Dear Prof. Lars-Erik Holm, Chairman of ICRP: As Professor emeritus of Nagasaki University where I was deeply involved in the investigation and treatment of the atomic bomb survivors and the victims of the Chernobyl accident, as the past Chairman of Radiation Effects Research Foundation which has the largest database of the atomic bomb survivors, and finally as one of the old friends in the thyroid group, I would like to make one comment on the draft recommendations of the ICRP. Comment: Cancer and hereditary effects must be handled separately. Reasons: 1) Cancer is confirmed as the late effects of radiation by the follow-up studies of the atomic bomb survivors. 2) Hereditary effects have never been found in human beings in spite of the extensive investigation on the atomic bomb survivors. 3) The public may believe that the risk of cancer and the risk of hereditary effects are similar and worry about hereditary effects as much as cancer, simply because cancer and hereditary effects have been handled together in the title of stochastic effects in ICRP publications. I had a lot of trouble explaining the risk of hereditary effects to the mass media, to the victims of the Chernobyl accident and the atomic bomb, as well as to patients at daily clinics. Even some experts who are in the position to explain to the victims and patients misunderstand the risk of hereditary effects. 4) A typical example in the draft recommendations is on page 24, 3.2.3. Table 2 gDetriment adjusted nominal risk coefficients for cancer and hereditary effectsh, in which cancer and hereditary effects are shown in the same table. 5) Finally, 3.2. The induction of cancer and hereditary effects has to be revised because (1) 3.2.4 Radiation effects in the embryo and fetus, 3.2.5 Genetic susceptibility to cancer and 3.2.6 Non-cancer diseases after radiation do not have any relation to 3.2 The induction of cancer and hereditary effects, and (2) cancer and hereditary effects are handled together. Recommendations: (A, B, C or D) A. ICRP members are kindly requested to revise the Draft Recommendations in a way that cancer and hereditary effects are handled separately. B. Add a part of the sentence in (65), gthere continues to be no direct evidence that exposure of parents to radiation leads to excess heritable disease in offspringh below Table 2 on page 24. C. Delete Table 2 on page 24, and explain the content in words instead. D. Revise 3.2.The induction of cancer and hereditary effects as follows: 3. BIOLOGICAL ASPECTS OF RADIOLOGICAL PROTECTION 3.1. The induction of tissue reactions 3.2. The induction of cancer Same as 3.2.1 Risk of cancer (54)-(64). Table 2 on page 24 should be deleted for the reason that cancer and hereditary effects are handled together. Hence, actual values should be added in (64) instead of referring to Table 2. 3.3. The induction of hereditary effects Same as 3.2.2 Risk of hereditary effects (65)-(68). The majority of 3.2.3 Detriment adjusted normal risk coefficients for cancer and hereditary effects can be moved to Annex A. Risk coefficients in cancer and hereditary effects differ greatly in Table 2 (whole 5.5 to 0.2, and adult 4.1 to 0.1). The reasons why these two values must be added to make the total (5.5+0.2=6, 4.1+0.1=4) can be discussed also in Annex A. 3.4. The induction of others (if items below must be included in 3) 3.4.1. Radiation effects in the embryo and fetus (same as 3.2.4.) 3.4.2. Genetic susceptibility to cancer (same as 3.2.5.) 3.4.3. Non-cancer diseases after radiation (same as 3.2.6) With best regards, Shigenobu Nagataki ******************************************************************************** Shigenobu Nagataki, M.D., Ph.D. Professor emeritus, Nagasaki University Executive Director, Japan Radioisotope Association 2-28-45 Honkomagome, Bunkyo-ku, Tokyo 113-8941 Japan E-Mail: nagataki@jrias.or.jp Home E-Mail: shigenobu.nagataki@nifty.com ********************************************************************************