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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 -37-

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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. -38-

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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. -39-

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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 -40-

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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 -41-

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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 -42-

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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 -43-

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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. -44-

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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.: IPL, 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. -46-

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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. -47-

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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. -48-