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Public Health Assessment Work Group
Meeting Minutes
May 5, 2003
Attendance
ORRHES Members attending:
Bob Craig (Work Group Chair), Kowetha Davidson (Subgroup Chair),
George Gartseff, David Johnson, James Lewis, Pete Malmquist, and LC Manley
Public Members attending:
Gordon Blaylock, Tim Joseph, and Roger Macklin
ATSDR Staff attending:
Paul Charp, Burt Cooper, Melissa Fish, Lorine Spencer (phone),
and Bill Taylor
ERG Contractor:
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 lessons learned and
the effectiveness of the new process that provides input into the Public
Health Assessment (PHA), and (2) present and discuss ATSDR’s preliminary
assessment of radionuclides released from White Oak Creek.
Discussion of the Lessons Learned and the Effectiveness of the New Process
to Provide Input into the PHA
Presenter: James Lewis, ORRHES
James Lewis wanted to review the new process for providing input into
the PHA so that the PHAWG could identify any weaknesses that needed to
be addressed. Mr. Lewis presented a copy of the process flow sheet that
was developed for this effort, and walked the PHAWG through the steps
to see what the group had done thus far. There were three major areas
in the process: preliminary assessment, data validation, and public comment
and final PHAs. Under the preliminary assessment, the PHAWG 1 meeting
was held. During this meeting, ATSDR identified the list of references
that would be used for the PHA. Mr. Lewis explained that he had reviewed
the minutes from that meeting, and that the PHAWG had indicated that it
wanted a press release, which would explain that ATSDR was preparing a
PHA and to request any additional information from the public. These minutes,
from the November 4, 2002, PHAWG meeting, indicated that the Communications
and Outreach Work Group (COWG) was supposed to contact Cathy Daniels.
During the PHAWG 2 meeting, there was a presentation by ATSDR’s
Federal Facilities Assessment Branch (FFAB). During this meeting, members
requested information, including uranium data from other areas surrounding
the Y-12 facility. There were issues raised in this area because there
were elevated levels of uranium from Bear Creek. The PHAWG discussed using
data from the Tennessee Department of Environment and Conservation (TDEC)
and suggestions were made about presenting information to the public.
James Lewis thought that the PHAWG should keep the public informed about
its activities.
During the PHAWG 2 and PHAWG 3 meetings, there were roundtable discussions
about some of the information that had been obtained. James Lewis thought
that the minutes should be re-read and that key points should be pulled
out and given to ATSDR.
James Lewis described the data validation part of the process. He said
that to his knowledge, this was where ATSDR came and presented its draft
PHA. Mr. Lewis noted that at that time, ATSDR failed to provide copies
to the subcommittee. He believed that ATSDR had corrected the problem,
but that as a general rule, the members of ORRHES should receive a copy
of the document when the PHAWG members receive their copy.
James Lewis noted that some people needed different levels of detail.
He suggested that the PHAWG have ATSDR’s Community Involvement Branch
(CIB) generate a document to summarize the PHA for the “lay people.”
Mr. Lewis thought that people needed an opportunity to provide their input,
and that the PHAWG needed to evaluate the process so that this input could
occur in a timely manner.
Discussion
Bob Craig asked James Lewis if he wanted the press release item added
to the flow sheet. Mr. Lewis responded that Dr. Craig was correct.
Lorine Spencer wanted to clarify a point in James Lewis’ discussion.
She asked where Mr. Lewis wanted to put the press release on the process
sheet because ATSDR had prepared a press release for the Uranium
PHA public comment release. Bob Craig explained that Mr. Lewis
wanted a press release to occur much sooner in the process. Mr. Lewis
said that Dr. Craig was correct.
Bob Craig disagreed with James Lewis. He said that the work group had
a process for distributing the PHA and that the PHAWG definitely wanted
to view the document before the ORRHES. He added that the PHAWG acted
as an “author” in this process, by working with ATSDR before
the document was given to the subcommittee. Dr. Craig said that if Mr.
Lewis was proposing that ATSDR give the document to ORRHES before the
PHAWG had time to review it, then he objected to this suggestion. Dr.
Craig explained that there were one or two minor mistakes in the distribution
of the document, but that he believed that it was only because the publishers
had thought that certain people who were on the PHAWG were also on the
ORRHES. He said that this was a bit of a problem, but that it was an administrative
issue that could be handled. However, he gathered that Mr. Lewis wanted
to incorporate the ORRHES into what Dr. Craig saw as the job of the PHAWG.
He thought that it was the PHAWG’s responsibility to carry out the
work for the ORRHES and to take care of the necessary details. Thus, Dr.
Craig disagreed with Mr. Lewis if that was what he proposed.
James Lewis responded that he had taken this idea to the COWG to look
at the distribution list and that he had prepared a matrix. He added that
he needed to go back to review what the recommendation was with regards
to this issue. However, Mr. Lewis’ main point was that he wanted
the ORRHES to become familiar with the process. Bob Craig recalled that
the publishers had thought that Don Creasia was on the PHAWG, but that
he had never been a member of the work group. Thus, he did not receive
the document until the day of the ORRHES meeting. Mr. Lewis said that
he had surveyed the group and that, in his opinion, some ORRHES members
may want the document during that part of the process. Dr. Craig said
that they could be notified, but that the PHAWG’s job was to “do
the work” because there was too much for the entire subcommittee
to handle.
Bob Craig stated that everyone was invited to the meetings and that the
meeting minutes were published. He did not know what more they could do
to elicit public participation.
Kowetha Davidson wanted to know the issue involved in James Lewis’
discussion. Mr. Lewis stated that this had been discussed at the COWG
meeting, and that the PHAWG was engaging in a general discussion to review
the process. He said that they should look at possible failures in communication
and any weaknesses in the process. Mr. Lewis added that he had heard that
more than one member of the ORRHES did not receive the PHA in time. He
looked at this process, along with the COWG, and prepared a matrix to
alleviate another similar occurrence. He said that he would bring the
matrix to a future meeting and that the PHAWG could vote on it.
