
too much moisture in the house. If the outside sash
has condensation, the inside window is leaking
warm, moist air which condenses on the cold
exterior pane.
A problem which is not immediately obvious is
condensation which occurs inside walls. Condensa-
tion can occur in exterior walls without vapor
retarders or in those that have vapor retarders on the
cold side of the wall or on both the cold and warm
sides. If a home is uninsulated, water vapor is
released from warm interior air as it passes through
the building envelope, and if the temperature is
cold enough, this moisture freezes. Over the course
of the winter, the ice builds up and melts as the
weather warms. Over time, serious structural
damage can result. If a house has insulation (loose,
batt, or foam), but no vapor retarder, the same
process occurs. The insulation does not prevent the
moisture from passing through the envelope, and
water vapor will condense inside the wall and also
pass through the wood and lift paint off the surfaces.
(Lifting paint is, therefore, one sign of moisture
problems).
There must be sufficient humidity in the home to
prevent drying and cracking of wood and irritation
to mucous membranes, but it must be controlled to
prevent mold, mildew, and structural damage to
building components and furnishings. Striking a
balance between these two extremes can be difficult,
but it is not impossible. Most moisture problems
can be solved by minimizing unnecessary sources,
minimizing temperature differences, increasing air
circulation and ventilation, and altering the mois-
ture transfer rate with the use of vapor retarders.
« Controlling the source of moisture prob-
lems is usually a cost effective solution.
Strategies include fixing water leaks,
ducting clothes dryer exhaust outdoors,
reducing humidifer use, improving drain-
age, and using kitchen and bathroom
exhaust fans.
« Since condensation depends on temperature
differences, minimizing these can solve
some problems. Strategies include insulat-
ing metal window frames, insulating
heating and cooling system ducting,
improving heating patterns, and installing
a vapor retarder.
" The moisture transfer rate can be reduced
by weatherizing before insulating, sealing
all air leaks from the inside, using a vapor
retarder for interior surfaces and in crawl
spaces, using moisture resistant exterior
wood or waterproofing it, using waterproof-
ing on the exterior or interior of basement
walls, installing exterior drainage systems,
and eliminating any exterior moisture
accumulation.
• Air circulation and ventilation strategies
include venting moisture out of enclosed
spaces (using existing fans); using ceiling
fans to improve circulation; installing wall,
roof, and crawl space vents; installing heat
recovery ventilators; and installing whole
house fans and roof ventilators.
Installation of Vapor Retarders
The effectiveness of the vapor retarder is measured
in permeance (perms) of the material. One perm
equals one grain of water per square foot per hour
per unit vapor pressure difference. The lower the
perm rating of'a material, the better it is at reduc-
ing the transfer of moisture. For example, 6 mil
(1 mil = .001 inch) polyethylene (provides good
control) has a perm rating of 0.06 perm compared to
concrete, which has a rating of 3.2 perm (NCAT,
1983).
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IAQ Reference Manual
Section 5
The purpose of a vapor retarder is to keep warm,
moist air from coming in contact with surfaces that
are below the dew point of the water vapor (the
temperature at which condensation occurs). For this
reason, a vapor retarder must be located on the
warm side of the wall, floor, or ceiling, and it must
be tight co prevent the transfer of water vapor.
Conventional Retrofits
In the attic or ceiling, vapor retarders may be the
only way to prevent moisture problems if sufficient
ventilation cannot be provided. It is important to
install the vapor retarder carefully. Batt insulation
can be tightly stapled to the rafters; or in attics with
loose fill insulation, polyethylene can be cut into
strips and tightly fitted between the joists (Exhibit
5-4). Regardless of the type of installation, there
must be sufficient attic ventilation (cave, ridge, or
vent).
In both warm and cold climates, crawl spaces
carefully fitted with ground cover and floor vapor
Exhibit 5-4. Installation of a vapor retarder in the attk.
Asroid gaps which
increase the
potential for air
movement and
condensation or
fros!
Polyethylern
Vapor ittwdsr
Partiti
framing underneath
Ceiing Joists
Battens hold
polyethylene tight
agoimt framing
Ceiling
Polyethylene strips can be installed prior to loose-fill or blown-in attic insulation.
When insulating rafters,
take care to insure
ventilation occurs
One Inch
Minimum
far Ihkk ceiling insulation,
attk ventilation can occur
through vent troughs
Vent Trough
Insulation work should net Hock attic ventilation at the eaves.
SOURCE; NCATU983)
-------
Section 5
IAQ Reference Manual
retarders can prevent moisture problems. Ground
vapor retarders are installed over the soil and can be
held in place with weights or bricks; a more secure
method is to cover the retarder with a layer of sand.
Floor vapor retarders can also be added to provide
greater protection and insulation. The installation
differs depending on the climate. In cold climates,
the vapor retarder is installed on the warm side of
the floor; in warm climates, the warm side is the
bottom of the floor (Exhibit 5-5).
The most cost effective strategy for minimizing
moisture problems in walls in retrofit installations
is to seal air leakage points from the inside and
Exhibit 5-5. Installation of a vapor retarder in the crawl space or floor.
Vapor retarder
face inside
Foundation
Vapor retarder
face outside
Foundation
Insulation installed
with vapor retard-
face upward
ler
Cold Climate
Sand cover
to protect
vapor
retarder in
traffic
areas
' 4 to 6 inches of
edge rolled up
Ground cover vapor
retarder held in place
with bricks
Insulation installed
with vapor retarder
face downward
Hat Climate
' 4 to 6 inches of
edge rolled up
Sand cover
<#fc£v>'.'' v'-.'.: to protect
" vapor
retarder in
traffic areas
Ground cover vapor
retarder held in place
with bricks
SOURCE: NCAT(1983)
-------
IAQ Reference Manual
Section 5
outside of the wall. After ensuring that the leakage
points have been sealed, a vapor retarding paint can
be applied to the wall surfaces to provide some
resistance to water vapor diffusion. In some in-
stances it may be necessary to install a vapor retarder
on interior walls. :
Weeping windows should be weatherstripped and
caulked inside first, and then weatherproofed
outside. If an interior-side storm window is used, it
must be sealed tightly around all edges. If an outer
storm window is added, weep holes at the bottom
are recommended. In very cold climates, triple-
glazing is recommended.
Vaipor Retarders In New Construction
When moisture problems are encountered in new
construction, problems are sometimes due to an
improperly installed retarder. Exhibit 5-6 shows
elements of a properly installed retarder. Any holes
or other leakage points will allow moisture to be
transferred. Seams must be carefully overlapped and
sealed, gaps around windows, doors, floor/ceiling/
wall joints, and electrical and plumbing installa-
tions must be sealed. This can be done with
polyurethane foam and other sealants and products.
Ventilation
Providing adequate ventilation to the living space
can solve and prevent many indoor air quality
problems. Adequate ventilation is necessary to
maintain comfort and to prevent the buildup of
indoor contaminants, moisture accumulation, and
odor problems. Ventilation requirements are given
in model and local building codes for conditioned
and unconditioned spaces and combustion appli-
ances (Lesson 7 of the Learning Module and Sections
7 and 8 of the Reference Moaned).
Ventilation requirements can be expressed in cfm
(Ips) per person or cfm (Ips) per unit area of floor
space. ASHRAE recommends outdoor ventilation
rates of 0.35 ach but not less than 15 cfm (7.5 Ips)
per person in residential construction (includes
single and multiple units) (ASHRAE, 1989).
ASHRAE does not address ventilation requirements
of combustion appliances or unconditioned spaces;
these are given in building codes and codes devel-
oped by professional associations for specific appli-
ances.
Attic and Crawl Space Ventilation.
Ventilation is needed in the attic during the
summer to remove excess heat (temperatures of
15 Or or more can be reached) and during the
winter to remove excess humidity that moves
through the ceiling and condenses in the insulation
of a cold attic. Attics can be ventilated using
natural "or mechanical vents. Natural vents take
advantage of the natural flow of air while mechani-
cal ventilation relies on electrically powered exhaust
fans.
The needed area for ventilation is determined by the
area of the attic space, climate, and the presence of a
vapor retarder in the attic. Four types of vents are
generally used to provide natural ventilation in
attics. Ridge vents provide a continuous opening
along the ridge line of a pitched roof. Air can pass
through, but rain and snow cannot enter the attic.
Roof vents are rectangular or circular openings at
intervals along the flat portion of the roof. Under
eaves or soffit vents are installed under the eaves in
discrete or continuous vents. Gable end vents are
located in the gable and they can be rectangular,
round, or triangular openings.
A ridge vent plus soffit vent configuration is
considered to be the best system for naturally
ventilating the attic. A roof and gable-end system
are typically used in older homes (Exhibit 5-7).
Houses with cathedral ceilings require a continuous
air space above the insulation with continuous eave
and ridge vents or individual vents in the eave as
well as near the ridge for each'rafter space.
The second most effective way of providing natural
ventilation in roofs is a combination of turbine
ventilators and soffit vents. Turbine ventilators that
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Section 5
IAQ Reference Manual
Exhibit 5-6. Installation of a continuous vapor retarder.
Ceiling vapor
retarder (apt
over wall vapor
retarder
Wall Framtng
Exterior
Shta thing
Wall Cavity
Insulation
Wall Vapor
Retarder
Caulk Under
Bottom Plate
Woll vapor
retarder overlaps
floor vapor retarder
approximately16 inches
Flap seals to
wal vapor
retordre
Staple
through
nylon
reinf. tape
Ceiling Joists
Ceiling Insulation
Ceiling Covering
Ceiling Vapor Retarder
WallCovering
.Finished Fbor
Subioor
Fbor Vapor
Retarder
•Window Frame
Sealant
& Stapled
Doybfe-fold technique for
wrapping window frame
with vapor retarder
Vapor retarder sealed
at overlap on framing
stud with acoustical
caulk.
Note;
Caulk window
frame prior
to wrapping
Vapor retarder sealed
to low-perm rigid
insulation at interior
partition joint (similar
detail at ceiling)
Technique for sealing
vapor retarder without
using window wrap,
House Wire
Framing Stud
Commercial
"Poly Pan"
Electrical Box
Acoustical
Sealant
Sealing vapor retarder
seams and overlaps
(All vapor retarders should be sealed with a flexible, non-hardening,
acoustical sealant. Pay special attention to seal window and door frames.
Ail penetrations such as outlet boxes, plumbing and electrical lines, etc.)
Sealing vapor retarder at
electrical outlet box
Note;. Put a bead of acoustical
sealant on nail head and house
wire penetration through
"poly pan"
SOURCB-. NCAT(1983)
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IAQ Reference Manual
Section 5
Exhibit 5-7. Attic ventilation strategies.
Fiat Roofs
Vents shoudl ba placed
evenly at the eaves.
Gable Roofs
Half of vent area
should be in the gables
or of the ridge vent,
with the other half at
the cornice or eaves.
Hip Roofs
Vent area should be
equally divided between
eaves and ridge with all
vents spaced evenly.
Placement of Attic Vents
-*m
H3k
*~~.
/k
-%k]5
Wind
Wind
Poor
Avoid single
vents only. Air
at roof peak is
not vented out.
Gable end and soffit vents.
Air enters of soffit and gable
and exits at opposite gable.
_L
*-,
i
_L
^C| Q^ Q/
\
i
^m\T}\
V, ™ S
Good
Roof cap and soffit vents.
Air enters ot soffit and exits
at roof cap and opposite soffit.
Wind
Best
Continuous ridge vent and
soffit vents. Air enters at
soffits and exits at ridge vent.
Ventilation Strategies to Reduce Trapped Air In Attics
SOURCE: NCAT(1983)
are 12 and 14 inches in diameter are typically used,
and they ventilate about 600 ft2 and 700 ft2,
respectively (Hedden, 1982),
Powered ventilation, in conjunction with natural
airflow can also provide adequate ventilation; the
fans can be installed in gables or on the roof. Whole
house fans, which are installed in the ceiling, draw
air in through windows and exhaust the air into the
attic and out the vents. There must be enough vent
area to exhaust the gases (1 ft2 net free area for each
750 cfm of fen capacity) [Hedden, 1982]. It is
important for any other ventilating fins (including
kitchen and bathroom fens) to be exhausted directly
outside and not into the attic space, otherwise air
will be forced from the attic back into the living
space.
Sizing attic vents: The area needed for venting
depends on the area to be vented, location, presence
-------
Section 5
IAQ Reference Manual
of a vapor retarder, and the type of vent obstruc-
tions. More vent area is needed if a vapor retarder is
not used. Based on moisture control requirements,
NCAT (1983) recommends the following procedure
for determining the minimum area required for
attic ventilation:
1) measure the area to be ventedj
2) multiply the area by 0,0067 if there is no
vapor retarder or 0.0034 if there is a vapor
retarder in place;
3) multiply the area obtained in. step two by
one of the sizing factors in Exhibit 5-8 for
the type of vent covering to obtain the total
gross vent area needed; and
4) Determine the proper vent location
(Exhibit 5-7).
The CABO code is less stringent and specifies a net
free ventilating area of at least 1/150 of the area of
the space to ventilate unless other conditions are
met {CABO, 1989). This area may be reduced to
1/300, providing that at least 50 % of the required
area is provided by ventilators located in the upper
portion of the space to be ventilated at least 3 feet
above cave or cornice vents. If a vapor retarder
having a transmission rate less than 1 perm is
installed on the warm side of the ceiling, the net
free cross-ventilation, area must be at least 1/300 of
the space ventilated (CABO, 1989).
Sizing crawl space -vents: The NCAT recommen-
dation for moisture control in the crawl space is
similar to the procedure for attics. The area to be
ventilated is measured, and whether or not there is a
ground cover in place, the area is multiplied by
0.0067 (or 1/150). Then this area is multiplied by
one of the factors in Exhibit 5-8.
The CABO code requirements potentially result in
less ventilating area whether or not a ground cover
is in place, but the difference is particularly greater
Exhibit 5-8. Sizing factors for different
went coverings.1
TYPE OF VINT COVERING
FACTOR
1A inch mesh hardware cloth 1
Vs inch (8 inch mesh screen) VA
No, 16 mesh insect screen (with or
without plain metal louvers) 2
Wood louvers and 1A inch mesh
hardware cloth2 2
Wood louvers and VB inch mesh screen 254
Wood louvers and No. 16 mesh insect
screen 3
1 la crawlspace ventilators, screen openings should not be larger
than 1/4 inch; ia attic spaces, no larger than. 1/8 inch.
2 IF metal lowers have drip edges that reduce the opening, use
the same ratio as shown for wood louvers.
SOURCE: NCAT (1983)
if a vapor retarder is in place. The CABO code
specifies that the number of openings should not be
less than 1 ft2 for each 150 ft2 of crawl space area,
and there should be one opening within 3 feet of
each corner of the building unless the building
qualifies for an exemption. The CABO code allows
the openings to be omitted on one side. Another
exemption is that the total required area can be
reduced to 1/1500 of the under-floor area when
there is an approved ground floor vapor retarder and
one opening is within 3 feet of each corner of the
building (the vents can have operable louvers). In
addition to these exemptions, ventilation openings
can be vented to the interior of buildings where
warranted by climatic conditions.'
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IAQ Reference Manual
Section 5
S.2. EVALUATION OF AIR CLEANERS
J.he evaluation of air cleaners requires
information on the efficiency, airflow resistance,
dust-holding capacity, effect of dust retention on
efficiency and on resistance, and the maintenance
which is required to maintain the air cleaner at top
efficiency. There is no single test which adequately
characterizes all filters or air cleaners. Testing is
complex and there are many factors that affect the
perfof mance of air cleaners in actual use.
Ideally, testing procedures should approximate the
conditions and contaminant concentrations which
can be expected to exist during actual use of the
devices. The use of standardized tests do allow the
performance of different air cleaners and filters to be
compared.
Test methods for evaluating air cleaner performance
are contained in ASHRAE Standard 52-76
(ASHRAE, 1976) and Military Standard 282 (U.S.
DOD, 1956), which is also referenced by ASHRAE.
These tests are used to evaluate in-duct systems
(filters and electronic air cleaners). Recently, the
American National Standards Institute (ANSI) and
the Association of Home Appliance Manufacturers
(AHAM) have developed a standard for evaluating
portable air cleaners.
A useful publication, Residential Air-Cleaning
Devices: A Summary of Available Information, which
summarizes the available information on residential
air cleaners, is available from the Public Information
Center, Environmental Protection Agency,
Washington, DC. 20460.
ASHRAE Test Methods
The ASHRAE Standard 52-76 test method specifies
the evaluation of in-duct air cleaners based on
collection efficiency (for total mass and by particle
size), pressure drop across the filter, and dust-
holding capacity.
Fractional Efficiency Or
Penetration Test
This test is used for high efficiency filters (efficien-
cies greater than 98%) which are used in clean
rooms and nuclear applications. The Thermal DOP
(di-octyl phthalate or bis-C2-ethylhexyl] phthalate)
test is conducted by feeding a cloud of uniform
particles (0.3 micron DOP) into the filter and
determining the percentage of particles removed by
the filter (U.S. DOD, 1956). The concentration of
particles upstream and downstream of the filter is
measured using a light-scattering photometer or
condensation nuclei counter. Results are usually
expressed in percent penetration (equal to 100
minus the percent efficiency) rather than efficiency
because HEPA filters are almost 100% efficient.
Weight Arrestan.ce Test
The weight arrestance test measures the mass
collection efficiency of a filter based on a standard
synthetic dust of various particle sizes. The syn-
thetic dust specified by ASHRAE (1976) is com-
posed of'12% standardized dust fine, 23% Molocco
black, and 5% cotton linters. The synthetic dust
cloud has a particle size range that is larger than
typical atmospheric dusts. This test is appropriate
for evaluating low efficiency filters which remove
larger particulates. These filters are used in residen-
tial furnaces, air-conditioning systems, or as up-
stream filters for other air cleaning devices. The test
is not appropriate for evaluating the removal of
respirable particulates.
Dust Spot Efficiency Test
The dust spot efficiency test (ASHRAE, 1976)
measures how well a filter reduces the soiling of
residential interiors. The test is conducted by
passing untreated atmospheric air through filter
paper targets and measuring the difference in light
transmittance before and after air is passed through
the filter being tested. The spot efficiencies are
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Section .5
IAQ Reference Manual
taken at intervals allowing the efficiency to be
evaluated as a function of filter loading. This test is
most appropriate for determining the efficiency of
high to medium efficiency filters and electronic air
cleaners.
Dust-holding Capacity Test
Dust-holding capacity is the amount of a particular
type of dust that an air cleaner can hold before its
efficiency drops significantly as a result of the
resistance imposed by the collected dust. Airflow
resistance, or simply resistance, is the static pressure
drop across the filter at a given airflow rate, and the
term pressure drop is used interchangeably with
resistance.
Because of filter variability, ASHRAE's test
(ASHRAE, 1976) determines that the dust holding
capacity has been reached based on the following
criteria: 1) when the maximum pressure drop
specified by the manufacturer or when two consecu-
tive measures of arrestance are less than 85%, or 2)
when one value is equal to or less than 75% of the
maximum arrestance.
Efficiency Ratings of Filters
Control strategies for indoor air contaminants have
recognized the need for efficiency versus size data for
submicron particles. Manufacturers have attempted
to respond to this need by categorizing the removal
efficiencies of filters based on particle size. How-
ever, these data are difficult to interpret because
there is no standard method for determining the
efficiency of air cleaners as a function of particle size.
Exhibit 5-9 summarizes the performance of viscous
impingement and dry media filters (ASHRAE,
1988). Note that the percent arrestance, percent
atmospheric dust spot efficiency, and percent DOP
efficiency do not correlate with one another. For
example, a filter with a 92% arrestance may be
# 20% efficient based on the dust spot test. This
lack of correlation is explained by the types of
particles that each test measures.
Exhibit 5-9, Comparative performance of
viscous impingement and dry
media filters.
HKiW«IESTANCE!«HHA£SiimdodS2-MtSTf>IBHC»)
1 M K SO ?0 91 97 98 »
I %MM0!DUSrSFOrEFFICI£NW(ASM!«Stand«d52-?
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IAQ Reference Manual
Section 5
Potential applications of these filters can be summa-
rized in terms of efficiency ratings from the
ASHRAE tests. Based on the atmospheric dust spot
test to evaluate efficiency, the following applications
and limitations apply (ASHRAE, 1979).
Efficiency Rating <10%: applications include
window air conditioners; protection of heat ex-
changer from lint accumulations; relatively ineffec-
tive on smoke, settling dust, and pollen.
Efficiency Rating of 10% to 20%: applications
include window air conditioners, packaged air
conditioners, domestic warm air heating; effective
on lint; somewhat effective on common ragweed
pollen; relatively ineffective on smoke and staining
particles.
Efficiency Rating of 20% to 40%: applications
include air conditioners, domestic heating, central
systems; at 20% efficiency, fairly effective on
ragweed pollen; relatively ineffective on smoke and
staining particles; effective as a prefilter for final
cleanup filters for clean room; same applications at
40%, but with greater degree of effectiveness;
somewhat effective in removing smoke and staining
particulates.
Efficiency Rating of 40% to 60%: applications
include building recirculated and fresh-air systems;
domestic heating and air-conditioning; use as
prefilters to high efficiency types; effective on finer
airborne dust and pollen; reduce smudge and stain
materially; slightly effective on fume and smoke;
ineffective on tobacco smoke at 40%; slightly
effective on tobacco smoke at 60%.
Efficiency Rating of 60% to 80%: 60% includes
same uses as for 40%, but with better effectiveness;
80% used in hospitals and other controlled areas;
effective on all pollens, majority of particles causing
smudge and stain, fume, coal and oil smoke;
partially effective on tobacco smoke; some types
reasonably effective on bacteria, but filters (espe-
cially in large buildings) can become a medium for
growth.
Efficiency Rating of 80% to 95%: applications
include hospital surgeries, pharmaceutical prepara-
tion areas, and other controlled areas; very effective
on particles causing smudge and stain, coal and oil
smoke and fume; highly effective on bacteria but
filters (especially in large buildings) may become a
medium for growth; quite effective on tobacco
smoke.
Efficiency Rating > 95%: applications include
hospital surgeries, intensive care wards, clean rooms,
pharmaceutical packaging; excellent protection
against bacteria, radioactive dusts, toxic dusts, all
smokes and fumes; filters above 98% efficiency are
generally rated using the DOP test method (Mili-
tary Standard 282).
ANSI/AHAM Test Methods
The ANSI/AHAM AC-1-1988 standard rates
(AHAM, 1988) the "clean air delivery rate" (CADR)
of portable cleaners. The CADR is a measure of
how much air a unit is delivering. The delivery of
"fresh" air is given in cfm. The fresh air is not
100% fresh because some contaminants may not be
removed from the airstream. A cleaner with a
CADR rating of 100 can reduce the concentration of
a given contaminant equivalent to reductions
achieved by adding 100 cfm of fresh air.
Air cleaners with CADR certifications based on the
ANSI/AHAM standard are evaluated in terms of the
removal of dust (10 to 350 CADRs), tobacco smoke
(10 to 300 CADRs), and pollen (25 to 400
CADRs).
Exhibit 5-10 shows a comparison of the removal of
smoke, dust, and pollen for portable units as a
function of CADR and room size, as estimated by
AHAM. These figures are representative of air
cleaning results based on tests in an airtight room,
and they should only be used as guides. At higher
CADRs, the importance of fallout from gravity
becomes less important.
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Section 5
IAQ Reference Manual
Exhibit 5*10. Estimated percentage of particle removal
and room size.
for portable
PERCENTAGE OF PARTICLES
Room Size
5x6
9x12
12x18
18x24
20x30
CADR
10
40
80
40
80
150
80
150
300
350
450
150
300
350
450
300
350
450
ACa
49%
89%
95 %
53%
76%
89%
53%
74%
89%
—
—
51%
73%
—
—
63%
—
—
Smoke
(20 min)
Tb
68%
97%
100%
71%
89%
98%
71%
87%
97%
—
—
70%
87%
—
—
79%
—
—
ACa
49%
88%
95%
52%
75%
89%
52%
73%
—
91%
—
50%
—
77%
—
67%
—
Dust
(20 min)
Tb
70%
98%
100%
72%
89%
98%
72%
88%
—
99%
—
71% '
—
91%
—
84%
—
air cleaners by CADR
REMOVED
Pollen
(10
ACa
57%
75%
24%
40%
58%
24%
38%
—
—
69%
23%
: •
50%'-
—
40%
min)
qpb
93%
99%
78%
86%
94%
78%
85%
—
—
97%
78%
—
—
91%
-
:
86%
Removal by the air cleaning device
b
Removal by ait cleaning device plus natural settling
NatK Estimates ignore the effect of incoming air. For smoke and, to a lesser extent, dust, the more drafty the room, the smaller the
CADR required. For pollen, which enters from outdoors, a higher CADR. is needed in a drafty room.
SOURCE; U.S. EPA (1990). Adapted from Association of Home Appliance Manufacturers (AHAM). 1990. AHAM Consumer Guide for
Room Air Cleaners. AHAM, 20 North Wacker Drive, Chicago, IL 60606. Used with permission of AHAM.
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IAQ Reference Manual
Section 5
Exhibit 5-11 compares the amount of time required
to achieve 90% removal of airborne particles based
on CADRs. As a general rule the higher the
CADR, the less time needed to remove the same
amount of contaminants from a room of identical
size because all things being equal, the more air a
cleaner processes, the faster it can remove contami-
nants.
5.3 PUBLIC AND PRIVATE SECTOR
ORGANIZATIONS INVOLVED IN
INDOOR AIR QUALITY ACTIVITIES
Oeveral public and private sector organiza-
tions have activities associated with the control of
indoor air quality. Exhibit 5-12 lists the activities
of public interest organizations. Exhibit 5-13
identifies activities of professional and trade organi-
zations in the private sector.
Exhibit 5-11. Minutes to achieve 90% removal of airborne particles.1
DUST
SMOKE
POLLEN
No air cleaner
operating
128
144
22
CADRs—air cleaner
operating
25 49
40 36
80 21
150 12
300 6
51
37
21
12
6
17
15
12'
8
5
'includes removal by fallout from natural forces
SOURCE: Association of Home Appliance Manufacturers {AHAM). 1990. AHAM Consumer Guide for Room Air Cleaners. AHAM, 20
North Wacker Drive, Chicago, IL 60606. Used with permission.
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Section 5
IAQ Reference Manual
Exhibit 5-12. Public interest organization indoor air activities*
ORGANIZATION
ACTIVITIES
American Lung
Association (ALA)
Americans for Nonsmokers'
Rights (ANR)
American Public Health
Association (APHA)
Consumer Federation of
America (CFA)
Consumers Union (CU)
Developed a slide-tape presentation on
indoor air pollution
Issued a position paper on indoor air pollution
Distributes information sheets on indoor air
pollution hazards
Aggressive "Stop Smoking" campaign
Develops and distributes model clean indoor air
legislation
Conducting study on validity and prevalence of
multiple chemical sensitivity
Publishes a model housing code that includes
indoor air quality
Testifies before Congress about indoor air
concerns
Publishes quarterly newsletter, Indoor Air
News
Convened EPA-cosponsored IAQ conferences,
1986-1988
Publishes product testing results in Consumer
Reports - recently tested air cleaners, unvented
kerosene heaters, air-to-air heat exchangers, and
radon detectors
National Coalition Against the
Misuse of Pesticides (NCAMP)
National Institute for Building
Sciences (NIBS)
Tobacco-Free Young America
Project (TFYA)
Publishes Chemical Watch fact sheets
Testifies before Congress about pesticide issues
Improves building regulatory environment
and facilitates the introduction of building
technology
Prepared report on building standards related to
indoor air
Provides guidance/information, conducts
workshops/conferences on building IAQ issues
Acquires and disseminates information
on state and local smoking regulations
SOURCE: Adapted from U.S. EPA (1989)
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IAQ Reference Manual
Section 5
Exhibit 5-13. Professional and trade association indoor air activities.
ORGANIZATION
ACTIVITIES
Air-Conditioning Contractors of
America (ACCA)
Air-Conditioning and Refrigeration
Institute (ARI)
Air and Waste Management Association
(AWMA)
American Conference of Governmental
Industrial Hygienists (ACGIH)
American Gas Association (AGA)
American Industrial Hygienists
Association (AIHA)
American Insurance Association
American Plywood Association
(APA)
American Society of Heating, Refrigerating,
and Air-Conditioning Engineers (ASHRAE)
Publishes technical manuals on air-conditioning
design, installation, and maintenance
Rates performance of air-to-air heat exchangers,
filter equipment assemblies, and refrigeration
systems
Convenes a standing committee on indoor air
quality
Convenes indoor air sessions at AWMA annual
meetings
Convenes specialty conferences on indoor air-
related issues
Develops indoor air quality guidelines for
industrial exposures
Convenes a committee on bioaerosols
Publishes a manual on air sampling instrumen-
tation
Develops standards addressing gas leaks and
combustion product emissions
Convenes an Indoor Environmental Quality
committee
Publishes industrial hygiene guidance docu-
ments
Monitors environmental issues for liability
implications to member insurers
Recommends practices for handling preserva-
tive-treated wood products, using chlorpyrifos,
and applying subfloor vapor barriers
Develops "Ventilation for Acceptable Indoor
Air Quality," Standard 62-1989
Develops thermal comfort and energy conserva-
tion standards
Publishes technical information
(continued next page)
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Section 5
IAQ Reference Manual
Exhibit 5-13. Professional and trade association indoor air activities (tontinued).
ORGANIZATION
ACTIVITIES
American Society of Testing and Materials
(ASTM)
American Institute of Architects
(AIA)
Building Owners and Managers Association
(BOMA)
Business Council on Indoor Air
Chemical Specialties Manufacturers Association
(CSMA)
Chemical Manufacturers Association
(CMA)
Electric Power Research Institute
(EPEI)
Gas Research Institute
(GRD
Hardwood Plywood Manufacturers
Association (HPMA)
• Convenes a technical committee on sampling
and analysis of atmospheres
• Develops test methods for atmospheric analysis
• Publishes technical information
• Producing an environmental resource guide to
help architects be more responsive to environ-
mental concerns, including IAQ
• Provides information on all aspects of building
ownership, operation and maintenance functions
• Provides guidance to building owners and
managers on prevention and mitigation of indoor
air quality problems
* Provides information to members on indoor air
trends and government and legislative activities
on indoor air
« Develops and represents positions on indoor air
quality before government and legislative
bodies to insure that policy is based on accurate
and comprehensive information
• Represents companies involved in the formula-
tion of household and institutional care products
« Develops and represents policy positions before
various regulatory and legislative bodies
• Represents chemical manufacturers before
various public and private sector bodies
• Sponsors research of indoor air quality as
it relates to energy consumption and HVAC
systems
• Sponsors research of indoor air quality concerns
of the natural gas industry
• Licenses manufacturers of burner inserts for
nitrogen oxide emission reduction
* Developed a voluntary standard for
formaldehyde emissions from wood products
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IAQ Reference Manual
Section
Exhibit 5-13. Professional and trade association indoor air activities (tontinued).
ORGANIZATION
ACTIVITIES
Home Ventilation Institute
(HVI)
National Association of Home
Builders (NAHB)
National Association of Realtors (NAR)
National Center for Appropriate Technology
(NCAT)
National Environmental Health Association
(NEHA)
National Plywood Association
(NPA)
Public Health Foundation
(PHF)
Service Employees
International Union
Sheet Metal and Air-Conditioning National
Association (SMACNA)
Tobacco Institute
SOURCE: Adapted from U.S. EPA (1989)
Develops standards for heat recovery ventilators
Supports research of building components and
operating parameters which affect indoor air
quality
Conducts an annual survey of construction
materials
Provides technical assistance to home builders
Supports comprehensive federal legislation that
increases the role of government in IAQ
research and informative dissemination
Committed to a new program of education on
IAQ for its membership
Publishes Moisture and Home Energy Conservation
Publishes technical information on energy
conservation
Provides grants and technical assistance on
energy-related topics
Provides information to state and local environ-
mental health officials on indoor air
Co-sponsored the Indoor Air Quality Learning
Module and Reference Guide
Developed a voluntary standard for formalde-
hyde emissions from particleboard
Developed a directory of state indoor air
contacts and surveyed state indoor air quality
programs
Surveys and investigates indoor air
problems of public service workers, educates
members and promotes legislative and regula-
tory solutions
Provides membership with education
through manuals and a home study course
Conducts programs to preserve the rights of
smokers and member companies against unwar-
ranted government restraint
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Section 5
IAQ Reference Manual
REFERENCES
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers (ASHRAE). 1976. Method of Testing Air-
Cleaning Devices Used in General Ventilation for Removing
Paniculate Matter, ASHRAE Standard 52-76. ASHRAE: New
York, NY.
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers (ASHRAE), 1979- 1979 AHRAE Handbook
and Product Directory. Equipment, ASHRAE: Atlanta, GA.
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers (ASHRAE), Inc. 1988. 1988 ASHRAE
Handbook. Equipment. ASHRAE: Atlanta, GA.
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers (ASHRAE), Inc. 1989. Ventilation for
Acceptable Indoor Air Quality. ASHRAE Standard 62-1989.
ASHRAE; Atlanta, GA.
Association of Home Appliance Manufacturers (AHAM). 1990.
"Consumer guide for room air cleaners," AHAM: Chicago, IL,
Association of Home Appliance Manufacturers (AHAM). 1988.
American Standard Method far Measuring Performame of Portable
Household Electric Cord-Connected Roam Air Cleaners, ANSI/
AHAM AC-1-1988. AHAM: Chicago, IL
Council of American Building Officials (CABO). 1989. CABO.
One and'Two Family Dwelling Code. CABO: Falls Church, VA.
Hedden, J. 1982. Heating, Coo/ing, Ventilation, Solar and
Conventional, Creative Homeowner Press: Upper Saddle River,
NJ.
Mann, P.A. 1989. Illustrated Residential and Commercial
Construction. Prentice Hall: Englewood Cliffs, NJ.
National Center for Appropriate Technology (NCAT). 1983.
Atoisture and Home Energy Conservation, NCAT: Butte, MT.
U.S. Department of Defense (DOD). 1956. filter Units,
Protective Clothing, Gas Mask Components and Related Products:
Performance-test Methods. MH-STD-282. U.S. DOD:
Washington, D.C.
U.S. Environmental Protection Agency (EPA). 1989. Report to
Congress on Indoor Air Quality, Vol. II. Assessment and Control of
Indoor Air Pollution. U.S. EPA, 400/1-89/001C. U.S. EPA,
Office of Air and Radiation: Washington, DC.
U.S. Environmental Protection Agency (EPA). 1990. Residen-
tial Air-Cleaning Devices. A Summary of Available Information,
U.S. EPA, Office of Atmospheric and Indoor Air Programs:
Washington, DC.
U.S. Department of Health, Education, and Welfare (DHEW).
1976. Basic Housing Inspection. HEW (CDC) 80-8315. U.S.
DHEW, Public Health Service: Washington, DC.
Wadden, R.A. and P.A. Scheff. 1983. Indoor Air Pollution.
John Wiley & Sons: New York, NY.
-------
SECTION 6.
INDOOR AIR QUALITY
MEASUREMENTS
Section 6.1 contains a detailed listing
of indoor air monitoring equipment
which can be used for personal or area
monitoring of various contaminants.
Section 6.2 discusses terms related to
the measurement process, and Section
6.3 provides general information to be
used in collecting representative
samples and determining proper
sampling sizes. Section 6.4 outlines
basic considerations for calibrating
field equipment and provides
examples of forms that could be used
for calibrations. Finally, Sections 6.5
and 6.6 provide overviews of passive
samplers and measurement methods
for air exchange rates, respectively.
Table of Contents
Section 6.1. Indoor Air Quality Sampling Methods 143
Section 6.2. Accuracy, Precision, and Related Terms 168
Section 6.3. Representative Sampling 170
Section 6.4. Calibration 172
Section 6.5. Passive Samplers 180
Section 6.6. Air Exchange Rates 181
list of Exhibits
Exhibit 6-1. Collection and analytical methods for
quantitative monitoring of some
contaminants. 146
Exhibit 6-2a. Commercially available indoor air
monitoring equipment. 147
Exhibit 6-2b. Identification codes for methods in
Exhibit 6-2a. 155
Exhibit 6-2c. Identification codes for manufacturers
in Exhibit 6-2a. 156
Exhibit 6-3. Battery-powered personal air samplers. 159
Exhibit 6-4. Properties of filters used in particulate
sampling. 160
Exhibit 6-5. Some storage properties of gases in
plastic bags. 163
Exhibit 6-6. Limitations of selected solid adsorbents. 164
Exhibit 6-7. Sources for testing and calibration
procedures applicable to indoor air quality
sampling. 165
(continued next page)
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Section 6 IAQ Reference Manual
Exhibit 6-8. National Institute of Standards and
Technology (NIST) Standard Reference
Materials (SRMs) for the calibration of
instruments and procedures utilized in
air quality analysis. 166
Exhibit 6-9. Precision and accuracy. 169
Exhibit 6-10. Example calibration or audit form for a
direct reading carbon monoxide or
carbon dioxide monitor. 176
Exhibit 6-11. Different types of airflow meters. 177
Exhibit 6-12. Sample rotameter calibration form. 178
Exhibit 6-13. Calibration using the soap-bubble meter. 179
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IAQ Reference Manual
Section 6
6.1. INDOOR AIR QUALITY SAMPLING
METHODS
Analytical Methods
irarticle and aerosol detectors and gas and
vapor detectors were introduced in Lesson 6 of the
Learning Module. Additional information on gas and
vapor detectors follows:
Gas and Vapor Detectors
In general, there are seven analytical methods that
can be applied to the analysis of gases and vapors
(Nader, Lauderdale, and McCammon, 1983). These
methods can be incorporated into direct reading
field instruments or laboratory-based instruments
and techniques.
Electrical methods are those in which a sensor
responds to chemical and/or physical properties of
the contaminant so that the output of the sensor is
related to the concentration of the contaminant,
Electrical methods include conductivity, potentio-
metric, coulometric, and ionization detectors.
These methods can be used for many contaminants
including carbon monoxide, sulfur dioxide, oxygen,
formaldehyde, ozone, and oxides of nitrogen.
Electromagnetic methods are those in which
electromagnetic radiation (in the form of ultraviolet,
visible, or infrared radiation) is scattered or absorbed
by a contaminant and the energy changes are related
to contaminant concentrations. Contaminants
which can be analyzed using these methods include
carbon monoxide, carbon dioxide, hydrocarbons,
and a variety of organic chemicals.
Cbemi-electromagnetic methods rely on a chemical
reaction which is detected through the measurement
of electromagnetic radiation. One of the most
widely used methods is colorimetry in which a
contaminant gas is collected and reacted with a
reagent to form a unique colored chemical. The
absorption or transmittance of visible light from a
source is measured by a detector to determine
contaminant concentrations. Ultraviolet and
infrared light sources can also be used. Additional
chemi-electromagnetic techniques are photometric
(chemiluminescent) methods, which involve the
generation and release of radiation followed by
detection using photometric techniques. These
methods can be used to analyze sulfur dioxide,
carbon monoxide, oxides of nitrogen, formaldehyde,
and a variety of organic chemicals.
Thermal methods can be used to detect contami-
nants based on conductivity or combustion or to
desorb contaminants from a substrate so they can be
further analyzed using other methods such as
chromatography. These instruments can be used to
detect carbon monoxide, carbon dioxide, and
combustible gases.
Gas chromatography is a technique which can
separate complex mixtures of contaminants into
individual components. The components of the
mixture will migrate differentially as they are
carried by a gas (carrier gas) through a porous
column which contains a soptive medium. As the
components are separated they will emerge from the
column at a unique time, and they can be identified
by different types of detectors (thermal conductiv-
ity, flame ionization, flame photometry, or electron
capture).
Gas chromatography can be very useful when
coupled with passive or active collection systems.
Portable direct reading chromatographic analyzers
are also available. These instruments can detect a
broad range of organic chemicals. They are
equipped with internal calibrators and libraries
which are used to identify unknown contaminants.
These devices must be evaluated carefully to ensure
that they will be able to detect contaminants in the
lower ranges typically encountered in nonindustrial
environments.
Magnetic methods include mass spectroscopy and
paramagnetic analyzers. Mass spectroscopy is a
technique which is used in conjunction with gas
chromatography to analyze a variety of contami-
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Section 6
IAQ Reference Manual
nants after they have been collected using active or
passive methods. Mass spectroscopy classifies
Ionized molecules, which have been deflected by a
magnetic field, according to their mass and charge.
Very small samples can be analyzed, and the method
is specific.
Paramagnetic analyzers are magnetic analyzers
which allow oxygen to be detected under the
influence of a magnetic field.
Radioactive detection methods are based on
radioactive decay and the release of energy (alpha
and beta particles; gamma rays) from radioactive
contaminants. Several different types of instru-
ments are available for measuring radon and other
radioactive contaminants.
Sampling Methods and Instruments
A list of sampling methods for individual contami-
nants is provided in Exhibit 6-1. Exhibit 6-2a
provides a summary of some of the currently
available instrumentation along with various
characteristics of the instruments. The listing is the
result of a survey of vendors which was conducted
by the National Environmental Health Association
and the School of Public and Environmental Affairs
during 1987 and 1988 (Deal and Ritchie, 1988).
The list is not inclusive since there were vendors
who did not respond to the survey. The listing
reflects those methods and equipment reported by
the vendors at the time of the survey.
Products that are listed met two criteria for inclu-
sion. First, the products are either portable or
personal equipment (not stationary). Second, lower
detectable limits, sampling ranges, and sampling
flows (if applicable) are suitable for detecting
commonly occurring indoor concentrations of
contaminants.
Sampling equipment is based on several different
analytical methods which are abbreviated in the
listings of equipment. Exhibit 6-2b provides the
abbreviation for each method and a corresponding
brief explanation of the method.
The manufacturer's code number is given in paren-
theses following each product. A key to the manu-
facturers, their corresponding code numbers, and
the products they manufacture is provided in
Exhibit 6-2b. Each product listed in Exhibit 6-2a
includes nine categories of information .about the
product. These include: 1) Method; 2) LDL/Range;
3) Sampling Rate; 4) Training/Maintenance; 5)
Price; 6) Personal/Portable; 7) Power; 8) Weight;
and 9) Dimensions. These categories were selected
for comparison purposes because of their usefulness
in evaluating specific sampling needs.
Method refers to the sampling method employed by
the product; a listing of the methods and corre-
sponding abbreviations is given in Exhibit 6-2b.
LDL/Range is the lower detectable limit followed
by the range as indicated by the manufacturer's
specifications. A blank space preceding or following
the slash (/) means that this category is not appli-
cable to the product, or that the information was
not provided by the manufacturer's specifications.
Samp Rate is the rate at which air is sampled
through active samplers. Sampling rates are not
given for passive samplers.
TIM. is the training and maintenance required to
operate the sampler. The codes "L" and "M,"
limited and moderate, respectively, are intended to
be general indicators. Limited training is a few
minutes to a few hours of self-instruction. Moderate
training includes several hours of self-instruction or
formal instruction. Limited maintenance refers to
preventative maintenance as well as procedures such
as regular filter changes. Moderate maintenance
indicates occasional trouble-shooting, component
replacement, and calibration. A blank before or
after the slash (/) indicates that not enough informa-
tion was provided to determine the required
training or maintenance.
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IAQ Reference Manual
Section 6
Price is the price listed in the literature provided by
the manufacturer. Prices are generally subject to
change at any time and should be regarded as
approximate for a basic sampler without options.
Per/Par indicates whether the sampler is personal
(Per) or portable (Por). Personal samplers are
actually attached to the person or an article of
clothing during the sampling period. Portable
samplers are those that can easily be carried from
place to place.
Power indicates whether the sampler operates on ac
or dc power or both. A "p" following the power
requirements means that the sampler utilizes a
passive sampling method even though another
aspect of the sampler requires power.
Weight and Dimensions indicate the weight and
dimensions listed in the manufacturer's specifica-
tions.
Additional Reference Tables
In addition to the tables on sampling methods and
instruments, this section contains tabulated infor-
mation on battery-powered personal air samplers,
properties of filters used in particulate sampling,
storage properties of gases in plastic bags, limita-
tions on solid adsorbents, sources for testing and
calibration procedures, and standard reference
materials. This information is contained in Exhibits
6-3 through 6-8.
-------
Section 6
IAQ Reference Manual
Exhibit 6-1. Collection and analytical methods for quantitative monitoring of some
contaminants.
CONTAMINANT
COLLECTION METHOD
ANALYTICAL METHOD
CO
NO,
S02
radon and
radon progeny
asbestos
respirable particles
biological aerosols
metals
volatile organtcs
organochlorine
pesticides
HCHO
pump
diffusion
direct reading
diffusion tube;
badge (TEA adsorbent)
pump; absorption
diffusion
direct reading
direct reading
pump; absorption
diffusion
direct reading
diffusion
adsorption (charcoal)
electrostatic
filtration
pump/filter
direct reading
direct reading
direct reading
pump/impaction
pump/filter
pump/adsorbent
pump/adsorbent
(polyurethane foam)
pump; adsorption
pump; adsorption
diffusion; adsorption
H2SO4 electrolyte; solid
polymer electrolyte
electrochemical
infrared
colorimetric
colorimetric (automated)
electrochemistry
chemiluminescence
electrochemistry
colorimetric
electrochemical
electrochemical
etching; microscopic
counting
scintillation counting
thermoluminescent dosimetry
alpha counting
gravimetric and
spectrophotometry
optical scattering
electrostatic precipitation
piezoelectric resonance
incubation; manual
counting
atomic absorption;
neutron activation;
X-ray fluorescence
gas chromatography/
mass spectroscopy
gas chromatography/
mass spectroscopy
colorimetric
spectrophotometry
colorimetric
-------
Exhibit 6-2a. Commercially available indoor air monitoring equipment.
NAME (MFR. CODE)
AEROSOLS
MIE Miniram (19)
Inspec-Aerosol Spectrometer (3)
Low-Pressure Impactor Model 20-900 (2)
MIE Model RAS-1 Real Time Aerosol Sensor (19)
Particle Fractioning Sampler (2)
MIE RAM-S Real Time Aerosol Sensor (19)
Series 12A Automatic Syringe Samplers (7)
Stainless Steel Syringe (7)
AMMONIA
Midget Air Sampler (2)
3-Gas Sampler (2)
5 -Gas Sampler (2)
Model PV Sequential Sampler (2)
SS2000 (30)
Liquid Sorbent Badge (31)
ASBESTOS
MIE FAM-1 Fibrous Aerosol Monitor (19)
BDX 74 Asbestos Pump (30)
BDX 99 Respirable Dust Sampler (30)
LV-1 (32)
VM-3 (32)
ASB-II (3)
BIOLOGICAL AEROSOLS'
Microbial Air Sampler (2)
Viable Microbial Sampler (2)
Stainless Steel Syringe (7)
CADMIUM
BDX 99 Respirable Dust Sampler (30)
METHOD
Ph
DD
I
Ph
I
Ph
we
F
F
AWC
AWC
AWC
Ech
D, G, 1C
Ph
I
I
F
F
I
I
I
F
I
LDL/RANGE
0.10mg/m3/
0.10-100 mg/m3
0.08 Hm/ 0.08-1.0 |Jm
0.01 mg/m3 / 0-100 mg/m3
0.4 pm / 0.4-10.0 Urn
0.1 mg/m3 / 0-200 mg/m3
/ 0-75 ppm
/6-l48ppm(8hr)
0.01 fibers/cm3 /
0.01-30 fibers/cm3
0.8 (tai / >0.8 Urn
0.65 (Jm /0.65-7.0 |Im
1.7 1/m
SAMP
RATE
3 1/m
0.2 1/m
28.3 1/m
0.2 1/m
0.1 1/m
200 ml/m
200 ml/m
200 ml/m
0.5-5 ml/m
1.5-2.5 1/m
1.5-4.5 1/m
1.7 1/m
15-35 1/m
3-25 1/m
11 1/m
28.3. 1/m
28.3 1/m
T/M
L/M
L/M
L/L
L/M
L/L
L/M
M/M
L/L
M/M
M/M
M/M
M/M
L/M
L/L
M/M
L/L
L/L
L/M
L/M
L/L
L/L
L/L
L/L
PRICE
$2350
$1975
$4676
$3000
$200-$400/14
$1095
$1315
$1125
$2855
$31/ea
$14,250
$630
$800
$500
$200-1400/14
PER/
POR
per
por
por
pot
por
por
por
per
por
por
por
por
por
per
por
per
per
por
por
por
por
por
per
per
POWER
dc,p
ac/dc,p
ac/dc
ac
dc
P
dc
ac
ac
ac
dc
P
ac/dc
dc
ac/dc
ac
ac/dc
P
WT.
