THI DC111JMFNT rX NGISTS OP 4 CG Y W PAGES SERIES A T iZ t 1945 SON1CTt Toxic Rffeete of the Atomic So $ lingering toxic effects are expected in the area over which the B b has bona used The bomb is detonated in coat at such a height above the ground as to give the maxima blast effect against structures and to disseminate the radioactive products as a 5 cloud On aoeount of the height of the expleetca practically elll of the radioactive products are carried upward In Now ew a ooluma of hot air and dispersed harmlessly over a wide area Aexieo the height of the ex loeiui was very ltu since the bomb was not dropped but was exploded just above the ground on a tower Available information both by theoretical calculations and actual 10 measurements indicates that the primary toxic hazard which may be encountered after the explosion at the center of impact is that of city is a small fraction I T of the original amount The Intes- radiation The intensity is indicated Ia Intensity in Roentgens R Constant The radiation measured at the site of the crater 130' in diameter bg the followings I 15 in the New Mexico teat T - - t4 e indicated that tian intensity near the center hour of the several hours crater was after the blast the radio- approxinately 150 roeatgesse This intensity diminished very rapidly as coca proceeded away from e crater and was co small as to be negligible at a distance of several 0t'he 20 time tgera is a snit of radiation measurement One roentgen represantc the absorption of 84 ergs per - CCHUMMED r f It oembines intensity and __- N N171 '1SS l an of body tissue SECRET DOD Dir NWD by 200 9 Sept 27 1958 date-- ttiouund yards from the orator Thres is meks after the blast the decay rate had reduced the radiation intensity to such an ezteat three per 25 to four hour that at a disteaoe of hnmdred yards from the crater the radiation was eel 5 romskeaa The radiation ieteaaity in the outer of the crater was still high however and from a biological point of view would be considered lethal for uninterrupted occupation of more than a few weeks This lethal area probably inv4ves a diameter of 100 to 200 yards The radiation following the blast is caused by the presence of a tre- n®ndova number of radiactive particles which emit both gamma and beta rays 30 Both decay at approximately are similar to X-Rays the same rate The gamma rays are very peaastrati g and are of great concern biologically since they can easily pass through to the most vital structures of the body The beta particles only 33 have less energy and have a very short range so that at best they can The under- pass through the skin from an externa radiating beta source lying vital structures of the body are not injured the akin very severely damaged It the beta however can be rays are introduced into the body by in- halation or by ingestion as in eating contcainated food the nay be fully as serious as those due to g A%a rays biological effects For the most part however the bets rays are of little consequence 40 The radiation produced by the blast divides itself into two portions of the that which becomes Imbedded and intermingled in the debris and dust crater and that which rises in the ball of fire and enamor ' smoke The latter is divided into two classes that radiation which is and dust produced in the blast and that aeoodarily induced by radiation of duet particles 45 secondarily induoed radiation The decays almost immediately Present indications are that most of the radioactivity which rises with the ball of fire and of smoke and remains suspended in the air is rapidly dissipated by _2- coluai wind sand thermal oonveetim sunsets ebiob soon reduoea the radiation to very low levels end in a few bars to a negli tb a are In the very unlikely and 50 unanticipated case that these radioactive particles should be suddenly pro- cipitated to the ground the amount-of radiation could be very high but Any attempt to predict the would remain so for only u short period of time amount of activities deposited from the column of smoke and duet would be very since the following factors among others would have great inaccurate $5 influence upon the precipitation of this materials A humidity Itstawrologioal oonditionsi wind volo- temperature city levels and degrees of inversion rain this is very unlikely to ocoer because of the tremendous force of the rising cloud Character of the terrain 60 area presence as built up of large amounts of vegetation hills etc g higher The height above the ground above the ground the explosion at which the bomb explodes--the occurs the lower the radiation and in- tensity at the point of impact will be The amount of radiation and the length of time 65 received directly determines the degree of biological toxicity Considerable information is available from recent from X-ray and gaga revs tbst the lethal experimentation and srevioue used in medicine and biology are lethal if delivered repeatedly entire It is established Much smaller lose intensities 10 r delivered daily to the prove lethal in most cases from which the body would recover fully indefinitely is safe For exs ples body for 150 to 200 days would radiation experience dose of gamm rays is approximately 700 to BOOT administered to the body if delivered within one to two days 7G during shish it is than lr per day --- lr per day standard for workers in laboratories The dose of d w Ch can be repeated has long been a recognised This naturally includes a wide 73 aargin of safety The biological changes ierediataly following a lethal doss prostretiana aause4 and wedging delivered in a fee days are severe bloody diarrhea becoming severe And prot 0 leukopenia and ly%hemytopeuia result followed by thraabocltopenia which produces hemorrhagic disturbances in the Death may occur within a few days or nay be postponed for various periods body 8o Radiation effects nay produce deleterious changes without as- up to 60 days tually causing thcodiate death These biological disturbances are usually neai- fasted by severe and protracted aneaias and severe of the white cello are the leu openia earliest changes following Sharp redu4tim sub-lathe doses Other sub-lethal changes which occur are sterility both temporary and permandetj 85 epilation both temporar7 and permanent chronic akin conditions usually of a permanent nature Various body tinsuea such as nerve and sale are in- bone sensitive to radiation and not easily affected The only manner in which 90 possible biologic dtuaage may be predicted is to determine the radiation levels at the sites of the craters These levels of these is determined by various radiation meters and an ample supply may be The following is an over-simplified being shipped to General Farrell table of probable injury for active troopsc Acute exposure within 1 - h're 95 I4eit of Safety Sons blood ahas$es with couplets recovery 100 Prolonged exposure _- 25% slightly injured 50% slightly injured will recover 75% slight to moderate injured 2' permanent damp 50 permanent damage 100% injured This presumes no further radiation or 50r 6or 50r 75r lOOr 75r lOOr 150r lOOr 150r 4th 20©r 250r 900r J 8TRACT The available information indicates that any biological toxicity C at the crater site at the center of would be due to radioactive material following after several weeks at a tion was jr per the blast Areas more distant than hour 10 4 00 yards from the crater had be considered safe rays The gamma rays--- are likely to be more serious because of the ability to penetrate deeply into the body The radioactivity induced two portionss that embedded in the blown into the air That greater and is rapidly 15 very rapidly so that from the crater the radia- suits beta and gamma The radioactive material X-rays but disiatshea point four hundred yards very low radiation intensity sod could like dosage of 190r the orator in the New Mexico test indicated per hour immediately s The dosage measured portion by the blast divides itself debris and dust generally into of the crater and that throuwn up into the air is usually much dissipated A total dose of 700 - 800r in one day is uew llly lethal generally accepted safe which naturally provides level for Indefinite an ample margin of 5 daily e safety osur The is 1 per day DEFIlITfONS Roentgen One roentgen is that amount of radiation which when absorbed in 001293 grams of air produces one electrostatic unit of charge of either sign Lymphocytopenia Reduction of lymphocyteg a special but necessary white blood cell about 30% of the total white cells Leukopenia Reduction of white blood cells Thrombocvtopenia Reduction of blood platelets a particle in the blood which initiates blood coagulation Erg The energy or work done in giving one gram an acceleration of one centpmeter per second 001 Epilation Loss of hair anemia reduction in the number of red blood Hemorraghic Pertaining to hemorrhage or bleeding cells