DOE
EPA
United States
Department
of Energy
Office of Conservation
and Renewable Energy
Washington, D.C. 20565
United States
Environmental Protection
Agency
Office of Environmental
Engineering and Technology
Washington. D.C. 20460
April 1981
Research and Development
Workshop on Indoor
Air Quality Research
Needs
Interagency
Research Group
on Indoor Air
Quality
Interagency
Energy/ Environment
R&D Program Report
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Foreword
A group of experts and members of the interested public met on December 3-5,
1980 in an open Workshop on Indoor Air Quality Research Needs. The Work-
shop was planned and sponsored by the Interagency Research Group on Indoor
Air Quality (IRG on IAQ), whose members include representatives of several
departments and agencies, including Department of Housing and Urban Develop-
ment, Department of Health and Human Services, Consumer Produce Safety
Comiflission, Environmental Protection Agency, Department of Energy, Department
of Defense, Department of Labor, Department of Commerce, and Department of
Interior.
The more than 200 workshop participants were given three responsibilities:
(1) to delineate the state-of-the-art of knowledge about indoor air
quality and to outline future research needs; (2) to comment on a general
"Strategy for Indoor Air Quality Research" drafted by the IRG on IAQ; (3) to
describe ongoing research efforts for inclusion in an "Inventory"
document on Federal and private research in the field. The present
document contains the Workshop report; the "Inventory" and the "Strategy"
will be published separately.
The Workshop report will be used as the basis for setting priorities within
a detailed research and development plan for Federal activities in indoor
air quality. The R&D plan will be written in the coming months by the
IRG on IAQ: it is believed that, through such collaborative efforts,
unnecessary and duplicative projects can be avoided and researchers can
benefit more readily from others' experience.
The emergence of indoor air pollution as a national issue was long overdue.
Participants reported that the average American spends upwards of 90 percent
of his or her time indoors. The elderly, the infirm, the very young, and
other most-at-risk groups spend a greater fraction of their time indoors.
Participants reported that, increasingly, research results suggest that
indoor exposures to several major pollutant classes dominate human exposure
in the United £tates. As a result of these and other points, most workshop
participants expressed their feeling that indoor air pollution will become
a major focus of new environment-related research efforts in the 1980's.
As co-chairpersons of the Workshop and of the IRG on IAQ we would like
to express our gratitude and admiration to all of the participants for
their contributions to the success of the Workshop, and especially to
the panel members who drafted this report. Additionally, we would like
to note the fine organizational efforts of GEOMET, led by Demetrios
Moschandreas and Jeannie Riordan, in administering the Workshop and in
preparing this report.
Howard Ross David Berg
Co-Chairperson Co-Chairperson
Department of Energy Environmental Protection Agency
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CONTENTS
Page
FOREWORD 111
EXECUTIVE SUMMARY xi
1.0 INTRODUCTION 1
2.0 OPEN PLENARY SESSION 5
Dr. Kurt Riegel, U.S. Environmental Protection Agency 6
Mr. David Berg, U.S. Environmental Protection Agency 7
Overview of the Draft Research Plan for Indoor Air Quality 7
Purpose and Structure of the Workshop 8
Mr. Dwain Winters, U.S. Environmental Protection Agency 9
Introduction to this Session 9
Indoor Air Quality Research Needs from Two Vantage Points 9
Physical Nature of the Indoor Air Quality Problems 10
Institutional Context of the Indoor Air Quality Problem 11
Mr. Howard Ross, U.S. Department of Energy 13
Department of Energy Policy 13
A Context for Remedial Indoor Air Pollution Control Actions 14
Governmental Action 16
DOE's Needs 16
DOE's Legislated Programs Relating to Indoor Air Quality 16
Dr. Irwin H. Billick, U.S. Department of Housing and Urban
Development 17
Concerns of the Department of Housing and Urban
Development 17
Dr. Peter £reuss, Consumer Product Safety Commission 18
Concerns of the Consumer Product Safety Commission 18
Research Needs 20
3.0 TECHNICAL GROUP REPORTS 21
MONITORING INDOOR AIR QUALITY 23
Aerosols 25
Introduction 25
Particles 25
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CONTENTS (Continued)
Page
Organics, Nitrosamines Pesticides and Odors 27
Introduction 27
Volatile Organics 27
Pesticides 28
Odors 28
Nitrosamines 29
Research Needs 29
Radon 31
Introduction 31
Research Needs 31
Formaldehyde 34
Introduction 34
Measurement Methods—Capabilities and Needs 34
Research Needs 34
Criteria Gases (Plus 0)3) 35
Introduction 35
Relationships to Ambient Air Quality Standards 36
Types of Monitoring Programs 36
Research Needs 36
Statistics and Modeling 38
REPORT OF THE INSTRUMENTATION SUBGROUP OF INDOOR AIR QUALITY 39
1.0 ABSTRACT 43
2.0 SUMMARY OF THE SESSION 44
3.0 REVIEW OF THE STATE OF THE ART AND STATE-OF-THE-ART PAPER 46
Overview 46
Quality Assurance 55
Evaluation of Instruments 55
Field and Laboratory Standards ? 55
Quality Assurance Programs ,. 56
Instrumentation for Measuring Radon,, Thoron and Their
Progeny in Buildings ^ 56
State of the Art 56
Research Needs 66
Aerosol Instrumentation 67
VI
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CONTENTS (Continued)
Page
Summary on the State of the Art 67
Standard Methods and Criteria for Acceptance
of New Developments 71
Research Needs 72
Personal Exposure Monitoring Instrumentation 72
Real-Time Aerodynamic Particle Size Analysis 72
Integrated Monitoring Package for Field Surveys 73
Sampling Methodology for Chemical and Biological
Analysis of Aerosols 73
Miniaturization of Fibrous Aerosol Monitor 73
Data Telemetry-Positional Transmission System 74
Instrumentation for Real-Time
Chemical Characterization of Aerosols 74
Development of Aerosol Standards for Validation
and Calibration 74
Organic Pollutants 74
State of the Art and Research Needs 74
Aldehydes/Formaldehyde 75
Nitrosamines 75
PNAs 76
Inorganic 76
Use of Monitors 83
Inorganic Monitors 83
The Palmes Tube 84
The Pro-Tek 84
The Monitox System 84
Leak-Tec 89
Nitrous Oxide Sensor 89
3M Mercury Vapor Monitoring Service #3600 89
Sipin-Environmetrics Mercury Badge 89
Solid State Sensor Mercury Monitor 89
Mini Monitor 89
Dead STOP 92
Organic Monitors 92
The Gasbadge, Organic Vapor Monitor, Pro-Tek and
Mini Monitor 92
The Gas Monitoring Dosimeter 92
General Monitors 92
Diff-Samp 92
Critical Orifice Personal Sampler 92
Air Quality Control 96
The Term "Control" Has Two Definitions 96
Recognized Areas of Ommission 96
Conclusions 96
VII
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CONTENTS (Continued)
Page
HEALTH EFFECTS INDOOR AIR QUALITY RESEARCH/STRATEGY PLAN 97
1.0 SUMMARY OF STATE OF THE ART OF POTENTIAL HEALTH EFFECTS
OF POLLUTANTS IN INDOOR AIR 99
\
Introduction 99
Nonoccupational Indoor Health Hazards from Particulates 99
2.0 ORGANIC INDOOR AIR POLLUTANTS 102
Aldehydes 105
Solvents 106
Polymer Components 109
Pesticides 110
Other Organic Chemicals 110
References 112
Inorganic Substances 113
Carbon Dioxide 113
Carbon Monoxide 113
Nitrogen Oxides 114
Sulfur Oxides 115
Ozone 116
Ammonia 116
Lead (as in Air and House Dust) 116
References 118
3.0 RADIATION 121
>'
Radon Progeny 121
Sources of Indoor Exposure 122
Health Effects 123
Nature of Exposures 125
Radiofrequency Radiation 127
Sources of Exposure 127
Radiofrequency Radiation and Health Effects 127
References 129
Biological Substances 130
Infections 130
Allergens 130
Hypersensitivity Pneumonitis (Extrinsic
Allergic Alveolitis) 131
Humidifier Fever 131
"Building Illness" 131
Toxins 132
Conclusion 132
References 133
Research Needs 134
viii
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CONTENTS (Continued)
REPORT OF THE CONTROL TECHNOLOGY SESSION
OF'THE WORKSHOP ON INDOOR AIR QUALITY RESEARCH NEEDS 137
1 SUMMARY OF THE SESSION 139
General 139
Control Technology State of the Art 139
Areas of Omission 141
Research Needs 141
2 REVIEW OF THE STATE OF THE ART FOR INDOOR AIR QUALITY
CONTROL METHODS 143
General Background 143
Types of Indoor Environment, Sources, . _ .
and Pollutants 144
Control Methods 146
State of the Art in Ventilation 148
Historical Perspective 148
Editor's Note 149
Criteria 149
Ventilation System Description 151
State of the Art in Contaminant Removal 153
Historical Perspective 153
Contaminant Removal Systems Description 153
State of the Art in Source Removal and Exclusion 156
State of the Art in Product Substitution 159
References 160
3 RECOGNIZED AREAS OF OMISSION 164
Scope of Indoor Air Problem 164
Product Substitution 164
4 RESEARCH NEEDS 165
General Problem Definition Needs 165
Evaluation Methodology Needs . 165
Control Technology Research Needs 166
Ventilation Research Needs 166
Ventilation Rate and Pollutant Measurement 166
Natural Ventilation 167
Forced Ventilation 167
General 167
Air-to-Air Heat Exchangers 168
Contaminant Removal Research Needs 169
Source Removal/Exclusion Research Needs 171
Product Substitution Research Needs 172
ix
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CONTENTS (Continued)
Page
5 CONCLUSIONS AND RECOMMENDATIONS 173
Conclusions 173
Recommendations 174
RISK ANALYSIS INDOOR AIR QUALITY RESEARCH STRATEGY 175
Report on the Panel on Risk Analysis 177
RISK ANALYSIS TO RADON AND RADON PROGENY 181
Indoor Air Quality Health Risk Analysis 183
APPENDIX A—List of Participants
APPENDIX B--Research Recommendations for Monitoring Indoor
Air Quality
APPENDIX C—State of the Art in Organic Vapor Monitoring
APPENDIX D—Selecting a Dust Monitor
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EXECUTIVE SUMMARY
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EXECUTIVE SUMMARY
The Interagency Research Group (IRQ) on Indoor Air Quality is a
continuously functioning body established to bring together Federal Agencies
concerned with research on the indoor environment. Agencies actively partici-
pating include the U.S. Environmental Protection Agency (EPA), U.S. Department
of Energy (DOE), U.S. Department of Housing and Urban Development (HUD),
Consumer Product Safety Commission (CPSC), Centers for Disease Control (CDC),
National Institute for Occupational Safety and Health (NIOSH), National Institute
of Environmental Health Sciences (NIEHS), Occupational Safety and Health
Administration (OSHA), National Bureau of Standards (NBS), U.S. Department of
Defense (DOD), Coast Guard, Bureau of Mines, and National Science Foundation.
The IRG has undertaken to (1) prepare an inventory of ongoing and
recently completed research on indoor air quality; (2) draft a research strategy;
(3) develop a preliminary research agenda; and (4) organize a workshop to
broaden the technical base for information on items (1), (2), and (3). To
facilitate meeting these responsibilities, the IRG established five working
groups of Federal experts in the following technical areas: (1) monitoring
and characterization; (2) instrumentation; (3) health effects; (4) controls;
and (5) risk analysis. Each group has the ongoing responsibility of assisting
the IRG in the appropriate area.
A smaller interagency Workshop Steering Group (WSG), consisting of
representatives from EPA, DOE, HUD, CPSC, and NIOSH, organized a national
Workshop on Indoor Air Quality Research Needs to solicit expert review
and public comment on: (1) the draft strategy plan and (2) indoor air quality
research needs and objectives. Preparatory materials on these two items and
other relevant information generated by the WSG and the working groups (includ-
ing a sixth group, on Radon and Radon Progeny) were compiled in a briefing book.
The sixth group was established specifically for the workshop to examine for
one class of pollutants information contributed by all of the technical areas.
The Workshop on Indoor Air Quality Research Needs was held in Leesburg,
Virginia, on December 3-5, 1980. Specific objectives included:
• Defining the research agenda necessary to obtain a
sufficient understanding of indoor air quality pollu-
tants, sources, measurement methods and instruments,
controls, and risks
• Completing a state-of-the-art review of knowledge on
indoor air quality
• Completing an inventory of recent and ongoing research
(Federal and non-Federal) related to indoor air quality
• Commenting on the research strategy for indoor air
quality.
x1
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A multidisciplinary group of about 200 U.S. and Canadian technical,
scientific, and policy experts representing the Federal, public, and private
industry sectors was assembled.
The workshop was comprised of an orderly sequence of plenary and
concurrent technical sessions. Four technical sessions corresponded to the
working groups on monitoring, instrumentation, health effects, and controls.
The topic of the fifth working group, Risk Assessment, was addressed in a
plenary session. The subject of Radon and Radon Progeny in indoor environ-
ments was also addressed at a plenary session as a case study. Each session
was led by a panel of nationally known experts.
The final plenary session was devoted to review presentations by the
chairs of the four technical working sessions. Each chairperson reviewed the
activities of his or her respective group, and presented comments and recom-
mendations made by the experts. Synopses of each of these presentations are
given in the remainder of this section to complete the executive summary of the
activities of the Workshop on Indoor Air Quality Research Needs.
Dr. Nathaniel F. Barr, Department of Energy;
Studies on risk analysis of exposure to indoor radon and radon
progency concentrations, were reviewed. The panel and the audience identified
and extensively discussed several potential problems to be recognized. These
were:
1. There would be a very wide range of uncertainty associated
with health risk estimation derived from current data base.
2. The use of results of health risk analysis for purposes other
than R&D planning (i.e., policy formulation, regulation and
.public information) should be approached with extreme caution.
3. The scope of health risk analysis should be broad enough to
provide perspective on factors such as the health implications
of inadequate housing and other safety features of the indoor
environment.
•4. It is suggested that results of ongoing risk analysis be
provided to participants in advance of future research and
development workshops and discussions of these scheduled
early in the agenda.
The need for a systematic approach to risk analysis studies specifically
addressing indoor environments was also established.
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Dr. Lance .Wallace, U.S. Environmental Protection Agency
The monitoring section was divided into six groups. Each group
considered not only research needs in monitoring but also paid explicit
attention to the availability and adequacy of the instrumentation needed
to perform the monitoring.
Central Themes
In the final plenary meeting of the monitoring session, the
combined groups identified four unifying themes:
1. The total exposure concept. A person's health can be
affected by indoor, outdoor, and in-vehicle exposure.
The total exposure concept (i.e., 24-hour exposure)
must be an integral part of all monitoring efforts if
only to determine the relative contribution of the
indoor air to that exposure. Another important consid-
eration is the multimedia effects of water and food
and the correlation of these data with body burden data
(e.g., breath, blood, and urine levels).
2. Coordination. The complexity of the indoor air quality
problem requires interagency cooperation; cooperation
among health, monitoring and instrumentation people;
and interactions with industry, architects, builders and
engineers, academia, and Government.
3. Careful planning of field monitoring. Many examples
exist of inadequately planned field studies that
neglected to record the one item of information that
4ater was found to be necessary. Thus, there is a
need to design monitoring studies that make precise
statements about the objectives, protocols, data
requirements, and interrelationships with other efforts
planned or in progress in the public and private sector.
4. The "sick building" concept. Many panel members felt that
there is a new and very real problem emerging in indoor
air studies: buildings, including very large areas, in which
considerable proportions of their inhabitants are affected
adversely. Such buildings associated with outbreaks of disease
or complaints present an opportunity to study a condition that
affords a high probability of source identification, provided a
thorough study can be launched.
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Group-Specific Comments
Orgam'cs, Odors, Nitrosamines, Pesticides and PCBs
Volatile Orgam'cs
«
For broad-spectrum sampling, the present method of choice employs
solid-adsorbent collectors such as Tenax-GC followed by thermal desorp-
tlon and gas chromatography/mass spectrometry (GC/MS) Identification and
quantification. More work is needed on this method, however, Including the
exploration of metal versus glass collectors, break-through volumes, prepara-
tion, artifact formation, and standards for quantification. (Standards exist
for only 40 of hundreds of volatile organic chemicals.) Retention and collec-
tion efficiencies also need Improvement. Studies to Improve and standardize
the performance of this method are strongly recommended. Intercomparison of
.results is presently Impossible in the absence of a standardized method.
Once the method is improved, a phase two effort 1s desirable to
study problem buildings, ventilation rates, occupant complaints, organics,
and pollution sources.
An additional monitoring study of organic emissions from building
materials is recommended. This would involve head space analysis and examina-
tion of ventilation rates, temperature and humidity effects, which may provide
some control over these emissions.
Three other monitoring recommendations are for studies of: wood-
burning stoves, fireplaces, kerosene space heaters, and unvented heaters;
auto Interiors, particularly new auto plasticizers, in conjunction with ventila-
tion rates; and correlations of breath and blood levels with Indoor or personal
exposures. For this last Item, more knowledge is needed on absorption, metabolic
pathways and ex6osure/dose relationships for numerous organic compounds.
The final research recommendation of the organics subgroup is for a
study of mutagens derived from cooking. Protein pyrolysls produces potent
mutagens, some of which volatilize 1n the air. One study Indicates that 90
percent of the basic fraction of mutagens from cooking escape to the air in
the kitchen. In such a situation, the Inhalation dose may be comparable with
that due to Ingestion. A second study concluded that female kitchen helpers
suffer about three times the cancer n'sk of the general population.
Pesticides and PCBs
The principal Instrumentation, which 1s to collect pesticides and
PCBs on polyurethane foam (PUF) followed by solvent elution and GC/MS,
appears to be adequate. Ethylene glycol has been used as a collection medium
but has limitations. The polyurethane foam 1s sometimes backed by Tenax GC to
collect a wider range of organic compounds, and has also been fronted with a
filter that can then be tested for metals and total particulate mass.
xiv
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The basic need Is for an automation method that will increase
the throughput of the analysis. Large numbers of samples will be required
to characterize homes and give a frequency distribution of exposure.
Second, organic particulate matter must be characterized in addi-
tion, to organic vapors. No adequate technology now exists, however, for
collecting sufficient volumes of indoor air using personal or portable
samplers to extract and analyze the organics in aerosols and on particulates.
The critical need is for the development of small, powerful, and quiet samplers
and an extremely sensitive analytical protocol for extracting and analyzing
organics from a very small mass of collected particulates. Organics that are
partitioned between aerosols and vapor (such as PCBs and possibly plasticizers
from auto interiors) also need special methods.
A third requirement is for analytical methods for synthetic pyrethrins
and carbamates, both compounds of increasing importance in the pesticides area.
The final research recommendation of instrumentation need by the pesticides
and PCBs subgroup is for a more compact medium flow personal pump for semi-
volatile collection on PUF. It is anticipated that instrument manufacturers
will produce this pump within the next year.
Other research needs for pesticides include the following:
t Coordinate with the nationwide pesticide usage survey
undertaken by the EPA Office of Pesticides and Toxic
Substances. Adding monitoring to that effort would
provide extremely valuable data.
• Monitor for PCBs, a major source of which is probably
burned out ballast from fluorescent light fixtures.
• iHbnitor for pentachlorophenol (PCP), particularly in log
cabins.
• Coordinate with body burden studies.
Nitrosamines and Odors
.Several major indoor sources of nitrosamines are gas stoves, rubber
products, tobacco smoke, and diesel oils and auto coolants. The instrumenta-
tion for nitrosamines appears to be adequate for laboratory studies only, and
Includes GC/MS analysis and the TEA analyzer developed specifically for
nitrosamines. While the latter instrument looks promising, it requires further
validation.
Recommended monitoring studies should examine nitrosamine concentra-
tions with respect to the following variables: gas versus electric cooking,
xv
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vented versus unvented hoods, the effect of tobacco smoking on Indoor concentra-
tions, gasoline versus diesel fuel 1n autos and buses, and the effectiveness
of charcoal filters in reducing nitrosamine concentrations (a control research
need).
,. A related compound of increasing interest is hydrazine, a possible
product of reactions involving bleaches and washing materials. Instrumenta-
tion is inadequate at present for personal or Indoor monitoring, and needs to
be developed. Once developed, a small monitoring program to learn the extent
of the problem would be a desirable first step.
This subgroup also urges the investigation of the increasing number
of complaints about odors. A potentially large economic impact may be
involved, particularly with air and carpet fresheners, which may anesthetize
the olfactory sense or mask the smell until normal ventilation reduces the
concentration of the odor. Present "instrumentation" (i.e., panels of persons
ranking the odors under investigation) is the only proven method of quantifying
odor levels. A more specific approach would be to link specific chemicals
with certain odors and develop instrumentation accordingly. The impact of
outside odors on indoor air should be examined.
Aerosols and Asbestos
The instrumentation is inadequate for aerosols and asbestos. A
personal monitor is needed for RSP that is capable of collecting sufficient
material over 8-hour periods to allow chemical analysis. One such system
is now under development at the National Bureau of Standards.
Also required is a personal monitor that gives ah instantaneous
readout of mass. (The Piezobalance and GCA's Respirable Aerosol Monitor
give instantaneous or near-instantaneous readout but are too bulky for a
person to carry easily.) In addition, the monitor should have the capability
for data logging", an electronic memory, a clock, and a code to indicate the
activity of the person at the time the exposure is occurring. These features
will allow identification of activities associated with increased exposures.
For monitoring, the parameters to be measured are size and mass,
chemical composition, time resolution, and activity patterns of the popu-
lation. The highest-priority monitoring effort is a total exposure
monitoring study to measure indoor, outdoor, and in-transit exposures as the
three major components. An ideal study would provide a frequency distribution
of exposures in one urban area and then use existing time budget studies to
extrapolate to exposures in other areas.
.rf"
Secondly, controlled or chamber experiments for such sources as
tobacco smoke, cooking, vacuum cleaning, diesel particulates, and wood
burning should be carried out. These would include studies 1n growth,
decay deposition, and transport.
xvi
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A third priority is for site-specific studies on office buildings,
residences, autos, and subway platforms.
For asbestos, the instrumentation is not adequate for airborne
analysis. We need continuous instrumentation and continuous fiber counts with
size,'determination, and identification of the fibers.
Criteria Pollutants
The subgroup strongly recommended the evaluation and calibration
of all present monitoring instruments for Indoor use. Instruments have been
tested by NIOSH at occupational concentrations, but they have not been evaluated
and validated at expected nonoccupational indoor levels (which may be 100 times
lower than occupational levels) and are not usable, except by trained personnel.
Carbon monoxide is the only pollutant for which instrumentation
appears adequate and for which a large scale study could be undertaken now.
Highly recommended studies include gas heating, cooking, transportation sources
and 24-hour exposure studies. (EPA presently plans a large-scale urban study
for next year.)
For NOp, the instrumentation is satisfactory for long-term (days
to weeks) integrated analysis. (The Palmes diffusion tube and the modified
West permeable-membrane badge have both been validated recently by the NBS.)
However, neither method is adequate for short-term monitoring. A short-term
standard for N02 soon may be issued. The standard is not expected to apply
to indoor levels, and short-term monitoring requirements may not be necessary
unless the N02 health effects deviate from the linear dose hypothesis.
Portable instrumentation that will measure ambient levels may be needed for
other uses.
Another recommendation is a chamber study that would Involve a
single, specialty-designed house to study combustion and appliance emissions of
N02. Concentration should be examined as a function of source strength and
air exchange rates, with and without exhaust hood operation.
Statistics and Modeling
A fourth group focused on statistics and modeling. Collectively,
the group agreed that environmental monitoring programs are sufficiently
diverse as to require unique sampling strategies. One possible solution to
this dilemma is the NIOSH Sampling Strategy Manual. In general, a potential
strategy should consider average versus peak exposures, time histories, short-
and long-term effects, and the relation of Individual exposures to individual
responses. Again, quality control and quality assurance were mentioned as
pressing needs for all exposure and monitoring studies.
xvii
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Exposure models are needed. Fugas and Ott have worked on deter-
mining exposure as the product of pollutant concentration in a particular
microenvironment and the time people spend in each microenvironment. The
difficult job of defining microenvironments has only recently begun, and
therefore no agreement exists as to the number to be studied. (The number
obviously depends on how finely they are subdivided.) However, if a reasonable
number of microenvironments can be identified and monitored to determine the
exposure range in each microenvironment and if the time that people spend there
can be determined from national time-budget studies, then the exposure of
large populations can be estimated. Nevertheless, individual exposure studies
are still needed for epidemiologic research.
The subgroup feels that a long-term study in economic analysis
components should be added to the activity pattern/sociologic type of
modeling that is being performed.
Radon
Substantial research efforts are needed in four areas. Studies of
indoor radon and radon progeny concentrations should be undertaken to under-
stand their dynamic behavior in buildings and to determine the range and
distribution of radon and/or its progeny in the nation's building stock.
Before proceeding with a large-scale survey it is necessary to evaluate the
usefulness of various passive techniques for characterizing the concentra-
tions of radon and/or radon progeny in residences, and to assess the
viability of short-term measurements to represent annual averages. Finally,
it is necessary to characterize radon sources and ground transport in order
to provide predictive capabilities for indoor concentrations of radon/radon
progeny.
Formaldehyde
The formaldehyde subgroup determined that the sampling methods
are inadequate in two areas. One is population exposure: the detection limit
is only 200 ppb, an inadequate level of sensitivity for long-term, low-level
exposures. A desirable level would be 20 ppb.
The second area of instrument inadequacy is in source assessment.
In this case, continuous monitoring is needed with a 30 ppb limit of detection.
The subgroup recommended a monitoring program (dependent on improving the
instrumentation) that would examine correlations between formaldehyde levels
in the air, sources, and ventilation effects.
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Dr. Laurence J. Doemeny, National Institute for Occupational Safety
and Healfn":
The Instrumentation Group recommends that trade associations, the
Small Business Administration, and educational and research institutions
such as EPRI and GRI actively participate in research and in information
dissemination on indoor air quality.
We know legionnaires disease is a real threat. We know formalde-
hyde has driven people from their homes; we know students in academic labora-
tories have been overcome by chemical vapors, and we know that excessive
levels of various pesticides, polychlorinated biphenols, and other pollutants
may occur in the indoor environment. The panel and the participants feel that
published materials and the indoor air quality research plan should focus on
the issues and use appropriate language to stress the problems where they
exist.
We note that the list of sources of pollutants should include impor-
tant areas such as landfills, water that is a source of radon, and chemical
dumps.
Quality Assurance
Quality assurance greatly concerned the instrumentation group.
Recent Supreme Court decisions have highlighted the need for good data.
Attention to quality assurance efforts may be an integral part of any
national program in indoor air quality. The group fully embraces the concept
of quality assurance described by J.S. Hunter in a recent Science, (210:
No. 4472, pp. 869, 1980) article titled "The National System for Scientific
Measurement." This is a sound and reasonable approach to quality assurance
for methods development and instrumentation.
The npw instruments needed for indoor monitoring also serve other
ends, such as ambient air monitoring, occupational exposure, and hospital
monitoring. Incentives will be required, however, if private enterprise is
to undertake significant efforts in instrument development. For industry
to invest in this research, instrument manufacturers must be convinced that
indoor air problems do exist and that regulations or guidelines will be
issued in an effort to eliminate these problems.
'Technology transfer is another key element of an indoor air quality
program. Physicians should be trained to understand symptoms relating to
poor indoor air quality and instructional materials should be upgraded. This
point Applies as well to the other technical areas addressed by the Workshop.
The group then broke into four smaller subgroups: aerosols, radon,
inorganics, and organics. The topic of biological agent sampling approaches
was not covered due to the absence of experts at the Workshop.
xix
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Aerosols
Aerosol calibration methodology is available for laboratory pur-
poses. No simple techniques exist, however, for field calibration except
secondary methods to check the operational performance of real-time monitors.
Most-^aerosol monitors require active sampling from the surrounding environ-
ment and exhibit some degree of particle size discrimination or bias. The
use of so-called total suspended particulate (TSP) samplers or monitors is
discouraged. Specific and well controlled particle size limitations (such
as by the use of size preselectors and/or properly designed inlet configura-
tions) should be required to prevent errors in inconsistencies associated
with open-endedness at the large particle end.
Accurate instruments and techniques often are difficult to find
because of the inherent inaccuracy and ambiguity in most of the reference
methods. In general, however, intermethod comparisons usually yield agree-
ments within a factor of two.
Repeatability, using a given device under similar monitoring
conditions, is frequently within 10 to 20 percent and occasionally much
better.
Radon
For radiation, much of the development work in the last 20 years
has responded to problems of uranium mine exposures, releases from uranium
tailings, high indoor exposures, and structures built on reclaimed phosphate
lands.
Adequate, if not optimal, techniques exist and are being applied
in research studies of radon and radon progeny concentrations in indoor
air. These studies are dependent on ventilation rate, heating and cooling
system operating parameters, meteorological variables, living habits, par-
ticulate size distributions, trace degree, and the degree of attachment.
Improvements are being made, however, in many of these techniques to make
larger-scale field studies more practical.
Passive integrators of radon gas exposure over periods of weeks
or months have recently been developed and are being evaluated. They are
likely to.be adequate for large-scale surveys. There is a strong need for
analogous integrators for radon progeny exposures.
Many of the techniques suitable for measurement of radon 222 can
be applied to radon 220.
Few data exist on exposure to thoron and on thoron's contribution
to radon readings. More effort is required to adequately define the measure-
ment techniques and protocols for general use, to provide standard calibration
facilities and sources, and to perform detailed evaluations of various instru-
ments and measurement methodologies.
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Inorganics
The inorganic subgroup confined its discussion to carbon dioxide,
oxides of nitrogen, carbon monoxide, and hydrazine.
Area monitors measure carbon monoxide at 1 ppm, carbon dioxide
at 18 ppm, and NO at 5 ppb. Area monitors are needed to measure nitrogen
dioxide at the 0.01 ppm level.
Personal integrating monitors may lack specificity indoors, but
are available for NOg at the 20 ppb level for 2-day samples.
Personal monitors are required for hydrazine at the 5- to 50-ppb
level and for carbon monoxide at the 1- to 5-ppm level.
None of the above methods has been validated, recognized, or had
.quality assurance practices applied for indoor air measurement. Alarms
to alert residents to unsafe levels of CO and 003 are needed, as are low-cost
miniaturized instruments.
Organics
The organics session devoted its time to nitrosamines and poly-
nuclear aeromatics (PNA). Although the nitrosamine methods may not have been
validated, suitable nitrosamine sampling and analytical methods are available.
Personal and area sampling/analytical methods may be available
for PCBs, fluorodane, and organic solvents. Methods for PNAs and formalde-
hyde are either feasible or available.
For control instruments, research is needed to determine if exist-
ing room sensors such as ionization smoke sensors can be adapted to indoor
air quality measurements. Ultrasonic, infrared, solid-state lasers should
be considered for control monitors. Control strategies to monitor the inter-
play between the ambient levels and filter loading situations will be
required.
Protocols do exist for measuring air exchange and filtration rates.
This is the ASTM method E-741. Inexpensive methodologies for measuring infiltra-
rates are, however, needed.
For general instrumentation, we need miniature mass spectrometers
and infrared analyzers. Pumps may need to be redesigned or reconfigured
for the. different sampling strategies that monitoring may employ. Basic
research is needed to further understanding of solid sorbants, and to define
the catalytic effects of the sorbent on the low-level samples.
xxi
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Dr. Lance Wallace made a statement regarding time and motion studies
where subjects push a button to register their locations. This topic has
been discussed by some of the staff at the National Institute for Occupational
Safety and Health. Technology 1s available to place position monitors on
persons 1n the workplace setting, although we must not Ignore the difficulties
Involved 1n using this type of monitoring.
xx11
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Dr. Robert Goyer, National Institute of Environmental Health Sciences;
The respiratory system Is the most vulnerable to Indoor air
pollutants. The most neglected 1s the nervous system, particularly in
behavioral effects.
«
No known causes have been determined for many chronic diseases
1n society. The role of the indoor environment should be considered in
relation to these diseases, either as augmentation factors or as primary
etiological factors.
The indoor environment offers an opportunity to study the effects
of a number of potentially harmful substances on a cross section of the popu-
lation, which includes the aged, the invalid, the chronically ill, pregnant
women, and infants.
All efforts to study health effects are dependent on the avail -
'ability of instruments and techniques for monitoring. For health studies,
two kinds of instruments are needed: an instrument to record peak short-term
exposures and long-term integrating Instruments.
The Health Effects Group clustered pollutant problems Into seven
classes of substances. These were: formaldehyde, radon, combustion products,
biologicals, organic compounds, particiilates, and tobacco smoke.
Formaldehyde
Rates of formaldehyde emissions and factors affecting the rates
of emission from various structural products should be characterized. We
need toxicological research concerning the carcinogenic effects of low levels
of formaldehyde.
Also needed are toxicologlc studies of the mechanisms of low-level
acute effects relating to sensitization and Immune mechanisms. Epidemio-
logic studies on the alleged health effects in the indoor levels must be
studied. These studies should include buildings where consumer products,
furniture, and wallboard emit formaldehyde.
Radon
Our group thought that the first priority in monitoring is to
obtain a national assessment of radon levels in personal dwellings. Once a
national assessment has been made, we could then identify regions or populations
where epidemiologic studies of low-level effects could be profitably performed.
Health studies should include miners who have been exposed to low levels of
radon where control measures are already in effect.
xxiii
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Combustion Products
A third topic 1n the Health Effects Group was combustion products.
Most homes today use multiple sources of fuel. Some of these fuel sources,
such as wood, have not been used extensively in recent years. The combustion
products of greatest concern are carbon monoxide, nitrogen oxide, nitrogen
dioxide, and aromatic hydrocarbons.
The measuring of carbon monoxide and nitrogen dioxide should be
correlated with carboxy and met-hemoglobln measurements. A number of par-
tlculates and organlcs may act synergistically with other Indoor pollutants
and produce adverse effects. These Interactions should be studied.
In addition, epidemiologic studies of people exposed to combustion
products should be correlated with emissions from other sources.
Biological Pollutants
The Health Effects Group considered biological pollutants a high
priority research need. Two aspects must be considered:
1. The allergenic properties of biologies
2. Biologic substances as infectious agents.
Common allergens found in the home include fungal spores, pollen,
mite dust and microbial products. The indoor environment may provide ideal
conditions for growth of fungi. An example is aspergilla, which may be an
allergen and may produce an infectious disorder, or aspergillosis.
Continued exposure to allergens may cause a hypersensitivity syndrome.
Subdivisions of this syndrome are hypersensitivity pneumonitis and/or humidifier
fever. Both jof these are thought to be due to fungal or protozoan contamina-
tion of the ventilation system or humidification apparatus. This deserves more
study.
Cats, dogs, birds and other pets in the home may also be sources
of allergens that cause either asthma or hypersensitivity pneumonitis.
• Many common Infectious agents may be airborne. As buildings are
sealed more tightly, the risk for airborne infections increases proportionately.
Therefore, Incidents of Infectious diseases must be correlated with levels of
air exchanges in buildings. Occasionally, organisms are Isolated in sealed
buildings, allowing such correlations to be made.
Organic Pollutants
The Health Effects Group also made recommendations on organic pol-
lutants which, with the exception of formaldehyde, were assigned lesser
xxlv
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priority. Nevertheless, many organic substances require further toxico-
logic and monitoring study. We have little Information about their presence
1n the Indoor environment.
The organlcs were broken Into three groups: pesticides, controlled
organlcs, and Indoor partlculates. Controlled organlcs were defined as
consumer products that are brought Into a house by Its occupants. There-
fore, the emissions from controlled organic pollutants could be controlled.
Uncontrolled organlcs are substances emitted from furniture,
household articles, or from the structure of the house.
Some organlcs are considered potential health problems for a variety
of reasons. These include 1,4-dichlorobenzene, nitrosamines, and pentachloro-
phenol and other related chlorinated hydrocarbons. The latter should be
studied because of their dioxin content. Dioxin should be monitored.
We need more complete tabulation and recording of the toxicologic
Information on these classes of organics. The National Toxicology Program
studies the toxicologic effects of chemicals, and the Consumer Product Safety
Commission has compiled a 11st of Ingredients contained in most consumer
products.
For controlled organic emissions, there is a need for product
emission data and for appropriate labeling to prevent misuse. This 1s being
done for pesticides. A central repository of toxicologic data should be
provided for consumer products.
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Dr. Janet C. Haartz, National Institute for Occupational Safety and Health;
Before I summarize the discussion of the Control Technology group,
I would Hke to acknowledge and thank the panel members that worked with
me: Dr. Amos Turk, Dr. James Woods, Mr. Gary Roseme, Mr. Bill Mi rick and
my cochairman, Mr. Robert Hartley. I'd also like to thank the participants,
who«contributed significantly to the development of our recommedations.
Most of the participants in the control technology session felt
that our state of knowledge about Indoor air quality is extremely rudimentary.
Although there are data relating to hazardous industrial workplace environ-
ments, little is known about hazardous pollutants 1n commercial and residen-
tial environments. The view was widely expressed that adequate controls
will be developed and implemented only after we determine, qualitatively and
quantitatively, the characteristic pollutants present in all types of Indoor
environments. Those pollutants which cause adverse health effects need to be
identified so that controls which are appropriate are developed. The group did
feel, however, that there is sufficient potential for hazardous conditions in
indoor spaces—made worse by pollutant build-ups associated with some energy
conservation techniques—that we cannot delay control technology research until
all of the problems are delineated.
In our discussions we periodically returned to the need for various
types of information or sets of data. Therefore, although these concerns
have been enumerated by the three previous speakers, those most directly
related to control technology research need to be reiterated. They include:
1. Standard methods for identifying and quantitating
emissions from materials
- In developing these methods, one must be cognizant of
variables such as temperature and actual use of the
materials, and thence include these variables in the
* standard methods.
2. A systematic characterization of indoor spaces
- The data could be used to develop models for air and
contaminant movement within Indoor spaces with which the
effectiveness of control strategies could be deter-
mined.
3. Standard methods for evaluating air cleaning equipment
- These methods would allow the determination of efficacy
in removing vapors or particles under real conditions and
not only under very constrained laboratory situations.
The use of standard methods would also allow comparison
of data from different laboratories or tests.
xxvi
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The discussion of and recommendations for control technology research
strategies were divided Into four categories: ventilation, source removal
or exclusion, contaminant removal, and product substitution.
Consideration of the last category, product substitution, was
unproductive 1n terms of developing research needs. Too little information
Is "available on hazardous materials to adequately define research leading
to substitutes. In the three remaining categories, we developed and suggest
priorities for 20 or more research recommendations 1n each. Details of these
recommended actions are in the panel report. A summary follows:
Ventilation—We include In this category, infiltration 1n addition
to mechanical and passive/natural ventilation. A prerequisite for control
technology research is an Inventory of contaminants. We need to determine
sources and generation rates, and reexamine the current prescriptive ventila-
tion rates, such as those recommended by ASHRAE, to ascertain if they provide
adequate levels of contaminant control. Although NIOSH has done some research
on ventilation as a control for industrial workplaces, other Indoor environments
are not covered in the NIOSH data. The technology developed for industrial
environments needs to be evaluated for possible transfer to use in commercial
and residential environments.
Techniques for use of air-to-air heat exchangers must be evaluated
and the need for these, 1n addition to or in place of other ventilation systems,
must be determined.
An inexpensive means of measuring the actual ventilation rate experi-
enced by a building over a period of time—not merely the mechanical or forced
ventilation rate, but the actual ventilation rate—Is needed.
We also need to determine the concentration of pollutants as a
function of ventilation rate 1n a statistically significant number of indoor
spaces. This Determination should cover not only residences, but all of the
categories of buildings Included in the research plan.
Source Removal and Exclusion—This category includes techniques
for actually removing the source of a pollutant or for excluding the pollutant
by, for example, sealing off the source. A prerequisite for development of
source removal/exclusion technology is Identification of the sources of
emissions. For example, we need to determine the emissions from construction
materials, from equipment and from other sources In the same way that the
Consumer Product Safety Commission has Identified and listed emissions from
various specialty chemical products. Emissions must also be examined as a
function of process. For example, what Is expected from cooking or from
operating a copy machine?
Emission rates and their dependence on ambient conditions are also
Important. For example, the rate of emission of formaldehyde from Insulation
xxvil
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materials has been shown to be somewhat dependent on humidity. It is reason-
able to assume that other pollutants also have a similar emission rate
dependence on ambient conditions. In order to develop effective control
technology strategies, we also need to develop an inventory of emission rates
by category.
An effective control strategy is the use of coatings and encapsulating
compounds that can retard or eliminate pollutant emission. However, a compre-
hensive listing of these materials is needed as a basis for identifying and
evaluating additional applications for them.
Another important research need is to develop construction tech-
nologies or techniques that will exclude pollutants. A corollary is to
develop remedial techniques which will exclude radon, pesticides, and other
pollutants. Although some research in this area has been initiated by DOE
and HUD, much remains to be done as there are no proven techniques in wide-
spread use.
Contaminant Removal—Included in this category are the control
strategies which remove the pollutants as they are formed, without removing
or excluding the sources thereof. The control technology panel felt that
there is a real potential for implementing technology transfer in this
area. There is a vast amount of knowledge on air cleaning mechanisms or
equipment that is used by industry and the military which could be adapted
for use in other indoor spaces. An end-of-service-life indicator for air
cleaners was considered an important research need. This mechanism would
indicate either visually or audibly that a buildup of pollutants had occurred
and the device was no longer effective. Finally, one research need in this
category which relates only to residential environments: the development of
energy-efficient range hoods or similar devices which are not only effective
for removal of air, but also are effective for actual contaminant removal
via use of charcoal or other types of filters that are easily used and main-
tained.
)
/
In closing, I would like to reiterate that the above is only a
summary of our discussions. A detailed compilation of the research needs
developed by the control technology group is included later in the text.
The remaining topics on the agenda consist of followup activities
and a general discussion.
xxvli1
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Mr. David Berg, Workshop Cochalr, EPA;
FoTlowup Activities;
Each panel will compile a written report. The Workshop report will
be^distributed to all workshop participants.
The revised Research Plan, which will be based in part on the Workshop
report, will Identify the research needs in indoor air quality. Before the
Plan becomes final, the Interagency Research Group will submit the Plan for
approval by policy level people in each participating agency. The research
agenda, when completed in draft form on the basis of suggestions made at this
meeting, will be used by the Interagency Research Group and Its subgroups to
design an overall Federal research program.
We are also asking workshop participants to assist 1n updating the
Inventory of current and ongoing research projects in indoor air quality.
Research now underway must relate closely to future work. Thus, through
this tool, we can improve the overall quality of indoor air research.
Meanwhile, the Office of Management and Budget has been made aware
that the Interagency Research Group exists. OMB has consented to the IRG's
continuation as an ad hoc organization.
The Clean Air Act will be reviewed by the Congress in the coming
legislative year. Various committees and subcommittees have indicated that
they may hold hearings on indoor air quality. These would be the first compre-
hensive hearings on indoor pollutants extending in scope beyond the workplace
environment.
xxix
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Section 1.0
INTRODUCTION
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Section 1.0
INTRODUCTION
The Interagency Research Group (IRQ) on Indoor Air Quality is a
continuously functioning body established to bring together Federal Agencies
concerned with research on the indoor environment. Agencies actively partici-
pating include the U.S. Environmental Protection Agency (EPA), U.S. Department
of Energy (DOE), U.S. Department of Housing and Urban Development (HUD),
Consumer Product Safety Commission (CPSC), Centers for Disease Control (CDC),
the National Institute for Occupational Safety and Health (NIOSH), the National
Institute of Environmental Health Sciences (NIEHS), Occupational Safety and
Health Administration (OSHA), National Bureau of Standards (NBS), U.S. Depart-
ment of Defense (DOD), Coast Guard, Bureau of Mines, and National Science
Foundation.
The IRG has undertaken to: (1) prepare an inventory of ongoing and
recently completed research on indoor air quality; (2) draft a research
strategy; (3) develop a preliminary research agenda; and (4) organize a
workshop to broaden the technical base for information on items (1), (2), and
(3). To facilitate meeting these responsibilities, the IRG established five
working groups of Federal experts in the following technical areas: (1)
monitoring and characterization; (2) instrumentation; (3) health effects; (4)
controls; and (5) risk analysis. Each group has the ongoing responsibility of
assisting the IRG in the appropriate area.
A smaller interagency Workshop Steering Group (WSG), consisting of
representatives from EPA, DOE, HUD, CPSC, and NIOSH, organized a national
Workshop on Indoor Air Quality Research Needs to solicit expert review and
public comment on: (1) the draft strategy plan and (2) indoor air quality
research needs and objectives. Preparatory materials on these two items and
other relevant Information generated by the WSG and the working groups (includ-
ing a sixth group, on Radon and Radon Progeny) were compiled in a briefing
book. The sixth group was established specifically for the workshop to examine
for one class of pollutants information contributed by all of the technical
areas.
The Workshop on Indoor Air Quality Research Needs was held in Leesburg,
Virginia,-on December 3-5, 1980. Specific objectives included:
• Completing a state-of-the-art review of knowledge on
indoor air quality
• Completing the inventory of recent and ongoing research
(Federal and non-Federal) related to indoor air quality
• Defining the research agenda necessary to obtain a
sufficient understanding of indoor air quality pollu-
tants, sources, measurement methods and instruments,
controls, and risks
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A multidisciplinary group of nearly 200 U.S. and Canadian technical, scientific,
and policy experts representing the Federal, public, and private sectors* was
assembled. All participants had current or recent experience in research,
research management, or manufacturing items associated with indoor air quality.
The workshop comprised an orderly sequence of specialty working and
plenary sessions. Specialty working sessions were led by panels whose members,
selected before the workshop, were recognized experts in the five technical
areas of the working groups: monitoring; instrumentation; health effects;
controls; and risk analysis. A sixth specialty group, on radon and radon
progeny, was also led by a panel of experts and represented a case study that
incorporated all subjects addressed in the other five specialty sessions.
The plenary sessions were led by representatives from EPA and DOE, the cochairs
of the IRG on Indoor Air Quality. Sessions were conducted as follows:
1. Opening Plenary Session - to formally convene the workshop,
explain its organization, and reiterate its purpose and
objectives (morning of December 3).
2. Technical Sessions - concurrent sessions in each of four
central technical areas (monitoring, instrumentation,
health effects, and controls) under panel leadership to
review the state of the art, discuss research strategies,
and identify research needs (afternoon of December 3,
morning and afternoon of December 4).
3. Technical Session in Plenary - to present and discuss issues
of the special topic of radon and radon progeny (evening of
December 3).
4. Technical Session in Plenary - to present and discuss issues
in the technical area of risk analysis (evening of December 4).
>
5. Closing Plenary Session - to allow the panel chairs to report
findings to all participants for discussion and then adjourn
the proceedings.
During the workshop, many ad hoc and executive meetings spurred further
discussion and fostered exchange of Information among the working sessions.
The workshop report will contribute to four clearly defined
products necessary for developing a national program in indoor air quality:
• State-of-the-Art Review
f
• Inventory of Related Ongoing Research
* A complete list of all participants is contained in Appendix A.
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• Inventory of Research Needs
• Unified Research Strategy
This document summarizes the conduct of the workshop and presents the findings
and recommendations that were developed. The first section presents the
Executive Summary; the second contains a synopsis of presentations given
during the plenary sessions on the mornings of December 3 and 5; and the third
provides technical reports generated by the panels of each specialty working
session and a summary report on risk analysis. Appendix A contains a complete
list of all workshop participants and the technical sessions to which each
contributed. The inventory of research is being published separately.
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Section 2.0
OPEN PLENARY SESSION
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Section 2.0
December 5, 1980/Morning Plenary Session
Synopses of the workshop keynote presentation by Dr. Kurt Riegel and
introductory remarks by Mr. David Berg, the workshop cochair, are found in
this section.
Synopses of the presentations on Policy Aspects given by Mr. Dwain
Winters (EPA), Mr. Howard Ross (DOE), Dr. Irwin Billick (HUD), and Dr. Peter
Preuss (CPSC) are also included in this section.
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Dr. Kurt Riegel, U.S. Environmental Protection Agency:
Welcome! We worked hard to Identify people who could bring a high
level of expertise to this meeting. We publicly announced it in hopes of
drawing additional knowledgeable persons. The attendance list contains an
exceptional collection of people who are well acquainted with many aspects of
Indoor air quality and, in some cases, the remedies.
The Federal Government's interest in indoor air quality extends
back at least 5 years and perhaps as many as 30 years. Recent events have
added to the sense of urgency that several Federal Agencies attach to the
exposure to indoor air pollutants. But, we have discovered a lack of coordina-
tion between the Federal Agencies in pursuing their individual research and
development responsibilities.
Thus, we formed the Interagency Research Group on Indoor Air Quality,
which has several purposes. The group first sought to acquaint the Federal
establishment with research and development related to indoor air quality in
each Federal Agency. Second, the group made a concerted attempt to coordinate
the activities of each Agency toward common objectives and clearly stated
goals.
This meeting is an important milestone toward coordinating a Federal
research and development program on indoor air pollution.
A number of changes are taking place on the Washington scene, which
will affect the way Federal Agencies address indoor air pollution. The idea of
trying to adopt traditional regulatory approaches to problems of exposures to
indoor air pollutants is scary—nonregulatory approaches, particularly in the
indoor case, are likely to be more appropriate to the subject, as well as to
our times. We hope that Federal activitites will address indoor air quality
in a way that is practical and not burdensome to the public.
>>
A number of recent events have affected EPA's outlook on indoor
air pollution. For example, EPA now believes that worrying only about the
outdoor ambient environment is less than completely desirable, since most
people spend most of their time indoors. Outdoor criteria alone do not protect
a person's health in a total exposure sense. This concept of total exposure to
pollutants is gaining wider and wider currency in the Federal Government.
Total exposure, or the total burden to which we are exposed, includes the
indoor environment. Research findings for the indoors may greatly affect
outdoor ambient air quality standards.
The interactive indoor/outdoor effect needs to be more widely
considered. We have made some progress in our knowledge about some of the
consequences of pollutants found indoors. For example, we know much about
radon. However, the state of knowledge for other indoor pollutants is less
complete. Before Government Agencies even consider action to address health
effects of indoor exposures, we must determine which indoor pollutants exist,
at what levels.
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Instrumental techniques must be developed for measuring pollutants
in practical ways. How do those levels affect human beings? What is the
total risk to a human being? What controls are available? What actions ought
Federal Agencies to take to help protect human health? That is the general
background of our concerns. We hope this meeting will sharpen the Federal
research and development plan for indoor air pollution over the next 5 to
10 years.
Mr. David Berg, U.S. Environmental Protection Agency;
Over the next few minutes, I will cover two topics:
1. The overview of the draft Research Plan for indoor
air quality
2. A review of the purpose and structure of this meeting
Overview of the Draft Research Plan for Indoor Air Quality
The emerging consensus that indoor air quality may be a national
health concern is a stimulus for having this meeting. Limited data suggest
that indoor exposures to several pollutants—including NOv, particulates,
asbestos, radon and formaldehyde—comprise a significant fraction of total
exposure. The concern for energy conservation increases the potential for
adverse exposures to pollutants as air exchange rates are reduced and new
sources are introduced to the indoor environment. Several Agencies have
responded to this feeling. These responses include the advent of the
Interagency Research Group on Indoor Air Quality.
Members of the Interagency Research Group come from several Agencies.
Environmental Protection Agency (EPA) and the Department of Energy (DOE) are
the cochairs. The Department of Housing and Urban Development (HUD), Consumer
Product Safety Commission (CPSC), Department of Health and Human Services
(DHHS), Centers for Disease Control (CDC), the National Institute for Occupa-
tional Safety and Health (NIOSH), and the National Institute for Environ-
mental Health Sciences (NIEHS) are also members. Participating groups include
the General Services Administration (GSA), Department of Defense (DOD), and the
National Bureau of Standards (NBS).
In summary, the purpose of the Interagency Research Group is to
coordinate Federal efforts to understand and deal with problems of indoor
air quality. Five working groups were established by the Interagency
Research Group to facilitate this process. These are monitoring, instru-
mentation, health effects, controls, and risk analysis. In addition, the
draft plan suggests that there would be two other groups established—one on
data handling and information and another on quality assurance.
-------
The Interagency Research Group has prepared a draft Plan to docu-
ment the working group structure, to detail the roles of the working groups,
and to suggest the broad research elements for each group. The Plan seeks
to establish a mechanism to coordinate federally sponsored research and to
use the research results to address the cleanup and prevention of potential
threats to public health. Thus, Federal efforts can be streamlined, made
more«eost effective, and can avoid unnecessary duplication.
The Plan proposes several functions by the working groups. These
functions are:
t To perform a state-of-the-art review of knowledge on
various aspects of the indoor air quality problem
• To review and update the draft Research Plan
• To review and correct the inventory of research
projects in indoor air quality that are underway
or were recently completed
• To develop a research agenda to guide the selection
of projects by several Agencies that will fund
research and to guide private and nongovernmental
groups that may conduct research
t To coordinate the research activities of the several
Agencies
t To conduct periodic technical reviews.
I stress that the research called for by the workshop and the
Interagency Research Group will not provide the basis for another major
Federal intrusion into private lives. Rather, the Plan identifies the
needs of severaf'organizations for reliable information on which to base
their decisions that will affect the public health. The need for informa-
tion on indoor air quality is also shared by individual architects, builders,
and building owners.
Purpose and Structure of the Workshop
This workshop has a number of purposes:
t To define clearly the specific research efforts needed
to assemble a research program to understand and mitigate
the indoor air problem
• To summarize the indoor quality problem, based on
implementation available to the experts present at the
workshop
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• To receive workshop comments on the draft Research Plan
• To correct the inventory of indoor air research and
programs.
The workshop is structured around five technical areas: instrumen-
tatioln, controls, monitoring, health effects, and risk analysis. A cross-
cutting session will look at one pollutant, radon. An expert panel for each
technical session will prepare a summary report on the information gathered.
