524578 THE UNIVERSITY OF CALIFORNIA LOS ANGELES CAMPUS SCHOOL OF MEDICINE ATOMIC ENERGY PROJECT CONTRACT No AT-04-1-GEN-12 Li S A E C N 0 0 UCL 40 6 REPORT N o - - - - This document consists of 25 pages Number 1 2 of 489 copies Series B UCLA-406 Biology and Medicine TEE UNIVERSITY OF CALIFORNIA Los Angeles Campus SCHOOL OF MEDICINE ATOMIC ENERGY PROJECT Po O Box 24164 West Los Angeles 24 California Contract No AT 04-l -GEN-12 Di vision Environmental Radiation Division Chief K H Larson Section Chemical Problems Section Chief J H Olafson THE DISTRIBUTION OF PLUTONIUM IN TEE SOILS OF CENTRAL AND NORTEEASTERN NEW MEXICO AS A RESULT OF THE ATCMIC BC JB TEST OF JULY 16 1945 by J H Olafson H Nishita K Ho Larson 9156o - 50025 Submitted by Stafford L Warren M D Director Report Issued September 19 1957 2 IEGAL NOTICE This report was prepared as an account of Government sponsored worko Neither the United States nor the Connnission nor any person acting on behalf of the Cornmissioni A Makes any warranty or representation express or implied with respect to the accuracy completeness or usefulness of the information contained in this report or that the use of any information apparatus m ethod or process disclosed in this report may not infringe privately owned rights or B Assumes any liabilities with respect to the use of or for damages resulting from the use of any information apparatus method or process disclosed in this report As used in the above person acting on behalf of the Canmission includes any employee or contractor of the Commission to the extent that such employee or contractor prepares handles or distributes or provides access to any information pursuant to his employment or contract with the Conunission Printed in USA Price 25 cents Available from the Office of Technical Services Department of Commerce Washington 25 9 D Co f'R C 'ECT DISTRIBUTION Copy No 2 1 P _y - 11g Grc1 _d be - ·G et1 A c c F rr 'C_ 5 'J I11c Argc n e Ci i ncer Resea c n Hcspi tal Ars • e r at 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of Atomic Radiation 1 Cor sc l Lde ted V· llt ee A L r c raft Corpo1·ation Co1Tv2 i r i G s-n eral Dy'nrunics De fc11 c Resea cl7 Mernbcr D8p3 •t me r cf Army 3 Office o f Quartermaster General DeF r 1 m 1t vf Food Tech o MIT Dep 9 r· r11er1 t 0 f Navy 1 ode l i 22 1 Dep ·tmen- - of Army Q 2 DiY si or - _ f Raw M ' tte ' a 1 s Denver T N · c- rnir aJ C o p _·t 3t 1 trg°t1 Dow Chemi al ' Jo Rcc --y Fla· s cL P r de Ncsr ruz•s 8 r Cunra r y Aiken d·t 1P 12 de Jl •emcur s 8- · C mpany J W lmington F s 11kf o d AT usenal IJ L '1f'' ''''1 t ' _ - ri· Ccn ·- ony Al TPP ' J - i r C-' ntircJl 'F leL'- r i c Ccmps ny Ri hlaY d GooC_yea A CJi'iT e · CoY· c a t i 011 __ F J l-o - '--- I H rN 1i t Mar no La to ·atory Ic 1n Stats CrJLlege K i c _ ind Ai - Fo cf ' ti _ 5 Knc -- s Ato m c PO'Ner L iboratory ' ·r ' · r o- · ora·H on BauE 'r J r-' -· v - • Lo -_ • Ji •- - _ - JI J V Le Ab mos Sc ientif c abor a tory Ma3 · 12 hu 3E tt s Insti 1- 3 of Technology Hardy Mc i -d I aoG ' 'a - ory Nat or ta B-1 tl ea 1 of S' andardz Atomic Energy Project Nat· cna 1 -i Con p8 ri r sf Ohio Nat 1 r nxil Litrary- c f t Kt- ciicine Ns val Med ' cal Re sea1'c''l Im-1tit ut e 6 16 ho 44 46 36 33 43 45 48 49 51 52 53 54 56 58 5S 59 J 61 62 - 63 64 65 66 67 - 68 69 70 71 73 76 72 75 '7 78 79 80 82 84 83 81 86 87 88 89 90 91 85 L Ne1'l 1°' ''o Copy No 92 - 93 ·st'J r ' l Of f cG Nu I- · Dt1Y• p ent C r r · r t i or of Amc 'ica Oak R J sE Li t i L s f N't · · ear S t-ud es Oak fc 5ic- o· Na _o ·a ' Labo t - ''f -Offi r- f N·a · a' R ese· 1 1 Jch O Ul 1f 8 gt - GE•r eral A F CSG 15· o 9h 95 96 99 lh 100 1 ·• ·i·r J a 0 J 5 Ph p•_ Pe •c· 2· 1 Gs-nrpa · r P b Brc aith Ss•1·v-ice 116 L 1 118 1i9 Ra ii s t cp2 s 1ab - • 1 tcry R r1r l r i r2r1o a -' - ·D t i Sa 1 ·'iia f lrJ o· r t- _c n '·' -•···· · r r 1 O