0.4kg
1kg
8.3kg
140 g
14.5 kg
2.0kg
10.9 kg
7.2kg
1-5 kg
11.4kg
1kg
2.7kg
5kg
13.6kg
7.7kg
(I
DIMENSIONS
10x10x5 cm
.12x18.8x5.3 cm
23.5x22.2x12.7 cm
10.5x6.5x2.5 cm
53x30x20 cm
20-500 ml
20.3x17.8x10.2 cm
39.2x33.7x21 cm
30.5x32.4x19.7 cm
21.6x10.9x17.3 cm
53x35x20 cm
10.2x11.4x6.1 cm
10.2x10.2x17.8 cm
11.4x14.6x23.5 cm
33x20.3x19 cm
41.9x16.5x43.1 cm
20-500 ml
SAMP
ontinued next page)
!
1
1
1
|
^~
1
5*
OS
-------
Exhibit 6-2a. Commercially available indoor air monitoring equipment (tontinued).
NAME (MFR. CODE)
CARBON DIOXIDE
Gastechtor (18)
RI-4ll(18)
RI-4ll(5)
RI-550A(5)
MEXA 211E Portable Gas Analyzer (21)
MEXA 321E Portable Gas Analyzer (21)
SS2000 (30)
Model APBA-210 CO2 Monitor (21)
Model APBA-200E CO2 Monitor (21)
Gastech Model 4776 (18)
CARBON MONOXIDE
CO-82 (18)
BSI210(12)
Gastechtor (18)
GX-82 (18)
InterScan 5 140 (22)
InterScan CO 1140 (22)
InterScan CO 4140 (22)
Ecolyzer Model 2000 (12)
GE CO Detector (20)
Dosimeter Model 3140 (22)
Model 4148 Compact Portable (22)
PAM Model 2 140 (22)
Model PV Sequential Sampler (2)
Carbon Monoxide Detector (14)
Ecolyzer Model 21 1(26)
Pure Air Monitor (4)
Model 1148 Standard Portable (22)
RI-550A(5)
Carbon Monoxide Indicator Badge (36)
Carbon Monoxide Dosimeter, Model 3 (25)
Exotox (27)
MiniCO Indicator and Alarm model IV (25)
MiniCOV(25)
Neotox Pocket CO Monitor (27)
Portable CO Indicator, Model 70 (25)
MEXA 321E Portable Gas Analyzer (21)
METHOD
Ech
NDIR
IRD
NDIR
NDIR
NDIR
Ech
NDIR
NDIR
NDIR
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ech
D
Ech
Ech
AWC
Ech
Ech
Ech
Ech
NDIR
Col
D/Col
Ech
Ech
Ech
Ech
Ech
NDIR
LDL/RANGE
/ 0-9950 ppm
20 ppm / 0-9950 ppm
1% fall scale/ 0-20%
/0-5%
/ 0-25%
0-10,000 ppm
/ 0-2000 ppm
/ 0-2000 ppm
/0-3000 ppm
/ 0-500 ppm
1 ppm/ 0-1999 ppm
2.5 ppm / 0-1000 ppm
1% fall scale / 0-500 ppm
1% fall scale/ 0-500 ppm
0.5 ppm / 0-600 ppm
1 ppm / 0-1000 ppm
1% fall scale/ 0-500 ppm
1% fall scale/ 0-50 ppm
1% fall scale / 0-500 ppm
1 ppm / 0-500 ppm
1 ppm / 0-1999 ppm
1% fall scale / 0-50 ppm
1% fall scale/ 0-20%
/ 10-500 ppm
1 ppm / 0-999 ppm
1 ppm / 0-500 ppm
/ 0-1999 ppm
1 ppm / 0-999 ppm
2 ppm / 0-100 ppm
/ 0-1000 ppm
SAMP
RATE T/M
L/M
M/M
M/M
6 1/m M/M
M/M
M/M
L/M
M/M
0-100 ml/m M/M
L/M
L/L
L/L
L/M
L/M
L/M
1.2 1/m L/M
1.2 1/m L/M
700 ml/m L/M
60 ml/m L/L
L/M
L/M
L/L
200 ml/m M/M
L/M
L/M
M/M
L/M
6 1/m M/M
L/L
L/L
L/M
L/L
L/L
L/L
M/M
M/M
PRICE
$670-$! 100
$2100
$1995
$2495
$2000
$595
$695
$670-$1100
$1295
$1145
$1675
$1895
$1900
$1195
$1235
$1895
$695
$2855
$725
$455
$1895
$2495
$2.25
$562
$1472
PER/
POR
por
por
por
por
por
por
por
por
por
por
per
per
por
per
per
por
por
por
por
per
por
per
por
per
per
por
por
por
per
per
por
per
per
per
por
por
POWER
dc.both
dc
ac/dc
ac
ac
ac
dc
ac/dc
ac
ac, dc
dc,p
dc,p
dc, both
dc,p
dc,p
dc
dc
ac/dc
dc
dc,p
ac/dc
dc,p
ac
dc,p
dc
ac
ac/dc,p
ac
P
P
dc
dc
dc,p
dc
dc
ac
WT.
9,5 kg
9.5kg
13kg
1.5kg
6kg
5kg
0.3kg
680 g
3.6kg
2.0kg
4.5kg
290 g
680 g
2.0kg
680 g
343 g
343 g
2.7kg
3.6kg
9.5kg
14.3 g
0.9kg
150g
3.2kg
13kg
DIMENSIONS
25.4x19x1 1.4 cm
22x19.8x32 cm
22x22.5x52 cm
33x22.5x52 cm
21x10.9x17.3 cm
31. 1x13x17 cm
18x32x9.1 cm
39.4x33.0xl 5.2 cm
14x8.5x3.8 cm
15.2x7.6x5.1 cm
18.4x15.2x2.9 cm
17.8x10.2x22.5 cm
17.8x17.8x33 cm
7.5x13.5x3.6 cm
15.2x7.6x5.1 cm
17.8x10.2x22.5 cm
16.5x7.6x5.1 cm
7.9x12.1x2.8 cm
14.6x8.9x3.8 cm
30.5x10.2x17.8 cm
18.4x15.2x29.2 cm
22x19.8x32 cm
7.6x12.7x0.6 cm
15.2x8.9x5.3 cm
15.2x8.9x3.8 cm
2.8x6.1x10.2 cm
21.6x16.5x8.9 cm
33x22.5x52 cm
I
8
c\
to
f
-------
Exhibit 6-2a. Commercially available indoor air monitoring equipment (tontinued).
NAME (MFR. CODE)
METHOD LDL/RANGE
SAMP
RATE
T/M
PRICE
PER/
POR POWER WT.
DIMENSIONS
10
£
CARBON MONOXIDE (continued)
Lamotte 7782 Carbon Monoxide Test Kit (34) WC
MEXA201E Portable Gas Analyzer (21) NDIR
Mini Monitor (30) Ech
VaporGard Dosimeter Tube (25) D/Col
CHLORINE
Model 1340 Standard Portable (22) Ech
PAM Model 2340 (22) Ech
Model 4340 Compact Portable (22) Ech
SS2000 (30) Ech
COMBUSTIBLE GAS
Scott 8-101(29)
Scott S-105A (with O2) (29)
Gastech Protechtor I & II (18)
FORMALDEHYDE
TGM 555 (5) AWC/Col
Formaldehyde Monitor 3750 (35) D
PF-1(1) D
Pro-Tek Formaldehyde Dosimeter (9) D
ETS Formaldehyde Dosimeter (15) DD
PRO-TEK Colorimetric Air Monitoring Badges (9) D
Formaldemeter (24) Ech
Lamotte 3408 Formaldehyde-in-Air Test Kit (34) Col
lamotte 6695 Formaldehyde Test Kit (34) WC
Liquid Sorbent Badge (31) D.Col
Passive Bubbler™ Sampler (31) D, Col
PF - 20 (1) D, Col
HYDROCARBONS
Gastechtor(lS) Ech
SP-203FU8) Ech
MEXA221E(21) NDIR
10 ppm /
/ 0-1000 ppm
0-400 ppm
specific to tube
1% fall scale / 0-10 ppm
\% fall scale / 0-10 ppm
1% fall scale / 0-10 ppm
/ 0-3 ppm
70-100%
/0-100%; /0-25% O2
/0-100%; 70-25% O2
0.002 ppm / 0-5 ppm 0.5 1/m
0.8 ppm-hr / 0.8-72 ppm-hr 65.9 1/m
0.01 ppm / 0.01-1.0 ppm 4.1 ml/m
1.6 ppm-hr 7 1.6-54 ppm-hr
0.03 ppm / 0.03-1.0 ppm
1.6 ppm /1.6-54 ppm
0.1 ppm/0.1-99.9 ppm
0.1 ppm/0.1-1.0 ppm
0.13 ppm /
0.02 ppm / 0.2-2 ppm 0.5-50 ml/m
0.1/0-1.5 ppm (8 hr.slowcap) 11.6 ml/m
0.5/0-5 ppm(15min, fastcap)
/0.1-3ppm (8 hr) 16 cmVm
/ low ppm
/ 0-500 ppm
L/L
M/M
L/L
L/L
L/M
L/L
L/M
L/M
L/M
L/M
L/M
M/M
L/L
L/L
L/L
L/L
L/L
L/M
L/L
L/L
L/L
L/L
L/L
L/M
L/L
M/M
$45
$24/10
$2156
$875
$2156
$483
$777
$5410
$35
$48/2
$222/10
$24/2
$38
$40
$30
$36/5
$670-1100
$500
por
por
per
per
por
per
por
por
por
por
por
por
per
por
per
por
per
per
por
por
per
per
per
por
per
por
P
ac
dc
P
ac/dc
dc,p
ac/dc
dc
dc
dc
dc
ac/dc
P
P
P
P
P
dc
P
P
P
P
P
dc, both
ac
9.5kg
200 g
3.6kg
680 g
2.0kg
1.5kg
-51kg
-51kg
14kg
17.8 g
17.8 g
200 g
9.5kg
22x22.5x52 cm
7.7x2.4x1 1.8 cm
18.4x15.2x29.2 cm
16.5x7.6x5.1 cm
17.8x10.2x22.5 cm
21.6x10.9x17.3 cm
7.9x15.9x4.1 cm
7.9x15.9x4.1 cm
51x41x18 cm
90x25 mm
7.6x7.1x0.9 cm
7.6x7.1x0.9 cm
12x6.3x3 cm
7.0x2.05 cm
22x22.5x52 cm
I
(continued next page)
-------
Exhibit 6-2a. Commercially availablt indoor air monitoring equipment (tontinutd).
NAME (MFR. CODE)
HYDROGEN SULFIDE
Ecolyzer Model 2000 (12)
Dosimeter Model 3170 (22)
Model 4170 Compact Portable (22)
PAM Model 2170 (22)
Midget Air Sampler (2)
3-Gas Sampler (2)
5-Gas Sampler (2)
Model PV Sequential Sampler (2)
TGM 555 (5)
Ecolyzer Model 241 (26)
Model 1170 Standard Portable (22)
Exotox (27)
Gold Film Hydrogen Sulfide Analyzer (23)
Neotox Pocket H2S Monitor (27)
Portable Indicator and Alarm, Model 361 (25)
Mini Monitor (30)
SS2000 (30)
METHOD
Ech
D
Ech
Ech
F
SaTr
SaTr
SaTr
AWC/Col
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ech
IJDJL/RANGE
0.5 ppm / 0-600 ppm
1% fall scale / 0-500 ppm
1% fall scale / 0-1 ppm
1% fall scale / 0-100 ppm
0.002 ppm / 0-5 ppm
1 ppm/ 0-1000 ppm
1% full scale/ 0-1 ppm
1 ppm / 0-500 ppm
1 ppb / 1-500 ppb
1 ppm / 0-999 ppm
/ 0-50 ppm
/ 0-100 ppm
/ 0-3- ppm
SAMP
RATE
700 ml/m
11/m
200 ml/m
200 ml/m
200 ml/m
0.5 1/m
150 ml/m
1.5 1/m'
T/M
I/M
1/M
L/M
L/L
M/M
M/M
M/M
M/M
M/M
L/M
L/M
L/M
L/M
L/L
M/M
L/L
L/M
PRICE
$1900
$1270
$2064
$765
$1095
$1315
$1125
$2855
$5250
$2064
$8500
$1685
PER/
POR
por
per
por
per
por
por
por
por
por
per
por
por
por
per
por
per
por
POWER
ac/dc
dc,p
ac/dc
dc,p
dc
ac
ac
ac
ac/dc
dc
ac/dc,p
dc
ac/dc
dc
dc
dc
dc
WT.
4.5kg
680 g
2.0kg
680 g
2.0kg
10.9 kg
7.2kg
13.6 kg
343 g
3.6kg
0.9kg
3.6kg
150 g
3.4kg
200 g
1.5kg
DIMENSIONS
17.8x17.8x33 cm
15.2x7.6x5.1 cm
17.8x10.2x22.5 cm
16.5x7.6x5.1 cm
20.3x17.8x10.2 cm
39.2x33.7x21 cm
30.5x32.4x19-7 cm
50.8x40.6x17.8 cm
14.6x8.9x3.8 cm
18.4x15.2x29.2 cm
15.2x8.9x5.3 cm
30.5x20.3x20.3 cm
2.8x6.1x10.2 cm
17.8x25.4x9.5 cm
7.6x2.4x1 1.8 cm
21.6x10.9x17.3 cm
LEAD
1
BDX 99 Respirable Dust Sampler (30)
MERCURY
Model 411 Gold Film Mercury Vapor Analyzer(23) Ech
Mercury Gas Monitoring Badge (31) D, AA
Mercury Vapor Badge 3600 (35) D,AA
NITROGEN DIOXIDE
TGM 555 NO2 Analyzer (5) AWC/Col
CSI 1600 NOx Analyzer (6) Ch
Air Check (1) D
DuPont PRO-TEK Type C30 Dosimeter (9) D
Toyo Roshi NO2 Badge (26) D/Ad
MDA Palmes Tube (24) D/S
Ecolyzer Model 2000 (12) Ech
Dosimeter Model 3150 (22) D
0.001 mg/m3
/ 0.001-1.999 mg/m3
0.002 mg/m3 (8hr)/
/0.005-0.20 mg/m3
0.005 ppm / 0-0.25 ppm
0.002 ppm / 0.002-5 ppm
0.005 ppm / 0.005-10 ppm
10 ppm-hr /10-100 ppm-hr
66 ppb-hr / 66-1066 ppb-hr
1 ppm-hr / 1-20 ppm-hr
0.5 ppm / 0-600 ppm
1% full scale / 0-500 ppm
1.7 1/m
0-75 1/m
L/L
L/M
$3750
per
por ac/dc 2.3 kg 33.0x16.3 cm
0.5 1/m
500 ml/m
1 ml/m
700 ml/m
L/L
L/L
M/M
M/M
L/L
L/L
L/L
L/L
L/M
L/M
$22.50/10
$5340
$7950
$48/2
$259/10
$12
$8-10
$1900
$1425
per
per
por
por
por
per
per
per
por
per
P
P
ac/dc
ac
P
P
P
P
ac/dc
dc,p
14kg
34kg
16g
15 g
14 g
4.5kg
680 g
5 1x41x18 cm
43.2x27.7x68.6 cm
7.6x7.1x0.9 cm
5x4x1 cm
8 cm x 1.3 cm dia.
17.8x17.8x33 cm
16.5x7.6x5.1 cm
(O
-------
Exhibit 6-2a. Commercially available indoor air monitoring equipment (tontinued).
NAME (MFR, CODE)
NITROGEN DIOXIDE (amtinuixt)
Model 1152 Standard Portable (22)
Model 4152 Compact Porwble (22)
PAM Model 2150 (22)
Midget Air Sampler (2)
3-Gas Sampler (2)
5-Gas Sampler (2)
VapotGatd Dosimeter Tube (25)
Mini Monitor (30)
NITROGEN MONOXIDE
CSI IfiOO NOx Analyzer (6)
Ecolyzer Model 2000 <12)
Dosimeter Model 3540 (22)
Model 1545 Standard Portable (22)
Model 4545 Compact Portable (22)
NITROGEN OXIDES
CSI 1600 NOx Analyzer (6)
Toyo Roshi NO2 Badge (26)
MDA Palmes Tube (24)
Atnbienr Air Sampler (2)
Model PV Sequential Sampler (2)
TGM5550)
IBS Model A100 (41)
AC35NO-NO>{40)
OSGANICS
Gas Monitoring Badges (31)
Charcoal Sampling Tubes (9)
PEO-TEK G-AA Air Monitoring Badges (9)
PRO-TEK G-BB Air Monitoring Badges (9)
Ambient Air Sampler (2)
VapotGard Dosimeter Badges (25)
METHOD
Bch
Ech
Ech
F
SaTr
SaTr
D/Col
Ech
Ch
Ech
D
Ech
Ech
Ch
D/S
D/S
AWC
AWC
AWC/Col
AWC
Ch
D
S
D
,D
AWC
D
LDURANGE
1% fall scale / 0-10 ppm ,
\% foil scale/ 0-10 ppm
1% full scale / 0-50 ppm
/ specific to rube
/ 0-10 ppm
0.002 ppm / 0.002-5.0 ppm
0.5 ppm / 0-600 ppm
1% foil scale / 0-500 ppm
1% Ml scale / 0-50 ppm
1% full scale/ 0-50 ppm
0.002 ppm / 0,002-5 ppm
66 ppb-hr / 66-1066 ppb-hr
1 ppm-hr / l-20fjpm-hr
I % Ml scale / 0-0.25 ppm
10-0,1 ppm; 0-100 ppm
0.01 ppm/0-2 ppm
varies
0.2 ppm-hr / 0.2-1 300 ppm
0,4 ppm-hr / 0,4-4000 ppm
SAMP
BATE
0.1 1/m •
200 ml/m
200 »l/m
500 ml/rn
700 ral/m
500 mi/m
1 ml/m
31/m
200 ml/m
0.5 1/m
varies
31/m
T/M
L/M
L/M
L/L
M/M
M/M
M/M
L/L
1/L
M/M
L/M
JJM
L/M
L/M
M/M
1/L
L/L
M/M
M/M
M/M
M/M
M/M
L/L
L/L
L/L
JJL
M/M
L/L
PWCE
12295
12295
I860
$1095
$1315
11125
$24/10
$7950
$1900
$1425
$2247
12247
17930
J12
18-10
1520-685
$2855
$5250
17995
$48/25
$520-685
174
PBR/
POR
por
por
per
por
por
por
per
por
por
por
per
por
por
por
per
per
por
por
por
por
por
pet
por
per
per
por
per
POWER
ac/dc
ac/dc
dc,p
dc
K
96
P
dc
ac
ac/dc
dc,p
ac/dc
. ac/dc
ac
P
P
ac
ac
ac/dc
ac
ac, dc
P
P
P
ac
P
WT,
3.6kg
2.0kg
680 g
2.0kg
10.9 kg
7,15kg
200 g
34kg
4.5kg
680 g
3,6kg
2.0kg
34kg
15g
14 g
6.4kg
14kg
18.6 kg
5.5kg
DIMENSIONS
18.4x15.2x29.2 cm
17.8x10.2x22.5 cm
16.5x7,6x5,1 cm
20.3x17,8x10,2 cm
39.2x33.7x21 cm
30.5x32,4x19.7 cm
7.6x2.4x11.8 cm
43.2x27.7x68.6 cm
17.8x17.8x33 cm
15.2x7.6x5.1 cm
18.4x15.2x29.2 cm
17,8x10.2x22.5 cm
43,2x27,7x68,6 cm
5x4x1 cm
8 cm x 1,3 cm dk.
20.3x25.4x27,3 cm
51x41x18 cm
27.9x30.5x36.8 cm
40x30x13 cm
50/100 mg 6x70 mm
7.7 g
11,1 g
6.4kg
(t
7.7x0.8x1. 4 cm
7.7x0,9x1,6 cm
20,3x25,4x27,3 cm
~ontintted next page)
IAQ Refere
9
f
1
*•«•*
s?
1.
8
ON
-------
El
Exhibit 6"2a. Commercially available Moor air monitoring equipment (tontinuad).
NAME (MER. CODE)
OEGANICS (continued)
Organic Vapor Monitor, Series 3500 <35)
OVA-108 (17)
OVA-128 (17)
OXYGEN
Gastechtor(18)
GX-82U8)
OX-82<18)
Model 3300 Oxygen Monitor (24)
Ecoiyzet Model 260 (26)
Personal O2 Monitor (14)
Portable Oxygen Analyzer (14)
Scott-Alert (29)
Exotox (27)
Neotox Pocket O2 Monitor (27)
Portable Indicator & Alarm, Model 361 (25)
Mini Monitor 00)
OZONE
CSI 2000 Portable Ozone Meter (6)
Ambient Air Sampler (2)
RADON AND PROGENY
Track Itch (33)
Mini CON H (8)
MiniCON-EAD II (8)
Portable Survey Meter (8)
RDA-2QOO Radon/Radon Daughter Detector (11)
LV-1 (32)
Model 442-A (28)
WLM-IA (10)
Model 05-420 AT EASE (39)
Model 05-418 Honeywell Professional (39)
E-Perm Introductory Kit (42)
METHOD
D
FI/GC
FI/GC
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ech
Ch
AWC
D
GM
GM
GM
Sc
F
DD
Ech
D
D
D
IDL/RANGE
compound specific
0.5 ppm / 1-10000 ppm
0.2 ppm/ 04000 ppm
/0-50SS
/ 0-25% or 0-100%
0,1% / 0-30%
1% foil scale/ 0-100%
1% full scale / 0-100%
3% fall scale/ 0-100%
0.1% / 0-35%
0.1% / 0-35%
/0-25%
/0-40%
0.004 ppm / 0-1 ppm
0.2 pCi/1 / 0.2-2000 pCi/1
2.3 MeV/ 0-5000 cpm
2.3 MeV/ 0-5000 cpm
•/0-0.5mR/hr
1 0-99,999 cts
/ 0-1000 cpm
0.1 pCi/l/0, 1-999 pCi/1
0.1pG/l/0.1-999pCi/l
l<\ to 50 pCi/1 (2-7 da)
SAMP
RATE T/M
L/L
11/m M/M
11/m L/M
L/M
L/M
in
M/M
L/M
L/M
L/M
L/L
L/M
L/L
• 1.5 1/m M/M
L/L
700 ml/m M/M
3 1/m M/M
L/L
L/M
L/M
M/M
variable M/M
15-35 1/m L/M
28.3-453 1/m M/M
0.12-0.18 1/m L/M
L/L
L/L
L/L
PRICE
$670-1100
$1295
$525
$695
$2695
$505
$1685
$6750
1520-685
$20-50
$485
$550
$440
$4450
$550
$2950
$449
$795
$2500
PER/
FOR
per
per
pot
por
per
per
por
per
per
por
per
por
per
por
per
por
por
por
pet
per
por
por
por
pot
por
por
por
por
POWER
P
dc
dc
dc, both
dc,p
dc,p
de
dc
dc,p
dc
dc
dc
dc
dc
dc
dc
K
P
dc,p
dc,p
dc,p
dc
ac/dc
ac
dc
P
P
P
"WT,
5.5kg
5.5kg
343 g
343 g
6.4kg
5l4g
0.9kg
150 g
3.4kg
200 g
7.7kg
6.4kg
454 g
454 g
1735 g
8kg
2.7kg
7.3kg
2.4kg
.12kg
DIMENSIONS
23x30x10 cm
23x30x1 Ocm
14.6x8.9x3.8 cm
7.9x12.1x2.8 cm
15.2x19x30.5 cm
7.9x15.7x4.1 cm
15.2x8.9x5.3 cm
2.8x6.1x10.2 cm
17.8x25.4x9.5 cm
7.6x2.4x1 1.8 cm
20.3x17.8x45.7 cm
20.3x25.4x27.3 cm
6.4 sq on
6.7x11.8x2.5 cm
6.7x1 1.8x2.5 cm
11. 1x22.2x10.8 cm
12.7x16.5x20 cm
10.2x10.2x17.8 cm
27.9x40.6x15.9 cm
14.6x1 1.8x20.3 cm
10.2x8.3 cm (chamber)
/50to200pCi/l(15-30da)
/<7pCi/l (up to 1 yr)
-------
Exhibit 6-2a, Commercially available indoor air monitoring equipment (tontinued).
NAME (MFK. CODE)
KBSP1RABLES
TSI Piezobalance Model 3500 07)
tow-Pressure Impactor Model 20-900 (2)
Mttple Personal Cascade Impactor Model 294 (2)
Marple Personal Cascade Impactor Model 296 (2)
Marple Personal Cascade Impactot Model 298 (2)
Mkrobial Ait Sampler (2)
Particle Fractfoning Sampler (2)
PS-4 PSrticulate Sizing Impactors (19)
MieMhuram(19)
Mie RAM-1 <19)
BOX 30 (30)
BDX 99 Respirable Dust Sampler (30)
P-5 Digital Dust Indicator (24)
Personal Dust Monitoring System (24)
Stainless Steel Syringe (7)
MayflLE, Cascade Impactor (3)
Portable Condensation Nuclei Monitor (13)
TEOM® Series 1200 (39)
SULFUR DIOXIDE
Dosimeter Model 3240 (22)
InterScan 5240 Dosimeter (22)
InterScan SO2 1240 (22)
InterScan SO2 4240 (22)
Model 4240 Compact Portable (22)
PAM Model 2240 (22)
Midget Air Sampler (2)
3-Gas Sampler (2)
S-Cas Sampler (2)
Ambient Air Sampler (2)
Model PV Sequential Sampler (2)
VaporGard Dosimeter Tube (25)
-Model 1240 Standard Portable (22)
Liquid Sorbett Badge (3D
METHOD
EP
I
I
I
I
I
I
I
«t
Ph
I
I
F
G
Ph
Im
D
Bcfe
Ech
Ech
Icfct
Ech
f
AWC
AWC
AWC
AWC
D/Col
Ech
D
LDI/RANG1
SAMP
KATE
0.001 mg/m3 / 0,01-10 mg/m3 1 1/m
0,08 (J»/ 0.08-1.0 (to
3.5 (Im / 4 stages
0.6 Jta / 6 stages
0.6 pm / 8 stages
0.4 pm / 0.4-10.0 Jim
l.lHm/l,l-8.0}tai
0.1 «ag/m3 / 0,1-100- mg/rf
0.1 mg/mj / 0.01-200 ffig/mj
0.001 mg/m3
/ 0.001-100 mg/m*
0.1 mg/m3 / 0.01-100 mg/mj
Q.5M»/0,5-32Hm
0.0025 (to /
Spg/ift'ClOrninave)/
15|%/m! (2 min ave)/
1%M scale/ 0-500 ppm
0.5% fall scale / 0-20 ppm
1% Ml scale/ 0-10 ppm
Wo fall scale / 0-10 ppm
We fall scale/ 0-1 ppm
1% fall scale/ 0-50 ppm
/ specific to tube
\% full scale / 0-1 ppm
0,1 ppm / 0.1-100 ppm
3 1/m
2 1/m
2 1/m
2 1/m
28.3 Vm
28.3 1/m
2 1/m
1-3 1/m
1.7 1/m
5 1/m
50-70- ml/sec
0.5 - 5 1/m
0.1 Ita
200 ml/m
200 ml/m
3 1/m
200 mllm
0,5-50 ml/m
T/M
M/M
VL
UL
ML,
VL
VL
in
t/M
L/M
M.
I/L
M/M
I/M
I/L
I/L
M/M
M/M
t/M
1/M
L/M
IM
IM.
VL
M/M
M/M
M/M
M/M
M/M
1/L
I/M
ML
PBR/
PRICE POR
14400
1775
$975
$1175
$960/4
$2350
$6250
$2004400/14
$4995
$1425
$1145
$1675
$1895
12211
$860
11095
$1325
$1125
$520-685
$2855
124/10
$2210
$30
por
por
per
per
per
por
por
por
pet
por
per
per
por
per
per
por
por
por
per
per
per
!»
por
per
pot
por
por
por
por
per
por
per
POWER
ac/dc
ac/dc
dc,p
dc
dc
»c/dc
dc
P
'dc
ae
dc,p
dc,p
dc
dc
ac/dc
dc,p
dc
ac
ac
ac
ac
P
ac/dc,p
P
WT.
4.5kg
170 g
185 g
200 g
8.3kg
130 g
0.4kg
4kg
600 g
20-500 ml
3.6kg
30g
12 kg
680 g
680g
3.6kg
2.0kg
2.0kg
680 g
2,0kg
10.9 kg
7.15kg
6.4 kg
3.6kg
(a
DIMENSIONS
31x13x17 cm
7.2x5 .7x4.0 cm
8,0x5,7x4,0 cm
8.6x5.7x4,0 cm
23.5x22.2x12,7 cm
8.8x4.8 cm dia.
10x10x5 cm
20x20x20 cm
10,2x11.4x6.1 cm
12x8,2x8.7 cm
12,7x17.8x40.6 cm
25x36x46 em (sensor)
36x45x19 cm
(computer)
15.2x7,6x5.1 cm
15.2x7.6x5,1 cm
18,4x1.5x29 cm
17.8x10.2x22.5 cm
17,8x10.2x22.5 cm
16,5x7.6x5.1 cm
20.3x17.8x10.2 cm
39.2x33,7x21 cm
30.5x32,4x19.7 cm
20.3x25.4x27.3 cm
18.4x15,2x29.2 cm
ntinued next past)
IAQ Refers,
1
f
1
**w
8s
1
Os
-------
Exhibit 6-2a. Commercially available indoor air monitoring equipment {(ontirwed).
NAME (MHL CODE)
METHOD imaiANGB
SAMP
EAOT
T/M
PRICE
PEE/
FOR POWEE WT.
DIMENSIONS
I.
§
SUtTOR DIOXIDE (eoalinaed)
TGM 555 (5)
SS200000)
Mini Monitor (30)
TOTAt SUSPENDED PAJOTCULATES
AWC/Col 1% fall scale/0-0.25 ppm
Ech / 0-10 pptn
icfa / 0-20 ppm
0,5 l/m
L/M
ML
15395
par
pot
per
*e/dc
de
dc
14kg
LSkg
200 g
51x41x18 cm
21,6x10,9x17.3 cm
7,6x2,4x11,8 an
Status 2100 (16)
Status 5000 (16)
BDX 74 Asbestos Pump (30)
PCD-1 Dltea-RedUng Dust Monitor (24)
LV-1 02)
VM-3 (32)
Setics 12A Automatic Sf tinge Sanipkis (7)
Midget Ait Sampler (2)
Ph
Ph
I
F
P
we
SaTr
Q.5H» / 0.5-5 Jto
0.3 pm / 0,3-5.0 |to
0,001 mg/m*
/ 0.001-9.9 mg/m3
23.3 ml/m
28.3 ml/ra
1.5-4,5 l/m
15-3J l/m
3-25 l/m
0.1 I/in
M/M
M/M
ML
M/M
UM
MM
M/M
M/M
$3950
$6950
J550
$680
13000
11095
pot
por
per
pot
por
por
por
per
ac
ac
dc
sc/dc
ac
dc
dc
7,2 kg 15,2x25.4x35.6 cm
10.8kg 11.4x29.2x41.9 cm
1 fcg 10.2x11.4x6.1 cm
2.7 kg 10.2x10.2x17.8 cm
5kg 11.4x14,6x23.5 cm
14.5kg 53x30x20 cm
2.0 fcg 20.3x17.8x10.2 cm
SOURCE; Ritchie and Deal (1988)
to
1
I
-------
IAQ Reference Manual
Section 6
Exhibit 6-2b. Identification lodes for met hods in Exhibit 6-2a.
ABBREVIATION
DESCRIPTION OF METHOD
AA
AWC
Ch
Col
D
DD
Ech
EP
F
H
G
GC
GM
I
1C
Atomic Absorption—ionized molecules are deflected by a magnetic field
according to their mass and charge
Automated Wet Chemistry—reagents are reacted with the contaminant to
determine its presence or concentration; reagents are automatically
introduced
Chemilttminescmce—the intensity of light emitted from a chemical reaction
between the contaminant and a reagent is directly related to the
contaminant concentration
Coiortmetry—~t:s&gents are reacted with the contaminant; the presence 0r
concentration of contaminant is based on a color change resulting from the
chemical reaction
Diffusion—-spontaneous transfer and mixing of contaminant based on
molecular motion
Dry Deposition—natural settling of particles due to gravity
Electrochemical—contaminant concentrations are based on the measurement
of electrical changes caused by chemical reactions
Electrostatic Precipitation—concentrations of particles are based on the use
of an electrical field to charge and separate the particles
Filtration—physical separation of suspended matter from a gas stream
Flame lonization—concentrations are proportional to ion currents which
are produced by contaminants which are introduced into a flame
Gravimetric—measurement by weight
Gas CforomatograpAy—concentrations are proportional to a signal that is
generated as contaminant gas is separated into its components and measured
by a detector
Geiger Mueller—measurement of pulses resulting from the ionizing effect
of radiation on an enclosed
Impoction—collection by forcing contact
Ion Chromotogrophy—sequential determination of anions or cations using ion
exchange and conductivity, amperometric, or colorimetric detectors
(continued next page)
-------
Section 6
IAQ Reference Manual
Exhibit 6-2b. Identification codes for methods in Exhibit 6-2a (
-------
IAQ Reference Manual
Section 6
Exhibit 6-2<. Identification todes for manufacturers in Exhibit 6-2a (tontinued).
CODE ADDRESS
CONTAMINANTS CODE ADDRESS
CONTAMINANTS'
AER, BIO AE&, SB
RSP, TSP
Rtt
N02,HCHO,ORG
Rn, Prog
Rn
7 Demaray Scientific
Instruments
1122LatahSt,
Pullman, WA 99163
(509-332-8577)
8 Dosimeter Corporation
P.O. Box 42377
Cincinnati, OH 45242
9 DuPont Co., Inc.
Batcley Mill Plaza
Marshall Mill Bldg.
Wilmington, DE 19898
(215-444-4188)
10 Eberline Instrument Corp,
P.O. Box 2108
SanteFe.NM 87501
(505-471-3232)
11 EDA Instruments, Inc.
5151 Ward Rd.
Wheat Ridge, CO
(303-422-9112)
12 Energetics Science Division CO, NO2, NO, H2S
Six Skyline Dr.
Hawthorne, NJ 10532
(914-492-3010)
13 Environment/One Corp. RSP
2773 Balltowa Rd.
Scfaenectady, NY 12309
(518-346-6161)
14 Environmental Tectontics CO, GOt
Corp.
County Line Industrial Park
Southampton, PA 18966
(800-523-6079)
15 Envirotech Services, Inc. HCHO
547 Park Avc.
Prairie Du Sac, WI 53758
(608-643-4755)
16
17
18
19
20
21
22
23
24
25
Faley International Corp.
P.O. Box 669
El Tore, CA 92630-0669
(714-837-1149)
Foxboro Company
38 Niponset Avenue
Foxboro, MA 07039
(714-837-1149)
Gastech
P.O. Box 390726
Mountain View, CA 94039
MIE, Inc.
213 Burlington Rd.
Bedford, MA 01730
(617-275-5444)
General Electric
333 W, Seymour Ave.
Cincinnati, OH 45216
(513-948-5065)
Horiba Instruments
1021 Diiryen Ave.
Irvine, CA 92714
(800-446-7422)
InterScan Corporation
21700NordhoffSt.
P.O. Box 2496
Chatsworth, CA 91311
(800-458-6153)
Jerome Instrument Corp.
P.O. Box 336
Jerome, AZ 86331
(800-952-2566)
MDA Scientific, Inc.
403 Batcley
Lincolnshire, IL 60069
(800-323-2000)
TSP
ORG
CO.aXQ.HC
RSP, ASB, AIR
CO
CO, CO., HC
CO, NOa, HjS, SO
NO, CO,
H2S,Hg
NO2, NOt, O3, SO2,
O,, RSP, TSP, HCHO
Mine Safety Appliances Co. ORG, CO, SO2, NO2,
400 Penn Center Blvd. O2, H2S
Pittsburgh, PA 15235
(800-672-2222)
(continued next page)
-------
Section 6
IAQ Reference Manual
Exhibit 6-2c. Identification (dins for manufacturers in Exhibit i-la fconfinvec/j.
CODE ADDRESS
26 National Draeger, Inc.
101 Technology Drive
Pittsburgh, PA 15275
(412-787-8383)
CONTAMINANTS
NO* NO,, CD, H£
O,
CODE ADDMSS
35 3M Corporation
220-7W, 3M Center
St. Paul, MN 55144
(612-733-6234)
CONTAMINANTS
HCHO, ORG, Hg
27
O2,CO,H2S
28
29
30
31
32
33
34
Ra
Neotronics
P.O. Box 370
411 Bradford Sc.,N.W.
Gainesville, GA 30503
(404-535-0600)
SAI Technology Co.
4060 Sorrento Valley Blvd.
San Diego, CA 92121
(619-452-9983)
Scott Aviation
Lancaster, NY 14086
016-683-5100)
Sensidyne, I»c. CO, CO2, NO.,, Oa,
12345 Starkey Rd,, Suite E SO2, Cl,, RSP, ASB,
Largo, EL 33542 TSP
(813-530-3602)
ORG, SO2, HCHO
SKC, tec,
RD11395 Valley ¥iew Rd.
Eighty Pour, PA 15330
(412-941-9701)
Staplex Air Sampler Division ASB, TSP, Rn
777 Fifth Ave,
Brooklyn, NY 11232
(212-768-3333)
Terwdex Corp. Rn
460 N. Wiget Lane
Walaut Creek, CA 94596
(415-938-2545)
Thomas Scientific HCHO, CO
Vine St. at Third
P.O. Box 779
Philadelphia, PA 19105
(609-467-2000)
36 Tracor Atlas CO
9441 Baythorne Drive
Houston, TX 77041
(713-462-6166)
37 TSI RSP
P.O. Box 64394
St. Paul, MN 55164
(612-490-2888)
38 Rttipprecht: & TSP, RSP
Patashnkk Co., Inc.
8 Corporate Circle
Albany, NY 12203
(518-452-0065)
39 Nuclear Associates Rn
100 Voice Road
P. O. Box 349
Carle Place, NY 11514-0349
(516-741-6360)
40 Environment SA NQ-NO^
111 Bd. Robespierre
78300 Poissy, France
(1) 39.7934,57
41 IBS Systems Corp, NO, NOZ,
4432 N. Kedzic Ave. HCHO
Chicago, IL 60625
(312-459-4655)
42 Rad Blec. Inc. Rn, Prog
5330 J, Spectrum Drive
270 Technology Park
Frederick, MD 21701
(301-694-0011)
SOURCE", Ritchie and Dal (1988)
-------
Exhibit 6
MFG.
CODE'
1
2
3
4
5
•3. Battery-powered personal air
MODEL
AFC 123
AFC400T
BDX30
BDX34LF
BOX 44
BOX SSH0
W-l.LV-2
BM, SNA
BS,BSA
MCS-15
224-PCXR7
224-PCXR3
(and 43XR)
222-3; 222-4
Airchedc 50
PAS-300011
PAS-1000
1 Accessories such as calibration kits, filters,
FLOW
RANGE
1.0-2.3 1/m
1.0-4.01 1/m
0.8-3 I/in
0.025-0.225 1/m
0.3-3 1/m
0.5-3 1/m
15-35 1/m
5-17 1/m
5-17 1/m
3-15 1/m "
1-5 I/in
1-5 1/m
0.02-0.08 1/m
0.05-0.20 Urn
0.75-3.0 1/m
0.005-3 1/m
0.005 2 1/m
filter cassettes, impingers,
samplers.1
BLOW CONTROL
ACCURACY
±555 of flow
±Wa of flow
±0.1 1/m of flow
±0.5* of flow
±0,1 I of flow
±Wa of flow
±5% of flow
±5* of flow
RUNNING
TIME
8+h«
4-8 hrs
Shrs
6hts
8 hrs
8 fats
Sine voltage
Ihr
2 hrs
8 hts-7 days
8hre
Shrs
4-8 hrs
10-12 he
4-8 hrs
PRICE
J425
11095
$420
$644
$495
$550
1630
$895
$995
1695
$645
$595 (J445)
1425
$345
$620
$420
WEIGHT
454 g
454 g
595 g
624 g
624 g
850 g
2.7kg
5kg
5.5kg
964 g
964 g
964 g
283 g
510 g
900g
283 g
DIMENSIONS
11.8x13.2x7.9 cm
14.6x9-5x6.3 cm
10.2x6.3xl 1.4 cm
10.2x6.3xl 1.4 cm
.10.2x6.3x1 1.4 cm
12.7x6.3xl 1.4 cm
10.2x10.2x17.8 cm
11.4x17.8x21.6 cm
11.4x17.8x21.6 cm
4.8x11,9x13 cm
4.8x1 1.9x13 cm
4.8x11.9x13 cm
13x6.4x3.3 cm
12.7x7.6x4.6 cm
10.7x1 1.7x6.1 cm
7.6x10.2x3.6 on
sampling bags, and sorbent tubes are also
included in the manufacturers' product lines.
Manufacturers'
Cads
i
Codes
Maoufietuiier
BGI, Inc.
58 Guinstn Street
Walttam, MA 02154
Cafe
3
Stsplex*
Air Sampler Division
777 Fifth Avenue
Cask
4
Manufacturer
SKX*
334 Valley View Ro«d
Eighty Pour PA,
15330-9614
Brooklyn, NY 11232-1693
2
Sensidyne (formerly Bendix)
12345 Starkey Road
Suite E
Largo, EL 34643
5
Spectre* Corp*
3594 Haven Avenue
Redwood City, CA 94063
1AQ Reference Mantta
*~
1
OS
-------
Section 6
IAQ Reference Manual
Exhibit 6«4. Properties of fillers used
FILTER MATERIAL
Whatman
No. 1 Cellulose Fiber
No. 2
No, 3
No, 4
No. 5
No. 40
No. 41
No. 42
Geltnan
Type A Glass Fiber
TypeA/E
Spectrograde
Microquartz
MSA 1106B
Pallflex
2500 QAO Quartz Kfaer
B70/2075W
T6QA20 Teflon Coated Glass Fiber
(another lot)
T6QA25
TX40H12O
(another lot)
Reeve Angel 934AH Glass Fiber
(acid treated)
Whatman
GF/A Glass Fiber
GF/B
GF/C
EPM 1000
Dclbag Polystyrene
Mkrosotban-$>8
Millipore
MF-VS Cellulose acetate/nitrate
MF-VC
in paniculate sampling.
POBJB FILTER PERMEABILITY
SIZE, VELOCITY, cm/sec
prat 99.99
99-6 - > 99.99
99.5 - >99.99
98.5 - >99.99
99.5 - >99.99
84 - 99.9
84 - 99-95
55 - 98.8
52 - 99.5
65 - 99.3
92.6 - 99.96
98.9 - >99-99
98,9 - >99.99
95.0 - 99.96
99.0 - >99.99
>99.99 - >99.99
99.6->99.99
99.0 - >99.99
98.2 - >99-99
99.999 - >99.99S>
99-999 - >99.999
-------
IAQ Reference Manual
Section 6
Exhibit 6-4. Properties off filters used In pnrtif ulate sampling (tontinued).
FILT1E
Millipore (cautiaueJ)
MF-PH
MF-HA
MB-AA
MF-RA
MF-SS
MF-SM
MF-SC
Polyvic-BD
Pdyvic-VS
PVC-5
Celotsce-EG
Celatste-EH
Celotate-BA
Mitex-LS
Mitex-LC
Fluotopore
BG
FH
FA
BS
Metrical
GM-6
VM-1
DM-800
Geloian Teflon
Ghia
S2 37PL 02
S2 37PJ 02
S2 37PK 02
S237PF02
Zefluor-
P5PJ 037 50
P5PJ 037 50
POE1
SIZE,
MAH5MAL pm
0.3
0,45
0,8
1.2
3.0
5.0
8.0
Polywnyl Chloride 0.6
2.0
5.0
Cellulose Acetate 0.2
0.5
1.0
Teflon 5.0
10.0
PTFl-polyethylene
reinforced
0.2
0.5
0.1
3.0
Cellulose acetate/nitrate 0.45
Polyvinyl chloride 5.0
PVS/Aoryloniaile 0.8
Teion 5.0
Teflon 1.0
2.0
3.0
10.0
Teflon
2.0
3.0
FILTER PERMEABILITY
VELOCITY, on/sec
(AP=lcmHg)
0.86
1.3
4.2
6.2
7,5
10.0
'14.1
0.86
5.07
11.
0,31
1.07
1,98
4.94
7.4
1.31
2.32
7.3
23.5
1.45
51.0
2.7
56.8
12.9
23-4
24.2
32.5
31.6
FILTER EFFICIENCY
RANGE, % *
99,999 - >9$>,999
99.999 - >99.999
99.999 - >99-999
99.9 - >99.999
98.5 - >99.999
98.1 - >99.99
92.0 - >99.9
99.94 ->99.99
88 - >99.99
96.7 - >99.99
>99-95 - >99-99
99.989 ->99.999
99.99 ->99.99
84 - >99.99
62 - >99.99
>99.90 - >99.99
•>99.99->99,99
>99.99 - >99.99
98.2 - >99.98
>99.8 - >99-99
49 - 98.8
99.96 ->99.99
85 - 99.90
>99.97 - >99.99
99-89 - >99.99
92 - 98.98
95.4 - >99.99
94.6 - 99-96
88 - 99.9
(continued next page)
-------
Section 6
IAQ Reference Manual
Exhibit 6-4. Properties of fillers used in parliculate sampling (tontinved).
PORE FILTER PERMEABILITY
SIZE, VELOCITY, cm/sec
F1JLTEI, MAT1MAL
Chcmplast
75-F Teflon Filter
75-M
75-C
Selas Flottonics
FM0.45 Silver
FM0.8
FM1.2
FM5.0
Naclepota
NQ10 Polycarbonate
N030
N040
N060
N100
N200
N300
N500
N800
N1000
N1200
MSA Personal
Aif Sampler
p« CAP
1,5
1,0
1.0
0.45
0.8
1.2
5.0
E. Nuclepore Filter
0.1
03
0.4
0.6
1.0
2.0
3.0
5.0
8.0
12.0
10.0
F. Miscellaneous Filter
12
• 1 cm Hg)
3-
6.6
32
1.8
6.2
9.2
19.0
0.602
3.6
2.9
2.1
8.8
7.63
12.
30.7
21.2
95.
