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Oak Ridge Reservation

Oak Ridge Reservation: Public Health Assessment Work Group

Public Health Assessment Work Group

April 7, 2003 - Meeting Minutes


Attendance

ORRHES Members attending:
Bob Craig (Work Group Chair), W. Don Box, George Gartseff, David Johnson, Susan Kaplan, James Lewis, Pete Malmquist, LC Manley, and Charles Washington

Public Members attending:
Gordon Blaylock and Danny Sanders

ATSDR Staff attending:
Burt Cooper, Jack Hanley, Lorine Spencer

DOE Staff attending:
David Page

ERG Contractor:
Michelle Arbogast (phone) and Liz Munsen (phone)

Purpose

Bob Craig called the PHAWG meeting to order and attendance was noted for the record.

The purpose of the meeting was to (1) discuss the minutes from the March 17, 2003, PHAWG meeting, (2) present and discuss ATSDR’s preliminary assessment of Y-12 mercury releases, (3) receive an update on the Epidemiology Ad Hoc Group’s effort regarding the Health Statistics Review, and (4) receive an update on the public health assessments (PHAs).

Minutes from the March 17, 2003, Meeting

Bob Craig asked the PHAWG for comments on the minutes. No one responded. There was a motion to approve the minutes and it was seconded. The March 17, 2003, minutes were unanimously approved.

Presentation and Discussion of ATSDR’s Preliminary Assessment of Y-12 Mercury Releases

Presenter: Jack Hanley, ATSDR

Jack Hanley provided an up-to-date summary of the mercury assessment. At the PHAWG meeting on January 21, 2003, Mr. Hanley presented a list of references that ATSDR would use in its preliminary portion of the mercury investigation. Since this time, ATSDR has been evaluating the available data, as well as working on the health assessment. Mr. Hanley explained that this meeting represented the PHAWG 2 meeting on the PHA process flow diagram. During this meeting, ATSDR will present its preliminary findings, have an informal discussion, and obtain community concerns. Following a couple of additional PHAWG meetings, ATSDR will return to the work group with a written version of the PHA. At that time, the PHAWG will provide comments to the ORRHES, and then the ORRHES will provide comments to ATSDR.

Video Presentation on DOE and Mercury Contamination on East Fork Poplar Creek

Jack Hanley presented a video to provide an introduction to mercury. He explained that the U.S. Department of Energy (DOE) prepared the video while it was conducting Superfund work at East Fork Poplar Creek (EFPC). The video would discuss some of the major operations that took place at the Y-12 facility, such as lithium separation. Mr. Hanley added that electromagnetic separation from uranium and uranium weapons production occurred at the facility; however, these processes were covered in the Y-12 Uranium Releases PHA. Mr. Hanley said that most of the mercury releases related to lithium separation took place in the 1950s; however, some did occur in the early 1960s.

According to the video, when DOE was formed in the late 1970s, it assumed ownership of the Oak Ridge Reservation (ORR) and its facilities. In 1983, DOE revealed that EFPC, which runs through the ORR and its floodplains, had been contaminated by releases from the Y-12 plant. This contamination began to occur in the 1950s, as a result of the initiation of lithium isotope separation operations at the Y-12 facility. These processes resulted in the release of between 259,000 and 470,000 pounds of mercury into EFPC. The discharge of mercury related to Y-12 operations discontinued in 1963. However, mercury continued to enter EFPC via secondary sources (e.g., sewers).

The video also explained that there were several remediation methods proposed for EFPC. DOE chose to use a combination of seven “action plans” to deal with the contamination. After much debate and research, a clean up level of 400 parts per million (ppm) was determined to be protective of human health. The remediation process consists of excavating contaminated soil, replacing the area with clean soil, and monitoring the area continuously. The cleanup will cost DOE under $10,000,000.

Timeline of Releases

Jack Hanley showed a “timeline of releases” overhead that was obtained from the Dose Reconstruction Study. The timeline showed the releases for water and the overall percentage released. The highest percentage was released in the late 1950s and small quantities continue to be released today.

Mercury Overview

Jack Hanley provided an overhead–Minimal Risk Levels for Mercury– to help explain the different forms of mercury, the primary pathways of exposure, and primary target organs. There are three different forms of mercury: elemental, inorganic, and organic. Elemental mercury includes liquid silver and metallic mercury (e.g., thermometer). Inorganic mercury, which basically consists of inorganic salts, could consist of mercuric chloride or mercuric sulfide. Organic mercury is the more toxic form and includes methylmercury.

Each of these forms has a different exposure pathway and various target organs. The primary exposure pathway for elemental mercury is inhalation. When mercury is inhaled, almost all of it (95-100%) is absorbed into the blood system, and most of it goes to the brain. Elemental mercury goes through the blood brain barrier to reach the brain; this type of mercury can also affect the kidney.

The primary exposure pathway for inorganic mercury is through ingestion and the primary target organ is the kidney. This form of mercury goes into the stomach, but a large amount of the mercury is not absorbed. Most of the inorganic mercury passes through, although a portion of it is absorbed by the stomach and small intestine. One type of inorganic mercury, mercuric chloride, is very soluble, and thus, it is more “bioavailable.” On the other hand, mercuric sulfide is relatively insoluble. If this form is consumed, less mercury is absorbed, and most of the substance passes through the system.

The primary exposure pathway of organic mercury is via ingestion, more particularly, through the ingestion of fish. This type of mercury, primarily methylmercury, is picked up by fish through the food chain. Tuna and other fish accumulate a large quantity of mercury in their bodies. Jack Hanley stated that this is a worldwide problem; it is not an isolated problem in Oak Ridge. Mercury is released through coal production, which produces mercury. The mercury is vaporized, travels long distances, goes into the water, and is picked up by the food chain.

Jack Hanley explained that issues related to mercury could be extremely complex. Each of these mercury contaminants has a different target endpoint, as well as a different lowest observed adverse effect level (LOAEL), no observed adverse effect level (NOAEL), minimal risk level (MRL), and reference dose (RfD).