ff' r _ _Jc 1 l r 1 J •1• V - _ _1 L l _ _ 120 121 The s· g2 C t1 Ciet •BI' -3 l Un1cn 0 ·'cid e N- 1c aa i · C pany 9 Cu Jl Plant Un ic 1 C9 rbide N J c 'lear Ck mpany K--25 Plant 128 129 United Air• J c f't l' orporaticr 1 30 IF 'I i S Nav s O-r o n nce Lab0'T ato r y 0 TJ S Na va 1 Pc6tg - aduat s S hoc l U So N s s 1 Ra t c g 1 ca'l Def mse Lab ratory Un ivers ty cf CaJ ifo rni 21 Medical C6nte U' -- c verctty cf Ca1 Lfornie Radiation Laboratory - ' 27 · 33 134 135 l To So CJ Sci _ r g·ic _ Surve r 9 Den·ve r 1 o ' -' 122 123 7''J4 l C 125 T' ' r 21 0pera ti-011s0 Inc u JJ6 9 Berkeley Unive tsl t y e f Ca i ifoi nfa Ra Hation I aboratory 9 Livermore UnivE'r' ity cf Chi agoj Air Force Radiatior laboratory uni 16 r - ity t I Roc 1ester Atomic Ene t·gy Project Univers _t y of Ter nessee Uni versi ty t f Utah UniYersi ty of Was hington Donaldson Waltey Rosd A 'my Medical Center Wei1 9 Dr GE-o rge Lo West-e- 'n Re ' lerve University Wes Gingr ouse Ele- tric Corporation Tecrm - f-r J Ir f rria ion S1 r- -l e Extensic-n Oak Ridge 137 J J8 1 39 lLO lh3 tli4 142 145 146 147 148 149 1 L 15'0 152 • 56 15J 157 1 58 51 1 2 189 nrrERNAL DISTRIBU·T'ION AEP Ll bra r·y Riorr e ii l Libr ry A1 'tf10 - 173 174 175 190 - 5 'rABIE OF CONTRNTS Page No ABSTRACT 6 EXPERDlEN'rA1 PROCEDURE Reagentc Plutoniu i11 Extraction Procedure Samp _c Collection and Preparati on Cou vit l_ng Pror ed ur· and Interpretation of Counting Data 0 RESULTS AND DISCUSSION F valuation of Extraction P ocedure The Distribution of Plutonimn in the Soil Gontaminat ed by Fall-out Debris from the Trinity Detonation Plutonium Content of Plant Materials Collected in the Alamogordo Area r i 8 10 11 12 12 16 19 SUM TARY 22 ACKNOWlEDGE lENT 23 22i 6 ABSTRACT Soils and plants from the area of central and northeastern New Mexico which was contaminated by fall-out from the atomic bomb detonation of July 16 19h 5 were analyzed for plutoniumo Plutonium was found in amounts up to O007 micrograms per square foot of soil one-half inch deep at a distance of 88 miles northeast of the site of detonationo A maximum of loh7 micrograms per square foot one-half inch deep was found on the Chupadera Mesa at a distance of 28 miles northeast of the detonation site No plutonium was found in samples collected 3 miles south of the site In assaying for plutonium the method of Eisenacher was adapted to soil and plant samples An estimated precision of 1 5 per cent was obtained when the method was applied to field samples A recovery of 98 0 3o0 per cent was obtained when the method was applied to a standard soil Uranium and thorium do not interfere in this method even when they are present in quantities much greater than the maximum amounts normally found in soils 7 THE DISTRIBUTION OF PLUTONiill IN THE sons OF CENTRAL AND NORTHEASTERN NEW MEXICO AS A RESULT OF THE ATOMIC BOMB TEST OF JULY 16 1945 The fatie of radioactive residt es released into the environment have been under serious consideration since the first nuclear detonations which occurred in New Mexico on July 16 9 1945' 1 9 7 o In order to docu- ment the fate and persistence of radioactive fall out originating from a nuclear detonation 9 a radiologi cal sm 'Vey of the Alamogordo area that was contaminated was begun in Aug c st 19h7o f the area were made up to 1956 Since 1947 9 periodic surveys This report presents a sununary of the dafa obtained by this laboratory on the plutonium content of soil and plant samples collected in the area Some of these data have been issued ea lier in a preliminary report 6 0 EXPERIME'NTAL PROCEDURE In detet nining plutonium the methcx1 of Eisenacher 2 which was developed to isolate minute runounts of plutonium from urine and other biological materials was adapted to the analysis of soils and plants Soil samples are prepared for analysis by wet ashing first with concen t