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CHAPTER 2
DATA RELATED TO ENVIRONMENTAL HAZARDS AND HUMAN EXPOSURE
a conceptual framework for the ongoing study was described in
Chapter 1, where Figure 1-1 depicts it schematically, indicating the
data needed and methods that can be used to derive information about
factors in the environment that affect human health.
This chapter reviews some attempts to assemble these types of
data, and describes the information needed to identify sources of
hazards and quantify the resulting human exposure to harmful
environmental factors, as shown in Boxes 1, 2, 3, and 3a of
Figure 1-1.
Existing Studies
Numerous reports identify possible sources of data and recommend
new sources of data that would be useful to the ongoing study.l-8
This committee has not comprehensively reviewed these past efforts,
but will highlight those of special interest for this planning study.
Certain activities of the National Center for Health Statistics
(NCHS), called for in Section 8 of Public Law 95-623, are
particularly relevant for this enterprise. NCHS developed a plan for
the collection and coordination of statistical and epidemiologic data
on the effects of the environment on health.3 In preparing its
report, NCHS identified 64 information data systems in 18 agencies
that gather program-related information of use to environmental
health epidemiologists. Profiles of these 64 data systems appear in
tables, arranged according to whether the systems amass data on
health status, on medical care use or need, or whether they test
specific interrelationships, record environmental inspections,
measure environmental pollutants or individual exposures, or relate
data on the environment to data on health.3 NCHS also identifies,
in general terms, some deficiencies in these data systems and makes
general recommendations for improving the available data.
Two other NCHS activities respond to further mandates in
P.L. 95-623. One is the preparation of guidelines for collecting
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data for determining health effects of the environment.9 Another
assesses the problems of locating and following people who might have
been exposed to environmental hazards.l°
In 1980, a comprehensive report on the U.S. federal statistics
effort was prepared by the Office of Federal Statistical Policy and
Standards.1 This report provides a framework for planning future
statistical activities of the various agencies, covering health
statistics, statistics on the environment, statistics on occupational
safety and health, and longitudinal surveys.
Other groups also have addressed data coordination
problems.5-8 ~ report by the Office of Technology Assessment (OTA)
on federal health statistics documents the lack of overall
coordination of assorted data collection projects.5 A report by
the Council on Environmental Quality inventories environmental
monitoring activities and makes recommendations for coordinating and
improving these data.6 - -
Some of the efforts in recent years to assess health impacts of
environmental factors have been made by sections of the National
Academy of Sciences (~AS). The Assembly of Life Sciences has
published a series of reports on the health effects of ionizing
radiation, on the effects of toxic substances on biological systems,
on the safety of food chemicals, and on drinking water and
health.11-15 The Environmental Studies Board of the Commission on
Natural Resources prepared a series of scientific and technical
assessments of environmental pollutants, including health effects,
for the Environmental Protection Agency (EPA).16-20 Some of the
reports detail steps to be taken to calculate the costs of
environment-related health effects, including 1) identifying
pollutant "sources and sinks"; 2) assessing potential for human
exposure; 3) extrapolating health effects information from animal
studies to humans; 4) quantifying the incidence of resulting human
illness and disease; and 5) estimating economic cost.
Continuing programs to assess the health effects of
environmental pollutants are conducted by many government agencies.
Examples of these are the National Toxicology Program of the
Department of Health and Human Services, the work of EPA to establish
standards for criteria air pollutants,* studies by the Council on
Environmental Quality, especially those concerning toxic substances,
and the work of EPA in conjunction with other agencies in
implementing the Toxic Substances Control ACt.2l-27 Numerous
*Criteria air pollutants are the six major air pollutants for which
the Clean Air Act mandates national ambient standards. The criteria
pollutants are total suspended particulates, sulfur dioxide, carbon
monoxide, photochemical oxidants (now ozone), nitrogen dioxide, and
hydrocarbons.
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interagency committees have been established to coordinate the work
of these agencies related to environmental health and toxic
substances. Appendix D lists many of these, together with the
agencies involved and the tasks they are to carry out.
Sources of Hazards, Types of Data Needed*
As shown in Figure 1-1, for each hazard to be evaluated in the
ongoing study, it will be necessary to determine where the substance
comes from and how much of it enters the environment in order to 1)
derive exposure data and 2) take effective steps towards decreasing
exposure from a particular source. Two types of sources of
pollutants include sources from which pollutants are released
directly, such as smelters or auto exhaust, and sources which result
when substances are transfo~-~`ed into pollutants subsequent to their
emission. These substances are dispersed into air, water, soil, and
food, which are the routes of human exposure. The following
descriptions indicate the difficulties of getting appropriate data
and measurir~g sources of hazardous agents.