In an attempt to simplify this topic, Jack Hanley will only cover current exposures during this meeting. He said that many of the questions being asked would be addressed during the evaluation of past exposures, which will be discussed in the near future. Mr. Hanley informed the PHAWG that ATSDR hired Dr. Bill Taylor to work in the Oak Ridge office. Dr. Taylor is a PhD chemist and a board certified toxicologist. He will be working with Mr. Hanley on this assessment, and will also be reviewing the Dose Reconstruction Study and the technical reviewers’ comments. Dr. Taylor’s analyses will be presented in a future meeting.

Current exposures from 1990 to the present will be discussed in this meeting. Jack Hanley asked the PHAWG to keep in mind that the primary pathway for inorganic mercury is ingestion of soil, sediment, and surface water; organic mercury is mainly ingested through fish and turtles; and elemental mercury is primarily carried via inhalation of contaminated air.

Primary Sources of Environmental Data for Current Mercury Exposures (1990 to Present)

Jack Hanley presented the PHAWG with a list of the primary sources of environmental data:

  • Lower East Fork Poplar Creek Remedial Investigation Feasibility Study (RI/FS)
  • Lower Watts Bar Reservoir RI/FS
  • Clinch River/Poplar Creek RI/FS
  • DOE Annual Monitoring Reports
  • Oak Ridge Environmental Information System (OREIS) Database
  • Tennessee Department of Environment and Conservation (TDEC
  • Tennessee Department of Natural Resources (TDNR)
  • Tennessee Valley Authority (TVA)

Inorganic Mercury–1993 ATSDR Health Consultation on Y-12 Weapons Plant Releases into East Fork Poplar Creek

Purpose

The purpose of this health consultation was to evaluate published environmental data that were available, and to assess public health implications related to the Y-12 releases of chemical and radioactive contaminants into the EFPC. At the time of this health consultation, DOE was moving forward with an RI and Superfund activities, whereas ATSDR was first becoming involved with the ORR.

Environmental Data Evaluated

ATSDR evaluated environmental data from a 1992 Phase IA remedial investigation. This preliminary sampling data included soil, sediment, surface water, air, fish, and groundwater from the EFPC floodplain. The environmental samples were analyzed for metals, volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), radionuclides, and polychlorinated biphenyls (PCBs). Jack Hanley said that samples could have also been analyzed for pesticides and additional contaminants.

Overall Findings

ATSDR evaluated the available data and developed three overall findings:

  • Inorganic mercury in soil and sediment, as well as PCBs and organic mercury in fish, are at levels of public health concern.
  • Other contaminants, including radionuclides found in soil, sediment, and surface water, were not at levels of public health concern.
  • The shallow groundwater along the EFPC floodplain contained a few metals and VOCs at levels of public health concern. However, the shallow groundwater along EFPC is not used for drinking water or for other purposes.

Jack Hanley explained that a health consultation is a first assessment, which basically provides a “narrow” review of the situation. Karl Markiewicz is re-evaluating these data to see if any standards have changed since this health consultation was prepared. He is also looking at additional data to see if there are other contaminants that should be considered.

Specific Inorganic Mercury Findings

ATSDR developed the following findings related to inorganic mercury and soil:

  • ATSDR determined that the soil and sediment in a few locations along the EFPC floodplain contained levels of inorganic mercury that posed a public health concern (up to 2,240 ppm in soil).
  • The mercury in the soil primarily consisted of some relatively insoluble inorganic forms of mercury (e.g., mercury salts), with less than 0.1% of the mercury in organic form. A portion of this inorganic mercury is converted to an organic form, washed off, and flushed into the water system. This conversion is a very slow process and it is the reason why there is not much mercury seen in soil; the mercury accumulates in the fish.
  • The primary route of exposure to inorganic mercury was through ingestion of soil from hand-to-mouth activities and from excessive dermal exposure.
  • ATSDR concluded that frequent, long-term exposure to the EFPC floodplain soil that contained elevated levels of mercury could result in effects on the kidney.

Specific Inorganic Mercury Recommendations

ATSDR made the following recommendations particular to inorganic mercury, and DOE took follow up actions based on these recommendations:

  • Determine the depth and extent of mercury contamination in the EFPC soil and sediment.
  • As an interim action, until permanent remedial action is implemented, post signs and restrict access to areas with elevated soil and sediment levels of mercury.
  • Conduct a survey of well water use along the EFPC floodplain.

Inorganic Mercury–1996 ATSDR Health Consultation on the Proposed Mercury Clean up Level for the EFPC Flood Plain Soil

Jack Hanley expanded on the clean up level discussion that was mentioned in the video. Mr. Hanley stated that after the mercury was detected in EFPC in the 1980s, the state health department was asked to develop a clean up level. The state looked at the information that was available about mercury toxicity, but little material could be found on inorganic mercury. Thus, organic mercury, which is the most toxic form, was used to develop an action level. The state decided to use a level of 10 ppm, which was derived from the World Health Organization (WHO). As the state conducted more work at the creek, it realized that the mercury was primarily an inorganic form, and as a result, it used the U.S. Environmental Protection Agency’s (EPA) standard default values to develop a clean up level of 50 ppm. This level was based on the exposure pathway and mercuric chloride.

Jack Hanley continued that when the state tried to define a more specific assumption for the remedial investigation, it came up with 180 ppm. As the video explained, the state presented this value to the public, and the public asked the state to reassess this value. The public feared that the expense associated with this level would be exorbitant and that this type of clean up would destroy the wetlands. As a result of the public’s concern and other reasons as well, the EPA, DOE, and TDEC worked together. These agencies used a “bioavailability factor,” which accounts for the fact that 100 percent of the mercury is not absorbed into the body. Based on this analysis, 400 ppm was developed as a clean up level. The City of Oak Ridge Environmental Quality Advisory Board asked ATSDR to evaluate the 400 ppm level, and thus ATSDR conducted this health consultation.