Each report will contain eight separate sections:
1. An abstract
2. A summary of the session
3. Comments on the draft Research Plan
4. A review of the state of the art
5. The preparatory documents from the technical working
groups
6. A list of major areas of omission in the draft
Research Plan
7. The descriptions of individual research needs
8. A commentary on specific recommendations.
The workshop report will have several uses. The Interagency
Research Group will use this document to help prepare an integrated
Federal research program. The document, which will represent the sum
of thinking among the most qualified experts, will be made available
to the technical community and to others who are interested in the
problems and mitigation techniques for indoor air pollution.
Mr. Dwain Winters, U.S. Environmental Protection Agency:
Introduction to this Session;
The panel members assembled for this session have not been asked to
speak as representatives of their respective Agencies. Instead we have asked
them to serve as a panel of experts who will speak of their personal perceptions
of the problems of indoor air quality, and their Agency's involvement with this
problem.
Indoor Air Quality Research Needs from Two Vantage Points
Indoor air quality is an emerging issue which is still in the
early stages of problem identification. As a consequence, Federal Agencies
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have not formed firm policy decisions, nor have they clearly identified
all of the issues that are involved. One job of the research community
is to provide the information needed to answer the questions asked by policy
makers, however it is also the job of research to help identify the questions
that need to be asked. For indoor air quality both roles are important.
In trying to identify these information needs, we need to look
not only at the physical nature of the Indoor Air Quality problems but also
the institutional context in which institutions will use this information.
Although major emphasis should be placed on the physical nature of the problem,
the institutional context in which issues are resolved and problems solved
cannot be ignored.
Physical Nature of the Indoor Air Quality Problems
Two examples show how the physical nature of the problem can drasti-
cally affect policy decisions. Let us look at two pollutants, radon and carbon
monoxide. Radon is a naturally occurring noble gas. It is generated by
'the decay of radium, an element commonly found in small amounts throughout
the earth crust. When radon is generated it easily moves through soil and
building materials, and becomes part of the gas mixture that makes up the
breathable air of a structure. Once there, it decays into a series of sticky
metal particulates which if inhaled will lodge in the lungs. These particulates
serve as internal alpha emitters and can therefore, result in an increased
occurrence of lung cancer. Lung cancer from radon is not an insignificant
problem; for after smoking, radon and its progeny are probably the single
most important contributing factor to this disease.
Contrast radon with CO, another indoor pollutant. Indoor CO problems
are primarily a product of fixed combustion sources found within the home.
Adequately venting these sources can make controlling CO a stamped and straight
forward problem to deal with. I think it should be apparent that the policy
issues surrounding the management of radon would be significantly different
from these for "tO; and that difference lies is the differences in the physical
natures of the pollutants.
Three variables affect the concentration of indoor air pollutants
in a structure. These variables are: source term, ventilation rate, and
extinction rate.
'How we choose to manage Indoor Air Quality depends greatly upon
which variable becomes dominant for a given pollutant. If the source term
is a dominant element, then sources become the target for management. Since
a wide variety of pollutants come from a wide variety of sources, a wide
variety of different mediating measures may be required if we are to deal
with the general problem of indoor air quality.
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If, however, the ventilation rate is the dominant factor, then
one may be able to deal with indoor air pollutants simply by controlling
the air exchange rates. If this is achieved with the aid of an air-to-air
heat exchanger, the energy penalty can be minimized.
If neither source nor ventilation rate is dominant, we may find
that'many pollutants can best be addressed by a device that will accelerate
the extinction rate. For example, it may be possible to address a whole
series of particulates, with an electrostatic precipitator or another type
of filtering device. We may find, however, that a device that accelerates
the extinction rate allows us to deal with classes of pollutants in some
cases but only individual substances in others.
Depending upon which factor dominates a given pollutant, the
nature of the programs and policies needed for its management will be quite
different. Thus, it becomes very important to determine all three character-
istics for any given pollutant.
At this point, I should raise the question: Is indoor air quality
a generic problem or simply a series of related but individual problems?
Agencies will find this question difficult to address. From a bureaucratic
standpoint, it would be helpful to deal with pollutants as a group, instead
of having to deal with a complicated decision process for each individual
pollutant. This may be easier and a simpler way to approach the problem
but if it does not reflect the physical reality of indoor air pollution,
then it is an approach bound to fail.
Institutional Context of the Indoor Air Quality Problem
The research needs for indoor air pollution must also be addressed
from the institutional context of the Agencies which will be responsible for
managing the problem. The major components to an Agency's institutional
context are its^egal mandate, its internal policies and procedures, its
budget, and the general political climate in which it must operate. EPA
is primarily a regulatory Agency. We do, however, seek nonregulatory solu-
tions to environment problems when we feel it is constant with our legal
responsibilities and in the public interest. This is how we are approaching
the questions of indoor air quality. EPA does not have, nor do we have plans
for, a regulatory program for indoor air quality. The Agency feels more
information is necessary before EPA can decide whether either regulatory of
nonregulatory action is called for. We are currently actively engaged in a
research effort to provide us with this information.
One of the activities we are engaged in is a review of our current
authorities with respect to Indoor Air Quality.
EPA's present authorities include the following:
• The Federal Insecticide, Fungicide and Rodenticide Act,
which includes labeling and restricting the use of many
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pesticides that could be characterized as indoor air
pollutants.
§ Drinking water standards which could control radon
levels in drinking water. Radon in drinking water can
represent a significant source of radon within struc-
tures.
• The Resource Conservation and Recovery Act which
controls the use of building materials made from
recovered or recycled wastes, and which could address
the radon problem as it relates to the use of phosphate
slag, zircon sands, and other materials that are
manufactured from waste high in radium.
t The Uranium Mill Tailings Radiation Control Act, which allows
EPA to write standards for the cleanup of lands contaminated
from uranium mill tailings.
• The Federal Radiation Guidance Authority, an advisory
activitiy that allows EPA to draft orders which, when
signed by the president, regulates activities of other
Federal Agencies.
• The National Environment Policy Act, which gives EPA the
authority to review Environmental Impact Statements and
major policy and regulatory activities of other agencies.
The Clean Air Act, which gives EPA authority to regulate ambient
air, was omitted because "ambient" air has been defined by EPA as outside
air. However, the Government Accounting Office report on indoor air quality
has suggested tljat the Clean Air Act be changed to give EPA greater flexibility
or responsibility in indoor air quality.
Although EPA does have some regulatory authorities, the Agency will
show great caution in approaching this problem in a regulatory manner. To make
a determination that a regulation is needed is an expensive and time-consuming
exercise. It generally requires the development of exposure assessment and an
assessment of health risk including estimate of the risk to the maximally
exposed individual, risk to the population exposed, and an estimate of the
total number of health effects involved. Also needed is an assessment of the
potential for abatement of the costs and the impacts associated with institut-
ing controls and, of course, a careful delineation and analysis of alternatives.
This may require up to 3 years of study and a cost of a million dollars before
EPA decides it should take action.
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Procedurally, before we can establish a regulation, EPA must
prepare a development plan and an advance notice of proposed rulemaking,
and these must be reviewed by a work group and a steering committee and
approved by the Administration. Once the development plan is prepared,
development can begin on the proposed rule. The proposed rule, again,
must .tie reviewed by a work group, then be approved by a steering committee
and a red border review process. It must then be signed by the administra-
tor. A period of public comment and, possibly, a peer review by the Science
Advisory Board may follow. After the public review, we revise the rule as
necessary and start all over again. Work Group, Steering Committee, Red
Border, etc. To initiate such an effort cannot be taken lightly, particularly
if no regulatory approaches can be instituted more quickly and effectively.
Competing priorities, budget and staff, political climate, public
attitude, and legal mandates all contribute to defining the institutional
context of an issue. It is this context that must be kept in mind as the
research program for indoor air quality is formulated and executed.
Let me add one final observation, on the status of Indoor Air
Quality. Indoor Air Quality is clearly recognized as an established issue
by many Federal and state governmental institutions. However, I think it
is fair to say, that these same institutions do not yet recognize indoor
air quality as a major problem. The distinction between a problem and a
issue is that issues are political entities that must be resolve but
problems are physical entities and should be solved. I do not see that
decision makers are willing to accept at this time that Indoor Air Quality
imposes a clear and present danger for enough people or from enough pollutants
to make Indoor Air Quality a problem that can compete successfully with other
priorities. Consequently, a primary short term goal of indoor air quality
research should be the identification and characterization of major pollutants
in the indoor air. Not until a more thorough and adequate assessment of
indoor air pollution risks is executed can decision makers be expected to
accept these pollutants as problems that require significant actions. For
this reason, we need a clear statement coming from our research effort which
establishes the extent to which the risks are real and identifies the possible
remedial measures that can be taken to reduce such risk. These are the ques-
tions that the research community must answer, and must answer quickly.
Mr. Howard Ross, Department of Energy:
Department of Energy Policy
DOE currently bases its policy on its Indoor Air Quality research
conducted over the last 5 years, totaling more than 6 million dollars. Five
main points emerge from that research:
1. Technology exists today to build a cost-effective air-
tight home with a winter air exchange rate of two-tenths
of an air change per hour, or less.
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2. Technology does not exist today to cost-effectively retro-
fit existing homes to reach the same levels of air exchange.
Typically, retrofitting reduces air infiltration rates by
10 to 20 percent--in some cases 25 percent.
3. New homes are the principal concern regarding indoor air
problems. They are much tighter with much newer furnishings
and building materials off gassing more pollutants. Similarly,
new commercial buildings with lower ventilation and infiltration
rates are of greater concern than existing commercial buildings.
4. Selection of a standard ventilation rate will not guarantee
lower indoor air pollution levels. Determining a building's
ventilation rate is not a reasonable surrogate for measure-
ment of the indoor air pollution levels.
5. The general solutions to the indoor air quality problem
will be source control--either removal or reduction—or
ventilation very near the source.
A Context for Remedial Indoor Air Pollution Control Actions
Infiltration by definition is when outdoor air leaks unintentionally
through imperfections in the shell of a closed building. Intentionally
opening a window or door provides natural ventilation. A window fan or an
air-to-air heat exchanger provides mechanical ventiTation. Each has different
implications for building design.
Reducing the infiltration rates in existing homes is a difficult
problem. Windows and doors are only 20 percent of the problem; most of the
problems are hidden from the homeowner's view, and thus left unattended.
Yet DOE research has found many sites of air leakage. In most homes, a person
can sweep back the insulation in the attic and find large holes in the attic
floor which leak air. Or, a light fixture can be pulled off to find a large hole
which just a few wires pass through. Hundreds of other imperfections can be
found in residential buildings. Homeowners simply cannot plug all of them.
One well known study shows that the average reduction in the infiltra-
tion rate by retrofit was 15 percent until^diagnostic instrumentation was used
to determine the leaks. An infrared thermographic camera used by energy audit-
ing firms costs $7,500, and it can locate hot and cold spots in the building,
otherwise invisible to the homeowner.
For existing homes, DOE recommends immediate remedial indoor air
pollution control action in three kinds of situations:
1. For a home in an anomalous geographical area (e.g., a home
built on uranium mill tailings or phosphate-reclaimed land)
DOE recommends remedial action whenever caulking or weather-
stripping is done.
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2. If the house has poor design features such as an unvented
gas stove or heater, remedial measures are necessary.
3. For those persons who have used instrumentation to find an
air leak and then reduced the infiltration rates by a
large amount, say 50 percent, remedial actions should be
considered.
For the remaining homes not in these categories, DOE informs the
homeowner of possible remedial actions but does not suggest that there
necessarily is a need in all cases to spend $300 or more for an air-to-air heat
exchanger or to buy an electrostatic precipitator. DOE cannot tell homeowners
that spending this money on remedial actions is worthwhile and required to
reduce serious health risks, for most homes do not have a grave indoor air
problem. At this stage, DOE has decided that we have a duty to tell the public
•what we know about the subject. Unfortunately, what we know does not always
permit straightforward, sound recommendations about what to buy, or if a
particular home has a problem.
DOE encourages reducing the infiltration rate in all homes, but
concurrently recommends remedial actions in those situations listed above.
The results are increased comfort, increased structural integrity, reduced
moisture condensation in the walls, and fuel bills are reduced. When outdoor
pollution sources dominate, there is an indoor air quality benefit. In addition,
conservative calculations show that a 25 percent reduction in air infiltration
saves 10 to 15 million kilowatts of reduced peak power, or 10 to 15 new
power plants probably nuclear or coal-powered, can be avoided.
Undoubtedly, people are aware of these benefits. A survey of 6,000
homes indicates that 41 percent of the people between April 1977 and December
1978 caulked, weatherstripped, or placed plastic over their windows. On
Federal income tax forms, 1-1/2 million homeowners claimed that they bought
caulking and weatherstripping. About 3 million more claimed storm windows.
The indoor air quality problem with existing homes differs from the
problem with new homes. Today's builders have responded to the energy crisis
(i.e., the market) by constructing tighter new homes. Yet, these new buildings
are of more serious concern for possible indoor air pollution, due not only to
these very low infiltration rates but to higher pollution source strength (new
materials). For new residences, air-to-air heat exchangers are frequently
touted as a panacea. An air-to-air heat exchanger fits in a window, is the
size of a window air conditioner, costs $250 to $300, and recovers 50 to
80 perc'ent of the heat In air which is being exhausted. Unfortunately, its
durability and effectiveness under freezing conditions are not yet completely
proven. DOE will continue to research its usage and promote its installation.
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Governmental Action
The Government can regulate a number of factors that would affect
indoor air quality. Infiltration rates, ventilation rates, indoor air
pollution levels, material emission rates, and no smoking areas can all be
legislated. Yet each would present a problem. For example, consider for-
maldehyde levels in a home. A recent study showed that when a home was
unoccupied and without furniture, it was below the current Danish standard for
indoor formaldehyde levels. When occupants moved in, the levels rose well
above the standard. At night, when windows were open, formaldehyde levels
dropped to just above the standard. Is the furniture or plywood manufacturer,
the builder, the landlord, or the occupant at fault?
There is little hope or desire for regulating numerical standards for
indoor air pollution levels. Therefore, DOE has opted to give information, and
in certain cases, to recommend remedial action. DOE will recommend a long
list of specific actions in a brochure that will be published soon. The
consumer-oriented brochure tells homeowners both how to tighten their build-
ings and how to solve most indoor air pollution concerns.
DOE would like to recommend that homeowners have a measurement of
radon and other pollutants taken in their homes. Yet, what should be said to
a homeowner who finds 5 nanocuries per cubic meter of radon? No national
health guidelines are in existence. Nor is there a guideline to suggest when
remedial action is necessary.
DOE's Needs
DOE would like to see standards set by industry for infiltration in
buildings. Airtight buildings can then be mechanically ventilated, which is a
more energy-efficient way to provide ventilation and improve pollution control.
Next, ODE needs guidelines for indoor air pollution levels, and
larger scale surveys of indoor air pollution levels. We may need to start some
sort of massive information program if indoor air pollution is a widespread
problem. In Sweden, where it is, I am told their radon problem is discussed
on television.
DOE's Legislated Programs Relating to Indoor Air Quality
At present, DOE has five such programs, as follows:
1. The Residential Conservation Service* requires that utility
companies offer all homeowners an onsite energy audit at a cost
of $10 to $15. In addition, the utilities must give homeowners
an estimate of the savings that will be realized with different
retrofit measures including caulking, weatherstripping, and
insulation.
* The new administration has proposed cancellation of these regulation programs,
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2. The energy tax credit which offers tax credits for insulation,
caulking, and weatherstripping.
3. The proposed Building Energy Performance Standards* apply to all
new buildings, establishing a maximum energy budget for those
buildings.
4. The Low-Income Weatherization Grant Program retrofits about
30,000 homes with insulation, caulking, and weatherstripping.
5. The School and Hospital Grant Program provides for the Federal
Government to pay for half the material and insulation costs of
retrofitting existing schools and hospitals.
.In addition, enabling legislation which formed DOE (and formally ERDA) allows
•research and development to be conducted in this field.
Dr. Irwin H. Billick, U.S. Department of Housing and Urban Development;
Concerns of the Department of Housing and Urban Development
What is the concern of the Department of Housing and Urban Development
the quality of the indoor residential environment?
The concern arises from the national housing policy outlined in the
Housing Act of 1949. This act declared that the general welfare and security
of the Nation and the health and living standards of its people require housing
production and related community development. Congress then stated that a
decent home and a suitable living environment is the goal for every American
family. However, HUD's jurisdiction over the housing of this country is
limited to thoseprograms that it supports either through insurance or through
direct subsidies.
Indoor air quality obviously has not been the most important issue
that HUD has pursued. Little thought was given by policymakers to indoor
pollution arising from combustion products that come from fossil fuels, solvents
that are used in household products, outgassing of chemicals from building
materials, and other possible suspected carcinogens, mutagens, allergens, and
other substances found in the indoor residential environment.
HUD, like most Agencies, is responsive to the immediate concerns
of the country. For example, after the oil embargo of 1973, Government
Agencies, builders and homeowners viewed thermal energy conservation as a
means of combatting the rapidly rising costs of heating and cooking fuel.
This led to structured and unstructured efforts to insulate housing and to
decrease ventilation rates.
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HUD provided monetary incentive for energy conservation through
the HUD Minimum Property Standards, which mandated energy conservation measures
as conditions for participating in HUD programs. At the same time, we learned
that unacceptably high concentrations of pollutants such as radon and its
progeny can exist in housing where air exchange rates were too low.
In response to this knowledge, HUD jointly sponsored with EPA the
study of indoor air quality in the residential environment. HUD also is
sponsoring several studies related to formaldehyde in mobile homes. These
studies will be used to support Departmental standards and policies.
Currently, HUD has a cooperative agreement with the State of Montana
to develop and evaluate methods for mitigating radiation hazards from radon
infiltration. The Department has also published an advance notice of rulemak-
ing related to setting air infiltration rates to be used in minimum property
standards.
With one of the smallest research budgets and staff among the
Federal Agencies, HUD must rely largely on the research of other Agencies
for guidance in setting health related standards and guidelines. HUD's
policymakers will ask for firmer evidence to support the decisions that
affect indoor air quality. The scientific work used to support health effects,
pollutant levels, and social and physical costs must be scientifically valid
before research can be translated into a regulatory action, since such actions
could severely impact both the cost and supply of housing.
HUD has a genuine desire to see that its programs do not inadvertantly
create unhealthy or unsafe indoor climates through the unwise location, design
of housing, or the use of certain materials in its construction. We also have
a great desire to protect the health and welfare of our constituents.
For this reason, HUD is depending on this workshop to assist in defining
an interagency research agenda which will lead to the scientific information
required to accomplishing its goals in the area of minimizing the effects
of indoor air pollution.
Dr. Peter Preuss, Consumer Product Safety Commission:
Concerns of the Consumer Product Safety Commission
•1. The decisionmakers in the Agency are five Commissioners
appointed by the President. These Commissioners need to
know if a problem exists with indoor air quality which
necessitates expenditure of significant Commission resources.
CPSC needs to know the degree to which the problem associated
with indoor air quality is a general problem rather than
one that is associated with specific consumer products or
chemicals. Of greatest import is the need for a method
for deciding which aspects of this problem require atten-
tion first rather than last.
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2. We also need to clarify how the statutory responsibilities
are divided among Federal Agencies. A fair division seems
to exist between statutory responsibilities and authorities.
Overlaps also exist. These must be clarified.
3. Finally, we need to resolve which Agencies are in fact
going to be working on indoor air quality. Are these
Agencies likely to cover the issues that concern CPSC?
If so, perhaps there is a lesser need for CPSC to become
involved. It is possible, however, that there are parts
of the problem in which other Agencies have no interest
or for which they lack statutory authority and which will
fall on the shoulders of the CPSC.
At present in CPSC, one of the most important statutes applicable
to indoor air quality is the Consumer Product Safety Act. This act allows
•CPSC to take action when a finding is made of unreasonable risk to health
or safety. It provides a variety of regulatory options; e.g., labeling,
setting a standard, or banning a specific product. In order to deal with
the numerous products in its purview, CPSC has divided the Agency programs
into a number of major hazard programs, two of which are involved to a sig-
nificant degree with the question of indoor air quality. One relates
to household structures, the other relates to the other sources of chemical
hazards that may affect health. These two programs converge for tighter
homes in which there may be increased levels of pollutants and household
structures or materials themselves may emit a harmful substance.
We have divided the pollutants into two groups. The classical
pollutants include nitrogen oxides, sulfur dioxide, and carbon monoxide,
and a number of other products of combustion. The nonclassical include
other chemicals (organic, particulates, etc.) generated by aerosols,
deodorizers, cleansing products, and other consumer products that may
introduce an unsafe level of pollution inside the home.
For example, many of you are familiar with the argument before the
Supreme Court concerning the standard in which OSHA proposed to reduce the level
of benzene in the workplace from 10 parts per million to 1 part per million.
While that discussion was taking place, CPSC examined the levels of benzene that
occur from the use of consumer products. Some time ago, CPSC proposed a regula-
tion to eleminate the intentional addition of benzene to consumer products and
to limit the contaminant level of benzene to 1/10 of 1 percent. That regulation
was never promulgated, but today, no intentional benzene is added to consumer
products. It does, however, remain as a contaminant, and laboratory work and
modeling have been performed to determine the levels of benzene that still can
be reached in homes. At very low air exchange rates, over a 50-hour time-
weighted average, we measured and modeled levels of benzene that were signif-
icantly higher than 100 parts per million when benzene was present in a product
at about 2 percent. Even when a product contained a tenth of a percent signifi-
cant levels of benzene were measured.
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Research Needs
CPSC has recommended an air pollution program in 1982. Before
that program comes into effect, we need the following information:
• The levels of pollutants that are likely to be found in
homes, particularly nonclassical pollutants
• The long term health effects of low levels of these
pollutants
• The additive or synergistic health effects that could
arise from the presence of two or more combined
pollutants.
We also need a mechanism to integrate hazard and exposure
information to help us determine study and regulatory priorities. It is
easy to discuss research that can provide solutions in 5 to 10 years,
but we need to determine which problems should be dealt with immediately.
Finally, it is extremely important in matters of policy to make
sure that the Government Agencies are preparing a coherent research plan.
This plan should be coordinated with the academic community, the industrial
community, and with other parts of Government.
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Section 3.0
TECHNICAL GROUP REPORTS
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WORKSHOP ON INDOOR AIR QUALITY
MONITORING SESSION
Dr. Lance Wallace, Chairman
U.S. Environmental Protection Agency
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MONITORING INDOOR AIR QUALITY
The monitoring section is organized according to six categories:
t Aerosols (including fibers)
«
• Organics (including pesticides, PCBs, nitrosamines, and
odors)
t Criteria Gases (plus C02)
t Radon
• Formaldehyde
• Statistics and Modeling.
Within each category, a brief introduction and discussion of measure-
ment methods precedes the summary of the research needs. Details of the recom-
mended research projects are listed in Appendix B.
A more detailed discussion of measurement methodologies (porous
polymer adsorbents for organic vapors) is included as Appendix C.
In the final plenary meeting of the monitoring session, the
combined groups identified four unifying themes:
1. The total exposure concept. A person's health can be
affected by indoor, outdoor and in-vehicle exposure.
The total exposure concept (i.e., 24-hour exposure)
must be an integral part of all monitoring efforts if
qnly to determine the relative contribution of the
indoor air to that exposure. Another important consid-
eration are the multimedia effects of water and food
and the correlation of these data with body burden data
(e.g., breath, blood, and urine levels).
2. Coordination. The complexity of the indoor air quality
problem requires interagency cooperation; cooperation
among health, monitoring, and instrumentation people;
and interactions with industry, architects, builders
and engineers, and Government.
3. Careful planning of field monitoring. Many examples
exist of inadequately planned field studies that
neglected to record the one item of information that
latter was found to be necessary. Thus, there is a
need to design monitoring studies that make precise
statements about the objectives, protocols, data
requirements, and interrelationships with other efforts
planned or in progress in the public and private sector.
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The "sick building" concept. Many panel members felt that
there is a new and very real-problem emerging in indoor
air studies: buildings, including very large ones, in which
considerable proportions of their inhabitants are affected
adversely. Such buildings associated with outbreaks of
disease or complaints present an opportunity to study a
condition that affords a high probability of source identi-
fication, provided a thorough study can be launched.
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AEROSOLS
INTRODUCTION
Instances of serious health effects from Indoor air pollution have
bee/v reported nationwide. Public hearings 1n California have shown that
these effects not only lead to morbidity, but also to significant economic
losses to the victims. Aerosols are an Important component of Indoor air
pollution, particularly those in the respirable size range, due to their
persistence in the human lung for periods which may be as long as several
months. Further, combustion-produced aerosols may contain large numbers
of harmful organic substances. When ventilation is insufficient to control
the indoor aerosol to levels that approximate clean outdoor air, indoor air
pollution results.
Recent studies indicate that personal and indoor exposure to respir-
able particles (RSP) is greater than outdoor exposure. A number of instances
have been reported around the country in which office buildings have been
polluted to the point where they have become virtually uninhabitable, frequently
in new, so-called energy efficient buildings which have been designed for
substantially reduced ventilation. Typical indoor sources of aerosol, such
as cooking, smoking, coughing, sneezing, flushing of toilets, flaking of
asbestos building materials, vacuuming, office reproduction equipment, microbes,
spores, and molds, and indoor traffic, will rise to higher concentrations and
become more persistent with reduced ventilation. Indoor exposures to such
agents need to be characterized chemically, physically, biologically, temporally,
and spatially.
Particles
Monitoring programs for particles should have two main objectives:
1. /'Determine population exposure to particles
2. Define source contributions to individual and population
exposures.
Knowledge gained in these two areas will:
1. Identify high-risk subpopulations
2. Define effective control strategies
3. Identify specific compounds for toxicologic or epidemi-
ologic testing
4. Determine how well (or poorly) ambient outdoor levels compare
with indoor or personal exposures.
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Four basic types of monitoring studies are recommended:
1. Chamber studies to Identify source strengths, composition, and
decay rates
2. Case studies to determine spatial and temporal patterns within
buildings as functions of activities, sources, and ventilation
and air cleaning systems
3. Large scale surveys to define the distribution of sources and
concentrations 1n a variety of indoor locations
4. Personal exposure studies to verify contributions from specific
sources.
Certain supporting efforts must be mounted concurrently:
1. Development of Instrumentation. In particular, increased sensi-
tivity for shorter sampling times is desirable. This can be
obtained either by increasing airflow (without increasing the
size or noisiness of the pump) or by increasing the sensitivity
of the analytical procedure. Another possibility is the use
of one instrument (such as the Piezobalance or GCA Resplrable
Aerosol Monitor) to measure mass nearly instantaneously, and
a second Instrument to collect the particles for chemical
analysis.
2. Time-motion studies of populations. This is required both to
plan monitoring efforts and to interpret and extrapolate
their results to the population at large.
3. Models of particle behavior. Included here are indoor-outdoor
models, as well as models of the transport, growth, decay,
^and deposition of particles.
4. Models of personal exposure. These models could combine the
results of monitoring, physical models of particle behavior,
and "sociological" time-motion studies to estimate total
exposure.
5. Inducements for volunteers. Participation from all socio-
economic classes is required to make these studies repre-
sentative of the population exposure. To date, participation
has been limited to narrow socioeconomic and occupational
ranges.
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ORGANICS, NITROSAMINES, PESTICIDES AND ODORS
, r
INTRODUCTION
Organic compounds 1n Indoor air are numerous, not well understood,
anrf could contribute strongly to effects on health and well-being. Major
sources include heating and cooking, pesticide use, and common products in
homes, offices, and vehicles.
The group considered four major classes:
1. Volatile organics. These low molecular weight compounds
Include many of the most important carcinogens such as
benzene, trichloroethylene and tetrachloroethylene. Major
sources include the automobile, dry cleaning, painting
and refinishing.
2. Pesticides and PCBs. These semivolatile organics are used
extensively in homes and yards. A major source of PCBs
may be burned-out ballasts from fluorescent lights.
3. Nitrosamines and Hydrazine. Major sources of these compounds
include cooking, washing, rubber products, tobacco smoking,
and auto exhaust.
4. Odors. These may serve as indicators of previously undetected
pollution sources, such as abandoned waste sites.
Volatile Organics
It was generally felt that the use of Tenax GC procedures involves
considerable experimental uncertainties. These are addressed in the section
on "State of the Art in Organic Vapor Monitoring."
The following specific monitoring efforts were suggested:
1. Extensive investigation of episodic emissons from household
appliances and activities, such as woodburning stoves,
fireplaces and spaceheaters, cooking, home repair such as
painting, varnishing, refinishing furniture, waxing, or
cleaning.
2. Complete exposure assessment correlating breath analysis and
possibly blood levels with ambient air concentrations.
3. Analysis of phthalates and phthalate acid esters from
automobile interiors. This is conditional on demonstration
that these compounds are collectable and desorbable from
Tenax GC.
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4. Complete characterization study of Tenax GC including
sampling, desorption, analysis, and characterization of
compounds' collection and desorption efficiencies.
5. Characterization and source identifcation of organic materials
in office buildings. Many complaints concerning air quality in
new office buildings are being received and this needs immediate
attention.
6. Headspace analysis of construction and building materials.
The purpose of this study would be to isolate sources of
specific contaminants and thus provide focal points for
control measures.
Pesticides
The methodology for study of semivolatile organics has progressed
from the ethylene glycol method to polyurethane foam collectors followed by
"GC/MS analysis. Desirable improvements include automation of the sample elution
and analysis to increase throughput. A personal sampling method is needed;
present equipment is too bulky and cumbersome. Analytical procedures need to
be developed for synthetic pyrothenes and carbamates. Finally, a method
is needed which will allow for separation of airborne pesticides and organics
from those entrained on particles. No satisfactory method exists for this
purpose.
Some of the specific monitoring efforts suggested include:
1. A study of PCB sources and the spatial pattern of PCB concen-
trations in homes. Evidence to date suggests that PCB levels
are higher in the kitchen than in other parts of the house.
2. A monitoring study to determine the extent of continuation
resulting from home pesticide use. A large-scale (10,000
homes) survey of home pesticides use will be conducted in the
very near future, and modification of the protocol would allow
a monitoring component to be added to the study. Body burden
should also be a component of this study.
Odors
Odor is probably the most common and best early warning signal
of potential problems stemming from polluted water, leakage from chemical
waste disposal sites into the home or other previously unrecognized sources
of air contamination. Fortunately, the state of the art in odor measurement
using trained human panels is fairly well developed. Unfortunately, this
technology is only slowly gaining acceptance by the regulatory Agencies,
notably in Texas. The most obvious odor problems stem from outside sources
such as rendering plants, feed lots, and a variety of other industrial opera-
tions. Other sources of odors which may lead to health problems or be indicative
of health problems are building materials (formaldehyde, water-based paints,
28
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etc.), consumer products, dead animals, transformer burnouts, Ink and paper
products, smoking, etc.
Specific monitoring efforts suggested Include:
,•
1. Determination of the impact of outdoor odors on Indoor
environments. This could be in the form of a survey
of regulatory Agency complaints followed up by specific
monitoring efforts.
2. Establishment of a protocol for classifying and handling
odor complaints. Not all odor complaints are nuisance
complaints; some may be real hazards, such as odors
associated with hazardous waste disposal (e.g., Love Canal).
Nitrosamines
The primary collection method Involves a specially designed collector
which traps nitrosamines from an air stream chemically, but allows NCL to
pass through, thereby lessening the opportunities for In situ formation of
nitrosamines from reaction of NCL and amine-containing compounds. The
collector can be used for practically any length of time with the shortest
time dictated by the sensitivity of the analysis system.
Elution of collected samples is accomplished by passing 1 ml of
solvent through the collector into a standard septum vial. This vial can
then be used in standard carousel auto Injectors. This greatly speeds
the analysis and allows for high productivity. The analysis can be performed
by GC, GC/MS, or TEA analyzers. The TEA is probably preferred as it is
specially designed for nitrosamine analyses.
Nitrosamines exist as contaminants 1n certain products found 1n the
home, namely, rubberized materials such as Indoor/outdoor carpeting and
upholstery. Automobiles also contain a large number of materials contaminated
with nitrosamines.
Nitrosamines are also present in ambient air as a result of activities
in which situations exist that promote their formation. These situations include
cooking-with gas appliances and passive and active smoking of tobacco.
Research Needs
1. A thorough Investigation of nitrosamine formation during
cooking and Investigation of possible methods of control.
Specifically, what are the differential concentrations
of nitrosamines In kitchen air as a result of:
- Cooking with gas stoves versus electric ranges
• Cooking meats and other greasy foods
29
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- Using vented versus unvented appliances
- Using various types of filters that may control
nitrosamines, especially the residence time in the
indoor environment
2. Investigate the concentration of nitrosamines in public
smoking versus nonsmoking areas
3. Determine the source of nitrosamines and to what extent
these sources impact on overall air quality in homes,
offices, etc. What effect does ventilation have on the
concentration of nitrosamines? Decay rates?
4. Extent of exposure in automobiles and other modes of
transportation.
One further monitoring effort was suggested which would involve
monitoring the levels of exposure of individuals by personal monitoring for
nitrosamines and other m'tro-organic compounds, including hydrazine. Hydra-
zine has not been studied extensively and the extent to which this carcinogen
exists in ambient air has not been characterized. A monitoring study on
hydrazine seems warranted.
30
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RADON
INTRODUCTION
One of the most important indoor pollutants is radon, a naturally-
occurVing radioactive element, and its progeny (the products of radio-
active decay). The risks of given large exposures are better known for these
substances than for any other indoor pollutant, and therefore monitoring
programs to determine the extent of population exposure will simultaneously
determine the overall risk associated with radon.
There is a need to establish quality assurance procedures and instru-
ment evaluation and validation in the monitoring of radon and its progeny.
Efforts in these areas have begun but need to be established on a
formal basis. Existing instrumentation is not optimal. There is a particular
need for inexpensive passive radon progeny and working level measuring devices
and for less expensive real time working level and progeny monitors.
Substantial research efforts are needed in four areas. Studies of
indoor radon and radon progeny concentrations should be undertaken to under-
stand their dynamic behavior in buildings and to determine the range and
distribution of radon and/or its progeny in the Nation's building stock.
Before proceeding with a large scale survey, it is necessary to evaluate the
usefulness of various passive techniques for characterizing the concentrations
of radon and/or radon progeny in residences, and to assess the viability of
short-term measurements to represent annual averages. Finally, it is necessary
to characterize radon sources and ground transport in order to provide predic-
tive capabilities for indoor concentrations of radon/radon progeny.
Although there is an urgent need to assess the seriousness
of radon/radon progeny problems indoors and survey the existing housing
stock, it is important to proceed carefully to collect data which will be
useful in and adequate for making these assessments. In order to assess
the impact of programs such as energy conservation retrofits, information
on parameters such as air exchange rate may be required. To proceed with
these studies requires three levels of research: (1) detailed studies need
to be performed in a laboratory or research-house environment in order to
characterize radon behavior and establish measurement protocols, (2) these
must be validated in moderate-sized field sampling programs before surveys
on a national scale are performed, and (3) attempts should be made to
coordinate large-scale radon surveys with other large-scale surveys such
as energy conservation audits or other indoor air quality studies.
• Research Needs
1. Study the behavior of radon and radon progeny indoors.
Intensive studies in a few research houses will serve as
a basis for designing and interpreting field studies
31
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and surveys. These houses will be instrumented to study
continuously radon and radon progeny concentrations,
infiltration/ventilation rates, radon progeny and particu-
late interactions and size distributions, removal processes,
the effects of temperature, humidity, and particulate levels,
and the effects of HVAC system operation and various control
strategies. Existing instrumentation except, perhaps, in
progeny/particle interaction work, is sufficient for these
studies. The estimated time required is 3 years at $300K
per year.
2. Evaluate passive monitoring techniques. Before proceeding with
large-scale surveys it is necessary to evaluate the usefulness
of various passive techniques for characterizing the concen-
trations of radon and radon progeny in residences. The
purpose of this study is to assess the viability of surrogate
(short-term) measurements to estimate annual average concentra-
tons and indoor exposures. Current studies in places, such as
Butte, Montana, where many detailed measurements are being
made over a 1-year period, can serve as a starting point
for this study. Other studies are needed on a progressively
larger scale. Parameters to be measured include radon and
radon-progeny concentrations on a real-time and integrated
basis, infiltration/ventilation rates, and radon flux from
the soil. These parameters will be monitored for a period
of 1 year to determine the feasibility of and to establish
protocols for shorter term integrated monitoring. This
project is estimated to last 3 years at $250K per year.
3. Designing and implementing a national radon survey.
In this survey a sufficient number of homes in the United
States would be monitored, with adequate sample stratifica-
Jtion, to project the extent of the U.S. indoor exposure to
radon and radon progeny. Existing passive monitors for
radon are currently being evaluated, but passive working
level monitors are needed if working level measurements
are deemed necessary. The recommended survey will aid
in making program decisions and in determining the need
for guidelines and standards. It is estimated that a
survey of this scope would take 2 to 3 years at a total
cost of $1M.
4. Studies of radon sources and ground transport. This research
would provide predictive capabilities for indoor radon and
radon progeny concentrations. By determining the relevant
parameters that contribute to high indoor concentrations in
residences and by understanding the mechanisms through which
radon enters the building spaces, builders could possibly
eliminate the construction of houses with elevated indoor
32
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radon levels. Parameters to be measured include radium
content in soil, radon concentrations in soil gas, radon
diffusion lengths, and the effects of groundwater and
moisture, atmospheric pressure, and temperature. It is
necessary to determine the temporal variations in these
parameters. In addition, the feasibility of making a
large-scale grid survey of radon concentrations over the
continental United States to determine the variations and
identify regional hot spots will be assessed. These
studies are estimated to last 3 to 4 years at $250K per
year.
33
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FORMALDEHYDE
INTRODUCTION
Although formaldehyde is part of the overall air quality (and organics)
issue; it must be recognized that it is a very special pollutant by comparison
with other pollutants because of its high chemical reactivity. Also, due to
the high level of public interest, formaldehyde warrants individual attention.
Monitoring of formaldehyde is extremely difficult because of the influence
of temperature, humidity, and history upon its emission. Refinement is needed
in both sampling methodology and analytical methods in the long term. There is
an urgent need for immediate measurements to determine the extent of the
formaldehyde problem. The monitoring program will depend on the detection
level required, that is, for irritation or for carcinogenic effects.
Measurement Methods—Capabilities and Needs
• Sufficient capability exists for industrial hygiene
monitoring but not for ambient indoor air monitoring.
• The NIOSH measurement limit is 0.5 ppm but much lower
levels can be detected with new devices; a 0.03 ppm low
level limit would be sufficient to satisfy all concerns.
• Investigators currently doing work in formaldehyde
monitoring should convene to compare equipment perfor-
mance and coordinate present and future activities.
a There is no standard source of formaldehyde, which makes
calibration and comparison difficult. (The particle-
board industry does have round-robin testing underway
for several products.)
>'.
Research Needs
1. Establishment of a measurement protocol for air monitoring.
Measurement simultaneously of other pollutants which create
similar symptoms is a necessary ingredient in this proposal.
Also, round-robin calibration should be incorporated.
2. Development of a low cost, short time (8 hour), inexpensive
dosimeter that can be used to begin to establish a data base
on a broad scale.
3. Development of continuous, real time instrumentation should
be continued.
4. Investigation of biological methods as a means of increasing
the sensitivity of formaldehyde measurement.
34
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CRITERIA GASES (PLUS C02)
INTRODUCTION
Five major pollutants were included in this category. Their import-
ance Velative to indoor air pollution will be discussed singly.
Carbon Monoxide—Since outdoor CO levels in several urban areas
exceed levels at which adverse health effects can occur, IAQ studies to
determine exposure to CO should be a high priority. Indoor exposures are
important because outdoor CO penetrates readily and is added to contributions
from indoor sources such as gas stoves, attached garages, smoking, and unvented
heaters. In-vehicle exposure should be looked at concurrently with IAQ studies
as motor vehicles are the most important source of CO. Work and recreation
exposures may sometimes be important, requiring determination of total human
.exposure to CO in future monitoring studies.
Nitrogen Dioxide—Indoor levels of N02 tend to be dominated by
indoor combustion sources such as unvented gas stoves and fuel-fired heaters.
Much has already been published on this effect. More work is needed in defin-
ing total human exposure in terms of short- and long-term exposures. In
addition, instrumentation should be developed for examining total human exposure
to N0£. Parallel health effects studies would also contribute to an enhanced
understanding of the dynamics of this gas.
Sulfur Dioxide—Except for special circumstancs such as leaky heating
systems, indoor 502 levels do not appear to require special attention. Indoor
S02 and sulfate levels should be surveyed in several nonattainment areas.
Ozone—Indoor concentrations of 03 are usually a small fraction
of those outdoors except in those rare instances where indoor sources (e.g.,
electrostatic pr>§cipitators and copying machines) may produce elevated indoor
levels. Therefore, monitoring programs to further define indoor 03 levels
are of low priority.
Carbon Dioxide—Indoor sources such as human occupancy, gas stoves,
and unvented heaters can add to the preexisting relatively high C02 background.
There is a need for monitoring programs to identify possible critical situations;
for example, modification for energy-saving purposes of older buildings with
inadequate ventilation systems, or use of unvented heaters. Again, parallel
health studies are needed.
- Measurement Methods—Instrumentation for continuously measuring outdoor
levels 'of criteria pollutants is at an advanced state of technological develop-
ment. . However, further work needs to be done in evaluating available instru-
ments for monitoring indoors, especially in view of the potentially large number
of compounds in the indoor atmosphere that could interfere with the response
of these available instruments.
35
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The state-of the art in small portable or personal devices (including
passive monitors) suitable for total human exposure studies is not advanced.
There is a critical need for devices that are capable of measuring both short-
and long-term exposures to a variety of pollutants.
Relationships to Ambient Air Quality Standards
4 «
The relationship to indoor air quality of the outdoor National Ambient
Air Quality Standards (NAAQS) is not clear. Since indoor air quality standards
are not likely in the foreseeable future, the contribution of IAQ monitoring
programs will lie in better defining total human exposure. The results
of such programs could then be evaluated with respect to the NAAQSs as
a means of developing more meaningful total exposure air quality standards.
Types of Monitoring Programs
Seven types of monitoring programs were identified:
1. Source Strength Measurements
2. Indoor/Outdoor Characterization Studies (for various types
of structures, activities, and energy conservation practices)
3. Indoor Episodic Situations (e.g., stove use, furnace leaks,
product usage, etc.)
4. Epidemiologic Studies (e.g., six-cities study)
5. Human Exposure Characterization
6. Chamber Studies (e.g., source impact on exposure of subjects)
7. Comparative Monitoring Programs (determining accuracy, sensi-
tivity, interferences, and response of instrumentation).
RESEARCH NEEDS
Research needs are presented in terms of eight specific projects.
The titles are listed as follows, and a description of each is presented
in Appendix A.
1. Human Exposure to CO
2. Screening Study to Determine Total Human Exposure to NOg
Using Passive Monitors
3. Human Exposure to both Short- and Long-Term Average Concen-
tration of N02 (Instrumentation is not yet available for
this study)
36
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4. Establishment of a Research House or Chamber to Determine
Fate of Emissions from Combustion Appliances
t
5. Assess Impact on IAQ of Alternate Space Heating Systems
(Coal stoves and kerosene heaters)
6. Evaluation and Calibration of Monitoring Instruments for
Application in IAQ Studies
7. Assessing the Importance of C02 Concentrations in Crowded
Rooms with Insufficient Ventilation
8. Development and Evaluation of a Simple Broad Spectrum Sensing
Device for the Rapid Detection of Degraded IAQ from Combustion
Effluents.
37
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STATISTICS AND MODELING
INTRODUCTION
Certain statistical techniques that will be required for indoor
monitoring programs are not well developed. Thus, several of the detailed
research proposals deal with this need. Similarly, existing physical
indoor-outdoor air quality models have not been validated in residences,
and such validation is suggested in other detailed proposals. Other
topics identified were:
t Relationship between monitoring to support health studies and
monitoring to support regulatory needs. Health scientists
and physical scientists should coordinate with one another
in designing monitoring studies.
• Mobility patterns and time budgets as they are needed to
extrapolate exposure measurements to a wider population.
• Exposure models incorporating mobility patterns and
physical models.
• Air filtration rates as they relate to energy conservation
and indoor air quality (particularly the relationship with
indoor source emission strengths).
• Characterization of building design and materials as they
affect indoor air quality.
• Statistical designs for large studies (as opposed to pilot
studies).
>'
t Use of data collected for several purposes.
38
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REPORT OF THE INSTRUMENTATION
SUBGROUP OF INDOOR AIR QUALITY
AUTHORS
Laurence Doemeny
National Institute for Occupational Safety and Health
Walter Zielinski
National Bureau of Standards
Pedro Lilienfeld
GCA/Technology Division
Dale Coulson
SRI, International
Robert Finnigan
Finnigan Corporation
Andreas George
Department of Energy
Wayne Lowder
Department of Energy
Richard Gammage
Oak Ridge National Laboratory
Mary Lynn Woebkenberg
National Institute for Occupational Safety and Health
39
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DISCLAIMER
The contents of this report Include comments received during the workshop
and do not necessarily represent the views of a single author or his/her
employer.
40
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ACKNOWLEDGEMENTS
Attached to the report is a list of participants. The authors thank the many
people at the workshop who provided interesting and provocative input to the
discussions.
41
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Section 1.0
ABSTRACT '
The following seven sections describe an initial attempt to
formulate a research strategy plan to begin the development of a comprehen-
sive program for developing sampling and analytical methods for hazardous
chemical and physical agents which people are exposed to in enclosed
structures like residences, offices, and public buildings. The plan calls
for the development of instrument requirements, quality assurance programs
for analytical laboratories, new and intelligent portable instruments, and
Government regulations or guidelines so that instrument manufacturers
recognize a market.
An inventory of ongoing IAQ or related research is included. Where
the working group felt there were omissions, projects were suggested.
43
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Section 2.0
SUMMARY OF THE SESSION
The Instrumentation working group was composed of distinguished
scientists from Government, national laboratories, and private industry.
Unfortunately, the academic community or a representative from the National
Science Foundation was not represented.
The working group began by a self-introduction and description
of one's personal or related experience in instrumentation relating to
Indoor Air Quality. As instructed, we then discussed the strategy plan.
This was followed by a review of the Inventory of Indoor Air
Quality Research, where the group found several instances of projects
relevant to Instrumentation. More than a half-dozen additional projects
•were added to the list. The group of more than 30 people then broke into
smaller units (Table 2-1) to review the state of the art and identify
research needs as they relate to the general topics of Table 2-2. Time,
and sometimes lack of an expert, prevented the group from addressing
all the issues.
Table 2-1
Aerosols (mass size)
Organics
Inorganics
Radiation
Biological (no expertise)
Comfort (no expertise)
Control Instruments
Quality Assurance
Table 2-2
State-of-the-art
Source Emissions
Chemical and Physical Interactions
Transport and Removal
Monitoring
Quality Control
44
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Efforts were made to work with the monitoring group; continuing
coordination is necessary. Some of our smaller units were able to make contact
with others in different working groups which helped increase our dialogue.
Upon completion of the working sessions, the units prepared a brief report for
the final plenary meeting.
The instrument working group offered these constructive remarks.
• Schedule the working groups in such a way that participants
can contribute to more than one topical area
0 Have the working groups closer to each other
• Future workshops on these subjects should focus on a specific
area or issue.
The subject of an international symposium on indoor air quality was
discussed. Feelings were mixed but generally cool to such a conference. How-
ever, several useful suggestions were offered such as having the conference
followed by a workshop, and having it in conjunction with a professional
society meeting (polarized response to this suggestion).
45
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Section 3.0
REVIEW OF THE STATE OF THE ART AND
STATE-OF-THE-ART PAPER
3.1 'OVERVIEW
The quality of the air we breathe and the effects of air pollution
on human health have been a major concern of health officials and the public
for years. Already research and regulatory Agencies have been involved in
measuring the effects of air pollution and enforcing standards in indoor
environments as well as outdoor. There are several reported cases of new
buildings where employees working inside these buildings became ill as a
result of emissions from building products. The Occupational Safety and
Health Administration and the National Institute for Occupational Safety and
.Health have assisted in determining the causes of the illness. Changes in
building practice in the United States, as a result of energy conservation
measures, are allowing fewer air exchanges in residential and commercial
buildings. Concomitantly, there will no longer be a dilution of the building
emissions, and chemical concentrations may reach hazardous levels.
As a result of these concerns, a comprehensive program is being
formulated by several Agencies which have experience or responsibilities
in this area. One area of concern is that of instrumentation needed to
carry out the monitoring functions of the program. The Subcommittee on
Instrumentation is responsible for quality assurance, development, and valida-
tion of sampling and analytical methods and development and evaluation (in both
laboratory and field) of instruments for monitoring and control of pollutants.
This would include instruments or methods to measure emission products and
their emission rates from building materials.
As in;industrial hygiene, monitoring and instrumentation are closely
linked. Valid sampling and analytical methods are required to obtain estimates
of individual exposure to pollutants for research needs, risk assessment,
and compliance with existing standards. It also seems likely that guidelines
will be developed for building ventilation rates and emission rates from
building materials. Valid methods and performance specifications will need to
be established for these physical/chemical measurements.
A large assortment of monitoring devices which were not available
to the industrial hygiene community in the 1970s are now commercially avail-
able. The application of century-old kinetic theories such as Pick's Law are
providing gas monitoring systems which do not require mechanical pumps. Some
of these passive monitors, as they are sometimes called, may contain liquids
and therefore provide ideal replacements for the frequently criticized bubbler
samplers. These new devices have not yet been validated, nor have any formal
sampling and analytical methods been developed for their use by a Government
Agency or consensus standard organization.
46
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The recent introduction of microprocessor controlled chemical and
physical agent monitors will force the rethinking of how some elements of
industrial hygiene and environmental monitoring will be done in the future.
These devices offer the potential to combine into nearly a single operation the
collection, the analysis, and the recording of pollutant levels. They can
also.compare the exposure to established standards and alert the worker or
responsible officials of potential problems. As the monitoring devices become
more intelligent, highly skilled environmental scientists will be free to
spend more of their time developing mechanisms to reduce exposure to chemical
and physical hazards and to assess the quality of life of the U.S. popula-
tion. Personnel with less training can be used to collect the samples and
thereby ease any shortage of industrial hygienists or environmental scientists.
Recordkeeping will be simplified because these computerized instru-
ments have the power to process the data and present them in a format tailored
to individual needs. This, again, eliminates mundane chores and permits atten-
.tions to be directed to studying exposure trends and the health of the popula-
tion. Furthermore, there will be more information available on the nature
of exposure, which was not previously available to epidemiologists and health
officials. Hopefully this information will increase the accuracy of our
decisions when determining risk and setting standards or guidelines. At
stake is our nation's health and quality of life.
The new instruments, like their passive monitor counterparts, are
just now being evaluated by several agencies (including NIOSH, DOE, EPA, BOM),
insurance companies, university scientists, etc. Their utility must be
examined for application to the indoor air quality program, where it is
expected that concentrations of these pollutants will generally be lower than
workplace concentrations. The largest collection of sampling and analytical
methods for chemical pollutants is published by NIOSH (NIOSH Manual of Analytical
Methods, second edition in six volumes). This manual describes more than 400
sampling and analytical methods. A companion publication summarizes a program
to validate many of the monitoring methods (NIOSH publication 80-133). These
two publications can form the basis for launching an indoor air quality
monitoring program; extension of the range of the methods and conversion
from pump-collected to diffusion-based sampling will be needed. Quite
naturally, the methods must conform to the demands of the monitoring strategies
proposed by the Monitoring Subcommittee. Sampling periods ranging from a
fraction of a day to a week or longer may be required. Some of the places to be
monitoredj because of their proximity to different industrial or chemical
dumps, will need surveys made to identify the composition of the indoor air in
more detail. Monitoring methods and portable instrumentation will be required
to makes these surveys.
Recent United States Supreme Court rulings have had significant
Impact on the current approach to establishing workplace and possibly other
health standards. It appears that health research institutions and regulatory
Agencies will be required to accurately quantify specific risks to individual
populations and relate them to specific exposure levels. Current exposure
and environmental data will form the framework for establishing these standards
47
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and their technologic feasibility. As always, the quality of the data
is important. The sampling must be properly done and the exposed population
specified. The laboratories engaged in performing the analysis should have
quality control practices in place and demonstrate their proficiency through
participation in the various interlaboratory quality assurance programs.
The portable, direct-reading monitors can create special problems in calibra-
tion, and hence in the accuracy of data. The direct-reading units transfer
quality control of the analysis from the confines of a centralized analytical
laboratory to satellite operations or to monitoring sites. Therefore, in
the coming years field usable standards will be needed for these instruments,
and the proficiency and quality assurance programs must take appropriate
steps to accommodate these trends. Protocols for the instruments, like
the sampling and analytical methods, are essential. The protocols should
include consistent methods for their use and evaluation.
Currently, it is unclear what the magnitude of the monitoring
.program will be. It is clear, that with some of the recent developments
in monitoring, there could be a significant backlog in analysis of the
samples. Research will be required to incease sample throughput. It is
not unlikely that hundreds of thousands of analyses will be performed each
year. This increase in analysis cannot be accommodated by just building
larger labs to accommodate slow analytical procedures. Methods and instru-
ments to speed the analyses will be needed. Laboratory automation and
recordkeeping systems will be essential.
The Environmental Protection Agency's October 1980 Indoor Air
Quality Research Strategy Plan calls for a Taxonomy of Instrument Needs.
This can start by defining in broad terms what some of the requirements
are. That is: laboratory or field instruments, degree of specificity,
accuracy, weight, etc. This effort can be expedited by making current such
instrument compendia as the Lawrence Berkeley Laboratory's "Survey of Instru-
mentation for Environmental Monitoring," and the American Conference of Govern-
mental Industrial Hygienists' "Air Sampling Instruments for Evaluation of
Atmospheric Contaminants." Table 3-1 lists several of the contaminants from
the EPA research plan and the availability of samping and analytical method-
ology and instruments which are now available or can be easily adapted to
measure them.