Sources of a pollutant determine its release into the
environment. Such source emissions can be broadly classified as:
1. products that are mined, manufactured, di stributed, and used
2. by-products of industrial processes
3. substances released by natural, rather than human, activity.
Subs Lances may enter the envi ronment from one or several
sources. And, because environmental hazards move among the various
media, not being confined only to air, water, or land environments,
human exposure to a substance may result from contact with a variety
of sources containing it. Contact may occur by means of drinking .
water, food ingestion, inhalation, dermal contact, and contact with
soil and dust. For each substance, it may be necessary to know the
entire range of its sources and environmental distribution to
determine human exposure.18 (However, exposure can also be
estimated other ways, such as by measuring body burden.) Initially'
qualitative understanding of potential sources and pathways of
exposure is needed; subsequently, these should be expressed in
quantitative terms.
odor simplicity, the discussion applies to harmful substances, that
is, pollutants, but could apply also to noise and radiation.
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Properties of the Substance
An understanding of the physical and chemical properties and
major reactions of the substance is important in studying its
dispersion into the environment and its subsequent actions. A report
by the Environmental Studies Boardl9 discusses detailed methods of
making the measurements needed to calculate exposures and to reduce
the amounts of substances with deleterious effects. The
determinations include whether the substance is a~liquid, gas, or
solid at normal temperatures, and its vapor pressure, Volubility,
specific gravity, vaporization rate, and absorption properties.
These properties influence the extent of vapor contamination,
biological availability, and persistence, transformation or
degradation of the substance in soil, water, and air.
In addition, information on product synthesis may be needed to
determine how best to reduce exposure. The date of first synthesis
or commercial production of a synthetic substance may be useful in
the evaluation of delayed toxic effects, allowing an estimate of the
maximum time during which exposure could have occurred.
Finally, the accuracy, sensitivity, and reliability of
techniques used to analyze and measure substances determine how
useful the data will be. The limit of detection varies greatly for
different substances and for different sources of exposure.
Techniques for measuring substances in the environment continue to
improve, and they are now so sensitive in some cases that it is
sometimes unclear what action is warranted by the very small amounts
detected. Problems of contamination, absorption, and degradation may
hinder interpretation of measurements.
Production and Uses
-
Information on the amount of the substance produced, the
locations where it is produced, and its uses will be needed to
determine the extent of exposure and environmental distribution of
the substance. For example, the primary sources for lead would
include mining and refining of lead for the consumer lead industry
and its use in pigments, gasoline, ammunition, and the lead metal
industry. Production and use of these products would release lead
into the environment.18 Often the required information is not
available. Although many data about national production and foreign
trade for individual substances exist, the accuracy of these data
needs to be ascertained.
Distribution in the Environment
After a substance enters the environment, whether its origins
are primarily natural or man-made, transport and environmental
occurrence must be determined. This information is needed not only
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to find the routes of human exposure, but also, in the absence of
actual human dose data, to calculate human exposure from
environmental concentration of the substance as discussed later in
this chapter. What are the levels of the substance found in air that
can be either inhaled or absorbed dermally? Are the concentrations
similar indoors and outdoors? How much of the substance is present
in foods or in drinking water? Analysis of environmental
distribution, concentration, and exposure pathways.will be needed to
establish intensity of exposure and the size and characteristics of
the populations exposed.
Environmental Monitoring
Monitoring of the environment provides information on source and
dispersion of pollutants. Since the 1950s, an elaborate system of
monitoring has been developed to define the environmental pollutants
and to demonstrate improvement or deterioration of selected
environmental characteristics.17 Source monitoring attempts to
identify the origins and amounts of chemical and physical agents
entering the environment. Ambient monitoring measures concentrations
of such substances in air, water, soil, food, and animal tissues, or
other locations.
For purposes of monitoring, pollutant sources are characterized
as point sources, area sources, and mobile sources.17 Industrial
stacks, di scharge pipes, and other stationary sources that contribute
residuals to air, water, and land are examples of point sources.
State authorities prepare inventories of point sources that include
the location, the pollutants, and estimates of the amounts emitted.
Area or nonpoint sources are groupings of small sources spread over
regions, such as cities or farmlands. Area source moni taring i s
carried out by state and local agencies as part of area-wide waste
treatment management plans and often is inferred from demographic and
industrial statistics. Pollution from mobile sources includes motor
vehicle emissions and spills of toxic and other hazardous substances
during transport. The Environmental Protection Agency monitors cars
for levels of emissions, and the Department of Transportation
monitors spills during transport.