Kowetha Davidson asked if the time provided to the ORRHES was insufficient.
Bob Craig explained that to save on printing, the publishers had given
the PHA to the PHAWG with plenty of time, and that the PHAWG had made
its comments. People who were not members of the PHAWG were given the
PHA five to six days ahead of time. One person was thought to have been
on the PHAWG, but he was not. Thus, he did not receive the document before
the meeting and he was unhappy about this.
Kowetha Davidson asked if there was a systematic problem with the distribution.
Bob Craig replied that he did not think so. James Lewis said that they
did not have an approach at that time. He added that they should not give
people this type of document and only give them five days to review it,
especially if those days fall over a weekend. Dr. Davidson noted that those members were given a cover letter that detailed
which parts of the document to read; they were not supposed to read the
entire document.
Bob Craig reiterated his point. The job of the PHAWG was to conduct the
detailed, technical work. The PHAWG shouldered the responsibility for
the subcommittee by reviewing the document and hoping that the ORRHES
accepts the work group’s advice. The subcommittee members could
review the document on their own, but the PHAWG had the main responsibility
with regards to the document review. Dr. Craig thought that five days
was plenty of time for the ORRHES to look at the document. James Lewis
responded that they needed to think about this and mentioned Herman Cember
as a person to keep in mind. He said that he would draw a timeline and
would survey people to see what type of timeframe was desired. From his
discussions with people, Mr. Lewis concluded that many members preferred
at least 10 “working days” (not including the weekend) to
review the document. Mr. Lewis added that he would present the COWG’s
recommendation for consideration by the PHAWG. Dr. Craig commented that
Dr. Cember was a member of the PHAWG and would have had plenty of time
to review the document and to provide input. Mr. Lewis said that he would
like to hear this from Dr. Cember and noted that he wished that Tony Malinauskas
were here because he had synthesized all of the comments. Mr. Lewis thought
that the PHAWG should make a “special effort” to give the
document to the interested parties with enough time to provide comments.
Dr. Craig looked forward to hearing the COWG’s recommendation.
Kowetha Davidson wanted to know if individuals had problems, and if so,
what were the nature of the problems. She wanted these individuals to
be sent to her. James Lewis stated that Dr. Davidson had given them a
responsibility to evaluate the distribution strategy. Thus, they went
back and developed a matrix, which was given to the CIB, and covered an
approach to distributing all of these materials. They did not have a chance
to present the matrix yet, but they would present it at a future meeting.
Dr. Davidson made a correction. She said that she had referred to a distribution
for the document that COWG was putting together, not for the PHA. She
said that the COWG had discussed generating some documents and that she
had asked for a distribution list for those COWG documents. Mr. Lewis
said that he would go back and review the minutes, but that was not how
they had interpreted her instructions. He added that they needed to focus
on ensuring that the public received materials in a timely manner.
Minutes from the April 7, 2003, Meeting
Bob Craig asked the PHAWG for comments on the minutes. Gordon Blaylock
noted the following corrections: (1) on page 20, third paragraph, the
word “vapor” should be replaced with “three forms of
mercury,” (2) on page 21, fourth paragraph, the “2003 Annual
Report” should be replaced with the “Bechtel Jacobs 2003 Environmental
Report,” (3) on page 25, third paragraph, the phrase should say
that “if a lot of mercury is released to the environment by coal
fire plants located in the vicinity,” and (4) on page 26, fourth
paragraph, the word “level” should be replaced with the word
“amount.”
Pete Malmquist made a motion to approve the minutes as corrected and
David Johnson seconded the motion. The April 7, 2003, minutes were unanimously
approved.
James Lewis asked if there were any action items in the body of the minutes.
Bob Craig recalled that a letter was going to be written by the COWG and
brought to the PHAWG. Dr. Craig had thought that the letter had been written
because he prepared a first draft and sent the letter to Kowetha Davidson.
Dr. Craig noted that Dr. Davidson re-worded the letter and made the document
more “politically correct.” Dr. Craig thought that the resolution
was that the COWG would draft the letter, but that he would write the
first draft and give it to Dr. Davidson. Then, the letter would be sent
to the COWG and the COWG would provide the letter to the PHAWG. Mr. Lewis
had thought that the letter would start at the PHAWG, be sent to the COWG,
brought back to the PHAWG, reviewed by the PHAWG, and presented to the
ORRHES. At that time, if approved, the ORRHES would endorse the letter
and send it out. Dr. Craig said that the final words at the last meeting
were for Dr. Craig to prepare the first draft of the letter.
A meeting participant asked if the motion was read at the ORRHES meeting
on April 8, 2003, but no one responded. James Lewis thought that the letter
would be given to the PHAWG and then to the ORRHES. Bob Craig asked if
the COWG was going to be involved in the process. Mr. Lewis thought that
the COWG was no longer involved because he had performed the requested
task. Pete Malmquist did not think that this letter went through the ORRHES.
He said that the subcommittee had some problems with the way that the
letter was written and that it was going to be re-drafted. Dr. Malmquist
added that he did not think that the ORRHES knew what was mentioned in
the letter, and that he did not think that the subcommittee had voted
on anything. Dr. Craig thought that the ORRHES had eliminated the COWG
from the process of generating this letter.
Presentation and Discussion of ATSDR’s Preliminary Assessment
of Radionuclides Released from White Oak Creek
Presenter: Paul Charp, ATSDR
According to the project plan, Paul Charp was going to discuss (1) past
releases from White Oak Creek, which was essentially the Task
4 Report of the state’s dose reconstruction project, and
(2) current exposures from White Oak Creek, which ATSDR reviewed previously.
During this meeting, Dr. Charp would review the Task
4 Report. Previously, ATSDR requested that three experts review
this report; those comments would be distributed at a later date. Dr.
Charp would discuss ATSDR’s review of current exposures (up to about
1996), give a summary of the Task 4 Report
findings, and provide a summary of ATSDR’s review.
