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Historical Document

This Web site is provided by the Agency for Toxic Substances and Disease Registry (ATSDR) ONLY as an historical reference for the public health community. It is no longer being maintained and the data it contains may no longer be current and/or accurate.

Y-12 Uranium Releases



ATSDR recognizes that infants and children can be more sensitive to environmental exposure than adults in communities faced with contamination of their water, soil, air, or food. This sensitivity is a result of the following factors: (1) children are more likely to be exposed to certain media (for example, soil or surface water) because they play and eat outdoors; (2) children are shorter than adults, which means that they can breathe dust, soil, and vapors close to the ground; and (3) children are smaller; therefore, childhood exposure results in higher doses of chemical exposure per body weight. Children can sustain permanent damage if these factors lead to toxic exposure during critical growth stages. As part of the ATSDR Child Health Initiative, ATSDR is committed to evaluating the special interests of children at sites such as the ORR.

Children living near the ORR are exposed to small amounts of uranium in the air they breathe, in the food they eat, and in the water they play in. However, no cases have been reported where exposure to uranium is known to have caused health effects in children (ATSDR 1999a). It is possible that if children were exposed to very high amounts of uranium, they might have damage to their kidneys, similar to what is seen in adults. However, the levels of uranium in the environment surrounding ORR are too low to cause these kinds of health effects.

Studies of developmental effects in the offspring of uranium miners and millers have not reported any chemical or radiological effects on the development of humans. Very high doses of uranium in drinking water (far above any plausible human exposure) can affect the development of the fetus in laboratory animals (one study reported birth defects and another reported an increase in fetal deaths). However, health scientists do not believe that uranium can cause these problems in pregnant women who take in normal amounts of uranium from food and water, or women who breathe the air around a hazardous waste site that contains uranium (ATSDR 1999a). Therefore, based on the estimated uranium exposure to people living near the Y-12 plant, ATSDR does not expect adverse health effects to a fetus from Y-12 uranium releases.


Having thoroughly evaluated past public health activities and available current environmental information, ATSDR has reached the following conclusions:


Having evaluated past public health activities and the available environmental information, ATSDR recommends that the community be informed that ATSDR has evaluated uranium releases from the Y-12 plant on the Oak Ridge Reservation and has concluded that there is no apparent public health hazard associated with past and current releases. ATSDR will work with the Oak Ridge Reservation Health Effects Subcommittee to determine the best way to communicate the results of the evaluation to the people in the community.


The public health action plan for the Oak Ridge Reservation (ORR) contains a description of actions taken at the site and those to be taken at the site following the completion of this public health assessment. The purpose of the public health action plan is to ensure that this public health assessment not only identifies potential and ongoing public health hazards, but also provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to harmful substances in the environment. The following public health actions at the ORR are completed, ongoing, or planned:

Completed Actions

Ongoing Actions

Planned Actions


Jack E. Hanley, M.P.H.
Environmental Health Scientist
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry

Paul A. Charp, Ph.D.
Senior Health Physicist
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry

Mark Evans, Ph.D.
Division of Health Assessment and Consultation
Agency for Toxic Substances and Disease Registry

Michelle Arbogast, M.S.
Environmental Scientist
Eastern Research Group


Agency for Toxic Substances and Disease Registry (ATSDR). 1993a. ATSDR record of activity for telephone communication with a representative from the Tennessee Department of Environment and Conservation. January 26, 1993.

Agency for Toxic Substances and Disease Registry (ATSDR). 1993b. Health consultation for U.S. DOE Oak Ridge Reservation: Y-12 Weapons Plant Chemical Releases Into East Fork Poplar Creek, Oak Ridge, Tennessee. April 5, 1993.

Agency for Toxic Substances and Disease Registry (ATSDR). 1996. Health consultation for U.S. DOE Oak Ridge Reservation: proposed mercury clean-up level for the East Fork Poplar Creek floodplain soil, Oak Ridge, Anderson County, Tennessee. Atlanta: U.S. Department of Health and Human Services.

Agency for Toxic Substances and Disease Registry (ATSDR). 1999a. Toxicological profile for uranium. Atlanta: U.S. Department of Health and Human Services. Available from URL:

Agency for Toxic Substances and Disease Registry (ATSDR). 1999b. Toxicological profile for ionizing radiation. Atlanta: U.S. Department of Health and Human Services. Available from URL:

Agency for Toxic Substances and Disease Registry, National Center for Environmental Health, National Institute for Occupational Safety and Health, Tennessee Department of Health, Tennessee Department of Environment and Conservation, U.S. Department of Energy. 2000. Compendium of public health activities at the U.S. Department of Energy. Atlanta: U.S. Department of Health and Human Services. Available from URL:

Carden D, Joseph T. 1998. Aerial radiological surveys of the Scarboro community. U.S. DOE, Oak Ridge Operations.

Cardis E, Gilbert ES, Carpenter L, Howe G, Kato I, Armstrong BK, Beral V, Cowper G, Douglas A, Fix J, et al. 1995. Effects of low doses and low dose rates of external ionizing radiation: cancer mortality among nuclear industry workers in three countries. Radiation research 142:117-32.

Centers for Disease Control and Prevention (CDC), National Center for Environmental Health, the Tennessee Department of Health, and the Scarboro Community Environmental Justice Council. 1998. An analysis of respiratory illnesses among children in the Scarboro community. Atlanta: U.S. Department of Health and Human Services.

ChemRisk. 1993a. Oak Ridge health studies, phase 1 report. volume II –part a– dose reconstruction feasibility study. tasks 1 & 2: a summary of historical activities on the Oak Ridge Reservation with emphasis on information concerning off-site emissions of hazardous materials. Oak Ridge: Oak Ridge Health Agreement Steering Panel and Tennessee Department of Health.

ChemRisk. 1993b. Oak Ridge health studies, phase 1 report. volume II –part b– dose reconstruction feasibility study. tasks 3 & 4: identification of important environmental pathways for materials released from Oak Ridge Reservation. Oak Ridge: Oak Ridge Health Agreement Steering Panel and Tennessee Department of Health.