State agencies and various establishments that discharge
substances into the environment collect data for inclusion in
federally maintained computer-based data systems. Several federal
agencies analyze and publish a variety of environmental statistics,
including those on air quality and emissions, water quality and water
supply, waste disposal, environmental contamination from radiation,
noise pollution, toxic substances, and the production, distribution,
and use of pesticides. 1
The Office of Air, Noise, and Radiation, EPA, collects
information on the concentration of substances in the ambient air and
on the emissions of point and area sources. Levels both of criteria
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and noncriteria pollutants are measured and reported by the
Aerometric and Emissions Reporting System (AEROS). AEROS integrates
point source information contained in the National Environmental Data
System (TEDS) with the ambient air quality data in the Storage and
Retrieval Aerometric Data System (SAROAD). Environmental data from
other agencies also are lodged with AEROS.1 Furthermore,
information from the National Air Surveillance Network (NASN), which
collects ambient data on radionuclides, five gaseous pollutants,
suspended solids in rainwater, and particles of matter suspended in
air, also is stored in SAROAD. These data largely are supplied by
states and local governments and in many cases are of poor quality.
Federal data on water quality and supply are collected by EPAts
Office of Water and Waste Management and the Water Resources Division
of the U.S. Geological Survey (USGS ~ in the Department of Interior.
The EPA collects data from the perspective of human use, consumption,
and municipal, industrial, and agricultural impacts, while the USGS
data are collected from the perspective of water as.a natural
resource.
The EPA's water quality data are generated by a Discharge Permit
Program and a Stream Monitoring Program and are entered into a data
bank (STOFET). Both programs are federal-state cooperative ~
programs. The Discharge Permit Program was designed to provide an
inventory of discharge point sources, while the Stream Monitoring
Program provides data on ambient water quality.2
Toxic substances are another class of hazard. A number of
federal laws exercise control over toxic substances in various forms
and places, from pesticides to foods, from the workplace to air and
water (appendix P). The broadest of the laws is the 1976 Toxic
Substances Control Act (TSCA) (Pot. 96-459), which gave SPA the
primary responsibility for regulating chemical substances that
present an unreasonable risk to health or the environment. The Act
authorizes the collection of an extensive range of information
including: trade names, chemical identity, molecular structure,
categories of use, volume of production by use category, by-products,
exposure of workers producing specific chemicals, methods of
disposal, volume of imports, adverse reactions, health effects,
environmental effects, quality control methods, and economic
consequences of production or stopping production. Evaluation of a
chemical results in a Chemical Hazard Information Profile (CHIP).28
More than 50 agencies collect or analyze info`~.ation on toxic
substances, although EPA has major coordinating responsibility under
TSCA. To reduce duplication, interagency committees have been
established to coordinate efforts in toxic substance data gathering
and analysis (Appendix D).29 One effort to develop a coordinated
chemical data system is the Chemical Substances Information Network
(CSIN), which will loosely couple data bases from different
agencies.7
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Exposure
To relate exposure to health effects, human populations with
exposures to the substance of concern must be identified and the
exposure quantified as far as possible, Exposure is defined as the
process by which a person comes into contact with the hazardous
material. Although the following discussion considers a single
substance, people are exposed to many potentially hazardous
substances at a time. Exposure may be determined by (1) direct
measurement or (2) estimates using surrogate measurements. Direct
measurements are preferable, but rarely are achieved.
The most direct and ideal measurement of exposure would be
determination of the amount of the substance or its active
metabolites at the site of action in the tissue or cell. This
information is almost never available. By analyzing human fluids or
tissues, it is sometimes possible to determine the amount of a
potentially harmful agent in the body (that is, the body burden for
the substance) and to relate the body burden to exposure. An example
are the data on body burdens of lead among chi ldren and exposed
workers.l8
In lieu of body burdens of a substance, use of personal
moni taring devi ces can provide individual exposure data. This type
of monitoring tells how much of the substance the individual has had
contact with, but not how much has been absorbed by the body or what
i ts actual dose is at the organ where the substance would have its
greatest effect. Exposure data obtained by use of personal monitors
is scanty, except in the case of radiation, for which badges and
other devices that record exposures have long been used. Personal
monitors that measure air in the individual's breathing zone also are
used to some extent in research laboratories and in the workplace.
