DISCLAIMER The following is a staff memorandum or other working document prepared for the members of the Advisory Committee on Human Radiation Experiments. It should not be construed as representing the final conclusions of fact or interpretation of the issues. All staff memoranda are subject to revision based on further information and analysis. For conclusions and recommendations of the Advisory Committee, readers are advised to consult the Final Report to be published in 1995. TAB F-2 þþþDRAFT þ FOR DISCUSSION PURPOSES ONLYþþþ MEMORANDUM TO: Members of the Advisory Committee on Human Radiation Experiments FROM: Advisory Committee Staff DATE: RE: Documentation on Worker Studies at Los Alamos and Oak Ridge National Laboratories EXECUTIVE SUMMARY The attached documents were retrieved by Committee staff from Los Alamos and Oak Ridge National Laboratories during recent site visits. They relate to the study of worker exposures in connection with intentional releases at Los Alamos National Laboratory and the handling of uranium compounds at Oak Ridge National Laboratory. I. DOCUMENTATION REGARDING HEMATOLOGICAL CHANGES IN LOS ALAMOS LABORATORY WORKERS CHRONICALLY EXPOSED TO WHOLE-BODY GAMMA RADIATION IN CONNECTION WITH INTENTIONAL RELEASES In 1944 Los Alamos National Laboratory undertook a program of radiolanthanum (RaLa) intentional releases in nearby Bayo Canyon that would continue into the early 1960's, and would involve about 250 releases. As early as August 1946, the laboratory's Health Division had recognized that the chemists who prepared the RaLa experiments were receiving "excessive exposures."1 [Memorandum from Louis H. Hempelmann to Norris E. Bradbury, August 30, 1946. Subject: "Excessive Exposures at Bayo Canyon."] Louis Hempelmann, head of the Health Division, called a temporary halt to the intentional release program due to these exposures. He recommended that replacements be obtained for each member of this team of chemists; it is not clear from the documents, however, what steps were actually taken to limit further exposures. 1 The RaLa program resumed after a four-month hiatus. A study was undertaken at this time to determine whether statistically significant hematological changes would occur in the Bayo Canyon chemists due to their chronic exposure to low-level gamma radiation. This research, conducted from 1946 to 1954 and beyond, consistently showed that blood changes did occur in this group of workers over the entire period of study. By late 1948, members of the Health Division at Los Alamos Laboratory had recorded the preliminary findings of this study in a report, entitled "The Changes in the Blood of Humans Chronically Exposed to Low Level Gamma Radiation." After review by the AEC's Declassification Branch, which agreed "with Los Alamos that is it properly issued as unclassified,"2 [Memorandum from Anthony C. Vallado to Clyde Wilson, December 8, 1948. Subject: "Review of Document by Knowlton."] the report was forwarded for declassification review to the AEC's Insurance Branch. A December 20, 1948 memorandum from Clyde E. Wilson, Chief of the Insurance Branch, to Anthony C. Vallado, Deputy Declassification Officer (Attachment 1), recorded fears that public knowledge of the study would open the AEC to occupational injury claims: The results of the studies indicate that the tolerance levels for chronic exposure to gamma radiation which have been accepted both within the A.E.C. and elsewhere may be too high. We can see the possibility of a shattering effect on the morals of the employees if they became aware that there was a substantial reason to question the standards of safety under which they are working. In the hands of labor unions the results of this study would add substance to demands for extra-hazardous pay. We can also see the definite possibility that general knowledge of the results of this study might increase the number of claims of occupational injury due to radiation and place a powerful weapon in the hands of a plaintiff's attorney. . . . In view of the above considerations we think the question of making this document public should be given very careful study.3 [Memorandum from Clyde E. Wilson to Anthony C. Vallado, December 20, 1948. Subject: "Review of Document by Knowlton." ACHRE No. DOE-113094-B. (Note: this document was released in Briefing Book #9, Tab I; it is being re-released here, however, with related documents for additional context.)] Advisory Committee staff has requested from Los Alamos a copy of this report and information on its classification at the time. 2 Drs. Norman Knowlton and Robert Carter of Los Alamos Laboratory Health Division continued to observe blood changes in this