ChemRisk. 1993c. Oak Ridge health studies, phase 1 report. volume II –part c– dose reconstruction feasibility study. Task 5: A summary of information concerning historical locations and activities of populations potentially affected by releases from the Oak Ridge Reservation. Oak Ridge: Tennessee Department of Health and the Oak Ridge Health Agreement Steering Panel.

ChemRisk. 1999. Uranium releases from the Oak Ridge Reservation–a review of the quality of historical effluent monitoring data and a screening evaluation of potential off-site exposures, task 6. Report of the Oak Ridge Dose reconstruction, volume 5. Oak Ridge: Tennessee Department of Health.

City of Oak Ridge. 2002. City of Oak Ridge water treatment web site. Available from URL: Exiting ATSDR Website. Accessed on December 18, 2002.

C.J. Enterprises, Inc. 2001. Public involvement plan for CERCLA activities at the U.S. Department of Energy Oak Ridge Reservation. U.S. Department of Energy. Available from URL: Exiting ATSDR Website.

DOE see U.S. Department of Energy.

End Use Working Group. 1998. Final report of the Oak Ridge Reservation End Use Working Group. Available from URL: Exiting ATSDR Website.

EPA see U.S. Environmental Protection Agency

Florida Agricultural and Mechanical University (FAMU). 1998. Scarboro Community Environmental Study.

Friday JC, Turner RL. 2001. Scarboro community assessment report. Joint Center for Political and Economic Studies. August 2001.

GAO see U.S. General Accounting Office

Harrison JD, Leggett RW, Nosske D, Paquet F, Phipps AW, Taylor DM, Metivier H. 2001. Reliability of the ICRP's dose coefficients for members of the public, ii. uncertainties in the absorption of ingested radionuclides and the effect on dose estimates. New York: International Commission on Radiological Protection. Radiat Prot Dosim 95(4)295-308.

International Commission on Radiological Protection (ICRP). 1990. Age-dependent doses to members of the public from intake of radionuclides: Part 1. ICRP Publication 56. New York: Pergamon Press.

International Commission on Radiological Protection (ICRP). 1991. 1990 recommendations of the International Commission on Radiological Protection. ICRP Publication 60. New York: Pergamon Press.

Joint Center for Political and Economic Studies. Environmental and health summaries for the Scarboro community. An analysis of respiratory illness among children in the Scarboro community. Number 4. Oak Ridge.

Kendall GM, Muirhead CR, MacGibbon BH, O'Hagan JA, Conquest AJ, Goodill AA, Butland BK, Fell TP, Jackson DA, Webb MA. 1992. Mortality and occupational exposure to radiation: first analysis of the National Registry for Radiation Workers BMJ 25:304(6821):220-5.

Leggett RW. 2001. Reliability of the ICRP's dose coefficient for members of the public. 1. sources of uncertainty in the biokinetic models. International Commission on Radiological Protection. Radiat. Prot. Dosim. 95(3):199-213.

Los Alamos National Laboratory. 2000. Uranium uptake study, Nambe, New Mexico: Source document. Los Alamos, New Mexico. LA-13614-MS.

Maurer RJ. 1989. An Aerial Radiological Survey of the Oak Ridge Reservation and Surrounding Area. Washington, DC. Report No. EGG-10617-1123. EG&G/EM.

National Council on Radiation Protection and Measurements (NCRP). 1999. Recommended screening limits for contaminated surface soil and review of factors relevant to site-specific studies. Report 129. Bethesda, Maryland: National Council on Radiation Protection and Measurements.

National Council on Radiation Protection and Measurements (NCRP). 2001. Evaluation of the linear-nonthreshold dose-response model for ionizing radiation. NCRP Report 136. Bethesda, Maryland: National Council on Radiation Protection and Measurements.

National Research Council (NRC). 1988. Health risks of radon and other internally deposited alpha emitters. Washington, DC: National Research Council.

Oak Ridge Comprehensive Plan. 1988. Comprehensive plan including 1988 update. Available from the Oak Ridge Reading Room, Oak Ridge Public Library, Oak Ridge Tennessee.

Oak Ridge Health Agreement Steering Panel (ORHASP). 1999. Releases of contaminants from Oak Ridge facilities and risks to public health. Final report of the ORHASP. December 1999.

Prichard HM. 1998. Scarboro community sampling results: implications for task 6 environmental projections and assumptions. Knoxville: Auxier & Associates. November 9, 1998.

Roman E, Doyle P, Maconochie N, Davies G, Smith PG, Beral V. 1999. Cancer in children of nuclear industry employees: report on children aged under 25 years from nuclear industry family study. BMJ. 318(7196):1443-50.

SAIC 2002. Land use technical report. Science Applications International Corporation. September 2002.

Storms R, Rector D. 1997. Radiological survey of Clinch River public parks and recreational areas from Melton Hill Dam to Kingston. TDEC/ORO3/20/97.

Stranden E. 1985. Sources of exposure to technological enhanced natural radiation. Science of the Total Environment. 45:27-45.

Teasley N. 1995. Deer Hunt Radiation Monitoring Guidelines. ORNL Chemical and Analytical Science Division. January 17, 1995.

Tennessee Department of Health (TDOH). 2000. Contaminant releases and public health risks: results of the Oak Ridge health agreement studies. July 2000.

U.S. Census Bureau. 2000. Census of population and housing: summary tape file. Washington DC: U.S. Department of Commerce.

U.S. Department of Energy (DOE). 1989. Oak Ridge Reservation environmental report for 1988. vol. 1: narrative, summary, and conclusions. Oak Ridge, Tennessee: U.S. Department of Energy, Office of Scientific and Technical Information.

U.S. Department of Energy (DOE). 1993. Final report on the background soil characterization project at the Oak Ridge Reservation, Oak Ridge, Tennessee. Volume 1- Results of field sampling program. DOE/OR/01-1175/V1. October 1993.

