3.2 Issue 2: Off-Site Exposure

3.2.1 Phase I Oak Ridge Health Study

Purpose

Phase I of the Oak Ridge Health Study is a dose reconstruction feasibility study. Phase I evaluates all past releases of hazardous substances and operations at the Oak Ridge Reservation. The objective of the study was to determine the quantity, quality, and potential usefulness of the available information and data on these past releases and subsequent exposure pathways. With this information, preliminary screening analyses were performed to identify priority hazardous substances of public health concern and determine the feasibility of conducting dose reconstruction studies that would reconstruct these releases and estimate exposure doses.

Findings

The dose reconstruction feasibility study indicated that a significant amount of information was available to reconstruct the past releases and potential off-site exposure doses for four hazardous substances that may have been responsible for adverse health effects. The materials that will be studied in detail are as follows.

1. Radioactive iodine releases associated with radioactive lanthanum processing at X-10 during 1944 through 1956.
2. Mercury releases associated with lithium separation and enrichment operations at the Y-12 plant during 1955 through 1963.
3. Polychlorinated biphenyls (PCBs) in fish from the East Fork Poplar Creek, Clinch River, and the Watts Bar Reservoir.
4. Radionuclides from White Oak Creek associated with various chemical separation activities at X-10 during 1943 through the 1960s.

Background and Agencies Involved

As provided by the health studies agreement project between the state of Tennessee and DOE, the Tennessee Department of Health is conducting dose reconstruction studies at Oak Ridge. This is an independent state evaluation of exposure to hazardous substances released from past operations at the reservation. The Oak Ridge Health Agreement Steering Panel-a panel of experts and local citizens-provides direction, recommendations, and oversight. The NCEH represents the CDC on the steering panel.

Time Line

Phase I began in August 1992, and the final documents were released in October 1993.

3.2.2 Pilot Survey of Mercury Levels in Oak Ridge

Purpose

The pilot survey of mercury 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.

Findings

The results of the pilot survey 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.

Background and Agencies Involved

From 1953 through 1963 the Oak Ridge Y-12 plant used elemental mercury in a lithium separation process to produce lithium deuteride fuel for thermonuclear weapons. In 1983 DOE released a declassified copy of a report on the mercury inventory at the Y-12 plant which estimated that 220,000 to 470, 000 pounds of mercury were discharged into the East Fork Poplar Creek. Soil samples documented mercury levels as high as 2,000 parts per million in the floodplain.

In the fall of 1983, the Tennessee Department of Health and Environment 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 of 1984, the Tennessee Department of Health and Environment and the CDC Centers for Environmental Health conducted the pilot survey.

Time Line

The pilot survey was released in October 1985.

3.2.3 Health Consultation on Y-12 Weapons Plant Chemical Releases into East Fork Poplar Creek

Purpose

A health consultation was conducted to evaluate the public health implications from all known and potential, current, exposure pathways to chemical and radioactive contaminants released into the East Fork Poplar Creek from the Y-12 weapons plant.

Findings

The East Fork Poplar Creek Phase IA data evaluated for this health consultation indicate that the creek's soil, sediment, groundwater, surface water, air, and fish are contaminated with various chemicals. However, only mercury in soil and sediment, and PCBs and mercury in fish are at levels of public health concern. The maximum levels of mercury in soil and sediment were 1,010 ppm and 2,240 ppm, respectively. In addition, the concentrations of a few metals and volatile organic compounds in the shallow groundwater are of public health concern, but there is no evidence that shallow groundwater along East Fork Poplar Creek is used for drinking water or other domestic purposes. Other contaminants, including radionuclides found in soil, sediment, surface water, and fish, were not detected at levels of public health concern.

ATSDR made the following conclusions.

1. Soil and sediments in certain locations along the East Fork Poplar Creek floodplain are contaminated with levels of mercury that pose a public health concern.
2. Fish in the creek contain levels of mercury and PCBs that pose a moderately increased risk of adverse health effects to people who eat fish frequently over long periods of time.
3. Shallow groundwater along the East Fork Poplar Creek floodplain contains metals at levels of public health concern; however, this shallow groundwater is not used for drinking or other domestic purposes.

