United States
              Environmental Protection
                  Air and
              August 1989
Report to Congress on
Indoor Air Quality
                            EPA/400/1 -89/OmC
Volume II:
Assessment and Control
of Indoor Air Pollution
    Issued under Section 403(e), Title IV of the Superfund
    Amendments and Reauthorization Act of 1986 (SARA)

             REPORT  TO   CONGRESS


             INDOOR  AIR   QUALITY

                Issued  Under

         Section  403 (e),  Title IV

                   of  the

 Superfund   Amendments  and  Reauthorization

            Act   (SARA)  of  1986
                 Prepared By:

             Indoor Air Division
Office of Atmospheric and Indoor Air Programs
         Office of Air and Radiation
    U. S. Environmental Protection Agency
           Washington,  D.  C.   20460

                        TABLE OF CONTENTS
     Chapter 1:  Building Systems and Factors Affecting
                 Indoor Air Quality	  1-1

          1.1  Characteristics of the U.S.  Building
               Stock	1-1
          1.2  Factors Affecting Indoor Air Quality  .  .  .  1-8
          1.3  Influence of Building Design,
               Operation, and Maintenance on Indoor
               Air Quality	1-10
          1.4  Summary	1-13

     Chapter 2:  Measuring and Modeling Pollutants and
                 Sources	2-1

          2.1  Pollutants and Sources	2-1
          2.2  Source Emission Testing 	  2-2
          2.2  Modeling	  2-5
          2.4  Field Measurements	  2-11
          2.5  Integration of Measuring and Modeling
               Techniques to Predict Exposure	2-22
          2.6  Measured Indoor Air Pollutant
               Concentrations and Exposures	2-22
          2.7  Summary	2-33

     Chapter 3:  Non-Cancer Health and Discomfort Effects
                 of Poor Indoor Air Quality	  .  3-1

          3.1  Summary of Pollutants, Sources and
               Health Effects	  3-1
          3.2  Potentially Sensitive Populations 	  3-4
          3.3  Non-Cancer Health and Discomfort Effects.  .  3-4
          3.4  Summary and Implications	3-15

     Chapter 4:   Carcinogenic Risk Assessments   .....   4-1

          4.1  Risk Assessment Methodology  ........  4-1
          4.2  Variations Within Risk Assessments   ....  4-8
          4.3  EPA Cancer Risk Assessments  for
               Indoor Pollutants .............  4-11
          4.4  Additional Risk Assessments  for
               Indoor Pollutants .............  4-16
          4.5  Comparison of Estimated Indoor Air
               Risks to Other Environmental Risks   ....  4-27
          4.6  Summary and Implications	4-29

     Chapter 5:   Economic Impacts of Indoor Air Pollution.  5-1

          5.1  Types of Economic Costs ..........  5-1
          5.2  Methodologies for Calculating Economic
               Costs ...................  5-2
          5.3  Calculating the Economic Costs of
               Indoor Air Pollution.  .....  	  5-4
          5.4  Summary and Conclusions	5-17
     Chapter 6:   Methods and Strategies of Control .... 6-1

          6.1  Engineering and Operational Control
               Strategies.  ................ 6-1
          6.2  Appropriate Design and Maintenance for
               Buildings ............  	 6-12
          6.3  Diagnostic Protocols for Indoor Air
               Quality Control	6-15
          6.4  Administrative Control Options. .  	 6-17
          6.5  Summary .................. 6-22

      Chapter 7:   Existing Indoor Air Quality Standards.  . 7-1

          7.1  Characterization of Standards  ....... 7-2
          7.2  Compilation of Standards. ......... 7-7
          7.3  Evaluation:  Significance of Existing
               Standards and Guidelines. ......... 7-7
          7.4  Ventilation Standards ........... 7-25
          7.5  Summary ..................7-30

Chapter 8:   Federal Authorities Applicable to
             Indoor Air Quality	  8-1

     8.1  National Environmental Policy Act 	  8-1
     8.2  Environmental Protection Agency 	  8-1
     8.3  Department of Energy	8-9
     8.4  Department of Health and Human Services .  .  8-10
     8.5  Consumer Product Safety Commission	8-11
     8.6  Department of Housing and Urban
          Development	  .  8-12
     8.7  Department of Labor	  8-13
     8.8  Summary and Implications	8-14

Chapter 9:  Indoor Air Pollution Control Programs .  .  9-1

     9-1  Federal Programs	9-1
     9.2  State and Local Indoor Air Quality
          Programs	9-12
     9.3  Private Sector Initiatives	9-19
     9.4  International and Foreign Programs. ....  9-19
     9.5  Summary and Implications.	9-26

Chapter 10:  Indoor Air Quality Policy Issues .   . .  .10-1

    10.1  Setting Standards 	  .10-2
    10.2  Providing Guidance On Measures to Identify,
          Correct, And Prevent Indoor Air Quality
          Problems in New and Existing Buildings  .  .10-6
    10.3  Establishing Public Information and
          Technical Assistance Programs	10-8
    10.4  Summary	10-10



      Total  human  exposure to environmental contaminants is the
 composite of exposure to the air we breath, the water we drink,
 the  food  we eat,  and the physical contact we have with our
 surroundings.   The  air we breath is a major component of this
 exposure  and,  since the majority of people in industrialized
 societies spend most of their time indoors, an examination of the
 indoor  air  environment and  its attendant affects on human health
 is an important public undertaking.


      Individuals  are exposed to a variety of indoor air
 pollutants  as they  progress through a succession of
 microenvironments during the course of their daily activities.
 The  environment at  home, in transit, at school, a€ work, and in
 recreational facilities all contribute to an individual's total
 exposure.   The contribution of each microenvironment is
 proportional to both the time spent and the pollutant
 concentration in  that microenvironment.

      Time budget  studies conducted in the United States and
 Europe  reveal that  persons  in industrialized countries spend over
 90%  of  their time indoors.  The most notable published time-use
 data are  those by Chapin (1974), and Szalai  (1972); these data
 are  summarized in Exhibit 1.  More recent work by Ott  (1982 and
 1988) has analyzed  the previously published data and incorporated
 results of  EPA-sponsored field studies; these aggregated data
 corroborate the earlier findings with respect to typical time-
 activity  patterns.

      People spend approximately 93% of their time indoors,  2%
 outdoors, and 5%  in transit (e.g. car, train, bus).  Thus,  from  a
 time  budget standpoint, indoor environments dominate the total
 exposure  spectrum.  In addition to the duration of exposure,  the
 adverse health impact of indoor air pollution depends  on  a
 variety of  factors, not the least of which  is the number  and
 strength  of sources, and the potency of the pollutants which  they
 emit. Thus,   several chapters of this report are devoted  to  a
 discussion  of  sources, pollutants, exposure, and risk.

      Since  most indoor environments are buildings  (residences,
 offices,  schools, etc.), the characteristics of buildings and the
 influence of  building systems on indoor environments  are of
utmost importance in any effort to address  indoor air  quality.
Buildings,  in  the broadest  sense, are enclosed  spaces  that
provide refuge  and  shelter  from the exterior environment.   Modern
buildings perform this function extremely  well.   One  important
implication  of  this is that building systems create  and control

interior environments,  so  that  the  health,  comfort, and
productivity of building occupants  is greatly influenced by the
design  operation, and  maintenance  of building systems.
Accordingly, interspersed  throughout the report are discussions
which reflect the  importance  of building systems to indoor  air
quality  and the role of proper building design and management  to
the prevention and mitigation of indoor air pollution  problems.


                           EXHIB8T 1
In Tran»it    Oth«r Indoor  Total Outdoor
            Data Soyrea:
      Szala! (1972)
             Chapln (1974)


     This document is organized in two parts.   Part I,  entitled,
Assessing Health and Economic Impacts of Indoor Air Pollution,
characterizes the nature and magnitude of indoor air pollution
problems in terms of both the exposure and buildings contexts
discussed in the preface.  Part II, entitled Controlling Indoor
Air Pollution, addresses controls in terms of the engineering and
operational methods, as well as the legislative and policy
instruments, that are available or that may be developed for use
in both the public and private sectors.

     Part I begins with a discussion of building systems and
factors that affect concentrations of indoor air pollutants.  It
outlines the factors, including building system components, and
discusses the importance of building design and management
practices.  The chapter also provides limited data on the U.S.
building stock, and lays the foundation for the discussion of
mitigation and control strategies which is presented in Chapter 6

     Chapters 2 through 5 characterize the health and economic
impact of indoor air pollution.  Chapter 2 identifies the major
pollutants, and sources, and discusses measuring and modeling
capabilities, practices, and limitations.  Chapter 2 also
discusses the results of some important indoor air and personal
exposure monitoring studies.  Chapter 3 provides an overview of
non-carcinogenic health effects and provides information on
populations with particular sensitivity to indoor pollutants.
Chapter 4 presents a discussion of carcinogenic risk assessments
for several indoor air pollutants.

     Chapter 5 presents a brief assessment of the economic
impacts of indoor air pollution, using, in part, information
provided in the health effects component of this report.  The
analysis examines the costs of damage to equipment and materials,
as well as the costs of illness and lost productivity.

     Part II of the report begins with Chapter 6 which covers
engineering and operational methods of control.  This chapter
also contains a discussion of protocols for diagnosing indoor  air
quality problems, and of policy options for implementing the
control methods.

     Chapter 7 presents available standards and guidelines  in
both the public and private sector, and assesses their
applicability to non-industrial indoor environments.

     Chapter 8 assesses the applicability  of available  federal
legislative authorities to the control of  indoor air pollution.

     Chapters 9 and 10 conclude the report with  assessments of
indoor air programs and policy issues.



Chapin, F.S.  1974.  Human Activity Patterns in the City_._  New
     York: John Wiley and Sons.

Ott, W.R.   1982.  Human Activity Patterns: A Review of the
     Literature for Estimation of Exposures to Air Pollution.
     Draft Report, U.S. EPA.

Ott, W.R.    1988.   Human Exposure to Environmental Pollutants.
     Presented at the 81st Meeting of the Air Pollution Control
     Association,  Dallas, TX,  June 20-24.

Szalai, A.  1972.   The Use of Time: Daily Activities of Urban and
     Suburban Populations in Twelve Countries.  The Hague, Paris:

Health and Economic Impacts
     Indoor Air Pollution

                AIR QUALITY

     This chapter characterizes the building stock and describes
the factors  that affect indoor air quality and how these factors
are influenced by the design, operation, and maintenance of
building systems.  By way of illustration, the chapter includes a
discussion of indoor air quality problems that have resulted from
building system inadequacies.


     The following paragraphs discuss some of the characteristics
of the building stock of the U.S. that are relevant to indoor air
quality.  These include general characteristics, heating and
cooling systems used, and the characteristics of the building
shell that affect air exchange rates.  Except as otherwise noted,
all data reflect 1984 levels for housing and 1983 levels for
commercial buildings as reported by the U.S. Department of Energy
(1986 and 1985).


     General Characteristics

     Exhibit 1-1 presents information on the general charac-
teristics of the stock of housing units in the U.S.  In 1984, the
U.S. residential housing stock was comprised of 86 million
occupied units  (U.S. Department of Energy, 1986).  These units
had a total  floor space of 144 billion square feet, an average of
1672 square  feet per housing unit.  Most of the housing units in
the U.S., with over three-quarters of all residential floor
space, are detached single-family dwellings.  About half as many
units are in apartment and condominium buildings containing two
or more housing units.  Just under six percent of U.S. residences
are mobile homes.  Half of these mobile homes are in the South
census region (Amols et al., 1988).

     Heating and Cooling Characteristics

     Exhibit 1-1 illustrates the distribution of heating and
cooling system types in U.S. residences.   The type of heating
appliance(s) and fuel(s) used in the residence can exert
significant  effects on indoor air quality; products of combustion
are commonly found at significant concentrations in residences
equipped with unvented heating units.  In addition, many
multifamily  residential buildings have central forced-air
heating and  cooling systems, wherein the quality of the indoor
atmosphere is influenced by the introduction and circulation of
outside air  into the occupied spaces of the building.  (These
issues are discussed more completely in a subsequent chapter.)

                                                      Exhibit  1-1

                                     Residential  Building  Stock  Characteristics a/
Number of
Housing Units
Single-Fami ly
Mobi le Home
2 to 4 Units
5 or More Units
Central Warm-Air Furnace
Steam or Hot-Water System
Room Heater/Other
Built-in Electric Unit
Wood Stove
Heat Pump
Gas Floor, Wall, or
Pipeless Furnace
Natural Gas
Fuel Oil
Room Air-Conditioner
Central Air-Conditioner
HDD > 7000
5500 < HDD < 7000
4000 < HDD < 5499
HDD < 4000
COD > 2000
(Single-Family Units Only)
Weatherstripping or Caulking
Roof or Ceiling Insulation
Wall Insulation
Floor Insulation
Combination of Storm Windows
and Doors and Roof /Ceil ing
No Weatherization









Percent of
All Units









Percent of
Floor Space Comments






Heating degree days (HDD) and cooling
11.6 degree days (CDD) are measures of the
28.6 heating and cooling effort, respectively,
27.3 required to maintain thermal comfort
19.8 indoors.
Ueatherization efforts affect indoor air
quality by restricting the flow of heat
and air through the building shell.

a/  From U.S.  DOE,  1986.
RECS:  Housing Characteristics,  1984, Energy Information Administration,

     A large percentage of domestic housing units are heated by
the combustion of natural gas, fuel oil, LPG, kerosene, or wood,
all of which produce air pollutants that can potentially degrade
the quality of the indoor atmosphere.  Multi-family dwellings are
more often heated with fuel oil and natural gas than the housing
stock in general, which is dominated by single-family dwellings.
Mobile homes, on the other hand, use electricity and liquified
petroleum gas (LPG) more regularly than other housing types.

     Thermal Characteristics

     Exhibit 1-1 presents data on the thermal characteristics of
U.S. residences.  Most of the residential stock of the U.S. is in
relatively mild climates with less than 2000 cooling degree days
(CDD) per year and less than 7000 heating degree days  (HDD) per
year.1  Nevertheless, ninety percent of all single-family housing
units have incorporated some type of weatherization material.
Weatherization efforts (e.g., insulation, storm doors and
windows, and weatherstripping) influence indoor air quality by
altering the flow of heat and air through building shells;
tightened buildings can lead to increased indoor air pollution
levels, unless ventilation is increased.

     Ventilation Characteristics

     Air exchange rates due to infiltration were measured in two
national surveys of houses   (Diamond and Grimsrud, 1983).  The
first involved a sample of 312 new houses in the U.S. and Canada.
Infiltration rate measurements were taken over the heating season
from November through March.  The mean value of the seasonal
averages for all houses was 0.63 air changes per hour; however,
since the distribution was skewed, the median value of 0.50 air
changes per hour may be more representative.

     Air exchange rates due to infiltration were also measured in
a second survey involving a sample of 266 low income houses.
Single measurements, rather than seasonal averages, were taken
for each house.  The mean air exchange rate from these
measurements was 0.9 air changes per hour.  The higher air
exchange rate results because the houses are older and of poorer
construction (Diamond and Grimsrud, 1983).
     1  Heating degree days and cooling degree days are measures
of the heating and cooling effort, respectively, required to
maintain thermal comfort indoors.  High values of HDD  indicate
large heating requirements; high values of CDD indicate large
cooling requirements.  For example, Detroit averages about  7000
HDD per year, New York about 5500 HDD per year, Nashville about
4000 HDD per year, and Memphis about 2000 CDD per year.


     Comme re i a1

     General Characteristics

     Exhibit 1-2 presents some general characteristics of
commercial buildings in the U.S.  In 1983 there were 3.9 million
commercial buildings (defined as all non-industrial and non-
residential structures) in the U.S. (U.S. Department of_Energy,
1985).  These units have a total floor space of 52 billion square
feet, an average of 13,300 square feet per building. Commercial
buildings have a variety of uses; these uses determine the
populations likely to enter their indoor microenvironments.  Over
one-quarter of all commercial buildings in the U.S. are for
mercantile or service uses.  Other uses of commercial buildings,
in decreasing order of number of buildings, include offices,
assembly, warehouses, food sales and service, vacant,
residential, educational, lodging, and health-care.  Educational
and health-care structures are on the average the largest types
of buildings, and food sales and service and mercantile and
service are the smallest.  Most commercial buildings have only
one floor, and less than one-fifth of all commercial buildings
have three or more floors.

     Most commercial buildings house a single establishment.
Government-occupied buildings represent almost 9 percent of all
U.S. commercial buildings; these buildings account, however, for
nearly 20 percent of the country's commercial floor space.

     Heating and Cooling Characteristics

     Exhibit 1-2 presents data on the heating and cooling of
commercial buildings in the U.S.  Over sixty percent of all
commercial buildings are fully heated and almost half of the rest
are partially heated.  Two-thirds of all commercial buildings  in
the U.S. are at least partially cooled.  Almost one-half of all
commercial buildings are heated by forced-air central systems,
and a similar percentage are centrally cooled.  Air-distributing
heat and cooling systems are most prevalent in office and
assembly buildings.  Heating systems which do not actively
distribute air are found in more than half of the country's
commercial buildings (especially structures other than office
buildings and places of assembly).

     Thermal and Energy Use Characteristics

     Exhibit x-2 presents data on the thermal and energy use
characteristics of the U.S. commercial building stock.  Roughly
three-quarters of the commercial building stock is  in moderate
climates.  Nevertheless, some energy conservation features, such
as roof/ceiling insulation, wall insulation, and special glass
are used in over two-thirds of all commercial buildings.
However,  just over 10 percent of these buildings incorporate all
three of these features.  Insulation and special glass use  in

                                                                                  Exhibit 1-2

                                                                            Building Stock Characteristics  a/

Food Sales/Service
Health Care
Mercant i le/Servi ces
Single Establishment
Hulti -Establishment
Government Occupant
Non- Government Occupant
Entire Bui Iding
Part of Building
Entire Bui Iding
Part of Building
Central Forced-Air
Other Central
Central Forced-Air
Heat Pimp
Number of





Percent of
Percent of Total
All Buildings Floor Space








Floor Space
(1000 sq. ft.) Comments
13.3 Total Floor Space = 52.3 billion sq. ft.
Building type influences the nature and
12.0 duration of typical occupant
34.2 exposures. The heating, cooling, and
5.4 thermal characteristics presented below
37.6 are related in part to building type.
21.1 (See text for discussion.)
Number and type of establishments in
11.1 commercial buildings influence the relative effort
24.2 required to identify and address indoor air quality
29.2 problems.

      a/   From U.S.  Department  of  Energy.   1985.
      Administration.  DC€/E1A-0246(83).
Nonresident!at Building Energy Survey:   Characteristics  of Commercial Buildings, 1983.  Energy Information

                                                                                   Exhibit 1-2 (continued)

                                                                         ial Building Stock Characteristics  a/
Nunfcer of
Natural Gas
Fuel Oil
Natural Gas
HOD > 7000
5500 < HDO < 7000
4000 < HDO < 5499
HDD < 4000
COD > 2000
Roof /Ceil ing Insulation
Special Glass Only
Wall Insulation Only
Roof /Ceil ing and Wall
Roof Ceiling and Special
Wall Insulation and
Special Glass
All Three Features






Percent of Average
Percent of Total Floor Space
All Buildings Floor Space (1000 sq. ft.) Carmen ts

Heating degree days (HOD) and cooling degree days (COD) are
10.7 10.9 measures of the heating and cooling effort, respectively.
29.2 32.4 required to maintain thermal comfort indoors.
25.7 26.4
17.2 14.3
17.2 16.0
Weather izat ion practices reduce the flow of air and heat
through the building shell.



       a/  From DOE.  1985.

                                                                      Exhibit 1-2 (continued)

                                                           CcoBercial  Building Stock Characteristics   a/
                            Number  of
Percent of
All Buildings
Percent of
Floor Space
 Floor Space
(1000 sq.  ft.)
  Computerized Control          105
  Occupant Control
    Heating                    2541
    Cooling                    1170
  Regular HVAC Maintenance     2914

  Reduced System Operation
  in Off Hours
    Heating                    3010
    Cooling                    2302

                               Occupant  control  allous personal comfort adjustments.
                               Maintenance  inproves  indoor air quality by correcting
                               ventilation  deficiencies and removing potential sources.

                               Reduced system operation in off hours allows pollutant
                               concentrations to build up and create potential
                               human exposure problems upon re-occupancy.
    From DOE.  1985.

building construction are far more prevalent in new buildings
than in old.

     Only a very small fraction of all mechanically heated and
cooled commercial buildings in the U.S.  have computerized control
of heating and cooling.   Most heated buildings under 10,000
square feet allow occupant control of heating and cooling.

     Most heated and cooled buildings have regular HVAC system
maintenance programs; the proportion of buildings with such
programs increases as building size increases.  About 70 percent
of buildings under 5000  square feet have regular maintenance
while nearly all buildings above 200,000 square feet have such
programs.  HVAC maintenance can be a critical influence on indoor
air quality-

     Ventilation Characteristics

     Whole building ventilation rates measured in 38 commercial
buildings in the Pacific North West ranged from 0.3 to 4.2 air
changes per hour, with an average of 1.5 air changes per hour
(Turk et al.,  1988).   Ventilation rates from a comprehensive
study of 14 commercial buildings, involving 3000 measurements
over a period in the order of one year have also been reported
(Persily, 1989).   The mean values for each building ranged from
0.29 to 1.73 air changes per hour.  The mean of all buildings was
0.94 and the median value was 0.89 air changes per hour.


     Concentrations of pollutants in the indoor air are
determined by (1) the indoor source emission rates (including
the rate of entry from soil gases),  (2) the rate at which indoor
air is exchanged with outdoor air, (3) the concentrations of
pollutants in the outdoor air, and (4) rates at which pollutants
are removed from or chemically transformed in the indoor
environment.   These factors will be discussed in turn.

     Source Emissions

     Concentrations of contaminants indoors depend most
importantly on the strength of the emissions from contributing
sources.  Indoor sources include building materials, furnishings,
combustion devices, a variety of consumer and commercial
products, as well as human occupants and their pets.  Emission
rates of volatile organic compounds from building materials,
furnishings,  and some commercial and consumer products often
increase under conditions of high temperature and humidity, but
generally decrease with age.  Emissions of particulate matter and
combustion gases from combustion appliances such as stoves and
space heaters depend on design, fuel, and use factors.
Generally, vented appliances pollute less than unvented ones; gas
appliances tend to burn more cleanly than liquid or solid  fuel
devices, and proper use and maintenance of the device is


essential to controlling emissions  (Tucker, 1987).   Bioeffluents
from people and their pets, as well as microbial contamination
of humidification systems and water damaged materials can
normally be adequately controlled  with proper hygiene and
maintenance practices.

     Radon and other soil gases enter the indoor environment
through cracks and other openings in the building foundation when
the air pressure in the structure is lower than it is in the
soil.  The rate of entry depends on the concentration in the
soil, the permeability of the soil, and the pressure difference
between the soil gas and the air in the structure,  and the
characteristics of the structure itself.

     Air Exchange Rate and Outdoor Concentrations

     Outdoor air can be exchanged for indoor air through natural
ventilation, mechanical ventilation, or through infiltration and
exfiltration.  Natural ventilation occurs when desired air flows
occur through windows, doors, chimneys, and other building
openings.  Mechanical ventilation is the mechanically induced
movement of air through the building.  Mechanical systems usually
condition and filter the air, and allow for the entry of outdoor
air through outdoor air dampers.  Infiltration and exfiltration
are the unwanted movement of air through cracks and openings in
the building shell.  A "tight" building is one in which
infiltration and exfiltration rates are very low.

     The air exchange rate of a building affects indoor air
quality in two ways.  First, it determines the extent to which
outdoor air can dilute or replace indoor air and prevent indoor
air pollutants from accumulating to high levels.  The extent to
which air exchange is effective in diluting indoor pollutants
also depends on how well outdoor air is mixed with indoor air.

     Ventilation effectiveness is a measure of the portion of
outdoor air brought into a building that reaches the breathing
zone of the occupants.  If, for example, outdoor air which is
brought into the building is short-circuited directly out the
exhaust, inadequate air quality can result regardless of the
overall air exchange rate.  Building layout, occupant
activities, and the location of supply and return registers can
all influence the effective circulation of ventilation air.

     However, bringing in outdoor air also brings in the
pollutants it contains.  Thus, the second effect of air exchange
on indoor air quality is to contaminate the indoor air with
outdoor pollutants.  As a general rule, outdoor air concen-
trations,  particularly in buildings with high air exchange rates,
will act as the background level for the indoor environment.
This is normally not a problem where ambient outdoor levels are
acceptable and no major sources exist in the immediate vicinity
of the building.  Indoor sources will increase concentrations

above this level, while pollutant removal mechanisms will lower

     Removal Mechanisms

     Pollutant removal mechanisms will lower indoor concentra-
tions and improve indoor air quality-  Pollutants can be removed
from the outdoor air prior to entering the indoor space, or they
may be removed directly from the indoor environment.  Removal
mechanisms may be physical or chemical.  They may be part of the
natural reaction of the chemical with its surroundings, or they
may be deliberately incorporated into the building operating
system.  Air filtration devices are examples of a physical
removal mechanism which is deliberately incorporated into most
building ventilation systems.

     Physical and chemical reactions of pollutants with their
surroundings may take several forms:  sorption or chemical
reactions with building materials and furnishings; chemical
reactions with other pollutants; and photodissociation and
catalytic reactions (Maki and Woods, 1984).   For some
pollutants,  these reactions may be quite important.  Concen-
trations of nitrogen oxides and sulfur oxides, for example, are
heavily influenced by the reactive properties of these compounds.
In fact, chemical reactions and sorption can reduce concen-
trations of nitrogen oxides 48% more quickly than dilution (Maki
and Woods, 1984).


     Indoor air quality problems often result from the inappro-
priate control of the factors described above with respect to the
design, operation, and maintenance of building systems.  Common
problems include inadequate ventilation, contamination from
indoor sources, entrainment of outdoor contaminants into the
building,  and microbial contamination due to improper design,
operation, and maintenance procedures (NIOSH, 1987).

     Inadequate Ventilation

     Inadequate ventilation is the cause of many indoor air-
related health complaints.  Specific ventilation deficiencies
that produce air quality problems include inadequate outdoor air
supply, poor air distribution (and hence poor ventilation
effectiveness), inadequate control of temperature and humidity,
insufficient maintenance of the ventilation system, inadequate
HVAC system capacity,  and inadequate exhaust from occupied areas
(NIOSH,. 1987? Honeywell Incorporated, 1988).  Inadequate outdoor
air supply and distribution and insufficient control of thermal
conditions can result from strategies to control energy

     Numerous case studies illustrate problems caused by
ventilation system design and operation deficiencies.  Morey
(1988) presents two cases in which air quality problems were
traced to energy management programs that altered HVAC system
operations.  Morey and Woods (1987) present examples of
insufficient air supply, poor maintenance, and restrictions on
heating, ventilation, and air-conditioning (HVAC) operation from
energy conservation strategies as originators of air quality
problems in buildings.

     Contamination from Indoor Sources

     Investigations into indoor air quality-related health
complaints often identify sources inside the building as the
primary cause of the problem.  Inside sources responsible for
indoor air pollution problems include copy and other office
machines, pesticides, cleaning agents, tobacco smoking, and
combustion devices. Contamination of the indoor atmosphere can
also result from emissions from building materials and products
including insulation, pressed wood products, floor and wall
coverings, carpeting and adhesives.

     The selection and proper installation of building materials
and furnishings during design and construction of a building may
have important impacts on the building's air quality.  This is
particularly true of potential pollutant sources such as ceiling
tiles, floor and wall coverings, or partitions which have large
surface areas capable of offgassing chemical contaminants
throughout the occupied space.  Special provisions for exhausting
contaminants from known source areas such as photocopy rooms,
designated smoking areas, or special use facilities such as print
shops, are most appropriately made during the design of the
building, and properly maintained during its operation.

     Re-entrainment and Contamination from Outdoor Sources

     Outdoor pollutants or re-entrainment of indoor pollutants
sometimes create severe indoor air quality problems because of
improperly located air intake vents.  For example, these vents,
which supply outdoor air into the building, may be located at
ground level near a roadway or a parking lot where they allow
motor vehicle exhausts to enter the building air supply.  Most
often, however, these vents are located on the roof; for
aesthetic reasons, they are often positioned on  the back of the
building which may overlook the loading dock or  trash  storage
area,  or may be located close to and downwind from the rest room
exhaust of the building or an adjacent building.

     In each 'case, unwanted air contaminants may be  incorporated
into the building air and result in health risk  and  comfort
complaints from the occupants.  Thus, while the  sources of these
indoor air pollution problems are outdoors, the  cause  of the
problem can be traced to faulty design of the HVAC system, and


inadequate consideration of the entrainment of pollutants from
outdoor sources.

     Microbial Contamination

     Hypersensitivity pneumonitis and other respiratory diseases
often result from microbial contamination of building heating,
ventilating, and air conditioning systems,  or from contamination
of building materials and furnishings.  Microbial contamination
commonly results from situations of high moisture or humidity.
Flooded areas, water-damaged carpeting or furniture, dirty and
moist air filters, pools of stagnant water in the drain pans of
the HVAC system, or improperly cleaned and maintained humidi-
fication systems can result in microbial contamination and
building related illnesses.  Microbial contamination is most
often avoidable through careful building system component design,
and through proper maintenance and hygienic practices (Morey, et
al. 1984).


     Building systems are designed, constructed, and operated to
provide safe, healthy,  and comfortable environments for a variety
of human activities.  The indoor microenvironments created by
building systems must provide for the biological, physical,
social, and psychological needs of their occupants.  Under-
standing building systems as mechanisms for the control of
environmental conditions points to occupant well-being an
important criterion by which building adequacy should be judged.
Successful  building systems produce an environment free from
stressors that threaten occupant health, comfort, and

     Building system design and operation can, and regularly do,
provide acceptable indoor environments.  However, neglect or
disregard of the sources of indoor air contaminants, or of the
proper design, operation, and maintenance of building system
components  which influence indoor air quality can create an
uncomfortable and unhealthy indoor atmosphere.


     Some data are available on the U.S. building stock with
respect to parameters that are important to indoor air quality -
Factors which affect indoor air quality include source emissions
from indoor sources, the air exchange rate, outdoor sources and
concentrations, and various chemical and physical removal
mechanisms.  Building system inadequacies commonly identified in
investigations of building indoor air quality complaints include
inadequate ventilation, contamination from indoor sources, re-
entrainment of indoor pollutants, contamination from exterior
sources, and microbial problems.  Proper design, operation, and
maintenance of building system components is important to the
achievement and maintenance of good indoor air quality.


Amols G.R., Howard K.B., Nichols A.K., Guerra T.D.  1988.
     Residential and Commercial Buildings Data Book.  PNL-
     6454/UC-98.  Pacific Northwest Laboratory-  Richland WA.

Diamond R.C., Grimsrud D.T. 1983.  Manual on Indoor Air Quality.
     Lawrence Berkeley Laboratory.  LBL-17049.  University of
     California, Berkeley, CA.

Honeywell Incorporated.  1988.  News Release:  Diagnosis of Sick
     Building Syndrome Points to HVAC Systems as Cause, Cure.
     Gerry Drewry.  Golden Valley, MN.

Maki H.T., Woods J.E.  1984.  Dynamic Behavior of Pollutants
     Generated by Indoor Combustion.  Indoor Air, Proceedings of
     the Third International Conference on Indoor Air Quality and
     Climate.  Berglund B., Lindvall T., Sundell J. (Eds.)-
     Stockholm.  5:73-78.

Morey, P.R., Hodgson, M.J., Sorenson, W.G., Kullman, G.J.,
     Rhodes, W.W., and Visvesvara, G.S. 1984.  Environmental
     Studies in Moldy Office Buildings: Biological Agents,
     Sources, and Preventive Measures.  Annals of the American
     Conference of Industrial Hygienists. Vol 10.

Morey P.R.  1988.  Microbiological Problems in Office Buildings:
     Recognition and Remedial Action.  pp. 445-454.  Proceedings
     of Energy Technology Conference XV.  Government Institutes,
     Inc.  Washington, D.C.

Morey P.R., Woods J.E.  1987.  Indoor Air Quality in Health Care
     Facilities.  Occupational Medicine.  July-September 1987.

NIOSH.  1987.  Guidance for Indoor Air Quality Investigations.
     Health Evaluations and Technical Assistance Branch.
     Cincinnati, OH.

NRC.  1987. ' Policies and Procedures for the Control of  Indoor
     Air Quality.  National Academy Press.  Washington,  D.C.

Persily, A. 1989.  Ventilation Rates in Office Buildings.  Paper
     presented at the ASHRAE Conference IAQ 89.  The Human
     Equation:  Health and Comfort. San Diego, CA.

Tucker,  W.  1987.  Chairman's Summary Session I  --
     Characterization of Emissions from Combustion  Sources:
     Controlled Studies, in Atmospheric Environment Vol. 21,
     No. 2.

U.S. Department of Energy  (DOE).  1986.  Residential Energy
     Consumption Survey:  Housing Characteristics, 1984.  Energy
     Information Administration.  DOE/EIA-0314(84).  Washington,

U.S. Department of Energy  (DOE).  1985.  Nonresidential Buildings
     Energy Consumption Survey:  Characteristics  of Commercial
     Buildings, 1983.  Energy Information Administration.
     DOE/EIA-0246(83).  Washington, D.C.



      Some  information  on indoor pollutants, sources, and health
 effects  is known,  but  extensive investigation is needed to
 adequately understand  the nature and magnitude of the indoor air
 pollution  problem.   For example, most pollutant sources do not
 emit single pollutants, but generate a mixture, which in turn
 becomes  part of the  complex mixture that people breathe.  The
 health effects of  such a complex mixture cannot be categorically
 stated,  and in most  instances, neither the interaction of
 pollutants with each other, nor the effects on human systems of
 these pollutants in  combination, have been established.

      Several hundred specific airborne pollutants have been
 detected in varying  concentrations in indoor environments.  These
 can  be grouped into  a  smaller subset of pollutants and pollutant
 classes, as shown  in Exhibit 2-1.

                           Exhibit 2-1
              Major Indoor Air Pollutants of  Concern

             Radon  and  radon daughters
             Environmental tobacco smoke  (ETS)
             Biological contaminants
             Volatile organic compounds  (VOCs)
             Polycyclic Aromatic Hydrocarbons (PAHs)
             Combustion Gases
             Particulate Matter  (Particles)
     Indoor pollutants can emanate  from a broad array of sources
that can originate both outside of  structures as well as from
within a building.  Knowledge of sources is critical to the
development of effective mitigation strategies  (see Chapter  6).
Internal sources  include, but are not necessarily  limited  to:
combustion appliances, consumer and commercial products, building
materials and furnishings, pesticides, HVAC systems, water
damaged materials, human occupants  and pets, and personal
activities such as smoking.  External sources include soil,  water
supplies, and the ambient  (outside) air.  The relationship
between pollutants and their sources may be complex.  For
example, the concentration of a single pollutant may result  from
the emissions of  several different  sources both  inside  and
outside a building.


      The magnitude of human exposure to indoor air pollutants is
 a  function of the ability of the pollutants to come in contact
 with  an individual. This depends on the time individuals spend in
 each  indoor micro-environment containing pollutants, and the
 concentration of each pollutant.  Concentrations, in turn, are
 determined by source emissions and transport processes, both
 within and between particular microenvironments.

      The ambient pollutant concentration in a given
 microenvironment, and the associated human exposure, can be
 measured directly or they can be estimated using mathematical
 models.  Developing and/or calibrating these models may require
 many  different types of data, e.g., pollutant sources and their
 respective emission rates, average and peak pollutant
 concentrations, air transport processes, and time-activity
 patterns and demographic characteristics.  Assessing indoor air
 pollutant concentrations can involve as many as three components:
 source emission testing, air pollution measurements, and

      Source emission testing measures the emission of pollutants
 from  specific sources under laboratory conditions.  Source
 emission testing provides the researcher with detailed
 information on pollutant emission rates, which allow prediction
 of the ambient concentrations under specified environmental

      Typical indoor pollutant concentrations can also be
 measured directly using monitoring instruments.  These
 instruments vary in size from hand-held portable monitors to
 large, stationary analytical monitors.

      Finally, pollutant concentrations can be predicted,  rather
 than  measured, using indoor air quality models.  Directly
 monitoring the concentration of the pollutant of concern  provides
 the most accurate information for any particular
 microenvironment, but technical and financial limitations
 usually necessitate the additional use of modeling.  The  models
 themselves are often calibrated using the results from  source
 emission testing and/or from pollutant concentration

      In this chapter, we discuss the techniques  and limitations
 of source emission testing, field monitoring, and modeling.   In
 addition,  we present data from selected studies  that measured
 indoor air pollutant concentrations or exposures.


     The emission of pollutants from indoor sources can be
measured directly under laboratory conditions.   These  tests  can
provide the researcher with detailed information upon  which  to


 estimate  or model  indoor  air pollutant concentrations.  In the
 past,  most  source  emission  studies have involved single compound
 analyses  and have  focused on three categories of sources:
 combustion  appliances,  consumer products, and building materials
 and  furnishings.

     The  source  emission  test can be divided into three steps:

      (1)     A sample  of the substance containing the pollutant of
             concern is  prepared in such a way that the sample
             will provide  emission data that approximate, or allow
             extrapolation to, emissions under normal use;

      (2)     A test chamber  is designed, incorporating
             environmental test conditions, such as temperature
             and  relative  humidity, that are consistent with
             normal use  characteristics; and

      (3)     The  pollutant emissions of concern are measured.

     Environmental test chambers vary in size, from small-scale
 chambers  with volumes of  less than 1.0 cubic meters (m3) to
 large-scale chambers  with volumes exceeding 15 m3.  Small
 chambers  are less  expensive to construct and operate, and allow
 greater experimental  flexibility with respect to test conditions.
 Large-scale chambers  may  simulate actual field characteristics
 more accurately  than  small-scale chambers, but are limited by
 cost,  logistical constraints, and problems with leakage.

     There  are several  major laboratories in the U.S. which use
 test chambers for  source  emission testing.  Oak Ridge National
 Laboratory  in Oak  Ridge,  Tennessee, has three chambers, with
 capacities  of 0.3, 3.3, and 17 m3.  Although Oak Ridge has the
 capability  to test a  broad  spectrum of pollutants, the focus of
 recent work has been  on emissions of radon and VOCs, particularly
 formaldehyde.  The three  chambers are constructed with different
 materials to minimize interactions with the tested pollutant: the
 VOCs are  tested  in a  stainless steel chamber, radon is tested in
 a plexiglass chamber, and the formaldehyde tests are conducted  in
 a teflon  chamber.  Broad-spectrum VOC testing has been limited  to
 a few building materials, although a variety of formaldehyde-
 containing  products are tested, including pressed wood and
 particle  board.

     EPA's  Air and Energy Engineering Research Laboratory
 (AEERL) at  Research Triangle Park, North Carolina has two sizes
 of emission  testing chambers, six with capacities of  0.05 m3  and
 two with capacities of  0.16 m3.  Most of AEERL1s efforts  are
 concentrated on VOC emissions.  AEERL has measured VOC  emissions
 from particleboard, floor adhesives, caulking compounds,  moth
 crystal cakes, wood stains, floor wax, and dry-cleaned  clothing.
This small  chamber testing  experience has lead to the development


of a draft ASTM guide on source testing.   The  laboratory  has
also cooperated with Oak Ridge National  Laboratory  in  its work
with petroleum-based solvents.  In addition, AEERL  sponsors a
large kerosene heater testing facility at Yale University, and  a
three-bedroom test house in North Carolina to  simulate normal
environmental conditions.

     AEERL has also constructed an automated emissions testing
facility,  which is used to study VOC emissions from common
building materials.  Air flow rates, temperature,  relative
humidity,  and other environmental data are controlled  and
recorded by an IBM personal computer.

     Lawrence Berkeley Laboratory,  in Berkeley,  California,
measures emissions of radon,  products of tobacco combustion,  and
combustion gases in a 25 m3 chamber.  Volatile and  semi-volatile
organic chemical emissions from gas appliances and  wood stoves
are tested in a 20 m3 chamber.  A four liter chamber is used  to
test emissions from building materials.

     Georgia Tech Research Institute,  in Atlanta,  Georgia, has  a
test chamber facility with a 25 m3 test  chamber and two smaller
0.2 m3 chambers.  The majority of the research involves VOC
source emission testing.  Tobacco smoke  emissions are  measured
with a specialized smoking machine that  can be loaded  into the
test chamber.  Georgia Tech is currently building a 25 m3 radon
testing chamber.

     The Research Triangle Institute in  North  Carolina uses a
small glass test chamber to measure formaldehyde and VOC
emissions  from building materials and electronic equipment.

     Limitations of Source Emission Testing

     There are several important limitations  to the use of
source emission data:

   o  Most source emission tests are performed with controlled
      humidity,  temperature,  ventilation, and  air flow
      characteristics.  In indoor environments, these factors
      vary dramatically over time and even within individual
      rooms.   As a result, actual pollutant concentrations
      and/or emission rates may be very  different from test
      results if the laboratory conditions do  not approximate
      actual field conditions.

   o  As textiles, building materials, and indoor combustion
      sources age, emission rates may vary-  Usually  source
      emission testing does not fully account for this
      phenomenon.  Most tests "age" the  sample to a specific
      level and test it over a short period of time.

   o  Some indoor air pollutants, especially VOCs from building
      materials and textiles, may be emitted at very low rates.
      To capture these emissions accurately may require long
      testing periods and extremely sensitive instruments,  all
      at a considerable cost.

     The costs of source emission testing vary widely depending
on the specificity of the tests, whether the experimenter has
already identified the pollutant(s) of concern, and the size and
complexity of the environmental chamber.  For example, costs for
commercial source emission testing of formaldehyde (or a narrow
spectrum of VOCs) from a single, identified source can range from
a few hundred dollars for a simple gas chromatography analysis of
a sample focusing only on the localized emissions, to tens of
thousands of dollars for conducting a broad spectrum VOC
analysis using a multi-compartment environmental chamber mock-up
of the actual setting.  Choosing the extent of the source
emission testing will depend on the importance of accuracy and
precision in the testing and on cost limitations.


     Modeling can be used to estimate pollutant exposure in
situations where direct empirical analysis is technically or
economically infeasible.  In addition, models provide a
conceptual framework for designing field experiments and for
testing our understanding of exposure.  Modeling is also an
important policy development tool, for it can be used to
estimate present and/or future pollutant exposure and the
resulting health risk under various policy or mitigation
scenarios.  There are four general categories of indoor air
pollutant models: source emission models, transport  (or indoor
air quality)  models, statistical models, and population exposure
models.  In most cases, these models are developed using
empirical data obtained from source emission testing and/or  field

     Source Emission Models

     Models that predict emissions from indoor pollutant sources
are commonly grouped into four categories  (Tucker,  1987):

   o  Combustion -- from unvented and poorly vented  appliances
      and from tobacco smoking;

   o  Material -- through emanation or evaporation  from building
      materials, furnishings, and consumer products;

   o  Activity -- direct physical contact with  sources  (e.g. the
      use of consumer or commercial products);  and

   o  External -- infiltration of pollutants from outdoor air,
      soil gas, or releases from indoor water use.

     Source emission models are generally developed from
controlled emission and transport studies in environmental test
chambers or test houses.  Exhibit 2-2 lists several of the most
recently developed source emission models.

     Combustion Sources

     A number of researchers have developed emission factors
(i.e., pollutant mass released per unit of fuel consumption) to
predict emission rates from several indoor combustion sources.
However, the age, condition, and use characteristics of indoor
combustion appliances, knowledge of which is crucial to creating
accurate emission models, are not well documented.   The VOC
emission rates from indoor combustors are poorly understood and
have not yet been modeled.  In addition, knowledge of the
cause(s), extent, and implications of leakage from vented
appliances, which is also important for modeling purposes, is
limited  (Tucker, 1987).   Lastly, emission rates for sidestream
smoke from tobacco smoking have been measured for only 100 of the
more than 4700 compounds found in sidestream smoke  (Sakuma et
al., 1984a; Sakuma et al.. 1984b).

     Material Sources

     Most of the source emission modeling for material sources
has in the past focused on formaldehyde.  The Oak Ridge National
Laboratory has developed a general organic compound emissions
model, based on a formaldehyde emissions model that used  input
variables for temperature, relative humidity, formaldehyde
transport characteristics, age and decay rate of the sample, and
formaldehyde concentration of the room and the particleboard, to
predict formaldehyde emissions per unit area of the sample
(Hawthorne and Matthews, 1987)„

     Activity Sources

     Activity sources are only qualitatively understood.  The
emission of pollutants that involve cooking, application  of
consumer products and pesticides, and the use of appliances  and
machines have not been analyzed extensively.  In one study,
however, Girman and Hodgson used a source/exposure  model  to
predict methylene chloride emissions from the use of consumer
products such as paint strippers  (Girman and Hodgson,  1986) .

                                           Exhibit 2-2
                                      Source Emission Models
  Source Type
               Independent  Variables
    Unvented appliances  NO,  NOj,  CO
               Appliance  type,  primary
               aeration level,  fuel
               consumption rate
    Tobacco smoking      ETS,  CO,  TSP   Density of  active  smokers
Temperature,  humidity,
formaldehyde in room air,
type of material
                           Relewani et al.  (1986)
                           Leaderer (1982)
                           Girman et al. (1982)
                           Borrazzo et al.  (1987)
                           Leaderer et al.  (1987)

                           Repace (1986)
                           Girman et al. (1982)
                           Sakuma et aj.. (1984a,b)
Matthews et al.  (1984)
Hawthorne et al.  (1987)
    Consumer products
Solvents       Product composition,  type
               of application
                            Girman  and  Hodgson  (1986)
    SoiI gas
Chemically     Soil gas concentration,
reactive       indoor-outdoor pressure
pollutants     gradient
                            Nazaroff  and Cass  (1986)
                            Nazaroff  et  al.  (1984)
1Exhibit 2-2 is based in part from information in EPA 1987a.

     External Sources

     Several models are available for estimating  the  effect  of
external sources on indoor concentrations.   For example,  Nazaroff
and Cass have developed a preliminary version of  a  general
mathematical model that will predict the concentrations  of
chemically reactive compounds in indoor air.   The model  accounts
for gas-phase photolytic and thermal reactions, and computes the
production rates associated with ventilation, filtration,
chemical reaction, and direct emission,  as  well as  the removal
rates associated with ventilation,  chemical reaction,
filtration,  and adsorption by walls (Nazaroff and Cass,  1986).
Models for the prediction of exhaust ventilation  on radon entry
into homes have been developed by Mowris and Fisk (Mowris and
Fisk, 1988;  Mowris, 1986)

     Indoor Air Quality (Transport) Models

     Indoor air quality, or transport, models are used to
characterize the movement of air pollutants through defined
indoor spaces.  These models provide an estimate  of the ambient
pollutant concentration in a given microenvironment under a
variety of user-specified scenarios.  Indoor air  quality models
are particularly important for complex indoor environments,  such
as office buildings, because the pollutant  concentration may vary
widely according to the pollutant transport patterns.  Important
transport models include the NBS model and  the AEERL model,  which
are discussed in this section.

     Indoor air pollutant transport patterns are  defined by the
physical pathways that conduct air from one place to another and
the pressure differences that provide the motive  forces.1
Modeling these pathways is a critical component of  developing
transport models.  Important pathways for pollutant transport
include penetrations through the building envelope, such as
through the windows, doorways, intakes/exhausts,  and cracks and
seams, that define the leakage patterns of  the building, as well
as the interior pathways, such as doorways  and
ventilating/heating ducts.  The effects of  wind,  thermal
buoyancy, and pressure differentials caused by mechanical
ventilation interact with the leakage configuration and  the
interior flowpaths to determine each building's transport

     For single-chamber models, the principal transport  process
considered is the air exchange across the building envelope.
Multi-chamber models require components that address the air
exchange for individual airspaces as well as the interior
transport among connecting airspaces.
     1This section is based on the discussion in EPA  1987a.


      NBS Multi-Zone Indoor Air Quality Model

      The Indoor Air Quality Model  Project, initiated by the
 Indoor Air Quality and Ventilation Group at the National Bureau
 of  Standards (NBS)  (now the National  Institute for Science and
 Technology,  or NIST)  has developed an indoor air quality model.
 The model is a generalized simulation program that accounts for
 pollutant generation,  dilution,  reaction, and removal as well as
 infiltration and exfiltration.   The model is currently being
 expanded to include pollutant  emissions from and absorption by
 various materials (EPA,  1988).

      AEERL Model

      The Air and Energy Engineering Research Laboratory (AEERL)
 has developed a preliminary version of an indoor air pollutant
 transport model,  which analyzes  pollutant migration patterns
 under user-specified air flow  conditions.  The model uses a basic
 pollutant mass balance equation, and  can be programmed for a
 number of indoor pollutant sources, such as cigarettes, kerosene
 heaters,  and unvented stoves,  utilizing user-specified source
 emission rates.   The output data provide estimates of the changes
 in  pollutant concentration over  time  (Sparks, 1988).

      Statistical Models

      Statistical  models  allow  the  researcher to expand the
 results of field studies to a  larger  population in the same type
 of  microenvironments as  were originally studied.  The models use
 empirical data regarding the distribution of pollutant
 concentrations,  building volumes,  air flow patterns, and other
 user-specified input data to derive estimates of the distribution
 of  pollutant concentrations on a larger scale.  All input
 parameters are assumed to fit  a  log-normal distribution.  The
 additional use of Monte  Carlo  computer simulations allows the
 distributions  to  be normal,  log-normal, empirical, or a variety
 of  other  functions  (NERDA,  and NMPC,  1985).

      Population  Exposure Models

      Population exposure models  estimate both indoor and outdoor
 exposure,  and  can be used to estimate exposure to a population  in
diverse settings.   Exposure models incorporate three types of

   o  Input data  on the  air pollutant concentration and route(s)
      of  exposure experienced by the  subject(s);

   o  The time-activity patterns of the subject(s)  during the
      exposure period; and

   o  Health or demographic characteristics of the subject(s)
      that would affect the dose received.

     Data on these characteristics are usually developed through
a combination of field monitoring, surveying or administering
questionnaires, and modeling.

     The basis for these exposure models is calculation of total
human exposure by summing microenvironmental exposures, which are
calculated by multiplying the time spent in a microenvironment
times its concentration.  Population exposure distributions can
then be calculated from microenvironment concentration
distributions as well as distributions of time activity patterns
which vary among different population subgroups.

     Complex population models are dependent on the ability of
the researcher to simulate accurately the range of human
exposure, activities, and demographic characteristics.  Exposure
modeling necessitates collecting detailed data or using broad
assumptions about these characteristics.  The strength of these
models is their ability to collapse an enormous amount of data
necessary for calculating population exposure profiles.

     Population exposure models, like all models, are inherently
limited by the tradeoffs between accuracy and cost.  For small,
relatively homogeneous populations in a limited number of
settings, reasonable accuracy is quite feasible. For large,
heterogeneous populations in diverse settings, however, accuracy
becomes more difficult to attain.  Exposure modeling becomes more
cost-effective compared to field monitoring as the scale of  the
project increases and as the required complexity of the model

     There are only a few sophisticated models that can estimate
indoor air pollutant exposure, though a number of outdoor air
pollutant exposure models have a component for estimating indoor
exposure to the outdoor pollutants.  Population exposure models
include SHAPE, PAQM, and NEM.2

     SHAPE (Simulation of Human Air Pollution Exposure)

     The SHAPE model estimates carbon monoxide exposure  to
specific individuals by using both background and
microenvironmental carbon monoxide concentrations.  Data  on
microenvironmental carbon monoxide concentrations were  obtained
from extensive field monitoring in the EPA TEAM  studies
     2This discussion is based on Pandian  (1987).


conducted  in  Denver, Colorado, and Washington, D.C.   The model
assumes that  the background carbon monoxide concentrations of the
indoor and outdoor  environments are constant over specified time
intervals  and that  the microenvironmental concentrations are
additive.   The total microenvironmental exposure is derived by
summing the individual microenvironment exposures (the product of
the pollutant concentrations to which an individual is exposed
multiplied by the duration of exposure) experienced during daily
activities.   The model uses U.S. Census data to estimate
demographic information  for the involved individuals.  The
exposure and  dosage estimations are based on a human activity

      SHAPE focuses  mainly on characterizing the population,
exposure,  and dosage based on user-specified data on background
and microenvironmental carbon monoxide concentrations — SHAPE
does  not use  dispersion  models to estimate carbon monoxide
concentrations.  Values  of demographic variables are determined
from  probability distributions, which are also user-specified.
Moreover,  SHAPE only estimates carbon monoxide exposure; it does
not assess health risks.

      PAQM  (Personal Air  Quality Model)

      PAQM  uses an hourly sequence of outdoor pollutant
concentrations to compute the indoor concentrations that would be
induced within each of several specified building types.  The
model uses simple mass balance equations and compensates for
leakage and mechanical ventilation.  PAQM also estimates the
exposure of user-specified individuals as they undergo their
typical pattern of  daily activities, moving between  indoor and
outdoor environments.

      NEM (National  Ambient Air Quality Standards Exposure

      NEM was  developed by EPA to assess total human  exposure  to
pollutants  regulated under Section 109 of the Clean  Air Act.  NEM
is a  simulation model capable of estimating human exposure to
ambient pollutants  as people move through time and space  as  they
undertake  their usual activities.  Indoor exposures  are accounted
for by adding microenvironment-specific concentrations  to  that
portion of  outdoor  air that enters the indoor environment. A
version of  NEM is available  (on a PC)  that explicitly
incorporates  air exchange rates and other indoor
microenvironmental  characteristics.