group of workers. In a February 1949 memorandum to Drs. Knowlton and Carter ' (Attachment 2), Thomas Shipman of the Health Division observed that significant changes in blood counts would require further study: . . . . it is obvious that significant changes in total and differential counts were, for all intents and purposes, observed in no group except the Bayo chemists. It seems to me that during the coming weeks a strenuous effort should be made to produce some useful information out of the figures presented and I suggest a rather intensive study to produce a correlation between the blood counts and the individual exposures of the Bayo group alone.4 [Memorandum from Thomas Shipman, Los Alamos Health Division, to Drs. Knowlton and Carter, February 16, 1949. Subject: "Analyses of Q-Building Blood Counts." ACHRE No. DOE-021095-B-2.] In the years to follow, investigators at Los Alamos continued to study these effects, writing two follow-up reports. The first, "Hematological Changes in Humans Chronically Exposed to Low-Level Gamma Radiation" (LA-1092) was issued on March 27, 1950.5 [Knowlton and Carter, "Hematological Changes in Human Chronically Exposed to Low-Level Gamma Radiation" (LA-1092), March 27, 1950. ACHRE No. DOE-030695-A.] It remains unclear what its original level of classification was; it was declassified, however, in November 1956. "Further Study of Hematological Changes in Humans Chronically Exposed to Low-Level Gamma Radiation" (LA-1440) was written in July 1952, but was not released until April 1953. It was evidently issued "Official Use Only," and was also declassified in November 1956.6 [Carter and Worman, "Further Study of Hematological Changes in Human Chronically Exposed to Low-Level Gamma Radiation" (LA-1440), April 1, 1953. ACHRE No. DOE-030695-A.] These reports continued to show a significant depression in the white blood-cell count of the exposed group versus control groups. A July 1954 letter from Gordon M. Dunning, Health Physicist with AEC's Division of Biology and Medicine (DBM), to Thomas Shipman (Attachment 3) shows that DBM knew of the results of these studies: We recently have had occasion to refer again to the LASL No. 1440 document, "Further Study of Hematological Changes In Humans Chronically Exposed to Low Level Gamma Radiation" by Carter. The purpose of writing to you is to inquire as to your present state of thinking on this subject. Has there been any additional information that might have a bearing either on the material as presented in the report or 3 on an extension of the data?7 [Letter from Gordon M. Dunning, Health Physicist with AEC's Division of Biology and Medicine, to Thomas Shipman, July 16, 1954. ACHRE No. DOE-020795-D-4.] Shipman responded to Dunning's query in a July 1954 letter (Attachment 4), and discussed the Health Division's issuance of the third report (LA-1440): When we finally decided to issue LA-1440 we were well aware of the fact that we would almost certainly live to regret it. There was the data, however, and we felt that we probably had an obligation to make it available to others. We attempted at that time to refrain from drawing any conclusions, nor have we yet arrived at any. The blood counts were done with extreme care by the same technicians throughout and we are satisfied that the changes in counts are actual and not imaginary. It is our belief, however, that they don't mean anything; if they do mean anything, we don't know what it is.8 [Letter from Thomas Shipman to Gordon Dunning, July 21, 1954. ACHRE No. DOE-020795-D-4.] Shipman went on to discuss continued monitoring of the same group of Bayo Canyon chemists: We are continuing periodic blood counts on the same group of subjects. Their level of exposure to radiation is more or less the same as it has been, and we are fortunate in still having the same hematology technicians. The records up to date indicate nothing that is startling or dramatic. For the present we do not anticipate any work other than the routine collection of data.9 [Ibid.] It remains unclear whether this group of workers was ever told of the abnormal findings of this study, or whether any steps were taken to further limit their exposures. Committee staff is still trying to understand the significance of these blood changes, and has recently requested answers to these and other related questions from Los Alamos Laboratory. 