The purpose of this consultation was to evaluate the public health impact of DOE’s proposed EFPC floodplain soil clean up level, which was 400 ppm of mercury in the floodplain. In order to conduct this assessment, ATSDR evaluated two exposure scenarios–the worst-case exposure scenario and the realistic residential exposure scenario. Jack Hanley explained that these scenarios considered mercuric chloride because this is the form that is used in toxicology studies, and ATSDR wanted to compare the same forms of mercury. Mercuric chloride is highly soluble and more is absorbed across the stomach and intestine than with other inorganic forms of mercury. In addition, ATSDR had an expert mercury panel that evaluated this issue. The panel suggested that mercuric chloride is a relatively insoluble inorganic form of mercury and that you could not “speciate”between the different types of inorganic mercury.

Worst-case scenario

The worst-case scenario assessed exposure based on: (1) the most sensitive population (young child), (2) the most absorbable form of inorganic mercury (mercuric chloride), and (3) the most probable route of exposure (ingestion), which was assumed everyday for six years.

Realistic residential scenario

ATSDR also developed a more realistic residential scenario that evaluated exposure based on: (1) a young child, (2) the most absorbable form of inorganic mercury (mercuric chloride), and (3) the most probable route of exposure (ingestion), which was assumed for five days a week, for 36 weeks per year, and for a period of six years.

Estimated Doses Compared with NOAELs and LOAELs

ATSDR estimated the dose to evaluate the quantity of mercury that a child would receive from each exposure scenario. To estimate the dose, ATSDR calculated the milligrams of mercury per kilograms of body weight per day (mg/kg/day). The estimated exposure doses for both scenarios were compared to the following: (1) the intermediate exposure NOAEL for mercuric chloride, which is the highest dosage administered that did not cause health effects, (2) the intermediate exposure LOAEL for mercuric chloride, which is the lowest dosage that did produce an observable health effect, and (3) the chronic exposure NOAEL for mercuric chloride.

Results–Worst-case Scenario

The results showed that the estimated oral exposure dose of 0.002 mg/kg/day for inorganic mercury is much lower then the LOAEL and NOAEL for mercuric chloride.

  • 115 times less than the intermediate exposure NOAE
  • 230 times less than the intermediate exposure LOAEL
  • 950 times less than the chronic exposure LOAEL

Results–Realistic Scenario

The results showed that the estimated oral exposure dose of 0.001 mg/kg/day for inorganic mercury is much lower than the LOAEL and NOAEL for mercuric chloride.

  • 230 times less than the intermediate exposure NOAEL
  • 460 times less than the intermediate exposure LOAEL
  • 1,900 times less than the chronic exposure LOAEL

Jack Hanley presented a graph entitled–Levels of Significant Exposure to Inorganic Mercury (Ingestion of Mercuric Chloride)–to demonstrate these results in relation to the results from mice and rat studies. He explained that the MRL is based on a study where there was no effect seen in rats, and that the MRL accounts for a safety factor of 100.

Jack Hanley said that the public had raised concerns with regards to the fact that EPA is a regulatory agency. EPA uses an RfD, which is a level that EPA considers to be safe; this is not a health level. ATSDR uses an MRL, which is used to assess health effects. If a dose fell below the level that would elicit an effect, then this would not be of concern. Mr. Hanley presented the chronic exposure RfD on the graph that was 0.0003 mg/kg/day, which is based on three studies, a review, and workshop discussions. Mr. Hanley said that anything below the intermediate exposure MRL of 0.002 mg/kg/day is not expected to be a problem.

Jack Hanley summarized that this is for EFPC. However, the mercury did not stop at this creek. It went to Poplar Creek, to the Clinch River, to Kingston, and into the reservoir. DOE conducted an RI/FS on this area in the mid-1990s, which looked at all of the data collected in the 1980s by TVA, DOE, and other agencies.

ATSDR’s Conclusions

The estimated oral exposure dose to mercury in the EFPC floodplain is much lower (2 to 3 orders of magnitude) than the relevant NOAELS and LOAELs for assuming mercuric chloride. ATSDR believes that the mercury in the floodplain is a relatively insoluble form of mercury, which is less absorbable than mercuric chloride. In addition, ATSDR concluded that the 400 mg/kg floodplain soil clean up level for mercury was protective of public health, and would not pose a health threat to children or adults.

As Jack Hanley had previously mentioned, ATSDR had used a science panel in 1995 to identify methods and strategies to develop a bioavailability factor. This panel was used to assess the amount of mercury that had crossed the gut from the stomach, had traveled into the blood, and was absorbed by the small intestines. This panel was a multi-disciplined group of individuals, including private consultants, analytical chemists, internationally known specialists, geologists, and several other people from different backgrounds. This panel investigated the bioaccessibility (i.e., how much mercury is released from the soil) and the speciation (i.e., can you tell if a substance is mercuric chloride, mercuric sulfide, or another form) of mercury. The panel prepared three papers that were published and the information was used for ATSDR’s clean up. ATSDR had the papers reviewed by experts worldwide. In addition, the Centers for Disease Control and Prevention (CDC), ATSDR, EPA, and the National Institute of Environmental Health and Safety were involved in the project.

As a result of these analyses, two clean ups were conducted at EFPC. In addition, continuous water monitoring is performed to assess the creek’s stability, and also to determine locations that have increased levels (in order to evaluate possible erosion). Also, fish are monitored on a regular basis and these remediation activities are reviewed every five years.

Inorganic Mercury–1996 ATSDR Health Consultation on Lower Watts Bar Reservoir

The purpose of this consultation was to evaluate the public health implications of chemical and radiological contaminants in the Watts Bar Reservoir and to assess the effectiveness of DOE’s proposed remedial action plan for protecting public health.

To obtain environmental data, ATSDR evaluated reservoir studies conducted during the 1980s and 1990s by DOE, TVA, the Tennessee Department of Environment and Conservation (TDEC), and the Tennessee Department of Natural Resources.