161.1
FILTER EFFICIENCY
RANGE, % *
83-99-99
54 - >99.99
26 - 99.8
93.6-99.98
90 - 99.96
73 - 99.7
25 - 99.3
>99,9 - >99,9
93.9->99.99
78 - >99J9
53 - 99.5
28 - 98.1
9-94.1
9 - 90.4
<5-90.7
1 - 90.5
1-46
1-66
89-99.97
*The range of filter efficiency value given generally corresponds to a particular diameter range of 0.035 to lA, a pressure drop range of 1 to 30 cm Hg
snd a &cc velocity range of 1 to 100 cm/sec.
SOURCE: ftoin Air Sampling Intintmttus for Evaluation efAtmtsp&erk Ceatuminants, American Conference of Governmental Industrial Hygieniws,
Cincinnati, OH, 1983. Reproduced with permission.
-------
Exhibit 6-5. Some
PLASTIC FOM
Mylar
Mylar and TeSon
Mylar, Aluminized,
Mylar Saean,
Scotchpak &
Aluuiiniztd
Scotchpak
Aluminized Scotchpak
Kel-F
Polyvinyl
Satan
FEP-Teflon
Tedlar
storage properties of gases in plastic bags.
GAS OR VAPOR STOBED
Oleflns
Formaldehyde
Formaldehyde
Ozone
NO
so2J
Acrolein
Aeralein
Aliphatic HC
Toluene
Bthyl ether
Ben2ene
Methyl alcohol
Perchlotoerhylene
Trichloioethylene
O.j deficient atmosphere
Methyl ethyl kecone
Amyl Acetate
Acetori*
Xylene
Benzene
Sulfur Dioxide
Nitrogen dioxide
Ozone
Hydrocarbons
Mixtures containing aliphatic
& aromatic hydrocarbons,
aldehydes, ketones, olefins,
sulfiit dioxide & nitrogen dioxide
Carbon monoxide
Nitrogen dioxide
Carbon monoxide
Chlorinated hydrocarbons
BydweadxjfM
Hydrocarbons
SOURCE: From American Conference of Governmental Industrial Hygienist*,
CONCENTRATION
20 to 400 ppm
2 to 3 ppm
Irradiated car exhaust
70 ppm
0.2 to 0.5 ppm
0.5 to 5 ppm
Car exhaust
0,1 to 10 pjwn.
0.1 to 130 ppm
200 ppm
200 ppm
JO ppm
200 ppm
100 ppm
100 ppm
10*
200 p|»a
100 ppm
200 ppm
100 ppm
25pp«
0.5 » 1,55 ppm
0,5 to 1.5 ppm
0.5 to 1.5 ppm
7 to 20 ppui
Ranges of appnw, 50 ppm to
100 ppm
1 to 100 ppm in expired air
1 ppm
1 to 100 ppm
200 ppm
Irradiated car exhaust
Irradiated cat exhaust
Cincinnati, OH, 1983. Air Saatflaig Ittstraia
REMARKS
5 tolOIS loss in 24 hrs
%% in 24 hrs in air mixture
5 » 10% loss in 2 hrs
10% loss in 5 hrs in synthetic »ir
5% in 8 hes in synthetic air
Stable for 4 hrs in bags reconditioned with SO2
10^ loss in 24 his
Stable air mixture
10K- loss for 5 dap in air samples
Data given fee conditioned and unconditioned bags for
up to 288 hr storage
2% loss after _5 days; 20S* loss after 13 days
Data given tor conditioned and unconditioned bags for
72 hr storage
Stontge data given fa periods varying from 16 to
65 hrs for different combinations of components
in different plasric containers
Stable several days
Stable fot 120 hrs
Storage variable with source of supply
Expired air and synthetic air standards
Stable for several hts
Stable for several hrs
tots for Evahadm oj ' Atmspbmc Contaminants. Used with permission.
IAQ Refei
1
8
f»
%
§
***
8
t-l.
**»
§
OS
-------
Section 6
IAQ Reference Manual
Exhibit 6-6. Limitations of selected solid absorbents.
ABSORBENT
LIMITATIONS
Charcoal
Silica gel
XAD-2
Tenax*
Carbon
molecular
sieve
high surface area causes artiiaet formation, during sampling
high background contamination if using thermal desorption
high affinity for water
high catalytic activity
incomplete sample recovery
impurities in solvent extraction may be high
solvent extraction causes dilution of sample
limited use in humid areas
thermal breakdown if using thermal desorption
solvent extraction causes dilution of sample
thermal stability questionable
compounds below C7 lost/breakthrough extensive
poor desorption of highly polar compounds
possibly retains oxygen which leads to sample oxidation
limited to some volatile compounds
high benzene background
low breakthrough volume for some organics
holds onto very volatile compounds
solvent extraction
desorption efficiency decreases with b,p. > 100 °C
SOURCE; U.S. EPA (1989)
-------
IAQ Reference Manual
Section 6
Exhibit 6-7. Sources for testing and calibration procedures applicable to indoor air
quality sampling.
Air Pollution Control Association (APCA)
Box 2861
Pittsburgh, PA 15230
(412-232-3444)
American Conference of Governmental Industrial
Hygienists (ACGIH)
6500 Glenway Avenue, Building D-7
Cincinnati, OH 45211
(513-661-7881)
American Industrial Hygiene Association (AIHA)
475 Wolf Ledges Parkway
Akron, OH 44311
(216-762-7294)
American National Standards Institute, Inc. (ANSI)
1430 Broadway
New York, NY 10018
(212-354-3300)
American Public Health Association (APHA)
1015 15th Street, NW
Washington, DC 20005
(202-789-5600)
American Society for Testing and Materials (ASTM)
Committee D-22 on Sampling and Analysis of
Atmospheres
1916 Race Street
Philadelphia, PA 19103
(215-299-5400)
National Institute for Occupational Safety and
(NIOSH)
Centers for Disease Control
Robert A. Taft Laboratories, MS-R2
4676 Columbia Parkway
Cincinnati, OH 45226
(513-533-8236)
U.S. Environmental Protection Agency (EPA)
Environmental Monitoring Systems Laboratory
Methods Standardization Branch
Quality Assurance Division (MD-77)
Research Triangle Park, NC 27711
(919-541-2622)
-------
Section 6
1AQ Reference Manual
Exhibit 6-8. National Institute off Standards and Technology (HIST) * Standard Reference
Materials (SRMs) for the calibration of instruments and procedures utilized in
air quality analysis.
SRMID
Calibration
1(570
1671
1672
2633
2634
26l9a
2620a
2621a
2<$22a
26l2a
26l3a
26l4a
I677c
2.635a
I678c
I679e
I658a
l<$59a
2627a
2628a
2
-------
IAQ Reference Manual
Section 6
Exhibit 6-8. National Institute off Standards and Technology (NIST) * Standard Reference
Materials (SRMs) for the calibration of instruments and procedures utilized in
air quality analysis Continued}.
SRMID
I693a
I694a
DESCRIPTION
Sulfar dioxide in nitrogen
Sulfur dioxide in nitrogen
COMPONENT
S02
S02
CONCENTRATION
50 ppm
100 ppm
Permeation Devices
1625 Sulfur dioxide 10 cm tube
1626 Sulfur dioxide 5 cm tube
1627 Sulfur dioxide 2 cm tube
l629a Nitrogen dioxide 10 cm tube
Analyzed Liquids and Solids
1579 Powdered lead base paint, 35 g
Sulfur in Fossil Fuels
1616 Sulfur in kerosene
Materials on Filter Media
2676c Metals on filter media (cone in (Jig/filter) Cd
Pb
Mn
Zn
2677 Beryllium and arsenic (cone in Jig/filter) As
Be
2.8 pg/min
1.4 |jg/mia
0.56 pg/min
1.0 p
Pb
Asbestos
1876a Chrysotile asbestos
0.107 ppm - 1.07 ppm
0.0535 ppm -0.535 ppm
0.0214 ppm -0.214 ppm
0.05 ppm-0.5 ppm
11.87
As
<0.01 - 10.09
<0.01 - 29,81
<0.01 - 19.85
<0.01 - 99.29
<0.002 - 10.5
<0.001 - 1.03
37 fibers/ 0,01 mm2
* Formerly the National Buteau of Standards (MBS)
SOURCE: Sewatd(1988)
-------
Section 6
IAQ Reference Manual
6.2. ACCURACY, PRECISION, AND RELATED
TERMS
JMLeasured data can provide an estimate of
the true value of a parameter which can be thought
of as the average or center of an interval. In order to
interpret a measurement, it is necessary to under-
stand the variability associated with the measured
data, and the overall quality of the data,
Accuracy and precision are two measures of data
quality that allow us to identify the center point or
average and the variability of a measurement.
Exhibit 6-9 illustrates these two concepts.
Accuracy is a measure of how close the measured
values are, on average, to the true value. The
concept of accuracy can be easily understood by
visualizing a dart board; the most accurate player is
the one whose shots are scattered evenly around the
bull's eye. A less accurate player may, for example,
tend to hit one side of the board more frequently. In
Exhibit 6-9 the most accurate measurements are
shown in Exhibits 6-9b and 6-9c; in these two
figures, the true value and the measured value
coincide. Accuracy can be described mathematically
as follows:
A=
(Xm - X ) (100)
where,
A = accuracy in percent;
X = measured value; and
m '
X = true value.
Precision describes the variation or scatter among
the results; it is a measure of the uncertainty of the
average—it is not related to the true value. Again,
visualizing the dart board, the most precise player is
the one who consistently places the darts in the
same place, even if they are not near the bull's eye.
In Exhibit 6-9, the most precise measurements are
shown in Exhibits 6-9a and 6-9b; in these two
figures the measured values are closely clustered
around the true value. Figure 6-9c shows measure-
ments that are both precise and accurate. The
standard deviation, s, or the variance, s2, provide a
good estimate of uncertainty of the average mea-
surement. The standard deviation for a sample of
measurements can be calculated from:
where,
and
S(x.-x>2
n-l i=l
s = standard deviation;
n = total number of measurements;
X, = ith measurement of X measurements;
X = arithmetic mean of n measurements.
In many cases, accuracy and precision can be
obtained with the other method and equipment
specifications. If measurements are performed in
the laboratory, the laboratory will evaluate accuracy
and precision through the use of standard reference
materials as part of its quality assurance program.
Ideally, the sampling or analytical method that is
employed by the investigator will be both accurate
and precise. However, it is possible for a method to
have high precision but low accuracy because of
improperly calibrated equipment or inaccurate
measurement/dilution techniques. Alternatively, a
method can be accurate but imprecise because of
low instrument sensitivity or factors beyond the
investigator's control.
Bias (B) is a term that describes the ratio of the
measured value to the true value:
B =
X
Reproducibility describes the extent to which a
measurement method yields the same response to
the same quantity of contaminant. It is similar to
-------
IAQ Reference Manual
Section 6
Exhibit 6-9. Precision and accuracy.
Precision
True Value of
Concentration
Measured
Average
Bias
A. Example of Inaccurate (Positive Bias) but Precise Measurements
Precision
Measured Average
B. Example of Accurate (No Bias) but Imprecise Measurements
True Value
and
Measured Average
C. Example of Accurate and Precise Measurements
SOURCE; U.S. EPA (1975)
-------
SecttoK 6
IAQ Reference Manual
precision, but it is a function of the instrument that
is used rather than the entire measurement process,
and it is evaluated over a long period of time.
Sensitivity is a measure of the accuracy of the
output signal of an instrument, usually expressed as
the ratio of the full-scale output of the instrument
to the full-scale input value. An instrument with
high sensitivity reproduces every fluctuation,
regardless of size, that is received as an input signal.
For example, a very sensitive thermometer may
reflect a ± 0.01 °C change in temperature, but a less
sensitive one may only reflect changes of ± 2.0 °C.
6.3. REPRESENTATIVE SAMPLING
Any sampling program, survey work, or
research problem should have a study design which
is contained in the protocol. The study design
addresses such questions as what contaminants and
equipment to use, the length of the sampling rime,
the sampling locations, and the sample si2e.
A major objective of the study design is to ensure
that a representative sample is collected. This
generally implies a random sample of a sufficient
size that will allow conclusions to be drawn about
the data. Not all investigations will require the
collection of many samples. Some indoor investiga-
tions may involve the collection of only one or just a
few samples. Even if only a few samples are col-
lected, the investigator must still be alert to the
basic principles of collecting representative samples.
Probability Sampling
Valid conclusions can be drawn only if all portions
of a population have a known probability of being
selected during sampling. Where elements of the
population have a higher probability of selection
than others, the selected sample elements must be
weighted to compensate for this difference during
statistical computations. This means that some type
of probability sampling plan must be used to ensure
that the sample is representative of the population
being measured.
The selection of a probability sample can be accom-
plished in several ways. In one method (used for
asbestos sampling) the area or volume to be sampled
is reproduced on paper and divided into numbered
units. The units to be sampled are selected from a
table of random numbers which can be found in
most books on statistics. Random numbers can also
be generated by computer programs. If random
sampling is employed, care must be taken to ensure
that samples are collected at the specified locations
or times. In large survey work, random sampling
can be costly.
An alternative to random sampling is systematic
sampling in which samples are collected at regular
intervals both in time and space. This sampling
scheme may be more cost effective and easier to
accomplish, but bias can enter into the sample
selection if there is a pattern in the data which is
correlated with the structure of the sampling frame.
Another approach is to stratify the sample (either in
time or in space) if the population under study is
known or suspected of being stratified in some way.
This approach has the advantage of resulting in
better precision than random sampling (and it may
be more cost effective). The population is divided
into strata (parts) that are as uniform as possible in
the component of interest. Each stratum is sampled
independently, and the average standard deviation is
calculated. The strata do not have to be equal in
size.
Before any large scale investigation, survey, or
research is undertaken, it is important to get advice
from someone who is knowledgeable in statistical
sampling. Considerable time, expense, and embar-
rassment can be saved by ensuring that the job is
done correctly the first time.
Determining Sample Size
Deciding on the proper sample size for a given
project can be a difficult decision because of the
usual trade-offs between budget constraints and the
ideal situation. Starting points for the selection of a
-------
IAQ Reference Manual
Section 6
sample size are the overall objectives of the monitor-
ing, and the availability of equipment for sampling
and laboratory analyses.
Within these two constraints, the selection of
sample size depends on many factors including:
• contaminarit(s) to be monitored;
• length of time each contaminant is to be
sampled (instantaneous sample, 24-hour, 3-
month, and so forth);
• type of structure, geographic area; and
« time when sampling occurs (season, day of
week, time of day).
The number of samples to be measured depends on
the accuracy desired in the data as well as the
expected variance in the data. When measured data
are arranged according to frequency, some data may
fit a symmetrical or normal distribution which is
defined by the mean or standard deviation. The
mean is found by dividing the sum of the individual
observations by the number of observations. In
many instances, the frequency distributions tend to
be .nonsymmetrical or skewed in one direction.
These data can be represented by a geometric mean
which is defined as the nth root of the product of n
values:
where,
X =
g
X = geometric mean, and
X. = individual data values.
The geometric mean can also be defined as the
antilog of the arithmetic mean of the logarithms of
the data values. Either common logarithms (Iog10)
or natural logarithms (loge) can be used to calculate
the geometric mean. When the data are distributed
according to the lognormal frequency distribution,
the geometric standard deviation, s , is used as a
measure of dispersion instead of the standard
deviation, s. The geometric standard deviation is
defined as the antilog of the standard deviation of
the logarithms of the measurements. It is computed
as for the arithmetic standard deviation, after
transforming each value to its corresponding log
value.
The sample size necessary to achieve a given preci-
sion (for example, being 95% confident that the
true value is plus or minus some amount) can be
approximated using the following equation:
n =
where,
t = the number of standard deviations that
account for the desired confidence level
(area under the normal curve); for example,
2.14 standard deviations account for 95%
of the area under a normal curve
s = standard deviation of the variable to be
estimated; and
d = the margin of error that is acceptable.
In this calculation, a preliminary estimate of the
standard deviation is required. The expected average
may also be desirable for deciding what margin of
error will be acceptable.
When the required information is not available for
calculating the sample size, the expected levels can
be estimated based on professional judgment and
experience, or a pilot'program (small-scale sampling
program) can be used to gather preliminary data
which are then used to refine the sample size
calculations as well as the overall protocol. It is
important to avoid making the sample so. small that
the estimate is too inaccurate to be useful, but
because of cost, a sample that is too large should be
avoided. Since the determination of sample size can
be complicated (for example, nonnormal distribu-
tions, stratified sampling), the investigator is
cautioned to consult with a statistician to be sure
that the proper sample size will be collected in a
cost efficient manner.
-------
Section 6
IAQ Reference Manual
Example Calculation
Assume that the average value of a contaminant
(normally distributed) is to be estimated within
±10% of its true value under a given set of environ-
mental conditions with a confidence of 95%. From
previous studies, it is known that the standard
deviation, s, is 0.20. The required sample size, 18,
is estimated as follows:
n= (2.142)(0.202)
.102
18.
The effect of the acceptable error can be evaluated
by comparing the above results to those if a margin
of error of 20% is acceptable as follows:
n = (2.142)(0.202)
.202
5.
In this example, accepting a greater margin of error
means that fewer samples must be collected.
Whether or not this is a good decision depends on
the consequences of accepting a greater margin of
error.
6.4. CALIBRATION
^Calibration methods and quality assur-
ance procedures for equipment and laboratory
methods are specified in several references (Taylor,
1987; Katz, 1977; and U.S. EPA, 1975, 1977,
1980, and 1989).
Direct reading instruments must be calibrated and
audited on a routine basis if they remain at a fixed
site. An audit is simply a check on the calibration
using one or two calibration points plus zero. Field
monitors which are routinely moved from site to
site should be calibrated before use at a new site (on-
site) and the calibration should be checked at the
end of the sampling period. The calibration curve
should be developed over the concentration range of
interest and should consist of zero plus 3 to 4 points
using standard calibration materials.
Exhibit 6-10 provides an example of a calibration
data sheet. This form can also be used for audits. If
the before and after calibrations differ significantly
from previously identified values (± 5% is a useful
guideline if a value is not specified in the proce-
dure), the data should not be used, and the contami-
nant should be resampled.
Indirect reading methods must also be calibrated.
This may involve calibration of flowmeters followed
by laboratory analysis some time after collection. If
so, the laboratory will have its own procedures for
calibrating equipment used to analyze the collected
contaminant. Some samplers such as passive
diffusion samplers are calibrated by the manufac-
turer—these calibrations can be checked by the
investigator who has the appropriate facilities, but
these checks are not routinely done.
AIRFLOW MEASURING DEVICES
Types of Airflow Measuring Devices
JLhe concentration of a contaminant that is
collected- (by filter, absorber, adsorber, direct
reading instrument) depends on the volume of air
sampled:
Concentration = mass of pollutant/volume
of air sampled.
The volume of air sampled, in turn, depends on the
flowrate, and it is the flowrate which must be
calibrated in both active ^.nd passive direct reading
and indirect reading samplers:
Volume = flowrate x time.
Flowrates can be measured by several different types
of devices (Exhibit 6-11):
-------
IAQ Reference Manual
Section 6
a) volume meters that measure the total
volume of gas over some period of time;
b) rate meters that measure the time rate of
' flow through them—the flowrate is
measured through some property of the gas;
c) variable area meters that measure the rate of
flow through a changing cross-sectional
area; and
d) velocity meters that measure the linear
velocity of a gas through a duct.
Widely used devices for measuring flowrates in
indoor applications are rotameters, orifice meters,
and mass flow meters.
Rotameters
The rotameter is a device that consists of a float that
is free to move up and down in a vertically gradu-
ated, tapered tube (made of glass, metal, or plastic)
which is larger at the top than at the bottom. As
the float moves up and down, a variable ring or
annulus is created between the outer diameter of the
float and the inner wall of the tube. As air flows
upward the float rises until the pressure drop across
the annular area between the float and the wall of
the tube is just sufficient to support it. The height
of the float is noted at the point of maximum
diameter (by convention) and this position on the
vertical scale is compared to a calibration chart to
obtain the flowrate.
The rotameter is the most commonly used device in
the laboratory and in commercial instruments.
Rotameters can be easily calibrated using a bubble
meter; accuracies are ±5% using the calibration
curve supplied by the manufacturer, but accuracies
of ± 1.0% to 2% can be achieved when rotameters
are calibrated in the sampling system as they will be
used (Wilson etal., 1983).
The vacuum pump and rotameter may be combined
into one unit as in personal sampling pumps. Since
rotameters are very sensitive to pressure changes,
they must be calibrated in place with the sampling
system exactly as it will be used during field
operation. Also, periodic cleaning of rotameters is
essential since performance is affected by the
accumulation of moisture and dust.
Orifice Meters
The orifice meter may be noncritical or critical.
Both types can be easily calibrated using a soap-
bubble meter. A noncritical orifice can consist of a
thin plate having one circular hole that is inserted
into a pipe. The pressure drop upstream and
downstream of the orifice can be related to the time
rate of flow. Flowrates from a few ml/min to 50 ml/
min can be measured (Wilson et al., 1983).
The term critical orifice designates an orifice in
which the pressure drop across the orifice is in-
creased until the downstream pressure is equal to
about 0.53 times the upstream pressure. As long as
this ratio remains constant, the flowrate remains
constant for a given upstream pressure and tempera-
ture, regardless of the pressure drop.
Critical orifices can easily be fashioned from hypo-
dermic syringe needles by trimming the plastic end
and inserting the needle into the airflow stream. A
22 gauge hypodermic needle 25 mm long results in
a flowrate of about 1 1/min for a 30 minute sam-
pling time; a 23 gauge needle 16 mm long results
in a flowrate of about 0.5 1/min. Only one calibra-
tion point is needed for a critical orifice, and
accuracies of ± 2% can be expected (Wilson et al.,
1983). Once critical orifices are calibrated, they are
relatively insensitive to pressure changes and can
maintain constant flow for a long time, provided
they do not plug.
Mass Flow Meters
The mass flow meter is a device that works on the
principle that when a gas passes over a heated
surface, heat is transferred from this surface to the
gas. The velocity of the gas is measured by the
-------
Section 6
IAQ Reference Manual
amount of current required to keep the surface at a
constant temperature. The term mass flow rate
arises because the amount of heat transferred
depends on the mass and velocity of the gas. Mass
flow meters are increasingly used in monitoring
instruments. The mass flow meter must be cali-
brated with the same gas which will be measured,
because different gases have different thermal
properties. Flows do not need to be corrected for
temperature and pressure, and the soap-bubble
meter can be used to calibrate the meters.
Calibration of Airflow Measuring Devices
Airflow measuring devices can be calibrated using
primary, secondary, or intermediate standards.
Primary standards are those for which the volume
can be determined by measuring the internal
physical dimensions alone. Accuracies of ± 0.30%
can be reached. Intermediate standards are those
that are calibrated against primary standards; 1% to
2% accuracies can be achieved. Secondary standards
are those that are calibrated against primary or
secondary standards; accuracies of less than 5% can
be achieved (Wilson et al, 1983).
The flowrates of active samplers are typically
calibrated in the laboratory or in the field by the
investigator before the sampling devices are used,
but the flowrates of passive samplers are calibrated
by the manufacturer.
Flowrates that are specified by the methods should
be used. Increasing the flowrate to increase sensitiv-
ity may result in sample loss or decrease the collec-
tion efficiency. Always consult with a knowledge-
able person before changing any parameters in a
method.
Flowrates for indoor air measurements must be low
enough not to affect air movement and air exchange.
Personal sampling pumps operate at flowrates up to
4 1/min for 8 hours and are powered by internal
batteries. Batteries must be fully charged before
sampling begins or data could be lost if the pump
quits before the sampling period is finished.
Standard methods will specify flow rates both as a
range and acceptable percent change during a given
sampling period. The flowrate must be measured
both before and after sampling to ensure that the
pump was operating properly during the entire
sampling period. This will also prevent a faulty
pump from being used for subsequent sampling
efforts. Routine calibration of the flowmeter is a
must.
It is important to perform the calibration with the
sampling system in place exactly as it will be used
during operation (that is, impingers should be filled
with solution, filters should be loaded onto cas-
settes, and so forth).
Flowmeters should be calibrated over several points
(4 to 5); however, devices with a fixed flow (critical
orifice) would be calibrated at a single point. A
sample calibration data form for the calibration of
rotameters is given in Exhibit 6-12.
Soap-Bubble Meter
The most commonly used devices to calibrate
flowrate measurements for indoor environments are
the soap-bubble meter and the wet test meter. A
soap-bubble meter is one of the simplest and most
basic primary standards; it is also relatively inexpen-
sive (less than $100 for the meter) and easy to use.
It is nothing more than a cylindrical tube that has
graduated markings to identify volume. Inverted
burets are commonly used as soap-bubble meters,
but they can only be used to calibrate vacuum
pumps. In order to calibrate positive pressure flows,
the soap-bubble meter must be used.
The soap-bubble meter must itself be calibrated
before it can be used to calibrate flows from pumps.
This is done by the manufacturer. The calibration
can be checked by filling the tube with water and
measuring the liquid from the top graduation to the
bottom graduation. A temperature correction must
be applied. The soap-bubble meter should only be
used to measure volumes between gradations that
have been calibrated. In an average laboratory
-------
IAQ Reference Manual
Section 6
setting the soap-bubble meter is accurate to about
± 1%; accuracy decreases for flows greater than
1 1/min or less than 1 ml/min. The calibration and
use of bubble meters a,re discussed in an article by
Levy (1964).
The set up for calibrating under vacuum and
pressure conditions is shown in Exhibit 6-13 for the
soap-bubble meter and an inverted buret. The
calibration procedure using either device begins by
wetting the inside of the tube with a soap solution.
Commercial surfactant products such as "Snoop" or
dishwashing soaps such as "Ivory" work well. Some
experimentation is needed to get the right propor-
tion of soap to water. Next, a bubble is formed by
either touching the tip of the buret to the soap
solution (Exhibit 6-13c) or by squeezing the rubber
bulb until the soap solution is raised above the gas
inlet (Exhibit 6-13 a,b).
The bubble is moved up the tube by either a
vacuum at the top or a slight positive pressure at the
bottom of the tube. The volumetric flow rate can
be calculated by measuring the time (with a stop-
watch) it takes the bubble to move through a given
volume:
Flowrate = V /time.
ffieas
Because of the potential variability in measuring the
time, each flowrate should be measured five times.
The average time should be used in the calculation
of the flowrate. Before the flowrate is calculated,
the measured volume must be corrected. First, a
pressure and temperature correction must be applied
if the room conditions are different from standard
atmospheric conditions:
V = V
STP n
„ (PJ760 mm Hg) (298»K/Tatm).
where,
VSTp'= volume at STP;
V = measured volume;
m*o« —-.-,-. — 3
Patm = atmospheric pressure (mm Hg);
T = atmospheric temperature (°K).
Second, the volume must be corrected for water
content of the air. If the gas behind the bubble has a
relative humidity greater than 50%>, the error is
small; if the gas is dry, the error can be large and
must be corrected:
V =
t(P - P
x atm
atm w' acm
where,
V = volume (STP) corrected for water
cocr x '
vapor, and
P^ = vapor pressure of water at room
temperature (mm Hg); can be
found in a handbook of chemistry.
Wet Test Meter
The wet test meter is an intermediate standard that
must be calibrated against a primary standard before
it can be used. It operates much like a waterwheel.
The meter consists of a series of inverted traps that
are mounted radially around a shaft that rotates.-
The traps are partially immersed in water, and gas
that enters the meter fills the traps which causes the
shaft to rotate. The volume of gas that enters and
exits the meter is registered by rotating index
pointers.
The meter is prepared by first leveling and then
filling it to the proper level with water. The water
should be allowed to equilibrate until it is the same
temperature as the surrounding air. Gas is passed
through the meter for several hours to saturate the
water with the gas. Once the meter water level is
set and the meter is equilibrated, it is ready to use.
Enough gas is drawn through the system to move
the drum, and each point is measured several times.
Wet test meters should not be used with gases (such
as sulfur dioxide) which produce a corrosive solution
with water. Temperature and pressure corrections
must be made.
-------
Section 6
IAQ Reference Manual
Exhibit 6-10. Example calibration or audit form for a direct reading carbon monoxide or
carbon dioxide monitor.
. Audit
Calibration
Site#
Location
Operational Period
Instrument
Serial #
to
Date
Operator.
Range Setting
Zero Setting _
Span Setting _
Cylinder #
Standard
Cone.
Response
% Chart
Measured Cone.
% Diff.
Remarks
To determine recorder response when setting span during calibration:
(cylinder concentration/.?) + baseline = % chart (100% of scale = 50 ppm)
Measured concentration = (Response % chart - baseline) (.5)
% Difference = Measured concentration - Standard concentration x 100
Standard Concentration
SOURCE: U.S. EPA (1977)
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IAQ Reference Manual
Section 6
Exhibit 6*11. Different types of airflow meters.
A. Volume Meters
(1) Soap Bubble Meter-
Primary Standard
To Vacuum Shaft
Calibration Point
for Water Level
(2) Wet-Test—Intermediate Standard
Water Manometer
.Thermometer
Rotating Partitioned Drum
Filling Funnel
Inverted-
Buret
-Stopcock
Moving
Bubble
Soap Solution Cock
B, Rate Meters
Orifice Meter—Secondary Standard
Gas In >
C. Variable Rate Meter
Rotometer—Secondary Standard
Air Out
Tapered Tube
bveling Screws
(b)
Gas Outlet
Direction of
Rotation
Water
Level
Gas Out
'Orifice
Section A A
Annulus
Section B B
SOURCE; Wilson etal, (1983)
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Section 6
IAQ Reference Manual
Exhibit 6-12. Sample rotameter calibration form.
Rotameter serial number Calibrated with
Location
Atmospheric ,j. ,,
temperature atm "
"C + 273 =.
°K
Atmospheric pressure (Patm), mm Hg .
Calibrated by
Vapor pressure of H2O (P ), mm Hg_
Date
Test
point
9
10
11
12
13
14
15
Rotameter Bubble
reading displacement
units time,
min
' V = V
STP men
Average Volume
time (t), ! displaced,
\ »meas/
min • ml
Volume at Flowrate,
STP (V V ' r» V
0 A r \ V CTD/ > i U STP
ml
ml/min
Remarks
SOURCE: U.S. EPA (1977)
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IAQ Reference Manual
Section 6
Exhibit 6-13. Calibration using the soap-bubble meter.
A. Vacuum Mode
Gas Out (2)
Bubble Breaker
Graduated Tube
Gas In (1)
Soap Bubble
Soap Solution
Rubber Bulb
•|Gasln(3)
C. Calibration of a Critical Orifice and Bubbler Train Using a Soap-Bubble Meter (Inverted Buret)
Bubble
Trap
t
1,000 a'i
'Air Flow
Membrane Filter (Millipore Type AA)
Hypodermic Needle
Bubble
Meter
Bubbler Trap Rubber Septum
Stopwatch
SOURCE: Wilson etal. (1983)
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Section 6
IAQ Reference Manual
Wet test meters are not for field use. They are
bulky, heavy and require special environmental
conditions; therefore, they are seldom used outside
the laboratory. They do have a high accuracy (< 0.5%)
and can be used to calibrate flowrates in the range of
0.5 to 20 1/min (Lioy, 1983).
SECTION 6.5. PASSIVE SAMPLERS
Recent technological advances have
resulted in the development of a variety of small,
lightweight devices that can be worn by an indi-
vidual to measure exposures over varying periods of
time. These sampling devices include both active
and passive monitors. Passive monitors have
expanded the ability of the investigator to collect
data unobtrusively and at a reasonable cost per
sample. Results are expressed as the measured
concentration during a given period of time (ppm-
hr); the time period for sampling should be in-
cluded in the reprint of results.
General descriptions of some types of passive
samplers are given below; further discussion of
passive samplers can be found in Wallace and Ott
(1982) and Berlin etal. (1987). Characteristics of
specific samplers are given in Exhibit 6-2a.
Sorbent Badges
Sorbent badges contain liquid or solid sorbents in a
reusable badge housing. These are widely used in
the workplace to collect both organic and inorganic
contaminants, and some of these may be appropriate
for indoor air measurements. Sorbent badges can be
attached to an individual's clothing to approximate
the breathing zone.
Liquid sorbent badges: Liquid sorbent badges
consist of a liquid-filled chamber which has a
bound-liquid membrane on the sampling face.
Contaminated air diffuses through a diffusion
barrier at a previously determined rate and comes
into contact with the bound-liquid membrane.
Sorbent badges can be obtained with a collecting
medium capacity of 5 ml to 25 ml and flowrates
from 0.5 to 50 ml/min. A variety of analytical
methods can be used to analyze the contaminant-
containing liquid including direct injection into a
GC, GC with purge and trap techniques, specific
ion electrodes, and colorimetric methods. Badges
can be reused if they are properly cleaned and
refilled (refill kits can be purchased). The cost is
about $30-$45 for each badge, and refill kits can be
purchased for about $30 for 10 kits. Not all of the
potential applications have been verified with
validation studies.
Solid sorbent badges: Sorbent badges with solid
sorbents also rely on diffusion to transport contami-
nants at a constant sampling rate into the sorbent.
These samplers can be purchased with a backup
sorbent which is located behind the primary
sorbent. Since sorbents have a finite capacity, the
use of a backup sorbent or two sorbents in parallel,
but at different sampling rates, is a recommended
practice. After the sample has been collected, the
sorbent capsule is removed, placed into a container,
sealed, and transported to the laboratory. Both the
primary and backup sorbents are analyzed. Analysis
can be accomplished by a variety of methods as
noted under liquid sorbents. Charcoal, silica gel,
XAD-2, and other sorbents can be purchased.
Typical costs are about $10-$ 15 for the resusable
capsule holder and about $2 for each sorbent
capsule.
Sorbent filters and me'tallic grids: A variety of
sorbent devices are available for sampling gases.
These devices are configured as both tubes and
badges. One example is the Palmes tube (or similar
device), which has been widely used to sample
nitrogen dioxide indoors. It is a small acrylic tube
(1.27 cm outside diameter, 0.95 cm inside diam-
eter, and 7.1 cm long) which has three stainless steel
grids stacked and held into place by a cap at one end
of the sampler. The grids are precoated with
triethanolamine (TEA). The bottom end of the tube
is open to the air and allows the nitrogen dioxide to
diffuse upward to the TEA coated grids. After
exposure the open end of the tube is capped and the
sampler is sent to the laboratory for analysis. The
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JAQ Reference Manual
Section 6
Palmes tube has also been used to sample sulfur
dioxide and carbon monoxide.
Color Badges
Color badges, which provide immediate results, are
also available. These badges are similar to colori-
metric detector tubes. The badges consist of a
sampling tube that contains a chemical which reacts
with a specific contaminant to produce a color
change. The length of the color stain and the
sampling time are used to determine concentrations.
In general, color badges are not sensitive enough for
indoor air monitoring.
Passive Bubbler
Another potentially versatile passive monitor is the
Passive Bubbler™. It consists of a glass vial sealed
with a TefkwoMaced Rttudsen diffusion disk and
cap. The disk can be reused up to three times, but a
new disk for each sample is recommended to
minimize sampling errors. A sorbing solution is
placed into the vial and the vial is clipped to the
clothing of a potentially exposed person or placed on
a stand to collect an area sample.
The Knudsen diffusion disk controls the rate of
sampling, which is accurate over a range of air
velocities from 25 tpm to 250 fpm without correc-
tion. The sampling rate of the bubbler can be
determined by comparison with a reference method
or by using a test atmosphere (Miksch, 1989a,b).
After the sample is collected the disk and septum
cap are removed and replaced by a solid Teflon-lined
cap. The collected sample can be analyzed by GC,
HPLC, ion specific electrodes, colorimetry, or other
methods.
SECTION 6.6 AIR EXCHANGE RATES
JMeasurements of air exchange rates may
be needed for some types of modeling studies or to
evaluate the effectiveness of control strategies.
Several tracer gas techniques, either short-term or
long-term, can be used for measuring infiltration in
residential and commerical buildings. Tracer gas
techniques and instrumentation for studying
building air exchanges are reviewed by Persily
(1988) and Dietz (1988).
A commonly used method is referred to as the
tracer-gas decay method. In this procedure a known
concentration of a gas such as sulfur hexafluoride or
nitrous oxide is injected into a space and the
decrease in the concentration of the gas, which is
referred to as the decay of the gas, is measured over
time. The concentration of the tracer gas is assumed
to be negligible outside of the structure, and the
rate of dilution of the tracer gas is proportional to
the rate at which outside air enters the structure.
A portable, nonintrusive passive system based on
the tracer-gas decay method has been developed at
Brookhaven National Laboratory {Dietz;, et at,,
1986). This method is available commercially
through the National Association of Home Builders
(NAHB) National Research Center, 400 Prince
Georges Center Boulevard, Upper Marlboro, MD
20772-8731.
The NAHB method, which is called the Air
Infiltration Measurement System (AIMS), uses
perfluorocarbon tracers (PFTs) to measure infiltra-
tion for periods of a few days to 6 months (Song and
Fan, 1989). The system uses a source emitter which
releases PFT gas at a rate of 1 to 4 x 10"81/min. A
uniform concentration is established within 5 to 6
hours. The receiver is a capillary adsorption tube
(CAT) which contains a small amount of activated
ambersorb to capture the perfluorocarbons. Air
enters the receiver by diffusion at a constant rate of
0.2 I/day. Since the rate of emission is temperature
dependent, air temperatures should be measured,
and the emitter and receivers must be placed
carefully. After exposure, the adsorption tube is
analyzed by a chromatograph using an electron
capture detector. The cost is about $50 per 500 ft2
of floor area or $50 per sampler tube. Multizone
analysis typically costs $60 per 500 ft2 of area or
i per sampling tube.
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Section 6
1AQ Reference Manual
Tracer-gas decay methods are relatively accurate,
but they do have shortcomings. First, they are
unable to provide much information about the
location of air leaks in a structure, and second,
short-term tests cannot determine infiltration under
weather conditions different from those present at
the time of the test, EPA has developed standard
methods for both the PFT-CAT system and the
suMur hexafluoride procedure (U.S. EPA, 1989).
Air exchange rates can be measured indirectly by
estimating the effective leakage area of the struc-
ture. The effective leakage area is equivalent to the
sum of the areas of all the openings In the building
shell through which air is able to pass. The effective
leakage area can then be used in an infiltration
model to estimate the uncontrolled air exchange
rates of the structure. These models are outlined in
Diamond and Gtimsrud (1984).
The fan pressurization method uses a variable-speed
fan, which is mounted oo. a door which connects to
the outside, to move large volumes of air into or out
of a structure. The fan is used to pressurize and
depseessurize the structure. The flow of ait through
the fan is determined at a given pressure differential
and fen speed by comparing measurements to a
calibration curve. A pressure versus flow curve is
determined by taking measurements at several fixed
pressure differentials, for example, from 10 pascals
to 70 pascals, at 10 pascal intervals. These data are
then used in a mathematical equation to determine
the effective leakage area of the structure. Addi-
tional overviews of these methods can be found in
Wadden and Scheff(1983) and Diamond and
Grimsrud (1984).
REFERENCES
Berlin, A,, R.H. Brown, and K.J. Saonders (eds). 1987,
Diffusive Sampling, An Alternative Approach to Workplace Air
Monitoring. Royal Society of Chemistry: London, England.
Diamond, R.C. and D.T. GrimsrucL 1984. Manual m Indoor
Air Quality. EPRIEM-3469. Lawrence Berkeley Lab.:
Berkeley, CA.
Dietz, R.N., R.W, Goodrich, B,A. CMC, and R.F. Wiesec.
1986, "Detailed description and jperferenance of a passive
perfiuorocarbon tracer system for building ventilation and air
measurements." Measured Air Lmkage of BuiUings. H,R.
Trechsel and P,L. Lagus (eds). ASTM STP 904. American
Society for Testing and Materials: Philadelphia, PA,
Dietz, R.N, 1988, "Overview of tracer technology instrumen-
tation for short-term and real-time building ventilation
determinations." BNL4lOd7. Brookhaven National Labora-
tory: Upton, NY.
Kat£, M. (ed). 1977. Methods of Air Sampling and Analysis,
2ad Edition, American Public Health Association: Washing-
ton, DC.
Levy, A. 1964. "The accuracy of the bubble meter method for
gas flow measurements." J. 3d, Instrum, 41: 449-453,
Lioy, PJ. (ed), 1983. Air Sampling Instruments for Evaluation of
Atmaiphtfic Contaminant!, 6th edition, American Conference of
Governmental Industrial Hyjjienists: Cincinnati, OH.
Mifcsch, R.R. 1989- "A new'Passive Bubbler'personal
monitor employing Knudsen diffusion: II. Application to the
measurement of formaldehyde." Submitted for publication.
Nader, J.S..J.F. I#udecd*le, and C.S. MeCammon, 1983.
"Direct reading instruments for analyzing airborne gases and
vapors." Chap, V, Air Sampling Imtrtaiants. 6th edition. PJ,
Lioy (ed). Amercso Conference of Government Industrial
Hygienists: Cincinnati, OH.
Persily, A.K, 1988, Tracer Gas Ttchniquss far Studying Building
Arr Exchange, NBSIR 88-3708, U.S. Department of Commerce,
National Bureau of Standards (now NIST): Gaithersburg, MD.
Ritchie, I.M. and C. Deal. 1988. "Survey of commercially
available indoor air monitoring equipment," SPEA/88-2G,
SPEA: Indianapolis, IN.
Sewatd, R.W. (ed), 1988, NBS Standard Reference Materials
Catalog 1988-89. NBS Special Publication 260. National
Bureau of Standards (now NIST), Office of Standard Reference
Matefiais: Gaithersburg, MD.
Song, B, and J.C. Fan, 1989- "An easy way to monitor air
infiltration in homes," National Association of Home Builders
(NAHB) National Research Cenrer; Upper Marlboro, MD,
Taylor, J.K. (ed.). 1987, Sampling and Calibration for Atmt>-
ipherit Measurements, ASTM STP 957. American Society for
Testing and Materials: Baltimore, MD.
-------
IAQ Reference Manual
Section 6
U.S. Environmental Protection Agency (EPA). 1975. Quality
Assurance Handbook for Air Pollution Measurement Systems. Volume
I - Principles, U.S. BPA, Quality Assurance and Environmental
Monitoring Laboratory, Office of Research and Development:
Research Triangle Park, NC.
U.S. Environmental Protection Agency (EPA). 1977, Quality'
Assurance Handbook for Air Pollution Measurement Systems, Volume
tt - Ambient Air Specific Methods, {revised 7/84 and 9/85) EPA-
600/4-77-027a: U.S. EPA, Environmental Monitoring Systems
Laboratory, Office of Research and Development: Research
Triangle Park, NC,
U.S. Environmental Protection Agency (EPA). 1980. Interim
Guidelines and Specificatiens for Preparing Quality Assurance Project
Plans. EPAQAMS-005/80. U.S. EPA, Office of Monitoring
Systems and Quality Assurance, Office of Research and «
Development: Washington, D.C.
U.S. Environmental Protection Agency (EPA). 1989. Compen-
dium of Methods for the Determination of Air Pollutants in Indoor
Air. Draft. U.S. EPA, Atmospheric Research and Exposure
Assessment Laboratory: Research Triangle Park, NC.
Wadden, R.A. and P.A. Scheff, 1983. Indoor Air Pollution,
Characterization, Pndtct'tm, and Control. John Wiley & Sons,
Inc.: New York, NY.
Wallace, L.A. and W.R. Ott. 1982. "Personal monitors: A
state-of-the-art survey." J. Air Poll. Coat. Assoc. 32(6): 601-
•610.
Wilson, MX., D.F. Elais, and R.C, Jordan. 1983. APTI.
Course 435. Atmospheric Sampling. 2nd edition. Revised by
K.C. Joerger and B.M. Ray. U.S. EPA, Air Pollution Training
Institute: Research Triangle Park, NC.
-------
Page Intentionally Blank
-------
SECTION 7.
STANDARDS AND
GUIDELINES FOR
VENTILATION AND
HEALTH EFFECTS
This section contains tabulated
information on available standards
and guidelines. Exhibit 7-1 provides
quantitative information on both
public health and occupational
concentration limits for various
chemical contaminants. Exhibits 7-2
and 7-3, which are taken from
ASHRAE Standard 62-1989, provide
outdoor air requirements for various
indoor spaces. Exhibit 7-4 provides
ventilation requirements for residen-
tial structures which are contained in
the current Uniform Building Code;
these requirements may be changed
pursuant to the issuance of ASHRAE
Standard 62-1989. Exhibit 7-5
summarizes acceptable seasonal ranges
of temperature and humidity from
ASHRAE Standard 55-81.
Unit 2, lesson 7 of the Learning
Module should be consulted for
explanations and guidance on the use
of these standards.
Table of Contents
list off Exhibits
Exhibit 7-1. Air quality standards and guidelines for
selected contaminants. 186
Exhibit 7-2. Outdoor air requirements for ventilation
of commercial facilities (offices, stores,
shops, hotels, sports facilities). 195
Exhibit 7-3- Outdoor air requirements for ventilation
of residential facilities (private dwellings,
single, multiple). 199
Exhibit 7-4. Uniform Building Code ventilation
requirements. 200
Exhibit 7-5. Acceptable ranges of temperature and
humidity during summer and winter. 202
-------
Exhibit 7-1.
Air quality standards and guidelines for
selected contaminants.
STANDARD OR GUIDELINE (m « mg/ra3! (1 * (Ig/m1)
AVERAGING PUBLIC HEALTH OCCUPATIONAL
SUBSTANCE
AcetaMehyde
Acetone
Acrolein
Acrylonitrile+
Aldehyde (total)
Ammonia
Arsenic*
Asbestos+
Benzene*
TIME EPA WHO ASHKAE
8hr
15 min
8hr
15 min
8hr
15 mjn
8hr *
ceiling
Ihr
8hr
15 min
ceiling
8hr
ceiling *
annual *
8hr
ceiling
8hr *
ceiling
CANADA OSHA NIOSH
180m
270m
1800m
2400m
250|i
soon
4340|i 2170(1
21700(1 21700(1
R<1
27m
34.8m
500(1
2jl
0.20cc
O.lffcc
0.10cc
3.1m 0.32m
7.8m 3.2m
ACGIH
180m
270m
1780m
2380m
230(1
690(1
4340(1
17m
24m
200(1
32m
COMMENTS
OSHA standard is given in 1910.1045
R = sum (ci/Ci)
ci = measured concentration over a 5 min.
period
Ci = 120(1 formaldehyde
50(1 acrokin
9000(1 acetaldehyde
NIOSH ceiling is set for 5 minute exposure.
OSHA standard is for organic compounds.
ACGIH TWA is set for soluble compounds.
NIOSHceiling is set for 15 minute exposure.
OSHA standard is given in 1910.1001.
NIOSH level for fibers over 5 um length.
ACGIH levels (TWA) are
arnosite O.Sffcc
chrysotile Z.Offcc
cwcidolite 0.26tc
other 2.0&CC
f/cc = fibers per cubic cm
NIOSH ceiling is set for 1 5 minute exposure.
OSHA standard applies to industry exempt
ftom 1910.1028,
§•„
o
MM
10
fc
•5
If*
1
R>
SN
8
-------
Exhibit 7-1.
