Public Health Assessment Work Group
Meeting Minutes
April 7, 2003
Attendence
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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