Besides environmental assessments, instruments and protocols will
be required to measure air exchange rates in commercial-sized and residential
structures. This is currently being done using gas chromatography or infrared
spectrophotometry. It is not clear at this time if exact protocols have
been established so that the scientific community can perform comparisons
of studies conducted by different groups.
48
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Table 3-1.
VO
1.
2.
3.
4.
5.
Substance
Asbestos
Silica
Manmade
Fibers
Nuisance
Dust. Tobacco,
Main and Side
Stream
Sulfur
Dioxide
Method
P4CAM 239
PSCAM 109
S 29
P4CAM 146
P«CAM 160
P4CAM 163
P4CAM 204
S 308
P4CAM 160
Adaptions
Medium-Procedure
Filter-Microscopic
Count
Membrane Filter-
X-ray Diffraction
Filter-Weight Dlff.
Cyclone-Resplrable
Dust
Impl nger-T1 tratlon
Imp1nger-Color1 metric
Impl nger-TI tratlon
Molecular selve-Mass.
Spec.
Bubbler-TI tratlon
Passive Dosimeter
Spectrophotometer
Range
0.1-60
fibers/cm?
5-200 g/cm*
V
0.01-10 ppm
0.003-5 ppm
0.01-5 mg
2-625 mg/m3
6.6-26.8
0.020-6 ppm
Sampling (Tubes or Direct-Reading)
Time Research Needs Instrument
4
Varies Fiber Sizing and GCA-Flbrous Aerosol Monitor (FAM)
Type
Varies
Development Work GCA-FAM
Required
1-8 hrs. GCA-Aerosol Monitors
TSI Aerosol Monitors
Up to 100 mln.
at 1 1/mln.
sampling rate
Up to 25 mln. Needs strict Envlrometrlcs Series S-364
at 0.2 1/mln. control of solution Sulfur dioxide analyzer and
variables many others
Up to 100 mln.
at 1 1/mln.
Up to 500 mln.
at 0.2 1/mln.
Up to 90 mln.
at 1 1/mln.
Up to 7 days Field studies DuPont Pro Tek™
Badge
(Continued)
-------
Table 3-1. Continued
Ul
o
Substance Method
6. CO? S 249
7. CO P8CAN 112
8. Ammonia S 347
S 340
PSCAM205
P*CAM 205
Adaption
P8CAM 108
Adaption
9. HC1 S 246
Medium-Procedure .
Gas Bag-GC
Gas Bag-IR
Silica-Gel on
specific electrode
Bag-Electrochem.
Midget Implnger-
Colorlmetrlc
Passive Dosimeter
Spec tropho tome ter
Passive Dosimeter
Spectrophotometer
Bubbler- I on
specific electrode
Range
2270-
10.000 ppm
(500-15,000
ppm)
"19-500 ppm
17-68 mg/m3
24.7-115.4
ppm
20-135 ppm
0.05-60 ppm
0.02-12 ppm
3.5-14
mg/m3
Sampling
Time Research Needs
8 hr.
Mln. to hours Cannot store
samples
Up to 70 m1n.
at 0.05 1/mln.
Up to 15 m1n.
at 1 1/m1n.
Up to 7 days Field Studies
Up to 7 days Field Studies
Up to 15 mln.
at 1 1/mln.
(Tubes or Direct-Reading)
Instrument4
General Electric, InterScan,
Energetic Science, Others
DuPont Pro Tek
Drager Multl Gas Detector
Milks Ml ram- 103 Portable
Vapor Analyzer
Second derivative UV
adsorption spectrometer
DuPont Pro Tek™ Badge
DuPont Pro Tek™ Badge
Bacharach Gas Hazard Ind.
Bacharach Instrument Co.
(Continued)
-------
Table 3-1. Continued
Substance
10. Chlorine
11. Ozone
12. NO?
NOz/NO
»x
13. Formalde-
hyde
Method
PftCAM 115
PACAM 209
S 8
PKAM 108
PACAM 231
See NO?
PACAM 108
PACAM 125
PACAM 235
ORHL/CPSC
PACAM 125
Adaption
Medium-Procedure
Implnger-Ion
specific electrode
Bubbl er-Col orme tr 1 c
Implnger-
Colorlmetrlc
Bubbl er-
Col orlmetHc
Solid Sorbent-
Spectrophotometry
Palmes Tube
Impl nger-Spec troph .
•
A1 uml na-Spectroph .
Passive Membrane
Spec troph.
Passive Dosimeter
Spectrophotome ter
Range
0.1-1750
mg/m3
0.015-1.0
X,
V
0.1-0.4
mg/m3
0.01-10
9/1
0.8-30 ppm
0.1 ppm-
2.0 ppm
0.4-5.2
mg/m3
2.0 ppb-
5 ppm
0.02-6 ppm
Sampling
Time Research Needs
Up to 80 mln.
at 2.5 1/mln.
Up to 30 mtn.
at 1 1/mln.
Up to 45 mln. Accuracy not
at 1 1/mln. established
Up to 30 mln.
Up to 20 mln. Accuracy not
at 50 ml /mln. established
Up to 24 hrs. Problems with
sample storage
Up to 30 mln.
200 ml /mln.
Up to 10 hrs. Field Studies
Up to 7 days Field Studies
(Tubes or Direct-Reading)
Instrument
Bacharach Gas Hazard Ind.
Bacharach Instrument Co.
CFA Model 555 Continuous
Col orl me trie Analyzer
(Multiple Gases)
Model 034 Ozone Recorder
Ozone Research A Equip. Co.
CEA Model 555 continuous
colorlmetrtc analyzer
(multiple gases)
Energetic Science
MDA-Monotoxx
Second derivative UV absorption
spectrometer
Bendlx Gastec Hazard Detector
System, National Environmental
Instruments, Inc., CEA, Wllks-
Mlran
DuPont Pro Tek™ Badge
(Continued)
-------
Table 3-1. Continued
Ol
NJ
14.
15.
16.
17.
18.
19.
20.
21.
Substance.
Total
Fluor1de/HF
Total A
Particle
Fluoride
Mercury A
Cmpds.
Trace
Metals
Lead A
Cadmium
Sulfate
SulfUe
S02
PC13
KH
Method*
PACAM 117
PACAM 212
PACAM 175
PACAM 173
PACAM 191
PACAM 125
PACAM 268
PACAM 305
PACAM 257
Medium-Procedure
Membrane Filter-
Specific Ion
Solid Sorbent-
Atomlc Abs.
Filter-Atomic Abs.
Membrane Filter-
Anodic Strip
Voltometry
Treated Filter/
Passive Dosimeter
Adaptive Spectroph.
Ion chromatograph
Bubbler-Colorlmetrtc
Fllter/Bubbler-
Colorlmetrlc
Sampling
Range Time Research Needs
0.05-475 Up to 80 mln.
mg/m3 at 2.5 1/mln.
0.005-5
x.mg/m3
V
0.001-1.0 10 mln. up to
g 1 hr.
Varies
0.0016- .01 66.7 mln.
mg/m3 pb
0.00008-.01
mg/m3 Cd
0.1-10 Up to 133 mln. Need to Investigate
mg/m3
0.02-6 ppm Field Studies
Up to 7 days
0.1-10 at 1.5 1/mln. Negative bias due
mg/m3 to oxidation
0.04-4 ppm
0.04-4 ppm
1.2-20 120 mln.
0.55-2.0 240 mln.
mg/m3
(Tubes or Direct-Reading)
Instrument
CEA Model 555 Continuous Color-
metric Analyzer
(Multiple Gases)
MSA Universal Tester Mine
Appliance Co.
Safety
Columbia Scientific Portable
XRF
MSA Universal Tester Mine
Safety Appliances Co.
DuPont Pro-Tek™
(Continued)
-------
Tabl* 3-1. Continued
Ui
OJ
22.
23.
24.
25.
26.
27.
Substance Method
Organophos- PftCAM 21
phorus
Pesticides
Vinyl PKAM 178
Chloride
(1ncl. halog. P4CAM 127
hydroc.)
Organic
Solvents
Petroleum S 380
Distillates
PNAt P«CAM 183
ORNL
NUroso- PSCAM 299
anrine
Medium-Procedure
Implnger/Fllter-GC
Charcoal -GC
Charcoal -GC
Charcoal -GC
Membrane-F11ter-GC
FIHer-Sorbent
Fluoresence
Tenax-GC
Thermosorb/
Thermo-energy
Analyze
Range
Varies
0.008-5.2
vmg/nH
Varies
937-393
mg/m3
2-1000
g/m3
1-1000
mg/m3
2-20 g/m3
10-1000
PPt
Sampling
Time
Up to 4 hrs.
Up to 100 mln.
Up to 97 mln.
Up to 20 mln.
at 0.2 1/mln.
Up to 250 mln.
at 2.0 1/mln.
Up to 8 hr.
Up to 500 mln.
at 0.01 1/mln
Up to 60 mln.
at 8 1/mln.
Research Needs
Precision not
determined
In progress
Research on nltro-
soamlnes Is con-
tinuing
Validation, auto-
mation and field
testing
(Tubes or Direct-Reading)
Instrument
Sequential Pesticide Sample
Model 88. Mlcrochemlcal
Specialties Co.
Bench x Gastec Hazard Detector
National Environmental Instru.,
Inc.
Drager Multlgas Detectors
National Drager, Inc.
(Continued)
-------
Table 3-1. Concluded
Substance • Method
Medium-Procedure Range
28. N Nltroso P&CAM 252 Tenax-GC 0.5 ppt-
dlmethyl 10 ppb
mine
29. Radon 6 Health Use charcoal If want
Radon Physics Radon specifically *•••
daughters 23:738- p. A- 8 Air Sampl.
Sampling
Time
Varies
5 mln.
Research Needs
(Tubes or Direct-Reading)
Instrument
789(1972) Instr. 5th Ed.
Thomas, (1978)
J.W.
30. Freon 114 S 108
12 S 111
Charcoa1-6C
Charcoal-GC
3500-
14,100
mg/m3
2940-10,500
mg/m3
Up to 300 mln.
at 0.01 1/mln.
Up to 300 mln.
at 0.01 1/m1n.
Probability of loss
If back-up tubes
exceed 12 mg.
Probability of sample
loss exist using tube
11-654
Meter,
Instr.
Portable Flame lonlz.
Scott Avlatlon-Davles
Ui
-------
3.2 QUALITY ASSURANCE
Existing, modified, and new instruments will be required for quan-
tifying the levels of specific indoor air contaminants and for evaluating
indoor air quality. In order that the data obtained in monitoring health-
risk 'contaminants in nonindustrial indoor environments (including residences,
schools, hospitals, restaurants, entertainment arenas) be accurate, reliable
and intercomparable, a number of criteria are essential. The critical components
of any valid monitoring study require at minimum that: (1) the instruments
used are fully evaluated (for specificity, useful dynamic range of detection,
uncertainties associated with the measurements, sensitivity, stability, inter-
ferences (physical and chemical), field use, and economy; (2) the instruments
used are calibrated with appropriate and reliable standards that assure
performance reliability prior to, during, and following monitoring exercises;
and (3) quality assurance and quality control protocols are developed and
followed that assure the quality of the data collected.
3.2.1 Evaluation of Instruments
Preevaluation of instruments employed in indoor air quality assess-
ments is critical. The use of unevaluated instruments often results in data of
unknown reliability. Further, the assumption of reliability for unevaluated
instruments can lead to misleading and erroneous results. At best, since the
resultant data quality for unevaluated systems has an accuracy certainty,
one is left with interpretations based on temporal trends, the precise
quantification of which may be unclear. Preevaluation of indoor air quality
instruments requires laboratory confirmation of measurement range, measurement
accuracy, and uncertainty associated with measurements over the established
range, assessment of interferences that might plausibly occur in field
monitoring studies, and the performance stability of the instruments selected.
A fully-evaluated instrument should also be tested for air movement effects
on measurements/associated with the indoor environments. Having evaluated
instruments in place, the quality of the data may be assured by the use of
meaningful protocols involving the use of standards and quality assurance
mechanisms. These are briefly discussed below.
3.2.2 Field and Laboratory Standards
Field and laboratory standards are intended to represent standard
materials used for the calibration of the instruments selected for indoor
air quality measurements. Laboratory standards are required to precalibrate
instruments prior to use in field monitoring studies. Field standards are
similar in nature to laboratory calibration standards, with the exception
that they need to be readily portable in nature for field calibration purposes
range .of response of the instruments used for measurement. The full composi-
tion of the standard materials should be known, covering both the concentration
of the standard and its true concentration uncertainty, and the presence and
concentration of impurities. Finally, the stability of the standards must
be determined to assure their reliable use over a useful lifetime. A number
55
-------
of gaseous standards identified in the Indoor Air Quality Research Strategy
are available as Standard Reference Materials (SRMs) from the National Bureau
of Standrds (NBS). These include carbon dioxide, carbon monoxide, nitrogen
dioxide, nitric oxide, and sulfur dioxide. Other relevant standards avail-
able or under development by NBS include asbestos, halogenated hydrocarbons
(frepns, and other low molecular weight organics determined by EPA to have
associated health risks), lead, sulfate, nitrate, tetrachloroethylene, air
particulates, trace elements, and vinyl chloride. Some of these exist as
current SRMs; some require further development. A number of additional
standards will likewise be required for indoor air quality programs.
3.2.3 Quality Assurance Programs
Allowing that evaluated instruments and reliable standards for
instrument laboratory and field calibrations are available, the success of
indoor air quality measurements will rely on the establishment of useful
.programs to provide a continuing quality assurance to indoor air quality
measurements. These types of programs have traditionally been established
at NBS for numerous other research activities involving measurement quality
assurance. For meaningful quality assurance and quality control for indoor
air quality measurements, it is imperative that protocols be developed for
(1) the establishment of a Measurement Assurance Program (MAP), (2) calibration
facilities, and (3) laboratory proficiency evaluation for laboratories involved
in field measurements. It is recommended that NBS, with its traditional
expertise in the establishment and conduct of MAPs and calibration facilities,
take the lead and be intimately involved in the development and provision of
Quality Assurance Programs and protocols for the indoor air quality research
program in collaboration with other Agencies involved in the indoor air quality
arena. It is anticipated that the activities in this domain of quality assurance/
quality control will and should include (a) round-robin analyses; (b) evalua-
tion of available instruments in collaboration with other NBS activities; (c)
statistics; and (d) interlaboratory proficiency testing.
/
3.3 INSTRUMENTATION FOR MEASURING RADON, THORON AND THEIR PROGENY IN BUILDINGS
3.3.1 State of the Art
Like other indoor air pollutants, radon (both radon-222, and radon-220,
"thoron") concentrations vary greatly with time and location. For this reason
the inference of long-term radon exposure requires that measured concentrations
should be averaged over as long a period as possible to eliminate short-term
perturbations and should include as many measurements as are reasonably possible.
The techniques for monitoring indoor radon-222 and its progeny are sufficiently
developed to meet most requirements. Choice of the instrument and method depends
on the'levels to be measured, length of exposure, and the accuracy required.
Of course instrument availability and cost must be considered.
56
-------
Considerably less attention has been paid to techniques for measuring
thoron and thoron progeny than is the case with radon-222. However, the
rather sparse data available indicate that, there are situations where indoor
thoron progeny working levels can be a significant fraction of, and even
exceed, the radon progeny levels. Thus, assessments of the thoron contri-
bution to total indoor radon exposure should become an integral part of
field,studies and associated instrument development.
Tables 3-2 through 3-5 show the most commonly used instruments and
methods for radon and thoron and radon progeny measurements in the field. For
indoor measurements, it is advantageous to use continuous or integrating
methods that provide direct estimates of the average radon and radon progeny
exposure. Grab sampling programs would have to be quite extensive to provide
comparable information.
For measuring, radon, integrating passive detectors such as nuclear
track detectors are the simplest to deploy in houses, but require lengthy
periods of exposure (minimum 1 month) for adequate signal registration.
•Fortunately, this is often desirable for the determination of mean exposure
levels. Passive integrating monitors using ion collection are more sensitive,
and exposures of a few hours to several days' duration can be attained at higher
cost. In cases where special studies are needed, continuous radon monitors
using the flow-through scintillation flask can be used at a limited number of
locations.
For measuring working level, time-integrating, or continuous monitors
can be used by collecting radon progeny on filters. Their radioactivity
is detected either by thermoluminescence materials or by alpha counters.
Monitors of both types can be assembled from commercially available components.
For calculation of lung dose to building occupants, information
on radioactive particle size distribution, unattached fraction and
respiratory deposition is desirable. Particle size distributions of radon
daughters can b% measured with different types of diffusion batteries; their
size and flow-rate depend on the radioactivity levels to be measured. Proto-
type diffusion batteries have been used successfully, but none are available
commercially. Particle size measurements are difficult to make, requiring
complex instruments for limited data. Fortunately, the limited measurements
of the particle size of radon progeny have ranged between 0.10 wm and 0.15 urn
in diameter, a somewhat narrow range, and perhaps particle size measurements
might be made in only a small number of homes.
The situation is more complicated with respect to the measurement
of the degree of attachment of indoor radon progeny to atmospheric partic-
ulates. This parameter is important because it influences the equilibrium
ratios'of radon progeny in air and the degree and location of lung deposition.
Moreover, it depends on aerosol concentration and size distribution, and the
surfaces to which both aerosols and atoms can attach. Data on these factors
57
-------
Table 3-2. Instruments and Methods for Measuring RaUoff in~JTTr
Instrument
and Method
Scintillation flask
Two filter
Application
Grab or continuous
sampling
Grab or continuous
Principle of Operation
Scintillation alpha count
v. Decay of radon and collection
Sensitivity*
< .01 - 1.0 pCi/jfc
0.01 - 5 pCi/J
Reference
1.
3,
2
4
Pulse ionitation
Track etch
Passive
Plastic bag
Passive monitor
Passive monitor
sampling
Grab (laboratory only)
Time Integrating
Continuous
of progeny products on second
filter; alpha count
Sample transferred into ion
chamber; pulse ion count
< 0.05 pCi/ji
Time integrating
Time Integrating
Continuous
Alpha sensitive films register 0.2 - 1.0 pCi-month/X
tracks when etched in NaOH
Radon diffusion into sensitive 0.5 pCi/4
volume. Po-218 collected on
scintillation counter
electrostatically
Collection of ambient air in < 0.1 pCi/Z
bag. Transfer in scintilla-
tion flask; alpha count
Radon diffusion into sens!- 0.03-0.3
tive volume. Po-218 collec-
tion on TLD electrostatically
Radon diffusion into sensi- 0.1 pCi/£
tive volume. Removal of radon
daughters by electret. Count
alpha particles from radon only
5
6, 7
8
10
11
*The precision of the measurements is about +20%
-------
Table 3-3. Instruments and Methods for Measuring Radon Progeny 1n Air
in
Instrument
and Method
Kusnetc and Rolle
Tsivoglou and
modifications
Application
Grab sample for
working level only
Grab sample for ^
individual radon
Principle of
Collect sample
alpha count
Collect sample
alpha count
Operation
on filter;
on filter;
Sensitivity*
0.0005 WL**
0.1 pCi/i each of
RaA, RaB and RaC -
Reference
12, 13
U, 15,
and 17
16
Alpha spectrometry
Instant vorking
level monitor
Working level
monitor
Working level
monitor
progeny and working
level
Grab sample for indi-
vidual radon progeny
and working level
Grab sample for indi-
vidual radon progeny
and working level
Time integrating
radon progeny
concentration
Time Integrating or
continuous radon
progeny concentration
Collect sample on filter,
count in alpha spectrometer
Automatic sample collection,
alpha or alpha and beta count
Collect sample on .filter
(1-2 weeks). Detect with
thermoluminescent material
Collect sample on filter con-
tinuously. Detect alpha radio*
activity with silicon surface
barrier detector.
0.0005 WL
0.5 pCi/4 each of
RaA, RaB and RaC -
0.002 WL
0.1-1.0 pCl/4 each
of RaA, RaB and RaC
0.001-0.01 WL
0.0005 WL in a week
0.00004 WL in a week
18, 19
20
21, 22, 23
24
*The precision of the measurements is about ±207..
**l WL (working level) is the concentration of radon progeny in 1 £ of air that will release 1.3 x 105 MeV
of alpha energy upon complete decay through Po-214.
-------
Table 3-4. Instruments and Methods for Measuring Thoron Working Level in Air
Instrument
and Method
Application
Principle of Operation
Sensitivity*
Reference
Strong and Duggan
Ogden
Alpha spectrometry
Grab sample for
working level
2-3 hour sample for
working level
Grab sample for indi-
vidual radon and
thoron progeny and
working levels
Collect sample on filter; alpha 0.001 WL
count in several successive
periods
Collect sample on filter; alpha 0.001 WL
count for two successive periods
Collect sample on filter; count 0.005 WL
in 3-channel alpha spectrometer.
Microprocessor controlled
25
26, 27
28
*The precision of the measurements is about +25%.
-------
Table 3-5. Radon Sources and Transport
Type of Measurement
Instrument and Method*
Principle of Operation
Reference
In Situ
Radon exhalation rates from
materials
Radium-226 content
Laboratory
Emanation power
Charcoal canister
Accumulation chamber
Gamma-ray spectrometry
Emanation chamber
Radon adsorption on activated charcoal;
count In Nal (Tl) analyser for 81-214
and Pb-214.
Transfer radon to scintillation flask;
alpha count.
Measure primary gamma ray flux from
Bl-214 and Pb-214 with high resolution
Ge (LI) detector.
Seal material In chamber; gamma count.
Open chamber, aerate sample and recount.
29
30, 31
32
33, 34
Radon In soil gas
Radon In water
Tube In ground
Passive CARD
Liquid scintillation
vial
Modified Marlnelli beaker
Transfer soil gas sample Into scintilla-
tion flask; alpha count.
Radon progeny plate-out on both sides
of alphaCARD; count both sides in two
solid state silicon detectors.
Water sample mixed with scintillation
fluid; count in liquid sctinillation
counter.
Count sample In Nal (Tl) analyser for
Bi-214 and Pb-214.
30
35
36
37
*The precision of most of these methods is better than 207..
-------
REFERENCES (Tables 3 -2 to
1. Improved Low-Level Alpha Scintillation Counter for Radon, H. F. Lucas, Review
Sci. Instrum., 28, 680 (1957).
2. Scintillation Flasks for the Determination of Low Level Concentrations of Radon,
A. C. George, Proceedings of Ninth Midyear Health Physics Symposium, Denver, CO,
Feb. (1976).
3. A Study of the Two-Filter Method for Radon- 222, J. W. Thomas and P. C. LeClare,
Health Phys., .18, 113 (1970).
4. Development and Operation of Continuous Radon Monitors 1974-77, J. W. Thomas,
U.S. Department of Energy, Environmental Measurements Laboratory, unpublished
report (1977).
5. EML Procedures Manual, ed. John H. Harley, U.S. Department of Energy Report
HASL-300, updated annually (1972).
6. Dosimetry of Environmental Radon, Methods and Theory for Low-Dose Integrated
' ."Measurements, R. L. Fleischer, General Electric Research and Development Center,
Schenectady, NY, unpublished report (1980).
7. Improved Type Track Etch Detector Calibration Results, H. W. Alter, Terradex
Corp., Walnut Creek, CA, unpublished report (1980).
8. Design and Application of a Continuous, Digital-Output Environmental Radon
Measuring Instrument, H. Spitz and M. W. Wrenn, Radon Workshop, ed. A. J. Breslin,
U.S. Energy and Research and Development Administration Report HASL-325, New York
(1977).
9. An Integrating Air Sampler for Determination of Radon-222, C. W. Sill, Health
Phys., 16, 371 (1969).
10. Measurement of Environmental Radon with Integrating Instruments, A. C. George and
A. J. Breslin, ^orkshop of Methods for Measuring Radiation in and Around Uranium
Mills, ed. E. D. Harward, Atomic Industrial Forum, Inc., Program Report, Vol. 3
(1977).
11. The Development of a Continuous Monitor for the Measurement of Environmental
Radon, P. Chittaporn and N. Harley, Institute of Environmental Medicine, New York
University Medical Center, New York, NY 10016.
12. Radon Daughters in Mine Atmospheres - A Field Method for Determining Concentra-
tions, U. L. Kushetz, Am. Ind. Hyg. Assoc. J. , 17, 85 (1956).
13. Rapid Working Level Monitoring, R. Rolle, Health Phys., 22_, 233 (1972).
14. Occurrence of Konequilibrium Atmospheric Mixtures of Radon and Its Daughters,
E. C. Tsivoglou, H. E. Ayer and D. A. Holaday, Nucleonics, 1., 40 (1953).
15. Measurement of Radon Daughters in Air, J. W. Thomas, Health Physics, 23, 783 (1972)
62
-------
16. A Radon Daughter Monitor for Use in Mines, A. C. James and J. C. Strong,
Proceedings 3rd International Congress, IRPA, Washington, DC, USAEC CONF-730907,
p. 932 (1973).
17. Analysis of the Activity of Radon Daughter Samples by Weighted Least Squares,
0. G. Raabe and M. E. Wrenn, Health Phys. J., JL7, 593 (1969).
18. Analysis of Atmospheric Concentrations of RaA, RaB and RaC by Alpha Spectroscopy,
D. E. Martz, D. F. Holleman, D. E. McCurdy and K. J. Schiager, Health Phys., 17,
131,,(1969).
19. The Measurement of Low-Concentrations of the Short-Lived Radon-22 Daughters in
the Air by Alpha Spectrometry, N. Jonassen and E. I. Hayes, Health Phys., 26.
104 (1974).
20. A Microprocessor-Assisted Calibration for a Remote Working Level Monitor,
W. B. McDowell, D. J. Keefe, P. G. Groer and R. T. Witek, IEEE Trans. Nucl.
Sci., NS-24:1, Feb. (1977).
21. Integrating Radon Progeny Air Sampler, K. J. Schiager, Am. Ind. Hyg. Assoc. J.,
35, 165 (1974).
22. A Working Level Dosimeter for Uranium Miners, A. J. Breslin, S. F. Guggenheim,
A. C. George and R. T. Graveson, U.S. Department of Energy Report EML-333 (1977).
23. A Time-Integrating Environmental Radon Daughter Monitor, S. F. Guggenheim,
A. C. George, R. T. Graveson and A. J. Breslin, Health Physics, 36, 452 (1979).
24. A Prototype Integrating or Continuous Working Level Monitor, N. Latner, S. Watnick,
R. T. Graveson and A. C. George, U.S. Department of Energy, Environmental Measure-
ments Laboratory, unpublished report (1980).
25. The Effect of the Presence of Thoron Daughters on the Measurement of Radon _
Daughter Concentrations, J. C. Strong and M. J. Duggan, Health Phys., 25. 299 (1980M
26. Radon and Thoron Working Levels from Ordinary Industrial Hygiene Dust Samples,
T. L. Ogden, Ajin. Occup. Hyg., 20, 49 (1977).
220 222
27. A Two-Count Filter Method for Measurements of Rn and Rn in Air, E. Stranden,
Health Phys., 38, 73 (1980).
28. A Portable Three-Channel Alpha Spectrometer for Measuring the Daughter Products
of Radon and Thoron, D. W. Carson, Division Report MRP/MSL 79-108(TR) CANMET,
Energy, Mines and Resources Canada, 1979.
29. Measurement of Radon Flux with Charcoal Canisters, R. J. Countess, Workshop of
Methods for Measuring Radon in and Around Uranium Mills, ed. E. D. Harvard,
Atomic Industrial Forum, Inc., Program Report, Vol. 3, No. 9 (1977).
63
-------
30. Measurements of the Effects of Atmospheric Variables on Radon-222 Flux and
Soil-Gas Concentrations, H. W. Kraner, G. L. Schroeder and R. D. Evans.
The Natural Radiation Environment, pp. 191-215, 1964, William Marsh Rice
University.
31. Measurements of Radon Flux by the Accumulation Method, M. Wilkening. Workshop
of Methods for Measuring Radon in and Around Uranium Mills, ed. E. D. Harvard,
Atomic Industrial Forum, Inc., Program Report, Vol. 3, No. 9 (1977).
32. In£itu Ge(Li) and Nal(Tl) Gamma-Ray Spectrometry, H. L. Beck, J. DeCampo and
C. 'Gogolak, US AEC Report HASL-258 (1972).
33. Radon Emanation from Domestic Uranium Ores Determined by Modifications of the
Closed-Can Gamma-Only Assay Method, S. R. Austin and R. Droullard, Bureau of
Mines Report of Investigations 8264 (1978).
34. A New Technique to Estimate the Contribution of Building Materials to Indoor
Radon, J. Ingersoll, LBL-10631, April 1980.
35. An AlphaCARD System for Measuring Radon in Soil-Gas. Technical Data 1080.
Alpha Nuclear, 6380B Viscount Road, Mississauga, Ontario, Canada L4V 9Z9.
36. Rapid Measurements of Radon-220 Concentrations in Water with a Commercial Liquid
Scintillation Counter, H. M. Prichard and T. Gesell, Health Phys. .33, 577-581,
(1977).
37. Measurement of Radon-222 in Water, R. J. Countess, Health Phys. 34. 389 (1978).
64
-------
are too sparse to permit any generalizations, due in part to the lack of
readily-available instrumentation for particle size and unattached fraction
measurements. More research in this area is clearly needed.
For diagnostic purposes, sources of radon and radon progeny
input into the indoor environment are important, necessitating measurements of
radon exhalation from building surfaces and from the soil, infiltraton through
openings in the foundation, and radon concentration in water supplies. Table 3-5
indicates some existing techniques. Radon exhalation can be readily measured.
Rapid measurements use the accumulation technique (0.5 - 2 hours), and inte-
grated measurements up to 3 days can be made with charcoal canisters. Radon
in water supplied to residences should be measured to ascertain its input
on the indoor radon levels. Radon in domestic water supplied from surface
waters need not be measured at all.
The air exchange rate inside homes is another measurement of interest
since air concentration is a function of ventilation rate as well as radon input
rate. There is a need for standardizaton of procedures among the numerous
techniques to facilitate interpretation of the rate of air exchange; ASTM's
standard should be taken into consideration by researchers.
The state of the art can be summarized as follows:
1. Much development work has been done over the last 20 years
in response to problems such as uranium mine exposure,
releases from uranium tailings piles, and high indoor
exposures in structures built on reclaimed phosphate lands.
2. Adequate, if not optimal, techniques exist and are being
applied in research studies of radon and radon progeny
concentrations in indoor air, their dependence on ventila-
tion rate, heating and cooling system operating parameters,
meteorological variables and living habits, the particulate
s/ize distribution of attached radon progeny, and the
degree of attachment of such progeny. However, improvements
are being made in many of these techniques to make larger-
scale field studies more practical.
3. Passive integrators of radon gas exposure over periods of
weeks or months have recently been developed and are being
evaluated. They are likely to be adequate for large-
scale surveys. There is a strong need for analogous inte-
graters of radon progeny exposure.
4. Many of the techniques suitable for measurements of radon-222
can be applied to radon-220 ("thoron"), but little data exist
on exposure to thoron and its progeny or on how thoron con-
tributes to "radon" readings.
65
-------
5. Some progress has been.made in quantifying and understanding
the uncertainties associated with various types of radon
measurement. Considerably more effort is required to ade-
quately define measurement techniques and protocols for general
use, provide standard calibration facilities and sources, and
carry out detailed evaluations of various instruments and
measurement methodologies.
3.3.2 Research Needs
Given the monitoring instruments on hand, the following instrumenta-
tion needs should be addressed:
1. A small and inexpensive passive radon progeny monitor, suit-
able for large-scale surveys of integrated exposure
2. Improved practical detectors for continuous radon monitoring,
suitable for diagnostic studies of radon variations inside
buildings
3. Further development of instrumentation for measurements of
particle size and unattached fraction on a routine basis
4. Development of improved methods and appropriate instrumenta-
tion for studies of radon transport through the soil and
building foundations
5. Development of improved methods for thoron and thoron
: progeny measurements
6. Evaluation of existing methods of radon and radon progeny
measurement through intercalibration and intercomparison
experiments, and the development of common measurement
protocols and methodologies
7. Development of calibration facilities and protocols, and
transfer standards relatable to national standards,
particularly for radon progeny
8. Establishment of ongoing measurement assurance mechanisms
that incorporate (6) and (7) above.
The priorities to be associated with some of these needs are
somewhat dependent on the identified monitoring needs. For example, there
are quite significant differences between the instrumentation needs for
large-scale radon studies and those for detailed diagnostic studies in individ-
ual structures. However, it should be emphasized that items (6)-(8) above are
outstanding needs in any case. Cooperation among the laboratories with
capabilities in these areas to respond to those needs is strongly encouraged.
66
-------
While considerable progress has been made, particularly in the past
year, in the consideration of the special problems associated with both large-
scale surveys and indepth studies of radon in structures, much more work needs
to be done to develop practical and commercializable detectors and optimum
protocols for field measurements. Informal intercomparisons of instruments
and iflethods have taken place, but more formal programs are much needed. These
concerns will continue to be addressed in the activities of the Interagency
Research Group and of the Indoor Radon Task Force of the U.S. Radiation Policy
Council.
A general need, not specific to radon, is the development of multi-
pollutant monitoring packages containing small, inexpensive integrating
detectors for radon and key chemical pollutants that could be left unattended
for long periods to provide measurements of integrated concentrations. Such
packages would provide a practical means of obtaining a data base on typical
ranges and trends of pollutant exposure in U.S. buildings. Such a development
•should be an important goal of interagency research programs.
3.4 AEROSOL INSTRUMENTATION
3.4.1 Summary on the State of the Art
Several instruments and instrumentation methods for aerosol monitoring
are presently available. As applied to indoor air quality characterizaton, these
instruments can be classified into two general categories: (1) personal
samplers and (2) area samplers and monitors. Personal samplers are typically
filter collection-pump combinations with or without size preselectors, and are
used for gravimetric (i.e., mass concentration) and/or chemical characteriza-
tion of the aerosol to which individuals are exposed over periods of the order
of hours or days.
Area samplers are usually filter collectors, with or without size
preselectors; cascade impactors; electrostatic precipitator samplers, etc.
Area monitors are available for real-time, or continual measurement of aerosol
concentration and/or particle size distribution. Real-time, or quasi real-time
instruments (i.e., with characteristic response time of the order of seconds or
minutes) most commonly available and applicable to indoor aerosol monitoring
and measurement are based on the following sensing principles: (a) beta radiation
attenuation, (b) piezoelectric resonance, (c) light scattering, (d) electrical
mobility, and (e) condensation nuclei counting. Beta attenuation and piezolectric
resonance are used for mass concentration determinations. Light scattering is
applied to either equivalent mass concentration or particle count and size
measurements, and in combination with an oscillating electric field, light
scattering has been applied to the selective detection and sizing of fibrous-
shaped particles (Fibrous Aerosol Monitor). Electrical mobility and condensa-
tion nuclei detection are methods applied to particle counting and sizing.
67
-------
Several of the above mentioned techniques have been incorporated in
instruments that are compact, self-contained (i.e., battery operated) and
portable. Table 3-6 briefly summarizes many aerosol sizing, calibration and
measuring instruments. Appendix D outlines how to select portable aerosol
instruments and provides more detailed information on selected instruments.
«
Aerosol calibration methodology is available for laboratory purposes.
There are, however, no simple and straightforward techniques for field calibration,
except secondary methods to check the operational performance of real-time
monitors. Table 3-7 is a selected list of common aerosol generators.
Most aerosol monitors require active sampling from the surrounding
environment, and exhibit some degree of particle size discrimination or
bias. The use of so-called "total suspended particulate" samplers or monitors
ought to be discouraged; specific and well controlled particle size limitations;
i.e., by the use of size preselectors and/or properly designed inlet configura-
tions, should be required to prevent errors and inconsistencies associated with
'"open endedness" at the large particle end.
Accuracy of presently existing instruments and techniques is often
difficult to define because of the inherent inaccuracy and ambiguity of many
of the reference methods. In general, however, intermethod comparisons usually
yield agreements within a factor of two. Repeatability of a given device, under
similar monitoring conditions, is frequently within 10 or 20 percent, and
occasionally much better.
Problems of measurement and monitoring of aerosols are inherently
more complicated than those of gases. Heterogeneity of particle size,
Composition and shape are idiosyncratic of most adventitious aerosols creating
'difficulties in representative sampling, detection, and characterization. Thus,
the concentration range of specific instruments and techniques exhibits complex
dependencies on those additional parameters. Number concentration sensitive
techniques (e.gy, electrical mobility, condensation nuclei counting and light
scattering particle counting) respond preferentially to or are dominated
by, the small particle fraction of an aerosol, whereas mass sensing devices
emphasize the larger particle fraction whose mass predominates over that
contributed by smaller particles. Inertial, optical, electrical, and chemical
properties of aerosols, as well as their physical state, affect the accuracy
of their measurement, and consequently no single technique exists at present
capable of covering their broad range of variability, and much less of pro-
viding their full characterization.
By combining several techniques it is possible, however, to cover
the wicje range of concentrations and particle sizes of interest that have to be
considered when monitoring such disparate environments as emission sources and
ambient air. The range of aerosol particle concentrations in indoor environ-
ments fluctuates between a few micrograms per cubic meter up to peaks of the
order of tens of milligrams per cubic meter. The size range of interest,
especially when health effects are the governing criteria, is the so called
respirable fraction, i.e., particles whose equivalent aerodynamic diameter
68
-------
Tebl* 3-6. Nut Real Tim* Aerosol Particle String, Calibration, end Concentration Measuring Instruments
SIM DvtnvuUov
Diffusion battery end condensation
nuclear counter
Electrical mobility anarysm
Optical particle connssr
Plesoelectric cascade Impacsor
Condensation uncle) 1 counter
O\
\O
Flbemni serosol monitor
M"ir CviiiTi'Hatio»
Piezoelectric mlcrobalanc*
Bit* radiation attenuation
Light •CBtttsriiig p**o toincteTy
M^c^Moe,,
TSI 3040, 3020, 6 3042
TSI 3090
Roger 218
Roger 225
Roger 226
Roger 245
CHmet CJ-208
CUmet O- 225
CUmet O-2SO
PMS ASAS-300
PMS CSASP-IOO
PMS LAS- 100
Met One 209
Brleflng document
Conference document
BQI-Pellek
E/l RU200
Gardner CN
CECN-2
TSI 3020
CCA FAM-I
TSI 3500
TSI 5000
CCA RDM-101
CCA RDM-201
CCA RDM-301
CCA APM-1
CCA RAM-1
Letts TM-Dlgltel
Slbsta P-S
Slmslln 1900
TSI 5150
Particle
Diameter Rang*
0.005-0.3 irm
.O.OOS-l.Oum
0.5-IOum
0.3-IOUtn
0. 15-10 um
0. 5- 10 um
0.3-IOum
0.3-IOpm
0. 5-IO|lm
a 15-3 um
0. 3- 10 um
0.3-5|im
0.5-lOum
0.15- 10 um
0. 15-10|!m
0.005- 1.0 pro
O.OOS-l.Oum
O.OOS-l.Oum
O.OOS-l.Oum
O.OOS-l.Oum
lO-300|*n (k-mydi)
0.01- 10 um
0.01- 10 urn
0.8- 10 Mm
0.01- 10 um
O.8-IO|lm
0.01-10 um
0.3-1 Sum
0.3- 100 Um
0.3-1 Sum
0.3-15 Mm
0.3-lSUra
Concentration Time for
Range 1 Management
O-lO°/cm3 240 MC
101-107/cm3 40 MC
0-400/cm3 1 or 1O mln
O-4000/cm3 1 or 10 mln
O-IOOO/cm3 SMC-lShrs
0.10/vc»i3 1 or 10 mln
0-400 Am3 1 or 4 mln .
0-400/cm3 1 mln
0-400/cm3 1 mln
O-ioVcm3 IMC- 16 mln
0-105/cm3 IMC- 16 mln
0-1000/cm3 1 MC-16 mln
O-IOOO/cm3 6-600 MC
100-2O,OOO Ug/m3 2 MC
IOO-2O 000 ug/m3 2 MC
10-SxIOS/cm3 1 mln
lOO-lofycm3 1 MC
200- 106/ cm3 1 MC
IO-)06/cm3 1 sec
O.Ol-lofi/cm3 1 sec
0.0001-30/cm3
S- 10,000 ug/m3 24 or 120 MC
5- 10, 000 ug/m3 1-9999 MC
200-20, 000 ug/m3 lor 4 mln
500-500,000 ug/ro3 1-240 mln
200-75,000 ug/m3 0.3-99 mln
2- 100,000 ug/m3 2-998 mln
2-200,000 ug/m3 1 sec
10- 100, 000 ug/m3 1 sec
10- 100,000 ug/m1 1 MC
10- 100,000 ug/m3 1 sec
10-100,000 ug/m3 1 MC
Sempl*
Flow
4 L/tnln
4 L/mln
0.01 ft3 /mln
O.O1 or 0.1 ft) mln
5 cm3 /Me
1 ftVmln
O^SftVmla
0. 25 ftVmln
l.Oft'/hr
0. 1 cm3/Mc
0. 1 cm3 /see
0. 1 cm3/Mc
1 ft3/ mln
0. 24 L/mln
0.24 L/mln
Dlchoromons, manual
1.8-4.2 L/mln
Dlchotomous, Minna!
5. 1 L/mln
0.3 L/mln
2 L/mln
1 L/mln
1 L/mln
2 L/mln
2 L/mln
2 L/mln
9 L/mln
2 L/mln
No sampling
Unknown
0.62S L/mln
4 L/mln
Comments
All string Instruments required under methods development sad refined development of characterfaation methc
Date reduction needs Improvement.
Used extensively for other emMent aerosol.
Requires dilution for Indoor emMent aerosol.
Require* dilution for Indoor emMent aerosol.
Requires dilution for Indoor emMent aerosol.
Requires dilution for Indoor ambient aerosol.
Requires dilution far Indoor emMent aerosol.
Requires dilution for Indoor eraMent aerosol*
Requires dilution far Indoor ambient aerosol.
Mey require dilution for Indoor ambient aerosol-
May require dilution for Indoor emMent aerosol.
Mey require dilution for Indoor emMent eerosol.
Requires dilution for Indoor emMent aerosol.
Requires msnual cleaning of 10 sensors for each measurement.
Requites msnusl cleaning of 1O scnsois for each meesuremcnt.
Expansion chamber, water condensation.
Expansion chamber, water condensation.
Expansion chamber, water condensation , battery power.
Expansion chamber, weter condensation
Continuous (low, butanol condensation
Direct mess sensor, direct recording, manual operation, battery.
4 kg, electrostatic collection.
Direct mess sensor, direct recording, manual operation, electrostatic collection.
Direct mess ssjisni, direct reconflng, manual operation, battery,
Direct mass sensor, direct recording, manual operation, battery,
Direct mess sensor, direct recording, manual operation, battery,
Direct men Mnsor, direct recording, msnual operation, bettery,
Require! calibration for maei concentration, battery, 5 kg.
Requires calibration for mass concentration, battery, 4 kg.
Requires calibration for rnaas concentration, battery, 4 kg.
Requires calibration for ma» concentration, battery, 8 kg.
Requires celibration for mass concentration, bettery, 4 kg.
4 kg, Impection collection.
4 kg, Impection collection.
15 kg, Impecsor collector, printer.
15 kg, Irnpector collector, printer.
-------
^7. sSRSard Aerosol GeHBRjw
Standard Aerorol
Nwf vntfofn HMI
Vibrating orifice genmtof
NctrallMf wttfi polyttytenv
Utex (PSL)
ElectroetetJc churJncatlon
Spinning d**
Other liquid eerotol generatom
NebuUier, etomber
OOP filter tett tyttem
Dry powder aeroeol generator*
fhddhedbed
Wright don feeder
Minttfccturer
end
Model
TSI 3050
TSI 3078
Reyco 258
CUmet Q-295
BCI
TSI 3071 G 3076
BCI
TSI 3400
TSI
CCA AC-1
BCI
Perdcle
Diameter
0. 5- 100 ym
O.O9-5pm
0.09- 5pm
0.09-5 pm
\J0.09-S pm
V
0.007-1 pm
1-30 pm
0.005-5 pm
0.05-5 pm
0.1-15 urn
O.I- IS pm
O.I- 15pm
0.1- IS pm
Production
Rate
Varle* with thet
targe rhei 1 x lOy*ec
Smell the 5 x 10 /we
Varle» with die
Verle* with the
Varie* with the
Verle* with the
Verlei with the end aeroeol
Verle* with the
Vtrle* with the end material
Verie* with (he and meterlel
Verle* with the end material
Verle* with the end material
Verlei with the end material
Varle* with the end material
Geometric
Standard
Deviation
•^1.05
•^1.05
^I.OS
-^l.OS
«£1.0S
•*Zl.<*
^1. 10
1.8-2.2
1.8-2.2
Comment*
Generate* droplet* which cen be dried
4
4
Cen eeparete on nearly any aeroeol material
Generates droplett which cen be dried
Generate* droplet* which may be dried
Generate* droplet* containing oil which may
be dried
Verle* with any powder
Verie* with any powder
Verie* with eny powder
Verle* with eny powder
-------
is less than about 5 urn (the actual limit varies with each particular convention)
Existing portable instruments using beta attenuation, piezoelectric resonance
and light scattering quite adequately cover the particle concentration and size
ranges mentioned above.
In summary, extant instruments, especially those that are portable,
are Vapable of providing the physical characterization of indoor aerosols; i.e.,
concentration, size, and for special cases, shape. No compact, self-contained
monitors are available for the direct chemical characterization of aerosols.
3.4.2 Standard Methods and Criteria for Acceptance of New Developments
Most of the standard or reference methods for the assessment of
aerosols are based on gravimetry or on microscopy of samples collected on
filters (e.g., EPA Hi-Vol method, NIOSH asbestos fiber counting method,
etc.). These methods are, in most cases, nonreal time, tedious, labor
intensive, and provide delayed results. The majority of these legislated
methods do not provide for an acceptance mechanism for equivalent and/or
alternate techniques. This situation tends to discourage the development
of new, more advanced measurement technology because general use of such
novel instrumentation is in conflict with existing regulations.
Although the stipulation of standard reference methods is mandatory
and indispensable, regulatory mechanisms permitting the determination of
equivalence and/or the acceptance of alternate approaches must be implemented
in order to promote the technical evolution of monitoring instrumentation,
especially in the field of aerosol characterization.
It is recommended that an official, perhaps governmental, testing
organization be assigned or recreated to test, evaluate, and report on newly
developed monitoring instrumentation. At present this evaluation procedure
is, at best, unreliable, and, at worst, inexistent. Even instrumentation
developed under>6overnment sponsorship is seldom evaluated objectively and
reported on in a disinterested manner. Usually the only published technical
documents are those issued by the contractor responsible for the development
itself, who is hardly to be considered an objective reporter.
Instrument acceptability, equivalence, performance limitations, and
range of applicability should be established on the basis of a clearly stipulated
and generally accepted methodology, performed by a competent and disinterested
scientific group.
The acceptance mechanism, coupled with a clear definition of the
potential market and specific instrumentation needs to carry out a wide ranging
monitoring program, are important preconditions to justify the risks and expenses
to be incurred by industry associated with the development of new instrumentation.
• As to developments sponsored by Government Agencies, a careful
review and revision of the existing patent laws is suggested. The abrogation of
patent rights by industry of inventions resulting from, or evolved within,
71
-------
such contractual activitites tend to discourage such collaborative efforts and
stifle inventiveness. Government contracts to industry for the development of
advanced and novel monitoring instrumentation should permit a continuing effort,
in a manner similar to government grants to research and academic institutions,
such that well planned developments can be executed without the usual overrid-
ing requirement for the immediate delivery of hardware, at the expense of
careful evaluation of such novel approaches.
3.4.3 Research Needs
Although a. complete definition of research needs in the area of
aerosol instrumentation can only be established by means of appropriate input
from the corresponding monitoring and health effects subgroups, several specific
directions can', however, be identified immediately, even in the absence of such
inputs.
Presently existing instrumentation should be applied to the immediate
'assessment of indoor conditions, and to determine the shortcomings of such
instrumentation in order to obtain criteria for further development needs.
Questions such as required particle size resolution (if any are needed beyond
respirable segregation), area monitoring vs. personal monitoring, etc. should
be addressed. It was realized that the ideal instrument to characterize indoor
aerosols should be capable of real-time measurement of the chemical composition
and concentration as functions of particle size and shape. This desideratum
does not exist at present and may not be reliable in practice.
Specific feasible R&D aerosol instrumentation needs that can be iden-
tified at this juncture are discussed in the following paragraphs.
3.4.3.1 Personal Exposure Monitoring Instrumentation
This is an extremely important instrumentation category. Presently
available devices to assess personal exposure are limited to pump-filter
samplers. The need exists for a personal monitor capable of both direct
real-time readout as well as of integrated or averaged measurements. A
high degree of miniaturization is required to provide an unobtrusive,
wearable monitor. Although, at present, a government funded (NIOSH-BOM)
program for such development is underway, the funding level available for
that overall project appears to be insufficient and should be increased
accordingly.
3.4.3.2 Real-Time Aerodynamic Particle Size Analysis
.. Although the specific particle sizing requirements have not
been established in this context, it appears that detailed size informa-
tion of the indoor environment is necessary to characterize the various
72
-------
contributors to indoor aerosol pollution and to provide guidelines for
the design of routine monitoring instrumentation. Private industry funds
are presently being expended to develop such instrumentation, but govern-
ment support would, most probably, accelerate and facilitate such efforts.
3.4.3.3 Integrated Monitoring Package for Field Surveys
•«
This development is not unique to aerosol measurements, but was
deemed to be an indispensable tool for the assessment and characteriza-
tion of indoor environments. This integrated monitoring package would consist
of a carefully designed back-pack, or.similar configuration, easily transported-
carried, containing an array of air pollution sensors, and a miniaturized
data recording-acquisition module. A common battery power source would be
used to energize this monitoring system. It would be used for walk-through
measurements or, alternatively, could be used as an integrated area, multi-
pollutant monitoring station. Specific pollutants to be sensed would include
organic gaseous contaminants. The monitoring package would be built in
a modular configuration, each of the pollutant species being sensed by an
independent detection unit. Data recording (e.g., cassette recorder,
bubble memory, etc.) would be common, as well as would the power source and
the sampling flow subsystem (this latter subsystem may be, however,
separate for specific sensors, if deemed preferable). Real-time readout
for each pollutant may be available in order to identify specific problem
areas. Within this project, miniaturization and redesign of existing
pollutant sensors would be required, in addition to the development of the
overall package.
3.4.3.4 Sampling Methodology for Chemical and Biological Analysis of Aerosols
The immediately available methodology for the chemical and/or bio-
logical characterization of indoor environment aerosols will remain restricted
to a two-step procedure: field sampling on a suitable medium, followed by
laboratory analysis of the collected sample. This nonreal-time approach
is the only one''presently applied for multi component characterization of
aerosol particles, and is expected to remain so in the immediate future.
Appropriate particle sampling and collection methodology should be established
in order to ensure representative and meaningful characterization of indoor
aerosols.
Sampling and collection techniques, sample storage, transport and
conditioning procedures, and analysis methodology must be defined and standard-
ized in order to permit meaningful data intercomparison.
3.4.3.5 Miniaturization of Fibrous Aerosol Monitor
As part of the overall sensor miniaturization and redesign effort
discussed.within project 3.4.3.3 (integrated monitoring package) there is
the specific need for miniaturization of the presently available GCA Fibrous
Aerosol Monitor. This instrument would be uniquely suited for walk-through
73
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indoor air pollution characterizations. The presently existing device is
too large for integration into the proposed portable multipollutant monitoring
package.
3.4.3.6 Data Telemetry-Positional Transmission System
As a complement to such monitoring instruments as the personal
exposure monitor and the integrated monitoring package mentioned above,
the need exists for a miniaturized data telemetry and positional sensor radio
system designed to permit time and motion studies of the indoor environment.
Real-time definition and transmission of the location of an individual wearing
a personal monitor or the integrated monitoring package is required to correlate
concentration level information with specific indoor locations and activities.
3.4.3.7 Instrumentation for Real-Time Chemical Characterization of Aerosols
This research activity must be considered as a long-term project
•and should be planned as such. Specific chemical species of interest must be
identified and carefully prioritized in order to provide reasonable bounds
to this overall problem. The extremely large number of elements and compounds
that constitute indoor airborne particles dictate such a careful selection before
any instrumentation needs can be established. Sensing methodology for the
selected chemical species must then be developed, modified, miniaturized, etc.
Instrumentation complexity tradeoff between multicomponent and single-
component sensing must be made. It is expected that significant advances
with respect to present state-of-the-art will be required within this
overall research program.
3.4.3.8 Development of Aerosol Standards for Validation and Calibration
Aerosol standards for laboratory and, possibly, field calibration
of instrumentation have to be established in order to ensure comparability
and standardization of methods and controlled and reproducible results.
Generation of monodisperse as well as polydisperse aerosols will be required
to calibrate, validate, and check the operation of monitoring instrumentation.
Special generation facilities such as required for the calibration of the
fibrous aerosol monitor will be required, as well.
3.5 ORGANIC POLLUTANTS
3.5.1 State of the Art and Research Needs
The task group concentrated on known problems of:
"- 1. Aldehydes
2. Nitrosamines
3. Pesticides including chlordane
. 4. PCBs
5. PNAs.
74
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The specifics of the development of suitable protocols and validation
studies before extensive field studies can be undertaken need developing.
The protocol outlined in NIOSH publication DHHS (NIOSH) No. 80-133, "Development
and Validation of Methods for Sampling and Analysis of Workplace Toxic Sub-
stances," is an excellent beginning. This protocol should be modified to:
• Include lower concentrations and cover a wider range
of concentrations
• Include the concept of diffusional type samplers
t Include field validation
• Include the concept of personal direct-reading instruments.
3.5.1 A1dehydes/Formaldehyde
NIOSH-SRI International developed and validated a bubbler sampling
method. The analysis can be performed by either HPLC with UV detector or
polarography. These methods are slow and do not lend themselves to large
numbers of samples.