SUBSTANCE
Beryllium*
Cadmium fume-F
Calcium oxide (lime)
Carbon dioxide
Carbon disulfide
Carbon monoxide
Chloidanet
Air quality standards and guidelines for selected
STANDARD OR GUIDELINE (m »
AVERAGING PUBLIC HEALTH
TIME 1PA WHO ASHRAE CANADA
8hr
ceiling
annual .01-.02
8hr
ceiling
8hr
continuous 1800m
long term 1800m 6300m
10 hr
8 far
15 min
10 min
24 hr .10m
10 hr
8hr
30 min .02m
15 min
8hr 10m 10m 10m 12.6rn
Ihf 40m 30m 40m 28.6m
30 min 60m
15 min 100m
maximum
8hr
continuous. ,005m
30 min
contaminants {(ontinued).
mg/m3; |l= pg/m3)
OCCUPATIONAL
OSHA NIOSH ACGIH
2p. 2jl
5H 0.5U
100(1
300^ 50p.
5m 2m
18000m
18000m 9000m
54000m 54000m
54000m
3m
12m 31m
100m
36m 30m
40m 40m 57m
458m
229m 229m
0.5m 0.5m
2m
COMMENTS
WHO guidelines ate annual:
-------
ra
Exhibit 7-1.
SUBSTANCE
Chlorine
Chloroform*
Chlorpytifos
Chromium
(II and III)
Cresol
Diazinon
Dichlorvos (DDVP)
p-Dichlorobenzene
1 ,2-dichloroethane+
(ethylene dichloride)
di-(2-ethyl hexyl)
phthalate(DEHP>+
Ethyl acetate
Ethyl benzene
Ithyl ether
Air quality standards and guidelines for selected
STANDARD OR GUIDELINE
-------
exhibit 7-1.
SUBSTANCE
Ethylene dichloride*
Formaldehyde*
{see, aldehyde*)
Heptaeihlor-t-
Hydrochloric acid
(hydrogen chloride)
Hydrogen sulfide
Lead*
Malatluon
Manganese .
Air quality standards and guidelines fer selected contaminants (tontinued).
STANDARD OE GUIDELINE (« =
AVJEHAGING PUBLIC HEALTH
TIME BPA WHO ASHSAI CANADA
8ht
15 mitt
8hr
30 min ,1m •_
15 min
ceiling
8hr
ceiling
24 hr .15m
8hr
30 min ,007m
15 ruin
ceiling
annual .5-1(1
3 month 1.5JI 1,5)1
10 br
8hr
8hr
annual ,001m
8hr
15 min
mg/m3; i
OSHA
4m
8m
I.2m
2,5m
0.5m
7m
14m
21m
SOjl
10m
1m
3m
OCCUPATIONAL .
NIOSH • ACGIH
40jn
1.2m
0,12m 2,5m
0,5m
7,5m
14m
21m
15«
<100Jl
150(1
15m 10m
1m
3m
COMMENTS
ACSIH proposed ceiling limit is 0.45m.
WHO level set to avoid complaints from •
sensitive people exjxjsed in non-industrial
indoor settings.
NIOSH level reflects lowest reliably
quantifiable concentration.
OSHA standard is given in 1910,1048.
1.2m a I ppm
WHO guideline of ,007m is based on
sensory effects.
NIOSH ceiling set for 10 minute exposure.
OSHA s«nd«d is given in 1910,1025.
NIOSH limit set so workers' blood lead
remains <60 g/lOOg blood.
ACGIH limit is fot inorganic dusts and
fumes.
WHO limit is based on the assumption that
this limit will result in blood lead levels
<0,2 Hg/rul for 98* of the population.
WHO: short-term guideline desirable; but
lack of data to set short-term limits.
ACGIH limit is fot femes; the 8 hr TWA
fot dust is Jra.
(continued next-paee)
IAQ Referent
ra
1"
a
!••
**
«?
|,
a
-------
Exhibit 7-1.
SUBSTANCE
Mercury
Methylene chloride*
CDichloHMMthane)
Methyl alcohol
Methyl ethyl ketone
Air quality standards and guidelines for selected contaminants (tontlnued).
STANDARD OR GUIDELINE (» -
AVERAGING PUBLIC HEALTH
TIME 1PA WHO ASHRAB CANADA
annual Iji
8ht
24 hi 3m
8hr
ceiling
10 hr
8hr
15 into
8hr
15min
Methyl isobutyl ketone 8 hr
Mictobial/biological
contaminants
Nickel*
Nitrogen dioxide
15min
annual *
10 br
8br
long cetm 100^
annual 100)1 • 100)1
24 hr 150(1
Shr
1 hr 400jl 48QH
15 rain
rngto'j ft- PS/IB*)
OCCUPATIONAL
OSHA NIOSH ACGIH
50|i SOp. 50|l
173.8m 174m
350rn
262m
260m 262m
310m 1048m J28rn
590m 590m
885m 885m
205m 205m
300m 308m
0,015m
,1m .1m
5600H
18QOH 1800ft 9400JI
COMMENTS
ACGIH and OSHA standard of 50 is for
non-alkyl vapor, but limits are 10JI
CTWA) and 30)1 (STEL) for alkyl
compounds.
WHO guideline is for indoor air.
NIOSH recommends reducing exposure to
lowest feasible limit.
OSHA standard is in rulemaking.
No forma! guidelines/standards; ACGIH
guideline! state that fungi conceattttions
less than 100 CHJsftrfate not of concern.
ACGIH proposed TWA is 0.05m for soluble
compounds and the metal.
OSHA and ACGIH staodatds are for soluble
compounds.
Section 7
1,4
(O
1
s
§
5
s»
1
-------
Exhibit 7-1. Air quality standards and guidelines for selected contaminants (tontinued), ,
SUBSTANCE
Nitrogen monoxide
(Nitric oxide)
Ozone
Particuhtes (PM-10)
Particnktes (PM-2,5)
Pefttaehlotophenol
Petroleum distillates
(naphtha)
Phenol
Polynudeat aroimtic
hydiocarbons*
(carcinagenic traction)
Propylene dichloride
Pyjwthrum
AVERAGING
TIME EPA
10 hr
8hr
conttewotis
8hr
1 hr 235(1
15 min
annual 50(1
24 hr 150(1
8hr
long term
8hr
Iht
8hr
8hr
10 hr
8hr
15 min
8hr
15 min
Shr
STANDARD OR GUIDELINE (at « rng/m3; (1 = }lg/rn>)
PUBUCHEA1TH OCCUPATIONAL
WHO ASHRAB CANADA OSHA NIOSH ACGIH
30m
30m 31m
100(1
100-200)1 200(1
150-200(1 235(1 240(1
600(1 200(1
150(1
1500QH 10000(i
40(i
5000(1
100(1
0.5m .0,5m
IfiOOm 1370iu
20m
19m 19m
60m
350m 347m
510m 509ni
5m 5m
COMMBNTS
. 'ASHRABstandardisforindoorsourcesonly.
OSHA standard is for total dust, not
otherwise classified.
OSHA standard is fix respitablc fraction, dot
- otherwise classified.
ACGIH and OSHA staodard for coal tar
pitch volatiles as benzene solubles is 0,2m
(TWA),
(continued n&xt paee)
IAQ Reference Manual
1
VI
-------
Exhibit 7-1. Iff
qualify standards
AVERAGING
SUBSTANCE
Radon
Styrene+
Sullur dioxide
Sultkricadd
TetrtchloioethyleBe-i-
(perchloroethylene)
Toluene
TIME EPA
annual 4 pCM
24 hr
10 hr
8hr
30 min
15 min
ceiling
long term
annul 80jj
24 hr 365(1
10 hr
Shr
Ibr
15 min
10 min
5 min
10 hr
Shr
15 min
24 hr
Shr
30 min
ISfflm
24 hr
Shr
30 min
15 min
10 min
^^^^^^^^^^^^^^^^^^^^^^^^^^^H "49
^^^^^^^^^^^^^^^^^^^^^^^^^^^B so
m*m^**mmm*
and guidelines for solactad contaminants (tontinuod).
STANDARD OR OUIDEUNi (m » mglafi |l - Pg/m1)
1PUB3UC HEALTH OCCUPATIONAL
WHO ASHRAE CANADA OSHA JNIOSH ACGIH
2.7 pGA 4 pa/1 2U|Ci/I
,80m
213m
215m 213m
,07m
425» 426m
426m
50|A
80(1
365H
BOOH
5000H. 5200(1
350JI
10000|i IJOOOp.
500(1
looon
1m
1m 1m
3m
5m
170m S39m
8m
1368m
7.5m
375« 375m 377m
1m
560m 565m
750m
1
(
COMMENTS
BPA recommends undertaking mitigation
In homes with levels above 4pCi/L
WHO guideline is foe new construction;
remedial action should be taken without
delay at >10,8pCi/l.
WHO 30 minute guideline is based on odor
direction.
WHO: more data needed; however,
repeated exposure at or above 0,1 mg/m3
is cause fer concern.
N1OSH recommends minimizing workplace
eqponue «nd limiting number of exposed
workers.
WHO guideline of 8m is bated on sensory ;
effects.
WHO guideline of 1m is based on sensory
effects.
|
1"
>M
«-.
10
f,
8
8
S
3
1
-------
Exhibit 7-1. Air
quality standards and guidelines for selected contaminants (continued).
AVERAGING
SUBSTANCE TIME EPA
Trichloroethylene+
1,1,1-Trichloroethane
Vanadium
Vinyl acetate
Vinyl chloride*
Water vapor
(relative humidity)
Xylene (o, m, f>-isomers)
Zinc
24 hr
10 hr
8hr
15 min
8hr
15 min
24 hr
10 hr
8hr
15 min
Shr
15 min
annual
Shr
15 niin
Shr
15 min
10 min
10 hr
Shr
15 min
STANDARD OR GUIDELINE (m = mg/m3; (l
PUBLIC HEALTH
WHO ASHRAE CANADA OSHA
• 1m
270m
' 1080m
1900m
2450m
1(1
50(1
30«
60m
*
1.5m
7.6m
20-60% 30-80% summer
30-55% winter
435m
655m
10000(i
= (lg/m3)
OCCUPATIONAL
NIOSH ACGIH
134m
269m
1070m
1910m
2460m
lOOOp,
50|i 50(1
35m
70m
13m
434m 434m
651m
868m
5000(1
10000(1
15000(1
COMMENTS
OSHA and ACGIH limits are for vanadium
respirable dust or fumes.
NIOSH 10 hr limit set for metallic
vanadium and vanadium carbide.
NIOSH recommends lowest reliable
detectable level.
OSHA standard is given in 1910.1017.
NIOSH recommends limiting exposure to
lowest reliably detectable level.
NIOSH limits ate for zinc oxide.
OSHA and ACGIH limits are for zinc oxide
total dust. Limit for respirable fraction is
SOOOji.
1 SOURCE: Adapted from US. EPA, (1989)
(continued next paee)
IAQ Reference Manual
**.
§
-------
Exhibit 7-1. Air quality standards and guidelines for selected contaminants, (tontinued)
Notes
Reported values were converted where necessary so that all values foe the same chemical are in the same units to facilitate comparisons. Canadian standards distinguish between short term or long
tefin exposures. Short term exposures are listed as 1 hr exposures in this table.
Abbreviations
ACGIH
ASHRAB
EPA
NIOSH
OSHA
WHO
American Conference of Governmental Industrial Hygienists
American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc.
Environmental Protection Agency
National Institute for Occupational Safety and Health
Occupational Safety and Health Administration
World Health Organization
05
I
S
References
ACGIH, Threshold Limit Values and Biological Expamre Indices for 1989-1990, Cincinnati, OH,
ACGIH. 1989. Guidelines for the Assessments/Bioaeroso/s of t&slsddQr Environment. Cincinnati, OH.
ASHRAE Standard 62-1989. Ventilatien fir Acceptable Indoor Air Quality, Atlanta, GA.
Environmental Health Directorate, Canada. 1987. Exposure Guidelines for Residential Indoor Air Quality. Ottawa, Canada,
NIOSH. 1986. "NIOSH recommendations for occupational safety and health standards." Morbidity and Mortality Weekly Report,
35(18).
U.S. DOL 1989. "Occupational safety and health standards." CM?. Title 29, Part 1910.
U.S. EPA. 1989, "National primary and secondary air quality standards." CFR, Title 40, Part 50, Section 50,1-50.12.
WHO. 1987. Air Quality Guidelines far Europe. WHO: European Series No. 23, Copenhagen, Denmark.
* WHO does not establish guidelines for these
substances; instead, the agency publishes risk
factors for each substance to indicate potential
human health risks per unit of exposure.
+ Substance identified as a suspected or
confirmed human carcinogen.
Conversion of Units: To convert mg/m3 to
ppm, use the following formula:
ppm =
(24.45Xmg/m3)
(gram molecular weight of the substance)
(O
r
I
-------
Exhibit 7-2. Outdoor air requirements for ventilation of commercial
(offices, stores,
facilities
shops, hotels, sports facilities).
OUTDOOR AIR REQUIREMENTS '
ESTIMATED MAX
OCCUPANCY cfm/
APJPJUCATION
Dry Cleaners, Laundries
Commercial laundry
Commercial dry cleaner
Storage, pick-up
Coin-op laundries
Coin-op dry cleaner
Food & Beverage Service
Dining room
Cafeteria fast food
Bats, cocktail lounge
Kitchens (cooking)
Ganges, Repair
Service Stations
Enclosed parking garage
Auto repair rooms
Hotels, Motels, Resorts
Dormitories
Dormitory sleeping atea
Bedrooms cfin/room
living room cfrnftoam
Baths cfm/room
tobbie*
Conference rooms
Assembly rooms
Gambling casinos
P/1000 ft* or IQOm2 pencil .
10
30
30
20
20
10
100
100
20
20
30
50
120
120
25
30
35
15
15
20
20
30
15
15
30
30
35
15
20
15
30
I/s/ cfin/ Val
person ff of
13
15
18
8
8
10
10
15
8
1.50 7.50
1.50 7.50
8
15
15
18
8
10
S
15
COMMENTS
Dry cleaning processes may requite more air.
Supplementary smoke removal equipment may be required.
Make-up air for hood exhaust may require more ventilating ait.
The sum of the outdoor and transfer air of acceptable quality
fora adjacent spaces stall be sufficient to provide an ssbaust
rate of not less than 1.5 cfin/ft?(7.5 Vtlof),
Distribution among people must consider worker location and
concentration of running engines; stands where engines are run must
incorporate systems for positive engine exhaust withdtawal. Con-
taminant sensors may be used to control ventilation.
See aiso fcod and beverage services,, merchandising, barber
and beauty shops, garages.
Independent of room size.
Independent of room size; installed capacity for intermittent use.
Supplementary smoke removal equipment may be required.
(continued next bam}
5
5
1
i
.3
I
^
1
-------
H
Exhibit 7-2. Outdoor air requirements for ventilation of commercial facilities
(offices, stores, shops, hotels, sports facilities) (tontinuod).
OUTDOOR ADR. REQUIREMENTS '
ESTIMATED MAX
OCCUPANCY cfui/ 1/s/ ctml list
APPLICATION P/1000fttorlOOm2 person person ft2 mz
Offices
Office space 7 20 10
Reception areas 60 15 8
Telecommunication 60 20 10
centers & data entry areas
Conference rooms 50 20 10
Public Spaces
Corridors & utilities 0.5 2.5
Public restrooms cfin/wc or urinal 50 25
Locker & dressing rooms 0.5 2.5
Smoking lounge 70 60 30
Retail Stores, Sales Floors
& Show Room Floors
Basement and street 30 0.30 1.50
Upper floors 20 0.20 1.00
Storage rooms 15 0.15 0.75
Dressing rooms 0.20 1.00
Malls and arcades 20 0.20 1.00
Shipping and receiving 10 0.15 0.75
Warehouses 5 0.05 0.25
Elevators 1.00 5.00
Smoking lounge 70 60 30
Specialty Shops
Barber 25 15 8
Beauty 25 25 13
Reducing salons 20 15 8
Florists 8 15 8
Clothiers, furniture 0.30 1.50
Hardware, drugs, fabric 8 15 8
Supermarkets 8 15 8
Pet shops 1.00 5.00
COMMENTS
Some office equipment may require local exhaust.
Supplementary smoke removal equipment may be required.
Mechanical exhaust with no recirculation is recommended.
Normally supplied by transfer air. Local mechanical exhaust with no
recirculation is recommended.
Normally supplied by transfer air. Local mechanical exhaust with no
recirculation is recommended.
Ventilation to optimize plant growth may dictate
requirements.
I
iO
I
ir
i
-------
Exhibit 7*2. Outdoor air requirements for ventilation of commercial facilities
(offices, stores, shops, hotels, sports facilities) (tontinuedh
OUTDOOR AIR BIQ0IRBMENTS >
ESTIMATED MAX
OCCUPANCY cfml M cftal Vd
APPLICATION P/lOOOtforlOOm2 person person ft2 m1
Sports & Amusement
Spectator areas ISO
Game loom 70
Ice arena (playing area)
Swimming pools (pool & deck area)
Playing flows (gymnasium) 30
Ballrooms and discos 100
Bowling alleys (seating areas) 70
Theaters
Ticket booths 60
lobbies 150
Auditorium 150
Stages, studios 70
Transportation
Waiting rooms 100
Platforms 100
Vehicles 150
Workrooms
Meat processing 10
Photo studios 10
Darkrooms 10
Pharmacy 20
Bank vaults 5
Duplicating printing
15 8
25 13
0.50 2.50
0.50 2.50
20 10
25 13
25 13
20 10
20 10
15 8
15 8
15 8
15 8
15 S
15 8
15 8
0.50 2.50
15 8
15 8
0.50 2.50
COMMENTS
When internal combustion engines are operated for maintenance of
playing surfaces , increased ventilation rates may be required.
Higher values may be required for humidity control.
Special ventilation will be needed to eliminate special stage effect
(e.g., dry ice vapors, mists, etc.).
Ventilation within vehicles may requite special consideration.
Spaces maintained at low temperatures (-10*F to +50°F, or -23*C to
+10°C) are not covered by these requirements unless the occupancy is
continuous. Ventilation fiom adjoining sources is permissible. When
the occupancy is intermittent, infiltration will normally exceed the
ventilation requirement.
Installed equipment must incorporate positive exhaust and control (as
required) of undesirable contaminants, (toxic or otherwise).
(continued next page)
£
»
1
i
§
i
*»M
1
*>J
-------
Exhibit 7-2. Outdoor air requirements for ventilation of commercial facilities
(offices,
stores, shops, hotels, sports facilities)
(tontinusd).
OUTDOOR AIR REQUIREMENTS'
ESTIMATED MAX
OCCUPANCY
APPLICATION P/1000 ft2 or IDOrrr2
INSTITUTIONAL FACILITIES
Education
Classroom
Laboratories
Training shop
Music rooms
Libraries
Locker rooms
Corridors
Auditoriums
Smoking lounges
Hospitals, Nursing Sc
Convalescent Homes
Patient rooms
Medical procedure
Operating rooms
Recovery and ICU
Autopsy rooms
Physical therapy
Correctional Facilities
Celk
Dining halls
Guard stations
50
30
30
50
20
150
70
10
20
20
20
20
20
100
40
cfm/
Vsl cfm/
person person ft2
15
20
20
15
15
15
60
25
15
30
15
15
20
15
15
8
.10
10
8
8
0.50
0.10
8
30
13
8
15
8
0.50
8
10
8
8
Ust
m* COMMENTS
Special contaminant control systems may be required for
processes or functions including laboratory animal occupancy.
2.50
0.50
Normally supplied by transfer air. Local mechanical exhaust with no
recirculation is recommended.
Special requirements or codes and pressure relationships may determine
minimum ventilation rates and filter efficiency.
Procedures generating contaminants may require higher rates.
2.50 Air shall not be recirculated in other spaces.
1 The outdoor air is assmned to be acceptable.
SOURCE: Reprinted with permission ASHRAE Standard 62-1989
Ventilation for AiceftaUs Inthar Air Quality, published by the American Society of Heating, Refrigerating, and Air-
Conditioning Engineers, Inc.
SP
8-,
o
I
I
a
?
&
-------
IAQ Reference Manual
Section 7
ixhibil 7-3. Outdoor air requirements for ventilation of residential facilities {private
dwellings, single, multiple).
APPLICATION
OUTDOOR
AIR REQUIREMENTS
COMMENTS
Living areas
Kitchens
Baths, toilets
Garages:
Separate for each
dwelling unit
Common for
several units
0.35 air changes per hour
but not less than 15 cfrn
(7.5 1/s) per person
100 dm (50 1/s) intermittent
-or-
25 cfm (12 1/s) continuous
~or-
Openable windows
50 cfm (25 1/s) intermittent
-or-
25 cfm (12 1/s) continuous
-or-
Openable windows
100 cfm (50 I/s) per car
1.5 cfm/ft2 (7.5 1/s/m2)
For calculating the air changes per hour,
the volume of the living areas shall include
all areas within the conditioned space. The ventila-
tion is normally satisfied by infiltration and natural
ventilation. Dwellings with tight enclosures may
require supplemental ventilation, supply for fuel
burning appliances. Occupant loading shall be
based on the number of bedrooms as follows: first
bedroom, two persons; each additional bedroom,
one person. Where higher densities are known, they
shall be used.
Installed mechanical exhaust capacity.
Installed mechanical exhaust capacity.
Normally satisfied by infiltration or natural
ventilation.
See enclosed parking garages, Exhibit 7-2.
SOURCE: Reprinted with permission From ASHRAE Standard 62-1989, Ventilation for Acceptable Indoor Air Quality, published by
the American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc.
-------
Section 7
1AQ Reference Manual
Exhibit 7-4. Uniform Building Code ventilation requirements.
OCCUPANCY TYPE
VENTILATION REQUIREMENTS
Group A, Assembly
Group E, Educational
general area ventilation
openable exterior openings with an area not less than 1/20 of total floor space
toilet rooms
a mechanical system that supplies a minimum of 5 cfm/outside air/person with a total
ciroilated of not less than 15 cfm/person at all times of occupancy
fully openable exterior windows at least 3 ft2 in area for each room; or a vertical duct not less
than 100 in2 in area for the first toilet facility, with 50 additional in2 for each additional
facility
Group B, Business
general area ventilation
toilec rooms
parking garages
(other than open)
mechanically operated exhaust system capable of providing a complete change of air every 15
min; exhaust must be connected directly to the outside and the point of discharge shall be at
least 5 ft from any openable windows
same as for Group A, unless Class I, II, or III-A liquids (flammable or combustible) are used
in a portion or all of the building; the use of these materials requites exhaust ventilation
sufficient to provide 6 ach
same as for Group A
ventilation shall be provided capable of exhausting a minimum of 1.5 cfm per ft2 of gross
floor area
Group H, Educational
general area ventilation and
toilet rooms
an approved alternate method that can, exhaust a minimum of 14,000 cfm for each operating
vehicle; automatic CO sensing devices may be employed to modulate the ventilation system
to maintain a maximum average CO concentration of 50 ppm during any 8-hr period, with a
maximum concentration of 200 ppm for a period not exceeding 1 hr; connecting waiting
rooms, office, ticket booth, etc. shall be supplied with conditioned air under positive pressure
same as for Group A; when recirculation of air is not permitted, the ventilation system shall
be capable of providing not less than 15 cfm of outside air per occupant to the general area
rooms containing
hazardous materials
mechanical ventilation system as requited by fire and mechanical codes; must have a manual
shutoff control for ventilation equipment; control must be outside the room adjacent to the
principal access door
-------
IAQ Reference Manual
Section 7
Exhibit 7-4. Uniform Building Code ventilation requirements (tontinued).
OCCUPANCY TYPE
VENTILATION REQUIREMENTS
Group H, Educational (continued)
garages for the repair of vehicles
operating under their own power
a mechanical ventilation system capable of exhausting a minimum of 1 cfm/ft2 of floor area;
each stall must have an exhaust pipe extension which, if over 10 ft long, must exhaust 300
cfm
fabrication areas
connecting offices and waiting rooms shall be supplied with conditioned air under positive
pressure
mechanical ventilation, which may include recirculated air, shall be provided throughout the
fabrication area at the rate of not less than 1 cfm/ft2 of floor area
service corridors and storage of
hazardous production material
the exhaust air duct system of one fabrication area shall not connect to another duct system
outside that fabrication area within the building
at least one manually operated remote control switch that will shut down the fabrication area
ventilation system shall be installed at an approved location outside the fabrication area
mechanical ventilation shall be provided at not less than 1 cfm/ft2 of floor area or not less
than 6 ach/hr, whichever is greater
Group R, Hotels, Apartment
Houses, Dwellings, and Lodging
Houses
general area ventilation
habitable rooms shall be provided with natural ventilation by means of openable exterior
openings with an area not less than 1/20 of the floor area of such rooms with a minimum
of 5 ft2
toilet rooms, bathrooms, laundry
rooms, and similar rooms
mechanical ventilation shall be provided at a rate of 2 ach in all habitable rooms and in
public corridors; 1/5 of the air supply shall be taken from the outside
natural ventilation shall be provided by means of openable exterior openings with an area not
less than 1/20 of the floor area of such rooms with a minimum of 1.5 ft2
mechanical ventilation shall be provided at 5 ach/hr; the system must be connected directly
to the outside; the point of discharge of the exhaust shall be at least 5 ft from a mechanically
ventilating intake
SOURCE: International Conference of Building Officials (ICBO). 1988. Uniform Building Code. ICBO: Whittier, CA.
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IAQ Reference Manual
Exhibit 7-5. A«optnb!e ranges of
temperature and humidity
during summer and winter.1
RELATIVE
HUMIDITY WINTER SUMMER
30%
40%
50%'
68.5°F-76.0°F 74.0°F-80.0°F
68.5°F-75.5°F 73.5°F-79.5°F
68.5°F-74.5°F 73.0°F-79.0°F
'Applies for persons clothed in typical summer and winter
clothing, at light, mainly sedentary activity.
•Humidities greater than 50% are considered unacceptable
because of the potential for microbial growth.
SOURCE: ASHRAEU981)
REFERENCES
American Conference of Governmental and Industrial Hygien-
ists (ACGIH). Threshold Limit Values and Biological Exposure
Indices for 1989-1990. ACGIH: Cincinnati, OH.
American Conference of Governmental and Industrial Hygien-
ists (ACGIH). 1989. Guidelines for the Assessment ofBioaerosols of
the Indoor Environment. ACGIH: Cincinnati, OH.
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers, Inc. (ASHRAE). 1981. Thermal Environmen-
tal Conditions for Human Occupancy. ASHRAE Standard 55-
1981. ASHRAE: Atlanta, GA.
American Society of Heating, Refrigerating, and Air-Condi-
tioning Engineers, Inc. (ASHRAE). 1989. Ventilation for
Acceptable Indoor Air Quality. ASHRAE Standard 62-1989.
ASHRAE: Atlanta, GA.
Environmental Health Directorate. 1987. Exposure Guidelines
for Residential Indoor Air Quality. Health Protection Branch,
Environmental Health Directorate: Ottawa, Canada.
International Conference of Building Officials (ICBO). 1988.
Uniform Building Code. ICBO: Whittier, CA.
National Institute of Occupational Safety and Health (NIOSH).
1986. "NIOSH recommendations for occupational safety and
health standards." Morbidity and Mortality Weekly Report.
35(1S).
U.S. Department of Labor (DOL). 1989. "Occupational safety
and health standards." Code of federal Regulations, Title 29. Part
1919.
U.S. Environmental Protection Agency (EPA). 1989- "National
primary and secondary air quality standards." Code of Federal
Regulations, Title40. Part 50, Section 50.1-50.12.
World Health Organization (WHO). 1987. Air Quality
Guidelines for Europe. European Series No. 23. WHO:
Copenhagen, Denmark.
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SECTION 8.
INVESTIGATION
TECHNIQUES
Section 8 provides a discussion of
general and specific investigation
techniques for combustion sources,
pesticides, microorganisms, formalde-
hyde, and other volatile organic
compounds.
Section 8.1 contains two exhibits which
can be used in their current form or
adapted to field investigations. Exhibit
8-1 is a health effects questionnaire and
Exhibit 8-2 is a general residential
building inspection form.
Sections 8.2, 8.3, and 8.4 provide
specific guidance for residential
investigation techniques, sampling
methods, interpretation of data, and
mitigation advice for individual
contaminant categories.
Table of Contents
Section 8.1. General Investigation Techniques for
Residences 205
Section 8.2. Investigation Techniques for
Combustion Sources 217
Section 8.3. Investigation Techniques for
Pesticides 242
Section 8.4. Investigation Techniques for
Formaldehyde and Other Volatile
Organic Compounds 258
Section 8.5. Investigation Techniques
for Biological Contaminants 277
List off Exhibits
Exhibit 8-1. Indoor air quality health effects form. 206
Exhibit 8-2. Indoor air quality residential
inspection form. 211
Exhibit 8-3. Location and operation of typical
backdraft diverter. 232
Exhibit 8-4. CABO building code combustion air
requirements for residential
fuel-burning equipment. 233
Exhibit 8-5. Separation guidelines to prevent
downdrafts into chimneys. 234
Exhibit 8-6. Examples of chimney caps. 235
Exhibit 8-7. Potential consequences when more
than one appliance is connected
to the same flue. 236
Exhibit 8-8. Combustion inspection form. 237
Exhibit 8-9- Features of proper stove installation. 238
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1AQ Reference'Manual
Exhibit 8-10. Suggested chimney sizes for
residential wood-burning
equipment. 239
Exhibit 8-11. Safety guidelines for unvented
gas-fired heaters. 240
Exhibit 8-12. Safety guidelines for unvented
kerosene heaters. 240
Exhibit 8-13. Sources of termiticide
contamination and potential
mitigation methods. 249
Exhibit 8-14. Pesticides that can be
measured using low -volume
PUF sampling with GC/ECD. 250
Exhibit 8-15. Useful sources of information
on pesticides. 251
Guidelines for using
pesticides safely. 252
First aid guidelines for
pesticide poisonings. 255
Exhibit 8-16.
Exhibit 8-17.
Exhibit 8-18.
Exhibit 8-19.
Guidelines for cleaning
pesticide spills and residues. 256
Examples of biological
control of pesticides.
Exhibit 8-20.
Exhibit 8-21.
Exhibit 8-22.
Exhibit 8-23.
Exhibit 8-24.
Exhibit 8-25.
Exhibit 8-26.
Exhibit 8-27.
Selected passive formalde-
hyde measurement methods. 270
A dose-effect relationship
between HCHO exposure
and health effects in mobile
and conventional homes. 271
Effect of temperature and
relative humidity on formal-
dehyde (HCHO) levels in a
mobile home under controlled
conditions. 272
Advantages and disadvantages
of nonspecifkrand specific
detector systems for VOC
and SVOC analysis. 273
Commercially available
portable VOC detection
instruments.
274
257
Characteristics of sorption
collection methods. 275
Environmental survey form
for evaluating the presence of
potential sources of allergens. 290
Commonly used samplers for
collecting indoor bioaerosols. 295
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IAQ Reference Manual
Section 8
8.1. GENERAL INVESTIGATION TECHNIQUES
FOR RESIDENCES
Cjeneral techniques for investigating
indoor air quality problems in residences are
provided in Lesson 8 of the Learning Module, This
section also contains examples of indoor air quality
survey forms which can be used to assist in the
collection of information. Exhibit 8-1 is a sample
health symptom questionnaire form. Exhibit 8-2 is
a general residential building inspection form. Each
of these forms are freestanding, and each may be
used directly by the investigator. Alternatively, the
forms may be used as models and modified to meet
the needs of the particular investigator or situation.
indoor air quality diagnostic and mitigation firms
published by EPA's Indoor Air Division (U.S. EPA,
1989). This report provides a listing of firms that
are involved in either migitation or diagnostics, and
it summarizes the services they offer by the type of
buildings serviced, the types of evaluation, monitor-
ing, and mitigation services, and the areas of
expertise for personnel in the firm. It should be
noted that EPA does not imply approval, recom-
mendation, endorsement, or accreditation of the
listed firms. Copies can be obtained for a fee from
the National Technical Information Service, 5285
Port Royal Road, Springfield, VA 22161. (The
NTIS report number is PB 90-130469.)
For individuals seeking private sector diagnostic or
mitigation services, a useful resource is a survey of
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Section 8
IAQ Reference Manual
Exhibit 8-1. Indoor air quality health effects form.
NOTE: This form contains example questions that apply to residential and nonresidential investigations—it
can be modified for either application.
Investigator.
Client's Name,
Address
A. Demographics
1. Male Female
Age,
2. What is your occupation?
3. Have you had a change in occupation, or
position since the onset of your symptoms?
yes no
B. Work Environment
1. How many hours per week do you work?
2. Does your job require you to photocopy?
yes no
3- Do you frequently use a video display
terminal?
yes
no
Date
4, Are there old or deteriorating books in your
primary work area?
yes
no
5. Have there been any water leaks on ceilings,
pipes, or walls in your primary work area
during the last six months?
yes
no
6. To your knowledge, .are you exposed to any
hazardous substances (chemicals, dusts,
solvents, gases, minerals) during the course of
your working day?
If yes, please describe:
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IAQ Reference Manual
Section 8
Exhibit 8-1. Indoor air quality health of foils form fconf/nuod).
7. Check as many of the following conditions
that describe your work area:
temperature too cold
temperature too hot
temperature just right
air too dry
air too moist
humidity just right
air too stuffy
air too smoky
too noisy
too quiet
frequent unpleasant odors
C. Personal Habits
1. Do you smoke tobacco products?
yes no
If yes,
how much at home?
how much at work?
2. Do you wear contact lenses?
yes
no
If yes,
how many hours at home?
how many hours at work?
3. Do you regularly drink coffee, tea, colas, or
eat chocolate?
yes
If yes,
how much ?
no
D. Are you currently taking any prescribed
medicines?
yes no
E. Do you have any of the following?
migraine yes no
heart problems yes no
allergies/
allergic reactions yes no
asthma
yes no
F. Check the times when you are most aware
of your symptoms
Winter Mornings At home
. Summer Evenings At work
. Spring At night Other place
.Fall Weekdays Weekends
(continued next page)
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Section 8
IAQ Reference Manual
Exhibit 8-1. Indoor air quality health effects form (
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IAQ Reference Manual
Section 8
Exhibit 8-1. Indoor air quality health effects form (continued).
J. Symptom Survey
Please place a check mark next to each symptom which you have or are experiencing. Indicate the severity and frequency of
each symptom:
Mild = noticeable, but no change in routine necessary
Moderate = some change in normal routine necessary
Severe = unable to maintain a normal routine
Occasionally = less than one time per week
Sometimes = one time per week
Frequently = more than one time per week
SYMPTOM
SEVERITY
FREQUENCY
Mild Moderate Severe
Occasionally
Sometimes
Frequently
Bye irritation, burning
Dry or sore throat
Skin irritation, dryness,
or scaling
Skin rash
Tightness in the chest
Runny nose
Asthma (exacerbation of)
Cough
Wheezing or other
breathing problems
Chest pain
Changes in the rate and
depth of breathing
Changes in pulse rate
Visual disturbances
Dizziness
Fatigue
Depression
(continued next page)
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Section 8
IAQ Reference Manual
Exhibit 8-1. Indoor air quality health effects form (tontinued).
SYMPTOM
SEVERITY
FREQUENCY
Mild Moderate Severe
Occasionally Sometimes Frequently
Clumsiness
Drowsiness
Headache
Fever
Repeated throat infections
Sinus irritation or infection
Muscular pains
Change in heart rhythm
Tingling or numbness
in extremities
Muscle twitching/
convulsions
Nausea or vomiting
Abdominal pain
Diarrhea
Loss of appetite
Cold/flu symptoms
Cold extremities
Difficulty in sleeping
Irritability
Backache/neckache
Eyescrain
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IAQ Reference Manual
Section 8
Exhibit 8-2. Indoor air quality residential inspection form.
Date and time of inspection.
Name of client
Home address
Telephone (home)_
Inspector
(work)_
Presence of odor on entering home? If so, describe.
Indoor Measurements
Relative humidty (%)
Temperature (°F)
Radon (pCi/1 or WL,
if tested)
Date of test
Carbon monoxide (ppm)
Other:
Client's description of the problem (health effects, odor, event).
SYSTEMS INVENTORY
Items applicable to newer homes (< 5 yrs) are
indicated with "N", those for recent (< 3 yrs)
renovations "R," older homes "O;" if there is no
designation the item applies to all homes.
A. Residence Background Information
1. Type of home:
Conventional
Mobile Pre-fab Apartment.
Single-story , Multi-story
Attached garage
2. Date of construction/
manufacture
3. Manufacturer (if manufactured)
4. Approximate size.
5. Move-in date
(continued next page)
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Section 8
IAQ Reference Manual
Exhibit 8-2. Indoor air quality residential inspection form (tontinued).
B. The Site
1. Attach sketch of house/surrounding obstacles
with orientation to north.
2. Check for air pollution and noise sources.
3- Check for low spots and poorly drained clay
soil.
4. Check for trash, food, harborage.
5. Check for proximity to agricultural fields.
C. The Building Materials
1. Type of construction:
Brick Stone Concrete
Wood Earth Other
2. Roofing materials (N/R): Are there asphalt
materials close to doors or operable windows?
Condition: Are there leaks, damaged shingles,
and corroded flashings which may lead to
dampness in the attic?
3. Exterior finish (N/R): Is there preservative
treated wood (creosote—black and tarry;
pentachlorophenol—greenish)?
Condition: Is there evidence of moisture
damage (rot, mildew, warping, blistering
paint)?
4. Interior materials (N/R): Is there interior
grade plywood, simulated wood wallboard, or
vinyl finish wallboard?
Condition: Is there evidence of moisture
damage?
5. Interior finish: (O) Is there lead-based paint?
(If so, caution about removal by sanding;
hazards to children.)
(N/R) Is there new (within 1 month) paint?
6. Type of insulation:
None UFFI Fiberglass
Cellulose Other
If UFFI, date of installation:
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IAQ Reference Manual
Section 8
Exhibit 8-2. Indoor air qualify residential inspection form Continued).
D. Hearing/Cooling Systems
1. Primary heating System:
Gas LP Wood Oil
Electric.
Other
Kerosene
Distribution System:
Forced-air .Gravity
Other
2. Secondary heating System:
Wood-burning stove
Coal-burning stove
Fireplace
Unvented space heater
Other
Btu
3. Cooling system:
Central air Window
Water cooler None
E. Inspection of Heating/Cooling Systems
1. Check all appliances for proper installation,
damage,
2. Check venting system for proper separation of
appliances; damage to flues and ducts; mainte-
nance of all systems; clearance and condition of
chimneys; combustion air supply to each unit;
and safety hazards.
3. Central furnaces should be checked for condi-
tion of filters; registers and ducting should be
checked for accumulation of dust/dirt/fiber
glass/moisture; inlets and cold air return
should be clear of obstructions. Interior
furnace rooms must have adequate air intakes
to allow for proper draft air for chimney.
4. Fireplaces and wood stoves should be checked
for creosote buildup; type of wood/fuel;
clearance of chimney; presence of unlined-
masonary chimney; procedures for loading/
cleaning.
5. Unvented heaters should be evaluated for
proper size; ventilation during use; operation
of heater unattended; proper fael and fading
practices.
6. Check for the presence of asbestos pipe
covering, insulation, and other materials
containing asbestos. Are any friable?
NOTES:
(continued next page)
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Section 8
IAQ Reference Manual
Exhibit 8-2. Indoor air quality residential inspection form (tontinued).
F. Ventilation Systems
1. Mechanical ventilation (check those that are
present):
Supply air fans. Check for short circuiting
ventilation and inadequate exit paths.
Exhaust fans. Check for backdrafting and
adequate supply air; ratings (at least 100 cfm
for bathrooms, 200 cfm for standard cook-
stove, 400+ cfrn for draft stoves).
Fresh air connection on central forced-air
systems. Check for uncontaminated outside
air supply.
Heat recovery ventilator. Check for type
of matrix, condensate removal, inlet and outlet
location, condensaton problems.
NOTES:
2, Air Cleaning/Conditioning Devices (Check
those that are present. Is the equipment sized
properly?) Determine condition and mainte-
nance.
_FiIters (fiberglass, fabric, electronic,
plastic)
Chemical adsorption devices (activated
charcoal, alumina)
Room air cleaners
Dehumidifiers
.Humidifiers Type
(Note the presence of slime and crusting.)
NOTES:
G. Utilities
1. Water supply. City Well _
2. Sewage removal. City Septic.
H. Cooking Appliances
Gas Electric .Other
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IAQ Reference Manual
Section 8
Exhibit 8-2. Indoor air quality residential inspection form Continued),
I. Chemical Usage (Indicate aerosols with "a").
Note ventilation practices.
1. List cleaning products:
2. List pesticides:
3. List personal care products:
4. List chemicals used in hobbies/crafts:
J. Foundation Inspection
1. Type: concrete brick wood.
poured concrete creek rock
2, Condition:
K. Crawl Space Inspection (note condition)
1. Floor material: dirt pea gravel
plastic over dirt or gravel
2, Vents: Total number
Number opened
3. Standing water:
At time of inspection: yes no
Reported by occupant: yes no
4. Sump: yes no
L. Basement Inspection (note condition)
1. Damp: yes no
2. Cracks: In walls—yes no
In floor —yes no
3. Floor drain/sump: yes no
Sealed drain/sump: yes no
4. Wall surfaces (construction):
concrete drywall plaster
5. Wall covering: paneling paint
wallpaper none
6. Floor surface (construction):
concrete dirt
particleboard sub-floor
7. Floor covering: carpet vinyl
paint none
(continued next page)
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Section 8
IAQ Reference Manual
Exhibit 8-2. Indoor air quality residential inspection form Continued).
M. Have any of the following occurred during
the last year?
1. Energy conservation measures:
2. Renovations:
3. New furniture:
4. Interior redecorating:
NOTES:
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IAQ Reference Manual
Section 8
8.2. INVESTIGATION TECHNIQUES FOR
COMBUSTION SOURCES
vJuidance for the investigation of indoor
air quality heating and cooling problems can be
found in the CABO One and Two Family Dwelling
Code (CABO, 1989), the ASHRAE handbook
(ASHRAE, 1989), and books on superinsulated
design (Lenchek et al,, 1987; Mann, 1989). The
Canada Mortgage and Housing Corporation
(CMHC, 1988a; 1988b) has several publications on
combustion systems that are useful. In addition, the
standards of the National Fire Protection Associa-
tion (NFPA) and the American National Standards
Institute (ANSI) should be consulted for the
installation of specific appliances. Some of these
standards include NFPA 31 for oil-burning equip-
ment, NFPA 54 for gas appliances and gas piping
(NFPA, 1988a), and NFPA 211 for chimneys,
fireplaces, and venting (NFPA, 1988b). Local codes
should always be consulted for specific require-
ments. Section 5 of the Reference Manual also
provides additional information on the types of
heating systems and air distribution systems.
A complete discussion of the different types of
heating system appliances which could be encoun-
tered during residential investigations is beyond the
scope of this section; however, basic information is
provided for a limited number of vented and
unvented systems. The investigator should become
familiar with the design and correct operation of
both vented and unvented heating systems and
accessories which may be encountered in the
geographical area served by the investigator.
The inspection provides a good opportunity to
educate the residents about contaminants from
combustion sources and the safe use of combustion
appliances. Public education efforts can be assisted
by the Consumer Product Safety Commission which
has several useful publications on the selection and
use of combustion appliances which can be obtained
free of charge. Some of these are also written in
Spanish.
EMERGENCY SITUATIONS
.High carbon monoxide concentrations and
leaking fuel are potential emergency situations
which may be encountered. The investigator should
be prepared to handle potential emergencies over
the telephone and in the field.
During a telephone contact, clients who complain
about a fuel odor should be instructed to eliminate
any sources of flame and contact the fuel supplier
immediately. All potential sources of flame or
sparking should be avoided; this includes using
telephones in the home. Clients should be in-
structed to call the gas company from an outside
telephone. These situations must be treated as an
emergency because the investigator cannot deter-
mine the nature and degree of the hazard.
If the investigator is conducting an inspection and a
fuel odor is detected, the degree of hazard can be
evaluated with a combustible gas meter. In the case
of a small, slow leak, all sources of flame should be
extinguished, windows should be opened, and the
fuel company should be called from an outside
telephone. The residence should be evacuated if the
leak appears serious (for example, caused by a
broken supply pipe) or as a general safety precaution
if the degree of hazard cannot be ascertained. If the
fuel company discovers a leak, the service will be
disconnected until the repairs are made to prevent
the possibility of fire or other hazards. If monitor-
ing equipment is not available, the situation must
be treated as an emergency.
Elevated carbon monoxide concentrations (evaluate
based on guidelines and length of exposure) from
leaking furnaces and other sources should also be
treated as a potential emergency. If sources are
suspected and the individual appears groggy,
disoriented, or has reddish-colored skin, emergency
action should be taken. The individual should be
taken outside of the building immediately (or
instructed to leave in case of a telephone contact). If
the contact is by telephone, emergency assistance
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Section 8
IAQ Reference Manual
should be requested because the individual may be
too disoriented to follow commands.
The investigator should also be alert to the possibil-
ity of chronic carbon monoxide poisoning, particu-
larly in children. A health care evaluation should be
obtained as soon as possible if chronic exposure is
suspected.
BACKGROUND INFORMATION FOR
INVESTIGATING COMBUSTION SOURCES
Useful Definitions
Chimney and Flue: A chimney is a masonry or
concrete channel which extends above the roof and
carries combustion gases away from the appliance to
the outside air. The chimney may be lined with a
pipe (fireclay or other approved material), called the
flue or chimney flue, which carries the combustion
gases from the appliance to the outside air. The flue
connector is that portion of the ducting that
connects the appliance to the chimney. The flue
collar is that portion of the appliance designed for
the attachment of a draft hood, vent connector, or
venting system.
"Vent: Vent is a term that refers to a passageway
(pipe or duct) that conveys flue gases (or plumbing
gases) from appliances (or vent connectors) to the
outside atmosphere. The vent connector is the pipe
or duct which connects a gas-burning appliance to a
vent or chimney. In woodstove installations, the
vent connector may also be called the stovepipe.
Draft: Draft refers to the flow of gases through the
chimney, flue, or vent caused by pressure differ-
ences. Draft may be natural (caused by temperature
or pressure differences) or mechanical.
Volume Damper: A volume damper is any device
which when installed will slow or direct the airflow
in any duct, or the products of combustion in any
heat-producing equipment, vent connectors, vents,
or chimneys.
Draft Regulator: A draft regulator is a device
which maintains a desired draft in the appliance by
automatically reducing the draft. Draft regulators
are generally used to maintain combustion stability
on appliances that require negative static draft at
the appliance flue gas outlet. These devices bleed
air into the chimney automatically when pressure
decreases (Section 5, Exhibit 5-1).
Vent Damper: A vent damper (also called auto-
matic vent damper device) is a device in the venting
system, in the outlet or downstream of the appliance
draft hood of a fuel-burning appliance, which
automatically opens the venting system when the
appliance is in operation and automatically closes
the venting system when the appliance is in a
standby or off condition. These devices control the
draft and can reduce energy consumption and
improve the seasonal efficiency of gas- and oil-
burning appliances, and they can be manually
operated, mechanically activated, electrically
operated, or thermally actuated, depending on the
system.
Draft Hood or Backdraft Diverter: The draft hood
or backdraft diverter (Exhibit 8-3) is a device built
into an appliance, or part of a vent connector from
an appliance. The draft hood ensures that the
natural-draft furnace operates safely (without
generating carbon monoxide) if the chimney is
blocked, if there is a downdraft, or if there-is an
excessive updraft. The draft hood neutralizes the
effect of stack action of the chimney or gas vent
while the appliance is operating, and it allows gases
to escape easily from the appliance if there is no
draft, backdraft, or stoppage beyond the draft hood.
In general, inlet and outlet flue pipe sizes of the
draft hood should be the same as that of the appli-
ance outlet connection. Spillage can result if
combustion air is not adequate for a gas appliance
with a draft hood.