Slides Presented from the Task 4 Report
Paul Charp presented an overhead that showed all of the pathways that
were evaluated in the Task 4 Report, as well
as the recreational use of the river. The diagram showed pictures of a
skier/swimmer, cattle, farmer, fisherman, hunter, and geese. The picture
also identified the locations of White Oak Creek and White Oak Lake, and
showed the Oak Ridge National Laboratory (ORNL, also known as X-10) as
the source term. ATSDR went over the key issues that were covered in the
Task 4 Report, which included contacting surface
water and sediment during recreation, consuming game animals (the Task
4 Report looked at geese and fish),
consuming fish and turtles, eating homegrown vegetables that grew along
the Clinch River and where the Clinch River was used as a water source,
and external radiation from materials that were present in the area of
concern.
Paul Charp displayed an overhead that detailed the area of interest.
The map showed the location of the X-10 complex, where White Oak Creek
dumped into the Clinch River below Melton Hill, when it merged with the
Tennessee River around Kingston, and then how it continued downstream
to Spring City where the Watts Bar Dam was located.
Paul Charp explained that the beginning figures in his presentation were
taken from the Task 4 Report. Dr. Charp presented
a figure (Figure 5.2 in the Task 4 Report)
that showed the significant events of waste management from X-10 starting
around 1943, when construction began on the Clinton Laboratory, until
1960, when White Oak Dam was flooded and Trench 5 was completed. (On May
19, 2003, Gordon Blaylock noted that this comment was incorrect because
White Oak Dam flooded in 1943.) The figure showed that there was about
16 to 17 years of burial material that was going into the burial grounds
at X-10 or grounds associated with X-10. The figure also pointed out significant
events, such as flooding and new pits that were built. Dr. Charp discussed
the settling basin part of the figure that referred to its storage of
1.5 million gallons of waste. (On May 19, 2003, Gordon Blaylock stated
that the term “settling basin” was out of context in this
situation, and that this term should not be referred to until later on.)
Paul Charp presented another figure from the Task
4 Report that identified three reference populations based on fish
consumption. This analysis was for people who lived along the Clinch River.
Category I consisted of people who ate the most fish; these persons consumed
an average of 1 to 2.5 meals per week on a regular basis. Category II
was made up of persons who consumed 0.25 to 1.3 meals of fish per week.
Category III was comprised of people who very rarely ate fish, with a
range of 0.04 to 0.33 meals per week.
Paul Charp showed the Task 4 Report’s
(Table 3.2 in the Task 4 Report) summary of
radionuclides and pathways that were identified for further analysis.
These included deep water, fish, external shoreline sediments, and various
dredging pathways. The report concluded that there was no swimming in
White Oak Creek and that there was no irrigation water, so those pathways
were eliminated for further analysis. (Gordon Blaylock submitted written
comments that noted that there is also no swimming and no irrigation water
in the Clinch River.)
A summary of reference individuals by exposure pathway (Table 13.2 in
the Task 4 Report) was presented. The exposure
pathways included drinking water, fish ingestion, external exposure, and
ingestion of milk and meat. According to Paul Charp, the majority of these
individuals were associated with the K-25 facility, the Kingston Steam
Plant, and fishing along the Clinch River.
The Task 4 Report also developed doses (Table
13.5 in the Task 4 Report). These doses looked
at the bone, breast (female), lower large intestine, red bone marrow,
and skin following ingestion of drinking water, milk, and meat. The doses
were in centi-Sievert (cSv), which is equal to one roentgen equivalent
man (rem). For example, 0.25 to 0.55 cSv equals 0.25 rem or 25 millirem
(mrem), or 0.55 rem or 500 mrem. Paul Charp explained that the dose to
skin was essentially non-existent and that the numbers in parentheses
in the table represented the 50th percentile. Thus, according to this
table, the 50th percentile for bone was 0.11 cSv or 0.11 rem to bone,
following the ingestion of drinking water.
Paul Charp explained that there were many graphs in the Task
4 Report that showed the analysis conducted by SENES. This analysis
evaluated the measured releases at several mile markers along the Clinch
River and compared these to SENES’ predicted measurements. Dr. Charp
showed cesium 137 as an example. He said that the predicted and measured
concentrations were fairly close, and that the concentration estimates
were in “very good agreement” from about 1945 through 1990.
In addition, the majority of the measurements conducted by SENES followed
this same type of trend—a good correlation between the predicted
and measured concentrations. (On May 19, 2003, Gordon Blaylock noted that
this statement was incorrect since SENES did not conduct any measurements.)
Because of the rise and fall of the river, some of the dissolved cesium
was deposited in the sediments. He noted that there was “good agreement”
between the measured and predicted cesium concentrations in shoreline
sediments for Clinch River Mile (CRM) 14. Also, Dr. Charp said that there
was not a lot of uncertainty in the data analysis. Furthermore, SENES
conducted this process for cesium, cobalt, ruthenium, strontium, and a
couple of other radionuclides.
A table with the measured and predicted radionuclide inventories in the
Clinch River for 1962 and 1977 (Table 6.8 in the Task
4 Report) was presented. The table showed the estimated and predicted
inventory for both 1962 and 1977. According to the report, ruthenium 106
had dropped to less than 1% during this time period.
Paul Charp explained that he had taken a 3-page long table from the Task
4 Report for the annual total releases to White Oak Creek. Instead
of putting in 90 figures for the various data points, Dr. Charp divided
the data into 6-year intervals. He presented a graph of the data, which
showed that the major releases to White Oak Creek occurred between 1956
and 1961. (Gordon Blaylock submitted written comments, which stated that
the releases to White Oak Creek were from White Oak Dam [WOD].) The period
with the second highest releases took place from 1962 to 1967. After these
two time periods, the numbers were very low.
Paul Charp presented a figure with a time line that showed how much cesium
had been absorbed in infants and adults. For infants, 10% was absorbed,
whereas 5% was absorbed in adults. An adult would receive 2.5 x 10-9 rem
or picocuries (pCi).