There are a number of laboratories actively involved in methods
development for formaldehyde. At the Oak Ridge National Laboratory several
approaches are in different stages of development. These include either
active or diffusional collection of the formaldehyde on molecular sieve and
traditional chemical analysis. ORNL has modified a CEA formaldehyde monitor
to extend the range from the 0.5 ppm level to the 0.01 ppm level. The
program needs laboratory and field evaluation and validation of the
instrument.
The DuPont Company is developing a diffusional monitor, based on
sodium bisulfate,* The detection limit for an 8-hour sample is 250 ppb.
The performance of the system seems to meet the NIOSH criteria outlined
in its publication 80-133.
3.5.2 Nitrosamines
There are several known and proven methods for detection and
measurement of low levels of nitrosamines:
0 Use of activated charcoal traps together with portable
pumps with subsequent analysis by capillary GC or GC/MS
•" • Use of Tenax GC sorbent traps with portable pumps and
analysis by capillary column GC/MS analysis (Pelazarri
technique)
• Use of cryogenic traps
• Use of potassium hydroxide
75
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t Use of Thermosorb traps with subsequent analysis by
Thermal Energy Analyzer (TEA).
All of the traps listed above display artifacts in the measurement
of nitrosamines and other volatile organic compounds. The reader is referred
to Pellizzari's publications for a more detailed description of these limitations.
«*
When the Thermosorb is used with a portable pump drawing 8-1/min, the
sensitivity which can be attained when analyzing with the TEA is 10-100 ppt.
Using this same combination of trap and instrument, Thermo Electron has measured
nitrosamines in the following places:
Kitchen of residence 0.5 ug/m3
New care 0.6 - 2.0 yg/m3
Rocket factory 5.0-10 yg/m3
Tire factory 200 ug/m3
Ambient level (general) 1 ng/m3
Analysis for nitrosames collected by Thermosorb trap can be alterna-
tively carried out using the Hall Detector or GC/MS. The Hall Detector has
1/8 sensitivity of TEA and GC/MS is approximately same as TEA. (Colorimetric
methods have failed thus far to detect nitrosamines.)
Research needs for instrumentation for detection of nitrosamines
are in the following areas:
• Quality validation of TEA
• Automation of TEA
t Pilot program for monitoring.
3.5.3 PNAs
The literature on PNA sampling and analysis is extensive and cannot
be fully addressed in this secton. A brief review is provided in Table 3-8.
3.6 INORGANIC
The state of monitoring is adequately described elsewhere in this
text. --Recently, there have been new developments In monitoring which incorpo-
rate diffusional sampling.
In 1855, Pick described molecular diffusion theory in what has come
to be known as Pick's Laws of Diffusion. This is physical-chemical law upon
76
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Table 3-8.
PNAs in indoor air: Methods of collection and analysis
Personnel
Monitors
P & CAM 217
Suitability
Too bulky and
Availability
Operational
Comments
Consensus
of the
Benzene--
Soluble
Compounds in
Air*.
obtrusive for
general indoor
use. Yields no
information on
composition of
benzene or cyclo-
hexane solubles
and is an order of
magnitude too
insensitive.
subgroup for orga-
nics instrumen-
tation was that
the method is
currently
Inappropriate for
monitoring indoor
air. Limit of
detection is 20 yg
of benzene-soluble
material U). For a
1000 lite«- air
sample (2£/min.
for 8 hr.)t the .
limit of detection
1s 0.02 mg/m3.
This is l/10th of
the TLV for occu-
pational exposure,
and is the stan-
dard to be antici-
pated for
exposures to the
general
population. Hence
for quantitation
(10 x the limit of
detection)(2), a
method with a
limit of detection
of 0.002 mg/m3 is
needed.
77
-------
Personnel
Monitors
Suitability
Availability
Comments
Silver
Membrane-
Chrornosorb
102/high flow
pumps.
For limited use
because of bulk,
size and cost.
Developed for occu- Thoroughly eva-
pational use by
Enviro Control
under contract to
NIOSH.
PNA Vapor
.Badge(4).
Will be small,
lightweight and
cheap, with quan-
tjtation for select
PNA compounds
adsorbed on a
filter paper
element.
s
luated procedures
and quality
control(3).
Individual com-
pound sped at ion
and quantitation
by GC/FID for
naphthalene and
quinoline and more
complex PNAs,
usually with 1-10
ng detection
limits. The
sampling train
operates at air
flow rates of up to
l£/min. For
Indoor air moni-
toring this system
1s probably more
suitable as an .
area monitor.
Experimental devi- Detects only PNA
ces requiring vapors or fine
further development liquid
and field testing. droplets(4). Has
the advantages of
being completely
passive and pro-
ducing specific
analysis for com-
pounds such as
pyrene by direct
reading of a paper
adsorbent for room
temperature
phosphorescence'5).
Still in the
early stages of
development -
estimated 1 year
for proving efficacy.
78
-------
Area
Monitors
Suitability
Availability
Comments
Combination
pump/filter/
adsorbent
backup.
Enviro Control per- No recognized com- Further develop-
sonal PNA moni- bination for
toring system could general use in
be adapted for home residences at this
use principally as time.
an area monitor.
Area Monitor
- real-time.
Unavailable.
ment work required
to minimize PNA
degradation on the
filter. Choice
needs to be made
between Tenax,
XAD-2 and
Chromasorb
adsorbents.
Protocol needed
for consistent
methods of use and
evaluation.
A need exists for
a real or near-
real-time instru-
ment for
monitoring and
analysis of indoor
sources of air-
borne PNAs.
79
-------
Analysis
Monitors
Suitability
Availability
Continents
Sens-ftized
fluorescence
for
screening.
Easy, sensitive
analysis for
total fluorescing
compounds in
collected par-
ticulates - rapid,
cost-effective
sample throughput.
"Eyeballing" the
fluorescence inten-
sity gives an order
of magnitude esti-
mate of the PNA
concentration.
Synchronous ^ Simple, sensitive
Luminescence "*spectroscopic ana-
- screening lysis at room tem-
for select perature for select
PNAs. PNA compounds at
<1 ngconcentra-
v- ' tlonsO).
Recently developed
by Arthur D.
Little, Inc., under
contract to the
EPA(6). used in
the Monsanto
study(7) of PNA
emissions from wood-
burning stoves.
Requires simple
commercially
available
spectrof1uorimeter
to measure
fluorescence and/or
phosphorescence of
solvent extracts.
Limit of sen-
sitivity for PNAs
of 10 pg in a 1 p£
sample spotted on
filter paper
(equivalent to 10
ng in solvent
extracted PNAs
reduced in volume
to 1 ml). EPA-MEG
for BaP in ambient
air is
20 ng/m3 (l/10th
of the standard
for BaP [0.2 pg/m3])
recommended by
the Standards
Advisory Committee
on Coke Oven
Emissions!8)- To
meet this demand,
the method needs
to be increased in
sensitivity using
alternative sen-
si tizers to
naphthalene and an
electronic means
of measuring the
fluorescence
Intensity.
Successful par-
ticipation in NBS
and EPA round-
robin analysis of
real-life PNA
samples CIO). Needs
more comprehensive
field evaluation.
80
-------
Analysis
Monitors
Suitability
Availability
Comments
EPA Level I
screening.
Precise
Analysis.
are being followed
by EPA contractors.
Intended for preli- Procedures are
mi nary environmen- publishedUl) and
tal assessment
within a target
accurcy factor of 3
- part of a phased
approach to sample
collection and ana-
lysis for enhanced
cost effectiveness.
Sophisticated
labortory tools
(GC/MS, GC2,
HPLC, etc.) provide
detailed informa-
tion on the PNA
composition.
Equipment and
Analysis are suit-
a1>le for analyzing
a limited number
of samples.
•Solvent extracts
are fractionated
by LC into 7 por-
tions. Aromatic
hydrocarbons are
analyzed by IR and
LRMS in fractions
2,3. Sensitized
and/or synchro-
nized luminescence
might be incor-
porated into a
broadened scheme
at the Level I.
Several schemes are In round-robin
available but no
standardized
procedures are
widely recognized
and accepted.
interlabortory
measurements,
agreement is only
mo derated 12).
Further intercom-
parisons will be
necessary.
81
-------
References to Table 3-8
1. Benzene-soluble compounds in air, Method No. P & CAM 217, Issued
01/29/76.
2. Guidelines for data aquisition and data quality evaluation in
environmental chemistry, Anal. Chem., ^2, 2242-2248 (1980).
3. 'Sampling and analytical procedures for the industrial hygiene
characterization of coal gasification and liquefaction pilot plants.
Report submitted to NIOSH Morgantown by Enviro Control, May 1980.
4. R. B. Gammage, A. R. Hawthorne, D. D. Schuresko and T. Vo-Dinh.
"New instruments for plant area and personnel monitoring", paper to
be presented at the 3rd Miami Int. Conf. on Alternative Energy
Sources, 15-17 Dec. 1980.
5. T. Vo-Dinh, R. B. Gammage and P. R. Martinez, "Identification and
quantification of polynuclear aromatic compounds in synthoil by
room-temperature phosphorimetry", Anal. Chim. Acta, 118. 313-323
(1980). '~
6. E. M. Smith and P. L. Levins, "Sensitized fluorescence detection of
PAHs, Polynuclear Aromatic Hydrocarbons: Chemistry and Biological
Effects, eds. A. Bjorseth and A. J. Dennis, Battelle Press, pp.
973-9S2 (1980).
7. D. G. DeAngelis, D. S. Rubbin and R. B. Reznik, "Preliminary
characterization of emissions from wood-fired residential combustion
equipment", EPA-600/7-80-040, March 1980.
8. Limit for BaP of 0.2 yg/m3 of air recommended by the Coke Ovens
Advisory Committee (29 CFR 1910 • 1029).
9. T. Vo-Dinh/and J. R. Hooyman, "Selective heavy-atom perturbation for
analysis of complex mixtures by room-temperature phosphorimetry",
Anal. Chem., 51, 1915-1921 (1979).
10. T. Vo-Dinh and P. R. Martinez, "Direct analysis of a coal liquefac-
tion product by synchronous luminescence techniques". Anal. Chim.
Act a, in-pc,ess.
11. IERL-RTP Procedures Manual: Level I Environmental Assessment,
EPA-600/7-78-201, Oct. 1978.
i2.^. H.. S. Hertz, National Bureau of Standards, Surrogate Materials
Program Meeting, January 15, 1980 at ORNL.
82
-------
which passive personal dosimetry is based. With Pick's First Law as a start-
ing point, passive personal dosimetry has grown into an area of widespread
scientific research and can have significant impact on determining individual
exposures to toxic chemicals.
To illustrate the short history of these devices, the earliest papers
on dlffusional samplers were presented by Palmes and Gunnison and by Braun at
the 1972 American Industrial Hygiene Conference. The following year Reiszner
and West reported on a permeation device for S02. Since the early 70s,
the industrial hygiene community has been presented with square, round, and
tubular badges, with monitors that contain liquids and others that use solid
sorbents, with badges that measure a time-weighted average and monitors that
yield a detailed time versus exposure profile. This list of differences is
far from exhaustive.
3.6.1 Use of the Monitors
The monitors are small, lightweight, and are easily worn in the
breathing zone, on the collar, lapel, on the pocket, or elsewhere. The monitors
can easily be placed in rooms on walls, in aircraft, etc. The devices require
that the time of monitoring be recorded. Standard practices should be followed
such as recording ambient temperature, pressure and humidity, possible inter-
ferences, and some indication of the air movement.
The health specialist must realize that many of these devices are
fairly new and that they have not been fully evaluated. It may be necessary
for the health specialist to determine the monitoring success or failure of
a given passive device for a specific application.
When the term "diffusion" is used in reference to these devices,
it is meant that the device collects the contaminant after the contaminant
has moved from an area of high contaminant concentration (outside the badge)
to an area of 10wer or no concentration (inside the badge). This movement
takes place through a quiescent air layer of defined geometry, called the
diffusion layer. Permeation, on the other hand, finds the contaminant
dissolving in a membrane, chosen for use based on its characteristics relative
to the contaminant of interest. This solvation is the rate limiting step as
the contaminant passes from the higher outside concentration to the sorbing
medium.
3.6.2 Inorganic Monitors
Inorganic samplers, one for sulfur dioxide (SOg) and one for
mercury (Hg), were the subjects of the first AIHC presentations of diffusional
monitors. The first permeation badge was also used for SOg. Inorganic
passive diffusional monitors are exclusively single compound monitoring
devices, with the greatest number of devices being available for oxides
or nitrogen.
83
-------
Tables 3-9 through 3-12 contain tabulated information on inorganic
monitors. The significant point to glean from these tables is the wide range of
responses and analytical methods from which a user may choose. This can be
coupled with a wide range of prices.
3.6.Z.I The Palmes Tube
« «*^__^^_^^^^^—••_••••••_
The tube, when used for sampling N02 contains only triethanolamine-
coated screen. When sampling for NOX (NO + N02J, an uncoated screen
and chronic acid impregnated glass fiber disc are added. This allows for
conversion of NO to N0£. The analysis of either configuration of Palmes tube
requires a reasonable amount of analytical laboratory support work (e.g.,
calibration curves, etc., for the spectrophotometer). The devices give a TWA
value for NOX, N02 and NO by subtraction.
3.6.2.2 The Pro-Tek
The Pro-Tek Colorimetric Air Monitoring System encompasses both
sampling and analysis. The badge is activated upon removal from the foil
pouch. After exposure, the blisters are broken allowing the reagents to
mix with the absorbing solution. The badge is then placed in the reagent
pack carrier and inserted in the read-out unit to determine ppm-hr exposure.
This system currently has badges available for N02, S02, and NHTj.
The liquids in the badge can also be removed and analyzed in a spectro-
photometer and thus extend the monitor.
3.6.2.3 The Monitox System
This system includes sampling, analysis, and recordkeeping. Units are
available for HCN, N02, phosgene, H2$, and CO. Before use, a functional
check is performed on the monitor using the matched dynamic gas generator.
Once turned on, the unit relies on diffusion of contaminant molecules through
a membrane to the measuring electrode in the sensor cell. The device will
sound an alarm when the concentration exceeds the threshold limit value. The
Chronotox is a microprocessor-based personal monitoring system, which accepts
output signals from Monitox detectors. The stored data may be read out in one
of two ways:
1. Digital Readout--which gives 15 minute TWAs and an 8-hour
TWA
2. The Datagram which is a graphical profile of concentration
vs. time, plus an 8-hour TWA.
Both data retrieval methods give hard copy documentation.
84
-------
Table 3-9.
Passive Personal Monitoring Devices for* Oxides of Ntr.ror.mi
Manufacturer
MDA, Inc., also
DACO Products
E.It Du Pont
MDA, Incorporated
American Gas and
Chemical Company
MDA, Inc.
DACO Products
Solid State
Sensors Company
/
/
j
Brarfd Name
/
Pal INKS Tuba
Nl>2
Pro-Tek
N02
Monitox
N02
Leak-Tec
N02
Palmes Tube
NOX '
Nitrous
Oxide N20
Sensor
X,
V
Response
nanomolcs
of N02
ppm-hrs
alarm, TWA,
profile.
> 1 ppm
color change
ppm
Analysis
Spoctroplioto-
mct.rtc
PT-3
Spectrophotometer
datagram
none
required
SpocUrophoto-
mctric
service
provided
(IR)
KccouuiiiMidcd
Exposure
Limits
0-5 •> 5 ppm
10 •*• 100 ppm-hrs
1-100 ppm hrs
'/
> 0.5 ppm
> 15 minutes
N/A
2-26 ppm-hrs
Col lection
Media nl sin
TKA-coatod screens
di f fusion
diC fusion/absorption
dif fuslon/clcctrochcm .
diffusion
diffusion/chromic acid
impregnated dlsc/TKA ad
diffusion
00
-------
Table 3-10.
Passive: Personal Monitoring Devices Tor: Mercury, Hg
Manufacturer
3M
•
Sipln-Environmctrics
Solid State Sensor
•
*
f
Urap'd Name
Mercury Vapor
Monitoring
Service
//3600
Mercury Badge
Mercury
Monitor
.
' '
''Response
T.W.A.
T.W.A.
T.W.A;
. -
Analysis
Service Provided
(Conductivity)
Flnmclcss atomic
absorption spcc-
trophocomctry
Service provided
(AA analysis)
*
•
Hxposure
Limits
0.00-* 0.20 mg/in^
0. 002*0. 25 mg/m3
N/A
•
Col 1 i;c lion
Mcch.'inir.in
diffusion onto. p,old
collection surface
diffusion through
membrane onto specially
treated sorbcnt
diffusion adsorption •
onto gold film
1 l
•
00
-------
Table 3-11.
Passive Personal Monitoring Devices for: Sulfur Dioxide, S02
Manufacturer
Rcisznor
Environmental and
Analytical Labs, Inc.
E.I. Du Pont
nrnnd Nrunn v
MlnlMonitor
Pro-Tck
•
Kcr.ponsc
ppm
ppm-hr
•
Analysis
Wcsl:-C;ieke
speclroplioto—
met. ric
PT-3
Colorimctric
Spectrophotometer
1 *.
Kcc.ouiim'mli'il
Exporiurc
Limit: r>
0.01-*- ? ppm
lO.-*- 100 ppm-lirs
1- 100 ppm hrs
I
Collection
permeation
QMS membrane (ii\
tctracliloromcrcuratc
diffusion/absorption
_
* •
00
-------
Table 3-12 ,
Passive Personal Monitoring Devices for: 'Carbon Monoxide
Manufacturer
Progressive Products
Marketing Company
American Gas and
and Chemical Company
MDA Scientific, Inc.
J .
Urand N:imc
Dead STOP
Leak-Tec
Monitox
.• '
5" Response
color change
color chnti|»t!
>50 ppm
alarm, TLV
exposure
profile
Analysis
none needed
none needed
datagram
readout
\
»•.• •. »*. »• .
Rxpocuro
Limits
N/A
N/A '
> 0.1 x STD
•
*
Collection
. Mechanism
Diffunion
* %
Diffusion
Diffusion
electrochemical
\ '
• 00
. 00
-------
3.6.2.4 Leak-Tec
Leak-Tec Personnel Protection Indicators are plastic badges with
areas specially treated to react with a given contaminant. Badges are available
•for ammonia, carbon monoxide, chlorine, hydrazine, hydrogen sulfide, nitrogen
dioxide, and ozone. The chemical area of the badge indicates excessive expo-
sure \o a particular contaminant by undergoing a color change when a given
critical accumulation is reached. This is a different mechanism from those
devices requiring diffusion through a defined volume. These critical
accumulations are indicated throughout Tables 3-7 through 3-12. Tables 3-13
and 3-14 show personal monitoring devices for other inorganics.
3.6.2.5 Nitrous Oxide Sensor
This is the only passive personal monitoring device available
for N20. The N?0 sensor has two sorbent beds. The first is a dessicant
section which allows the N^O to pass to the second sorbent bed where it
is collected. This badge is returned to the manufacturer for post-exposure
analysis.
3.6.2.6 3M Mercury Vapor Monitoring Service 13600
This badge is one of the original passive sampling devices. The
badge collects HG vapor via diffusion onto a gold collection surface. Con-
ductometric analysis of the Gold-Hg amalgam is provided by the manufacturer.
3.6.2.7 Sipin-Environmetrics Mercury Badge
This Hg badge also collects mercury via diffusion. However, the
collection takes place on a specially treated solid sorbent. TWA results
are obtained via fTameless atomic absorption spectrophotometry.
3.6.2.8 Solid State Sensor Mercury Monitor
It collects the mercury vapor by adsorption onto gold film. The
analytical service (atomic absorption) is provided by the manufacturer.
3.6.2.9 Mini Monitor
.This badge—or line of badges—is a permeation rather than diffusion
controlled device. Permeation-type personal monitors are available for sulfur
dioxide, chlorine, vinyl chloride, alkyl lead, methyl chloride, and Freon 12.
For each of these badges, the selected toxic gas permeates a dimethyl
silicone membrane and is either absorbed or adsorbed as a function of each
gas1 unique sorbent. The analytical determination used with each badge is a
classical method--spectrophotometry or gas chromatography—frequently an
adaption of a NIOSH method.
89
-------
Table 3-13.
Passive Personal Monitoring Devices for Other Inorganics
Contaminant
„„,
* •
Cl
•
V"2
v
/
Manufacturer
E.I. Du Pont
American Gas
and Chcm. Co.
American Gas
and Chcm. Co.
Reiszncr
Environmental
and Analytical
Labs, Inc.
American Can
and Chcm. Co.
American Gas and
Chemical Company
MDA Sciontific,Inc
Brand Name
Pro Tek
teak-Tec ,:
Leak-Tec
MtniMonitor
Leak-Tec
Leak-Tec
Monitox
Response'
ppm-hrs
ppm-hrs
> 25 ppm
color change
> 1 ppm
color change
ppm
>1 ppm
color change
> 5 ppm
color change
alarm /TWA
exposure
profile
Analysis
PT-3
colorimctric
Spectrophotomete
none
required ,
none
required
spcctrophoto-
mctric
none
required
none
required
datagram
readout
Limits
50-500 ppm
5-500 ppm
r
N/A
N/A
> 0.013 ppm
0.1 •> 2,0 ppm
N/A
N/A
>0.1 x STD.
Collection
Mechanism
diffusion/
nbr.orption
diffusion
diffusion
permeation/
absorption
diffusion
diffusion
diffusion/
olcctroclipmtstr
SO
O
-------
Table 3-14.!
Passive Personal MonitorinR Devices for Other Inorp.anlcw
Contaminant
°3
Alky I Pb
UCN
/
ManuCactur/r
f
American C.-in
and Chom. Co.
Rclszncr
Environmental and
Analytical Labs,
Inc.
MDA, Scientific,
Inc.
X.
Brand Njimi!
I,cak-Tcc
MlnlMonitor
Monitox
Response
> I ppm
color change
y u(pp«")
ill arm/TWA
exposure
proCilc
Analysis
none
required
speccro-
photomctric
or AAS
datagram
readout
l!lTiH!t>l!lMu!l vl
l-'.xpii.'iurc
him Its
N/A
>0.2 Vg
>0.1 X STD
Col led ion
Hocli.-uiisin
flif fusion
permeation/
ndsorpt ion
diffusion/
cloct.ro-
chotnistry
VO
-------
3.6.2.10 Dead STOP
Via diffusion of carbon monoxide,'this badge undergoes a color change
after a critical accumulation of CO. The detector has the ability to regener-
ate itself after being exposed to CO.
« «
3.6.3 Organic Monitors
3.6.3.1 The Gasbadge, Organic Vapor Monitor, Pro-Tek and Mini Monitor
The commercial organic monitors, Table 3-15, Gasbadge, Organic
Vapor Monitor, Pro-Tek and the Mini Monitor, all use an activated charcoal
as the collection medium. All require gas chromatographic analysis of the
collected pollutant. The Gasbadge, Organic Vapor Monitor and the Pro-Tek
are diffusion devices, while the Mini Monitor is a permeation device. Each
has unique properties. The Gasbadge allows for a blank field. The organic
Vapor Monitor has in situ elution. The Pro-Tek has a variable sampling
'rate and a two-stage version. The Mini Monitor is specific for vinyl
chloride.
3.6.3.2 The Gas Monitoring Dosimeter
The Gas Monitoring Dosimeter for phosgene is a color change badge
which provides an alert in the 0.4 mg/m3 range. This color change device
can also be quantified by means of a color chart or analytical instrument.
3.6.4 General Monitors
3.6.4.1 Diff-Samp
The Diff-Samp, Table 3-16, is an acrylic tube with a closed liquid
well at the top, filled with a solution that would normally be used in an
impinger. An irtert wick, kept wet by the liquid is the absorption surface.
The analysis is a function of the chemistry of the absorbing solution.
3.6.4.2 Critical Orifice Personal Sampler
This device is neither diffusion nor permeation controlled. Sampling
is accomplished by ambient air leaking through a critical orifice into an
evacuated-chamber. By this technique a portion of the whole gas is collected.
The collected sample, unlike a grab sample, is time integrated. The device,
Table 3-15, samples constantly for extended periods of time, from 15 minutes
to 8 hours, with the maximum sampling interval dependent upon the size of the
orifice, and the volume of the evacuated vessel. Analysis is a function of the
contaminant of interest.
All of the monitors mentioned in this report are passive, personal
monitoring devices and all are commercially available. The field of passive
dosimetry goes far beyond this.
92
-------
Table 3-15.
Passive personal Monitoring Devices fort Organic Solvent Vapors
VO
CO
Manufacturer
Abcor Development
Corporation
3M Company
E.I. du Pont
REAL, Inc.
MDA Scientific, Inc.
SKC, Inc
•
•
Brand Name
Casbadgc
Organic Vapor
Monitor
Pro-Tck
1 and 2 Stage
MiniMonitor
(vinyl chlor-
ide)
Monitox
( phosgene)
Phosgene
Dosimeter
Response
ppm-TWA
ppm-TWA
ppm-TWA
ppm-TWA
nlnrm-TWA
exposure/
profile
0.4 tng/m
co lor change
Analysis
C.C.
C.C.
G.C.
G.C.
datagram
readout
color chart or
analy. instrument
Uucoimiu'TuliMl
Exposure
Limits
varies
varies
•
varies
>0.1+.2 X STD
0.1 X STD
N/A
Collection
Hocltani r.in
dfffunion/
ndsorption
dltfuslon/
adsorption
diffusion/
adsorption
.permeation/ •
adsorption
diffusion/
olcctrochcm
diffusion
(Continued)
-------
Table 3-15. (Concluded) ,
Passive Personal Montioring'Devices for; Formaldehyde, CH^O
x. •' .
Manufacturer
E. I. Du Pont
VO
,^>
(
.
•
j
Brand Name
i
Pro-Tek
•••
i
i
t
•
•
Response
' * •
,
ppm-hr
.
, •
,.
•/ *
•
'•' '
i: *
•
.
•
'
•
" • . i
b
' ' !*•
: ' ">•
Analysis
",.
, '.
Sodium Bisulfite
Colbrimetric V*
Spectrophotometer
• ' i
I ..
,
, •
•i
• •
!
..
. ' ' '
*' %
; i%
•.
i
i «
t :'
'•*
i 'i
i 1
,
.
*
i ;V '.-.
i ;••"
! / •';
^Recommended
Exposute Limits
2-50 ppm-hrs
1
i'
i •
il
'
•
' •
. ' »
!
Collection * "
. . Mechanism
. f' .
i •':'.'
diffusion/absorptloT
* * ' \
''. } '*
:' 1
• * t - •'
I
• | i i
'" t
.: :>1 ; • ':'
• 1 -i- •' ;:
•! 1 '
1 , ! i
• •' •' i '
5 i •• •
1.," ': ;"'
1 • ; •
• ' ' : .
i t
:
4 •'. '
I • 1 ,
- i
'•'•'!•
•;.!.'
' i 'i. ":
•' ^! •'.
1 ;• .
-------
Table 3-16.
Passive Personal Monitoring Devices for: Other Contaminants
Manufacturer
Daco Products, Inc.
MDA Scientific* Inc.
.
•
BramI Name
Dif f-Samp
.
Critical
Orifice
Personal
Sampler
.
Ruspon.se
TWA
TWA
•
Analysis
varies
varies
•
«
KirConmiOiulcd
F.xpoKitrc
Limits
varies
varies
•
Col lection
Mecli.mism
diffusion/ «
absorption
critical leak
**% .
•"
NO
U1
-------
3.7 AIR QUALITY CONTROL
3.7.1 The Term "Control" Has Two Definitions
• A control device is the device or process that controls
the variable of interest, e.g., temperature controller of a
furnace. For air quality, this could be the air filter
or scrubber.
t A control device can be an intelligent sensor and/or
actuator system that senses the parameter of interest
and contols the operation of the system or provides
an alarm in cases of process failures or emergency.
3.8 RECOGNIZED AREAS OF OMISSION
• As stated earlier, participants from many colleges and univer-
sities were not present. Furthermore, Federal Agencies or
professional societies which could represent the interest of
the academic profession were also absent. The academic community
is a vital component of this program if research is to be
conducted and contemporary texts are to include the health
aspects of indoor air pollution.
• Also absent from the group were persons with expertise in
the sampling and quantitation of pathogens (biological
hazards) and the characterization of odors.
0 The working group was under-represented in the area of
control instrumentation.
There were probably other omissions, but the working group
failed to identify them.
3.9 CONCLUSIONS
The programs in sampling and analytical method development, quality
assurance, research and development in new instrumentations should be pursued
as an interagency program in indoor air quality. A steering committee should
be established to coordinate the efforts of the different agencies. This
committee should also have discretionary funds to monitor the program as well
as fund special R&D projects.
96
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HEALTH EFFECTS
INDOOR AIR QUALITY RESEARCH STRATEGY PLAN
Robert Goyer
97
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1.0 'SUMMARY OF STATE OF THE ART OF POTENTIAL HEALTH EFFECTS OF POLLUTANTS
IN INDOOR
Introduction
Topics included in the state-of-the-art reports were selected because
of prior visibility as potential health hazards in the indoor environment.
These reports are only summaries and prepared for the purpose of identifying
research needs. These summaries do not include discussions of confounding
factors such as cigarette smoke which is synergistic to most substances of
concern. These, of course, must be considered in any specific research plan.
It must be emphasized that various substances or factors assume
various levels of importance in different clinical settings such as multistory,
tightly constructed buildings, family dwellings, or mobile homes.
Nonoccupational Indoor Health Hazards from Particulates
Robert S. Bernstein, M.D., Ph.D.
Clinical Investigations Branch, National Institute for Occupational
Safety and Health
1. Nature, Sources, and Vehicles for Indoor Particulates--A consider-
able amount of research has been done or is in progress regarding the health
effects of occupational and nonoccupational exposures to a variety of fibrous
and nonfibrous dusts. For fibrous inorganic particulates, there exist some
problems regarding the methods of sampling, analysis, and nomenclature which
impact on the interpretation of environmental and epidemiologic studies As
used herein, fibers are those particulates with an aspect ratio of 3:1 or more.
Respirable fibers have a maximum diameter of 5 ym or less, but may be up to
200 Mm in length. Respirable particles of irregular shape have a maximum
diameter of 10 urn or less.
, Respirable inorganic fibers may include the naturally-occurring
asbestos fibers of all varieties (chrysotile, crocidolite, tremolite, and
"amosite" which consists of a mixture of anthophylite and actinolite), some
fibrous zeolites, and the comminuted talcs (with or without contamination
by amphi boles or quartz). Respirable man-made fibers include mineral wools
(rock wool, slag wool, and fibrous glass wool) and ceramic fibers. The latter
man-made products may include binders (often a thermo-setting resin of the
phenol -formaldehyde type), lubricants, and other coating materials; or they may
be used as vehicles for pesticides and other consumer products. Nonoccupational
exposures to these fibrous agents may occur indirectly (e.g., bystanders in
99
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shipyards), by take-home familial exposures, by environmental exposures (e.g.,
amphibole contamination of Lake Superior, or zeolites in the volcanic tuff near
the Turkish village of Karain), or by exposure to friable consumer products
during installation, maintenance, operation, or replacement.
Respirable organic fibers may include cotton, grain, tea, wood, and
othei» vegetable dusts, as well as animal dander or feathers. With the excep-
tion of wood-dust-induced asthma, nonoccupational hazardous exposures to some
of these dusts may be rare events; or their sequelae may be subtle in onset or
chronic in nature and thus in need of further study. Bystander take-home
exposures may result from reentrained dusts carried into the home by pets and
others.
Among the sources of nonfibrous types of particulates, consumer
products provide a variety of potentially hazardous respirable agents including
talcs, attapulgite, or other clays (e.g., in kitty litter) and silaceous dusts
from plaster, spackling compounds, and cement. Road dusts may also be a source
'of silaceous dust, containing small amounts of free silica. In the vicinity of
heavy industrial activity (e.g., coal-fired power plants, foundries, smelters,
coke plants, and incinerators), there may be periodic or continuous excessive
emissions of industrial particulates, because of inadequate control technology,
which infiltrate indoors.Chemicals such as oxides of sulfur and nitrogen,
heavy metals, or polynuclear aromatics may be absorbed on these particulates
and may affect their toxicity. The increasing cost of oil and gas for heating
has caused homeowners to use wood and coal in their stoves and fireplaces, the
maintenance and operation of which may result in exposures to dust like those
from the industries just mentioned. The literature contains adequate documenta-
tion of the potential for "take-home" industrial exposures (e.g., lead and
asbestos). Respirable organic dusts (e.g., wood dust) are" the subject of
ongoing research. Contact, irritant, and allergic dermatitis may occur as a
result of exposure to vegetable dusts (e.g., in baking flours and biologicals).
Recently residents of the States of Washington and Oregon have had to contend
with uncontrollable and unpredictable emissions of volcanic ash, containing
abrasive, biologically active, highly-respirable particles of plagioclase
minerals and free silica. Household exposures to free silica and heavy metals
may result from the use of grinding wheels, making of pottery and ceramics,
etc. Another source of respirable particulates for a large segment of the
general community comes from tobacco and nontobacco smoking habits.
2. Known or Suspected Health Hazards from Exposure to Particulates--
Particulate agents may cause acute, subacute, and/or chronic diseases depending
on the specific agent and the intensity, frequency, and duration of exposures.
Most of the epidemiologic data we have, regarding hazardous exposures and
adverse.health effects of these particulates, have been gathered in occupational
settings among relatively young, healthy, adult males, often of a particular
ethnicity and sociodemographic status. Further epidemiologic data are available
in the ambient air pollution literature.
100
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The mucous membranes of the digestive and upper respiratory tracts as
well as the skin and eyes are vulnerable routes of entry which are also subject
to acute and subacute direct tissue Injury by Irritant particles (e.g., mineral
wool and glass fibers, sllaceous dusts, organic dusts, and absorbed chemicals).
The long-term health effects of low-level, Intermittent exposures to such
Irritants may Include the onset of exacerbation of disabling chronic diseases
(e.g., chronic obstructive lung diseases) 1n susceptible Individuals. Some
partfculates possess pharmacologlc or 1mmunosens1tiz1ng activity which can Induce
asthmatic, or allergic responses In susceptible Individuals (e.g., vegetable dusts,
pollen, and animal dander).
The chronic diseases which are suspected or known to be caused or
exacerbated by these particulates 1n high-dose occupational settings Include
chronic obstructive lung diseases (e.g., bysslnosls from cotton dust, chronic
bronchitis from silaceous dusts, and asthma or hypersensitivity pneumonitis from
organic dusts); pneumoconioses (e.g., from talc, asbestos, and silaceous dusts);
and malignant respiratory diseases (e.g., pleural and peritoneal mesothelioma
from asbestos, zeolite fibers, and possibly fibrous glass; bronchogenic
carcinoma from asbestos fibers; and nasal cancer from wood dust.
Characterizing representative prevalent and historical exposures
to these particulates in community indoor environments (homes, mobile homes,
automobiles, etc.) presents very difficult problems when compared to
Industrial settings. Occupational threshold limit values (TLVs) have been
established or proposed for most of the particulate agents mentioned above.
In some instances and for only a brief time (1 day or so), these TLVs
may be exceeded in the home—e.g., when laying down fiberglass or other insula-
tion materials. However, the relevance of these standards for the general
population (which Includes a high proportion of hypersusceptibles such as
Infants, elderly, chronically 111, malnourished, or poverty-sticken) requires
further evaluation. The types of medical-ep1dem1ologic procedures necessary
for case Identification Include:
}
• Standardized Questionnaire for Occupational, Environmental, and
Medical History, and Respiratory or other Symptomatology
• Spirometry and other tests of lung function (lung volumes,
diffusing capacity, etc.)
-t PA and Lateral Chest X-Ray
• Physical Exam for Clubbing of the Fingers, Chest Auscultation,
or other Target Organ Abnormalities
• Laboratory studies of Immunologlcal competence (Immune proteins).
It should be noted that in the case of most malignant tumors, medical
evaluation will be of no avail In prevention since there 1s a long latency
period between exposure and ultimate response, and no reversible early indicators
are known at present.
101
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Section 2.0
ORGANIC INDOOR AIR POLLUTANTS*
A.G. Ulsamer,** K.C. Gupta,** and H. Kang***
*
«
Recent Interest 1n energy conservation has resulted In an overall
effort to tighten the thermal envelopes of homes, schools, and other public
and private buildings. This effort has reduced the rate of air exchange and
caused concentrations of Indoor air pollutants to Increase to levels that can
possibly harm the Inhabitants. Attention has been drawn to a particular class
of Indoor air pollutants, the organic pollutants, primarily as a result of
problems associated with consumer exposure to formaldehyde. Formaldehyde and
other organic indoor air pollutants may be released from:
• Structural materials such as particleboard, plywood,
paneling, and Insulation
• Furnishings such as carpets, drapes, clothing, and
furniture
• Combustion processes such as unvented heaters, fireplaces,
furnaces, and stoves
t Consumer products such as aerosols, room deodorizers,
cleaning products, and coatings
• Human activities such as cooking, smoking, and practice
of arts and crafts.
The number of organic pollutants that may be present in an indoor
atmosphere can b$ exceedingly large. As seen in Table 1, a rather substantial
number of organfc pollutants have been Identified 1n home environments. Con-
centrations of these pollutants vary widely from home to home depending on
source, strength, rate of ventilation, and other factors. In any consideration
of Indoor organic pollutants, It 1s Important to remember that, although most
of the chemicals are volatile, some nonvolatile organic chemicals may also be
released from the use of aerosol products, smoking, and cooking.
"The National Academy of Sciences (NAS) is currently preparing an
extensive review of Indoor air pollutants which will evaluate existing data
* This article reflects the opinions of the authors and not necessarily their
organizations, since it has not been reviewed or approved.
** Consumer Product Safety Commission.
Occupational Safety and Health Administration.
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Table 1. Distribution of Organic Gases and Vapors
Over 32 Building Materials
Compound
Toluene
n-Decane
3-Xyl ene
n-Undecang
1,2,4 TMB5
n-Propyl benzene
2-Xyl ene
Ethyl benzene
Alkane C]f)
C3-Benzene
n-Nonane
n-Pinene
Mesitylene
n-Hexane
4-Xyl ene
C10H1fi
AoCarene
C4-Benzene
Styrene
Alkane C7-13
n-Propanol
2-Butanone
1,3,5 TMB5
Acetone
Disethyl benzene
Hexanol ^
Limonene
Butanol
Isooctane
I sopropyl benzene
Alkane C9
Heptane
Heptene-1-
3-Methyl heptane
Freon
1,2-Dichlorethane
Pentanql
«
i as Mesitylene
£ as Nonane
f as Octane
J Danish TLV (HGV 1976)
Trimethyl benzene
TYL 1976
(6)
375
-
435
-
120 .
(100)1
435
435
(100)1
1050
-
100
360
435
-
-
-
420 „
(1050T
500
590
120
2400
-
-
-
150 ,
(1450)?
(100)J
(io5or
1600
0
(1450)3)
-
200 '
(360)4
Number of
Identification
17
15
13
12
12
9
9
8
8
7
7
6
6
5
4
4
3
3
3
3
2
2
2
2
2
2
2
2
2
2
2
1
1
1
1
1
1
Average
Concentration
(mg/m )
36
1.45
30
0.58
0.29
0.11
5.8
4.1
2.4
0.45
0.92
2.8
0.04
8.7
7.6
31
0.07
0
0.61
0.36
0.15
0.16
0.55
0.56
0.25
1.45
0.55
29
0.11
0.06
0.97
7.3
1.90
3.7
0.18
3.3
0.25
(Continued)
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Table 1. Distribution of Organic Gases and Vapors
Over 32 Building Materials (Concluded)
Compound
Ethanol
Me th .tert. butyl ester
Nonene-1
Ethyl acetate
Octane-1
Octane
Decene-1
C4-Cyclohexane
Methyl 2-butanone
Ketone C5
Ketone C8
TYL 1976
(6)
1900
-
-
1400
-
1450
-
1050
700
700
-
Number of
Identification
1
1
1
1
1
1
1
1
1
1
1
Average
Concentration
(mg/m )
0
0
0
.0.11
0
0.29
0.26
0
0.4
0.7
0.06
104
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and Identify research needs. Since the NAS report will soon be available,
the present report will confine itself to only a very preliminary discussion
of the general classes of chemicals Involved, their possible sources, and
their general toxicology.
At present little is known about possible adverse or synergistic
effects on human health resulting from long-term, low-level exposure to most
chemicals. This type of exposure causes special concern in the case of
carcinogens or chemicals which promote or enhance the development of cancer.
Our discussion of organic indoor air pollutants will proceed according to the
following outline:
A. Al dehydes
Formaldehyde
Acetaldehyde
Acrolein
Other Aldehydes
B. Solvents
Aliphatic Hydrocarbons
Halogenated Hydrocarbons
Al cohol s
Aromatic Hydrocarbons
Ketones
Ethers
Esters
C. Polymer Components
Monomers
PJasticizers
Stabilizers
Other Chemicals
D. Pesticides
E. Other Organic Chemicals
Benzo-a-pyrene
Pentachlorophenol
Organic Acids
ALDEHYDES
The aldehydes comprise one of the most important classes of organic
Indoor.pollutants due to their toxic effects and widespread consumer exposure.
They are in general highly reactive chemicals which are strong sensory irri-
tants, producing in some instances sensitization and, more importantly, cancer
In animals.
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Forma1dehyde, for example, 1s used to make a wide array of industrial
and consumer products. Major uses of fbrmaldehyde and Its Intermediate chemicals,
are summarized in Table 2, and Include partlcleboard, plywood, and Insulation.
It 1s, In addition, a product of many combustion processes. Formaldehyde is a
strong Irritant and sensitlzer that produces a variety of symptoms, depending
on the. mode, duration, and concentration of exposure. Generally, short-term
exposure produces eye, nose, throat, and skin irritation as well as a variety
of other signs and symptoms 1n humans and animals. Long-term exposure has
been associated with changes 1n respiratory tract structure and function.
Sensitized Individuals undergo more severe, but similar, reactions at lower
concentrations of formaldehyde. The National Academy of Sciences has 1n
fact determined that there 1s no population threshold for the effects of
formaldehyde. Of even greater concern, however, are the recent findings in a
study sponsored by the Chemical Industries Institute of Toxicology, that
formaldehyde is carcinogenic to rats. These findings are supported by tests
showing mutagenic effects of formaldehyde 1n a number of test systems ranging
from bacterial to mammalian.
Acetaldehyde 1s used 1n glues and deodorants, in fuels, and in
the prevention of mold growth on leather. It 1s also present in tobacco
smoke. Acetaldehyde is an Irritant to skin and mucous membranes and continued
exposure may cause central nervous system (CNS) depression. While no defini-
tive association between acetaldehyde and any chronic toxic effect in humans
has been established, studies in animals indicate that acetaldehyde is both
carcinogenic and mutagenic.
Acrolein has been detected at a mean level of 51-102 wm/cigarette in
tobacco smoke. It has also been identified as a volatile component of essential
oils extracted from the wood of oak trees; and it has been found in the smoke
resulting from the combustion of wood, kerosene, and cotton. Acrolein is
one of the strongest cytotoxlc and ciliotoxic agents known and may cause
Impairment of mitochondria! function and DMA replication. Administration of
acrolein to experimental animals also caused increased pulmonary resistance.
It 1s mutagenicMn D. melanogaster and S. typhimurlum.
Other aldehydes may also be present in the Indoor air. Some of
these aldehydes are toxic and are known to be carcinogenic in various animal
species. Thus, for example, propionaldehyde, glyeidaldehyde, malondialdehyde,
and 3,4,5-tr1methoxyc1nnamaldehyde have been demonstrated to be carcinogenic.
SOLVENTS
Organic solvents and their vapors are likewise a common part of
our modern Indoor environment. Exposures 1n the home may occur from the use
of aerosol products, spot removers, paint removers, cleaning products, paints,
and numerous other consumer products.
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Table 2. List of Products Containing Free Formaldehyde
Products
Exposure
Material/Process
Agricultural Products
Artificial Ivory PF
Concrete PF
Contraceptives PF
Dialysis Units FS
Dry Cleaners FS
Dye FS
Embalming Fluid FS
Explosive FS
Fumigants FS,F
Furniture FS.FG
Germicides FS,F
Hide Preservers FS,F
Hospital Products FS.FG,
Inks FS
Insulation FG
Latex FG,FS
Mining Products PF
Mirrors FS
Mobile Homes FG
Paint FG.FS
Paper FG
Photographic Supplies FS.PF,
Plastics FS.PF,
Printing Products FS
Rubbers FG
Textiles FS,FG
,
t,
Shoe Products FG
Wood Products FS.FG
Note: FG = Formaldehyde gas
Prevention of mildew on grain
Principal ingredient
Minor ingredient
Major Ingredient
Disinfectant
Waterproofing, permanent press
Minor ingredient
Major ingredient
Minor ingredient
Minor/major ingredient
Off gasing from wood
Major ingredient
Leather processing, dyeing
F Disinfection procedure
Minor ingredient
Major ingredient
Major ingredient
Floatation agent
Minor ingredient
In wood products, insulation
Ingredient in Latex paint
Exposure to melamine resin
FSB Hardener, toner, fixing agent
F Resin production
Ink, dyes, preserver
Adhesive, coagulating agent
Waterproofing, fireproofing, crease
resistance, crush proofing, dis-
infectant
Resins, dyes, preservatives
Manufacture of plywood, parti cleboard
and pressboard (preservative and
adhesive)
FS = Formaldehyde solution
FSB = Formaldehyde sodium
PF = Paraformaldehyde
F = Formicin
bisulfite
107
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Aliphatic hydrocarbons such as propane, butane, and isobutane with
less than four carbon atoms are gases. These chemicals are used primarily as
propel 1 ants in many aerosol products and have no known chronic health effects.
Higher molecular weight aliphatic hydrocarbons such as hexane, heptane, and
octane are liquids and are used as solvents in many consumer products includ-
ing aerosol products, glues, varnishes, paints, and inks. Exposure to n-hexane
has Been associated with demyelination and axonal degeneration of the peripheral
nerves resulting in polyneuropathy in workers. Animal studies have confirmed
the neurologic effect of n-hexane and its metabolites. Other aliphatic
hydrocarbons induce primarily CNS depression at higher concentrations.
Halogenated hydrocarbons are excellent solvents and are widely used
in many kinds of consumer products. Exposure to these solvents has typically
caused myocardial depression and hepatotoxic effects at higher concentrations.
A number of these chemicals also have demonstrated carcinogenic effects in
animals. Chlorinated hydrocarbons include methylene chloride, a volatile
solvent widely used as an aerosol solvent and flame suppressant, paint
•stripper, and degreasing agent. In addition to the more general effects
associated with exposure to chlorinated hydrocarbons, methylene chloride is
metabolized to carbon monoxide by many mammalian species. Methyl chloroform is
also used in large quantities in many consumer products including many aerosols
and paints. This solvent also acts as a myocardial and CNS depressant. Neither
of these chemicals is known to be a carcinogen. Chlorinated hydrocarbons for
which there is evidence of carcinogenicity in animals include 1,1,2-trichloro-
ethane, hexachloroethane, 1,2-dichloroethane, vinyl chloride, vinylidine
chloride, trichloroethylene, and tetrachloroethylene.
Alcohols are used as solvents in aerosol products, window cleaners,
paints, paint thinners, cosmetics, and adhesives. They produce irritation
of mucous membranes, and affect the nervous system, producing excitation, ataxia,
drowsiness, and narcosis at higher concentrations. Methanol also affects the
optic nerve at higher concentrations. Synergistic effects between alcohols
and other solvepis may be of interest.
Aromatic hydrocarbons are also extensively used as solvents. Toluene,
for example, is widely used as a solvent in paints, varnishes, glues, enamels,
and lacquers. It causes symptoms of fatigue, weakness, and confusion in
humans exposed to 200-300 ppm for 8 hours. In contrast to benzene, there is
no definitive evidence to link toluene exposure to chronic adverse hematologic
effects. Chlorinated aromatics are also used to a limited extent as solvents.
In addition, benzene may be present as a contaminant in many hydrocarbon products.
Chronic exposure to benzene leads to the injury of the blood-forming tissues.
Relationship of benzene exposure to leukemia is of major importance.
Ketones may be encountered as solvents in lacquers, varnishes,
laquer and varnish removers, lubricating oils, adhesives, cosmetics, and
perfumes. Some of the ketones are irritants to mucous membranes, while
several cause CNS depression and pulmonary vascular dilation. Methyl butyl
ketone, which is still used in a few consumer products, causes peripheral nerve
108
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degeneration, which is enhanced by the concomitant presence of methyl ethyl
ketone.' Commonly encountered ketones may Include acetone, methyl ethyl ketone,
and methyl isobutyl ketone.
Ethers used in consumer products include methyl, ethyl, and butyl
ethers of ethylene glycol and dioxane. The glycol ethers are widely used as
solvents, since they are soluble in both water and organic solvents, and are
thus used in many oil-water combinations. They are also used as solvents for
resins, paints, varnishes, lacquers, dyes, soaps, and cosmetics. Exposure
to these solvents, usually in combination with other organic solvents, has
caused headaches, weakness, drowsiness, disorientation, and lethargy. Dioxane
produces irritation of skin and eyes, and possibly lung, liver, and kidney damage.
It also causes tumors in animals.
Esters are used in plastics, resins, plasticizers, lacquer solvents,
flavors, and perfumes. Some of the esters may irritate mucous membranes of
the eye, nose, and throat, and some esters may cause depression of the nervous
.system. Commonly encountered esters include ethyl acetate, butyl acetate,
and ethyl butyrate.
POLYMER COMPONENTS
Various manmade polymeric compounds are used in building structures,
furniture, packing systems, clothing, and numerous other consumer products. These
polymers contain unreacted monomers and other chemicals such as plasticizers,
stabilizers, fillers, colorants, and antistatic agents. Recently, attention has
been focused on the potential release of these chemicals into Indoor air and the
resultant toxicity.
Monomers, for example, vinyl chloride, esters of acrylic acid,
epichlorohydrin, and toluene-diisocynate, may be released from various
polymers. Esters of acrylic acid are used to prepare a large class of
plastics referred, to as the acrylics. The low molecular weight esters of
acrylic acid are irritants to skin, eyes, and mucous membranes. Epichloro-
hydrin is used 1n the synthesis of a number of epoxy resins. Epichlorohydrin
is highly Irritating to all types of tissues. Inhalation of the vapors is
extremely caustic to the mucous membranes in the respiratory tract. It is
also carcinogenic in man, as is vinyl chloride. Toluene dilsocynate (TDI)
and other isocynates used in the synthesis of polyurethane are strong
Irritants of skin, eye, and respiratory system. They are also strong sensi-
tlzers and chronic exposure can lead to asthmatic attacks.
Plasticizers are used to provide flexibility and as a processing aid
to convert a polymer into a final plastic product. Alkyl phthalates constitute
the major portion of the U.S. plasticizer market. Others include expoxy esters,
phosphates, ad1pates, polyesters, trlmellitates, and dlbenzoates. The toxiclty
data far plasticizers are Incomplete. In general, they are not acutely toxic
except at very high doses. Mutagenic and animal teratogenic effects have been
109
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reported for some alkyl phthalates. Recently the National Toxicology Program
Carcinogenesis Bioassay Program found that di-(2-ethylhexyl) phthalate (DEHP)
and di-(2-ethylhexyl) adipate are carcinogenic to both rats and mice; however,
butylbenzyl phthalate was not clearly carcinogenic in rats and has no carcino-
genic response in mice. DEHP accounts for more than 20 percent of all the
plastjcizers produced in the U.S.
«
Stabilizers such as organotin compounds are used as stabilizers for vinyl
plastic. From an acute toxicity point of view, the compound can be considered
extremely toxic. These compounds are.highly irritating to tissues and cause
neurologic effects.
Other chemicals in plastics: a number of chemicals used as curing
agents and accelerators may also be of interest. These are d.iethyltetramine,
mercaptobenzothiazole, tetramethylthiuram, monosulfide, and diphenyl guanidine
among others. Antioxidants added to polymers such as the monobenzylether of
hydroquinone and phenylbeta naphthylamine may also be possible indoor pollutants.
PESTICIDES
On the basis of EPA residential indoor monitoring data, the most fre-
quently found pesticides and their concentrations (in ug/nn) are: chlordane
(0.1-10); ronnel (0.2-2); dursban (0.2-2); DDVP (0.5-10); malathion (0.2-2);
and, diazinon (0.2-2). These pesticides are organophosphates, except for
chlordane which is an organochlorine compound. The general toxic effects of
organophosphates derive from their anticholinesterase activity, and include
wheezing, salivation, lacrimation, sweating, nausea, vomiting, bradycardia,
constriction of pupils, fatigue, tension, anxiety, restlessness, headaches,
apathy, confusion, and tremors. Chlordane produces blurred vision, confusion,
ataxia, cough, abdominal pain, nausea, vomiting, headaches, dizziness, and
mild chronic jerking. Chlordane also causes cancer in mice.
OTHER ORGANIC CHEMICALS
j
Benzo-a-pyrene (BaP) is a natural product of incomplete combustion
of carbonaceous material, cooking, and cigarette smoking. Its presence in
cigarette smoke ranges from 0.2-12.2 wgm/100 cigarettes. It has been found
to produce cancers in several species.
Pentachlorophenol is used as a preservative for wood, wood products,
starches,'dextrins, and glues. Its widespread use and persistent nature raise
concern about human exposure. PCP has been found in human tissues, with
inhabitants of log homes having higher tissue concentrations than the general
population. Blood levels of 0.39 ppm in log home residents versus 0.04 ppm
for the general population have been recorded. In the log homes the air levels
of PCP range from less than 4 wg/m^ to 1000 ug/m^. PCP causes lung, liver,
and kidney damage, and is currently being tested as a possible carcinogen by
the National Toxicology Program.
110
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Organic adds that may be found in indoor air include acetic acid.
Inhalation of these acids causes irritation of mucous membranes, and chronic
exposure may produce irritation of the respiratory system, gastrointestinal
disturbances and nervous system complaints.
ill
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REFERENCES
T
Flshbein, L. 1979. "Potential Industrial Carcinogens and Mutagens." Elsevier
Scientific Publishing Company, New York.