Surrogate measures of exposure are calculated by combining
information on the amounts and chemical forms of the substance in
environmental reservoirs, such as air, soil, water, and food; the
amount of air inhaled or water or food ingested by members of the
population; and the duration and distribution of exposure over
time.16~19 Such calculations assume average intakes of food,
water, and air. Some of the difficulties and complexities associated
with determining human exposure to air pollutants by using ambient
measures have been discussed by Repace30 and by Spengler.31~32
A ma jor EPA study is underway to measure a population's
exposures to selected pollutants by analyzing air, foods, and water
to which the individuals under study are exposed. This study will be
able to compare exposure estimates obtained by fairly direct measures
with those that would be calculated using surrogate measures.33~34
Environmental specimen banks are another potentially valuable
source of exposure information. These facilities store biological
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\
and environmental samples, such as body tissues or soil samples, that
can be analyzed years later. It then becomes possible to monitor
changes in pollutant concentrations by comparing recent and old
samples, and to analyze samples for factors or characteristics that
were not suspected when the sampling occurred. For example, "baby
teeth" can be used to document lead exposures in children.35
The National Bureau of Standards and the U.S. Environmental
Protection Agency set up a pilot environmental specimen bank in late
1979 that is expected to provide about 30,000 samples after five
years.36 These samples will be of human liver, marine bivalve
mollusks, food grains, and atmospheric particulates.
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lo
REFEPENCES
1. U.S. Department of Commerce. Office of Federal Statistical
Policy and Standards. A Framework for Planning U.S. Federal
Statistics for the 1980's. Washington, D.C. U.S. Government
Printing Office, 1980.
2. U.S. Department of Health, Education, and Welfare. Statistics
Needed for Determining the Effects of the Environment on
Health. Beport of the Technical Consultant Panel to the United
States National Committee on Vital and Health Statistics. DREW
Publication (HRA)77-1457. July 1977.
U.S. Department of Health and Human Services. Environmental
Health A Plan for Collecting and Coordinating Statistical and
Epi demi o logi c Dat a . DHUS Publ i cat i on too . (PHS )80-1248 .
Washington, D.C. U.S. Government Printing Office, 1980.
Task Force on Environmental Cancer and Heart and Lung Disease.
Environmental Cancer and Heart and Lung Disease, Second Annual
Report to Congress. Gaithersburg, MD: GEOMET, Inc., August 7,
1979.
U. S. Congress. Office of Technology Assessment.
Topics In Federal Health Stati sties. Washington, D.C.
U. S. Government Printing Office, June 1979.
Selected
6. Council on Environmental Quality. Report of the Interagency
. .
Task Force on Environmental Data and Monitoring.
Springfield, VA U.S. Department of Commerce, OTIS, March 21,
1980.
7. Bracken, H., Dorigen, J., Huston, J. and Overbey, J., II.
Chemical Substances Information Network. Volume II
Appendices. Mitre Technical Report MTR-7558. McLean, VA: The
Mitre Corporation, June 19 77.
8. Interagency Regulatory Liaison Group. Scientific Bases for
~ yens and for Estimating Their
Risks. Washington, D.C.: IPLą, February 6, 1979.
9.
U.S. Department of Health and Human Services. National Center
for Health Statistics. Draft (guidelines for Statistics and
Information on Effects of the Environment on Health.
Hyat t svi 1 le ~ Mn · Na t i one 1 Center for Heal th ~ tat i s t i cs 3
December 1980 .
-45-
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10. U.S. Department of Health and Human Services. Environmental
Health A Study of the Issues in Locating, Assessing, and
Treating Individuals Exposed to Hazardous Substances. DHHS
Publication No. (PHS)81-1275. Washington, D.C.:
U.S. Government Printing Office, 1981.
11. National Research Counci1. Committee on the Biological Effects
of Ionizing Radiation. The Effects of Exposure to Low Levels of
.
Ionizing Radiation. Washington, D . C .: National Academy of
Sciences, 1980.
12. National Research Council. Committee on Sulfur Oxides. Sulfur
Oxides. Washington, D.C.: National Academy of Sciences, 1978.
13. National Research Council. Committee on Medical and Biological
Effects of Environmental Pollutants. Ozone and Other
Photochemical Oxidants. Washington, D.C. National Academy of
Sciences, 1977.
14. National Research Council. Committee on Food Protection of the
Food and Nutrition-Board. Risk Assessment/Safety Evaluation of
Food Chemicals. Washington, D.C.: National Academy of
Sciences, 1980.
15. National Research Council. Committee on Safe Drinking Water.
Drinking Water and Health. Washington, D.C.: National Academy
of Sciences, 1977.