ATSDR’s Overall Findings

ATSDR’s health consultation revealed the following:

  • The maximum chemical and radioactive contaminant concentrations reported in the recent surface sediment data would not present a public health hazard.
  • Current levels of contaminants in the reservoir surface water and sediment were not a public health concern. The reservoir was determined to be safe for swimming, skiing, boating, and other recreational purposes.
  • The levels of PCBs in the Lower Watts Bar Reservoir fish posed a public health concern. Frequent and long-term ingestion of fish from the reservoir posed a moderately increased risk of cancer in adults, and increased the possibility of developmental effects in infants whose mothers consumed fish regularly during gestation and while nursing. Turtles in the reservoir might also contain PCBs at levels of public health concern.
  • DOE’s selected remedial action was protective of public health.

DOE’s remedial action plan mainly requires the monitoring of fish, monitoring of water, and leaving the sediment untouched. In addition, if people want to build a pier, dig in the reservoir, or put down a piling, they have to obtain a permit. All of the state agencies, as well as the U.S. Army Corps of Engineers (USACE), have a unified system to handle these permits.

Organic Mercury–1993 ATSDR Health Consultation on Y-12 Weapons Plant Releases into East Fork Poplar Creek

The purpose of this consultation was to evaluate the published environmental data and to assess the public health implications associated with the Y-12 releases of chemical and radioactive contaminants into the EFPC.

Specific Organic Mercury Findings

ATSDR’s health consultation yielded the following specific findings:

Fish in the creek contain levels of mercury that pose a moderately increased risk of adverse health effects to people who eat fish frequently over long periods of time.

  • Organic mercury is the primary form of mercury found in fish.
  • Frequent ingestion of EFPC fish over the long-term may result in neurotoxic effects.
  • Continue the EFPC fish advisory.

Organic Mercury–1993 ATSDR Health Consultation on Lower Watts Bar Reservoir

The purpose of this health consultation was to evaluate the public health implications of chemical and radiological contaminants in the Watts Bar Reservoir, and to assess the effectiveness of the DOE’s proposed remedial action plan for protecting public health. ATSDR concluded that the level of exposure to mercury from eating fish from the Watts Bar Reservoir was not a public health concern.

Organic Mercury–ATSDR Exposure Investigation on Serum PCB and Blood Mercury Levels in Consumers of Fish and Turtles from Watts Bar Reservoir

Jack Hanley explained that because the PCB levels were a concern, DOE held a public meeting in Spring City, Tennessee, to discuss the results of the RI/FS. During the public meeting, a man from the community stated that he consumed turtles and he wanted to know if this was a problem. DOE was unable to answer this man’s question because turtles had not been sampled. At this time, Mr. Hanley was working on the health consultation and he requested that the state collect turtle samples. The samples showed that the PCBs in turtle meat were about 2 to 3 ppm. However, the PCBs in turtle fat were found up to 500 ppm. Since turtle consumption could not be estimated, an exposure investigation was conducted.

EPA, DOE, and ATSDR conducted risk assessments to estimate these doses. The results showed that consumption of these fish could potentially be a problem for people who consumed a lot of fish over a long period of time.

The purpose of this exposure investigation was to determine if people consuming moderate to large amounts of fish and turtles from the Watts Bar Reservoir were being exposed to elevated levels of PCBs or mercury. PCBs were the focus of the exposure investigation. However, blood mercury levels were evaluated due to the historical contamination of mercury.

Jack Hanley explained that the objective was to measure the serum PCB level in the blood mercury level. If needed, ATSDR would follow up with education and would set objectives to see if further assessment was necessary. He said that the study was also conducted because the state of Tennessee had performed a feasibility study on epidemiological studies with the Oak Ridge Reservation Health Effects Subcommittee (ORRHES). One of the recommendations of the feasibility study was to conduct a bio-prevalence study to measure for contaminants that could be measured. In addition, ATSDR wanted to calculate actual levels of exposure.

Study Design and Methods

This study was cross-sectional in design as it evaluated exposures at one point in time. However, because mercury blood levels are an indicator of chronic exposure, the results of this investigation provided information on both past and current exposure. The target population for this investigation was persons who consumed moderate to high amounts of fish and turtles from Watts Bar Reservoir. The specific objectives of this investigation included:

  • Measuring levels of serum PCBs and blood mercury in consumers of fish or turtles.
  • Identifying appropriate health education activities and follow-up health actions.
  • Providing new information to help evaluate the need for future region wide assessments.

Specific Mercury Findings

ATSDR screened out 550 people and drew blood from 116 people. The 116 people were from six to eight different counties and represented a wide variety of subjects (e.g., young, old, fisherman). Only one participant had an elevated blood mercury level that was higher than 10 ppb. The remaining participants had mercury levels up to 10 ppb, which is comparable to levels found in the general population.

Before conducting the exposure investigation, ATSDR estimated organic mercury doses from eating fish in the Watts Bar Reservoir. ATSDR looked at the striped bass, which had the highest average mercury concentration in the reservoir, and evaluated the dose if a person consumed striped bass (8 ounces) two times a week. Jack Hanley presented a graph entitled–Levels of Significant Exposure to Organic Mercury (Ingestion)–to show the dose compared to the chronic exposure MRL. The calculated dose was 0.00031 mg/kg/day, which would not elicit an effect at this level. However, if this were an intermediate exposure, there would be a slight effect. ATSDR’s blood analysis showed that people consuming a lot of fish were not being exposed.

Elemental Mercury–1993 ATSDR Health Consultation on Y-12 Weapons Plant Releases into East Fork Poplar Creek

The purpose of this consultation was to evaluate the published environmental data and to assess the public health implications associated with the Y-12 releases of chemical and radioactive contaminants into the EFPC.

ATSDR evaluated data using two different methodologies–short-term monitoring and long-term monitoring. Ambient air data from one meter off of the ground were collected from three EFPC floodplain locations, which were known to have mercury soil concentrations up to 3,000 ppm.