«
Doull*, J., C.D. Klaassen and M.O. Amdur, eds. 1980. "Casarett and Doull's
Toxicology: The Basic Science of Poisons." MacMillan Publishing Company, Inc.,
New York.
Ahlborg, U.6. and T.M. Thunberg. 1980. "CRC Critical Reviews in Toxicology,"
7(1), 6.
Environmental Health Perspectives, 3, 9, 1973.
IARC Monograph on the Evaluation of Carcinogen Risk of Chemicals to Man,
Vol. 19, 1979, pp. 377-418.
Formaldehyde - An Assessment of Its Health Effects. Prepared by National
Academy of Sciences for CPSC, March 1980.
Aldehydes class study prepared for National Cancer Institute Chemical
Selection Working Group, 1978.
112
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INORGANIC SUBSTANCES
Thomas L. Gleason, Office of Health Research,
U.S. Environmental Protection Agency
Carbon Dioxide
Although carbon dioxide is produced and released into the atmo-
sphere 1n much greater quantities than carbon monoxide, 1t 1s not usually
classified or defined as an air pollutant. Little can be done at this time
to control carbon dioxide emissions despite a regularly observed and sig-
nificant (0.7-1.0 ppm/yr) annual increase in the already large concentrations
of global ambient carbon dioxide (330 ppm) or the associated global climatic
Implications should the annual increase trend continue. The gas is a natural
end product of all combustion processes involving carbonaceous material
(MAS).
In a recent study Moschandreas, et al., reported that observed
hourly indoor concentrations of C02 were constantly higher than correspond-
ing levels 1n the ambient environment. The observed typical range for
ambient CO, levels was between 100 and 500 ppm. The Indoor 8-hour standard
recommendea by the American Society of Heating, Refrigeration and Air Condi-
tioning Engineers (ASHRAE) of 500 ppm was violated frequently. C02 con-
centrations indoors were a function of the number of Inhabitants and activity
patterns of the residents. In a tightly constructed building with little
exchange of air flow, C02 could be a health problem. Since it is an end
product of human metabolism, carbon dioxide rates may vary from 0.2 to as
high as 5 liters per minute (0.007 to 0.18 cubic feet per minute). This gas,
depending on the number of occupants and physical activity, could pose
physiologic and toxicologic problems such as simple asphyxia and mild
CNS depression.
>,
Carbon Monoxide
Generated Indoors by a variety of sources, Including gas appliances,
leaking furnaces, chimneys, vehicles 1n attached garages, and cigarette
smoking, carbon monoxide (CO) 1s a colorless, odorless gas which can cause,
1n extreme cases, death due to asphyxiation. The aged, the very young, and
those with cardiac or respiratory diseases are particularly affected by carbon
monoxide.
Moschandreas, et al., reported that Indoor CO concentrations were gen-
erally higher than corresponding outdoor levels 1n all residences monitored.
H1gher"concentrat1ons may be attributed to the above mentioned sources. Their
study showed the effect of typical urban rush hour traffic, and typical high
Indoor level periods. Seasonal variations were observed, with higher CO levels
during, the winter months. Observed measurements of CO concentrations both
Indoors and outdoors are generally not considered high enough to cause a health
113
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hazard. The hourly National Ambient Air Quality Standards (NAAQS) level of
35 ppm was not violated by either outdoor or indoor levels in this study. In
a tightly constructed building with low air exchange rate, CO could cause
elevated carbqxyhemoglobin levels in the blood, resulting in toxicological and
physiological effects. The inhalation of carbon monoxide causes asphyxiation
(anoxia, hypoxia) by forming chemical compounds, primarily with hemoglobin and
secondly with other biochemical constituents, which in a complex manner reduce
the availability of oxygen for the cellular system of the body. Symptoms
such as headache, fatigue, and dizziness appear early at low concentrations.
Disturbance of coordination, judgment, psychomotor tasks and visual acuity
occur with HbCO saturation of 4-6 percent. The current EPA standard for
carbon monoxide is 9 ppm maximum for 8-hour exposure or 36 ppm for 1-hour
average exposure. These standards are designed to prevent HbCO saturation
over about 2.5 percent (NAS 1977). A major hazard of carbon monoxide is the
insidious nature of its toxic effects.
Nitrogen Oxides
Nitrogen oxides (NOX) that are produced as a combustion byproduct
from energy-related technologies developed by man can create local pollutant
levels that are 10 to 100 times greater than natural concentrations. Nitrogen
oxides are emitted from combustion sources primarily as nitric oxide (NO).
Atmospheric processes may convert the nitric oxide to nitrogen oxide (N02)
and nitric acid (HN03). Exposure to NOX itself is believed to increase the
risks of acute respiratory disease and the susceptibility to chronic respiratory
infection. Nitrogen dioxide (N0£) contributes to heart, lung, liver, and
kidney damage. At high concentrations this pollutant can be fatal. At
lower levels of 25 to 100 ppm it can cause acute bronchitis and pneumonia.
Occasional exposure to low levels of N02 can irritate the eyes and skin.
Moschandreas, et al., showed the complexity of the dynamics involved
in establishing the indoor-outdoor relationship for the interpretation of
a data base gene/ated for NO. In houses equipped with gas cooking appliances,
observed indoor'levels are consistently higher than observed outdoor levels.
Houses with gas furnaces but electric cooking appliances display higher NO
indoor levels than outdoor levels most of the time. Indoor NO concentra-
tions in totally electric homes are almost always lower than corresponding
outdoor concentrations.
.Variation of the indoor concentrations of NOX is associated with
emissions from gas stoves. The observed indoor NO concentrations from totally
gas houses are generally higher than the observed indoor NO concentrations
in other types of houses. During the winter months the residential NO concentra-
tions are higher than the NO levels during the summer months. NAAQS for NO do
not exfst; an 8-hour average residential NO standard of 2.5 ppm has been recom-
mended by ASHRAE. The residential environment often provides a shelter from
high outdoor N02 levels. The 1979 Harvard School of Public Health study
mentioned in a General Accounting Office (6AO) report is in agreement with the
Moschandreas, et al., study in that N0£ levels were significantly higher in
homes with gas stoves than homes with electric stoves. In some cases the daily
114
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peak level In gas stove households exceeded the Federal air quality standards
for nitrogen dioxide.
A study done in England in 1972 compared respiratory illness of
children living in homes where natural gas and electric stoves were used (Melia
et al.). The study reported that children living in homes with gas stoves had
more-instances of respiratory disease than children living in homes with
electric stoves. The researchers concluded that elevated levels of nitrogen
dioxide from gas stoves might have caused the increased incidence of respiratory
Illness.
Sulfur Oxides
More than 25 million metric tons of sulfuric oxides (SO ) were
emitted annually in the United States. Sulfur oxides account for approximately
14 percent of the total estimated national air pollutant emissions. Released
primarily in the form of sulfur dioxide, they are converted by atmospheric
processes to sulfates, which interfere with normal breathing patterns, reduce
visibility, and contribute to the formation of acid rain. SO pollutants
are released by furnaces that heat homes, business and public institutions. A
small amount is derived from the exhaust of cars, trucks, aircraft, and
other vehicles. As a concentration of sulfur oxides in the air Increases,
breathing becomes more difficult, resulting in a choking effect known as
pulmonary flow resistance. The degree of breathing difficulty is directly
related to the amount of sulfur compounds in the air. The young, the elderly,
and individuals with chronic lung or heart disease are most susceptible to the
adverse effects of sulfur oxides. Sulfates and sulfur acids are more toxic
than sulfur dioxide gas. They interfere with normal functioning of the mucous
membrane within the respiratory passages, increasing vulnerability to infec-
tion. The toxicity of these compounds varies according to the nature of the
metals and other chemicals that combine with sulfur oxide in the atmosphere.
National Ambient Air Quality Standards for sulfur oxides establish
a maximum safe fevel of the pollutant in the atmosphere. According to these
standards, atmospheric concentrations of SO should not exceed 0.5 parts
per million (ppm) during a 3-hour period or 0.14 ppm during a 24-hour period.
The annual mean concentration should not exceed 0.03 ppm.
Moschandreas, et al., observed that S02 concentration samples in
the residential environment are very low. They attributed this to: (1) the
observed ambient S02 levels, although higher than the corresponding
Indoor concentrations, are low; (2) S0« is relatively reactive and it is
absorbed by indoor surfaces; and, (3) the high CO, concentrations found in
the indoor environment Interfere negatively with S02 in the monitoring
Instrument used.
115
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Ozone
Moschandreas', et al., studies coincide with the National Academy
of Sciences report 1n that Indoor ozone (03J concentrations are lower than
outdoor levels. 03 1s the surrogate pollutant for photochemical smog.
Ambient 03 levels are primarily of automotive origin, but other sources
Include tne combustion of fuels for heat and electric power, the burning of
refuse, the evaporation of petroleum products, and the handling and use of
organic solvents. 03 is highly reactive and decays rapidly by absorption on
Indoor surfaces. The half-life of 03 is variable because it depends on the
surface-to-volume ratio and the material of the furnishings. Owing to its high
reactions, 03 1n the indoors is normally found at levels ranging from 50-
70 percent of the corresponding outdoor concentrations. Moschandreas, et
al., report that ambient hourly 03 concentrations have been observed at
levels higher than the NAAQS of 0.08 ppm. The NAAQS for ozone has been
revised upward to 0.12 ppm since this study. 03 is not generated Indoors
1n great quantities. Hollowell, et al., have attributed small increases in
..03 concentrations to the use of electric stoves. The National Academy of
Sciences report states that indoor exposures may be substantially reduced by
appropriate choices of ventilation systems, air filters, and Interior surface
materials.
03 is a highly Injurious and lethal gas at relatively low concentra-
tions (a few ppm) and at short response periods (a few hours). The primary
Site of acute injury is the lung, which is characterized by pulmonary congestion,
edema, and hemorrhage. Ozone in excess of a few tenths ppm may cause headache
and dryness of the throat and mucous membranes of the nose and eyes.
Ammonia
The main source of ammonia (NH3) in the Indoor environment would
be expected from commercially available Household cleaners used for washing
the floors and windows and removing wax. Moschandreas, et al., introduced
ammonia Into the*' Indoor environment by mopping the kitchen floor with some of
the commercially available cleaning agents, 100 ml ammonia and 2 gallons of
water. Measurements showed the kitchen contained the highest ammonia concen-
tration. They observed very low levels of ammonia. The indoor standard
recommended by ASHRAE 1s 2.5 ppm. In the office environment, workers could be
exposed to NH3 from blueprinting and copying machines. In a tightly closed
house, one would experience irritation of the eyes and respiratory tract before
toxic levels would be manifested.
Lead (as In Air and House Dust)
The major sources of lead 1n the Indoor environment are from the
following sources:
116
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0 Airborne lead levels. These are likely to be elevated adjacent
to heavy traffic and near stationary sources, such as secondary
lead refineries.
• Water supply. In some areas leaded pipes in water distribution
systems may be corroded by soft, acid water creating localized
zones of high exposure.
• Food. Locally grown food from urban gardens may be high in lead
in some cases.
Children may ingest street dust, house dust, paint flakes, and soil
through norma\ hand-to-mouth activity, pica, or contact with pets, toys, and
other household objects. The dust is generally considered to be the largest
component of background exposure to lead. The lead in indoor dust to which
urban children are likely to be exposed may come from the dispositon of
aerosols, from the weathering or removal of paint, or from other sources.
It is not known to what extent lead enters houses through tracked in outdoor
soil and street dust, by wind transport, or through building ventilation.
Contributions from dust on clothing of adults with occupational exposure to
high levels have been reported (Rice, et al.). Exposure of children to lead
in paints remains a public health problem of serious magnitude. The greatest
area of uncertainty in assessing exposures to lead-based paints is establish-
ing how much lead from paint is actually ingested by children. Other indoor
sources of lead could be hobby activities such as making pottery with lead
glazes and soldering of wires for electronic devices.
Although permanent effects of lead poisoning, including blindness,
mental retardation, behavior disorders, and death, can occur at excessively high
exposure to lead, there is much evidence to indicate the occurrence of more
subtle, reversible health effects at much lower levels of exposure (Lin-Fu);
and damage to the heme-synthesis system, the renal system, and the central
nervous system g^n occur at prolonged exposure to levels of lead typical of
very urban residential environments. Preschool-age children with low levels of
lead exposure from all source may be experiencing adverse health effects even
though no overt symptoms are apparent.
Studies have shown that children absorb most of their lead orally,
about half, in contrast to 10% in adults. In addition to lead intake from
food sources, preschool children may ingest substantial quantities of lead in
soil, dirt, and paint chips. EPA has set a standard of 1.5 yg/m^ as the
maximum permissible ambient air lead level under the Clean Air Act.
117
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REFERENCES
r
Carbon Dioxide
National Academy of Sciences, Committee on Medical and Biological Effects
of Environmental Pollutants. "Carbon Monoxide." Washington, D.C., 1977,
p. 29.
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution 1n the Residential Environment." Vol. 1, EPA 600/17-28-229a,
December 1978. U.S. Environmental Protection Agency, Office of Research
and Development, Environmental Monitoring and Support Laboratory, Research
Triangle Park, North Carolina.
National Aeronautics and Space Administration. "Bioastronautics Data Book."
.NASA SP-3006. Washington, D.C., 1973, p. 48.
Carbon Monoxide
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution in the Residential Environment." Vol. 1, EPA 600/7-28-229a,
December 1978, U.S. Environmental Protection Agency, Office of Research
and Development, Environmental Monitoring and Support Laboratory, Research
Triangle Park, North Carolina.
U.S. General Accounting Office. "Indoor Air Pollution: An Emerging Health
Problem." Washington, D.C., September 1980.
National Academy of Sciences, Committee on Medical and Biologic Effects of
Environmental Pollutants. "Carbon Monoxide." Washington, D.C., 1977.
Nitrogen Oxide flIO )
A
U.S. Environmental Protection Agency Research Summary. "Controlling Nitrogen
Oxides." U.S. Environmental Protection Agency, Office of Research and Develop-
ment, Washington, D.C., February 1980.
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution in the Residential Environment." Vol. 1, EPA 600/7-78-229a,
December 1978. U.S. Environmental Protection Agency, Office of Research and
Development, Environmental Monitoring and Support Laboratory, Research
Triangle Park, North Carolina.
U.S. General Accounting Office. "Indoor Air Pollution: An Emerging Health
Problem." Washington, D.C., September 24, 1980.
Spengler, J.D., B.G. Ferris, D.D. Dockery, and F.E. Speizer.
118
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"Sulfur Dioxide and Nitrogen Levels Inside and Outside Homes and the Implica-
tion on Health Effects Research." Environmental Science and Technology, Vol. 13,
October 1979.
r
Melia, R.J., C. Florey, D.G. Altman, and A.V. Swann. "Association Between
Gas Cooking and Respiratory Disease." British Medical Journal, July 1977.
*
Sut'ftfr Oxides
U.S. Environmental Protection Agency Research Summary. "Controlling Sulfur
Oxides." EPA 600/8-80-029, U.S. Environmental Protection Agency, Office of
Research and Development, Washington, D.C., August 1980.
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution in the Residential Environment." Vol. 1, EPA 600/7-78-229a,
December 1978. U.S. Environmental Protection Agency, Office of Research and
Development, Environmental Monitoring and Support Laboratory, Research
Triangle Park, North Carolina.
Ozone
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution in the Residential Environment." Vol. 1, EPA 600/7-78-229a,
December 1978. U.S. Environmental Protection Agency, Office of Research and
Development, Environmental Monitoring and Support Laboratory, Research
Triangle Park, North Carolina.
National Academy of Sciences, Committee on Medical and Biologic Effects of
Environmental Pollutants. "Ozone and Other Photochemical Oxidants,"
Washington, D.C., 1977.
Hollowell, C.D., R.J. Budnitz, G.C. Case, and G.W. Traynor. "Combustion
Generated Indoor Air Pollution - I. Field Measurement." 8-75-10/75.
LBL Report No. i416, Prepared by U.S. Energy Research and Development
Administration, Contract W-7405-4(ENG 48), Lawrence Berkeley Laboratories,
Berkeley, California.
American Conference of Governmental Industrial Hygienists. "Documentation of
the Threshold Limit Values for Substances in Workroom Air," 3rd Edition.
Cincinnati, Ohio, 1971.
Ammonia
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution in the Residential Environment." Vol. 1, EPA 600/7-78-229a,
December 1978. U.S. Environmental Protection Agency, Office of Research and
Development, Environmental Monitoring and Support Laboratory, Research
Triangle'Park, North Carolina.
119
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Lead
U.S. EPA Background Document. "Lead Distribution and Marketing of Sewage
Sludge Products," 40 CFR, Art. 258 (Proposed Rule, Office of Solid Waste,
Washington, D.C., September 1980.
L1n-Fu, J.S. "Undue Absorption of Lead Among Children—A New Look at an
Old Problem," The New England Journal of Medicine, 286 (13):702-810,
March 30, 1972.
"Lead in the Human Environment." Environmental Studies Board, National Academy
of Sciences, Washington, D.C., 1980.
Moschandreas, D.J., J.W.C. Stark, J.E. McFadden, and S.S. Morse. "Indoor Air
Pollution in the Residential Environment." Vol. 1, EPA 600/7-78-229a,
December 1978. U.S. Environmental Protection Agency, Office of Research and
Development, Environmental Monitoring and Support Laboratory, Research
Triangle Park, North Carolina.
"Air Quality Criteria for Lead." U.S. Environmental Protection Agency,
Office of Research and Development, EPA 600/8-77-01, Washington, D.C., 1977.
Nriagu, J.O. "Lead in the Atmosphere," The Bipgeochemistry of Lead in the
Environment, Part A. Edited by J.O. Nriagu.New York:Elsevier/North
Holland Biomedical Press, 1978, pp. 137-184.
"Lead: Ambient Water Quality Criteria." U.S. Environmental Protection Agency,
Criteria and Standards Division, Office of Water Planning and Standards,
Washington, D.C., 1979.
Drill, S.J., H. Kunz, H. Mahr, and M. Morse. "The Environmental Lead Problem:
An Assessment of Lead in Drinking Water from a Multimedia Perspective." EPA
570/9-79-003. ]J.S. Environmental Protection Agency, Office of Drinking Water,
Washington, D.C.', 1979.
Mahaffey, K.R. "Environmental Exposure to Lead," The Biogeochemistry of Lead
in the Environment, Part B. Edited by J.O. Nriagu~New York:Elsevier/North
Holland Biomedical Press, 1978, pp. 1-36.
R1ce, C...A. Fischbein, R. Liles, L. Sarkozi, S. Kon and I.J. Selikoff. "Lead
Contamination in the Homes of Employees of Secondary Smelters." Environmental
Research, 15:375-380, 1978.
120
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Section 3.0
RADIATION
W.H. Ellett,* F. Gal pin,* and W.Lowder**
«
Radiation is a normal constituent of the indoor environment. Except
in'unusual circumstances, the levels of radiation indoors are comparable
to those in the outdoor environment. An important exception to this general
rule is the radioactive gas radon and its immediate decay products where
indoor levels typically exceed outdoor levels by a factor of three or more.
For this reason, this summary will focus mainly on indoor radon and its poten-
tial hazards. However, a brief discussion of other sources of ionizing and
nonionizing radiation affecting the indoor environment is appended for
completeness.
Although radon has a number of isotopic forms, radon-222 is of most
concern. It is part of the uranium decay chain and its immediate predecessor,
radium-226, is ubiquitous in nature. Ordinary soils and rocks contain about
1 picocurie (pci) of radium-226 per gram, corresponding to about 1000 disin-
tegrations per minute per pound. This decay rate is also the production rate
for radon-222 atoms. Natural radium concentrations 10 times larger or smaller
than this are not unusual (UN77). The inert radon-222 gas has a moderate
solubility in water and a 3.8-day half-life, decaying into polonium-218 by
alpha particle emission. Polonium-218 is the start of a four-member series
of radon progeny, all of which have half-lives of less than 30 minutes.
Radon Progeny
Because of its relatively long half-life compared to the time air
is in the lungs, radon itself is not a significant source of exposure; rather
the short-lived radioisotopes which occur after radon decay contribute most of
the dose, particularly the two alpha emitters, polonium-218 and polonium-214.
Since the degree of equilibrium between the various short-lived radon progeny
can vary appreciably with time, exposures to radon progeny are measured and
expressed in a specialized unit called the working level (WL). A working level
is any combination of the short half-life radon progeny in 1 liter of air
which ultimately emits 1.3 x 10$ million electron volts (Mev) of alpha-ray
energy. This is the amount of alpha-ray energy emitted by an equilibrium
mixture of 100 pci per liter each of polonium-218, lead-214, bismuth-214, and
polonium-214. The working level'was originally developed as a measure of
exposure to workers in uranium mines and the common unit of cumulative expo-
sure is the working level month (WLM), i.e., occupational exposure to air
containing one working level of radon progency for 170 hours, a working month.
Continuous residential exposure to one working level for one year would result
in about 20 WLM if it is assumed that the breathing rate is less for common
* U.S. Environmental Protection Agency
** U.S. Department of Energy
121
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Indoor activities than for mining and that 75 percent of the time is spent
indoors (EP78).
The mechanisms for tissue exposure from radon progeny is understood
fairly well. Unlike the radon gas, the charged polonium atoms become attached
to microscopic dust particles and these particulates, less than a few tenths
of a*micrometer in diameter, are inhaled. Such small particulates have a
good chance of being retained on the moist epithelium lining of the bronchial
tubes. The short-lived decay products release ionizing energy as alpha
radiation before the particulates to which they are attached are cleared from
the lung. However, it is not clear as to which exposed cells of the lung give
rise to bronchial cancer. Therefore, most studies have correlated the lung
cancer mortality with exposure conditions expressed in working levels rather
than some estimate of energy deposited in tissues, i.e., the dose in rads.
Sources of Indoor Exposure
Outside air typically has an average radon progeny concentration of
about one thousandth of a working level. These levels are not constant,
since they depend on radon release rates from soils and the amount of dilution
occurring from local weather conditions. Indoors, the situation is quite
different. Because there is less rapid radon dilution due to the limited
exchange rate between indoor and outdoor air (typically three quarters to one
air change per hour in closed structures), radon progeny concentrations in
buildings are usually several times higher than in outside air. While a
comprehensive evaluation of population exposure has never been made, one
set of data on the annual average radon progeny levels on the first floors of
residential structures in uncontaminated areas shows a mean value of 0.004 WL
(0.08 WLM per year) with some indication that 5 percent of typical residences
might have a concentration greater than 0.01 WL (0.2 WLM per year). Radon
progeny levels also vary with location within structures. In the study described
above, the average concentration in basements was two times greater than in
living areas. *
It is possible that not all pathways for radon entry into structures
have been properly identified, but the current belief is that the most significant
pathway, in most cases, is radon migration from soil into basements through
cracks and places where pipes enter. Groundwater may also be a significant
radon source in some areas. Many wells have substantial quantities of radon
in solution even though radium contents are relatively low. Water use
in the home (showers, washing machines, etc.) results in the release of
radon into the home atmosphere. The problem of elevated concentrations of
radon in water is being studied extensively, but its geographical extent is
not well known. A third source of indoor atmospheric contamination is
building materials, from which some of the radon produced by radium decay
diffuses into room air. An occasional source of high radon levels in buildings
1s the use of reprocessed waste materials to fabricate new building materials
such as-gypsum board and cinder blocks. Because reprocessing of wastes is not
a we11-developed industrial practice in the United States, the occurrence of
such situations is probably not common. However, a few have been identified.
122
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While there are some studies under way on the release of radon from common
building materials, comprehensive data for U.S. construction materials are not
yet available. Crushed rocks in solar heat- storage units can be a significant
source of radon. Since their use is associated with tight, energy-efficient
homes, and energy efficient homes are becoming more prevalent, this potential
source should be investigated on a priority basis.
«
Although the average level of U.S. population exposure to indoor
radon decay products has not been well established, numerous studies have
been conducted in specific locales where there was cause to expect elevated
exposure levels. Most of these evaluations have been in areas contaminated
with uranium mill tailings. Others have included areas of phosphate mining,
reclaimed land in Florida (EP78), mineralized lands in Montana, energy efficient
homes, and ordinary dwellings in uncontaminated areas. Table 1 summarizes
most of the readily available data. Good determinations depend on long-term
measurements, so that some of the data for "grab samples" given in Table 1 may
not be indicative of actual exposures.
Health Effects
The emission of alpha particles by radon decay products is a signif-
icant factor in the subsequent health effects. Unlike X-rays and the electrons
they produce as secondary radiation, alpha particles are heavy, doubly charged
particles which produce a large number of excitations and ionizations along
a very short path in tissue. For this reason, alpha particles are classified
as a high-LET (linear energy transfer) radiation. Because of their dense
pattern of ionization they can cause more radiation damage per unit absorbed
energy than X- and gamma-radiation, and consequently the International Council
on Radiological Protection has assigned a quality factor of 20 to alpha particle
doses. This means that for equal doses, measured in rads, or energy absorbed,
the dose equivalent, in rems, attributed to alpha particles is 20 times larger
than for X-rays.
ji
Alpha particle irradiation is demonstrably carcinogenic. Moreover,
reducing the dose rate appears to have little or no effect on the amount of
biological damage per unit dose that they cause. This is thought to be due
to lack of effective repair processes for alpha particle damage. At low doses,
the frequency of cancer from high-LET radiation increased at least proportion-
ally with dose, but increases more slowly at high doses, because cell killing
reduces the population of the cells at risk.
A significant increase in lung cancer has been observed at cumulative
occupational exposures that are comparable to those which could occur from
lifetime exposure to the most highly exposed members of the general public.
The possibility of a threshold dose for lung cancer induction following alpha
particle irradiation cannot be positively excluded. However, we are aware of
no radiobiologic or epidemiologic support for a threshold for lung cancer
induction due to radon progeny exposures.
123
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Table i. Indoor Radon and Radon Decay Product Levels1 (RP80)
Approximate
Number of
Noaea
II V
II
29
100
29
21
13
96
16
5
1?
9
29
1?
100
22
Proarama. 0.
Average
Radon
Cone (pCl/1)
1.0
1.0
(I.I)**
(2.9)
(0.9)
(0.69)
0.1*
(3.3)
(2.6)
(2.1)
(3.6)
(2.1)
0.3
4
1.4+
• houaeo > 10.0
9 houaea > 9.0
.R.R.f.A.
Average
ML
.01
.007
.007*
0.019
0.0011
0.004
0.004+
0.02
6.011
0.01?
0.011
0.014
(0.002)
(0.02?)
0.006+
pCl/1 of Rn
pOl/l of Rn
Maeaureaient
Conditions
TR*
»
TR
TR
TR
TR
TR
TR
Jan-Hay
Jan-Hay
Jan-Hay
Crab
Dttt Oloaed++
Crab
DIM Cloaed
Crab
DiU Oloaed
Creb Saatplo
DIW Cloaed
I above
.01 UL
19X
I7X
».
40X
IX
4X
I4X
79X
96X
40X
76X
60X
OX
76X
29X
(411
I ebove
.02 ML
I7X
OX
ox
29X
OX
ox
I4X
36X
2SX
40X
15X
40X
OX
15X
11
> 0.01 1
Home Location
HT/MJ - OIL
(baeeoiento)
(flret floor*)
Grond Junction, CO - COM
(background)
FIorIda
(pltoephate) - EPAftDIIM
(background) - EPA
(background) - DIIRI
(background) - UP
Rutto, MT - EPA ft HDnei
Anaconda, MT - EPA ft MDHE8
Alabaaia and Neighbor Itataa TVA
(phoapbato alag, flrat floora)
(phoipbato eleg, baacnenta)
(control, baaenanca)
•an Franeleco Region - LRL
Energy Efficient Itoaiea
(varloua locatlona) - LIL
•ode Sprlnga, Idaho - IDIW
(plioaphate alag, baaeaianta)
Illlnola - AMI
(with unpaved crawl apace)
* TR aieana year round average under occupied condition* (air pu»p Integrated aieaaurtMenta)
* Geometric aiean
** Valuea In parenthetic are not direct •eaaurtMcnte, but are e*leul*ted ualng • characterlatle r*don decay
producta/radon equilibrium retlo of 0.1 for baaeaient* and 0.41 eleewher*.
«» Door* and window* of atructuro ware eloeed for a tine before taking a grab aaaple or eontlnuoua neaaurcMant.
-------
Estimates of the risk due to inhaled radon progeny are based on studies
of occupational exposure to underground miners. There are many uncertainties
in extrapolating those results to the gener'al population because of significant
differences in such factors as age, smoking habits, and physiologic condition.
Estimates of risk due to exposure to radon decay products were tabulated in a
recent study of indoor radon prepared for the Radiation Policy Council (RP80) and
are reproduced in Table 2.
Table 2. Estimated Life Time Risks of Fatal Lung
Cancer from Radon Progeny (RP80)
Cases per 106
Estimator
UNSCEAR
NRC
EPA-absolute risk
EPA-relative risk
BEIR III
Victor Archer-absolute risk
NCRP-absolute risk
Person WLM
200-450
360
350
860
850
1050
130
Comments
30-year exposure to adults
all ages, 1967 U.S. population
cohort (stationary population)
cohort (stationary population)
cohort (stationary population)
cohort (stationary population)
all ages, 1975, U.S. population
All of these estimates assume that children are no more harmed by radiation
than adults. While there is no evidence to support or reject this assumption
for lung cancer^ data on Japanese bomb survivors do not indicate a higher
child sensitivity for other cancers. Even without considering this possibility,
the range of risks listed in Table 2 is broad and somewhat indicative of the
degree of uncertainty in current estimates of risks due to radon. Nevertheless,
even the smallest of the risk estimates in Table 2 indicate that living in homes
having abnormally high radon would have considerable health impact.
-Nature of Exposures
Indoor exposures to radon daughters are chronic, but with widely vary-
ing levels. Indoor levels depend primarily on source strength and ventilation
rates. .As ventilation rates are decreased, all else being equal, levels of
radon increase proportionally. The level of radon progeny increases somewhat
more rapidly since the mixture of daughters approaches an equilibrium value
(CL78). For this reason there has been considerable discussion of the potential
effect-of reducing ventilation to save energy unless remedial measures to
control radon levels are introduced, or other measures simultaneously reduce
the source strength.
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Indoor levels are quite variable throughout the year as ventilation
and source strength fluctuate. Fall and spring seasons, when windows may be
open, will exhibit much lower levels of radon daughter products than in summer
or winter when a home is closed up for air conditioning or heating. Other
factors related to home heating and air conditioning systems can affect radon
decay«product exposure if they change the concentration of particulates in the
air. Apparently any filtration systems, electrostatic precipitators, or even
extended duct work that removes particulates can reduce exposures. Our present
understanding of this is that when the concentration of air particulates
becomes low enough, the radon progeny.plate out on room walls and other surfaces,
but further investigation is needed.
As indicated above, many of the parameters controlling indoor radon
progeny levels are poorly understood and require further research. It is
expected that in wet climates, moisture acts to reduce the exhalation of radon
from soil and inhibit transport so that indoor levels are reduced, but soil
moisture and porosity have not been measured in studies to date, nor have
different kinds of housing been seriously investigated in the United States.
It is expected that multistoried dwellings will have much lower radon levels,
but this needs to be verified since building materials are also a factor, as
had been found in Sweden. Moreover, a recent survey of residential structures
in Austria indicated that the levels of radon and progeny can be poor predictors
of actual exposures to inhabitants since the living pattern of the occupants
plays an important, but often neglected, role. As yet we do not have good
general models to predict levels in closed homes. Eventually models that
can reflect how houses are actually used will be needed. In the meantime,
long-term monitoring is the best source of data on human exposures.
For purposes of perspective, Table 3 indicates approximate estimates
of U.S. population exposure to various sources of radiation. The exposures
are given in terms of annual effective (whole-body) dose equivalent as defined
by the ICRP, a quantity that can be considered as roughly proportional to
overall risk. This perspective is particularly important in the assessment
of possible future trends in radiation exposure resulting from the introduction
of energy conservation practices that reduce air exchange rates and from a
more widespread use of radium-rich waste materials in building construction.
In the former case, a significant reduction in the average indoor-outdoor air
exchange rate in U.S. housing will have a substantial impact on the radiation
exposure of the U.S. population in the absence of appropriate control measures
or "radon-reducing" conservation measures. However, it appears likely that
such measures can be developed as part of an overall research and development
program. This perspective highlights the importance and urgency of research
into the magnitude and range of present radon exposures, the effect of various
environmental parameters on such exposures (notably air exchange rates and
heating and air conditioning practices) and the efficiency of possible radon
control methods.
126
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Table 3. U.S. Population Exposure Due to Various
Sources of Radiation* (RP80)
Source
Annual Collective Effective
Whole Body Dose - 10^ Person rem/y
Cosmic Rays
Terrestrial Radiation
Internally Deposited Radionuclides
Radon and Progeny (0.004 WL)
All Others
Medical Diagnostic X-Rays
Fallout
Building Materials
Airline Travel
6
6
10**
8
10
1
1
0.1
**
UNSCEAR - 1980 (Draft) (NA80)
Reduction of average air exchange rates in houses by one-half without
additional controls would increase this collective dose to 20 x
person rem/y.
RADIOFREQUENCY RADIATION
Sources of Exposure
Virtually all of the public's exposure to radiofrequency radiation
comes from radio and television broadcasting—mostly FM radio and VHF and UHF
television. Frotn field measurements at 486 sites in 15 U.S. cities, EPA
estimates that only 0.6 percent of all U.S. residents are exposed to radio-
frequency radiation at levels of 1 microwatt per square centimeter or more,
and that half of all residents are exposed to less than 0.005 microwatts per
square centimeter. There are no U.S. exposure standards applicable to the
general population. The American National Standards Institute (ANSI) has
suggested the standard of 10,000 microwatts per square centimeter which has
been adopted in many occupational exposure situations. ANSI and the National
Institute for Occupational Safety and Health are both pursuing revised
occupational criteria. The EPA intends to propose standards for the general
population within the next 2 years.
Radiofrequency Radiation and Health Effects
Animal studies show beyond doubt that high levels of exposure to
radiofrequency radiation; i.e., far greater than 10,000 microwatts per square
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centimeter, convey a risk of cataracts, and produce thermal injuries.
The risks from lower levels of exposure are,less well established. Some
experiments have shown that animals exposed to levels even somewhat below
10,000 microwatts per square centimeter can show some physical and psychological
effects and may affect people, but how and to what extent are unclear. Extend-
ing the results of animal studies to human beings is difficult and uncertain.
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REFERENCES
CL 78 Cliff, K.D. "Assessment of Airborne Radon Daughter Concentrations
in Dwellings in England," Phys. Bio. Med. 23, p. 696.
EP 78 Environmental Protection Agency, Indoor Radiation Exposure Due to
1 Radium-226 in Florida Phosphate LlmdTEPA 520/4-78-013, USEPA,
Office of Radiation Programs, Washington, D.C.
GE 80 George, A.C. and A.J. Breslin, "Distribution of Ambient Radon and
Radon daughters in New York and New Jersey residences," Proceedings
of Natural Radiation Environment III, April 23-28, 1978.In press,
University of Texas, Houston, Texas.
NA 80 National Academy of Sciences, National Research Council. The
Effects on Populations of Exposure to Low Levels of Ionizing
Radiation"! Report of the Advisory Committee on the Biological
Effects of Ionizing Radiations, National Technical Information
Service, P.B. 239 735/AS, Springfield, Virginia.
RP 80 Radiation Policy Council Task Force, Position Paper on Radon in
Structures, August 15, 1980. U.S. Radiation Policy Council,
726 Jackson Place, N.W., Washington, D.C. 20503.
UN 77 United Nations, Sources of Ionizing Radiation. Report of the United
Nations Scientific Committee on the Effects of Atomic-Radiation,
1977 Report of the General Assembly, United Nations Publication
E.77.IX.I. U.N. Publications, New York.
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BIOLOGICAL SUBSTANCES
Peter J. Baxter, M.D., Centers for Disease Control
INFECTIONS
*
Most infectious diseases are spread by direct transmission, or are
vehicle or vector borne. For common illnesses; e.g., colds and influenza,
direct transmission is the mode of spread (usually limited to a distance of
1 meter or less between people) and density of occupants in a room is thus
an important factor (1). A few diseases; e.g., legionnaires disease, tuber-
culosis, and certain fungal diseases (e.g., histoplasmosis) can be spread
by airborne transmission; i.e., dissemination of microbial aerosols to a
suitable port of entry, usually the respiratory tract. Droplet nuclei (small
residues which result in evaporation of fluid in droplets emitted by an
infected host) and dust (under 5 urn in diameter) or fungal spores are the modes
of transmission. Indoor air quality may, therefore, be a factor in the spread
of the above mentioned diseases, but few studies have been undertaken on this
topic (G. Mallison, CDC, personal communication).
Outbreaks of legionellosis have been linked with air ventilation
systems. Legionnaires disease clinically resembles other pneumonias except that
it is more likely to present with encephalopathy and diarrhea; Pontiac fever,
caused by the same organism, is nonpneumonic and occurs in explosive outbreaks
involving all exposed persons within a short incubation period. L. pneumophila
has been isolated,, from cooling towers or evaporative condensers. Drifting of
clouds of infected droplets given out by these devices results in the intro-
duction of organisms into buildings, often through the air intakes of the
air handling systems. Legionellosis has not so far been associated with home
air conditioning units (2).
ALLERGENS
*
Hypersensitivity is an abnormal reaction to a foreign substance. An
allergic reaction is a form of hypersensitivity that can be shown to be mediated
by immune mechanisms and is clinically encountered most commonly as allergic
rhinitis, asthma, or dermatitis. Common inhalant allergens are pollens, fungi,
and house dust. Enclosed spaces are refuges from outdoor airborne allergens,
the air concentrations being lower indoors if the windows are closed. The
efficiency of air handling units to remove pollen is greatly enhanced by the
use of high efficiency air filtration devices (not usually found in most offices
and homes).
." The numerous specific indoor occupational allergens will not be con-
sidered further: these are usually localized to a specific process or work
practice. However, certain allergic syndromes have recently been identified
which relate to general indoor air quality in the home and workplace, and these
are described here:
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1. Hypersensitivity Pneumonitis (Extrinsic Allergic Alveolitis^
Hypersensitivity pneumonitis occurs in some subjects after repeated
Inhalation of any of a wide variety of organic materials. Thermophilic actino-.
mycetes have been implicated most often, but numerous fungi as well as animal
proteins have been demonstrated to be etiologic agents (3). It is now widely
recognized that outbreaks can occur in offices and homes (4,5) and are due to
aerosols from forced air heating or cooling systems contaminated with micro-
organisms. The hypersensitivity reaction in these disorders usually results
in chills, fever, cough, and dyspnea 4 to 6 hours after inhalation of the
offending agent. In a few cases, however, there is a more insidious progression
of symptoms: the patients may have pulmonary fibrosis or emphysema. The
focus of contamination is usually in the recirculated water in air condi-
tioning and ducted air heating systems or domestic cold-mist vaporizers.
2. Humidifier Fever
In Great Britain a variant of the above syndrome has been described
occurring in offices, factories, and operating theaters (6,7) and has also
been described in the United States (8). Biologic contamination of humid-
ifier systems is again also considered to be the cause. Cough, dyspnea, and
fever and malaise have their onset on Monday (after a weekend break) within
hours of returning to work, and improving as the week progresses. As in
hypersensitivity pneumonitis, the diagnosis is readily missed and the symptoms
put down to "Monday morning feeling," or influenza. The reason for the
difference in presentation is probably because different organisms are involved
in the British outbreaks. Thermophilic actinomycetes have not been isolated:
the main causal organism may be an amoeba, Naegleria gruberi. Recent CDC
studies indicate that amoeba (Acanthameba) are also common contaminants of air
conditioning systems (without humidification) in the United States. These
organisms can cause primary amoebic meningoencephalitis, an uncommon, almost
invariably fatal, disease. All reported cases so far, however, have had a
recent history yf swimming in lakes where the organism lives.
3. "Building Illness"
Recently, reports of illnesses of a mild allergic or irritative
nature in office workers and others employed in large buildings have been
received by CDC from all over the United States. Characteristically, over half
of the "exposed" people are affected with nonspecific symptoms such as headache,
burning eyes, and irritation of the upper and lower respiratory tracts and
sinuses. Severe fatigue and diarrhea have also been reported. The symptoms
come on soon after beginning work and initially clear up on leaving the build-
ing, but with repeated exposures symptoms may hang over to the following day.
In view of the published reports of hypersensitivity pneumonitis and humidifier
fever, 'CDC has investigated some of these outbreaks paying particular attention
to the air handling systems; no specific cause has yet been identified.
A common observation, however, is that the air handling systems are equipped
with inadequate filtration and are designed for minimum air exchange with
the outside in order to conserve energy (e.g., "sealed buildings"). One
current hypothesis is that the concentrations of particulates of biologic
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origin rise to levels which can trigger off mild allergic reactions, but much
more research is needed before this syndrome can be satisfactorily explained.
TOXINS
Swedish investigators have suggested that endotoxin produced by gram
negative bacteria growing in water humidifier reservoirs may also cause the
symptoms of humidifier fever (9). This hypothesis cannot be verified at
present because of the inherent dangers in challenging volunteers to endotoxin.
To our knowledge mycotoxins have not so far been studied in buildings
with fungal contamination problems. One difficulty is the absence of an
adequate animal model.
CONCLUSION
1. Undoubtedly energy conservation measures resulting in low air
exchange could result in a build-up of potentially harmful
agents, including microorganisms and their products. Outbreaks
of "building illness" already suggest that the "cost" of certain
energy conservation measures is an increase in morbidity from
either chemical or biologic irritants or allergens.
2. The effect of inadequate air exchange on airborne, and
perhaps other, infectious diseases has not been adequately
studied.
3. Increasing dependence on air conditioning units with humid-
ification to control air quality inside buildings and
factories is likely to perpetuate outbreaks of hyper-
sensitivity pneumonitis and humidifier fever. Almost
certainly, milder outbreaks of these illnesses go undetected.
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REFERENCES
1. Control of Communicable Disease 1n Man 12th Edition. American Public
Health Association, Washington, D.C., 1975.
2.; Broome C.V. and D.W. Fraser. Epidemiologic Aspects of Legionellosis.
Epidemiologic Reviews, 1979, 1, 1-16.
3. Salvaggio, J.E. and R.M. Karr. Hypersensitivity Pneumonitis: State of
the Art. Chest, 75, 270-4, 1979.
4. Banaszak, E.F. et al. Hypersensitivity Pneumonitis Due to Contamination
of an Air Conditioner. New England Journal of Medicine, 283, 271-6, 1970.
5. Fink, J.N. et al. Interstitial Pneumonitis Due to Hypersensitivity to an
Organism Contaminating a Heating System. Annals of Internal Medicine 74,
80-3, 1971.
6. Humidifier Fever. MRC Symposium, Thorax, 32, 653-63, 1977.
7. Humidifier Fever Revisited. Editorial, Lancet, 1, 1286-7, 1980.
8. Granier, M. et al. Humidifier Lung: An Outbreak in Office Workers. Chest
77, 183-7, 1980.
9. Rylander, R. et al. Humidifier Fever and Endotoxin Exposure. Clinical
Allergy, 8, 511-16, 1978.
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RESEARCH NEEDS
In order to assess the risk posed,by pollutants that may be present
in the indoor air and to make decisions as to how to make homes and public
places healthier, safer, and hopefully more pleasant, it is essential to
understand the health effects of pollutants contained in the indoor environ-
ment:* Since risk assessments are usually made on a substance-by-substance
basis, a similar approach has been used to identify research needs. It must
be emphasized, however, that indoor air quality per se is the result of a
very complex interaction of both chemical and physical factors. In the final
analysis, in order to know the risk to the people that occupy buildings, we
will have to resolve the problem of multiple risks and have some knowledge of
synergism and interactions.
A few general statements should introduce more specific research
needs. First, it can be said from observations of health effects induced
by inhaled substances, that there is reason to believe that multiple organ
.systems in the body may be affected in one way or another. The respiratory
system is perhaps the most vulnerable since it is the system most frequently
the subject of complaint. The nervous system, particularly behavioral effects,
is also a matter of concern and should be studied in more detail. There are
also a number of chronic diseases for which there are no known causes and for
which indoor air quality might be assessed as a contributing factor.
Secondly, the indoor environment offers opportunity to study the
effects of a number of potentially toxic substances on a cross section of
the population that includes the most susceptible members--the aged, the
invalid, the chronically ill, the fetus, and the newborn child.
Another general comment is that nearly all efforts to study health
effects are dependent on the instruments and techniques of monitoring. Two
classes of instruments are needed: those that measure peak short-term
exposures and l^ng-term integrating instruments.
Research needs are provided for seven substances or classes of sub-
stances. These are formaldehyde, radon, combustion products, biologicals,
organic compounds, indoor particulates, and tobacco smoke. It was difficult
to establish priorities because of the differing role and level of importance
a particular substance might have in individual structures or indoor environ-
ments. For each substance, attention was given to the need for epidemiology,
surveillance monitoring, and toxicology.
Formaldehyde—There is a need to characterize rates of formaldehyde
emissions and factors affecting these rates from various structural and consumer
products in buildings. There is also need for toxicplogic research concerning
the neural, respiratory, and reproductive effects of formaldehyde at low levels,
cocarcinogenic effects with other pollutants, mechanism of sensitization, and
identification of sensitive populations.
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Additional epidemiologic studies are needed concerning the relation-
ship between health effects induced by formaldehyde and levels of indoor expo-
sures. Current studies in mobile homes should be extended to offices and other
buildings where products emitting formaldehyde are present.
Radon—The first priority for radon involves monitoring to obtain
a national assessment of radon levels in dwellings. These studies might
include miners exposed to lower levels present after control measures have been
introduced. Nonoccupationally exposed groups may be identified for study for a
more complete national assessment.
Combustion Products—There are a number of combustible fuels and
combustible sources used in buildings. An emerging problem is the use of
alternate fuels, such as wood, in addition to the usual fuels (gas, oil, etc.).
The products of most concern are CO, NOX, formaldehyde, and aromatic hydro-
carbons. Both CO and N0£ have a high affinity with hemoglobin and may
induce chronic effects if exposure is prolonged. Combustion product studies
must also take tobacco smoke products into account. Other combustion products
of concern include particulates and other other organics, which may act syner-
gistically with other indoor pollutants in producing adverse effects. Monitor-
ing and epidemiologic studies are most critical. More is known about acute
effects than chronic effects. Measurement of peak versus long-term, high-level
effects are needed. Studies of chronic effects are definitely required.
Several epidemiologic studies are now underway and these should be evaluated
to determine what additional studies are needed.
Biologicals--High priority should be given to the study of biologic
substances from two aspects, as allergens and as infective agents. Common
allergens include fungal spores, pollen, mite dust, and microbial products.
The indoor environment may provide ideal conditions for the growth of fungi,
such as aspergillis, producing either asthma or aspergillosis. Hypersensi-
tivity syndromes that have been identified as being associated with air handling
systems are hypersensitivity pneumonitis and humidifier fever. Both are due to
fungal or protoitan contamination of humidification systems. Pets, such as
cats, dogs, and birds, kept in the home may also be sources of antigen-causing
asthma or hypersensitivity pneumonitis. In terms of the role of indoor
environment and infectious disease, it has been known for a long time that
viruses and various bacteria may be transmitted in air and there is concern
that sealed buildings enhance the risk to airborne infectious agents. Answers
to these concerns may be learned by epidemiologic studies—such studies must,
of course, be correlated with performance characteristics of the air handling
system.
Organic Compounds—Apart from formaldehyde, there is also concern
about possible health effects associated with other organic substances. This
is in part due to the large number of organic compounds that may be present
in the indoor environment. Also, it is an area where considerable basic or
toxicologic study needs to be done. Organic compounds in the indoor environ-
ment may be divided into three large groups: pesticides, controlled organics
(e.g., basically consumer products), and uncontrolled organics (e.g., emissions
from degassing of structural materials, furniture, and furnishings). It should
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be recognized that there are specific organic compounds of special concern
since toxicological data indicate potential-health effects: aldehydes,
1,4-dichlorobenzene, nitrosamines, hydrazines, dioxins, phthalates, pentachloro-
phenol, and other chlorinated hyrocarbons. Others may be also included.
All of these compounds require more extensive exposure monitoring before health
effects can be determined. In terms of controlled organic emissions, there is
need for product emission data and appropriate labeling to prevent misuse, as
is required for pesticides. There should also be a central respository of
toxicologic data on consumer products. It is also recognized that many of
the organic chemicals that are found in the indoor air are also present in
diet, water, or from industrial exposures.
It is recommended that indoor monitoring data should be correlated
with HANES* data on the presence of pesticides in human blood. There also needs
to be similar technology to measure other organic compounds in human blood.
Exposure data may then be correlated with results of the National Health
Survey data.
Particu1ates--Indoor particulates include fibers, dust, metals
aerosols, and combustion products. Basic research is needed to characterize
and measure these materials within defined environments. We must also identify
pathways of particulates into the indoor environment. Particulates are vehicles
for the transport of other pollutants; e.g., radon.
Tobacco Smpke--The interest in tobacco smoke is in the insult result-
ing from passive>smoking where the mixture of smoke products is poorly defined.
Priority should be given to the monitoring of smoke products, e.g., CO, formal-
dehyde, particulates, and NOX. Information is needed on the decay of smoke
products and their dispersion. Epidemiological studies of CO and N02 levels
(carboxy and met-hemoglobin) should be performed. The effectiveness of air
handling systems to reduce smoke products in indoor air should be evaluated.
It must be emphasized that smoke products must always be studied in relation
to other indoor''air quality problems.
In summary, in order to study the generic problem of indoor air
quality there is need to characterize features of air handling systems so
they can be correlated with clinical complaints on one hand and the levels
of pollutants as determined by monitoring efforts. If this is done, given the
appropriate monitoring capability, there will begin to be available appropriate
data to make risk assessments for effects of pollutants on people in buildings.
Health and Nutrition Evaluation Survey of America done by the National
Center for Health Statistics.
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REPORT OF THE CONTROL TECHNOLOGY SESSION
OF THE
WORKSHOP ON INDOOR AIR QUALITY RESEARCH NEEDS
December 3-5, 1980
Panelists
Dr. Janet C. Haartz, NIOSH, Chairperson
Df, James E. Woods, Jr., Iowa State University
Dr. Amos Turk, City University of New York
Mr. William Mirick, Battelle Columbus Laboratories
Mr. Gary Roseme, Lawrence Berkeley Laboratory
March 1981
137
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Section 1
SUMMARY OF THE SESSION
GENERAL
: The Control Technology Group session of the Workshop on Indoor Air
Quality Research Needs met during the afternoon of December 3 and for a full
day on December 4, 1980. Panel members were:
Dr. Janet C. Haartz, (Chairperson), National Institute
for Occupational Safety and Health
Dr. Amos Turk, City University of New York
Dr. James E. Woods, Jr., Iowa State University
Mr. Gary Roseme, Lawrence Berkeley Laboratory
Mr. William Mirick, Battelle Columbus Laboratories
Thirty-five to 40 participants were in attendance, representing trade
associations, utilities, universities, Government Agencies, and consultants.
Most of the session dealt with the development of control technology
research needs. Also the draft text of "A Plan for a National Program of
Indoor Air Quality Research" was briefly reviewed by the group.
The following paragraphs summarize the findings and recommendations
of the Control Technology group.
CONTROL TECHNOLOGY STATE OF THE ART
The Control Technology Group, other than commenting on the workshop
preparatory materials for the group, did not address the state of the art
for control tecjyiology. Subsequent to the workshop, the Control Technology
Panel members prepared descriptive materials for each of the technologies:
ventilation, source removal/exclusion, contaminant removal, and product
substitution.
Ventilation has been used for centuries for comfort conditioning.
During the past century standards have been developed and used for ventilating
public access buildings. Generally these types of building standards are
prescriptive, requiring minimum air flow within the indoor air space. On the
other hand, occupational standards are performance-oriented, being directed at
concentrations of pollutants in the indoor air space.
Ventilation may be natural or mechanically forced, or infiltration
simply (unintentional air leakage into and out of indoor spaces). Forced
systems may be thermostatically or manually controlled and may include air
cleaning systems for make-up and/or recirculated air.
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An innovative approach in building ventilation is the use of air-to-
air heat exchange ventilators, which reduce-the energy costs of heating as
cooling outdoor ventilation air. These devices are designed to save energy by
(in winter) transferring heat from the exhausted air to the intake air. During
summer air conditioning periods the reverse transfer would operate.
«
«
Contaminant removal from indoor air has been successfully used
for many years in the form of particulate filters (including electronic air
cleaners). Gas removal devices, such as activated carbon or activated alumina,
are also common.
When air cleaners are installed in an HVAC system, the entire air space
is cleaned after being "contaminated." When the cleaner is interposed between
the source and the indoor air spece, such as in a range hood, contamination
of the occupied space may be avoided.
Problems with contaminant removal systems include capture in efficiency,
noise, pressure drops, high cost, and in rare cases, the possibility of pro-
ducing contaminants themselves. One system that can circumvent some of these
problems uses carbon adsorption, which has been used in range hoods. Present
systems do not include an effective means of indicating saturation and need
for maintenance, however.
Source removal and exclusion may be the most effective means of
contaminant control, the former being a permanent solution to a contamination
problem. Exclusion means installing a barrier or a sealant and is not con-
sidered permanent, since both are subject to rupture and subsequent leakage.
The problem of asbestos in buildings is serious and corrective measures include
source removal and exclusion. Sealants are being developed and tested, but are
not permanent solution and their correct application is difficult. Removal
systems are being researched; the development of safe removal techniques is
hampered by the ^ery small size of asbestos particles.
Radon entry from soils through foundations is locally significant.
Various sealing, ventilation, and filtration techniques are being tried in
high radon areas. Exclusion may be accomplished by subfloor ventilation, by
sealing cracks and holes, or by applying impermeable membranes on porous
surfaces. Correction of the problem is expensive and more of the techniques
have been adequately tested in the U.S. cost problems appear to be frequently
more severe in retrofit situations.