      Field  measurement involves two components:  (1)  collecting  a
sample of  the medium in  which the pollutant  is typically
transported,  e.g.,  air for most indoor pollutants,  and  (2)


analyzing the sample to identify the pollutant(s)  and measure the
concentration(s).   In addition,  field monitoring may measure the
factors that affect pollutant dispersion,  such as humidity,  the
air exchange rate, the concentration of the pollutant of concern
in the surrounding outdoor air,  and the pollutant infiltration

     Types of Measurement Instruments

     Important technical considerations for selecting measurement
instruments (monitors) are:  sampling mobility, operating
characteristics, output characteristics, space and power
limitations, noise levels, and analytical requirements.3  There
are three classes of sampling mobility:

   o  Personal — the monitor may be worn or hand-held;

   o  Portable —• the monitor may be hand-carried; and

   o  Stationary — the monitor must be operated from a fixed

     Within each class of sampling mobility, monitors can be
classified as either active or passive, depending on whether a
power source is required for sample collection.  Most active
monitors use a pump or blower to collect the sample by absorbing
the sample in a liquid medium or onto a solid surface.  Active
monitors can be used for either gaseous or particulate matter.
Passive monitors either diffuse the sample directly into a
collection medium or diffuse across a permeable membrane to a
collecting medium.  Passive monitors are used primarily for
measuring gaseous pollutants.  Passive monitors can also be used
for particulate matter, but because they collect only the
particles which fall out of suspension, passive monitors may not
accurately estimate the total airborne particulate matter

     Lastly, within each mobility and operating class, the
output characteristics fall into two categories:

   o  Analyzer —  the monitor produces an instantaneous  (or
      nearly instantaneous)  signal that corresponds to the
      pollutant concentration or parameter that is being
      measured;  and

   o  Collector — the sample is collected by the unit and
      subsequently analyzed in the laboratory.
     'This discussion is based on Nagda et al., 1987.


     Other considerations in selecting the appropriate field
monitoring instruments include cost, availability,  convenience of
use, and desired level of accuracy.  Another important factor is
whether the pollutant of concern poses the greatest risk from
acute or chronic exposure.  Toxic pollutants that cause adverse
health effects only above a threshold dose should be monitored
with an analyzer if the pollutant concentration varies
significantly over time.

     Pollutant-Specific Measurement Ins-famm^n-ha

     A wide variety of monitors are available for the major
indoor air pollutants.  These monitors range in size and
complexity from small personal exposure monitors (PEMs) to large,
stationary continuous analyzers.  Some of these devices can be
operated by an untrained individual; others require the services
of a trained professional.

     For a number of the major pollutants, EPA and/or other
organizations have developed protocols that standardize the
monitoring procedures.  EPA is drafting a Compendium of Methods
for the Determination of Air Pollutants in Indoor Air, which when
completed will provide regional, state, and local environmental
agencies with available protocols for measuring selected indoor
air pollutants (EPA, 1987b).  For other pollutants, however,
generally accepted protocols have not yet been established.  In
this section, we summarize the measurement instruments that are
currently available for the major indoor pollutants, and briefly
discuss the generally accepted measurement protocols that address
their use in the field.

     The number and diversity of the commercially available
indoor air pollution measurement instruments precludes a detailed
discussion in this report.  Nonetheless, in Exhibit 2-3, we have
provided a brief summary of the available monitors  for the major
pollutants; a more detailed summary is included in  Exhibit  2-4.

     Measurement Protocols


     EPA has developed interim protocols for measuring radon  and
radon decay products  (EPA, 1987c).  EPA recommends  a  two-step
strategy, beginning with a screening measurement made  under
closed-house conditions in an area where radon  concentration is
expected to be greatest (usually the basement or ground level).
Depending on the results of the screening measurement,  a second
series of follow-up measurements may be required to assess more
completely the average concentrations  in the  living areas of the

                                Exhibit 2-3
 Types of Available Measurcaent Instruments by Pollutant  (Nagda et al.. 1967)
                              Active Passive  Active Passive  Active Passive
Col lector
B i oIog i caI
Carbon monoxide
Nitrogen dioxide

                                                                               E«hibit 2-4
                                                                           Available Monitors (Hagda,  1987)

               Biological Contaminants
               Carbon Monoxide


Persona I/Ac t i ve/AnaIyzer

Stat i onary/Act i ve/Analyzer

Fortable/Ac t i ve/AnaIyzer




S tat i onary/Pass i ve/ColIec tor



Stat i onary/Ac t i ve/Collector

Stationary/Active/Col leetor

PersonaI/Passive/CoI lector

S ta t i onary/Ac t i ve/Analyzer

Persona I/Passive/Co Hector

Persona I/Passive/Co Hector

Por table/Ac t i ve/AnaIyzer


Per sonaI/Pass i ve/AnaIyzer


500 Series, Alpha PRISM System

RGM-2, Radon Gas Monitor

Working Level Monitor

RDA-200, Radon/Radon Daughter

RGA-400 Radon Gas Monitor



Radon Daughters Analyzer

Track Etch, Radon Detector

#10-800, Viable Sample Kit

#10-850, Tyo-Stage Microbial  Sampler

PF-1, HCHO Passive Monitor

TGM 555, Formaldehyde Analyzer

PRO-TEK, HCHO Passive Dosimeter,
Type C60

Formaldehyde Monitor 3750

FAM-1, Fibrous Aerosol Monitor

2000 Series, CO Analyzer

Model 210,  Personal CO Monitor

 AeroVironment,  Inc.

 Alpha  Nuclear

 Eberline  Instrument Corporation

 Eberline  Instrument Corporation

 EDA  Instruments,  Inc.

 EDA  Instruments,  Inc.

 EDA  Instruments,  Inc.

 EDA  Instruments,  Inc.

 Harshaw Chemical Company

 Terradex Corporation

Andersen Samplers, Inc.

Andersen Samplers, Inc.

Air Quality Research,  Inc.

CEA Instruments, Inc.

Du Pont Applied Technology

3M Company

GCA Corporation

Energetics Science,  Inc.

Energetics Science,  Inc.

                                                                         Exhibit 2-4 (continued)
                                                                        Available Monitors (Nagda et ml..  1987)

                Carbon Monoxide

 Persona I/Active/Analyzer

 Por table/Ac t i ve/AnaIyzer

 Persona I/Passive/Analyzer
                                                                                 CO Detector

                                                                                 Models 1KO and 4140 CO Analyzers

                                                                                 Model 5140 CO Analyzer and CX-5
                                                                                 Data Interface
                                              General Electric Company

                                              InterScan Corporation

                                              InterScan Corporation
                Nitrogen Dioxide
 Persona I/Passive/Col tector


 Portable/Ac 11ve/AnaIyzer

 PersonaI/Passive/Col leetor


 Por table/Ac t i ve/Analyzer

 Persona I/Passive/Analyzer

Air Check, N02 Home Test Kit

TGM 55, W02
                                                                                 Model 2200, Portable WOX Analyzer
PRO-TEK, NO-, Passive Dosimeter Type

2000 Series, NOj Analyzer

Models 1150 and 4150, N02 Analyzers

Model 5150, N02 Analyzer and CX-5
Data Interface

M02 Badge
Air Quality Research,  Inc.  Int.

CEA Instruments, Inc.

Columbia Scientific Industries

Du Pont Applied Technology

Energetics Science, Inc.

InterScan Corporation

InterScan Corporation

Micro Filtration Systems
               Participate Natter
PersonaI/Pass i ve/Analyzer


Persona I/Pass i ve/AnaIyzer

Stationary/Active/Col leetor



Por table/Ac t i ve/AnaIyzer
Stat i onary/Act ive/Analyzer
MINIRAH Aerosol Monitor

RAM-1, Aerosol Monitor

Handheld Aerosol Monitor

Oichotomous Sampler, Series 241

Medium Flow Samplers, Series 254

Marple Personal Cascade Impactor

Piezo Balance, Model 3500/Modet 5000
GCA Corporation

CCA Corporation

PPM, Inc.

Sierra-Andersen,  Inc.

Sierra-Andersen,  Inc.

Sierra Instruments,  Inc.

TSI, Incorporated

      If  the  screening measurement result is less than about four
pCi/1, or  0.02 WL,  follow-up measurements are probably not
required.  If the  result  of the screening measurement is less
than  about 20 pCi/1, or 0.1 WL, but greater than about 4 pCi/1,
or  0.02  WL,  EPA  recommends that the follow-up measurement consist
of  an integrated measurement or series of measurements over a
12month  period made in the general living areas of the house.
These levels are not high  enough, however, to warrant immediate
action.  If  the  screening measurement result is greater than 20
pCi/1, or  0.1 WL,  EPA recommends a more intensive follow-up
measurement, because concentrations could cause a significant
increase in  health risk  (EPA,  1987d).

      EPA has established  a Radon/Radon Progeny Measurement
Proficiency  Evaluation and Quality Assurance Program to evaluate
the companies offering radon measurement services.  Currently,
EPA recognizes the use of  a number of different types of radon
monitors and accompanying measurement protocols.  These monitors
include  alpha-track detectors, charcoal canisters, radon progeny
integrating  sampling units, continuous radon monitors, continuous
working  level monitors, and grab sampling devices (see EPA,
1987c; EPA,  1987d).

      Environmental Tobacco Smoke

      ETS is  not  typically measured directly.  ETS is difficult
to  measure in indoor microenvironments because it is a complex
mixture  of constituents, many  of which may also arise from other
sources.   Moreover,  it is  not  practical, or even possible, to
measure  the  full range of  ETS  constituents, even under
laboratory conditions.  As a result, most studies of ambient ETS
concentrations have instead focused on single constituents of ETS
as  proxies for total ETS  concentration.  Proxy constituents have
included nicotine,  carbon monoxide, particulate matter, aromatic
hydrocarbons, and  various  tobacco-specific chemicals.
Monitoring these constituents  is described in the relevant
sections below.

      EPA has developed a protocol for determining the nicotine
concentration in indoor air  (EPA, 1987b).  The method is based  on
the collection of  nicotine by  adsorption onto a sorbent resin  or
acidic surface.  Gas chromatography separation with  nitrogen-
phosphorous  detection is  employed for analysis.

      Biological  Contaminants

     A common method for  sampling biological contaminants  is
gravity  collection,  either on  culture plates or adhesive  slides.
As  it monitors only the particles that fall out of  suspension,
this method  is not  volumetric, and produces a qualitatively
biased picture of  the air  spora.


     Volumetric sampling (in which a measured quantity  of  air is
collected and analyzed)  includes two general  types:  1)  viable or
cultural methods in which microorganisms are  collected  and grown
under given conditions,  and 2)  particle methods in which
biological particles are visually counted and identified or
biochemically or immunologically analyzed.

     Cultural methods are useful when information on viability
is essential (e.g., for infectious agents),  or if the biological
organisms must be cultured to be identified  (e.g., actinomycetes,
bacteria, viruses,  and many fungi).   The choice of culture media
for these samplers is, therefore, critical.

     Particle sampling is the method of choice when total
biological particles are being assessed or when biological
products (toxins, antigens) are being measured.  Total fungal
spore counts can be conducted using microscopic counting.   Newer
methods using fluorescent staining may enable counting of
bacterial particles as well.  Biochemical or immunological
analysis of particulate samples is especially useful when known
contaminants are to be analyzed.  These methods have been used
for airborne endotoxins, mycotoxins, and a variety of antigens
(e.g., mites and thermophilic actinomycetes).  Sampling for
particles to be analyzed biochemically or immunologically
requires, however,  advance knowledge of the  compounds of
interest.  These methods are not useful for  surveys of general
biological contamination.

     Volatile Organic Compounds

     Most VOCs can be identified and quantified with gas
chromatography and mass spectrometry.  In gas chromatography, the
sample is vaporized and injected into a column containing a
liquid or particulate solid.  The column separates the sample
into its component compounds according to their affinity  for the
contents of the column.   Mass spectrometry,  a more expensive
procedure, separates the gaseous sample into its component
compounds according to their differing mass  and charge.

     A significant portion of early monitoring studies  for VOCs
have utilized Tenax-GC sorbent tubes to collect these compounds.
This sorbent suffers from many problems associated with artifact
formation, limited capacity for the more volatile compounds
(e.g., vinyl chloride and methylene chloride) and for the polar
VOCs (e.g., acrylonitrile and ethylene oxide), and variable
background contamination.  Particular problems occur with
toluene,  benzene, and, to a lesser extent, styrene, chloroform,
and 1,1,1-trichloroethane, all of which are prevalent  indoor air

     Despite the limitations of Tenax, a monitoring system was
successfully employed during 1979-85 in the EPA TEAM studies


 involving  600 residents in four states.  Battery operated pumps
 capable of 12-hour continuous operation were used to sample air
 through a  cartridge containing Tenax.  The pump and cartridge
 were carried in a specially-designed vest worn by the test

     Canister-based collection systems have recently been under
 development because of the increasing concerns over the
 reliability of VOC data obtained with Tenax-based monitors.
 Canister systems use stainless steel canisters which have
 specially  electropolished interiors.  This process, known as
 SUMMA polishing, makes the interior walls of the canister less
 reactive,  which substantially improves the storage capacities for
 VOCs (up to 30 days).

      EPA  has designed a protocol for sampling and analysis of
 VOCs in indoor air  (EPA, 1987b).  The method collects VOCs in
 SUMMA canisters for subsequent analysis with gas chromatography.

     Portable gas chromatographs are also available for on site
 analysis.  Gas chromatographs may be used to analyze many
 different  pollutants singly or in combination.


     Two methods can be used to measure asbestos in air: optical
 (or light) microscopy, and electron microscopy-  Measurements of
 low-level  air pollution from asbestos rely on the much higher
 resolution obtained from electron microscopy.  Higher resolution
 is needed  in this situation for two reasons.  First, asbestos
 constitutes a small fraction (only 0.0001% to 1%) of the
 particulate matter in a given air sample.  Second, the vast
 majority of fibers in ambient air are too thin to be seen with
 optical microscopy.

     Optical microscopy is the major technique used to determine
 levels of  asbestos in occupational settings, where the size
 distribution of asbestos fibers is generally larger and the
 proportion of asbestos fibers to total fibers is higher.  Using
 standard optical microscopy procedures, only fibers longer than  5
 urn are measured; electron microscopy allows the enumeration  and
 sizing of  all asbestos fibers  (EPA, 1986).

     Samples for electron microscopy are  collected on 0.4 urn
 (polycarbonate) or 0.8 urn (cellulose ester) filters and counted
 either directly, after dissolving the  filter media, or
 indirectly, following the ashing of the filter in  a furnace.
Many earlier analyses by the indirect method resulted  in
breakdown  of the individual fibers, with  the loss  of  information
on the distribution of fiber size,,  For those analyses,  air
concentrations were reported in terms  of  mass  (e.g.,  ng/m3)
rather than fiber counts (e.g., fibers/ml)  (EPA,  1986).


     Because carcinogenic risk estimates for asbestos are based
on occupational exposures (in optical microscopy measures of
fibers longer than 5 um), exposure data obtained by electron
microscopy must be converted to the related optical fiber counts
to assess risk.  However, the range of conversion factors varies
30-fold in relating optical fiber counts to electron microscopy
mass measurements-  In addition, direct measurements of electron
microscopic fiber counts longer than 5 um cannot be directly
converted to optical microscopy counts because a large number of
fibers are undetected by optical microscopy (EPA, 1986) .

     Combustion Gases

     The most common method for continuous carbon monoxide
monitoring in indoor air is based on non-dispersive infrared
(NDIR) spectroscopic detection.  Although sensitive enough for
typical indoor air concentrations, NDIR instruments are too bulky
and complex for personal exposure monitoring.   To address this
need, carbon monoxide personal monitors have been developed, most
of which are based on electrochemical detection; that is, they
employ a liquid or solid electrolyte in which carbon monoxide is
converted to CC>2,  thereby generating an electrical signal.  The
signal is proportional to the quantity of carbon monoxide present
in the gas stream, and the continuous electrical signal is either
recorded internally or displayed on a digital readout system.

     The most promising electrochemical personal exposure monitor
was developed by the General Electric Company and was used in the
EPA TEAM pilot studies in Denver, Colorado in 1982-83.  While
this active monitor functioned well, it required daily servicing.
For a large survey, use of this or similar active monitors would
incur prohibitive costs.  A sensitive and reliable passive carbon
monoxide monitor has not yet been developed.

     Two main passive devices are available for measuring
exposure to N02: the Palmes tube and the Yanagisawa badge.  These
devices rely on N02 diffusion to and reaction with
triethanolamine, forming a stable complex for subsequent
analysis by spectrophotometry.  Considerable progress has been
made in the development of portable real-time N02 monitors, based
on the chemiluminescent (light-producing) reaction between N02
and luminol.  Recent research and development sponsored by  EPA
has led to the commercialization of a small, light-weight
monitor.  A prototype electrochemical sensor system was  recently
developed by a private company with EPA support.  Two  active  N02
monitors are currently being tested for indoor  sampl:'

     Particulate Matter

     Particle samplers for outdoor air monitoring are  large,
noisy, and cumbersome to use.  Some continuous particle  monitors
are available (i.e., the piezo balance),  but are large and
complex for indoor monitoring.  Generally,  particle samplers  have
poor sensitivities and/or unknown accuracy  at the low  particle
concentrations found in non-occupational  settings.   The  newly
developed 4 and 10 1pm samplers have been documented to  be
reliable when compared with standard ambient monitoring

     Limitations of Measurement Methods

     Recent scientific advances have considerably increased the
accuracy of sampling and analytical methods.  Accurately
measuring indoor air pollutant levels, however, remains  limited
by a number of factors:

   o  The concentrations of some indoor air pollutants are  often
      too low to generate accurate and reproducible results,
      given current monitoring technology.   Although sampling
      techniques are being developed quickly in response to
      growing public concern over indoor air pollution,  standard
      technical measurement methods are needed for several  of the
      major pollutants to ensure consistency-

   o  Although sampling and analytical methods for biological
      aerosols are available, insufficient  knowledge of
      background levels makes interpreting  the results difficult
      (Knoppel,  1987).

   o  The concentration of many indoor pollutants varies
      significantly within and between rooms.  This complicates
      the association between measured concentrations and actual
      human exposure.  The use of personal  exposure monitors
      circumvents this problem by directly  measuring personal

   o  Other chemical compounds may interfere with the
      measurement process.  For example,  nitrogen oxides
      interfere with the measurement of carbon monoxide, and ETS
      interferes with the measurement of nitrogen oxides (Wadden
      and Scheff, 1983).

   o  The costs of large scale field monitoring studies may  be
      prohibitive, particularly when they involve the
      development and administration of surveys, and
      sophisticated research measurements.


     As noted above,  in most cases,  estimating or predicting
exposure to indoor air pollutants is an integrated procedure.
Most sophisticated indoor air pollutant models use the  data from
source emission testing and field monitoring to calibrate and
verify the components of the model being developed.   Although
indoor air quality modeling is still an emerging field, it can
provide useful estimates of indoor air pollutant concentrations
in specific settings and under specified conditions,  and  is
useful in predicting the effectiveness of various policy  or
mitigation alternatives.  Field monitoring is needed to collect
actual, site specific concentrations or concentration


     Many studies in which indoor air pollutants were measured
have been conducted.  The results of these studies provide
valuable insights into the extent of the potential health risks
posed by exposure to indoor air pollutants.  There are, however,
many gaps in the current knowledge regarding the scope and
magnitude of the average and peak exposures to indoor air
pollutants.  In this section, we summarize some of the efforts to
characterize indoor air pollution concentrations and/or measure
actual personal exposure to these pollutants.

     Summary of Reported Concentrations in Indoor Environments

     Many researchers have characterized indoor air quality for
a wide variety of pollutants  (Exhibit 2-5).  Most of these
efforts have been directed toward determining average  or typical
pollutant levels. However many studies have focused on measuring
pollutant levels in "sick buildings" or other microenvironments
with elevated concentrations of certain pollutants.  Comparison
and interpretation of different studies is made difficult  by  the
disparity of methodologies used, and the limited  reporting of
quality assurance procedures, particularly in some of  the  earlier
studies. In addition, there  is great variability  in indoor air
pollutant concentrations, both within and  across
microenvironments, depending on a multitude of  factors,  as
described in previous chapters.

     The studies reported here are  not meant  to be  representative
of typical indoor concentrations, or the  range  of concentrations.
Providing a representative data base  for  indoor air pollutant
concentrations is beyond the  scope  of this report.  The  studies
do demonstrate, however, that a wide  spectrum of indoor  air
pollutants are present  in most indoor environments.


                                                     Exhibit 2-5
                               Sumaty of Reported Indoor Air Pollutant Concentrations
Measured Concentration
Pollutant Minimum Maximum
0.5 pCi/l 2000 pCi/l
0.14 pCi/l 4.11 pCi/l
0.3 pCi/l 1.68 pCi/l
ETS (as RSP)
(as nicotine) --
0.8 pCi/l

1.7-2.4 pCi/l
28 ug/m3 (1)
74 ug/m3 <2>
32 ug/m3 (3>
50 ug/m3 (A)
0.7-3.2 ppb
Type of
Bui I ding
New pub. bldgs.
Old pub. bldgs.
3 office bldgs
3 office bldgs
EPA (1987d)
EPA (1987b)
Sheldon et al .
Sheldon et al .
Bayer & Black
NRC (1986b)
NRC (1986b)
DHHS (1986)
DHHS (1986)
Bayer & Black


564-5360 CFU/m3  <5)
3 office bldgs    Bayer & Stack  (1988a)
VOCs (see also Exhibits  2-6,  2-7,  and 2-8)

Carbon tetra-
D i ch lorobenzenes
ND not detected;
131-319 ug/m3
NO 192 ppb
ND 103 ppb
120 ug/m3
14 ug/m3
47 ug/m3
250 ug/m3
200 ug/m3
1200 ug/m3
CPU = colony forming units
78-144 ug/m3
25-39 ppb
20 ug/m3
2.5 ug/m3
3.6 ug/m3
10 ug/nr
8 ug/m3
41 ug/nr

New pub. bldgs.
Old pub. bldgs
3 office bldgs

Hawthorne et al. (1984)
Sheldon et aU. (1987)
Sheldon et al. (1987)
Bayer & Black (1988a)
Wallace et al . (1983)
Wallace et al. (1983)
Wallace et al. (1983)
Wallace et al. (1983)
Wallace et al. (1983)
Wallace et al. (1983)

      73 residences without  smokers
      28 residences with  smokers

      Nonsmokers  not exposed to ETS

      Nonsmokers  exposed  to ETS

      Simation of  mesophilic bacteria,  fungi,  and  thermophilic  bacteria


                                           Exhibit 2-5  (cant.)
                         Sunary of Reported Indoor Air Pollutant Concentrations
Measured Concentration Type of


Contusticn gases
Carbon monoxide

Nitrogen dioxide

Particulate matter

ND not detected;



O.OU ug/m3

0.89 ppm
10 ppb
2 ppb

trace (IP)
trace (RP)
4.1 ug/m3 (IP)
3.5 ug/m3 (RP)
IP = inhalable
Maximum Mean Building
320 ug/m3 13 ug/m3 Various
12 ug/m3 4.4 ug/m3 Residences

49 ug/nr 7.8 ug/m3 Various
120 ug/m3 21 ug/nr Various
54-697 ug/m3 17-44 ug/m3 Residences
58-655 ug/m3 27-62 ug/m3 Residences

15 ug/nr 2.4 ug/nr Residences
8.8 ug/nr 1.4 ug/m3 Residences
1.7 ug/m3 0.51 ug/nr Residences
0.66 ug/nr 0.23 ug/nr Residences
0.31 ug/m 0.89 ug/nr Residences

3.1 ppm -- Old pub. bldgs
<2 ppb 3 office bldgs
49 ppb -- Elderly home
70 ppb -- Older pub. bldgs

53.3 ug/m3 (IP)-- New pub. bldgs
52.8 ug/m3 (RP)-- New pub. bldgs
26.7 ug/m3 (IP)-- Old pub. bldgs
55.5 ug/m3 (RP)-- Old pub. bldgs
0.04-.57 mg/m3 3 office bldgs
74 ug/m3 (IP) -- Various
100 ug/m3 (RP) -- Various
24.4 ug/m3 <6)Residences
36.5 ug/m3 (7)Residences
70.4 ug/m3 (8)Residences
Wallace et al. (1983)
Hawthorne et al. (1984)

Wallace et aU (1983)
Wallace et al. (1983)
Hawthorne et al. (1984)
Hawthorne et al. (1984)

Lewis et al. (1986)
Lewis et al. (1986)
Lewis et al. (1986)
Lewis et al. (1986)
Lewis e_t al. (1986)

Sheldon et al. (1988)
Bayer & Black (1988a)
Sheldon et al. (1988)
Sheldon et al. (1988)

Sheldon et al. (1988)
Sheldon et aU (1988)
Sheldon et al. (1988)
Sheldon e_t al_. (1988)
Bayer & Black (1988a>
Sheldon et al. (1988)
Sheldon et al. (1988)
Spengler & Ferris (1985)
Spengler & Ferris (1985)
Spengler & Ferris (1985)
(coarse) particles; RP = respirable (fine) particles.
RP concentrations  in  55  homes, no smokers
RP concentrations  in  55  homes,  1  smoker
RP concentrations' in  55  hones, 2 smokers

     Monitoring in and Around Public Access Buildings

     In a project for EPA's Environmental Monitoring and Support
Laboratory in Research Triangle Park, NC, Sheldon  et al.
monitored the air in and around a variety of public buildings,
and measured the emission rates of chemicals from  building
materials used in one of the same buildings (Sheldon et al.,
1987).  The researchers compared the emission testing data with
the field monitoring data and reported activities  in the
buildings in order to relate potential sources with measured
pollutant levels.

     The pollutants in the study included VOCs,  nitrosamines,
pesticides/PCBs, particles, polynuclear aromatic hydrocarbons,
metals, formaldehyde, radon, carbon monoxide,  nitrogen dioxide,
and asbestos.  Six buildings were sampled: a new hospital,
office, and nursing home, and an older office, office/school, and
nursing home.  The new buildings were monitored immediately (one
to four weeks) after construction and again one or two times
after occupancy.  Each building was sampled at three  indoor
locations and one outdoor location.  Twelve hour air exchange
rate measures were made in parallel with sampling  for  target

     The sampling results are summarized in Exhibit  2-6.  Radon
levels  at all buildings were generally low (<2.0 pCi/1).  Only
one sample,  collected at the new office, showed an elevated level
of 4.11 pCi/1.

   The  VOC data show several interesting trends:

   o  The new buildings showed very high levels of VOCs
      immediately after construction; these levels decreased
      dramatically during subsequent field monitoring trips.

   o The major indoor air pollutants in  the new buildings
     monitored immediately after construction were the
      aliphatic hydrocarbons. Levels of  the aliphatic
     hydrocarbons in the older buildings were quite  low, while
     the mean outdoor concentrations were below the
     quantifiable limit in all cases.

   o Although the aromatic hydrocarbons were ubiquitous,  they
     were also found in the highest concentrations in  the new
     buildings immediately after construction.

   o Mean indoor concentrations for chlorinated hydrocarbons
     were highest for the existing  office building,  presumably
     from the use of solvent-based  cleaning  products.

                                            Exhibit 2-6
                     Indoor Air Quality Honitoring Data (Sheldon et al.. 1987)
Building       Pollutant           Hin            Max          Mean      Std Dev
New Public BuiIdings
               Radon               0.14 pCi/l     4.11 pCi/l
               ETS                 NT
               Biological          NT
               Total  VOCs          --             --           21-1100 ug/m3--
                 Aromatic hydrocarbons            •-           11-270  ug/nr  -
                 Aliphatic hydrocarbons           --           4.7-810 ug/nr--
                 Chlorinated hydrocarbons         •-           3.9-56  ug/nr  -
                 Oxygenated hydrocarbons          --           ND-9.6  ug/nr  -
Carbon monoxide
Nitrogen dioxide

Older Public Buildings
Total VOCs
trace (IP)
trace (RP)

0.3 pCi/l

Ararat ic hydrocarbons
Aliphatic hydrocarbons
Chlorinated hydrocarbons
Oxygenated hydrocarbons
Carbon monoxide
Ni trogen dioxide

0.89 ppm
2 ppb
4.1 ug/m3 (IP)
9.9 ug/m3 (RP)
192 ppb
20 ng/m3

53.3 ug/m3 (IP)--
52.8 ug/m3 (RP)--

1.68 pCi/l

18-130 ug/m3
12-74 ug/m3
1.9-18 ug/m3
4.1-46 ug/m3
NO-4.3 ug/m3
103 ppb
43 ng/m3
3.1 ppm
70 ppb
26.7 ug/m3 (IP)--
55.5 ug/m3 (RP)--







    not tested; MO = not detected; IP - inhalable (coarse) particles;  RP  -  respirable (fine) particles.

      Formaldehyde  levels were highest in the new buildings.   The
 researchers  concluded that the formaldehyde (and the a-pinene)
 had  outgassed  from furniture that had been recently moved into
 the  buildings.  The pesticide concentrations were low (23 ng/m3
 and  below),  because most of the pesticides targeted for
 monitoring had not been applied in the buildings.

      In areas where there was no smoking, indoor particle
 concentrations were generally lower than outdoor concentrations
 for  both  inhalable (course) and respirable (fine) particulates.
 This is not  surprising since all buildings had mechanical
 Carbon monoxide levels ranged from 0.89 to 3.1 ppm; nitrogen
 dioxide levels ranged from 2 to 63 ppb.  There were no general
 trends in the combustion gas data.

      Air  exchange  rates were generally within the range of 0.3  to
 0.6  air changes per hour.  Air exchange rates at night were
 generally less than during the day.

      Indoor  Air Quality Evaluations of Three Office Buildings

      In a project  supported by ASHRAE and EPA, Bayer and Black
 conducted monitoring analyses at three office buildings, focusing
 on three  parameters:  (1) ventilation effectiveness,  (2) human
 health and comfort factors, and  (3) air pollutant concentrations
 (Bayer and Black,  1988a).  The first building was a 6000 square
 foot three story building approximately one year old. It had been
 designed  to  incorporate special construction and furnishing
 features  in  order  to optimize indoor air quality and to minimize
 the  levels of  indoor air pollutants.  The second building was
 used as the  control building.  It was a 12,000 square foot three
 story building of  approximately the same age as  building 1.
 However,  it  had been constructed without the special efforts used
 in building  1 to minimize the level of indoor air pollutants.
 The  third building had been associated with adverse health
 symptoms.  It was  a 57,800 square foot three story building
 approximately six  years old.

      Bayer and Black evaluated air quality by assessing  personal
health and comfort, ventilation effectiveness, environmental
conditions,  i.e.,  temperature and humidity, and  concentrations  of
ten  pollutants.  The pollutants were formaldehyde  and  other
VOCs, nicotine, particles, nitrogen dioxide, carbon  monoxide,
carbon dioxide, biological contaminants, trace metals,  and  radon.
The  results  of the pollutant analyses  are presented  in
Exhibit 2-7.

                                           Exhibit 2-7
                   Indoor Air duality Monitoring 0«t« (Bayer and Black. 1988a,b)
Building Pollutant Min
8ui Iding 1
ETS (as nicotine) --
Total VOCs
Pesticides NT
Asbestos NT
Carbon monoxide
Nitrogen dioxide
Bui Iding 2
ETS (as nicotine)
Total VOCs
1,1, 1-Trichloro-
Pesticides NT
Asbestos NT
Carbon monoxide
Nitrogen dioxide
Max Mean

2.4 pCi/l
0.07 ppb
5360 CPU (total)
237 ug/m3
25 ppra

31.0 ug/nc
14.9 ug/nc
1.16 ug/nc
3.66 ug/nc
7.84 ug/nd
1.42 ug/nc
4.70 ug/nr
0.52 ug/m5

<2 PPH
4 ppb
0.04 mg/nr

2.0 pCi/l
0.34 ppb
1580 CPU (total)

401 ug/m3
30 ppm

14.8 ug/nc
12.9 ug/nc
4.60 ug/nc
10.6 ug/nc
48.7 ug/nd
19.2 ug/nc
68.7 ug/nr
0.02 ug/nr

<2 PPH
12 ppb
0.57 mg/nr
Std Oev

1 pCi/l
1 ppb
182 ug/m3
5 ppm


3 ppb
0.02 mg/nr

1 pCi/l
1 ppb

653 ug/m3
9 ppm


4.8 ppb
1.3 mg/mr
NT - not tested;  CFU  = colony forming units

                                        Exhibit 2-7 (cant.)
                    Indoor Air Quality Monitoring Data  (layer and Black, 19B8a)
                                                                             Std Oev
BuiIding 3
               ETS  (as nicotine)
               Total VOCs
               Carbon monoxide
               Nitrogen dioxide
                                                1.7 pCi/l
                                                3.2 ppb
                                    564 CPU  (total)

                                                1090 ug/irr
                                                39 ppn

                                                214 ug/m3,
                                                43.2 ug/rr
                                                17.2 ug/n
                                                16.8 ug/n
                                                98.7 ug/n
                                                37.6 ug/n
                                                68.1 ug/n

                                                0.02 ug/m3
                                                <2 PPM
                                                8 PPb    ,
                                                0.12 mg/nr
                                               2 ppb
                                               4 ppm
                                                3 ppb
                                                0.16 g/nr
NT = not tested; CFU * colony forming units

     Bayer and Black formulated a number of  conclusions  regarding
 the  indoor air quality at the three buildings  (Bayer  and Black,

   o   The pollutant concentrations of nicotine,  particles,
       formaldehyde, NO2 ,  and total VOCs were lowest in Building
       1, which had been constructed to optimize  indoor air
       quality.  The low nicotine and particle  concentrations
       were attributed to the absence of smoking  in the building.
       The use of electricity-generated heat, and natural
       materials for construction materials,  furnishings, and
       upholstery in this building contributed  to the low N02
       levels  (natural materials are more efficient sinks for
       N02)•  The measures taken to reduce or eliminate the use
       of formaldehyde in the building did not  significantly
       reduce formaldehyde levels relative to the other two
       buildings.  The high total levels of biological
       contaminants were probably caused by a flood that had
       occurred on the first floor prior to the field monitoring

   o   In Building 2, the control building, VOC,  trace metal, and
       particle concentrations were highest in the graphic arts
       area.  The elevated N02 levels were linked to the use of a
       gas-fired heating system.

   o   Elevated VOC levels were the most significant finding in
       Building 3, which had been the subject of occupant

     Total Exposure Assessment Methodology Studies (TEAM)

     Measuring indoor air pollutant concentrations provides
 important data on the extent of contamination in major
microenvironments.  The potential impact of pollutants  on human
health, however, also depends on the amount of time  individuals
spend  in the presence of these pollutants.  Accordingly,  actual
human  exposure to these pollutants has become the  focus of  recent
research efforts.  A number of studies have estimated actual
pollutant exposure through a combination of field  monitoring  and
exposure assessment.  The most extensive of these  research
efforts have been the EPA Total Exposure Assessment  Methodology
 (TEAM)  studies.

     In 1979, EPA began the Total Exposure  Assessment Methodology
 (TEAM)  studies to directly measure human  exposure  to pollutants,
largely focusing on VOCs  (Wallace, 1987) .   This  program developed
methods to measure individual total  exposure  and the resulting
body burdens of toxic and carcinogenic  chemicals.   The  main TEAM
study  involved 600 participants  from New  Jersey,  North  Carolina,
North Dakota, and California.  These participants  were  chosen to


represent a total population of 700,000 residents.   Each
participant carried a personal air sampler throughout a normal
24-hour day, collecting a 12-hour daytime sample and a 12-hour
overnight sample.  Identical samplers set up near some
participants' homes measured the outdoor ambient air.  Each
participant also collected two drinking water samples.  At the
end of the 24 hours,- each participant contributed a sample of
exhaled breath.

     All air, water, and breath samples were analyzed for 20
target VOCs.   Eleven of the target chemicals were prevalent in
the personal air samples, and measured personal air
concentrations were generally significantly higher than outdoor
concentrations.  The results for the New Jersey and California
studies are summarized in Exhibit 2-8.  In New Jersey, average
personal air VOC concentrations for the 11 compounds ranged from
338 ug/m3 during Fall 1981 to 200 ug/m3 in Summer 1982.  In
California, average personal air VOC concentrations for 19
compounds ranged from 240 ug/m3 during February 1984  (Los
Angeles) to 72 ug/m3 in June 1984 (Contra Costa).  EPA concluded
that likely residential sources of the VOCs were furniture,
solvents, paints, drapes, and construction materials.  The TEAM
study had several important findings  (Wallace, 1987):

   o  Mean personal air exposures to essentially every one of
      the 11 prevalent target VOCs were greater than mean
      outdoor concentrations at seven of eight locations/
      monitoring periods.

   o  The breath levels correlated significantly with personal
      air exposures to nearly all chemicals, but did  not
      correlate with outdoor air levels.

   o  A number of specific sources were identified,  including
      smoking  (benzene, xylenes, ethylbenzene, and  styrene  in
      breath), passive smoking  (benzene, xylenes, ethylbenzene,
      and styrene in indoor air), visiting dry cleaners
      (tetrachloroethylene in breath), and pumping  gas  or
      exposure to automobile exhaust  (benzene  in breath).

   o  Other sources were hypothesized, including use of  hot
      water in the home  (chloroform  in indoor  air)  and  room air
      fresheners, toilet bowl deodorizers, or  moth  crystals
      (p-dichlorobenzene in indoor air.

   o  For all chemicals, except the  trihalomethanes,  inhalation
      provided greater than 99 percent of the  exposure.

                                                          Exhibit 2-8
           Uei^ited Estimates of Air and Breath Concentrations of 11  Prevalent Compounds for 130,000 Elirabeth-Bayonne
                    Residents (Fall 1981);  110,000 Residents  (Stumer 1982); and 49,000 Residents (Uinter 1983)
                                                     (Source: Wallace 1987)

1 ,1 ,1-Trichloroethane
m,p-Dich I orobenzene
Tetrach loroethy lene
Carbon tetrachloride
Total (11 compounds)
Season I
Season 11 (Summer)
Pers- Out-


III (Winter)

a.  Average of arithmetic means of day and night  12-hour  samples  (ug/nr)
b.  Arithmetic mean
c.  Not calculated - high background contamination
d.  Not detected in most samples
      Weighted Estimates of Air and Breath Concentrations of Nineteen Prevalent Compounds for 360,000 Los Angeles
   Residents (February 1964); 330,000 Los Angeles Residents (May 1964);  and 91,000 Contra Costa Residents (June 1984)
1,1,1 -Trichloroethane
m, p- D i ch I orobenzene
Tetrach loroethy lene
a - P i nene
Carbon tetrachloride
1 ,2-Dichloroethane
o-O ich I orobenzene
Total (19 compounds)
CC (June)
a.  Average of arithmetic means of day and night 12-hour samples tug/iff')
b.  One very high value


       Several hundred specific airborne pollutants have been
detected in varying concentrations in indoor environments. These
are grouped into a convenient subset of pollutants and pollutant
classes.  Indoor pollutants emanate from a broad array of sources
that can originate both outside structures as well as from within
a building.

       Ambient pollutant concentrations in a given
microenvironment, and the associated human exposure, can be
measured directly or they can be estimated using mathematical
models.  These techniques include source emission testing,
modeling, and field measurements.  Various source emission
models, indoor air quality models, and human exposure models have
been developed.  Measurement protocols are needed to accurately
determine indoor concentrations.  Such protocols are specific to
individual pollutants or pollutant classes, and to measurement

       Estimation and prediction of human exposure to indoor
contaminants involves the integration of measurement and modeling
procedures.  Most models use the data from source emission
testing and field measurements to calibrate and verify components
of the model.  Models can provide estimates of exposure to
specified conditions and are therefore useful in evaluating
alternative policy or mitigation options.  Field monitoring is
necessary to collect site specific concentrations and
concentration distributions.


Bayer,  C.W.  and Black,  M.S.   1988a.   Indoor Air Quality
     Evaluations of Three Office Buildings:  Two of Conventional
     Construction Designs and One of a Special Design to Reduce
     Indoor Air Contaminants.  Georgia Institute of Technology,
     Athens, Georgia.

Bayer,  C.W,  and Black,  M.S.   1988b.   Indoor Air Quality
     Evaluations of Three Office Buildings.  Engineering
     Solutions to Indoor Air Problems, ASHRAE.

Borrazzo,  J.E., Osborn, J.F., Fortmann,  R.C., reefer, R.L., and
     Davidson, C.I. 1987.  Modeling and Monitoring of CO, NO and
     NO2 in a Modern Townhouse.   Atmospheric Environment, Vol.
     21, No. 2.

Department of Health and Human Services (DHHS).   1986.  The
     Health Consequences of Involuntary Smoking — A Report of
     the Surgeon General.

Environmental Protection Agency (EPA).  1986.  Airborne Asbestos
     Health Assessment  Update, EPA/600/8-84/003F, Office of
     Research and Development.

Environmental Protection Agency (EPA).  1987a.  Draft Report:
     Indoor Air Pollution -- The Magnitude and Anatomy of
     Problems and Solutions, A Scoping Study.

Environmental Protection Agency (EPA).  1987b.  Compendium of
     Methods for the Determination of Air Pollutants in Indoor
     Air.   Environmental Monitoring Systems Laboratory.

Environmental Protection Agency (EPA).  1987c.  Interim Protocols
     for Screening and  Follow-up Radon and Radon Decay Product
     Measurements.  EPA 520/1-86-014,  Office of Radiation

Environmental Protection Agency (EPA).  1987d.  Radon Reference
     Manual.  EPA 520/1-87-20, Office of Radiation Programs.

Environmental Protection Agency (EPA).  1987e.  EPA Indoor Air
     Quality Implementation Plan -- Appendix A:  Preliminary
     Indoor Air Pollution Information Assessment.  Office of
     Health and Environmental Assessment.

Environmental Protection Agency (EPA).  1988.  Current Federal
     Indoor Air Quality Activities.   Office of Air and Radiation.

Girman, J.R., Apte, M.G., Traynor, G.W., Allen, J.R., and
     Hollowell, C.D..   1982.  Pollutant Emission Rates from
     Indoor Combustion  Appliances and Sidestream Cigarette Smoke.
     Environment  International, Vol. 8:213-221.

Girman, J.R. and  Hodgson, A.T.  1986.  Source Characterization
     and Personal Exposure to Methylene Chloride from Consumer
     Products.  Presented at the 79th Annual Meeting of the Air
     Pollution Control  Association, Minneapolis, MN.

Hawthorne, A. and Matthews, T.  1987.  Models for Estimating
     Organic Emissions  from Building Materials: Formaldehyde
     Example.  Atmospheric Environment, Vol. 21, No. 2.

Hawthorne, Alan,  et al.  1984.  An Indoor Air Quality Study of
     Forty East Tennessee Home.  Oak National Laboratory.

Knoppel, H.  1987.  Sampling and Analysis: Chamber and Field
     Studies.  Atmospheric Environment, Vol. 21, No. 2.

Leaderer, B.P.  1984.   Air Pollutant Emissions  from  Kerosene
     Space Heaters.  Science, Vol. 218.

Leaderer, B.P., Zagraniski, R.T., Berwick, M.,  and Stolwijk, J.A.
     1987.  Predicting  N02 Levels in Residences based upon
     Sources and  Source Use: A Multivariate Model.   Atmospheric
     Environment, Vol.  21, No. 2.

Lewis, R.G., and  Bond,  A.E.  1987.  Non-Occupational Exposure to
     Household Pesticides.  Presented at the 4th International
     Conference on Indoor Air Quality and Climate, Berlin.

Lewis, R.G., Bond, A.E., Fitz-Simons, T.R., Johnson, D.E.,  and
     Hsu, J.P.  1986.   Monitoring for Non-Occupational Exposure
     to Pesticides in  Indoor and Personal Respiratory Air.
     Presented at the  79th Annual Meeting of the Air Pollution
     Control Association, Minneapolis, MN.

Matthews, T.G., Reed, T.J., Daffron, C.R., and  Hawthorne,  A.R.,
     1984.  Environmental Dependence of Formaldehyde Emissions
     from Pressed-Wood  Products: Experimental  Studies  and
     Modeling.  Proceedings, 18tn International Washington State
     University Particleboard/Composite Materials  Symposium.

Meyer, B.  1983.  Indoor Air Quality, Addison-Wesley Publishing

Mowris, R.J.  1986.  Analytical and Numerical Models for
     Estimating the Effect of Exhaust Ventilation on Radon Entry
     in Houses with Basements or Crawl Spaces.   Applied Science
     Division, Lawrence Berkeley Laboratory.

Mowris R.J., and Fisk, W.J.  1988.   Modeling the Effects of
     Exhaust Ventilation on 222Rn Entry Rates and Indoor 222Rn
     Concentrations.  Health Physics Vol.  54, No. 5.

Nagda, N.L., Rector, H.E, and Koontz, M.D.   1987.  Guidelines for
     Monitoring Indoor Air Quality, Hemisphere Press.

National Research Council  (NRC).  1986b.  Environmental Tobacco
     Smoke: Measuring Exposures and Assessing Health Effects,
     National Academy Press.

Nazaroff,  W. and Cass, G.  1986.  "Mathematical Modeling of
     Chemically Reactive Pollutants in Indoor Air," in
     Environmental Science Technology, Vol. 20:924-34.

Nazaroff,  W.W.,  Fuestel, H., Nero,  A.V., Revzan, K.L., Grimsrud,
     D.T.,  Essling, M.A., and Toohey, R.E.   1984.  Radon
     Transport into a Single-Family House with a Basement.
     Atmospheric Environment, 19(l):31-46.

New York State Energy Research and Development Authority  (NERDA),
     and Niagara Mohawk Power Corporation  (MMPC).  1985.  Indoor
     Air Quality,  Infiltration and Ventilation in Residential
     Buildings.   NYSERDA Report 85-10.

Pandian, M.  1987.  Evaluation of Existing Total Human Exposure
     Models.  Environmental Monitoring Systems Laboratory, U.S.
     Environmental Protection Agency.

Relewani,  S.M.,   Moschandreas,  D.J., and Billick, I.H.  1986.
     Effects of Operational Factors on Pollutant Emission Rates
     from Residential Gas Appliances.  JAPCA, 36:1233-1237.

Repace, J.L.  1986.  Indoor Concentrations of Environmental
     Tobacco Smoke: Models Dealing with Effects  of Ventilation
     and Room Size.  IARC Scientific Publication No.  81,
     Environmental Carcinogens -- Selected Methods of  Analysis,
     Vol.  9.

Sakuma, H., Kusama, M.,  Munakata, S., Ohsumi, T., and Sugawara,
     S.  1984a.   The Distribution of Cigarette  Smoke  Components
     between Mainstream and Sidestream Smoke II: Bases,  in  Beitr.
     Tabakforsch,  Vol. 12, pp.  63-71

Sakuma, H., Kusama, M., Munakata, S., Ohsumi, T.,  and Sugawara,
     S.  1984b.  The Distribution of Cigarette Smoke Components
     between Mainstream and Sidestream Smoke III:  Middle and
     Higher Boiling Components, in Beitr. Tabakforsch, Vol. 12,
     pp. 63-71

Sheldon, L. , Zelon, H., Sickles, J., Eaton, C., and Hartwell,  T.
     1988.  Indoor Air Quality in Public Buildings, Volume II.
     Environmental Monitoring Systems Laboratory,  Office of
     Research and Development, U.S. Environmental Protection

Sparks, L.E. 1988.  Indoor Air Quality Model: Version 1.0.  EPA
     Report no. EPA-600/8-88-097a.

Spengler, J.D., and Ferris, B.C.  1985.  Harvard Air Pollution
     Health Study in Six Cities in the U.S.A.  Tokai Journal of
     Experimental Clinical Medicine, Vol. 10, No.-4.

Tucker, W.  1987.  Chairman's Summary Session I —
     Characterization  of Emissions from Combustion Sources:
     Controlled Studies.  Atmospheric Environment, Vol. 21, No.

Tucker, W.G.  1986.  Research Overview: Sources of Indoor  Air
     Pollutants, IAQ-86 ASHRAE Conference, Atlanta, GA.

Wadden, R.A. and Scheff, P.A.  1983.  Indoor Air Pollution, John
     Wiley and Sons.

Wallace, L.A., et al.  1983.  Personal Exposure to Volatile
     Organic and Other Compounds  Indoors and Outdoors -- The  TEAM

Wallace, L.A.  1987.   The Total Exposure Assessment Methodology
     (TEAM) Study: Summary and Analysis: Volume 1.

World Health Organization  (WHO).  1987.  Air Quality  Guidelines
     for Europe,  WHO  Regional Publications, European Series
     No. 23.

Wright, C.G., and Leidy, R.B.  1982. Chlordane and Heptachlor in
     Ambient Air of Houses Treated  for Termites,  in  Bull.  Env.

              INDOOR AIR QUALITY

     This chapter summarizes the adverse health effects
associated with exposure to poor indoor air quality,  and provides
detailed information on non-carcinogenic health impacts as well
as acute discomfort effects.  Carcinogenic risk assessments are
the subject of Chapter 4.

     In June 1987, EPA submitted a detailed report to Congress
describing its plans for implementing an indoor air quality
program.  A major component of that report was Appendix A:
Preliminary Indoor Air Pollution Information Assessment,
prepared by EPA's Office of Research and Development.  The
Information Assessment provides detailed information on the
current state of knowledge concerning indoor air pollutants,
sources, and health effects and forms the basis for much of the
information presented in this chapter.  Where additional
information has been added from other sources, these other
sources are referenced.


     Our knowledge of the major indoor air pollutants, pollutant
sources, and potential health effects are summarized in Exhibit
3-1.  The reader is reminded again that while Exhibit 3-1 is
organized by individual pollutants and pollutant classes,
pollutants are not breathed in isolation, but constitute complex
and changing mixtures.  Exposures to these mixtures may be more
important than exposures to individual pollutants.  The health
effects of complex mixtures is not well understood (see
discussion of pollutant mixtures in Section 3.3).

     For many indoor pollutants, there is insufficient data to
determine the exposure levels at which the listed effects would
occur, and/or exposure information is insufficient for
quantitative risk determinations.  Controlled animal studies have
been conducted for some pollutants the results of which can,
under some circumstances, be extrapolated to humans.  Animal and
human health studies have, in some instances, allowed
quantitation of the relationship between exposure to specific
doses of an individual pollutant, and the severity or range of
effect on health that can be expected from such exposure.  Some
human exposure data encountered  in industrial work settings is
also available for some pollutants.  For most pollutants of
concern, however, the dosages used for animal studies, as well
as the exposures encountered by healthy workers in an  industrial
setting, are generally at higher levels than those that have been
measured in non-industrial indoor environments.

     Some epidemiologic studies have linked specific pollutants
to specific changes in health or changes in mortality  patterns  in


                                                  Exhibit 3-1
                                     Pollutants, Sources, and Health Effects
                                                                           Health Effects
Soil, well water,  some building
                                      Tobacco smoking
                                                                           Irritation to mucous membranes
                                                                           Chronic & acute pulmonary effects in
                                                                           Cardiovascular effects*
Biological Contaminants
 (viruses, bacteria,  molds
 insects and arachnid excreta,
 pollen, animal  and human dander)
Outdoors, humans,  animals,  (moist
 building areas are amplifiers
 for some)
Infectious diseases
Allergic reactions
Toxic effects
Volatile Organic Compounds (VOCs)
Paints, stains, adhesives,  dyes,
 solvents, caulks, cleaners,  pest-
 icides, building materials,  office
Neurotoxic effects
Hepatoxic effects
ETS, UFFI, particle board,  plywood,
 furnishings, upholstery
                                      ETS,  kerosene heaters, wood stoves
                                      Cardiovascular effects
                                      Pesticide  application  indoors
                                       and outdoors
                                      Asbestos  cement,  insulation,
                                       other building materials
                                      Animal data show decreased
                                       immune function, atherosclerosis

                                      Reproductive effects

* The 1986 NRC Report and the Surgeon General's  Report  found the available data to be insufficient to draw firm
conclusions about cardiovascular effects.

                                               Exhibit 3-1 (cent.)
                                     Pollutants, Sources, and Health Effects
                                                                            Health Effects
Combustion gases
                                      Combustion appliances, ETS,
                                       infiltrated exhaust
Combustion appliances,  ETS
Increased frequency and severity
 of angina in patients
Decreased work capacity in healthy
 adult males
Headaches, decreased alertness,  flu-
 like symptoms in healthy adults
Exacerbation of cardiopulmonary
 dysfunction in compromised patients

Decreased pulmonary function in
Increased susceptibility to
 infection in animals
Effect on pulmonary function in
 children, perhaps adults
Synergistic effects with other
 pollutants in animals
Animal studies indicate decreased
 immune capability, changes in anatomy
 and function of lung
Combustion of fuels containing
Decreased lung function in asthmatics
 (in synergism with particles
 increased (doubled) airway
Animal studies show decreased lung
 Combustion particles
Combustion appliances, ETS
 Dust sprays, cooking aerosols
Personal activity
Cancer (soot, PAH adsorbed to
Irritation of respiratory tissues,
Decreased lung  function alone and
 in conjunction with SOj

Unknown; can  range  from irritation  to
Source:  EPA Indoor Air Quality Implementation Plan, Appendix A: Preliminary Indoor Air Pollution Assessment
        (EPA 1987).

human populations.  Such studies are useful in identifying the
hazards that such pollutants present indoors, even when specific
exposure information concerning that pollutant in the indoor
environment is not known, or when the full extent of the effect
of a mixture containing such a pollutant can only be surmised.


     Certain individuals may be especially sensitive to indoor
air pollutants because their age and/or health conditions may
reduce their physiological defenses to the effects of indoor air
pollutants.  For example, some elderly have a reduced resistance
to pulmonary irritants and infections, and have a higher
incidence of preexisting pulmonary disorders; some new born and
young children may also be especially sensitive to air
pollutants.  An estimate of the sizes of these potentially
sensitive subpopulations is summarized in Exhibit 3-2.  It is
important to note that these subpopulations are not additive,
e.g., the elderly and heart patient subpopulations clearly


     The potential health and discomfort effects of the major
indoor air pollutants range from mild sensory irritation to acute
toxicity,  chronic organ damage, and death.  The extent to which
such effects actually occur depends on many factors, including
the degree of exposure and the susceptibility of the individuals
exposed.  This section presents available information on non-
cancer health impacts to the general population or to specific
subpopulations. It must be emphasized that while it can be
generally agreed that indoor air can and does cause many adverse
health effects, quantitative relationships of the health impact
from actual population exposures are not well established.

     Few quantitative estimates are available for non-cancer
health and discomfort effects.  This does not imply that cancer
is the most critical health endpoint for indoor air pollutants.
To the contrary,  many scientists believe that non-cancer health
and discomfort are the most important for indoor air.

     Available information on these effects for individual
pollutants is summarized below and, except where otherwise
indicated,  is based on Appendix A of EPA's 1987 Indoor Air
Quality Implementation Plan,  Preliminary Indoor Air Quality
Information Assessment (EPA 1987) .   Information on pollutant
mixtures,  biological contaminants,  and on building sicknesses not
necessarily associated with individual pollutants is presented in
separate subsections.