Plenum: A plenum is a compartment or chamber
to which one or more ducts are connected and which
forms part of the air distribution system.
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1AQ Reference Manual
Section 8
Combustion Air
It is important for an appliance to have sufficient air
for fuel combustion, draft hood dilution, and
ventilation of the enclosure for the appliance; this
air is called combustion air. It is not the same as
circulating air which is air that moves into and out
of a conditioned space by means-of a circulating
system. In construction that is not energy efficient,
combustion air is normally supplied by infiltration.
If there is insufficient combustion air, incomplete
combustion and backdrafting will result. To
determine the required combustion air, the air
requirements for exhaust fans, kitchen vents, clothes
dryers, fireplaces, and other combustion appliances
must be considered.
In energy efficient homes, inadequate combustion
air can be a significant problem which can be solved
in several ways. In new construction, appliances
that have sealed combustion units can be used, or
the appliance can be located in an unheated and
unsealed room (typically, exterior to the house). In
existing construction, the appliance can be con-
nected to a combustion air intake, providing the
unit is designed for such a remedy. A relatively easy
solution (but not an energy efficient one) is to crack
open windows on the floor where the appliance is
operating. This is a potential solution for infre-
quently used fireplaces that may be subject to
backdrafting when fires are low or smoldering.
If woodburning stoves and furnaces do not have a
sealed air intake, they should have a 3-inch diameter
(minimum) outdoor-air inlet, ducted close to the air
control of the appliance. A sealed damper or
gasketed door that will not leak air when the stove
or furnace is not in use is also needed. Combustion
air requirements from the CABO code are given in
Exhibit 8-4 for residential fuel-burning equipment.
Supply and Return Ducts
Ducts carrying supply air into the building from the
outside or from evaporative coolers should be
constructed of galvanized steel or corrosion-resistant
metal. Although sheet metal is the preferred
material for both supply and return air ducts,
alternatives are permitted under most codes.
Flexible material (fiberglass sandwiched between
plastic) is also used. Another technique is to use the
spaces between studs in walls or floor joists to form
an air channel by nailing sheet metal or fiberboard
over the openings (called open joist ducts). When
these spaces are used to create ducts, the duct space
should be sealed from unused portions by tight-
fitting stops of sheet metal or wood. Gypsum
products should not be exposed in ducts serving
evaporative coolers. Although these approaches are
permitted in some codes, they can allow the release
of organics such as formaldehyde into the living
space as hot supply air comes into contact with floor
joists, subflooring, or plastic.
An underfloor space can be used as a supply plenum
providing the entire ground surface is covered with
a vapor retarder having a maximum permeability of
1 perm and all loose combustible scrap material is
removed. In addition, fuel gas lines and plumbing
waste cleanouts should not be located within the
space. Foil-coated fiberboard is also used to create
ducts in floor joists—this practice should be discour-
aged in crawl spaces because of the possibility of
moisture damage to the fiberboard which would
create a substrate for microbial growth. In addition,
any openings in ducts can allow termiticides to
enter the living space.
All ductwork installed in an attic should be insu-
lated to prevent condensation. All metal supply
ductwork installed in a ventilated crawl space or
other nonconditioned area should also be insulated.
When ducts used for cooling are insulated, the
insulation should be covered with a vapor retarder
having a maximum permeance of 0.05 perm or
aluminum foil having a minimum thickness of 2
mils. Exterior ducts must be protected by an
approved weatherproofed vapor retarder.
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IAQ Reference Manual
Venting of Appliances
There are two basic types of problems related to
venting of appliances which can result in the release
of contaminants indoors. Backdrafting is the flow
of combustion gases back into the house as a result
of outside air being drawn into the flue or chimney.
Flue gas spillage (or spillout) is the flow of combus-
tion gases back into the house as a result of a
blockage in the flue or chimney or because flue
gases do not have sufficient velocity to clear the
backdraft diverter of the combustion appliance.
There are many causes of these problems including
defective or unsafe equipment; improper installation
of combustion appliances; blocked chimneys or
flues; inadequate combustion air; and downdrafts in
chimneys or flues. Depressurization caused by
operating too many appliances that exhaust air out
of the house (fans, fireplaces, and so forth) can be a
significant cause of backdrafting and spillage in new
energy-efficient construction.
Useful publications about combustion spillage and
backdrafting can be obtained from the Canada
Mortgage and Housing Corporation (682 Montreal
Road, Ottawa, Ontario K1A OP7) which has done
extensive research in this area.
The CMHC (1988b) has published a manual that
describes a series of procedures for testing the
performance of a residential chimney system. These
tests are used to identify houses in which spillage of
combustion gases from fireplaces, natural-draft oil
and gas furnaces, and hot water heaters. The
manual includes five test procedures which are
described in detail and are complete with checklists
and report forms. The tests include house and
venting systems tests (described as follows) which
are designed to detect the susceptibility of the
chimney system to spillage caused by the combined
operation of fans, fireplaces, and any other exhausts.
Furnace and flue tests are included which are
designed to detect spillage caused by a leaky heat
exchanger, weak chimney draft due to leaks or
constrictions within the flue, or maintenance
problems that can be detected through careful
inspection of the system.
The venting system pre-test consists of making a
visual inspection and simple calculations which
include estimating the exhaust flow and leakage
area which are combined into a maximum house
depressurization estimate which is compared to a
house depressurization limit (HDL). If the esti-
mated maximum depressurization is larger than the
HDL, more detailed testing is needed. If it is
smaller, the system is alright, and no further
testing is needed. The test requires 10 to 15
minutes.
The venting system test is a detailed test that can be
used to test the effect of fans and fireplace operation
on the chimney serving the furnace and the hot
water appliance, and it can also be used to evaluate
the effect of fans and furnace operation on the
chimney serving a fireplace. This test also includes
a procedure for determining spillage under depres-
surization. The test requires about 40 to 80
minutes to complete.
Vents
Appliances which require venting must be vented to
the outside. Vents should be installed with an
upward slope to maintain the velocity of the
escaping gases, prevent moisture, and reduce the
chances of backdrafting. Even if the vent slopes
upward, it is possible for hot gases to flow down-
ward (or horizontally) under some conditions.
Vents that slope downward should be corrected.
Too many and/or sharp elbows or bends in the vent
will prevent it from drawing properly. A general
rule of thumb is to have no more than two 90°
elbows; ideally elbows should be limited to 45°
which will result in an upward slant of about 45°.
The vent vertical length should be at least 5 feet
above the highest vent collar for gravity-type
systems with the exception of venting systems
which are integral to the appliance or Type BW
vents (vented wall appliances).
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Section 8
To prevent contamination of indoor air, direct vents
(vents in sealed systems) should be at least 9 to 12
inches from any door, window, or gravity air inlet.
The bottom of the vent terminal and air intake
should be at least 12 inches above grade. In addi-
tion to these requirements, the venting system
should end at least 3 feet above forced air inlets
•located within 10 feet (CABO, 1989; NFPA,
1988a),
The horizontal run of a gravity vent (circulation of
air by gravity) and its connector should not be more
than 7596 of the vertical height of the venting
system measured from the appliance outlet, and the
rise of the connector should not be less 1/4 in/ft of
length measured from the appliance vent collar to
the vent.
Two or more appliances (oil or gas fuel only) may be
connected to gravity-type venting systems provid-
ing they have the required safety controls and listed
safety shutoff devices. The appliances should
typically be located on the same story of the build-
ing, the connectors should be offset (should not
enter directly opposite one another), and the venting
area should be no less than the area of the largest
vent connector plus 50% of the areas of the addi-
tional vent connectors,
Chimneys
Appliances can be vented with unlined masonry
chimneys, metal pipe, or factory-built chimneys.
Whichever is used, it must be installed and main-
tained according to local and national building
codes. A masonry chimney should be checked to
make sure the mortar is intact between the bricks or
stones. Metal chimneys should be checked for rust
damage or spaces between the joints. These checks
should be made both inside and outside (a flashlight
and mirror are useful; smoke can also be used).
Clients should be instructed to seal any openings
which would allow combustion gases to seep back
into the dwelling.
The chimney must be sized properly to prevent
spillage and condensation problems. The correct
size can be determined in several ways. In the case
of venting a solid fuel burning appliances, the cross-
sectional area of the flue should not be less than the
cross-sectional area of the appliance flue collar, or
more than 3 times the cross-sectional area of the
appliance flue collar (NFPA, 1988b).
In the case of sizing a single gas-burning appliance,
the effective areas of the vent connector and the
chimney flue should not be less than the area of the
appliance flue collar or draft hood outlet. A chim-
ney that is connected to more than one gas-burning
appliance is sized properly if the effective area of the
chimney flue is not less than the area of the largest
vent connector plus 50% of the area of additional
flue collars or draft hood outlets (NFPA, 1988a).
Avoiding Backdrafts on Chimneys: Chimneys
should extend above the roof to avoid possible
downdrafts into the chimney in windy weather and
to prevent overheating of the roof from the hot flue
gases. Local codes specify required clearances. A
general guideline is that the residential chimney
should extend at least 3 feet above the highest point
where it passes through the roof of a building and at
least two feet higher than any portion of the roof
within a horizontal distance of 10 feet (Exhibit 8-5).
Another potential problem is overhanging tree
limbs which can result in significant downdrafts.
The chimney should be properly capped to prevent
rain water from entering (Exhibit 8-6). The
chimney should also be checked (at least yearly) to
prevent the buildup of soot and debris which could
cause improper functioning. Birds' nests, in
particular, can cause blockage.
Chimney connections must be checked to ensure
that backdrafts and other problems will not result
(Exhibit 8-7). A gas or an oil furnace should not be
connected to a chimney that serves a separate
appliance that burns solid fuel because the draft to
the furnace may be significantly reduced. No two
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IAQ Reference Manual
appliances should enter the chimney in the same
location at the same level; rather, they should be
staggered along the vertical shaft. This prevents
fumes from blowing across the chimney rather than
up and out the other appliance. Another problem
associated with shared chimneys is the possible
release of sparks or burning creosote from an open
wood-burning appliance into the room.
It should be noted that exterior chimneys are more
likely to have problems with backdrafting than
interior chimneys because the gases are quickly
cooled and draft is lost.
INSPECTION OF COMBUSTION APPLIANCES
JL he main fuels for central heating appli-
ances in the U.S. are natural gas (97% methane),
liquid petroleum gas or LPG (propane, butane, or a
combination of these), fuel oil, or electricity. In
addition to these fuels, wood and coal are also used
for central heating.
All of these appliances (except electricity) can
become sources of indoor air contaminants includ-
ing carbon monoxide, carbon dioxide, nitrogen
oxides, inhalable particulates, and in the case of fuel
oil, kerosene, coal, and sulfur dioxide. Improper
installation and maintenance are most often the
causes of fires and the release of contaminants into
the living space.
On routine investigations, the evaluation begins
with a visual inspection of the appliance. The use of
a standard form is recommended (Exhibit 8-8 is an
abbreviated form). The following types of questions
should be answered:
• Does the appliance work? If not, is the
equipment faulty or is there insufficient
fuel. If the fuel correct for the equipment?
• Is the appliance vented properly? Is there
any obvious damage to the appliance or
venting system?
• Is there sufficient combustion and circulat-
ing air?
• Is the appliance maintained and operated
properly?
Fuel-fired heating appliances should be inspected
and cleaned on an annual basis. Regular inspection
and maintenance will improve efficiency and
prevent problems. In some cases regular inspection
and maintenance can be performed by the home-
owner who carefully follows the manufacturer's
instructions; in other cases, a professional will be
required. During the visual evaluation, the investi-
gator can usually determine if a service call by a
professional is needed.
The following general guidelines for vented appli-
ances include checks that the investigator can make
and general recommendations which can be given to
the client. These guidelines only provide an
introduction to this important area, and the investi-
gator should become familiar with local codes for
specific requirements.
Central Forced-Air Fuel-Fired Furnaces
A properly installed central heating system will not
result in safety or indoor air quality problems. The
evaluation should determine if the unit is properly
installed and operated so that harmful contaminants
are not emitted indoors. The unit should also be
checked for other safety hazards.
One of the first clues that can be obtained in an
investigation is the presence of any smoke, odor,
black dust, or ash. If any of these exist, the cause
should be determined. Next, the location of the
appliance should be noted. Warm-air fuel-fired
furnaces should not be installed under stairways, in
a room used as a bedroom or bathroom, in a closet,
or in any small space with access only through a
bedroom or bathroom. These installation require-
ments, however, do not apply to direct vent furnaces
or enclosed furnaces.
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Section 8
Natural Gas Appliances; Appendix G of the
National Fuel Gas Code contains tables for sizing
venting equipment serving appliances equipped
with draft hoods and appliances listed for use with
Type B vents (Category I furnaces). These tables
indicate the maximum appliance input rating for
different vent sizes.
It should be noted that the Tables in Appendix G
can result in flue condensation in some installa-
tions. This is most likely to occur in new mid-
efficiency furnaces that have fan-assisted combustion
systems rather than draft hoods. Like the draft hood
appliances, the fan-assisted furnaces still rely on the
buoyancy of the hot combustion gases to vent the
flue gases. However, since these appliances operate
with reduced dilution air, the vent gas volume is
reduced for a given input and smaller vents can
therefore be used.. The flue gases in this instance
will have a higher dew point temperature which
increases die potential for condensate formation.
This, in turn, increases the corrosion of the vent
materials. The 1988 version of the National Fuel
Gas Code does not address this problem (it will in
updated versions), but expanded tables have been
developed by the Gas Research Institute and these
can be consulted to ensure that vents aije properly
sized (tables can be obtained from any gas utility).
The investigator should make the following obser-.
vations for gas-fired appliances:
1) Check the position and.condition of the
blower doors; doors that have been removed
or which are ajar can allow contaminants
from the burner chamber to enter the living
space. This problem must be fixed imme-
diately.
2) Examine the furnace filters. This is
accomplished by disconnecting the power
and removing the blower access door or
filter assembly door. Clients should be
instructed to replace soiled disposable
filters with filters of the same size every
four to six weeks during the heating season
or according to the manufacturer's instruc-
tions. Filters that are not disposable should
be cleaned (by "vacuuming or washing with
detergent according to the manufacturer's
instructions) twice a month during periods
of heavy use and once a month during other
times.
3) Examine the burn chamber for the accumu-
lation of lint and the heat exchangers for
soot and jrust. If any of these are present,
the furnace should be cleaned so that the
fuel will burn properly,
4) Check the flame in the burn chamber to
determine if combustion is optimum.
Natural gas furnaces should not have yellow
tipped flames; LP units may have some
light yellow tipping of the outer mantle,
. but the inner mantle should be bright blue.
A service call is needed if yellow tipping
exists,
5) Check the combustion air inlet and air
openings in the casing of the furnace for
any obstructions which could reduce
airflow. The combustion chamber opening
side should not be less than 6 inches for
fuel-burning appliances.
6) Check the venting system for evidence of
corrosion, leaks, and proper sizing. Prob-
lems should be corrected.
7) Check heat inlet registers and cold air
returns to ensure that they are free and clear
of carpets, furniture, and other obstruc-
tions. Any obstructions should be re-
moved.
8) Check the cooling coil condensate drain of
air-conditioning units if negative air is
created inside the furnace or if the drain is
connected directly to the structure's sewer
system, Condensate should be discharged
outside of the building. Condensate
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IAQ Reference Manual
drained to the sewer system must be
drained through an observable airbreak. If
the drain is not draining freely, it should be
cleaned. The outside condensing unit
should have a clearance of 3 inches above
grade; manufacturer's clearances for proper
airflow should be strictly observed.
Oil'FiredAppliances: Oil furnaces are similar to
gas furnaces in size, shape, and function; they are
available as upflow, downflow, horizontal, and low-
boy configurations for ducted systems. However,
the heat exchanger, burner, and combustion control
system are different. Oil-fired forced-air ducted
systems are usually forced-draft furnaces and
equipped with pressure-atomizing burners. The hot
flue products flow through the inside of the heat
exchanger into the chimney; conditioned air flows
over the outside of the heat exchanger and into the
air supply plenum. A barometric draft regulator is
used in lieu of a draft hood. The checks for an oil-
fired furnace are "similar to those for the gas-fired
system.
Oil-fired furnaces must also be checked for proper
location of the fuel tank and sizing of the tanks
(Section 5, Exhibit 5-1). If tanks are located inside
the building the tanks should be evaluated for
proper separation from boilers, furnaces, stoves, or
exposed flames. Tanks must be vented to the
outside. Sufficient combustion air must enter the
furnace room; a general rule of thumb is to provide
15 In2 of opening for each gallon of oil burned per
hour.
Any odors, partkulates, or staining in the furnace
room suggest problems. The burner jets should be
checked for cleaning. The blower compartment
door should be tight. Filters and burner fan should
be checked to determine if they need cleaning. The
barometric damper should be checked for lubrica-
tion and the need for balancing. The air supply
should be evaluated for adequacy and the unit
should be evaluated for clearance from combus-
tibles. In addition to these checks, the guidance
listed under flues and chimneys also applies.
Coal-Fired Appliances: Coal-fired appliances are
still used in some areas; these appliances include
boilers, furnaces, and space heaters (resemble pot-
bellied stoves). Coal should be burned only in those
appliances specifically designed for coal. These
units should be carefully checked for condition and
possible leaks through the venting system.
Coal-fired furnaces and boilers must be sized
properly for the particular supply of coal; improp-
erly sized furnace grates and flues can result in
excessive coal gas. Owners of coal-fired appliances
should be questioned about procedures used to fire
the unit. Sufficient time must be allowed to pass
before damping to prevent the release of excessive
coal gas; this is most likely to be a problem at night
or other periods when full draft'is not needed.
Proper ventilation is needed to provide adequate
combustion air and prevent heat buildup,
Wood-Burning Stoves
Because of rising fuel costs, many people are turning
to wood as their main or supplementary fuel.
Fireplaces, with or without an insert, and various
types of freestanding stoves are the most common
wood-burning appliances; the term "stoves" will be
used to refer to these devices. If wood appliances are
used, they should be approved or listed and the
NFPA or local code installation guidelines should
be followed.
Conventional stoves have a single combustion
chamber which is not airtight; these stoves have a
low efficiency compared to airtight stoves which
have a secondary chamber for combustion unburned
gases from the primary chamber. Simpler stoves
typically have a damper in the chimney to control
the flow of air through or over the fire. More
complicated stoves have a thermostat-controlled
damper which controls the draft.
Improperly installed, maintained, or operated wood-
burning appliances can create serious indoor air
quality and safety hazards. The investigator should
evaluate each stove and installation for proper
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Section 8
installation, condition, venting to the outside,
proper clearance to all combustible materials, proper
fuel supplies, and fire stoking techniques. The
investigator should initially look for evidence of
smoke, soot, or creosote in the living spaces; flues
should be evaluated for evidence of leakage. The
cause of any of these problems should be determined
and corrected.
Installation: Proper installation is the key to the
safe usage of a wood-burning stove (Exhibit 8-9).
The stove should be located away from all combus-
tible materials, NFPA 211 recommends a clearance
of 36 inches at the ceiling, back, and sides from
combustibles. The use of a fireproof barrier can
reduce the required clearances, but local codes
should be consulted for specifics.
The floor on which the stove is placed should also be
protected (except concrete, clay tile, or ceramic), •
The condition of any asbestos floor protection
should be noted; if the material is not intact or
cannot be repaired, it should be removed. The stow
should not be placed on carpeting or any other type
of combustible surface. Combustible floors should
be protected by a sheet of noncombustible material
under the stove; the sheet should extend out from
the stove 18 inches in all directions.
Wood and oil or wood and gas appliances should not
be served by the same flue or chimney because of the
possibility of insufficient draft for safe combustion
in each appliance (Exhibit 8-7).
Stovepipe refers to the single-wall metal piping that
is used to connect the appliance to the chimney;
stovepipe should not be used as a chimney. It
should not be routed through a ceiling, closet,
alcove, or concealed space. When it must pass
through interior combustible material, a ventilated
thimble must be used.
The chimney for a stove (also oil appliances, domes-
tic-type incinerators, and solid fuel-burning) should
be of the right material and si2ed correctly (see
NFPA, 1988B for guidance). In residential
installations, single-walled metal flues should not
be used; flues must be double- or triple-lined. To
prevent backdrafts, the chimney should not have a
flue area more than twice the size of the stovepipe.
Exhibit 8-10 provides suggested flue sizes for
residential wood-burning appliances in the absence
of manufacturer's instructions. Guidelines for the
clearance of a stove chimney at the rooftop are
identical to those for central heating appliances.
These clearance guidelines should be followed to
prevent downdrafts in windy weather and to prevent
roof fires caused by hot flue gases.
Unlined masonry chimneys should not be used.
Factory built chimneys should be labeled as "Class
A," "All-Fuel," or "Solid Fuel." Metal thinner than
28 gauge should not be used as a chimney because it
can rust or corrode easily, and it is not a good
insulator which means that combustion gases will
condense in the flue and increase creosote formation.
The stovepipe connection should be as short aad
straight as possible to minimize creosote buildup
and maximize draft. Lengths up to about 8 feet are
typical, and the horizontal portion should be less
than 3/4 of the vertical part of the pipe and should
rise a minimum of 1/4 inch per foot (ASHRAE,
1988; CABO, 1989). Smoke leaks typically occur if
the stovepipe joint does not overlap properly; the
crimped end should be pointing down toward the
stove.
Long stovepipes increase heat output, but also result
in more creosote accumulation and less draft. If the
stovepipe is too small for an attached stove, smoke
will spill out, or the stove will not be able to get hot
enough because it does not get enough air. If the
stovepipe is too large, decreased draft and increased
creosote can result.
The connection of the stovepipe to the chimney
should be examined to be sure that it is secure and
does not leak creosote or gases. The stovepipe
shouldn't move more than 1-2 inches horizontally.
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NFPA requires that horizontal tuns slope up from
the stove. This upward slop maintains draft and
prevents creosote drip.
Operat/on and maintenance: Stovepipes and
chimneys should be checked frequently for creosote
buildup. Black stains on the exterior of a chimney,
flue, or stovepipe may indicate creosote buildup or
water damage. Creosote has an unpleasant, acrid
odor. It may be pooled on the floor, or it may
appear as bubbles, flakes, curls, or as a dry or tacky
shiny glaze on the inside of flues, stovepipes, or
chimneys. After it dries, creosote is flammable. As
a general rule, cleaning is needed when creosote and
soot are more than 1/4 inch thick.
Creosote can be minimized by proper installation
and operation of the stove. One of the best ways to
minimize creosote formation is to use the correct
type of fuel. Seasoned hardwood is recommended
over softwoods because hardwoods burn hotter and
result in less creosote formation. Resinous woods
bum quickly, and they can be used in small
amounts for starting fires. However, they should
not be used as the primary wood because of creosote
and smoke formation. Recommended moisture
content ranges between 15% and 25%. "Green" or
wet wood is likely to result in smoke and creosote
problems.
As a safety precaution, wood should be stored at least
36 inches away from the stove. No more than 25
pounds of wood should be stored inside the dwelling at
any time. Treated wood, raikoad ties, plastics,
charcoal, metal, tires, trash, and other nonwood
materials must not be burned in stoves because-they
emit harmful contaminants when they burn.
Wood-burning furnaces and boilers may also be
used in residential heating systems; some of these
furnaces are multi-fuel furnaces which have a gas or
oil burner which provides heat if the fire goes out or
becomes low. Wood-burning boilers and furnaces
require more care and maintenance than furnaces
which are fueled by gas or oil only. Indoor air
quality problems for wood appliances can result
from stoking operations, creosote deposits and
plugging of the chimney, or draft problems. Local
codes should be consulted for the legality of these
appliances and specific requirements.
Space Heaters
Vented Gas Space Heaters
Many older homes use large gas-fired room heaters
to heat the entire living space. Vented heaters
which are not properly installed or maintained can
release carbon monoxide, carbon dioxide, and
nitrogen oxides into the living space. These
appliances are usually vented through the chimney
and should be installed in the same way as a fuel-
fired central heating system.
The investigator should check the vent installation
and clearance from the vent to any combustible
walls. There should be 12 to 18 inches of clearance.
The condition of exposed ducting should be evalu-
ated. Joints should be examined to be sure that
screws are present and tight. Any deteriorated or
loose joints are likely sources of leaks. Vented
heaters do not burn as efficiently as a central heating
system, and these flues should be cleaned 2-3 times
during the heating season.
Safety features which the investigator can identify
are certification of the appliance by the American
Gas Association Laboratory. Vented gas space
heaters manufactured after June 1, 1984 are re-
quired to have a thermal shut-off device that will
activate when the heater is not being vented
properly.
Unvented Kerosene or
Gas Space Heaters
Unvented fuel-fired space heaters that use kerosene
or gas are of serious concern to public health
officials. An important marketing tool used to sell
these devices is a fuel efficiency that is almost
100%, compared to 60% for most residential
furnaces or 80% to 90% for high efficiency furnaces.
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Section 8
When unvented space heaters burn, the heat
generated by the burning fuel is released directly
into the living space, but the byproducts of combus-
tion are also released. Burns from hot surfaces and
fire hazards are additional concerns when unvented
heaters are used. .
Fire hazards are of great concern when unvented
heaters are used. Each appliance should be in-
spected for obvious damage, improper burner
settings, improper fuels and storage of fuels,
distance to combustibles, absence of fuel shut-off
devices in the event of tip-over or flare-up, and
other fire safety hazards.
The combustion byproducts of unseated space
heaters contain many potentially harmful contami-
nants such as carbon, monoxide, nitrogen oxides, and
carbon dioxide in the case of gas heaters; sulfur
dioxide, aldehydes, polycyclic aromatic hydrocar-
bons, and acid aerosols are additional potential
contaminants from kerosene heaters,
Emissions from kerosene heaters depend on a several
factors including maintenance of the unit, flame
setting, age of the heater, Btu rating of the heater in
relation to the space to be heated, type of kerosene,
and type of heater. Emissions from unvented gas
heaters also depend on age and maintenance of the
unit, Btu rating, and other factors.
The concentrations of these contaminants can be
reduced, but not eliminated, by using heaters in
well-ventilated areas. Most manufacturers recom-
mend opening the door to the room with a kerosene
heater to provide air exchange with the rest of the
house. This practice does not provide sufficient
ventilation air.
Adequate ventilation must be provided by bringing
fresh outdoor air into the living space. This can be
accomplished by opening a window(s), A general
rule of thumb is to open a standard sized window 4
in2 for every 1000 Btu of heater capacity. Using
this general rule, an 11,000 Btu heater would
require a window opening of about 2 inches.
Additional areas of concern and safety tips for
unvented gas and kerosene heaters are given in
8-11 and 8-12.
Household Appliances
Gas-fired Ranges
Gas-fired ranges should not be used as a source of
heat during cold weather. The use of gas-fired
ranges and ovens as a source of heat could result in
the buildup of potentially fatal concentrations of
carbon monoxide, and this practice also poses safety
and fire hazards. Additional contaminants that are
released by gas-fired ranges include carbon dioxide
and oxides of nitrogen.
Local building codes should be consulted for specific
installation requirements. In general, the back and
sides of gas ranges are required to have a clearance of
6 inches to combustible materials. The vertical
clearance should be at least 30 inches, but this is
allowed to be reduced to 24 inches if the combus-
tible material is protected by a fireproof material.
Vents serving range hoods should not terminate in
an attic, crawl space, or any area inside the building.
Most ranges that are vented to the outside require a
ventilation rate of about 100 cfrn; updraft or
downdraft ranges require higher rates (a'round '40Q
din for some models) that vary depending on the
particular model. The fan ratings can be found on
identification plates on the hood. Many newer
single and double family homes and apartment
buildings have redrculating hoods rather than range
hoods that vent to the outside,
Pilot lights must be adjusted properly so that the
burners will burn efficiently, and gas will be
prevented from escaping if the pilot light goes out.
Gas-fired Hot Water Heaters
Proper venting of hot water heaters is also impor-
tant to prevent combustion-related contaminants
from entering the living space. The vent should be
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IAQ Reference Manual
maintained In a safe condition, and installation
should follow the same guidelines as for a central
heating system. The water heater should be located
as close as possible to the chimney. It should not be
located in bathrooms or bedrooms, closets, or
confined spaces opening to the bedroom or bath-
room.
If a water heater is located in a garage, it should be
installed at least 18 inches above the ground. This
clearance is required to prevent explosions which
could occur if gasoline or other flammable volatile
liquids are spilled onto the floor in proximity to the
heater.
Gas-fired Clothes Dryers
Gas-fired clothes dryers can release nitrogen oxides,
carbon dioxide, and carbon monoxide if they are not
vented properly. Clothes dryers should be vented
directly to the outside and not through a chimney,
flue, gas vent, or vent connector (or to the attic or
crawlspace). The duct should not be joined with
screws or anything else that would project into the
duct and trap lint because removal efficiency will be
reduced.
Devices which can be attached to the dryer vent to
allow heat to come back into the house should not
be used with gas-fired clothes dryers because they
allow passage of the combustion-related contami-
nants back into the living space. They also increase
the humidity level in the home.
Other Combustion Sources
There are other sources of combustion products in
homes such as candles, lamps, and certain hobbies
such as soldering, wood burning, and interior
combustion engines. These sources can release a
variety of gases and particulates. Emissions from
these sources have not been characterized ad-
equately. The investigator should be alert to these
sources and ensure that adequate ventilation is
present when they are used.
Fire Safety
Every home should have a fire detector and extin-
guisher, but this is especially important in homes
that utilize wood-burning stoves. An extinguisher
and detector is recommended in the room with the
stove. Other detectors should be placed strategi-
cally based on guidance from the local fire depart-
ment.
MEASURING COMBUSTION-RELATED
CONTAMINANTS
Instrumentation
JVlost investigations of combustion-related
complaints will require a carbon monoxide monitor
and a combustible gas meter. A carbon dioxide
monitor may be also be useful, but it should not be
purchased in lieu of the carbon monoxide monitor
or combustible gas meter. Instruments for field
inspections should be portable, lightweight, rugged,
battery-operated, easily read, and convenient to use.
The combustible gas meter measures the concentra-
tion of a flammable gas or vapor in the air, and the
results are indicated as a percentage of the lower
explosive limit (LEL). The LEL is the minimum
concentration of the gas or vapor in air which will
propagate the flame if an ignition source is present.
The upper explosive limit (UEL) is the concentra-
tion above which ignition will not occur. The
flammable range is between the UEL and the LEL.
The combustible gas meter usually does not specify
what gas is present, it just warns of a potentially
dangerous situation with an audible sound or
flashing light. The meter is not accurate for low
concentrations, and it must be calibrated to the gas
of interest. The zero and calibration checks should
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IAQ Reference Manual
Section 8
be performed at the location where sampling will
occur because the response of the instrument is
affected by temperature.
Combustible gas meters are available for area
sampling or can be configured with a probe for
testing point sources such as gas pipes. Regardless
of the type of meter, it should be intrinsically safe.
These instruments are easy to use and require
minimal training. The cost ranges from, about |700
to over $1000.
Combination oxygen and combustible gas meters
are available which can detect oxygen deficiencies
and combustible gases in a single unit. The oxygen
content of the air is normally 21%; \6% oxygen is
the minimum needed to support life, and air with
less than 19-5% oxygen is considered deficient.
Although there are several methods which can be
used to measure both carbon monoxide and carbon
dioxide, nondispersive infrared spectrophotometry
(NDIR) is probably the method of choice for several
reasons. Current generation NDIR instruments are:
1) insensitive to variations in flow rates and room
temperature, 2) require no wet chemicals, 3) sensi-
tive over a wide concentration range, 4) quick
responding, 5) small and portable^ and 6) require
minimal training to operate,
The concentration of carbon monoxide is usually
recorded in ppm while carbon dioxide is given in
percent. Both instruments should be calibrated
routinely using zero and multi-point calibration
gases in the range of concentrations to be measured.
If measurements are conducted in the range of 0 to
10 ppm, a single point calibration outside of the
sampling range may not be adequate.
Carbon monoxide, carbon dioxide, and combustible
gas meters can handle most situations involving
combustion-related appliances. But there are
occasions when concentrations of other gases are
needed. A variety of active and passive monitors are
available to test for specific contaminants such as
sulfur dioxide and nitrogen oxides if this informa-
tion is necessary.
Most active samplers are not convenient for routine
residential investigations of sulfur dioxide and
nitrogen dioxide levels, but active bubbler methods
which were developed for ambient air sampling can
be used to collect 1 hour or 24 hour samples. These
can be built at a nominal cost (about $150 for each
sampler). Sample collection is relatively
uncomplicated, but a laboratory is required for
analysis of the samples by colorimetric methods.
Portable electrochemical samplers can also be
purchased for about $1500 to $3000. Passive
samplers (at about $30 each) are another potentially
useful alternative, but they cannot be reused, and
they do require laboratory analysis which is usually
included in the cost of the sampler.
Indoor sampling methods afe also available for
organic particulates from fuel combustion and
compounds found in cigarette smoke. Further
information on equipment and methods for these
contaminants is contained in Lesson 6 of the
Learning Module, Section 6 of the Reference Manual,
and EPA's Compendium of Methods for Indoor Air
Quality (U.S. EPA, 1989).
It may also be necessary to monitor levels of
carboxyhemoglobin in cases of acute exposures or
when low-level chronic exposures are suspected.
These analyses require a blood sample to be drawn
by a health care provider.
Measurement Locations
The combustible gas meter should be operating
before entering the residence. Readings are taken
upon entry. If safe levels are measured, the investi-
gator proceeds to the room with the appliance and
measures levels next to the appliance. If unsafe
levels are measured (guidelines are given below), the
residence should be evacuated and the gas company
should be notified.
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Section 8
IAQ Reference Manual
When fuel leaks are suspected during the course of a
routine investigation, readings should be taken
adjacent to the appliance and at any points where
leaks might occur. If leaks are detected, the gas
company should be notified; a qualified contractor
will be needed to correct problems.
If fuel leaks are not suspected, carbon monoxide and
other contaminants are usually measured in the
general living area at breathing height or close to
the floor if infants are present. Measurements can
also be taken adjacent to the appliance or heat
registers. Regardless of the location, measurements
should be made during routine investigations after
combustion appliances have been operating for at
least one hour.
Interpretation of Combustion-Related
Contaminant Data
Combustible Gas
Combustible gas meters must be calibrated to the
specific gas of interest. A meter calibrated to
natural gas should not be used for investigations
involving liquified propane, butane, or a mixture of
these compounds (liquified petroleum gas, LPG)
because the lower explosive limits for these com-
pounds are lower than for natural gas (methane).
General guidelines which can be used are given by
EPA (U.S. EPA, 1990) for hazardous materials
investigations:
* greater than or equal to 25% of LEL—
evacuate immediately; explosion hazard!,
• 10% to 25% of LEL—proceed with
extreme caution,
• less than 10% of LEL—lower hazard,
proceed cautiously with investigation.
Carbon Monoxide
Indoor levels of carbon monoxide (CO) vary consid-
erably depending on the sources that are present and
consumer use patterns. Concentrations of 1 ppm to
2 ppm can result indoors from using a normally
operating gas-fired central furnace; concentrations
considerably over 100 ppm have been measured in
homes with faulty furnaces. Levels of 35 ppm to
120 ppm have been measured after 4 burners on gas
stoves were operating for 20 minutes (Sterling and
Sterling, 1979)- Kerosene heaters can result in
concentrations from several parts per million to over
20 ppm (U.S. CPSC, 1983). Traynorsf*/. (1983)
measured concentrations ranging from 1.9 ppm to
89-4 ppm in a test house (1150 ft2) heated by
unvented gas heaters.
Since the potential effects of measured concentra-
tions of CO depend on the % COHb in the blood,
the WHO recommends a carboxyhemoglobin. level
of 2.5% - 3% for the protection of the general
population, including sensitive groups (WHO,
1987). The WHO's air concentration guidelines to
protect these levels include: a maximum permitted
exposure of 100 mg/m3 (about 87 ppm) for periods
less than 15 min.; and time-weighted average
exposures of 50 ppm (60 mg/m}) for 30 minutes, 25
ppm (30 mg/m3) for 1 hour, and 10 ppm (10 mg/
m3) for 8 hours.
The U.S. EPA ambient standard and the Canadian
indoor exposure guidelines for CO are similar.
EPA's standards are 9 ppm for 8 hours and 35 ppm
for 1 hour; Canada's guidelines are < 11 ppm for 8
hour exposures and < 25 ppm for 1 hour exposures.
It should be noted that these guidelines may not
provide sufficient protection for individuals who are
chronically ill with heart and/or lung problems.
Nitric Oxide
Nitric oxide will be present whenever combustion
products are emitted directly into the living space.
Undersized and oversized kerosene heaters have
resulted in nitric oxide concentrations of 0.21 ppm
and 0.43 ppm, respectively, when burned for a 4
hour period in a townhome (Ritchie and Oatman,
1983). Concentrations as high as '0.94 ppm were
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IAQ Reference Manual
Section 8
measured when a convective kerosene heater was
operated in a room with the door opened 1 inch
(Ritchie and Arnold, 1984). Concentrations of 0.00
ppm to 5.14 ppm were measured by Trayrior et al,
(1983) in a test house heated by unvented gas space
heaters.
There are no guidelines for acceptable concentra-
tions of nitric oxide indoors.
Nitrogen Dioxide
Nitrogen dioxide concentrations between 0,003
ppm and 0,540 ppm have been measured in homes
with gas-fired stoves, ovens, or unvented heaters
(Spengler and Cohen, 1985). Steady-state levels up
to 0.250 ppm have been measured a home with a
radiant kerosene heater operating in a room with a
door opened 1 inch; levels pf 0,057 ppm were
measured when a convective heater was operated in
a room with the door open (Ritchie and Arnold,
1984), Nitrogen dioxide concentrations ranging
from 0.225 ppm to 135 ppm were measured in a
test house heated by unvented gas space heaters
(TmynoretaL, 1983).
Based on its review of the nitrogen dioxide litera-
ture, the WHO recommends nitrogen dioxide
guidelines of 0.21 ppm (400 |4g/m3) and 0.08 ppm
(150 |4g/m3) for 1 hour and 24 hour ambient
exposures, respectively. The Canadian exposure
guidelines for residential indoor air quality are
<0,25 ppm for 1 hour and < 0.05 ppm for long-
term exposures. The U.S. EPA standard for ambi-
ent air is 0.053 ppm (0.1 mg/rn5) as an annual
arithmetic average.
Carbon Dioxide
Outdoor concentrations of carbon dioxide are
generally in the range of 300 to 330 ppm (multiply
by 10"4 to convert to %). In homes without sources,
concentrations might be in the range of 0.07% -
0.20% (NRC, 1981). Concentrations in homes
with kerosene heaters can reach concentrations
above 0.3% within several hours, and concentrations
greater than 0.5% have been measured (Ritchie and
Arnold, 1984). Concentrations of 0.177% to
0.815% were measured by Traynor et al, (1983) in a
test house heated by unvented gas heaters.
The Canadian exposure guidelines for residential
indoor air quality are <3500 ppm (<0.35%).
ASHRAE's guideline for acceptable indoor air
quality is 1000 ppm. ASHRAE, however,, chose
this level because it is used as an indicator of
inadequate outdoor air, and not because of the
potential health effects from carbon dioxide expo-
sure. '
Sulfur Dioxide
Outdoor concentrations vary from <0.002 ppm in
pristine areas to about 0.01 ppm for annual averages.
in urban areas (higher concentrations do occur).
Homes without sources are not likely to have •
measurable sulfur dioxide levels unless the outside
air is contaminated-. Indoor sources are primarily
faulty furnaces that burn oil or coal and kerosene
heaters. Depending on the concentration of sulfur in
kerosene, indoor levels have been reported from min-
imal to over 0.14 ppm (Ritchie and Arnold, 1984).
The WHO recommends a guideline value for sulfur
dioxide of 0.174 ppm for a 10 minute maximum
(equivalent to a 1 hour maximum of about 0.122
ppm). The Canadian exposure guideline is <0.38
ppm for a 5 minute maximum and < 0.019 ppm for
long term exposures.
Benzo(a)pyrene
Benzo(a)pyrene (BaP) is probably the most widely
known and measured of the several hundred PAH
compounds which have been detected as byproducts
of combustion. BaP is a potent carcinogen. The
ambient air has background BaP levels of nearly
zero (WHO, 1987); levels of less than 5 ng/m3 were
measured in the U.S. during the 1970s (Faqro and
Manning, 1981).
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Section 8
IAQ Reference Manual
Indoor levels of BaP have been measured during the
combustion of wood, coal, kerosene, and tobacco.
Because BaP and PAH compounds are carcinogens,
there is no safe level of these compounds indoors.
Mitigation Advice For Combustion
Contaminants
It is important to instruct residents about the
problem of depressurization of the house when other
fuel-burning appliances are present and there is
insufficient oxygen. This problem is particularly
important in tightly constructed homes.
It is important for all vented appliances to be
properly installed, maintained, and operated in
order to prevent emissions from entering the living
space. If there are problems with the condition or
installation of the appliance, flues, chimneys,
chimney connectors, and so forth, these must be
repaired, usually by a qualified contractor.
The most effective method of controlling gaseous
and particulate combustion products is removal of
the source or substitution with sources that emit
fewer contaminants (for example, replacing
unvented kerosene heaters with electric heaters).
However, in many instances substitution and/or
removal will not be possible. In those cases,
increased ventilation (local exhaust or whole house)
will help reduce emissions.
Whenever local building codes allow unvented *
space heaters, the heaters should be checked for
proper installation and specific limitations. Some
jurisdictions allow the sale of kerosene heaters, but
prohibit their use in single family and/or multiple
family dwellings. Whenever this situation exists,
efforts should be made to provide the consumers
with information about of allowed and prohibited
uses.
Regardless of the primary purpose of an investiga-
tion, if unvented heaters are present and their use is
allowed by the local code, the investigator should
take time to educate the occupants on safe usage of
the appliance. It is important to first determine
why unvented space heaters are being used in lieu of
vented appliances. Whenever possible, central
heating systems or vented appliances should be
encouraged.
Exhibit 8-3. Location and operation of typical backdraf t diverter.
Gas Vent
Draft
Hot Furnace
-Hood
ft
•Mixing Air
Hat Water Healer-Gas
SOURCE: U.S. HEW (1976).
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IAQ Reference Manual Section 8
Exhibit 8-4. CABO Building Code combustion air requirements lor residential fuel-burning
equipment.
ONE AND TWO FAMILY DWELLINGS
A. Combustion air requirements for unconfined spaces (M-1202):
• No special combustion air source is required .for unconfined spaces. Unconfined spaces are those
with a volume not less than 50 ft3 per 1000 Btu/hr or per the input rating of all appliances installed
in the space. Rooms which open into the space where appliances are installed are considered part of
the unconfined space if the openings do not have doors.
Exception: Sealed combustion system (direct vent) appliances or enclosed furnaces are
exempt from these requirements.
B. Combustion air requirements for confined spaces (M-1203):
• Combustion air requirements are 2 in2 of combustion air opening for each 1000 Btu/hr of input rating
with a total area of not less than 200 in2.
Exception: 1 in2 for each 1000 Btu/hr input rating may be permitted if the compartment floor
area is >2 times the floor area of the appliance and the total area is not less than 100 in2.
If the outside air is used, it must be supplied through the required cross-sectional area
extending to the appliance room; the same duct should not serve both the combustion air
openings; the upper duct must be level or extend upward from the appliance room.
• One-half of the required opening must extend within the upper 12 in of the room and one-half within
the lower 12 in of the room.
Exception: In any room that has gas- or liquid-burning appliances which has more than 2
times the floor area of all such appliances, the required combustion air supply may be re-
duced by 50%, but not less than 100 in2.
• The combustion air source can come from outside air or interior spaces. If an interior space is used it
must have a volume in ft3 that is equal to 1/20 of the input Btu/hr rating of all fuel-burning and
water-heating appliances in the space (M-1204).
• Each appliance must have its own supply duct, and combustion air openings cannot have volume
dampers. Requirements for cold climates are given in Section M-1211 of the CABO Code.
C. Attic combustion air
• Combustion air can be obtained from an attic if the required volume of combustion air can be provided.
The combustion air opening must have a galvanized sleeve of not less than No. 26 gauge steel (or other
approved material) extending from the appliance enclosure to at least 6 in above the top of the ceiling
joists.
• Circulating air supplies for blower-type furnaces shall not be obtained from the attic area.
D. Under-floor combustion air
• The lower combustion air supply required in M-1203 of the code can be obtained from under-floor
areas having unobstructed openings to the outside equal to at least 2 times the required combustion
air openings.
SOURCE: CABO (1989)
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Section 8
1AQ Reference Manual
Exhibit 8-5. Separation guidelines to prevent downdrafts into chimneys.
•10 Ft.-
f
To prevent downdrafts, chimney height must
be af least 2 ft. above any roof surface within 2 Ft,
10 ft. horizontally
1
1
I
1
1
1
I
1
I
1
1
1
— 1
1
t
1
1
1
1
1
1
•^
3 ft.'minimum
from roof
penetration
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IAQ Reference Manual
Section 8
Exhibit 8-6. Examples of chimney caps.
Tracking
Swivel
Joint
Turbine
Clay
Chimney Pot
Cone with
Spark Screen
SOURCE: Shelton, J. W. 1979. Wood Heater Safety. Garden Way Publishing: Carlotte, VT. Used with permission.
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Section 8
IAQ Reference Manual
Exhibit 8-7. Potential consequences when more than one appliance is connected to
the same Hue.
Gas
Wafer
Heater
Creosote bo Idup can clog
chimney, with serious
consequences for oil and gas
appliances'connected to the
same flue
Air leaking into chimney through
other appliances or their chimney
connectors may cause more
creosote accumulation and will
result in hotter and less controllable
chimney fires, should such fires
occur,
a
Barometric
draft regulator
t
Chimney capacity, even with clean _
chimney, may not be adequate to
handle all appliances together.
Explosions in chimney of oil or gas
fumes may blow out stovepipe or
blow sparks out of air inlet
Fumes from furnace may blow
across chimney and cut through
another appliance, or impede its
venting
.
Accumulated creosote and ash
may block furnace breeching
Sparb originating elsewhere in
system may come out through a
fireplace or fireplace stove
SOURCE: Shelton, J.W. 1979- Wood Heater Safety. Garden Way Publishing: Carlotte, VT. Used with permission.
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IAQ Reference Manual
Section 8
Exhibit 8-8. Combustion inspection form.
Address:
Date:
HOME H1ATING INSPECTION CHECKLIST
Central Heat: Present?
N
Fuel Source:
VISUAL INSPECTION
Cover on Furnace
Obvious Damage to Any Part
Duct Work Connected
Chimney in Good Condition
Smell Fuel Source/Odor
Registers Clean
Loeation in BA or BR
Cold Air Return Clean/Open
Combustion Air Intake Blocked/
Dirty
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
N
N
N
N
N
N
N
N
Operable? Y N
If no, why not? ;
(Turn on if not in operation at time of
inspection, if possible.)
BLUE/VENT
Secure to Chimney
Correctly Sized
Secure to Furnace
Flue/Vent Slopes Upward
Y N
Y N
Y N
Y N
OTHER SOURCES OF HEAT.