16. National Research Council. Environmental Studies Board.
Kepone/Mirex/Hexachlorocyclopentadiene An Environmental
Assessment. Washington, D.C. National Academy of Sciences,
1978.
17. National Research Council. Environmental Studies Board.
Environmental Monitoring. Washington, D.C.- National Academy
of Sciences, 1977.
18. National Research Counci1.
in the Human Environment. Washington, D.C
of Sciences, 1980.
Environmental Studies Board. Lead
. National Academy
19. National Research Council. Environmental Studies Board.
Chloroform, Carbon Tetrachloride, and Other Halomethanes An
_ . . .
Environmental Assessment. Washington3 D.C. National Academy
of Sciences, 1978.
20. National Research Counci1. Environmental Studies Board.
Regulating Pesticides. Washington, D.C. National Academy of
Sciences, 1980.
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21. U.S. Department of Health, Education, and Welfare. National
Toxicology Program. National Toxicology Program Annual Plan for
Fiscal Year 1980. NTP-79-7. Washington, D.C., 1979.
22. U.S. Environmental Protection Agency. Air Quality Criteria for
Particulate Matter and Sulfur Oxides. Volume IV, Health
Effects. April 1980. Draft.
23.
U.S. Environmental Protection Agency. Health Consequences of
Sulfur Oxides A Report from CHESS, 1970-1971.
EPA-550/1-74-004. May 1974.
24. Council on Environmental Quality. Toxic Substances Strategy
Committee. Toxic Chemicals and Public Protection A Report to
the President by the Toxic Substances Strategy Committee.
Washington, D.C. U.S. Government Printing Office, 1980.
Council on Environmental Quality. Environmental Quality, 1979.
Tenth Annual Environmental Quality Report. Washington, D.C..
U.S. Government Printing Office, 1979.
26. U. S. Environmental Protection Agency. Office of Pesticides and
Toxic Substances. TSCA Chemical Assessment Series. Initial
Evaluations of Substantial Risk Notices, Section 8(e) January 1,
1979. Washington, D.C. U.S. Environmental Protection Agency.
March 1980.
27. Scoring Chemicals for Health and Ecological Effects Testing
TSCA-ITC Workshop. Rockville, MD Enviro Control, August 1979.
28. U.S. Environmental Protection Agency. Office of Pesticides and
Toxic Substances. Chemical Hazard Information Profiles
(CHIPs ~ August 1976-August 1978. EPA 550/11-80-011.
Washington, D.C.: April 1980.
29. U.S. Environmental Protection Agency. Office of Pesticides and
Toxic Substances. Directory of Federal Coordinating Groups for
Toxic Substances. Compiled by J. Colle and K.A. Slake. March
1980.
30. Repace, J.L., Ott, W.~., and Wallace, L.A. Total human exposure
to air pollution. Paper presented at the 73rd Annual Meeting of
the Air Pollution Control Association, Montreal, Ouebec, June
22-27, 1980.
31. Spengler, J.D. and Dockery, D.W. Long-term measurements of
respirable sulfates and particles inside and outside homes.
Presented at session on Environmental Monitoring and
Assessment. Electro Professional Programs. New York. April
24-26, 1979.
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Spengler, J.D., Ferris, B.G., and Dockery, D.W. Sulfur dioxide
and nitrogen dioxide levels inside and outside homes and the
implications on health effects research. Environmental Science
and Technology 13:1276-1280, 1979.
33. U.S. Environmental Protection Agency. Quality Assurance and
~ Preliminary Study on Toxic
Monitoring System Division.
Chemicals in Environmental and Human Samples. Part T.
Formulation of an Exposure and Body Burden Monitoring Program.
Program Manager Lance Wallace.
RTI/1521/00-265. 1980.
34. U.S. Environmental Protection Agency.
Contract No. 68-01-?849.
Ouality Assurance and
Monitoring System Division. Preliminary Study on Toxic
Chemicals in Environmental and Human Samples. Part II.
Protocols for Environmental and Human Sampling and Analysis.
Program Manager Lance Wallace. Contract No. 68-01-3849.
RTI/1521/00-265. 1980.
35. Needleman, H.L., Gunnoe, C., Leviton, A., et al. Deficits in
psychologic and classroom performance in children with elevated
dentine lead levels. New England Journal of Medicine
300 689-695, 1979.
36. U.S. Department of Commerce, National Bureau of Standards.
Technical Activities--1980. Center for Analytical Chemistry.
Publication No. NBSIP 80-2164. Washington, D.C.: National
Bureau of Standards. 1980.
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Representative terms from entire chapter:
human exposure