U.S. Department of Energy (DOE). 1995a. Record of decision for Lower East Fork Poplar Creek, Oak Ridge, Tennessee. U.S. Department of Energy, Office of Environmental Management. July 1995.

U.S. Department of Energy (DOE). 1995b. Oak Ridge Reservation annual site report for 1994. environmental, safety, and health compliance and environmental management staffs of the Oak Ridge Y-12 plant, Oak Ridge National Laboratory, and Oak Ridge K-25 site. October 1995.

U.S. Department of Energy (DOE). 2001. Overview of CERCLA actions at off-site locations. Environmental Management Program fact sheet. September 2001.

U.S. Department of Energy (DOE). 2002a. 2002 Remediation Effectiveness Report for the U.S. Department of Energy Oak Ridge Reservation, Oak Ridge, Tennessee. Prepared by SAIC. March 2002.

U.S. Department of Energy (DOE). 2002b. Record of decision for phase I interim source control actions in the Upper East Fork Poplar Creek Characterization Area, Oak Ridge, Tennessee. U.S. Department of Energy, Office of Environmental Management. May 2002.

U.S. Department of Energy (DOE). 2002c. Oak Ridge Reservation Annual Site Environmental Report for 2002. September 2003. Available from URL: Exiting ATSDR Website.

U.S. Department of Energy (DOE). 2003. Boneyard/Burnyard Waste Site Cleanup. Environmental Management Program fact sheet. April 2003.

U.S. Environmental Protection Agency (EPA). 1988. Limiting values of radionuclide intake and air concentration and dose conversion factors for inhalation, submersion, and ingestion. Federal Guidance Report No. 11. Washington, DC: U.S. Environmental Protection Agency.

U.S. Environmental Protection Agency (EPA). 1989. Toxicological review of uranium, soluble salts. Integrated Risk Information System. Washington, DC. October 1, 1989. Available from URL: Exiting ATSDR Website.

U.S. Environmental Protection Agency (EPA). 1993. External exposure to radionuclides in air, water, and soil. Federal Guidance Report No. 12. Washington, DC.

U.S. Environmental Protection Agency (EPA). 1997. Exposure Factors Handbook. August 1997. Available from URL: Exiting ATSDR Website.

U.S. Environmental Protection Agency (EPA). 1999. Understanding the Safe Drinking Water Act. Available from URL: Exiting ATSDR Website. December 1999.

U.S. Environmental Protection Agency (EPA). National Primary Drinking Water Regulations, Part II: Radionuclides; Final Rule. Federal Register, 65 (236): 76712-15; Government Printing Office, Washington, DC; December 7, 2000.

U.S. Environmental Protection Agency (EPA). 2002a. Tennessee NPL/NPL caliber cleanup site summaries. U.S. DOE Oak Ridge Reservation, Oak Ridge, Anderson County, Tennessee. Available from URL: Exiting ATSDR Website (last updated 10/15/02; accessed 10/16/2002).

U.S. Environmental Protection Agency (EPA). 2002b. NPL site narrative for Oak Ridge Reservation (USDOE), Oak Ridge, Tennessee. Available from URL: Exiting ATSDR Website (last updated 10/4/02; accessed 11/26/2002).

U.S. Environmental Protection Agency (EPA). 2002c. Strontium. Last updated on 12/3/02. Available from URL: Exiting ATSDR Website.

U.S. Environmental Protection Agency (EPA). 2003. September 2001 sampling report for the Scarboro community, Oak Ridge, Tennessee. Athens, Georgia. April 2003.

U.S. Environmental Protection Agency (EPA), Region III. 2003. October 2003 Update. Updated Risk Based Concentration Table Cover Memo. October 15, 2003. Available from the following URL: Exiting ATSDR Website.

U.S. General Accounting Office (GAO). 1994. Report to the chairman, Committee on Governmental Affairs, U.S. Senate. Nuclear Health and Safety: Consensus on acceptable radiation risk to the public is lacking. GAO/WED-94-190.

U.S. General Accounting Office (GAO). 2000. GAO report to the Honorable Pete Domenici, U.S Senate. June 2000 radiation standards: scientific basis inconclusive, and EPA and NRC disagreement continues. GAO/RCED-00-152.



The Agency for Toxic Substances and Disease Registry (ATSDR) is a federal public health agency with headquarters in Atlanta, Georgia, and 10 regional offices in the United States. ATSDR's mission is to serve the public by using the best science, taking responsive public health actions, and providing trusted health information to prevent harmful exposures and diseases related to toxic substances. ATSDR is not a regulatory agency, unlike the U.S. Environmental Protection Agency (EPA), which is the federal agency that develops and enforces environmental laws to protect the environment and human health.

This glossary defines words used by ATSDR in communications with the public. It is not a complete dictionary of environmental health terms. If you have questions or comments, call ATSDR's toll-free telephone number, 1-888-42-ATSDR (1-888-422-8737).

The process of taking in. For a person or animal, absorption is the process through which a substance gets into the body through the eyes, skin, stomach, intestines, or lungs.

The number of radioactive nuclear transformations occurring in a material per unit time. The term for activity per unit mass is specific activity.

Occurring over a short time [compare with chronic].

Acute exposure:
Contact with a substance that occurs once or for only a short time (up to 14 days) [compare with intermediate-duration exposure and chronic exposure].

Adverse health effect:
A change in body function or cell structure that might lead to disease or health problems.

Surrounding (for example, ambient air).

Analytic epidemiologic study:
A study that evaluates the association between exposure to hazardous substances and disease by testing scientific hypotheses.

Background level:
An average or expected amount of a substance or radioactive material in a specific environment, or typical amounts of substances that occur naturally in an environment.

Background radiation:
The amount of radiation to which a member of the general population is exposed from natural sources, such as terrestrial radiation from naturally occurring radionuclides in the soil, cosmic radiation originating from outer space, and naturally occurring radionuclides deposited in the human body.

