and inadequate. It is important to recognize that The quality of the radiation (specific ionization, linear energy transfer) would be a consideration fatal radiation casualties, for which treatment will be of little avail, will succumb within a few weeks after exposure, whereas those who may survive, and can be benefited even by limited treatment, will probably not develop full signs of radiation illness for two to three weeks. By that time radiation levels will be greatly reduced and such persons may be only in regard to the neutron irradiation. However, some experimental workindicates that in dogs, at least, the relative biological effectiveness of fast neutrons for bone-marrow damageis about the same as for gamma radiation.(7) Skin irradiation. In regard to the hazard of skin channeled to aid stations or hospitals for more definitive treatment than can be offered in most shelters. burns from fallout, shelters would offer complete protection. The small amounts of fallout material that might sift into a closed shelter would be negligible with regard to skin irradiation. In personnel who are contaminated when they enter the shelter, radiation skin burns can be prevented simply by removing contaminated clothing and washing the skin, or simply wiping the skin with a damp cloth. References 1. Cronkite, E.P. et al., Effects of Ionizing Radiation on Human Beings. Report on Marshallese and Americans Accidentally Exposed to Radiation from Fallout and Discussion of Radiation Injury in Human Beings, U-S. Government Printing Office, 1956, pp. 1-106. Clipping the hair or even shaving the head may be indicated if the hair and scalp are heavily contaminated. 2. Conard, R.A. and A. Hicking, Medical Findings in Marshallese People Exposed to Fallout Radiation. Results from a Ten-Year Study. J.A.M.A. 191, No. Internal irradiation. The hazard of internal absorption of fallout should not be significant in 19, May 10, 1965. the shelter. Except for closed underground shelters, 3. most will require no air filtration or special ventilation systems, since sufficient air to maintain life will filter through cracks in doors, windows, etc.(8) In such situations, it is possible that temperature and body odors might cause some discomfort, but under the circumstances they would be of negligible importance. During the period when fallout is actually falling—only a matter of hours—the shelter should be kept closed except for short periods when a door or window may be opened to refresh the air. 4. International Commission on Radiological Protection, Report of Committee IV (1953-1959) on Protection against Electromagnetic Radiation above 3 mev and Electrons, Neutrons, and Protons, Pergamon Press, Inc., New York, 1964, pp. 1-44. 5. Wilson, R. and J.A. Carruthers, Measurement of Bone Thereafter no special ventilation precautions should Marrow Dose in a Human Phantom for Co60 y Rays and be necessary. Low Energy X-Rays. Health Physics 7: 171, 1962. 6. Treatment of Radiation Casualties Spiers, F.W., The Influences of Energy Absorption and Electron Range on Dosagein Irradiated Bones. Brit. J. Radiol. 22: 521, 1949. 7. With regard to treatment of radiation casualties associated with nuclear warfare, the importance of using protective structures as a prophylactic treatment for avoiding exposure to penetrating radiation, skin contamination, or internal absorption cannot be overemphasized. Because of the chaotic circumstances at such a time, and the shortage of trained Bond, V.P. and J.S. Robertson, Comparison of Mortality Responses of Different Mammalian Species to X-Rays and Fast Neutrons; in Biological Effects of Neutron and Protron Irradiation, Vol. 2, pp. 365-377, International Atomic Energy Agency, Vienna, 1964. 8. An Evaluation of the Need for Filtration Systems to Protect Sheltered Personnel from Radioactive Fallout; Naval Research Co. 3-9 Brookhaven National Laboratory, Upton, New York, Office of Naval Research medical personnel, the use of active treatment for ACR-72, May 1962. serious radiation effects will necessarily be limited 57 5gg 1409 Cronkite, E.P., V.P. Bond, and R.A. Conard, Diagnosis and Therapy of Acute Radiation Injury, Chapter 10 in Atomic Medicine, Fourth Edition, Eds. C.F. Behrens and E.R. King, The William and Wilkins Co., Baltimore, 1964, pp. 238-250.