ATSDR found that the metallic mercury vapor levels in the ambient air at the three creek areas were not at levels of public health concern. However, the excavation of contaminated soil may result in mercury vapor being released from the soil, especially as the air temperature increases.

Jack Hanley presented a graph entitled–Levels of Significant Exposure to Elemental Mercury (Inhalation). According to Mr. Hanley, the maximum air concentration during the EFPC clean up was .00008 milligrams per cubic meter (mg/m3). He showed the PHAWG this leveon the graph, which was below the ATSDR’s MRL and the EPA’s RfD.

Discussion

Bob Craig asked Jack Hanley if he could remind the PHAWG about the time period between PHAWG 2 and PHAWG 4. Mr. Hanley responded that he does not have the exact number of days, but that this meeting will occur sometime in July. At that time, ATSDR will present the PHAWG with a written document.

A meeting participant asked if the column exchange (COLEX) and electric exchange (ELEX) were two separate processes. Jack Hanley believed that these were two separate processes. David Page said that he also understood these to be two processes. The participant requested that Mr. Hanley evaluate this further. Mr. Hanley said that he could explain the different mercury processes in more detail within the document.

Following the video presentation, L.C. Manley asked if the mercury was in liquid or solid form, and if the mercury was vaporizing. Jack Hanley responded that this would be covered in his upcoming presentation. David Page, the program manager for the clean up of EFPC, explained his understanding of the lithium separation operations. He said that once mercury was used, the substance was cleaned with a diluted nitric acid solution. This solution provided an ionic form of mercury, which was discharged to EFPC. Mr. Page added that these activities pre-dated the Clean Air Act, which was passed in 1970. Thus, pollution laws were not yet in effect. He believed that clays in the floodplain have a large affinity for absorption, so they bind and form mercuric sulfide complexes. He explained that Steve Hildebrand from the Oak Ridge National Laboratory (ORNL) had conducted studies in the floodplain area to see if there were concentrations of metallic mercury being released into the atmosphere; however, he did not see this occur.

L.C. Manley was concerned that mercury had been heated to a point where it would be vaporized. David Page said that this did not happen. Mr. Page stated that he deals with the mercury when it “hits” the water. He said that what occurred in the building is another matter, and that he does not know about the processes that took place there. Charles Washington stated that the answer to Mr. Manley’s question is “yes” because the mercury could be vaporized.

Gordon Blaylock asked David Page about the video, which said that most of the mercury in the floodplains was mercuric sulfide. Dr. Blaylock said that there has been disagreement about the three forms of mercury, and that he did not think that a conclusion was ever reached. He asked Mr. Page if there was any new information on this. Mr. Page explained that they conducted a simulated digestion process, where they found that this waste did not leach at 2,000 parts per billion (ppb). He added that there were no conclusive studies that pure sulfide was the final compound, but that “this is not a homogenous system.” Dr. Blaylock continued that the conclusion was that this was a compound that would not leach from the soil. Mr. Page said that this was correct.

Gordon Blaylock mentioned a conference that was held to determine if this compound was mercuric sulfide, but that no one had reached an agreement. He thought that the conference had involved DOE and another entity. David Page explained that DOE had a collaborative effort with the University of Las Vegas, where they used different methods that the K-25 chemistry lab uses. He said that Ralph Turner disagreed with this methodology of using two normal nitric acid on the soils, and saying that this was the cause of the release. He added that if there was two normal nitric acid in the environment, then people would not be worried about mercury. Mr. Page said that there have been other studies that looked at using various chemical and physical means. These studies found that two normal nitric acid or higher was needed to cause leaching.

George Gartseff asked if Jack Hanley’s chart on the facility’s processes into the early 1990s referred to primary or secondary sources. Bob Craig added that he found this confusing as well. Mr. Gartseff stated that his confusion is with the chronology of relative quantities of mercury over time. He gathered that the largest quantity was released before 1963, that this amount declined after this year, and that there is still some mercury being released following remediation activities. Mr. Gatseff asked David Page if he could comment on the relative percent reduction that has occurred. Mr. Page said that he did not have these numbers. Mr. Hanley described a recent DOE presentation that discussed levels from 1989 to 2000. Mr. Hanley said that water concentrations have gone down, but that fish concentrations have not declined significantly over this period of time.

George Gartseff asked if, during any of these stages of release reduction, there had been any change in the form of mercury that was predominant with when it was released. David Page thought that a couple of things had occurred. When the mercury was released, primarily they looked at the COLEX process, but mercury was also lost through the storm drain system. Mr. Page said that some people believe this came from sumps under Alpha 4 because there are springs there.

David Page added that Ralph Turner conducted a study where Lake Reality is located. Presently, the creek is being channeled away from Lake Reality and only using it as a catch basin. The reason for this is that mercury-contaminated lake waters would travel into Lake Reality. As you go into the later months of the year, such as late July and August, there is a loss of the dissolved oxygen concentration. As a result, anaerobic conversion by bacteria occurs in the sediments in the basin, and mercury is converted from a metal to methylmercury or di-methylmercury. Dr. Turner set a couple of fish corals and ran water that was being pumped to Lake Reality through the corals, and then used groundwater as his control. In addition, Mr. Page said that they saw what they assumed to be an uptake of methylmercury, and that they conducted other work at a lab in Oregon that showed that some of the body burden of mercury had been increased. In conclusion, Mr. Page explained that this is what they think occurred there and that this could possibly explain some of the accumulation in the fish downstream.

Gordon Blaylock thought that they were told at the last ORRHES meeting that there was an increase in mercury in EFPC. He asked if there was any information collected on this matter. Jack Hanley responded that he was not at that meeting. Dr. Blaylock added that the Bechtel Jacobs 2003 Environmental Report stated that there was an increase in fish concentrations at one of the downstream sampling stations. Mr. Hanley said that he would look into this matter. Dr. Blaylock noted that there are a couple of hypotheses for this occurrence, for instance, that this may be due to a more complex environment that is developing because of less environmental degradation. David Page stated that at one time, there had been a lot of discussion about runoff at the plant and within the plant, in regards to transporting residual mercury to the creek.