Tobacco smoke is considered to be one of the most offensive contam-
inants in public (i.e., nonresidential) spaces. Control of tobacco smoke can
be achieved by source removal, by particulate and gaseous removal devices, or
by dilution.
Biologic contaminants must also be controlled, whether they are
introduced to the occupied space through ventilation with outdoor air or
are generated indoors by the occupants or by processes. Airborne contaminants
can be controlled by removal with filtration devices, by irradiation by
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ultraviolet lamps, or by dilution with outdoor air. Surface contaminants can
be controlled by sealing, containing, or cleaning the contaminated surfaces.
Product substitution is a relatively new technique as applied to
control of indoor air quality. It is generally spurred by user complaints.
An .example of substitution is solid deodorants to replace sprays.
A problem with substitution is the possibility of replacement with a similar or
greater hazard.
AREAS OF .OMISSION
The Control Technology Panel did not, for lack of time, seriously
consider product substitution as a control technology. Also the emphasis
was on residential indoor air with a tendency to neglect nonresidential indoor
environments. Finally, the Panel did not systematically review the research
inventory as a prerequisite to research needs development.
RESEARCH NEEDS
The Control Technology Group identified many research needs in the
control technology area. These needs followed a list of general research to
acquire information on problem definition requisite to control technology
development. Those problem definition needs include pollutant identification,
source identification, determination of emission rates and mechanisms, descrip-
tion of transport mechanisms, determination of health risks, and development of
evaluation methods.
Several needs were listed for ventilation research that dealt with
rate measurement techniques, effects of ventilation operational configurations,
acceptability and efficiency of devices (including air-to-air heat exchangers
and general space versus spot ventilation), and effectiveness of various systems
in reducing pollution while conserving energy.
>>
Contaminant removal research needs included several on adsorption
filters, such as their efficiency versus time, how to signal adsorbent satura-
tion, and potential emissions from saturated absorbent. Other research
needs dealt with evaluating the effectiveness of other filtration systems and
various kinds of applications. Various filter media should be evaluated,
end-of-service indicators would be developed, and electrostatic particulate
removal should be examined. Suggestions were made to evaluate other techniques
such as climate control for control of pollutants, the use of indoor plants,
and other natural sinks.
Source removal and exclusion research needs emphasized determina-
tion of emission rates from various sources. Control technology research
needs included the development of building technologies to exclude sources,
examination of human activities that could exclude sources, in addition
to examining protective barrier coatings and physical removal techniques.
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Product substitution was not examined in detail by the Control
Technology Group although suggestions regarding potential identification,
product labeling, ingredient labeling, and the need for cost/benefit
criteria were presented. One important point brought up here was the fact
that substitution in building materials can require massive economic changes
because of the large quantities of materials used.
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Secton 2
REVIEW OF THE STATE OF THE ART FOR INDOOR
AIR QUALITY CONTROL METHODS
GENERAL BACKGROUND
In focusing attention and resources on outdoor pollutant sources
and contaminant concentrations, the scientific and regulatory communities
may have neglected an equal or perhaps a more important component of total
exposure to air pollutants: The component is that which occurs in the indoor
environment. Individuals may spend as much as 90 percent of their time indoors.
Most of the pollutants to which people are exposed are found indoors, as well
as outdoors. The predominant component of exposure to some of these pollutants
occurs indoors.
Of increasing concern are the effects that energy conservation
measures may have on the air quality of indoor environments. One of the
most popular and cost-effective means of conserving energy is weatherization--
the reduction of outdoor air infiltration—which can result in a buildup
of indoor-generated pollutants. In larger buildings ventilation rates are
reduced to save energy with a similar indoor air quality effects. Thus,
elevated indoor air pollutant concentrations, which in some instances are
already a problem, may be further accentuated by the implementation of certain
energy conservation measures. Unless specific controls are simultaneously
applied, or intervening factors occur, either the pace of building energy
conservation programs will be constrained or indoor air quality will suffer.
There are three general objectives relating to the indoor environ-
ment that are functionally related so that, in the absence of other measures,
only any two of the three can be realized simultaneously. The purpose of
measures to control indoor contamination is to break the web of dependence
so that all three objectives can be attained at the same time. The three
objectives are:
1. Maintain thermal comfort (not too cold in winter or too
hot in summer)
.2. Maintain good indoor air quality (not toxic or odorous)
3. Keep energy costs low.
Traditionally, the variable subject to control is air exchange rate
which fs made up from ventilation and infiltration. .If this variable is
extravagant, objective (2) and a choice of either (1) (at high cost) or
(3) (at the expense of thermal comfort) are achieved. If the air exchange rate
is too restricted, objectives (1) and (3) are achieved, but good indoor air
quality (2) must be sacrificed. Indoor air quality controls should be designed
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to reduce the dependence of objectives (1) and (2) on air exchange rate, either
by improving its efficiency, by substituting air cleaning methods for it, or by
removing, excluding, or providing a substitute for the source.
In the following pages, a summary of indoor air quality control
technology concerns is presented. A more comprehensive treatment of this area
is being developed by a "Committee on Indoor Pollutants" of the National
Academy of Science (see Reference 26). That report, which should be published
in 1981, includes a more extensive consideration of control aspects (sources of
emissions, exposure rates, control methods, equipment and strategies) than it
is possible to include in this workshop report.
Types of Indoor Environment, Sources, and Pollutants
Despite the increasing concern about indoor air quality, a concensus
has not yet been reached regarding the definition of various types of indoor
environments. An indoor environment is any enclosed environment which is
.distinguished from the open, outdoor environment. The separation between
occupational and nonoccupational indoor environments is not clear, because an
indoor environment may be a workplace for one individual but not for another.
In this section, indoor environments will be defined according to their func-
tion. The following indoor environment types may be identified:
Domicile:
Educational:
Laboratory:
Medical:
Office:
Public Assembly:
A place of residence, such as single family dwellings,
multifamily dwellings, public housing, row houses,
apartments, or condominiums
A building used for classrooms or instructional
functions
A building used predominantly for research and diag-
nostic work and not necessarily for instructional use
Buildings used for health care facilities, such as
hospitals, clinics, medical centers, sanitariums, day
nurseries, infirmaries, orphanages, nursing homes, or
mental health institutions
Buildings such as offices, civil administration build-
ings, or radio and television stations
Buildings where groups of people gather for different
functions, such as theaters, restaurants, cafeterias,
retail stores, art galleries, museums, banks, post
offices, court houses, assembly.halls, churches, dance
halls, field houses, coliseums, passenger terminals, or
libraries
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Rehabilitation: Nonhealth care buildings used for instructional purposes
but not of the regimental classroom type; pertaining
more toward readjustment, such as jails, prisons,
reformatories, or halfway houses
Warehouse: Buildings used for storage of materials and supplies,
t " such as storage facilities, maintenance facilities,
garages, airplane hangers, or bus barns
Industrial: Buildings such as factories, assembly plants, foundries,
mills, power generating plants, telephone exchange
facilities, water and wastewater treatment facilities,
solid refuse plants, zoos, greenhouses, aviaries,
arboretums, or other facilities requiring environmental
control for process control
A broad classification of pollutants, presented below, relates pollutants to
their source, and therefore to potential control technology.
1. Pollutants infiltrated from outdoors. All pollutants
found in the outdoor environment (e.g., NOX, SOX, CO,
TSP, microbial spores, dust, pollen, etc.) can infiltrate
indoors. In addition to outdoor air, soil gases (e.g.,
radon) may directly find their way into buildings in
significant quantities.
2. Pollutants generated by indoor activities. Domestic sources
include routine cooking, cleaning, smoking, hobbies, use
of sprays, and emissions from the human body. In the indus-
trial workplace, other sources are likely to be often over-
shadowed by industrial process emissions.
3. pollutants transported indoors. Pollutants found in an
environment may be transported from a second environment
as an individual moves from one space to another. Pollutants
found in indoor industrial environments may be brought into
residential environments. Soil, along with all chemical
contaminants often associated with soil, may be transported
indoors from outdoor environments. Bacteria are often carried
by individuals from one environment to another. Pesticides
may be carried from outdoors to indoors (for example by
termites).
4. Pollutants emitted from building construction materials.
Building materials, including concrete, wood products, paint,
plastics, and insulation material may emit pollutants such as
radon and its progeny, asbestos, formaldehyde, and others.
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Control Methods
Four types of control technologies are available to control the
quality of indoor air: (1) ventilation, (2) source removal/exclusion,
(3) contaminant removal, and (4) product substitution. The status and general
applicability of these techniques are summarized in Table 2. A fifth method,
education of the inhabitants, does not involve a systems control approach, yet
it may well be an effective approach in controlling indoor air quality. Any
indoor air quality control strategy should satisfy health, safety, comfort
and energy conservation objectives while minimizing costs and changes in the
way of life. The four control methods are not always independent. A simple
steady-state mass balance for a system which does not recirculate air indicates
that a relationship among those methods can be expressed as:
Table 2. Indoor Air Quality Control Technologies
Control Method
Comment
Forced Ventilation
Natural Ventilation
Infiltration
Local Ventilatign and
Heat Exchangers
Source Exclusion
(entry prevention)
Source Removal
Continuous Con-
taminant Removal
Source Substitution
Widely used in industrial, institutional, commercial,
residential, and transportation environments. May
require substantial energy for heating and cooling,
or may improve energy efficiency, depending upon
control system.
Efficiency as a control strategy is not well documented,
but is expected to vary considerably. Noise considera-
tions and high indoor pollution levels may limit
effectiveness.
Ordinarily unintentional air leaks; energy waste is
closely associated.
Efficient control strategies for both small and large
buildings; research needed to quantify the efficiency
of each strategy.
Can be very effective but requires extreme care in
application to assure effectiveness; retrofit
application may be very costly.
Pollutant dependent; effectiveness requires further
documentation. Contaminant control devices are often
large, expensive, noisy and require maintenance. May
be more appropriate for large building complexes than
for residences.
Has not been widely implemented; is effective if the
source is substituted with an equally functional
alternative that does nto generate any indoor pollu-
tants.
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(1)
where: Cs = indoor concentration
C0 = outdoor concentration
•
N = net generation rate of contaminant indoor (affected
by source removal, exclusion, and product substitution)
•
E = contaminant removal rate
•
V = air exchange rate (ventilation air and infiltration).
Source removal and exclusion and product substitution involve methods
•which minimize the net generation rates of contaminants indoors, N. These
methods currently include:
• Isolation of the source from the indoor environment,
such as product substitution or prohibition of smoking
in certain areas (27, 28)
• Containment of the source by treatment with paints or
other barriers
0 Local exhaust such as biological cabinets in laboratories
(13), or kitchen range hoods (9).
Source control is probably the most cost-effective and energy-
efficient method of indoor air quality control, but also provides the least
assurance of control to the occupants, if other methods are not present.
for example, if'removal control, E, has not been installed, and ventilation,
V, has been minimized for energy efficiency, only a small perturbation in N
can be tolerated without excessive changes in the indoor concentration, Cs,
at a constant value of outdoor concentration, C0.
. Ventilation or dilution control, which pertains to methods that
affect V, is the most common method of indoor air quality control in non-
industrial facilities. This method of control may be achieved by:
• Infiltration through cracks around windows, doors and
construction joints (30)
t Natural ventilation through open windows and doors, and
through other openings or vents designed for that purpose
(31. 32)
• Forced or mechanical ventilation systems which include
supply or exhaust fans, and which also may include
dampers and filters (21).
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Dilution control methods may be applied independently or in combina-
tion. Their relationships are shown schematically in Figure 1. Note that when
dilution control is employed, the presence of a contamination source, with genera-
tion rate N, is implied.
Removal control, which pertains to methods that affect E, is commonly
used *as an alternative to, or in combination with, dilution control to reduce
indoor concentrations by means of air cleaning devices. These can be located
either in the forced air systems, as shown in Figure 1, or directly in the
occupied space. Examples of this latter type of control are fan-filter
modules which are often used in hospitals (35), laminar flow clean benches
located in electronic and biomedical laboratories (36), or simple particle
filters on residential furnaces.
STATE OF THE ART IN VENTILATION
Historical Perspective
Ventilation of indoor spaces has been recognized as necessary for
several hundred years, but research on required ventilation rates dates back
only to the nineteenth century. In 1824, Tredgold proposed that four cubic
feet per minute (cfm) per person of outdoor air was necessary for removal
of COg in enclosed spaces (1). By 1893, the accepted minimum ventilation
rate was 30 cfm per person, based on Billings' recommendations for control of
other unknown contaminants (2). In 1895, the American Society of Heating
and Ventilating Engineers (ASHVE) agreed to develop a ventilation standard
at its First Annual Meeting (3). A minimum of 30 cfm per person ventilation
air was adopted in that standard, and by 1925, the codes of 22 states in the
United States had promulgated that value (4).
The research of Yaglou, et a!., in the 1930's showed that the amount
of ventilation air required for "odor-free" environments was a function of
available air sgace per person (5). Based on these studies, the American
Standard Association (ASA) adopted a minimum ventilation rate of 10 cfm per
person in 1946 (6). In 1973, the American Society of Heating, Refrigerating
and Air Conditioning Engineers (ASHRAE) revised the ASA odor-based standard and
reduced required ventilation rate to 5 cfm per person for energy conservation;
also specified were recommended values for comfort or odor-free environments
which were two or three times greater than the minimum values (7). This
standard was adopted by the American National Standards Institute (ANSI,
formerly ASA) in 1977 and designated ANSI Standard B 194.1.
ASHRAE also developed another standard for energy conservation
in 1975 (8) which conflicted with the ASHRAE Standrd 62-73 (ANSI B 194.1).
That standard stated that the minimum values shall be used for design purposes,
thus effectively deleting the recommended values. To resolve this conflict
and tg incorporate new information available on ventilation control, ASHRAE
has recently revised Standard 62-73 (9). The revised standard (designated
ANSI/ASHRAE 62-1981) specifies required ventilation rates for smoking and
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nonsmoking spaces. Generally, the nonsmoking values are similar to the
previous minimum values, and the smoking values are similar or greater than
the previous recommended values. In addition to these changes (now called
the "Ventilation Rate Procedure"), ANSI/ASHRAE 62-1981 also describe a new
"Indoor Air Quality Procedure." This latter procedure allows new, creative
methods of control if assurance is provided that concentrations of indoor
contaminants will not be excessive. Guidelines for concentrations are given,
but control methods are not.
Editor's Note
The ASHRAE standards are widely used by building code officials
and designers attempting to ensure reasonable air quality inside buildings.
Such standards are badly needed. As can be seen from the historical develop-
ment of ventilation standards, has a single criterion such as order or carbon
.dioxide levels have served as the basis of the minimum ventilation require-
ments. The new ASHRAE standard, while now addressing more pollutants, is
widely acknowledged as reliant on an insufficient data base of pollutant levels
in buildings, the health effects caused by exposures to those pollutants and
nonventilation control methods. For example, research since the ASHRAE
standards' promulgation has shown that much higher levels of ventilation are
needed to dilute tobacco smoke odor. On the other hand, recent radon guide-
lines and standards in other countries are higher than the ASHRAE radon guide-
line. Thus, the ASHRAE standard is not viewed as definitive, but as based upon
the optimum of a group of experts at a particular point in time. These standards
are likely to change in the future as more research is performed; ASHRAE
recognizes this likelihood, and updates its standards, normally, on a 5 year
basis.]
Criteria
fi
Systems for environmental control can be designed to meet either
performance or prescriptive criteria. To a limited degree, performance
criteria are now specified for industrial environments. Specifications for
maximum allowable concentrations (MAC) and time-weighted averages (TWA) have
been developed to protect the workers from potential industrial health hazards
(11). Generally, the methods to achieve these criteria are not specified,
and the responsibility to provide and maintain acceptable conditions resides
with the designer, owner and operator of these systems. Although ANSI/ASHRAE
62-1981 now includes a performance type "Indoor Air Quality Procedure," environ-
mental criteria are usually prescriptive for nonindustrial (i.e., residential
and commercial) facilities. Either volumetric air flow rates are specified
per person or per unit area, or room air exchange rates are specified. Unlike
performance standards, compliance with prescriptive standards is generally
assumed to be met if systems are designed and installed according to the
appropriate standards. The standards do not address the need for periodic
evaluation of the performance of these systems during their subsequent years of
operation.
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Prescriptive values are usually established to meet both objective
and subjective criteria. Four objective criteria are generally recognized
as the basis for ventilation control:
0 Provision of sufficient Q£ for normal respiration
• Dilution of contaminants within the occupied space
• Pressurization of occupied spaces to control infiltration
or exfiltration
• Dissipation of thermal loads present in occupied spaces.
The criteria do not emphasize control strategies other than dilution.
When ventilation is provided for dilution, pressurization, or heat
dissipation, sufficient outdoor air is supplied so that maintenance of 03
concentrations is seldom a problem. Outdoor air, however, may introduce
pollutants to the indoors. Dilution, pressurization and thermal dissipation,
however, are less dependent on one another.
Ventilation rates or air exchange rates for dilution control are
specified in standards such as ASHRAE standards (7, 9), and the HUD Minimum
Property Standards (12). Pressurization values are usually only specified
for critical areas, such as laboratories (13, 14) and hospitals (15).
Ventilation rates for dissipation of thermal loads are usually not specified,
but this method of control may be used as described in the ASHRAE thermal
comfort standard (16).
In addition to objective criteria for indoor air quality (i.e.,
mass or thermal concentrations), subjective responses of the occupants
to the environmental conditions must be considered. Subjective criteria
for indoor air quality are usually expressed in terms of (17):
t Perceived odor intensity
0 Odor acceptability.
Perceived odor intensities are expressed in terms of odor threshold (i.e.,
the concentrations of the odorant necessary to produce a "just detectable"
odor) and 'in terms of perceived odor magnitudes for suprathreshold intensities
(18). The levels of suprathreshold intensities, or perceived odor magnitudes,
depend on the degree of pleasantness or unpleasantness associated with the
odor. Moreover, combinations of odors are not additive, and behavioral
responses to combined odors are not well known (19).
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Because dilution is commonly used for odor control, ventilation
rates in standards, such as those previously mentioned, are often specified
with consideration given to the function of the space. For example, ventila-
tion rates in conference rooms where smoking' is permitted may be specified
as two or three times those for theaters, where smoking is not permitted,
even'though the occupancy densities may be identical.
-*• «
: Economic evaluations are currently based on low first-costs of
nonindustrial systems. However, after construction is completed, owners
and operators often try to minimize operating costs. A common result of
minimized first cost design, and subsequent improper operating procedures,
is that neither cost reduction nor acceptable indoor air quality may be
realized (20, 21).
Energy criteria often translate to economic criteria, but some
noneconomic factors (e.g., socio-political) must also be considered. Whether
resulting from social concerns or economic values, efforts are currently
underway to reduce energy consumption in buildings. On a national basis,
ventilation has been reported to account for 25-50 percent of the annual
energy consumption in buildings (21, 22). Accordingly, significant govern-
mental funding has been directed to research projects and energy auditing
procedures which may result in reduced ventilation (24, 25). Concern
regarding these reduced rates has also resulted in a Government-funded
study on indoor pollutants by the National Academy of Sciences (26) and other
studies. It is expected that the MAS Report will be published early in 1981.
Ventilation System Description
For the simple case of no air recirculation for the occupied space
(i.e., 100% ventilation or outdoor air) and no contaminant removal control
(i.e., E = 0), Equation (1) indicates that the contaminant concentration
indoors, Cs, varies inversely with the air flow rate V,* when referring to
indoor generated pollutants. This presence that the outdoor concentration of
the contaminant being studied is negligible and assumed to be zero. This
relationship is the basis for the ventilation rates commonly specified in
current standards (7, 9, 12).
When circulation air is used in a system, which is common practice
for residential and commercial systems, the air entering the occupied space
is no longer considered ventilation air, but supply air, as shown in Figure 1.
Thus, supply air is a thermally conditioned mixture of recirculated and outdoor
air.
Editor's Note: This sentence suggests that as ventilation rates approach
infinity, indoor contaminant concentrations approach zero. This is correct
rfor only indoor-generated pollutants, for pollutants introduced in ventila-
tion air (outdoor air) indoor concentrations will approximate outdoor levels,
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Typical residential forced air systems have been designed to recir-
culate 100% of the supply air and infiltration has been depended upon
for dilution control. In this case, a filter, if present, is located in
the recirculation air stream. The steady-state indoor concentration can be
expressed by Equation (1) if the air flow rate, V, is taken as the infiltration
rate,.Vi, only. As energy conservation efforts have been adopted, the
amount of infiltration air rates have often been reduced to less than 0.5 air
changes per hour in new construction (12, 30). Reductions in air infiltration
rates in existing residences have not been reduced to levels as low as those
in new construction; reductions in infiltration are still substantial. In new
residences, indoor air quality may be significantly degraded if care is not
taken to provide alternative control strategies (26, 33). Conversely, with the
alternative strategies, drafts and cold wall effects caused by infiltration
can be reduced resulting in improved thermal comfort as well as energy savings
(16).
Forced air systems for commercial facilities vary considerably;
some may employ 100% recirculated air, some may be required to use 100% outdoor
air (14, 15), and some may use thermostatically controlled mixed-air systems
(7, 9, 15). As shown in Figure 1, the location of air cleaners in these
commercial systems may also vary. For these systems, the steady-state irjdoor
concentration can also be expressed by Equation (1) with air flow rate, V,.
assumed to be the sum of the variable infiltration and outdoor air rates (V-j
+ tf0). As i° residential facilities, energy conservation efforts in commercial
buildings have resulted in reduced infiltration rates. In addition, the
ventilation systems are often deactivated during reduced occupancy periods. If
the major sources of contamination within a facility are the occupants, the
deactivation may not cause degradation of the indoor air quality for the
remaining occupants. Conversely, if the sources of contamination are processes
or materials which are independent of the occupancy density, deleterious
effects to the remaining occupants could result.
Thermostatically controlled mixed-air systems are of particular
concern today because of their energy implications. Advice and demands
have recently caused set-points of the mixed-air controllers to be reset to
higher values, deactivation of the thermostatic function of these systems,
manual adjustment to a minimum amount of ventilation, or complete deactiva-
tion of the systems (24, 25, 34). Unfortunately, these courses of action
have usually been counterproductive. Thermostatically controlled mixed-air
systems, with either temperature or enthalpy control (i.e., "economizer"
systems), were probably designed to provide supply air conditions to meet
cooling requirements imposed by thermal loads (21). Thus, the desired
amount of outdoor air introduced for cooling may exceed the minimum required
for mass air quality control. Moreover, the proper use of mixed-air control
allows-refrigeration equipment to remain deactivated when thermal conditions
of the outdoor air are sufficient to meet the cooling loads. Conversely,
if these mixed-air control systems are improperly operated (i.e., set to higher
set-points), thermal comfort may be degraded or additional refrigeration loads
may be required which would increase energy consumption.
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STATE OF THE ART IN CONTAMINANT REMOVAL
Historical Perspective
Contaminant removal using pollution control devices (generally
some'type of filter) has been successfully used in industrial, commercial,
institutional, and residential indoor environments in lieu of or in addition
to ventilation (dilution). Such devices are most often used in air recircula-
tion systems or mixed air systems where energy conservation is economically
important, where stabilized and/or "pure" air quality is desired, or where
make-up air is nonexistent or in limited supply (e.g., space and submarines).
Examples of common applications of contaminant removal devices are:
t Furnace/air conditioner (low efficiency) particulate air
(disposable) filters
• Medium to high efficiency particulate air filters
• Electronic air cleaners
• Activated carbon and activated alumina gas cleaners
• Ultraviolet lamps (incineration).
Contaminant removal is a much newer technology than ventilation.
The common applications have evolved, for the most part, in the last two
generations, along with automated space heating and cooling systems, sealed
buildings, and the associated use of fuels such as gas and electricity.
Contaminant Removal Systems Description
Air cleaning devices for residential or commercial systems may be
classified as:
• Particle removal devices which include mechanical filters
and electronic air cleaners (37)
- • Gas and vapor removal devices with contain sorbents, such as
activated charcoal or activated alumina (38).
•
The removal rate of the indoor contaminant E, in Equation (1), can
be expressed as:
d)
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where: 5 = efficiency of contaminant removal device
•
Vu = air flow rate through contaminant removal device
Cu = concentration of contaminant in the airstream entering
the contaminant removal device.
«
•
The upstream air flow rate, Vu, is usually known explicitly:
for fan-filter modules, Vu is given as part of the rating of the device.
In central systems with 100% recirculated air or 100% outdoor air, Vu is the
same as the air flow rate through the system fan. In mixed-air systems, Vu
is the sum of the outdoor and recirculated air flow rates. It should be noted
that Vu in larger systems may vary depending on changes in system resistances
or variable volumetric flow rates (39).
The contaminant concentration in the air entering the contaminant
removal device, Cu, should be equal to the concentration in the occupied
space for fan-filter modules and 100% recirculated air central systems. If
stagnation or stratification exists within the occupied space, the concentra-
tions to which the occupants may be exposed could be significantly different
from those entering the air cleaning equipment (22, 40). For 100% outdoor air
systems, Cu should be the same as the ambient air. But, if the outdoor air
intake is not carefully located, these concentrations can be influenced by
local effects, such as automobile emissions (41), particle entrainment (42), or
"short circuiting" from system exhaust ducts (43). The concentrations, Cu, in
mixed-air control systems can vary between those in the occupied space and
those in the outdoor air, depending upon the mode of mixed air control.
The efficiency of the contaminant removal device, £, must be expressed
as a dimensionless fraction. It is usually determined as the complement of the
penetration, P, of the contaminant through the device:
> 5 • 1 - P (2)
C
.
where P = -z=-
Cjj = concentration of the contaminant in the airstream leaving
the contaminant removal device.
•
As seen from Equation (1), an increase. in the removal rate, E, has
the same effect as reducing the generation rate, N (i.e., N - E-^o). The result,
therefore, is to decrease the difference between the indoor and outdoor concen-
trations. In fact, with sufficiently high values of air cleaner efficiency,
and of air flow rate through. the air cleaners, Vu, the removal rate, E, will
exceed the generation rate, N, and the indoor concentration, Cs, can be less
than the outdoor concentration, C0, independent of the value of the air flow
rate, V (21, 36).
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A distinction must be made between two modes of applying contaminant removal
devices (air cleaners) to the purification of indoor air. In one mode, the
air cleaner is interposed between the source and the indoor environment.
Such a system serves in effect as an attempt at source exclusion.
In the second mode, the air cleaner treats the indoor air after
the contamination has been more or less thoroughly dispersed therein. Typical
examples of such devices are air cleaners applied to central HVAC systems or
free-standing air'cleaners located somewhere in the building. In the ideally
simple case in which both the contaminant sources and the treated air are
completely and instantaneously mixed in the entire indoor space, the concentra-
tion of contaminants drifts exponentially to a steady-state value that depends
on the volume of the space being treated, the rate at which contaminants are
being generated, and on the air handling capacity and contaminant-removal
efficiency of the air cleaner (44, 45, 46).
The situation in real HVAC systems is complicated by various
other factors, such as inhomogeneous dispersal of contaminants, variations
in rates of generation, and progressive changes in the efficiency of the
air cleaner. Approaches to some of these complexities have been studied
by various investigators (21, 22, 35, 37, 38, 40, 46, 47).
The effects of these nonideal factors on the performance of air
cleaners can manifest themselves in either of two directions: (a) The air
cleaner can be more effective than it would be in the ideal case if the concen-
tration of contaminants in the air that reaches it is higher than the average
level in the building. Such a condition represents, in effect, a partial
approach to source exclusion, (b) The air cleaner can be less effective than
it would be in the ideal case if the concentration of contaminants in the air
that reaches it is less than the average level in the building. Such a condition
represents, in effect, a partial "short-circuiting" of the treated air back
into the air cleaner before it is thoroughly mixed in the indoor space.
>
Not all air cleaning devices are suitable for indoor applications.
Some are too noisy, some occupy too much space, some generate too much heat,
and some produce contaminants that do not decay rapidly enough. Furthermore,
the capital and operating costs of all such devices must be considered to be
competitive ,with the cost of an equivalent rate of ventilation. Ultimately,
of course, both control approaches must be weighted in terms of the value of
health benefits gained.
The following outline will categorize air cleaners according to
their applicability either to particulate or to gaseous contaminants, and
will identify those that are unsuitable for indoor applications.
Air Cleaners for Particulate Matter
Mechanical filters
Electrostatic precipitators
Inertial separators (cyclones)
Settling chambers
Scrubbers
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Of these, the last three are generally unsuitable for nonindustrial
environments because they occupy too much space for the throughput of contaminants
to which they would be exposed in indoor environments. Inertial separators and
scrubbers are frequently used for industrial applications, but require too much
power to be practical for noncommercial uses. &
•
Air Cleaners for Gaseous Contaminants
Adsorbents with chemical impregnations
Incinerators (flame or catalytic)
Scrubbers
Ozonizers
Of these, the last three are generally inapplicable to noncommercial
environments—scrubbers for the reasons mentioned above, incinerators because
they require and release too much heat, and ozonizers because ozone is toxic.
An adsorbent often chosen for indoor air cleaning appears to be
activated carbon. The reason for this selection of carbon in preference to all
oxygen-containing adsorbents, such as silica gel, activated alumina, or surface-
active clays, is that oxygenated adsorbents are strongly polar. Therefore,
unlike carbon, they bind and hold moisture and, in such condition, lose much of
their effectiveness for adsorbing organic substances. Carbon, too, adsorbs
water from humid air, but this moisture is displaced as the surface and pores
of the carbon become loaded with organic matter.
The manufacturing and utilization of activated carbon as an air
cleaner is a well established technology. For indoor application, carbon
granules (diameter ^1 to 5 mm) are packed into thin (^2 cm) beds. Good design
of the adsorber makes it possible to achieve high air cleaning efficiency
(v95 percent) with small pressure drop for reasonable air flow (^5000 N/m2
per m of bed depth at a linear flow rate of ^25 cm/s). However, as the carbon
saturates, its Effective bed depth becomes thinner. Various problems associated
with this progressive saturation will be discussed under "research needs."
The restriction to activated carbon does not apply to adsorbents
with chemical impregnation. In fact, for those reactions that require
aqueous media (reactions involving ionic pathways) polar adsorbents may be
preferable because of the water they retain. The most widely used polar
adsorbent for such applications is activated alumina. Table 3 lists various
adsorbent impregnations and their applications.
STATE OF THE ART IN SOURCE REMOVAL AND EXCLUSION
Source removal and exclusion, as the terms imply, are applied
to the pollutant source to prevent entry of the pollutant to the indoor air
space. • Examples include sealing of basements and foundations to prevent infil-
tration of radon; the removal of materials, equipment, and products that emit
pollutants; and the removal of exterior sources that are in the proximity of
occupied indoor spaces.
156
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Table 3. Adsorption
Adsorbent
Impregnant
Pollutant
Action
Activated
carbon
Ot
Activated
alumina
Bromine
Lead acetate
Phosphoric acid
Sodium silicate
Iodine
Sulfur
Sodium sulfite
Sodium carbonate
or bicarbonate
Oxides of Cu, Cr,
V, etc; noble
metals (Pd, Pt)
Potassium
permanganate
Sodium carbonate
or bicarbonate
Ethylene; other alkenes
H2S
NH3 mines
HF
Mercury
Mercury
Formaldehyde
Acidic vapors
Oxidizable gases,
including reduced
sulfur compounds
such as H2S, COS,
and mercaptans
Easily oxidizable
gases, especially
formaldehyde
Acidic gases
Conversion to dibrtomide, which
remains on carbon
Conversion to PbS
Neutralization
Conversion to fluorosilicates
Conversion to Hgl20
Conversion to HgS
Conversion to addition product
Neutralization
Catalysis of air oxidation
Oxidation
Neutralization
-------
Many controls in the work environment are in the source removal
and source exclusion category. The containment of process chemicals to prevent
vapor escape is an example. Another is the isolation of a process by barrier
walls to minimize worker exposures.
A source removal/exclusion problem of enormous proportions has
resulted from the application of asbestos to building interior surfaces for
insulation and sound absorption. Although this practice has ended, there are
hundreds of thousands of buildings where asbestos has been applied and which
are potential sources of airborne asbestos as the material deteriorates or its
surfaces are disturbed. Of particular concern are the many applications of
asbestos in school buildings.
Asbestos in buildings may be sealed (temporary solution) by coating
or impregnating it with certain materials, or it may be removed (permanent
solution) and permanently contained elsewhere. Both techniques suffer from
many potential difficulties that may result in the escape of asbestos.
Although research is underway in identifying usable sealants and in developing
removal methods, much remains to be done in the development of safe and reliable
techniques.
A source-exclusion problem of increasing significance is that
of radon, a radioactive gas that occurs naturally in rocks and soils, and that
may also occur in building materials derived from rock, such as concrete. The
greatest concern is in areas where source materials such as uranium and radium
are present in significant amounts near the surface. Unless excluded, radon
gas may permeate building foundations, accumulating in indoor air. Since radon
gas is short-lived, the alpha-emitting, electrically-charged radon daughters
are the contaminants of greatest concern.
Several radon exclusion techniques are being evaluated, particularly
in Canada and Florida. Techniques reported successful by Canadian researchers
include finding^and plugging holes and cracks in concrete foundations, membrane
sealing of porous surfaces, and subfloor venting and ventilation. These
source-exclusion techniques may be augmented by containment removal techniques
such as indoor air filters and precipitators, which extract the respirable
particulates to which the charged radon progeny attach, and ventilation of the
indoor air space using air-to-air heat exchangers.
Most other source removal and exclusion techniques have resulted
from (a) complaints of nuisance or discomfort, or (b) from findings regarding
the safety of consumer products. Formaldehyde emissions from urea formaldehyde
from insulation and from particle board have caused both complaints from
building occupants and perceptible health effects. The material has had to
to be removed in some cases and several sealing methods have been tried with
varying success. Asbestos-containing hair dryers and fluorocarbon-containing
aerosol sprays are examples of products being removed from the marketplace
because of research findings in the environmental safety area.
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Source removal is, of course, the most effective way to control a
pollutant. Source exclusion has the drawback of potential failure of the
barrier through accidental rupture, deterioration, deliberate or unintentional
breaching of the system, etc. Both methods, however, should be prime considera-
tions in any indoor air quality control strategy.
STATE. OF THE ART IN PRODUCT SUBSTITUTION
Product substitution can be as effective as simple source removal
where a product emits an indoor air contaminant. The principal reservation to
product substitution is the potential.of replacement product to also emit
contaminants or to be harmful in some other way.
Examples of product substitution include nonfluorocarbon propel 1 ants
to replace fluorocarbons in aerosol sprays, solid deodorant sticks to replace
sprays, various types of bug killers to replace many found hazardous, water-
based finishes to replace those containing volatile organic solvents, and
mineral insulation (or others) to replace urea-formaldehyde.
It is difficult to recommend a program directed at product sub-
stitution because of the nature of the occurrence of amenable problems. Each
occurrence is product-specific and depends upon discovery to spur development
of substitutes. One aspect that must be emphasized, however, is the need for
evaluation of the hazard potential of the replacement. History has demonstrated
that the replacement is sometimes more damaging than the original product.
159
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and Dwelling Houses.Published by J. Taylor, London, 1824.
2. 'Billings, J.S. Ventilation and Heating. Engineering Record, New York,
1893.
3. Proceedings of the First Annual Meeting. ASHVE Transactions 1:40-41, 1895.
4. Klauss, A.K., R.H. lull, L.M. Roots and J.R. Pfafflin. "History of the
Changing Concepts in Ventilation Requirements." ASHRAE Journal 12(6):51-55,
1970.
5. Yaglou, C.P., E.C. Riley and D.I. Coggins. "Ventilation Requirements."
ASHRAE Transactions 42:133-163, 1936.
6. American Standard Building Requirements for Light and Ventilation A53.1.
American Standards Association, 1946.
7. ASHRAE Standard 62-73. Standards for Natural and Mechanical Ventilation.
American Society of Heating, Refrigerating and Air Conditioning Engineers.
Circulation Sales Department, New York, 1973.
8. ASHRAE Standard 90-75. Energy Conservation in New Building Design.
American Society of Heating, Refrigerating and Air Conditioning Engineers,
Circulation Sales Department, New York, 1975.
9. ANSI/ASHRAE 62-1981. Ventilation Required for Acceptable Indoor Air
juality.American Society of Heating, Refrigerating and Air Conditioning
:ngineers, New York (in Press).
10. Stoeker, W.F. Design of Thermal Systems. McGraw-Hill, 1971.
11. Code of Federal Regulation 29 CFR 1910. Occupational Safety and Health
Standards, Subpart Z—Toxic and Hazardous Substances. U.S. Government
Printing Office, Washington, D.C., 1979.
12. Minimum Property Standards for One- and Two-Family Dwellings, Publication
No. 4900; Minimum Property Standards for Multi-Family Housing, Publication
No. 4910; Minimum Property Standards for Care-Type Housing, Publication
No. 4920, U.S. Department of Housing and Urban Development, Washington,
D.C. 1973, and revisions of 1974-80.
13. Department of Health, Education, and Welfare; National Institutes of Health.
"Recombinant DNA Research—Guidelines." Federal Register 41(131):27909-
27943, 1976.
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14. Standards for the Breeding, Care and Management of Laboratory Dogs;
Standards for the Breeding, Care and Management of Laboratory Rabbfts;
Standards for the Breeding, Care and Management of Laboratory Mice,
Institute of Laboratory Animal Resources, National Resource Council,
Washington, D.C., 1967.
15. ^Minimum Requirements of Construction and Equipment for Hospital and
: Medical Facilities.U.S. Department of Health, Education, and Welfare,
: Public Health Service, Health Resources Administration, Rockville,
Maryland, Public No. (HRA) 79-14500, 1979.
16. ASHRAE 55-1981. Thermal Environmental Conditions for Human Occupancy.
American Society of Heating, Refrigerating and Air Conditioning Engineers,
Circulation Sales Department, New York (in Press).
17. ASHRAE Handbook of Fundamentals. Chapter 12, "Odors." American Society
of Heating, Refrigerating and Air Conditioning Engineers, New York, 1977.
18. Stevens, S.S. "Problems and Methods in Psycho-physics." Psycho!. Bull.
54:177-196, 1958.
19. Odors from Stationary and Mobile Sources, Chapter 4, "Measurement Methods."
National Research Council, Washington, D.C., 1979.
20. Smith, G.W. Engineering Economy; Analysis of Capital Expenditures.
Third Edition, The Iowa State University Press, Ames, Iowa, 1979.
21. Woods, J.E. and R.G. Nevins. "Ventilation Requirements and Energy Con-
servation." Proceedings of Sixth Interna
Milan, Italy, pp. IV-11.1 to 11.25, 1975.
servation." Proceedings of Sixth International Congress of Climatistics.
ITT7I
22. Kusuda, T. "Control of Ventilation to Conserve Energy While Maintaining
Acceptable>Indoor Air Quality." ASHRAE Transactions 82 (Part I):1169-1181,
1976.
23. "Energy Performance Standards for New Buildings; Proposed Rule." U.S.
Department of Energy, Office of Conservation and Solar Energy. Federal
Register 44(230);68120-68181, 1979.
24. Public Law 95-619 (November 9, 1978), National Energy Conservation Act.
92 Stat. 3204. U.S. Government Printing Office, Washington, D.C., 1978.
25. Public Law 94-385 (August 14, 1976), Energy Conservation and Production
Act. 90 Stat. 1125. U.S. Government Printing Office, Washington, D.C.,
T976.
26. Frazier, J.A. "Study of Indoor Pollutants Requested by EPA." ALS Life
Lipes 5(4):1, 1979.
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27. Gold, Michael. "Indoor Air Pollution," Science 80 1(3):30-33, 1980.
28. State of Iowa. The Code of 1979, Vol. 1, Chapter 98A, Section 98A.2,
p. 514. Published by the State of Iowa, Des Moines, 1979.
29. Auxier, J.A., VI.H. Shinpaugh, G.D. Derr and D.J. Christian. "Preliminary
"Studies of the Effects of Sealants on Radon Emanation from Concrete."
Health Physics 27:390-392, 1974.
30. Grimsrud, D.T., M.H. Sherman, A.K. Blomsterberg and A.H. Rosenfeld.
"Infiltration and Air Leakage Comparisons: Conventional and Energy
Efficient Housing Designs." In Changing Energy Use Futures, Vol. Ill,
R.A. Fazzolare and C.B. Smith, Editors, pp. 1351-1358.Published by
Pergamon Press, Oxford, 1979.
31. Brundrett, G.W. "Window Ventilation and Human Behavior." In: Indoor
Climates, P.O. Fanger and 0. Valbjorn, Editors, pp. 317-330. Published
by the Danish Building Research Institute, Copenhagen, 1979.
32. Evans, B.H. "Energy Conservation with Natural Air Flow Through Windows."
ASHRAE Transactions 83 (Part 2), 1979.
33. Indoor Air Pollution: An Emerging Health Problem. Report to the Congress
of the United States by the Comptroller General. Report No. CED-80-111.
Published by the U.S. Government Printing Office, Washington, D.C., 1980.
34. Department of Energy. "Emergency Building Temperature Restrictions.
Final Rule." 10 CFR Part 490, Federal Register 44 (130):39354-39368,
1979.
35. Luciano, J.R. Air Contamination Control in Hospitals. Chapter 9,
"Reverse Isolation Systems."Plenum Press, New York, 1977.
36. ASHRAE Handbook and Product Directory: 1978 Applications Volume. Chapter 17,
"Clean Spaces."Published by the American Society of Heating, Refrigerat-
ing and Air Conditioning Engineers, New York, 1978.
37. ASHRAE Handbook and Product Directory; 1978 Applications Volume. Chapter 10,
~"Air Cleaners."Published by the American Society of Heating, Refrigerat-
ing and Air Conditioning Engineers, New York, 1979.
38. Turk, A. "Adsorption." In: Air Pollution, Vol. IV: Engineering Control
of Air Pollution. Edited by A.C. Stern, Third Edition, Academic Press,
New York, 1977.
39. ASHRAE Handbook and Product Directory: 1976 Systems Volume. Chapter 3,
"All-Air Systems."American Society of Heating, Refrigerating and
Air Conditioning Engineers, New York, 1976.
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40. Nevins, R.6. Air Diffusion Dynamics. Business News Publishing Company,
Birmingham, New Jersey, 1976.
41. ASHRAE Handbook and Product Directory: 1978 Applications Volume. Chapter 14,
"Enclosed Vehicular Facilities."American Society of Heating, Refrigerat-
ing and Air Conditioning Engineers, New York, 1978.
«
42. Fraser, D.W. and J.E. McDade. "Legionellosis." Scientific American 241(4):
82-99, 1979.
43. Nevins, R.G. "Environmental Control of Health Care Facilities." Critical
Reviews in Bioengineering 1(2):217-239, December 1971.
44. Turk, A. "Adsorption," in Stern, A.C. (ed.), Air Pollution, Vol 4, Third
Edition, Academic Press, New York, 1977, pp. 329-63.
45. Turk, A. "Measurements of Odorous Vapors in Test Chambers: Theoretical."
ASHRAE Journal 5(10), 1963.
46. Turk, A., H. Mark and S. Mehlman. "Tracer Gas Nondestructive Testing of
Activated Carbon Cells." Materials Research Standards 9(ll):24-26 (1969).
47. Brief, P.P. and M. Corn. "Contribution to the Assessment of Exposure of
Nonsmokers to Air Pollution from Cigarette and Cigar Smoke in Occupied
Spaces," Environmental Research 5:192, 1972.
163
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Section 3
RECOGNIZED AREAS OF OMISSION
SCOPE.OF INDOOR AIR PROBLEM
The Control Technology Group concentrated on the residential
environment relative to nonresidential, nonindustrial environments. The
industrial environment was not addressed significantly. Because the general
public has less control of nonresidential indoor environments to which it is
exposed, it could be exposed to a greater risk in these environments. The
group feels strongly that this large sector of the built environment not be
omitted from research plans.
PRODUCT SUBSTITUTION
The Control Technology Group did not deal significantly with the
product substitution area. One of the reasons was a lack of time to adequately
address the subject. Another, perhaps more important, reason was that the
group felt that the product substitution area was one that is product-specific
with each offending product demanding a unique approach to finding an adequate
replacement. This area is, perhaps, less a government function than one for
industry.
164
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Section 4
RESEARCH NEEDS
GENERAL PROBLEM DEFINITION NEEDS
«
Although indoor air pollution control methods should be studied
in parallel with other indoor pollution research, there are a number of areas
where controls research would be greatly aided by further developments in
the areas of instrumentation, monitoring techniques, pollutant characterization,
health effects and risk analysis. For instance, a ventilation standard will
not be definitive until the health risk associated with specific pollutant
concentrations have been determined. The following is a list of some of these
general research needs that controls research will depend on:
1. Identification of the pollutants of concern
2. Determination of the concentrations to which these pollutants
need to be lowered
3. Characterization of the pollutants including:
- Source identification
- Source emission mechanisms and rates
- Chemical and physical interactions/transformations
- Transport and removal mechanisms
- Measurement methodology
4. Development of models for air and contaminant movement within
buildings.
Evaluation Methodology Needs
A method of evaluating and deciding between various control strategies
needs to be agreed upon. This method should take into account the following
points:
1. Technical effectiveness
- Laboratory and field studies
2. Consumer acceptability
- Lifestyle effects
- Reliability
- Maintenance requirements
- Hazards from use
165
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3. Commercial availability
- Manufacturing/marketing capabilities
- Installation
- Maintenance
4. Cost-benefit analysis
- Application to control of other pollutants
- Initial, operating and maintenance costs
- Benefit of mitigation of health effects.
CONTROL TECHNOLOGY RESEARCH NEEDS
Indoor air quality research is underway to some extent in all
areas—characterization, health effects, risk analysis, controls and monitoring
methods, and instrumentation. With the exception of industrial hygiene studies,
most research efforts have not been oriented toward specific indoor air quality
goals, but rather have been undertaken to show the existence of a problem. The
research has established that some pollutants can accumulate in indoor air to
concentrations that exceed workplace and/or ambient standards.
The limited research in control technology has been largely directed
at controlling indoor exposures of asbestos, radon and radon daughters, and
formaldehyde. Several strategies have been considered for these pollutants.
Source removal and covering with sealants (source exclusion) have been employed
to control asbestos in schools. Sealant covering may be only a temporary
solution, but source removal is expensive and time-consuming and may present
severe exposure problems during the removal process. Source removal, source
substitution, and masking have been considered for indoor formaldehyde control.
Research for controlling indoor radon and radon daughters has been principally
directed at source exclusion, electronic air filters, and ventilation. Air-to-
air heat exchanger ventilators appear to be effective dilution devices for
reducing radon and other pollutant concentrations.
Ventilation Research Needs
The following research needs apply, in most cases, to all building
types. The needs have been organized into generic measurements followed by the
categories of ventilation systems.
Ventilation Rate and Pollutant Measurement
t Develop and verify the accuracy of an inexpensive method
of measuring the average ventilation rate in a home over
periods ranging from 1 week to 1 year.
• Develop an accurate model of infiltration rate versus weather
conditions based on a simple measurement, and/or building type.
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• Determine the ventilation rate (infiltration, natural ventila-
tion, and mechanical ventilation) and the concentration of the
pollutants of concern in a statistically significant number
of U.S. homes and other buildings over at least month-long
periods during different seasons of the year. Correlate
this information with building type, air tightness level,
general weather conditions, heating and cooling system
type and energy usage.
t Develop air and contaminant movement models for residences.
Natural Ventilation
• Determine the effects of window opening frequency, amount
and duration on ventilation rate, pollutant concentration,
and energy usage.
FORCED VENTILATION
General
Determine the acceptability to building occupants of the
various types of mechanical ventilation systems, considering:
first cost, noise, discomfort, energy savings, pollution
control.
Determine of mechanical ventilation systems can be operated
intermittently during periods of severe outdoor weather
conditions and still be effective at reducing pollutant
concentrations.
Determine if an extensive distribution system is necessary
/for a residential mechanical ventilation system or whether
pollutants can be controlled by just exhausting and supply-
ing air to one area of the house.
Determine if ventilation rates can be varied either manually
or by automatic control to take into account the decay in
the source strength of certain pollutants with time. If
an automatic control system is used, what pollutant should
the system be based on?
Determine impact of different tyeps of heating systems on
the necessary ventilation rate and examine solutions to the
problem of inadequate combustion air supply in buildings
where infiltrtiori has been reduced.
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• Evaluate methods for the control of pathways for contaminant
transmission to building occupants, e.g., examine the need
for pressure control to prevent cross contamination, consider
the location of air intakes and exhaust, and examine air
flow around buildings.
• Determine if spot ventilation at a pollutant source, such as
using a range hood over a gas stove or ventilating a base-
ment directly if the basement is the source of radon, is
more cost-effective and more effective in pollution reduction
than whole-house ventilation.
• Determine if combining spot ventilation with a heat
exchanger is cost effective.
• Determine if a spot ventilator, such as a range hood, can
be used for whole house ventilation.
Air-to-Air Heat Exchangers
t Determine effectiveness versus flow rate at various operating
conditions (i.e., dry, condensing, and freezing) for
commercially available residential units.
• Determine mass transfer for both water vapor and pollutants.
• Determine if any pollutants are given off by the materials
that make up the heat exchanger.
0 Test the heat transfer and mass transfer effectiveness of
commerically available units that have operated in the field
for at least 1 year to determine degradation versus time.
t
• Model heat exchanger heat transfer.
• Perform corrosion durability and fire testing.
• Determine the stability of airstream flow rates through the
heat exchanger and the effect of instabilities on the energy
consumed to condition ventilation air.
• Determine the effectiveness of ventilation systems with heat
exchangers in reducing pollution and saving energy when
compared to other ventilation systems without heat recovery.
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0 Determine the cost-effectiveness of ventilation systems with
heat recovery versus climate and ventilation rate when
compared with a simple exhaust ventilation system.
• When are heat exchangers economical in a retrofit situation?
• When is the recovery of latent heat desirable in a residential
system?
. • Should a ventilation .system with heat recovery be combined
with a forced air furnace system or should the units be
separate?
Contaminant Removal Research Needs
Carbon adsorption offers a significant potential in removing contam-
inants from indoor air. Research needs are associated with the following
characteristics of these devices:
1. Their saturation is not signalled by a change in color,
resistance to air flow, or total mass.
2. Adsorption efficiency is sensitive to ambient temperature and
humidity, to the extent of saturation of the adsorbent, and
to the nature and concentration of the contaminants.
3. As the carbon approaches saturation, some previously adsorbed
contaminants are desorbed.
4. The carbon surface is catalytic, and can promote reactions
among adsorbed molecules, including oxidation and hydrolysis.
5. ./Saturated carbon cannot be effectively reactivated by the
heating or washing methods available to the householder or
to maintenance workers in commercial buildings.
6. To a first approximation, the effect of activated carbon
for physical adsorption of gases in ventilating systems depends
on the increment of molecular weight of the contaminant gas
over that of air. Therefore gases of low molecular weight,
such as formaldehyde and ammonia, are not effectively adsorbed.
The following set of research needs is based upon the above-listed
characteristics of carbon adsorption:
• Develop standardized methods for evaluating the degree of
saturation of a partially saturated adsorber.
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• Develop data base for expected service life of adsorbers.
0 Develop end-of-service-life indicator for carbon air cleaners.
• Evaluate the patterns of carbon saturation with particular
reference to fractionation and chemical conversions that
can occur on the carbon surface and can influence the quality
of the post-carbon air.
• Develop range hoods which are effective for removal as
opposed to dilution; also reduce noise level.
• Develop more effective adsorption technique.
0 Develop effective impregnation for activated carbon.
0 Develop more effective filter media.
A variety of additional research needs in the area of contaminant
removal have been suggested. Some of these are similar to those listed
specifically above for carbon:
0 Develop strategies for use of filters of various media for
forced air systems.
0 Develop end-of-service indicators for various types of
air cleaners.
0 Determine particle size efficiency and useful life of
particulate filters.
0 ^Study applications of electrostatic fields for removal of
particulate contaminants.
0 Investigate potential for technology transfer of air cleaning
mechanisms from industrial and military applications.
0 Study contaminant removal in energy storage devices.
. 0 Study the application of climate control for control of
pollutants, for example, formaldehyde versus humidity.
0 Study the effectiveness of using independent filtering systems
on the return and the makeup air.
0 Study the relationship between greenhouse plants and indoor
air quality.
0 Investigate models for natural sinks and ways in which they
might be enhanced.
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Source Removal/Exclusion Research Needs
The research needs listed here are directed at finding methods to
prevent the entry of contaminants to indoor space so that dilution and air
cleaning systems will not be required:
• Identify sources and source strengths (i.e., emission rates).
Emission rates may be influenced by ambient conditions and
time of emission.
• Develop techniques for establishing material standards based
on emissions. The Institute of Hygiene - Denmark has done
some work in developing this type of standard. Emission
testing standards also require development.
t Develop models for building materials based on emission rates.
Some pollutants to be considered are radon/daughters, plastics
and plasticizers, formaldehydes, rubber, paint (e.g., mercury),
combined materials.
• Control strategies for removal of sources, including synergistic
emission rates or synergisms from different emissions, should
be identified and evaluated.
0 Determine inventory of coatings and encapsulating compounds
which can intervene or retard emission rates. Safety factors
(i.e., emissions from the encapsulating compounds) must be
considered.
0 Determine alternative control strategies for eliminating
combustion products (e.g., substitution for standing pilots).
• 'Determine total characterization of indoor spaces which
may be used to:
- Model effectiveness of control strategies
- Match control strategy to types of emissions.
t Develop building technologies which will exclude soil gas,
pesticides, etc. Also develop reliable remedial techniques.
• Determine inventory of emission rates/fates for consumer
products:
- Appliances and equipment (heating, cooking, etc.)
- Solvents and chemical specialties
- Home furnishings.
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0 Identify occupant activities (i.e., human factors)
which can be considered as control strategies for source
removal/exclusion.
t Determine inventory of emission rates/fates from processes:
- Cooking
- Use of copy machines, etc.
• Map and compile inventory of hazardous building site areas
relative to ambient emissions, such as radon.