                           Exhibit 3-2
    Subpopulations with Potentially Increased Responsiveness
                    to Indoor Air Pollutants
                    Subpopulation       Percent of
Subpopulation       Size                Population
Newborns1            3,731,000               1.5
Young children2     18,128,000               7.5
Elderly3            29,172,000              12.1
Heart patients4     18,458,000               7.7
Bronchitis5         11,379,000               4.7
Asthma6              9,690,000               4.0
Hay fever7          21,702,000               9.0
Emphysema8           1,998,000               0.8
Smokers9            69,852,000              29.9
     1Live births in 1986; 1986 national population of
241,078,000  (USBC, 1988).

     2Children under the age of five in 1986  (USBC, 1988).

     3Persons over 65 or older in 1986  (USBC, 1988).

     4Persons with heart diseases in 1986  (NCHS, 1987).

     5Persons with bronchitis in 1986  (NCHS,  1987).

      6Persons with asthma in 1986  (NCHS,  1987).

     7Persons with hay Sever or allergic rhinitis without asthma
in 1986 (NCHS, 1987).

     8Persons with emphysema in 1986 (NCHS,  1987).

     9Persons 20 years of age and over who smoked  in  1983;  1983
national population of 233,981,000  (PHS, 1985;  USBC,  1985).

Effects of Individual Pollutants

     Environmental Tobacco Smoke

     On the basis of controlled experiments and field studies,
nonsmokers are exposed to significant amounts of tobacco
combustion products, as measured by urinary cotinine (Sepkovic et
al., 1982; Matsukura et al..  1984; Wald and Ritchie, 1984; Jarvis
et al., 1984; Greenburg et al..  1984; Surgeon General, 1986).
These  exposures amount to, in the most exposed individuals,
levels 5-7% of those in smokers, and in the average case, about
1% of  the levels in active smokers.

     Non-cancer effects from environmental tobacco smoke include
cardiovascular effects, increased susceptibility to infectious
diseases in children, chronic and acute pulmonary effects in
children, mucous membrane irritation, and allergic response  (EPA
1987).  While no definitive estimates of acute effects are
available, respiratory symptoms such as wheezing, coughing, and
sputum production are increased in children of parents who smoke.
The  increased risk is estimated to be between 20 and 80%
depending on the symptoms being assessed and the number of
smokers in the household  (NRC 1986a).  Since approximately 40% to
60%  of children reside in households with smokers (CDC, 1986, and
Bonham and Wilson, 1981), a significant number of children may be
at increased risk for these effects.

     Wells (1986, 1988) made preliminary estimates of the number
of fatalities from heart disease and emphysema occurring in
nonsmokers due to exposure to ETS.  His preliminary assessment of
the  U.S. incidences of deaths from these diseases was based on
estimates, obtained from epidemiological studies, of the relative
risk resulting from exposure to ETS (i.e., the ratio of disease
in those exposed to ETS versus those unexposed).  The relative
risks  from the epidemiological studies were multiplied by
nonsmoker death rates from an American Cancer Society study of
mortality in 1,000,000 U.S. men and women (Hammond 1966).
Estimated incidences of death from heart disease and emphysema
were 32,000 and 170 cases, respectively.

     Volatile Organic Compounds

     More than 900 different volatile organic compounds have
been identified in indoor air, and the health effects for some of
these  compounds are known, but the concentrations at which
identified health effects occur are usually much greater than
those measured in indoor air.  Health effects reported for VOCs
range  from sensory irritation to behavioral, neurotoxic and
hepatotoxic effects.

     Concentration-response effects for aggregate mixtures of
volatile organic compounds commonly found in indoor air have been


studied in Denmark.  Human subjects suffering from indoor
climatic symptoms, but who were healthy and had no obvious
medical reason for their complaints, were exposed to controlled
concentrations of 5 and 25 mg/m3.  Significant effects of mucous
membrane irritation and reduced ability to concentrate were
experienced.  Typical concentrations of total organic vapors and
gases in new buildings range from 0.5 to 19 mg/m3 (Molhave 1984,
Molhave, et al. , 1986).  This suggests that exposure to mixtures
of VOCs commonly found in building materials may be an important
source of sick building syndrome complaints, but research is
just beginning (see discussion below on sick building syndrome).

     Formaldehyde and Pesticides

     Irritation of mucous membranes from formaldehyde has been
shown to occur in chamber studies at 0.1 to 0.2 ppm.  Individuals
sensitized to formaldehyde react allergically at concentrations
of less than 0.1 ppm.  Concentrations measured ih mobile homes
range from 0.03 to 8 ppm, with approximately 9,000,000 mobile
home residents potentially exposed to formaldehyde for 10 to 24
hours per day.  Concentrations in offices, public buildings,
schools and homes can also range into irritatory levels,
especially after remodeling or after installations of new
furnishings and carpets.

     Pesticides are by definition poisonous substances,
affecting the nervous system, the liver, or the reproductive
systems. Allergic reactions have been documented, though the
extent of this impact is not known.

     Combustion Gases

     Carbon Monoxide:  The EPA ambient air quality standard for
carbon monoxide is 35 ppm for 1 hr duration and 9 ppm for 8
hours.  However up to 60 ppm CO have been measured inside cars
stopped in traffic jams, while up to 18 ppm were measured in
public garages.  Even when properly vented, homes that are very
weather-tight may have downdrafts through the chimney which can
cause dangerous levels of CO.  Concentrations from faulty
appliances have been measured in excess of 100 to 200 ppm.  While
no cause and effect relationship with the above concentrations  is
implied, it is useful to note that approximately 300 deaths due
to carbon monoxide poisoning from consumer appliances are
reported annually to the Consumer Product Safety Commission.
These figures provide a general indicator of the hazard posed  by
exposure to carbon monoxide.

     Nitrogen Dioxide and Sulfur Dioxide;  Nitrogen dioxide is  a
deep lung irritant capable of producing pulmonary edema if
inhaled in sufficient quantities.  It should be noted that while
results from both epidemiological studies of children exposed  to
gas stove emissions and controlled laboratory studies on  adults


are inconsistent,  the Clean Air Scientific Advisory Committee of
EPA, in review of these studies,  concluded that preliminary
evidence suggests that repeated exposure to 0.3 ppm NO2 may cause
increased bronchial reactivity in some asthmatics.   Levels of NO2
during cooking with gas or during use of kerosene heaters can
exceed 0.53 ppm.

     Sulfur dioxide exposure is associated with reduced lung
function; however,  there is an extremely large variation of
sensitivity to sulfur dioxide.  Asthmatics are at least one order
of magnitude more sensitive than are otherwise normal
individuals.  Sulfur dioxide may act in concert with the
particulate matter to double the airway resistance in infants
and the elderly at concentrations of 0.75 ppm (1 min).
Concentrations of 0.1 to 2.0 ppm (12 hour average)  have been
measured with unvented kerosene heaters using low-sulfur fuel.

     Approximately 96 million persons may be exposed to emissions
from gas stoves for an average of 4 hours per day,  while
approximately 7 million persons may be exposed to kerosene heater
fumes for an average of 2 hours per day-  Only a subset of these
individuals are expected to be at risk and the extent of their
risk is highly uncertain.

Pollutant Mixtures

     As previously stated, pollutants are not breathed in
isolation, but constitute complex and changing mixtures.  The
health effects may be additive, synergistic (combined effects are
greater than the sum of effects from individual components), or
antagonistic (combined effects are less than the sum of effects
from individual components).  In addition, the complexities
involved with changes in composition of mixtures in time, in
different spaces,  and with changes in human activities, have not
yet been studied.

      Pollutant mixtures may play an important role in causing
acute symptoms associated with the "sick building syndrome"  (see
discussion below)  (Molhave 1984).  In a controlled experiment
conducted at the Institute of Hygiene in Denmark, 62 human
subjects were subjected to a mixture of 22 organic vapors and
gases that are common in residential building materials, and
which are known upper airway irritants.  The subjects were all
healthy, without asthma, allergy, or chronic bronchitis.  They
were selected from a group contacted via the press, all suffering
from "indoor climate symptoms", primarily irritation of the  eyes
and upper airways (Bach, Molhave and Pedersen 1984) .  When
exposed to a total concentration of 5 and 25 mg/m3, subjects
showed significant mucous membrane irritation and memory
impairment compared to exposure to clean air.  These
concentrations correspond to the average and maximum found  in new
Danish houses (Molhave 1984; Bach, et al., 1984).  The


concentrations of each of the individual experimental compounds
were significantly below levels generally thought to cause
effects.  Exposure experiments between 0 and 5 mg/m3 were not
conducted.  Reactions to mixtures of organic gases and vapors may
also depend on other environmental factors as well as individual
disposition to such symptoms  (Molhave 1984).

Building Sickness

     Acute health impacts, including those associated with sick
building syndrome, are receiving increased attention, but because
of data limitations, and difficulties in quantitation, little
quantitative information is available on the extent of these
impacts at this time.  However, while data are insufficient to
provide quantitative estimates of these risks, the data which are
available are provided as an  indicator of the potential risks
associated with indoor air.   The only quantitative non-cancer
risk estimates which are available pertain to heart and lung
diseases associated with environmental tobacco smoke.

     In the 1970s, new energy-conserving building designs
introduced tight building shells, inoperable windows, and
centrally controlled ventilation systems which could operate with
minimal introduction of outdoor air.  These designs, combined
with the emission of indoor air pollutants from synthetic
building materials, cleaning  and pest control products, office
machines, smoking, and biological sources, have caused increases
in indoor air pollution levels.  Because these and other factors,
complaints by building occupants have become increasingly more
widespread.  The physiological reactions to these pollutants,
coupled with the psycho-social stresses of the modern office
environment, and the wide range of human susceptibility to
indoor air pollutants has led to some tentative classifications
of acute building sickness: building related illness, sick
building syndrome, and multiple chemical sensitivity.  These
emerging problems are the subject of continued inquiry in the
scientific and medical community-

     Building-related Illness

     Building related illness is a term which refers to an
illness brought on as a result of exposure to the building air,
where symptoms of frank illness, including  infection, fever, and
clinical signs of pathology,  are identified and an airborne
pathway for the stressor is recognized  (NRG 1987). Legionnaires'
disease and hypersensitivity  pneumonitis are examples of
building-related illness.

     Sick Building Syndrome

     Sick building syndrome is a term which refers to a  series
of acute health and comfort effects which  are experienced  by a


substantial percentage of the building occupants,  the onset and
relief of which are associated with entering and leaving the
building, and where no specifically defined illness or etiology
can be identified.   The list of symptoms includes irritation of
the eyes, nose, throat, and skin;  neurotoxic symptoms, such as
mental fatigue or headache; unspecific hyperreactions, such as
runny nose or asthma-like symptoms; and odor and taste
complaints.  Generally, sensory irritation dominates the
syndrome; systemic symptoms are infrequent (WHO, 1983; Molhave,
1987) .

     Investigators of sick building syndrome are typically
unable to identify any single exposure factor exceeding a
generally acceptable threshold and are therefore not able to
identify any single specific cause of the problem.  The
causality, therefore, is often assumed to be multifactorial,
involving combined environmental and psycho-social stresses
(Molhave 1984).  Contributing factors may include the additive or
synergistic effect of multiple contaminants,  the effect of
climatic factors such as temperature, relative humidity, noise
and lighting, and psycho-social stresses experienced by
individuals at work and in non-work situations.

     A full discussion of all the potential factors associated
with sick building syndrome is beyond the scope of this report.
Nevertheless, several studies of sick building syndrome in the
United States and Europe offer some evidence of both building-
related and psycho-social factors that may be associated with
this problem.  A major British study found higher prevalence
rates of sick building syndrome complaints in air conditioned
buildings (Hedge, et al., 1987; Harrison, et al.. 1987).  Among
the air conditioned buildings, those with humidification systems,
particularly spray or evaporative types, had the highest
prevalence rates  (Hedge, et al..  1987).  However, only limited
monitoring of air contaminants was conducted.  Monitoring of air
contaminants in the Harrison study was limited to particulate
matter, fungi and bacteria, which did not correlate with symptom
prevalences.  No monitoring data were reported by Hedge.

     A major multidisciplinary study in 14 Danish Town Halls
(Skov and Valbjorn 1987;  Valbjorn and Skov, 1987) found no
association between sick building syndrome and ventilation
characteristics, but found strong positive correlations with the
age of the building, the total weight and potential allergenic
portion of floor dust, the area of fleecy material, the open
shelving per cubic meter of air, and the air temperature.  The
investigators also found higher health complaint rates to be
associated with lower job status,  being female, being involved in
photoprinting activity, working with video display terminals,  and
handling carbonless paper.

     Levin  (1988) offers some preliminary interpretations to the
results of various studies:

   o  Elevated temperature can directly affect occupant comfort,
      and indirectly affect contaminant concentrations by
      increasing offgassing of VOCs, particularly from large
      surface areas, such as ceiling tiles, fibrous linings of
      air ducts, fabrics covering walls, and free standing
      partitions.  Microorganisms may also proliferate in higher
      temperatures and  in buildings with reduced outside air

   o  Many mechanical ventilation systems will reduce air flow
      and outside air supply when temperatures rise toward the
      upper end of the  comfort range, thus reducing ventilation
      precisely when it is needed most to remove elevated
      contaminant levels and to provide evaporative cooling of
      occupants' exposed skin.

   o  Newer buildings are often constructed from softer, less
      durable  materials on floors, ceilings, and walls,
      resulting in higher  pollutant concentrations.  Newer
      buildings are also designed to accommodate open offices
      with higher occupant densities, larger surface areas
      generating contaminants, and less physical, visual, and
      acoustical privacy.  Open office areas also provide less
      personal control, and partitions may interrupt the flow of
      air necessary for health and comfort.

   o  Lower status jobs tend to offer less environmental variety
      and may be associated with windowless interior spaces.  In
      addition, many air handling systems deliver outside air and
      ventilation primarily to the perimeter of the building, in
      order to control  thermal loads from the exterior
      environment, with interior spaces receiving less outside

     Multiple Chemical  Sensitivity

     In addition to building related illness and sick building
syndrome, a considerable body of anecdotal data suggests the
possibility that a small subset of the population has become
sensitized to chemicals in the environment. Such individuals
appear to repeatedly suffer acute reactions upon exposure to
levels commonly found in indoor environments, exposures to which
most persons would suffer no discernable adverse effects.
Although such individuals report significant disability, the
attribution to cause is hindered by lack of clear diagnostic
criteria, data, or tools to evaluate the extent of the
impairment.  The situation often leads to a suspicion that the
condition is psychosomatic in origin.

     The condition has come to be known as multiple chemical
sensitivities (MCS),  but it is not known to what extent MCS
affects health or productivity,  or what the size of the affected
population is,

     MCS is a subject of considerable intraprofessional
disagreement concerning the existence and etiology of this
potential disorder (Cullen, 1987).  While no widely accepted test
of physiologic function has been shown to correlate with the
symptoms, the sheer mass of anecdotal data is cause of concern.

     In an attempt to focus discussion and facilitate potential
research, Dr. Mark Cullen from the Yale University School of
Medicine suggests that a working definition of multiple chemical
sensitivity include seven major diagnostic features (Cullen,
1987) :

   1. The disorder is acquired in relation to some documentable
      environmental exposure(s), insult(s), or  illness(es).

   2. Symptoms include more than one organ system.

   3. Symptoms recur and abate in response to predictable

   4. Symptoms are elicited by exposures to chemicals of diverse
      structural classes and toxicologic modes of action.

   5. Symptoms are elicited by exposures that are demonstrable
      (albeit at low levels).

   6. Exposures that elicit symptoms must be significantly below
      exposures known to cause adverse human response.

   7. No single widely available test of organ system function
      can explain symptoms.

     Building related illness, sick building syndrome, and
multiple chemical sensitivities are increasingly being recognized
as potentially serious,  albeit untraditional, health and comfort
consequences of modern indoor environments. But they are poorly
understood and there is a lack of scientific consensus concerning
the important environmental or physiological determinants of
these problems.   As a result,  these problems create a dilemma  for
those charged with the clinical treatment of suffering
individuals as well as for those responsible for the management
and control of building environments.

Biological Contaminants

     Airborne biological contaminants are present in all indoor
and outdoor environments and emanate from a variety of sources,
including plants, animals, and humans.  Bacteria and viruses are
brought into the indoor environment largely through human
exhalations.  Indoor appliances, such as air conditioners,
humidifiers, and flush toilets, are often major sources of
biological contaminants, as are water-damaged carpets or other
furnishings.  These appliances, especially room humidifiers, may
function as fertile breeding grounds for microorganisms, and have
been implicated in a number of cases of building-related illness.
Molds and fungi may be brought in from outdoors and may
proliferate in warm damp indoor environments.

     Biogenic aerosols can produce direct toxicity, as with the
mycotoxins produced by some molds and fungi, or they may be
pathogenic  (provoking infectious disease) or allergenic
(provoking hypersensitive or allergic diseases).


     Some molds are known to produce mycotoxins. Such toxins
produce direct toxic effects as well as immunosuppression.  At low
concentrations, some mycotoxins produce gastrointestinal lesions,
hematopoietic suppression, and suppression of reproductive
function.  Toxicity to the central nervous system produces
symptoms such as anorexia, lassitude, and nausea. Trichocene
mycotoxins can produce non-specific symptoms such as those
described in "sick building syndrome". (EPA 1987).

     Some fungi also produce mycotoxins which are known to be
highly potent systemic poisons.  The concentration of mycotoxins
in the spores of toxigenic fungi are often very high.  While the
effects of these poisons are primarily known from their
ingestion, it is reasonable to assume that these toxins have a
systemic effect when inhaled, since inhalation more effectively
allows systemic entry for dissolved substances.  (EPA 1987).


     Many pathogens, which are infectious agents, are
communicated by airborne transmission.  These agents induce
serious diseases, including influenza, chicken pox, measles,
pulmonary tuberculosis, and smallpox, which affect millions of
people each year.  An infected individual, however, is the  source
of the particular biological agent, and as such, these health
effects are typically not considered building-related  (Kreis and
Hodgson 1984) .   Nevertheless, airborne transmission of
infectious agents is believed to be related to the ventilation  of
buildings; a recent study involving four Army training centers
demonstrated that the rates of acute febrile respiratory disease


were 50 percent higher in modern barracks (that had been
constructed with energy-efficient designs) than in older barracks
(Brundage et al..  1988).

     Some infectious bacteria, which proliferate in humidifiers,
air conditioners,  and in other building components, have caused
building-related epidemics, including outbreaks of Legionnaires'
disease, and Pontiac fever.

     Legionnaires' disease is caused by Legionella pneumophila
which, in addition to affecting the lungs, may also involve the
gastrointestinal (GI) tract, the kidneys, and the central nervous
system.  This illness was first identified during an epidemic at
a Legionnaires' convention in a Philadelphia hotel in 1976, which
affected 182 persons and caused 29 deaths.  Since 1976, numerous
building epidemics have been associated with this bacterium.
Approximately 1-7  percent of persons exposed to L. pneumophila
become ill with Legionnaires' disease. Sources of the bacterium
include aerosols from cooling towers, evaporative condensers, and
humidifiers, and dusts from landscaping and construction
activities. (Kreiss and Hodgson 1984).

     Pontiac fever, named after a 1968 building epidemic in
Pontiac, Michigan, is caused by the same bacterium which causes
Legionnaires'  disease.  Unlike Legionnaires' disease, however,
Pontiac fever is a short term (two to five day) illness
characterized by fever, chills,  headache, and muscle ache, and
sometimes coughing, sore throat, chest pain, nausea, and
diarrhea.  Pontiac fever is not fatal but nearly 100 percent of
those exposed to the bacterium get the disease.  No consensus
exists as to why the same bacterial strain causes two distinct
clinical syndromes.  (Kreis and Hodgson 1984).


     Unlike infectious agents, which induce infections in normal
individuals, allergenic agents do not affect most persons, but
provoke an allergic  (hypersensitive) reaction only in a small
subset of the population (Solomon and Burge 1984).  While some
chemicals can provoke allergic responses, most allergens are
biological and include both viable and nonviable agents.  Viable
organisms provoking such responses are molds, amoebae, algae, and
bacteria.  Nonviable agents such as house dust mite fecal
pellets, cockroach feces, insect and arachnid dried hulks and
body parts, animal danders, nonviable remains of molds and their
spores, dried reentrained animal excretions such as saliva,
sweat, urine and feces, pollens, and biogenic volatiles have also
been identified as actors.   Common allergic illnesses include
allergic rhinitis, bronchial asthma, and hypersensitivity
pneumonitis (EPA 1987).

     Allergic rhinitis is characterized by nasal air passage
obstruction, itching, sneezing and excessive secretion of mucus.
Allergic rhinitis is commonly referred to as "hay fever" when it
is seasonally related. Conjunctivitis, which involves irritation,
itching, and reddening of the eyes, is often associated.
Excessive mucus secretion and blocking of sinus and eustachian
passages provide growth reservoirs where secondary bacterial
infections may implant, thus predisposing individuals to
bacterial infections in the upper airways (EPA 1987).

     Bronchial asthma involves a recurrent narrowing of
bronchioles and hypersecretion of thick mucus that can block
airways, is accompanied by varying degrees of wheezing,
shortness of breath, and coughing.  Secondary bacterial
infections can result in bronchitis and more sensitive reactions
to irritants and other allergens (EPA 1987).

     Hypersensitivity pneumonitis  (extrinsic allergic
alveolitis) is a serious acute immune reaction to sensitizing
substances.  It involves the production of large amounts of IgE
antibody, cellular hypersensitivity, and the formation of
interstitial granulomas.  It causes filling and variable
destruction of the alveoli by inflammatory cells (EPA 1987).
With continued exposure irreversible pulmonary fibrosis and
eventual pulmonary failure, ending in death, ensues (Reed 1981,
and Solomon and Burge 1981, as cited in EPA 1987).


     Health effects from indoor air pollution cover the range of
acute and chronic effects, and include eye,  nose, and throat
irritation, respiratory effects, neurotoxicity, kidney and liver
effects, heart functions, allergic and infectious diseases,
developmental effects, mutagenicity, and carcinogenicity.  Non-
carcinogenic health effects may constitute the most significant
indoor air quality problem.

     Building sicknesses, such as sick building syndrome,
building related illness, and multiple chemical sensitivity are
issues of potentially great significance but are poorly
understood.  Additive or synergistic effects from pollutant
mixtures, where concentrations of each individual compound are
below its known health effect threshold, may help to explain  some
sick building syndrome complaints.  Biological contaminants are a
principal cause of building related illness, and can be the
principal problem in some buildings.  Building related  illness
can result in death, as in Legionnaire's disease, or serious
infectious or allergic diseases.  A considerable body of
anecdotal evidence suggests that a small subset of  the  population
has become sensitized to chemicals in the environment.  The
phenomenon is referred to as multiple chemical sensitivity, but
little definitive scientific evidence is available.



Bach,  B.  Molhave,  L.,  and Pederson,  O.F.,  1984.  "Human Reactions
     During Controlled Exposures to  Low Concentrations of Organic
     Gases and Vapours Known as Normal Indoor Air Pollutants:
     Performance Tests,  in Indoor Air: Proceedings of the 3rd
     International Conference on Indoor Air Quality and Climate,

Bonham,  G.So  and Wilson,  R.W. 1981.   Children's  Health in
     Families with Cigarette Smokers.   American  Journal of Public
     Health,  71, 290-293.

Brundage, J.F., Scott, R.M., Lednar, W.M.,  Smith, D.W., and
     Miller,  R.N., 1988.  Building-Associated Risk of Febrile
     Acute Respiratory Diseases in Army Trainees.  Journal of
     the American Medical Association, Vol. 249, No. 14.

Bureau of the Census  (BC).  1988.  Statistical Abstract of the
     United States: 1988.

Bureau of the Census  (BC).  1985.  Statistical Abstract of the
     United States:  1985.

Center for Disease Control (CDC).  1986  Adult Use of Tobacco.
     Atlanta, GA.

Cullen,  M. R., 1987.   The Worker with Multiple Chemical
     Sensitivities: An Overview Workers with Multiple Chemical
     Sensitivities, Occupational Medicine,  State of the Art
     Reviews, Volume 2,  No.  4, Hanley and Belfus, Inc,

Coburn,  R.F., Forster, R.E., Kane, P.  B.,  1965.  Considerations of
     the Physiological Variables that Determine the Blood
     Carboxyhemoglobin Concentration in Man. J.  Clin. Invest. 44:
     1899-1910  (as cited in EPA 1987).

Environmental Protection Agency.  1987.  EPA Indoor Air Quality
     Implementation Plan, Appendix A:  Preliminary Indoor Air
     Pollution Information Assessment, Office of Research and
     Development,  EPA/600/8-87/014.

Greenburg, R.A., et al..  1984.  Measuring the Exposure of Infants
     to     Tobacco Smoke: Nicotine  and Cotinine in Urine and
     Saliva.   New Engl.  J.      Med. 310^1075-1078.

Hammond,  C.  1966.  Smoking in Relation to Death Rates of One
     Million Men and Women.   Epidemiological Approaches to the
     Study of Cancer and Other Chronic Diseases, Haenszel, w.,
     ed., NCI Monograph 19,  pp. 127-204.


Harrison, J., Pickering, A.C., Finnegan, M.J., and Austwick,  P.K.
     1987.  The Sick Building Syndrome - Further Prevalence
     Studies and Investigations of Possible Causes, Indoor
     Air'87.  Proceeding of the 4th International Conference on
     Indoor Air Quality and Climate, Berlin.

Hedge, A., Wilson, S., Burde, P.S., Robertson, A.S., and Harris-
     Bass.  1987. Indoor Climate and Employee Health in Offices,
     in Indoor Air'87, Proceeding of the 4th International
     Conference on Indoor Air Quality and Climate, Berlin.

Jarvis, M.J., et al.. 1984.  Biochemical Markers of Smoke
     Absorption and Self-reported Exposure to Passive Smoking.
     J. Epi. and Comm. Health 38:335-339.

Kreiss, K.,  and Hodgson, M.J.  1984. Building-Associated
     Epidemics. Indoor Air Quality, Walsh, P.J., Dudney, C.S.,
     and Copenhaver, E.D., eds.  CRC Press.

Levin, H.  1988.  Edifice Complex: An Anatomy of Sick Building
     Syndrome Control and Abatement.  Presented at the Annual
     Meeting of the Air Pollution Control Association, Dallas,
     TX, June 24-24, 1988.

Matsukura, S. et al., 1984.  Effects of Environmental Tobacco
     Smoke on    Urinary Cotinine Excretion in Nonsmokers:
     Evidence for Passive Smoking.   New Engl. J. Med. 311:828-

Molhave, L.   1984. Volatile Organic Compounds as Indoor Air
     Pollutants. Indoor Air and Human Health Proceedings of the
     7th Life Sciences Symposium, Gammage R., et al., eds.
     Knoxville, Tennessee.

Molhave, L.   1987.  The Sick Buildings  - A Subpopulation Among
     the Problem Buildings, Indoor Air"87 Proceeding of the 4^n
     International Conference on Indoor Air Quality and Climate,

National Center for Health Statistics (NCHS).   1987.  Current
     Estimates from the National Health Interview  Survey:  1986.

National Institute for Occupational Safety and  Health  (NIOSH).
     1987.  "Guidance for Indoor Air Quality  Investigations."

National Research Council  (NRC).   1986a.  Environmental Tobacco
     Smoke:  Measuring Exposures and Assessing Health  Effects,
     National Academy Press.

National Research Council  (NRC).   1986b.  The Airliner  Cabin  Air
     Environment: Air Quality and  Safety, National  Academy


National Research Council (NRC).  1987.  Policies and Procedures
     for Control of Indoor Air Quality,  National Academy Press.

Public Health Service (PHS).   1985.   Health United States 1985.

Reed,  C.E.   1981.  Allergic Agents.  Bull.   New York Academy of
     Medicine.  57:  897-906.

Sepkovic,  D.W.,  et al..  1986.  Elimination in Smokers and in
     Passively Exposed  Nonsmokers.   J.  Amer. Med. Assoc. 256:863.

Solomon, W.R and Burge,  H.A.   1984.   Allergens and Pathogens,
     Indoor Air Quality,  Walsh,  P.J.,  Dudney,  C.S., and
     Copenhaver, E.D.,  eds.,  CRC Press.

Skov,  P. and Valbjorn,  0.  1987.   The Sick Building Syndrome in
     the Office Environment:  The Danish Town Hall Study, Indoor
     Air'87. Proceeding of the 4th International Conference on
     Indoor Air Quality and Climate,  Berlin.

Surgeon General, 1979.  Smoking and Health. U.S. Dept. of Health,
     Education,  and Welfare,  Washington, DC.

Surgeon General, 1986.  The Health Consequences of Involuntary
     Smoking.  U.S. Dept. of Health & Human Services, Washington,

Wald,  N.J., et al., 1986.  Does Breathing Other People's Smoke
     Cause Lung Cancer?  British J.  Med. 293:1217-1222.

Wells, A.J.  June 1986.   Passive Smoking Mortality: A Review and
     Preliminary Risk Assessment.  Presented at 79th annual
     meeting, Air Pollution Control Association, Minneapolis.

Wells, A.J.  1988.   An Estimate of Adult Mortality in the United
     States from Passive Smoking.  Environ. Internat. 14:in

Valbjorn,  0. and Skov,  P.  1987.   Influence of Indoor Climate on
     the Sick Building Syndrome,  Indoor Air'87 Proceeding of the
     4th International  Conference on Indoor Air Quality and
     Climate, Berlin.

World Health Organization (WHO).   1983.  Indoor Air Pollutants:
     Exposure and Health Effects EURO Reports and Studies No. 78
     Report on a meeting of the Working Group on Assessment  and
     Monitoring of Exposure to Indoor Pollution, Copenhagen, WHO
     Regional Office 4.


      Most  of  the  risk assessments  conducted to date have
 focused  on  carcinogenic  effects.  As stated in Chapter 3, this
 does not imply that non-cancer health effects are less important.
 To the contrary, risk  assessments are normally conducted for
 carcinogenic effects largely  because the methodology for
 assessing cancer risks has  received the most attention.  However,
 many scientists and policy  makers believe that the non-cancer
 effects  discussed  in Chapter  3 are  among the most important and
 pervasive for  indoor air.

     The only  estimate established  by EPA of the US population
 cancer incidence  (in cases  per year) for exposures to pollutants
 in indoor air  is that  for radon.  Some information is also
 available on lifetime  individual risks for formaldehyde for
 specific subsets of the  U.S.  population, based on exposure to a
 specific concentration of formaldehyde in indoor air.  The
 remaining EPA  estimates  are unit risk estimates, providing
 information on the cancer risk that is estimated to occur from
 continuous  lifetime exposure  to a specific unit air
 concentration.  These  numbers, therefore, can only be used to
 determine risks to specific individuals in the population or to
 determine cancer incidences if combined with appropriate exposure
 data.  Other assessments of the expected risks resulting from
 indoor air  pollutants  appear  in the literature, but the adequacy
 of data,  the assumptions, and the methodology used in these
 assessments have not been reviewed  and evaluated by EPA, and
 their presentation in  this  report should not be interpreted as an
 endorsement.   Rather,  these estimates are presented solely to
 indicate to the reader what information and analysis has been
 conducted in the scientific community on this subject.


     EPA Cancer Risk Assessment Methodology

     The  four  elements of risk assessment are hazard
 identification, dose-response assessment, exposure assessment,
 and risk  characterization.  EPA (1986a) has established specific
 guidelines  for  performing risk assessments for carcinogens.  A
 discussion  of  the  four components of risk assessment, as they
 apply to  carcinogenic  risk  assessment, is presented below.

     Hazard Identification

     Hazard  identification  consists of a review and analysis of
all relevant chemical  and biological information bearing on
whether an  agent may pose a carcinogenic hazard to humans.  This
review concludes with  an evaluation of the overall weight of the
evidence  for carcinogenicity  based  on that analysis.  Elements

evaluated in hazard identification,  in increasing level of
importance, include:

     (1)    Physical and chemical properties,  which affect a
            large number of factors  in the risk assessment, such
            as absorption into the body,  partitioning in various
            media, and decay rates;

     (2)    structure-activity relationships,  a comparison of the
            structure and activity of the chemical and its
            possible metabolites to  those of known carcinogens
            and noncarcinogens,  to evaluate the likelihood of
            carcinogenic activity;

     (3)    Pharmacokinetic interactions, a study of absorption,
            distribution, metabolism, and excretion of the
            chemical in animals and  humans, used to determine
            important differences to consider in extrapolations
            between species;

     (4)    Routes of exposure,  which may alter the
            carcinogenicity of the compound due to factors such
            as pharmacokinetic differences and interactions with
            other compounds;

     (5)    Short-term predictive tests,  which detect chemical
            interactions with DNA and assess mutagenic activity,
            thus providing preliminary evidence of carcinogenic

     (6)    Long-term animal bioassays, in which lower mammalian
            species (usually rodents) are used as surrogates for
            humans, to determine the potential tumorigenicity
            and/or carcinogenicity of the chemical; and

      (7)   Epidemiological studies, which are used to examine
            the association between  human exposures to the agents
            and the incidence of cancer.

     Of these seven elements, well-designed and well-conducted
epidemiological studies provide the  most direct information
regarding the human carcinogenicity  of a chemical. Unfortunately,
adeg_uate epidemiological data are not available for most
chemicals due to several limitations.  One is that large numbers
of human subjects are often needed for statistically-defensible
studies, especially if the exposures are low or rare or if the
carcinogenic effect is small.  Other complications are the long
periods of time necessary for many cancers to be observed
(usually greater than ten years) in the human population, the
high cost of epidemiological studies, and the lack of accurate
exposure data.   Finally, data are not always available in
epidemiologic studies to adjust for all risk factors which may


have confounding influences, such as sensitive populations,
socioeconomic conditions, and exposures to other chemicals (OSTP,
1984).   Because of these limitations, estimates of human cancer
risk must usually be derived from animal bioassay data and must
rely on the other elements of hazard identification described
above for evidence of presumptive carcinogenicity in humans.

      Evaluating animal bioassay data for evidence of presumptive
human carcinogenicity involves considering both the quality and
adequacy of the data and the kinds and consistency of responses
induced by a chemical.  Criteria for the technical adequacy of
animal bioassay studies have been published (e.g., OSTP, 1984;
NTP, 1984).  The criteria address issues such as the selection of
appropriate species, strains, doses, routes of exposure, and
study duration; animal care and diet; the selection of control
groups; data collection and reporting; and the statistical
evaluation of the results.  Criteria such as these are useful in
determining the scientific validity of the data obtained in the
individual studies and how well each study serves as a surrogate
for human studies.  In evaluating the kinds and consistency of
response induced by the chemical, the strength of the evidence
that an agent may act as a human carcinogen is increased with:

     (1)    an increase in the number of animal species and
            strains showing a response, and whether one or both
            sexes respond;

     (2)    an increase in the number of tissue sites affected by
            the agent;

     (3)    the occurrence of a clear dose-response relationship;

     (4)    a high level of statistical significance of the
            increased tumor incidence in treated as compared to
            control groups;

     (5)    a dose-related decrease in the time to tumor
            formation or death with tumors; and

     (6)    a dose-related increase in the proportion of
            malignant versus benign tumors.

     In characterizing the overall weight of the evidence for
human carcinogenicity, the human and animal studies are evaluated
both individually and in combination, followed by an analysis of
all the supporting information to determine if the overall weight

of the evidence should be modified.  This analysis results in a
grouping by EPA into one of the following categories:

      (1)    Group A (Known Human Carcinogen):  Used only when
            there is sufficient evidence from epidemiological
            studies to support a finding that a causal
            relationship exists between exposure to the chemical
            and cancer;

      (2)    Group B (Probable Human Carcinogen):  Used when there
            is sufficient evidence of carcinogenicity based on
            animal studies and limited epidemiological evidence
            (Group Bl) or inadequate or no human data (Group B2);

      (3)    Group C (Possible Human Carcinogen):  Used when there
            is limited evidence for carcinogenicity in animals
            and inadequate or no human data;

      (4)    Group D (Not Classified): Used when there is
            inadequate animal evidence of carcinogenicity and
            inadequate or no human data; and

      (5)    Group E (No Evidence of Carcinogenicity for Humans):
            Used when no evidence for carcinogenicity is found  in
            at least two adequate animal tests in different
            species or in both adequate epidemiologic and animal

     The EPA classifications undergo review and evaluation by the
EPA Science Advisory Board (SAB),  and may be revised by EPA if
differences in classification occur.

     Although the above guidelines, based on the available animal
and human data, are generally used in classifying chemicals, in
some cases the known chemical or physical properties of a
chemical and the results from short-term tests allow transfer of
a chemical from groups B2 to Bl, C to B2, or D to C.

     Dose-Response Assessment

     There are three major components to dose-response
assessment: selection of the appropriate data based on factors
such as the data's quality and its relevance to human modes of
exposure, the choice of a relevant mathematical model to
extrapolate from high to low doses, and the choice of the
appropriate factors to be used when extrapolating data from
animal studies to humans.  Dose-response assessments may provide
carcinogenic unit risk estimates (i.e., estimates of the cancer
risk that would occur from exposure to a specific unit
concentration of the agent).   Unit risk estimates should be
presented in those circumstances in which there is a reasonable
possibility that an agent is carcinogenic to humans based on a


weight of the evidence analysis (classification in group C or
above); it is not necessary that the agent be causally
associated with cancer in humans.

     Selection of data for the assessment relies heavily on
experience gained in the hazard identification.  Whenever
possible, estimates based on human epidemiological data are
preferred.  Use of these data forgoes the uncertainties of
interspecies extrapolation.  On the other hand, these studies may
have several shortcomings, as discussed earlier.  In the absence
of well-designed and well-conducted epidemiological studies, data
from well-conducted animal studies are used.

     Selection of the appropriate animal data is made based on
their perceived relevance to human exposures and response
(e.g., similarities in pharmacokinetic parameters, exposure
route, length of exposure, and/or site of action).  Within this
context, the most sensitive animal species and s^ex is used for
estimating human cancer risk.

     Exposures of the general population to carcinogens are
generally much lower than those in animal or epidemiological
studies.  Animals are often exposed to levels 10,000 to 1,000,000
times that in the ambient environment, while levels in human
occupational environments, those generally used for
epidemiological studies, are typically 100 to 10,000 times that
of nonoccupational groups.  Therefore, it is necessary to use
mathematical extrapolation models to estimate the carcinogenic
response expected at lower exposure levels.  Selection of the
appropriate model for low-dose extrapolation of animal studies is
critical because large differences in the projected risk may
occur at low doses.  Of the numerous models which have been
developed, no single model is recognized as the most appropriate.
The models or procedures employed should be consistent with any
relevant biological data on the mechanisms of action of the
carcinogen.  When such data do not exist, the EPA guidelines
recommend use, as appropriate, of the multistage procedure.  This
procedure is based on a currently-held theory that carcinogenesis
results from a series of heritable changes or stages required for
a normal cell to become malignant.  The EPA uses a minor
variation of this procedure called the linearized multistage
procedure, which forces a linear term into the low-dose risk
extrapolation.  Use of this procedure results in a plausible
"upper limit" to the risk (i.e. the true risk is not likely to
exceed the value, but may be lower and even zero).

     In addition to extrapolation of the dose-response data from
high to low doses, dose-response assessments must estimate  a
human exposure which will result in an equal carcinogenic
response in humans to that obtained in the animal studies.  A
variety of factors differ between humans and animals, including
life span, body size, genetic variability, pharmacokinetic  and


pharmacodynamic parameters,  and the exposure regimen.   Because
data to address these differences are generally limited,  the
usual approach to making interspecies comparisons is the use of
standardized scaling factors for dose equivalence.   For example,
EPA uses mg/m2 body surface  area/day since certain
pharmacological effects scale according to surface area.   FDA
uses a scaling factor based  on body weight that leads to dose
response extrapolations that are generally an order of magnitude
less than the EPA approach.

     The general outcome of  the dose-response assessment is an
estimate either of the cancer risk that would occur from
exposure to a specific unit  concentration of the agent (i.e., the
incremental unit risk, often shortened to unit risk) or of the
dose of the carcinogen that  would result in a given level of
increased risk.

     Exposure Assessment

     To obtain estimates of  cancer risk for exposures to the
population of interest, the  results of the dose-response
assessment must be combined  with exposure estimates.  At present,
there is no single approach  to exposure assessment.  Each
exposure assessment must be  tailored to the needs of the problem
at hand.  However, EPA has prepared guidelines (EPA, 1986b) for
exposure assessment which outline the following five major

     (1)    Sources: an assessment of the relevant sources of the
            chemical to the  environment, including an analysis of
            production, distribution, use, disposal, and
            environmental release;

     (2)    Exposure pathways and environmental fate:  an analysis
            of how the chemical moves through the environment
            from the source  to the exposed individual or

     (3)    Measured or estimated concentrations: an estimation
            of the environmental concentrations of the chemical
            available for exposure based on measured data, the
            use of mathematical models, or both;

     (4)    Exposed populations: an evaluation of populations and
            sensitive subpopulations (e.g., infants, the elderly,
            and the chronically ill)  which may be exposed to the
            chemical by the  various routes of interest; and

     (5)    The integrated exposure analysis: a set of exposure
            profiles which address, for each source, the size of
            the exposed population, and the routes, duration,
            frequencies, and intensities of exposure.


     The final exposure assessment should be designed to be
readily integrated with the dose-response assessment data.
Generally, lifetime average daily exposures (LADEs) are
calculated assuming that a high dose of a carcinogen received
over a short time period is equivalent to a corresponding low
dose spread over a lifetime.  EPA will continue to use this
assumption until more data or newer procedures become available.
These exposures are then combined with an estimate of the
additional lifetime unit risk from exposure to the carcinogen to
characterize risk.

     Risk Characterization

     Risk characterization combines the results from the hazard
identification, the dose-response assessment,  and the exposure
assessment to estimate the adverse health effects from pollutant
exposure.  Risk characterization is comprised of two parts.  The
first part involves numerically estimating the risk to human
health.  The second part involves developing a framework in which
the uncertainties associated with these risk estimates can be

     Presentation of numerical risk estimates vary with the needs
of the program offices within EPA.  In some cases, the unit risk
or the dose associated with a particular level of risk will be
presented.  These values can then be compared with information in
the exposure profiles to estimate the risk of particular

     Generally, risks are reported in terms of additional
lifetime risk estimates for individuals exposed to maximum and
average levels of the agent or in terms of risks for an entire
exposed population.  For example, to obtain the individual
lifetime risk for a person exposed to a particular concentration
of a carcinogen, the incremental unit risk may be multiplied by
the lifetime average daily exposure of that person.  Population
(or aggregate) risk, on the other hand, applies across the
population of interest, and is expressed as expected increased
cancer in the population over some specified time period
(generally, annually).

     Some risk estimates are prepared for exposure to multiple
chemicals.  In such cases, it is assumed that the population
risks for each chemical may be added together, unless there is
toxicological evidence to the contrary.

     The predicted risk should be presented with an accompanying
estimate of the uncertainty of the data from the hazard
assessment, the dose-response assessment, and the exposure
assessment.  This evaluation provides the decision-maker with a
better understanding of the impact of these uncertainties  on the
risk estimate.



     As discussed in the previous section,  numerous variables are
analyzed in performing a risk assessment,  each variable having
its own associated uncertainty.   In addition,  although the
standard framework for performing a risk assessment does not vary
(i.e.,  hazard identification, dose-response assessment, exposure
assessment, and risk characterization),  the methods used to
perform each of these elements can vary widely based on factors
such as the type of information available,  its associated
uncertainties,  and its perceived scientific validity.  Scientific
assessments of the accuracy and relevance of information used for
each of the variables in a risk assessment may diverge,
resulting in vast differences in the final outcome of each risk
assessment and its associated uncertainties.

     Scientific disagreement regarding risk assessments can occur
both in the proper classification of a carcinogen (i.e., the
determination of the weight-of-the-evidence for carcinogenicity)
and in the final determination of the quantitative risk estimate.
An example of divergence of scientific opinion concerning
classification is perchloroethylene.  For perchloroethylene, the
main issue concerning classification is centered around the
evidence for carcinogenicity in the rat.  The EPA Human Health
Assessment Group (HHAG)  has proposed to classify
perchloroethylene as a Group B2 "probable human carcinogen" based
on statistically significant increases in liver carcinomas in
male and female mice, a marginally statistically significant
increase of mononuclear cell leukemia and an increased incidence
of normally rare kidney tumors in male rats, and supporting
evidence showing that an epoxide metabolite of perchloroethylene
is a mutagen.

     The Halogenated Organics Subcommittee of the EPA Science
Advisory Board (SAB), upon reviewing the HHAG's risk assessment,
has questioned the evidence for carcinogenicity in the rat,
initially concluding that perchloroethylene should be classified
as a group C "possible human carcinogen."  With respect to the
kidney tumors,  the Subcommittee questioned the diagnosis of
neoplasia, and objected to combining benign and malignant tumors.
With respect to leukemia, the Subcommittee questioned the
diagnosis and evaluation of the disease and objected to the
inclusion of preleukemic stages in the statistical analysis of
tumor incidence.  Concerning the increase of mouse liver tumors,
the Subcommittee agreed that perchloroethylene caused these
tumors but questioned their relevance to humans.

     After a further review of the HHAG position regarding
classification of perchloroethylene, the SAB Subcommittee has
modified their classification, stating that perchloroethylene
should be viewed as on the "continuum" between Groups B2 and C.


The HHAG is currently reevaluating its classification of this
chemical, in response to the SAB review.

     Variations in the estimation of the quantitative risk can
come from differences of opinion regarding the hazard
identification, the dose-response assessment, or the exposure
assessment.  Para-dichlorobenzene is another example of
differing views regarding hazard identification.  At this time,
para-dichlorobenzene has been classified as a Group C carcinogen
by EPA based on studies in laboratory animals using the oral
route of exposure  (52 FR 25690, July 8, 1987).  However, in
making this classification, EPA has stated that "the
classification of para-dichlorobenzene as a Group B2 or Group C
substance is a controversial one.  EPA will reassess this
classification as new information becomes available."

     A second issue of controversy is the uncertainty involved in
using the oral bioassay data to estimate risks from inhalation
exposure.  A para-dichlorobenzene inhalation bioassay was
performed which failed to detect an increase in tumor incidence
in rats.  However, because of the short duration of exposure in
the inhalation study (18 versus 24 months) and the possibility
that a higher dose of para-dichlorobenzene may have resulted in a
different response, the adequacy of this study has been
questioned.  Nevertheless, in view of these results and
additional questions regarding the relevance of the tumors
observed in the laboratory animals to tumor formation in humans,
quantitative estimates of carcinogenic risks from para-
dichlorobenzene, based on the oral exposure bioassays, are
considered by EPA to be very uncertain.  The EPA Office of
Pesticide Programs (OPP) has required an industry-sponsored
bioassay to further address the carcinogenicity of para-
dichlorobenzene by the inhalation route.

     There are also differences of opinion on both whether and
how pharmacokinetic data should be factored into the analysis of
carcinogenic risks, and whether pharmacokinetic models should be
used only to extrapolate carcinogenic risks from high to low
doses, or also to extrapolate between species.  Recently,
various models have been developed to relate an exposure (e.g.,
inhalation) to the corresponding dose at the organ level.  This
reflects the contention that carcinogenic activity is more
directly the result of the delivered dose (i.e., the dose at the
organ level)  than the applied dose (i.e., the exposure level).
Therefore,  these models may more accurately equate an exposure to
its corresponding carcinogenic risk.  EPA has recently applied
pharmacokinetic modeling to determine the risks from exposures to
methylene chloride.  The use of these models has had an impact on
EPA's assessment of the risks from exposure to this compound,
causing a 9-fold decrease in EPA's previous unit risk estimate.

     One of the major sources of variations and uncertainties in
cancer risk assessments is the choice of the data and methods
used for low-dose extrapolations.  Data from one study or from
several different studies may be used in the analysis.  Even when
using data from one bioassay, results can vary widely due to
factors such as the choice of a particular sex or tumor type, the
grouping of data from several tumor types in the analysis, and
the pooling of benign and malignant tumors.  In addition, methods
used for low-dose extrapolation of the same data set can result
in differences of many orders of magnitude.  Therefore, choice of
an appropriate low-dose extrapolation model is important and
should be based on an overall knowledge of the agent and its

     Risk assessments can also vary widely based on whether the
unit risk estimate chosen is the "maximum likelihood estimate"
(MLE) or the "upper confidence limit" (UCL).   The MLE is a
statistical estimate of the most likely value within the observed
(i.e. high dose) range of the dose-response.   It should be noted
that the MLE for the low dose range is calculated by an extension
of the MLEs in the high dose range and may therefore not
represent the optimal value.  The UCL is larger than the MLE and
represents the upper confidence level of the risk (i.e., for the
95% UCL, 95% of the time,  the true risk is not expected to exceed
this value, and may be lower and even zero).   Although the MLE
and the UCL for many chemicals are within an order of magnitude,
this is not always the case.  An example of the wide variations
which may occur due to this choice is formaldehyde,  for which the
EPA estimates of the MLE and UCL vary by six to seven orders of
magnitude at very low doses.

     Another source of variation and uncertainty is the exposure
data used.   For the same agent, the estimated exposures can vary
widely depending on factors such as the monitoring protocol used,
the types of modeling used, the parameters chosen to represent
the frequency and duration of exposure,  and the populations and
subpopulations of concern and their locale.  Likewise, averaging
exposure over a lifetime (e.g., use of an LADE) may not
characterize risks from acute exposures, where  detoxification
metabolic pathways are saturated at low levels.

     In summary, different risk assessments for the same agent
may diverge greatly due to the numerous variables analyzed and
their associated uncertainties.  An understanding of the number
and types of elements that go into a risk assessment and their
associated uncertainties are necessary to a complete
understanding of the risk characterization presented.


     In this section of the report, a number of the cancer risk
assessments that have been conducted by EPA for indoor air
pollutants are discussed.  Exhibit 4-1 presents a summary of
cancer risk estimates for selected indoor air contaminants.  An
estimate of the annual cancer incidence resulting from indoor air
pollution has only been provided for one pollutant, radon.  The
remaining estimates are unit risk estimates, providing
information on the cancer risk that is estimated to occur from
continuous lifetime exposure to a specific unit air
concentration.  These numbers, therefore, can only be used to
determine risks to specific individuals in the population or to
determine cancer incidences if combined with appropriate exposure

     Estimates of annual cancer incidences for pollutants in
indoor air, other than radon, have not presently been established
by EPA.  Estimates of lifetime individual risks for formaldehyde
have been made only for subsets of the U.S. population, based on
exposure to a specific concentration of formaldehyde in indoor
air.  Lifetime individual risk estimates for indoor air exposures
to the other pollutants have not been established by EPA.

     Risk estimates presented for radon, asbestos, and benzene
are "maximum likelihood estimates" (MLEs) based on human
epidemiological data.  The unit risk estimates presented for the
organic chemicals, with the exception of benzene, are based on
animal bioassay data and represent the "upper-bound" estimate of
the risk.  A further discussion of the EPA risk estimates by
pollutant type follows.


     Assessing the total cancer risk to the general population
for radon exposure is complicated by two factors.  First, the
distribution of radon levels in the U.S. is not well documented.
Indoor radon levels vary widely according to region, building
construction, and indoor air flow characteristics.  Second, radon
risk assessments are based on epidemiological data on male
uranium miners who tended to be smokers.  Nonetheless, EPA has
attempted to predict the lung cancer deaths caused by exposure to
typical levels of radon, classified by EPA as a Group A

     The EPA Office of Radiation Programs  (EPA, 1987a) has
estimated the risk of death from lung cancer caused by exposure
to indoor radon in four steps:  (1) determining the radon  decay
product concentrations from the radon concentration;
(2)  estimating the cumulative radon decay product  exposure;
(3)  converting the individual cumulative exposure  to the  lifetime
risk; and (4) projecting the individual lifetime  risks to  the


                           Exhibit 4-1
                   EPA Cancer Risk Assessments
 Unit Risk1
Annual Excess
Cancer Cases
 2.3  X 10~4  to
 9.2  X 10~4/WLM(A)
EPA (1987a)







Benz(a) -

pyrene  (BaP)
 8.3  x 10~6/ug/m3(A)

 4.7  x 10~7/ug/m3(B2)   —

 2.3  x 10~5/ug/m3(B2)   —

 1.5  x 10~5/ug/m3(B2)

 2.6  x 10~5/ug/m3(B2)

 1.7  x 10~6/ug/m3(B2)
 5.8  x 10"7/ug/m3
FORMALDEHYDE     1.3 x 10~5/ug/m3(Bl)
 8.9  x  10~4/ug/m3(B2)

 1.7  x  10~3/ug/m3(B2)
                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1987b)
                 EPA  (1988)

                 EPA  (1988)
     l-Unit risk of the pollutant  is the  lifetime risk of
contracting cancer per unit exposure.

                       Exhibit 4-1  (cont.)
                   EPA Cancer Risk Assessments
Unit Risk
Annual Excess
Cancer Cases
PAHs (cont.)


1.4 x 10~2/ug/m3(B2)

2.7 x 10~3/ug/m3(B2)  —
                 EPA  (1988)
                 EPA  (1988)






4.9 x 10~3/ug/m3(B2)

3.7 x 10~4/ug/m3(B2)

4.6 x 10~3/ug/m3(B2)

1.3 x 10~3/ug/m3(B2)

3.8 x 10~4/ug/m3(C)
                 1.6 x  10
                 2.3 x  10~3/
                 0.01 fib/ml(2'3)(A)
                 1.8 x  10
                 2.7 x  10~3/
                 0.01 fib/ml(3'4)(A)
                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1988)

                 EPA  (1986d)

                 EPA  (1986d)
     2Lung cancer

     3Fibers as measured by phase  contrast microscopy


entire U.S. population.   Using data from uranium miners,  the
model estimated the carcinogenic unit risk from radon exposure to
be a 1 - 4% increase in baseline risk per working level month
(WLM) .   For the US population, the lifetime unit risk projected
by the model is 2.3 x 10~4 to 9.2 x 10~4 per WLM.  At an average
U.S. lifetime radon exposure of 0.004 WL, this translates to
between 5,000 and 20,000 excess lung cancer deaths per year.
[Note:  Based on revised estimates of risk and background exposure
soon to be published by EPA, about 20,000 excess lung cancer
deaths are projected annually.]