Plants and animals in an environment. Some of these plants and animals might be sources of food, clothing, or medicines for people.

Body burden:
The total amount of a substance in the body. Some substances build up in the body because they are stored in fat or bone or because they leave the body very slowly.

Any one of a group of diseases that occurs when cells in the body become abnormal and grow or multiply out of control.

Cancer risk:
A theoretical risk of for getting cancer if exposed to a substance every day for 70 years (a lifetime exposure). The true risk might be lower.

A substance that causes cancer.

Case-control study:
A study that compares exposures of people who have a disease or condition (cases) with people who do not have the disease or condition (controls). Exposures that are more common among the cases may be considered as possible risk factors for the disease.

Central nervous system:
The part of the nervous system that consists of the brain and the spinal cord.

[See Comprehensive Environmental Response, Compensation, and Liability Act of 1980.]

Occurring over a long time (more than 1 year) [compare with acute].

Chronic exposure:
Contact with a substance that occurs over a long time (more than 1 year) [compare with acute exposure and intermediate-duration exposure].

Committed Effective Dose Equivalent (CEDE):
The sum of the products of the weighting factors applicable to each of the body organs or tissues that are irradiated and the committed dose equivalent to the organs or tissues. The committed effective dose equivalent is used in radiation safety because it implicitly includes the relative carcinogenic sensitivity of the various tissues. The unit of dose for the CEDE is the rem (or, in SI units, the sievert–1 sievert equals 100 rem.)

Comparison value (CV):
Calculated concentration of a substance in air, water, food, or soil that is unlikely to cause harmful (adverse) health effects in exposed people. The CV is used as a screening level during the public health assessment process. Substances found in amounts greater than their CVs might be selected for further evaluation in the public health assessment process.

Completed exposure pathway:
[See exposure pathway.]

Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA):
CERCLA, also known as Superfund, is the federal law that concerns the removal or cleanup of hazardous substances in the environment and at hazardous waste sites. ATSDR, which was created by CERCLA, is responsible for assessing health issues and supporting public health activities related to hazardous waste sites or other environmental releases of hazardous substances.

The amount of a substance present in a certain amount of soil, water, air, food, blood, hair, urine, breath, or any other medium.

A substance that is either present in an environment where it does not belong or is present at levels that might cause harmful (adverse) health effects.

Curie (Ci):
A unit of radioactivity. One curie equals that quantity of radioactive material in which there are 3.7 1010 nuclear transformations per second. The activity of 1 gram of radium is approximately 1 Ci; the activity of 1.46 million grams of natural uranium is approximately 1 Ci.

Decay product/daughter product/progeny:
A new nuclide formed as a result of radioactive decay: from the radioactive transformation of a radionuclide, either directly or as the result of successive transformations in a radioactive series. A decay product can be either radioactive or stable.

Depleted uranium (DU):
Uranium having a percentage of U 235 smaller than the 0.7% found in natural uranium. It is obtained as a byproduct of U 235 enrichment.

Referring to the skin. For example, dermal absorption means passing through the skin.

Dermal contact:
Contact with (touching) the skin [see route of exposure].

Descriptive epidemiology:
The study of the amount and distribution of a disease in a specified population by person, place, and time.

Detection limit:
The lowest concentration of a chemical that can reliably be distinguished from a zero concentration.

Disease registry:
A system of ongoing registration of all cases of a particular disease or health condition in a defined population.

The United States Department of Energy.

Dose (for chemicals that are not radioactive):
The amount of a substance to which a person is exposed over some time period. Dose is a measurement of exposure. Dose is often expressed as milligrams (a measure of quantity) per kilogram (a measure of body weight) per day (a measure of time) when people eat or drink contaminated water, food, or soil. In general, the greater the dose, the greater the likelihood of an effect. An "exposure dose" is how much of a substance is encountered in the environment. An "absorbed dose" is the amount of a substance that actually gets into the body through the eyes, skin, stomach, intestines, or lungs.

Dose (for radioactive chemicals):
The radiation dose is the amount of energy from radiation that is actually absorbed by the body. This is not the same as measurements of the amount of radiation in the environment.

Dose-response relationship:
The relationship between the amount of exposure [dose] to a substance and the resulting changes in body function or health (response).

Environmental Media Evaluation Guide, a media-specific comparison value that is used to select contaminants of concern. Levels below the EMEG are not expected to cause adverse noncarcinogenic health effects.

Enriched uranium:
Uranium in which the abundance of the U 235 isotope is increased above normal.

Environmental media:
Soil, water, air, biota (plants and animals), or any other parts of the environment that can contain contaminants.

Environmental media and transport mechanism:
Environmental media include water, air, soil, and biota (plants and animals). Transport mechanisms move contaminants from the source to points where human exposure can occur. The environmental media and transport mechanism is the second part of an exposure pathway.

The United States Environmental Protection Agency.

Epidemiologic surveillance:
The ongoing, systematic collection, analysis, and interpretation of health data. This activity also involves timely dissemination of the data and use for public health programs.

The study of the distribution and determinants of disease or health status in a population; the study of the occurrence and causes of health effects in humans.

Equilibrium, radioactive:
In a radioactive series, the state that prevails when the ratios between the activities of two or more successive members of the series remain constant.

Contact with a substance by swallowing, breathing, or touching the skin or eyes. Exposure can be short-term [see acute exposure], of intermediate duration [see intermediate-duration exposure], or long-term [see chronic exposure].

Exposure assessment:
The process of finding out how people come into contact with a hazardous substance, how often and for how long they are in contact with the substance, and how much of the substance they are in contact with.

Exposure-dose reconstruction:
A method of estimating the amount of people's past exposure to hazardous substances. Computer and approximation methods are used when past information is limited, not available, or missing.

Exposure investigation:
The collection and analysis of site-specific information and biological tests (when appropriate) to determine whether people have been exposed to hazardous substances.