Product Substitution Research Needs
The Control Technology Group participants did not identify specific
research areas, at least in any formal way, that should be addressed in the
product substitution area. The discussion brought forth several ideas, however,
that are summarized as follows:
• Perhaps research should be undertaken to identify and label
products that emit contaminants.
• Perhaps ingredient labeling is needed.
• A standard outgassing test is needed.
• A list of criteria for cost-benefit analysis is needed.
• Perhaps tests under the Toxic Substances Control Act are
needed.
• What do we do about UF foam? Mineral wool can substitute.
t
0 What do we do with retrofit versus new buildings?
• How can we detoxify or remove existing materials?
• Identify materials that should be banned.
• Changing building materials requires massive economic changes,
because materials are made in very large quantities.
t Copying machine emissions are an example among many others.
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Section 5
CONCLUSIONS AND RECOMMENDATIONS
CONCLUSIONS
The findings of the Control Technology Group of the Workshop on Indoor
Air Quality Research Needs can be summarized as follows:
1. Ventilation is a centuries-old technology that has been used
for increasing human environmental comfort, significantly
recognized only as controverting energy conservation objectives.
2. Contaminant removal technologies have been in use for many
years, emphasizing various kinds of filters and adsorbers,
mainly in combination with heating and air-conditioning,
air-recirculation systems.
3. Source removal and exclusion technologies are relatively
new, brought to the fore by recent developments in energy
conservation, health effects research discoveries, and
chemically-based consumer products. In at least one case,
that of radon, the source can only be excluded; it cannot
be removed because it is a natural soil emission.
4. Product substitution is a product-specific method of indoor
air quality control, not conducive to a generic control
development program.
5. There is an unfortunate tendency to view indoor air quality
problems as residential, rather than as problems of all types
^of interior environments.
6. Research to this point has emphasized problem definition,
but because the realm is so large, the data base is grossly
inadequate.
7. Indoor air quality control technology research is just
beginning, spurred by the problems being exacerbated by
building energy conservation measures.
8. Control technology devices and regulations are likely to
be imposed upon suppliers of consumer products and building
materials, but not upon building occupants; use by occupants
will remain optional.
9. Heating/air-conditioning and cooking equipment manufacturers,
home builders, utilities, and building products manufacturers
are especially interested in indoor air environmental develop-
ments because of the potential economic effects upon them.
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RECOMMENDATIONS
The Control Technology Group of the Workshop on Indoor Air Quality
recommends that the Interagency Research Group on Indoor Air Quality undertake
to do the following:
1. In developing a coordinated national program for indoor air
quality research, specifically providing for communication
between researchers and public users, involve the private
sector in research planning, and conduct indoor air research
outside the residential environment.
2. Design a research program that includes addressing the research
needs outlined in this document.
3. Integrate that research program into the "National Plan," assign-
ing responsibilities for specific research to specific Agencies
with recommended funding.
4. Continue, as an ongoing responsibility, the updating of the
Indoor Air Quality Research Inventory as a valuable input to an
evolving program.
5. Continue, on a periodic or as-needed basis, the convening of
workships and broadening the base of technical input to
facilitate a coordianted, dynamic, results-oriented research
effort.
6. Ensure that all indoor air environments are addressed and
afforded the research necessary to resolve air quality
problems within them; this means addressing residential
and all the various subtypes of nonresidential building
^environments.
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RISK ANALYSIS
INDOOR AIR QUALITY RESEARCH STRATEGY
Nathaniel F. Barr
175
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REPORT ON THE PANEL ON RISK ANALYSIS
The panel expressed agreement with the objectives of and strategy
for health risk analysis developed by the Interagency Research Group (Table 1),
and vfith the comments of the Risk Analysis Working Group on the inventory of
current research and the Draft Indoor Air Quality Research Strategy (Table 2).
The consensus of the panel was that the discipline of conducting
analyses of current knowledge and uncertainties regarding the health effects
of indoor air pollution could lead to improved perspective on and sharpen the
definition of research requirements.
The panel approved the level and scope of the risk analysis recom-
mendations by the work group. These recommendations are presented in Table 4.
The panel and audience identified and extensively discussed several
cautions to be observed in the conduct and utilization of health risk analyses.
These were:
1. There would be a very wide range of uncertainty associated
with health risk estimates derived from the current data base.
2. The use of results of health risk analysis for purposes other
than R&D planning (i.e., policy formulation, regulation and
public information) should be approached with extreme caution.
3. The scope of health risk analysis should be broad enough to
provide perspective on factors such as the health implications
of inadequate housing and other safety features of the indoor
environment.
4. It is suggested that results of ongoing risk analysis be
provided to participants in advance of future workshops and
discussions of these analyses be scheduled early in the agenda.
A Risk Analysis study presented by Dr. Anthony Nero is included as
an example of such scientific work.
177
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Table 1. Objectives and Strategy for Health Risk Analysis
Objective
*
r " The objective of health risk analysis 1s to strengthen the basis for
planning and conducting research and development programs by analyzing
current knowledge and uncertainty regarding the potential health con-
sequences of Indoor air pollutants.
Strategy
This objective will be accomplished by establishing 4 to 6 groups to
gather, review and analyze, 1n a continuous manner, existing knowledge and
the results of ongoing research. These groups will provide analytical
descriptions of knowledge and uncertainty regarding the potential health
Impacts of indoor air pollutants and of technologies that generate Indoor
air pollutants.
Each group will operate at a level from 2 to 5 person-years per year
(py/y) and issue annually a report which identifies potential health
Impacts and analyses of what is known and not known regarding impacts.
Table 2. Working Group Comments on Inventory of Current
Research and the Draft Research Strategy Plan
1. Comment pn Inventory of Current Federal Research and Development to
Indoor Air Pollutants (Table 3)
The Risk Analysis Working Group was unable to Identify any projects
listed in the Inventory of current Federal Research and Development
that are devoted to the analysis of potential health risks of
specific Indoor air pollutants or of specific technologies which
produce Indoor air pollutants.
II. Comment on Draft Indoor Air Quality Research Strategy Plan (IAQRSP)
The Working Group notes the IAQRSP does not include projects which
would undertake to assess the potential health Impacts of Indoor air
.pollutants or of technologies, programs and/or policies that would
modify Indoor air pollutants.
178
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Table 3. Status of Risk Analysis on Indoor Air Pollutants
VO
Agency
EFA/CAC
CPSC
CPSC
CPSC/EPA/
IRLG
EPA/TSCA
USEPA/ORP
EPA/ORP
• Substance •
Formaldehyde
Formaldehyde
Formaldehyde
Formaldehyde
Asbestos
Radon and
Radon Progeny
Radon and
Radon Progeny
Health
Effects
Cancer •
Chronic Health
Effects Using
CUT Data
All adverse
effects
All adverse
effects
Lung Cancer
Lung cancer
Other cancers
Lung Cancer
Other Cancers
Sources
Evaluated
Unspecified
Unspecified
s.
Urea formal-
dehyde foam
All sources
Friable asbestos-
containing
materials In
schools
Uranium miners
Exposure
Analysis
Unspecified
Unspecified
Unspecified
Unspecified
School children,
teachers and other
school personnel
Average 85 HIM
Risk
Analysis Status
Completed
Nov. 1979
Forthcoming
Forthcoml ng
Forthcoml ng
Completed
Sept. 1980
Computer
Papers In
preparation
Comments
Testing of health effects
models to determine sensi-
tivity to perturbations
of Input assumptions and
parameters
Through contract.
-------
Table 4. Recommendation for Health Risk Analysis Research
Research
Area
Research
Subarea
Priority Rank
Recommended Project Description
Funding
Duration Level
Agency
Risk
Analysis
Technology
Analysis
-Building
Energy
Conservation
Gas and
electric
stoves
-Wood burning
stoves
- Rndim
Initiate analysis of potential risks to human health of Continuous 3 to 5 py/y
building energy conservation programs
Initiate analysis of potential risks to human health of Continuous 3 py/y
using gas and electric stoves for cooking
Initiate program to extend current analysis of the
potential health impacts of wood burning for residen-
tial space heating
Continuous 2 py/y
Kxpnml current nnnlynln of rlwkn to liumnn licnltlt of font Imioun 2py/v
rndon In the Indoor atmosphere.
- r'urajnlileliyde
Continue current analysis of potent Inl rlaku to human contlnuoua 3py/y
health or formnldrltyde In the Imloor environment.
00
o
- l!ydror nrlions
Inltlnte an annlynln of the potential rlskn to liumnn continuous 3py/y
hcnlth or liydrocnrbonp In the Indoor environment.
Inltlnte an •nnlyals of the potent Inl rlnkn to lumuin font Inuoun
licnltli ol pathogenic orgJinlBina In the Indoor eiivl'ronnenl.
- Pnrf
Initiate an onnlyala of the potent Inl risks to tumuin continuous
health of pnrtlclcn In the Imloor c.nv Ironnent.
C.irlxin
Monoxide
Initiate an nnalysla or the potent Inl rtska to hinuiu contlnuoua lpy/y
health or cnrhon pmnoxlde In the Inloor environment.
-------
RISK ANALYSIS TO RADON AND RADON PROGENY
by
Anthony V. Nero, Jr.
181
-------
INDOOR AIR QUALITY HEALTH RISK ANALYSIS*
Anthony V. Nero, Jr.
The purpose of this talk 1s to demonstrate briefly some of the
principal considerations in performing indoor air quality (IAQ) health risk
analysis. I will indicate these considerations generally and, in addition,
use the case of radon and its daughters as an example. Discussion of this
case will effectively constitute an extension of the session on radon. How-
ever, this shouldn't be taken to imply that radon is necessarily the main
pollutant of concern. It is merely the one we will use to demonstrate the
principles of risk assessment for indoor air pollutants.
Just to indicate where we might be going, there are two major
questions we can ask ourselves in the area of IAQ risk assessment. One is
the question of what the current risk is; i.e., the risk from present indoor
exposures to air pollutants. The second question, which can be distinguished
from the first, is what change in the net risk can be expected from a partic-
ular change in the current situation; e.g., a strategy for saving energy or
improving air quality in housing.
In trying to examine current risk or changes in it, an array of
different pollutants have to be considered. There are several categories
into which we can place these different pollutants. I list several categories
that arise fairly naturally: smoking products; combustion emissions, which
may be considered to include those from smoking; organics, such as formaldehyde,
but including all sorts of other materials; radon and its daughters; bacteria;
and others that I haven't listed here, simply because I've only included the
most familiar categories.
In terms of a health risk assessment, there are several risk cate-
gories or health end points that one might examine. Again, I list several
classes only as examples. One general class of effects includes respiratory
irritation or disease; lung cancer, of course, is a member of this class,
but I've singled this out because I will treat it explicitly as we proceed.
There are other classes of effects; e.g., acute syndromes associated with
carbon monoxide exposures (even leading to death), formaldehyde exposures,
and so on. .But, in addition to these specifically "health" effects, there
is a more general class of "environmental" effects. Some of these effects
are those that are ordinarily noted by house occupants; I.e., general comfort
parameters, odors, etc. There are, in addition, all sorts of other effects,
including direct or indirect effects that might occur outdoors. I'll point
out later how these arise as part of risk assessment.
* Edited transcript of talk given at session on risk assessment,
183
-------
Let me turn first to the problem of assessing the current risk
from radon daughters, just as an example of the assessment process. In
order to assess the risk, several kinds of information are needed. One clearly
needs information on exposures, and even this is divided into two kinds of
information as I frame it here. The first is data on average exposures, and
the second is information on the distribution of exposures; i.e., how many
people are getting exposures of various sizes. In order to understand this
distribution, one has to have information on concentrations of pollutants,
in this case the radon daughters; one also has to have information on patterns
with which people use their houses or are present in their houses.
I should make two comments in passing that I'll elaborate on in
a few minutes. One is that the average exposure is not known to be better than
about a factor of 2. One can argue about the precise uncertainty, but I'll use
this factor in what follows, indicating where it comes from. A second point
that I would make is that the exposure distribution is not known well at all.
For example, the question of how many people are receiving exposures above any
specific level cannot be answered with any certainty. We cannot characterize
exposures adequately either on the basis of direct measurements of concentra-
tions or on the basis of an understanding of what the sources of radon are and
how radon gets into buildings - we don't have that information, nor do we know
much about the behavior of radon daughters indoors. So our information base on
daughter exposures is not very good. However, unlike other indoor air pollutants,
radon information is still good enough to make rough estimates of the kind I'll
indicate below.
The second class of information required for risk assessment is what
the health effects of a given exposure are. This information was discussed in
a fair amount of detail by William Ellett, in the session on radon, so that I
will not discuss the basis of the dose-response information that we have.
However, as I go along I'll use some of that information, as you'll see. In
any case the range of uncertainty is large - about a factor of 10 from low
estimates to high - or a factor of 3 around the geometric mean. Now, in using
such information, it is very important to remember that there are two kinds of
health risk estimates that one might make. First is an estimate of the total
population risk, which information can be used for certain purposes. A second
kind of estimate that one could make is what the risk is to those who are
exposed to relatively large concentrations. These people are at the highest
risk, and one might want to devote more attention to them than to people who
are at lower risk.
Let us turn now to actually making a risk estimate, beginning
with the.question of what the average concentrations might be. I show you a
large table, not so that you should remember the specific data, but merely to
Indicate what the state of information is. The total number of houses in
which radon or radon daughter concentrations have been measured in this
country is of the order of hundreds. Most of these arise from studies in
which 10 to 100 houses were monitored. There have actually been more studies
than indicated in the table, because I've excluded studies of only one or two
houses and generally speaking I have only included studies that had about 10
or more houses. In any case, the information base is not very large and,
184
-------
because the distribution of exposures Is very large, we don't really have much
Information about either the average or the distributions.
However, I suggest In the next figure that we do have some Informa-
tion, although the figure must be taken only as suggestive. This curve Is
only schematic and Is not an attempt to represent the actual data.; Neverthe-
less, we could say that a typical concentration of radon daughters, given 1n
the usual units; I.e., working level (WL), 1s probably on the order of 0.005
WL. I emphasize the word "typical." The average concentration In houses 1s
probably not far from that number. It could be virtually anywhere 1n the
range between 0.001 (or 0.002) and 0.01 WL. So I've written down that the
average concentration 1s about 0.003 WL, with an uncertainty factor of 3.
Another question of substantial Interest 1s what highly exposed
individuals might be encountering. What I've Indicated both by the tail
that extends very far out, far above the average of the distribution, and by
the number that I've cited, is that there are probably some people 1n the
United States who are exposed routinely to concentrations of the order of
0.05 WL - a factor of 10 above the average. However, we don't know how many
people they are. It would be interesting to know.
Given information on concentrations, we can calculate a typical
exposure, which I've written down in the usual unit, working level months
(WLM), the definition of which isn't needed to follow the discussion. But in
terms of this unit, the average exposure could be about 0.15 WLM per year and
the "maximally exposed" Individuals we have just mentioned would be receiving
a factor of 10 greater exposure than this.
Knowing these exposures and the kind of dose-response information
presented at the radon session, we can make an estimate of the risk from indoor
radon. From the data discussed in that session (see Table 2), we can see that
the dose-response1 factor, assuming a linear dependence of effect on dose, has
been estimated by various entities to have values ranging over a factor of 10.
Each one of those estimates Itself has, of course, some uncertainty. But
loosely speaking, we might say that we know the dose-response factor to within
a factor of 3 about some mean. I've written down the dose-response coefficient
as 300 cases per million WLM exposure among a population; the usual unit is
"person-WLM."
Using this dose-response factor, together with exposure information,
we can make a risk estimate. What we obtain from the values indicated is a
radon-daughter induced lung-cancer Incidence of approximately 45 cases per
million people per year among the U.S. population. But the range is large
because of the factors of 3 uncertainty 1n exposures and dose-response. What
the overall uncertainty 1s depends on how these factors of 3 are folded
together. One purely statistical approach would yield, overall, a factor of
5 In either direction. On the other hand, the extremes yield a factor of 9
In either direction. Taking the first approach, the estimated average risk
among the U.S. population 1s 9 to 225 cases per million per year.
185
-------
We would get a somewhat different number for the Individual risk
of those who are exposed continuously to an exposure of 0.05 WL, the number
we cited earlier for those at higher risk. Estimating the risk of an Individual
living In that concentration for a lifetime, based on our dose-response factor,
yields the result that such an Individual has an added lifetime chance of
getting lung cancer of about 4 percent. Now again, the uncertainty 1n the
dose-response factor, a factor of 3 1n either direction, would cause us to
modify this to about 1 to 10 percent. This is a very large risk.
This 1s the kind of procedure one could go through in examining
this particular facet of current indoor air quality risks. If we look at the
mean radon-related lung cancer Incidence that I have written down, 45 cases
per million per year, this turns out to be very close to the lung cancer
Incidence among those who don't smoke; roughly within a factor of 2. The
uncertainty in this radon-related estimate is of course large. Increasing
it by a factor of 5 to 225 cases per million per year (the estimate associated
with the upper end of the uncertainty range) yields an estimate that exceeds
the observed lung cancer Incidence among nonsmokers. If we take the other
end of the range of risk estimates, 9 per million per year, we obtain a much
smaller number. But it is still more than a thousand lung cancer cases per
year 1n the United States. This Is significant.
Let us now go on to the next major point. If we understand what
the current risk is from current exposures to radon or other indoor pollutants,
how do we understand the health effects of a change in the building stock.
Such a change could be due either to an interest in energy conservation or to
an Interest In indoor air quality. In either case we would like to know what
the net change in the risk would be. There are several possible sources for
a change in the risk. It is possible to change the source strength of the
Individual pollutants; it is possible, by Implementing energy conservation or
Indoor air quality measures, to change the infiltration or ventilation rate;
It 1s possible tp clean the air actively. Any of these changes could effect
a change In the net risk.
There are several broad considerations that have to be kept in mind.
There are, in fact, many indoor air pollutants. For each of them, we would
need exposure information and dose response Information. In effecting a
change, for example a change In energy use 1n buildings, we would not only
change Indoor concentrations; we would also change outdoor exposures to some
pollutants. These pollutants could come from the individual houses, from
energy production facilities that supply energy to those houses, and so on.
I'll explain this further in a moment.
•' As I stressed, we are Interested, In questions of population average
both exposures or risks and of Individual risks. Moreover, just to emphasize
a point that Is obvious to anyone who has been looking at risk assessment,
a great danger Is to emphasize those parts of the risk that we are able to
quantify and to Ignore those that we aren't able to quantify, even when the
latter are comparable in Importance, or even more important.
186
-------
As I've said, one of the possible factors that might cause a change
in indoor air quality risks is the implementation of measures to save energy.
In order to understand the change in net risk from a saving of energy, we have
to consider both the effect on indoor~aTr quality and other effects. In fact,
we have to look at the entire energy system that supplies the energy for, as
an example, space heating and cooling. I don't want to explore this in detail,
but merely to Indicate through a rather complex figure the kind of things we
might consider. I've tried to indicate on the left the energy supply technol-
ogies and, on the right, the points of use of different energy supplies. In
considering energy use for space heating and cooling, the end uses are at the
lower right. But in order to consider the net effect of a change in end use,
we have to look at the effect on the entire system. Let me just indicate what
this means in another way, using a simpler figure indicating classes of envi-
romental effects. In a house one has what we could call "internal" risks due
to exposures indoors. One would also induce "external" risks; for example,
burning oil, gas, or anything else (wood?) in the house that results in emis-
•sion of pollutants into the (outdoor) air. This can affect people outside
the house. In addition, if energy is supplied from some centralized energy
technology, there are risks associated with using that technology, including
what I call external risks; I.e., risks due to emissions into the external
environment, and also occupational risks that are internal to that technology.
These may appear to be obvious things, but it is important that they not be
neglected when performing an assessment aimed at estimating changes in the net
risk.
Finally, let us return to the case of a change in the infiltration
rate, considering in particular the effect on radon daughter exposures. The
effect of a change in infiltration rate on radon daughter exposures is itself
not simple, depending as it does on how the change is brought about and on
what control technologies are associated with 1t. In addition, any complete
risk analysis would have to Include other Indoor pollutants, some of which are
Identified, but many of which have not yet been associated quantitatively with
risks. Moreover, the externalities that I have referred to would have to be
considered.
For the case of indoor radon, let me just Indicate two key points.
First, by changing the infiltration rate, we can have a highly variable
effect on radon daughter concentrations, depending on how that change is
accomplished. I show some data from a house in Maryland in which the venti-
lation rate was controlled by use of a mechanical ventilation system with an
air-to-air heat exchanger. The upper figure shows the variation in the radon
concentration as a function of time over a 2-week period. During that 2-week
period, the ventilation rate was maintained at about five different values.
The equilibrium radon concentration corresponds pretty well, as we would
expect, to the inverse of the ventilation rate. However, the daughter con-
centration, which Is shown on the lower figure, is much more complicated. A
variety of different kinds of mechanisms can remove daughters, including not
only ventilation but also filtration and adhesion to various surfaces in the
house and the air circulation system. The point is that predicting the effect
of a particular change In the building stock on radon daughter exposures is
not a simple question.
187
-------
The second point on Indoor radon is Indicated In the final very
schematic figure, which in fact presumes we know something about the effect
of ventilation rate reduction. What I want to indicate conceptually is
the kind of trends we might expect from different strategies beginning now,
I.e., in the year 1980. What I've tried to plot schematically is the average
population exposure to radon daughters over a period extending from the year
1900 through 1980 to some time in the future. What I've suggested in the
figure 1s that there has probably been a modest increase in radon daughter
exposures during this century. This presumption, based not on experimental
evidence, but on conjecture, assumes some decrease 1n infiltration rate from
tightening of houses over the years.
Whether or not this has actually occurred, the present point of
interest is what might happen in the future, say for the next 20 years and
beyond. Changing the housing stock Is a relatively slow process. Considering
the energy-saving measures that might be employed in existing houses and the
.related practices that might be employed In building new housing, I suggest
that 1f we employed no explicit control concepts or specific control technol-
ogies, radon daughter exposures could Increase by about 25 percent over the
next 20 years. Taking this conjecture for the sake of argument, we can con-
sider what else might happen. If we give some explicit attention to the
question of radon exposures, e.g., if we try to identify those areas or indi-
viduals that have particularly high exposure, we could effectively cut the
tail off the exposure distribution that I showed you, eliminating much of the
risk to the highly exposed portion of the population. Moreover, if we also
employ control technologies 1n very tight houses, we would be avoiding a large
amount of associated exposures. With such attention, we could hold radon
daughter exposures below the trend of the last century or so, and even decrease
average exposures. These are, of course, just two examples of what might hap-
pen.
I close by summarizing what we have been talking about: broadly
speaking, the rote of Indoor air quality risk assessment. One purpose is to
quantify the current risk, both to Identify problems that we don't understand
very well and as a basis for understanding what research might be done to
Improve our information base. A related interest 1s to Indicate the need for
development of control technologies. The other purpose of risk assessment
1s to understand the effect of a particular action, whether a program to save
energy or a decision to employ a control technology, on the total risk. Such
assessment involves the risk both indoors and outdoors, arising both from the
end use and from the rest of the energy system. Risk assessment is an impor-
tant tool for understanding what priorities we might set in trying to increase
our Information base and doing research relevant to it. It is also Important
as a tool for understanding the health effect of decisions we might make to
change buildings in the United States.
188
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INDOOR HEALTH RISK ASSESSMENT
MAJOR QUESTIONS:
• RISK FROM CURRENT INDOOR EXPOSURES
• CHANGES IN NET RISK FROM VARIOUS STRATEGIES
MAJOR INDOOR POLLUTANTS:
• SMOKING
• COMBUSTION EMISSIONS
• ORGANICS
• RADON
• BACTERIA ,,?
MAJOR POTENTIAL HEALTH EFFECTS:
• RESPIRATORY IRRITATION OR DISEASE
• ACUTE SYNDROMES., INCLUDING DEATH
• LUNG CANCER
>
OTHER ENVIRONMENTAL EFFECTS:
• INDOORS - ODORS, COMFORT
• OUTDOORS - INDIRECT EFFECTS
189
-------
ASSESSING PRESENT RISK FROM RADON DAUGHTERS
EXPOSURE AVERAGE AND DISTRIBUTION:
• NEED CONCENTRATIONS AND USE PATTERNS
• AVERAGE NOT KNOWN TO BETTER THAN FACTOR OF 2
• DISTRIBUTION NOT KNOW AT ALL
• CAN'T YET CHARACTERIZE ON BASIS OF SOURCE STRENGTHS AND BUILDINGS
CHARACTERISTICS
DOSE - RESPONSE:
• BASED ON MINERS
• RANGE OF UNCERTAINTY IS LARGE: FACTOR OF 10
ESTIMATING EFFECTS:
• POPULATION RISKS: E,G, AS BASIS FOR BUILDING STRATEGIES
• INDIVIDUAL RISK: E,G, AS BASIS FOR CONCENTRATION LIMITS
190
-------
1
C3
o
1
o
o
O
SCHEMATIC REPRESENTATION
OF DISTRIBUTION OF INDOOR
RADON-DAUGHTER CONCENTRATIONS
0.01
0.05
Indoor Daughter Concentration [Working Level)
Average daughter concentration (U.S. housing): a»0.003 WL (x 1/3 to x 3)
Some incidence of much higher concentrations ^O. 05 + WL
Average daughter exposure: s*0. IS WLM/yr (x 1/3 to x 3)
Exposure of those in high concentrations: ="1.5 + WLM/yr
Dose-response factor: ="300 lung cancers/106 person-WLM (x 1/3 to x 3)
Estimated U. S. lung cancer incidence from
radon daughter exposures =*45 cases per million population per year (9 to 225, considering uncertainty
of x 1/5 to x 5)
191
-------
Selected Radon and radon daughter measurements in U.S.
(residences are single family except where noted)
residences
Location
ORDINARY AREAS:
Tennessee
Boston
Reference
Lowder 1980 '
Yeates 1972
222Rn(nCi/mV
0.07(0.005-0.2)
0.09(0.01-0.2)
Daughter PAEC (NL)a
0.008(0.0008-0.03)
(up to 0.002)
v, (up to 0.002)
Number of
Residences
IS
7
3
Type of
Measurement
Grab
Grab and venti-
lation
Grab and venti-
Comments
ft
1
Shale area; mostly concrete
construction
Single family; air exchange
rate; 1-6/h
Multiple family, air exchan)
NY/NJ
Illinois
George 1978
Rundo 1979
0.8 (0.3-3.1)
(0,5-33)
0.004(0. 002-0. 013)
[0.003 - 0.08]
21
22
lation
Several integrated 17 single family; 3 multiple
measurements over family; 1 apartment bldg.
year
Grab
San Francisco
area
U.S. /Canada
SPECIAL AREAS:
Grand Junction
Colorado
Florida
Montana: Butte
Anaconda
Berk 1980 (0.4-0.8)
Hollowell 1980 (0.6-22)
Barnes 1975
Florida 1978
Guimond 1979
Guimond 1979
EPA 1980
EPA 1980
[0.00) - 0.002]
[0.002 - 0.05]*
0.006b
0.004
0.004(0.0007-0.014)
0.014
0.02
0.013
26
17
29
28
26
133
56
16
Grab and venti-
lation
Grab and venti-
lation
Integrated year
round
Integrated year
round
Integrated year
round
Integrated year
round
Integrated year
round
Integrated year
Wood-frame construction,
unpaved crawl spaces
(windows closed)
Air change rate: 0.02-1.0/h
(windows closed)
Energy-efficient houses;
air change rate: 0.04-1.0/h
(windows closed)
Controls for remedial
action program (which
has included houses in
range 0.02-1 NL)
Controls on unmineralixed
soils
Controls on unmineralized
soils
Houses on reclaimed phosphate
lands
Intensive mining area
Intensive mining area
round
'individual values are averages; values given in parentheses are ranges. All measurements are in living space; values in basements are typically higher.
Geometric mean.
4>Calculated from measured radon concentration assuming 0. 5 equilibrium factor.
9/80 aa
-------
Table 2 (RP80)
Estimated Life Time Bisks of Fatal Lung Cancer from Radon Progeny
•Estimator
UNSCEAR
WRC
EPA - absolute risk
EPA - relative risk
BETR HI
Victor Archer -jabsolute risk
HCRP - absolute risk
Cases per
Person WLM
200-450
360
350
860
650
1050
130
30-yr. exposure to
adults
all ages, 1967 U.S.
. population
cohort (stationary
population)
all ages, 1975
U.S. population
-------
ASSESSING CHANGES IN NET RISK
CAUSES:
• CHANGES IN SOURCE STRENGTH (E,G,, DUE TO
CHANGES IN BUILDING TECHNOLOGY)
• CHANGES IN INFILTRATION OR VENTILATION RATE
(DUE TO ENERGY CONSERVATION OR IAQ MEASURES)
• ACTIVE AIR CLEANING
MAJOR CONSIDERATIONS:
• MANY POLLUTANTS
• NEED EXPOSURES AND DOSE-RESPONSE FOR EACH
• CHANGES BOTH INDOOR AND OUTDOOR EXPOSURES
• HAVE/TO EVALUATE BOTH POPULATION-AVERAGE AND
INDIVIDUAL RISKS
A COMMON DIFFICULTY IN ANY SUCH EVALUATION IS TO PAY
MOST ATTENTION TO THE RISKS THAT CAN BE QUANTIFIED
AND TO IGNORE THE REST,
•cv
-------
FIGURE 4: ENERSt SYSTEM
J
Q
OIL md GAS. convention* 1
on-shore/off-shore
primary.. .enhanced
[OIL shale
| GAS. unconventional
[PEAT
[COM., direct use
("COM! . el ectrl c centers Ion
COM., liquid fuels
[NUCLEAR.~fiss1on
[ NUCLEAR, fusion or hybTld
[ MUNICIPAL HASTES
[BIOHASS
[GEOTHERMAL
h
P
h
[ OCEAN THERMAL (
[SOLAR
[HIND
\
\
[ HYDROELECTRIC \
TRANSPORTATION
light-duty Vehicles
- gasoline (gawhol). dlesel. electric
Iwavy-duty vthlcln
r dlntl
rail
- tlKtrlc
(tMp. btrgt)
INDUSTRIAL
(proctti htitj
(iMchlniry)
(•pet hMtlng/coolIng)
(lighting)
rnMroriai rarcinrirrtli I °*'le« bulldlngs.Other
COH1ERCIAL/RESIDENT1AL { ,,„,,, fili,1y. .partwe
CMMTClal
14-Central or Urge-seal i
PRODUCTION-
distributed or Mill scale-
heating and cooling conversion equipment
- furnaces
» heat pumps and air conditioners
- electric resistance heating
- active solar
- other
structural features-
- architectural: MSS. window placement
- Insulation, wlndOM glazing
- Infiltration/ventilation
appl lances
• cookers. Mter heating, refrigerators
- washers, dryers: clothes, dishes....
- lighting .
• other
USE (each requiring Inclusion of efficiency Measures)
-------
internal
(occupational)
small number
voluntary?
(environmental)
external
(public)
very large number
Involuntary
internal
(occupant)
large number
voluntary?
FIGURE 3: CLASSES OF ENVIRONMENTAL EFFECTS
196
-------
EXAMPLE
EFFECTS OF CHANGE IN INFILTRATION RATE?
RADON DAUGHTER EXPOSURES
• COMPLICATED IN ANY CASE
• DEPENDS ON MANNER OF IMPLEMENTATION
OTHER INDOOR POLLUTANTS
• NOT ALL IDENTIFIED
• RISKS USUALLY NOT QUANTIFIED
ASSOCIATED CHANGES IN OUTDOOR POLLUTION
• EFFECTS FROM CENTRAL STATIONS
• EFFECTS FROM LOCALLY GENERATED POLLUTANTS?
INDIRECT HEALTH EFFECTS
• i L WAR?
2
C0?
(MORE GENERAL ENVIRONMENTAL EFFECTS)
197
-------
— Continuous
radon
monitor
Grab samples
Lob analysis
D Field analysis
I
1
3/B/79
MMMMMMMMMMM
9/15 9/16 9/17 9/18 9/19 9/20 9/21 9/22 9/23 9/24 9/25 9/26 9/27 9/28/79
Time
Date
KBL79D-4440
.____!
•
•
1I5>
^H
1
uqj-
•
i
_J
Tp c
1,
n 1 — i
1 1 1 1 i
a
1
a07och
l
0 i
or n
o ! ft
k ° a
? . 1 •
Furnace
ton off
1
i i
*^
1 I _L
1 1 1 1 1
• *
0.4 ach
• •
rt
Q
a
V-CM* C
1 1 1 1 1
1 1 — 1 —
0.6 ach
i i i i i
QI3ach
Q)
D
a
a
1 1 1
0.8 ach
* —
\° "B tt02vyt -
jl" rtOft ijfm
i ^^ i T i i i . i
toper iimt tm
recommended
/ guideline
D
0 i "^fen i 0
MMMMMMMMMMMM M 0/ M ,
9/14/79 9/15 9/16 9/17 9/18 9/19 9/20 9/2t 9/22 9/23 9/24 9/25 9/26 9/27 9/28/79
Time
Date
Radon concentration (pCi/1) and daughter concentration (Working Level)
as a function of time in an energy research house. Measurements were
performed over a 2-week period during which the ventilation rate was
varied from 0.07 to 0.8 ach using a mechanical ventilator with an air-
to-air heat exchanger.
XBLT9O-44B4
-------
ILLUSTRATION
OF POSSIBLE TRENDS
FOR PUBLIC RADON
DAUGHTER EXPOSURES
&
I
CO
13
O
11
i_ i— \
21
beginning of substantial
programs to reduce
residential infiltration rates
past
behavior
8
nolAQ
measures
JD
a
a>
o>
2
modest attention to
radon daughter
control
1900
1920
1940
1960
1980
2000
YEAR.
199
-------
Appendix A
LIST OF PARTICIPANTS
-------
CONTAMINANT CONTROL
Mr. David Berg
U.S. Environmental Protection Agency
Room 629W
401 M Street, S.W.
Washington, D.C. 20460
202-755-2737
Dr. Julius Bochinski
Enviro Control, Inc.
One Central Plaza
11300 Rockville Pike
Rockville, Maryland 20852
301-468-2586
Dr. Ronald Bruno
U.S. Environmental Protection Agency
Office of Radiation Programs
401 M Street, S.W.
Washington, D.C. 20460
202-557-8927
Dr. William Cain
John B. Pierce Foundation
Yale University School of Medicine
New Haven, Connecticut 06520
203-562-9901
Dr. Wing Chan ,
General Services Administration
Safety Management Branch, PBAB
19th and F Streets, N.W.
Washington, D.C. 20405
202-566-0961
Dr. Ronald Colle
Room C229
Building 245
National Bureau of Standards
Washington, D.C. 20234
301-921-2551
Mr, Kenneth Credle
U.S. Department of Housing
and Urban Development
451 7th Street, S.W., Room 6170
Washington, D.C. 20410
202-755-6590
A-l
-------
Dr. Stephen E. Frazier
Rosh-Hampton Industries
Longwood, Florida 32750
305-834-3000
-4
Dr. fhad Godish
Department of Natural Resources
Ball State University
Munsey, Indiana 47306
317-285-1302
Dr. David Grimsrud
Lawrence Berkeley Laboratory
University of California
Berkeley, California 94720
415-486-4023
Dr. Janet Haartz (Chairperson)*
National Institute for Occupational
Safety and Health
4676 Columbia Parkway
Cincinnati, Ohio 45226
513-684-4321
Dr. Jerry Harper
330 CRU
Solar Applications Branch
Tennessee Valley Authority
Chattanooga, Tennessee 37401
615-755-2846
Mr. Eugene Harris
Director, Energy Pollution Control Division
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
513-684-4207
* Panelist
A-2
-------
Mr. Lynne Harris
Environment and Energy Science Advisor
Office of Extramural Coordination and
Special Projects, Room 8-55
National Institute for Occupational
Safety and Health
5600 Fishers Lane
Rockville, Maryland 20857
301-443-6377
Mr. Robert Hartley
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
513-684-4334
Mr. Ralph Johnson
.National Association of Home Builders
Research Foundation, Inc.
P.O. Box 1627
Rockville, Maryland 20850
301-762-4200
Mr. F. Richard Kurzynske
Gas Research Institute
10 West 35th Street
Chicago, Illinois 60616
312-567-6690
Mr. David Harris
National Institute of Building Sciences
Suite 700
1015 15th Street, N.W.
Washington, D.C/ 20005
202-887-0500
Mr. John Liskey
Consumer Product Safety Commission
Office of Program Management
5401 Westbard Avenue
Bethesda, Maryland 20207
301-492-6453
A-3
-------
Mr. Robert Macriss
Assistant Director, Environmental Research
Institute of Gas Technology
3424 South State Street
IIT Center
Chicago, Illinois 60616
312-567-3888
Dr. John Mathur
U.S. Department of Energy
Mall Station E201
Environmental and Safety
Engineering Division (EV-142)
Washington, D.C. 20545
301-353-5511
Mr. Mike McGrath
Edison Electric Institute
1111 19th Street, N.W.
Washington, D.C. 20036
202-828-7511
Dr. Preston E. McNall, Jr.
Thermal Performance Division
National Bureau of Standards
Building 226, Room B114
Washington, D.C. 20234
301-921-3637
Mr. Bill Mi rick*
Battelle Columbus Laboratory
505 King Avenue *
Columbus, Ohio 43201
614-424-5543
Mr. Charles Phillips
U.S. Environmental Protection Agency
P.O. Box 3009
Montgomery Alabama 36193
205-272-3402
Dr. Kurt Riegel
U.S. Environmental Protection Agency
RD-681
401 M Street, S.W.
Washington, D.C. 20460
202-755-4857
* Panelist
A-4
-------
Mr. Gary Roseme*
Lawrence Berkeley Laboratory
University of California
1 Cyclotron Road
Berkeley, California 94720
415-486-4062
Dr. David M. Rosenbaum
U.S. Environmental Protection Agency
ANR458
Deputy Assistant Administrator for Radiation Programs
401 M Street, S.W.
Washington, D.C. 20460
202-557-9710
Mr. Howard R. Ross
U.S. Department of Energy
Room GH-068
1000 Independence Avenue, S.W.
Washington, D.C. 20585
202-376-4672
Mr. Peter Russell
Project Manager
Technical Research Division
Canada Mortgage and Housing Corporation
Montreal Road
Ottawa, Canada K1A OP7
613-746-4611
Mr. Arthur Scott
DSMA Atcon Limited
4195 Dundas Street, West
Toronto, Canada M8X 1Y4
416-239-3011
Mr. David Sterling
Simon Fraser University
Burnaby, British Columbia B5A1S6
604-291-4685
Mr. A.J. Thompson
Southern California Gas Company
720 West 8th Street
Los Angeles, California 90017
213-689-3653
Panelist
A-5
-------
Dr. Amos Turk*
7 Tarrywill Lake Drive
Danbury, Connecticut 06810
212-609-8306
Dr. David L. West
National Institute for Occupational
Safety and Health
5600 Fishers Lane
Rockville, Maryland 20857
301-443-3843
Ms. Georgeann Wheler
Carrier Research Division
Syracuse, New York 13221
315-432-3398
Mr. George E. Winzer
Room 8214
U.S. Department of Housing
and Urban Development
Washington, D.C. 20410
202-755-7340
Dr. James E. Woods, Jr.*
Department of Mechanical Engineering
Iowa State University
Ames, Iowa 50011
515-294-8660
Dr. Bernard Zak
Sandia National Laboratories
Environmental Research Division
4533
Albuquerque, New Mexico 87185
505-844-7328
* Panelist
A-6
-------
MONITORING
Dr. H. Ward Alter
President, Terradex
460 North Wiget Lane
Walnut Creek, California 94598
415-938-2545
Dr. Lyndon Babcock
Director, Environmental and Occupational
Health Sciences
University of Illinois
P.O. Box 6998
Chicago, Illinois 60680
312-996-2591
Dr. Nathaniel L. Barr
EV-32
Health and Environmental Risk Analysis
Program-OHER
U.S. Department of Energy
Washington, D.C. 20545
202-353-3571
Dr. Tom Bath
Midwest Research Institute
2555 M Street, N.W.
Suite 404
Washington, D.C. 20037
202-293-6190
)
Mr. Frank E. Belles
American Gas Association
8501 East Pleasant Valley Road
Cleveland, Ohio 44131
216-524-4990
Dr. James Berk
Lawrence Berkeley Laboratory
University of California
Building 90, Room 3058-E
Berkeley, California 94720
415-486-4651
Mr. Stan Blacker
Office of Mobile Source A1r
Pollution Control (ANR-455)
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
202-426-2514
A-7
-------
Dr. Jan S.M. Boleij
Agricultural University
Department of Environmental Sciences
Air Pollution Section
Binnenhaven 12, Uageningen
Netherlands
(08370) 82684
Dr. Joseph Breen
U.S. Environmental Protection Agency
TS-798
Exposure Evaluation Division
401 M Street, S.W.
Washington, D.C. 20460
202-755-8060
Mr. Frank Brower
Dow Chemical Company
2030 Dow Center
Midland, Michigan 48640
517-636-2856
Dr. Bert Brunekreef
Agricultural University
Department of Environmental Sciences
Air Pollution Section
Binnenhaven 12, Wageningen
Netherlands
(08370) 82684
Mr. Franz Burmann
U.S. Environmental Protection Agency
Mail Drop 75 *
Research Triangle Park, North Carolina 27711
919-541-2106
Mr. Kenneth A. Busch
Chief, Statistical Services Branch
Division of Technical Services
National Institute for Occupational
Safety and Health
4676 Columbia Parkway
Cincinnati, Ohio 45226
513-684-8306
Mr. K. J. Caplan
Industrial Health Engineering, Inc.
P.O. Box 9342
Minneapolis, Minnesota 55440
612-941-8410
A-8
-------
Mr. Thomas A. Clark
U.S. Environmental Protection Agency
Mail Drop 75
ERC Annex
Room S-222
Research Triangle Park, NC 27711
919-541-2723
Dr. Sanford Cohen
Teknekron, Inc.
1483 Chain Bridge Road
McLean, Virginia 22101
703-734-0800
Dr. John Dement
Deputy Director, Division of
Respiratory Disease Studies
National Institute for Occupational
Safety and Health
944 Chestnut Ridge Road
Morgantown, West Virginia 26505
304-923-7474
Dr. Arthur Eckles
U.S. Environmental Protection Agency
Industrial Environmental Research Laboratory
Mail Drop 63
Research Triangle Park, North Carolina 27711
919-541-2745
Mr. James A. Frazier
National Academy of Sciences
2101 Constitution Avenue
Washington, D.C. 20410
202-389-6805
Dr. Alan Hawthorne
4500 S Building
Oak Ridge National Laboratory
P.O. Box X.
Oak Ridge, Tennessee 37830
615-576-2081
A-9
-------
Mr. Robert Herrick
National Institute for Occupational Safety
and Health
Division of Surveillance, Hazard
Evaluation and Field Studies
Industrial Hygiene Section, MS-F7
4676 Columbia Parkway
Cincinnati, Ohio 45226
513-684-3255
Dr. M.J. James
Occupational Health Branch
Ontario Ministry of Labor
205 Oxford Street East
London, Ontario N6A5G6
519-439-3231
Mr. Frank Jarke*
IIT Research Institute
10 West 35th Street
Chicago, Illinois 60616
312-567-4334
Mr. Joseph E. Jones
Owens Corning Fiberglass Company
P.O. Box 415
Grandville, Ohio 43023
614-587-0610
Mr. Neil Jurinski
Nuchemco, Inc.
9321 Raintree Road
Burke, Virginia 22015
703-978-0642
Mr. Frank Kabot
Rockwell International
Environmental Monitoring and
Services Center
5529 Chapel Hill Boulevard
Durham, North Carolina 27707
919-493-2471
Mr. Roman Kuchkuda
TS-779
U.S. Environmental Protection Agency
East Tower - 612
401 M Street, S.W.
Washington, D.C. 20460
202-755-2110
* Panelist
A-10
-------
Mr. Frank Stanonik
1901 North Fort Meyer Drive
P.O. Box 9245
Arlington, Virginia 22209
703-525-9565
»,
Dr. Brian P. Leaderer
Pierce Foundation Laboratory
Yale University School of Medicine
Department of Epidemiology and
Public Health
290 Congress Avenue
New Haven, Connecticut 06519
203-562-9901
Dr. Robert S. Lewis
U.S. Environmental Protection Agency
Chief, Analytical Chemistry Branch
MD-69
Research Triangle Park, North Carolina 27711
919-541-2510
Dr. Alfred Lowrey
U.S. Environmental Protection Agency
401 M Street, S.W.
A-104, Room 2119
Washington, D.C. 20460
202-755-0780
Mr. R.G. McGregor
Radiation Protection Bureau
Health and Welfare, Canada
Brookfleld Road *
Ottawa, Canada K1A1C1
613-998-8656
Mr. Alan McKee
c/o Maryann Batlis
Armstrong World Industries
1025 Connecticut Avenue
Suite 1007
Washington, D.C. 20036
202-296-2830
A-ll
-------
Mr. Gene Metz
Solar Technology Program
National Bureau of Standards
Building 225-Room B143
Washington, D.C. 20234
301-921-3285
Dr. C. Beat Meyer
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
513-684-4334
Dr. Demetrios J. Moschandreas
GEOMET Technologies, Inc.
15 Flrstfield Road
Gaithersburg, Maryland 20760
301-948-0755
Dr. James L. Repace*
Office of Policy Analysis (ANR-444)
Assistant Administrator for Air, Noise
and Radiation
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
202-426-2482
Major James Rock
U.S. A1r Force - OEHL
Brooks A1r Force Base
Texas 78235 *
512-536-3214
Mr. Don Rutt
Energetic Science
6 Skyline Drive
Hawthorne, New York 10532
914-592-3010
Dr. Frederick H. Shair
Department of Chemical Engineering
California Institute of Technology
Pasadena, California 91125
213-795-6811
* Panelist
A-12
-------
Dr. Sam Silberstein
National Bureau of Standards
Center for Building Technology
B226
Washington, D.C. 20234
301-921-3602
Dr. John D. Spengler*
Environmental Health Sciences
Harvard School of Public Health
665 Huntington Avenue
Boston, Massachusetts 02115
617-732-1255
Ms. Mary Stuart
Research Department
Washington Gas Light Company
6801 Industrial Road
Springfield, Virginia 22151
703-750-4389
Mr. Jack D. Verschoor
Johns Manville R&D Center
P.O. Box 5108
Denver, Colorado 80217
303-978-5293
Mr. Richard Walcott
Clayton Environmental Inc. Consultants
25711 Southfield Road
Southfield, Michigan 48075
313-424-8860 >
Dr. Lance Wallace (Chairperson)*
U.S. Environmental Protection Agency
Office of Monitoring and Technical
Support, RD-680
401 M Street, S.W.
Washington, D.C. 20460
202-426-2175
Mr. Ralph Wallace
Tennessee Valley Authority
River Oaks Building
Mussel Shoals, Alabama 35660
205-386-2991
* Panelist
A-13
-------
Mr. Dwain Winters
U.S. Environmental Protection Agency
ANR-443
401 M Street, S.W.
Washington, D.C. 20460
202-755-0460
Mr. George E. Winzer
Room 8214
U.S. Department of Housing
and Urban Development
Washington, D.C. 20410
202-755-7340
Mr. John Yocom*
TRC Corporation of New England
125 Silas Dean Highway
Wethersfield, Connecticut 06109
203-563-1431
Dr. Robert Ziegenfus
U.S. Environmental Protection Agency
Office of Monitoring and Technical Support
401 M Street, S.W.
Washington, D.C. 20460
202-426-4153
Dr. Richard Ziskind
SAI
1801 Avenue of the Stars
Suite 1205
Century City, California 90067
213-553-2705 '
Panelist
A-14
-------
INSTRUMENTATION
Mr. David Bernhardt
U.S. Environmental Protection Agency
P.O. Box 18416
Las Vegas, Nevada 89114
702-798-2476
Dr. Joseph J. Brooks
Monsanto Research Corporation
Station B
Box 8
Dayton, Ohio 45407
513-268-3411
Dr. Wayne A. Cassett
Room C229
Radiation Physics Building
National Bureau of Standards
Washington, D.C. 20234
301-921-2551
LT Guy Colonna
Commandant (G-DMT-1/54)
U.S. Coast Guard Headquarters
2100 Second Street, S.W.
Washington, D.C. 20593
202-426-1058
Dr. Dale Coulson
SRI International
333 Ravenswood Avenue
Menlo Park, California 94025
415-326-6200
Dr. J.J. DeCorpo
Code 6110
Naval Research Laboratory
Washington, D.C. 20375
202-767-3244
Mr. Doug DeWerth
American Gas Association
8501 East Pleasant Valley Road
Cleveland, Ohio 44131
216-524-4990
A-15
-------
Dr. Laurence J. Doemeny (Chairperson)*
Chief, Monitoring and Control
Research Branch
National Institute for Occupational
Safety and Health
4676 Columbia Parkway
Cincinnati, Ohio 45226
513-684-4266
Mr. Paul Edgerton
Energetic Science
6 Skyline Drive
Hawthorne, New York 10532
914-592-3010
Dr. David Fine
Thermo Electron Corporation
125 Second Avenue
Waltham, Massachusetts 02254
617-890-8700
Dr. Robert E. Finnigan*
Finnigan Corporation
845 W. Maude Avenue
Sunnyvale, California 94086
408-732-0940
Dr. Richard Gammage
Monitoring Technology and
Instrumentation Group
4500 S Building
Oak Ridge National Laboratory
P.O. Box X J
Oak Ridge, Tennessee 37830
615-574-6256
Mr. Andreas George
Environment Measurements Laboratory
U.S. Department of Energy
376 Hudson Street
New York, New York 10014
212-620-3653
Mr. Charles E. Giffin
Jet Propulsion Lab
Building 11, Room 116
Pasadena, California 91103
213-354-2494
* Panelist
A-16
-------
Mr. Richard Hefflefinger
Battelle Columbus Laboratory
505 King Avenue
Columbus, Ohio 43201
614-424-5249
^
Dr. James Hodgeson
National Bureau of Standards
Chemistry Building
Room B326
Washington, D.C. 20234
301-921-2067
Dr. Craig Hollowell*
Lawrence Berkeley Laboratory
University of California
1 Cyclotron Road
Building 90, Room 3058
Berkeley, California 94720
415-486-6591
Mr. John E. Janssen
Honeywell, Inc.
TSC
1700 West Highway 36
St. Paul, Minnesota 55113
612-378-4937
Mr. Charles Jennings
Tennessee Valley Authority
Power Service Center
DB PSC6 J
Chattanooga, Tennessee 37401
615-755-3656
Dr. W. J. Lautenberger*
Dupont Company
Applied Technology Center
P.O. Box 10
N. Walnut Road
Kennett Square, Pennsylvania 19348
215-444-1060
Mr. Pedro LIHenfeld
GCA/Technology Division
215 Burlington Road
Bedford, Massachusetts 01730
617-275-5445
* Panelist
A-17
-------
Dr. Wayne Lowder
U.S. Department of Energy
Environment Measurements Laboratory
EMAS Division
376 Hudson Street
New York, New York 10014
212-620-3632
Dr. Thomas G. Matthews
Building 4500 S
Oak Ridge National Laboratory
Oak Ridge, Tennessee 37830
615-574-6248
Dr. Robert Miksch
Lawrence Berkeley Laboratories
University of California
1 Cyclotron Road
Berkeley, California 94720
415-486-5301
Dr. Anthony V. Nero, Jr.
Building 90, Room 3088
Lawrence Berkeley Laboratory
Berkeley, California 94720
415-486-6377
Mr. Russell Newton
Dynatech Company
99 Erie Street
Cambridge, Massachusetts 02139
617-868-8050 '
Mr. James Perkins
520 Wakara Way
Salt Lake City, Utah 84108
801-581-8267
Mr. Warren Porter
Consumer Product Safety Commission
5401 Westbard Avenue
Westwood. Towers Building, Room 714
Bethesda, Maryland 20207
301-492-6994
A-18
-------
Dr. John Rundo
Argonne National Laboratory
Radiological and Environmental
Research Division
Building 2093
Argonne, Illinois 60439
312-972-4168
Mr. Paul Schwengels
U.S. Environmental Protection Agency
RD-681
401 M Street, S.W.
Washington, D.C. 20460
202-426-9434
Mr. Gilmore Sem
TSI, Inc.
P.O. Box 43394
St. Paul, Minnesota 55112
612-633-0550
Dr. James Stemmle
U.S. Environmental Protection Agency
RD-682
401 M Street, S.W.
Washington, D.C. 20460
202-426-0264
Mr. Greg Traynor
Lawrence Berkeley Laboratory
University of California
Berkeley, California 94720
415-486-4033
Dr. Walter L. Zielinski, Jr.*
Air Program Manager
Office of Environmental Measurements
U.S. Department of Commerce
National Bureau of Standards
Room A261, Metrology Building
Washington, D.C. 20234
301-921-3775
* Panelist
A-19
-------
HEALTH EFFECTS
Dr. Roy E. Albert
U.S. Environmental Protection Agency
Chairman, Carcinogen Assessment Program
RD-689
401 M Street, S.W.
Washington, D.C. 20460
202-755-3968
Dr. Henry Anderson
Division of Health
Bureau of Prevention
P.O. Box 309
Madison, Wisconsin 53701
608-266-1253
Mr. Mike Atherton
Columbia Gas System
20 Montchanin Road
Wilmington, Delaware 19807
302-429-5454
Mr. Victor Avitto
Public Health Service
Division of Federal Employees
Occupational Health
6525 Bel crest Road
Hyattsville, Maryland 20782
301-436-6631
Dr. Peter Baxter*
Chronic Diseases Division
Centers for Disease Control
Atlanta, Georgia 30333
404-452-4086
Dr. Irvin H. Billick
U.S. Department of Housing and
Urban Development
451 7th Street, S.W.