rated nitric acid and then with 70 per cent perchloric acid followed by the conversion of the residue to soluble fluorides by treatment with per cent hydrofluoric acid tonium sampleso In this form they may be assayed for plu- Plant ash samples are process d in the same manner as soil The detailed procedure is presented below Reagents 1 Nitric acido 2 Perchloric acid o 48 Concentrated 9 reagent grade 9 68 per cent Reagent grade 9 70 per cent 8 3 Hydrofluoric acid Reagent grade 9 h8 p ir oento 4 Nitric acid - hydroxylamin e hydrochloride solution Dissolve 609 5 g hydroxylamine hydrochloride in approximately 800 ml distilled water add 130 ml concentrated nitric acid and adjust volume to 1 liter 5 Lanthanum nitrate solution a rul of distilled wa·ter 6 Hydrofluoric acid 12 M 7 Hydrofluoric acid lo 5 M To 945 ml of distilled water in a polyethylene container 9 add 55 ml of 48 per cent HFo 8 Jl luminum nitr te 3olution 9 Sodiwn nitrite solution Di ssolve 12 g of reagent grade NaND2 in 100 ml oi distilled water Prepare just before using Dissolve 2 g of Ls N03 3 06 H20 in 100 To 570 ml of dist tlled water in a polyethylene containerj add 430 ml of 48 per cent HF Dissol·ve l 36o g reagent grade Al N03 3 9 0 plus 2S ml of concentrated HN03 in distilled water and dilute to 2 liters 10 Th enoyltrifluoroac etone TTA solution 500 ml of benzene Dissolve 25' g of TTA in 11 Nitric acid 8 M Dilute 520 ml of concentrated HN03 to 1 liter with distilled water Plutonium Extraction Procedure 1 To 1 g of oven ctried soil 250 microns diameter and less in a 125 mJ platinum evaporating dish add 5 ml of concentrated nitric acid and 8'vaporate to dryness on a steam bath 2 Add 5 ml of 70 per cent perchloFlc acidJ stir to break up aggregates and evaporate to dryness on a hot plate 3 Add 15' ml of 48 per cent hydrofluoric acid 9 stir to break up aggregates and evaporate to dryness on the steam bath 4 Add 50 ml of nitric aeid-hydroxyla min e hydrochloride solution 9 stir to break up aggregates and heat on the s-team bath to 75° C 9 5 Transfer the clear liquid to a 150 ml beaker leaving any solid matter in the platinum disho 6 Add an additional 50 ml of the nitric acid-hydroxylamine hydro- chloride solution to the platinum dish and again heat to 750 C before transferring the clear solution to the beakero 7 Cover the beaker with a watch glass and allaN to stand· over- nighto 8 tubeso Divide the solution equally into two 80-ml Lusteroid centrifuge Add 2 ml of lanthanum nitrate solution and 10 ml of 12 M hydro- fluoric acid to each tubeo Stir and centrifuge at 2500 rpm for 10 minutes a 9 Discard the clear supernatant liquido Break up the precipi tate with a stirring rod add 15 ml of lo5 M hydrofluoric acid and centrifuge againo 10 Discard the supernatant liquid o Break up the precipitate in each of the centrifuge tubes with a glass stirring rodo 25 Add a total of ml of aluminum nitrate solution to each centrifuge tube at the rate of 3 to 4 drops per additiono Stir with glass rod after adding each aliquot until the precipitate has dissolved completely 9 and quantitatively transfer the 2 fractions to a 125 ml glass stoppered separatory funnel by using the remainder of the aluminum nitrate solution 11 Add 0o25 ml of freshly prepared sodium nitrite solution to the solution in separatory funnel stopperJ shake 9 and let stand 15 minuteso 12 Add 10 ml of thenoyltrifluoroacetone TTA solution and shake on a mechanical shaker for 15 minutes a 10 13 Allow the 2 phases to separate completely Carefully draw off and discard the lower aqueous phaseo 14 Wash the benzene phase in the separatory funnel twice with 35 ml of distilled water with 1 minute shaking after each addition Allmr the 2 phases to separate cleanly before carefully drawing off the washings • D'iscard the washings o 15 Add 10 ml 8 M nitric acid to the washed benzene phase