Exposure pathway:
The route a substance takes from its source (where it began) to its end point (where it ends), and how people can come into contact with (or get exposed to) it. An exposure pathway has five parts: a source of contamination (such as an abandoned business); an environmental media and transport mechanism (such as movement through groundwater); a point of exposure (such as a private well); a route of exposure (eating, drinking, breathing, or touching), and a receptor population (people potentially or actually exposed). When all five parts are present, the exposure pathway is termed a completed exposure pathway.

Exposure registry:
A system of ongoing follow up of people who have had documented environmental exposures.

Feasibility study:
A study by EPA to determine the best way to clean up environmental contamination. A number of factors are considered, including health risk, costs, and what methods will work well.

Grand rounds:
Training sessions for physicians and other health care providers about health topics.

Water beneath the earth's surface in the spaces between soil particles and between rock surfaces [compare with surface water].

Half-life (t½):
The time it takes for half the original amount of a substance to disappear. In the environment, the half-life is the time it takes for half the original amount of a substance to disappear when it is changed to another chemical by bacteria, fungi, sunlight, or other chemical processes. In the human body, the half-life is the time it takes for half the original amount of the substance to disappear either by being changed to another substance or by leaving the body. In the case of radioactive material, the half-life is the amount of time necessary for one half the initial number of radioactive atoms to change or transform into other atoms (normally not radioactive). After two half-lives, 25% of the original number of radioactive atoms remain.

A source of potential harm from past, current, or future exposures.

Hazardous waste:
Potentially harmful substances that have been released or discarded into the environment.

Health consultation:
A review of available information or collection of new data to respond to a specific health question or request for information about a potential environmental hazard. Health consultations are focused on a specific exposure issue. They are therefore more limited than public health assessments, which review the exposure potential of each pathway and chemical [compare with public health assessment].

Health education:
Programs designed with a community to help it know about health risks and how to reduce these risks.

Health investigation:
The collection and evaluation of information about the health of community residents. This information is used to describe or count the occurrence of a disease, symptom, or clinical measure and to estimate the possible association between the occurrence and exposure to hazardous substances.

Health statistics review:
The analysis of existing health information (i.e., from death certificates, birth defects registries, and cancer registries) to determine if there is excess disease in a specific population, geographic area, and time period. A health statistics review is a descriptive epidemiologic study.

Indeterminate public health hazard:
The category used in ATSDR's public health assessment documents when a professional judgment about the level of health hazard cannot be made because information critical to such a decision is lacking.

The number of new cases of disease in a defined population over a specific time period [contrast with prevalence].

The act of swallowing something through eating, drinking, or mouthing objects. A hazardous substance can enter the body this way [see route of exposure].

The act of breathing. A hazardous substance can enter the body this way [see route of exposure].

Intermediate-duration exposure:
Contact with a substance that occurs for more than 14 days and less than a year [compare with acute exposure and chronic exposure].

Ionizing radiation:
Any radiation capable of knocking electrons out of atoms and producing ions. Examples: alpha, beta, gamma and x rays, and neutrons.

Nuclides having the same number of protons in their nuclei, and hence the same atomic number, but differing in the number of neutrons, and therefore in the mass number. Identical chemical properties exist in isotopes of a particular element. The term should not be used as a synonym for "nuclide," because "isotopes" refers specifically to different nuclei of the same element.

Lowest-observed-adverse-effect level (LOAEL):
The lowest tested dose of a substance that has been reported to cause harmful (adverse) health effects in people or animals.

The conversion or breakdown of a substance from one form to another by a living organism.

Milligrams per kilogram.

Milligrams per cubic meter: a measure of the concentration of a chemical in a known volume (a cubic meter) of air, soil, or water.

Moving from one location to another.

Minimal risk level (MRL):
An ATSDR estimate of daily human exposure to a hazardous substance at or below which that substance is unlikely to pose a measurable risk of harmful (adverse), noncancerous effects. MRLs are calculated for a route of exposure (inhalation or oral) over a specified time period (acute, intermediate, or chronic). MRLs should not be used as predictors of harmful (adverse) health effects [see reference dose].

Death. Usually the cause (a specific disease, condition, or injury) is stated.

A substance that causes mutations (genetic damage).

A change (damage) to the DNA, genes, or chromosomes of living organisms.

National Priorities List for Uncontrolled Hazardous Waste Sites (National Priorities List or NPL):
EPA's list of the most serious uncontrolled or abandoned hazardous waste sites in the United States. The NPL is updated on a regular basis.

No apparent public health hazard:
A category used in ATSDR's public health assessments for sites where human exposure to contaminated media might be occurring, might have occurred in the past, or might occur in the future, but is not expected to cause any harmful health effects.

No-observed-adverse-effect level (NOAEL):
The highest tested dose of a substance that has been reported to have no harmful (adverse) health effects on people or animals.

No public health hazard:
A category used in ATSDR's public health assessment documents for sites where people have never and will never come into contact with harmful amounts of site-related substances.

[See National Priorities List for Uncontrolled Hazardous Waste Sites.]

A radionuclide which, upon disintegration, yields a new nuclide, either directly or as a later member of a radioactive series.

A volume of a substance that moves from its source to places farther away from the source. Plumes can be described by the volume of air or water they occupy and the direction in which they move. For example, a plume can be a column of smoke from a chimney or a substance moving with groundwater.

Point of exposure:
The place where someone can come into contact with a substance present in the environment [see exposure pathway].

A group or number of people living within a specified area or sharing similar characteristics (such as occupation or age).

Parts per billion.

Parts per million.

The number of existing disease cases in a defined population during a specific time period [contrast with incidence].

Actions that reduce exposure or other risks, keep people from getting sick, or keep disease from getting worse.

Public comment period:
An opportunity for the public to comment on agency findings or proposed activities contained in draft reports or documents. The public comment period is a limited time period during which comments will be accepted.

Public health action plan:
A list of steps to protect public health.

Public health advisory:
A statement made by ATSDR to EPA or a state regulatory agency that a release of hazardous substances poses an immediate threat to human health. The advisory includes recommended measures to reduce exposure and reduce the threat to human health.

