. 6S EFFECTS OF IONIZING RADIATION Table §.1—Biologically Hazardous Internally Deposited Fission Products ‘ —|-— Sr‘ y" 4.6 Biol. 53 | 3.9 x 10 65 42 | 8 | 180 La | 35 p 5.9 sr B 0.5 365 Bae B. + 6.0 12.5 | ~200 Celt Pria B. 6 5.7 5.4 25 | 13.8 ! Zr’ Rus 8. Boy ys B.4 Rules Lalie - B Celss A, B, 6. 4 3.7 2.8 6. 0 5.3 £ . ? Raniot. hs 275 | | | By Ixaestion . 22 28x10! > 100 20 20 BY TNitata- _. . 25 «6500 O14 35 . O4 . O4 |.02 >100 50 500 feted is Ratiatiox ABUNDANCE Fractiox Keacinxe Orcas 2 Criticar eae ary * teromyae wae sartey 4 te eit ay 2 Rapio-E, ew ext >. Hacr-Lire Fission! 0.15 07 . 20 12x 10s 0. 1 2x 107! 0. 10 . 23 | 13x 1077 . 063 Froin: ' Seaborg and Perlman, Rev. ‘Mod. Physics, 20:583, 1945. results in a reduction of Liood cells, and thus affects the entire vody. Information on the biological effects of internally deposited isutopes is derived from the limited studies of accidental vadioisotopic poisonme in hhumans,.ov from animal expevimentation, The best documented data on the effects of small amounts of internally deposited emitters in humm beings are obtained from studies of radium poixoning, As a resntt of radium deposition, terurmnal anemia, bone necrosis and osteovenic sarcoma appeared after a numberof years. “The residual activity im the body associated with these effects ix 1 to 2 microtrams of radium. Raditun is a particularly hazard- ous element when deposited internally because of its Jong liglhogical aud radiological half-life. Very few data are available on the lone term bialogical effects inhuman beines of the shorter lived isotopes such as Si, 7) P™ apd Na®, The metabolism, excretion and biological effects of a number of fission products have been b 9002113 Few data are available concerning the effects of internal contamination with mixed fission products from nuclear detonations. Contaimtnation is not produced .by every detonation of a nuclear device. For example, no internal contamination wax detected in tadividuals ex- posed to the vir burst at Nagasakt and Tire- shin. In field tests of the contaminating type of atomic detanation, antmials that inhaled fission — products during short periods of exposure were found (o have insignificant amounts of internal contamination, . - +. The long term effects (primarily inalignant changes) resultins from radium deposition have been used to set the Himits for maximum permissihle body concentrations of a few bone seeking radioisotopes in the body (5). Maxiniuan permissible body content of other radioisotopes are estimafed on quantities resulting in a dose of O.3 vem per week to the tissue of highest concentration. , t tissues. The ciunage tothe blood forming tissue (2), Bloom (3). However, most of these studies do not cover the problem of the long term etfects in animals produced by small amounts of internally deposited isotopes. tea tee. A wets the radiosensitive bone marrow than to other studied in animals by Hamilton (1), Abrams SOMES SteeSear:_~ SREY ok general, Jong radiological and biological halflives and produce high-energy beta particles. Thus, they cause creater damage to bone and ta oe! ig ? Hamilton, J. G. Rev. Mod. Physies, 20:718, 1945. 1 Handbook 52, U. S. Dept. of Commerce, National Bureau of Standards. ae ee ty set Coden . toe se lee oe ee teh wee oe cna MD cm ee el oe Sen eeeone ee ee gyre tor