in the separatory funnel and shake for 15 mi rmtes on a mechanical shaker 16 Allow the 2 phases to separate completely 10 to 15 minutes Draw off the acid phase 4 ml at a time into a stainless steel counting planchet and evaporate to dryness a t approximately 70° C on a low temperature hot plate In the transfer of the acid phase care should be exer- cised to avoid the passage of the Tl'A solution into the planchet 17 When all of the acid phasej except far that amount in the stem of the funnelj has been added to the planchet carefully add 1 2 ml of distilled water to the separatory funnel rate cleanly Allow the two phases to sepa Transfer the aqueous phase to the counting planchet allowing of the TTA solution to reach the planchet Evaporate to dryness 18 Using platinum topped crucible tongs carefully heat the plan- chet just to redness in the open flame of a Meeker burner to remove any volatile matter cool and counto Sample Collection and Preparationi Surface inch or half ineh samples were collected from approximately 2 square feet of soil and placed in pint metal cans o See Fig l for looa tions These samples were taken adjacent to grass roots as well as from surface soil having 11 no vegetative covero In the laboratory 9 the soil samples were oven-dried in the cans overnight at 105° C and then sieved to obtain the less than 250-micron fraction This particle size fraction was selected 9 because 9 in comparing radioactivity with resi ect to soil particle size 9 the less than 250-micron fraction was the most consistent 1 Two 1 g portions of the less than 250 micron fraction were taken for plutonium assay Plant samples consisted of grass 6 juniper and pi Iton pine trees 8 weeks old and tips of Grass sampling was restricted to one species in order to eliminate species differences in mineral uptake In every casej vegetation that was observed to have a mininn nn of dust on the leaves was collected All grass and tree branch tips were washed in tap water and then in distilled water 70° Co The grass samples were oven-dried at After washing 9 the branch tips from trees were separated into needles bark and the present year I s growth 9 and dead wood o from each tree sample were then dried in a vacuum oven at 5o 0 The µtrts c All plant samples were ground in a Wiley mill to pass through a 40-mesh screen and ashed prior to analysis Counting Procedure and Interpretation of Counting i All samples were counted for 4 hours in alpha scintillation counters employing RCA5819 end-window photomultiplier tubes and scintillating screens of powdered zinc-cadmium sulfide on Scotch tape 9 Counting geometries ranged between 18 and 23 per cent while instrument background values ranged f'rom 4 to 10 counts per houro Standard counting errors calcu- lated by the method of Jarrett 5 were less than 5 per cent for the standard soil which was a mixed desert soil artificially contaminated with plutonium at the rate of l4o3 d m g 9 and less than 10 per cent for 12 soils from the Alamogordo area containir g plutonium in amounts from 3 to 80 d m g RESULTS AND DISCUSSION Evaluation of Extraction Pro edure In addition o t he instrument background there was observed a sma 11 nu 'Ilber of c· m nts asso ia ed with the reagents and un ontaminated es r cor tro soi l mate of the magnitude of the 11 TABIE I gives an esti-- ba Jkgr ' mnd 11 ·va 1es c btair ed o Yolo s0il collected from an experimental p ot of the Un i versity of California at Dav is California was chosen as most nea rl y t eprest'Z ting the Chupadera Mesa soils in New Mexi Jo while the mixed desa t•t soi was chosen as most nearly representing the desert soils f'rom the Trini ·ty c·egion As indi- cated above the mixed desert soi r orrtam nated with a known amount of plutonium was chosen as the standard soil The aJ ph ac tivity from the reagents was the major contributor