4 II. DOCUMENT ENTITLED "PROPOSED TOXICOLOGICAL STUDIES" Attachment 5 , a June 1949 memorandum entitled "Proposed Toxicological Studies," was recently declassified at the request of Committee staff following a visit to a classified vault at the Oak Ridge Operations office of DOE. This document recorded plans of the Health Physics Department at Oak Ridge National Laboratory to perform toxicological studies on two groups of workers chronically exposed to compounds of uranium. The first observational experiment would focus on the absorption and excretion of uranium-234; the second, however, would be designed to "establish clearly that measurable physiological injury either does, or does not occur as a result of long term, minimal exposure."10 [Memorandum from E.G. Struxness to C.E. Larson, June 14, 1949, p 1. Subject: "Proposed Toxicological Studies." ACHRE No. DOE-032495-A.] These studies were planned, and were to be carried out, in cooperation with the University of Rochester's Atomic Energy Project. The memorandum described the first study, which would follow workers involved in the electromagnetic separation of uranium-234: Recent attempts at this site to obtain medium level concentrations of U-234 by electromagnetic separation have been quite successful. In an effort to determine the extent of the hazards involved in the handling of this highly active material, it was definitively established that some uranium is absorbed in spite of precautions taken to prevent it. That is, complete protection is not afforded by elaborate ventilation facilities and respiratory protective devices. Now a further effort to obtain higher concentrations is being planned. And it is this project to which the proposed study has reference. Only one or two subjects are involved in the study and, in view of the potential benefits to personnel in this plant and others which may result, it is felt that full advantage should be taken of this opportunity.11 [Ibid, p 2.] The memorandum went on to propose a four-part study of these workers, involving tests meant to determine kidney function and uranium intake, absorption, and deposition. The second study was to involve workers in the "Sunflower" and "Daffodil" programs. (Committee staff is still inquiring as to the exact nature of these programs): For the past year a rather intensive effort has been put forth by the Health Physics Department and the Chemical Division to identify the hazardous conditions inherent in the two processes and to correct them. Vast improvements have resulted from this effort to the extent that 5 present thought questions the wisdom of proceeding further in this direction. About all that can be done has been done, short of installing elaborate and probably unnecessary local ventilation facilities. Effective as these improvements appear to be, however, present measurements continue to indicate the possibility of minimal exposure via contaminated air, hand, clothing, et cetera. This fact has led to the thought that additional protection is needed by these employees, over and above that which is presently afforded, viz., exposure monitoring of the workers and their surrounding together with annual physical examinations. Moreover, concomitant with an improved program of health protection, there is an opportunity to secure the type of medical information required by the physician to interpret, in terms of human experience, the toxicological findings of small animal research.12 [Ibid, p 3.] Unlike the first study, this study was to involve tissue sampling whenever possible, as well as clinical testing every three months, in addition to occupational monitoring: Dr. Harold C. Hodge, head of the Division of Pharmacology and Toxicology at the University of Rochester, suggested the need for securing samples of soft and hard tissues for purposes of analysis whenever possible. This will involve making arrangements with various hospitals and dental clinics in the vicinity so that when these employees have an appendix removed, a tooth extracted, or some similar medical service performed, these tissue samples will be available for analysis. Furthermore arrangements should be made to secure samples of hard tissue, i.e., rib, sternum, vertebra and femur, on post mortem examinations when such an opportunity is presented. . . . 6 The Medical Director will arrange for an Industrial Health Recheck of each employee once every three (3) months. In addition to the clinical procedures prescribed by him the following additional tests will be made: (1) Urinary Catalase; (2) Urinary Protein; (3) Urinary Amino Acid Nitrogen/Creatinine Ratio; and (4) Urinary Uranium.13 [Ibid, p 4.] Furthermore, hand counts and clothing contamination measurements were to be "taken with a view to controlling rather than monitoring exposure by ingestion, skin absorption or skin punctures."14 [Ibid, p 5.] It is again unclear what these workers were told--whether these plans were shared with them, and whether they were ever told about their exposures. 7