Background and Agencies Involved

Under the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund), ATSDR is mandated to conduct a public health assessment for each facility listed on the NPL. In 1989 the DOE Oak Ridge Reservation was placed on the NPL.

ATSDR conducted the health consultation in response to community concerns reported in 1993 about current exposure to hazardous substances released into the East Fork Poplar Creek from ongoing and past operations at the Y-12 plant.

Time Line

The final health consultation was completed in March 1993.

3.2.4 Lower East Fork Poplar Creek Remedial Investigation/Feasibility Study

Purpose

This study was performed as a requirement of the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund) to assess contamination-primarily mercury-contaminated floodplain soils-resulting from releases since 1950 from the Y-12 plant. The objectives of the study were to determine the extent of contamination of the East Fork Poplar Creek floodplain, to develop a baseline risk analysis based on the level of contaminants, and to determine whether remedial action is required.

Findings

The remedial investigation indicated that portions of the floodplain were contaminated with mercury and that floodplain soil with mercury concentrations of more than 400 parts per million (ppm) would constitute an unacceptable risk to human health and the environment. Based on this determination, the Record of Decision called for remedial action. The remedial action included the excavation of four areas of the floodplain where soils had mercury concentrations of more than 400 ppm; confirmatory sampling during excavation activities to document the removal; disposal of contaminated soil into Landfill V at the Y-12 plant under a special waste permit; backfilling of excavated areas, including a 0.6-acre wetland, with clean borrow soil; and revegetation of the affected areas.

Background and Agencies Involved

Lower East Fork Poplar Creek is an off-site operable unit associated with the Oak Ridge Reservation, which was placed on the NPL in December 1989. Under Comprehensive Environmental Response, Compensation, and Liability Act (Superfund), a remedial investigation/feasibility study must be conducted on NPL sites. The Oak Ridge Reservation environmental restoration activities are conducted within the Federal Facility Agreement, a triparty agreement among DOE, the TDEC, and the EPA.

Time Line

The remedial investigation/feasibility study for lower East Fork Poplar Creek was completed in 1994. The Record of Decision was approved in September 1995, and remediation field activities began in June 1996. The volume of soil to be excavated differed so much from the original estimate and the value stated in the Record of Decision that an Explanation of Significant Differences was published in September 1996. Remediation activities were completed in October 1997. The Comprehensive Environmental Response, Compensation, and Liability Act (Superfund calls for a review within five years after commencement of remedial action to ensure that the actions adequately protect human health and the environment.

3.2.5 ATSDR Science Panel Meeting on the Bioavailability of Mercury in Soil

Purpose

An ATSDR science panel meeting was held to identify methods and strategies for the development of data-supported, site-specific estimates of the bioavailability of inorganic mercury and other metals from soils.

Findings

Three technical papers and an ATSDR overview paper on the findings of the panel meeting were published in the International Journal of Risk Analysis in 1997 (Volume 17:5).

Background and Agencies Involved

ATSDR is mandated to conduct a public health assessment for each facility listed on the NPL by the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund). The Oak Ridge Reservation was placed on the NPL in 1989.

After a review of the DOE studies and investigations on mercury in the flood plain and the clean-up levels, ATSDR determined that outside experts would be required to evaluate some technical mercury issues, such as speciation and bioavailability. In addition, ATSDR determined that an assessment of these technical issues by an independent scientific body would be especially warranted in presenting information to the community, which had been divided concerning the proposed mercury clean-up levels.

Private consultants and academicians internationally known for their metal bioavailability research were invited to be on the panel, which was sponsored by ATSDR. In addition to these members, the panel included experts from ATSDR, CDC, EPA, and the National Institute for Environmental Health Science.

ATSDR used information obtained from the panel meeting and technical papers to evaluate the East Fork Poplar Creek mercury clean-up level for soil.

Time Line

The panel meeting was held in August 1995, and the technical papers were published in October 1997.