     As noted throughout this report, VOCs as a class of indoor
air pollutants are poorly understood.  Data are incomplete at
best regarding the carcinogenicity and dose-response
relationships for most of the VOCs that are detected indoors.
Concentration levels to which people are exposed are highly
variable.  Periods of relatively intense exposure, which are not
necessarily captured by a general monitoring survey, may make a
significant contribution to lifetime exposure to a particular
VOC.  Identifying and characterizing the sources of indoor air
pollutants is in an early stage of development.  The
identification and characterization of the size and makeup of
populations exposed to different sources and indoor air
concentration levels of VOCs is likewise in an early stage of
development.  Because of these limitations, EPA has not
established either individual risk estimates or estimates of the
number of cancer cases resulting from exposures to VOCs in indoor
air environments.

     EPA has established unit risk estimates for atmospheric
exposures to many VOCs for other purposes  (e.g., estimating risks
from outdoor sources of these pollutants).  Exhibit 4-1 presents
EPA's unit risk estimates for benzene and several halogenated
hydrocarbons.  Although the unit risk estimates for these VOCs
represent only a small fraction of those available for indoor air
pollutants, they were selected because the compounds are
frequently detected in indoor environments.


     EPA (1987b) has classified formaldehyde as a probable  (Bl)
human carcinogen based on sufficient animal and limited human
evidence, and other supporting data.  The upper-bound  (UB) unit
risk estimate for a lifetime ambient exposure to  1.0 ug/m^  is
1.3 x 10~5.  Using this unit risk estimate, EPA has calculated
an upper-bound lifetime cancer risk estimate of 2 x 10~4 for
residents of mobile homes who are exposed  for ten years to  an
average level of 0.10 ppm, or twice the estimated background
level of 0.05 ppm; and 1 x 10~4  (UB) for residents of  some

conventional homes who are exposed for ten years to an average
level of 0.07 ppm.

     The corresponding maximum likelihood estimates (MLEs) for
these exposures are much lower; 2 x 10~10 and 6 x 10"11,


     EPA unit risk estimates for four PAHs found in indoor air
are presented in Exhibit 4-1.  These four PAHs are classified as
"probable human carcinogens" (Group B2).


     EPA has computed unit risk estimates, based on animal
studies, for several of the major pesticides commonly detected
indoors (Exhibit 4-1).  With the exception of lindane,
classified C, these pesticides are classified as B2 carcinogens.


     EPA has listed asbestos as a Group A human carcinogen based
on human epidemiological data.  Data developed since the early
1970's, from large population studies with long follow-up, have
strengthened the association of asbestos exposure with cancer in
occupational settings.  However, because of large uncertainties
in extrapolating the occupational data to levels measured in the
environment, estimates of risks from asbestos at low
concentrations should be viewed with caution (EPA 1986d).

     EPA (1986d) has estimated the unit risks of lung cancer and
mesothelioma from asbestos exposure (Exhibit 4-2).  These two
cancers are the most important causes of death among asbestos-
exposed individuals.

                           Exhibit 4-2
Risks  (x 10~6)  from Lifetime Asbestos  Exposure to 0.01 Fibers/ml

Population            Lung Cancer              Mesothelioma
Female Smokers
Female Nonsmokers
Male Smokers
Male Nonsmokers


Source:  EPA (1986d)


     In this section of the report, the additional information
 available in the literature on the risks from exposure to
 pollutants in indoor environments is described.  It should be
 noted that the studies presented in this section of the report
 have not generally undergone any form of critical review by EPA.
 More importantly. EPA has not provided a detailed written
 evaluation of these studies, examining their strengths and
 weaknesses in addressing a quantitative analysis of the level of
 risk from indoor air pollutants.  From a cursory analysis, it. is
 clear that some aspects of these analyses would not be acceptable
 to EPA [e.g.. Tancrede et al.'s use of acute lethality data
 (LDSOs) to estimate carcinogenic unit risk estimates for
 chemicals without bioassay data] .  Therefore, EPA does not.
 necessarily agree with the study designs used or with the
 conclusions reached by the authors of these assessments.
 Nevertheless, risk assessments prepared outside the Agency are
 presented here because, in many cases,  they represent the only
 quantitative estimates of the individual risks or annual cancer
 incidences presently available for certain indoor air pollutants.

     As discussed above, estimates of quantitative risk are
 subject to large variations, due to uncertainties occurring at
 each step in the analysis.  These variations are apparent in many
 of the studies presented here, emphasizing the large
 uncertainties associated with these assessments.

     Exhibit 4-3 summarizes the risk estimates for indoor
 pollutants obtained from sources outside the Agency.  Estimates
 are provided for radon, ETS, VOCs,  formaldehyde, and asbestos.
 Estimates for radon and asbestos are unit risk estimates based on
 human epidemiological data.  Estimates for radon fall within a
 factor of two of the range of EPA unit risk estimates, presented
 earlier.   EPA unit risk estimates for asbestos are within the
 range of estimates presented by others.   However, it should be
 noted that the similarity of these estimates to EPA-generated
 estimates does not lend any particular credence to their

     Several estimates of the annual cancer incidence from ETS
exposure,  based on human epidemiological studies, are also
presented.   The estimates range from 12 to 5,200 cases per year.

     The risk associated with exposure to VOCs has not been
well-studied because of the number and diversity of these
compounds,  and a scarcity of exposure data for indoor air
environments.   Two investigators,  however, have estimated the
additive individual risk posed by exposure to typical levels of
several VOCs in indoor air.  Another investigator has estimated
that the additive annual cancer incidence from exposure to six


                                                       Exhibit  4-3
                                            Non-EPA Cancer Risk Assessments

Pol lutant


Excess Ind. Estimated
Lifetime Amual Excess
Unit Risk1 Risk (x 10"6)2'3 Cancer Cases
3.5 x 10"4/WLM
1.3 x 10"4/WLM
5 x 10"5/person- -- 5,000 +/- 300(4)
year/mg tar/day

NRC (1988)
NCRP (1984)
Repace & Lowrey (1985a,
1986, 1987)
 6 VOCs
 9 VOCs (NJ)



(98th perc.)(6)
Arundel et al. (1987)

Robins (1986)

Wells (1988)

Wells (1988)

Wallace (1985)

Tancrede et al. (1987)
 NOTE:  The studies presented in this Exhibit have not been critically evaluated by EPA for their strengths
 and weaknesses in addressing a quantitative analysis of the level of risk froi indoor air pollutants.
 Therefore. EPA does not necessarily agree with the study designs used or with the conclusions reached
 by the authors of these assessments.
      Unit risk of the pollutant is the lifetime risk of contracting cancer per unit exposure.

      Excess individual lifetime risk is the risk of death (over and above normal risk) due to lifetime
exposure to the pollutant.

      Exposures on which these values are based are discussed in the text.
      Lung cancer
      Non-lung cancers

     6Tancrede and coworkers calculated mean and 98th percent!le values assuming that both exposure and
risk were random variables which can each take on a range of values, some more probable than others.  This
approach  varies from EPA's approach, where a specific "maximum likelihood estimate" or "upper-bound" unit
risk estimate is multiplied by an individual exposure level.


                                                 Exhibit 4-3 (cont.)
                                           Non-EPA Cancer Risk Assessments

Pollutant Unit Risk
Excess Ind.
Risk (x 10"6)2'3
Annual Excess
Cancer Cases

VOCs (cont.)

19 VOCs (CA)

15 VOCs

1.1  x 10~1/
(3.3 x 10~5/
               7.5 x 10"5  to
               1.6 x 10"3/
               0.01  fib/ml(4'7)
2.3 x 10"4/
0.01 fib/ml
               1.6 x 10"4  to
               1.6 x 10"3/
               0.01  fib/ml(4/7)
               1.7 x 10~3  to
               2.7 x 10~3/
               0.01  fib/ml(7'8)

               4 x 10"6 to
               7.6 x 10~4/
               0.01  fib/ml<4'7)
                    2,000  (mean)(6)
                    (98th  perc.)(6)
34,000 (mean)
(98th perc.)

                                            Tancrede et al.  (1987)

                                            McCann et al.  (1986)

                                            Tancrede et al.  (1987)
                                                                               McCann et al. (1986)
                                                                WAS (1984), as cited  in
                                                                  EPA (1986d)
                                             WAS  (1984),  as  cited in
                                                    EPA  (1986d)

                                             CPSC (1983),  as cited in
                                               EPA (1986d)
                                                                CPSC (1983), as cited  in
                                                                  EPA  (1986d)
                                                                Ontario  Royal  Commission
                                                                   (1984),  as cited  in EPA
MOTE:   The studies presented in this Exhibit have not been critically evaluated by EPft for  their  strengths
and neatnesses in addressing a quantitative analysis of the  level of risk from indoor air pollutants.
Therefore. EPA does not necessarily agree  uith  the study designs used or uith the conclusions  reached
by the authors of these assessments.
      Fibers  as  measured  by  phase  contrast microscopy


                                                 Exhibit 4-3 (cont.)
                                            Non-EPA  Cancer Risk Assessments
Unit Risk
                                   Excess  Ind.
Risk (x 10"°)
Annual Excess
     Cancer Cases
ASBESTOS (cont.)
               1.4 x 10"5  to
               1.9 X 10~3/
               0.01  fib/ml
               8.6 x 10~5 to
               2.9 x 10~3/
               0.01  fib/ml
               2.5  x 10~4/
               0.01  fib/ml
               5.6 x 10~5/
               0.01 fib/ml(7'8)
               6.8 x 10~5 to
               1.5 x 10"3/
               0.002 fib/ml
               7.8 x 10~4/
               0.002 fib/ml
                                             Ontario  Royal Commission
                                               (1984), as cited  in EPA

                                             Advisory Committee  on
                                               Asbestos  (1979),  as
                                                   cited in EPA (1986d)

                                             Doll  and Peto (1985), as
                                                   cited in EPA (1986d)

                                             Doll  and Peto (1985), as
                                                   cited in EPA (1986d)

                                             Breslow  et  al. (1986)
                                                                 Breslow et  al.  (1986)
NOTE:  The studies presented in this Exhibit have not been critically evaluated by EPA for their strengths
and weaknesses in addressing a quantitative analysis of the level  of  risk  froa indoor air pollutants.
Therefore. EPA does not necessarily agree nith the study designs used or with  the conclusions  reached
by the authors of these assessments.

specific VOCs in indoor air ranges between 1,000 and 5,000 cases
per year.

     Unit risk estimates and individual risk estimates for
formaldehyde vary widely, apparently due to the non-linearity of
the dose-response curve for this chemical.  EPA risk estimates
(both the MLE and the upper-bound estimates)  are generally lower
than the estimates provided by other sources.

     Finally, the carcinogenic risks from exposure to
particulate matter, biological contaminants,  and the combustion
gases have not been addressed.  A further effort is clearly
needed in these areas in assessing the overall risks from indoor
air pollution.  The studies summarized in Exhibit 4-3 are
discussed in greater detail below.


     Two groups, in addition to EPA, have provided unit risk
estimates for radon exposure based on epidemiological data for
male uranium miners.  The National Research Council (NRC, 1988),
in the BEIR IV Report, estimated a unit risk for radon exposure
of 3.5 x 10~4 per WLM, based on data from four studies of uranium
miners.  The National Council on Radiation Protection and
Measurement (NCRP, 1984), estimated the unit lung cancer risk
from lifetime exposure to radon of 1.3 x 10~4 per WLM.  These
estimates are within a factor of two of the range of unit risks
established by EPA.

     Environmental Tobacco Smoke

     In 1986, the U.S. Public Health Service (Surgeon General,
1986)  and the National Research Council (NRC, 1986) concluded
that environmental tobacco smoke  (ETS) is a cause of lung cancer
and other disease in nonsmokers.  Tobacco smoke intentionally
inhaled is known to cause the premature deaths of 1000 smokers
per day,  from lung cancer and other cancers,  cardiovascular
diseases, and respiratory diseases  (Surgeon General, 1979).
Independent scientific committees organized by the Surgeon
General and National Research Council  (Surgeon General, 1986;
NRC,  1986),  in reviewing thirteen epidemiologic studies that have
implicated ETS as a cause of lung cancer in nonsmokers, have
judged these studies to prove causality between ETS exposure and
lung cancer.  Several investigators have estimated the annual
incidences of lung cancer and other cancers resulting from
exposure to ETS.  A discussion of some of these studies is
provided below.

     Robins (1986) estimated U.S. lung cancer death rates  from
ETS by combining data on urinary cotinine dosimetry and estimates
of the relative risk of passive smoking, as well as by fitting
the multistage procedure to the data on the lung cancer


experience of active smokers.  Based on extrapolations from
urinary cotinine, Robins estimated.a range of exposure for
nonsmokers to ETS of from 0.1 to 2.8 cigarettes per day (cpd).
Estimates for nonsmokers with smoking spouses ranged from 0.4 to
2.8 cpd, and estimates for those with nonsmoking spouses ranged
from 0.1 to 0.9 cpd.

     Based on urinary cotinine and epidemiological studies
showing a relative risk of 1.3 for passive smoking, Robins (1986)
estimated 1770 deaths per year in women and 720 deaths per year
in men, for a total of about 2,500 U.S. lung cancer deaths per
year from ETS.  Based upon the multistage procedure and the risks
of lung cancer from active smoking,  Robins estimated about 5,200
US deaths per year, 3,320 in females, and 1,940 in males.
[However, it should be noted that extrapolations of the data on
cancer risks from smokers to nonsmokers are uncertain.  One
problem with this approach is that smokers are a very high
exposure group in whom the normal pulmonary defense mechanisms
are overwhelmed  (e.g., paralysis of respiratory cilia).  Non-
smokers may not be exposed to high enough levels for such effects
to occur and they may be at risk from different components of the
smoke than are smokers and as such there may be considerable
uncertainty in using tumor data in smokers to extrapolate to
nonsmokers].  The range of Robin's estimates is from 2,500 to
5,200 lung cancer deaths per year.

     Robins also estimated that the lifetime lung cancer death
risk to lifelong nonsmokers from ETS ranges from 4 x 10~3 to
1 x 10~2, and that the estimated lifetime lung cancer death risk
to ex-smokers (who smoked for about 25 years and quit at age 45)
from ETS is from 5 x 10~3 to 2 x 10~2.  Robins estimates are
adjusted for "true relative risk", which accounts for the fact
that nonsmokers in most epidemiological studies of passive
smoking and lung cancer who are termed "unexposed" by virtue of
having a nonsmoking spouse indeed have finite urinary cotinine,
generated by exposures outside the home (e.g., the workplace).

     Repace and Lowrey (1985a) assessed nonsmokers' risk of lung
cancer due to respirable particulate (RSP) exposure from ETS.
RSP exposures were estimated from a model and from empirical
data.  Lung cancer response was estimated from epidemiologically
assessed, age-standardized differences in lung cancer mortality
rates between two demographically comparable cohorts of lifelong
nonsmokers.  One of these cohorts, Seventh Day Adventists  (SDAs),
has a lifestyle with a high percentage of restrictions on smoking
at home and at work relative to the other cohort, demographically
comparable nonSDAs.

     Repace and Lowrey (1985a) estimated that 4,700 lung cancer
deaths occurred annually in lifelong nonsmokers and ex-smokers
due to ETS exposure in the home and the workplace among the  62.4
million nonsmokers aged > 35 years.  The initial calculation did


not differentiate between male and female nonsmokers,  and age-
standardized the calculation to the entire US population, which
included smokers. A later refinement for these factors estimated
1,441 male nonsmoker and 3,450 female nonsmoker deaths, for a
revised total of about 4,900 lung cancer deaths per year (Repace
and Lowrey, 1986; 1987).  Repace and Lowrey (1985a, 1986, 1987)
estimated the uncertainty in their risk estimate at + 300.

     The unit risk estimate for Repace and Lowrey's studies was
5 x 10~5 lung cancer deaths per person-year at risk, per mg of
exposure to tobacco tar per day, with the average exposure
estimated at 1.4 mg of tar daily.  A lifetime risk of about
2 x 10~2 to the most-exposed population was estimated.  The loss
of life expectancy for lung cancer mortality, averaged over the
population, was estimated to range from 15 to 148 days, and the
loss of life expectancy per fatality was estimated at 17 + 9

     Arundel et al. (1987) estimated particulate tobacco smoke
exposure from empirical data, and response from the lung cancer
risks in smokers.  By factoring in the ratio of estimated
relative deposition of tar in the lungs of smokers and
nonsmokers, and linearly extrapolating to the estimated exposure
levels of nonsmokers from the exposure levels in smokers, Arundel
et al. estimated 12 lung cancer deaths per year from passive
smoking.  However, it should be noted that while tar deposition
in nonsmokers may be far less than in smokers, other putative
carcinogens may be more concentrated in the smoke to which
nonsmokers are exposed.  Arundel et al. suggested that the
differences between their estimates and those based upon
epidemiologic methods in nonsmokers may be due to bias in the
epidemiology (unspecified), a supralinear relationship between
exposure and risk, or a greater carcinogenicity for sidestream
relative to mainstream smoke.

     Wells (1986, 1988) calculated the risks for nonsmokers of
lung cancer and other cancers based on epidemiological data on
adult mortality from passive smoking.  A preliminary risk
assessment of U.S. passive smoking deaths from cancer was made by
applying the risk ratios from the epidemiology studies to
estimates of the exposed population and to non-smoker death rates
from an American Cancer Society study of mortality in one million
U.S. men and women (Hammond, 1966).  Wells (1988) estimated 3000
lung cancer deaths per year in lifelong nonsmokers aged > 45 yrs
and 11,000 deaths from other cancers.

     Kuller et al. (1986) constituted a workshop panel assembled
to review the data from the epidemiologic studies of passive
smoking.  The Workshop on the Contribution of Airborne
Pollutants to Respiratory Cancer was sponsored by the Interagency
Task Force on Environmental Cancer and Heart and Lung Disease,
established by the Clean Air Act Amendments of 1977, and chaired


by EPA.  The panel concluded that data indicate that "the greater
number" of an estimated 6,000 to 8,000 lung cancers in lifelong
nonsmoking women is probably related to environmental tobacco

     In summary, estimates of annual lung cancer cases in
nonsmokers resulting- from passive smoking range from 12 to 5,200.
Most of the estimates fall between 2,500 and 5,200 lung cancer
deaths per year (see Exhibit 4-3).

     Volatile Organic Chemicals

     As discussed above for EPA VOC risk assessments, limited
data are available for assessing risks from indoor air exposures
to these chemicals.  As a consequence, there have been few risk
assessments conducted for VQCs in indoor environments, either
individually or as a group.  Those that have been done have
combined available personal exposure or indoor air monitoring
data for specific VOCs with unit risk estimates for these
compounds.  Each of these studies has determined the additive
risk posed by the chemicals evaluated, although it is not clear
if these risks are additive, or whether synergistic or
antagonistic effects occur in indoor air mixtures.  It should be
noted that the studies have addressed only a small subset of the
VOCs present in indoor air; a much more comprehensive study is
needed to fully evaluate these risks.  A summary of the available
studies is provided below.

     Wallace (1985) used 24-hr personal exposure monitoring data
from the EPA TEAM study to construct a risk assessment for
benzene, chloroform, carbon tetrachloride, trichloroethylene,
tetrachloroethylene, and para-dichlorobenzene in indoor air.
This personal exposure monitoring data was chosen to apply to
700,000 residents of four states (New Jersey, California, North
Carolina, and North Dakota), but was employed in this risk
assessment as representative of the total U.S. population.  In
addition, data from the former two states were assumed to
represent exposures to individuals in metropolitan areas, while
data from the latter two states were assumed to represent those
in non-metropolitan areas.

     Lifetime average exposures were estimated based on the
limited monitoring data available (one to three 24-hr air
monitoring samples for each of 600 individuals monitored  in the
study), but Wallace stated, based on the variation across five
sampling areas, that the error in the mean value may not be more
than a factor of two.  [It should be noted that the use of
personal monitoring data, rather than indoor air monitoring data,
may over- or underestimate risks from indoor air, since exposures
during the periods spent in other settings  (e.g., outdoor or
industrial)  would be included in the total personal exposure.

However, data indicate that individuals spend the majority of
their time indoors.]

     Of these six chemicals,  only benzene is a known human
carcinogen (EPA Group A).  The rest are animal carcinogens.
Chloroform, carbon tetrachloride, and trichloroethylene have been
classified by EPA as Group B2 human carcinogens.   As discussed
earlier, the classification of tetrachloroethylene into either
Group B2 or Group C is controversial. Para-dichlorobenzene has
been classified in Croup C.

     Two separate sets of unit risk estimates were used by
Wallace.  The first set relied on EPA unit risk estimates which
were available for five of the six chemicals (i.e.,  all but para-
dichlorobenzene).  Wallace's estimate for benzene is based on a
"maximum likelihood estimate" (MLE)  from human epidemiology
data; all other estimates are "upper-bound" (UB)  estimates based
on animal studies.  In these latter estimates, it should be noted
that the lower bound is always zero, allowing for the possibility
that the chemical is not in fact a human carcinogen.  Based on
the EPA unit risk estimates,  estimates of individual risk for
the VOCs studied ranged from 5 x 10~6 to 1.6 x 10~4.

     The second set of risk estimates was based on unit risk
values  (MLEs and upper-bound) developed by Tancrede and coworkers
at Harvard.  The EPA and Harvard unit risk estimates varied
widely  (up to 30-fold).  For para-dichlorobenzene, two unit risk
estimates  (high and low)  were calculated based on NTP bioassay
data for the mouse.

     To determine the combined risk from these six VOCs in indoor
air, Wallace summed estimates of risk for each specific chemical.
He concluded that the annual cancer incidence ranged from about
1,000 cases using CAG estimates to about 5,000 to 7,500 cases
using the Harvard upper-bound estimates.  The Harvard MLEs ranged
from 1,600 to 2,400 cases per year.   Overall, Wallace estimated
that about 1,000 to 5,000 excess cancer cases per year could be
attributable to the six VOCs studied.

     A large portion of the Harvard estimates, however, are due
to estimates for para-dichlorobenzene.  As discussed earlier,
estimates of the quantitative risks from inhalation of para-
dichlorobenzene are considered by EPA to be very uncertain since
adequate inhalation bioassay data are not available.  EPA is
currently requiring industry to perform an inhalation bioassay
on the chemical in order that risks by the inhalation route may
be more adequately addressed.  Excluding estimates  for para-
dichlorobenzene,  the Harvard additive risks would approximate
1,000 cases using the MLE estimates and 3,500 cases using the
upper-bound estimates.

     Tancrede et al.  (1987) presented individual risk estimates
for 9 and  19 VOCs that had been detected in EPA TEAM studies of
residences in New Jersey and California, respectively.  The
investigators reported that they deliberately made overestimates
of cancer  risks to individuals by assuming: 1) that every
chemical poses such a risk, and 2) that the relationship between
exposure and risk is linear.  In presenting this conservative
assessment of risk, Tancrede et al. estimated risks for some
chemicals  for which EPA has not established an Agency position on
carcinogenicity  (e.g., n-octane, n-decane, n-undecane,
n-dodecane, ortho- and meta-dichlorobenzene, 1,1,1-trichloro-
ethane, xylenes, ethylbenzene, and alpha-pinene).

     Unit  risk estimates were computed by several different
means, including: 1) human epidemiological data (benzene), 2) a
procedure  based on the TD^Q, the dose leading to 50% lifetime
tumor incidence in NTP/NCI bioassays  (carbon tetrachloride,
trichloroethylene, tetrachloroethylene, chloroform,
1,2-dichloroethane, styrene, 1,4-dioxane); 3) use of a maximum
likelihood technique procedure for NTP/NCI data
(ortho-dichlorobenzene, 1,1,1-trichloroethane) or other bioassays
(ortho- and meta/para-xylene, ethylbenzene), when the TD5Q had
not been calculated; and 4) by analogy with other chemicals,
using theoretical methods based on LD5QS (m-dichlorobenzene,
alpha-pinene) or other toxicological parameters (n-octane,
n-decane,  n-undecane, n-dodecane).  The investigators acknowledge
that the latter estimates may be "very uncertain, but can
occasionally be bounded above by results of more direct
experiments with negative outcomes."  (The use of theoretical
methods based on noncarcinogenic effects to estimate carcinogenic
unit risks would not be acceptable to EPA.)

     Exposure data used in the risk assessments were overnight
personal exposure samples, which were assumed to represent
continuous lifetime exposures.  These data are probably more
representative of indoor exposures than the 24-hr samples used by
Wallace (1985).  However, the data are limited  (49 samples from
New Jersey, representing an estimated 94,000 individuals; and 112
samples from California, representing an estimated 359,000
individuals).  In addition, to be conservative, the investigators
deliberately chose samples collected in winter when
concentrations may have been higher than in other seasons.

     Tancrede et al. treated both potency and dose as random
variables which can take on a range of values, some more probable
than others.   They stated that this emphasis on random
variability is an important difference from the EPA approach.
The additive mean individual risk  (i.e., the sum of the mean
individual risks for each of the VOCs) ranged from 1.9 - 3.0 x
10~2 for residents of New Jersey, and was 2.0 x 10~3 for
residents of California.  The additive 98th percentile individual
risks were 4.6 - 4.8 x 10~2 and 1.1 x 10~2, respectively.  The


authors also presented additive mean individual risks for those
13 chemicals, discussed earlier, for which there is either animal
bioassay data or human epidemiology data (3 x 10~3 in New Jersey
and 1 x 10~3 in California).

     McCann et al. (1986) presented several estimates of
individual risks, based on mean or median levels monitored in
indoor air, for each of 16 VOCs (including formaldehyde and the
pesticide, lindane).   Of these 16 chemicals, two
(1,1-dichloroethane and ethanol) are not established as
carcinogens by EPA.  The unit risk estimates used in the
assessment were obtained by:  1) use of the multistage procedure
[for both MLEs and upper-bound  (95%) risk estimates]; 2) use of
the TD5Q, as discussed previously, assuming linearity, and, where
risks were reported to be non-linear, a less than or greater than
sign, as appropriate; and 3)  use of EPA (upper-bound) unit risk
estimates.  (Note: Some of the EPA unit risk estimates used by
McCann are not current.  For example, the estimate used for
methylene chloride is an order of magnitude above current

     Exposures were estimated based on monitoring data from homes
and public buildings, which were assembled as a base for a
preliminary analysis only.  The collection of data focused on
measurements that reflected everyday exposure in normal (non-
complaint) homes and offices.  Because the data obtained were
limited, the investigators stated that the averages cited could
only be used with great uncertainty -

     The additive mean individual risks (i.e., the sums of the
individual risks for each of the 16 VOCs)  ranged from 2.8 x 10~4
(multistage MLEs) to 9.8 x 10~3 (TD50)•  The wide range is caused
primarily by large variation in different estimates of the cancer
risk posed by formaldehyde, which will be discussed further in
the next section of this report.  If formaldehyde risks are
subtracted from the assessment, the additive mean individual
risks for the remaining 15 VOCs ranges from 2.8 x 10~4
(multistage MLEs) to 1.5 x 10~3 (EPA unit risks).


     Tancrede et al.  (1987) estimated the individual risk from
formaldehyde exposures in U.S. houses using rat bioassay data.
The study design used was as described above for the VOC
analysis.  The author noted that the dose-response curve for
nasal cancers in rats exhibits a strong upward curvature so that
the risks at low doses may be overestimated.  A unit risk
estimate of 0.11 mg/kg-day (3.3 x 10~5/ug/m3) was calculated,
similar to EPA's upper-bound unit risk estimate.  A log-normal
distribution with a median indoor concentration of 0.05 ppm
(60 ug/m3) from several studies in US homes were used to estimate
exposures.  Mean and 98th percentile lifetime risks of  3.4 x  10~2


and  2.4  x  10  ! were  estimated based on these data.  The mean
estimate is many  orders  of magnitude above the MLE and two orders
of magnitude  higher  than the upper-bound estimate calculated by
EPA  based  on  exposures at the median, rather than mean,

     McCann et al.  (1986) also provided estimates of formaldehyde
cancer risks  from  indoor air exposures.  Four different methods
were used  to  calculate risks, as discussed above for the VOCs.  A
2600-fold  variation  in estimates of lifetime individual risk,
from 3.7 x 10~6  (multistage MLE) to 9.5 x 10~3 (TD50), were
calculated by these  investigators. They state that the variation
observed is most  likely  due to the nonlinearity of the dose-
response curve, which is reflected in the large difference in the
multistage MLE and its upper-bound estimate (6.7 x 10~4).  (An
even greater  variation of 6 to 7 orders of magnitude between the
MLE  and  upper-bound  estimate is observed in the EPA analysis,
presented  earlier.)


     Unit  risk estimates for asbestos from sources other than EPA
were summarized in EPA (1986d) and are presented in Exhibit 4-4.
These estimates varied widely.  Unit risk estimates for lung
cancer from lifetime exposure to 0.01 fibers/ml ranged from
4 x  10"^ to 3 x 10~3.  Unit risk estimates for mesothelioma based
on the same exposure ranged from 1.4 x 10"^ to 3 x 10~3.  In
comparison, EPA unit risk estimates fall into the upper end of
these ranges.

     Following publication of the EPA (1986d)  document, Breslow
et al. (1986) revised the risk estimates of the National Academy
of Sciences.  These  estimates, based on concentrations of 0.0004
and  0.002  fibers/ml  and  provided in Exhibit 4-5,  are several-fold
higher than the previous NAS estimates and two- to three-fold
higher than the EPA  estimates.


     EPA recently conducted a comparative study of environmental
problems in the United States (EPA 1987d). Their report, although
subjective and based on  imperfect data, represented a credible
first step toward a promising method of analyzing, developing,
and  implementing environmental policy.  Based on this analysis,
EPA  concluded that indoor air pollution represents one of the
most important environmental problems based on population risks.
Four major types of effects were considered: cancer risks, non-
cancer risks, ecological effects, and welfare effects.  Thirty-
one environmental problems in four broad categories were
evaluated:  indoor and outdoor air pollutants,  water

                           Exhibit 4-4
 Risks (x 10"6)  from Lifetime Asbestos Exposure to 0.01 Fibers/ml

Population            Lung Cancer              Mesothelioma

                            NAS (1984)

Female Smokers          575  (0-2,750)       225  (0-8,750)
Female Nonsmokers        75  (0-325)         225  (0-8,750)
Male Smokers          1,600  (0-7,250)       225  (0-8,750)
Male Nonsmokers         150  (0-550)         225  (0-8,750)

                           CPSC (1983)

Female Smokers          952  (301-3,012)   2,460  (780-7,799)
Female Nonsmokers       157  (50-4,960)    2,666  (843-8,429)
Male Smokers          1,550  (490-4,901)   1,742  (551-5,510)
Male Nonsmokers         175  (554-5,540)   2,153  (681-6,808)

                Ontario  Royal Commission (1984)(1)

Hypothetical workforce of
385 male smokers,
385 male nonsmokers,         4 - 760          14  - 1,875
115 female smokers,
115 female nonsmokers

            Advisory Committee on Asbestos  (1979) (2)

Males and females          86 - 2,860

                     Doll and Peto (1985)(3)

Males                        252                 56

Source: EPA (1986d)
     1Exposure of 25 years from age 22,

     250 years exposure.

     3Exposure of 35 years from age 20,

                           Exhibit 4-5
 NAS Revised Estimates of Risks from Lifetime Asbestos Exposures

                                Estimated Lifetime Risk (x 10~6)
Disease       Exposure Group    	
                                0.0004 fibers/ml  0.002 fiber/ml
Lung cancer

Male smoker
Female smoker
Male nonsmoker
Female nonsmoker
Mesothelioma  All groups             156                  780

Source: Breslow et al. (1986)

contamination, toxic and hazardous waste, and exposure to
pesticides and chemicals.

     Risks from human exposures to environmental contaminants
are generally less than many occupational health and safety risks
in the mining and industrial environments. In addition,
ecological and welfare losses for some environmental problems may
dominate their public importance.  Nevertheless, the population
health risks posed by exposure to indoor air pollutants appear to
be significantly greater than the health risks posed by some of
the environmental problems that receive the most public concern
and governmental funding, including hazardous and non-hazardous
waste sites, and contaminated sludge.  These risk rankings are
very rough and are greatly limited by incomplete data, but the
rankings demonstrate that, in relative terms, indoor air
pollution is an important public health problem which merits more
serious attention and study.


     Except for radon, population risk estimates specific for
indoor air pollutants have not been conducted by EPA.
Nevertheless, the information available suggests that exposure to
indoor air pollutants in nonindustrial environments poses a
significant health threat to the domestic population.  It appears
that, in addition to radon, pollutants that pose significant
cancer risk include ETS and VOCs. Radon and ETS are present  in a
very large number of residences, and ETS  is present in office
buildings.  VOCs are ubiquitous in indoor environments.
Additional cancer risks, not quantified here on a population
basis,  come from asbestos, formaldehyde,  PAHs and pesticides in
indoor air.

     If diseases, such as heart disease and emphysema, were also
considered,  the mortality risks could increase significantly.  In
addition, the significant health burden associated with the known
acute and non-fatal health effects described in Chapter 3 has not
been quantified.


Advisory Committee on Asbestos. 1979. Asbestos Volume 1:  Final
     Report of the Advisory Committee and Asbestos Volume 2:
     Papers Prepared for the Advisory Committee.  Health and
     Safety Commission, London, as cited in EPA 1986d.

Arundel, A., Sterling, T.,  and Weinkam, J. 1987. Never Smoker
     Lung Cancer Risks from Exposure to Particulate Tobacco
     Smoke.  Environ. Internat. 13: 409-426.

Breslow, L., et al.. 1986.  Response to letter on Risk from
     Exposure to Asbestos.   Science 234:923.

Consumer Product Safety Commission (CPSC). 1983. Report to the
     U.S. Consumer Product Safety Commission by the Chronic
     Hazard Advisory Panel on Asbestos.  Directorate for Health
     Sciences, as cited in EPA 1986d.

Doll, R., and Peto,  J., 1985. Asbestos: Effects on Health of
     Exposure to Asbestos.   Health and Safety Commission, London,
     as cited in EPA 1986d.

Environmental Protection Agency (EPA).  September 24, 1986a.
     Guidelines for Carcinogenic Risk Assessment.  51 Federal
     Register 33994.

Environmental Protection Agency (EPA).  September 24, 1986b.
     Guidelines for Estimating Exposures.  51 Federal Register

Environmental Protection Agency (EPA).  December 1986c.
     Carcinogenicity Assessment of Chlordane and
     Heptachlor/Heptachlor Epoxide.  Office of Research and

Environmental Protection Agency (EPA).  June 1986d.  Airborne
     Asbestos Health Assessment Update.  Office of Research and

Environmental Protection Agency (EPA).  September 1987a.  Radon
     Reference Manual.  Office of Radiation Programs.

Environmental Protection Agency (EPA).  April 1987b.  Assessment
     of Health Risks to Garment Workers and Certain  Home
     Residents from Exposure to Formaldehyde.   Office of
     Pesticides and Toxic Substances.

Environmental Protection Agency (EPA).  August  1987c.
     Carcinogenicity Assessment of Aldrin and Dieldrin.   Office
     of Research and Development.

Environmental Protection Agency (EPA).   February 1987d.
     Unfinished Business: A Comparative Assessment of
     Environmental Problems.  Office of Policy Analysis.

Environmental Protection Agency (EPA).   June 1987e.  EPA Indoor
     Air Quality Implementation Plan:  Appendix A. Preliminary
     Indoor Air Pollution Information Assessment.  Office of
     Research and Development.

Environmental Protection Agency (EPA).   February 1988.  Updated
     List of TSDF Health-based Constituents (from Hazardous Waste
     TSDF- Background Information for Proposed RCRA Air Emissions
     Standards, Volume II- Appendix E).  Memorandum from A. A.
     Voorhees to S.  R. Wyatt,  Office of Air Quality Planning and

Hammond, C.  1966.  Smoking in Relation to Death Rates of One
     Million Men and Women.  Epidemiological Approaches to the
     Study of Cancer and Other Chronic Diseases, Haenszel, w.,
     ed., NCI Monograph 19, pp. 127-204.

Kuller, L.H., et al..  1986.  Environmental Health Persp.

McCann, J., Horn, L.,  Girman,  J.,  and Nero, A.V.  October 1986.
     Potential Risks from Exposure to Organic Carcinogens in
     Indoor Air.  Presented at the EPA Symposium in the
     Application of Short-term Bioassays in the Analysis of
     Complex Environmental Mixtures, Durham, NC.

Molhave, L. 1984.  Volatile organic Compounds as Indoor Air
     Pollutants. Indoor Air and Human Health.  Proceedings of the
     7th Life Sciences symposium.   Gammage, R. et al.. eds.
     Knoxville, Tenn.

National Academy of Science (NAS). 1984. Asbestiform Fibers:
     Nonoccupational Health Risks, National Academy Press, as
     cited in EPA 1986d.

National Cancer Institute  (NCI).  1987.  1986 Annual Cancer
     Statistics Review.  NIH Publication No. 87-2789.

National Cancer Institute  (NCI).  June 1988.  Personal

National Council on Radiation Protection (NCRP).   1984.
     Evaluation of Occupational and Environmental  Exposures  to
     Radon and Radon Daughters in the United States.  NCRP Report
     No. 78.

National Research Council  (NEC).  1986.  Environmental Tobacco
     Smoke: Measuring Exposures and Assessing Health Effects.
     National Academy Press.

National Research Council  (NRC).  1988.  Health Risks of Radon
     and other Internally Deposited Alpha-Emitters (BEIR IV).
     National Academy Press.

NTP.  August 17, 1984.  Report  of the NTP Ad Hoc Panel on
     Chemical Carcinogenesis Testing and Evaluation.   U.S.
     Department of Health and Human Services.

OSTP- May 22, 1984. Chemical Carcinogen; Notice of Review of the
     Science and Its Associated Principles.  49 Federal Register

Ontario Royal Commission, 1984. Report of the Royal Commission on
     Matters of Health and Safety Arising from the Use of
     Asbestos in Ontario; V. 1-3.  Ontario Ministry of the
     Attorney General, as cited in EPA 1986d.

Repace, J.L., and Lowrey, A.H.  1985a.  A Quantitative Estimate
     of Nonsmokers' Lung Cancer Risk from Passive Smoking.
     Environ. Internat. 11:3-22.

Repace, J.L., and Lowrey, A. H., 1985b. An Indoor Air Quality
     Standard for Environmental Tobacco Smoke Based Upon
     Carcinogenic Risk.  New York State J. Med. 85:381-383.

Repace, J.L., and Lowrey, A.H., 1986. A Rebuttal to Criticism of
     the Phenomenologic Model of Nonsmokers1 Lung Cancer Risk
     from Passive Smoking.  Environ. Carcino. Revs.(J. Environ.
     Sci. & Health) C4:225-235.

Repace, J.L., and Lowrey, A.H., 1987.  Predicting the Lung
     Cancer Risk of Domestic Passive Smoking.  American Rev.
     Resp. Dis. 136:1308.

Robins, James.  1986.  Appendix D: Risk Assessment — Exposure
     to Environmental Tobacco Smoke and Lung Cancer.  NRC,
     Environmental Tobacco Smoke: Measuring Exposures and
     Assessing Health Effects.  National Academy Press.

Surgeon General, 1979. Smoking  and Health. U.S. Dept. of Health,
     Education, and Welfare, Washington, DC.

Surgeon General, 1986. The Health Consequences of Involuntary
     Smoking.  U.S. Dept. of Health & Human Services, Washington,

Tancrede, M.,  Wilson, R.,  Zeise, L.,  and Crouch, E.A.C.  1987.
     The Carcinogenic Risk of Some Organic Vapors: A Theoretical
     Survey.  Atmospheric Environment 21(10):2187-2205.

Wald, N.J., and Ritchie C. 1984.  Validation of Studies on Lung
     Cancer in Nonsmokers Married to Smokers.   Lancet  1: 1067.

Wald, N.J., et al. ,  1986.   Does Breathing Other People's Smoke
     Cause Lung Cancer?  British J. Med. 293:1217-1222.

Wallace, L.A.   1985.  Cancer Risks from Organic Chemicals in the
     Home, in Proceedings: Environmental Risk Management: Is
     Analysis Useful?  Air Pollution Control Association.

Wells,  A.J.  June 1986.  Passive Smoking Mortality: A Review and
     Preliminary Risk Assessment.  Presented at 79th annual
     meeting,  Air Pollution Control Association, Minneapolis.

Wells,  A.J.  1988.  An Estimate of Adult Mortality in the United
     States from Passive Smoking.  Environ. Internat.  14:in


     This chapter discusses the economic costs imposed by indoor
air pollution.  The costs of both health effects and damages to
equipment and materials are considered.  The limited available
evidence on indoor air pollution effects is used to develop
estimates for selected types of costs.  These cost estimates are
incomplete and are subject to great uncertainty.  However, the
available evidence suggests that the costs imposed by indoor air
pollution are very high. The costs of controlling indoor air
pollution are not covered in this chapter.

     The first section of this chapter discusses the nature of
the economic effects of indoor air pollution.  The second section
describes methodologies for valuing economic effects, and the
third section presents available estimates of economic costs and
implications for business managers.


     Three major types of economic costs are addressed in this
chapter:  (1) materials and equipment damages,  (2) direct medical
costs, and (3) lost productivity.  These are defined as follows:

     Materials and Equipment Damages

     Indoor air pollution can soil indoor surfaces and can damage
equipment and materials of various types.1  The costs associated
with equipment and materials damage include costs incurred to
mitigate the effects of contamination  (e.g. the costs of
cleaning) and the costs of repair or premature replacement of
equipment and materials.

     Direct Medical Costs

     People whose health is affected by poor indoor air quality
may incur costs for medical services to alleviate the health
effects.  These medical costs include the costs of visits to the
doctor or emergency room, hospital care, surgery, medication and
the like.

     Lost Productivity

     Adverse health effects or general discomfort resulting from
indoor air pollution may result in lost economic productivity.
Lost productivity may occur on a continuum and  include  (1) lost
productive years due to major illness,  (2) lost time due to
increased number of sick days taken from one's  job, and  (3) lost
     ^-Soiling refers to an effect that is reversible via
cleaning, whereas materials damage is an irreversible effect.

productive efficiency while on the job.   All reduce the nation's
capacity to product goods and services of value.   Estimates of
productivity should include the effects  on both income earning
and non-income earning activities of value.  Activities such as
child care in the home, homemaking,  and  learning activities in a
school or university setting should be included,  although often
they are not because they are difficult  to quantify.

  Costs not Considered

     These three categories of costs —  materials and equipment
damage, direct medical costs, and lost productivity -- represent
only a part of the total economic losses due to indoor air
pollution.  Some economic costs not included in the above
categories are:

  o    other welfare loss associated with pain and suffering due
       to health effects that are not fully alleviated by medical

  o    the value of unpaid time spent by persons taking care of
       those whose health is affected in the home; and

  o    losses due to reduced enjoyment of recreational and other
       non-productive activities affected by indoor air

No attempt was made to estimate costs in these categories.

     In addition, this report does not consider the effects of
exposures to commercial or occupational  sources of pollutants
other than those occurring in white collar work environments.
The categories of economic costs considered in this report
therefore represent only a portion of the true losses to society
resulting from poor indoor air quality.


     A variety of approaches may be used to estimate the costs
associated with indoor air pollution.  These approaches have been
described in a number of sources2, and are only briefly
summarized here.

     Market-Based Measures

     Economists generally prefer to use measures of costs based
on people's actual behavior in response to pollution, as the best
measure of the true economic costs.   To the extent that observed
     2See,  for example, Bentkover et al (1986) ; Freeman  (1979
and Hartunian. (1981).

market behavior can be used to assess costs, all effects of the
pollution — including such hard-to-measure effects as "pain and
suffering" or reduction in the quality of life -- are included.

     Estimating costs due to indoor air pollution lends itself to
use of market-based estimates in theory.  The pollution is
associated with specific buildings, and buildings are traded in
real estate markets.  Therefore, some of the costs of indoor air
pollution can potentially be observed in reduced property values
for buildings with air pollution problems.

     EPA is not aware of any previous property value studies
focusing on the effects of indoor air pollution.  Such studies
could eventually be useful.  However, it is doubtful that they
would provide reliable estimates of the true social costs of
indoor air pollution at this time.  People must be aware of
problems with a building and must know that the problems are
attributable to the building itself, before market behavior could
accurately reflect the costs of indoor air pollution.  Currently,
there appears to be widespread ignorance about the sources and
effects of indoor air pollution.  Therefore, it is unlikely that
current market values for buildings reflect the costs of indoor
air pollution.

     Contingent Valuation Measures

    ~Ih the absence of market-based data on the effects of
pollution, survey techniques are sometimes used to develop the
equivalent of market valuations.  These surveys seek respondents'
views on their "willingness-to-pay" to reduce pollution -- in
this case, to reduce their exposure to indoor air pollution.

  There are difficult methodological problems with such surveys,
but they have the virtue -- like market-based valuations -- of
including all sources and types of welfare loss due to the
pollution.  EPA is not aware of any previous contingent valuation
surveys designed to measure the costs of indoor air pollution.

     Damage Function Measures

     An alternative to using market-based data or contingent
valuation measures is to develop estimates of the costs of
individual end-effects of pollution, based on predictions of
physical effects and use of various methods to value the effects.
As described above, the drawback with the measurement of costs on
an effect-by-effect basis is that it is limited to the effects
that have been quantified.  Quantifiable effects, plus welfare
losses that are difficult to quantify inevitably are excluded.
Therefore, summing the costs estimated for individual effects  of
pollution tends to understate the true social costs of
pollution.  However, this is the only approach available at this
time to estimate the costs of indoor air pollution.


     Two steps are involved in developing an effect-by-effect
estimate of indoor air pollution costs.  First, it is necessary
to estimate "incidence" of each physical effect attributable to
indoor air pollution — e.g. numbers of cancer cases, levels of
soiling, days of lost work, etc.  Second, it is necessary to
assign an economic value to those physical effects.


     Available Data and Approach

     In the absence of market-based or contingent valuation
estimates of the costs of indoor air pollution, this report
relies on damage function procedures to develop cost estimates.

     Because of data limitations, it was not possible to develop
quantitative estimates of the economic costs associated with
equipment and materials damages caused by indoor air pollution,
though these costs are discussed in the text.

     For major illnesses, the pollutant-by-pollutant estimates of
specific health effects along with estimates of the costs of
those effects were used to estimate the economic costs of major
illnesses resulting from indoor air pollution.   Quantitative
estimates of cases attributable to indoor air pollution for a
limited number of pollutants and health effects were presented
in Chapters 3 and 4.   For those health effects quantified (cancer
and coronary heart disease due to exposures to radon, volatile
organic chemicals (VOCs)  and environmental tobacco smoke (ETS)),
predicted numbers of cases annually were multiplied by estimates
of costs per case to provide national annual cost estimates.  Two
types of costs are calculated:  (1)  direct medical care costs for
each type of case (doctor visits, hospitalization, medication,
surgery, etc.),  and (2)  the present value of lost lifetime
earnings per new case,  including imputed earnings for homemaking
activities.   In addition, information from a study of emergency
room visits for asthmatic children was used to estimate the costs
of exposure to ETS for asthmatic children.

     Because of data limitations, it was not feasible to develop
reliable estimates of the economic cost of the increased number
of sick days or of lost productivity while on the job, due to
indoor air pollution.   However,  available surveys were used to
provide information on these issues.  While potential costs based
on this data were calculated,  these estimates are excluded from
the final tabulations of economic costs because of uncertainties
surrounding the data.

     Economic Costs of Equipment and Materials Damage

     Previous chapters of this report have focused primarily on
the human health effects of indoor air pollution.  High
concentrations of contaminants in indoor air can also have
adverse effects on materials and equipment.  The effects of
indoor air pollutants on indoor materials are influenced by a
number of factors, including the type of pollutant, its
concentration and exposure pattern, the type of material exposed,
and other environmental factors.  These effects are discussed in
some detail in another report  (EPA, 1987).  Exhibit 5-1 taken
from that report, summarizes the major materials damages
according to the materials potentially at risk, the air
pollutant(s) associated with the effect, and other environmental
factors that can also contribute to materials damage. Microbial
contamination, while potentially significant, is not included in
this table.

     The pollutants most often associated with these material
damages include sulfur oxides  (SOx), nitrogen oxides (NOx),
ozone, particulates, and several acid gases  (EPA, 1987).  In
addition, particulates in the  form of water-soluble salts have
been associated with damage to electronic equipment.  Damages
may include corrosion of electronic components and electrical
current leakage, which may eventually result in equipment
malfunction (EPA, 1987; Walker and Weschler, 1980).  Finally,
microbial contamination can result in significant damage to some

     The costs of materials and equipment damage by indoor air
pollutants include the maintenance, repair, and/or replacement
costs resulting from (1) soiling or deterioration of a material's
appearance, or  (2) reduced service life for corroded or degraded
appliances, furnishings, and equipment.  For example, if house
textiles such as draperies fade or change color as a result of
exposure to nitrogen oxide pollutants, then costs would consist
of the cost of either repair or premature replacement of the
draperies.  In certain circumstances, such as in art museums or
galleries, costs associated with installation of environmental
controls such as air filtering systems may also be incurred.

     Few damage functions have been developed for the effects of
indoor air pollution on materials and equipment.  Studies
performed for EPA to support national ambient air quality
standards (Manuel, 1981; 1983) provide household economic damage
functions for soiling due to S02 and particulates.  These
studies rely on the results of several previous  studies to
estimate economic benefits due to reduced soiling, and might be
applied to estimate the costs  of indoor air  particulate and  S02
levels.  However, the studies  generally  include  categories  of
benefits (e.g. reduced washing of outside as well  as inside
window surfaces, cleaning of screens and storm windows, and


                                             Exhibit 5-1
                                 Air Pollution Effects on Materials
 Type of Damage
                                            Principal  Air
Sulfur oxides and
other acid gases
Moisture, air, salt,
microorganisms, par-
ticulate matter
Paint and organic    Surface erosion,
coatings             discoloration,
                     Sulfur oxides,
                     hydrogen sulfide,
                     paniculate matter
                      Moisture,  sunlight,
                      ozone,  microorganisms
Reduced tensile
strength,  soiling
                                          Sulfur  oxides,
                                          nitrogen oxides,
                                          particulate matter
                      Moisture,  sunlight,
                      ozone,  physical wear
Textile dyes
Fading, color
Nitrogen oxides,
soi ling
Sulfur oxides,
particulate matter
Moisture, physical
Magnetic storage
Loss of signal
Particulate matter    Moisture, heat, wear
Sulfur oxides,
hydrogen sulfide
Moisture, sunlight,
heat, other acid
gases, particulate
matter, ozone and
other oxidants
                                           Sunlight,  physical
                     Weakening,  pow-
                     dered surface
                     Sulfur oxides
                                           Physical wear
                     Changes surface
                     Acid gases,  HF
                      Moisture, micro-
Source:   EPA,  1987.

cleaning of gutters) that are not relevant for estimating indoor
air pollution costs.  The studies also estimate benefits at
concentrations well above those reported for indoors, and are
based on 1972-1973 consumer expenditure data that are likely to
be substantially out-of-date.  For these reasons, the available
soiling damage functions were not considered adequate to estimate
soiling damages attributable to indoor air pollution.

     Similarly, no quantitative estimates are available of the
effects of indoor air pollution on equipment.  Information from
Dr. Charles Weschler of Bell Communications Research, however,
provide examples of such damages that indicate that the costs may
be high (Weschler, 1988).  Telephone switching and computing
equipment is susceptible to corrosion caused by air particles and
gases.  Weschler reported that the seven regional telephone
companies have spent large sums to replace, clean or repair
switches and other electronic equipment malfunctioning as a
result of indoor air contaminants.  Failures are known to have
occurred throughout the system, and to range in cost from as
little as $10,000 to as high as $380,000 per event.  Bell
Communications Research has developed guidelines for preventing
such damages, including use of high efficiency filtration,
constant use of fans, minimum air changes per hour, and keeping
buildings pressurized to prevent infiltration of outdoor

     Various studies have also reported that home and office
computing equipment and other electronic devices are subject to
failure due to indoor air contamination (see, for example,
Comizzoli et al., 1986).  However, no estimates are available of
the extent or costs of such damages.

     In addition, it is known that microbial contamination can
cause significant damage to buildings and equipment, and there is
anecdotal evidence that damage can be so severe as to make a
building unfit for human occupation.  However, no quantitative
data as to the extent of such damage is available.

     Direct Medical Care Costs

     Specific Major Illnesses

     Available estimates of the annual number of health
impairments resulting from indoor air pollution were presented in
Chapters 3 and 4.  Estimates of annual health impairments could
be developed only for some of these health effects.  To estimate
the costs of medical expenditures associated with this subset of
health effects, estimates of the present value of direct medical
care costs per case were taken from Hartunian et al.  (1981).
These costs were developed for different types of illnesses  from
actual case experiences, and costs occurring in future years

                         Exhibit 5-2
           Direct Medical Care Costs  for Major Illness
                                             Present Value of
                                             Medical Cost per
                                                 New Case
     Health Effect                               ($1986)
     Lung Cancer                                 21,285

     All Cancers                                 24,938

     Coronary Heart Disease                       9,684

Source:     Hartunian et al.  (1981)  -- Hartunian values in 1975$
            updated to 1986 dollars  using an inflation factor for
            medical costs of 2.57 (1986 index of 433.5 divided by
            1975 index of 168.6;  index of medical care prices
            from U.S. Bureau of Labor Statistics.  CPI Detailed

were discounted to develop present values.  Present value costs
calculated at a six percent discount rate were used in this

     Exhibit 5-2 presents these costs per case taken from the
Hartunian study.  The average costs  per case for all cancers and
for coronary heart disease (CHD)  were developed in the Hartunian
study by weighting costs per case for different types of cancer
or CHD by the relative prevalence of each type in 1975.  The
Hartunian estimates were inflated to 1986 dollars for use in
this study.

     Exhibit 5-3 presents estimates  of the annual national costs
of medical care resulting from the major indoor air pollution
health effects identified in Chapters 3 and 4.  As shown,
estimated costs are over $1 billion  annually.  The range of cost
estimates reflects estimates of numbers of cases annually from
different sources reported in Chapters 3 and 4.  Cancer cases due
to exposure to VOCs,  radon, and ETS  account for the largest
portion of estimated costs.

