and products (milk, cheese, etc.), as well as human materials (particularly skeletons of stillborn infants and human milk).[ notable that radiostrontium has been observed in many parts o _ World; however, the concentrations are too lowto establish logical hazard as a result of detonation of anypractical It is atomic weapons. Present considerations of biological hazards on avalue of maximmpermissible body burden established by National Committee on Radiation Protection. In times of neti _ardy, however, this value would be unrealistic. A group of radiobiologists, with radioisotope experience assembled to consider the practical aspects of biological haz to radiostrontimm. This group estimated the degree of hazard ated with various amounts of radiostrontium in the human skel from barely observable effects up to lethality. These calcul can'form the basis for further estimates of secondary bomb ha In addition to making the estimates, it is plamed to initiat tory experiments to check the estimates. All available data cases, particularly those in which patients have been treated radiostrontium,will be assembled and reviewed for pertinent i tion. Additional tracer experiments on humans may also be pr Liver Protein Alteration in Radiation Injury. (UNCLASS By the use of electrophoresis, investigators at the Medical of Virginia have recently revealed a substantial change in th@ stitution of the proteins of the liver of rabbits exposed to x-irradiation. One of the major components, constituting abo cent of the normal soluble liver proteins, disappears within con- after irradiation and is still absent after 50 days (the limi observations at the time of the report). It is known that this particular component undergoes a electrophoretic mobility under circumstances in which the oxi the protein's sulfhydryl groups is to be expected. Such a shi make this component indistinguishable (electrophoretically) f large components and could account for its apparent "disappe The idea that this oxidation is actually what happens after i is supported by the fact that the missing components can be reappear by incubation of the protein extract with certain s donating chemicals, and that the loss can be prevented by givi immediately before the X-ray exposure. isolation and analysis of this reactive component is now eing attempted, and if this is successful, its biological activity ventive or therapeutic agent against radiation damage will be vested. d R DOE ARCHIVES