3.2.6 Health Consultation on Proposed Mercury Clean-up Levels

Purpose

A health consultation was conducted to evaluate the public health implications of DOE's proposed mercury clean-up levels. DOE proposed mercury clean-up levels of 180 ppm and 400 ppm for the soil of the East Fork Poplar Creek floodplain.

Findings

ATSDR concluded that the East Fork Poplar Creek flood plain soil clean-up levels of 180 mg/kg and 400 mg/kg mercury are protective of public health and will pose no health threat to children or adults.

Background and Agencies Involved

Under the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund), ATSDR is mandated to conduct a public health assessment for each facility listed on the NPL. The DOE's Oak Ridge Reservation was placed on the list in 1989.

In response to a request from community members and the city of Oak Ridge, ATSDR evaluated the proposed mercury clean-up levels.

Time Line

The final health consultation was completed in January 1996.

3.2.7 Lower Watts Bar Reservoir Remedial Investigation/Feasibility Study

Purpose

This study to assess contamination in the Watts Bar Reservoir from the Oak Ridge Reservation was performed as a requirement of the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund). The objectives of the study were to determine the extent of contamination of the Watts Bar Reservoir, develop a baseline risk analysis based on the concentration levels of the contaminants, and to determine whether remedial action is required.

Findings

The results of the remedial investigation indicated that sediment, biota, and water of the Watts Bar Reservoir were contaminated with organic compounds, metals, and radionuclides. The baseline risk analysis indicated that human and environmental health standards would not be met if deep channel sediments containing cesium-137 were dredged and deposited in a residential setting and if people consumed moderate to high amounts of certain fish containing elevated levels of PCBs. These findings in the remedial investigation/feasibility study led to a Record of Decision that required the DOE to maintain controls to prevent unacceptable health and environmental impacts from these contaminants. These controls include (1) monitoring; (2) fish consumption advisories administered by the TDEC; and (3) controls on sediment-disturbing activities. The controls on the sediment activities are overseen by the Lower Watts Bar Reservoir Interagency Working Group: DOE, EPA, TDEC, the Tennessee Valley Authority, and the US Army Corps of Engineers.

Background and Agencies Involved

The Watts Bar Reservoir is an off-site operable unit associated with the Oak Ridge Reservation, which was placed on the NPL in December 1989. Under the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund), a remedial investigation/feasibility study must be conducted for each NPL site. The Oak Ridge Reservation environmental restoration activities are conducted through the Federal Facility Agreement, a triparty agreement among DOE, EPA, and the TDEC. Data used in the investigation were collected by the state of Tennessee, the Tennessee Valley Authority, and the Oak Ridge National Laboratory.

Time Line

The remedial investigation/feasibility study was published in March 1995. A Record of Decision was finalized in September 1995. Monitoring activities are ongoing. The Comprehensive Environmental Response, Compensation, and Liability Act (Superfund) calls for review within five years after commencement of remedial action to ensure that the actions adequately protect human health and the environment.

3.2.8 Health Consultation on Lower Watts Bar Reservoir

Purpose

A health consultation was conducted to evaluate the public health implications for all known and potential, current, exposure pathways for chemical and radiologic contaminants released into the lower Watts Bar Reservoir.

Findings

ATSDR concluded that PCBs in lower Watts Bar Reservoir fish pose a public health concern. Frequent and long-term ingestion of fish from the reservoir poses a moderately increased risk of cancer and may increase the possibility of developmental effects in infants whose mothers consume fish regularly during gestation and while nursing.

ATSDR also found that current levels of contaminants in the reservoir surface water and sediment were not a public health concern, and that the reservoir was safe for swimming, skiing, boating, and other recreational purposes. Additionally, water from the municipal water systems was safe to drink.

ATSDR also reported that DOE's selected remedial actions will protect public health. These actions include maintaining the fish consumption advisories; continuing environmental monitoring; implementing institutional controls to prevent disturbance, resuspension, removal, or disposal of contaminated sediment; and providing community and health professional education about the PCB contamination.

Background and Agencies Involved

Under the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund), ATSDR is mandated to conduct a public health assessment for each facility on the NPL. The Oak Ridge Reservation was placed on the NPL in 1989.