     These estimates do not include  the costs of many potential
major illnesses and indoor air pollutants presented in Chapters  3
and 4,  due to the limited quantitation of health impacts for
these pollutants.  For example, quantified national health


                          Exhibit 5-3
           Annual Direct Medical Costs of Major Illness
New Cases/
Total Cost


Six VOCs
Total Cancer

( Lung )

$21,285 $426
$21,285 $0.26-111
$24,938 $274
$24,938 $25-125
(Heart Disease)
Total Medical Costs
Source: Section 3.3, and Exhibits 4-1, 4-3, and 5-2.

Note: Except for radon, risk estimates have not been critically
evaluated for their strengths and weaknesses in addressing a
quantitative analysis of the level of risk from indoor air
pollutants.   Therefore, EPA  does not necessarily agree with the
study designs used or with the conclusions reached by the authors
of these assessments. See footnote to Exhibit 4-3.

                          Exhibit 5-4
         Costs of Additional Emergency Room Visits for
         Asthmatic Children in Households with Smokers

Increased number of emergency room visits per year,
  asthmatic children in smoking vs. non-smoking households: 1.26a

Estimated cost of additional visits per year:                $92a

Estimated percent of children in smoking households:      43-62%^

Estimated percent of population that are asthmatic:

     o    total population                                  4.0%c

     o    ratio of prevalence in children to prevalence
          in the total population                           1.25^

     o    estimated percent of children that are asthmatic   5.0%
          (1.25 X 5)

Number of children in the United States under 18 (1985):    63 Me

National annual cost of additional emergency room
visits for asthmatic children in smoking households:  $157-226 M^

a.   Evans et al.  (1987).
b.   43% from CDC (1986).   62% from Bonham and Wilson (1981) as
     cited in Repace and Lowrey (1985).
c.   Chapter 3, Exhibit 3-2.
d.   National Center for Health Statistics, private
     communication,  1988.
e.   U. S. Census Bureau,  Current Population Reports
f.   1.26 * 92 * (0.43-0.62) * 0.05 * 63

impacts are not available for indoor exposures to pesticides,
asbestos, formaldehyde or many types of VOCs, nor are estimates
available for number of cases of emphysema, or other illnesses
due to ETS exposure.

     Effect of ETS of Asthmatic Children

     A recent study of 237 children from low-income families in
New York City (Evans et al. . 1987) found that asthmatic
childrenfrom smoking households visited emergency rooms more
often on average than did asthmatic children from non-smoking
households.   Children from smoking households averaged 3.09
emergency room visits per year compared with 1.83 times per year
for children from non-smoking households.  Exhibit 5-4 presents a


calculation of aggregate national costs due to increased
emergency room visits for asthmatic children due to ETS in the
home, based on this study.  The costs are estimated to total
between $157 and $226 million per year.

     Employee Sick Days

     Little data exists on the number of employee sick days or on
the productivity lost because of poor indoor air quality.
However, some survey studies have been conducted.  The problems
with these studies are twofold.  First, it is difficult for an
employee to causally link a health effect to poor indoor air
quality.  Second, it is not known if the buildings from some of
these studies represent the general building population.

     One survey of office workers conducted by Honeywell
(Honeywell, 1985) found that 19 percent of respondents  (115 of
600) often or sometimes had difficulty doing their work because
of office air quality.  Of the 155, 64 (or 11 percent of all
respondents) reported that a "tired/sleepy feeling" was a "very
serious" or "somewhat serious" problem because of office air
quality.  Similarly, 52 (nine percent of all respondents)  cited a
"congested nose," 47  (eight percent) cited "eye irritation," and
46  (eight percent) cited "difficulty breathing" as being "very
serious" or "somewhat serious" problems.

     However, while the Honeywell survey was scientifically
administered, it does not provide sufficient information for
quantifying economic costs.

     In addition to the Honeywell survey, a recent survey of 94
state government office buildings was conducted by a coalition
of employee unions in the New England states of Maine and New
Hampshire during the summer of 1987.  The survey sought
information on the extent and effects of poor indoor air quality,
including the losses in productivity, the increased number of
sick days, and the frequency of doctors visits, attributed by
respondents to poor indoor air quality.

     The New England survey results report large numbers of
complaints about health symptoms that respondents attribute to
poor air quality;  30 percent of all respondents reported having
headaches, 44 percent reported fatigue or drowsiness, 37 percent
reported eye strain, and 69 percent reported some loss  in
productivity on a daily or weekly basis due to poor indoor air
quality -

    The kind of information provided in the New England survey
is useful for estimating three elements of economic cost --
direct medical cost of increased doctors visits, the economic
cost of lost productivity from increased sick days, and the
economic cost of lower productivity while on the  job.   However,


the New England survey was not scientifically administered and
may have significant biases.

     While the Honeywell survey and the New England survey are
not directly comparable, the prevalence rates in the New England
survey appear to be three to four times higher than those
reported in the Honeywell survey-  However, other data suggest
that prevalence rates of the New England survey may not be far
from the norm. For example, in a major British study (Wilson and
Hedge, 1987), prevalence rates of work related symptoms were:
lethargy (57%), headache (43%), stuffy nose (47%),  and itchy eyes
(27%). In addition, 24% of the respondents thought that their
work environment decreased their productivity by 20% or more, 59%
thought it had little or no effect, and 16% thought it increased
their productivity.  Likewise, in a major study of Danish Town
Halls (Skov and Valbjorn, 1987) and other buildings, approximate
prevalence rates of work related symptoms were fatigue (28%),
headaches (20%), eye irritation  (13%), and nasal irritation
(18%) .

     In order to obtain at least a qualitative estimate of the
economic costs from medical visits, sick days lost, and
productivity losses, some adjustments were made to the New
England survey data, and conservative assumptions concerning
those not responding were incorporated into the analysis.   The
adjusted survey results show that an average of 0.24 doctor
visits per worker per year were attributable to poor indoor air
quality.  If this figure were applied to the nation's 64 million
white collar work force  (BLS, 1988), and an average cost of  $30
is assumed for a medical visit to a doctor or medical
practitioner, national medical care costs  for doctors visits
(other than  for major medical illness) of white collar workers
due to indoor air pollution would be on the order of half a
billion dollars per year.

      Economic Cost of Productivity Losses

      Loss of Earnings Due to Major Illnesses

      Exhibit 5-5 shows estimates of the present value of  lost
lifetime work output for three types of major health effects.
These estimates are taken  from Hartunian,  1981 and  include  an
imputed value for homemaking activities.   The Hartunian values
have  been updated to 1986 dollars and  inflated by  37 percent to
     3Excluded from the data were responses  indicating  more than
6 doctor visits per year, more than  12 days  of  sick  leave,  or
more than 30 percent productivity loss due to indoor air
pollution.  In addition, it was assumed that no effects of  indoor
air pollution were experienced by those not  receiving the
survey, and those who received the survey but did  not respond.


reflect the value of fringe benefits for all private industry
employers (Nathan, 1987).   These costs per case are the present
value of present and future lost worktime due to a new case of
cancer or CHD, with future years' values discounted at six

                       Exhibit 5-5
            Productivity Costs of Major Illness
                      (Cost per Case)
                                             Present Value of
                                               Lost Earnings
                                                 Per Case
     Health Effect                               ($1986)
     Lung Cancer                                  99,532

     All Cancers                                  92,645

     Coronary Heart Disease                       44,896

Source:     Hartunian, et al.  (1981) — Hartunian values in 1975
            dollars updated to 1986 dollars using the ratio of
            the 1986 to the 1975 GNP price deflators (114.1/59.3
            = 1.92; U.S. Department of Commerce, Statistical
            Abstract of the United States, 1988, p. 252), and
            inflated by 37 percent to reflect the added value of
            fringe benefits (Nathan, 1987).

     Exhibit 5-6 shows the calculation of the national annual
cost of productivity losses associated with major illnesses
caused by indoor air pollution.  This calculation uses the same
approach as the calculation of direct medical costs in Exhibit
5-3.  The estimated cost ranges from $4.7 billion to $5.4 billion
for new cases caused by indoor pollution annually.

     Productivity Loss While on the Job and from Increased Sick

     Productivity losses on the job due to indoor air pollution
may take several forms.  For example, workers may be less
effective with their work because they feel fatigued, or suffer
from headaches, eye irritation or other effects.  These are
typical symptoms of sick building syndrome.  Workers may
therefore accomplish less per hour worked or may spend more time
away from their work location — e.g. taking breaks or walks


outdoors to avoid poor air quality where they work.   These
effects will result in lower output per hour at work.   In
addition,  workers may be out sick more often.

     The value of both reduced output while at work and increased
sick leave time lost from work can be measured by multiplying
average hours of productive work lost by an average hourly

                          Exhibit 5-6
          Annual Productivity Costs of Major Illnesses
                    New Cases/
                    Total Cost




(Heart Disease)

 Total Cancer



Total Cancer and Non-Cancer

Source: Section 3.3 and Exhibits 4-1, 4-3 and 5-5.

Note; Except for radon, risk estimates have not been critically
evaluated for their strengths and weaknesses in addressing  a
quantitative analysis of the level of risk from indoor  air
pollutants. Therefore, EPA  does not necessarily  agree  with the
study designs used or with the conclusions reached by the authors
of these assessments. See footnote to Exhibit 4-3.

compensation rate.  The average total compensation rate per hour
worked for white collar workers is $15.56.  This rate includes
benefits such as paid leave, premium pay for overtime, insurance
and retirement benefits, and legally required benefits such as
Social Security (Nathan, 1987).

     Data from the New England survey, which was adjusted as
previously indicated, would attribute an average productivity
loss of 3% to poor indoor air quality.  This is equivalent to
approximately 14 minutes per day in lost work time.  Respondents
would also attribute an average of 0.6 added sick days per year
to poor indoor air quality.  If these results were applied to
the nation's white collar labor force, the economic cost to the
nation would be in the order of $60 billion annually-  While this
can not be regarded as a reliable estimate, it suggests quite
strongly that productivity losses may be in the order of tens of
billions of dollars per year.

     Implications for Business Managers

     Many efforts to improve indoor air quality in office
environments can be administered at little or no cost. These
include, for example, proper storage of toxic cleaning and
maintenance products, and basic maintenance of the ventilation
system.  Nevertheless, some buildings may require actions which
increase energy or other operation or maintenance costs, and for
this reason they are often resisted.  But, we have seen that
poor indoor air quality increases labor costs through losses in
productivity, increased employee sick days, and medical costs.
This suggests that measures to cut building construction and
operating costs may increase the total cost to business because
of a higher wage bill, and that money spent to improve indoor air
quality may be profitable from a purely business profit and loss

     It is useful to ask whether costs incurred to improve indoor
air quality would pay for themselves in increased productivity.
Labor costs in a typical office setting will depend on salary
levels and occupant densities.  Typical labor costs are on the
order of $100 to $300 per square foot per year.4 (Dorgan, 1988;
Woods et al.. 1987).  In comparison, energy costs are on the
order of only $1 or $2 per square foot per year, while total
environmental control costs  (energy, operation and maintenance)
are on the order of $2 to $10 per square foot per year.  (Dorgan,
1988; Woods et al.. 1987, Eto and Meyer, 1988). It is clear,
     4For example, ASHRAE standard 62-1981 assumes an occupant
density amounting to about 150 square feet per person in office
environments. With a labor cost rate of $15.56 per hour and a
yearly work rate of 2000 hours per year, labor cost for office
environments would be $207 per square foot per year.

 therefore, that from a profit and loss standpoint, productivity,
 not  energy consumption, is the dominant consideration for office

     While cost increases to improve indoor air quality could be
 substantial  in absolute dollar terms, Exhibit 5-7 demonstrates
 that such costs would be more than offset by very modest
 productivity increases.  For example, a 5.0 percent increase in
 energy costs (or a 1.67 percent increase in total environmental

                           Exhibit 5-7
  Productivity Gains Necessary to Offset Operating Cost Increases

       Cost  Increases
     Energy or Total Env.           Offsetting Productivity Gain
5 % 1.67 %
15 % 5.00 %
25 % 8.33 %
50 % 16.67 %
05 %
15 %
25 %
50 %
     Base cost assumptions:
     Energy costs = $2 per sq. ft. per yr.
     Labor costs =  $200 per sq. ft. per yr.
     Total Environmental costs = $6 per sq. ft. per yr.

control costs), would require only a 0.025 to 0.05 percent
increase in productivity to make this a worthwhile expense.  A 50
percent increase in energy costs (or a 16.67 percent increase in
total environmental control cost) would require only a 0.25 to
0.50 percent increase in productivity.  This result suggests that
expenditures for improved indoor air quality could generate
exceedingly high returns to the business community, where labor
is an important cost category, and where the building community
is unaware or has neglected to implement this potential
productivity gain.

      Increasing ventilation capacity from 5 to 20 cfm per
occupant is estimated to increase total construction costs less
than $0.50 per sq.  ft. under typical circumstances (Eto and
Meyer,  1988).   However,  for existing buildings, significant
retrofit costs may be required to increase ventilation, improve
air distribution, or to otherwise improve indoor air quality.  It
is useful to ask, therefore, whether productivity gains could be
expected to offset capital expenditures either for new
construction or for retrofit applications.  Productivity gains
needed to offset alternative capital expenditure requirements,
with and without a modest (15 percent) increase in energy
operating costs,  are displayed in Exhibit 5-8.  For example, a


capital expenditure of $15 per square foot would require about 1
percent increase in productivity to offset the expenditure.   If,
in addition, energy operating costs were increased
15 percent, productivity would have to increase by 1.14 percent.
Given the dominance of labor costs, even a modest increase in
productivity could justify substantial capital expenditures to
improve indoor air quality.

                           Exhibit 5-8
   Productivity Gains Necessary to Offset Capital Expenditures

Capital Cost   Annualized Cost    Offsetting Productivity Gains
  ($/sq.ft)      ($/sq. ft)       No Change in    Operating Cost
                                 Operating Cost   Increase by 15%
07 %
33 %
66 %
99 %
64 %
29 %
.22 %
.48 %
.81 %
. 14 %
.80 %
.44 %
Base cost assumptions:
Energy costs = $2 per sq. ft. per yr.
Annualized costs are capital costs amortized at 10% over a 15-
year life.

     Exhibit 5-9 summarizes the estimates developed in this
chapter of the economic costs attributable to indoor air
pollution.  As shown in the exhibit, cost estimates are
available only for a limited set of potential indoor air
pollution effects.  The reported costs were developed by
extrapolating from limited evidence.  Substantial additional
basic research and analysis will be required to improve on these
estimates of economic costs.

     Despite the limitations in the available evidence, the
calculations presented in this chapter suggest that the costs of
indoor air pollution are very high.  Many costs of indoor air
pollution have not been calculated. Nevertheless, because of the
large numbers of people and buildings potentially affected, as
well as the wide range of effects for which there is an economic
cost component, it is reasonable to conclude the aggregate costs
of indoor air pollution amount to tens of billions of dollars per

       Of the costs  shown in Exhibit 5-9,  ETS accounts  for  a  large
portion of the costs  attributed to specific sources  (cancer,
heart disease,  and effects on  asthmatic children).   Not
displayed  in  Exhibit  5-9  because  of data  limitations  are  specific
estimates  of  the economic costs associated with  losses in
productivity  and increases in  employee sick days  from unspecified
sources typified by the sick building  syndrome.  As indicated  in

                                    Exhibit 5-9
                Sumary of Annual Economic Costs of Indoor Air Pollution
                               (S millions)
           Direct Medical Expenditures  Lost
                                            Materials and
        Non-Cancer   Productivity  Equip. Damage Calculated Costs
Radon and radon


$447-516  $2,457-2,974

NC      $3,178-3,875

    6 VOCs
    Other VOCs    NC

Asbestos         NC


Combustion gases
Particulate matter
Unspeci f ied
NC (see text) (see text)
(see text)
(sick building syndrome)
NC   Costs not calculated

1.   Includes only costs associated with those types of cancer and other health effects for which estimates of
    numbers of annual health impairments were calculated in Chapters 3 and 4.  The estimated costs shown here
    are therefore understated.

Source:  Exhibits 5-3, 5-4, and 5-6.

the text, these costs may be on the order of tens of billions of
dollars per year.

     Subsequent chapters will discuss methods that can be used to
improve indoor air quality.  In some cases, the costs of changes
needed to correct poor indoor air quality will be high.  This
chapter suggests, however, that the costs imposed by continuing
to live with poor indoor air conditions are also very high,  and
for business establishments where labor is an important cost
factor, remedial actions are likely to be cost effective, even if
they require expensive retrofit.  Over time, development and
dissemination of information on the costs of poor indoor air may
encourage building owners to upgrade the quality of indoor air to
prevent decreases in the value of their buildings as tenants and
clients become more knowledgeable about the effects of indoor air


American Society of Hating,  Refrigeration,  and Air-Conditioning
     Engineers ASHRAE.  1986.   ASHRAE Proposed American National
     Standard:  Ventilation for Acceptable Indoor Air Quality,
     Public Review Draft,  ASHRAE 62-1981R.

Bentkover, J. et al.  1986.  Benefits Assessment: The State of the
     Art.  D. Reidel  Publishing Co.

Bonham, G.S. and Wilson,  R.W.  (1981).  Children's Health in
     Families with Cigarette Smokers.  Amer. J. Public Health 71,

Bureau of the Census.  1986.  Statistical Abstract of the United
     States: 1987.

Comizzoli, R.B., et al.  1986.  Corrosion of Electronic
     Materials and Devices.   Science, 17 October, 1986.

Dorgan, C. E.  1988.   Advanced Control Concepts Related to
     Comfort, Indoor Air Quality,  and Productivity.  Engineering
     Solutions to Indoor Air Problems; Proceedings of the ASHRAE
     Conference, IAQ 88,  Atlanta GA.

Environmental Protection Agency (EPA).  1987.  EPA Indoor Air
     Quality Implementation Plan,  Appendix A.

Eto, Joseph H, and Meyer,  Cecile.   1988.  The HVAC Costs of
     Fresh Air Ventilation in Office Buildings.  ASHRAE
     Transactions, V 94 (II).

Evans, D., et al.  1987.   The Impact of Passive Smoking on
     Emergency Room Visits of Urban Children with Asthma.
     American review of Respiratory Diseases, 135:567-572;
     summarized in Residential Hygiene, Vol. 4, No. 2. p. 12.

Freeman, A.M.  1979.   The Benefits of Environmental Improvement,
     Johns Hopkins University Press.

Hartunian, N. et al.   1981.   The Incidence and Economic Costs of
     Major Health Impairments.  Lexington Books.

Honeywell Techanalysis.  1985.  Indoor Air Quality: A National
     Survey of Office Worker Attitudes.  Minneapolis, MN.

Manuel, E.H. et al.  1983.  Benefits and Net Benefit Analysis of
     Alternative National Ambient  Air Quality Standards  for
     Particulate Matter.   Report for Office of Air Quality
     Planning and Standards, U.S.  EPA.

Nathan, F.  1987.  Analyzing Employer's cost for Wages,
     Salaries, and Benefits.  Monthly Labor Review, October
     1987, pp. 3 ff.

National Center for Health Statistics.  1986.  National Health
     Survey, Series 10, No. 164.

Repace, J.L. and Lowrey, A.H.  1985.  A Quantitative Estimate of
     Nonsmokers' Lung Cancer Risk from Passive Smoking.
     Environment International, Vol. 11.

Skov, P- and Valbjorn, 0., 1987. "The "Sick" Building Syndrome in
     the Office Environment: The Danish Town Hall Study.
     Environment International, vol. 13-339-349.

U.S. Department of Labor. Bureau of Labor Statistics (BLS).
      1988.  Employment and Earnings, June.

Walker, M. and Weschler, C.  1980.  Water-Soluble Components of
     Size-Fractionated Aerosols Collected After Hours in a Modern
     Office Building.  Environ. Sci. Technol. 14:594-597.

Weschler, C.  1988.  Bell Communications Research.  Personal
     Communication with David Mudarri, EPA, June 30, 1988.

Wilson, S., and Hedge, A., 1987.  The Office Environment Survey:
     A Study of Building Sickness.  A study sponsored by the
     Health Promotion Research Trust, Building Use Studies, Ltd.,

Woods, J.E., et al.  1987.  Relationships Between Building
     Energy Management and Indoor Air Quality: Perceptions of
     Conflict and Opportunity  in the United States and  Europe.
     Proceedings of the Third  International Congress on Building
     Energy Management, Presses Polytechniques Romandes,
     Lausanne, Switzerland.

           PART II
Controlling  Indoor Air Pollution


     This chapter discusses strategies for controlling indoor air
quality.  In the first section we present engineering and
operational control strategies to mitigate or prevent indoor air
problems.  The second section addresses the importance of
appropriate building design and maintenance in controlling indoor
air pollution.  In the third section we introduce protocols to
diagnose air quality problems as a critical first step in
effective indoor air problem mitigation and prevention.  Finally,
in the fourth section we present options for the administrative
control of indoor air quality.


     Engineering control of  indoor air pollution relies on three
general processes:   (1) source control, (2) ventilation control,
and (3) air cleaning.  Source control improves indoor air
quality by directly reducing the contribution of sources to
indoor air pollutant levels.  Ventilation control, in contrast,
dilutes indoor air with outdoor air to reduce concentrations of
indoor pollutants.  Finally, air cleaning controls indoor air
pollution by actively removing pollutants from the indoor air
through chemical and physical methods.  This section introduces
the principles involved in each of these control strategies and
the range of indoor air concerns to which they can be
successfully applied.

     Source Control

     Combustion appliances, tobacco smoking, building materials,
soil gas, commercial and consumer products, and microbial growth
potentially generate indoor air pollutants, and emissions from
these sources can be controlled to reduce indoor air quality
concerns.  Source control strategies fall into four categories:
(1) source substitution and/or removal; (2) source encapsulation
and/or confinement;  (3) proper source operation and maintenance;
and (4) source modification.

     Removing indoor pollutant sources from the indoor
environment and replacing them with non-polluting substitutes can
directly and substantially improve indoor air quality.
Successful use of this strategy requires sacrificing the function
of source materials or finding suitable substitutes.  Therefore,
decisions to remove and substitute for pollutant sources require
a careful balancing of economic, functional, and health concerns.

     Some sources of indoor air pollution that cannot be easily
removed or replaced can be controlled by encapsulation or
confinement.  These processes do not eliminate potential
pollution sources, but rather restrict the movement of the
pollutants of concern in the indoor atmosphere.


     Properly operating and maintaining appliances and products
can also reduce their emissions of indoor air pollutants.   This
control strategy can include tuning or cleaning sources to reduce
pollutant generation or curtailing source use or shifting source
use in time and space in order to separate emissions from human
activity and thereby reduce human exposure.

     Many product-related sources of indoor air pollutants can be
modified to reduce their contaminant emissions.  Some of these
modifications can be carried out by the manufacturer while others
may take place at the location of source use.

     Source control for combustion appliances,  tobacco smoking,
building materials, consumer and commercial products, biological
sources and radon are discussed below.

     Combustion Appliances

     Pollutant emissions from combustion appliances can be
controlled through exhaust ventilation, confinement, proper
operation and maintenance, and burner modification.

     Combustion pollutants can be controlled by venting flue
gases.  Confining combustion appliances to specially partitioned
rooms or compartments prevents them from polluting the larger,
general-use habitable space.  In addition, combustion appliances
burn more cleanly  (i.e., emit reduced quantities of pollutants)
if kept properly adjusted and cleaned through appropriate

     A number of manufacturer modifications to combustion
appliances have resulted in cleaner emissions.   Advances in gas
burner technology may improve appliance performance by reducing
the rate of pollutant formation.  For example,  tests have shown
that inserts for burners in gas ranges, ovens,  and other
appliances reduce emissions of combustion gases and particulates
(DeWerth and Kurzynske, 1986).  Also, replacing pilot lights with
electronic ignition for gas burners eliminates the continuous
low-level emission of combustion products from the gas pilot
(Fisk et al.,  1985).   Inserts in fireplaces and air-tight stoves
have improved the combustion performance of, and reduced the
leakage of, combustion products from these appliances into the
indoor air (Fisk et al., 1985).

     Tobacco Smoking

     ETS can be controlled by removing its source, tobacco
smoking,, from indoor environments or confining tobacco smoking  to
designated spaces apart from general habitable areas.  Effective
control of ETS by source confinement requires that designated
smoking areas be depressurized and vented directly to the
outside.  Smoking restrictions have been most widely applied  to


public buildings and public areas of buildings, but are becoming
increasingly used in private spaces.

     Building Materials

     Control of pollutant emissions from building materials can
be accomplished through replacement or substitution, confinement,
or modification of problem materials.

     Many building materials emit indoor air pollutants.
Examples of those which can be replaced in building construction
or renovation include pressed wood products and foam insulation
(formaldehyde), bricks and concrete (radon), and asbestos and
glass fiber products.  Urea-formaldehyde foam insulation and
pressed wood products may have superior durability, economic,
and structural qualities compared to their available substitutes.
Consequently, it may be desirable to reduce emission rates from
these materials through product modifications  (Fisk et al.,
1985).  However, high-radium building products can be replaced
with similar products with less potential to emit radon, and
substitutes for most uses of asbestos in building materials have
been found.  Asbestos-containing building materials are no longer
used in new construction.  [Removing asbestos from existing
buildings can produce high concentrations of airborne asbestos
and requires efforts to limit exposures to airborne fibers during
and after removal activities (D'Angelo et al., 1987). Asbestos
should only be removed by experts using EPA approved methods.

     Encapsulation of building materials is said to reduce
pollutant release from the source material to the indoor air.
However, only rudimentary information is available on the effects
of encapsulation.  Formaldehyde emissions were reported to have
been significantly reduced by covering pressed wood products with
linoleum (Matthews, et al. 1986) or with sealants and varnishes
(Godish and Rouch, 1987).  Encapsulation is also reported to have
been effective in reducing pentachlorophenol emissions from wood
products treated with this pesticide (Levin and Hahn, 1984).

     Manufacturers may also modify their product to reduce
emissions,  as, for example, in changing the resin content of
pressed wood products, or curing their products prior to sale.

     Consumer and Commercial Products

     Products such as furnishings, carpets, paints, wall
coverings,  pesticides, cleaners, and personal care products
contain a variety of potential air pollutants.  Controlling
indoor air pollution from these products can be accomplished by
substituting non-polluting products, properly using and
maintaining potential problem products, or modifying product
composition to mitigate potential indoor air concerns.

     Discontinuing or curtailing the use of products that emit
air pollutants would reduce associated pollutant concentrations
in the indoor environment,  but would,  in many cases, require the
provision of acceptable substitutes or,  at least,  the adoption of
alternative practices (e.g.,  better general hygiene and less
dependence on aerosol room air fresheners).

     Altering the timing and location of product use can reduce
human exposure to pollutants without necessarily reducing
concentrations.  Some products (e.g. household pesticides,
furniture strippers) will necessarily produce air pollution, but
altering use patterns can help separate pollutants from human

     The replacement of lead-based paints and the decreased use
of aerosol-propelled personal comfort products illustrate the use
of source substitution to control consumer product-related
pollution problems.  As an indication of the potential for
continued progress in this area,  Levin (1987a) reported that a
manufacturer modified a shelving product by enclosing its
particleboard core in response to indoor air quality concerns.

     Biological Sources

     General hygiene can control the proliferation of biological
agents such as dust mites and bacterial and fungal growth,
particularly in areas which can act as growth media for such
sources.  Regularly changing filters in ventilation systems,
cleaning humidifiers and air conditioners, and disposing of water
damaged rugs and furnishings will help control biological

     Morey, et al.  (1984b)  provides the following recommendations
to prevent contamination:  (1) prevent moisture incursion into
occupied spaces and HVAC system components, (2) remove stagnant
water and slimes from building mechanical ventilation systems,
(3) use steam as a moisture source in humidifiers,  (4) eliminate
water sprays as components of office building HVAC systems,
(5) maintain relative humidity below 70%,  (6) use filters with
50-70% rated efficiency, (7)  remove water-damaged material  and
furnishings, and (8) provide a fastidious maintenance program for
HVAC air handling and fan coil units.

     Radon Infiltration

     Outside sources of radon can be controlled by a number of
source control methods.  Sealing cracks and seams in slabs,
basement walls, and floors can restrict or eliminate radon
infiltration into the indoor air  (EPA, 1987), though it  is  not
always effective. The technique may work better in some  buildings
than others, and is often combined with subslab ventilation.
Radon infiltration has also been controlled by ventilating  and


pressurizing basements and by applying suction to drain tiles or
the area beneath building slabs in order to redirect radon laden
soil gas away from the indoor environment (Henschel and Scott,
1987; Ericson et_al., 1984).

     Ventilation Control

     A common method of controlling the quality of indoor air
uses outside air to dilute indoor concentrations of air
pollutants.  This approach to indoor air quality control relies
on a relatively clean outside atmosphere and mechanisms to
exchange air between the inside and outside of a building system
and to distribute outdoor air throughout the building.  The
following paragraphs discuss indoor air quality control by
general and specific ventilation strategies.

     General Ventilation

     Incorporating outdoor air into the indoor environment has
been a component of building design and operation for thousands
of years.  Indoor environments, except for the extreme cases of
spacecraft and submarines, are not isolated from their
surroundings and use outside air to revitalize indoor air.  Since
ventilation replaces indoor air with outdoor air, this control
strategy effectively dilutes and removes indoor airborne
contaminants at a rate dependent on the effective rate of
ventilation and outdoor pollutant concentrations.

     Ventilation requirements, such as those incorporated in
ASHRAE Standard 62-1981, "Ventilation for Acceptable Indoor Air
Quality," are intended to control the products of human
metabolism and other contaminants under most circumstances.
However, source control, air cleaning, and increased ventilation
may also be required in the presence of strong sources.  The
ASHRAE requirements, as discussed in a subsequent chapter,
prescribe minimum outdoor air ventilation rates to be provided by
properly designed systems.  The specified rates are based on the
assumption of complete mixing of outdoor air throughout the
indoor atmosphere (ASHRAE, 1981).  The ventilation rates are
specific to building type and usage.  A recent proposed revision
to the ventilation standard (ASHRAE 62-1981R) specifies a minimum
ventilation rate of twenty cubic feet per minute  (cfm) per person
for office environments (ASHRAE, 1986).

     It has become common in recent years, with rising energy
costs,  to decrease ventilation rates to conserve energy.  The use
of variable air volume ventilation systems can reduce energy
costs arising from conditioning outside air, but such systems may
not maintain exchange rates protective of indoor air quality
(ASHRAE, 1986; Guttman, 1987).  Indoor air quality problems  in  a
number of office buildings have been related to  inadequate
ventilation and were remedied by retrofitting HVAC systems.  It


is important to reiterate,  however,  that adequate ventilation in
accordance with ASHRAE 62-1981R does not guarantee acceptable
indoor air quality;  many indoor air  quality problems require some
form of source control in addition to better ventilation,  and,
for problems such as radon,  some forms of ventilation may
actually exacerbate  the problem.

     Local or Exhaust Ventilation

     A specific method of using ventilation to control indoor air
quality is local ventilation in the  vicinity of pollutant
sources.  Local ventilation, also called exhaust ventilation,
typically involves providing a separate exhaust system for a
plume of contaminants from a pollutant source.  This strategy
decreases source strength and removes indoor air contaminants
before they are dispersed throughout the indoor air (Bearg and
Turner, 1987).  In this regard local ventilation can be thought
of as a source control strategy.

     Local ventilation is often combined with the use of pressure
differentials to contain contaminants within specific negative
pressure areas.  This technique is used routinely in sensitive
health-care microenvironments and has been applied to the
asbestos removal process to contain  the pollutant within the
working area  (D'Angelo et al.,  1987), and is regularly used for
exhausting toilet facilities and preventing contaminants from
entering other parts of the building.

     Demand-Induced  Ventilation

     A sensor may be used to trigger increased outdoor
ventilation rates when levels of some specified contaminant reach
or exceed a specified level.  This technique attempts to balance
the need for adequate indoor air quality, thermal comfort, and
energy conservation  by integrating indoor contaminant and
temperature levels within the same control mechanism.

     A carbon dioxide (C02)  sensor has been suggested for use in
general office environments (Vaculik, 1987; Fecker et al.,
1987).  However, other pollutants may also be used, singly or in
combination, depending on the circumstances.  In a demonstration
of air quality control using this strategy, for example, an
office building air  quality problem  caused by a parking structure
was corrected, in part, by a carbon  monoxide sensor used to
increase ventilation rates when CO levels from the garage reached
a preset threshold (Boelter and Monaco, 1987).

     Ventilation Effectiveness (Efficiency)

     The extent to which ventilation air reaches the breathing
zone of building occupants is termed ventilation effectiveness  or
ventilation efficiency.  ASHRAE ventilation standards assume that


ventilated air is perfectly mixed into the occupied zone.  In the
event that complete mixing does not occur, ventilation control of
contaminants is compromised, and readjustment of the HVAC system
or implementation of some other operational control strategy
becomes necessary to maintain the air quality expected from
compliance with ASHRAE's standards.

     Air Cleaning

     Air cleaning involves the physical or chemical removal of
pollutants from the indoor air.  Three basic technologies have
been developed:  particulate filtration, electrostatic
precipitation, and gas or vapor sorption.

     Air Cleaning Technologies

     Particulate Matter Filtration;  Filtration removes airborne
particles by inertial  impingement, interception, straining,
and/or diffusion (NRC, 1981).  Inertial impingement collects
airborne particles on  filter material as the direction of air
flow changes abruptly.  Based on the principle of momentum, this
method most effectively removes larger particles.  Interception
is a special case of impingement in which particles in the air
stream collide with and collect on filter material.
Interception does not  rely on high rates of flow as does inertial
impingement.  Straining of particulates from the airstream
results from the capture of particles between closely spaced
filter fibers.  Diffusion removes pollutants from the air through
the random molecular movement of small particles onto filter
material.  Each of these mechanisms preferentially removes
particles of a different size class.  By properly designing air
flow and filter materials, a combination of these mechanisms may
provide suitable particulate removal (NRC, 1981).

     Three kinds of filters corresponding to different levels of
efficiency are commonly applied for distinct purposes. Different
measures of performance are applied to each type.  Low-
efficiency filters are used as upstream prefilters (which remove
coarse particulate matter from an air stream before it is
filtered by more efficient filters) or to protect fans and other
air handling equipment.  These filters remove large, heavy
particles.   The weight arrestance test in ASHRAE Standard 52-76
is generally used to evaluate performance of these filters.
Medium-efficiency filters are more expensive than their low-
efficiency counterparts and remove smaller particles for material
and general health protection.  The dust spot efficiency test in
ASHRAE Standard 52-76 normally used to measure performance of
these filters.  High-efficiency particulate air  (HEPA) filters,
more expensive still, can be used for health protection in
especially sensitive situations such as clean-room and surgical
suite applications.  Military Standard 282 which measures the

percent removal of 0.3 urn particles of dioctylphthalate (DOP) is
used to measure performance of these filters.

     Electrostatic Precipitation;  An alternative method of
removing particles from air, electrostatic precipitation, induces
a charge on the particles and then collects the charged particles
on oppositely charged surfaces.  Electrostatic precipitation
requires three steps:  (1) air ionization, (2) particle charging,
and  (3) particle migration  (Fisk et al.,  1985).  Air ionization
occurs in the vicinity of a high voltage electrode in direct
contact with air.  The high voltage creates an electric field
which ionizes gas molecules.  Ionized gas molecules, or the
electrons they release, disperse into the air and attach to
particles.  The charged particles created thereby are drawn
toward oppositely charged surfaces at rates dependent on their
electrical charge and size.

     The efficiency of electrostatic precipitation is measured
similarly to that of filters, and its performance compares to
medium-efficiency and HEPA filters.  This technology presents
potential problems in the form of high voltages at the ionizing
location, as well as the production of ozone.

     Gas Sorption;  Gases are removed from air by chemical and
physical sorption.  Sorption processes include absorption of air
pollutants into sorbent material, fixation of pollutants onto
external surfaces, and physical or chemical adsorption on
internal surfaces (NRC, 1981).

     Adsorption is a dynamic process, and its effectiveness  in
removing pollutants depends on the concentration of the pollutant
in the atmosphere, the surface area of the sorbent, the volume of
pores small enough to facilitate condensation of adsorbed gases,
the presence of competing gases, and the physical and chemical
nature of adsorbate and sorbent  (NRC, 1981).   Common sorbents
include neutral substances, such as activated carbon, and more
selective, oxygenated substances, such as activated alumina  and

     Sorbents can be impregnated with substances that enhance the
sorption process.  Potassium permanganate is an example of a
compound that enhances sorbent efficiency by oxidizing air
contaminants to facilitate their interaction with the sorbent.

     Air Cleaning Devices

     Because different technologies perform different types  of
air cleaning functions, these varied air cleaning technologies
may be incorporated into integrated air cleaning systems.  Multi-
stage devices are needed if air cleaning is to remove both
particulate and gaseous air pollutants.  These devices can be
incorporated into central air systems to treat ventilation air  or

                               6 = 8

can stand alone and treat ambient air drawn through a cleaning
system independent of ventilation.

     The effectiveness of air cleaning devices depend on the air
flow rate, as well as removal efficiency.  The effectiveness of
portable units may also depend on their location in the room.
This is particularly true of ion generators which are most
effective when centrally located.

     HVAC Air Cleaning Systems:

     Typical air cleaning components in HVAC systems are
comprised of low-efficiency filters that remove only the largest
of airborne particles.  Filters to remove the smaller viable
microbes and respirable particles are not generally used except
in special applications such as nuclear industry facilities and
sensitive areas of health care facilities.  These highly
efficient (HEPA) filters are rarely used because they are
expensive to install and operate  (Fisk, 1986).

     Electrostatic precipitation  is used in HVAC systems to
remove particulate air pollutants.  These devices, however, emit
ozone which may be a problem if the unit is oversized.

     Gas serpents include activated carbon, silica, and alumina,
the choice of which depends on the pollutants of concern.  A
promising HVAC-related air cleaner currently under development
would use desiccant materials in  a vapor compression air
conditioner to remove gases such  as NOX  (Relwani et al., 1987;
Novosel et al., 1987).

     Stand-Alone Units:  Stand-alone air cleaning devices have
been developed as indoor air quality concerns have become more
prevalent.  The performance of these devices, which utilize  ion
generators and filters, varies considerably.

     Consumer Reports  (1985) tests of twenty-three portable  air-
cleaning units found that only eight appliances could effectively
clean ETS and pollen-size particles from indoor air.  These  eight
units appear to be capable of removing only particulate matter.
An example of a stand-alone device that may provide some gas
removal capability is a one square foot filter which was shown to
reduce CO concentrations by 34 percent in test studies  (Collins,
1986) .

     Despite the effectiveness of some models, Consumer Reports
concluded that "small, inexpensive air cleaners are almost
useless" in providing indoor air  quality control  (Consumer
Reports, 19§5).  Fisk  (1986) confirms these results in  claiming
that tabletop air cleaners are almost totally ineffective  in
removing pollutants.  The ineffectiveness of many portable
devices relates not to their ability to remove pollutants  from


the air they process, but in their limited ability to circulate a
significant portion of the indoor atmosphere, and the potential
emission of pollutants from their air cleaning surfaces when
improperly maintained.

     Difficulties in Cleaning ETS

     ETS has proven to be a difficult pollutant'to control by air
cleaning (Bearg and Turner, 1987).  This difficulty arises
largely because of the complexity of the ETS mixture.  Olander
and coworkers  (1987) attempted to clean ETS from air with over
thirty devices and concluded that no air cleaning device could
replace dilution control for removal of this pollutant.
Peltier (1986), in a theoretical study, determined that ETS
cleaning required the processing of seventeen times more air for
particulate removal than for gas removal.  Repace and Lowery
(1985) calculated that it would require about 250 times as much
ventilation air as standards require for offices to control the
lung cancer risk from the particulate phase of ETS to an
"acceptable" level of risk.  This leads to the conclusion that
ETS is best controlled by smoking bans, or by restricting smoking
to rooms that are depressurized relative to the nonsmoking part
of the building and directly exhausted to the outside.

     Summary of Control Strategies

     The control strategies discussed in this chapter span a
variety of control mechanisms and vary in their accessibility to
parties interested in the control of indoor air quality.  Exhibit
6-1 illustrates the agents who can implement these control
opportunities and presents brief comments on the range of
problems that each category of strategies can address.

     Source strategies are limited to the extent to which sources
can be identified and are accessible to the responsible agent.
Some form of source control is generally available to consumers
and building managers.  However, source substitution and
modification of building materials must, for the most part, be
done before buildings are occupied, so occupant and building
manager options in this regard are limited.  Source maintenance
and operation control are entirely in the hands of the user of
the source, and cannot be practically influenced by builders,
designers,  or product manufacturers.  Manufacturers can in many
cases modify the composition and/or characteristics of their
products in ways that would improve indoor air quality.

     Ventilation approaches to indoor air quality control can
effectively remove all airborne contaminants, but are limited by
ventilation system design and the presence of sources that emit
pollutants  too rapidly to be well dispersed by dilution.  Because
ventilation capacities are determined in the building design
stage,  most, existing systems may not be flexible enough to allow


                                                                               Exhibit 6-1
                                                                         Control  Strategy
                                  ACEHTS UHO CM IMtBCMT COMTROL STRATEGY
ft Building   Builders £
Building t
                                                                              Controls indoor concentrations of pollutants which have attributable sources.
      Encapsul at i on/Conf i nement
      Operation end Maintenance
                                            Performed during  construction or  renovation.  Voluntary  or  required in building
                                              code.  Smoke-free  buildings designated by occupants, building managers,  or  by

                                            Performed during  design,  construction,  or renovation.  Voluntary or required  in
                                              building  code.   Smoke-free areas  designated by building managers  or regulators.

                                            Performed during  building occupancy by  parties operating the  building.   Voluntary or
                                             regulated  in  health or  fire codes  for  some building  types.

                                            Performed by occupants,  building  managers,  builders,  or  manufacturers.   Voluntary or
                                             regulated  in  building codes or product standards.
     Ventilation Control
                                                                              Controls indoor concentrations of ALL airborne contaminants.
      Po11ut i on-i nduced
                                           Operated by  occupants  or  building manager.  System design  influences performance.
                                             Minimum rates may be mandated  in building codes.

                                           Operated as  required by occupants or building manager.  Performance influenced
                                             by design.  Building codes may require  local exhaust from certain sources and

                                                                              Controls indoor concentrations of particulates and reactive gases.
      Stand Alone
                                            installed and operated by building occupants or managers.  Maintenance by occupants
                                              or  managers necessary  for proper operation.  Unit capacity must be matched to room
                                                 volume.  Many  units are  ineffective.

                                            Operated by building managers,   installed during building construction or as
                                              a renovation.

their use to control all air quality concerns.   Ventilation
design and operation for indoor air quality control are
frequently sacrificed for energy efficiency; air quality control
can be greatly impaired if indoor air concerns  are subjugated to
concerns for energy consumption.  Because of limitations
inventilation capacity or practice, building occupants and
managers often cannot take full advantage of pollution control by

     Air cleaning may be added to ventilation control of
particulate and reactive gas pollution problems when
incorporating sufficient outside air is not feasible.  When the
outside air requires extensive conditioning for thermal comfort,
ventilation can be a costly control method, and some
recirculation with added cleaning of indoor air becomes
economically attractive.  HVAC-based air cleaners are preferred.
Many available stand-alone air-cleaning units provide almost no
assistance in removing contaminants.  All air cleaners must be
properly operated and maintained to be effective.


     Because of the important role building systems play in
determining indoor air quality, building design and maintenance
provide excellent opportunities to control potential indoor air
problems.  Appropriate design of interior space, mechanical
systems, and the building envelope can optimize the air quality
potential of a building, and proper maintenance can ensure that
building operation maximizes indoor air quality to the extent
allowed by design.

     Design Requirements for Indoor Air Quality Control

     Appropriate building design for indoor air quality
encompasses such considerations as HVAC system design, building
envelope and structure design, and spatial layout of interior
activity areas and their relationship to potential indoor and
outdoor pollutant sources.  Design of these components to
optimize indoor air quality must work within the constraints of
other building system performance requirements such as structural
integrity, economic viability, and comfort and safety issues
related to lighting, noise, and temperature.

     HVAC engineers and architects typically provide the
professional support needed to assure that the full array of
performance requirements are met by a building's design.  The
traditional separation of design roles between HVAC engineers and
architects may prohibit either discipline  from adequately
addressing all design requirements independent of the other.  The
following discussions of important building design components
point to the necessary cooperation between these professions  in
properly designing building systems.


     HVAC Design Criteria

     HVAC design criteria serve to ensure that the indoor
atmosphere can be conditioned to provide thermally comfortable
air throughout the occupied zone of a building.   In addition to
thermal comfort, indoor air quality design goals should also be
incorporated.  They may be prescribed in building codes or
standards.  Design'goals are achieved by (1)  supplying adequate
outdoor ventilation air, (2) properly distributing the outdoor
air throughout the occupied zone, and (3) taking further steps as
necessary to ensure that the resulting air of the occupied zone
does not contain deleterious concentrations of airborne

     HVAC system design must balance ventilation with indoor
source emissions and outdoor pollutant levels to create an
acceptable indoor atmosphere.  Consideration of indoor sources
requires consulting with the building's architects and owner to
learn of planned uses of the space and materials employed in
constructing, decorating, and furnishing the building.  The
potential introduction of contaminants from sources outdoors,
including those on the exterior of the building (e.g. exhaust
vents), necessitates attention to the location and design of air
intakes to prevent contaminated air from entering the building,
restricting entry of contaminants by creating positive interior
pressures, and, if necessary, pre-treating ventilation air.

     Building Envelope and Structure Design Requirements

     Appropriate design of building systems recognizes the
importance of the building structure to the indoor atmosphere.
Materials must meet criteria for durability, structural
integrity, functional utility, and ease of maintenance.  They
should also meet low pollutant emission criteria.
Characterizing potential pollution sources in a building
structure during the design stage can allow their effects to be
mitigated through substitution or other appropriate source or
ventilation controls before they create indoor air problems.

     Building envelopes may be designed to minimize infiltration
and exfiltration for energy conservation reasons.  Adequate
outdoor air ventilation must be designed into the building
structure, and can be provided by natural or mechanical means.
Buildings designed to minimize infiltration and exfiltration must
provide adequate outdoor air ventilation through mechanical
means.  Roof designs must minimize water accumulation and  leakage
to minimize biological contamination and structural damage.

     Sub-slab ventilation can be designed into new building
construction to indoor radon problems. Several of the nation's
largest home-building firms are currently "roughing-in"

provisions for sub-slab ventilation in all new residential
construction (Spears,  1988) .

     Interior Space Design Requirements

     Interior space design must provide adequate floor space for
occupant activities, and meet aesthetic,  acoustic,  light, and
privacy requirements.   It should also maintain occupant exposures
to indoor pollutants below detrimental levels.  Future occupant
exposures to indoor air pollutants can be controlled through
source confinements, locating problem sources away from occupied
areas, and using air flow patterns to draw source emissions away
from occupants.   Care must be taken in the selection and location
of movable partitions which can be pollutant sources and may also
interrupt the flow of ventilation air to building occupants.

     Maintenance Requirements for Indoor Air Quality Control

     Proper maintenance allows building performance to meet or
exceed design goals for indoor air quality-   The performance
requirement of indoor air quality protecting the health, comfort,
and productivity of occupants can be advanced through proper
maintenance of occupied spaces and the HVAC system (Levin,
1987b).   Cleaning and maintenance can themselves create indoor
air pollution by suspending accumulated pollutants and should
therefore be conducted so as to minimize exposures to elevated
contaminant concentrations (Green, 1984).

     Occupied areas need to be maintained as free as practical
accumulations of dust, microorganisms, and pests.  General
hygiene usually suffices to control dust accumulation and
microorganism growth,  as well as pest populations.

     The humidity of the building system affects microorganism
viability, and should be limited to prevent fungal and bacterial
amplification and subsequent accumulation.  Water damaged
materials should be discarded if feasible to prevent microbial
contamination.   Contaminated building surfaces should be vacuumed
using a vacuum cleaner incorporating a HEPA filter and
subsequently disinfected (Rask and Morey, 1987).  Microbial
damage is difficult and costly to clean and should be
scrupulously avoided.  Cleaning may not be possible where severe
contamination occurs.

     Maintenance of HVAC systems includes keeping them clean of
dust, microorganisms,  and water accumulations; maintaining
mechanical parts; and operating under conditions to achieve
design requirements for air flow and distribution, temperature,
and humidity (Rask and Morey, 1987).


     Building diagnostic protocols provide standardized methods
to assess the current and future performance of building systems.
Indoor air quality diagnostics focus on assessments of those
components of building system performance which affect indoor air
quality.  Through diagnostic protocols, expert observers and
analysts can identify indoor air problems and recommend remedial
actions to address building design and operation difficulties.

     Building diagnostics provide expert assessment of the degree
to which individual building performance requirements are met,
the degree to which the overall building purpose is being served,
implications of deficiencies in building performance, and causes
of performance deficiencies which suggest remedial actions.  The
relevant individual building performance requirement in indoor
air quality diagnostics is the ability of the indoor atmosphere
to sustain the health, comfort, and productivity of building

     Building diagnostic protocols call for a series of steps to
fully characterize building performance and to relate that
performance to goals and design expectations.  Woods et al.
(1987) describe phases in the diagnosis of buildings experiencing
indoor air quality problems as (1) consultation, (2) qualitative
diagnostics, and  (3) quantitative diagnostics.  These phases are
defined and explained in Exhibit 6-2 by the procedures they
entail and the information that they are designed to provide.  By
performing diagnoses in this staged manner, it is possible to
prevent and resolve many problems without resorting to time and
resource-consuming data acquisition unless absolutely necessary
(Woods et al.. 1987).

     Specific actions performed as diagnostic aids include
measuring physical criteria, and interviewing building managers,
facilities staff, and occupants.  Physical criteria which might
point to air quality problems include indoor temperature,
humidity, and pollutant concentrations; characterization of
possible pollutant sources in the building system; operating
conditions of HVAC systems; and outdoor conditions which might
influence the indoor environment.  Occupant interviews can
provide information on perceived detrimental effects potentially
associated with poor building performance, and the temporal and
spatial extent and patterns of such effects.  These data can then
be analyzed as part of the assessment of building performance.

     Since indoor air quality problems can result from such a
variety of factors, manifest themselves in such diverse ways, and
can hinder the proper functioning of building systems, building
diagnostic procedures (and explicit, structured protocols to
conduct them) are essential to the control of indoor air quality.
Performing diagnostic evaluations on a regular basis can prevent


                                                                                Exhibit 6-2
                                                                  Indoor Air Quality Diajrwstic Protocol  a
                                 Meet HIth Senior Administrative Officer and
                                      Safety Officer

                                 Meet with Facilities Manager/Staff

                                 Tour Facility

                                 Develop Hypotheses and Recoranendations
                                                            Explain objectives and acquire preliminary information.
                                                            Acquire  information about building system characteristics.

                                                            .Inspect  occupied spaces and mechanical equipment to determine condition
                                                                 of  space,  to observe HVAC performance, and to communicate with

                                                            Focus attention on possible recorrenendations for remedial action or
                                                                 additional phases of diagnosis.
   Qualitative Diagnostics
Establish Performance Criteria  in Consultation
     Mith Building Owner's Representative

Characterize Occupant Problems  or Conplaints
     through Interviews

Define System Boundaries

Analyze Control Strategies

Analyze Loads

Determine limits of acceptable indoor air quality.

Learn extent of problem and its relation to building layout  and

Limit scope of further study to problem area.

Assess differences between design and actual building system performance.

Assess HVAC system capabilities to cope with environmental  requirements.
     This may include simulations or tracer gas tests of HVAC components.

Communicate findings and additional recommendations to the  client.
   Quantitative Diagnostics
Select Sampling Sites

Objective Measurement

Subjective Measurement

Analysis, Interpretation, and Report
Prepare for cost-effective, thorough collection of air samples.

Coordinate measurements of occupied space and HVAC system to correlate
     indoor conditions to HVAC performance.  Quality assurance and
     quality control of these data guarantee their utility.

Assess occupant response to environmental conditions at the time that
     objective measurements are taken.

Assess and coamnieate information gained during the diagnoses.   Report
     should identify causal agents of and practical remedies for observed
       a   Summary of  protocol described by Woods et al. 1987.

air quality problems from occurring or minimize their duration
and magnitude.


     The previous sections of this chapter covered the physical
control methods that could be used to prevent and mitigate indoor
air pollution in both new construction and in existing buildings.
The agents capable of employing these methods include individual
occupants, building owners and managers, architects,  builders,
and manufacturers.

     Public and private sector organizations, including trade and
professional associations, consumer and health organizations, and
governments, also have significant roles to play in terms of
informing, encouraging, or requiring these agents to take action
to protect building occupants.  Exhibit 6-3 provides examples of
individual and organizational roles.

     In this section, we discuss regulatory and non-regulatory
policy options available to organizations and governments in
fulfilling these roles. Subsequent chapters will discuss the
actual policies and programs which are currently in place.

     Government Regulations

     Regulations impose requirements on individuals or
organizations in the conduct of activities which pose a threat to
the public health and welfare, and are commonly regarded as the
main policy instrument for environmental protection.  Because
environmental regulations carry the force of law., and generally
contain provisions for either civil or criminal penalties for
non-compliance, their use is normally limited only to situations
of significant risk, and follow directly from legislation
specifically authorizing such regulations.

     Legislative authorities specifically authorizing regulations
which affect indoor air, and examples of government regulations
employed under those authorities are discussed in subsequent
chapters.  The most common types of regulations are those which
are specific to a given pollutant or source.  Such regulations
may take several forms:

   o  a ban or restriction on the use of specific chemicals  or

   o  requirements that products meet certain standards;

   o  requirements that products be tested and certified  prior  to
      manufacture; or

                                                                                   Exhibit 6-5
                                                                         Pii>tic and Private Sector  Roles

 1.   Find  low
     emission products
     in purchasing

 1. Be knowledgeable
    of symptoms, effects
    and mitigation and
    advise clients.

                                                    . Adopt test proce-
                                                      dures and standards
                                                      to minimize product
                                                      and material
                                                                        BUILDING OWNERS
                                                                         AND  MANAGERS

                                                                        Adopt ventilation
                                                                        procedures to
                                                                        eliminate and  prevent
                                                                        contamination  and
                                                                        ensure an adequate
                                                                        supply of clean  air
                                                                        to  building  occupants.

Adopt indoor air
quali ty as a
design objective.
                                                                                                                             STATE AWO LOCAL

                                                                                                                          1. Conduct studies of
                                                                                                                             specific problems
                                                                                                                             in state or local
                                                                                                                             area and adopt
                                                                                                                             mitigation strategies.