to the background values of the soils o The sour e of the alpha act vity f ou nd in reagent blanks has be en identified by Healy 4 as actinium and protactintu m e cmtaminating the lant banum nitrate This was confirmed wi er purified lanthanum nitrate reduced the alpha activity extracted from ·c rccnntamir ated Mixed Dese r't and Yolo soils to O 020 _ 0 008 d m g No fit tempt was Illb de to pur1fy the lanthanum nitrate used dttr'ing the c ourse of the aasay of AlalT ogordo soils The average background valu e of o d m g t bsel 'ed for t he Mixed Desert soil TABLE I was subst ratted from the -es lts contaminated II standard soil used tc e•va i w -t e the 011 the plutonium 6 Xtra 1 s i i0n meth0d o 13 TABLE I Alpha Activity Obtained from Reagents and Uncontaminated Soils by the TTA Method and the Bismuth Phosphate Method Bismuth Phos hate Method Mixed Desert Reagents Soil TTA Method Sample Reagents Mixed Desert Soil Yolo Soil Disintegrations Minute 6 7 8 Oo73 Oo85 0086 1 06 Oo59 1 24 Oo64 Oo6u Mean Standard Deviation 0 082 0 023 1 2 3 4 LJ 4 L36 L36 LOl L62 LOO L32 lol7 L23 Oo22 lo34 1 2 L26 Oo99 L34 1066 2o04 L52 lol L45 1L3 609 12o4 10 7 602 12 ol 0 --- Oo33 9 o9 2 o7 To further check the background value for soil 9 the method of Farabee 3 modified 10 to include single bismuth phosphate and lant hanmn fluoride precipitations 9 was applied to the uncontaminated Mixed Desert soil after its conversion to soluble fluorideso By this method 9 the amount of alpha emitters found was about 8 times greater than that found by the TTA method TABLE I o Apparently 9 the TTA method did not extract certain alpha emitting components of the soilo Since small amounts of uranium and thorium are known to be present in rocks the recovery of these elements by the TTA method was investigatedo Based on the data presented by Rankama and Saha ma 8 9 the maximum amounts of uranium and thorium likely to be present in one gram of soil are 0000514 mg and Ool40 mg 1 respectivelyo TABIE II shows that significant amounts of thorium were extracted only after adding as the nitr ate 150 times the maximu m amou r t expected to -oe present in soil o U ra ium was not extracted even after the addition as ni·trate of 500 times the amount expected in soiL Thus 9 at least p9 rt of the high 11 bac ground 11 valt e obt ained by the modified Farabee method appeared to be UTanium and or thori umo Furthennorey it may be concluded that uranium and t horJ u rr de not interfere in the assay of soil for pl toni 1m by the TTA method TABIB IT Extraction of Uranium and Thorium from Mixed Desert Sojl by t 1e T'I'A Method Amount of Uranium c r Thorium Added mg g Soil Oo25 Amount Extracted d m g Uranium OoO Thorium 2o 33 O o005Jlr Uranium 6 1 0 00140 Thorium P'Rr cent Urani 11l11 or Thorium Recovered 0 o 1 1 0 o C' oO o o 0 0 TABIE III shows the recovery of plutonium from the 11 stancfard11 soiL The plutonium added 14 3 d m g soil has 9 in each case been q_uanti-• tatively extracted Columns 3 and 4 show the aciditiona 1 variable int ro duced in field samples by the sampling techniqueso lmown about the physical che racter of the 11 Since little l s fa i l-out 11 from the Trir l y detonation i t is difficult to estimate the original 1umber and size of fall out'' particles per square foot of sm·i'ace soiL One or 2 particJ E 18 difference may accourrt for extreme variatio1 s in samples fa ctors of 2 have been encountered between one gram duplicate samples 15 TABLE III The Recovery of Plutonium from Standard and Field Soils Replicate a Series #23 Soil Standard Soil 1947 AE-3 Soi disintegrations minute gram l 4o78 lho7 13J-114 3 l4o0 1506 6 14 2 7 8 lh 3 14 o L 01 77o3 75oO 104 8 75oS 88 6 104 6 78 9 80o9 Mean Standard Deviation 14 3 o 6 4oJ'7 l 03 85 7 12 s 2 3 4 5 6063 3 99 3 23 4 h4 I 4 2c· 3o59 0 • Approximately 100 aliquots of the standard