ATSDR conducted the health consultation in response to the request from residents in the vicinity of the Oak Ridge Reservation and the Watts Bar Reservoir for an evaluation of the public health implications of chemical and radiologic contaminants in the reservoir. ATSDR also rendered an independent opinion on whether the DOE-selected remedial actions will be protective of public health.

Time Line

The health consultation was released to the public in February 1996.

3.2.9 Clinch River/Poplar Creek Remedial Investigation/Feasibility Study

Purpose

The Clinch River/Poplar Creek study was performed as a requirement of the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund). The purpose of the study was to investigate the impact of current and historical releases to the off-site surface water environment to determine whether remedial action is required at the site.

Background and Agencies Involved

Clinch River/Poplar Creek is an off-site operable unit associated with the Oak Ridge Reservation, which was placed on the NPL in December 1989. Sites on the NPL must be investigated under the Comprehensive Environmental Response, Compensation, and Liability Act (Superfund). Environmental restoration activities at the Oak Ridge Reservation are conducted through the Federal Facility Agreement, a triparty agreement among DOE, EPA, and TDEC.

Time Line

The results of the Remedial Investigation/Feasibility study were published in a report in March 1996. A Record of Decision was finalized in September 1997. The Remedial Action Report was approved in February 1998. The Comprehensive Environmental Response, Compensation, and Liability Act (Superfund) calls for review within five years after commencement of remedial action to ensure that the actions taken adequately protect human health and the environment.

Status

The remedy selected for Clinch River/Poplar Creek is similar to that of the lower Watts Bar Reservoir: fish consumption advisories administered by TDEC and the establishment of controls on sediment-disturbing activities. The controls on sediment-disturbing activities will be overseen by the Tennessee Valley Authority, the US Army Corps of Engineers, the TDEC, EPA, and DOE. The Remedial Action Report calls for monitoring of fish, sediment, surface water, and turtles.

3.2.10 Community and Physician Education on PCBs in Fish

Purpose

This health education program was conducted to inform local residents and physicians of the health risks associated with PCBs in fish in the Watts Bar Reservoir.

Findings

1. Approximately 40 community members attended a community health education meeting in Spring City, Tennessee, on September 11, 1996. A presentation was given on the health risk associated with PCBs in fish. Health educational materials developed for the presentation were handed out.
2. A physician and health professional education meeting for health care providers in the vicinity of the Watts Bar Reservoir was held at the Methodist Medical Center in Oak Ridge, Tennessee, on September 12, 1996. Physicians specializing in family practice, obstetrics and gynecology, and pediatrics were mailed letters of invitation to the grand round, along with a copy of two publications from the series of ATSDR Case Studies in Environmental Medicine, "Polychlorinated Biphenyls" and "Taking an Exposure History." The grand round included a presentation on the health risks associated with PCBs in fish.
3. ATSDR developed an instructive brochure on the TDEC fish consumption advisories for the Watts Bar Reservoir. The brochure was the result of the collaborative effort of local citizens, organizations, and state officials.

Background and Agencies Involved

ATSDR developed community and physician education programs on PCBs in the Watts Bar Reservoir to follow up on recommendations contained in the health consultation. Daniel Hryhorczuk, MD, MPH, ABMT, of the Great Lakes Center, University of Illinois at Chicago, made presentations on the health risks associated with PCBs in fish. This health education program also included the participation and cooperation of the Association of Occupational and Environmental Clinics (AOEC), the Tennessee Department of Health, the TDEC, the Oak Ridge Reservation Local Oversight Committee, and the Methodist Medical Center in Oak Ridge.

Time Line

This is an ongoing program that was initiated in September 1996.

3.2.11 Watts Bar Reservoir and Clinch River Turtle Sampling Survey

Purpose

The Watts Bar Reservoir and Clinch River Turtle sampling survey was undertaken to determine body burdens of contaminants in snapping turtles in the Watts Bar Reservoir and Clinch River.

Findings

The results of the survey indicate that turtles in the Watts Bar Reservoir and Clinch River do accumulate PCBs and other contaminants. The concentrations of PCBs in turtle tissue were found at levels of concern for human consumption based on data from the fish consumption advisories for the area. Most of the PCB contamination, however, was found to be in fat tissue, as it is with fish. Methods of food preparation, therefore, especially tissue selection, can greatly effect the amount of PCBs consumed with the turtle meat.