Paul Charp presented a summary of the measured radionuclide concentrations
in shoreline sediment from 1991 to 1994 (Table 6.11 in the Task
4 Report). This table looked at the cesium and cobalt detected
in the shoreline from the Clinch River to Melton Hill Dam, and essentially
to Watts Bar Dam. Because these concentrations were in becquerel/kilogram
(Bq/kg), the pCi/gram (pCi/g) would be derived by multiplying by 27 and
then dividing by 1,000. Dr. Charp explained that there were extremely
low levels of both cesium and cobalt in the Tennessee River, and from
the Clinch River to the Watts Bar Reservoir.
A table was shown that provided the potential exposure pathways, locations
of interest, applicable time periods, and estimated exposure populations
for the Clinch River (Table 7.10 in the Task 4 Report).
The table included the following exposure pathways: drinking water, fish
ingestion, milk and/or meat ingestion, and external exposure. According
to Paul Charp, the population estimates shown indicated that these could
have been fairly insignificant. The figures ranged from 25 people in Jones
Island to over 20,000 people along the Clinch River, and took about 60
years of exposure into account. (Gordon Blaylock submitted written comments
that noted that references to people in Jones Island should be written
as “people in the area of Jones Island.”)
Paul Charp explained that SENES looked at other data from laboratory
reports from 1951 (Table 8.4 in the Task 4 Report).
The radionuclide concentrations in carp, crappie, and other fish were
analyzed. He used an example of 360,000 Bq/kg that was detected in the
bone of redhorse on upper White Oak Lake. If 360 was multiplied by 27,
then a concentration of approximately 1,000 pCi/g would be derived for
upper White Oak Lake.
A table containing the organ doses for adults based on material in the
sediments (Table 13.4 in the Task 4 Report)
was shown next. Paul Charp said that these were mainly for cesium, cobalt
60, and possibly strontium 90 exposure. He pointed out the mid-doses for
bone. Dr. Charp said that an individual at Jones Island had a central
value of 12 mrem, and that an individual in the city of Kingston had a
50 mrem central value. (Gordon Blaylock submitted written comments that
noted that references to people in Jones Island should be written as “people
in the area of Jones Island.”) He noted that these doses were relatively
small doses to the organs.
Paul Charp presented a table with the fish consumption for Jones Island
and the city of Kingston (Table 13.3 in the Task 4
Report). (Gordon Blaylock submitted written comments that noted
that references to people in Jones Island should be written as “people
in the area of Jones Island.”) He used an example of cesium in the
breast in females for Kingston. Dr. Charp said that the risk for Category
I was about 30 mrem/year. He selected cesium because it was a whole body
isotope, meaning that it was uniformly distributed to all of the tissues
in the body. He also pointed out that the dose for the lower large intestine
for cesium was about 54 mrem/year.
ATSDR’s Summary of the Expert Panel (Task 4)
Paul Charp explained that ATSDR had three experts review the Task
4 Report to answer the following question—Does the White
Oak Creek radionuclide releases report provide a foundation on which ATSDR
can base follow-up public health actions or studies (i.e., is there sufficient
information for public health professionals to draw conclusions and make
public health decisions)? Dr. Charp presented the following slides, which
summarized the comments from the expert panel. Dr. Charp’s comments
during the presentation are denoted by quotation marks.
The task requirements for the review consisted of 9 tasks:
- the study design and scientific approaches
- methods of data acquisition, models and analyses, and statistical
reliability
- completeness of data and analyses included bioconcentration factors
- “a uniform bioconcentration factor does not exist; these
are based on the media and species”
- data interpretation and clarity of report
The major areas of consideration were the following:
- source terms and radionuclide concentrations
- “these will drive the doses and the decisions in the evaluation”
- uncertainty and sensitivity analysis
- “indicate if the reviewers thought that the correct parameters
were used to determine the doses”
- health effects and public health
The summary of the comments on the overall content was:
- well written and its objectives were clearly stated
- overall design and scientific approach were appropriate
Direct comments from the reviewers included:
- “break new and important ground in the use of uncertainty analysis
in environmental assessment”
- “truly exemplary compared to other projects in risk assessment
and dose reconstruction”
Overall design questions:
- Radionuclide concentrations in water and sediment at downstream locations
in the Clinch River from 1944 to 1991.
- Radionuclide concentrations in fish from the Clinch River had deficiencies
in their approaches.
- the analysis fails to separate influence of the uncertainty and
variability in model parameters on risk estimates
- the report fails to properly calibrate the HEC model used for
predicting radionuclide concentrations in water and sediment
- the report fails to study model uncertainty in predicting radionuclide
concentrations in water and sediment
- the analysis fails to incorporate radionuclide-specific adjustment
factors for using reconstructed radionuclide concentrations in water
at one river mile from measurements at another river mile
- the use of site-specific bioconcentration factors to model radionuclide
concentrations in fish is not well supported by the field data
Additional overall comments:
- Quite valid and consistent with earlier studies in Oak Ridge and
the Columbia River.
- Useful for public health decision making; careful attention given
to assumptions behind the estimates; may be applicable for preliminary
decision making, but may not be sufficient to allow detailed
public health decision making.
- Results of the assessment on the estimates of radionuclide concentrations,
and the dose and risk estimates based on these concentrations, are limited
and are not scientifically defensible since the implementation involved
with the treatment of empirical data (general and specific) and modeling
is often inappropriate.
Additional comments:
- Scientific interpretations were appropriate.
- Agreed that the conclusions and recommendations were based on the
information provided in the report.
- Exception—total estimated release of radioactivity for
all years was not documented in the report.
- The report presents enough details to allow for independent evaluation
and verification of models and estimates (1 reviewer).
- Not enough details are available (2 reviewers).
- One identified this as the primary weakness of the report and
specifically pointed out that the details of the models used to
estimate the radionuclide concentrations in the Clinch River water
and sediment are not provided.
Public health related comments:
- Provides sufficient and adequate information for later public health
analysis and decisions (1 reviewer).