Room 8214
Washington, D.C. 20410
202-755-7340
Dr. Thomas Borton
Applied Environmental Research
444 South Main Street
Ann Arbor, Michigan 48104
313-994-4506
* Panelist
A-20
-------
Mr. Hugh Brady
Manager, Environmental Regulations
American Gas Association
1515 Wilson Boulevard
Arlington, Virginia 22209
703-8*1 -8645
Ms. Peggy Brown
U.S. Department of Energy
6D033 Forrestall Building
1000 Independence Avenue
Washington, D.C. 20585
202-252-6947
Dr. John Buccini
Environmental Health Center
Health and Welfare, Canada
Ottawa, Ontario K1AOL2
Canada
613-992-5205
Dr. Ch1a Chen
Occupational Safety and Health Administration
U.S. Department of Labor
200 Constitution Avenue, N.W.
Washington, D.C. 20210
202-523-7283
Dr. John Clary
Toxicology Director
Celanese Corporation
1211 Avenue of the Americas
New York, New York 10036
212-764-8809
Dr. Robert Clerman
MITRE Corporation
1820 Dolley Madison Boulevard
McLean, Virginia 22102
703-827-6743
Ms. Pamela Danner
National Manufactured Housing Federation
1806 T'Street, N.W.
Washington, D.C. 20009
202-667-6855
A-21
-------
Dr. Robert Edgar
University of Texas at Dallas
Environmental Sciences Department
P.O. Box 688
Richardson, Texas 75080
214-690-2238
Dr. William Ellett*
Chief - Biological Analysis Branch
Office of Radiation Programs
U.S. Environmental Protection Agency
AW-460
401 M Street, S.W.
Washington, D.C. 20460
202-557-9380
Dr. Tom Gesell
University of Texas
School of Public Health
P.O. Box 20186
Houston, Texas 77025
713-792-4376
Mr. Thomas Gleason
U.S. Environmental Protection Agency
RD-681
401 M Street, S.W.
Washington, D.C. 20460
202-426-4567
Dr. Inge F. Goldstein
Columbia University School
of Public Health
Division of Epidemiology
600 West 168th Street
New York, New York 10032
212-928-7674
Dr. Robert Goyer (Chairperson)*
National Institute of Environmental
Health Sciences
Building 1, Room 111
P.O. Box 12233
Research Triangle Park, North Carolina 27707
919-541-3201
* Panelist
-------
Dr. Bruce Graham
IIT Research
Suite 310
1825 K Street, N.W.
Washington, D.C. 20206
202-296-1610
Dr. Kail ash C. Gupta
Consumer Product Safety Commission
Westwood Towers Building, Room 714
5401 Westbard Avenue
Bethesda, Maryland 20207
301-492-6996
Dr. Leonard Hamilton
Brookhaven National Laboratory
Building 475
12 Upton
Biomedical and Environmental Assessment Division
Upton, New York 11973
516-345-2123
Mr. Jim Hicks
Staff Executive
American Gas Association
1515 Wilson Boulevard
Arlington, Virginia 22209
703-841-8456
Dr. Janice Jensen
411 North Nelson Street
Arlington, Virginia 22203
202-557-7347
Dr. Richard Keenlyslde
National Institute for Occupational
Safety and Health
HETAP
4676 Columbia Parkway
Cincinnati, Ohio 45226
513-684-2732
Dr. Alex Kelter
Centers'for Disease Control
Chronic Disease Division
1600 Clifton Road
Atlanta. Georgia 30333
404-452-4161
A-23
-------
Mr. Eugene Kramer
Manager, Environmental Engineering
Sears, Roebuck and Company
Department 817
925 Sojith Homan Avenue
Chicago, Illinois 60607
312-265-4076
Dr. Michael D. Lebowitz*
Section on Pulmonary Diseases
University of Arizona Medical Center
Tucson, Arizona 85724
602-626-6379
Dr. Marshall Levine
Johns Hopkins University
•Division of Environmental Medicine
Room 7032, School of Hygiene
615 North Wolfe Street
Baltimore, Maryland 21205
301-338-3504
Dr. William E. Lotz
Electric Power Research Institute
1800 Massachusetts Avenue, N.W.
Washington, D.C. 20036
202-872-9222
Mr. Justice Manning
Tennessee Valley Authority
River Oaks Building
Mussel Shoals, Alabama 35660
205-386-2795
Ms. Carole McNally
Tobacco Institute
1875 I Street, N.W.
Washington, D.C. 20006
202-457-4855
Dr. George Milly
GEOMET, Incorporated
15 Firstfield Road
Gaithersburg, Maryland 20760
301-948-0755
* Panelist
A-24
-------
Mr. Ralph G. Mitchell
Battelle Columbus
505 King Avenue
Columbus, Ohio 43201
614-434-7816
Dr. Niren L. Nagda
GEOMET Technologies, Inc.
15 Firstfield Road
Gaithersburg, Maryland 20760
301-948-0755
Mr. Harvey Nozick
U.S. Environmental Protection Agency
ANR-471
401 M Street, S.W.
Washington, D.C. 20460
202-557-2126
Dr. John A. Pickrell
Inhalation, Toxicology Research
Institute
P.O. Box 5890
Albuquerque, New Mexico 87116
505-844-7020
Dr. Peter Preuss
Consumer Product Safety Commission
5401 Westbard Avenue, Room 700
Bethesda, Maryland 20207
301-492-6957
t
Dr. George Provenzano
U.S. Environmental Protection Agency
Office of Research and Development
RD-675
401 M Street, S.W.
Washington, D.C. 20460
202-755-2611
Dr. Edward P. Radford
Graduate School of Public Health
University of Pittsburgh
Pittsburgh, Pennsylvania 15261
412-624-3009
A-25
-------
Ms. Sarah Reyes
Joint Legislative Audit Committee
Subcommittee on Investigations of
California Legislature
925 L Street, Suite 750
Sacramento, California 95814
916-323-4444
Dr. Richard Rhoden
Office of Science and Technology
Executive Office of the President
Washington, D.C. 20500
202-456-6272
Ms. Leslie S. Ritts
Environmental Law Institute
Suite 600
1346 Connecticut Avenue, N.U.
Washington, D.C. 20036
202-452-9600
Mr. David W. Scott
Department of Engineering and Public Policy
Carnegie-Mellon University
Pittsburgh, Pennsylvania 15213
412-578-2673
Professor Maurice A. Shapiro
Room A-728
Crabtree Hall, GSPH
University of Pittsburgh
Pittsburgh, Pennsylvania 15261
412-624-3113 *
Mr. Charles Spooner
Bolt, Beranek and Newman
50 Moulton Street
Cambridge, Massachusetts 02238
617-497-3108
Mr. EUa Sterling
Cornerstone Planning Group
22 CreekJiouse
Granville Island
Vancouver, British Columbia
604-687-5896
A-26
-------
Dr. Jan Stolwljk
John B. Pierce Foundation Laboratories
290 Congress Avenue
New Haven, Connecticut 06519
203-5£2-9901
Dr. David L. Swift
The Johns Hopkins University
School of Hygiene and Public Health
615 North Wolfe Street
Baltimore, Maryland 21205
301-955-3602
Mr. John L. Swift
GEOMET Technologies, Inc.
6000 Executive Boulevard
4th Floor
Rockvllle, Maryland 20852
301-770-1500
Mr. William E. Thompson
Shook, Hardy and Bacon
1101 Walnut Street
20th Floor
Kansas City, Missouri 64106
816-474-6550
Dr. Andrew G. Ulsamer
Consumer Product Safety Commission
Health Sciences, Room 714
5401 Westbard Avenue
Bethesda, Maryland 20207
301-492-6994
Mr. Dwight Underhill
Associate Professor
School of Public Health
A734 Crabtree Hall
University of Pittsburgh
Pittsburgh, Pennsylvania 15261
412-624-3043
Dr. John V1ren
Ofice of Health and Environmental Research
Division of Human Health Assessments
EV32
U.S. Department of Energy
Washington, D.C. 20545
202-353-4739
A-27
-------
Mr. Eugene Wyszpolski
U.S. Environmental Protection Agency
ANR-471
401 M Street, S.W.
Washington, D.C. 20460
202-5^7-2126
Mr. Stewart Young
Arthur D. Little Company
Acorn Park
Cambridge, Massachusetts 02140
617-864-5770
A-28
-------
RADON AND RADON PROGENY
Dr. H. Ward Alter
President, Terradex
460 North Wiget Lane
Walnut Creek, California 94598
415-938-2545
Mr. Philip Altomare
MITRE Corporation
1820 Do!ley Madison Boulevard
McLean, Virginia 22102
703-827-6743
Dr. Wayne A. Cassatt
Radiation Physics Building, Rm. C229
National Bureau of Standards
Washington, D.C. 20234
301-921-2551
Dr. Sanford Cohen
Teknekron, Inc.
1483 Chain Bridge Road
McLean, Virginia 22101
703-734-0800
Dr. Ronald Colle
Room C229, Building 245
National Bureau of Standards
Washington, D.C. 20234
301-921-2551 ,
Dr. William Ellett (Cochalrperson)*
Chief - Biological Analysis Branch
Office of Radiation Programs
U.S. Environmental Protection Agency
AW-460
401 M Street, S.W.
Washington, D.C. 20460
202-557-9380
Mr. Andreas George*
Environment Measurements Laboratory
U.S. Department of Energy
376 Hudson Street
New York, New York 10014
212-620-3653
Panelist
A-29
-------
Dr. Tom Gesell
University of Texas
School of Public Health
P.O. Box 20186
Houston, Texas 77025
713-792-4376
Dr. Alan R. Hawthorne
Oak Ridge National Laboratory
P.O. Box X
Oak Ridge, Tennessee 37830
615-576-2081
Dr. Craig Hollowell*
University of California
Lawrence Berkeley Laboratory
1 Cyclotron Road
Building 90, Room 3058
Berkeley, California 94720
415-486-6591
Dr. Wayne Lowder (Cochairperson)*
U.S. Department of Energy
Environment Measurements Laboratory
EMAS Division
376 Hudson Street
New York, New York 10014
212-620-3632
Dr. Anthony V. Nero, Jr.
Building 90, Room 3088
Lawrence Berkeley Laboratory
Berkeley, California 94720
415-486-6377
Mr. Charles Phillips*
U.S. Environmental Protection Agency
P.O. Box 3009
Montgomery, Alabama 36193
205-272-3402
* Panelist
A-30
-------
Dr. David Rosenbaum
U.S. Environmental Protection Agency
ANR-458
Deputy Assistant Administrator for Radiation Programs
401 M-Street, S.W.
Washington, D.C. 20460
202-557-9710
Dr. John Rundo
Argonne National Laboratory
Radiological and Environmental
Research Division
Building 2093
Argonne, Illinois 60439
312-972-4168
Mr. George E. Winzer
Room 8214
U.S. Department of Housing
and Urban Development
Washington, D.C. 20410
202-755-7340
A-31
-------
Research Needs for IAQ: Monitoring
Pollutant CO-and Other Reducing Gases jjane Frank Belles
Development and Evaluation of Siaple Broad .
-Spectrum-Monitoring Methods to Detect Combustion Tel. (216) 5Z4-499U
Effluents in Indoor Air
or J. E. Yocom
Instrumentation adequate? (203> 563-1431
• -Yes • Describe preferred instruments or analytic methods
«
. Gas detector based on Foguchi sensor.
_ No Describe what has to be done to provide adequate monitoring equipment
Extent of previous monitoring efforts
Institution or investigator AGA Labs
Describe the study briefly Detecting leaky heat exchangers.
Description of suggested monitoring effort
Rationale A quick and dirty'method of assessing presence of combustion contaninants
in irfaoor AQ. _
Description Carry out monitoring studies to determine _pollutanc responses^
whetner device couj.d be'u&eu t-u ou*. &<=.,. iuz 3-.ua.-jn_ -- a-...- - .
poor IAQ. If successful, run pilot field study to monitor a large
' •
^MHB^^^^^MV^^^^«WMM.^»B^^
numoer 01 nocies
-greatest potential for leaky furnaces
Duration 1 Year Funding Level (per year) $100'000
12/4/80
B-31
-------
RESEARCH RECOMMENDATIONS: RADON
B-32
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Radon and Radon Daughter Behavior in the Indoor Environment
OBJECTIVE: To determine the behavior of radon and radon daughters indoors.
BACKGROUND/
RATIONALE: Development of the initial radon data base requires basic
information about the overall behavior of the pollutant in
question.
DESCRIPTION: Parameters to be measured include radon and radon daughter
concentrations, infiltration/ventilation rates, radon daughter
and particulate interactions and size distributions, removal
processes, the effects of temperature, humidity, and particulata
levels, and the effects of HVAC system operation and various
control strategies.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY: Existing instrumentation except, perhaps, in
daughter/particle interaction work, is sufficient
for these studies.
PREVIOUS RESEARCH:
B-33
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Short-term Radon Measurements
OBJECTIVE: To assess the viability of short-term radon measurements
to estimate annual average concentrations and indoor
exposures.
BACKGROUND/
RATIONALE: Detailed measurements' for a one-year period such as the
Butte, Montana study need to be supplemented by additional
work at prograssively larger scales.
DESCRIPTION: Measure radon and radon-daughter concentrations on a real-time
and integrated basis, infiltration/ventilation rates, and
radon fluz from the soil. Measurements should occur on
real-time and integrated bases for a period "of one year
to determine the feasibility of and to establish protocols
for shorter term integrated monitoring.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-34
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: National Indoor Exposure to Radon and Radon Daughters
OBJECTIVE: To determine the extent to which indoor radon and radon
daughters are a national problem.
BACKGROUND/
RATIONALE: A data base is necessary in order to make program decisions
and to consider the need for guidelines and standards.
DESCRIPTION: Survey a sufficient number of hones in the U.S.to project
the extent of the national level of indoor exposure to
radon and radon daughters.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
Existing passive monitors for monitoring
radon are currently being evaluated, but
passive working level monitors are needed
if working level measurements are deemed
necessary.
PREVIOUS RESEARCH:
B-35
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Radon Sources and Ground Transport
OBJECTIVE: To develop predictive capabilities for indoor radon and
radon daughter concentrations.
BACKGROUND/
RATIONALE:
By determining the relevant parameters that contribute to
high indoor concentrations in residences and by understanding
the mechanisms through which radon enters building spaces,
houses can be constructed with lower indoor radon levels.
DESCRIPTION:
Measurements must be made of radium content in soil, radon
concentrations in soil gas, radon diffusion lengths, and the
efforts of ground water and moisture, atmospheric pressure,
and temperature. It is necessary to determine temporal
variation in these parameters.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-36
-------
RESEARCH RECOMMENDATIONS: FORMALDEHYDE
B-37
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Continuous (Real-Time) Instrumentation for Formaldehyde
OBJECJIVE: To support the on-going development of a continuous, real-time
instrument for detecting formaldehyde in the indoor environment.
BACKGROUND/
RATIONALE: To be able to relate formaldehyde emissions to sources, a
real-time continuous monitor capable of achieving levels as
low as 30 ppb is required.
DESCRIPTION:
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY;
PREVIOUS RESEARCH:
B-38
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Eighc-Hour Dosimeter for Formaldehyde
OBJECTIVE: To design and construct an eight-hour dosimeter for detecting
fonnaldehyde in the indoor environement.
BACKGROUND/
RATIONALE: To measure personal exposure to fonnaldehyde is required,
DESCRIPTION: The dosimeter would give integrated 8-hour average values of
fonnaldehyde levels. It could collect the gas and be analyzed
later in the laboratory; real-time continuous readout capacity
would not be required for this use.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-39
-------
RESEARCH NEEDS FOR MONITORING LAQ
SUBJECT:
Formaldehyde Measurement Protocol
OBJECTIVE: To establish a measurement protocol for monitoring formaldehyde
in the indoor environment.
BACKGROUND/
RATIONALE: As a major pollutant emitted by home insulation and other
materials, and also because detection and analytical procedures
are specific to it, formaldehyde deserves special attention.
DESCRIPTION:
Select and evaluate a protocol for measuring formaldehyde as
one constitutent of IAQ. Simultaneous measurements of other
pollutants that create similar symptoms must be a part of the
research. In addition, round-robin multilaboratory techniques
should be incorporated into the project.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
Refinement of both sampling and analytical
methods needed in the long term. Present
NIOSH limit of 0.5 ppm should be lowered to
about 30 ppb.
PREVIOUS RESEARCH: NIOSH protocols adequate for occupational exposure.
B-40
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Biological Methods Related to Formaldehyde Measurement
OBJECTIVE: To investigate biological methods as a means of increasing
the sensitivity of formaldehyde .measurements.
BACKGROUND/
RATIONALE:
DESCRIPTION:
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY;
PREVIOUS RESEARCH:
B-41
-------
RESEARCH RECOMMENDATIONS: STATISTICS AND MODELING
B-42
-------
RESEARCH SEEDS FOR MONITORING IAQ
SUBJECT:
Statistical Sampling Strategies
OBJECTIVE:
BACKGROUND/
RATIONALE:
To provide statistical methods which can be selected as needed
for data acquisition in support of epideniological adequacy
of control measures.
Although many statistical techniques exist that can be applied
to IAQ, certain problems specific to IAQ required modified
sampling and statistical strategies.
DESCRIPTION: The following specific statistical tools need to be developed:
1. Strategy to isolate true peak exposures
2. Strategy to identify amplitude distributions of exposures
3. Strategy to identify time history of exposures
4. Strategy to relate individual exposures to individual
responses even in the presence of a latent period
5. Stategy to identify the most significant exposures for
each individual (i.e. , home vs. work vs. community vs.
recreation)
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
Statistics for integrated sampling are adequately
described in NIOSH, but statistics for determining
time histories, temporal correlations and peak
exposures are not well investigated. Problem of
correlating exposure to (time-dependent) response
is not solved.
PREVIOUS RESEARCH:' R.M. Tuggle (U.S. Army Env. Hygiene Agency), Steve Rappaport
(U.C.- Berkeley), J.C. Roch (USAF/OEHL)- Examination
of sampling environments without time correlation for
average, peak and variability of exposures.
B-43
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Exposure Monitoring Strategies
OBJECTIVE: To select efficient sampling strategies for exposure monitoring,
BACKGROUND/
RATIONALE:
DESCRIPTION:
Few exposure monitoring 'studies have been carried out. The
type and extent of exposure monitoring will vary according
to study design. Different designs must be developed to
satisfy different objectives, (e.g. long-term chronic
exposure to low-level indoor pollutants vs. "episodic"
monitoring for short-term peak exposures).
Design a research project that will consider the main types
of studies related to exposure monitoring and evaluate the
different sampling strategies associated with each. Both
retrospective and prospective studies should be considered
for acute and chronic health effects.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY;
PREVIOUS RESEARCH:
B-44
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Exposure Models
OBJECTIVE: To determine population-weighted 24-hour exposure
BACKGROUND/
RATIONALE:
Existing information about population mobility patterns
and tine budgets is obtained from sociological studies.
Special effort must be nade to develop questionnaires
that deal specifically with indoor air quality topics.
DESCRIPTION: Formulate deterministic or statistical models that will
estimate exposure to pollutants as a function of population,
time budgets, activity patterns, environmental models and
pollutant concentrations.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
Existing models are not comprehensive, lacking
information on indoor activity patterns, ranges
of exposures characteristic of indoor environ-
ments, etc.
PREVIOUS RESEARCH:
B-45
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Defining and Classifying Microenvironments
OBJECTIVE: To design and implement a research program leading to the
establishment of acceptable categories of microenvironnents
BACKGROUND/
RATIONALE:
Previous measurements have shown that fixed monitoring stations
do not adequately reflect human exposures. To estimate population
exposures with greater accuracy, it is necessary to collect
data on pollutant concentrations in selected raicroenvironner.ts.
DESCRIPTION:
Establish a research program that will lead to a realistic
method for the establishment of microenvironnents as required
in studies designed to monitor differential exposures, assess
health effects, and design controls. Develop a suitable
statistical basis for identifying microenvironnents.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
£*.'* W. "Concepts of Human Exposure to Air Pollution,"
*SIMS Technical Report No. 32, July 1980, Stanford Univ.
B-46
-------
RESEARCH NEEDS FOR MONITORING IAO
SUBJECT:
Indoor-Outdoor Numerical Models
OBJECTIVE: To validate existing indoor-outdoor models
BACKGROUND/
RATIONALE: Existing models of indoor-outdoor relationships among air
pollutants have not been tested or evaluated. Such models
are required to extrapolate monitoring data to the major
types of indoor environments. .
DESCRIPTION: Identify all monitoring conditions under which the models
must be validated. Define exact validation protocol and
parameters, perform a sensitivity study, and establish
needs for future monitoring.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
Existing models have not been extensively
validated.
PREVIOUS RESEARCH:
B-47
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Dynamic Infiltration Model
OBJECTIVE: To evaluate the effect of energy conservation measures on the
IAQ of a particular house and to extrapolate the results of an
IAQ audit to a full year profile.
BACKGROUND/
RATIONALE: Little is known of effects of infiltration on IAQ.
module of an IAQ indoor-outdoor model.
This is one
DESCRIPTION: Develop an IAQ model for residences that has a dynamic infil-
tration component. The infiltration component would have imputs
of wind degree days, house size and volume, a terrain factor,
and the house air leakage area.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-48
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Statistical Design for National Characterization of IAQ
OBJE£TIVE: To determine if IAQ is a potential problem on a national
scale.
BACKGROUND/
RATIONALE: Several pilot studies have established a trend for potential
problems.
DESCRIPTION:
Design a statistically valid experiment to assess IAQ on a
national scale. Design should include all parameters that
affect IAQ and address cost-effectiveness issues. Elements
to be included are: instrumentation; pollutants of interest;
types of indoor environments; location; housing type;
monitoring protocols; source characterization;
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-49
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Monitoring Source Strengths
OBJECTIVE: To develop a national IAQ profile of source strengths
BACKGROUND/
RATIONALE: Project should be part of the on-going effort to develop a
comprehensive nationwide IAQ data base.
DESCRIPTION: Develop a data base to identify indoor pollution sources and
the frequency distribution of source strengths for a particular
class of houses (e.g. , No2 emissions in houses with only gas
stoves as an N02 source).
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY;
PREVIOUS RESEARCH:
B-50
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: "Case Study" Evaluation of IAQ Monitoring Studies
OBJECTIVE: To develop a "case-study" method for evaluating monitoring
projects.
BACKGROUND/
RATIONALE: To avoid repeating mistakes in aonitoring IAQ, a nechanisn
should be developed whereby a particular aonitoring project
can be evaluated in terns of its success in meeting its
research objectives.
DESCRIPTION: (1) Select already completed studies for a "case study"
approach, or
(2) Incorporate into future studies a procedure to evaluate
the cost-effectiveness of the study itself.
INSTRUMENTATION*/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-51
-------
RESEARCH SEEDS FOR MONITORING LAQ
SUBJECT:
Pollutants Emitted from Building Materials
OBJECTIVE: To determine the types and amounts of pollutants emitted from
building materials commonly used in the construction of
enery-efficient structures.
BACKGROUND/
RATIONALE:
Energy conservation measures reduce the air exchange rate of
structures and potentically harmful concentrations of pollutants
may be accumulating inside residential as well as commercial
structures (sick buildings).
DESCRIPTION:
Establish a monitoring program that will foster the procurement
of a data base on the types and amounts of pollutants generated
by building materials considered to be energy efficient.
Measurements should be conducted for different temperature
levels, air flow rates, and humidity levels.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-52
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Space Heaters
OBJECTIVE: To examine fugitive emissions from soace heaters.
BACKGROUND/
RATIONALE: Increased usage of space heaters, some of new design, requires
investigation of their possible effects on IAQ.
DESCRIPTION: Evaluate fugitive emissions on a temporal and operating
function basis for solid, liquid, and gas felled space heaters,
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY;
PREVIOUS RESEARCH:
B-53
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT: Ventilation
OBJECTIVE: To develop: (1) a macro-scale data base to characterize USA
building stock on an average basis, (2) a micro-scale data
base to correlate real-time pollutant levels with other
variables.
BACKGROUND/
RATIONALE:
DESCRIPTION: (1) Establish a monitoring program to obtain data bases
useful for characterizing ventilation rate by building
type, geographic location, life-style, operation of
building, and observed "average" pollutant level by
season.
(2) Establish a monitoring program to obtain a micro-scale
data base for correlating air exchange rates with
pollutant level, pollutant source generation race", and
physiological effects.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY: Both instruments available: 1) fan pressurization
method for determination of air leakage rate, and
2) tracer gas decay method for determination of
air change rate at a particular time.
PREVIOUS RESEARCH: LBL, Princeton University, and Ohio State University -
studies (on limited number of buildings) correlating
air leakage rate with air change rate and weather, and
with pollutants level.
B-54
-------
RESEARCH NEEDS FOR MONITORING IAQ
SUBJECT:
Retrofit Technology
OBJECTIVE: To explore the feasibility of retrofitting as a partial
* solution to the IAQ problem.
BACKGROUND/
RATIONALE;
Retrofitting will probably be the major mechanism to improve
IAQ in already existing buildings. Current costs nay hinder
adoption.
DESCRIPTION:
Assess and improve the engineering flexibility of retrofit
technology. Ventilation rates and recirculate/make-up air
heavily influence indoor concentrations, dosages, and energy
use. Selective filtration and variable ventilation rates will
be desirable technological characteristics.
INSTRUMENTATION/
METHODOLOGICAL ADEQUACY:
PREVIOUS RESEARCH:
B-55
-------
Appendix C
STATE OF THE ART IN ORGANIC VAPOR MONITORING
-------
STATE OF THE ART IN ORGANIC VAPOR MONITORING
The state- of the art in Organic Vapor Monitoring has recently been
reviewed by a group at UCLA and appeared in the October issue of The
m
Journal of the Air Pollution Control Association, 30, 1098 (1980). This
supplies extensive detail on the higher molecular weight hydrocarbons.
Therefore, this section concentrates on the methods used for lighter
molecular weight compounds.
While the use of adsorbents to concentrate ambient air vapors was
first proposed in the mid 1960's, the state-of-the-art is still not as
highly developed as one would expect.
Solid Adsorbents - Porous Polymers
The majority of the ambient air work has been done on porous polymers
of various types. Activated carbon is by far the best adsorbent, but the
compounds can only be removed quantitatively by solvent elution; this
defeats the concentration effect by rediluting the compounds.
Of the porous polymers used to date, Tenax GC (2,6-diphenyl-p-phenylene
J
oxide) embodies the most versatile set of properties. It has a fairly high
collection efficiency in spite of a fairly low porosity compared to XAD
resins and activated carbon. It has the highest thermal stability of any
O
porous polymer allowing for thermal desorption at high temperatures ( 300 C)
and it has fewer problems with artifact formation due to reaction of chemicals
the resin or because of catalytic conversions.
D.L. Brooman and E. Edgeley. Concentration and Recovery of Atmospheric
Odor Pollutants Using Activated Carbon. J. APCA. 16,25 (1966).
A. Dravnieks and B.K. Krotoszynski. Collection and Processing of Airborne
Chemical Information. J. Gas Chrom. 1966,367 (1966).
F.W. Williams and M.E. Unstead. Determination of Trace Contaminants in
Air by Concentrating on Porous Polymer Beads. Anal. Chera. 40,2232 (1968).
C-l
-------
Tenax GC adsorbs and desorbs an extremely wide variety of chemicals.
The adsorption and desorption efficiencies have been studied for only a
limited number of compounds, but in one laboratory, highly unstable
(thermally) compounds have been collected and desorbed with little or no
«
problems encountered.
Water vapor appears to have little or no effect on the use of Tenax
GC as an adsorbent and this makes it ideal for atmospheric applications.
Tenax GC also can be easily cleaned up and reused either by thermal
*.' •
means or by Soxhlet extraction.
The major difficulties in the use of Tenax GC as an adsorbent for
trace organic vapors in air are: (1) trap configuration, (2) sampling
train and its use (3) the" dilution apparatus or technique.
Commercial systems for these aspects as yet do not widely exist.
Nutech is the only commercial company that is routinely providing equipment
specifically for this purpose and many of their users report that the
equipment does present problems in its use. Hewlett-Packard provides an
automated purge and trap system that can be used for these types of
)
measurements but certain user modifications are necessary.
Trap Configuration
There are two versions of trap in common use: glass and metal. All
chromatographers know that certain compounds containing reactive functional
groups are chromatographed more clearly in glass coluans than in metal
columns; however, the process that is going on in a GC column may be
entirely different than in a vapor preconcentration trap. Therefore, the
controversy over glass versus metal ambient air collectors continues in
spite of the success of at least two major laboratories—one using glass
collectors, the other metal collectors. This question should be investi-
gated in detail once and for all. The advantages and disadvantages of glass
versus metal are summarized in Table 1.
-------
TABLE 1. GLASS vs METAL COLLECTORS
Glass
Metal
ADVANTAGES:
1. Packing is visible and can be
inspected for deterioration.
2. Packing can be removed easily
and cleaned-up externally for
reuse.
1. Connectors assuring positive
leak-free connections are more
readily available. Most are
bakeable.
2. Metal is rugged and withstands
rough handling.
3. Thermal desorption can be
achieved by direct electrical
resistance heating.
A. No special shipping or storage
containers needed.
DISADVANTAGES:
1. Easily br/Dken.
2. Connections are difficult and
not readily available.
3. Higher risk of cross contamination
from extensive use of Teflon
closures and seals.
4. No direct desorption capability.
1. High initial cost.
2. Packing is not visible.
C-3
-------
Sampling Train
Sampling trains are as numerous as. the number of researchers working
in the field. The only common element is that all use some form of vacuum
supplied by a vacuum pump but from here all resemblance ends. The greatest
discrepancies are (1) the method used to determine the volume of gas
sampled (2) the method used to set and monitor the flow rate, and (3) the
use or lack of use of a particle filter upstream of the sampling trap.
Two types of samples have been collected in using" Tenax GC for ambient
air sampling of volatile organic vapors. One technique is called integrated
sampling and sampling periods of 12-24 hours are used with flow rates of
15-45 mL/min. A collector of approximately 2-3 grams of Tenax GC is used
for this type of sample and breakthrough volumes of €5 molecules are approxi-
mately 20-30 liters.
The second type of system is the grab sample which uses a sampling
period of only one hour at 30-45 mL/ain with final collected volume of
approximately 2 liters. Only about 90-100 mg of Tenax GC are used in
this mode. t
The limit of sensitivity in the grab sample mode is about 0.5 ppb
vol/vol for decane, and in the integrated mode, about 30-40 ppt.
Elution Apparatus and Techniques
The most difficult aspect of this type of analysis is achieving reliable
and quantitative transfer of the collected vapors to the GC or GC/MS. Once
they have been transferred the analytical techniques are well defined and
perfectly suitable for this type of analysis.
The grab sample method is the only system employing Tenax GC that allows
for reproducibile, quantitative thermal desorption of the preconcentrated
vapors directly into a capillary or packed column at room temperature with
C-4
-------
no cryogenic focussing or other conditioning steps.
All systems for integrated samples require a cryogenic step preceding
injection into a gas chroniatograph. The problem with these systems is
to ensure that compounds are not lost in the cryogenic step. This can
happen if (a) the trap and cryogenic system does not trap all compounds,
(b) the system leaks or does not adequately transfer the vapors from the
trap to the cryogenic loop and (c) the trap is blocked by water vapor,
resulting in the cessation of flow and inadequate transfer.
Using internal standards is the most effective way to determine
trapping and transfer efficiency, but these methods suffer from a lack of
effective means for transferring known quantities of standard onto the
trap without disturbing the collected sample or in a reproducibly
quantitative manner. Methods that have been tried are direct liquid
injection, permeation tubes, and flash evaporation in a flowing air stream.
The actual desorption over any length of time as well as temperature
can greatly effect the reproducibility in the transfer step. The greater
the diameter of the collector the longer it takes to heat the Tenax GC
0
at the enter of the bed and some data indicates it may be as much as 100 C
lower in temperature.
Another potential problem area with Tenax GC is artifact formation
through reactions with atmospheric constituents such as NCb and 03. Benzene
is frequently mentioned as a contaminant but whether it cones from the
Tenax-or the cleanup method is unclear.
Shelf life is an unknown aspect of this tenchique. How long after a
sample is collected should it be used? The lack of adequate methods for
putting known quantities on Tenax makes it difficult to determine this
aspect. How long can a collector sit around before use? The larger
C-5
-------
diametar co?.lector seems to have more of a problem with this than the
smaller diameter collectors. This may come from inadequate desorption.
A thorough study of all aspects of the Tenax GC method and standardi-
zation must be achieved to ensure that data collected during the IAQ study
is accurate and meaningful.
The recent contractor's comparison held at Love Canal by the EPA
indicates that with nine different labs participating the results can
vary over a wide range. This variation stems from the nine different
sets of sampling trains, collector configuration, and desorption appara-
tuses. Even when labs use the same equipment the results can differ markedly.
With proper care and attention to details the results may be reproduci-
ble within +10-15%; however, this level of precision should be adequate
enough to determine the extent to which organic vapor contamination in
homes differs and its relation to occupant health, safety, and comfort.
C-6
-------
Appendix D
SELECTING A DUST MONITOR
-------
Select iry< .1 Pur.I Monitor
Type of In format ion Dp si reel:
Relative or Quantitative Concentrations
Periodic or Continuous Monitoring
Alarm Function
Dust Source Detection
Filter Efficiency or Breakthrough
Range of Dust Concentrations
Size Distribution Measurements
Types of Dust
Important Parameters
Dust & Environmental Parameter
I. Size Distribution
Refractive Index and
Density
(affects light
scattering instruments
only)
Aerosol Phase (Solid/
Liquid/Vapor)
4. Particle Shape
^
5. Humidity ^"v
6. Temperature
Relevant Instrument Parameter
- Type of Preselector
- Inlet Losses
- Detection Principle
- Collfiction Mechanism
(if any)
Detection and Calibration
- Detection Principle
- Collection Mechanism
(if any)
- Detection Principle
- Detection Principle
- Collection Mechanism
(if any)
- Electronic Drift
- Detection Principle
- .Battery Output
D-l
-------
Direct Rending Portable
Field Instruments
«
The following information is intended only as guideline to give the
reader a feeling for the relative merits of each instrument in terms
of cost and field usage. For more comprehensive or up-to-date
information, contact the manufacturer or a current user of the
instrument.
D-2
-------
Tyndallometer T.M. Digital
Manufacturer:
Distributor:
Operating
Principles:
Size:
Weight:
Cost:
Leitz, Germany
Preiscr/Mineco,
St. Albans, W. Va.
Forward (70°) light scattering,
LED light source, passive sampling.
26 x 27 x 6.5 cm
3.5 kg
$10,000.
Separate Battery Pack
Size: 25 x 17 x 10 cm
Weight: . 4 kp.
Cost: $1,250
Field Maintenance
and Operation: - Zeroing requires a separate pump
to clear the air in the sampling
chamber.
- Calibration requires insertion
of a separate reference scatterer.
Sampling is achieved passively
through an 8 cm hole through the
•case.
— Depending on length of use and
dust concentration, the light
traps have to be replaced.
- The instrument can operate for
about 9 hours on its separate
NiCad battery pack.
- Readout is by Light Emitting
Diodes
- The instrument time constant
is about 15 sec.
- There is a voltage level
indicator for monitoring
battery condition.
D-3
-------
icat ions:
Advantages:
Disadvantages
The T.M. was designed to oonitor
in German coal mines and is avail-
able in an intrinsically safe
version. It will respond to
virtually all types of dusts.
Samples passively
Rapid response
Easily operable
No respirable dust preselector.
Bulky when used with battery pack.
Meeds calibration for different
dusts.
Zero and calibration checks are
not readily performed.
Optically critical surfaces are
not protected from gradual contam-
ination.
•VA
-------
SIMSLIH
Manufacturer:
Distributor:
Operating
Principle:
Size:
Weight:
Cost:
Field Maintenance
and Operation:
Rotheroe and Mitchell,
United Kingdo-.n
Clasrock,
Atlanta, Georgia
Forward light scattering
laser diode light source,
pump flowrate 0.625 LPM,
horizontal elutriator pre-
selector, digital-memory,
internal filter for
calibration
A x 11 x 15 cm
7 kg
about $15,000
- No field calibration.
- Self adjusting for light
source level changes.
- Indicate low battery level
and other malfunctions.
- The SIMSLIN must be placed
in a horizontal position for
preselector to vrork properly.
- The output is indicated in
mg/ro^ and is fairly accurate
for some common dusts such as
coal, limestone and quartz.
- The digital memory records one
data point every 15 seconds.
- Operation time on NiCad
batteries is up to 30 hours.
- There arc two Liquid Crystal
Displays, one on the back
and one on the side. There .
are several LED warning lights.
D-5
-------
Applications:
Advantages:
Disadvantages;
- The instrument time constant is
30 seconds.
The SIHSL1N was designed for use
in British coal mines and meets
requirements for operation in ex-
plosive environments. It should be
applicable to virtually all types
of dusts and fumes. The pre-
separator is not removable so only
respirable dust (according Co BMRC
curve) can be measured. The
digital memory allows dust concen-
tration vs time data to be recorded
in the field and played back in the
laboratory. The manufacturer's in-
dicated two ranges of operation are
O.I to 200 mg/m-* and 0.01 -
20 mf»/m3.
Rapid response
Easily operable
Portable
Has data storage capacity
Long operation period
(more than one day)
Intrinsically safe for
explosive atmospheres
Internal filter sample
available for calibration
purposes.
Needs calibration for each
type of dust (refractive
index and size distribution)
No reference or secondary
calibration check available.
D-6
-------
Renl Time Aerosol Monitor RAhi-l
Manufacturer:
Operating
Principles:
Size:
Weight:
Cost:
Field Maintenance
and Operation:
CCA/Technology,
Bedford, Mass.
Near forward light scattering,
pulsed IR Light Emitting Diode
light source, punp flow rate
2 LPM (variable), clean air sheath
over optics, 10 mm cyclone
preselector.
20 x 20 x 20 cm
4 kg
approx. $5,000.
- An internal reference scatterer
can be inserted for field
calibration.
- For humid atmospheres ( 90%
RH) the dessicant cartridge
nay need occasional replacement
- Two filter cartridges protect
the pump. These need replace-
ment depending on sampling tine,
dust concentration and size of
aerosol particles. Fumes will
clog the filters more rapidly
than coarser dust.
— Operation time on NiCad
batteries — 6-8 hours.
- Has battery voltage indicator.
- The Liquid Crystal Display read-
out is updated atO.3 second in-
tervals with selectable time
constants of 0.5, 2, 8 and 32
seconds. The time constant is
selected to optimize sensiti-
vity, response time and readout
stability.
- The- RAM-1 has a removable 10 mm
D-7
-------
Applications'.
Advantages:
Disadvantages
nylon cyclone on the inlet.
Total dust can be measured, but
calibration may be difficult.
- Manufacturer indicated range of
operation 0.001 mg/m3 to
200 mg/nr* in three selectable
ranges.
The RAH-l was originally developed
to measure respirable coal mine
dust. A version is available that
is safe for explosive atmospheres.
The RAM-1 will respond to virtually
all kinds of aerosols.
Rapid response v
Clean air sheath on optics
for good long-term stability
Easily operable
Minimal maintenance
Output for analog recording
Direct readout in mg/rn^
Needs calibration for each type
of dust (size distribution and
refractive index).
0-8
-------
Fibrous Aerosol Monitor FAM-l
Manufacturer:
Operating
Principles:
Size:
Weight:
Cost:
CCA/Technology,
Bedford, Mass
Right angle light scattering,
electrostatic alignment and
rotation of fibers, HeNe laser
light source, pump flowrate
2 LPM (nominal).
53 x 35 x 17'cm
12.5 kg
$10,000
Separate Battery Pack BP-FAM
Size:
Weight:
Cost:
31 x 13 x 17 cm
7 kg
$500
Field Maintenance
and Operation: '- Field calibration not
available.
- Field checks of flowrate,
laser beam alignment,
electrostatic field level,
dust scattering level and
battery level available.
f Normally line operated, but
battery pack, BP-FAM available.
- Internal filter cartridge may be
used for approximate
calibration.
- -The Liquid Crystal Display
indicates fiber count
continuously. Concentration
in fibers/cc is indicated at
selectable periods of 1, 10,
100, or 1000 minutes
- The instrument operates up to
to 4 hours on the battery pack.
D-9
-------
App! ic.itions:
Advantages:
Disadvantages:
Tim FAX-I wns designed to measure
ar.bastus aorosol concentrations
and give results equivalent to tho
standard method. Fibers other than
asbestos will also be detected.
Fibrous glass may not be detected
in dry (<30% BH)) atmospheres.
Manufacturer's indicated range of
operation 0.0001 - 30 fibers/cc.
Only available direct reading
portable instrument.for asbestos
and other fibers.
Rapid response.
Requires calibration for different
types of fibers.
Responds to fibers other than
asbestos.
Respomlr; to elongated dust
particles.
Laser beam alignment sensitive
to rough handling of the ,
instrument (corrected on latest version)
D-10
-------
Digital Dust Indicator Modol P-5
Manufacturer:
Distributor:
Operating
Principle:
Size:
Weight:
Cost:
Field Maintenance
and Operation:
Sib.ita, Japan
MDA Scientific,
Chicago, Illinois.
Right angle light scattering,
tungsten lamp light source, pump
flowrate I LPM, labyrinth type
preselector corresponding to
BKRC respirable dust curve.
20 x 18
3.5 kg
$2,000
x 8.4 cm
Zero is set by placing a filter
on the inlet.
An internal reference scatterer
can be inserted for field
calibration.
The labyrinth preselector needs
occasional cleaning depending on
measurement time and dust
concentration.
Operation time on NiCacl
batteries about 8 hours.
The Liquid Crystal Display
output is selected on a
O.I, I, 2, 5, or 10 min or
continuous interval. A
convential meter also indicates
the concentration. The concen-
tration is indicated by a count
that is proportional to the
light scattering signal. One
count/min indicates 0.01 mg/rn^
of 0.3 MOI stearic acid
particles.
The labyrinth preselector can be
removed for total dust sampling.
but calibration may be difficult.
D-ll
-------
Appl ic.-»cions:
Advantages:
Disadvantages:
The l'-5 is designed to rr.oot
Japanese requirements for treasur-
ing workplace air standards. It
should be applicable to virtually
all dusts and fumes. A higher
sensivity version of the instru-
ment is available. The manu-
facturer's indicated range of
operation is 0.01 - 500 rag/m-*.
(0.3 iiia stearic acid)
Rapid response.
Easily portable.
Easily operable.
Minimal maintenance.
Needs calibration for .each type
of dust (size distribution
and refractive index).
Critical optical surfaces not
protected from gradual contam-
ination.
D-12
-------
Kcspirable Ao.ro.sol Photo:aot.er
5l!>0
Manufacturer:
Distributor:
Operating
Principle:
Size:
Weight:
Cost:
Field Maintenance
and Operation:
KKK (Knnomax), Japan
Thermo Systems, Inc.
(TSI),
Minneapolis, Minnesota
Right angle light scattering,
tungsten lamp light source,
pump flowrate 4 LPM. lOym cut
size impactor preselector.
31 x 13 x 17 cm
4 kg
$2,800
Zero is set by placing a
filter on the inlet.
- An internal reference
scatterer can be inserted
for field calibration.
- The iinj'f-ictor preselector
needs occasional cleaning
and regrcasing depending on
measurement time and dust
concentration.
- Operation time on NiCad
batteries about 6 hours.
- Has battery voltage indicator.
- The LED readout is on a one
minute or operator selected
period. The concentration is
indicated by a count that is
porportional to the light
scattering signal. One count/
min equals 0.01 mg/nr* 0.3 um
stcaric acid particles.
- The 10 ym impactor can be re-
moved for total dust sampling.
Inlet losses for larger
particles may be significant and
calibration may be difficult.
D-13
-------
Applications:
Advantages:
Disadvantages:
The Model 5150 is designed to meet
Japanese requirements for
measuring workplace air standards.
The manufacturer's indicated range
of operation is 0.01 - 100 mg/m-*
(0.3 um stearic acid).
Rapid response.
Easily portable.
Easily operable.
Minimal maintenance.
Moderate cost.
Needs calibration for each type
of dur.t (size distribution
and refractive index).
Critical optical surfaces not
protected from gradual contam-
ination.
D-14
-------
Portable Continuous Aerosol MoniLor (PilAM)
Manufacturer:
Operating
Principles:
Size:
Weight:
Cost:
ppn, Inc.
Knoxville, Tennessee
Near forward light scattering,
Light Emitting Diode light source,
separate detection channel for
large particles, nominally 1.85 LPM
flowrate, optional vertical
elutriator preselector, 10 period
memory.
41 x 23 x 20 cm
9 kg
$7,500.
Field Maintenance
and Operation:
Provides automatic rezeoin?*
and calibration.
Requires purchase of separate
lead acid battery and inverter
for remote operation. Primarily
designed as a 115 VAC line
operated instrument.
Has one minute stand-by battery
in case of temporary line
failures.
Has continuous LED display Vith
instrument time constant of
about 4 sec.
Has 10 memory locations in
microprocessor controller. This
allows instrument to operate for
10 user selectable periods of
0.25, 2, or 8 hours and retain
total scattering and large
particle fraction data.
Manufacturer's indicated range
of operation: 0.005 - 20.0
rog/nr*.
D-15
-------
Applications:
Advantages:
- PCAM has a removable lioixontnl
elutriator, so total dust can
be measured.
- Has an internal filter that
protects the pump and allows
instrument calibration.
PCAK was originally designed to
measure cotton dust. By
installing a 10 mm nylon cyclone,
other types of respirable dust can
be measured. The sensor will
respond to virtually all types of
dust and fume. The large particle
fraction data allows better
calibration under changing size
distribution conditions. The
automatic zero calibration and
data logging allows extended
unattended data accumulation.
Rapid response.
Auto zero and calibration.
Easily operable.
Minimal maintenance.
Disadvantages:
Needs calibration for each
type of dust (size
distribution and refractive
index).
D-16
-------
TSI-3500 I'ioxo Kalaiue
Manufacturer:
Operating
Principles:
Size:
Weight:
Cost:
Operation:
TSI Incorporated,
St. Paul, Minnesota.
The TSI-3500 ir. a portable aerosol
measuring instrument that employs
the principle of piczo-electri.c
mass measurement. Thn aerosol
particles are collected by an
electrostatic prccipitator onto an
oscillating quartz crystal and the
frequency of oscillation is changed
by the collected mass. The in-
strument operates at I LPM with an
optional 3.5 ym impactor pre-
selector. Without the impactor,
a measurement .of total dust can be
made.
61
5 kg
$3,850.
13 x 15 cm
The instrument power is turned on and the chk button
is depressed. The battery voltajjc is checked and
thep the STRT button is presscc' to check the crystal
frequency. If the crystal frequency is more than 1000
Hz above the clean crystal frequency, the crystal must
be cleaned. After the crystal is clean the Heas.
button is pressed. The precipitator current is '
checked and then the measurement is started by
depressing the STKT button. After a preset period of
t^me, the concentration in mg/m-* is indicated on a
digital display. Two different measurement times of
120 seconds and 24 seconds may be chosen. If the 24s
time is used, the indicated concentration must be
multiplied by 5 by the operator.
Range:
.1 mg/m3 - 20 wg/ra3
' D-17
-------
r'aintor.anc'.*:
Batteries must be charged prior to use. The
instrument will operate for at least 8 hours on fully
charged batteries. The crystal must be cleaned after
approximately 5-20 readings depending on dust
concentration using the built in cleaning mechanism.
The cleaning operation requires about 5 minutes to
perform. The cleaning mechanism has sponges that must
be wetted before use and the sponges must be cleaned
periodically. The precipitator must also be cleaned
about once a week or whenever the current is low.
Applications:
Advantages:
Disadvantages:
The instrument performs best with
aerosols less than 5pm. Some
aerosol where it has been applied
are metal fumes, coal, silica, and
fibrous glass. Some materials
such as liquids and chained
particles (e.g. carbon black) do
not couple well to the measurement
crystal and are detected with
reduced .>:ensivity.
The instrument is portable, easy to
use and responds directly to
collected mass.
The instrument does not respond
well to aerosols with large
particle sizes (>5 urn).
Crystal must be cleaned
periodically and this operation
requires about five minutes.
The instrument cannot be used in
explosive atmospheres.
The instrument does not respond
well to liquids and particle
chains.
D-18
-------
Kaufacturer: CCA Technology,
Bedford, Mass.
Operating
Principles: Tnc RDM-10I (Respirable Dust
Monitor) is a portable dust
instrument 'employing the principle
of B -attenuation. The- dust
particles are impacted onto a thin
grease coated plastic film where
the mass of the deposit is
measured by B-attenuation. The
instrument can be used at 2 LPM
with a 10 ir.m cyclone; to obtain a
mesureroent of respirable dust and
without a cyclone to obtain a
measurenvnt of total dust.
Size: 23 x 9 x 18 cm (without cyclone)
Weight: . 3 kg
Cost: $4,690
Operation:
A clean collection substrate area is rotated under the
impact ion nozzle and the instrument is turned on. The
measurement is started by depressing a Start switch.
After a preset period of time, the measured
concentration in mg/nr* is indicated on a digital
display. There are several different instruments
available with preset measurement times of .2, 1, 4
and 8 minutes. The instrument may also be used in a
semi-manual mode by placing start switch in a down-
ward position after the measurement period is
commenced. This allows the measurement period to be
extended, but the operator must keep track of sampling
time and calculate the concentration.
Range: .06 - 200 rag/m^ (depending
on measurement time.)
D-19
-------
Nnintrnnnce:
The batteries in the instrument should be charged for
\ft hours before use. Approximately 200 - 1 minute
measurements can be taken with a fully charged
instrument. The impact ion substrate disc needs to be
replaced after all the impact ion areas are used up.
There arc 95 areas available on each disc. The
instrument must be calibrated periodically using a
factory supplied calibration disc. The calibration
disc is put into the instrument in a specified
position instead of the collection dine. A
measurement cycle is started and the disc is advanced
manually at a specified time. The reading can be
adjusted vith a potentiometer on the side of the
instrument.
Applications:
Advantages:
Disadvantages:
Since the instrument uses an
impact ion principle for collection
of the dust on the collection
substrate, the instrument wil^ n.ot
collect particles smaller than about 0.
The instrument has been used for
coal, fibrous glass, silica, and •
Arizona voad dust.
The instrument is portable
and easy to use.
The instrument responds directly
to collected mass.
The instrument is intrisincally .
safe.
7 urn.
Instrument will
particles less than about 0.7 urn.
Not tor use with fume's or
liquid aerosol.
Collection substrate discs must
be cleaned and coated after
every 95 measurements.
The aerosol concentration must
remain relatively constant
during the measurement period
if only a single measurement
is performed.
D-20
-------
RUM-201
Manufacturer:
Operating
Principle:
Sixe:
Weight:
Cost:
Operation:
GCA/Technol ogy,
Bedford, Mnss.
Tae RDM-201 (Respirable Dust
Monitor) is a portable mass
measurement instrument employing
the principle of $-attenuation.
The aerosol particles are
collected on a high efficiency
glass fiber filter where' the mass
of the collected dust is measured
by 0-attenuat Ion. The instrument
cam be ised at 2 LPM with a 10 mm
nylon cyclone to obtain a
measurement of respirable dust and
without a cyclone to obtain a
measurement of total dust.
23 x 9 x 18 cm (without cyclone)
3 kg
$4,800.
A clean filter is mounted in the instrument and the
instrument is turned on. The measurement is started
by depressing a Start switch. After a preset period
of time, the collected mass in mg is indicated on n
digital display. The operator must then calculate the
concentration in mg/m^. The instrument can also be
used in a semi-cumu.il mode by placing the Start switch
in a downward position after the measurement period
ha.s commenced. This allows the measurement period to
be ^c?3tt.ended but the operator must keep track of the
sampling time and calculate the concentration.
Range:
.2 mg/m^ - 150 rag/m-* sampling
time must be extended to obtain
accurate measurements at lower
concentrations.
D-21
-------
Ma i ntenancct : .
The batteri&s ir.ust \tc charged prior to use. The
instrument will perform for five hours on fully
charged batteries. Tim instrument must be calibrated
periodically using a factory supplied calibration
disc. A measurement cycle is started and the
calibration disc is put into the instrument after a
certain period of time. 'The reading can be adjusted
using a potentiometer on the side of the instrument.
Applications:
Advantages:
Disadvantages:
Coal dust
Fiber glass
Fuaias
Instrument is portable,
easy to use, and re-
sponds directly to
collected mass.
The instrument can
measure particles less
than 1 ]im.
The instrument needs a fairly
long measurement time to.
obtain accurate readings at
lower concentrations.
The instrument doer, not cal-
culate the concentration
directly.
The filter ir.ust be changed
periodically, or after
each measurement. •
D-22
-------
KUi'i-JOl
Manufacturer: CCA Technology,
Bedford, Mass.
Operating
Prinipcles: The RDM-301 is an automated version
of the RDM-101 and employs the same
operating principles.
Size: 46 x 33 x 28 cm
Weight: 19 kg
Cost: $11,900 (with battery'pack)
Operation:
A clean collection substrate disc is mounted in the
instrument. The instrument pov;er is turned on and n
measurement cycle is started by depressing a Start
button. After a preset amount of time the collected
mass in mg and concentration in mg/m-* is printed on
a tape. The measurement time is adjustable by use of
a thumbwheel. The instrument may be operated in a
single measurement mode where the operator initiates
each measurement or in a continuous mode where the
instrument proceeds automatically to the viftxt . ..
measurement cycle. The results are printed so that
there is a record of the .concentration measurements as
a function of time.
)
Range: .01 - 75 mg/m^
Maintenance:
The batteries in the instrument must be charged prior
Cp use. The instrument can operate for up to eight
hours, of continuous use without recharging the
batteries. The impact ion substrate disc must be
cleaned and regreased when all the 495 impaction areas
are used up. The instrument must be calibrated
periodically using a factory supplied calibration .
disc. The instrument must be disassembled if the
calibration requires adjustment. This adjustment
is made using some BCD switches in one of the boards
in the instrument.
Application: See RDM-101 write up.
D-23
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Advantages: The \nst> u;:irnt is fully automated
and re-.ij'onils directly to
collected mass.
Disadvantages: The instrument is not easily
portable. (See RDM 101
write up for other comments.)
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