Background and Agencies Involved

For several years, the TDEC fish consumption advisories warning of PCB contamination in fish were issued for the Watts Bar Reservoir and many other national reservoirs. Because of the concern regarding PCBs in fish and the recognition that turtles from the reservoirs were also being consumed, this survey was undertaken by TDEC to sample the turtles in the area. Many agencies were consulted and involved in the project, including ATSDR, DOE, the Tennessee Department of Health, the Tennessee Valley Authority, and the Tennessee Wildlife Resources Agency.

Time Line

The Watts Bar Reservoir and Clinch River Turtle sampling survey report was released in May 1997.

3.2.12 Watts Bar Reservoir Exposure Investigation

Purpose

The exposure investigation was conducted to measure actual PCBs and mercury levels in people consuming moderate to large amounts of fish and turtles from the Watts Bar Reservoir and to determine whether these people are being exposed to high levels of PCBs and mercury.

Findings

1. The exposure investigation participants' serum PCB levels and blood mercury levels are very similar to levels found in the general population.
2. Only 5 of the 116 people tested (4%) had PCB levels that were higher than 20 micrograms per liter or parts per billion, which is considered to be an elevated level of total PCBs. Of the five participants who exceeded 20 micrograms per liter, four had levels of 20-30 micrograms per liter. Only one participant had a serum PCB level of 103.8 micrograms per liter, which is higher than the general population distribution.
3. Only one participant in the exposure investigation had a total blood mercury level higher than 10 micrograms per liter, which is considered to be elevated. The remaining participants had mercury blood levels that ranged up to 10 micrograms per liter, as might be expected to be found in the general population.

Background and Agencies Involved

In following up on the findings of previous studies and investigations of the Watts Bar Reservoir, ATSDR conducted the exposure investigation with cooperation from the Tennessee Department of Health and the Roane County Health Department.

Previous studies by state and federal agencies concluded that consumption of PCB-contaminated fish or turtles are the only current exposures of public health concern. These studies estimated that people who eat moderate to large amounts of certain fish or turtles may have higher than average PCB levels. However, these studies do not have actual evidence of elevated exposure to PCBs among consumers of large amounts of Watts Bar Reservoir fish or turtles.

Time Line

1. In September 1997, ATSDR screened more than 500 individuals and obtained blood samples from 116 individuals who met the criteria and volunteered, including 13 individuals from the Scarboro community. These participants were interviewed and blood was drawn for analyses of serum PCB and blood mercury.
2. In November 1997, ATSDR sent all participants written notification and interpretation of their individual results. In December 1997, an ATSDR physician conducted follow-up interviews with those participants who had been identified as having elevated values.
3. Between March 16 and 19 of 1998, ATSDR held public meetings in Oak Ridge (Scarboro community), Kingston, and Spring City to discuss the results of the exposure investigation.

3.2.13 Chestnut Ridge East Borrow Area Study

Purpose

The purpose of the Chestnut Ridge East Borrow area study was to locate groundwater exit pathways across the eastern boundaries of the Oak Ridge Reservation on Chestnut Ridge.

Findings

Sampling of "Bootlegger Spring," a perennial spring located east of Scarboro Creek, provided evidence that water flowing from the spring was contaminated with volatile organic compounds. These organic compounds were similar to those found near the Chestnut Ridge security pits. A reconnaissance of the surrounding areas found several swallets or swallow holes in a large unreclaimed borrow area between the security pits and Scarboro Road. Fluorescent dye was dropped into a swallet, and the dye was detected in Bootlegger Spring.

Background and Agencies Involved

The Chestnut Ridge East Borrow area study was initiated by the TDEC. This project stemmed from an effort to find the source for suspended sediments that appeared in the waters of a perennial spring at the University of Tennessee arboretum after storms. Analysis of the samples collected was conducted by the state of Tennessee Environmental Laboratories in Knoxville and Nashville.