- While the report provides a good starting point in supporting public
health decisions and a number of conclusions about historical releases
of radionuclides can be drawn, it does not
provide sufficient and adequate information to determine follow-up public
health actions or policies (2 reviewers).
Radionuclide concentration estimates:
- The estimates of concentrations either are or appear to be appropriately
compared with historically measured concentrations (2 reviewers).
- The modeled concentrations are not in agreement with historically
measured concentrations (1 reviewer).
- This does not agree with the justification for using the proposed
models to estimate doses and risks.
Bioconcentration factors:
- Appear reasonable and incorporate a reasonable degree of uncertainty,
are based on a wide range of information, and make use of local information
where possible (2 reviewers).
- The use of bioconcentration factors in fish is not adequately supported
(1 reviewer).
- Grouping species of several tropic levels.
- The resulting distribution is much lower than the recommended
values of the International Atomic Energy Agency (IAEA).
- A better job could have been done in comparing the bioconcentration
factors in the study to values from the literature.
Uncertainty and sensitivity analysis:
- Impressed with the extensive use of statistical approaches, uncertainty
analyses, and sensitivity analyses throughout the report.
- Most comprehensive seen, but the analysis is incomplete and its interpretation
is limited.
- Variability is not addressed in the assessment.
- Two reviewers commented that the distribution functionsappropriately
describe the variability of the parameters.
Uncertainty:
- Overall, the approach is reasonable and appropriate.
- Uncertainty estimates were not expanded for periods of time when
data on radionuclide concentrations were not available.
- Tendency to make use of uncertainty factors, rather than examine
the model more closely, in an effort to understand the reason for
differences between model predictions and measured values.
- Several instances when the uncertainty factors are not implemented
appropriately (i.e., the adjustment factors for spatial scaling
of measured radionuclide concentrations should be radionuclide-specific).
Two omitted sources of uncertainty:
- The use of the linear non-threshold hypothesis for cancer risks may
cause the lower end of the risk estimate intervals presented in the
report to be too high.
- The upper end of the risk estimate intervals may be lower than in
the real situation because the risk estimates do not incorporate possible
synergistic effects, and some choices of probability distribution functions
appear overly restrictive.
- “ATSDR does not support the use of risk.”
Highest risk:
- Those people who consumed large amounts of fish (or wildlife) from
1944 to 1953 have the highest risk of an adverse health effect.
- One of the reviewers stated that the report provides only limited
information to allow identification of a population at significant
increased risk.
- Both reviewers concluded that it is unlikely that adverse health
effects would be statistically detectable.
Epidemiological impact:
- Estimated doses and risks are far below the observed threshold necessary
to guide epidemiological planning and decision-making.
- Information about doses from individual exposure pathways, together
with estimates of the number of individuals who were potentially exposed
to these doses, would probably be useful for epidemiologic planning
and decisions.
- The extent to which the data can be interpreted for epidemiologic
purposes may be limited because the report does not provide details
on the number of people who were potentially impacted by the combined
pathways.
- “This comment is incorrect as there is a table in the Task
4 Report that shows that there could be as many as 20,000
people affected.”
ATSDR’s Evaluation of the Lower Watts Bar Reservoir
(LWBR)
Paul Charp explained that Carol Connell, a health physicist with ATSDR,
conducted an evaluation of the LWBR. He showed the following slides, which
summarized this health consultation.
Purpose:
- ATSDR was asked by the community to evaluate whether DOE actions
were sufficient to protect the public from ORR contaminants in the LWBR.
- DOE proposed to leave the contaminated sediment in place at the LWBR.
Background based on the Task 4 Report:
- Radionuclides, predominantly cesium 137, strontium 90, and cobalt
60, were released from the ORR to the Clinch River and eventually reached
the LWBR.
- White Oak Dam is the main point of release to the Clinch River.
Assessment methodology:
- In evaluating potential health hazards associated with leaving the
contaminated sediment in place at the LWBR:
- ATSDR used available environmental data collected from the LWBR
in the 1980s and 1990s:
- surface water
- sediment—surface and subsurface samples
- fish—channel catfish, bluegill, and largemouth bass
- ATSDR considered various exposure situations along the LWBR.
- ATSDR used worst-case assumptions when evaluating hazards.
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Primary Contaminants |
Maximum Concentration (pCi/g) |
Surface Water |
H-3, Sr-90, Co-60, Cs-137, Pu-238,
Pu-239, total uranium
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All below EPA’s MCLs or proposed/current
limits
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Surface
Sediment |
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Subsurface
Sediment |
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Paul Charp explained that all of the concentrations that were detected
in surface water were below the U.S. Environmental Protection Agency’s
(EPA) proposed/current drinking water standards. Dr. Charp said that this
suggested that people could drink water from the Clinch River.
Paul Charp presented another table to show the exposure situations and
routes by media:
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Exposure Situations |
Route of Exposure |
Surface Water |
Domestic use (unfiltered)
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Domestic use (unfiltered)
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Sediment |
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Biota |
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Findings:
- Surface water exposure
- Low level of radionuclides in surface water.
- No hazards for persons drinking or swimming in the water.
- Sediment exposure
- Subsurface sediment had the highest detected levels of contamination.
- No hazards for contacting surface or subsurface sediments.
- Fish consumption
- No hazards from eating fish containing detected concentrations
of radionuclides.
Paul Charp read a portion of the executive summary of the Task
4 Report from page ES-11, which stated that … “it is
unlikely that any observed trends in the incidence of disease in populations
that utilized the Clinch River and Lower Watts Bar Reservoir after 1944
could be conclusively attributed to exposure to radionuclides released
from the X-10 site, even though this present dose reconstruction study
has identified increased individual risks as high as 1 x 10-3 resulting
from these exposures.” Dr. Charp added that the detailed peer review
comments were “shaky,” but that the overall comments indicated
that this was a good report.
