ito Consiceravon in aoe Uha i ‘methods for increasing Vhs claw et PG hic Posslue ~ curacy of the assessment. So far, most attention 1... obcen centered around St. George, Utah. This is natural, since the maximum single Iduiddlon radiation incident as a result of fallout occurred there. However, the St. George area, located in the lower Sonoran life zone, is arid with very low humidity during the major portion of the growing season and it contains almost no swamp or wet land pastures. Furthermore, it hasrelatively few milk producers who feed “green chop” (fresh cut alfalfa). Standing water in fields, sparse vegetation in pastures, and feeding of green chop, all lead to accentuated accumulation of radioactive materials. The virtual absence of these factors near St. George would tend to reduce the yield to milk supplies in that area, whereas other parts of Utah in which these conditions are common could accumulate as much, or more, iodine 131 as entered the St. George milk supply from less total fallout. The St. George region was hit by high levels of fallout relatively few times, whereas the central and northern parts of Utah have been laced by fallout tracks repeatedly. Conditions of relatively high humidity, standing water, feeding of green chop and relatively poor pastures are commonly found in the northern part of Utah. As a consequence,it is entirely possible, indeed very probable, that the radiation effects to children inhabiting the north and central parts of Utah may exceed those for the St. George children. In the 1962 incident, the highest observed levels of iodine 131 in Utah milk occurred near Altonah, over 400 miles from the Nevadatest site, whereas much lower CApPuUsUTes LO Ladlauicla, 4 ds Ulislnciy ta defini*’ -~-~swers can be obtained by restricting t prese.. _ to the small number of children in 1 St. George region. Arthur H. Wolff Arthur H. Wolff is chief of the Research Branch, Di: sion of Radiological Health, for the U.S. Public Hea! Service with headquarters in Rockville, Maryland. We have reviewed Dr. Mays’ article and your ec torial introduction scheduled for the next edition Scientist and Citizen. The close deadline does not pe mit an exhaustive commentary and I am responding some major points raised by the article and editori introduction particularly the recommendation concer ing future studies of Utah children. I might add th these comments have been discussed with Dr. Jose; E. Rall, Director of Intramural Research, National I stitute of Arthritis and Metabolic Diseases, and th meet with his concurrence. As an overall comment, I think that Dr. Ma: hypotheses on dosimetry and dose-effects are reasonat but I believe that several of the assumptions made Dr. Mays’ paper are oversimplified. Whereas they m serve as a semi-quantitative basis for risk estimates ar may be useful to bracket the risks of environment contamination, there is a reason to believe that th may not be valid for designing extensive epidemiclog studies. Some of my reservations in this regard we submitted to Dr. Mays when I reviewed an earlier drz levels were observed from farms in southwest Utah that were closer to the source. Even with the long lived of his paper. However, I was out of the country duri that time and myearlier comments mayhave been su mitted to him too late for his consideration. mous differences in concentrations in milk result from the location of the fallout tracks and the effects of ecological factors. For example, the cesium 137 concentration in milk in May, 1962 was 173 times higher in our “highest” station than in our “lowest” station. (Note that this was before the tests of July, 1962.) In July, 1962 the variation was 248. It is probable that As you know, we now have had considerable exp: rience with epidemiologic field studies of the childre in, Washington County, Utah. We are convinced, base emitters, such as cesium 137 and strontium 90, enor- sizable numbers of infants received doses much greater than the population average, Efforts should be made to identify all high yield farms and study groupsof children from them. The study of irradiated children should not only be expanded to northern Utah, but should also include areas in the surrounding states wherever the indicated doses appear significant. Because of uncertainties in conventional methods of dose estimation, new methods such as iodine 129 evaluation in thyroid tissue from pathologists’ files should be explored. The expense of proper studies is justified by the urgent need to learn more about the long term effects 2 on this experience, that the screening studies of childre are not only extremely difficult and costly but do nc appear to be a practical means of diagnosing presume radiation-induced pathology in large population group Indeed, this latter point is the crux of the problem } that there is no characteristic clinical picture that ca be objectively or reliably screened ‘out of a “‘well” popr lation without recourse to intensive study. Our effor to date have uncovered a spectrum of thyroid abno malities in a “well” juvenile population which so fi do not appear to be radiation-related. Definitive dia: noses of very carefully screened cases could only f made after extensive clinical, laboratory, and surgic. study—the latter being not without some risk to th patient. We do intend to continue, prospectively, t study in depth the populations initially selected fc study in Anzona, Utah, and Nevada but the fie! DOE ARCHIVES Scientist and Citiz