Letter to W L Robison, Subject: Draft of the Enewetak Doses

Page 1

Post Office Box 1663 Los Alamos, New Mexico 87545 In reply refer to: HH-7o University of California Lawrence Livermore Laboratory I have put together some detailed comments on your latest draft of the Enewetak doses. Overall, I think that you have done an excellent job in the short time available. However, I find the computer printouts in the appendix (aside from external dose) less than useful because the living condition is not specified. I find, for example, five separate tables labeled ‘living conditions - Janet’?. Each one has different numbers and the correspondence to the numbers in the tables in the report is poor. , I would suggest a definitive label for each jastened ~ that it will stav with th~ document. Detailed comments follow. I would guess that on your map of the atoll. Throughout we find the term R/h. pp. 4, yR/h is meant but cannot I cannot find Tainel (Percy) on 4. pp. 10, 2nd parag. Perhaps Dick Gilbert could tell me why you include the average using the MDA instead of the actual measured value. This does bias the results. 5. pp. 11, 2nd parag. Is the difference in levels between the west tip of Aomon and the rest of the islands large or small? I am concerned with the probable establishment of wato!s that could affect the dose to An affumalwe actionlequal opportunely employer

Page 2

LOS ALAMOS SCIENTIFIC LABORATORY 6. pp. 11, 2nd parag., last sentence. The source of the conversion factor from pR/h to mrem/y is not given. In the previous draft it was 8.23 and in this one 6.24. It appears that this conversion factor includes shielding in the body. If this is the case, it should differ somewhat for cobalt and cesium and would be different for different organs. Thus, the organ that the conversion factor is derived for should be given and the difference for other organs of interest should be stated. (See comment 26.) 7. PP. 11, last parag., pp. 12, 1st parag. I have some concern with these beta dose rates. The results are given at 1 cm depth in tissue. However, the presumed sensitive cells are much closer to the surface than this so that the beta dose could be considerably highe5* I would use the generally assumed depth of 7 mg/cm . The beta dose varies greatly with height so that the dose at 1 m is not representative of that close to the ground or the dose received by sitting or squatting. While it may make little difference, I believe that we should make the best and most realistic estimate possible of the skin dose and dose to the lens of the eye. 8. pp. 14, last parag. A little more discussion on the personnel sampler~3would be in or+er. From Table 5, I estimate about 10 !is/reinper m in the air. Thus, a sample of 100-1000 m would be needed to get a positive indication. This is more air than any personnel sampler that I have seen would draw. Which data in Table 5 are from these personnel 9. pp. 15, lines 1 and 2. It is not clear to me how one gets an enhancement factor of 1.54 for “normal conditions” from the data in Table 5. Are there other data not given? If so they should be included and the derivation of these values made explicit. In Table 5 under the heading “at Roadside”, it is not clear to me how the individual survived at a breathing rate of 0.023 m3/h. 5 15, 1st parag. How was the breathing rate of 20

Page 3

Unlverslty of California LOS AIAMOS SCIENTIFIC LABORATORY Los Alamos, New Mexico 87545 PPl 15, 3rd parag. Where did the respirable fractions of O.19 and 0.24 in Table 5 come from? Are these comparable to the value of 0.3 used for calculation? Table 7, 8 and 9. Here we find assumptions that the cistern drinking water is the same as that for Bikini or Kwajelein. Is there any justification for these pp. 17, Ist sentence. This sentence is not complete. PPl 20, last parag. As I indicated on the phone, I believe the word ‘famine” to be completely non-descriptive of the situation of no imported foods. Even if it is an accurate---translationitit--implies--a-- condition that does not exist, at least at the present, because there will be ample food in the lagoon and on the islands once the crops are of a sufficient size. “subsistence food” to describe foods adds confusion to the discussion and implies that this is a “subsistence” diet. However, if one looks at the diets, a considerable amount of. local food is included even under “normal” conditions. I would drop this term with its implication and refer simply to local foods. Note that the diet figures----donot really support your statement that imported foods are preferred over local foods.--About the-same amounts of local foods are eaten in either condition. pp. 21. Has any consideration been given to the fact that this survey was made for Ujelang, a much smaller atoll? What is the justification that the consumption of local foods md...types of local foods will be the same on Enewetak? Shouldn’t this at least be mentioned pp. 28, last parag. No information is given on how the child dose was calculated. This would include body weights, GI uptake and method of calculating dose to bone marrow in the immature skeleton. tract that was used should be given for each of these.

Page 4

University of California LOS ALAMOS SCIENTIFIC LABORATORY Los Alamo% New Mexico 87545 PP. 32, _Inhalation. I am puzzled by the statement that the dose is calculated only for the pulmonary compartment? Werentt the doses to bone and liver must be done carefully because the fraction absorbed is different for the two. PP. 339 Results~ lines 7-10” I am no Oclear as to how the buildup of dose from ingestion of Was a whole body dose calculated for Sr? If so, what does it mean? pp. 48, Ist parag. Shouldn’t you acknowledge the 630 pp. 48. In the discussion of probabilities you have largely considered island averages. How about the question of people living on a wato. Wouldn’t this serve to minimize the independence of these values and possibly result in a higher fraction of high doses? pp. 49, 1st parag. As I read the preceding material, 3X seems to be about 95-96% of the people. Thus, with people above this value. While characterized as a “very small fraction” in this report, it means that future monitoring efforts ”have a“ 5% chance per person of values above the limit. Can this be handled? Table 30 et al. You have never told us how the bone marrow doses from the transuranic nuclides were caalg~ed. They are sizeable in comparison to those Sr so that the calculational method is of Fig. 1. Shouldnlt you indicate on this map the islands that are no longer there because of the tests? I thought that Enjebi was spelled with a j. Appendix B. The value of 0.82 used for the conversion from absorbed dose in air to absorbed dose in the body is specific for the gonads. It would be well to quote values for other organ systems.

Page 5

University of Celbrrh LOS ALAMOS SCIENTIFIC LABORATORY Los Alamo% New Mexico 87545 27. Appendix E (I think). What is GIT? How does one calculate a whole body dose from plutonium and americium? This should be described in the text along with an explanation of what it means.