(Specify)
a) Unvented Gas Space Heater
b) Kerosene Heater
c) Gas Cooking Stove
d) Fireplace
e) Vented Gas Space Heater
f) Wood Stove
g) Coal Stove
h) Electric Space Heaters
WATER HEATER
Present
Gas
If in Garage, 18 in Off Ground N/A
Cover on-Water Heater
Obvious Damage/Rust
Located in BA or BR
VENT
Y N In Good Condition Y N
Y N Slopes Upward Y N
Y N Connected Directly/Securely Y N
Y N to Chimney
Y N Chimney in Good Condition Y N
Y N Correctly Sized Y N
WOOD/COAL STOVES
36 in Minimum Floor Protection
Accessible to Children
Combustibles 36 in Away
<25 Ibs Logs Stored Inside
Y N
Y N
Y N
Y N
Use Double/Triple Wall Flue Y N
Fhje Correctly Sized Y N
Sheet Metal Screws in Flue Y N
ASBESTOS MATERIALS (List location and note condition)
Present
Friable
Y
Y
N
N
Comments and Code Violations:
SOURCE: Adapted from Marion County Health Department (1988).
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Section 8
IAQ Reference Manual
Exhibit 8-9. Features of proper stove installation.
Creosote then runs down
inside of pipe.
Joints lapped and
fastened with screws
Crimped end of
connector pipe
should point
downward.
Securely fasten
joint with sheet
Floor Protection Pad
(Stove Board)
Radiant Type"
Stove
SOURCE: Jenkins and Vacca (1979)
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IAQ Reference Manual
Sections
Exhibit 8-10. Suggested chimney sizes for residential wood-burning equipment.1
APPLIANCE TYPE:
SUGGESTED INSIDE
DIAMETER FOR
ROUND CHIMNEYS
OR FLUE LINERS
(INCHES)
SUGGESTED
RECTANGULAR
FLUE DIMENSIONS
(NOMINAL EXTERIOR)
(INCHES)
Small stoves4
Medium and large stoves4
4-6
5-7
6-8
7-8
4x8
8x8
8x8
8x8
Fireplace stoves,3'4
small fireplaces
furnaces, boilers
8-10
10
8x12
8x12
Medium fireplaces3
Large fireplaces5
10
12
15
81/2x8 1/2*
8 1/2 x 13b
8 1/2 x 13C
8 1/2 x 18d
13xl3e
13 x 18f
1 Additional sizes can be found in Sheldon (1979), Self (1980), or other handbooks.
2 Each type of appliance spans a range of collar sizes; thus location of type in table is approximate.
3 A common rule of thumb for fireplace and fireplace-stove chimneys is that the cross-sectional area of the flue should be about
1/10 of the area of the fireplace opening if the chimney is 15 feet or more in length from the hearth to the chimney top. If the flue
is unlined or less that 15 feet tall, the needed flue size is 1/8 of the fireplace opening. Bigger is not always better. Oversize flues
tend to create less draft and accumulate more creosote.
4 Shelton (1979)
5 Self(1988)
." fireplace opening — 28"x24"x (IS" - 18")
b fireplace opening — (30" - 32") x 28" x 18"
c fireplace opening — 36"x28" x 18"
d fireplace opening — 42"x28"x 18"
e fireplace opening — 48" x 32" x (18" - 20")
f fireplace opening — 54" x 36" x 20"
SOURCE: Shelton (1979); Self(1988)
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Section 8 IAQ Reference Manual
Exhibit 8-11. Safety guidelines for unvented gas-fired heaters.
» Turn off the fuel valve whenever there is a strong fuel odor, and call for service.
• Strike the match before the gas valve is opened. This prevents the possible buildup of fuel vapor
which could easily ignite. If there is an accumulation of fuel vapor, sufficient time should be
allowed to pass before relighting to dissipate the fuel.
• Observe the flame to be sure it is adjusted properly. A yellow flame indicates incomplete combus-
tion and will result in higher carbon monoxide and particulate levels.
• Always keep a window partially open whenever a fuel-burning unvented space heater is in use.
Adequate ventilation is needed to reduce contaminant levels and to replace oxygen that is used for
combustion. One inch of open window space for every 10,000 Btu of heater rating is a general
rule of thumb (equal to about 4 in2 for every 1,000 Btu of heater rating).
* Never leave the heater unattended while it is in operation. Never use the heater overnight while
people are sleeping.
Exhibit 8-12. Safety guidelines for unvented kerosene heaters.
TO MINIMIZE INDOOR AIR POLLUTION:
* Use only water clear, or K-l kerosene, as a fuel. K-2 kerosene and fuel oil have a greater sulfur
content and will increase emissions. Never use gasoline because of explosion/fire hazards. Do not
use kerosene that is yellow or that has been stored over a period of time (summer season).
« Examine wicks and burners for excessive carbon buildup after burning 1 or 2 tanks of fuel.
Carbon buildup is indicative of inefficient combustion.
» Do not operate the heater in confined areas such as bathrooms. Never operate the heater in
bedrooms while people are sleeping.
• Size the heater correctly for the space to be heated. A general rule of thumb for calculating the
required Btu is to multiply the floor area by 28. The resulting number is an approximation;
anyone who is contemplating the purchase of a kerosene heater should consult with the sales
representative to more closely match the space to be heated with the correct size of heater. Avoid
oversized heaters.
• Always keep the wick at the proper setting. A wick that is too high or too low can significantly
increase emissions. Do not "turn down" the flame in an effort to cool a room that is too hot. This
will only decrease the efficiency of combustion and increase the emissions of carbon monoxide and
particulates. Do not "turn up" the flame in an effort to generate more heat because this will
increase the oxides of nitrogen.
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IAQ Reference Manual
Section 8
Exhibit 8-12. Safety guidelines for unvented kerosene heaters Continued).
• Always provide adequate ventilation. Do not use heaters in a closed room. Some manufacturers
recommend using the heater in a room that is open to other rooms. Air exchange with other
rooms in the house does not provide sufficient ventilation air. Fresh outside air must be provided.
Windows should be opened at least 4 in2 for every 1000 Bra of heater capacity.
» Consider other heating options if anyone in the house is ill, has allergies or asthma, pregnant, or if
there are small children in the house.
TO MINIMIZE SAFETY HAZARDS:
• Do not leave kerosene heaters unattended.
» Be sure there is sufficient clearance between the heater and combustibles,
• Do not move the heater while it is burning or if the flame flares or appears to be uncontrolled.
Turn off the heater, and if this foils or cannot be done, leave the area immediately and call the fire
department.
* Store kerosene in a container labeled "kerosene." Do not store other fuel in this container. Store
fuel in a safe place, where children cannot reach it.
• Do not store fuel inside the house. Fill heaters with fuel outdoors, never indoors. Never add fuel
to a heater that is burning or hot.
* Keep children away from kerosene heaters to protect them from touching hot surfaces.
* Check the temperature of rooms where heaters are being used to be sure that rooms are not too
hot. Temperatures over 100°F have been measured.
REFERENCES
American Society of Heating, Refrigerating, and Air Condition-
ing Engineers, Inc. (ASHRAE). 1989. 1989 ASHRAE
Handbook. Fundamentals. I-P edition. ASHRAE: Atlanta, GA.
Canada Mortgage and Housing Corporation (CMHC). 1988a.
Residential Exhaust Equipment. EEE/ESC-88-35. CMHC:
Ottawa, Ontario.
Canada Mortgage and Housing Corporation (CMHC). 1988b.
Chimney Safety Tests Users' Manual. Procedures for determining the
safety of residential chimneys. 2nd edition. CMHC: Ottawa,
Ontario.
Council of American Building Officials (CABO). 1989. CABO
One and Two family Dwelling Code. CABO: Falls Church, VA.
Faoro, B..B. and J.A Manning. 1981. "Trends in benzo-
(a)pyrene, 1966-77." J. Air. Poll. Cant. Assoc. 31: 62-64.
Jenkins, J. and R. Vacca. 1979- "Wood for home heating.
Safety and wood heating systems." G2936. Wisconsin Energy
Extension Service: Madison, WI.
Marion County Health Department. 1988. "Home heating
inspection checklist." Bureau of Environmental Health, Health
and Hospital Corporation: Indianapolis, IN.
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IAQ Reference Manual
National Fire Protection Association (NFPA). 1988a, National
Fuel Gas Code. NFPA 54. NFPA: Quincy, MA.
National Fire Protection Association (NFPA). 1988b. Chimneys,
Fireplaces, Vents, and Solid Fuel Burning Appliances. NFPA 211.
NPPA: Quincy, MA.
Ritchie, I.M. and L,A. Oatman. 1983, "Residential air
pollution from kerosene heaters." J. Air Pall, Cunt, Asm. 33
(91): 879-881.
Ritchie, I.M. and F.C. Arnold. "Characterization of residential
air pollution from unvented kerosene heaters." Indoor Air. Vol.
4. Chemical Characterization and Personal Exposure, Swedish
Council for Building Research: Stockholm, Sweden, pp. 253-
258.
Self, Charles R. 1982. Wood Heating Handbook. 2nd edition.
Tab Books, Inc.: Blue Ridge Summit, PA.
Shelton.J.W. 1979. Wood Heater Safety. Garden Way
Publishing: Carlotte, VT.
Spengler, J.D. and M.A. Cohen. 1985. "Emissions from indoor
combustion sources." Indoor Air and Human Health. R.B.
Garnmage and S.V. Kaye (eds). Lewis Publishers: Chelsea, MI,
Sterling, T.D. and E. Sterling, 1979. "Carbon monoxide levels
in kitchens and homes with gas cookers." Air Pott. Coat. Assoc.
29(3): 238-241.
Traynor, G.W., J.R. Girman, J.R. Allen, M.G. Apte, A.R.
Carruthers.J.F. Dillwoith, and V.M. Martin. 1983. "Indoor
air pollution due to emisions from unvented gas-fired space
heaters." LBL-15878. Lawrence Berkeley Laboratory:
Berkeley, CA.
UJ. Department of Health, Education, and Welfare (DHEW).
1976. Basic-HousingInspection. HEW (CDC) 80-8315. U.S.
DHEW, Public Health Service: Washington, DC.
U.S. Environmental Protection Agency (EPA), 1990. Air
Surveillance for Hazardous Materials, (165.4). U.S. EPA, Office
of Emergency and Remedial Response: Cincinnati, OH.
World Health Organisation (WHO). 1987. Air Quality
Guidelines for Eunfe, European Series No. 23. WHO: Copen-
hagen, Denmark,
8.3 INVESTIGATION TICHNIQUES FOR
PESTICIDES
A. routine indoor air quality investigation
should identify which pesticides are present and the
potential hazards posed by storage and use practices.
Education about the prudent control of pests can be
an important goal of an indoor air quality program
and individual inspections. Clients should be
informed about potential hazards of products they
store or use, encouraged to dispose of products
which are used infrequently, and encouraged to 'use
less hazardous products whenever possible,
During an inspection, the investigator should ask if
pesticides are used. If so, the following information
should be obtained:
• inventory of pesticides which are present;
• frequency of use and the date of last use;
• methods of storing, mixing, and disposal;
• methods of application (for example, spray);
• ventilation and personal protection used for
mixing and application; and,
• for termiticides and large area applications,
date of application, method, and chemical
(if known).
The inventory should include questions to identify
the use of products such as flea and tick collars,
insect repellents, disinfectant sprays, no-pest strips,
roach and rodent baits, insect sprays, and so forth.
A request to see the location where these products
are stored can reveal important information about
storage practices. Products which are stored in areas
where children have access should be relocated. Any
evidence of spills or leakage requires removal and
cleanup. Pesticide products which are in unmarked
containers or those which are not in original
containers should be disposed of properly. Any
products which have been banned should be re-
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Section 8
moved and disposed of properly; a list of these
pesticides can be obtaiaed from the EPA regional
office.
The investigator should also determine the type of
applicator that is or has been used (aerosol cans,
foggers, bombs, handsprayers, pressurized hose
sprayers, brushes/cloths, lawn or garden spreaders,
hand dusters, or shake containers) and the proce-
dures used to apply the products. If any of the
equipment appears to be contaminated, the investi-
gator should inform the client of the need to clean
equipment after application and the procedures to
be followed.
Mixing and application practices are important
factors that affect personal exposures during applica-
tion and contamination of the indoor environment.
Asking for a demonstration of how the client uses
equipment and products (even aerosol or pump
sprays) can sometimes reveal more information than
asking for a simple explanation of procedures which
are followed. Attention should also be given to the
ventilation which is provided and reentry after
application.
A history of the recent application of pesticides and
flu-like symptoms should alert the investigator to a
possible pesticide contamination problem.
Termiticide Investigations
Termiticides are applied to the soil in one of two
ways. Pre-treatment (before a house is built) is done
by trenching around the foundation. Remedial
treatment is done by drilling, rodding, and some-
times by trenching chemicals into the soil.
The levels of the termiticide that might result in
the indoor air depends on the volatility of the
termiticide, the method of application and route of
entry, and environmental factors that affect the
movement of air and degradation of the termiticide.
A buildup of termiticide can result when the
heating system becomes contaminated, when
building is depressurized, or when there are entry
points into the living space.
If odors (even faint ones) linger more than a few
days, structural problems or improper application
should be suspected.
All structural elements located between the treated
soil and the inside of the building should be
examined if possible. Typical problems include
cracks or openings in the floor, ductwork in the
crawl space which leaks, and holes around plumbing
and utility lines in slab foundations.
Misapplication problems can include accidental
contamination of ducts, spraying termiticides onto a
wooden structure, open or poorly sealed injection
holes, not cleaning spills that occur during injec-
tion; transfer from one hole to another; and applying
termiticides to areas which provide the termiticide
access to the indoor air. Potential problem areas
and mitigation methods are summarized in Exhibit
8-13.
Wells and drinking water can also become contami-
nated during termiticide applications. Common
problems include wells that are not properly sealed,
old cistern or dug wells that are not properly filled,
and tree roots which act as channels for pesticide
flow. If a well is located within the foundation, the
house should not be treated with a termiticide.
Contaminated wells require expert assistance.
Crawl space contamination problems
If a crawl space is present and odors intensify when
the heating or cooling system blower operates, the
crawl space should be evaluated. Problems can
come from several sources;
1) openings in the floor between the crawl
space and the living space;
2) a furnace which draws combustion air from
the crawl space;
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IAQ Reference Manual
3) cold air return ductwork which has faulty
seams or openings;
4) contamination of joists, piers, and other
subflooring members;:
5) contamination of insulation or water pipe
wrapping;
6) contamination of the surface soil of the
crawl space; and
7) ducting which uses joists and sheet metal
and/or flberboard to make the air channels.
Termiticides should not be applied to crawl spaces
when the crawl space is used as a hot or cold air
plenum.
Intra-slab or sub-slab contamination
problems
A lingering odor in a structure with intra-slab or
sub-slab ductwork suggests that contaminants from
the treated soil are entering the living space through
openings, cracks, or deteriorated sections of
ductwork,
Termiticides should not be applied to sub-slab or
intra-slab floors made with cardboard, defective
metal, tile, cracked concrete, or fiberglass ducts.
Application of pesticides in these areas is likely to
result in duct contamination.
Accidental injection of termiticide into the
ductwork should be suspected if odors occur
immediately after the termiticide has been applied
and as a result of operating the blower on the
heating and ventilating system.
To investigate these problems, ventilate the home to
clear odors. Then starting with the registers nearest
to the blower, smell each vent to determine the
source of the odor. Work from the blower outward.
If an odor is detected from a particular vent, the
duct near that vent is the most likely source. If the
source of the odor cannot be determined, each
register should be removed and a light and mirror
should be used to look for rusty or moisture-stained
sections of the duct.
Other surface contamination problems
Any puddles, seepage, wet or moist surfaces in
floors, walls, or insulation that have a chemical odor
suggest contamination with a termiticide, if a recent
application has occurred. Sampling may be required
to verify the contaminant.
Measuring Pesticide Contaminants
Pesticide measurements will probably not be taken
during routine investigations of indoor air quality
problems. As mentioned previously, a recent
history of use, lingering chemical odors, and
symptoms may be sufficent to diagnose a problem.
There may be instances when measurements of
pesticides will be useful and surface residues,
airborne samples, or water can be collected and
tested. Measurement of airborne residues provides
as estimate of respiratory exposure to the pesticide;
water samples and surface residues (soil, wood,
furniture, household objects) can help identify
potential hazards and the sources of contamination.
Procedures for air and residue samples are outlined
below. Water samples should be collected as
instructed by the laboratory doing the analysis.
Air sampling
Pesticide concentrations can be measured to deter-
mine if pesticides are present or to evaluate the
efficiency of mitigation efforts. Collecting pesticide
samples is relatively easy, but the analysis is com-
plex and requires highly trained analysts and
sophisticated equipment. Extreme care must be
used to prevent contamination problems during
all phases of sampling and analysis.
Cooperative agreements between local and state
agencies can generally be developed for analytical
capability. Private consulting laboratories can also
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Section 8
conduct sampling and analysis, but costs are high,
generally $100 to $200 per sample. The laboratory
must have a rigorous quality assurance program, and
the analyst should be experienced not only with the
general analytical technique, but should also have
experience with pesticide analysis,
EPA has developed a method for collecting and
analyzing several pesticides in ambient and indoor
air using low volume polyurethane foam (PUF)
sampling with gas chromatography/electron capture
detection (GC/ECD) (U.S. EPA, 1989a,b). Exhibit
8-14 identifies pesticides which have been measured
using this method.
The indoor sample is collected by using a personal
sampling pump to draw air through a polyurethane
foam'cylinder that is slightly compressed into a
borosilkate glass tube; these can be purchased
assembled or fashioned by the user. The sample is
collected by using low flow rates in the range 1 to 5
1pm for sampling periods of 4 to 24 hours. Station-
ary or personal samples can be collected. After
collection, the samples are extracted, concentrated,
and analyzed using GC/ECD. Gas chromatography
can also be followed by mass spectroscopy/multiple
ion detection (GC/MS/MID) for confirmation and to
quantify nonchlorinated compounds.
Quality control procedures and proper technique are
very important in this procedure to prevent the
possibility of contamination. The laboratory should
include field, process, and solvent blanks at a level
of 5%. Blank levels should not exceed 10 nano-
grams (ng)/sample for single components or 100 ng/
sample for mixtures with multiple pesticides.
Replicate determinations of collection efficiency
should be made using spiked samples. Relative
standard deviations for the replicate determinations
of ± 15 % or less are acceptable, and recoveries of
75% are acceptable (U.S. EPA, 1989b).
Air samples should be placed at the breathing
height (3 feet to 6 feet above the floor) for the
occupants. The sampler should be located at least
12 inches from any obstacle to insure adequate air
flow. Sampling is conducted at a rate of 1 to 5
1/min., and the sampling pumps are calibrated
before and after sampling in the laboratory. The
collected samples should be refrigerated until
analysis.
Ideally, for complaint and emergency investiga-
tions, duplicate samples should be collected from
each living area for a period of 4 hours to 24 hours.
A field blank should be included if a single resi-
dence is sampled; if more than one residence is
sampled, field blanks at a rate of 5% should be
included (U.S. EPA, 1989b).
Special Samples
Wipe samples (sometimes called swipe or smear
samples) can be collected from surfaces such as
kitchen tops, floor surfaces close to walls and
injection areas, furniture, walls, and other areas
where contamination is suspected. Wipe samples
should not be used in lieu of air samples, but they
can provide useful information about sources and
extent of contamination. EPA does not have
guidelines for wipe samples, but wipe sampling
procedures developed by OSHA can be used [(29
CFR 1910.132(a)}. The OSHA procedure is not
limited to pesticides.
Clean gloves which are impervious to the contami-
nant should be worn during all phases of collection.
Surface samples are collected by wetting Whatman
42 (7 cm) filter paper with acetone, water, or other
solvent as recommended by the analytical labora-
tory) and wiping across the suspected area,
The OSHA procedure is as follows: Moisten the
filter paper with the solvent, and wipe an area of
about 100 cm2. Without allowing the filter to
contact any other surface, fold it with the exposed
side in, and then fold it over to form a 90-degree
angle in the center of the filter. Place the filter,
angle first, into a clean glass vial (provided by the
laboratory to minimize contamination problems),
replace the top, seal it, and send it to, the laboratory
for analysis. A blank filter also moistened with
solvent should be submitted in a separate vial along
with the samples.
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The Wood Protection Council (1987) recommends a
similar, somewhat abbreviated procedure; a filter
size of at least 10 cm x 10 cm is recommended.
Swipe samples should not be used on carpets or
furnace filters; instead a 10 cm x 10 cm section of
these materials should be collected (Wood Protec-
tion Council, 1987).
Interpretation of Pesticide Data
Interpreting measured air data can be difficult
because of the lack of guidelines on acceptable
concentrations of pesticides. The National Acad-
emy of Sciences reviewed the seven most frequently
used termiticides in the U.S. and recommended the
following guidelines: aldrin—1 pg/m3; chlor-
dane—5 \lglm?', chlorpyrifos—10 |%/mj; hepta-
chlor—2.00 |4g/m3 (NEC, 1982). The NAS also
reviewed the data for lindane and pentachlorophe-
nol, but guidelines were not suggested for these
contaminants.
In the absence of guidelines for the general popula-
tion and the uncertainty about the long-term health
effects of exposure to pesticides, a conservative
approach is indicated. The presence of pesticides on
swipe samples should prompt an investigation of
possible sources and corrective action. The investi-
gator should attempt to contact and consult with
physicians in those instances where respiratory, '
allergic, or other effects appear to be experienced by
exposed individuals. Every effort should be made to
minimize pesticide exposures, even in situations
where the complaint is limited to odors.
Mitigation Advice for Pesticides
General Advice
It is almost impossible to eliminate pests entirely.
Regular use of pesticides often initiates a vicious
cycle of pesticide applications that are more fre-
quent and potent in order to maintain the same
degree of control. The best control strategy is to
prevent pests from invading in the first place and
avoid the unnecessary use of pesticides. The use of
nonchemical pest control methods (particularly
proper hygiene and removal of food, water, shelter,
and breeding sites) and maintaining healthy plants
should be encouraged in place of chemical control
methods.
If pests become established, nonchemical controls
may not be sufficient to correct problems, and
pesticides may be necessary. The use of a combina-
tion of methods to control pests is called integrated
pest management (IPM), and education programs
which emphasize the prevention of pest infestations
and integrated pest management may be available
from (or could be developed in conjunction with)
county cooperative extension agencies. Useful
sources of consumer information on pesticides are
contained in Exhibit 8-15-
When pesticides must be used, clients should be
instructed verbally or by fact sheets about the safe
use, storage, and disposal of pesticides. In general,
if pesticide products have not been used during the
preceding 6 months, the proper disposal of these
products should be encouraged. (A community-
sponsored free drop-off program for the disposal of
household hazardous waste is an effective way to
dispose of pesticides and other hazardous materials
that may be found in the home.) If professional
applicators are hired, consumers should ask what
products will be used, what potential health effects
could result, and what reentry times are needed.
Exhibit 8-16 contains a list of safety tips for the
safe use of pesticides in the home. This list can be
modified easily for other applications.
Pesticide Spills, Improper Applications,
and Odors
If pesticide spills occur in or around the home or
office, quick action is important. The investigator
should be prepared to respond if he/she is on scene
and emergency help is not-available. Exhibit 8-17
provides guidelines for administering first aid in
emergencies. ' ;
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Section 8
When spills or accidents occur, the basic response
includes stopping the source, containing the
pesticide, securing the area, obtaining first aid if
needed, removing excess pesticide, cleaning the
area, disposing of waste, and evaluating the area
after cleanup. Proper respiratory protection (organic
vapor and particulate cartridges) and clothing ,
(impervious gloves, apron, and shoes; disposable
coveralls) must be worn during all phases of cleanup
and residue removal. These should be part of the
investigator's field equipment. General guidelines
for cleaning spills and residues which can be given
to clients as part of an education program are
summarized in Exhibit 8-18.
One problem related to pesticide application is
premature reentry. Safe reentry times vary depend-
ing on the product, and these must be followed as
specified by the manufacturer to prevent accidental
poisonings.
If professional applicators are responsible for
improper applications, they should be contacted to
provide remedial assistance. If pesticides have been
applied and odors linger, the area should be venti-
lated and checked for the presence of liquid pesti-
cide. If present, liquids should first be absorbed,
then removed. Manufacturers of products should
also be contacted to obtain information on proper
mitigation. Sampling should be conducted to verify
the effectiveness of ventilation and cleanup.
Methods for mitigating termiticide contamination
are given in Exhibit 8-13-
Pest Management Indoors
There are some types of products that consumers
could replace with other control measures in order
to reduce their exposure to pesticides. Solid baits
can provide a safer alternative -to sprays, and pumps
that deliver larger droplets can provide more control
than aerosolized products. The use of pesticide
strips (containing propoxur, chlorpyrifos, diazinon)
and paint-on formulations have! been suggested as
safe alternatives to sprays because sprays (aerosol or
compressed) are likely to result in higher concentra-
tions of contaminants compared to paint-on formu-
lations or strips. A two-fold increase was observed
in one study (Ware and Cahill, 1984).
Pest strips, however, still release pesticides into the
living space and over a longer period of time
because they are formulated as controlled releases.
A safe alternative to pest strips are sticky paper
strips which are coated with a sugar attractant
instead of pesticides.
The use of insect repellents (containing DEBT or
other active ingredients) which are applied as a
lotion or spray should not be used on infants and
young children because of potentially serious health
effects.
There are many simple, but often effective,
nonchemical pest control methods which can be
used in and around residences. Hand removal,
vacuuming, and the use of a flyswatter can control
many flying and crawling insects,. Maintaining
healthy plants and thorough washing of stems and
leaves at the first sign of some pests can minimize
pest problems.on plants. Ants can usually be
controlled by removing visible ants and eliminating
all food sources. Diatomaceous earth or a mixture of
boric acid and sugar can be effective controlling
roaches, ants, and blister beetles. Rats and mice can
be controlled by ratproofing structures; Vitamin
D3 pelleted bait can also be effective. Infestations
of fleas -can often be controlled by thorough vacu-
uming of floors, carpets, and upholstery, followed
by shampooing. All removable bed and furniture
coverings should be laundered. Heavy infestations
may require two of these cleanings, or the use of
pesticides.
In general, removing food and water and eliminat-
ing shelter and breeding sites are fundamental
principles to be encouraged,
Removing food and water sources: All pests need
food and water to survive, and an important step in
controlling pests is to remove needed nutrients.
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IAQ Reference Manual
Standing water can be eliminated from the home by
fixing leaky plumbing, removing water collectors
such as tires from yards, correcting drainage prob-
lems, and by removing standing water from trays
under houseplants. Food sources should also be
removed. Foods (including pet foods) should be
stored in sealed containers and should not be
allowed to stand open for long periods of time.
Garbage should be placed in tightly covered, heavy-
gauge garbage cans and stored outside.
Eliminating shelter and breeding sites: Shelter
and breeding sites can be eliminated by sealing
cracks and crevices to keep pests from entering the
building, removing wood and paper debris from the
yard or under houses in crawl spaces, removing
standing water, maintaining relative humidity
below 50% in all areas, and removing pet feces.
Pest Management Outdoors
Pesticide use can be reduced significantly by
keeping grass, yard, and garden plants healthy.
Healthy plants can be grown by planting new plants
at the right time of the year to minimize the stress
of transplantation; watering adequately, but not
overwatering; and applying mulch to retain mois-
ture, reduce weeds, and maintain even soil tempera-
tures. If pests become well established in gardens, it
may be necessary to apply pesticides judiciously
according to instructions on the label. Only the
minimum required for the job should be used. For
example, instead of applying an herbicide to an
entire lawn, weeds can be individually spot-sprayed.
This can dramatically reduce the amount of pesti-
cide that is applied.
A new industry is emerging to support and foster
sustainable gardening and agriculture through
integrated pest management which focuses on
preventive cultural practices and nonchemical
controls. The careful selection of disease-resistant
seed or plant varieties, using plant (crop) rotation
and diversification, and ensuring good drainage and
soil aeration are important cultural practices which
can help prevent pest infestations. Other cultural
strategies include using "trap" plantings to lure
pests away from vulnerable plantings, planting
companion plants which have insect-repellent
properties, and spacing plants properly.
Nonchemical alternatives must be tailored to the
individual pest and location of the problem. Bio-
logical controls include using beneficial birds,
insects, and pathogens such as bacteria, viruses', and
other microorganisms to limit the pest population
(Exhibit 8-19)- Other biological control methods
•include pheromones (sexual attractants which lure
the pest to the trap), release of sterile males, and
hormones to inhibit the growth of juvenile pests.
Physical controls can also effectively reduce pest
populations. A simple, but effective measure for
residential lawns and gardens is to handpick pests
from gardens and flowers, and weeds from lawns
and gardens. Some other examples of physical
controls include traps to remove insects and rodents,
vacuums to remove insects from crops, screening
living spaces to limit mosquito and fly access, and
the use of oils to prevent mosquito larvae from
growing to adulthood.
Healthy lawns, gardens, or commercial crops can be
achieved through the use of nonchemical controls.
While nonchemical pest control generally requires
more work, attention to timing of the application of
methods, and a longer period of time for results,
these methods do not pose a hazard to humans or
pets. In addition, pesticide-resistent populations are
not created, and special clothing and respirators are
not required for application of pesticides.
-------
Exhibit 8-13. Sources of termiticide contamination and potential mitigation methods.
GENERAL
1) Call the manufacturer for specific information about the appropriateness and
likely success of a particular method, required personal protective equipment,
cleaning agents, and other procedures.
2) Conduct air monitoring after mitigation to determine whether or not the
method was successful.
CRAWL SPACE
1) contaminated crawl space
• install vents if none exist
• install fans to create a slight vacuum in the space; fans should be
installed away from the furnace and ducts inside the space; air should be
exhausted away from air conditioners, windows, and doors
• remove contaminated soil; install a plastic vapor retarder over the soil
surface and use untreated soil to seal the edges
• correct site grade problems or install drainage tiles to divert excess soil
moisture
• pour a concrete slab at least two inches thick over the soil within the
crawl space
2) termiticide enters through faulty ductwork
• insure that any outside combustion air supply is not located in the crawl
space
• repair any cracks, or openings in the duct work and seal joints with duct
tape
• seal or remove ductwork and install an attic ducting system
INTRA-SLAB OR SUB-SLAB DUCTWORK
1) termiticide enters through openings, crack, or deteriorated sections of the
ductwork
• install air filters at furnace intake ducts and at the floor vents; a qualified
contractor should be used; actitivated charcoal filters or polyurethane
foam (60 pores/in) can be tried; filters should be changed every two
weeks initially and less frequently after odors are reduced
• sleeve the ducts by inserting a new liner; a qualified contractor should be
used
• plug all duct openings and seal with concrete at least 12 in on both sides
of vent registers; install an above-floor duct system
2) termiticide has been injected into ductwork
• for limited problem, remove affected section and replace with new
ducting
• for significant contamination, seal all duct openings with concrete;
install an above-slab heating system
FOUNDATION WALL SEEPAGE AND ODORS
1) termiticide enters through cracks or openings in subflooring members above
the foundation walls
• seal all drilled application holes in foundation walls and pillars with
concrete patching
• cap hollow foundation blocks by filling the top row of blocks with
expandable polyurethane foam or concrete; the tops can also be coated
with roofing cement, followed by a strip of roofing paper on the cement;
the roofing paper is held in place with a wood strip over the paper which
is toenailed in place
2) termiticide seeps through hollow block or masonry wall and causes damp or
wet surfaces
• wash and rinse until the wall is clean; apply a commercial basement
sealer when the wall is dry
• install drainage tiles and a sump pump
• correct surface grade
3) termiticide enters through cracks or openings in the hollow or masonry wall
• cracks should be cleaned as above, sealed with a silicone-based caulk and
painted over with polyurethane or silicone-based paint
CONTAMINATION OF NON-TARGET SURFACES
1) joists, piers, and other subflooring members are contaminated
• wash the affected subflooring and rinse; repeat several several times
• remove the affected areas and replace with new materials
2) insulation is contaminated
• remove and install new insulation
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IAQ Reference Manual
Exhibit 8-14. Pesticides that can be measured using low volume PUF sampling with
GC/ECD.
ORGANOCHLORINE
Aldrin
p.p.-DDT
p,p,-DDE
Dieldrin
Dicofol
2,4,5 -Trichlorophenol
Pentachlorophenol
BHC (- and-hexachlorocyclohexanes)
Captan
Chlordane, technical
Chlorothalonil
2,4,-D esters
Methoxychlor
Mexacarbate
Mirex
trans-Nonachlor
Oxychlordane
Pentachlorobenzene
Folpet
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Lindane (-BHC)
ORGANOPHOSPHOROUS
UREAS
Chlorpyrifos
Diazinon
Dichlorvos (DDVP)
Ethylparathion
Malathion
Methyl parathion
Ronnel
Chlortoluron
Diuron
Fluormeturon
Linuron
Tebuthiuron
CARBAMATES
TRIAZINE
Bendicarb
Carbaryl
Carbofuran
Mexacarbate
Propoxur
Atrazine
Propazine
Simazine
PYRETHRIN
Allethrin
d-trans-Allethrin
Dicrotophos
Fenvalerate
Pyrethrin I
Pyrethrin II
Resmethrin
SOURCE: U.S. EPA (1989t>)
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IAQ Reference Manual Section 8
Exhibit 8-15. Useful sources of information on pesticides.
The following publications are available on request from EPA, Office of Pesticide Programs (TS-766C), 401
M Street, S.W., Washington, DC. 20450. Additional publications and sources of information are also
available from EPA.
• Pesticide Fact Book. Brief summary of EPA pesticide regulatory program.
• Labeling Fact Sheet. Brief description of EPA requirements for the contents of a pesticide label.
• Pesticide Safety Tips. Suggested safety tips for consumers.
• Suspended, cancelled, and restricted pesticides. List of pesticides which are no longer available to the
public.
• Recognition and Management of Pesticide Poisoning. Reference manual for health care professionals which
categorizes pesticides according to toxicity, describes symptoms or signs of poisoning, gives informa-
tion for confirming diagnosis, identifies antidotes.
• List of Pesticide Fact Sheets. Lists the different fact sheets that EPA has developed for specific pesti-
cides.
• Citizen's Guide to Pesticides. Provides general and specific information on the safe use of pesticides and
an overview of EPA's regulatory programs for pesticides.
Other Resources
Bio-Integral Resource Center (BIRC) BIRC publishes a journal, Common Sense Pest Control
P.O. Box 7414 Quarterly, which focuses on the least toxic alterna-
Berkeley, CA 94707 tives to pesticides and pamphlets on specific
pesticide problems.
Natural Resources Defense Council NRDC has additional information on hazards of
Toxic Substances Information Line toxic substances.
(1-800-648-6732)
Rachel Carson Council, Inc. This organization has information about pesticides
8940 Jones Mill Road and lawns.
Chevy Chase, MD 20815
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Section 8 IAQ Reference Manual
Exhibit 8-16. Guidelines for using pesticides safely.
GENERAL PRECAUTIONS
• Identify the pest to be controlled and select a pesticide which is effective on that pest; help can be
obtained from county extension agents or supply houses.
• Select the least toxic product that has the required active ingredient—help can be obtained from your
state agencies or EPA regional offices.
• Do not use restricted pesticides. These are especially dangerous and should only be used by a certified
applicator.
• Make sure the product bears an EPA registration number.
• Look for the signal words on the front of the label and observe warnings:
DANGER, POISON (Skull & Crossbones) — "Fatal (poisonous) if inhaled."
"Do not breathe vapors."
WARNING — "May be fatal if inhaled." "Do not breathe vapors."
CAUTION — "Harmful if inhaled." "Avoid breathing vapors."
CAUTION — (no additional signal words required)
• Read the entire label for correct application technique, timing of the application, precautions, and
treatment measures. (Failure to use pesticides in accordance with label directions is subject to civil
and/or criminal penalties.)
• Use with adequate ventilation.
• Use protective clothing and respirators as recommended. Paper masks, canvas, leather, and fabric do
not provide protection. Information on protective equipment can be obtained from safety supply
houses, local, or state agencies.
• Prepare only the amount needed for each application—do not use or store extra material.
• If the pesticide requires mixing or dilution, do this outdoors. Be sure that the product will not
become airborne because of wind.
• Keep children and pets away from areas where pesticides are mixed, used, or stored.
• Never smoke while using pesticides. Some formulations are flammable and residues on the hands can
be carried to the mouth.
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IAQ Reference Manual Section 8
inhibit 8-16. Guidelines for using pesticides safely (tontinued),
* Do not transfer pesticides to containers, such as empty soft drink bottles, which were not intended for
them.
• Do not store pesticides in living areas. Store outside living spaces, in the original containers, and in
secure areas not subject to flooding.
* Shower and shampoo thoroughly after using a pesticide product. Wash all clothes that were worn
separately from the family laundry. Also, rinse boots and shoes.
• Clean up spills promptly. Do not wash spills with water. Instead sprinkle with kitty litter, sawdust,
or vermiculite; sweep into a plastic garbage bag; and dispose with the rest of the trash. Follow
product instructions for further cleanup. In the absence of instructions, call the local or state poison
control center.
• Triple rinse tools or equipment that have contacted the pesticide. This should be done in a toilet or
sink taking care not to splash water.
DISPOSAL
• Follow label directions.
•5
• Determine if local regulations allow pesticides to be disposed of with municipal waste. Strictly
comply with local regulations.
In general, if local regulations allow the disposal of pesticides with municipal wastes, unused containers can be
handled as follows: Be sure that container caps are tight, then wrap the containers or packages in several layers
of newspapers and tie securely. Place the package into a covered trash can for collection along with household
wastes.
» Empty pesticides containers are hazardous. Handle as above. Do not puncture pressurized containers.
• If there is no regular trash collection, crush and then bury empty containers at least 18 inches deep in a
place away from water sources, where food is grown, or where children may play.
« Do not burn pesticide containers inside or outside of the home. Hazardous fumes, gases, or explosions
could result.
* Do not pour unused portions of pesticides dowij the sink! Pesticides can interfere with the operation
of septic systems and can contaminate waterways.
(continued next page)
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Section 8 IAQ Reference Manual
Exhibit 8-16. Guidelines for using pesticides safely Continued).
INDOOR APPLICATIONS
« Remove all food, dishes, utensils, food wrappings, pots and pans before treating kitchen cabinets. Do
not let pesticides come in contact with these items. Wait until shelves are dry before refilling them.
» Make sure that adequate ventilation is provided when applying pesticides indoors. This means fresh
outdoor air! Vacate the house for at least the length of time given by the label.
• If pesticides are sprayed outdoors, close the doors and windows of the home and keep them closed for
several hours after spraying. Fresh air intakes should be closed.
« Apply surface sprays only to limited areas. Do not treat entire walls, floors, or ceilings. Be sure to
remove pets and cover aquaria and fishbowls.
OUTDOOR APPLICATIONS
» Never spray or dust on windy days.
" Do not use spray nozzles that deliver a fine mist; a coarse droplet spray is less hazardous.
*
• When spraying or dusting outdoors cover fish ponds and avoid wells.
* Do not spray nontarget plants; use only the smallest amount of pesticides needed to do the job.
Overspraying can contaminate water supplies and leave harmful residues on home-grown produce.
• Do not spray plants which are in bloom.
PERSONAL APPLICATIONS
• Do not use sprays or lotions on infants or toddlers. Use of these products on small children can result
in health problems, and the long term health effects are not known. Use these products cautiously on
older children. Do not use these products routinely. Do not use pesticides on pets which are kept
indoors.
LOCAL EMERGENCY TELEPHONE NUMBERS
Poison Control Center:
Physician:
SOURCE: Adapted from U.S. EPA (1987)
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lAQReference Manual Section 8
Exhibit 8-17. First aid guidelines for pesticide poisonings.
GENERAL GUIDELINES
* Avoid direct contact with heavily contaminated clothing, gloves, or bodily excretions.
» Give first aid, if it can be rendered without contaminating the responder,
» Call for immediate emergency aid or transport the victim to a medical facility,
• Provide accurate information to medical personnel. Do not rely on memory. Bring pesticide containers (with
labels attached) with the victim. Do not transport pesticide containers in the passenger space. Transport
containers in the trunk of the vehicle. If medical help is coming, have the pesticide container available.
• Determine appropriate actions from the "Statement of Treatment" on the container if it is available. If the
container is not available, contact a poison control center, emergency room, or the National Pesticide Telecom-
munications Network (1-800-858-7378).
DERMAL OR EYE CONTACT
• For skin or eye contact, flood with water and remove contaminated clothing. Wash affected skin and hair with
soap and water. Wear rubber gloves to prevent secondary contamination. Dry and wrap the victim until
medical assistance arrives.
* Do not administer ointments, drugs, eye drops, or other preparations.
INHALATION
» Do not attempt rescues in contaminated areas unless protective clothing, respirators, and a "buddy" are avail-
able. Call for emergency assistance instead.
• If the area is not contaminated, move the victim to fresh air immediately.
• Loosen clothing and give CPR if the victim is blue or is not breathing.
INGESTION
• If the victim is unconscious, be sure that no further exposure will occur via skin contact or inhalation. Get
emergency aid immediately. Do not attempt to induce vomiting if the victim is unconscious or has convul-
sions.
* A conscious victim should rinse his/her mouth with plenty of water and drink up to one quart of milk. Emer-
gency help should be called and information should be obtained to determine if vomiting should be induced.
Vomiting should not be induced if the poison is corrosive, an oil solution, or an emukifiable concentrate.
* Aspiration of vomitous into the lungs is a potentially life-threatening situation, and the victim should be
monitored carefully to prevent this possibility.
SOURCE: Morgan (1989); U.S. EPA (1987)
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Exhibit 8-18. Guidelines for cleaning pesticide spills and residues11.
i) STOP THE SOOTCE
* Stop leaking application rods by shutting off the pump *nd releasing
hose pressure. Place the leaking tad into a waste container.
» Eight containers only if it can be done without contamination or if
protective equipment is available.
2) CONTAIN THE PESTICIDE AND SECURE THE ARIA
* Prevent spilled liquids ftoin spreading by adsorbing with spill control
pillows, paper towels, and cat littet, (Cat litter that contains bleach ctn
cause stains in some materials),
* Prevent people and pets from entering the area until the cleanup has
been completed and determined to be successful,
3) REMOVE EXCESS PESTICIDE
* Soak up excess liquid with commercial spill control material, cat litter,
paper towels, sawdust, or soil. Approach the spill from the outer edges
and woik toward the center. Sweep the contaminated material into
heavy duty plastic bags,
* Sweep solid pesticides into plastic bags.
4) CLEAN UP THE AREA
« Large areas or the cleanup of liquid pesticides which have dried onto
porous surfaces such as unfinished concrete or wood flooring require
expert assistance.
« Small areas should be washed using a soft bristle brush and heavy-duty
detergent followed by rinsing with clean water. Used detergent and
rinse water should be removed to a separate container before washing
and rinsing again.
5) VENTILATE THE AREA
« Ventilate the area after the cleanup has been completed by opening
doots and windows for several hours or more depending on the extent of
the spill.
6) WEMOVEPBSTiaDBEISIDUES
I
* Minimize pesticide residues on unfinished wood or concrete by applying
two coats of sealant after the area has beea washed and rinsed. If large
areas are-involved, the material should be removed. Sealants which seem
to be effective include polyurethane and epoxy. Latex paints should not
be used,
» Washing will remove small spills of pesticides from most vinyl flooring.
If the pesticide penetrates beneath the tile, the tile and the underlying
floor should be removed and replaced. In some instances it may be
possible co simply wash and rinse the underlayment and replace only the
floor tile.
» If a pesticide is spilled or sprayed on carpeting or padding, they should
be removed and replaced. Steam cleaning should not be used,
* Plaster walls and other porous wall surfaces should be washed and rinsed
to remove residues. If large areas are affected, removal is necessary.
• Clothing should be washed separately using hot water and the maximum
wash time. Presoaking and repeat washings may be needed. In the case
of small spills, it may be possible to professionally clean drapery and
upholstered furniture (the cleaning company should be informed of the
pesticide residue). If the affected area is large or if the pesticide has
penetrated into batting materials, disposal is needed. Other household
goods such as dishes, silverware, and applicances can be washed and
rinsed to remove residues.
7) DISPOSE OP WASTE MATERIALS
•--Dispose-of waste according to local, state, and federal regulations; "
8) POST CLEANUP EVALUATION
» Evaluate the effectiveness of cleanup procedures by monitoring the air.
aNo action should be attempted without proper protective equipment and clothing.
I
S
I
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IAQ Reference Manual
Section 8
Exhibit 8-19. Examples of biological control of pesticides.
BENEFICIAL ORGANISM
TARGET PEST
ladybugs
predatory mites
lacewing larvae
Trichogramma pretiosuml
Trkbogramma minutum
(wasps which will
not bother humans)
Encarsia formosa
Cryptolaemus
^ediobious fovelolattts
(wasps)
Bacillus thuringiensh
(bacteria)
Bacillus thurtngimns
israeleasis
(bacteria)
Nosema locustae
(disease spore)
Milky Spore'Disease
aphids, mites, and other soft bodied pests
spider mites, greenhouse mites
aphids, mealybugs, leafhopper nymphs,
mites, caterpillar eggs, thirps, scales
eggs of corn borer, cabbage loopeir,
cutworm, codling moth, budmoth,
leafroller, and many caterpillars
whiteflies
mealybugs
Mexican bean beetles
cabbage looper, imported cabbage
worm, tomato hornworm, diamond-back
moth, gypsy moth, fruit maggots, cotton
bollworm, tent caterpillars
mosquito, blackfly midges
grasshoppers
Japanese beetle grubs
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Section 8
IAQ Reference Manual
REFERENCES
Dow Chemical Company. 1985. Dursban Odor Reduction and
Deactivation, Dow Chemical Company: Midland, MI,
Morgan, D.P. 1989. Recognition and Management of Pestidde
Poisonings, 4th edition. EPA-540/9-88-001. U.S. Environ-
ment*! Protection Agency, Office of Pesticide Programs:
Washington, DC.
National Research Council (NEC). 1982. "An assessment of
the health risks of seven pesticides used for termite control."
National Academy Press: Washington, DC.
U.S. Environmental Protection Agency (EPA). 1987. A
CemtMu's Guide to Safer Pesticide Use. OPA 87-013. U.S. EPA:
Washington, DC.
U.S. Environmental Protection Agency (EPA). 1989a.
CompttuRum MethodTO~lQ. "Determination of pesticides in
ambient air using low volume polyurethane foam (POT)
sampling with gas chromatography/eiectron capture detector
(GOECD)." U.S. EPA, Office of Research and Development:
Research Triangle Park, NC.
U.S, Environmental Protection Agency (EPA), 1989b.
"Determination oforganochlorine pesticides in indoor air."
Chap. IP-8. Compendium of Methods far the Determination of Air
Pollutants in Indoor Air. Draft. U.S. EPA, Atmospheric
Research and Exposure Assessment Laboratory: Research
Triangle Park, NC.
Velsicol Chemical Corporation. 1984. Safe Application is No
Accident. Residue Management Guide for Professional Pest, Control
Operators, Velsicol Chemical Corp.: Jefferson, WI.
Velsicol Chemical Corporation, (undated), Termiticide Cleanup
Manual. Velsicol Chemical Corp: Jefferson, WI,
Wood Protection Council. 1987. Indoor Sampling Guidelines for
Ttrmiticidu. National Institute of Building Sciences: Washing-
ton, DC.
8.4. INVESTIGATION TECHNIQUES FOR
FORMALDEHYDE AND OTHER
VOLATILE ORGANIC COMPOUNDS
Investigation Techniques for
Formaldehyde (HCHO)
Any new or recently remodeled home or
office area can be a potential source of HCHO.