Bob Craig asked if the timeline of releases was showing one-tenth of one percent. Jack Hanley said that Dr. Craig was correct. He added that this was the same with the air releases, although those had basically stopped when the operations ceased. Mr. Hanley added that all of the operations (e.g., COLEX) would be fully described within the PHA.

Don Box detailed how the ecology division of X-10 worked on streams at the Y-12 facility in the late 1980s and early 1990s. Bob Craig noted that this was Ralph Turner and other scientists. Mr. Box continued that he brought his camera into the streams and to the spring to try and locate mercury, but that he could not find any. Danny Sanders asked Jack Hanley if the elemental mercury that he described was at room temperature. Mr. Hanley responded that this was correct.

Charles Washington stated that the ORNL is conducting a study on mercury in fish because it has become a worldwide problem. Jack Hanley said that EPA has been actively working on this problem for the past 10 years. Mr. Hanley explained that oftentimes, this kind of mercury is metallic mercury that is vaporized and deposited in the ocean. This would result in exposure to metallic mercury; the primary effect of this type of exposure is developmental effects in offspring.
Gordon Blaylock stated that the EPA standard was originally 0.5 ppm, but because they were destroying so much tuna on the West Coast, EPA raised its standard. Dr. Blaylock added that the EPA changed its standard only because it was receiving a lot of pressure. Jack Hanley responded that EPA sometimes has to take an “economic impact” into consideration, but ATSDR does not.

A meeting participant asked about the Food and Drug Administration (FDA) standards. Jack Hanley asked Michelle Arbogast if she could provide this information. For mercury in fish, Ms. Arbogast said that the FDA’s standard is 1.0 ppm and that the EPA’s risk based concentration (RBC) is 0.14 ppm.

Pete Malmquist said that this argument occurs everywhere. He explained that there is controversy in Florida because the state standards are less strict than EPA’s standards for ocean and local fish consumption. He said that the residents feel that the state of Florida should “toughen up.”

Bob Craig stated that the inorganic mercury at the site is being found in sulfide form, not chloride form, and asked if this was biologically available. Jack Hanley said that he would discuss this point further in his presentation. Mr. Hanley said that DOE says that it is mercuric sulfide and other people disagree. He will provide ATSDR’s opinion during his presentation.

A meeting participant asked if there would be handouts. Jack Hanley said that handouts are not provided because this is a preliminary discussion.

Bob Craig asked if the shallow groundwater samples taken along the EFPC exceeded the standards used (e.g., drinking water standards). Jack Hanley responded that these pockets of groundwater samples did exceed the health-based levels used by ATSDR. However, since the water was not used for drinking water or other domestic purposes, it was not a public health problem.

James Lewis asked if it was a concern that people play in the water during the summer when the water is up. Jack Hanley replied that there would have to be frequent exposure over long periods of time (e.g., weeks, months), unless a person went to where the water was extremely high and started to eat the water. This behavior would possibly result in a minor stomachache.

Susan Kaplan explained that there was a new housing development located further west on the turnpike. She said that there is a swing set near the floodplain and asked if this was an issue. Jack Hanley responded that this was a concern before it was built, and that it was one reason why ATSDR became involved in this project. DOE conducted a full remedial investigation. During its process, DOE sampled every 100 feet for 14 miles–from the “head waters by the Y-12 plant to Poplar Creek.” DOE took a transecter across the floodplain and went out and sampled every 20 feet. Mr. Hanley explained this further by showing the PHAWG a map of the area. Gordon Blaylock commented that the map showed several dots that were below 400 ppm (red were above 400 ppm). Mr. Hanley presented detailed maps from the remedial investigation that showed each 100 feet, the transects that went across, and the sampling at 16 and 32 inches, and at 0 and16 inches. The sampling was conducted from 1992 to 1993, and the map showed all of the concentrations.

Susan Kaplan asked about the potential impact of a recent flood and if this could recontaminate the area. Jack Hanley stated that all of the areas detected above 400 ppm were cleaned up. James Lewis suggested that the term “flood” be defined. Mr. Lewis said that if they had a recent flood that did not exceed the 100-year floodplain, then it would not go outside of the range. He asked if he was correct. Mr. Hanley explained that there is no development inside of the floodplain. David Page said that they did not have a flood of record that was equal to 100 or greater than the 100-year floodplain. Mr. Page added that USACE had independently conducted modeling and analyses. Ms. Kaplan said that she was talking about the present. She wanted to know the likelihood that a current flood could recontaminate some of these areas. Mr. Hanley stated that this was possible. He added that the large pockets of mercury are visible, and that if the mercury was concentrated in one area and it was moved by water, then the mercury would be dispersed.

Gordon Blaylock asked about the samples taken by USACE. He asked if these samples had been measured from 15 inches and then down to 32 inches. Jack Hanley replied that it was done “16” at a time. Dr. Blaylock asked if the samples were conducted an inch at a time. Mr. Hanley replied that this was not done. Dr. Blaylock stated that when these numbers are combined, you might not actually know the measure of concentration in an area. Mr. Hanley said that Dr. Blaylock was correct and explained that these “hot spot” areas were found and when USACE dug in this area, they could see where the mercury was located.

David Page responded that this was an issue that had been discussed with EPA because USACE’s protocol called for “homogenizing” the samples. Back in 1985/1986 when Mr. Page worked for TVA, he had conducted a study at the creek. During this study, they had used fractions and could see the horizons and different “deposition” areas. Mr. Page added that the mercury could always be seen because it is dark black in color. He added that this addresses risk because risk is based on exposure. Thus, if mercury is underground, a person needs to know how they could be exposed to it. Mr. Page stated that he thinks that 32 inches was used because if someone was to farm, this was the level that the soil would be tilled. Jack Hanley added that most of the mercury was found within the first two feet.