1.  Conduct research
   and technology
   transfer programs.
2.  Maintain and use    2. Develop  information   2.  Adequately label
products to
minimize emissions.
    Exercise discre-
    tionary control
    over ventiI at ion
    to ensure clean
    air supply.
Be knowledgeable
of indoor air
quality problems
and take actions
to avoid personal
                           and education
                           programs  to
                           constituent publics.
                            products as to
                            emission level and
                            proper use and
                            maintenance of
                                                                           2. Use zone ventilation
                                                                              or local exhaust for
                                                                              indoor sources.
                         3.  Substitute materials 3. Develop specific
                            to minimize emis-
                            sions from products
                                                                              procedures for use
                                                                              of cleaning solvents,
                                                                              paints, herbicides,
                                                                              insecticides, and
                                                                              other contaminants
                                                                              to protect occupants.
                                                4. Develop  training      4.  Adopt  investigatory
                                                   programs  for             protocols  to
                                                   commercial users  to      respond  to occupant
                                                   ensure low emissions.    complaints.
                                                5. Conduct  research  to
                                                   advance  mitigation
                                                                                              2. Ensure compliance
                                                                                                 with  indoor air
                                                                                                 quality ventilation
                                                                                              3. Adopt  low emission
                                                                                                 requirements  in
                                                                                                 specifications for
                                                                                                 buiIding materials
                                                                                                 from manufacturers.
                                                                           4.  Contain or ventilate
                                                                              known sources.
                         2. Establish building
                            codes for design,
                            construction,  and
                            requirements to
                            ensure adequate
                            indoor air quality.

                         3. Enforce and monitor
                            code compliance.
                                                                                                                                                    2. Coordinate actions
                                                                                                                                                       of other sectors.
                                                                                                                                                    3. Conduct specific
                                                                                                                                                       programs to inform,
                                                                                                                                                       encourage, or
                                                                                                                                                       require specific
                                                                                                                                                       sectors to take
                                                                                                                                                       actions toward
                                                                                                                                    Educate and inform
                                                                                                                                    building community,
                                                                                                                                    health conrtinity,
                                                                                                                                    and pUblic about
                                                                                                                                    problems and solutions.

   o  requirements that products be labelled with important
      information concerning content,  effects,  and proper
      instructions for use.

     Some regulatory requirements may be in the form of standards
or guidelines which are discussed below.

     Standards and Guidelines

     Standards and guidelines are frequently issued by private
sector organizations as well as governments.  The standards and
guidelines may be mandatory (regulatory) or voluntary (non-
regulatory) ,  but the distinction is not always clear.  For
example, while the majority of private sector standards are
voluntary, they may be as effective as a government regulation
because they become the basis for professional practice and, as
such, are often used for licensure.  Compliance with such
standards may also be necessary for protection against liability.
Thus, a violation of a private sector standard may carry with it
sanctions which are similar to or more stringent than government

     In addition, standards set or adopted by organizations such
as the American Society for Testing and Materials (ASTM), the
American National Standards Institute (ANSI),  the American
Conference of Governmental Industrial Hygienists (ACGIH), and the
American Society of Heating, Refrigerating, and Air Conditioning
Engineers (ASHRAE) are often incorporated into government
regulations either directly or by reference, and in that way
become mandatory.

     Standards or guidelines most relevant to indoor air include
air quality standards; source emission standards; ventilation
standards; building codes; and diagnostic protocols.

     Air quality standards specify maximum concentration
     levels of a contaminant beyond which health risks from
     exposure are deemed to be unacceptable.  Standards will
     vary according to the level of protection, the
     population protected, and the extent to which technical
     and economic feasibility are taken into account.  A
     discussion of available indoor air quality standards is
     given in Chapter 7.

     Source emission standards specify maximum rates at
     which a contaminant can be emitted from a source.  The
     rates are designed to protect the user and/or third
     parties that might be exposed.  Such standards are
     normally imposed on the manufacturer.

     Ventilation standards specify minimum rates for the
     introduction of outdoor air into indoor spaces.
     Standards are designed to service occupant needs for
     temperature, humidity, and air quality control.  Rates
     will vary with occupant density and activity. Available
     ventilation standards are discussed in Chapter 7.

     Building codes provide design and construction
     specifications for buildings.  Portions of building
     codes which are important to indoor air quality include
     ventilation specifications which affect the dilution
     and exhaust capacity of the ventilation system,
     material specifications which affect emission rates of
     building materials, and design specifications which
     affect the overall relationship between sources,
     pollutant transport, and human activity.  Most
     building codes are administered by State and local

     Diagnostic protocols establish methodologies for
     measuring and assessing indoor air quality problems.  A
     comprehensive system of protocols for indoor air would
     include criteria and measurement methods for assessing
     occupant health, building system performance, and
     building air quality.  No such comprehensive set of
     protocols for indoor air has yet been developed, though
     specific elements are being addressed by a number of
     individuals and organizations.

     Non-regulatory Options

     Non-regulatory policy instruments include research,
coordination, training and technical assistance, and public
information.  These activities are both complements, and in some
cases,  alternatives to regulations.

     Research on indoor air pollution is essential to determine
the nature and magnitude of the problem including its causes,
consequences, and methods of control.  Information from research
activities forms the foundation for policy development and
control in both the public and private sectors.  Research is
normally coupled with technology transfer activities to ensure
that information from research is "transferred" to potential
users in order to facilitate the implementation of control

     Coordination is a policy function designed to ensure
efficient implementation of policy objectives among several
players.  Coordination may be used to eliminate duplication, to
share information, or to integrate actions into a common program
guided by common objectives.  True integration is seldom achieved
among federal agencies because of the disparity between agency


legislative mandates.  The interagency Committee on Indoor Air
Quality (CIAQ) is a formal arrangement for coordinating federal
activities in indoor air.

     Training and technical assistance programs are policy
instruments by which individuals receive technical information or
develop expertise for implementing policy objectives.  Training
and technical assistance programs for indoor air may be used to
build capacity among state and local governments or the private
sector for solving problems, or for establishing indoor air
quality programs.

     Public information dissemination is particularly relevant to
indoor air because of the sometimes wide degree of control that
individuals have in limiting their own exposure to indoor
pollutants.  Individuals' behaviors which affect exposure and
health include choices in the products they purchase, the storage
and use of those products, and actions they take to properly
ventilate occupied spaces.  Examples of public information
activities include fact sheets, booklets, handbooks, press
releases, and workshops.

     Choices Among Administrative Options

     Administrative options may be as mild as public education,
or as stringent as an absolute ban on the use of certain
chemicals.  Programs may be centrally focused in the federal
government, may be decentralized and delegated to state and local
governments, or may be primarily left to the private sector with
coordinated governmental involvement.

     Choices will depend on a  full understanding of the
multiplicity of issues and control options.  Problems can occur
in large commercial office buildings, in private homes, and in
restaurants and other public spaces.  Sources include building
materials  (e.g. treated wood products), combustion products  (e.g.
kerosene heaters), office equipment  (e.g. copying machines),  and
consumer products  (e.g. pesticides).  Causes may be natural  (e.g.
radon gas) or human behavior  (e.g. smoking).

     Mitigation alternatives are likewise numerous and complex,
ranging from modifying or substituting sourcesf to treating the
air or changing behaviors.  Moreover, the agents which can effect
change include a wide variety  of individual, professional,
institutional, and governmental actors.

     A comprehensive program will  include a mix of  administrative
options.  Each may be targeted to  a  different need.   In  making
choices, several issues will have  to be  considered:

   o  the extent of health  risks,  and whether they  are voluntary
      or involuntary;


   o  the energy and economic impacts involved;

   o  whether a particular issue involves acute  health effects
      requiring immediate response,  or chronic health problems
      requiring long-term strategies;

   o  whether the problem being addressed is best characterized
      in terms of a few high-risk pollutants and sources, or as a
      multifactorial problem involving mixtures  of diverse
      pollutants, sources, building  system parameters, and varied
      human sensitivities; and

   o  whether protection should be directed at the general
      public, or specific sub-populations including the elderly,
      the young, and the hypersensitive,  who may have special


   Engineering options available to  control indoor air quality
include source control, ventilation,  and  air cleaning strategies.
Source control is preferred where sources are known and control
at the source is feasible.  Ventilation is a necessary component
to any control strategy but ventilation alone does not guarantee
good indoor air quality.  Air cleaning is a useful adjunct to
other control strategies, and is more generally  available for
controlling particles than for controlling gases and vapors.

   Good building design, maintenance and  operational practices
which incorporate indoor air quality control principles are
mechanisms by which indoor air quality may be achieved and
maintained in buildings.  Diagnostic protocols are needed to
insure that where problems occur, they can be adequately
diagnosed and mitigated. Finally, administrative controls may be
regulatory or non-regulatory.  Administrative controls may be
used by governments and others to encourage or require that the
engineering controls, the design, maintenance and operational
practices, and the diagnostic protocols described above are
appropriately followed.


ASHRAE.  1986.  ASHRAE Proposed American National Standard:
   Ventilation for Acceptable Indoor Air Quality.  Public Review
   Draft.  ASHRAE 62-1981R.  Atlanta GA.

ASHRAE.  1981.  ASHRAE Standard:  Ventilation for Acceptable
   Indoor Air Quality.  ASHRAE 62-1981.  Atlanta GA.

Bearg D.W., Turner W.A.  1987.  Achieving Tobacco Smoke-Free
   Environments:  The Problem and Some Solutions.  pp. 334-337.
   Proceedings of the ASHRAE Conference IAQ 87:  Practical
   Control of Indoor Air Problems.  Arlington VA.

Boelter F.W., Monaco E.A.  1987.  Ventilation Modification in a
   Parking Structure.  pp. 41-46.  Proceedings of the ASHRAE
   Conference IAQ 87:  Practical Control of Indoor Air Problems.
   Arlington VA.

Collins, M.  1986.  Room Temperature Catalyst for Improved Indoor
   Air Quality.  pp. 448-460.  Transactions of an APCA Specialty
   Conference.  Indoor Air Quality Control in Cold Climates:
   Hazards and Abatement Measures.  Walkinshaw D.S.  (Ed.).

Consumer Reports.  1985.  Air Cleaners.  January 1985.  pp. 7-11.
   Consumers Union.

D'Angelo W.C., Spicer R.C., Mease M.J.  1987.  Sophisticated
   Asbestos Removal:  Occupied Buildings and Operating HVAC
   Systems.  pp. 119-130.  Proceedings of the ASHRAE Conference
   IAQ 87:  Practical Control of Indoor Air Problems.  Arlington

Dement J.M.,  Smith N.D., Hickey J.L.S., Williams-T.M.  1984.  An
   Evaluation of Formaldehyde Sources, Exposures, and Possible
   Remedial Actions in Two Office Environments.  Indoor Air,
   Proceedings of the Third International Conference on Indoor
   Air Quality and Climate.  Berglund B., Lindvall T., Sundell
   J. (Eds.).  Stockholm.   3:99-104.

DeWerth D., Kurzynske R.  1986.  Burner Flame Inserts for Lower
   NOX Emissions,  pp. 437-447.  Transactions, of an APCA
   Specialty Conference.  Indoor Air Quality Control in Cold
   Climates:   Hazards and Abatement Measures.  Walkinshaw D.S.

Environmental Protection Agency.  1987.  Radon Reduction Methods.
   A Homeowner's Guide.  Second Edition.  Office of Research and
   Development.  OPA-87-010.  Washington, D.C.

Ericson S.O., Schmeid H. ,  Clavensjo B.  1984.  Modified
   Technology in New Construction, and Cost Effective Remedial
   Actions in Existing Structures, to Prevent Infiltration of
   Soil Gas Carrying Radon.  Indoor Air, Proceedings of the Third
   International Conference on Indoor Air Quality and Climate.
   Berglund B.,  Lindvall T.,  Sundell J. (Eds.)-  Stockholm.

Fecker I., Hangartner M.,  Wanner H.U.  1937,  Measurement of
   Carbon Dioxide of Indoor Air to Control the Fresh Air Supply.
   Indoor Air '87:  Proceedings of the Fourth International
   Conference on Indoor Air Quality and Climate.  Seifert B.,
   Esdorn H., Fischer M.,  Ruden H.,  Wegner J. (Eds).  Berlin
   (West).  2:635-639.

Fisk W.J., Spencer R.K., Grimsrud D.T., Offerman F.J., Pederson
   B., Sextro R.  1985. Indoor Air Quality Control Technologies.
   A Critical Review.  Bonneville Power Administration.
   Conservation Engineering Branch.   Division of Resource

Fisk W.J.  1986.  Research Review:  Indoor Air Quality Control
   Technologies.  pp. 568-583.  Proceedings of the ASHRAE
   Conference IAQ 86:  Managing Indoor Air for Health and Energy
   Conservation.  Atlanta GA.

Frey A.H.  1987.  Control of a Severe Odor Problem in a Building.
   pp. 265-274.   Proceedings of the ASHRAE Conference IAQ 87:
   Practical Control of Indoor Air Problems.  Arlington VA.

Giles J.H.  1987.  The Benefits of Using Filtered and
   Recirculated Air as Ventilation Air.  pp. 275-280.
   Proceedings of the ASHRAE Conference IAQ 87:  Practical
   Control of Indoor Air Problems.  Arlington VA.

Godish T., Rouch J.   1987.  Control of Residential Formaldehyde
   Levels by Source Treatment.  Indoor Air  '87:  Proceedings of
   the Fourth International Conference on Indoor Air Quality and
   Climate.   Seifert B., Esdorn H.,  Fischer M., Ruden H., Wegner
   J. (Eds).  Berlin (West).    3:221-225.

Godish T., Rouch J.   1984.  Efficacy of Residential Formaldehyde
   Control Measures:  Source Removal.  Indoor Air, Proceedings
   of the Third International Conference on Indoor Air Quality
   and Climate.   Berglund B., Lindvall T., Sundell J.  (Eds.).
   Stockholm.   3:127-132.

Green G.H.  1984.  The Effect of Vacuum Cleaners on House Dust
   Concentration.  Indoor Air, Proceedings of the Third
   International Conference on Indoor Air Quality and Climate.
   Berglund B. ,  Lindvall T.,  Sundell J. (Eds.).  Stockholm.


Guttman K.  1987.  Proposed Method of Indoor Air Pollution
   Control by Dilution with Outside Air.  pp. 223-232.
   Proceedings of the ASHRAE Conference IAQ 87:  Practical
   Control of Indoor Air Problems.  Arlington VA.

Henschel P.B., Scott A.G.  1987.  Some Results from the
   Demonstration of Indoor Radon Reduction Measures in Block
   Basement Houses.  Indoor Air '87:  Proceedings of the Fourth
   International Conference on Indoor Air Quality and Climate.
   Seifert B., Esdorn H., Fischer M.,  Ruden H., Wegner J. (Eds).
   Berlin (West).   2:340-346.

Kalnins R.,  Guadert P.C.  1986.  Formaldehyde Emissions from
   Typical Particleboard Applications and Assessment of Specific
   Abatement Measures.  pp. 402-412.  Transactions of an APCA
   Specialty Conference.  Indoor Air Quality Control in Cold
   Climates:  Hazards and Abatement Measures.  Walkinshaw D.S.

Levin H.  1987a.  The Evaluation of Building Materials and
   Furnishings for a New Office Building.  pp. 88-103.
   Proceedings of the ASHRAE Conference IAQ 87:  Practical
   Control of Indoor Air Problems.  Arlington VA.

Levin H.  1987b.  Protocols to Improve Indoor Environmental
   Quality in New Construction.  pp. 157-169.  Proceedings of
   the ASHRAE Conference IAQ 87:  Practical Control of Indoor
   Air Problems.  Arlington VA.

Levin H., Hahn J.  1984.  Pentachlorophenol in Indoor Air:  The
   Effectiveness of Sealing Exposed Pressure-Treated Wood Beams
   and Improving Ventilation in Office Buildings to Address
   Public Health Concerns and Reduce Occupant Complaints.
   Indoor Air, Proceedings of the Third International Conference
   on Indoor Air Quality and Climate.   Berglund B., Lindvall T.,
   Sundell J. (Eds.).  Stockholm.   5:123-130.

Matthews T.G., Dreibelbis W.G., Thompson C.V., Hawthorne A.R.
   1986.  Preliminary Evaluation of Formaldehyde Mitigation
   Studies in Unoccupied Research Homes.  pp. 389-401.
   Transactions of an APCA Specialty Conference.  Indoor Air
   Quality Control in Cold Climates:  Hazards and Abatement
   Measures.  Walkinshaw D.S.  (Ed.).

Meyer B.  1983.   Indoor Air Quality.  Addison-Wesley.  Reading

Moschandreas D.J.  1987.  Indoor Air Pollution Controls.  Indoor
   Air '87:   Proceedings of the Fourth International Conference
   on Indoor Air Quality and Climate.   Seifert B., Esdorn H.,
   Fischer M., Ruden H. , Wegner J.  (Eds).  Berlin  (West).


Mudarri, D.H.  1986.  Toward a National Strategy for the
   Mitigation of Indoor Air Pollution.  Paper presented at the
   79th Annual Meeting of the Air Pollution Control Association,
   Minneapolis, MN.

NRC.  1987.  Building Diagnostics:  A Conceptual Framework.
   National Academy Press.  Washington, D.C.

NRC.  1981.  Indoor Pollutants.  National Academy Press.
   Washington, D.C.

Novosel D,, Relwani S.M., Moschandreas D.J.  1987.  Development
   of a Desiccant-Based Environmental Control Unit.  pp. 261-
   263.  Proceedings of the ASHRAE Conference IAQ 87:  Practical
   Control of Indoor Air Problems.  Arlington VA.

Olander L., Johansson J., Johansson R.  1987.  Air Cleaners for
   Tobacco Smoke.  Indoor Air  '87:  Proceedings of the Fourth
   International Conference on Indoor Air Quality and Climate.
   Seifert B., Esdorn H., Fischer M., Ruden H.,  Wegner J.  (Eds).
   Berlin (West).   2:39-43

Peltier R.G.  1986.  Tobacco Smoke Ventilation and Air Cleaners:
   Particulates versus Gases.  pp. 611-617.  Proceedings of the
   ASHRAE Conference IAQ 86:  Managing Indoor Air for Health and
   Energy Conservation.  Atlanta GA.

Rask D.R., Morey P.R.  1987.  Strategies for Indoor Air Control
   of Bioaerosols in Office Buildings.  Presented as the 80th
   Annual Meeting of APCA.  New York.  June 21-26, 1987.

Relwani S.M., Moschandreas D.J., Billick I.H.  1987.  Indoor Air
   Quality Control Capabilities of Desiccant Materials.  Indoor
   Air  '87:  Proceedings of the Fourth International Conference
   on Indoor Air Quality and Climate.  Seifert B., Esdorn H.,
   Fischer M., Ruden H., Wegner J.  (Eds).  Berlin  (West).

Repace & Lowrey. 1985.  An Indoor Air Quality Standard for
   Abient Tobacco Smoke based on Carcinogenic Risk.  New York
   State Journal of Medicine, Vol. 85.

Revzan K.L.  1984.  Effectiveness of Local Ventilation in
   Removing Simulated Pollution from Point Sources.  Indoor Air,
   Proceedings of the Third International Conference on Indoor
   Air Quality and Climate.  Berglund B., Lindvall T., Sundell J.
   (Eds.).  Stockholm.  5:65-71.

Spears J.  1988.  National Research Center, National Association
   of Home Builders.  Personal Communication.

Sterling T.D., Mclntyre E.D., Sterling E.M.  1987a.  Reducing
   Radon Levels in Tightly Sealed Residences Through Crawlspace
   Mechanical Ventilation.  pp. 132-136.    Proceedings of the
   ASHRAE Conference IAQ 87:  Practical Control of Indoor Air
   Problems.  Arlington VA.

Sterling E.M., Collett C.W., Mueller B., Meredith J., Blomfield
   T.  1987b.  Case Studies of Ventilation Retrofits Designed to
   Resolve Air Quality Problems in Public Buildings.  pp. 308-
   317.  Proceedings of the ASHRAE Conference IAQ 87:  Practical
   Control of Indoor Air Problems.  Arlington VA.

Ueno Y.  1984.  The Effects of Ventilator, Air Cleaner, and
   Humidifier on Indoor Air Pollution Caused by Cigarette
   Smoking in a House.  Indoor Air, Proceedings of the Third
   International Conference on Indoor Air Quality and Climate.
   Berglund B., Lindvall T., Sundell J. (Eds.).  Stockholm.

Vaculik F.  1987.  Air Quality Control in Office Buildings by a
   C02 Method.  pp. 244-251.  Proceedings of the ASHRAE
   Conference IAQ 87:  Practical Control of Indoor Air Problems.
   Arlington VA.

Woods, J.E., Morey, P.R., and Rask, D.R., 1987. Indoor Air
   Quality Diagnostics:  Qualitative and Quantitative Procedures
   to Improve Environmental Conditions.  Presented at the
   Symposium on Design and Protocols for Monitoring Indoor Air
   Quality, sponsored by ASTM, Cincinnati, Ohio.


     The purpose of this chapter is to characterize the  public
health standards most commonly used to address indoor air quality
problems.  Standards covered include:

   o  National Ambient Air Quality Standards established
      by the U.S. Environmental Protection Agency (EPA),

   o  Air Quality Guidelines for Europe established by the
      United Nations'  World Health Organization (WHO),

   o  Ventilation Standards for Acceptable Indoor Air Quality
      established by the American Society of Heating,
      Refrigerating, and Air-Conditioning Engineers  (ASHRAE),

   o  Exposure Guidelines for Residential Indoor Air Quality
      established by the Canadian Ministry of National Health
      and Welfare.

     The chapter briefly describes how each organization
establishes its standards or guidelines,  noting in particular the
primary public health objectives each standard or guideline

     For comparative purposes, the chapter also reviews several
occupational standards and guidelines.  Occasionally,
occupational standards are used to address indoor air quality
problems in non-industrial environments when appropriate public
health standards are unavailable.  The occupational standards
covered include:  Permissible Exposure Limits established by the
U.S. Occupational Safety and Health Administration  (OSHA),
Recommended Exposure Limits established by the U.S. Department of
Health and Human Services' National Institute for Occupational
Safety and Health (NIOSH), and Threshold Limit Values established
by the American Conference of Governmental Industrial Hygienists

   The remainder of this chapter is organized as follows:

   o Characterization of Standards:  a brief discussion of the
     primary public health objectives the standards  and
     guidelines address.

   o Compilation of Standards:  matrix of observed  indoor air
     pollutants and existing exposure standards and  guidelines
     for each substance.

   o Evaluation:  discussion of broad differences among public
     health and occupational standards,  and identification of
     important gaps among existing health standards that
     pertain to indoor air quality.

   o Ventilation Standards:  discussion of ventilation
     requirements for the control of indoor air quality.

   o Summary:  existing public health standards and guidelines
     and their applicability to indoor air quality problems.


     Air quality standards control by law the amount of specific
pollutants that are permissible in the air.  There are, however,
many substances for which there are no standards.  In these
cases, guidelines can provide useful rules-of-thumb for deciding
whether a given situation may be a problem.  At times, guidelines
are also used as substitutes for standards known to be out of
date.  Practically all current standards and guidelines focus on
exposure to one pollutant at a time.

     This section reviews public health standards and guidelines
used to address indoor air quality problems.  For comparative
purposes, several occupational standards and guidelines are also
discussed.  The discussion is intended to provide a general over-
view of the concepts, terminology, and guiding principles used to
establish each of the standards and guidelines.

     Standards and Guidelines for Protecting the General Public

     EPA National Ambient Air Quality Standards

     EPA establishes National Ambient Air Quality Standards
(NAAQS) under authority of the Clean Air Act.  Enforcement is
limited to outdoor ambient levels.  Primary standards are
designed to protect the public health, and secondary standards to
protect the public welfare (crops, structures, animals, and human
comfort).  Section 109(b) of the Act prescribes that primary
standards allow an adequate margin of safety to protect the
public health.  Levels are set to protect even sensitive portions
of the population (e.g., asthmatics).  To establish which
standard provides an adequate margin of safety, the EPA considers
the extent to which uncertainty exists in the scientific data;
however, there is no established system that dictates the manner
in which this uncertainty is considered, and this can vary  from
pollutant to pollutant.  The standards protect against short-term
(e.g., one hour) and long-term health effects.  Technological and
cost considerations are not a factor in establishing the
standards, but do play a role in implementing the controls
necessary to achieve the standards.

     The standards specify concentrations of pollutants that
cannot be exceeded (or exceeded more than once, or have a
probability of being exceeded more than once, depending on the
pollutant).   They have been promulgated for carbon monoxide,
nitrogen dioxide, sulfur dioxide, ozone, suspended particulates
smaller than 10 microns in diameter (PM-10), and lead.  When
determining exposure limits and setting its standard, the Agency
considers to some extent the possibility of alternate exposure
pathways, and the activity level of the exposed populace (see for
example the final EPA regulations for lead (43 FR 46246, Oct. 5,
1978) and for carbon monoxide (50 FR 37484, Sept. 13, 1985)).

     The states are responsible for enforcing the standards and
must develop State Implementation Plans (SIPs) to provide for
attainment and maintenance of primary NAAQS by specific dates,
and secondary NAAQS within a reasonable time.

   [Note:  under the Clean Air Act, Section 112, the EPA also
establishes National Emission Standards for Hazardous Air
Pollutants (NESHAPS).  NESHAPS are emission standards set to
provide an ample margin of safety from exposure to hazardous
pollutants.   However, since these are emissions limits rather
than limits on air concentrations, they are not included in this

     WHO Air Quality Guidelines for Europe

     The Regional Office for Europe of the World Health
Organization (WHO), an agency of the United Nations, recently
published air quality guidelines for 28 organic and inorganic
substances.   The guidelines were created to help governments make
risk management decisions controlling exposure to indoor and
outdoor air pollutants.  Health effects were the major con-
sideration in establishing the guidelines, though ecological
guideline values are recommended for some substances.  The
guidelines are established to help protect the public health;
occupational exposure limits are not addressed.  The guidelines
either (1) indicate levels combined with exposure times at which
no adverse noncarcinogenic effect is expected, or (2) provide an
estimate of lifetime cancer risk arising from exposure to
substances that are proven human carcinogens or substances for
which there is at least limited evidence of human
carcinogenicity.  Guidelines are set to protect all people in the
European region, including sensitive population subgroups such  as
asthmatics.   Both short- and long-term exposures are addressed
(WHO, 1987) .

     ASHRAE Standard 62-1981:   Ventilation for Acceptable Indoor
     Air Quality

     ASHRAE Standard 62-1981 defines acceptable indoor air
quality as "air in which there are no known contaminants at
harmful concentrations and with which a substantial majority
(usually 80 percent) of the people exposed do not express
dissatisfaction,"  The objective of the standard is to establish
ventilation rates which, under most circumstances,  would achieve
acceptable indoor air quality while maintaining efficient energy
utilization,,  To do this, the standard contains a ventilation
rate procedure and an indoor air quality procedure.  The latter
procedure references the EPA NAAQS standards and other standards
selected from current practices in various states,  provinces, and
other countries.  These standards are designed to cover con-
taminants from both outdoor and indoor sources.  The ASHRAE stan-
dards cover 35 substances.  For contaminants not contained in the
standard, ASHRAE recommends that levels should not exceed 1/10
the occupational standards used in industry.  In the case of
odors, and some mucous membrane irritants, ASHRAE specifies that
the air can be considered to be free of annoying contaminants if
at least 20 untrained observers, after exposure for no more than
15 seconds, deem the air to be not objectionable under
representative conditions of use and occupancy (ASHRAE, 1981).

     Canadian Exposure Guidelines for Residential Indoor Air
     In 1981, the Federal-Provincial Working Group on Indoor Air
Quality was formed to develop guidelines for concentrations of
selected contaminants in residential indoor air.  The guidelines
were published in 1987 under the authority of the Minister of
National Health and Welfare.  The guidelines contain specific
quantitative limits for nine pollutants or pollutant categories,
plus recommendations to eliminate or control exposure for other
pollutants for which specification of exposure limits was not
practical.  Their application is designed for residential
environments,, and is based on assumptions of 24-hour (i.e.,
continuous) exposure,  The guidelines take into account such
factors as "sensitivity of groups at special risk and sources and
mechanisms of action of contaminants."  The principle guiding the
development of the standards was to ensure that there is
"negligible" risk to the health and safety of occupants.  The
working group acknowledges that the levels "may not provide
complete protection to the hypersensitive portion of the
population which requires extraordinary measures to achieve such
protection„"  Effects from both short-term and long-terra  (i.e.,
lifetime)  exposures are covered (Environmental Health
Directorate, 1986)„

     Occupational Standards and Guidelines

     OSHA Standards

     The Occupational Safety and Health Administration (OSHA),
which is part of the U.S. Department of Labor, is responsible for
protecting workers from unsafe or unhealthful working
environments.  Pursuant to the Occupational Health and Safety Act
of 1970, OSHA sets standards called Permissible Exposure Limits
(PELs).  In January 1989, the Agency successfully updated the
PELs for about 600 hazardous substances found in the workplace
during January  1989.  The standards are based on the criteria of
ensuring that "no worker will suffer material impairment of
health or functional capacity even if such employee has regular
exposure to the hazard dealt with by such standard for the period
of his working life."

     PELs are concentration limits usually set for 8-hour expo-
sures.  If a chemical can produce a toxic effect after only a few
minutes of exposure, a 5- to 15-minute limit and/or a ceiling
will also be set.  The ceiling limits must never be exceeded.
The 8-hour limit is a time-weighted average (TWA) that may be
exceeded as long as the average concentration over the whole
period does not exceed the PEL.  The PELs are set at levels that
will protect the average American worker to the extent feasible.
This reflects an explicit acceptance that some sensitive workers
may experience adverse health effects at or below the PEL, and an
implicit acceptance of the principle of using economic or
technological feasibility as a criterion for setting standards.

     NIOSH Recommended Exposure Limits

     NIOSH is a part of the U.S. Department of Health and Human
Services' Centers for Disease Control.  Acting under the
authority of the Occupational Safety and Health Act, and the Mine
Safety and Health Act, NIOSH develops and periodically revises
Recommended Exposure Limits (RELs) to potentially hazardous
substances or conditions in the workplace.  These RELs are
submitted to the Department of Labor for their consideration in
developing PELs. The submissions to the Department of Labor
include sampling and analysis guidelines, suggestions for medical
surveillance and record-keeping, work practices, and processes
for informing employees of hazards in addition to the con-
centration levels (RELs).

     In formulating these recommendations, NIOSH evaluates all
known and available scientific information relevant to the
potential hazard (NIOSH, 1988).  NIOSH recommendations are
published in a variety of documents.  Criteria documents  specify
NIOSH RELs and appropriate preventive measures designed to reduce
or eliminate the adverse health effects.


     The American Conference of Governmental Industrial
     Hygienists  (ACGIH)

     The ACGIH is an association of professional personnel in
governmental agencies or educational institutions engaged in
occupational safety and health programs.  The ACGIH develops
Threshold Limit Values (TLVs) for airborne concentrations of some
600 substances to assist in the control of health hazards.

     TLVs represent concentration levels at which it is believed
nearly all workers could be repeatedly exposed day after day
without adverse effect.  However, it is recognized that "a small
percentage of workers may experience discomfort" under conditions
at or below the TLV and that "a smaller percentage may be
affected more seriously by aggravation of pre-existing
conditions or by development of an occupational illness."

     The ACGIH specifically cautions that the limits are not
intended for other uses such as "evaluation of continuous
uninterrupted exposure" or for evaluation of "community air
pollution nuisances."  The health criteria for some contaminants
may be "protection against impairment of health," whereas
"freedom from irritation, narcosis, nuisance or other forms of
stress" may form the basis for other contaminant limits.
However, the ACGIH Chemical Substance TLV Committee states that
"... limits based on physical irritation should be considered no
less binding than those based on physical impairment.  There is
increasing evidence that physical irritation may initiate,
promote, or accelerate physical impairment through interaction
with other chemical or biological agents."

     There are three categories of TLVs.  The first is a time-
weighted average (TWA) and represents a concentration to which a
worker could be continuously exposed during an 8-hour work day,
40 hours a week,  over a normal working lifetime, without being
adversely affected.  The second is a short-term exposure limit
(STEL)—a 15 minute time-weighted average concentration.  The
STEL is intended to supplement the TWA for cases in which a
chemical has both acute and chronic toxic effects.  STELs cannot
be exceeded, and should not be sustained for longer than 15
minutes at a time and for no more than four times a day. In
addition, there must be at least an hour between successive
exposures to the STEL limit.  The third category is a ceiling
(TLV-C), which is a concentration that should never be exceeded
when workers are present (ACGIH, 1988).

     Summary Exhibits

     The previous information is summarized in Exhibits 7-1,  7-2,
and 7-3 (a and b).   Exhibit 7-1 outlines the health protection
goals of each standard and guideline; it also notes the typical
setting to which each applies.  Exhibit 7-2 describes each
standard's target population group,  the time periods for which
the standards are set, and the number of substances covered.
Exhibits 7-3 (a and b) compare the factors considered in
establishing each standard and guideline.


     This section outlines existing standards for various
substances observed in indoor air environments.  The substances
included are those covered by the existing public health
standards and guidelines commonly applied to indoor air quality
problems; included are six from EPA's NAAQS, 28 from the WHO Air
Quality Guidelines for Europe, 35 from ASHRAE ventilation
standards, and nine covered under the Canadian exposure guide-
lines  (there is some overlap among those covered; hence, the
total substances included number approximately 50).  Where
available, occupational standards, including OSHA PELs, NIOSH
RELs, and ACGIH TLVs are included for comparison.  The substances
and relevant standards and guidelines are described in
Exhibit 7-4, Sample Air Quality Standards and Guidelines.

     As discussed in a later section, there is a shortfall
between the number of known indoor air pollutants and the
availability of public health exposure standards and guidelines
that can be applied to each of these substances.  Therefore,
although there are hundreds of substances known to occur in
indoor air environments, Exhibit 7-4 does not comprehensively
address all known indoor air pollutants.


     Several points emerge from the  information outlining
existing air quality health standards and guidelines.  These
include  (1) differences between public health  and occupational
standards; and (2) major omissions among existing standards with
regard to indoor air quality problems.

     Differences Between Public Health and Occupational  Standards

     The most significant differences between  various  standards
and guidelines are related to the differences  between  standards
set to protect the general public versus those set  to  protect an
occupational workforce.  Public health standards  (e.g.,  EPA
NAAQS, WHO guidelines, Canadian exposure guidelines)  are


                                                                           Exhibit 7-1
                                        General Health Protection Goals of Existing Air Quality Standards and Guidelines.
   Type of Standard
     or Guideline     Agency   Standard/Guideline          Setting
                                    Health Protection Criteria/Goals
   Public Health
                      EPA       NAAQS
                      WHO       Air  quality
                                guidelines  for

                      ASHRAE    Guideline
Any outdoor environment
Indoor and outdoor
Indoor environments
                      Canada    Indoor  air  quality   Residences
                      OS HA
Workplaces in the
United States
Workplaces in the
United States

Workplaces in the
United States
Protect public health with an adequate margin
of safety.  Set so that even sensitive
portions of the population should not be
adversely affected.

"By 1995, all people of the [European] Region
should be effectively protected against
recognized health risks from air pollution."

Established so a substantial majority (usually
80%) of people exposed do not express dissatis-

Protect all exposed individuals, except those that
might be "hypersensitive."

Insure that no worker shall suffer material  impair-
ment of health or functional capacity, to the extent
feasible (assumes average American worker).
Exposure assumptions are 8 hrs per day or 40 hrs per week
over a normal working lifetime.

Same as OSHA.
Protect "nearly all workers" (all healthy workers
of working age and not particularly sensitive to
pollutants).  Exposure assumptions are 8 hours a
day and/or 40 hours a week over a normal working

                                                            Exhibit  7-2

Caparison of Target Population, Tiae Periods,  and Muiter of  Substances Covered by Existing Air Quality Standards and Guidelines.
Type of Standard Standard/
or Guideline Agency Guideline
Public Health EPA NAAQS

WHO Air quality
for Europe
ASHRAE Concentra-
tion of
Canada Exposure
People to Whom
Standard Applies
American public
(including sensi-
tive portions of
the populace)
General European
People in indoor

General Canadian
Time Periods Approx. Number
Considered of Substances Notes
1, 3, 8, 24 hrs, 6

Various 28
24 hrs 35
30 min

Various 9
Standards are designed to protect
primarily against ambient (outdoor)

Guidelines are set assuming both
indoor (nonindustrial settings)
and outdoor exposures.
Uses various sources of pre-
existing standards and guidelines.

Guidelines are set for residential
exposure only and exclude radon.
 I  Occupational
       OS HA
                                      American workers
                                      American workers
                                      American workers
                                                8 hrs                 600
                                                some ceilings

                                                8 hrs                 150
                                                some ceilings
                                                                                8 hrs,  40 hrs/wk;      600
                                                                                ceiling (never to  be
                                                                                exceeded); 15 min
Process for regulating chemicals
considers technological and economic

Exposure limits are recommendations
to OSHA and do not generally consider
technological feasibility.

390 of current 400 OSHA regulations are
from 1968 ACGIH TLV list.  Developed for
workers in American settings but are used
in other countries as well; updated

                                                                           Exhibit 7-3a
                                   Coifierison of the Factors Considered in Establishing Public Health Standards and Guidelines
Factors Considered Uhen Adapting Existing
Standards or Guidelines
Health Effects to be prevented
Population groups of concern
Long/short term
General public
WHO Guidelines
Long/short term
General public
ASHRAE Guidelines
Long/short term
General public
Canada Guidelines
Long/short term
General public
   Population group targeted for protection

   Number  of  substances  covered

   Exposure assumptions  for  which standards apply

   Condition  of  cost  or  feasibility

   Potential  synergistic or  additive  effects
                           All  including
                             high  risk groups
All including
 high risk groups
                           6                     28

                           Cont i nuous/1i fet i me   Cont i nuous/1i fet ime

                           No                    No
Substantial  majority
 (80 %)


Cont i nuous/1i fet i me


All including
 high risk groups
                                                Cont inuous/1i fet ime


     WHO guidelines have been set  for  exposure to mixtures  of  sulfur dioxide and particulates.
     Additive effects  for  aldehydes  are  computed  by formula.
                                       Exhibit 7-3b
Caparison of the Factors Considered in Establishing Occupational  Standards and Guidelines
   Factors Considered When Adapting Existing
    Standards or Guidelines            	
                           OSHA PELS
                                                 NIOSH RELs
                                                                        AC6IH TLVs
                   Health Effects  to be prevented

   Population groups of concern

   Population group targeted for protection

   Number of substances covered

   Exposure assumptions for which  standards apply

   Condition of cost or feasibility

   Potential synergistic or additive effects

                           All workers



Long/short term        Long/short term          Long/short term

Workers                Workers

All healthy workers    Nearly all healthy workers

100                    600

Indoor/work            Indoor/work

Yes                    Yes
   1 Limited to presumed additive effects addressed by formula (see text)

                Exhibit 7-4

Sanple Air Quality Standards and Guidelines
Acrylonitri le
Aldehyde (total)
Standard or Guideline (m = mg/m ; u = ug/nr)
Averaging Public Health Occupational
24 hr 7m
8 hr 1800m 1780m
30 min 24m
15 min 2400m 2375m
8 hr 250u 250u
15 min 800u 800u
Ceiling 25u
8 hr * 461u
Ceiling 4610u
1 hr R<1 R = Sun (.C-/C-)
c- = measured concentration
C,- = 120u formaldehyde
50u acrolein
9000u acetaldehyde
Annual 0.5m NIOSH ceiling is set for 5
8 hr 35m 18m minute exposure.
15 min 27m 27m
Ceiling 7m 34.8m

                                                                  Exhibit 7-4  continued
                                                        Sample Air Quality Standards and Guidelines
                                                     Standard  or  Guideline  (m = mg/m  ; u = ug/nr)
                                                      Public  Health
Cadmium fume
                       8 hr
                       Ce iIi ng
                       8 hr
8 hr
30 days
8 hr
30 min

24 hr
8 hr
                                                             500u              200u
                                                            various   100 000
NIOSH ceiling is set for 15
minute exposure.

ACGIH levels (TWA) are
  amosite     0.5f/cc
  chrysotile  2.0f/cc
  crocidolite 0.2f/cc
  other       2.0f/cc
f/cc = fibers per cubic cm
NIOSH level for fibers over
5 um in length

NIOSH ceiling is set for 15
minute exposure.
                                                                                                                            WHO guidelines are annual:
                                                                                                                              1-5 nanograms (rural areas)
                                                                                                                              10-20 nanograms (urban areas)
                                                                                                                            OSHA standard is 100u(TWA)  for
                                                                                                                            cadmium fume, and 200u(TWA) for
                                                                                                                            cadmium dust.
                                                                                                                            ACGIH proposed TWA is 10u
                                                                                                                            NIOSH recommends reducing
                                                                                                                            exposure to  lowest feasible
Calcium oxide (lime)
8 hr

                                                                              Exhibit 7-4  continued
                                                                    Sample Air Quality Standards and Guidelines
Carbon disulfide

Carbon dioxide

Carbon monoxide



Standard or Guideline (m = mg/m ; u = ug/m )
Averaging Public Health Occupational
24 hr .10m .15m
10 hr 3m
8 hr 12m 30m
30 min .02m .45m WHO guideline of .02m is based
15 min 36m 30m sensory effects.
Continuous 1800m
Long term 6300m
10 hr 18,000m
8 hr 18000m 9000m
15 min 54000m 54000m
10 min 54,000m
8 hr 10m 10m 10m 9.9m 40m 40m 55m WHO CO guidelines are designed to
1 hr 40m 30m 29m protect nonsmokers.
30 min 60m
15 min 100m 440m
Maximum 229m 229m
8 hr 0.5m 0.5m
Continuous .005m
30 min 2m
24 hr .1m ACGIH proposed guideline is
8 hr 1-5m 3m 1.5m (8 hr)
30 min -3m 3.0m (15 min)
15 mi-n 9m NIOSH 15 minute limit is a
Ceiling 3m 1.45m ceiling limit.

          Exhibit 7-4  continued
Sanple Air Quality Standards and Guidelines


(ethytene dichloride)

Ethyl acetate


24 hr
10 hr
8 hr
15 min

24 hr
10 hr
8 hr

24 hr
8 hr
30 min
15 min
24 hr
8 hr
30 min
8 hr
24 hr
8 hr
1 hr
30 min
15 min
Cei I ing

Standard or Guideline (m = mg/m ; u = ug/nr)
Public Health Occupational
0.001m NIOSH 10 hour limit is for
.5m .5m carcinogenic chromium; other
chromiums have a 0.025 m
0.05m 10 hour limit
22m 22m

0 . 7m 2m
4m 40m
1400m 1400m
(see WHO level set to avoid corn-
aldehydes) plaints from sensitive
1.2m(1ppm) 1.5m people exposed in non-
industrial indoor settings.
6m(5ppm) 0.12m 3m NIOSH level reflects lowest
.1m reliably quantifiable

           Exhibit  7-4  continued
Sample Air Quality Standards and Guidelines
Hydrochloric acid
(hydrogen chloride)
Hydrogen sulfide
24 hr
30 min
24 hr
8 hr
1 hr
30 min
15 min
Ceil ing
3 month
24 hr
10 hr
8 hr
8 hr
15 min
1 hr
Standard or Guideline (m = mg/m ; u = ug/nr)
Public Health • Occupational
7m 7m
.15m .04-. 05m
14m 14m
.007m WHO guideline of .007m is based
21m 21m on sensory effects.
15m NIOSH ceiling set for 10 minute
<100u NIOSH limit set so workers'
50u 150u blood lead remains < 60ug/100g -
.001m WHO: short-term guideline
1m 1m desirable; but lack of data to
set short-term limits.
3m OSHA standard is for manganese fumes.

                                                                      Exhibit 7-4  continued
                                                           Sanple Air Quality Standards and Guidelines

Substance Time
Mercury Annual
24 hr
8 hr

Methyl alcohol 24 hr
10 hr
8 hr
30 min
15 min
Methylene chloride Annual
(Dichloromethane) 24 hr
8 hr
"T1 15 min
._, Ceiling
Standard or Guideline (m = mg/m ; u = ug/nr)
Public Health Occupational
2u ACGIH and OSHA standard of 50u is for
50u 50u 50u non-alkyl vapor, but is lOu (TWA) and
30u (STEL) for a Iky I compounds.
WHO guideline is for indoor air.
260m 260m
310m 1048m 310m
20m NIOSH recommends reducing
3m 50m exposure to lowest feasible
1740m 300m limit.
No formal guidelines/
standards; ACGIH draft report
states that concentrations
exceeding 500 fCUs/nr require
remedial action (see tex).

Nitrogen dioxide

Annual *
24 hr .002m
10 hr 0.015m
8 hr -111 -1m OSHA and ACGIH standard is for soluble
Long term 100u
Annual 100u 100u
24 hr 150u
8 hr 6000u
1 hr 400u 480u
15 mjn ISOOu 1800u 10000u

           Exhibit  7-4  continued
Sample Air Quality Standards and Guidelines
Nitrogen monoxide
Nitrogen oxides
Particulates (PM-10)
Particulates (PM-2.5)
Standard or Guideline (m = mg/m ; u = ug/nr)
Averaging Public Health Occupational
24 hr 500u
10 hr 30,000u
30 min 1000u
24 hr 150u
1 hr 400u
Continuous 100u
8 hr 100-120u 200u 200u ASHRAE standard is for indoor
1 hr 235u 150-200u 240u sources only.
15 min 600u 600u
Annual 50u
24 hr 150u
Long term 40u
8 hr 500u
1 hr 100u

                                                                     Exhibit 7-4  continued
                                                           Sample Air Quality Standards  and Guidelines


24 hr
10 hr
8 hr
15 min
Standard or Guideline (m = mg/m ; u = ug/trr)
Public Health Occupational
19m 19m
   Polynuclear aromatic
   hydrocarbons  (car-
   cinogenic fraction)

.02UL    .013WL    .027UL
ACGIH standard for coal tar
pitch volatiles (benzene
solubles) is 0.2m (TUA).

WL = working level; one WL
is approximately equivalent to
200 picccuries per liter (PCi/l).
EPA recommends that mitigation be
undertaken in homes with levels
above 4PCi/l (.02UL).

WHO: recommended level for
remedial action in buildings is
> 100 Bq/nT.

Sul fates

24 hr .80m WHO 30 minute guideline is based
10 hr 213m on odor detection.
8 hr 215m 215m
30 min .07m
15 min 425m 425m
Ceiling 426m
Annual 4u
24 hr 12u

           Exhibit 7-4 continued
Sample Air Quality Standards and Guidelines

Sulfur dioxide

Sulfuric acid



Long term
24 hr
10 hr
8 hr
1 hr
15 min
10 min
5 min
10 hr
8 hr
24 hr
8 hr
30 min
15 min

24 hr
8 hr
30 min
15 min
10 min
Standard or Guideline (m = mg/m ; u = ug/irr)
Public Health Occupational
80u Ou
365u 65u
10000u 10000u
.05m WHO: more data needed; however.
1m repeated,exposure at or above
1m 1m .01 mg/nr is cause for concern.
5m NIOSH recommends minimizing
170m 335m workplace exposure and limiting
8m number of exposed workers
1340m WHO guideline of 8m is based
on sensory effects.
8m WHO guideline of 1 is based on
375m 375m 375m sensory effects.
560m 560m

                                                                     Exhibit 7-4  continued
                                                           Sample Air Quality Standards and Guidelines


Vinyl chloride

Water vapor
(relative humidity)

24 hr
10 hr
8 hr
30 min
15 min
24 hr
10 hr
8 hr
15 min

8 hr
1 hr
15 min

24 hr
10 hr
8 hr
15 min

Standard or Guideline (m = mg/m ,• u = ug/nr)
Public Health Occupational
1m 5m
270m 270m
1080m 1080m

1u 2u
50u OSHA standard is for vanadium
50u respirable dust or fumes.
MIOSH 10 hour limit set for
metallic vanadium and vanadium
2.6m 10m
NIOSH recommends limiting
12.8m exposure to lowest reliably
detectable level.
20-60% 30-70% summer
30-55% winter
50u NIOSH limits are for zinc
100u oxide.
10,000u OSHA limit is for zinc oxide total
15,000u dust. Limit for respirable fraction
is 5,000u.

                                                                   Exhibit 7-4 concluded
                                                        Sample Air Quality Standards and Guidelines

 Reported values were converted where necessary so  that all values  for the same chemical are in the same units to facilitate  comparisons.
 Canadian standards distinguish between short  term  or  long  term exposures. Short term exposures are listed as 1 hr exposures  in  this table.

 ACG1H                  American Conference of Governmental Industrial Hygienists
 ASHRAE                 American Society of Heating, Refrigerating  and Air-Conditioning Engineers, Inc.
 EPA                    Environmental Protection Agency
 NIOSH                  National Institute for Occupational Safety  and Health
 OSHA                  Occupational Safety and Health Administration
 WHO                    World  Health Organization


 ACGIH, Threshold  Limit Values and  Biological  Exposure indices for  1987-88.
 ASHRAE Standard 62-1981,  Ventilation for Acceptable  Indoor Air Quality.
 Environmental  Health Directorate,  Canada, Exposure Guidelines for  Residential Indoor Air Quality, July 1986.
 NIOSH, 1986.   NIOSH recommendations for occupational  safety  and  health standards.  Morbidity and Mortality Weekly Report. 35(1S).
 OSHA Standards for Air Contaminants, 29 CFR Part  1910.1000.
 UNO, 1987.  Air Quality  Guidelines for Europe.  World Health Organization Regional Office for Europe, Copenhagen.  WHO Regional Publications,
    European Series No. 23.   1987.

 *  WHO does not establish guidelines for  these substances;  instead, the agency publishes risk factors for each substance  to  indicate potential
"    human health risks per unit  of  exposure.

generally one to two orders of magnitude lower (more protective)
than occupational standards (e.g.,  those set by OSHA,  NIOSH,  and
ACGIH).   These differences occur for both short- and long-term
exposure limits.  Several reasons account for these differences;
the most important are:

   o Public health standards include protection for the
     old, young, pregnant women, those with preexisting
     respiratory ailments, and other sensitive population
     subgroups; occupational standards typically presume a
     healthy adult workforce,  and may explicitly accept
     that a very small percentage of the workforce will
     experience adverse health effects at the occupational
     exposure limit;

   o Public health standards generally assume continuous
     exposures  (24 hours per day, over a 70-year lifetime);
     occupational standards are realistically based on an 8-
     hour exposure periods for no more than 40 hours per

   o Public health standards are usually established with
     health concerns as the sole criteria; occupational
     limits may be established in consideration of the
     technical and economic feasibility of their
     implementation (e.g., OSHA permissible exposure

   o Implicit in occupational standards is the assumption
     that exposure is voluntary  (inherent in the chosen
     occupation),  whereas public health standards generally
     assume exposures to be involuntary.

   Notwithstanding these differences, some organizations apply
occupational standards to public health problems because of the
limited number of available public health standards or
guidelines.  Fewer than 60 of the hundreds of known chemical
contaminants found indoors are covered by public health
standards or guidelines.  By comparison, occupational guidelines
have been established for hundreds of substances (e.g., the ACGIH
and OSHA have established standards for approximately 600 sub-
stances) .  Some organizations apply these occupational guidelines
to public health problems by lowering the occupational limits
with a "safety" or "protection11  factor  (e.g., dividing the ACGIH
threshold limit values by a factor of 10 or 100).

     Major Omissions Among Existing Standards with Regard to
     Indoor Air Quality Problems

     Two areas of particular concern to indoor air quality
problems have yet to be adequately addressed by  existing
standards and guidelines.  These include exposure to pollutant


mixtures and to biological contaminants (e.g., molds, fungi,
mites, bacteria, and viruses).

     Pollutant Mixtures

     The effects of exposure to more than one contaminant, i.e.,
to mixtures, in indoor air is an important issue since the
typical indoor environment contains multiple contaminants.
Effects from mixtures may be synergistic,  antagonistic, or
additive.  A synergistic reaction results in a total effect that
is more than the sum of the individual effects? an antagonistic
effect results when the combined effect is less than the sum of
the individual effects,

     One example of the threats from multipollutant exposure is a
potential adverse reaction from an excessive "total contaminant
body burden."  The total body burden concept implies that
exposure even to low pollutant concentrations can "add up" to a
toxicity level that can trigger an adverse reaction known as
"environmental maladaptations syndrome," with adverse effects on
muscle tissue, mucous membranes, and respiratory, vascular, and
other biological systems (Repace, 1982).

     Given the complexity of possible synergistic reactions,  and
the fact that knowledge about them is rudimentary, guidelines for
mixtures based on synergistic effects are rare, and an adequate
way to address pollutant mixtures has yet to be developed.  One
approach is simply to treat pollutant mixtures on an additive
basis.  For example, ACGIH and OSHA recommend an additive
approach for exposures to mixtures when the components have
similar toxicological effects.  The equivalent exposure for the
mixture is calculated as:

   Em = Ci/Ti + C2/T2 + • •  • Cn/Tn

where Em is the equivalent exposure to the mixture, Cj_ is the
concentration and Tj_ is the standard (e.g., TLV) for the "ith"
pollutant.  Exposure to the mixture violates the standard if Em
exceeds 1.  The allowed exposure to any individual contaminant  is
reduced as exposures to concentrations of others in the mixture
are accounted for.

     Other preliminary approaches under development would
establish exposure guidelines for combinations of volatile
organic compounds (VOCs).  These approaches are based on studies
indicating when acute human health effects  (such as those
associated with sick building syndrome) are likely to occur.
Research has so far indicated that total VOC concentrations below
0.16 mg/m3 will not cause acute effects, while total VOC
concentrations above 5.0 rng/m3 are. found to generate acute
effects (Molhave, 1984).  Partly on the basis  of these findings,
some investigators recommend an action level of  1.0 ppm total

VOC as an indicator of indoor air quality problems (Gammage and
Kerbel,  1987).   (1.0 ppm VOC is approximately 5 mg/m3 total VOC
assuming an average molecular weight of 100).

     Biological Contaminants

     Existing standards and guidelines do not address biological
(or "microbial")  contaminants,  yet biological contaminants pose
significant indoor air quality problems.