Although there has been a shift away from particle-
board/plywood construction in manufactured homes
(mobile homes), these homes may still have HCHO
concentrations which are of concern. The age of the
structure or time since remodeling is important
information because HCHO emissions are known to
decrease over time. The emission rate appears to
decrease rapidly (probably due to the release of free
HCHO) just after manufacturing of the HCHO-
containing product. The rate then decreases more
slowly over a period of months or years.
Several monitoring and modeling studies have been
conducted in an attempt to determine the decay rate
of HCHO. In general estimates range from a half-
life of several months to over 5 years. Indoor
concentrations of HCHO from urea formaldehyde
foam insulation (UFFI) and other urea-HCHO
products depend on changes in ventilation rate, the
operation of air cleaners, indoor and outdoor
temperatures, and humidity. The rate of release of
HCHO from UFFI and other urea-HCHO products
increases with the temperature, wood moisture
content, humidity of the surrounding air, and with
decreased HCHO concentrations in the surrounding
air (Fisk et al., 1987). HCHO also demonstrates
diurnal and seasonal variations. HCHO concentra-
tions vary by as much as 50% throughout the day
and are higher during the summer than during the
winter (Gammage and Gupta, 1989).
CPSC staff reviewed data for HCHO emissions from
particleboard and concluded that a rapid decrease in
HCHO concentration occurs during the first year
followed by a "semi-steady" emission rate for at least
the next four years (CPSC, 198(5). CPSC staff
concluded that there were insufficient data to
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IAQ Reference Manual
Section 8
evaluate the decay rates of HCHO after five years.
HCHO in mobile homes has been reported to have a
half-life of about 4-5 years (Colin et al., 1984).
One of the first activities in the investigation of
potential HCHO problems is identifying possible
HCHO-releasing materials, the age of these materi-
als, and time periods when symptoms appear to get
worse or better. Because HCHO levels can vary
diurnally, it is important to characterize adequately
when and where symptoms occur along with
occupant activities so that sampling will identify
worst-case exposures. It should be remembered that
susceptibility to HCHO varies widely—it is
possible for some family members to experience
effects daily, while others are not affected at all.
Symptoms can vary from person to person, and
usually no one has all symptoms.
Recognizing Formaldehyde-containing
Materials
The most likely sources of HCHO (pressed wood,
partkleboard, hardwood plywood, and UFFI) can be
recognized visually in many instances. Other
sources which can contribute to elevated indoor
concentrations and health effects are more difficult
to recognize visually, and a process of elimination
may be required to evaluate their impacts.
In new homes the most likely sources of HCHO are
those which contain pressed wood or particleboard.
CPSC staff estimated that about 24% of new single-
family detached house construction uses some type
of urea-HCHO pressed wood material (CPSC,
1986). In new single-family detached homes,
particleboard may be used as underlayment over a
softwood plywood (not a urea formaldehyde resin
product). The particleboard underlayment might
be used throughout the entire house or only in the
kitchen and bathrooms. The underlayment may be
covered by carpeting, carpet padding, ceramic tile,
resilient flooring, and solid hardwood coverings
which generally reduce emissions into the living
space, but higher levels of HCHO can still occur.
The presence of particleboard underlayment can be
confirmed by lifting the floor covering to expose the
material underneath (this should be done in an
inconspicuous area). If the home has floor registers,
these can be removed and the wood material can be
inspected.
Waferboard and oriented-strand board can also be
present as subflooring material. These products use
phenol-HCHO as the bonding material and do not
produce significant HCHO emissions. Waferboard
and oriented-strand board are characterized by large
wood flakes in contrast to particleboard which is
produced from small flakes.
Cabinets and furniture made of wood products can
be additional sources of HCHO. Today's kitchen,
bathroom, and other "wood" cabinets are typically
made of wood products—not solid wood. Even top
grade products advertised as solid wood usually have
medium density fiberboard (MDF) shelves covered
by hardwood plywood. In top grade cabinets, wood
products are used as shelving because solid wood is
more likely to warp when in contact with moisture.
These products may have an alkyd urea-HCHO
finish. Less expensive cabinets usually have a core of
MDF which is covered by hardwood plywood, vinyl,
or a paper overlay. Exterior doors of this product
grade are usually solid wood or hardwood plywood.
The least expensive grades of cabinets usually have
all parts made of MDF covered by vinyl or paper
overlay.
Lower grades of furniture are typically constructed
from particleboard or MDF with a paper overlay;
some components may be plastic. Medium to
higher grade furniture might be constructed of
particleboard or MDF with an overlay of hardwood
veneers. The particleboatd or MDF components can
usually be identified by examining unfinished
exposed areas such as the underside of tables, chairs,
or other pieces. All grades of furniture and some
hardwood floors may be finished with alkyd urea-
HCHO finishes which can increase indoor HCHO
levels.
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Section 8
IAQ Reference Manual
Another important source of HCHO indoors is urea
formaldehyde foam insulation (UFFI); homes
insulated with UFFI can be recognized by sealed
openings in the exterior siding which were used to
inject the UFFI. This clue can, on occasion, be
misleading because cellulose insulation is also blown
into similar openings. Another problem is that
openings may not be visible if the exterior siding
was replaced.
If openings are present, a screwdriver or similar tool
can be used to lift the opening cap or mortar and
inspect the material underneath. UFFI may be
present if the material is soft, spongy to granular in
texture, and white to brown in color. If exterior
openings are not visible, the presence of UFFI can
be evaluated by removing and inspecting electrical
outlets which are-located on exterior walls. Studies
of the release of HCHO from UFFI products show
that even if UFFI is installed under optimum
conditions, the products can still emit significant
HCHO and interior levels of HCHO can be elevated
for long periods of time.
In the past, manufactured housing had HCHO
levels that were significantly higher than conven-
tional housing. This was due to the greater use of
HCHO-emitting materials in construction and the
high surface to volume ratio of these homes. In an
effort to reduce HCHO levels, construction tech-
niques have shifted to include the use of gypsum-
board panels rather than plywood paneling. How-
ever, manufactured housing is still constructed with
particleboard decking, and the cabinets and furni-
ture in these homes are still likely to be made of
patticleboard, hardwood plywood, or MDF.
Measuring Formaldehdye
There are many different methods available for
measuring HCHO concentrations including
personal and stationary methods and active and
passive methods. Evaluations of some of these
methods are given in Wallace and Ott (1981),
Kennedy etal. (1985a, b)s and Godish<1985).
Both automated and nonautomated measurement
systems can be purchased ranging in price from
several hundred dollars for nonautomated systems to
over $5000 for a fully automated system. The
continuous monitors allow longer term real-time-
measurements to be made, but their usefulness for
routine residential monitoring is limited by the
time required for instrument stabilization and
standardization.
Regardless of which method is used, it is important
to use standardized conditions during testing.
Closed house conditions should be observed for
short-term samples (1/2 to 1 hour); this means that
doors and windows should be kept closed for about
12 hours prior to testing. Temperatures before and
during sampling should be at about 23-25°C (73°-
77°F), if possible.
Because of the seasonal differences in the release of
HCHO, it has been recommended that sampling
should not be conducted during the winter months,
from December to March (Godish, 1985). As a
practical matter, if an individual appears to have
symptoms related to HCHO then sampling should
be conducted regardless of the season, recognizing
that it may have to be repeated at a later time.
Since HCHO concentrations vary diurnally, mea-
surements should be taken during the times of the
day when, and in locations where, symptoms appear
to be worse. It may be necessary to sample more
than once or to collect samples over a longer period
of time in order to sufficiently characterize the
environment, but for most sampling a single set of
two samples will be sufficient. Samples should be
collected at the breathing height and away from
drafts and impediments to airflow. Outside walls
should be avoided, and samplers should be located
6 inches to 12 inches away from inside walls.
Locations near sources of heat should be avoided. A
rigorous quality assurance program should be
maintained throughout sample collection and
analysis.
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IAQ Reference Manual
Section 8
After the samples have been collected, instructions
given in the method for storage, transport, and time
to analysis should be followed strictly. Some
methods require refrigeration of the collecting
medium and collected samples.
Regardless of the sampling method which is used,
the outdoor and indoor temperatures, barometric
pressure, and indoor relative humidity should be
measured and recorded. Godish and Rouch (1985)
have recommended standardizing measured HCHO
concentrations to a temperature of 25°C and relative
humidity of 60% B.H using the Berge equation:
Cx=CCl + A(H-Ho)e
.-Xfl/T-l/ToXl-l
t1
where,
Cx = standardi2ed concentration (ppm),
C = measured concentration (ppm),
R = temperature constant (9799),
T = measured indoor temperature (8K),
TO = standardized indoor temperature (°K),
A = humidity constant,
H = measured indoor relative
humidity (%), and
HO = standardized relative humidity (%').
Active Methods
EPA's Method IP-6A (DNPH HPLC Method),-
This method utilizes solid adsorbent sampling
followed by high performance liquid chromato-
graphk analysis (HPLC) (U.S. EPA, 1989). HCHO
gas (and other aldehydes or carbonyl compounds) is
adsorbed onto acidified DNPH (2,4-dinitrophenyl-
hydrazine)-coated silica gel cartridges to form a
stable derivative. Commercial cartridges are
available, but random samples from each lot should
be analyzed to determine background levels of
HCHO.
Samples can be collected at a rate of 500-1200 ml/
min. Samples should be refrigerated after collec-
tion, and they can be stored for not more than 90
days. The precision of field replicates should be
±20% or better, and repicate HPLC injections
should have a precision of ± 10% or better.
This sampling procedure requires a moderate degree
of skill and training; the analysis requires a highly
skilled person who is proficient in HPLC techniqes,
EPA's Method IP-6B (Automated Colorimetric
Method): This method utilizes a commercially
available continuous colorimetric gas analyzer
(Model TGM-555-FD) manufactured by CEA
Instruments, Inc. or its equivalent (U.S. EPA;
1989). The method of analysis is based on the
HCHO selective pararosaniline method in which
HCHO is absorbed into sodium tetrachloro-
mercurate (II) solution containing a fixed amount of
sulfur dioxide. Acid bleached pararosaniline is
added to form a purple dye. The concentration of
HCHO is proportional to the intensity of the dye.
This method has been modified (Model TGM-155-
D analyzer) to eliminate the toxic mercury reagents.
The instrument can be calibrated using liquid
formaldehyde standards or certified permeation
tubes. If permeation tubes are used, alpha-
polyoxymethylene is recommended rather than
paraformaldehyde because the paraformaldehyde
, tubes are unstable and lack reproducibility.
This instrument has a range of 0-5ppm in the
standard range and 0-250 ppm in the low level
range. The accuracy is ±3% referenced to the
chromotropic acid procedure; the reproducibility is
1%; and the minimum detection limit is 0.003
ppm at 0 to 0.25 ppm full scale. It has an optimum
temperature range of 60°F to 80°F and a relative
humidity range of 5% to 95%.
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Section 8
IAQ Reference Manual
Advantages of this instrument are that it is por-
table, provides real time measurements, and has a
practical detection limit of about 0.02 ppm.
Disadvantages include cost (about $6000), and the
need for personnel with the expertise to operate the
instrument and conduct the required calibrations.
Modified NIOSH Method P&C'AM 125 (Chroma-
tropic Acid Method): The chromotropic acid
procedure (NIOSH, 1977) utilizes midget
impingers to collect HCHO into an absorbing
solution. Modification of the method to use \%
sodium bisulfite rather than distilled water as the
absorbing solution increases the collection
efficiciency to 98% and eliminates the need for a
second impinger for sample collection (Meadows
and Rusch, 1983).
HCHO reacts with chromotropic acid-sulfuric acid
solution to form a purple-colored complex which is
read in a spectrophotometer at 580 nm. Samples ate
typically collected at a flow rate of 11pm for 30
minutes to 1 hour. This method has a sensitivity of
0.16 ppm for 15 minute samples and 0.04 ppm for
1 hour or longer samples.
A relatively simple, portable active sampling system
can be built using readily available equipment
(sampling pump, critical orifice, sampling
impinger, trap impinger, tubing) for about $150.
Commercially available sampling systems cost $500
to $800.
This method has been widely used in both residen-
tial and nonresidential sampling. Advantages are
that it is a relatively simple technique which utilizes
equipment that is readily available. A moderate
degree of training is needed for the sampling and
analytical techniques. Disadvanges are that confi-
dence decreases significantly below 0.10-ppm and
that concentrated sulfuric acid is used in the
analysis. It should not be used in situations where
phenol may be present.
Modified Pararosaniline Method: One of the most
sensitive methods available is the Lawrence Berkeley
Laboratory (LBL) pararosaniline method (Mikseh et
al., 1981). This method utilizes midget impingers
for sample collection and spectrophotometry for
analysis. HCHO reacts with pararosaniline in the
presence of sodium sulfite to produce a colored
product which is read at 570 nm. The method has a
sensitivity of 0.01 ppm and is not subject to
interferences from nitrate, nitrite, phenol, ethanol,
or higher molecular weight alcohols. Other
advantages of the methqd are that toxic mercury
compounds are not required, and it is more sensitive
and more reproducible than the chromotropic acid
procedure. A disadvantage is that refrigeration is
required during collection and storage,
Passive Methods
Passive personal collectors are available in which
HCHO diffuses through a tube onto a treated filter,
onto an impregnated media, or into a liquid sor-
bent. Sample collection is relatively easy in all of
these methods, but the analytical methods require
moderate to high skill levels. Exhibit 8-20 summa-
rizes some of the available methods. If monitors are
returned to the manufacturer for analysis, the cost is
typically $15 to $30 for the monitor plus analysis.
Lower detectable limits range from 0,005 ppm to
0.01 ppm for a 1 week exposure; shorter sampling
times result in decreased sensitivity (typically, 0,1
ppm to 0.3 ppm for 8 hours and 0.7 ppm to 8 ppm
for 15 minute samples). .
Care must be taken to ensure proper detection
limits for the proposed application and proper
placement of the samplers. Another problem with
these monitors is lack of .reliability and cost for
routine monitoring programs.
EPA's Method IP-6C (Passive DNPH HPLC
Method); This method utilizes a passive sampler
which consists of DNPH-impregnated glass fiber
filters which are placed behind diffusion screens and
sandwiched between two protective caps (U.S. EPA,
1989). The size of the completed sampler is 1.5
inches in diameter and 0.5 inches in depth. HCHO
and other aldehdyes diffuse to the sampler and react
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IAQ Reference Manual
Section 8
with the DNPH treated filters to form a stable
DNPH derivative.
Precision for field replicates should be better than
±20%, and HPLC replicates should have a preci-
sion of ±10% or better. Advantages of this method
include the small size of the sampler, no noise, low
unit cost, and the ability of unskilled personnel to
place and retrieve the samplers. The major disad-
vantage of this method is the sophistication of the
analysis which requires highly trained personnel.
MBTH Bubbler Method: The MBTH passive
bubbler method has been designated as a standard
test method for HCHO by the American Society of
Testing and Materials (ASTM, 1990). This method
utilizes the Passive Bubbler™ which consists of a
glass vial with a septum cap that retains a Knudsen
disk. The vial, which contains an aqueous solution
of 3-methyl-2-benzothiazolinone hydrazone
hydrochloride (MBTH), is inverted for sampling.
HCHO diffuses through the Knudsen disk at a
constant rate. After collection, a solution of ferric
chloride-sulfamic acid is added to form a derivative
which is measured in a spectrophotometer at 628
nm. This method allows HCHO to be measured in
the range of 0.025 ppm to 14 ppm for sampling
times between 15 minutes and 8 hours. A four-
hour sampling time is recommended to measure
HCHO concentrations in the range of 0.05 to 1 ppm.
A major advantage of this method is that laboratory
support is not needed. Kits can be purchased which
contain a mini-spectrophotometer and all needed
reagents.
Interpretation of Formaldehyde Data
Both workplace and residential standards and
guidelines have been recommended and promul-
gated for HCHO. These standards and guidelines
are based primarily on the irritant effects of HCHO.
In 1984 the WHO Working Group on Indoor Air
Quality Research (WHO, 1986) identified <0.06
ppm as a consensus concentration of limited or no
concern and >0.12 ppm as a consensus concentra-
tion of concern for both long-term and short-term
exposures.
The Canadian exposure guidelines identify 0.05
ppm as the long-term target level and 0.10 ppm as
action level for long-term exposure (Environmental
Health Directorate, 1987).
The U.S. Department of Housing and Urban
Development established a product standard for
HCHO emissions from particleboard and hardwood
plywood paneling used in manufactured housing
(U.S. HUD, 1984). This standard limits the
emissions of HCHO as measured by a specific air
chamber test to no more than 0.3 ppm from
particleboard floor decking and no more than 0.2
ppm from interior plywood. Although HUD did
not establish an ambient standard, the intent of the
emissions standards is to limit ambient HCHO
concentrations to less than 0.4 ppm. HUD recog-
nized that sensitive subgroups of the population
would react to lower levels, and the regulations
require posting of health notices in the home and in
consumer manuals to alert potential buyers to this
risk.
Exhibit 8-21 shows a dose-effect relationship
between HCHO concentration and reports of
irritation effects in a study of nearly 2000 residents
living in 397 mobile homes and 494 conventional
homes (Ritchie and Lehnen, 1987). The results of
this larger-scale study support the conclusions of the
WHO Working Group that concentrations greater
than 0.1 ppm may cause adverse reactions in some
people and may require corrective action.
Standards or guidelines should not be the sole basis
for determining whether a given low-level concen-
tration might result in irritant health effects for two
reasons. First, there is considerable variability in
response to exposure to HCHO. Although it
appears that 0.1 ppm is a concentration of concern,
some individuals may be affected at lower HCHO
concentrations. Second, existing standards are not
based on the carcinogenic potential of HCHO.
-------
Section 8
IAQ Reference Manual
Each case must be considered individually based on
the symptoms that are presented. Even though
occupants report no symptoms, they should be
should be encouraged to reduce their exposures, if
possible, because of HCHO's potential role as a
carcinogen.
Mitigation Advice for Formaldehyde
Manufacturers' Strategies
Manufacturers can reduce HCHO emissions by
improving quality control during the manufacture
of pressed wood products or the installation of
UFFI. In addition, the use of alternative resins
(phenol-HCHO, methyl diisocyanates, lignosulfon-
ates), resin modifications, processing changes to
condition the product (increasing temperature or
curing time) (Fisk et al., 1987). The substitution of
alternative resins, however, for urea-HCHO resins
may pose other health problems. For example,
interior grade products which are made of
diisocyanate resins pose a potential health risk
because diisocyanate is a potent sensitizing agent.
Another problem with products using diisocyanate
resins is the potential formation of hydrogen
cyanide under fire conditions.
Consumers' Strategies
Consumers can minimize their exposures to HCHO
by not purchasing potential HCHO-emitting
products such as UFFI and those made of urea-
HCHO resins and urea-HCHO wood finishes.
Although the use of UFFI has diminished in the
U.S., it is still available. It is also used to insulate
concrete blocks and panels which are used to
construct nonresidential structures. There is some
concern that as UFFI ages and deteriorates, HCHO
and particulates with irritant properties could be
released into the indoor air (Fisk, et al., 1987).
Fiberglass batts and cellulose are possible substi-
tutes for UFFI. Cellulose, however, settles in
sidewall applications which reduces its effectiveness.
Products made of particleboard, hardwood plywood,
and MDF should be avoided unless they have a
barrier which covers any exposed surfaces. Accept-
able substitutes are products made of solid wood,
metal, plastic, or other material that does not emit
HCHO. Another strategy is to limit HCHO-
emitting products to small areas.
Because HCHO is released from its sources over a
period of time, time itself, is a way of reducing
HCHO concentrations. Additional storage of
HCHO-emitting materials such as particleboard
prior to use could decrease initial HCHO indoor
concentrations, but this is not generally practical
once consumers have purchased products. HCHO
decay rates (and half-life) will vary depending on the
product and its environment. If occupants are
experiencing symptoms, allowing additional time
for decay is not an effective strategy.
Coatings and Barriers
Both manufacturers and consumers can apply
coatings and barriers to pressed wood products (or
to MDF or hardwood plywood) to reduce emissions.
These act in one of three ways: 1) by preventing the
release of HCHO, 2) by preventing the transport of
moisture into the board, or 3) by the reaction of
scavenger chemicals with HCHO.
Coatings are most effective on products such as
particleboard shelving, subflooring and decking,
and unfinished surfaces such as joints, edges, and
undersides of cabinets or countertops. Coatings
which have been reported to be moderately effective
include polyurethane and lacquer (Fisk et al,, 1987).
Standard latex paints are not reported to be effec-
tive, but some other paints may be effective. For
maximum effectiveness, several coats should be
applied and all exposed edges should be coated.
Other barriers which are reported to have varying
effectiveness include melamine-impregnated paper,
acid curing lacquers, decorative laminates, veneers,
-------
IAQ Reference Manual
Section 8
polyacrylamide, vinyl wallpaper, vinyl carpet, vinyl
flooring, and a paint with HCHO-reactive chemi-
cals (Fisk et al., 1987). When consumers apply any
of these barriers, care should be taken to cover all
exposed edges. It should be noted that many of
these materials can release other volatile organic
compounds.
Environmental Strategies
Using environmental factors to control HCHO (and
other volatile organic compounds) has been reported
by several investigators (Andersen et al., 1975;
Godish and Rouch, 1986). Exhibit 8-22 shows
measured decreases in HCHO concentrations as a
function of temperature and relative humidity. A
disadvantage of reducing temperature and relative
humidity to control HCHO might be energy
penalties of about 20-30% depending on the season.
Also, even if dehumidification were used to slow the
rate of HCHO emission, the total amount of
HCHO released over time might remain the same
(Fisk etal., 1987).
Residential dehumidifiers, increased ventilation
with less humid outdoor air, and local ventilation
near humidity sources (bathroom, kitchen) are
dehumidification methods which might reduce
HCHO concentrations. Fisk et al, report that
dehumidification alone or in combination with
other methods may be effective in reducing small
increases in HCHO concentrations caused by
infiltration from house tightening.
Other Strategies
Laboratory data suggest that adsorbents and
absorbents have some potential to remove HCHO
from nonindustrial indoor air, but there is limited
field data to evaluate these techniques.
In some instances, HCHO-emkting products will
require removal. Caution must be used when
multiple sources are present because there is a
possibility that removal of only one major source
might result in only marginal decreases in HCHO
concentrations. All major sources may require
removal in order to provide the greatest decrease in
HCHO concentration. In the case of UFFI. removal,
the National Research Council of Canada (Bowen, et
al., 1981) recommends treating wall cavities with a
3% solution of sodium bisulfite after removal. This
treatment prevents HCHO release from urea-HCHO
resin which might remain in gypsum board, wall
studs, and other surfaces.
Ammonia fumigation has been identified as a post-
installation treatment for HCHO in residences (Fisk
etal,, 1987). Application methods have included
setting out pans of ammonium hydroxide, spraying
ammonium hydroxide, and releasing gaseous
ammonia. These methods have not been verified for
different situations., The treated house cannot be
used during treatment and for several weeks after
treatment, and an irritating ammonia odor can
remain for as long as several months after treatment
(Muratzky, 1987).
Investigation Techniques for Volatile
Organic Compounds (VOCs) Other Than
Formaldehyde
VOCs should be considered as a source of
health complaints whenever there are sensitization
reactions or symptoms typical of sick building
syndrome (typically, irritation of nose, throat, eyes;
fatigue; nausea; difficulty concentrating; skin
irritation; headache; and dizziness).
The investigation of these symptoms should focus
on the characterization of health effects and identifi-
cation of potential sources which could contribute
to those effects. Any recent changes in household or
workplace environments should be evaluated
carefully to identify the potential presence of VOCs.
Any new home or office building is a potential
source of hundreds of VOCs which are emitted by
wood products, plastics, solvents, glues and adhe-
sives, fillers, dyed fibers, and floor and wall cover-
ings. If occupants in a new building complain of
odors or symptoms, the building should be evalu-
-------
Section 8
IAQ Reference Manual
ated for sources of VOCs and adequate ventilation.
Suspect materials in any home or office include new
carpeting, paint, furnishings, wallpaper, and vinyl
flooring. Recently dry-cleaned clothing or uphol-
stery and activities such as smoking tobacco prod-
ucts and the recent use of pesticides, solvents and
solvent-based cleaners, caulks, glues or adhesives, or
paints and related supplies are also suspect. In
addition, any changes in brands of products such as
personal care products or cleaning products may be
suspect. In the office environment, the use of
copiers, spirit duplicators, and other equipment
which might release VOCs can also be suspect.
In many instances, the sources can be identified and
various strategies can be employed in an attempt to
reduce emissions and eliminate symptoms. For
example, shortly after the carpeting in a home was
replaced, the eyes of one of the children in the home
became irritated and somewhat swollen. When the
child left the home, the irritation and swelling
improved, but the symtoms became worse when the
child returned to the home. This scenario suggests
that the carpeting (dyes or adhesives) may be
responsible for the child's condition. This is a
relatively simple and straightforward example; in
other instances there may be so many potential
sources that a health effects or building systems
questionnaire alone may not be able to identify
sources.
Measuring Volatile Organic Compounds
(Other Than Formaldehyde)
Extensive sampling and analysis of VOCs may not
be possible or practical for most investigations for
several reasons. There are many potential organic
compounds in the indoor environment, and these
compounds are generally present in very low
concentrations. There is a general lack of data that
relates low level exposures to health effects, and
there is considerably variability in the response to
exposure to VOCs and other contaminants. Finally,
the measurement of VOCs and other organic
compounds is complicated and expensive.
However, sampling may be needed in situations
where sources cannot be identified easily or in
situations where a physician recommends identify-
ing specific contaminants.
If sampling is conducted, portable VOC detectors
might be useful in determining if VOCs are present
or identifying potential sources, but these devices
may not be sensitive enough to detect very low
concentrations which might affect some individuals.
Methods for sampling VOCs must be capable of
measuring concentrations in the ppb-ppt range.
These methods include both passive and active
methods, methods which are direct reading, and
those which require laboratory analysis. An addi-
tional review of analytical methods for VOCs in
indoor air is given by Sheldon et al. (1985).
EPA has developed guidelines for two methods
which are based on either the collection of whole air
samples in SUMMAR passivated stainless steel
canisters or collection on solid adsorbent tubes (U.S.
EPA, 1989).
Method 1P-1A (Collection Using Stainless Steel
Canisters); This method utilizes passivated
stainless steel canisters (chemically treated to form
an inert chrome-nickel oxide on the inner surface)
under subatmospheric pressure or pressurized
sampling modes to collect the sample. The col-
lected gases must be transported to a laboratory for
analysis.
At the laboratory the contents of the canister are
concentrated, separated by a gas chrornatograph
(GC), and analyzed by one or more detectors.
Possible detectors for the high resolution gas
chrornatograph include specific detectors such as the
mass spectrometer (MS) in the selected ion monitor-
ing (SIM) mode or the SCAN mode or ion trap
detector. Nonspecifwrdetectors such as the flame
ionization detector (FID), electron capture detector
(BCD), nitrogen-phosphorous detector (NPD) and
the photoionization detector (PID) can also be used.
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IAQ Reference Manual
Section 8
Exhibit 8-23 summarizes some of the advantages
and disadvantages of different systems. The selec-
tion of the most appropriate detector depends on
many variables including the type of compounds to
be identified, budget, required detection limits,
potential interferences, project objectives, equip-
ment, and personnel capability.
The precision, accuracy, sensitivity, and potential
interferences will vary depending on the compound
of interest. EPA will provide at no charge some
cylinder gas standards which are traceable to NIST.
Advantages of this method include the ability to
identify and quantify a variety of VOCs and SVOCs
at very low levels (ppb-ppt range). The primary
disadvantages include the cost of analysis by an
outside laboratory (about $200/sample) or develop-
ing in-house analytical capability, the high level of
skill required by analytical personnel, and the
caution needed to prevent accidental contamination
or loss of samples.
Method 1P-1A also contains operating procedures
for a portable gas chromatograph equipped with a
photoionization detector. This method is intended
to provide qualitative information on the presence
and intensity of unknown volatile compounds which
assists in the placement of fixed-site samplers.
Exhibit 8-24 contains a summary of commercially
available portable VOC detection instruments.
Solid Sorbents: Solid sorbents are the most com-
monly used materials for collecting vapor phase
organics. Once the samplers are prepared they can
be deployed and collected easily which makes them
useful in large-scale surveys. Samplers must be
returned to the laboratory for analysis by GC/MS or
GC combined with nonspecific detectors (FID,
BCD, NPD). The collection of vapor phase organics
by solid sorbents involves three basic steps: collec-
tion on the sorbent, desorption of organics from the
sorbent, and analysis of the desorbed organics.
Solid adsorbents have several limitations which
include:
* formation of artifacts on some adsorbents,
especially Tenax11 in the presence of NOx;
« extensive cleanup and thermal conditioning
is required to ensure contaminant-free
cartridges; cartridges must be carefully
handled, shipped, and stored to prevent
contamination prior to and after sampling;
* breakthrough volumes of certain com-
pounds are very small on some resins
sorbents which prevents quantitative
results; and
* irreversible adsorption may occur onto
charcoal which decreases the recovery of the
analyte (U.S. EPA, 1989).
In spite of these limitations, adsorption onto solid
sorbents has several advantages including the small
size of the samplers, portability of the sampling
devices, ease of use, and the ability to collect
integrated samples over periods of 8 hours to 12
hours.
Exhibit 8-25 summarizes some of the characteristics
of different collection methods. Either thermal or
solvent desorption techniques can be used to desorb
the organics from the sorbent. The preferred method
of analysis for polymeric resins which adsorb
through thermal desorption is GC/MS because it
provides broad spectrum analysis as well as identifi-
cation of target compounds. Solvent desorption can
limit the analysis of low molecular weight organics
because of interferences from the solvent and the
overall sensitivity of the analysis compared to
thermal desorption because only a fraction of the
sample (1/100 or 1/500) is used for the analysis."
Method IP-IB (Adsorption using Tenasf):
Method IP-IB utilizes solid adsorbent tubes
containing l-2g of TenaxR to capture a variety of
VOCs. The cartridges are stored under refrigeration
until analysis when the organics are thermally
desorbed, collected into a cryogenic trap, and
analyzed by a GC/MS data system.
-------
Section 8
IAQ Reference Manual
The analytical finish is the same as for Method IP-
1A. The precision and accuracy of the method will
vary depending on the contaminant of interest and
factors such as breakthrough volumes, background
contamination of the cartridges, and factors related
to the analytical instrument and skill of the analyst.
Interpretation of Volatile Organi<
Compounds Data
There are limited standards and guidelines for
evaluating exposures to VOCs (Exhibit 7-1, Section
7 contains a summary of some existing standards
and guidelines; Exhibit 3-3, Section 3 contains a
summary of EPA risk assessments; and Section 8.3
contains guidelines for some pesticides). The use
of OSHA, NIOSH, and ACGIH standards and
guidelines do not provide adequate protection to
the general public, and their use in nonindustrial
environments is not appropriate.
Because of the inherent variability in response to
VOCs and other organics, guidelines should not be
the sole basis of determining whether a given low-
level concentration might result in irritant health
effects. Each case should be considered individually
based on the symptoms that are presented.
Mitigation Advice for Volatile Organic
Compounds
It is difficult to provide mitigation advice for VOCs
other than HCHO because there is very little
information on control methods and concentrations
of concern. In general, the methods suggested for
the mitigation of HCHO also apply to other VOCs.
Consumer Strategies
Clients who are concerned about VOCs should be
encouraged to use products which do not contain
VOCs or contain lower levels of VOCs whenever
possible. A major problem with this advice is that
consumers may not be able to identify which
products contain VOCs; and further, emissions of
VOCs may vary from product to product. In those
instances where VOC-containing products must be
used, adequate ventilation during storage and use
should be emphasized.
Consumer practices can also be important in
minimizing indoor air quality impacts from the use
of VOC-containing products. Storage of these
products outside the living area (perhaps in the
garage) can reduce indoor air concentrations. In
addition, minimizing the use of VOC-containing
products or using these products with adequate
ventilation is critical. In general, clients can be
advised that cross-ventilation should be enough to
prevent any noticeable odor when VOC-containing
products are used in the home.
Caulks, sealants, glazing compounds, and joint
fillers release VOCs (typically aliphatic hydrocar-
bons, xylene, toluene, petroleum hydrocarbons, or
methyl ethyl ketone) at varying rates depending on
the formulation. Fast-drying products (those
containing styrenes, for example) emit a significant
fraction of their total weight, but they do so in a
relatively short period of time (several to 10 days).
Slow-drying products can be significant contribu-
tors to indoor air contaminants over a longer period
of time (up to one year). Consumers can reduce
their exposure to contaminants from these products
by proper selection and use of the product.
For example, the release of emissions from the
installation of carpet or other flooring materials can
be minimized by selecting a fast drying adhesive
and using maximum ventilation during the installa-
tion.
There appear to be some instances, however, when
consumer practices will not appreciably reduce VOC
concentrations. For example, emissions from
recently dry cleaned clothing can result in elevated
levels of perchloroethylene in homes. But airing
clothes out in a garage for 4 hours did not proved
effective in reducing indoor perchloroethylene
concentrations (Tichenbr, et al. 1988). In this case,
-------
IAQ Reference Manual
Sections
other methods such as venting the closet to the
outside might be effective in reducing these concen-
trations.
Conditioning
The potential effectiveness of VOC control by
conditioning is illustrated by VOCs chamber
studies of cauik. VOC emissions decreased by more
than 90% from caulk treated for 4 hours at room
temperature and 1.8 ach. At 0.4 ach the time for
90% of VOCs to be emitted increased to about 20
hours, or five times as long as for 1.8 ach (Tucker,
1988). This method can be used for individual
products or larger areas (for example, after installa-
tion of new carpeting or after painting).
HCHO and other VOCs might also be reduced by
using increasing temperature and ventilation for
some period of time (several days to 1 to 2 weeks).
Under these conditions, emissions of volatile
organic compounds will accelerate and be exhausted
from the building. Girman ef al. (1987) provided
one of the first reports of the potential effectiveness
of this procedure in office buildings.
Removal
When concentrations cannot be reduced or symp-
toms persist, avoidance of the product or removal of
the source may be required. The mitigation of
VOCs and other organics in the environment of
hypersensitive individuals is difficult and requires
an integrated approach including substitution of
products and materials, removal, mechanical
ventilation, and control devices.
-------
Exhibit 8-20.
Selected passive formaldehyde measurement methods.
ANALYTICAL TECHNIQUES
Method
Air Quality
Research3
DuPonta
3M8
U.S. BPAb
Sampling
HCHO reacts with sodium
bisulfite-treated filter
paper in a vial
HCHO reacts with sodium
bisulfite solution in a badge
HCHO reacts with sodium
bisulfite-treated filter paper
in a badge
HCHO reacts with DNPH
impregnated filter paper in
the presence of acid
Air Technology Labsc HCHO reacts with MBTH
solution in the Passive
Bubbler™
SOURCE: - "Nagda, Rector, and Koontz (1987); bU.S. EPA (1989);
Analysis
spectrophotometry
{chromotropic acid
procedure)
spectrophotometry
(chromotropic acid
procedure)
spectrophotometry
(chromotropic acid
procedure)
HPLC
spectrophotometry
(MBTH)
CASTM (1990)
Sensitivity, ppm
1.68 ppm-hr (0.01 1 ppm
for 1 week exposure)
1.6 ppm-hr (0.010 ppm
for 1 week exposure)
0.8 pprn-hr (0.005 ppm
for 1 week exposure)
0.05 ppm for 4 hr
exposure
0.025 ppm for 8 hr
exposure; 0.05 ppm
for 4 hr exposure
Comments
recommended minimum exposure of
1 week; reproducibility of ±25%; not
sensitive for short-term residential
sampling
shelf life of sampler is 2 weeks after
exposure which suggests a maximum
exposure of 2 weeks; accuracy of
±13.1% over the range of 1.6 to 54
ppm-hrs; precision of 5.9%
not sensitive enough for short-term
residential sampling; requires
sophisticated equipment and
analytical skills; accuracy ±25%
overall accuracy of ±10% to ±19".8%
in laboratory and field testing,
respectively; precision of ±5%
samples should be stored in the dark;
overall system accurately in field
testing of ±19.8%
Section 8
N<
to
eference Mat
«
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IAQ Reference Manual
Section 8
Exhibit 8-21. A dose-effect relationship between formaldehyde (HCHO) exposure and
selected health effects in mobile and conventional homes.
100%
Mobile Homes
Eye
Noseffhroat Headache
Conventional Homes
Eye
ppm
Nose/Throat
.1 to .3 ppm
Skin Rash
Headache Skin Rqsh
> ,3 ppm HCHO Concentration
SOURCE: Ritchie and Lehnen (1987).
-------
Section 8
IAQ Reference Manual
Exhibit 8-22. Effect of temperature and relative humidity on formaldehyde (HCHO) levels in
a mobile home under controlled conditions.
.4-
.3-
a
r
1 _
70% RH
30% RH
I
20
I
25
Temperature °C
I
30
I
35
SOURCE: Adapted from Godish and Rouch (1986),
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IAQ Reference Manual
Section 8
Exhibit 8-23. Advantages and disadvantages of nonspecific and specific detector systems
for VOC and SVOC analysis.
ADVANTAGES
NON-SPECIFIC MULTIDETECTOR ANALYTICAL SYSTEM
DISADVANTAGES
somewhat lower equipment cost than GC-MS
less sample volume required for analysis
more sensitive
* cost of calibrating multiple detectors
• compound identification is not positive
* lengthy data interpretation (2 hr for analysis
and data reduction)
• interference(s) from similar (co-eluting
compounds
* cannot identify unknown compounds
outside of calibration and without standards
• does not differentiate targeted compounds
from interfering compounds
ADVANTAGES
SPECIFIC DETECTOR ANALYTICAL SYSTEM
GC-MS-SIM
DISADVANTAGES
positive compound identification (ions)
greater sensitivity than GC-MS-SCAN
less operator interpretation than for multi-
detector GC
resolve co-eluting peaks to achieve
enhancement in sensitivity
more specific than the multidetector GC
can't identify nonspecified compounds
somewhat greater equipment cost than
multidetector GC
greater sample volume required than
for multidetector GC
universality of detector sacrificed
ADVANTAGES
GC-MS-SCAN
DISADVANTAGES
positive compound identification
can identify all compounds
less operator interpretation than for
multidetector GC
can resolve co-eluting peaks
» lower sensitivity than GC-MS-SIM
• greater sample volume requited than for
multidetector GC
» somewhat greater equipment costs
SOURCE: U,S. EPA (1989)
-------
Exhibit 8-24. Commercially available portable VOC detection instruments.
MONITOR
550,551
555,580
(AID, Inc.)
OVA 108, 128
Century Systems, Inc.
(Foxboro)
PI-101
(HNu Systems, Inc.)
TLV Sniffer
(Bacharach)
Ecolyser*0
(Energetics Science)
Mitan 1A
(Foxboro)
Miran IB
(Foxboro)
Scentor
(Sentex)
Photovac Standard
Automatic Computer
Auto Camp.
Communication
Photovac Tip
DETECTION
PRINCIPLE
FID
FID
HD
PID
Catalytic
combustion
Catalytic
combustion
1R
1R
GC/EC, Argon
lonizarion PID
PID
(UV Light)
PID
RANGE,
PPM
0-200,
0-2000,
0-10,000
0-10,
0-100,
0-1000,
0-10,000
0-100,000
1
1-20
1-200
1-2000
0-500
0-3000
0-50,000
Q-lOtKf 1FL
ppm to 5?
ppm to 5?
0
0-2000 ppm
SENSITIVITY
0,1 ppm at
0-200 ppm
0.2 ppm
(Model 128)
0.5 ppm
{Model 108)
0.1 ppm
Low molecular
weights aromatks
2.0 ppm
1* LFL
1 ppm
Q.Olppbd
Ofganics
0.1 ppb Benzene
with signal-to-
noise ratio 4:1,
Good for
aiomatics
0.05 ppm
Benzene
RESPONSE
TIME.S
<5
2
2
<5
5
15
1,4,10
and 40
2
2
3
ACCESSORIES
• Thermal
Desorbers
available
» Optional GC
available
• Three tamps
available
• 9.5 (aromatics)
• 10.2 (2-4
compounds)
• 11.7
(balocarbons)
Preconcentraror
Thermal
Desorption
GC Columns
Auto Cat from
Integral Gas
Cylinder
• Dual Column
• Manual/ Auto
Injection
• Column Cond
• Pre-flush
• Auto Dial
Modem
• Programmable
CALIBRATION
TECHNIQUES
• Bag Sampling
• Hand Space
• Direct Injection
• Bag Sampling
• External Gas Cyi.
• Bag Sampling
• Bag Sampling
• Head Space
• Bag Sampling
• Internal gas cyl,
• Precoscentratoc
• GC Column
WEAKNESSES
• Umbilical tort!
tooshorr
• Digital readout hard
to read
• Flame out frequently
• Battery failure
• Sample line kinks
• Compounds
containing O£/N give
low response
• Neg. resp. to
co/coa
• Three lamps — may
miss something
• Changes in gas temp/
humidity aflects
response
• Column operates at
ambient temperature
• STD in lab, then to
field at different
temperature
• Can't inject liquid
sampling
• Light fractions
interfere
SERVICE
RATE
Shis
Shs
lOhrs
LACK OF
RESPONSE
• Cl hydro-
carbons
•CH4
• H,O
•o2-
COST,*
. 4300
aoo
4955
900
9500
12,500
12,950
6995
8995
10,500
10,955
12,955
SAMP
RATE
LPM
1,5
0.5
IS
00
to
SOURCE: U.S. BPA (1989)
-------
Exhibit 8-25. Characteristics
SORBENT
organic polymeric resins
(Tenax GC, XAD)
inorganics (silica gel,
alumina, florisil, molec-
ular sieves)
activated carbon
carbon molecular
sieve
SOURCE: U.S. EPA (1989) Method IP-IB
of sorption collection methods.
APPLICATION DESORPTION ANALYSIS
sample by 60-300°C, except thermal CG/MS
highly polar compounds
strongly sorb water; not — —
generally useful
sample bp 0-300°C, polar solvent GC/FID
and nonpolar compounds GC/ECD
GC/NPD
sample bp 0-70°C, very polar thermal GC/MS
and volatile compounds
. Collection using solid absorbent tubes.
IAQ Reference Manual
Section 8
-------
Section 8
IAQ Reference Manual
REFERENCES
Andersen, I., G.R. Lindqvist, and L. M01bave, 1975. "ladoor
»ir pollution due to chipboard used as a construction material."
Atom. Environ. 9: 1121-1127.
American Society for Testing and Materials (ASTM). 1990.
"Standard test method for measurement of formaldehyde in
indoor air (passive sampler methodology)." Method D 5014-
89. ASTM: Pittsburgh, PA.
Bowen, R.P., C.J. ShirtlifFe, and G.A. Chown. 1981. Urea-
formaldehyde foam insulation: Problem identification and remedial
measures far wood frame construction. Building Practice Note 23.
ISSN 071-5216. National Research Council of Canada:
Ottawa, Canada.
Cohn, M.S., A.G. Ulsamer, and P.W. Preuss. 1984. "Sources
contributing to formaldehyde indoor air levels." Indoor Air.
Vol. 3. Sensory and' Hyperreactivity Reactions to Sick Buildings. •
Swedish Council for Building Research: Stockholm, Sweden.
pp. 133-138.
Environmental Health Directorate. 1987. Exposure Guidelines
for Residential Indoor Air Quality. Health Protection Branch,
Environmental Health Directorate: Ottawa, Canada.
Fisk, W.J., R.K. Spencer, D.T. Grimsrad, F.J. Offermann, B.
Pedersen, and R. Sextro, 1987. Indoor Air Quality Control
Techniques. Radon, formaldehyde, Combustion Products. Noyes
Data Corp.: Park Ridge, NJ.
Gammage, R.B. and K.C. Gupta. 1989. "Formaldehyde,"
Chap. 7. Indoor Air Quality. PJ. Walsh, C.S. Dudney, and
B.D. Copenhaver (eds). CRC Press: Boca Raton, EL.
Girman, J., L. Alevantis, G. Kuiasingam, M. Petreas, and L.
Webber. 1987. "Bake-out of an office building." Indoor Air
'87. Vol. 1, Volatile Organic Compounds, Combustion Gases,
Particles and Fibers, Microbiological Agents. Oraniendrack
GmbH: Berlin, Germany, pp: 22-26.
Godish, T, 1985. "Residential formaldehyde sampling—
Current and recommended practices." Am. Ind. Hyg, Assoc.J.
46{3): 105-110.
Godish, T. and J. Rouch. 1985. "An assessment of the Berge
equation applied to formaldehyde measurements under
controlled conditions of temperature and relative humidity in a
mobile home." J. Air Poll, Coat. Assoc. 35: 1186-1187.
Godish, T. and J. Rouch, 1986. "Mitigation of residential
formaldehyde contamination of indoor climate control." Amur.
Indust. Hyg. Assoc.J. 47:792-797.
Kennedy, E.R., D.L. Smith, and C.L. Geraci, Jr. 1985a. "Field
evaluations of sampling and analytical methods for formalde-
hyde." Advances in Chemistry Series. No. 210. Formaldehyde;
Analytical Chemistry and Toxicology. V. Turoski (ed). American
Chemical Society, pp. 151-159.
Kennedy, E.R., A.W. Teass; and Y.T. Gagnon. 1985b.
"Industrial hygiene sampling and analytical methods for
formaldehyde. Past and present." Advances in Chemistry Series,
No. 210, Formaldehyde: Analytical Chemistry and Toxicology.
V. Turoski (ed). American Chemical Society, pp. 1-12.
Meadows, G.W. and G.M. Rusch. 1983. "The measuring and
monitoring of formaldehyde in inhalation test atmospheres."
Am. Ind. Hyg. Assoc.J, 44: 71-78.
Miksch, R.R., D.W. Anthon, L.Z. Fanning, C.D. Hollowell, K.
Revzan, and J, Glanville. 1981. "Modified pararosaniline
method for the determination of formaldehyde in air." Anal.
53: 2118-2123.
Muratzky, R, 1987. "Formaldehyde injuries in prefabricated
houses: causes, prevention, and reduction." Indoor Air '87,
Vol. 2. Environmental Tobacco Smoke, M.ulticomponent Studies,
Radon, Sick Buildings, Odors and Irritants, Hyperreattivities and
Allergies. Oraniendruck GmbH: Berlin, Germany, pp: 690-
694.
Nagda, N.L., H.E. Rector, and M.D. Koontz. 1987. Guidelines
for Monitoring Indoor Air Quality. Hemisphere Publishing Corp.:
Washington, DC.
National Institute of Occupational Safety and Health (NIOSH).
1977. "NIOSH 77-157'A Method No. P & CAM 125."
Manual of Analytical Methods. Vol. II. 2nd edition. U.S.
Department of Health, Education and Welfare: Cincinnati,
OH.
Ritchie, I.M. and R. G. Lehnen. 1987. "Formaldehyde-related
health complaints of residentsliving in mobile and conven-
tional homes." Am. J. Pub. Health. 77(3): 323-328.
Sheldon, L.S., C.M. Sparacino, and B.D. Pellizzari, 1985.
"Review of analytical methods for volatile organic compounds
in the indoor environment." Indoor Air and Human Health.
Gammage, R.B, and S.V. Kage (eds). Lewis Publishers:
Chelsea, MI.
Tichenor, B.A., L.E. Sparks, M.D.Jackson. 1988. Evaluation tf
Perchlorotthyhne Emissions From Dry Cleaned Fabrics. EPA-600/2-
88-061. U.S. Environmental Protection Agency; Research
Triangle Park, NC.
