Savannah River Site Health Effects Subcommittee (SRSHES) Meeting

Final Meeting Minutes
September 15, 2005

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SRSHES asked CDC to take action in three areas during the process of finalizing the ATL report. First, CDC should incorporate SRSHES’s previous recommendations on the ATL report and new recommendations that will be formulated on Dr. Hertel’s independent review. Second, CDC should provide SRSHES with a list of Dr. Hertel’s “open-ended” questions or “follow-up” issues. The members will be able to use this document as a checklist while reviewing the final ATL report to ensure these items were addressed. Third, CDC should ask Dr. Hertel to state his position in the final peer review report on whether ATL appropriately used the model to answer questions specifically related to SRS.

Mr. Green and Mr. Wood noted several factors in the overall dose reconstruction process. A manual published by the National Research Council served as the guiding principle for conducting dose reconstructions at SRS and all other DOE facilities, but the guidance was modified to account for characteristics that were specific to each site. CDC implemented a competitive contracting process to select ATL and other contractors to conduct health-related research at SRS and all other DOE facilities. Awarded contractors were charged with completing specific tasks as defined by the government. In terms of SRS, CDC continues to welcome formal recommendations and other input from SRSHES on the ATL report or additional areas Dr. Hertel should examine in preparation of the final peer review report.

Dr. Lee provided additional details based on her long tenure as an SRSHS member and expertise in the field. The statement of work for Phase III of the SRS dose reconstruction study allowed the contractor to use its best judgment in selecting a model. However, the scope of work changed after the contract was developed due to budget constraints. Most notably, activities for Phases III, IV and V were combined into Phase III. Several different approaches could have been selected to successfully conduct the Phase III activities, but the model chosen by ATL is widely used in the industry and is equally as solid and reasonable as others.

Mr. Wood summarized key findings from CDC’s dose reconstructions conducted at other DOE facilities in response to a previous action item. The most significant dose at the Fernald, Ohio site was from a uranium silo that resulted in radon to the lungs. Radon doses to persons could have been as high as 100 rads. The most significant dose at the Idaho National Laboratory (INL) was ~6 rads of an effective dose of iodine 131 from multiple isotopes. No epidemiological studies were conducted at INL.

The most significant dose at the Hanford, Washington site was airborne iodine 131 from the milk pathway with a median dose of ~200 rads to the thyroid of an infant. The upper uncertainty bound was found to be as high as nearly 600 rads. River doses, hot particles and plutonium emissions were found to be considerably smaller than the iodine 131 doses. Two epidemiological studies conducted at Hanford found no correlation between dose and thyroid disease in the affected population and also did not show an increase in the incidence of thyroid cancer, hypothyroidism, hyperthyroidism or Graves’ disease. The most significant doses at SRS were from multiple isotopes and pathways with an effective dose of 1 rem.

CDC is currently retrieving documents from the Los Alamos, New Mexico site. Findings from these efforts to date can be reviewed on the CDC web site. Los Alamos is the only DOE site where CDC is still conducting activities. The states of Tennessee and Colorado conducted dose reconstructions at the Oak Ridge, Tennessee and Rocky Flats, Colorado sites, respectively. Each state has posted a dose calculator on its respective web site for persons to enter specific parameters and calculate individual doses.

Mr. Wood provided additional details to further guide SRSHES’s discussion on next steps. The Health Physics Society (HPS) position statement does not recommend an epidemiological study in an area with exposures <10 rem. HPS acknowledges that health effects can be caused by exposures <10 rem, but results at this low rate cannot be statistically detected or measured. The National Council on Radiation Protection and Measurements concurs with HPS’s position. CDC is reluctant to conduct an epidemiological study at SRS because similar research performed at other DOE sites with higher doses did not show significant health effects to persons. The SRS doses will still not be as high as those at other DOE sites even if gross errors are detected in previous SRS analyses or new data are located.

Ms. Carol Connell of NCEH/ATSDR clarified that in addition to radon, CDC also examined uranium in drinking water at the Fernald site due to significant public health concerns about an offsite plume. An extensive epidemiological study was launched and is still ongoing because of a lawsuit. Anticipated increases in lung cancer were not seen in Fernald residents, but a slight increase in urinary tract cancer and disease was detected. Overall, doses used in dose reconstruction studies are extremely conservative or cannot be identified by epidemiological studies. Ms. Connell added that the University of South Carolina conducted a five-year cancer incidence study for SRS in Georgia and South Carolina.

Ms. Jane Perry is the SRSHES liaison to the Georgia Division of Public Health. She conveyed that ATSDR’s public health assessment (PHA) will continue to formally address epidemiological issues at SRS and other sites outside of the advisory committee process.

Mr. Ortaldo opened the floor for SRSHES to provide CDC with guidance on the nine recommendations in the ATL report. The ATL recommendations and SRSHES responses are outlined below.