     Several reports have documented numerous indoor microbial
contaminants (e.g., Sexton, 1986; Morey et_al., 1986; Blumenthal
et al.,  1987).   Measured health effects from research and case
studies will help to establish indoor air quality standards for
biological contaminants.  For example, one study noted that 28
percent of workers develop coughing and shortness of breath when
exposed to 27,000 spores/m3 of Aspergillus fumigatus (Solomon and
Burge, 1984).  Another report notes that "most mite allergic
patients will record symptoms either of rhinitis or asthma" at 10
ug of allergen per gram of dust.

     Recently,  efforts have been made to develop biological
contaminant guidelines.  For example, a report of the ACGIH
Committee on Bioaerosols suggests that indoor levels of
saprophytic bioaerosols should be less than one-third of outdoor
levels where outdoor air is the only source and should be
qualitatively similar  ( Burge et al., 1987).   The report,
however, provides guidance on measurement methods, interpretation
of data, and remedial actions but does not recommend specific
guidelines for acceptable exposure.

     In reporting on a recent study of fungi in 50 Canadian
houses,  Miller et al. propose the following criteria of
acceptability for fungal pollution in indoor air  (Miller et al.
1988, as reported in Walkinshaw, 1988):

   o  The presence of certain pathogens (such as A. fumigatus)
      and certain toxigenic fungi  (such as S. atra) should be
      considered as unacceptable.

   o  More than 50 CFU/m3 should be reason for concern if there
      is only one species present.

   o  Less than 150 CFU/m3 should be considered acceptable if
      there is a mixture of species.

   o  Less than 300 CFU/m3 should be considered as acceptable  if
      the species present are primarily Cladosporium or  other
      common phylloplane fungi.

     Other Standard-Setting Activities

     In addition to the guidelines and standards previously
discussed, other agencies develop air quality health standards
which sometimes apply to more specific situations.   For example,
the Consumer Product Safety Commission uses levels of carbon
monoxide and nitrogen dioxide as the basis for decision-making
for combustion appliances which differ from EPA ambient air
quality standards.  The levels for carbon monoxide are 15 ppm
(17.2 mg/m3)(8 hr time-weighted average)  for long term exposure
and 25 ppm  (28.6 mg/m3) as a peak limit for no more than 1 hour.
The level of concern which is used for nitrogen dioxide is 0.3
ppm (0.56 mg/m3).

     In addition, the National Academy of Sciences has developed
exposure limits for military and space applications, the United
Nations' International Labour Organization (ILO) has developed
occupational exposure guidelines, and several U.S,  states have
established exposure limits for specific indoor pollutants
(particularly formaldehyde).  Moreover, individual countries set
a variety of public health, ambient air quality standards.
Exhibit 7-5 provides examples of ambient air quality standards
for over 140 substances set by various countries around the
world.  These are general air quality standards; they have not
necessarily been created for, or applied to, indoor air quality


     Minimum ventilation rates provide additional control of
indoor air quality.  ASHRAE Standard 62-1981 contains a
ventilation rate procedure for indoor air quality.  This
procedure specifies minimum ventilation rates for more than fifty
types of indoor spaces.  Mandatory ventilation standards of
model building codes, typically based on ASHRAE's ventilation
requirements,  are part of many local building codes, and the U.S.
Department of Housing and Urban Development  (HUD) minimum
property standards and manufactured housing construction
specifications also contain ventilation requirements for
residences subject to HUD regulations.

     ASHRAE Standard 62-1981

     ASHRAE 62-1981R, the public review draft of an ongoing
revision to Standard 62-1981, specifies a ventilation rate of
twenty cubic feet per minute  (cfm) per person for office
environments (ASHRAE, 1986).  Exhibit 7-6 presents  the
ventilation requirements for a portion of the commercial,
institutional, and residential indoor spaces specified  in the
standard.  In order for ventilation at these rates  to provide

                                                                       Exhibit 7-5

                                                    Sanple Air Quality Standards from other Cdaitries.
Substance Standard
30 minutes
Benzene 0.2
Formaldehyde 0.012

Sulfur dioxide 0.07
V 0.11
,!, 0.14
ON 0.5

Trichloroethylene 1.0

Vinyl chloride 0.4
Zinc oxide
j;for averaging time noted)
24 hours 12 months
0.1 0.025
03 0043





0.4 0.15


Hungary, USSR
Hungary, DRG

Turkey, New Zealand
Hungary, DRG

protected zones
specially protected zones
Democratic Republic of Germany
specially protected zones
protected zones

specially protected zones

protected zones

(other than protected or
specially protected zones)
99th percent lie for summer months

Federal Republic of Germany

98th percent! le of values/year

specially protected zones
protected zones
(other than protected or
specialty protected zones)

 Concentrations in
Bouscaren et al.. 1986 (note that Bouscaren et al. list standards for more than 140 substances;  this  list
exemplifies the wide variety of standards set by various nations).

                                                  Exhibit 7-6

                       ASHRAE Standard 62-19818 Outdoor Air Requirements  for Ventilation  a/
                                                  cfm/person               l/s/person
Commercial Facilities

     Office Space                                      20                       10
     Reception Areas                                   15                       8
     Conference Rooms                                  20                       10
     Hotel Bedrooms (cfm/room)                         30 b/                    15  b/
     Dry Cleaners                                      30                       15
     Supermarkets                                      15                       8
     Theater Audi tori tins                               15                       8
Educa t i onaI Fac iIi t i es

     Classrooms                                        15                        8
     Laboratories                                      20                       10
     Libraries                                         15                        8
Institutional Facilities

     Hospital Patient Rooms                            25                       13
     Hospital Medical Procedure Rooms                  15                        8
     Hospital Operating Rooms                          30                       15
     Correctional Facility Cells                       20                       10
     Correctional FaciIity Dining Halls                15                        8

Residential Facilities

     Living Areas                                      15                       7.5
     Kitchens                                         100 c/                    50  c/
     Garages                                          100 d/                    50 d/
a/  Source:  ASHRAE 1986.

b/  Units are per room.

c/  Units are per room with intermittent mechanical exhaust.

d/  Units are per car.

adequate indoor air quality,  the procedure sets requirements for
supply air of acceptable quality and assumes that ventilation
system design and operation remove contaminants from the
occupied zone at least as effectively as would be accomplished by
complete mixing in the occupied zone (ASHRAE, 1986).

     Ventilation Requirements in Model Codes

     Building Officials and Code Administrators International
(BOCA),  the Southern Building Code Congress International
(SBCCI), the Council of American Building Officials (CABO),  and
other code writing organizations often incorporate ventilation
requirements into their model codes (NIBS, 1986).  For example,
the BOCA Basic/National Mechanical Code specifies ventilation
rates dependent on occupancy similar to ASHRAE 62-1981, but at
generally lower rates.  Similarly, the CABO One and Two-Family
Dwelling Code requires air exchange rates of 0.5 per hour for
general living areas and 5.0 per hour for bathrooms with
mechanical ventilation.

     HUD Ventilation Requirements

     HUD incorporates ventilation requirements into its minimum
property standards for residences constructed in its mortgage
insurance and low-rent public housing program and in construction
requirements for manufactured housing (U.S. HUD, 1986a; U.S. HUD,
1986b).   The ventilation requirements for manufactured housing
construction specify that an area equivalent to not less than
four percent of the floor area must be provided for natural
ventilation, or, alternatively, that a mechanical system capable
of changing room air every thirty minutes be present.  Bathroom
and toilet compartments require either one and one-half square
feet of openable glazed area or a mechanical system capable of
producing five air changes per hour.  Manufactured housing
construction requirements also specify venting of combustion
appliances and require that purchasers are presented with options
to improve overall ventilation.

     Limitations on the Effectiveness of Ventilation Standards to
     Achieving Acceptable Indoor Air Quality

     Prescribing ventilation standards in the design of new
buildings is an extremely important element in an overall
strategy to control and mitigate indoor air quality problems.
Ventilation standards do not guarantee adequate indoor air
quality and several limitations to such standards are addressed
below. These include the indirect nature of ventilation control,
ventilation efficiency problems, operational compromises to
design standards,  and procedural limitations of the ASHRAE
Standard 62-1981.

     Ventilation as an Indirect Control Method

     Ventilation improves indoor air quality by diluting indoor
air with outdoor air.  It is a strategy which is not targeted to
any individual pollutant or source,  and there is therefore a
limit on the extent to which ventilation can be relied on to
adequately mitigate all pollutants,  particularly in the presence
of strong sources.   For example, an outdoor air ventilation rate
of 250 cfm per occupant would be necessary to adequately protect
occupants from cancer risk due to environmental tobacco smoke
(Repace and Lowrey, 1985).   Nevertheless,  ventilation can be very
effective in mitigating problems associated with low or moderate
levels of large numbers of environmental contaminants emanating
from multiple sources throughout a building.  Thus, ventilation
has a critical role in the overall strategy to control indoor air
pollution which may also include source control and air cleaning
mitigation methods.

     Ventilation Efficiency

     Even if the outdoor air ventilation rates are delivered into
the building, they may not be sufficiently distributed to
individual work areas, or to the breathing zone of occupants in
those areas.  Thus, an overall assessment of the distribution of
ventilation air to occupant work areas is an appropriate adjunct
to determining whether ventilation rates are adequate or whether
they comply with indoor air quality ventilation standards.

     Design verses Operational Application of Standards

     ASHRAE ventilation standards, and standards which are
contained in some building codes, are most often applied to the
design of new and renovated buildings.  Standards appropriate to
building use should also be applied during the normal operation
of existing buildings, but this is often not the case.  In fact,
most building codes do not require that ventilation systems even
be turned on.

     Investigations of indoor air quality complaints in problem
buildings reveal that the ventilation system in many of these
problem buildings do not perform according to design standards.
This may be due to inadequate maintenance, changes in building
occupancy which can increase requirements above original design
loads, reduced operation for energy conservation purposes, or
lack of appreciation or understanding of operators with the
design logic of the system.  Thus, while design standards may be
adequate, subsequent operation and maintenance of  the system will
often compromise those standards and reduce their  potential to
control indoor air quality.

     Procedural and Other Issues with ASHRAE 62-1981

     ASHRAE Standard 62-1981 and its most recent revised draft,
ASHRAE 62-1981R,  contain a ventilation procedure and an indoor
air quality procedure.   The indoor air quality procedure may be
used as an alternative to the ventilation procedure and would
allow the user to reduce outdoor ventilation rates to any level
determined to provide acceptable indoor air quality, based on
guidance given in the standard.

     While this concept makes sense theoretically, EPA believes
that in practice, the lack of adequate criteria to predict the
acceptability of the  building's indoor air has the potential to
render the standard ineffective  when minimum ventilation rates
prescribed in the standard are not met in the design of the
ventilation system.


     Approximately 50 public health standards and guidelines are
currently applied to indoor air  quality situations.  These
standards cover a small fraction of the hundreds of individual
pollutants known to occur in indoor environments, and they fail
to comprehensively address problems involving pollutant mixtures
or biological contaminants.  Notwithstanding these difficulties,
important steps are under way to improve the application of air
quality standards to indoor settings.  Among these are the recent
publication of World Health Organization guidelines that
explicitly consider indoor exposures, and research involving
pollutant mixtures and biological contaminants.  However,
important information gaps still persist.  Information is sparse
concerning (1) mixtures and biological pollutants, and (2) the
effects of using safety factors  in the application of
occupational standards to public health problem settings.

     Minimum ventilation rates provide an important element in an
overall strategy to control indoor air quality.  ASHRAE Standard
62-1981R provides a comprehensive list of outdoor air ventilation
rates for a variety of indoor spaces.  In addition, ventilation
requirements are contained in some building codes, and in
requirements for the construction of housing under programs
administered by the Department of Housing and Urban Development.
Use of ventilation standards as  a method of controlling indoor
air pollution is important, but  it's potential in controlling
indoor air quality is constrained by both technical and
institutional limitations.


American Conference of Government Industrial Hygienists (ACGIH).
     1988.  TLVs:  Threshold Limit Values and Biological Exposure
     Indices for 1988-1989.  American Conference of Governmental
     Industrial Hygienists.

American Society of Heating, Refrigerating, and Air-Conditioning
     Engineers (ASHRAE).   1981.  ASHRAE Standard 62-1981.
     Ventilation for Acceptable Indoor Air Quality. Atlanta, Ga.

American Society of Heating, Refrigerating, and Air-Conditioning
     Engineers (ASHRAE).   1986. ANSI/ASHRAE 62-1981R.  A Proposed
     American National Standard:  Ventilation for Acceptable
     Indoor Air Quality.  Public Review Draft. Atlanta, Ga.

Blumenthal, M., B. Roitman-Johnson, R. Sigford, and A. Streifel.
     1987.  Indoor Aeroallergens:  Measurement and Their
     Clinical Significance.  Presented at the 80th Annual
     Meeting of the Air Pollution Control Association, New York,
     21-26 June 1987.

Bouscaren, R., M. J. Brun, A.C. Stern, and R, Wunenburger.
     1986.  Air Pollution Standards.  Chapter 5 in Stern,  A.C.
     1986.  Air Pollution.  Third edition, Volume VIII.
     Supplement to Management of Air Quality.  Academic Press,

Burge,  Harriet A., et al., 1987.  Bioaerosols: Guidelines for
     assessment and sampling of saprophytic bioaerosols in the
     indoor environment.  A report of the Bioaerosols Committee of
     the ACGIH. Applied Industrial Hygiene. September.

Environmental Health Directorate.  1986.  Exposure guidelines for
     Residential Indoor Air Quality (Excluding Radon).  A Report
     of the Canadian Federal-Provincial Advisory Committee on
     Environmental and Occupational Health, Environmental Health
     Directorate, Health Protection Branch.  Office of the
     Minister of National Health and Welfare.  July 1986.

Environmental Protection Agency.  1977.  Air Quality Criteria
     for Lead.  Office of Research and Development, U.S.
     Environmental Protection Agency  (EPA-600/8-77-017).

Environmental Protection Agency,  1980.  Air Quality Criteria
     for Particulate Matter and Sulfur Oxides; Volume  1,  Summary
     and Conclusions.  Environmental Criteria and Assessment
     Office,  Office of Research and Development, U.S.
     Environmental Protection Agency  (External Review  Draft No.
     1) -

Gammage, R.B.,  and W.S.  Kerbel.   1987.   American Industrial
     Hygiene Association,  Indoor Environmental Quality Reference
     Manual.  Proc. Fourth International Conference on Indoor Air
     Quality and Climate,  17-21  August 1987,  West Berlin.

HUD.  1986a.  Minimum Property Standards.   Part 200.  Subpart S.
     Code of Federal Regulations, Title 24,  Sections 200.925 and

HUD.  1986b.  Manufactured Home  Construction and Safety
     Standards.  Part 3280.   Code of Federal Regulations, Title
     24, Sections 3280.103 and 3280.710.

Molhave, L.  1984.  Volatile organic compounds as Indoor Air
     Pollutants.  In Indoor Air  and Human Health, R.B. Gammage
     and S.V. Kaye, eds.  (1985), Lewis Publishers, Chelsea,

Morey, P.R., J.L. Clere,  W.G. Jones, and W.G. Sorenson.  1986.
       Managing Indoor Air for Health and Energy Conservation.
       Proc. IAQ  '86 for the American Society of Heating,
       Refrigerating and Air-Conditioning Engineers, 20-23 April
       1986, Atlanta, Georgia.

Miller, J.D., P., Laflamme,  A.M., Sobol, Y.,  Lafontaine, and
     Greenhalgh.  1988.  Fungi and Fungal Products in Some
     Canadian Houses, International Biodeterioration, in press.
      (As reported in Walkinshaw, 1988).

NIBS.  1986.  Standards,  Regulations, and Other Technical
     Criteria Related to Indoor  Air Quality-   National Institute
     of Building Sciences.  Washington, D.C.

NIOSH.  1988.  NIOSH Recommendations for Occupational Safety and
     Health Standards 1988,  Atlanta, 1988.

Repace, J.L. 1982.  Indoor air pollution.   Environ. Int., 8:21-

Repace, & Lowrey. 1985.  An Indoor Air Quality Standard for
      Ambient Tobacco Smoke based on Carcinogenic Risk.  New York
     State Journal of Medicine,  Vol. 85.

Sexton, K. 1986.  Indoor Air Quality:  An Overview  of Policy and
     Regulatory Issues.   Science, Technology, and Human Values,
     ll(l):53-67, Winter 1986.

Solomon, W., and H. Burge.  1984.  Allergens and  Pathogens.  In
     Indoor Air Quality,  CRC Press.

Walkinshaw, D.S.  1988.  Canadian Indoor Air Quality Standards,
     Guidelines and Research Activities.  In Indoor and Ambient
     Air Quality, R. Perry and P- W. Kirk eds., Selper Ltd.,

WHO.  1987.  Air Quality Guidelines for Europe.  World Health
     Organization, Regional Office for Europe, Copenhagen.  WHO
     Regional Publications, European Series, No. 23.


     This  chapter  covers  the  Federal laws which address various
 aspects  of indoor  air  quality.  Except for the National
 Environmental  Policy Act, whose requirements affect all federal
 agencies,  the  laws are grouped according to the Agency with the
 primary  role in  implementing  their provisions.  Aspects of the
 laws which relate  to indoor air quality are summarized in
 Exhibit  8-1.


     The National  Environmental Policy Act  (42 USC 4331 et seq.)
 established a  national goal to "assure for all Americans, safe,
 healthful,  productive, and aesthetically and culturally pleasing
 surroundings"  and,  required that all agencies of the Federal
 government (1) develop procedures to insure that "presently
 unquantified environmental amenities and values may be given
 appropriate consideration in  decision-making..." and (2) develop
 an environmental impact statement for any major Federal action
 "significantly affecting  the  quality of the human environment".
 The policies and goals set forth in this Act are to be
 "supplementary to  those set forth in existing authorizations."
 While not  specific to  indoor  air, this broad overarching
 legislation provides a context for the consideration of indoor
 air quality and  other  environmental concerns in all major Federal
 actions  taken  pursuant to other authorities.


     The Environmental Protection Agency was established in 1970
 under Reorganization Plan No. 3  (42 USC 4321) in which the
 environmental  pollution control functions of several federal
 agencies were  consolidated.   The general roles and functions
 given to EPA under Reorganization Plan No.  3 were to
 (1) establish  and  enforce environmental protection standards,
 (2) research the effects  and  controls of environmental pollution,
 and  (3)  provide grants and technical assistance to others as  a'
 means of arresting environmental pollution.  Legislation with
 specific authorities related  to indoor air  includes the Clean Air
 Act; the Toxic Substances Control Act; the  Federal Insecticide,
 Fungicide,  and Rodenticide Control Act; the Safe Drinking Water
 Act; and Title IV  of the  Superfund Amendments and Reauthorization

     Clean Air Act fCAJU

     The Clean Air Act (42 USC 7401 et seq.)  is the  legal basis
 for air  pollution  control efforts in the United States.   Its
stated objective is "to protect and enhance the quality of  the
nation's air resources so as  to protect the public health and the
productive  capacity of the population".  Progress  toward this


           Load A0mcy/5latute

           DqpartBent of Labor
            OccupBtianul  Safety and Health Act
 Departmt of  Health and Mm Services
  Public Health Service Act                        B
  Hazardous Substances Act                         B
  Consuter  ProoLct  Safety Act                      B

 DepartHent of  Housing and Urban Develop*!*
  National  Manufactured Housing  Construction
  and Safety Standards Act
  42  USC 1548-re 0.0.0.  Housirg                  B
  42  USC 14371  re  low-rent housing
  42  USC 1437o re  residential rentals
  10  USC 2701  re contaminated D.O.D.

Housing and Unban Development Act

Environmental Protect ion Agency
 National Environmental  Policy Act
 Clean Air  Act                                     B
 Superfind Amendnants and Reauthorization Act      B
 Racbn Gas  and Indoor Air Quality Research Act
 Safe Drinking Uater Act                           C
 Federal Insecticide,  Firgicide and Rodenticide    B
 Toxic Substances Control Act                      B
 Asbestos Hazard Emergency Response Act           A
 Asbestos School Hazard Detection and Control     A
                                       Erfiibit 4V1
              liwts of Regulatory Authority by Agency. Statute,  mi Activity

                               Type and Level of Authority

                                      DcMonstration             Advisory     Technology
„..       . .                           °*         Monitor/  GoHJttees   Transfer/                          ard        EKrgency Public
Starter*    OfldeHnes  EnfortaEnt    I«*nology      Sa^le   or Beards    fesisttre    Grants  Beseard,   Cor^tatj,,,  ^£ts   Pc«r   Info

    B                        ft              R           a          a                      n         „






         Dtfju tertt of Energy
          Department of Energy Organization Act
          Energy Conservation and Production Act                        B
          Pacific Northwest Electric Power Planning                     C
           and Conservation Act
          Atomic Energy Act                                C            B
          A = Statutes that grant the Agency explicit authority to conduct  indoor air Ofjality-related activities.
          B - Statutes that grant the Agency authority to conduct  activities Jiich, ty inplication,  include  indoor air.
          C = Statutes that give the Agency authority rfiich could  be  interpreted to include ircbor air.
          0 = Statutes that reojjire a forced interpretation to include  indbor air activities.

goal  is  accomplished through a complex program involving  a  close
partnership between EPA and the states.

      The Clean Air Act provides EPA with regulatory authority  to
establish standards for two categories of air pollutants:

      Criteria pollutants are pollutants which can reasonably
      be  expected to "endanger public health or welfare" and
      the presence of which result from "numerous and diverse
      mobile or stationary sources."  In response to the
      potential threat posed by these agents, EPA
      establishes National Ambient Air Quality Standards
      (NAAQS).  States are required to develop State
      Implementation Plans (SIPs) designed to meet those
      standards.  There currently are NAAQS for six criteria
      pollutants: inhalable particulate matter (<10 micron
      diameter), sulfur oxides, nitrogen dioxide, ozone,
      carbon monoxide, and lead.

      Hazardous pollutants are those which "may reasonably be
      anticipated to result in an increase in mortality or an
      increase in serious irreversible, or incapacitating
      reversible, illness."  EPA formally "lists" pollutants
      as  hazardous and then promulgates national emission
      standards for significant source categories of the
      designated substances; these emissions limits are
      called National Emissions Standards for Hazardous Air
      Pollutants  (NESHAPS).  Eight pollutants have been
      listed as hazardous: mercury, beryllium, asbestos,
      vinyl chloride, benzene, radionuclides, inorganic
      arsenic compounds, and coke oven emissions.

      The CAA gives EPA authority to regulate air pollutants.
However, the overall structure and terminology of the  Act  --  in
particular the scale on which it defines air pollution problems
and prescribes solutions-- indicate that Congress conceived of
air pollution as an outdoor phenomenon and  contemplated
regulation only of the outdoor air.

      The heart of the statutory scheme is a nationwide system of
ambient  air quality standards and area-wide approaches to
implementation through intra- and inter-state planning and
controls.  The Act thus creates a regulatory  structure that
treats air pollution as a large-scale  problem that  begins,  for
example, with the "emission" or "discharge" of  pollutants  from
"any  building, structure, facility or  installation"  into the
"atmosphere" or "ambient air.'8

      The Act-considers that air pollution  may have impacts
across state and international boundaries.   In  addition, the  Act
directs  EPA to monitor air quality  "in major  urban areas and
other appropriate areas throughout the United States" and thus


appears to be directed to outdoor  rather  than  indoor pollution.
This focus on outdoor pollution appears also in the legislative
history where Congress voiced concern  about "the  air over most
cities and towns".   Consistent with  this  view, EPA regulations
adopted in 1971 defined "ambient air"  for certain purposes  to
mean air "external1"' to buildings and other structures  (40 CFR

     In summary,  the Clean Air Act confers general responsibility
to EPA to protect the public health  and welfare  from air
pollution,  but its  structure and provisions direct EPA to control
air pollution outdoors.

     Toxic Substances
     Congressional intent as stated in TSCA is  the  development by
the manufacturers and processors of "adequate data...with respect
to the effect of chemical substances and mixtures  on health and
the environment..." and "adequate authority..„to regulate
chemical substances and mixtures which present  an  unreasonable
risk of injury to health and the environment..." (15 USC 2601).
The statute grants to the Administrator the authority to require
testing of suspect chemicals,  and to establish  rules and
schedules for performing those tests*   An advisory committee can
recommend priority chemicals to the Administrator  for which rules
should be developed.   In addition,  manufacturers and processors
can petition the Agency to develop test standards  for a chemical
of interest.

     The most important data gathering authorities of TSCA are as

   o  Section 4 of TSCA was included to develop data that would
      be useful in assessing the potential risks from existing
      chemicals.  In order to require testing,  EPA must determine
      that there are insufficient data about the effects of the
      chemical, and that testing is needed to dev~\op these data.
      The testing that can be required for a chemical depends  on
      the findings made and the data already available.  Health
      tests may include: acute,, subchronic, reproductive and
      developmental toxicity,  neurotoxicity, skin sensitization,
      mutagenicity, pharmacokineti.es,  and carcinogenicity.
      Testing to determine exposures to a chemical  or the  fate of
      the chemical may also be obtained.

      Several offices in EPA havs or are using  Section  4  to
      gather data to support their programs.  This  could  also be
      a useful tool in supplementing data^on indoor air.
      Chemicals may be referred by the  Interagency  Testing
      Committee, which consists of representatives  from other
      governmental agencies, such &s, the OSHA.  These  agencies

      also provide testing recommendations of relevance  to  their
      Agency needs.

   o  Section 8  (Reporting and Retention of Information)

         Section 8(a) gives EPA the authority to promulgate
         rules to collect existing use, production and exposure
         data on specific chemicals.  EPA has promulgated rules
         under the authority of Section 8(a)  which provide  a
         mechanism for collecting basic information on the
         manufacture, processing, and use of chemicals.

      -  Section 8(b) requires EPA to keep a current inventory of
         chemicals manufactured and processed in the U.S.
         originally published in 1977, the inventory currently
         contains approximately 15,000 chemicals.

         Section 8(d) allows EPA to collect unpublished health
         and safety studies and related information on selected

         Section 8(e) requires industry to report information to
         EPA that indicates a chemical may present a substantial
         risk.  Information is continually being received under
         this provision.

     TSCA also authorizes EPA to consult with the Secretary of
Health and Human Services in conducting research, development,
and necessary monitoring.

     In addition to data gathering, TSCA has provisions that
enable EPA to control exposure to chemicals that present or may
present an "unreasonable risk or injury to human health or the
environment".  The Act provides EPA with authority to impose a
variety of regulatory sanctions.  However, before issuing a
regulation,  EPA must weigh the reduction in risk attributable to
the regulation against the regulatory burdens to society,
including costs.  Further, EPA must use the "least burdensome"
sanction, taking into account whether the health threat  could be
eliminated or reduced to a sufficient extent under other Federal
statutes.  Potential sanctions which could be applied include the
following (15 USC 2605):

   o  prohibit or limit the manufacture, processing,  or
      distribution of the chemical;

   o  require the chemical to be marked with warnings and

   o  require the manufacturers and processors  to  monitor  or
      conduct tests of the manufacturing  and processing


   o  prohibit or regulate commercial  use or disposal;

   o  require public notice of  the  health risk, and require
      replacement or refunds; and

   o  require revision of manufacturing  quality control

     Regulations  adopted by EPA pursuant to  its authority  under
TSCA are found in Subchapter R  of Title  40 of  the  Code of  Federal

     In summary,  with some restrictions, TSCA  provides EPA with
the ability to restrict the manufacture, distribution, and use of
toxic chemical agents,  including any that may  be significant
indoor air pollutants.

     Federal Insecticide, Fungicide, and Rodenticide  Act (FIFRA)

     One of the primary purposes of FIFRA  is to ensure that  the
use of pesticides,  when applied in  accordance  with EPA-approved
label directions, will not cause "unreasonable adverse effects"
(as defined in the Act)  to humans or the environment.  In  some
respects,  FIFRA is similar to TSCA,  in that  it provides  EPA  with
authority to require the submission of chemical-specific data,
and to restrict the distribution and use of  the chemicals  which
lie within its statutory domain.  Although pesticides are
commonly thought  of in the context  of agriculture,  they  are
widely used throughout our society  for a variety of purposes,
both indoors and  out.  Regardless of the locus of  its use, any
pesticide (as defined in FIFRA  section 2(u))  is  subject  to
regulation under  FIFRA.

   o  Section 3(a)  prohibits any person from selling,
      distributing, or holding  any  pesticide which is not
      registered  by the Agency, FIFRA section 3(c)(5)  requires
      EPA to register a pesticide upon a determination that
      (among other things) its  use  in accordance  with labeled
      directions  will not cause "unreasonable adverse effects."
      FIFRA section 2(bb) defines this latter term as:  "...any
      unreasonable risk to man  or the environment, taking into
      account the economic, social, and environmental costs and
      benefits of the use of any pesticide."  Upon a
      determination that a pesticide cannot  otherwise meet the
      "3(c)(5)" criteria for registration,  EPA may classify that
      product as  a "restrictsd-use" pesticide, thereby  limiting
      its  use to  certified applicators, or persons under  the
      certified applicator's direct supervision...the rationale
      being that  trainee; applicators are more conscientious about
      following label directions and precautions.

   o  Section 3(c)(2)(B) authorizes EPA to require additional
      data, whenever deemed necessary by the Agency,  in support
      of an existing pesticide registration.  This same provision
      of the Act further authorizes the Agency to suspend the
      registration of any pesticide for which the registrant does
      not comply in a timely manner with any such requirement.

   o  Section 6 authorizes EPA to suspend, cancel, or change the
      conditions of an existing registration if information
      arises which indicates that the pesticide in question does
      not meet the "no unreasonable adverse effects" standard.

   o  Section 13 authorizes EPA to issue a "stop sale, use, or
      removal" order for any pesticide found to be in violation
      of the conditions of its registration.

   o  Section 20 provides monitoring authority.  Under this
      section, EPA has developed a National Pesticide
      Monitoring Plan which stresses cooperation and
      information sharing with other agencies.  Information
      collected under this provision could provide information
      on the use of pesticides indoors.

     In conclusion, FIFRA is similar to TSCA in terms of its
regulatory scope and the methodological approach  (source control)
for protecting indoor air quality.  Under its provisions, EPA
regulates certain indoor air pollutants (indoor pesticides) by
banning or limiting their distribution or use, or by establishing
guidelines for their safe application.  In addition, information
collected by the developing National Pesticides Monitoring Plan
can be used to better define the magnitude of human health risks
posed by pesticides in indoor air.

     Asbestos Hazard Emergency Response Act  (AHERA) and the
     Asbestos School Hazard Detection and Control Act

     The Asbestos Hazard Emergency Response Act  (15 USC 2641) was
adopted to remedy the problem of asbestos in schools. The Act
requires EPA to promulgate regulations that prescribe methods of
assessing and addressing the school asbestos problem which
include: (I) procedures for determining the presence  of asbestos;
(2) appropriate response actions for defined conditions;
(3) operations, maintenance, and repair programs;
(4) surveillance programs;  (5) methods of transporting and
disposing of asbestos wastes;  (6) warning labels  for  asbestos
risk areas; and (6) contractor and laboratory  certification

     The Asbestos School Hazard Detection and  Control  Act  of 1980
(20 USC 3601) established an Asbestos Hazards  School  Safety Task
Force,  which includes representatives  from  EPA and  several other
Federal agencies.  The Task Force is directed  to compile


information regarding the health  and  safety  hazards  of  asbestos;
determine means of identifying, sampling,  and  testing asbestos
containing materials; distribute  information;  review the  EPA
guidelines; and assist the Secretary  of  Education  in formulating

     Safe Drinking Water Act (SDWA)

     The Safe Drinking Water Act  (42  USC 300f  et seq) authorizes
EPA to conduct research on the identity  and  effects  of
contaminants in drinking water.   Contaminants  found  in  the water
supply for certain parts of the country  may  affect the  indoor air
quality of the households and businesses being served.   Radon,
for example, may contaminate the  groundwater serving a  house  or
community,  or the water may contain volatile organic compounds.
These pollutants may then be introduced  into the building by
aerosol action from showers,  or other uses of  the  water.

     The authority of the Administrator  under  the  SDWA  includes
the establishment of primary and  secondary regulations  to protect
the safety of public water systems.   The regulation  of
constituents that may degrade indoor  air quality are peripheral
to the intent of the SDWA.  However,  regulations are to apply to
contaminants which "may have any  adverse effect on the  health of
persons" (42 USC 300f(l)(B)).  The Act therefore provides clear
authority to set standards for indoor air pollutants that
originate in the public water supply.

     SARA Title IV (Radon Gas and Indoor Air Quality Research

     SARA Title IV requires EPA to establish a research program
for the study of radon gas and indoor air quality.  The purpose
of such a program is to (1) gather information on all  aspects of
indoor air, (2) coordinate government and private sector
research, and  (3) assess appropriate  federal actions to mitigate
^ndoor air associated risks.   Program requirements are specified
in the Act and include the investigation of:

   o  sources and levels of indoor contaminants, including
      instrumentation, monitoring, and the study of  high risk
      building types;

   o  the effects of indoor contaminants on  human health;

   o  control technology and other mitigation measures,  for
      both new and existing buildings, including both
      individual and generic mitigation techniques;  and

   o  the dissemination of information.

      The Act requires EPA to  establish  advisory committees, to
 submit an implementation plan within  90 days and a comprehensive
 report with recommendations within  2  years after enactment. The
 implementation plan was  submitted to  Congress  in June 1987.

      In summary,  this legislation provides EPA authority to
 conduct research,  coordinate  activities in the public and private
 sectors,  and disseminate information  on indoor air.  However, it
 provides no control authority or standard setting authority.

      In addition  to SARA Title IV,  section 118 (k) of SARA
 provides authority for the Administrator to conduct a national
 assessment of the locations and risks from radon gas,
 demonstrations of control techniques, and the  dissemination of
 public information.


      The Department of Energy is responsible for the management
 of federal energy-related programs.   These responsibilities
 include coordinating the Federal energy policy; maximizing energy
 conservation nationwide;  and  conducting a comprehensive energy
 research and development program.   Given the close link between
 energy sources and air pollution, and between  energy
 conservation in buildings and indoor  air quality, the activities
 conducted under authorities administered by DOE can have
 important implications for a  national indoor air quality program.

      Department of Energy Organization Act: of  1977

      The  Department of Energy Organization Act of 1977  (42 USC
 7112)  authorized  DOE to  provide for the functions of the Energy
 Research  and Development Administration (ERDA--DOE's predecessor
 organization).  One of the stated purposes of the- Act was to
 "assure  incorporation of national environmental protection goals
 in the  formulation and implementation of energy programs, and to
 advance  the  goals  of restoring,  protecting, and enhancing
 environmental  quality, assuring public health  and safety-"
 Another  section of the Act directed DOE to conduct " a
 comprehensive  program of research and development on the
 environmental  effects of energy technologies and programs."

      Energy  Reorganization Act of 1974

      The  Energy Reorganization Act  of 1974 specifically provided
 that  the  responsibilities of  ERDA shall include "... engaging  in
and supporting  environmental,  biomedical, physical, and safety
research  related to  the  development of  energy  sources and
utilization  of  technologies...."

     Atomic Energy Act

     The Atomic Energy Act authorizes research important to
characterizations of the problems of radon and non-ionizing
radiation.  The Act provided the initial  charter for a
comprehensive program of applied and basic radiobiological
research and authorized DOE to conduct research and development
related to the utilization of fissionable and radioactive
materials for medical, biological and health purposes.  It also
provided for the protection of health during the same research
and development activities.  The Act also authorizes the Atomic
Energy Commission "to conduct research on the biologic effects of
ionizing radiation..." for "...the protection of health and the
promotion of safety during research and production activities..."
and for "...the preservation and enhancement of a viable

     Energy Conservation and Production Act

     The goal of the Energy Conservation and Production Act is
the reduction of energy demand of the nation through the
development of Federal and State conservation programs.  The Act
authorizes DOE to develop voluntary performance standards for
energy efficient residential and commercial buildings, to provide
technical assistance in implementing those standards, and to
encourage state and local governments to incorporate those
standards in building codes (42 USC 6831 et seq.).  The Act also
requires DOE to undertake a residential weatherization assistance
program f42 USC 6863).

     The Act also directs DOE to take into account the impact of
energy conservation standards on "habitability" as well as the
"impact on affected groups" (42 USC 6839), and to "achieve a
balance of a healthful dwelling environment and maximum
practicable energy conservation" in its weatherization program
(42 USC 6863(b) (2) (A) .


     HHS has been delegated the majority of the health-related
functions of what was once the Department of Health,  Education,
and Welfare (HEW).  It is through the role of HHS to  protect  the
public health and to prevent disease that most programs  of the
Department encompass potential indoor air pollution  issues.   The
major statutory authority defining this  role  is the  Public Health
Service Act.

     Public Health Service Act  fPHSA)

     The Public Health Service Act provides  the  general mandate
for the HHS to conduct research and other activities related to
the causes, diagnosis, treatment, control,  and  prevention of


 disease.   This statute authorizes grants, studies, dissemination
 of  information,  and an annual  report  on carcinogens.  A
 comprehensive program addressing the  effects of low-level
 ionizing  radiation is specifically  authorized.  Regulations
 pursuant  to this authority  can be found at 21 CFR 1020, and 1030.

      The  PHSA directs the Secretary to identify pollution and
 other environmental conditions "responsible for human disease and
 adverse effects  on humans"  (42 USC  242b).  The Secretary is
 further directed to conduct,  in cooperation with EPA, the
 National  Academy of Sciences,  Department of Labor, Consumer
 Product Safety Commission,  and Council on Environmental Quality,
 an  ongoing study of the health costs  of pollution and other
 environmental activities resulting  from human activities
 "including human activity in  any place in the indoor or outdoor
 environment,  including places  of employment and residences" (42
 USC 242(d)(1)).

      The  PHSA which specifically provides for the study of the
 health consequences of indoor  pollution, also establishes a
 number of health related research entities whose mandate would
 include specific health aspects of  indoor air pollution.  These
 mandates  apply to all of the  entities within the Department of
 Health and Human Services.

      Other Legislation

      The  National Institute for Occupational Safety and Health
 obtains its primary authority  for conducting indoor air quality
 investigations from Section 20 of the Occupational Safety and
 Health Act,  and  the Agency  for Toxic  Substances and Disease
 Registries obtains its authority for  related investigations from
 the  Comprehensive Environmental Response Compensation and
 Liability Act of 1980,  and  the Superfund Amendments and
 Reauthorization  Act of 1986.


      The  CPSC is an independent regulatory agency that was
 established by the Consumer Product Safety Act  (15 USC 2051) to
 fulfill the national  goal of protecting consumers from
 unreasonable  risks of injury.   CPSC is responsible  for enforcing
 other  statutes,  including the  Federal Hazardous Substances Act.

      Consumer Product Safety Act

     The  Consumer Product Safety Act  (CPSA) provides  CPSC with
authority  to  control  certain  aspects  of  indoor  air  quality by
regulating  "consumer  products." The  CPSC can promulgate
consumer  product safety standards when the standard  is
"reasonably  necessary to prevent or reduce an unreasonable  risk
of injury  associated  with such product"  (15 USC  2056).   Such  risk


or injury may include health effects associated with  contaminant
emissions that affect indoor air quality.   In addition to setting
standards, CPSC can ban a consumer product from the market.

     For "substantial product hazards"  CPSC has authority to (1)
give public notice, (2)  mail notice to  manufacturers,
distributors and retailers,  or (3)  mail notice to every person
known to have been sold such a product.  CPSC can also order the
manufacturer to repair or replace the hazardous product,  or
refund the purchase price (15 USC 2064).   Finally,  if an
"imminent hazard" exists, CPSC may sue  manufacturers,
distributors, or retailers (15 USC 2061).

     The CPSA contains provisions applicable to the control of
indoor air pollution through its provisions relating  to control
of consumer product sources.  It vests  no authority to establish
indoor air quality or ventilation standards.  Consumer products
are defined as those for use by consumers "in and around"
residences.  It does not include the building itself,  and the
extent to which it includes building materials is unclear.  In
addition, product standards only apply  to currently produced
products, and the substantial hazard and imminent hazard
provisions may be useful only if CPSC can identify the
manufacturer.  The CPSC is also restricted to corrective actions
that cannot be taken under the terms of OSHA, the Atomic Energy
Act, or the Clean Air Act.

     Federal Hazardous Substances Act

     The Federal Hazards Substances Act (FHSA) supplements CPSC
authority under the Consumer Product Safety Act.  The FHSA
specifies labeling requirements for household products which are
"hazardous substances", as that term is defined in the FHSA.  The
FHSA defines "hazardous substances" as  including certain
household substances or mixtures of substances which are toxic,
corrosive, flammable, combustible, irritants, strong sensitizers,
or substances which generate pressure through decomposition,
heat, or other means.  The FHSA requires labeling  for hazardous
substances and also bans the sale of any toy or children's
article that contains or consists of a hazardous substance.
Additionally, the FHSA authorizes the Commission to establish
specific labeling requirements for household products containing
hazardous substances if no labeling which could be required  under
the FHSA would adequately protect the public health and  safety.


     The Department of Housing and Urban Development  administers
the nations housing and urban development policies which are
implemented primarily through a variety of  financial  and
technical assistance programs to state and  local governments.
The preeminent theme through all of  its enabling statutes and


which forms the basis of HUD's responsibilities in indoor air is
its mandate to provide " a decent home and suitable living
environment to every American family" (12 USC 1701t and 42 USC
1441).  In addition, HUD is to assure that its programs provide
"decent, safe, and sanitary housing" (12 USC 1701z and 42 USC
1401) or to "ensure safe and healthful working and living
conditions" (12 USC 17012-2).

     In addition to this broad mandate which pervades all of
HUD's authorized activities, HUD's most specific authority
related to indoor air is its authority to develop construction
and safety standards for manufactured housing.

     National Manufactured Housing Construction and Safety
     Standards Act of 1974

     HUD is directed by the terms of this statute (42 USC 5401)
to establish standards for the construction and safety of
manufactured housing.  While safety aspects to be considered are
primarily concerned with accident-related personal injuries, they
include health and safety features related to indoor air.  For
example, HUD has included formaldehyde emission controls for
certain wood products, and outdoor air ventilation requirements
for manufactured housing using forced heat, within its
regulations for manufactured housing (24 CFR 3280 and 3282).


     The Department of Labor has been delegated authority to
regulate health and safety conditions in places of employment.
While this authority has traditionally been interpreted as
applying primarily to the industrial work environment, the
enabling legislation for this activity is quite broad, and covers
all private sector and most public sector work environments.   The
primary statute of concern with respect to indoor air quality  in
the workplace is the Occupational Safety and Health Act.

     Occupational Safety and Health Act  (OSHAct)

     The Occupational Safety and Health Administration  (OSHA)  was
created in 1970 under OSHAct  (16 USC 651 et seq.), wherein
Congress declared it a national policy "to assure as  far  as
possible every working man and woman in the Nation safe  and
healthful working conditions and to preserve  our human  resources
..." by, among other things, directing the Secretary  of  Labor to
develop and enforce occupational safety and health standards.

     The OSHact requires the Secretary of  Labor,  in  the case of
standards dealing with toxic substances, to set  "the  standard
which most adequately assures to the extent feasible,  on the
basis of the best available evidence, that no employee  will
suffer material impairment of health or  functional capacity even


if such employee has regular exposure to the hazard dealt with by
such standard for the period of his working life."

     In addition to safety and health,  the standards must take
into account issues of feasibility-  OSHA occupational indoor air
standards are enforced by inspecting workplaces and where
warranted by prescribing abatement, and proposing civil monetary

     The National Institute for Occupational Safety and Health
(NIOSH),  which resides in the Department of Health and Human
Services, was created by Congress in the OSHAct to develop and
establish recommended occupational safety and health standards
and to perform other functions (29 USC 671).


     The preceding discussion illustrates a number of significant
points that are pertinent to assessing the adequacy of existing
laws to protect indoor air quality.

     First, many Federal agencies have the explicit legal
authority to regulate certain products and/or activities that
affect indoor air quality, or to regulate the quality of the air
in specific indoor environments.   Existing authority ranges from
the ability to ban or restrict the use of pesticides and
consumer products, to setting and enforcing indoor air quality
standards in occupational settings.  However, these authorities
are fragmented, are limited to specific products or environments,
and some address indoor air concerns secondarily or only

     Second, most legal authority related specifically to
building systems affecting indoor air quality is limited in
scope, allowing only research activities and provision of public
information and technical guidance.  Most of this authority rests
with the Department of Energy and is directed to energy
conservation, with indoor air quality as a secondary concern.

     Finally, there is currently no Federal law that explicitly
establishes a goal of establishing acceptable indoor air quality
in non-occupational environments which protect the public health
and welfare.  In addition, while SARA Title IV vests  in  EPA the
responsibility to conduct research, coordinate, and disseminate
information, it does so in the context of  research, and  does  not
delegate authority for controlling indoor  air pollution.  Thus,
there is currently no Federal agency with  comprehensive  authority
to develop a coherent, national indoor air pollution  control
program for residential, most educational, and other  non-
occupational indoor air environments.


     Government and private entities at the local,  state,
national, and international levels have developed programs to
execute indoor air quality control policies and strategies.   This
chapter summarizes indoor air quality efforts of federal, state,
and local agencies; private sector organizations; foreign
governments; and international organizations.


     The Federal government participates in the study and control
of indoor air quality through the activities of a number of its
agencies and departments.  The agencies that comprise the
Interagency Committee on Indoor Air Quality  (CIAQ)  have
implemented indoor air quality control programs based on the
legislative authority discussed in Chapter 8.  This chapter
summarizes the indoor air quality assessment and control
activities of Federal agencies, especially the CIAQ co-chairs and
the Bonneville Power Administration.  Volume I of this report
contains a more complete description of current and planned
indoor air quality control activities at the Federal level.

     Environmental Protection Agency

     The Environmental Protection Agency's (EPA's)  indoor air
quality control efforts attempt to  (1) characterize indoor air
problems; (2) identify, assess, and implement strategies to
mitigate indoor air hazards; and  (3) disseminate information
about indoor air quality control.  In accordance with these aims,
EPA uses mandatory standards and procedures, voluntary
guidelines, research activities, and dissemination of public
information and technical assistance to implement its indoor air

     EPA efforts to understand and control indoor air hazards  are
presented in Exhibit 9-1.  EPA has developed a limited number  of
regulatory controls on indoor air hazards.   Most of EPA's current
mandatory standards and procedures arise from the pesticide and
asbestos programs of the Office of Pesticides and Toxic
Substances.  EPA actively studies many facets of indoor  air
concerns, ranging from characterizing typical concentrations and
exposures to evaluating control strategies.  EPA also actively
disseminates information on indoor air quality concerns  through
booklets, fact sheets, telephone hotlines, product  labelling,  and
manuals and workshops for professionals.

     Consumer Product Safety Commission

     The Consumer Product Safety Commission  (CPSC)  addresses
indoor air quality concerns by developing  voluntary guidelines

                                                 Exhibit 9-1
                                  EPA  Indoor Air Quality Control Activities
   Activity                               Description
Mandatory Standards and Procedures

MCLs for Radon and VOCs 	 Drinking water standards incorporating indoor air exposures

Asbestos Ban and Phase Down  Rule.  .  .  . Restriction on the use of asbestos-containing materials in buildings

Asbestos Worker Protection Rule  .... Procedures and standards for asbestos removal work

Asbestos Materials in Schools  Rule.  .  . Support for identification and removal of problem asbestos in schools

Ban on Sates of Chlordane and
     Heptachlor 	 Sales ban pending demonstration of safe application methods

Restrictions on Lindane Use   	  Ban  on use of  indoor  fumigating devices

Restrictions on Pentachlorophenol
     and Creosote  	  Ban  on treating wood  used indoors with these chemicals

Proposed Suspension of Indoor  Use
     of Certain Anti-Microbials  .... Proposed ban on use of certain anti-microbials  in  indoor  environments

Voluntary Guidelines

Model Building Code 	 Appropriate design features to control radon infiltration


Measurement and Estimation of
     Exposures and Concentrations  .  .  . More than 30 projects investigating  sources, monitoring,  and exposures

Health Effects	 Nine projects  involving ETS,  radon,  VOC mixtures,  and combustion gases

Risk and Hazard Assessment	Five projects  involving ETS,  para-dichlorobenzene,  and solvents

Diagnosis, Assessment, and
     Mitigation Protocols 	 Five projects  investigating sick  building syndrome,  air exchange, and
                                          radon control measures

Controls Assessment   	 Three projects including  radon/chlordane  control,  air cleaner
                                          evaluation,  and  testing  radon control methods

information Dissemination

Publications for Public Education  .  .  . Fact Sheets,  indoor  air booklet,  and radon "citizen's guide" and
                                          mitigation pamphlets

Telephone Hotlines	Toll-free  numbers  for questions  about asbestos and pesticides

Product Label Requirements	Inert ingredients  in pesticides,  support  of voluntary consumer
                                          awareness  programs by pesticide manufacturers

Technical  Support Manuals and
     Services     .      	 Course  for public  health  specialists, information on  radon  provided to
                                          AMA and  Conference of State Legislators

                                                  Exhibit 9-2
                                   CPSC Indoor Air Quality Control Activities
Mandatory Standards and Procedures
Carbon Tetrachloride Use Ban	 Ban on use of carbon tetrachloride  in  consumer products

Asbestos Use Ban	Ban on use of asbestos in consumer  products  such  as patching conpounds

Vinyl Chloride Ban	Ban on use of vinyl  chloride in aerosol  products

Voluntary Guidelines
Combustion Device Performance
     Guidelines 	 Recomnended limits for emissions from  kerosene heaters and  unvented gas
                                          space heaters

Formaldehyde Emission
     Guidelines for Wood Products . .  . Recommended limits on emissions from manufactured wood products

Measurement and Estimation of
     Exposures and Concentrations . .  . Seven projects studying pollutant emissions, biological  monitoring, and

Health Effects	Three projects involving MOj; kerosene heaters;  and biologicals  in
                                          humidifiers, air conditioners, and vaporizers

Risk and Hazard Assessment	Two projects involving para-dichlorobenzene  and  solvents

Controls Assessment 	 Three projects investigating wood stoves and air filter  evaluations

InfornBtion Dissemination
Publications for Public Education . .  . Indoor air guidance including "Asbestos in Homes"

Product Label Requirements	Including warnings for asbestos and methylene chloride

for consumer product composition or performance,  promulgating
mandatory standards, conducting research,  and disseminating
information to consumers.  Exhibit 9-2 summarizes the activities
undertaken by the CPSC to study and control indoor air quality
concerns.  CPSC activities focus on controlling the detrimental
effects of consumer products, such as combustion appliances and
products containing volatile organic chemicals, on indoor air
quality.  The Commission implements these controls primarily
through voluntary guidelines and research.

     Department of Energy

     In support of its policies to eliminate potential hazards to
the public from radioactivity at past and current atomic energy
program facilities, and to develop and provide information needed
to maintain healthful indoor environments with the continuing use
of energy conservation measures in buildings, the Department of
Energy  (DOE)  undertakes indoor air quality problem
characterization and mitigation research and disseminates public
information and technical assistance.

     Specific DOE research and information dissemination
activities directed at improving knowledge of indoor air quality
concerns are described in Exhibit 9-3.  DOE primarily directs its
research efforts to investigating the hazards of indoor radon and
the effects of building weatherization.

     Bonneville Power Administration

     Within DOE, the Bonneville Power Administration  (BPA) has
undertaken a variety of activities to control indoor air quality
in response to the potential indoor air health hazards created by
its energy conservation program.  Exhibit 9-4 summarizes BPA's
standards, guidelines, research activities, and information
dissemination efforts related to indoor air quality.  As a
consequence of its development in the Administration's energy
conservation program, BPA's indoor air effort focuses on
residential air quality as it is affected by weatherization

     Department of Health and Human Services

     The Department of Health and Human Services  (HHS)
participates in indoor air quality control through research  and
information dissemination activities.  Exhibit 9-5 presents  a
summary of these HHS activities.  The Department's research
activities center primarily on indoor pollutant health effects.
Through the National Institute for Occupational Safety and
Health, HHS investigates buildings for indoor  air  quality
problems.  HHS also disseminates information and  technical
assistance on indoor air concerns to  state and local  governments
and the public.

                                                  Exhibit 9-3
                                   DOE Indoor Air Quality Control Activities
     Activity                                Description
Measurement and Estimation of
     Exposures and Concentrations . . . Nineteen projects focusing on radon,  modeling,  and energy conservation

Health Effects	 Four projects concerning radon

Risk and Hazard Assessment	Two projects concerning radon

Diagnosis, Assessment, and
     Mitigation Protocols 	 Five projects investigating infiltration and ventilation

Controls Assessment	Review arid development of current technology
Information Dissemination
Publications for Public Education  .  .   Handbooks on cotrfoustion sources, indoor radon, and building systems

Technical Support Manuals and
     Services 	 Database of indoor pollutant concentrations, handbooks on indoor air

                                                   Exhibit 9-4
                                   BPA Indoor Air Quality Control Activities
     Activity                                Description
Mandatory Standards and Procedures
Emission Limit for Formaldehyde
     in Wood Products .........  Required use of low-formaldehyde materials in residential buildings

Voluntary Guidelines
Action Limit for Radon	Mitigation assistance for weatherized homes with radon
                                          concentrations greater than 5 pCi/L

Measurement and Estimation of
     Exposures and Concentrations .  .  .  Seven projects investigating monitoring and weatherization effects

Controls Assessment 	 .....  Six projects investigating radon control methods,  local exhaust, heat

Information Dissemination
Publications •for Public  Education .  .  .  Pamphlets on ventilation and air quality,  issue "backgrounders"

Technical  Support Manuals and
     Services ...         	  Manuals on radon monitoring, installing mitigation devices, auditing
                                           and operating HVAC systems;  distributing radon detectors

                                                  Exhibit 9-5
                                   HHS Indoor Air Quality Control  Activities
     Activity                                Description
Measurement and Estimation of
     Exposures and Concentrations . . .  Six projects including surveys of attitudes and practices,  radon
                                          screening, post-remedy tests, and studies of ETS and fibrous
Support for Indoor Air Quality
     Investigation	Ongoing research studying the ventilation,  clinical,  and psychosocial
                                          parameters of indoor air quality investigations

Health Effects	More than 30 projects studying Legionel la.  allergens,  and chronic
                                          lung disease
Information Dissemination
Publications for Public Education  .  .  . Report on passive exposure to tobacco smoke

Technical Support Manuals and
     Services 	 Services for state health departments, epidemiological information on
                                          radon, campaign to encourage smoking restriction legislation, and
                                          a manual of analytical methods for air sampling and analysis

Assessment Services  	 NIOSH a/ Health Hazard Evaluations

a/ NIOSH is the National Institute for Occupational Safety and Health, part of HHS.