Public health assessment (PHA):
An ATSDR document that examines hazardous substances, health outcomes, and community concerns at a hazardous waste site to determine whether people could be harmed by coming into contact with those substances. The PHA also lists actions that need to be taken to protect public health [compare with health consultation].

Public health hazard:
A category used in ATSDR's public health assessments for sites that pose a public health hazard because of long-term exposures (greater than 1 year) to sufficiently high levels of hazardous substances or radionuclides that could result in harmful health effects.

Public health hazard categories:
Statements about whether people could be harmed by conditions present at the site in the past, present, or future. One or more hazard categories might be appropriate for each site. The five public health hazard categories are no public health hazard, no apparent public health hazard, indeterminate public health hazard, public health hazard, and urgent public health hazard.

Public health statement:
The first chapter of an ATSDR toxicological profile. The public health statement is a summary written in words that are easy to understand. It explains how people might be exposed to a specific substance and describes the known health effects of that substance.

Public meeting:
A public forum with community members for communication about a site.

Quality factor (radiation weighting factor):
The linear-energy-transfer-dependent factor by which absorbed doses are multiplied to obtain (for radiation protection purposes) a quantity that expresses - on a common scale for all ionizing radiation - the approximate biological effectiveness of the absorbed dose.

The unit of absorbed dose equal to 100 ergs per gram, or 0.01 joules per kilogram (0.01 gray) in any medium [see dose].

The emission and propagation of energy through space or through a material medium in the form of waves (e.g., the emission and propagation of electromagnetic waves, or of sound and elastic waves). The term "radiation" (or "radiant energy"), when unqualified, usually refers to electromagnetic radiation. Such radiation commonly is classified according to frequency, as microwaves, infrared, visible (light), ultraviolet, and x and gamma rays and, by extension, corpuscular emission, such as alpha and beta radiation, neutrons, or rays of mixed or unknown type, such as cosmic radiation.

Radioactive material:
Material containing radioactive atoms.

Spontaneous nuclear transformations that result in the formation of new elements. These transformations are accomplished by emission of alpha or beta particles from the nucleus or by the capture of an orbital electron. Each of these reactions may or may not be accompanied by a gamma photon.

An unstable or radioactive isotope (form) of an element that can change into another element by giving off radiation.

Any radioactive isotope (form) of any element.

Risk-based Concentration, a contaminant concentration that is not expected to cause adverse health effects over long-term exposure.

[See Resource Conservation and Recovery Act (1976, 1984).]

Receptor population:
People who could come into contact with hazardous substances [see exposure pathway].

Reference dose (RfD):
An EPA estimate, with uncertainty or safety factors built in, of the daily lifetime dose of a substance that is unlikely to cause harm in humans.

A unit of dose equivalent that is used in the regulatory, administrative, and engineering design aspects of radiation safety practice. The dose equivalent in rem is numerically equal to the absorbed dose in rad multiplied by the quality factor (1 rem is equal to 0.01 sievert).

Remedial investigation:
The CERCLA process of determining the type and extent of hazardous material contamination at a site.

Resource Conservation and Recovery Act (1976, 1984) (RCRA):
This act regulates management and disposal of hazardous wastes currently generated, treated, stored, disposed of, or distributed.

[See reference dose.]

The probability that something will cause injury or harm.

Route of exposure:
The way people come into contact with a hazardous substance. Three routes of exposure are breathing [inhalation], eating or drinking [ingestion], and contact with the skin [dermal contact].

Safety factor:
[See uncertainty factor.]

A portion or piece of a whole; a selected subset of a population or subset of whatever is being studied. For example, in a study of people the sample is a number of people chosen from a larger population [see population]. An environmental sample (for example, a small amount of soil or water) might be collected to measure contamination in the environment at a specific location.

Sievert (Sv):
The SI unit of any of the quantities expressed as dose equivalent. The dose equivalent in sieverts is equal to the absorbed dose, in gray, multiplied by the quality factor (1 sievert equals 100 rem).

A liquid capable of dissolving or dispersing another substance (for example, acetone or mineral spirits).

Source of contamination:
The place where a hazardous substance comes from, such as a landfill, waste pond, incinerator, storage tank, or drum. A source of contamination is the first part of an exposure pathway.

Special populations:
People who might be more sensitive or susceptible to exposure to hazardous substances because of factors such as age, occupation, sex, or behaviors (for example, cigarette smoking). Children, pregnant women, and older people are often considered special populations.

Specific activity:
Radioactivity per unit mass of material containing a radionuclide, expressed, for example, as Ci/gram or Bq/gram.

A person, group, or community who has an interest in activities at a hazardous waste site.

A branch of mathematics that deals with collecting, reviewing, summarizing, and interpreting data or information. Statistics are used to determine whether differences between study groups are meaningful.

A chemical.

Surface water:
Water on the surface of the earth, such as in lakes, rivers, streams, ponds, and springs [compare with groundwater].

[see epidemiologic surveillance]

A systematic collection of information or data. A survey can be conducted to collect information from a group of people or from the environment. Surveys of a group of people can be conducted by telephone, by mail, or in person. Some surveys are done by interviewing a group of people.

Toxicological profile:
An ATSDR document that examines, summarizes, and interprets information about a hazardous substance to determine harmful levels of exposure and associated health effects. A toxicological profile also identifies significant gaps in knowledge on the substance and describes areas where further research is needed.

The study of the harmful effects of substances on humans or animals.

Uncertainty factor:
A mathematical adjustment for reasons of safety when knowledge is incomplete–for example, a factor used in the calculation of doses that are not harmful (adverse) to people. These factors are applied to the lowest-observed-adverse-effect-level (LOAEL) or the no-observed-adverse-effect-level (NOAEL) to derive a minimal risk level (MRL). Uncertainty factors are used to account for variations in people's sensitivity, for differences between animals and humans, and for differences between a LOAEL and a NOAEL. Scientists use uncertainty factors when they have some, but not all, the information from animal or human studies to decide whether an exposure will cause harm to people [also sometimes called a safety factor].