From its evaluation of the LWBR, ATSDR concluded that the LWBR sediment,
if left in place and undisturbed, did not and would not pose a health
problem for people who use the river for swimming, fishing, and domestic
purposes. In addition, ATSDR made the following three recommendations:
(1) the current advisory along the LWBR for polychlorinated biphenyls
(PCBs) should remain in effect, (2) any plans to construct or dredge in
the reservoir should be evaluated by the Interagency Working Group, and
(3) municipal water systems that draw water from the reservoir should
continue to be analyzed for radionuclides, particularly if and when the
ORR is aware of increases in surface water contaminant releases from the
reservation.
Discussion
Gordon Blaylock asked when ATSDR conducted its health consultation. Paul
Charp said that it was in 1996 or 1997. Dr. Blaylock asked if ATSDR had
data up to 2003; Dr. Charp said that the agency did not.
Bob Craig asked if White Oak Creek dumped into the Clinch River above
Melton Hill Dam. Many people answered that the creek dumped into the river
below Melton Hill Dam.
Gordon Blaylock explained that when the ORNL was built, it was designed
to be open for only one year. However, this time period was extended and
when the facility started to release radioactivity, all of the waste was
supposed to be put into large gunite tanks. When the facility started
to release the waste from the tanks, it went down to White Oak Creek.
Because this caused the concentrations to increase insignificantly, a
large retention area was constructed. It was built in 1944 within a time
period of about six months. Paul Charp asked if these were the 500,000-gallon
tanks that were located by the cafeteria. Dr. Blaylock said that Dr. Charp
was correct. Dr. Blaylock continued that these tanks were originally supposed
to hold everything from the facility and to receive all of the radionuclides.
However, when the facility was not closed as intended, there had to be
a method devised to deal with the radioactive waste. Thus, the facility
started to release the waste to White Oak Creek. Two ponds were used—one
held the waste for 24 hours, while the other pond released the waste.
These ponds were used alternatively, and the waste was released to White
Oak Creek. As a result of these disposal practices, the activity in the
river was too high. Thus, this retention area was built for the waste,
and the facility discontinued releasing waste into the river.
Tim Joseph pointed out that the retention basins were not lined, unlike
today’s type of basins. Paul Charp wanted to clarify that there
was not an engineering barrier (other than gravel) used. Dr. Joseph said
that this was correct and that it was important to note. Dr. Charp added
that any seepage was dependent on the veracity of the soil.
Gordon Blaylock noted that there was a barrier at White Oak Creek, but
that people still fished there. Tim Joseph asked if Dr. Blaylock was referring
to the cable barrier and he said that Dr. Joseph was correct. Dr. Joseph
continued that the barrier was simply a cable that went across with a
sign that said not to enter the area. He said that people would lift this
up, go under the cable, and fish at the creek.
A meeting participant suggested that when the tables from the Task
4 Report were redone, that ATSDR change the values to mrem. Paul
Charp said that these were only kept as cSv because of the timeframe.
Gordon Blaylock did not think that ruthenium was included in the sediment
analysis because it usually moves right out of the water. Paul Charp replied
that one of the figures showed that ruthenium 104 had a very short half-life
and that it dropped off to almost no concentration around 1970. Dr. Blaylock
said that it was ruthenium 106 that dropped off. A meeting participant
asked Paul Charp about the units of measure. Dr. Charp thought that it
was in picocuries per liter (pCi/L). Gordon Blaylock said that it could
not be in pCi because more than a curie per year (Ci/year) was currently
released to White Oak Creek. The group discussed the matter and resolved
that the measurements were in total Ci.
Bob Craig asked if ruthenium 106 was the primary isotope that was released.
Paul Charp replied that it would be if it had been done in Ci. Dr. Craig
asked if it was water soluble. Gordon Blaylock said that ruthenium 106
had a very short half-life and that it did not go to the sediments because
it stayed in the water. He explained that these releases occurred in 1956
when the facility was reprocessing fuel rods. Three big pits were dug
on the side of White Oak Lake and waste from the rod reprocessing was
dumped into these pits. Later, so much waste was accruing that a pipeline
was built through the pits, and then the pits started running over and
seeping. One of these pits leaked a maximum of 50 Ci/day. Dr. Blaylock
thought that over 2,000 Ci were released in one year (1956) over White
Oak Dam, but this was a short half-life. He thought that it was two weeks
for ruthenium 106. Dr. Charp checked in a book and said that it had a
half-life of one year. Dr. Craig noted that one-year was not that short,
but that the radionuclide stayed in the water column. Dr. Blaylock thought
that ruthenium went to rhodium, which had the largest beta of any radionuclide.
Thus, a person could receive a large dose of rhodium.
A meeting participant asked what the biological affinity was for ruthenium
106. Gordon Blaylock replied that it had a concentration factor of about
one.
Bob Craig thought that cesium was the radionuclide of concern with White
Oak Lake. Gordon Blaylock stated that it was because it had a long half-life.
Dr. Craig asked if it remained in the sediment. Dr. Blaylock replied that
SENES measured and estimated that roughly 170 Ci of cesium remained in
White Oak Creek sediment after White Oak Lake was drained. (On May 19,
2003, Dr. Blaylock said that this statement was incorrect because SENES
estimated, but did not measure anything.) Paul Charp responded that there
were similar problems with Savannah River. Dr. Blaylock added that the
amount of cesium in Park Pond was very small compared to White Oak Lake.
Gordon Blaylock said that he was not sure about the current levels, but
that the last time he checked, the total amount of activity in White Oak
Lake was 350 Ci in sediment (primarily cesium, strontium, and other isotopes).
Tim Joseph mentioned that the main reason that the coffer dam was built
was because the lake would go up and down, and it would bring in sediments.