Charles Washington identified an area of the creek that was of concern because people used it for swimming. Jack Hanley clarified that this was prior to 1990 and that it was an exposure scenario that would be evaluated.

David Page stated that the 50 ppm mercury clean up level developed by the state considered exposure pathways. He stated that no one was growing crops in the floodplain, so this pathway was eliminated. He also said that people were not using the water for drinking or showering, so this pathway was eliminated. Mr. Page stated that the primary exposure pathway was via ingestion of soil.

A meeting participant asked which species were used to assess the NOAELs and LOAELs for mercuric chloride. Jack Hanley replied that both rats and mice were used in these studies.

A meeting participant asked Jack Hanley if there are any human studies. Mr. Hanley replied that there are not any for inorganic mercury, except for acute exposures.

Gordon Blaylock noted that all three of the panel’s papers stated that additional information was needed before conclusions could be made regarding the development of a bioavailability number. Jack Hanley responded that this was the reason that ATSDR did not deal with this issue, and assumed mercuric chloride throughout its analyses. Dr. Blaylock added that he thought that the papers stated that further investigation was needed, not solely on bioavailability. Mr. Hanley asked Dr. Blaylock what area had required further investigation, but Dr. Blaylock could not recall. Dr. Blaylock asked if ATSDR had prepared a summary report for the papers, and Mr. Hanley said that this was correct.

Charles Washington thought that it would be interesting to know which species were dependent on the pH of the soil of the surrounding medium. Jack Hanley responded that the main question is not which species; the main question is what is the bioavailability of the species. Mr. Washington replied that the species will determine what is available to react with, and that some species have more of an affinity than others. Mr. Hanley added that if he had a choice of knowing the species or the bioavailability, he would choose to know the bioavailability.

Gordon Blaylock asked if a lot of mercury was released to the environment by cold fire plants located in the vicinity. David Page replied that he did not know; however, he knew that these ponds leak. Mr. Page said that during the “winter draw down,” little pools and low pH are evident in the floodplain areas. He described a study that he had worked on to measure the travel time of water through the ponds. Some of the increased concentrations were found at a pH of 2.5. He added that fly ash is excluded under the Resource Conservation and Recovery Act (RCRA), but that it could be a source. Dr. Blaylock stated that he knew that this was excluded, but that he knows that arsenic is a problem in these ponds and that this cannot all be contributed to the ORR. Jack Hanley said that ATSDR is looking at the concentrations that are there.

David Page explained that in 1984/1985, TVA conducted core sampling down along the Clinch River. As TVA took “fractions” or “horizons,” TVA would also conduct a split sampling and analyze these samples for cesium. Thus, there was a particle association between the mercury and the cesium. This was very important when TVA went to the Chickamagua Reservoir and other locations that had chlor-alkaline plants that use a lot of mercury. Gordon Blaylock explained that this is also very important because cesium was released from White Oak Creek in 1956, and that cesium is a particle reactive substance, similar to mercury. Dr. Blaylock said that if you went to the end of Poplar Creek, you would find that mercury and cesium are at the same levels. Jack Hanley believed that this was also true for the Watts Bar Reservoir.

Bob Craig asked if ATSDR asked for volunteers for the exposure investigation on serum PCB and blood mercury levels. Jack Hanley replied that ATSDR placed newspaper and television advertisements, called over 500 people, and spent two weeks around the reservoir to find people while they were fishing. Specific criteria were evaluated to assess if people consumed a certain number of fish. If so, then ATSDR would ask if the volunteer would complete a questionnaire, and ATSDR would use these answers to screen people out.

Charles Washington asked if ATSDR found enough people to make the exposure investigation statistically viable. Jack Hanley said that the study could not be a statistical sample because ATSDR was only focusing on people who consumed a lot of fish and turtles. In addition, Mr. Hanley noted that 25% of the people tested consumed turtles.

David Page added that a lot of PCBs are released from Fort Loudon. He said that the Tennessee riverside of Watts Bar and upstream from this point have more elevated levels of PCBs, particularly in Crystal Creek and Second Creek (where Rohm and Haas used to be located). Mr. Page added that some people have said that Alcoa had a major transformer “blow out” in that area. Jack Hanley asked if this was more of a regulatory issue.

Gordon Blaylock noted that the amount of PCBs coming down the Tennessee River from Watts Bar is greater than the total amount coming down the Clinch River, but that the total concentration is about the same. Dr. Blaylock also explained that Alcoa buried its transformers at Spring Creek, which goes into Fort Loudon, and comes down into Little River. As a result, the fish in Little River are highly contaminated, with levels around 3 to 4 ppm. James Lewis asked Dr. Blaylock if he had used the word “buried.” Dr. Blaylock explained that Alcoa had taken old transformers that contained PCBs and buried them in a disposal area. He added that this practice occurred at several places, not just at Alcoa. David Page said that they had found elevated levels in that area, but that they could never find the exact location. They talked to residents who said that Alcoa “allegedly” took the transformers, poured out the oil, and took out the copper core before burying them.

Bob Craig asked how many people ATSDR would expect in the normal population (out of the 116) to have a level above the 10 ppb. Jack Hanley replied that he does not know for mercury. However, in regards to PCBs, out of the 116, there were four or five people above the upper 95% confidence level. He said that he would expect to see about six, and ended up with four. Mr. Hanley added that there was one extremely high case, which was a man from Florida.

Charles Washington asked how Jack Hanley determined whose blood should be checked. Mr. Hanley replied that ATSDR conducted interviews and screening to see how much fish these people consumed. Mr. Washington asked if you would find a higher amount in people who ate larger fish. Mr. Hanley stated that ATSDR provided people with a chart of different types of fish and figured out how much fish people ate, how often they ate fish, and what types of fish they consumed.

