A TWENTY-SEVEN YEAR STUDY GF SELECTED LOS ALAMOS PLUTONIUM WORKERS Compiled and Written by ¥ L. H. Hempelmann, C. R. Richmond, and G. L. Voelz ABSTRACT eo te ae 8 Rage Twenty-five male subjects who worked with plutonium during World War II under extraordinarily crude working conditions have been followed medically for a period of 27 years. Within the past year, 21 of these men have been examined at the Los Alamos Scientific Laboratory, and 3 more will be studied in 1973. In addition to physical examinations and laboratory studies (complete blood count, blood chemistry profile, and urinalysis), roentgenograms were taken of the chest, pelvis, knee, and teeth. The chromosomes of lymphocytes cultured from the peripheral blood and cells exfoliated from the pulmonary tract were also studied. Urine specimens assayed for plutonium gave a calculated current body burden (excluding the lungs) ranging from 0.005 to 0.42 uCi, and low-energy radiation emitted by intemally deposited transuranic elements in the chest disclosed lung burdens probably of less than approximately 0.01 uCi. To date, none of the medical findings in the group can be attributed definitely to internally deposited plutonium. The bronchial cells of several of the subjects showed moderate to marked metaplastic change, but the significance of these changes is not clear. Diseases and physical changes characteristic of a male population Because of the small body burdens on the order entering its sixth decade were observed. of the maximum permissible level in these men so heavily exposed to plutonium compounds, we conclude that the body has pretective mechanisms which are effective in discriminating against these materials following some types of occupational exposures. This is presum- ably explained by the insolubility of many of its compounds. Plutonium is more toxic than radium if deposited in certain body tissues, especially bone; however, from the practical point of view, plutonium seems to be less hazardous to handle. I, INTRODUCTION II. PROCESSING This is the story of how 25 young men were heavily exposed to plutonium at what is now the Los The potential danger of exposure to plutonium Alamos Scientific Laboratory (at Los Alamos, New was recognized early in 1944 by its discoverer, Mexico) in the days of the Manhattan Project during Glenn Seaborg.- World War II and of what has happened to them in of the radioactive properties of plutonium and the subsequent 27 years. Tee: a SAFETY PROBLEMS CONCERNED WITH PLUTONIUM All but a few of the sub- He was aware of the similarity radium and of the extreme toxicity of the latter jects of this study were college science majors who element which caused bone cancer in man after were drafted into the Army and assigned to a Special deposition of microgram quantities in the body. Engineering Detachment of the Manhattan Project. In an effort to learn more about the biological All were sent to Los Alamos (Project Y) and metabolic properties of plutonium (and, hope- in 1944 or 1945 and given various technical jobs in the Chem- fully, thereby to avert another disaster such as istry and Metallurgy Research Division. happened in the radium dial painting industry capacities, In these they were engaged in processing pluto- nium prior to fabrication and testing of the first atomic bomb. Almost all of these subjects had body burdens of plutonium estimated from the urine assay for plutonium used at Los Alamos before 1950 that ranged from 0.1 to 1.2 ugl (0.006 to 0.08 UCi). in the 1920's), Seaborg gave about 10 mg of plutonium out of the first half gram produced to Joseph Hamilton of the Crocker Radiation Laboratory in Berkeley, California, for biological experimenta- tion. Thanks to Seaborg's foresightedness, many basic facts related to the biclogy of plutonium