     Other Federal Agencies

     A number of other Federal agencies play smaller, but active, roles in
controlling indoor air quality.  The indoor air-related activities of the
Departments of Defense (DOD), Housing and Urban Development (HUD), State
(DOS), and Transportation  (DOT); the Federal Trade Commission (FTC); the
General Services Administration (GSA); the National Aeronautics and Space
Administration (NASA); the National Institute of Standards and Technology
(NIST) ; the National Institute of Building Sciences  (NIK) ; the National
Science Foundation (NSF); the Occupational Safety and Health Administration
(OSHA); the Tennessee Valley Authority (TVA); and the Veterans'
Administration (VA) are presented in Exhibit 9-6.  These agencies promulgate
mandatory standards and procedures, conduct research, and disseminate
information to the public and concerned professionals.

     Sunmary of Federal Agency Indoor Air Quality Control Programs

     In this section, we have described the indoor air quality control
programs of federal agencies in terms of mandatory standards and procedures,
voluntary guidelines, research activities, and public information and
technical assistance.  Exhibit 9-7 summarizes these federal activities
according to the directness of their application to indoor air quality

     Indoor Air Quality Control Activities

     Federal efforts to control indoor air quality can be classified as  (1)
air quality standards; (2) restrictions on potential indoor emissions of
pollutants through restricting the manufacture, sale, and/or use of
potential sources of indoor air pollution; and (3) assessment and mitigation

 o  Only OSHA has implemented comprehensive air quality standards for the
    indoor environment.

 o  EPA, CFSC,  BPA, DOD,  HUD,  DOT, GSA, and VA have developed efforts to
    control indoor air quality by restricting pollutant emissions from
    specific products.

 o  EPA, DOD,  GSA,  and NASA have implemented assessment and mitigation
    procedures to identify and correct indoor air problems.  These
    assessment and mitigation programs apply to small subsets of the
    building population of the U.S.; for example, EPA's asbestos removal
    program applies only to schools and GSA's proposed assessment
    procedure only to buildings under GSA control.

                                                  Exhibit 9-6
                         Other Federal Agencies'  Indoor Air Quality Control Activities
   Activity and Agency                                 Description
Mandatory Standards and Procedures
               DOO	    Restrictions on smoking  in  Air  Force  structures, assessment and
                                          mitigation plans for Air  Force  structures, chlordane assessments
               DOT	Restrictions on smoking  on  commercial  airline  flights, standards for
                                          pollutants and ventilation in airline  cabins
               HUD	Formaldehyde emission limits for  materials  in  manufactured housing
               GSA	Smoking restrictions in  GSA buildings, building assessment procedures
               NASA 	 Adoption of OSHA values  for NASA  facilities, Legionella control, and
                                          HVAC maintenance
               OSHA 	 Concentration and exposure  limits for the  industrial  workplace
               VA	Prohibition on purchase  or  use  of asbestos
     Exposure and Concentration Estimation and Measurement
               DOT	Evaluate effects of smoking on airliner  cabin  air  quality
               NASA 	 Test material offgassing
               NIST	IAQ concentration model
               NSF	Awards scholarships, fellowships,  grants,  loans, and  contracts  for
                                          basic research
               TVA	 Radon, N02 dynamics, energy conservation

     Health Effects
               TVA	 NOj effects on school children

     Risk and Hazard Assessment
               DOS	Indoor air hazards  in DOS buildings

     Diagnosis. Assessment, and Mitigation Protocols
               HUD	Housing site assessment
               GSA	Diagnostic technique validation
               NIST	Air movement test method

     Controls Assessment
               NASA   	 Pollutant gas removal by houseplants
               NIST	Test method for removal equipment in HVAC
               TVA	Assessments of radon mitigation methods, heat  exchangers

Information Dissemination

     Publications for the General Public
               HUD	Guide to new home  investigations
               TVA	 IAQ materials, speakers for public meetings

     Telephone Hotlines
               TVA	 Citizen Action Line  for citizen inquiries

     Product label Requirements
               FTC	Guidelines for advertising of products  with indoor air  impacts
               HUD	Certification of  wood products used  in  manufactured  housing

     Technical Support Manuals and Services
               NASA 	 Chapter on indoor  air concerns in  "Space  Biology  and Medicine"
               NIST 	 Radon measurement  standard and calibration
               NIBS 	 Building performance criteria and  technical standards  for
                                           incorporation  into building codes  or  other  regulations

     Workshops and Training Courses
               NIST	Modeling workshops

                                                 Exhibit 9-7
                           Smsary of Federal Indoor Air Quality Control Activities
Point of
Direct Control  of  Indoor
  Concentrations and/or
OSHA Air Standards	Limited  to  industrial  environments
BPA Radon Action Level.  ....  .Limited  to  residences  in  BPA's  weatherization
NASA Air Standards	Adopted  OSHA  standards
Control of Emissions
  by Restricting
  Activities or
  Product Composition
EPA Drinking Water
  MCLs for Radon and VOCs .

EPA Pesticide Restrictions.

CPSC Consumer Product Bans.

Smoking Restrictions
  Imposed by DOO,  DOT, and
.Indoor air exposures considered in
   determining drinking water levels
.Restricts use and sales of pesticides which
   may cause indoor air pollution
.Bans on use of some potential  indoor
   pollutants in consumer products
                                VA  Restrictions on
                                 Asbestos Use.  . .
.Restricts smoking in specified indoor

.Restricts use of asbestos in VA buildings
Control Through
  Assessment and
  Mitigation Procedures
Efforts to Increase
  Knowledge of Indoor
  Air Quality Problems
  and Controls
EPA Asbestos Rules.	Provides for the assessment and mitigation
                                   of asbestos hazards in schools
GSA Building Assessments	Investigates GSA-controlled buildings for
                                   indoor air problems
NIOSH Building Assessments.  .  .  .Responds to air-quality health complaints
DOO/USAF Chlordane
  Assessments	Investigates USAF facilities for chlordane
NASA HVAC System Maintenance.  .  .Assesses and corrects HVAC operation to
                                   optimize indoor air ojuality

Research efforts by EPA, CPSC,

Information Dissemination by EPA,

     Agencies have  implemented these indoor air quality
activities through  mandatory standards and voluntary guidelines.

      VA control indoor air concerns with mandatory
      standards and procedures.

   o  CPSC, EPA, and BPA have used voluntary guidelines to
      control indoor air concerns.

      — CPSC has assisted in the development of voluntary
         standards  for emissions from wood products and some
         combustion devices to control the quality of the
         indoor atmosphere.

      — EPA is developing a voluntary guideline approach to
         radon mitigation through its work on a model building
         code and its use of a radon action level for
         recommending mitigation.

      -- The BPA weatherization program's radon monitoring and
         mitigation activities are available to homeowners on a
         voluntary  basis.

     Federal Efforts to Increase Knowledge of Indoor Air Concerns

     Federal research of indoor air quality issues is directed
toward improving our ability to  (1) estimate and measure
concentrations and  exposures;  (2) relate indoor air quality to
health effects; (3) assess risk and hazard; (4) develop
diagnosis, assessment, and mitigation protocols; and (5) assess
control techniques.  Federal agencies have distributed their
efforts among these areas of research according to functional

   o  EPA has a lead role in most areas of research,

   o  DOE leads efforts to characterize and identify the
      hazards of radon,

   o  HHS efforts lead investigations of the health  effects of
      indoor air pollution.

     Federal agencies provide public information and technical
assistance to lower levels of government and the public through
(1)  publications for the general public,  (2) telephone hotlines,
(3)  labeling requirements, (4) technical manuals or  procedures,
and (5)  workshops and training courses.

   o  Publications  for public and specialized  technical
      consumption are the most commonly used communication

   o  Product labeling requirements have been implemented by
      agencies with the appropriate statutory authority.


     Much of the governmental effort to ensure clean indoor air
occurs at the State and local level.  Many State and local
governments address indoor air concerns through restrictions on
smoking in public spaces, ventilation requirements in building
codes, asbestos inspection and removal programs, pollutant
concentration and emission standards, problem building
evaluations, and research and public information dissemination
activities.  California has implemented the most comprehensive
indoor air quality program (Wesolowski, et al.,  1984).  This
section describes some notable State and local efforts to control
the quality of the indoor atmosphere through these types of

     Smoking Restrictions

     Forty-two states and at least 194 localities regulate
smoking in public places to some extent (TFYA, 1988).  The extent
of restrictions imposed by these regulations varies considerably,
but all aim to protect the right of occupants of public spaces to
a smoke-free indoor atmosphere.  Exhibit 9-8 illustrates the
range of public areas affected by some State and local smoking

   o  Most State smoking restrictions limit smoking in buses,
      health care facilities, schools, elevators, government
      buildings, gymnasia/arenas, restaurants, retail and
      grocery stores, and at public meetings (TFYA, 1987).

   o  Half of the State regulations control smoking in the
      public sector workplace (TFYA, 1988).

   o  Less than half of the State smoking limitations apply to
      hotels,  libraries, museums, public places, restrooms,
      and theaters (TFYA, 1987).

     Building Operation Requirements

     A number of State and local governments incorporate indoor
air quality considerations into building codes.  Exhibit 9-9
presents examples of this type of regulation.  These examples do
not attempt to provide a complete list of such regulations, but
merely illustrate the variety of the regulatory mechanisms  to
address indoor air concerns that may be found in contemporary
building codes.   Refer to Standards, Regulations,  and Other
Technical Criteria Related to Indoor Air Quality  (NIBS,  1986)  for
more detailed  information on these requirements.

                                                  Exhibit 9-8
                                      State and Local SBoking Restrictions
   State or Locality
Affected areas include public buildings,  public  meetings,  health  care  and day
care faciIities
Los Angeles
San Diego
Affected areas include public buildings,  places of  business,  offices,  eating
Specifies size and posting requirements for segregated smoking areas

Affected areas include elevators, health care institutions,  public schools,
retail food stores, and part of any restaurant with 25 or more seats,  and
during government meetings

Prohibits smoking in elevators, nurse rooms, restrooms,  theaters,  and public
business places
Employers are required to provide nonsmoking areas  for employees

Prohibits smoking in retail stores, retail service  establishments, food
markets, theaters, auditoriums, places of public assembly, meeting rooms,
restrooms, elevators, and museums

Regulates smoking only in retail food establishments
Sources: NIBS, 1986; Oatman, 1988.

                                                  Exhibit  9-9
                                State and Local  Building Operation  Rec^jirodents
   State or Locality               Regulations Relevant to Indoor Air Quality Control
California                    »  The tightest  of  new  residences  must  achieve  at  least  0.7 air changes per hour
                              •  ASHRAE  Standard  62 ventilation  requirements  adopted
                              •  Workplaces must  be monitored  to ensure  that  ASHRAE Standard 62-1981  ventilation
                                rates are met in building  operation

New York (State)              •  Energy  Conservation  Construction Code adopts ASHRAE  Standards 62-73  and 90-75

South Dakota                  «  Medical  Facilities Building Cede specifies ventilation system design and
                                operation requirements  to  supply acceptable  indoor air cfuality

New Jersey                    «  Public  Errployee  Occupational  Safety  and Health  Act requires ASHRAE Standard
                                62-1981  ventilation  rates  in  State occupied  buildings

Hassachusetts                 »  Ban on  the use of urea-forma Idehyds  foam insulation  in building construction

Los Angeles                   •  Adopted  1982  Edition of  the Uniform  Building Code,  incorporating minimum
                                ventilation limits for  places of asseittoly, garages,  and residences
Sources:  NIBS,  1986;  COSHS8,  1986;  Oomarcki,  1984;  WJOH,  no  date;  MSCIAP,  1987.

      A  number  of  States have developed procedures for evaluating
 buildings  in response  to health complaints related to indoor air
 quality.   Assessment procedures used in West Virginia and New
 Jersey  provide examples of State developed problem building
 evaluation procedures.  West Virginia has developed a set of
 general principles  to  guide the resolution of indoor air
 complaints:  complaint screening,  interview/investigation,
 testing, and data interpretation  (NIBS, 1986).  West Virginia
 measures carbon monoxide and carbon dioxide concentrations as
 indicators of  building air quality.  New Jersey emphasizes
 implementing control options rather than monitoring air quality
 in  its  standardized response to indoor air quality-related health
 complaints by  State employees  (Freund, 1987).

      Asbestos  Inspection and Removal

      Exhibit 9-10 summarizes state asbestos programs.  Under the
 Asbestos Hazard Emergency Response Act states have implemented
 programs for building  inspections, building management plans,
 accreditation  programs for asbestos professionals, abatement
 standards,  and enforcement standards.  Refer to the survey
 results by Neilander and Sacarto  (1988) for more detailed

      New Jersey asbestos abatement standards provide an example
 of  requirements which  go beyond federal standards; New Jersey's
 Uniform Construction Subcode on Asbestos Hazard Abatement
 requires that  only  personnel with  approved training may undertake
 removal actions and specifies  that major actions require
 "substantial protection and precaution" and must not exceed
 airborne asbestos limits during removal activities (NIBS, 1986).

      Radon Programs

      States have undertaken a  variety of activities to study and
mitigate radon, problems in buildings.  State efforts may be
classified  into four categories:   (1) information programs,
 (2)  formative  programs, (3) developing programs, and  (4)
operational programs (EPA, 1987)„  Exhibit 9-11 presents a
summary of  the status  of state radon programs.  Refer to EPA's
Summary of  State Radon Programs (EPA, 1987) for a more detailed
discussion  of  State radon programs.

      Pollutant Concentration and Emission Standards

      Few states have addressed indoor air pollution concerns by
promulgating limits on indoor  concentrations or emissions of
various contaminants.  Some states have adopted standards for
formaldehyde and. at least two  states have incorporated OSHA
standards  for  non-industry workplaces.  Exhibit 9-12  presents
examples of these standards.   Refer to Standards, Regulations,

                                                  Exhibit 9-10
                                  Sumary of State Asbestos Control  Progra
 Building  Inspections

    Schools                  • Eleven states require inspections by statute
                            • Three states conduct inspections as a matter of  policy

    State-Owned Buildings    » Eleven states require inspections by statute
                            • Nine states conduct inspections as a matter of policy

    Other  Buildings          • Four states require inspections of other types (e.g., municipal) of buildings

 Building  Management Plans

    Schools                  • Eight states require management plans by statute or regulation

    State-Owned Buildings    • Nine states require management plans by statute or regulation
                            • Eight states develop and implement management plans as a matter of policy

    Other  Buildings          • Four states require management plans in other buildings


     •    39 States have some type of accreditation program

     •    Ten states have statutes and are currently promulgating regulations

     •    Four states license contractors with demonstrated completion of an EPA-
          approved asbestos training course

 Abatement Standards

          38 States have adopted NESHAP-type regulations and have enforcement authority from  EPA

          23 States have adopted OSHA-type standards relating to asbestos

 Enforcement Standards

          Host states can conduct on-site inspections and levy civil fines  for violations

Source:  Neilander and Sacarto,  1988.

                                                 Exhibit 9-11
                                        Summery of State Radon Progra
Program Type        Definition
                    No active program,
                         Arkansas,  Hawaii,  Louisiana,  Mississippi,  Nevada,  South Dakota,
Preliminary surveys      Alaska, Arizona, California,  Delaware,  Georgia,  Idaho,  Iowa,
                         Massachusetts, Minnesota,  Missouri,  Montana,  Nebraska,  New
                         Hampshire, New Mexico, North  Carolina,  North  Dakota,  Ohio,
                         Oklahoma, Oregon, South Carolina,  Utah, Vermont,  Washington,  West
Extensive surveys
Alabama, Colorado,  Connecticut,  Illinois,  Indiana,  Kansas,
Kentucky, Maryland, Michigan,  Rhode Island,  Tennessee,  Virginia,
Wisconsin, Wyoming
Comprehensive surveys    Florida, Maine, New Jersey, New York, Pennsylvania
demonstrating problems
Source:   EPA, 1987.

                                                 Exhibit 9-12
                             State Pollutant Concentration and Emission Standards
   State                           Standard
Minnesota                     •  Formaldehyde emission  limits  for all building materials  in  all  types  of
                              •  Maximum ambient  concentrations  of combustion products  in arenas where
                                combustion devices  are used

Wisconsin                     •  Formaldehyde emission  limits  for mobile homes

Wyoming                       •  OSHA threshold concentrations incorporated  into  standards applicable  to
                                workplaces,  warehouses,  commercial buildings, offices, and  hospitals

New York                      •  OSHA standards and  regulations  adopted for  places  of State  employment
Sources:   NIBS,  1986;  Oatman,  1988;  WDHSS,  no  date.

 and  Other  Technical Criteria Related to Indoor Air Quality
 (NIBS,  1986)  for more detailed information about these standards.

 Information  Dissemination and Research Programs

     State and  local public information programs communicate
 indoor  air quality concerns and control options to the public and
 other governments within their jurisdiction by way of
 informational brochures, telephone response to inquiries, and
 training programs.  States are also active in indoor air research
 to a limited extent.  Examples of these types of State and local
 activity are presented  in Exhibit 9-13.


     A  diverse  group of private organizations actively
 participates in efforts to understand and control indoor air
 pollution.   Standard setting organizations, trade associations,
 public  interest groups, and private companies offering services
 or products  related to  indoor air quality control all contribute
 their expertise to control the quality of the indoor
 atmosphere.   The following discussion is not a complete
 accounting of all private groups active in indoor air quality
 control, but illustrates the efforts of groups most actively
 involved in  indoor air  quality issues and the range of
 contributions available from the private sector.  Exhibit 9-14
 presents summary information about the indoor air quality control
 activities of standard  setting organizations, Exhibit 9-15
 illustrates  indoor air-related activities of some professional
 trade associations, and Exhibit 9-16 presents indoor air-related
 activities of public interest organizations.  EPA is currently
 investigating the capabilities of the private sector to provide
 diagnostic and  mitigation services.


     Foreign and international efforts to study and address
 indoor  air concerns parallel activities undertaken in this
 country.   The governments of Canada and several Western  European
 countries, and  the World Health Organization European Regional
 Office  are the  leading  contributors to understanding and
 controlling  indoor air  quality concerns outside the United
 States.  In  this section we briefly present some o  their
 important  indoor air quality control efforts.

     World Health Organization. Regional Office for Europe

     The World  Health Organization  (WHO) has, during the past ten
years,   taken the lead in indoor air quality  issues  in Europe.
WHO has implemented research and communication programs  related
to indoor  air quality and developed guidelines  for  pollutant
concentrations  in the indoor and outdoor atmosphere.

                                                 Exhibit 9-13
                        State and Local Information Dissemination and Research Programs
   State or Locality                    Program Description
California                    • "Consumer Cleanup Kit"  to help reduce  residential  exposures
                              • Training program for local  governments
                              • Permanent research unit to integrate  indoor  air  quality  and  human monitoring
                                studies -- actively investigates  a  variety of  indoor  air quality concerns

West Virginia                 • Formaldehyde hazards pamphlet

New York                      • Formaldehyde hazards pamphlet

Pennsylvania                  • "How-to" publication of general techniques for reducing  radon concentrations

Maryland                      • Booklet explaining indoor air  pollution  and  mitigation for use by local  school

Massachusetts                 • Special commission to study indoor  air issues  and  control options

St. Louis                     • Pamphlet on hazards of  dusts and  fumes from  lead-based paints

Sources:  NIBS,  1986;  MSOE,  1987;  Uesolowski  et  al..  1984;  MSCIA,  1987.

                                                  Exhibit 9-H
                              Standard Setting Organization Indoor Air Activities
American Conference of
  Governmental  Industrial
  Hygienists (ACGIH)

American Society of Heating,
  Refrigeration, and Air-
  Condi tioning  Engineers
American Society of
  Testing and Materials
Building Officials and
  Code Administrators,  Inc.

Council of American
  BuiIding Officials

National Environmental
  Balancing Bureau
Southern Building Code
  Congress International,
  Inc. (S8CCI)

Underwriters' Laboratory
• Develops indoor air quality  guidelines  for  industrial exposures
• Convenes a committee on bioaerosols
• Publishes a manual  on air  sampling  instrumentation

• Develops "Ventilation for  Acceptable  Indoor Air Quality," Standard 62-1981
• Develops a thermal  comfort standard
• Develops an energy conservation  standard
• Publishes technical information
• Provides continuing education for  its membership
• Supports research

• Convenes a technical committee on  sampling  and analysis of atmospheres
• Develops test methods for  atmospheric analysis
• Publishes technical books
• Sponsored 1987 conference, "Design and  Protocol for Monitoring  IAQ"

• Develops National Building and Mechanical Code -- specifies ventilation
  design and operation requirements  which affect indoor air quality
  Develops One and Two Family Dwelling Code  --  specifies  ventilation
     requirements which affect indoor air  quality
  Develops procedural  standards for testing,  adjusting,  and  balancing
     environmental systems
   Produces a directory of firms certified to perform environmental  testing,
   adjusting, and balancing

  Develops building, fire, and mechanical  codes --  specifying procedures
  which affect indoor air quality
• Conducts product and equipment testing for public safety --  including
  ranges, ovens, ESP, manufactured fireplaces,  HEPA filter units
Sources:  NIBS, 1986; Morev et aI..  1986; ASHRAE,  no date; ASTM,  1988; NEBB, no date; Przybylski,  1988.

                                                 EidvJbiJ 9-15
                            Professional snd Trstfe Association
                                                                     Air Activities
                                        Actiwi ties
Air Conditioning
  Contractors of America

Air-Conditioning and
  Refrigeration Institute

Air Pollution Control
  Association (APCA)

American Gas Association

American Industrial
  Hygienists Association

American Insurance Assc.

American Plywood Association

Architects Institute of
  America (AiA)

Electric Power Research
  Institute (EPRI)

Gas Research Institute

Hardwood Plywood
  Manufacturers Association

Home Ventilation Institute

National Association of
  Home BuiIders (NAHB)
National Plywood Association

Public Health Foundation

Service Employees
  International Union

Sheet Metal and Air
  Conditioning National
  Association (SMACNA)

Tobacco Institute
  Publishes  technical  manuals  on  air conditioning design,  installation,  and
  Rates performance of  air-to-air heat exchangers,  filter equipment  assemblies
  and refrigeration systems
  Convenes a standing committee  on  indoor  air quality

  Convenes indoor  air sessions at APCA annual meetings
  Convenes specialty conferences on  indoor air-related  issues

  Develops standards addressing  gas  leaks  and combustion product  emissions
  Convenes  an Indoor  Environmental Quality  committee
  Publishes industrial  hygiene  guidance documents
  Developing guidance on indoor air quality

  Monitors  environmental issues for  liability  iirpli cat ions  to  m«T±«r insurers

  Recommends practices  for  handling preservative,  treated wood products,
  using chlorpyrifos, and applying subfloor vapor  barriers

  Sponsored and published proceedings  of  a  national  symposium  on indoor
  air pollution and the architect's  response

  Sponsors  research of  indoor air quality as it  relates to  energy consumption
  and HVAC  systems

  Sponsors  research of  indoor air quality concerns of  the natural gas industry
  Licenses  manufacturers of burner  inserts  for nitrogen oxide  emission reduction

  Developed a voluntary standard for  formaldehyde  emissions from wood products
° Active in ASHRAE Project Committee on Standard 62-1981
' Develops standards for heat  recovery ventilators

° Supports research of building components and operating parameters which
  affect indoor air quality
° Conducts an annual survey of construction materials
° Provides technical assistance to home builders

° Developed a voluntary standard for formaldehyde emissions from particleboard

° Developing a directory of state indoor air contacts and surveying state  indoor
  air quality programs

= Surveys and investigates indoor air problems of public service fctorkers,
  educates members, and promotes legislative and regulatory solutions

° Provides membership i-iith education through manuals and a home study  course
                                Conducts programs to preserve the rights of smokers and manber  companies
                                against unwarranted government restraint
Source:    NIBS,  19S6:  ACCA,  1987;  APCA,  19S8; GECC-1ET, 1987; Tinkleman,
          Barron,  1985;  Bevirt,  1948; personal conmuni cat ions.
                                             ; GRI,  1986  and  1985;  HPMA,  1987;

                                                   Exhibit 9-16
                               Piriblic interest Organization Indoor Air Activities
American Lung Association

Americans for Nonsmokers'
  Rights (ANR)

American Public Health
Association (APHA)

Consumer Federation of
  America (CFA)
Consumers Union (CU)
• Issued a position paper  on  indoor  air pollution
v Distributes information  sheets  on  indoor air pollution hazards

» Develops and distributes model  clean  indoor air  legislation
« Conducting study on validity and prevalence of multiple chemical

• Testifies before Congress about  indoor  air concerns
• Publishes Quarterly newsletter.  Indoor  Air News"
• Convened EPA-cosponsored IAQ conferences, 1986-1988

• Publishes product testing results in  Consumer Reports.  Recently tested air
  cleaners, unvented kerosene heaters,  air-to-air heat  exchangers, and  radon
National Council for
  Clean Indoor Air
« Convened EPA-cosponsored policy forum on indoor  air  quality  '"ssues
» Testifies before Congress about indoor air  concerns
National Institute for
  Building Sciences (NIBS)
  Improves building regulatory environment  and facilitates  the
  introduction of building technology
  Prepared report on building standards related to indoor air
  Provides guidance/information,  conducts workshops/conferences on building
  IAQ issues
Tobacco-Free Young
  America Project (TFYA)
  Acquires and disseminates information on state and Local  smoking
Sources:  NIBS, 1986; ALA, 1982; ANR, no date; Weiss,  1988; GEOMET, 1987; Helm, 1988; TFYA, 1987.

     In 1978, WHO formed a working group,  with  members  from ten
European countries,  on assessing and monitoring exposure to
indoor air pollutants.  This group has co-sponsored several
international conferences on indoor air quality and climate.
These conferences address such topics as identifying indoor
sources, monitoring concentrations of pollutants in indoor
microenvironments,  and assessing indoor air pollution health
effects and control strategies.

     WHO has issued air quality guidelines for  12 organic and
16 inorganic air pollutants (WHO,  1987).  WHO carefully
considered the relative importance of indoor air quality in
developing these guidelines, which do not differentiate between
indoor and outdoor exposure.  (These guidelines are discussed
more completely in Chapter 7.)   WHO presents these guidelines as
tools for use by decision makers in determining appropriate
courses of action for the control of air pollutants; the
guidelines should not be considered standards,  although in the
proper context they can assist in the development of standards or
other control strategies.  A number of European countries are
currently considering the WHO guidelines as they develop indoor
air quality control programs (Stolwijk,  1988).

     An important ongoing WHO research program  is the Human
Exposure Assessment Location (HEAL) project.  Similar to EPA's
TEAM studies, HEAL involves field investigations to measure
comparative pollutant exposures and body burdens in different


     Under the auspices of the Ministry of Health and Welfare,
Canada formed a Federal-Provincial working group on indoor air
quality in 1981 that is modeled after the WHO working group.  The
Canadian group has issued guidelines on maximum acceptable indoor
air concentrations for nine substances and recommendations for
controlling exposure to nine other substances.   The scope of the
guidelines is restricted to "domestic premises" and they are
designed to protect the general public, assuming exposure  for  24
hours per day.  The use of these guidelines as regulatory  limits
is left to the provinces, some of which are attempting  to
implement them as mandatory standards at the present time
(Walkinshaw, 1988).

     In other indoor air quality control efforts, Canada controls
formaldehyde exposures from urea-formaldehyde  foam  insulation
(UFFI)  through a product ban and specifies ventilation
requirements in a national building code.  Canada banned the  use
of UFFI in 1980 and implemented an assistance  program  for  its
removal from residences  (Shurb, 1986).  Canada's national
building code (1985 edition) requires a ventilation rate  of  at
least 0.5 air changes per hour with either manual  or automatic
controls (Kerwin, 1986).

     United Kingdom

     The United Kingdom  (U.K.) has addressed a number of indoor
air quality concerns through direct regulation and voluntary
standards.  Programs are in place to control indoor exposures to
asbestos, formaldehyde, and combustion products (Llewellyn and
Warren, 1986).

     The U.K. asbestos control program consists of two major
initiatives.  The first part of the program involves
disseminating information on the hazards of asbestos through two
publications and a monitoring and removal program to control
asbestos emissions at the source.  The second major initiative
bans asbestos spraying and all uses of some types of asbestos.

     Formaldehyde control with respect to UFFI in the U.K. relies
on self-enforcement by industry of foam insulation formulation
and installation codes.  The codes specify proper formulation and
installation procedures; manufacturers sell supplies only to
members of trade associations that have adopted these standards.

     Combustion products, especially CO, have received attention
in the building code of the U.K.  The national building
regulations attempt to control combustion pollutants through
ventilation requirements to ensure adequate supply air.

     Scandinavian Countries

     Scandinavian countries conduct extensive research on
building-related indoor air quality problems and several
countries have specific ventilation requirements to control
indoor air quality.  A Nordic Committee on Building Codes has
adopted a minimum whole-house ventilation rate of 0.5 air changes
per hour.  Similar requirements have been adopted in the national
building codes of Denmark, Finland, Norway, and Sweden.  Norway
and Finland have adopted the 0.5 air changes per hour minimum.
Norway supplements this requirement with prescribed duct sizes
for natural ventilation or air flow rates required for the
mechanical ventilation of specific indoor environments.
Finland's national building code specifies ventilation rates  for
various indoor locations and defines goal concentrations of  C02
and other pollutants in the indoor atmosphere.  Sweden's
mandatory whole house ventilation rate  is 0.35 liters per second
per square meter of dwelling area.  Danish building  regulations
require ventilation of at least 0.4 air changes per  hour  for
general living areas and 0.7 air changes per hour  for  kitchens
and bathrooms.  Other chapters of this  code specify  rates  for
mechanical ventilation and restrictions on humidifying  and
cooling inlet air.

     Formaldehyde contamination  is also a concern  in Scandinavian
countries (Stolwijk, 1988); accordingly, Danish building
regulations limit the use of  formaldehyde-containing products in
building construction.


     Some programs related to the control of indoor air quality
are available in the United States and in other countries.
Significant potential exists for cooperative coordinated indoor
air control programs of Federal, State,  and local governments,
and in the private sector.  Currently, coordination is achieved
through professional associations, voluntary standards
organizations,  and the Federal Interagency Committee on Indoor
Air Quality.  Current programs at all levels of government and
the private sector are generally fragmented and underfunded.
     Programs of various agencies of the U.S.  government relate
to individual agency mandates which were discussed in Chapter 8.
Some state and local governments conduct programs, most of which
involve restrictions on smoking, or specific provisions in
building codes.   Some states have taken specific actions on
individual contaminants. Many foreign governments conduct indoor
air quality activities.  International coordination is fostered
through such entities as the World Health Organization.


 Air Conditioning Contractors  of America  (ACCA).  1987.  1987 ACCA
      Catalog.   Washington,  D.C.

 Air Pollution  Control  Association  (APCA).   1988.  Personal
      Communication  with  APCA  Information Center.

 American  Lung  Association  (ALA).   1982.  Position on  Indoor Air
      Pollution.   New York,  NY.

 Americans for  Nonsmokers' Rights  (ANR).  No date.  Model Clean
      Indoor Air Act.   Berkeley, CA.

 American  Society of Heating,  Refrigerating, and Air-
      Conditioning Engineers (ASHRAE).  No date.  Improving the
      Quality of Life.  ASHRAE.  Atlanta, GA.

 American  Society of Testing and Materials  (ASTM).  1988.  ASTM
      Technical Books Catalog.  Philadelphia.   ASTM Information
      Center, Personal  Communication.

 Barron  L.  1985.  Home Ventilation Institute.  Personal
      Communication.   (Letter  to David  Mudarri, EPA, dated
      November  6,  1985.)

 Bernstein R.S.,  Falk H., Turner D.R.,  Melius J.M.  1984.
      Nonoccupational Exposures to  Indoor Air Pollutants:  A
      Survey of State Programs and  Practices.   American Journal of
      Public Health.  74:1020-1023.

 Bevirt  D.  1988.  Sheet  Metal and  Air  Conditioning Contractors
      National  Association  (SMACNA).  Personal  Communication.

 California Occupational  Safety and Health Standards Board
      (COSHSB).   1986.  Standards Presentation.  New Section 5142.
      Control by Ventilation.

 Domarcki  AJ.   1984.  Emerging Energy Conservation Policy and
      Regulatory Issues in New York State.   Indoor Air '84.

 Environmental  Protection Agency  (EPA).   1987.  Summary  of State
      Radon Programs.   Office  of Radiation  Programs.   EPA 520/1-
      87-17-1.   Washington,  D.C.

 Freund A.  1987.  Development of a New Jersey  Indoor  Air Quality
      Standard.   Proceedings of the ASHRAE  Conference, IAQ  87:
      Practical  Control of Indoor Air Problems. pp.  21-32.
      Arlington,  VA.

Gas Research Institute (GRI).  1986.   Gas  Research  Institute
      Digest.   Fall  1986.  p.23 and 32-33.

Gas Research Institute (GRI).  1985.  Gas Research Institute
     Digest.  Fall 1985.   p.20.

General Services Administration (GSA).   1987.  Draft Policy
     Statement. October 30, 1987.

GEOMET.  1987.  A Brief Reconnaissance of Private Sector
     Involvement in Indoor Air Quality.  Germantown, MD.

Hardwood Plywood Manufacturers Association (HPMA).  1987.
     Voluntary Standard.   HPMA FE-86.   Voluntary Standard for
     Formaldehyde Emissions from Hardwood Wall Paneling, Wood
     Composition Board Wall Paneling and Industrial Panels having
     Face Veneers.  February 19, 1987.

Hayward S.  1988.  Air and Industrial Hygiene Lab. California
     Department of Health.  Personal Communication.

Helm A.  1988.  National Council for Clean Indoor Air.  Personal

Kerwin L.  1986.  Opening Address.  Proceedings of an APCA
     Specialty Conference, Indoor Air Quality in Cold Climates:
     Hazards and Abatement Measures.  Walkinshaw D.S. (Ed).

Llewellyn J.W., Warren P.R.  1986.  Regulatory Aspects of Indoor
     Air Quality - A U.K. View.  Proceedings of an APCA Specialty
     Conference, Indoor Air Quality in Cold Climates:  Hazards
     and Abatement Measures.  pp.  478-487.

Maryland State Department of Education (MSDE).  1987.  Indoor Air
     Quality,  Maryland Public Schools.

Massachusetts Special Commission on Indoor Air Pollution
     (MSCIAP).  1987.  Minutes of September 30, 1987 meeting.

Miller S.  1988.  New Jersey Department of Health.  Personal

Morey P., Otten J.,  Burge H., Chatigny M., Feeley J., LaForce
     F.M., Peterson K.  1986.  ACGIH Committee Activities and
     Reports.   Bioaerosols:  Airborne Viable Microorganisms  in
     Office Environments:  Sampling Protocol and Analytical
     Procedures.  Applied Industrial Health.  April 1986.

National Environmental Balancing Bureau  (NEBB).  No date.
     Publications List.  Vienna, VA.

National Institute of Building Sciences (NIBS).  1986.
     Standards, Regulations, and Other Technical Criteria Related
     to Indoor Air Quality.  National Institute of Building
     Sciences.  Washington, D.C.

Neilander DK, Sacarto DM.  1988.  State Asbestos Programs Related
     to the Asbestos Hazard and Exposure Reduction Act:  A Survey
     of State Laws and Regulations.  National Conference of State
     Legislatures.  Denver, CO.

New Jersey Department of Health (NJDH).  no date.  Proposed
     Standard.  Ventilation and Air Quality for Public Buildings
     and Places of Employment for Public Employees.

Oatman L.  1988.  Minnesota Department of Health.  Health Risk
     Assessment Branch.  Personal Communication.

Przybylski F.J.   1988.  Underwriter's Laboratory-  Personal

Scanlon T.  1987.  CPSC's Role in Indoor Air Issues.  Indoor Air
     Pollution Law Report.  October 1987.

Shurb RW.  1986.  The Canadian UFFI Assistance Program.  pp. 496-
     503.  Proceedings of an APCA Specialty Conference, Indoor
     Air Quality  in Cold Climates:  Hazards and Abatement
     Measures.  Walkinshaw D.S. (Ed).  APCA.

Stolwijk J.  1988.  Chairman, Department of Epidemiology and
     Public Health, Yale University, School of Medicine.
     Personal Communication.

Tinkleman M.  1988.  Presentation at CIAQ.  April  26,  1988.

Tobacco Free Young America Project  (TFYA).  1987.  State
     Legislated Action on Clean Indoor Air, Cigarette  Excise
     Taxes, and Sales of Cigarettes to Minors.  Revised October
     1987.  Tobacco Free Young America Project.  Washington, D.C.

Tobacco Free Young America Project  (TFYA).  1988.  Update  to
     State Legislated Action on Clean  Indoor Air,  Cigarette
     Excise Taxes, and Sales of Cigarettes  to  Minors.  January
     1988.  Tobacco Free Young America Project.  Washington, D.C.

Walkinshaw D.  1988.  Office Coordinator.   Indoor  Air  Program.
     Ministry of  Health and Welfare Canada.  Personal

Weiss S.  1988.   Consumer  Federation  of  America.   Personal

Wesolowski J.J., Sexton K.,  Liu K.,  Twiss S.   1984.  The
     California Indoor Air Quality Program:  an Integrated
     Approach.  Indoor Air '84.  1:219-275.

Wisconsin Department of Health and Social Services (WDHSS).   No
     date.  Formaldehyde in the Home.  Division of Health,

Woods J.E.  1988.   Senior Engineer.   Honeywell, Inc.   Personal

World Health Organization (WHO).  1987.  Air Quality Guidelines
     for Europe.  WHO Regional Office for Europe.  WHO Regional
     Publications.   European Series,  No. 23.


     In the EPA Indoor Air Quality Implementation Plan, submitted
to Congress in 1987, the Environmental Protection Agency set
two objectives for its indoor air program.  These general
statements could serve well as the goals for all Federal
activities related to indoor air quality:

   o  to adequately characterize and understand the risks to
      human health which pollutants pose in indoor environments;

   o  to reduce those risks by reducing exposure to indoor
      pollutants through efficient utilization of available

This chapter discusses the major policy choices available to
those who must determine what the appropriate Federal activities
are to implementing these objectives.

     Because indoor air pollution is the product of many diverse
sources and is found in many types of buildings,including
private residences, it presents policy makers with some
particularly thorny policy issues.  As described elsewhere in
this report, the sources are as diverse as naturally occurring
radon; human activities such as smoking and cleaning, pest
control, and hobby activities; building materials such as pressed
wood products and asbestos-containing materials; and combustion
devices such as unvented space heaters and stoves, furnaces, and
fireplaces.  In addition to chemical pollutants, there are also
biological pollutants.  Indoor air quality problems can arise in
homes, office and other public buildings, and schools.

     There are many abatement techniques that may prove
effective, depending on the particular indoor air pollutants and
building types.  In some cases, improved ventilation may be
effective while in other cases, reduction of pollutants may best
be achieved by the banning or redesign of products brought into
buildings and materials used in constructing buildings.  In yet
other cases, changes in the behavior of building occupants may
bring about the most effective reduction in pollutant

     There are a variety of control and prevention actions that
the Federal government could take to address the risks from
indoor air pollution.  Many of them can be pursued in  either a
regulatory or a nonregulatory manner.  As policies are
formulated, decision-makers can choose any of the options singly
or in combination.  This fact is particularly important  in  light
of the fact that some options are "pollutant-by-pollutant"
strategies and others are "multi-pollutant" strategies.

     To select and implement  any  of  the  options  effectively  will
require a Federal indoor air  research  program.   Volume  III of
this Report to Congress is  devoted to  a  discussion  of the indoor
air research needs that have  been identified  by  EPA and other
Federal agencies.

   The options discussed below are:

   o  setting standards for

         individual indoor  air pollutants  or  mixtures of

         design,  operation, and maintenance of ventilation
         systems; and

         products brought into buildings;

   o  providing guidance on identifying,  correcting, and
      preventing indoor air quality  problems  in  new and existing
      buildings;  and

   o  establishing public information  and  technical assistance


Establishing Pollutant Standards

     Establishing limits on levels of  individual pollutants that
will protect public health  or welfare  is often  a basic  component
of environmental programs.  Whether  or not to establish such
limits for the large number of pollutants  found  in indoor air is
a basic policy decision.  Indoor  air quality  standards  could be
established as either enforceable limits,  as  part of a  regulatory
program, or as recommended  limits,  as  part of a  nonregulatory

     There are a number of  reasons why it is  advisable to
examine what role, if any,  indoor air quality standards should
play in a federal indoor air  quality program.  The considerations
listed below may argue for not setting such standards at all or
for setting recommended limits (or "guidance")  instead of
enforceable standards.

     Number of pollutants of  concern;   There  are hundreds of
indoor air pollutants. However, little information  is available
about how many are potentially harmful,  or about the levels  found
indoors and their associated  health effects.   Putting an emphasis
on indoor air standards will  necessarily require the expenditure


of significant resources and would foster a pollutant-by-
pollutant approach to improving indoor air quality.

     Availability of multi-pollutant strategies;    Since indoor
air quality problems by definition emerge in enclosed spaces,  it
will be possible to effectively address some problems by changing
the ventilation rate or by air cleaning.  Ventilation and air-
cleaning, which are discussed in more detail in one of the
following policy options, are multi-pollutant strategies.

     Applicability of standards to residences:  Traditionally
there have been sharp distinctions between setting standards or
guidance for private homes as opposed to public spaces such as
offices and public buildings.  The EPA radon program established
guidance — in the form of an action level — not an enforceable
standard for reducing the risks of radon, when radon
concentrations in homes were found to be a significant health

     Health or combination of health and technological basis:
The principal argument for setting a purely health based standard
is that it gives the public a clear message about the level that
are thought, given current scientific evidence, to protect
health.  The principal argument for setting a standard that is
based on some combination of health and technical feasibility is
that such a standard will motivate more action because it is
demonstrated to be an attainable goal.  Attaining standards that
are strictly health based, on the other hand, may require
measures that are technically infeasible or economically
prohibitive.  For example, if a health-based standard for a
carcinogen were to be completely protective of all risk, it would
have to be zero because carcinogens at any level are expected to
pose some risk to public health.

     Availability of monitoring equipment and mitigation
techniques:  Standards for individual pollutants are useful only
if effective monitoring equipment and feasible mitigation
techniques have been identified.  If policy makers determine that
setting pollutant standards or guidance  is an appropriate role
for the Federal government, they will need to build  a
supplementary program devoted to developing reasonably-priced,
easy-to-use, dependable monitoring equipment  (or evaluating
available monitoring equipment) and to  assessing the
effectiveness of prevention and control  measures.

     Health Advisories

     Issuing health advisories on specific pollutants  or
mixtures of pollutants can be a supplement or alternative  to
setting  standards. They would describe  a range  of  potential
effects  at a range of concentrations.  If standards  have been
set, the advisories would  include them.  To be most  useful,  the


contents of such advisories should include information on
mitigation measures as well as potential health effects and
should be written in language appropriate to the targeted

Setting Standards for the Design.  Operation, and Maintenance of
Ventilation Systems

     Ventilation standards have historically been developed with
an eye to maximizing thermal comfort and, since the energy
crisis of the 1970's, to conserving energy-   Altering ventilation
standards offers a promising "multi-pollutant" option to
preventing the simultaneous build-up of many pollutants. Air
cleaning,  if found to be an effective mitigation technique, may
be used in combination with ventilation strategies to reduce
pollutant levels.  Work done to date suggests that increasing
ventilation rates need not come at the expense of undoing efforts
to conserve energy,  but it is likely that policy-makers will want
to do further analysis of the impact of increasing ventilation
rates on energy consumption.

     The American Society for Heating, Refrigerating, and Air-
Conditioning Engineers, a private  standard-setting organization,
has taken the lead in establishing ventilation standards on a
"consensus" basis.  Private sector groups affected by the
decision have worked with others including research
professionals and government officials in writing these
standards.  Model building code organizations and State and local
government code agencies rely heavily on the ASHRAE standards as
they set model codes and enforceable state and local codes,

     Individuals from the Federal  government with expertise in
ventilation and indoor air quality have served as members of the
committees developing these standards.  A possible direction for
the Federal government is to play  a more active role in the
development of future ventilation  standards. Two types of
ventilation standards are possible:  Those for the design of
ventilation systems, and those for system maintenance and

     Standards for the Design of Ventilation Systems

     Drawing on the expertise of people in the public and
private sector, the Federal government could set a national
indoor air quality standard or guidance policy that prescribed
particular ventilation design features, or it could work more
actively with ASHRAE, the model code organizations, and others  as
the ventilation standard is revised in the future.  Any effort  to
write such a standard would have to include, at a minimum, all
the groups that participate in the development of the ASHRAE


     Standards  for the Operation and Maintenance of Ventilation

     Virtually  all ventilation standards govern only the design
of new systems  as they are installed in new buildings.
Substantial indoor air quality problems arise from the improper
maintenance or  operation of these systems once the building is
occupied and in use.  One state, California, has recently
developed a set of enforceable requirements for the operation and
management of ventilation systems in workplaces under the State's
jurisdiction; it is too soon, however, to judge the potential
effectiveness of these requirements.  In addition to, or as an
alternative to, setting standards for the design of ventilation
systems, the Federal government could set a national standard or
guidance policy for the operation and maintenance of ventilation
systems or it could work actively with ASHRAE, the model code
organizations,  and others for the development of such standards.

      Public participation and public debate would be an
important element in the development of any policy guidance even
if the process  did not fall under the Administrative Procedures
Act requirements for public notice and comment.

     Actions taken by ventilation operators and building
managers often  have important ramifications for indoor air
quality, yet individuals within these groups are given little
opportunity for increasing their knowledge about the
interconnections between ventilation and indoor air pollution.
The Federal government could develop training materials and
technical assistance projects for people managing buildings and
operating ventilation systems in conjunction with trade and union
organizations.  (This is one example of the type of activities
that could be part of a public information and technical
assistance program described in Section 10.3 below.)

Setting Product Standards

     Controlling indoor air pollution by setting standards that
affect the sale, manufacture, or use of products that are sources
of indoor air pollution is another potentially important
mitigation option.  Existing statutes such as the Consumer
Product Safety  Act, the Toxic Substances Control Act, and the
Federal Insecticide, Fungicide, and Rodenticide Act authorize
Federal agencies to set standards.  See Chapter 8 for a
discussion of these laws.

     Federal agencies have already set some product standards for
the purpose of  enhancing indoor air quality.  For example, EPA
has banned the  use of asbestos in certain building materials  and
is developing additional rules concerning asbestos-containing
products and CPSC has banned the use of asbestos in spackling


compounds and artificial fireplace logs,  and requires hazard and
use labelling of asbestos containing products.  CPSC has also
banned the use of vinyl chloride in consumer aerosol products.
EPA has also prohibited indoor uses of several  pesticides:
manufacturers are prohibited from using lindane in indoor
fumigating devices; homebuilders are prohibited from using logs
treated with pentachlorophenol in log home construction; and all
other indoor applications of pentachlorophenol  and creosote are
also forbidden.

     Given the thousands of products that are used inside
buildings, however, it is clear that only a small proportion have
been regulated under existing laws.  One choice open to policy-
makers is, therefore,  to place additional emphasis on setting
either mandatory or voluntary standards on such products.

     Product Advisories

     On some occasions, Federal agencies have issued product
advisories or alerts to the public.  For example, EPA has entered
into an agreement with manufacturers of wood preservatives for
the development of a consumer awareness program.  CPSC has
recently issued a consumer alert on the use and maintenance of
room humidifiers. CPSC also recently issued regulations requiring
manufacturers of many consumer products containing methylene
chloride to put hazard warnings on the product containers.   There
have been few efforts to evaluate the effectiveness of such
consumer alerts, but CPSC is going to assess the impact of the
methylene chloride alert over the next three years.  Increasing
the emphasis on such consumer alerts is an option for a Federal
indoor air program that seeks to address indoor air quality
problems through attention to specific products.


     Providing Guidance for Existing Buildings

     Buildings are identified as potentially having an indoor air
quality problem when a large number of occupants complain of
health problems or when occupants contract a identifiable disease
that is transmitted via the indoor air.  Since the number of such
buildings is on the increase, the problem of indoor air quality
complaints in public buildings  (sometimes referred to as the
"sick building" phenomenon) is growing in importance.  Why these
complaints arise in some buildings and not in others is still not
well understood; however, the demand for public and private
sector services to help people correct these types of problems  is
large and growing.

     Addressing indoor air quality problems  in buildings with


large numbers of occupant health complaints is not necessarily a
problem of setting and attaining some uniform standards for
specific pollutants, although such standards may be appropriate
where the cause of the problem can be traced to a specific source
or pollutant. It is likely there will never be enough standards
to prevent these problems because there are hundreds of
pollutants at very low concentrations.  Indoor air quality
problems may arise from the additive or synergistic effects of
these pollutants, as well as from single pollutants.  Instead,
the immediate need appears to be to decide on appropriate
federal actions that will give indoor air quality investigators
and building managers the tools to identify and correct these

     Most of the understanding about how to conduct indoor air
quality building investigations currently resides in the private
sector.  Within the Federal government, the National Institute
for Occupational Safety and Health has the most experience in
this field, and other Federal agencies, including EPA and DOE
have some experience.   Various standard-setting agencies,
including the American Society of Testing and Materials and the
American Council of Governmental and Industrial Hygienists are
considering how they might contribute to the growing body of
resource materials for building investigations.  There is,
however, an opportunity for the Federal government, in
conjunction with other public and private sector groups, to
develop some commonly-accepted building investigations procedures
targeted at both professional investigators and at building

     Training and Competency Testing

     The next step for Federal, State or local governments
could be the development of training programs for building
investigators and building managers.  Officials in State and
local governments might also find such training courses useful.
A possible long-range outgrowth of these courses is some type of
competency testing for professionals offering building
investigation services.  Such training and testing programs could
decrease the potential for fraud when people employ companies to
conduct indoor air quality investigations in buildings.

     Providing Guidance for New Buildings

     Another frequently-voiced concern is how to prevent  indoor
air quality problems from occurring in the first place.
Considering the need for professional expertise that resides  in
the private sector about building practices, such  a program could
be carried out effectively only through close collaboration with
professional architecture, design, and construction associations.

     Providing guidance on how to prevent indoor air quality
problems in new buildings could entail many activities from the
publication of materials that describe recommended construction
techniques to the preparation of training courses.  A logical
extension of providing such guidance would be to work with
private sector model code associations to incorporate these
design features as part of local and State building codes.
EPA's work in assisting the model code organizations as they
write model codes for radon prevention in one and two-family
dwellings is an example of how the federal government can work
directly with model code organizations.


     While limited to single pollutants and focusing on one type
of building, at least initially, the asbestos and radon programs
within EPA have given the Agency experience in developing indoor
air quality information and technical assistance programs.  From
these programs, EPA has learned much about developing cooperative
partnerships with State agencies, targeting information at
specific audiences (e.g., school districts, homebuilders,
building contractors),  and developing joint projects with private
sector organizations.  Other agencies also have valuable
experience in the conduct of information and technical assistance
programs. A public information program could involve one or more
of the  following elements:

     Developing and Disseminating Information to the Public

     There are not many materials on indoor air quality issues
for the general public at present.  Increased emphasis on
transferring information to the general public could be one
component of a larger Federal role in indoor air.

     A few private sector organizations, such as the American
Lung Association and the Consumer Federation of America, have
been actively involved in developing and disseminating indoor air
information to the public.  Some Federal agencies, including the
Consumer Product Safety Commission and EPA, have written
brochures on asbestos and radon.  The Department of Energy has
also developed some indoor air quality information.

     This past year the EPA Indoor Air Division published two
pieces for the non-technical public:  A Directory of State Indoor
Air Contacts and The Inside Story: A Guide to Indoor Air Quality.
Other indoor air publications for more technical audiences are  in

     Establishing an Information Clearinghouse

     An information clearinghouse differs from a program that
simply develops and disseminates informational materials because
it provides a central place where people can get answers to
specific questions.  There are a number of clearinghouses or
hotlines run by EPA and other Federal agencies that could be
used as possible models for an indoor air quality clearinghouse.
It is most important that both the purpose and the targeted
audience be clearly specified (e.g. State and local governments,
industry, public interest organizations, the general public)  and
that the clearinghouse be formed with adequate participation
from the targeted groups.

     Developing Technical Assistance Programs With Targeted

     There are many groups with power to effect indoor air
quality — to name a few, homebuilders,  building owners and
managers, architects and engineers, many agencies within State
and local governments, industries offering investigative and
remedial services, and the general public.  To improve indoor air
quality will require informed actions by many of these groups.
Technical assistance, delivered through such vehicles as regional
training centers, joint government/industry ventures, and readily
accessible training courses are potential means of accomplishing
the goal of information dissemination.  EPA has learned much
about how to develop and disseminate technical guidance on
indoor air problems from its radon and asbestos programs.

     Building the Capacity of State and Local Governments

     The prime contact point for the public on indoor air
quality issues is appropriately the agencies in State and local
governments.  A Federal indoor air quality program could
therefore include actions to develop requisite knowledge at the
State and local government level, including those that allow
States to learn from one another.  Key elements to achieving  such
a goal are likely to be activities to promote information
exchange among States and to encourage the development of model
State programs.  All the steps that the Federal government takes
to develop standards, guidance, and informational materials are
likely to enhance State efforts to address similar problems.
Financial assistance, in the form of pilot programs,
demonstration projects, and grant programs, is also  viewed by
most States as a critically-needed component of a Federal
response to indoor air quality problems.


     There are many potential actions that the Federal government
could take to address the problem of indoor air pollution, as
this chapter demonstrates.  The first set of options described
above would set different types of standards or guidance,
pertaining to indoor air pollutant concentration levels,
ventilation system design and operation practices,  or product
composition, function,  and use.  The second set of options would
provide guidance to the public, including targeted technical
audiences, about methods to identify, correct,  and prevent indoor
air problems.  The third option listed components of a public
information and technical assistance program.   Within each
option,  there are many  possibilities for Federal participation
because a successful response to these problems must ultimately
include active interaction between all levels  of government and
many groups within the  private sector.