Update on the Epidemiology Ad Hoc Group’s Effort – Health Statistics Review

Presenter: Pete Malmquist, ORRHES, and James Lewis, ORRHES

Pete Malmquist stated that as of this date, they have not received anything from the state. He has gathered some information with Jack Hanley and will meet with the cancer subgroup. At the next PHAWG meeting, they will have some recommendations. In addition, it appears that the ORRHES will have to formally request a health study review from the state.

Pete Malmquist would like to obtain information similar to a study that was conducted in New York, but he does not know if they will reach this point. Dr. Malmquist explained that this study looked at cancer data.

James Lewis explained that they have not submitted a formal request, but that the information has been requested in an informal manner. He mentioned that the state has been occupied with working on issues related to small pox.

James Lewis showed the New York example to the group. He hopes that they would receive comparable data from the state of Tennessee. Mr. Lewis said that ATSDR had conducted a similar study in Memphis, Tennessee. He said that he had showed the New York study to Al Brooks, who did not see a lot of cancers except in one area that was industrialized. As he looked closer, he saw that a lot of retirees had moved into one area, which was the area with the highest number of cancer cases.

Pete Malmquist said that the PHAWG needed to answer the public’s question, which is “Is it safe to live here?”

Discussion

Bob Craig asked if the process seemed to be moving and if Pete Malmquist expected to see the data fairly soon. Dr. Malmquist said that he did not expect to see the material soon.

Jack Hanley stated that Dee Williamson (ATSDR) is going to come to the next ORRHES meeting and give a presentation on a health statistics review.

Jack Hanley noted that people should read the second page of the document, which details the types of inferences that can be made from these data. He thought this should be read before a vote is taken on this issue.

Update on PHAs

Presenter: Jack Hanley, ATSDR

Jack Hanley stated that ATSDR would release the Uranium PHA at the next ORRHES meeting. A 45-day public comment period will follow this release. He added that ORRHES’ work with this PHA is basically completed.

Jack Hanley said that mercury and White Oak Creek had been on the project plan for tonight’s meeting. However, he thinks that ATSDR will come in on April 21, 2003, to talk about the comparison value for radiogenic cancer. White Oak Creek will be discussed at the first meeting in May.

Discussion

Bob Craig asked about iodine 131. Jack Hanley replied that this is a decision that Paul Charp needs to make. Dr. Charp needs to determine if he can make a decision by himself or if he needs to bring in outside experts. Dr. Craig recalled that this was supposed to have been completed by April. Mr. Hanley said that he will discuss the issue with Dr. Charp, and that hopefully Dr. Charp could come and give an update to the PHAWG.

New Business

James Lewis explained that he was looking at a map of Scarboro andwas wondering why core samples were not conducted there. He said that the community needed to know why different types of samples were taken. David Page explained that they had held workshops before the sampling began. These workshops were open to the public and mainly property owners (110) attended. They sat down with the property owners and explained the types of equipment that they would see, what they were specifically doing on the properties, and additional aspects of the sampling. Mr. Page said that they went back with every property owner and showed them the data, explained the data, and allowed everyone to ask questions. Mr. Lewis reiterated that this had not been clarified to the public. Mr. Hanley explained that this effort was made in advance in Scarboro with all of the mercury data. He added that ATSDR is looking at all of these data and that the information will be explained in the PHA. In addition, ATSDR is electronically taking all of the data from the 1990s and is re-evaluating the data. The reason for this is that ATSDR has new data since the mid-1990s and it is possible that some of the levels have increased since that time. In relation to Scarboro, Mr. Hanley stated that the levels were “way below” anything that would cause concern. Mr. Lewis suggested publishing a “sampling sheet” so that people can understand the different types of samples conducted and why a certain method was chosen for their particular area.

Pete Malmquist stated that there has been an informal request, which was made at least twice, concerning exhuming bodies to check for cancer. Dr. Malmquist suggested formulating a proposal that ORRHES request that ATSDR give a declaration whether they will or will not conduct this process. He said that this issue needed to be resolved. Jack Hanley replied that even if ATSDR evaluated the bones of these bodies, there would be no comparison value (e.g., a reference point). James Lewis stated that when these issues surface, people expect to receive answers.

Danny Sanders stated that he had received some photographs from Tim Joseph, along with an explanation that Dr. Joseph was going to further investigate Happy Valley. Jack Hanley explained that Dr. Joseph had located a number of photographs of Happy Valley. He stated that there were 15,000 people who lived there. There was also Happy Valley West, which was a smaller residential area, and another neighborhood that was located next to K-25. However, Happy Valley was the largest of these communities. Mr. Hanley detailed that most of the residents lived there between 1942 and 1948; Dr. Joseph is researching the exact dates. By the end of the war, nicer homes had been built and these areas were closed down. Dr. Joseph is also looking into a potential water issue related to those areas. Mr. Sanders said that there is a water treatment plant there. Mr. Hanley said that ATSDR would consider this issue when they evaluate K-25 and the releases from that facility. In addition, ATSDR will conduct modeling that will take these residents into account.

Bob Craig mentioned that the local office has not been “attuned” to the need of providing representatives for the PHAWG. Dr. Craig commented on the great help that Tim Joseph and David Page have been to the work group. James Lewis requested that Dr. Craig define “attune.” Dr. Craig explained that the office does not want these representatives spending time on this committee and that they do not want them “coming here.” Mr. Lewis asked if they needed to make some recommendations. Dr. Craig said that he had talked to Gerald Boyd (DOE) about this issue. Mr. Lewis said that the subcommittee needed to work on this. He added that they did not “have to wait for this to hit us in the face.” He suggested that they write recommendations in advance and have them ready. He said that these liaisons are extremely helpful and that if DOE is going to pull the PHAWG’s manpower, then perhaps the PHAWG should look into writing a proposal. Dr. Craig made a recommendation to ORRHES that the subcommittee write a letter to these operations and he entertained a motion to make a committee to write a letter to the PHAWG. It was decided that the Communications and Outreach Work Group (COWG) would write a letter and bring it to the PHAWG.

The motion was seconded and unanimously approved.

The meeting was adjourned at 7:50 pm.


 
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