-------
IAQ Reference Manual
Section 8
Tucker, W.G. 1988. "Emissions of air pollutants from indoor
materials: An emerging design consideration." 5th Canadian
Building and Construction Congress. Montreal, Canada.
November 27-29.
U.S. Consumer Product Safety Commission (CPSC). 1986.
Briefing Package on Formaldehyde Emissions from Urea-Formaldehyde
Pressed Wood Products. CPSC: Washington, D.C.
U.S. Department of Housing and Urban Development (HUD).
1984. "Manufactured home construction and safety standards;
final rule." Federal Register. 49(155): 31995-32013.
U.S. Environmental Protection Agency (EPA). 1989. Compen-
dium of methods for the determination of air pollutants in indoor air.
Draft. Atmospheric Research and Exposure Assessment
Laboratory: Research Triangle Park, NC.
World Health Organization (WHO). 1986. Indoor Air Quality
Research. Euro Reports and Studies 103. WHO, Regional Office
for E.urope: Copenhagen, Denmark.
Wallace, L.A. and Ott, W.R. 1982. "Personal monitors: A
state-of-the-art survey." J. Air Poll. Cant. Assoc. 32(6): 602-610.
8.5. INVESTIGATION TECHNIQUES FOR
BIOLOGICAL CONTAMINANTS
JMany investigations of biological con-
taminants, particularly those involving fungi, can be
handled by obtaining a detailed symptom history
and performing a careful inspection of the building.
Discussions with the physician or other health care
provider (if one has been consulted) may be helpful.
It is important to identify the presence of activities
which may precipitate or aggravate symptoms and
any changes in lifestyle and/or building characteris-
tics which could contribute to symptoms.
A useful reference to assist in the investigation
of bioaerosols is a document developed by the
Bioaerosols Committee of the ACGIH (1989). The
focus of this document is on the office environment,
but the principles also apply to residential environ-
ments. Areas which are covered in the guidance'
document include medical preassessment, on-site
investigations, air sampling, and remedial actions
for viruses, bacteria, endotoxin, fungi, protozoa, and
antigens. Biocides are also discussed.
Walk-Through
A telephone interview can be used to obtain pre-
liminary information, but a walk-through is
generally needed to identify potential sources of
contamination. A survey form that can be used for
potential sources of allergens is given in Exhibit
8-26.
Both indoor and outdoor environments must be
evaluated to identify materials or situations which
can foster the growth and amplification of biological
agents. It should be remembered during these
investigations that some problems depend on season
or climatic changes, and these may not be detected
during the inspection.
An important area of emphasis during investiga-
tions related to fungi and some bacterial contami-
nants is identifying moisture problems; Section 5 of
the Reference Manual provides a foundation for
understanding the moisture balance in the home.
Other useful references that can help the investiga-
tor to detect and solve moisture problems are
published by the National Center for Appropriate
Technology (NCAT, 1983) and ASHRAE (1988,
1989).
Outdoor Environment
Any barriers to air movement around the house,
such as heavy vegetation or firewood, can result in
the accumulation of moisture and promote mold
growth. The outdoor environment should be
evaluated for landscaping close to the house which
might result in shade and moisture levels which
favor the growth of microorganisms. The grounds
should be evaluated for proper drainage; any
standing water should be noted. If a sump pump is
used, the outlet for the drainage pipe should be
evaluated for adequate distance from the house, and
the slope of the ground should be checked to be sure
that drainage occurs away from the house.
The presence of accumulated bird droppings around
the grounds or in air intakes should be noted. The
-------
Section 8
IAQ Reference Manual
grounds should be evaluated for trash and food
sources, harborage, and fecal material from pets.
Exterior of the House
The soffits, fascias, gables, bottom edges of siding,
areas below windows, exterior siding at bathrooms,
flashing, and remaining exterior should be exam-
ined for signs of physical and moisture damage.
The presence of blistering paint or black/dark
streaks or lines which border a discoloration may
indicate problems. Uneven, warping, or sloping
surfaces should be noted. Wood can be tapped to
detect wet or decaying wood (characterized by a
dull, dead, muted sound in contrast to dry wood
which has a sharp, clear sound when tapped).
The foundation should be examined for signs of
"efflorescence" (a white powdery substance or line of
minerals that is left after moisture has moved
through it) which may indicate the presence of
microbial contamination. Crumbling concrete may
also indicate problems.
Some moisture problems are weather or seasonally
dependent. For example, some roof drainage
problems can only be observed if it is raining. Also,
roof designs with valleys are more likely to have ice
dams during the winter which can damage roofing
materials and promote moisture problems through
constant freeze/thaw cycles.
The exterior of mobile homes should be checked for
unusual water stains which may appear along the
outside corner where the wall meets the ceiling.
The foundation area of all homes should also be
evaluated for signs of rodent entry. Downspouts
and the slope of the ground around the foundation
should be checked to determine if water drains
properly away from the foundation.
The House and Its Interior
A major emphasis of the interior inspection should
be to identify evidence of situations or conditions <
which foster or could lead to moisture problems.
There are many visual and sensory clues that suggest
moisture problems, but some problems may be
hidden and require additional investigation.
Although microbes will not typically be sampled,
temperature and relative humidity should be
measured. A relative humidity between 30% and
50% promotes comfort and reduces the likelihood
of problems with microorganisms. A relative
humidity below 30% can cause problems with
dryness and irritation of the mucous membranes;
humidities greater than 50% are more likely to
cause problems with mold and mildew. If someone
in the household has respiratory problems which
require a more humid environment, a potential
solution is to humidify only one area of the house,
rather than the entire house.
Visible mold and mildew: The interior should be
examined for evidence of visible mold and mildew.
Special attention should be given to wall-ceiling
joints and wall-floor joints, areas behind furniture,
plants, poorly ventilated closets, and window
coverings. Greenhouses (all areas, including plants),
bathrooms (showers, bathtubs, behind and at the
base of the toilet, windows, underneath sinks), and
kitchens (underneath sinks) should be carefully
checked for signs of mold, mildew, and rotting
wood.
Indoor swimming pools and hot tubs should be
checked for visible mold and mildew problems, and
the method and adequacy of moisture control
should be noted. The interior should also be
evaluated for the presence of organic substrates. If
carpeting or other flooring materials are damp or
have been water damaged, the floor underlayment
and any pads must be examined for evidence of
microbial growth. If water leaks have occurred, it
may be necessary to examine insulation inside of
walls for damage.
Presence of organic substrates: Other sources of
microbes and biological agents such as carpeting,
wicker and straw items, pets, and plants should be
noted. The presence and condition of pets should be
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IAQ Reference Manual
Section 8
evaluated, (For example, do dogs have fleas? Are
bird cages cleaned regularly?) General dust levels
should be noted along with the presence of pests
such as cockroaches.
Dampness, standing water, and condensation on
surfaces: A history of water damage (flooding,
broken pipes, overflowing toilets, sinks, or bath-
tubs) should be obtained. The interior should be
examined carefully for evidence of water damage or
moisture. Smaller houses (under 800 ft2) tend to be
more prone to moisture problems because of the
ratio of sources to total living area. Musty odors or
a sensation of dampness in the air are indicative of
mold, mildew, or rot. Also, lingering odors from
normal household activities may indicate inadequate
ventilation, which in turn, could be related to
moisture problems.
Condensation problems can occur during the winter
or summer. The presence of condensation on
windows or other smooth surfaces such as concrete
or masonry walls is a sign of excessive moisture (or
the need to insulate or warm the surface). Based on
average window glazing and 74°F interior tempera-
ture, the maximum relative humidity within a space
for no condensation on single glazed (ASHRAE,
1988) and for double glazed windows (ASHRAE,
1989) is:
Maximum Relative Humidity
Temperature
40°F
30°F
20°F
10°F
0°F
-10°F
-20°F
-30°F
Single
Glazing
39%
29%
21%
15%
10%
07%
05%
03%
Double
Glaring
59%
50%
43%
36%
30%
26%
21%
17%
Moisture problems with double-hung windows
might not be as readily visible because condensation
can occur inside the wall cavity as a result of warm
moist air condensing on the cold weights inside the
wall cavity.
Sweating pipes and water leaks are potential causes
of microbial growth. If plumbing runs underneath
a crawl space, it should be checked for leaks (after
running the water for 10 to 15 minutes); exterior
faucets should also be checked. Standing water in
the crawl space or basement should be noted.
Areas where insulation is easily accessible (attic,
crawl space, basement) should always be checked for
dampness and adequacy of air spaces.
It may be necessary to examine the building
materials on the cold side of the building envelope
to determine if a vapor retarder is present or has
been improperly installed. Tightly built and well-
insulated homes require a properly installed vapor
retarder to prevent moisture transfer through
building materials. If a vapor retarder is absent or if
it has been improperly installed, every point subject
to air leakage could be a potential cause of conden-
sation within the walls. Common problems in-
clude: 1) the installation of vapor retarder on the
cold side of the wall surface resulting in condensa-
tion in the walls, 2) installation of low-perm
retarders on both sides of a wall designed to prevent
moisture intrusion can also prevent moisture from
escaping; 3) breaks in the vapor barrier; and 4) the
lack of a ground-cover vapor retarder in the crawl
space.
The building materials on the cold side of the home
should be inspected to determine whether sheathing
or siding may be acting as an unwanted vapor
retarder, and the building should be evaluated to
determine if there are areas where the vapor retarder
was not installed (rim joists, between floors, and so
forth).
Heating, -ventilating, and air-conditioning
systems; The heating, ventilating, and air-condi-
tioning systems should be checked for condition and
obvious problems. Special attention should be
given to the condition, operation, and maintenance
-------
Section 8
IAQ Reference Manual
of humidifiers and dehumidifiers (in-line and
portable), water or swamp coolers, heat recovery
ventilators; these should be examined for the
presence of moisture, stagnant water, and slime
growth. Filters and air cleaning devices should be
evaluated for the presence of dust buildup and
moisture.
It is important to determine if there have been any
changes in the energy efficiency of the home or
other factors which could affect the efficiency of the
heating and cooling system. If the house has been
weatherized and tightened, but the heating and
cooling systems have not been upgraded, problems
can result. The temperature settings that are
typically maintained during the different seasons
should be noted.
Humidifiers which are commonly used include
ultrasonic, steam, evaporative, warm-mist, and cool-
mist units. All humidifiers can be a source of
microbial contamination, and they must be cleaned
frequently. Portable and console humidifiers should
be examined for the presence of film or scum on the
water surface, on the sides or bottom of the tank, or
on exposed motor parts. The presence of any of
these conditions may indicate the presence of
bacteria or fungi. A crusty deposit or scale within
the tank, or on parts of the tank, or a white deposit
in the surrounding area is minerals which have
settled out of the water or become aerosolized,
creating a surface where bacteria or fungi can grow.
Ducting in crawl spaces should be examined for
obvious openings. Fiberboard plenums should be
evaluated, particularly in the absence of vapor
barriers in the crawl space. Interior registers should
be removed and ducts should be checked for signs of
microbial growth and a buildup of dust.
Crawl space, basement, and attic: The crawl
space, basement and attic should be examined for
moisture damage and/or standing water. Floor and
ceiling joists and exposed sheathing should be
checked for signs of rot, mildew, or mold. Rotting
wood can be detected easily by tapping the wood as
described previously or by using a sharp implement
(ice pick, small chisel, screwdriver) to test the
toughness of the wood. To perform this test, the
implement is jabbed into the wood and pried up.
Decayed or rotting wood breaks out with little
resistance and in relatively short lengths; wood in
good condition is hard to pry up, and it breaks into
long slivers.
Decayed wood can be affected by white rot (wood
appears whiter than normal with dark lines border-
ing the discoloration), brown rot (brown or black
discoloration), soft rot (wood is soft and cracked),
and blue stain (a blue, brownish black, or steel-gray
colored stain). White rot and brown rot are the
most serious forms of damage, and removal of wood
is indicated if these forms are present.
Sumps and drains should be checked for proper
capping and drainage (run water for 5 minutes and
observe for water backup). The crawl space floor
should be checked for the presence of a vapor
retarder. Any standing water, loose insulation,
wood, and paper products must be removed. Vents
should be evaluated for condition, total number and
si2e, and obstructions.
The basement should be checked for additional
signs of moisture—damp air, damp walls, seepage
of water, efflorescence, and visible mold or mildew.
Any insulation in the basement or attic should be
checked for dampness.
Measuring Biological Contaminants
House Dust Mites
House dust mites can be identified directly through
air sampling or indirectly by analyzing dust
samples. Air sampling is complicated by the fact
that the allergen is associated with larger particles
(> 10 microns) which may be removed rapidly from
the air and are subject to reentrainment through
routine activity. Dust mites can be reliably counted
microscopically, but counting mites is not a direct
measurement of allergen and it is subject to large
-------
IAQ Reference Manual
Section 8
sampling errors. Allergen assays are more rapid,
direct measurements that are easily standardized and
have accuracies of 620% (Platt Mills etal., 1990).
A simple test is available in the U.S. for testing dust
mite allergen levels indirectly by a semiquantitative
analysis of guanine levels (ACAREX test kit) in
house dust. Guanine is contained in the excreta of
dust mites and other arachnids, but the dust mite
appears to be the primary source of guanine in
indoor dust. In this method, guanine is first
dissolved out of the dust sample. The solution is
then tested with a strip containing an azo reagent.
A positive test is indicated by a red color which
varies in intensity depending on the guanine
concentration. Test kits can be purchased for about
$15 for ten tests and $7.50 for four tests. Bischoff
(1987) reports on evaluations of house dust mites
using this test in European homes.
Airborne Microorganisms
In many instances the symptom history, combined
with the walk-through inspection will be sufficient
to determine if microbial contamination exists and
is a likely cause of problems. At this stage of the
investigation if no apparent microbial sources are
found, it is unlikely that air sampling will provide
additional, useful information (ACGIH, 1989).
However, sampling may be required in some
instances. If so, it is important to have adequate
information and knowledge. The investigator must
work closely with the laboratory to ensure the use
of proper sampling techniques, correct enumeration
of organisms, correct interpretation of data, and
the development and use of a quality assurance
program.
The ACGIH Committee on Bioaerosols stresses that
careful thought and planning must precede any
sampling program. The investigator should be
aware that there is no single sampling method
which will recover all potential bioaerosol compo-
nents, and air sampling rarely provides proof of
inappropriate exposures to bioaerosols. It is espe-
cially important to utilize a laboratory that has
mycologists and bacteriologists who are experienced
in the assessment of environmental microbial prob-
lems.
Some guidelines for sampling and analyzing fungi
are provided below. These methods are appropriate
for organisms that result in hypersensitivity dis-
eases, but not for infectious disease-causing organ-
isms such as bacteria and viruses. The reader should
consult the ACGIH's guidelines and Chatigny
(1983), Chatigny et al. (1983, 1989) for further
information on sampling bioaerosols.
Surface Sampling: A relatively simple technique
that can be used in residential investigations is to
collect surface samples using sterile cotton swabs
that are premoistened with water to maintain
viability of the collected organisms. An area that is
about 25 cm2 (about 4 in2) is swabbed and the
collected material is innoculated directly onto the
surface of culture plates. Also, bulk samples can be
collected into sterile sample containers and then
processed onto culture media; dilution may be
required. Both of these methods can prove useful in
identifying "hot spots." Used in conjunction with a
symptom questionnaire, further sampling may not
be required to make an informed judgment. An-
other relatively simple technique, cellophane-tape
imprinting, can be used for the rapid identification
of mold colonies growing on organic materials
(KozaketaL, 1980).
The ACGIH Committee on Bioaerosols does not
recommend taking surface swabs and "bulk"
samples unless these are taken in conjunction with a
well-controlled indoor/outdoor sampling program.
However, the Committee acknowledges that
collecting these samples during the walk-through
may prove useful if indoor air sampling is subse-
quently needed. (Burge and Solomon, 1987;
ACGIH, 1989; KozaketaL, 1985).
Air Sampling: The sampling of bioaerosols is
similar to sampling for particulates. Biologically-
derived particles that can become airborne indoors
range in size from less than 1 micron for viruses to
-------
Section 8
IAQ Reference Manual
over 200 microns for fungal spores. This large
range in particle size and the variety of particles that
can be present in the airstream combine to make
sampling and characterization of bioaerosols a
challenging task. The collection of quantitative
data requires special expertise and is expensive;
several different sampling devices and analytical
schemes may be required. For this reason, most
investigators report qualitative results and these
may be sufficient in many investigations.
Sampling location should include both outdoors
and indoors. The outdoor sample (from a site that is
removed from obvious sources) serves as a reference
point to determine whether or not amplification is
occurring indoors. During nonresidential investiga-
tions outdoor samples should also be collected from
the air intake of buildings.
Indoors, samples should be collected in areas near
occupants who complain of symptoms and those
who do not. Samples should be collected from or
near potential sources such as humidifiers and air
inlet and exhaust diffusers at different times during
the day.
For example, in an office building samples can be
collected before the HVAC is turned on and before
workers arrive. During work hours, samples can be
collected at the beginning of the day, when maxi-
mum occupancy occurs, and before and after
operational changes are made in the HVAC system.
Samples can also be collected at the end of the day,
after occupants leave and with the HVAC off.
Kozak et al. (1985) recommend at least one outdoor
sampling site to evaluate taxonornic groups and
concentrations, multiple indoor studies with
emphasis on areas with water damage, and at least
one volumetric survey in the area suspected of
having a problem.
Sampling equipment for bioaerosol sampling
includes gravity samplers, inertial impactors, and
filtration samplers. Gravity samplers such as
culture plates and adhesive-coated glass are the
most widely used samplers, but these are not
recommended by the Committee on Bioaerosols.
The efficiency of sampling depends both on particle
size and the movement of air over the sampling
device. Gravity samplers tend to overestimate the
concentration of large-sized particles, and underesti-
mate smaller-sized particles which may be more
important biologically. Another weakness of these
devices is that they do not provide volumetric data.
Exhibit 8-27 summarizes the samplers that have
been recommended by the Committee on
Bioaerosols. Of these samplers, the slit to agar
samplers and the glass impingers are the most
efficient and accurate. But this level of accuracy is
not always needed and other samplers such as filter
cassettes may be used. Filter cassettes underesti-
mate viable aerosol concentrations, but they can be
used in situations when high concentrations are
suspected. Filter cassette samplers are not recom-
mended for bacteria because of potentially low
viability which results from drying; however,
impingers with appropriate media can be used.
In situations where the investigator does not know
what agents to expect, a combination of samplers is
recommended. A broad range of agents can be
identified using a combination of slit sampler and
visual identification, culture plate cascade samplers
with several culture media, and either a filter
sampler or liquid impinger followed by bioassay,
biochemical, or immunological analysis (Burge and
Solomon, 1987). Collected samples should be
transported to the laboratory within 24 hours, and
source samples should be processed immediately.
There may be instances when illness exists, but
measured spore counts are low using the recom-
mended techniques. In these situations large
volume air samples can be collected either into a
liquid or onto a filter. If the air flow rate of the
sampler is greater than that provided by the ventila-
tion system, samples can still be collected for
identification of spores, but the data should be not
be used for quantitative purposes.
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IAQ Reference Manual
Section 8
The ACGIH Committee on Bioaerosols recom-
mends the following sampling modalities for
organisms associated with specific fungal diseases:
1) Histoplasmosis—sample at the source
only; cannot culture from air samples;
2) Aspergillosis—culture plate sieve or slit
impactor with efficient collection to 1 fJm;
3) Hypersensitivity pneumonitis—culture and
. particulate sieve or slit impactors with
efficient collection to 1 |Jm or high-volume
filtration when the antigen is known;
4) Allergic asthma, rhinitis—culture and
particulate impactors with known particle
collection efficiency or high-volume
filtration when the antigen is known.
Quality assurance programs that begin with
sample collection and end with data analysis are
vital to the success of bioaerosol sampling. A
quality assurance program includes, but is not
limited to, proper sampler selection, sampler
disinfection, routine calibration of flowrates, proper
choice of media and checks for sterility, quality
control procedures for analysis, and written proto-
cols. In addition, it is important to use blank
samples (duplicates or triplicates) for each culture
medium used at the sampling and control sites.
Samplers should be sterilized before each use, but
this may not always be possible. Samplers that use
culture plates should be swabbed with alcohol or
bleach before each use. Plastic culture plates are
recommended, particularly if samples are to be
mailed to a laboratory. Fluids for impingers should
be sterile, and before the impinger is used it should
be rinsed with sterile fluid. Filter cassettes can be
presterilized before use, and the Committee sug-
gests that disposable cassettes from major manufac-
turers are clean enough for most saprophytic
sampling.
Samplers should be calibrated according to the
manufacturer's instructions before and after field
use. Calibrations should be performed with the
equipment set up as it will be used in the field;
sampling pumps should not be calibrated unless
they are in the sampling train.
Enumeration of organisms which are collected
can be determined by a variety of methods includ-
ing culture assay, bioassay, immunological assay,
biochemical assay, and direct microscopy. These
methods which are summarized below are discussed
further by Burge and Solomon (1987; Platts-Mills
et al., 1989). Consultation with the analyst is
advisable before sampling. The type of analysis
should be specified to the laboratory before sam-
pling begins.
Cultural assays involve growing the collected
organisms and identifying them macroscopically,
microscopically, or biochemically. These methods
can be used with culture plate collectors, for
processing eluates from filters, and for processing
source samples such as swabs collected from con-
taminated surfaces. Cultural assays are appropriate
when only viable organisms are of interest; for
example, for infectious agents (Legionella, Staphylo-
coccus) and invasive fungal pathogens (Aspergillusf.).
Culture plate assays, however, underestimate actual
levels and the investigator should be aware of
limitations of the method.
Bioassays rely on a living substrate to indicate the
prevalence of allergenic agents. Allergists use
bioassays in skin testing. Human skin can react to
microgram quantities of specific antigens which are
typically introduced as extracts of dust, pollens, or
spores, but suitably prepared filter eluates and
impinger fluids can also be used.
Immunological assays are newer methods that are
proving increasingly useful. These tests can be
useful in studying building-related epidemics such
as hypersensitivity pneumonitis, humidifier fever, or
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Section 8
IAQ Reference Manual
residential problems such mite and cockroach
antigens, animal-derived sensitizers, and fungal-
related antigens.
Direct microscopy is useful for the identification and
counting of morphologically distinctive particles or
total fungal spores. Total colony counts (CFU/m3)
are calculated by dividing the adjusted number of
colonies on the plate by the total volume of air
sampled in cubic meters. In order to facilitate the
identification of sources and amplification sites for
microorganisms, the Committee on Bioaerosols
recommends identifying the predominant taxo-
nomic groups for fungi at a minimum. In addition,
viable microorganisms that are present in concentra-
tions greater than 75 CFU/m3 should be identified.
Interpretation of Biological
Contaminant Data
Fungi
If the walk-through reveals the presence of overt
mold or mildew contamination (for example, mold
covering a portion of a wall or floor underlayment),
sampling is generally not required. Evidence of
overt contamination is sufficient for recommending
control measures, and these may be enough to bring
relief.
If sampling is conducted, the interpretation of data
is complicated by the complexity of natural aerosols
and the large population variances that are encoun-
tered. There are no published standards for accept-
able exposures to saprophytic aerosols in indoor
environments. There is no agreement on exact
levels of fungal bioaerosols which are responsible for
the onset of disease, nor is there adequate informa-
tion on dose-effect relationships.
Some allergists consider fungal levels of 1000 CPU/
m3 to be unacceptable to sensitive individuals
(Tyndall et al., 1987), but levels lower than this
have been shown to be problematic (Morey, 1988).
Ohgke et al. (1987) have identified levels of 100
CFU/m3 to be indicative of fungal colonization.
Some researchers suggest that levels greater than
500 CFU/m3 are high enough to warrant a detailed
environmental survey (Gammage and Kerbel,
1987).
Indoor vs outdoor levels: Indoor levels of sapro-
phytic organisms can also be compared to outdoor
levels to evaluate if a problem exists. During the
growing season outdoor fungus spore concentrations
have been reported to range from 1000/m3 to
100,000/m3 of air (Burge, 1987). If outdoor air is
the only source, indoor levels of pollen and fungus
spores are likely to be in the range of 10% to 40%
of outdoor levels. Levels in mechanically ventilated
buildings are generally less than 10% of outdoor
levels depending on the quality of filtration (Burge,
1988).
Another method that can be used to compare indoor
levels to those outdoors is rank order assessment. In
this method individual taxa are identified and listed
in descending order of importance for both indoor
and outdoor locations. A nonparametric statistical
test such as the Spearman rank order correlation can
then be used to determine statistical significance of
differences between the indoor and outdoor ranking.
Mites
It is not clear what level of dust mites or dust mite
allergens should be regarded as a risk level, nor is it
clear if floor dust levels and exposure are related in
the same way for different allergens (cat, dust mites,
and so forth). Proposed values of 2 |Jg/g Group I
Dermatophagoides allergen (equivalent to 100 mites/g
dust or 0.6 mg guanine/g dust) have been suggested
as a risk factor for sensitization, the development of
bronchial reactivity, and symptomatic asthma;
10 |Jg/g Group I allergen (or 500 mites/g dust)
should be regarded as a risk factor for acute attacks
of asthma (Platts-Mills etal., 1988).
Bacteria
Legionnella can be isolated from a variety of sources
indoors (humidifiers, shower heads, hot water tanks,
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1AQ Reference Manual
Section 8
and so forth). The significance of these findings,
however, is not clear. If a known case of disease has
occured, sources must be cleaned and disinfected.
In the absence of disease, each case must be evalu-
ated individually.
Mitigation Advice for Biological
Contaminants
Efforts to control microbial growth and the disper-
sion of allergens in residential and office settings
should initially focus on removing the offending
agent or contaminated material. After initial
control has been achieved, the basic requirements
for growth (food and water) should be removed and
good housekeeping activities should be maintained.
In some cases, the removal of the offending agent or
source will be direct and simple; for example,
removing a cat or portable humidifier in a residence.
In other cases, removal may be difficult or impos-
sible (contaminated floor joists or air ducts in an
office or residence). In some of these instances,
cleaning, disinfection, and drying may be effective.
After remedial actions have been taken, it is impor-
tant to reevaluate the original complaint both in
terms of symptoms and sampling. Sensitized
individuals should be interviewed to determine if
remedial action has been effective. If sampling is
conducted, the area may need to be resampled using
the same protocol. The occupants should be
encouraged to report any signs of microbial
regrowth.
In some office situations personnel may have to be
reassigned to another area even after remedial action
because the offending agents have not been elimi-
nated. Relocation may also be needed in some
residential problems. The investigator should
consult with the attending physician to verify the
condition of sensitized individuals and determine if
further action is needed.
House Dust Mites/Animal Danders/
Plants
A variety of measures have been recommended for
reducing dust mite populations and symptoms in
mite-sensitive asthmatic children. These include
replacing feather and down pillows with pillows
that have synthetic fillings; thoroughly vacuuming
mattresses, pillows, carpets, and other furniture;
covering the mattress and box springs with plastic;
and damp wiping the mattress and box springs
(Sarsfielda?*/., 1974; Murray and Ferguson, 1983;
Mathison et al., 1982). However, other studies have
not found these measures to be effective.
Of these methods, removal of carpeting and fibrous
furniture coverings may be effective. High effi-
ciency filtration systems are probably not effective
because the dust quickly settles after becoming
airborne.
Frequent vacuuming using conventional machines is
probably not effective because dust particles are not
efficiently collected in the size range which has the
greatest allergenic potential. Vacuums employing
steam should be avoided because they may increase
mite proliferation by increasing warmth and
moisture levels. Vacuum attachments which
prevent the release of collected particulates may be
more effective than conventional vacuums alone.
HEPA-type vacuums are also more effective.
Enclosing the mattress and box spring in plastic
covers can be effective; these can be purchased from
department stores or purchased from allergy
specialty supply companies. Even when these are
used, it is important for all bedding to be removed
and washed each week in a hot wash and rinse cycle
(a water temperature of 130°F is needed to kill
mites). The liners of waterbeds should also be
washed with hot water on a weekly basis.
Dust mite populations can also be controlled by
applying acaricides to mite-infested materials; the
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Section 8
IAQ Reference Manual
use of these chemicals should be considered cau-
tiously to avoid potentially dangerous products and
application methods. Benzyl benzoate (4.6%) can
be applied as a dry powder to materials such as
carpets, followed by vacuuming to remove the
miticide and killed mites. Although this miticide
is considered to be safe (Morgan, 1989), it is
important to remove all of the miticide before
allowing children or pets to reenter the area. If
residues remain, irritation effects could result from
contact. Ingestion of toxic amounts can result in
seizures.
Since avoidance measures have not been as effective
as desired, Korsgaard (1983) has proposed climate
control as a potentially effective strategy for reduc-
ing mite populations. Specifically, mite populations
can be reduced if indoor humidity levels are main-
tained below 45%. Anderson and Korsgaard (1986)
have suggested designing new and remodeled
buildings so that interior environmental tempera-
ture and humidity conditions will control the
number of house dust mites to less than 100 mites
per gram of dust.
Removal of pets from household interiors may be
required to avoid allergic responses. If an individual
is sensitive to plant pollens, removal of interior
plants is not needed, providing that flowering
plants are not allowed to pollinate. Air-condition-
ing and air filtration are usually effective in remov-
ing outdoor pollen from the circulating air.
Airborne Microorganisms
The growth and dispersion of microorganisms can
be controlled by maintaining the proper moisture
balance in the home; some specific strategies which
can be implemented are as follows.
Outdoor Environment
Any obstructions to airflow should be removed; for
example, firewood should be relocated to an area
away from the house. Problematic trees and shrubs
should be pruned or removed. If bird droppings are
a problem, nesting areas and feeders should be
removed or relocated. Trash, garbage, and other
food and harborage should be removed.
Chronic dampness near the structure can be elimi-
nated by ensuring that all surface drainage slopes
away from the house. Porous borders such as
washed gravel can be installed around foundations
to facilitate drainage. Perimeter footing drains can
be installed, but this is a relatively costly procedure.
These drains should be installed in new construction
if drainage is poor. If a high water table is a
problem, the crawl space can be ventilated and a
ground water retarder can be installed. Drainage
problems in the basement and crawl space can be
solved by sump pumps, drain pipes, or drain tiles.
Exterior of the House
The exterior of the house should be kept in good
repair; this includes painting if needed; repairing or
replacing roofs, flashings, chimneys, vents, soffits,
fascias, siding, and so forth. Downspouts should be
installed, cleaned, or repaired as needed to ensure
proper drainage. Foundation cracks and any entry
points for rodents should be repaired.
The House and Its Interior
Indications that moisture control is needed indoors
include humidity greater than 50%; a sensation of
dampness; lingering odors; or the presence of visible
contamination, water damaged or rotting surfaces,
and condensation.
Excessive humidity indoors can be eliminated by
four general approaches: 1) eliminate unnecessary
evaporation and sources; 2) discharge moisture to
the outdoor air; 3) ventilate the interior; and 4)
prevent condensation from occuring by providing
the proper barriers.
Ventilation and air circulation: If high outdoor
humidity is a seasonal or year around problem,
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IAQ Reference Manual
Section 8
crawl spaces, attics, and interior spaces should be
ventilated. Ventilation can also be increased
through wall vents or window vents.
Bathrooms and kitchens should be vented to the
exterior, and venting fans should be used. In the
bathroom ventilation can be provided by windows
or a fan rated at about 100 cfm. In the kitchen, a
fan rated at about 100 cfm for conventional stoves is
adequate, but 400 cfm and greater may be needed
for draft stoves. A central exhaust fan or attic fan
may be needed.
Aquaria should be covered; too many houseplants
can also pose problems. Clothes dryers should not
be vented indoors, to the crawl space, or to the attic.
If there is less than 250 ft2 per person or animal,
increased circulation and ventilation alone may solve
the problem, but dehumidifiers may also be needed.
Visible mold and mildew: Smooth surfaces that
have been contaminated should be washed and
disinfected. A dilute bleach solution (1:10 to 1:50
solution) is recommended by the Committee on
Bioaerosols (ACGIH, 1989). Stronger solutions
may be needed. Adequate ventilation and proper
protective equipment should be used during cleaning.
Other disinfecting agents include phenol com-
pounds (Lysol), ethylene oxide for items that cannot
be discarded or would be damaged by water, and
parafotmaldehyde. UV light can be used for
bacteria, but it is not adequate for fungal spores
(Surge, 1985).
Porous materials that are contaminated will prob-
ably require removal and disposal. These materials
can include carpets and pads, upholstery, ceiling
tiles, paper, leather, wicker or straw baskets, wall
coverings, window frames, baseboards, and others.
In some instances, particularly aggressive action
may be needed such as the removal of subflooring or
even floor joists.
After interior walls, floors, and furniture have been
cleaned, disinfected, and dried, they can be sealed
with impermeable finishes such as alkyd paints.
As a preventive measure in the bathroom, regular
cleaning of all surfaces is a must. Vinegar, borax,
and bleach solutions (1 cup to 1 gallon of water) and
trisodium phosphate solutions (4 T to 1 gallon of
hot water) are inexpensive, but effective cleaning
solutions.
Condensation on surfaces, dampness, and stand-
ing water: Any condensation or standing water
must be eliminated. Dripping pipes should be
identified and repaired. Plants should not be
overwatered or allowed to stand in water. Increased
air circulation and ventilation may be needed.
In the bathroom, dampness can be controlled by
careful caulking to seal all seams around tubs,
baseboards, sinks, and shower doors. Tight fitting
shower doors of glass and metal are preferred to
plastic shower curtains. Insulation under the tub,
cold water pipe insulation, and insulated toilet tank
liners can reduce sweating.
Floor materials in the bathroom and kitchen should
be impervious to water; carpeting should be dis-
couraged (it is not allowed in building codes).
Walls and ceiling paints should be waterproof;
alkyd oil paints are preferred. An exception to
waterproofing ceilings is if humidity will be
removed through attic spaces. Bathroom windows
with metal or plastic frames are easiest to clean and
keep dry; wood frames require more maintenance.
Greenhouses should have floor drains and drainage
built into beds and planters to prevent standing
water. To minimize the collection' of water on
exposed surfaces, all cracks should be sealed and the
space should be well ventilated (preferably by an
automatic ventilator). If greenhouse humidity is
high, air circulation from it into the living space
may not be advisable. Vapor retarders and insula-
tion should be evaluated and corrected as needed.
Damp insulation and wood in the attic may require
replacement of insulation, installation of vapor
retarders, or the installation of natural or mechanical
exhaust vents.
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Section 8
IAQ Reference Manual
Vapor retarders that are not installed properly (for
example joints and penetrations are not sealed) can
be upgraded by a skilled homeowner or a skilled
tradesperson. If a double vapor retarder (on both
sides of a wall surface) is causing problems, or if the
vapor retarder is on the cold side, the remedy may
be to place a vapor retarder on the warm side only.
There are several strategies for waterproofing walls.
Vapor retarding paints can be applied. Another
method is to remove the wallboard or plaster, staple
up sheets of polyethylene (4 to 6 mils), and replace
the wallboard with new material. Other methods
can also be used.
Concrete block homes (1940s and 1950s construc-
tion) that have not been renovated may have
condensation problems because of poor circulation
of warmed air. These homes often require the
installation of second wall against the existing wall.
Insulation can be stapled between the studs, and a
vapor retarder can be installed over the insulation.
Wallboard is then nailed to the framing. Door and
window frames must also be adjusted.
Heating, -ventilating, and air-conditioning
systems: Improperly sized heating, ventilating, and
air-conditioning systems should be corrected. Any
venting systems that introduce potential aerosols
into the living space should be corrected. Intake
ducts should be relocated, or sources of contamina-
tion should be removed.
In general, any condensation pans or drainage tubes
in the heating, ventilating, and air-conditioning
systems should be checked on a regular basis.
Drainage tubes that are plugged should be cleaned;
drain pans should be emptied and slanted toward
drains. Regular cleaning and maintenance of all
system components is a must.
Condensation in the venting system of mid-effi-
ciency furnaces (or other furnaces) may be solved by
checking and correcting the size of vents; these
vents should not be insulated unless specifically
approved by the manufacturer.
If disinfection of the heating, ventilating, or air-
conditioning system components is required, the
system should be off during cleaning. Disinfecting
agents should not be sprayed through the system.
Removal and replacement of entire units or ducts
may be required if the contamination is heavy or if
components are not accessible.
The continuous use of humidifiers particularly in
new houses (which have a naturally higher moisture
content from construction materials) and in houses
without vapor retarders can be a problem. If
humidifiers are used, water should be changed daily,
and the tank should be emptied completely before
filling. If the tank is not removable, it should be
cleaned according to the manufacturer's instruc-
tions. If instructions are not available, units should
be free of scale and slime at all times. These units
should be disinfected (5% bleach or 3% hydrogen
peroxide solution) every third day (ACGHI, 1989).
Antifoulant agents that are added to humidifier
fluid reservoirs to control microbial populations can
become aerosolized, and they may not be effective
(Burgee^/., 1980).
The Consumer Product Safety Commission (1988)
recommends against the use of tap water in humidi-
fiers to minimize mineralized aerosols (does not
appear to be a problem with evaporative humidifi-
ers). Instead, distilled or demineralized water
should be used to reduce the buildup of scale and
release of aerosols. If demineralization cartridges or
filters are recommended for a particular unit, they
should be used. Before humidifiers are stored, the
tank should be drained and cleaned; the units
should also be cleaned again prior to use.
Air conditioners are effective in reducing moisture
levels indoors and indoor concentrations of
bioaerosols, but they can also act as sources of
contamination. Filters should be cleaned or re-
placed regularly (once/month to once/3 months).
Air conditioner condensation should be drained to
the outside, not to the crawl space.
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IAQ Reference Manual
Section 8
Condensate from the air cooling coil of air condi-
tioners should be collected and diverted to the
outside of the building or other approved location;
any other drainage methods such as dischage into a
crawl space, under concrete slabs, or through a rigid
connection into the building sanitary drainage
system, must be corrected. If drainage is into the
sewer system, an observable air gap must be in-
stalled if it is not present; this prevents sewer gas
from entering the heating and cooling system.
If surface condensation is a possibility, all refriger-
ant ducts, pipes, and fittings installed within a
structure should be sealed, insulated, and vapor
retarders should be added as needed.
If the cooling coil or air-conditioning unit is located
above a living space or if structural damage could
result from condensate overflow additional measures
may be needed. These include installing an addi-
tional watertight pan of corrosion resistant metal
beneath the cooling coil or unit to catch overflow
condensate due to a clogged condensate drain.
Water or "swamp" coolers are not recommended in
humid climates because they are a constant source of
humidity.
Basement, crawl space, and attic; Standing water
in the crawl space should be removed by a properly
working sump pump. Loose wood, paper, and
insulation should be removed.
Vent openings should be clear of foundation
plantings and other obstructions to airflow. An
adequate number of vents should be installed
(oriented to take advantage of the prevailing wind)
and vents should be kept open during the summer
to provide good airflow in the crawl space. If
foundation vents are not sufficient to provided the
required ventilation, an exhaust fan can be installed.
Uninsulated heating ducts which are located in the
crawl space should be wrapped at the joints with
duct tape and insulated.
Ground moisture can be controlled in the crawl
space by placing a layer of sheet plastic on leveled
soil, followed by a 3 inch layer of sand. The founda-
tion should be waterproofed on the outside wall
(described below) and a drain tile should be in-
stalled around the footings to drain away any water.
An alternative method of controlling ground
moisture in the crawl space is to seal the undersides
of the floor joists with a vapor retarder. Ducts or
pipes that pass through the retarder are sealed with
duct tape to the retarder. A moisture-tight surface
is needed, and this method may not be practical if
many ducts or pipes are present.
In the basement, leaks should be sealed; cement-
based sealants can be used. The walls and floors can
be covered with a waterproofing compound. If this
measure does not work, leakage can be stopped by
adding a drain tile and waterproofing the founda-
tion. This can be costly because excavation of the
foundation is required. After the foundation has
been excavated and the drain tile installed, the
foundation walls are coated with a thick application
of asphalt roofing cement (from the footing to grade
level). A vapor barrier of black 4 mil polyethylene
film is applied onto the asphalt roofing cement.
Joints should be overlapped, and the entire barrier
should be coated with a thin application of the
roofing cement. The filled area should slope away
from the house (about 1 in/ft). A knowledgeable
contractor should be consulted for leakproofing
operations.
It may be necessary to install a heater and/or
dehumidifier in the basement to control moisture.
Showers in the basement should be discouraged.
Sumps or other openings to the ground should be
sealed, and water traps must be properly main-
tained. If possible a source of light, preferable
daylight, should be introduced.
In new construction a vapor retarder should be
installed in crawl spaces and before pouring concrete
slab floors and basements.
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Exhibit 8-26. Environmental survey form for evaluating the preseme of potential sources of allergens.
Date
Name
Phone.
Age of House.
Square Footage.
Address
Construction Material.
Number of Occupants.
I
Qo
1. OUTDOOR SURVEY (describe each category that applies)
a. weather conditions at time of survey
b. cultivated fields _
c. number of trees
d. other landscaping.
e. shade level adjacent to structure.
£ soil drainage
g. presence of organic debris.
h. any unusual outdoor activity prior to survey
i. presence of accumulated bird droppings
2. EXTERIOR OF HOUSE
a. Evaluate the condition of the exterior shell (warping, blistering
paint, rot or mildew on wood surfaces).
b. Evaluate the condition of the exterior foundation (water stains,
efflorescence, crumbling concrete, rot or mildew on wood surfaces).
c. Exterior footing drains present? If yes, is the point of discharge clear
or buried?
d. Evaluate condition of downspouts? Do they hamper drainage away
from the house?
e. Evaluate condition of roofing material (peeling or flaking, evidence
of ice dams).
£ Are attic vents present? If yes, describe type and number.
g. Evaluate condition of chimneys (capping, chimney cracks, nests).
3. EVIDENCE OF INTERIOR WATER DAMAGE OR MOISTURE
a. Relative humidity :
b. Is there a sensation of dampness or a musty odor? If yes, give loca-
tions.
I
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Exhibit 8-26. Environmental survey form for evaluating the presence of potential sources of allergens (tontinued).
c. Is there any visible mold, mildew, or rot? If yes, give locations.
d. Is condensation present on windows or smooth surfaces? If yes, give
locations.
e. Is there evidence of water damage or dampness? (around tub and
shower, behind and under toilet, behind sinks, at baseboards, around
splash boards, ceilings, walls, around skylights) If yes, give locations.
f. Is stan'ding water present? If yes, give locations.
g. Has there been any water disaster io the history of the home? (water
softener/washer/bathtub/toilet overflow, chronic interior water leaks,
roof leaks, basement leaks, backflushing of sumps) Describe in detail.
4. HEATING SYSTEM: ON or Off during survey (circle one)
a. forced air b. electric
c. gravity d. fireplace
e. space heater (indicate type
£ Heat recovery ventilators. If present, describe condition maintenance
procedures, and frequency of maintenance. Especially note if conden-
sation removal is needed.
g. Have any renovations, weatherproofing, or other energy efficiency
measures occurred since the original system was installed? If yes,
describe: _^_^_____
h. Has the heating system been changed? If yes, describe:
(continued next page)
I
Q
a
00
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Exhibit 8-26. Environmental survey form for evaluating the presence off potential sources of allergens ((ontinucd).
5. AIR CLEANING DEVICES (circle one)
ON or OFF during survey (circle) PORTABLE or CENTRAL (circle)
a. HEPA b. electrostatic
c. other
d. Evaluate condition, maintenance procedures, and frequency of
maintenance.
6. AIR-CONDITIONING SYSTEM ON or OFF during survey
(circle one)
a. portable.
b. central
c. swamp cooler.
d. Evaluate condition, maintenance procedures, and frequency of
maintenance. Especially note condensate removal procedures.
e. Has the cooling system been changed? If so, describe:.
7. HUMIDIFICATION OR DEHUMIDIFICATION DEVICE
ON or OFF during survey (check one)
a. humidifier b. dehumidifier
c. in-line d, portable
e. How often is the device used?
f. If present, evaluate condition and cleaning procedures.
g. How frequently is the unit cleaned?.
h. Are slime or scale present?
8. PRESENCE OF ORGANIC SUBSTRATES
a. Are there wicker or straw items? If yes, check for history of water
damage.
1
to
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Exhibit 8-26. Environmental survey form for evaluating the presence of potential sources of allergens ((ontinued).
to
b. Are there indoor pets? If yes, which and how many?
c. What type of bedding is used? Is it cleaned regularly?
d. Are there house plants? If so, how many, and location. Is there an
attached greenhouse? Is greenhouse air circulated into the living
space?
e. Is there carpeting? If so, what percent of the floor is covered?
Describe condition (note water stains, dust loading). Note if carpet-
ing is present ia bathrooms.
9. BASEMENT, CRAWL SPACI, AND ATTIC
a. Is there standing water in the basement or crawl space? If yes, check
for length of time present.
b. Check sumps and drains for proper drainage by running water in
them with a hose for about 5:min.to see if they back up. Are the
drains clear?
c. Are there cracks or seepage in the basement?.
d. Are vapor retarders present in the crawl space, basement (floors or
walls), or attic?
e. Are ducts, pipes, and fittings properly insulated in the basement,
crawl space, or attic?
(continued next page)
3
I
I
o
8
00
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Exhibit 8-26. Environmental survey form for evaluating the presence of potential sources of allergens (tontinued).
f. Are there signs of water-damaged wood, damp or wet insulation, or
visible mold in the basement, crawl space, or attic?
g. Do the attic, basement, and crawl space have adequate ventilation?
Describe vents and exhaust fens.
h. Do the attic or crawl space act as air plenums? If yes, are there prob-
lems associated with this use?
NOTES:
I
o
8
Qo
to
3
s
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Exhibit 8-27. Commonly used samplers for collecting indoor bioaerosols.
SAMPLER
1. Slit to agar impactor
2. Sieve type impactors
a. single-stage portable
b, single-stage impactor
e. two-stage impactor
3. Filter cassettes
4, High-volume filtration
5. All glass impingers
6. Centrifugal sampler
PRINCIPLE OF
OPERATION
impaction onto
agar on rotating
plate or stationary
plate
impaction onto
agar on "rodac"
plate
impaction onto
agar, 100 mm
plates
impaction onto
agar, two 100mm
plates
filtration
electrostatic
collection
into liquid
impingement
into liquid
impaction onto
agar, plastic strips
SAMPLING
RATE, 1pm
30-700
continuous
90 or 185
28
28
1-2
up to 1000
12,5
40
RECOMMENDED
SAMPLE TIME
variable; 1-60 min
or 7-day
0.5 or 0.3 min
1 min
1-5 min
15-60 min or 8 hr
variable
30 min
0.5 min
MINIMUM
CFU DETECTED
. 22 or 16
35
35
8-33
3
50
APPLICATIONS/REMARKS
Provides information on
aerosol concentration over
time; bulky AC operation
About 40% as efficient as slit
sampler; portable, useful as
probe
Nearly as efficient
as slit, bulky to handle, AC
operation
Same as 2b but
divides samples into
respkable and non-
respirable fractions
Some dessication loss;
portable, inexpensive,
useful as a probe
Fungi require •wetting agent;
useful over wide range of
particle concentrations
Cannot be calibrated; small,
portable, useful as a probe
10
I
8
SOURCE: .Adapted from ACGIH (1989)
00
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Section 8
IAQ Reference Manual
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IAQ Reference Manual
Section 8
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Mann, P. A. 1989- Illustrated Residential and Commercial
Construction. Prentice Hall: Englewood Cliffs, NJ.
* U.S. GOVERNMENT PRINTING OFF!CE:1994-S1S-Q03/01Q48
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