Units, radiological:
Units Equivalents
Becquerel* (Bq) 1 disintegration per second = 2.7 ×10-11 Ci
Curie (Ci) 3.7 ×1010 disintegrations per second = 3.7 × 1010 Bq
Gray* (Gy) 1 J/kg = 100 rad
Rad (rad) 100 erg/g = 0.01 Gy
Rem (rem) 0.01 sievert
Sievert* (Sv) 100 rem
*International Units, designated (SI)

Urgent public health hazard:
A category used in ATSDR's public health assessments for sites where short-term exposures (less than 1 year) to hazardous substances or conditions could result in harmful health effects that require rapid intervention.

Other Glossaries and Dictionaries:
Environmental Protection Agency Exiting ATSDR Website
National Center for Environmental Health (CDC) Exiting ATSDR Website
National Library of Medicine Exiting ATSDR Website


Summary of ATSDR Activities

Exposure Investigations, Health Consultations, and Other Scientific Evaluations. ATSDR health scientists have addressed current public health issues and community health concerns related to two areas affected by Oak Ridge Reservation (ORR) operations–the East Fork Poplar Creek (EFPC) area and the Watts Bar Reservoir area.

Following are summaries of other ATSDR public health activities involving EFPC:

Following are summaries of other ATSDR public health activities involving Watts Bar Reservoir:

Clinical Laboratory Analysis. In June 1992, an Oak Ridge physician reported to the TDOH and the Oak Ridge Health Agreement Steering Panel (ORHASP) that approximately 60 of his patients may have been exposed, either occupationally or from the environment, to several heavy metals. The physician felt that these exposures had resulted in a number of adverse health outcomes (for example, increased incidence of cancer, chronic fatigue syndrome, neurological diseases, autoimmune disease, and bone marrow damage). In 1992 and 1993, ATSDR and CDC's National Center for Environmental Health (NCEH) facilitated clinical laboratory support by the NCEH Environmental Health Laboratory for patients referred by an Oak Ridge physician to the Howard Frumkin, M.D., Dr.PH., Emory University School of Public Health.

Because of patient-to-physician and physician-to-physician confidentiality, results of the clinical analysis have not been released to public health agencies. However, Dr. Frumkin recommended (in an April 26, 1995 letter to the Commissioner of TDOH) that one should "not evaluate the patients seen at Emory as if they were a cohort for whom group statistics would be meaningful. This was a self-selected group of patients, most with difficult to answer medical questions (hence their trips to Emory), and cannot in any way be taken to typify the population at Oak Ridge. For that reason, I have consistently urged Dr. Reid, each of the patients, and officials of the CDC and the Tennessee Health Department, not to attempt group analyses of these patients."

Review of Clinical Information on Persons Living In or Near Oak Ridge. In addition to the above Clinical Laboratory Analysis, an ATSDR physician reviewed the clinical data and medical histories provide by the Oak Ridge physician on 45 of his patients. The purpose of this review was to evaluate clinical information on persons tested for heavy metals and to determine whether exposure to metals was related to these patients' illnesses. ATSDR concluded that this case series did not provide sufficient evidence to associate low levels of metals with these diseases. The TDOH came to the same conclusion. ATSDR sent a copy of its review to the Oak Ridge physician in September 1992.

Health education. Another essential part of the public health assessment process is designing and implementing activities that promote health and provide information about hazardous substances in the environment.

Coordination with other parties. Since 1992 and continuing to the present, ATSDR has consulted regularly with representatives of other parties involved with the ORR. Specifically, ATSDR has coordinated efforts with TDOH, TDEC, NCEH, NIOSH, and DOE. This effort led to the establishment of the Public Health Working Group in 1999, which led to the establishment of ORRHES. In addition, ATSDR provided some assistance to TDOH in its study of past public health issues. ATSDR has also obtained and interpreted studies prepared by academic institutions, consulting firms, community groups, and other parties.

Establishment of the ORR Public Health Working Group and the ORRHES. In 1998, in collaboration with the DOE Office of Health Studies, ATSDR and CDC embarked on a process of developing credible, coherent, and coordinated agendas of public health activities and health studies for each DOE site. In February 1999, ATSDR was given the responsibility to lead the interagency group's efforts to improve communication at ORR. In cooperation with other agencies, ATSDR established the ORR Public Health Working Group to gather input from local organizations and individuals regarding the creation of a public health forum. After careful consideration of the input gathered from community members, ATSDR and CDC determined that the most appropriate way to meet the needs of the community would be to establish the ORRHES.

Site visits. To better understand site-specific exposure conditions, ATSDR scientists have conducted site visits to the ORR and visited surrounding areas numerous times since 1992. The site visits included guided tours of the ORR operation areas, as well as tours of the local communities to identify how community members might come into contact with environmental contamination.

Summary of U.S. Department of Health and Human Services Activities

U.S. Department of Health and Human Services' Evaluation of Data in The Tennessean Article. In a November 2,1998 letter, the Honorable William H. Frist, M.D., United States Senator requested Donna E. Shalala, Secretary of the Department of Health and Human Services (DHHS), have the CDC, ATSDR, and the National Institutes of Health (NIH) evaluate the data on which the The Tennessean article describes reports of a pattern of illnesses among residents living near nuclear plants, including the DOE ORR.

In particular, Senator Frist requested the following:

In a February 22, 1999, Donna E. Shalala, Secretary of DHHS, responded to Senator Frist's request. The DHHS evaluated the The Tennessean article and responded to the Senator Frist's five specific issues. DHHS concluded the following:

  1. The data in The Tennessean article were not compiled from an epidemiologic study and thus have many limitations. It is impossible to calculate rates for the reported illnesses or to determine whether rates of the illnesses were abnormal. It is also difficult to relate excess illnesses to specific nuclear plants because primary exposures differ among the plants.