Dr. Blaylock explained that when the lake was drained in 1956 and the
flood occurred after that, the activity was washed over the dam. A lot
of the radionuclides were transported to Watts Bar and down the river,
and a lot was deposited in White Oak Creek Embayment. He knew that there
were high concentrations in the creek going up to 2,500 pCi/g (rough estimate)
for cesium. (On May 19, 2003, Dr. Blaylock corrected this statement to
read, “He knew there were high concentrations in the creek going
up to 40,000 pCi/g [rough estimate] for cesium.”) This was down
deep in the sediment, about 20 or 30 centimeters below the surface, so
it was not of concern. However, it was later found that the sediment surface
in White Oak Creek had a little lower than that level caused by Melton
Hill Dam. They had a “lock and release,” where everyday they
released water from the dam. The “sloshing back and forth”
was taking the sediment out of White Oak Creek and moving it down to the
river.
Bob Craig asked for clarification concerning the 54 mrem/year in Kingston.
He wanted to know if this was annually. Paul Charp believed that this
was over 47 years. Gordon Blaylock was not sure. Dr. Craig thought that
this was insignificant.
A meeting participant said that the reviewer comment that the “total
estimated release of radioactivity for all years was not documented in
the report” was incorrect.
Gordon Blaylock commented on the bioconcentration factors slide. Paul
Charp explained that a study should not have grouped fish of several tropic
levels (i.e., bottom feeders would not be grouped with top feeders). Dr.
Blaylock said that the study was not conducted in that manner and that
he had written the IAEA reports. Dr. Charp said that this only represented
one reviewer’s comments. Dr. Blaylock thought that it “would
have been nice” if SENES was given an opportunity to see the reviewers’
comments and to respond to them. Dr. Charp said that the comments would
be attached to the document. Dr. Blaylock expressed that this was too
late to receive the comments because SENES could have responded to the
comments. Tim Joseph added that SENES should have been able to respond
to the comments, especially because they were “clearly mistaken.”
Dr. Joseph thought that incorrect comments should not be included. Dr.
Blaylock said that a person who reviewed a document should be able to
stand by his/her comments.
Bob Craig mentioned that an “anonymous” peer review could
be conducted to enable reviewers to respond, while also keeping their
anonymity. Burt Cooper explained that this was not “technically”
their area. He said that Henry Falk at ATSDR worked with the “peer
review.” Gordon Blaylock asked if Dr. Falk had people respond to
the comments. Mr. Cooper stated that people were not asked to respond
to the comments because the peer review was only used for internal ATSDR
decision-making. James Lewis asked if Dr. Blaylock could respond now that
he had seen the reviewers’ comments. In response to Dr. Craig, Paul
Charp explained that ATSDR would not necessarily disregard these comments,
but that it would “weigh in” that they may not be correct.
Tim Joseph thought that it was important for the working group to not
have these mistakes published.
Kowetha Davidson said that there were too many contradictions within
the reviewers’ comments. Based on what they had seen so far, she
did not think that the comments were very useful. Bob Craig added that
he did not know who the reviewers were, but that they certainly had expertise
in different areas. Paul Charp replied that he knew two of the reviewers
and had heard of the other reviewer.
Gordon Blaylock said that the Clinch River water was used for drinking
water at the K-25 facility for several years. Bob Craig asked if the water
was treated. Dr. Blaylock replied that the water was treated with a water
intake structure at CRM 14. He added that in the 1950s and 1960s, there
was a spill at White Oak Creek and this was shut down.
Kowetha Davidson asked if there was a maximum contaminant level (MCL)
for total radionuclides. Paul Charp responded that there was an MCL for
man-made beta and photon emitters, which was 50 pCi/L. Dr. Charp added
that the MCL for tritium was about 20,000 pCi/L. He noted that these MCLs
were derived by the dose. Dr. Charp explained that EPA used a dose of
4 mrem/year in water to determine the MCL. He added that the isotope had
to be known, and that the MCL was calculated by using EPA dose factors.
However, the MCL might not be equivalent to the National Council for Radiation
Protection and Measurements (NCRP) or International Commission on Radiological
Protection (ICRP) standards.
A meeting participant asked how the screening numbers were selected (e.g.,
50 pCi/L). Paul Charp replied that the MCL was defined as 50 pCi/L for
man-made beta and gamma radionuclides. He used the example of tritium,
which was proposed for an increase to 60,400 pCi/L, but that it was decided
it could not be raised. The meeting participant thought that this may
be worth discussing.
Kowetha Davidson asked if doses were added when there was more than one
radionuclide. Paul Charp said that this was normally done for MCLs, which
was called the “sum of the ratios technique.” The concentration
of water was taken and divided by the MCL. If the sum of the ratio was
greater than 1.0 (as defined in the Drinking Water Act), then the MCL
was exceeded.
In regards to a question about the duration of doses, Paul Charp referred
to an appendix from the Task 4 Report. Dr.
Charp explained that he looked at a number of the equations that were
used to estimate dose and risk. He looked at the screening level risk
estimate for ingestion of beef exposed to dredge sediment. He brought
the PHAWG’s attention to “ED”, which stood for exposure
duration in years. He said that all of the exposure durations were based
on the number of years from the time of release to the Task
4 Report. Thus, the duration was from the beginning of the exposure
to 1991. In reference to the recommendations slide, Gordon Blaylock believed that
a person had to go through a committee before dredging or building a pier.
He said that this process was already in place.
Gordon Blaylock asked if Kingston was the municipal water system below
the Watts Bar. Several meeting participants agreed. Tim Joseph noted that
the city of Kingston’s water intake was one mile up from the Tennessee
River. Pete Malmquist thought that it was only a couple of hundred yards.
Dr. Blaylock said that when the Clinch River was “pulling down,”
the water could back up to the intake structure. He said that SENES evaluated
this in the Task 4 Report and that he thought that the distance
was about a mile. Paul Charp asked about Spring City. Dr. Malmquist said
that the city of Kingston was the only city that was close to the intake.
He added that this would be “low flow” out of the Tennessean
and flow out of the Clinch River to go back up. Dr. Blaylock thought that
this was “very unusual.” He asked if Broadway used a small
stream. Dr. Malmquist replied that Broadway took it from the embayment.