• “Examine large acute releases to determine if the pattern of doses will significantly change.” SRSHES recommends that a determination be made on whether acute releases as a total amount released in a year were incorporated into the source term calculation. Dr. Hertel should review existing data on SRS onsite acute releases and dose calculations to make a qualitative statement on whether this information will affect the doses in terms of a significant increase or decrease. CDC should review previous SRSHES meeting minutes and include SRSHES’s previous position on acute releases in the final ATL report.
• “Examine the buildup of long-lived radionuclides in soil to determine if terrestrial doses will significantly change.” SRSHES agrees with Dr. Hertel’s plan to address this issue in the final peer review report.
• “Model contaminants in reservoirs to determine if significant doses occur.” SRSHES recommends that the word “reservoir” not be used because the independent review focuses on significant doses from fish consumption.
• “Compare modeled concentrations in foodstuffs with monitoring data for model validation.” SRSHES recommends that CDC conduct this activity by compiling and reviewing sampling data previously collected for SRS.
• “Perform an auxiliary analysis to determine if breast-feeding of infants substantially changes doses.” SRSHES does not recommend that any actions be taken to address this issue.
• “Perform an auxiliary analysis to determine how in utero doses change total dose and cancer risk.” SRSHES does not recommend that any actions be taken to address this issue.
• “Model consumption of venison more carefully to determine if the result changes.” SRSHES recommends that Dr. Hertel review ATL’s white paper on this issue in preparing the final peer review report.
• “Model doses from the consumption of drinking water taken from the Savannah River for municipal water supplies some distance downstream from the SRS.” SRSHES recommends that CDC review existing data to locate the highest level of each isotope measured in any part of the Savannah River. The data should then be calculated to determine the amount of water an individual would need to ingest to obtain a dose of 1 rem.
• “Obtain technical peer reviews by publishing papers on the study methods and results in peer-reviewed journals.” SRSHES does not recommend that any actions be taken to address this issue.

SRSHES turned the discussion to the current status of the ATL report. Mr. Christensen believed the report should be finalized and released to the public at this time, but Dr. Lee pointed out that several deficiencies must first be resolved. Most notably, data are missing from the current version of the report to run ATL’s calculations and confirm the accuracy of figures. The report has not been revised to capture technical and scientific comments from SRSHES, Dr. Hertel, the public or other sources. Mislabeled tables, duplicate text and other typographical or editorial errors have not been corrected. Additional flaws may be detected in the report while Dr. Hertel completes his independent review. Dr. Lee added that the final ATL report should reflect a high-quality and accurate product to honor the tremendous amount of funding, extensive efforts and long period of time of the SRS dose reconstruction project.

Ms. Ali Simpkins of WSRC agreed with Dr. Lee’s comments. The current version of the ATL report cannot be used to run the calculations and easily reproduce doses. Data are entirely missing or are extremely difficult to locate in the text or appendices. An individual with Ms. Simpkins’ experience of over ten years in the dose reconstruction field should be able to easily replicate ATL’s figures in one day. However, Ms. Simpkins needed one month to complete this task using the current version of the report. WSRC submitted comments to CDC to document these technical issues.

Based on these comments, SRSHES placed a formal motion on the floor to recommend that CDC take the following actions to finalize and release the ATL report to the public. Additional data should be provided to easily reproduce ATL’s calculations and confirm the accuracy of the figures. SRSHES’s editorial and technical comments noted in the January 25, 2005 meeting minutes should be addressed. Dr. Hertel should complete the independent peer review and comments from his assessment should be addressed. Technical and scientific comments submitted to CDC from WSRC, the public and other sources should be addressed. The motion was properly moved and seconded by Mr. French and Mr. Stringer, respectively, and unanimously approved.

In addition to the formal motion recorded in the minutes, SRSHES also reached agreement for Dr. Lee to draft a letter to CDC. SRSHES’s letter will provide more explicit details on specific areas that should be addressed before the ATL report is finalized and released to the public, such as editorial and technical comments submitted by SRSHES, WSRC, the public and all other sources; ATL’s nine recommendations listed in the report; and comments from Dr. Hertel’s final peer review report. Dr. Lee will forward the letter to Mr. Ortaldo for an initial review and the revised document will be distributed to SRSHES for review and comment. The members will be given two weeks to submit comments to Dr. Lee and the letter will then be finalized and sent to CDC.

Mr. Green and Mr. Wood described CDC’s next steps to respond to SRSHES’s consensus recommendation. CDC will meet with ATL shortly after the meeting to discuss actions that should be taken to address comments from SRSHES, Dr. Hertel and all other sources in finalizing and releasing the report to the public. SRSHES and the public are welcome to submit additional comments to CDC before the ATL report is finalized. CDC will provide Dr. Hertel with comments submitted by SRSHES and WSRC to assist in his preparation of the final peer review report. CDC will also distribute WSRC’s comments to all SRSHES members. CDC will provide a written response to SRSHES’s letter on its formal motion