‘methocology that we have crmloped is not directly _ applicable to larger populatic > currently have under investigation over 2000 chilu:en in Washington County, Utah, (St. George area) and about 1400 from an area in Arizona essentially free from Nevada test site fallout. This fall we are expanding the potentially ex- posed group to include about 400 Nevada children and planning to add about another 1000 to the Arizona comparison group. We have elected another approach to define the problem of statewide risks in Utah and Nevada. For the past several years we have been collecting records of every surgical procedure involving the thyroid glands of persons under 30 years of age in these states. Records covering the year 1948-1962 already have been assembled and are in the process of review and analysis for any significant changes in the pattern of thyroid pathology with respect to age, sex, diagnoses, geographic and temporal distribution. Concomitantly, we are col- lecting reports and data from other parts of the country presumably not exposed to significant amounts of iodine for comparative purposes. So far we have found no striking anomalies with respect to statewide occurrence of thyroid diseases or clustering of this condition in one region or another. You may beinterested to know that the Division of Radiological Health has other studies under way which mayhelp clarify the dose-tumorigenic response to iodine 131.Qneis a followup study of 37,000 patients who were treated for thyrotoxicosis. In this study we are compar- ing the frequency of neoplasia in patients treated with iodine 131 to those treated surgically. Another study just initiated concerns the followup of juvenile patients who received doses of 5-100 mc of iodine 131 for diagnostic purposes. I appreciate the opportunity to review this paper and hope you find our commentshelpful. Tamplin and H._L. Fisher was issued by the University of California. ice Radiation Laboratory, Liver- more. This study, a part of the fallout research program supported by this Division, represents an attempt to dopart of what Dr. Mays is recommending, namely to reconstruct the dosimetry. The results are not inconsistent with those of Dr. Mays. I shall not comment on the medical aspects of the paper since others are much better qualified to do so. John Garner John Garner is director of the Radiological Health Animal Research Laboratory, Fort Collins, Colorado, and has done pioneer research in iodine fallout in the food chain. I am obliged to you for your invitation to comment on the final version of Dr. Mays’ paper. I feel that Scientist and Citizen has expressed my own views so admirably in the editorial! comments which accompanied the draft that all I can add is an expression of my pro- found respect for Dr. Mays’ objectivity in his treatment of this highly emotional subject. Arthur R. Tamplin Arthur R. Tamplin is a member of the Biomedical Research Division of the Lawrence Radiation Laboratory, Livermore, California. He has recently published (with H. Leonard Fisher) a report on iodine 131 dose estimates from the 1952-1955 nucleartests. Mycolleague, H. Leonard Fisher, and I have recently made a detailed study of the thyroid dosimetry folkgw- ing the Nevada tests conducted from 1952 through, Joshua Z. Holland Josuha Z. Holland is chief of the Fallout Studies Branch, Biology and Medicine Division of the Atomic Enérgy Commission. Dr. Mays’ suggestions for obtaining the maximum possible information on thyroid iodine 131 burdens, radiation doses, and possible effects in the areas immediately downwind of the Nevada Test Site are laudable. They should be analyzed carefully by the experimental scien- tists who might have the capability of carrying them out. While Dr. Mays’ paper was being prepared, a report entitled “Estimation of Dosage to Thyroids of Children in the U.S. from Nuclear Tests Conducted in Nevada During 1952 Through 1955” (UCRL-14707) by A. R. September, 1966 1955.' Our best estimate of the thyroid dosage to children in the Salt Lake City area, who were drinking one liter of milk per day from cows on pastures, is approximately 50 rad for the period 1952 through 1955. Thus, our analysis would support Dr. Mays’ contention that the Utah children received sufficient dosage to justify consideration of an expanded study in the Utah area in an effort to shed some light on the question of the effects of low dosage radiation. If adequate samples are available Dr. Mays’ suggestion of using iodine 129 to improve the dosimetry would represent another line of evidence that has the potential of reducing the overall error of the dosage estimates. Since it might be of general! interest, I went through our analytical procedure with iodine 129, These calcula- tions suggest that following a single deposition the concentration of iodine 129 in human thyroids (assuming DOE ARCHIVES | 3