Time Line

This project began in 1994 and ran through 1995. It was reported in the 1995 Environmental Monitoring Report of the TDEC.

3.2.14 Scarboro Community Environmental Study

Purpose

The purpose of the study was to address community concerns about environmental monitoring in the Scarboro neighborhood. These concerns included the validity of measurements taken at air monitoring station 46 (located in the Scarboro community) and external radiation results collected during past aerial surveys.

Findings

Analytical results were compared with results contained in the report entitled "Final Report on the Background Soil Characterization Project at the Oak Ridge Reservation, Oak Ridge, Tennessee," DOE/OR/01-1175/V2, October 1993 (BSCP). Mercury concentrations obtained in this study ranged from 0.021 milligrams per kilogram (mg/kg) to 0.30 mg/kg. These values are generally within the range of values given in the BSCP report. Radionuclide results including total uranium concentrations were within expected ranges. However, approximately 10% of the soil samples showed evidence of enrichment in uranium 235. In one sample, alpha-chlordane, gamma-chlordane, heptachlor, and heptachlor epoxide were above detection limits. In this sample, lead and zinc concentrations exceeded typical values in the BSCP by a factor of two.

Background and Agencies Involved

During May 18-27, 1998, 48 sites were sampled in the Scarboro community (40 soil sites and 8 sediment/surface water sites). The study was designed to incorporate community input and meet the requirements of an EPA investigation of this type. The analytical component of the study was conducted by the Environmental Sciences Institute at Florida Agriculture and Mechanical University (FAMU) and its contractual partners at the Environmental Radioactivity Measurement Facility at Florida State University and the Bureau of Laboratories of the Florida Department of Environmental Protection, and by DOE subcontractors in the Neutron Activation Analysis Group at the Oak Ridge National Laboratory.

All samples were analyzed for mercury and gamma-ray emitting radionuclides. Neutron activation analysis was used to analyze all soil and sediment samples for uranium. Approximately 10% of the samples collected were tested for the presence of analytes on the target compound list, the target analyte list, and isotopes of uranium, plutonium, and thorium by alpha spectroscopy. Radiological walkovers were conducted at all soil sampling sites.

Time Line

The final Scarboro Community Environmental Study was released in September 22, 1998, during a Scarboro community meeting.

3.2.15 K1070-A Dye Trace Sampling Project

Purpose

The purpose of the K1070-A dye trace sampling project was to locate groundwater exit pathways across the western boundaries of the Oak Ridge Reservation at the K1070-A burial ground and along the Clinch River.

Findings

Sampling of spring 21-002 provided evidence that water flowing from the spring was contaminated with volatile organic compounds similar to those found in the K1070-A burial ground. Fluorescent dye was introduced into wells at the burial ground and was detected in spring 21-002 after 13 hours. Dye was also detected off the site in a spring on the Clinch River.

Background and Agencies Involved

The K1070-A dye trace study was initiated by the TDEC. This project was part of an effort to cooperate with and assist the DOE and its contractors, Science Applications International Corporation and Crawford and Associates, during a dye trace study initiated by DOE. The TDEC was responsible for the collection of data and samples for the project. The state of Tennessee environmental laboratories in Knoxville and Nashville conducted the analysis of the samples.

Time Line

This project began in 1995 and continued through January of 1996. The project was reported in the 1996 Environmental Monitoring Report of the TDEC.

3.2.16 Oak Ridge Environmental Information System (OREIS)

Purpose

The Oak Ridge Environmental Information System (OREIS) is a centralized, standardized, quality-assured and configuration-controlled electronic environmental data management system.

It is comprised of hardware, commercial software, customized integration software, and documentation for the OREIS Environmental Measurements Data Base and the OREIS Geographic Data Base. The mission of OREIS is efficient retrievability and long-term retention of Oak Ridge operations environmental data. The scope of OREIS includes data supporting environmental restoration, compliance, and surveillance activities. Data from all major environmental monitoring and surveillance projects are entered into OREIS (e.g., annual site summary reports, studies of Upper and Lower East Fork Poplar Creek, the Clinch River embayment, Lower Watts Barr, Bear Creek, and the Scarboro Community Environmental Study).