  2. Epidemiologically, it is neither acceptable to tabulate data collected in an unstandardized manner, nor to assess illnesses and symptom based on limited diagnostic information. Thus, it is not possible to determine if data in this report represent a new or unusual occurrence of symptoms in this population.

  3. DHHS has a significant number of ongoing studies that seek to analyze environmental exposure at each of the 11 sites rather than focusing on general medical evaluations of the populations near the sites. However, clinical data from the Fernald Medical Monitoring Program and the Scarboro, Tennessee survey focus on respiratory illnesses in children and, although quite limited, are most relevant to the issues raised by the report.

  4. Sound data using standardized information is essential in order to establish increased prevalence of a disease and linkage to the nuclear plants.
  5. First, the occurrence of a single, definable illness would have to be assessed.

    Second, studies including structured population surveys would need to be developed for general health and illness data in well-defined population groups near the nuclear sites. The finding would then be compared to results form other well-defined populations living elsewhere.

    Third, any attempt to determine a causal relationship between disease or illness rates in these populations and exposures to hazards would be difficult since historic exposures are difficult to identify and measure.

  6. CDC, ATSDR, and NIH are working with DOE to plan appropriate public health follow-up activities to address the concerns of communities and workers regarding the nuclear weapons complexes. Embarking on such a comprehensive program will require considerable resource, planning, and evaluation. Please note that CDC, ATSDR, and NIH do not provide direct primary medical services to communities. However, where possible, CDC, ATSDR, and NIH will continue to support community leaders and existing medical care systems to address public health concerns of communities that are near nuclear plants.

Summary of TDOH Activities

Pilot Survey. In the fall of 1983, TDOH developed an interim soil mercury level for use in environmental management decisions. CDC reviewed the methodology for the interim mercury level in soil and recommended that a pilot survey be conducted to determine whether populations with the highest risk for mercury exposure had elevated body burdens of mercury. In June and July 1984, a pilot survey was conducted to document human body levels of inorganic mercury for residents of Oak Ridge with the highest potential for mercury exposure from contaminated soil and fish. The survey also examined whether exposure to mercury-contaminated soil and fish constituted an immediate health risk to the Oak Ridge population. The results of the pilot survey, released in October 1985, suggested that residents and workers in Oak Ridge, Tennessee, are not likely to be at increased risk for having significantly high mercury levels. Mercury concentrations in hair and urine samples were below levels associated with known health effects.

Health Statistics Review. In June 1992, an Oak Ridge physician reported to TDOH and ORHASP that he believed approximately 60 of his patients had experienced occupational and environmental exposures to several heavy metals. The physician felt that these exposures had resulted in increased cancer, immunosuppression, chronic fatigue syndrome, neurologic diseases, autoimmune disease, bone marrow damage, and hypercoagulable state including early myocardial infarctions and stroke. In 1992, the TDOH conducted a health statistics review to compare cancer incidence rates for the period of 1988 to 1990 for counties surrounding the ORR to rates from the rest of the state. Findings of the review are in a TDOH memorandum dated October 19, 1992, from Mary Layne Van Cleave to Dr. Mary Yarbrough. The memorandum details an Oak Ridge physician's concerns about the health status in the Oak Ridge area. Also available from the TDOH are the minutes and handouts from a presentation given by Ms. Van Cleave at the ORHASP meeting on December 14, 1994.

Health Statistics Review. In 1994 local residents reported that there were many community members with amyotrophic lateral sclerosis (ALS) and multiple sclerosis (MS). The TDOH in consultation with Peru Thapa, MD, MPH, from the Vanderbilt University School of Medicine conducted a health statistics review of mortality rates for amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), and other selected health outcomes.

TDOH found that because ALS and MS are not reportable diseases, it is impossible to calculate reliable incidence rates. Mortality rates for the period of 1980 to 1992 were reviewed for the 10 counties surrounding the ORR and compared with mortality rates for the state of Tennessee. The following results were reported by the TDOH at the ORHASP public meeting on August 18, 1994.

Knowledge, Attitude, and Beliefs Study. A study, coordinated by TDOH, was conducted in an eight-county area surrounding Oak Ridge, Tennessee. The purpose of the study was to (1) investigate public perceptions and attitudes about environmental contamination and public health problems related to the ORR, (2) ascertain the public's level of awareness and assessment of the ORHASP, and (3) make recommendations for improving public outreach programs. The report was released in August 1994. Following is a summary of the findings.

Health Assessment. A health assessment of the East Tennessee region was conducted by TDOH's East Tennessee Region to evaluate the health status of the population, assess the availability and utilization of health services, and develop priorities in planning to use resources. In December 1991, the East Tennessee Region released the first edition of A Health Assessment of the East Tennessee Region, which included data generally from 1986 to 1990. The second edition, released in 1996, included data generally from 1990 through 1995. A copy of the document is available from the TDOH East Tennessee Region.

Presentation. Dr. Joseph Lyon of the University of Utah gave a presentation to inform the ORHASP and the public of the multiple studies related to the fallout from the Nevada Test Site, including the study of leukemia and thyroid disease. The presentation was sponsored by TDOH and held on February 16, 1995, at the ORHASP public meeting.

Summary of Joint Center for Political and Economic Studies Activities

Scarboro Community Assessment Report. In 1999, the Joint Center for Political and Economic Studies conducted a survey of the Scarboro community to identify environmental and health concerns of the residents. The surveyors attempted to elicit responses from the whole community and achieved an 82% response rate. Additionally, with support from DOE Oak Ridge Operations, the Joint Center has been working with the community since 1998 to help residents articulate their environmental, health, economic, and social needs. Because Scarboro is a small community, the community assessment provided new information about the community that is not available through sources such as the U.S. Census Bureau. It also identified Scarboro's strengths and weaknesses and illustrated the relative unimportance of environmental health issues to other community concerns–environmental and health issues are not a priority for most Scarboro residents; rather the community is more concerned about crime and security, children, and economic development. The Joint Center recommended more active community involvement in city and community planning (Friday and Turner 2001).

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