Burt Cooper said that ATSDR conducted an exposure investigation several
years ago that identified people who consumed the greatest number of fish
and turtles from the Lower Watts Bar Reservoir. Blood samples were taken
from the individuals and evaluated for PCBs and mercury. According to
Mr. Cooper, ATSDR did not find levels that were generally elevated among
people identified as the greatest consumers of fish and turtles.
Gordon Blaylock said that he knew that ATSDR was not trying to indicate
any facilities, but that there were more PCBs coming down the Tennessee
River than the Clinch River.
Bob Craig asked where they were on the outline. James Lewis asked if
they had already listed the resources, as detailed under the PHAWG 1 meeting.
Paul Charp said that he would check with Jack Hanley. Mr. Lewis thought
that they were between PHAWG 1 and PHAWG 2.
Bob Craig said that it looked as though they already had their conclusions.
Paul Charp responded that the conclusions were only based on the Task
4 Report. Dr. Charp thought that the “big issue” was
to resolve the reviewers’ comments. Dr. Craig questioned preparing
a complete PHA since they already know the conclusions. He said that they
were stripped for resources and had a lot of work that still needed to
be completed. He asked if there was an expedited PHA that could be done
in lieu of using technical time and technical resources that could be
better utilized for other topics (e.g., iodine 131). Burt Cooper said
that if the PHAWG made a recommendation to ATSDR that a full-blown PHA
not be conducted, then this recommendation would be considered.
Tim Joseph wondered if it was really going to take that much additional
time to prepare a full-blown assessment, rather than a shorter version,
since ATSDR already had the needed information. Dr. Joseph was concerned
about how the reviewers’ comments would be handled if they were
placed into the report. Bob Craig wanted SENES to look at the comments.
Gordon Blaylock pointed out that people would question why radionuclides
were not addressed. However, he believed that a shorter version would
be appropriate.
Bob Craig wanted to know if they should ask ATSDR if there was anything
to be saved by not conducting a full-blown PHA.
Kowetha Davidson asked if the PHA would still have to be released for
public comment if the document was expedited. Burt Cooper stated that
ATSDR would have a public comment period for anything that it prepared.
Paul Charp explained that ATSDR could prepare documents other than PHAs.
For instance, ATSDR could conduct a health consultation that would explain
the presentation given today and put it in an organized manner. It would
also show the Task 4 Report results, as well
as the reviewers’ comments on the report. It would provide the current
review of the Clinch River, and also include information from Dee Williamson
concerning the state data (once it is received). A consultation would
detail any changes from the time that Carol Connell conducted her assessment
to the recent data. The consultation would then be sent out for public
comment. If the document included the technical reviewers’ comments,
then SENES would have an opportunity to respond.
Burt Cooper said that Congress gave ATSDR some relief in its mandate
a few years ago. ATSDR is no longer required to conduct a PHA at every
National Priorities List (NPL) site. A health consultation, or something
similar, could be conducted if it was deemed appropriate. Tim Joseph asked
if the conclusions differed. Mr. Cooper said that the conclusions did
not differ, and that the document contained conclusions and recommendations.
Dr. Joseph was concerned that if the public wanted a health assessment,
then the public may not be satisfied if ATSDR did not produce a PHA.
James Lewis said that they had talked about “down streamers”
(i.e., where Pete Malmquist lived). Mr. Lewis wanted to know if this was
a primary issue. A meeting participant responded that it was. Mr. Lewis
asked if the people living downstream would accept something that was
not a complete assessment.
Tim Joseph asked what the time and resource difference were between a
PHA and a health consultation. Burt Cooper replied that he could not supply
an answer at the time, but that he would check. Dr. Joseph thought that
it was extremely important to finally put the public’s questions
to rest.
Pete Malmquist noted that one of the recommendations for the LWBR was
that there was no dredging without approval. He noted that people were
already required to obtain permission, so if ATSDR did not prepare a health
assessment, then people may ask why they needed to do that. Paul Charp
responded that those recommendations were based on information that was
known in 1996. Thus, once the data have been reviewed, these recommendations
could change.
James Lewis thought that they were behind in looking at the community
concerns database. He said that they needed to look at the database to
see what the issues and concerns were before they “leapfrog”
into something else. Burt Cooper said that ATSDR would look at the new
data regardless of which path it decided to take.
Kowetha Davidson had two questions. First, would a health consultation
become part of the overall health assessment? Burt Cooper responded that
it would. Second, could an expedited health assessment be conducted without
going through all of the usual steps? Mr. Cooper said that ATSDR would
have to go through the usual procedures.
Bob Craig asked for clarification on if the PHAWG wanted ATSDR to evaluate
the possibility of conducting a technical consultation. James Lewis said
that the PHAWG needed to look at the outstanding issues to see what the
“down streamers” were concerned about. Paul Charp made a suggestion
to let ATSDR review the most recent data to see if there were any drastic
changes. In addition, ATSDR would try to obtain clarification on the reviewers’
comments.
Bob Craig wanted to obtain input from SENES about mixing the trophic
levels. George Gartseff thought that the assessments would be based on
available data. He said that in the course of finding out that the Task
4 Report was good enough for ATSDR to use, there were differences
in opinion. Mr. Gartseff believed that this was ATSDR’s chance to
say that it looked at these differences, and that for certain reasons
it concluded that a comment was valid or not valid. He added that he would
not direct ATSDR to prepare a different document.
New Business
Pete Malmquist summarized a conversation that he had with Jack Hanley.
Mr. Hanley had notified Dr. Malmquist that Ed Fromm from ATSDR had offered
his services as a statistician to work with Dee Williamson. James Lewis
had also read this e-mail and noted that they should accept expertise
when it is offered.
Two ATSDR employees hired to work out of the Oak Ridge office were introduced
to the PHAWG. Bill Taylor, a chemist and toxicologist who had previously
worked with ATSDR (1992-1999), and Melissa Fish, who previously worked
as an intern with ATSDR, were introduced.
The meeting was adjourned at 7:30 pm.
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