A computer terminal linked to OREIS is available for public use at the Information Resource Center. It is equipped with a CD write drive and a floppy drive so that data can be copied and removed. A data library of CD ROMs of all OREIS files is being developed to make all data accessible to the public through the Internet from home computers. OREIS can be found on the Internet at the following address: http://www-oreis.bechteljacobs.org:8080/oreis.

Background and Agencies Involved

Due to the tremendous amount of environmental data developed on and around the Oak Ridge Reservation, a single data base was developed by DOE to assure data quality and availability. Federal and State agencies have direct terminal access into OREIS.

Time Line

By April 1999, this information should be available to the public through the Internet.

Status

All new environmental data is placed into OREIS upon completion of studies.

3.2.17 Phase II of Oak Ridge Health Studies

Purpose

The purpose of the Oak Ridge Health Studies was to evaluate exposure of off-site populations to hazardous substances released into the environment from operations at the Oak Ridge Reservation since its creation. Phase II of the Oak Ridge Health Studies reconstructed past releases of mercury, polychlorinated biphenyls (PCBs), radioactive iodine, radionuclides from White Oak Creek, and uranium, and estimated the past exposure or doses of these hazardous substances to off-site populations. The estimated exposure, or doses, were used to help determine which off-site populations were exposed to hazardous substances and what resulting adverse health effects they might have experienced.

Findings

The following study conclusions were reported in seven technical reports in 1999:

• Radioactive iodine releases were associated with radioactive lanthanum processing at X-10 during 1944 through 1956. Results indicate that children born in the area in the early 1950s who drank backyard cow's or goat's milk had an increased risk of developing thyroid cancer. Within a 25-mile radius of Oak Ridge, it is likely that these children had an increased risk of more than 1 in 10,000 of developing thyroid cancer.
• The study evaluated mercury releases associated with lithium separation and enrichment operations at the Y-12 plant during 1955 through 1963. Results indicate that, during the years mercury releases were highest (mid-fifties to early sixties), individuals may have received annual average doses of mercury exceeding the reference dose, depending on their activities. The reference dose for a substance is an estimate of the largest amount of a substance that a person can take in on a daily basis over their lifetime without experiencing adverse health effects.
• Additional studies were conducted on polychlorinated biphenyls (PCBs) in fish from the East Fork Poplar Creek, Clinch River, and the Watts Bar Reservoir. Preliminary results indicated that individuals who consume a large amount of fish from these waters may have received doses that exceeded the reference dose for PCBs.
• Radionuclides associated with various chemical separation activities at X-10 from 1943 through the 1960s were released intoWhite Oak Creek. Eight radionuclides deemed more likely to carry significant risks were studied. The results indicate that the White Oak Creek releases caused small increases in radiation dose in consumers of fish from the Clinch River near the mouth of White Oak Creek. However, less than one excess cancer case is expected from 50 years of fish consumption.
• Uranium was released from various large-scale uranium operations, primarily uranium processing and machining operations at the Y-12 plant from 1944-1988 and uranium enrichment operations at the K-25 and S-50 plants. Because uranium was not initially given high priority as a contaminant of concern, a Level II screening assessment for all uranium releases was performed. Preliminary screening indices are slightly below the decision guide of one chance in 10,000, indicating that more work may be needed to better characterize uranium releases and possible heath risks.

Background and Agencies Involved

As provided by a health studies agreement between the state of Tennessee and DOE, the Tennessee Department of Health conducted the Oak Ridge Health Studies (dose reconstruction studies). This is an independent state evaluation of exposure to hazardous substances released from past operations at the Oak Ridge Reservation. The Oak Ridge Health Agreement Steering Panel-a panel of experts and local citizens-provided direction, recommendations, and oversight. NCEH represented the CDC on the panel.

Time Line

Reports were released for review in the fall of 1997 and spring of 1998. Final draft reports were released in the summer and fall of 1998, and seven final technical reports were released in July 1999. The Oak Ridge Health Agreement Steering Panel issued a summary report, with recommendations, in December 1999. The reports are available from the DOE.

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