seastagays USSR ery 4 PSs Soh OTTER SOONG rg a ar RADIATION STANDARDS, INCLUDING FALLOUT scat os BN yen et BOE De arAL 109 26. Wasserman, R. H., and Comar, C. L. Annotated Bibliography of Strontium and Calcium Metabolism in Man and Animals. U.S. Department of Agriculture. Misc. Publ. No. 821,135 pp. (1961) 27. Wasserman, R. H. and Comar, C. L. Effectiveness of dietary substances in reducing the retention of chronically ingested radiostrontium: studies with tannin. Nature, 785,629-6380. (1960) 28. Wasserman, R. H. and Comar, C. L. Dietary considerations of the radionuclide contamination of non-milk foods. J. Agr. Food Chem., 9, 113-116. (1961) 29. Wasserman, R. H. and Comar, C. L. The influences of dietary K on the retention of chronically ingested Cs'” in the rat. Radiation Res., 15, TO-T7. (1961) 30. Wasserman, R. H., Kalifelz, F. A. and Comar, C. L. Active transport of calicum by rat- duodenum in viro. Science, 1338, 8838-884. (1961) 31. Widdowson, E. M., Slater, J. E., Harrison, G. E. and Sutton, A. Absorption, excretion and retention of strontium by breast-fed and bottle-fed babies. The Lancet, 941-944. Oct. 29. (1960). STATEMENT OF DONALD R. CHADWICK, M.D.,' CHIEF, DIVISION OF RADIOLOGICAL HEALTH, U.S. PUBLIC HEALTH SERVICE Dr. Cuapwick. Thank you, Mr. Chairman. My discussion this morning is entitled “The Intake of Radioactive Contaminants by the U.S. Population.” The U.S. Public Health Service has in recent years been developing surveillance systems to measure the levels of radioactivity in the environment. The purpose of these systems is to provide quantitative data from which exposures of the U.S. population to radiocontaminants in the environment can be compared with appropriate radiation protection standards. ‘ The details of these surveillance systems will be described in other testimony before this committee. It will be the purpose of this discussion to present briefly some of the more pertinent findings from these surveillance systems since the previous hearings held before this committee in May 1959. PHS milk network: Milk is an important source of information on human intake of many significant radionuclides from the environment. There are several reasons for this. (1) Many of the radio- nuclides considered to be of principal health interest oceur in milk. Indeed, milk is often the most important source of the radioactive material in the diet. I think the discussion during the previous testimony brought out the fact that radioiodine in muk is perhaps virtually the only source of this nuclidein the diet. Second, milk and milk products represent a significant part of the diet for all age groups, and a very large portion of the total diet in infants and children. (3) The production of milk throughout the 1 Biographical sketch, Donald R. Chadwick, M.D.: Dr. Chadwick, a native of Boston, Mass,. after graduating from Hurvard Medical School und after internship in Philadelphia, worked as a local heaith officer in North Carolina from 1951 to 1953. He entered the Public Health Service in 1954, and after serving an ussignment in South Carolina, received special training in radiological health at Reed Coliege, Oregon. In 1955, he was assigned to the oecupational heaith program in Cincinnati, Ohic, This was followed by assignment as Chief, Program Services, in the field of radiological health, and then an assignment as liaison officer for radiation, Office of the Surgeon General, Publie Health Service. With the establishment of the Division of Radiological Health in 1958, Dr. Chadwick became Chief, Program Operations Branch. Frem 1959 to 1961, Dr. Chadwick served as secretary, Federal Radiation Council. Then in November 1961, he was named Chief of the Division of Radiological Health in the Public Health Service. patentingge SERREMahhryBTA