soil were analyzed and all data fall in the range shown above TABIE IV Alpha Activity in 4 - 5-Inch Depth Soil Samples Collected in 1950 Location AE-1 AE-2 P 21-B P 21-C P 20 HoG 0 0 #14 #17 #22 #24 #29 #36 Mean Standard Deviation Soil Depth Inches Activity d m g 4 - 5 4- 5 LO 4444 44- 5 5 5 S S 5 4 - 5 4- 5 4- 5 4- 5 L3 o 7 Oo9 Oo9 1 3 o 6 Oo7 0 7 0 7 o 8 o 8 0 9 0 2 16 Consideration of the data accumulated on soil collected 4 to 5 inches below the surface of mesa and mes - 't ik G soi ls TABIE IV resulted in the establishment of Ll d m g mean plus l standard deviation as a realistic background value for these soi l 1 o Th l s value was subt c·acted from the results of all assays on sails of this GT0 The Distribution of Plutoniu 11 in the Debris from the Trinity DAtonation Contaminated by Fall ou t Samples of 11 T ·initite ' the fus 3d glass-like material from wit hin the fenced area a t Trinity Site and several glass beads found near the fence and along the line of drift oi the cloud see Report UCLA-32 toniumo 1 for locations were assayed for plu- The data are presented in TABIE 1 T TABIE V Plutonium Content of Trinitite and Glass Beads from the Fenced Area along the Four Principle Transects Established in 1947 Location ft Sample Trinitite Trinitite Trinitite Trinitite Trinitite Trinitite 0 0238 0 0284 0 0062 0 0302 T90 T90 - 200 Jo - 1 000 T90 '1'270 - 200 6oo T270 T270 - 1 000 g Glass beads black g Glass beads blach g Glass beads green g Glass beads green Inside Inside Inside Inside fence fence fence fence Pu Content cf Material dL mfg2 io0' J J 2 3 22 X X X 55 7 X 9 24 17 l X X 103 103 103 103 103 103 X 103 0 X 103 284 X 103 10-' ' 322 528 0 4006 X Micrograms Pl 239 g of Mater1a1 66 3 25' 8 23 • 6 408 t_ ' 6 0 125 2' 36J 3 98 J 2 080 298 0 0 X X 10-· J ' lQ J y·- X U -' X X X 10 3 10- lo J X 10-3 - X J_ -J X X 10 J lo-3 TABLE VI presents data accumulated for the lateral reference points and boundaries established during the radiological survey of the Alamogordo area in 19h8 1 These data suggest that the area originally con- taminated by fall-out from the Trinity detonation was greater than the 17 1 9 100 square miles estimated by the 1948 survey the Harvey Gate series and lateral O Data o TABIE VII on present a good est m ate of tl le TABIE VI Plutonium Content of Alamogordo Soil 0 1 Inch Depth Collected from Various Locations in 194 8 Lateral Reference Point 4 7 9 l 16 16 16 18 Distance from Ground Zero Miles 4 7 d m g Micrograms Pu239 3q ft 1 Inch Deep OoOl Oo09 12 o o o o Oo3 2o 0 019 OoJ2 20 OoO 3 5 2 9 3 2 left 5 2' right O O 9 24 28 21 30 21 32 o o o o 3 o 7 2 o o 5 left d ght 3 8 le 't 6 9j rLght 22 _ 2' 23 23 P- i Co atent of Soil OoO 0 o 20 22 D 1 stBnce and Direction from Reference Point Miles 34 23 o o 4 3 left 6 6 right l • L 0 10 o o4 9 1 21 0 2 8 OoOO 0 31 Oo73 OolO 0 01 o s 0 03 o 4 24 o o 8J OoO o oo 8 5 0 29 1 Oo06 LB 0 Oo06 See map in UCLA-32 1 for locations plutonium content of a small section of the Chupa dera Mesa An a ea of ahout 1 square mile was estimated to average Oo83 microgram of plutonium per square foot 1 inch deep Similarly the profiles of Area 21 1 4 7 and 13 located on the south slope and A B and C located on the valley floor establish the average contamination of this area at 0 91 micrograms per square foot 1-inch deep The relatively slight change in plutonium level from 1948 to 1956 in these locations indicates that no 18 TABIB VII A Comparison of the Plutonium Content of Surface Soils Collec t ed at Various Locations on the Chupadera Mesa dU 'fr1g August 1947-19 56 Pu tontent of Soil Location Area 21 Profile A B C 1 4 7 13 Harvey Gate Year 1950 1951 19SO 1951 1956 1949 1950 1951 1950 1951 1950 1951 1950 1951 1950 1951 1948 19c o 1951 1956 0 2 mi E Harvey Gate Lateral 20 h7 4 8 24 25 26 11 o hJ-r Oo90 Oo38 230 0 080 23 0 2h o 83 o so 34 1 18 30 Oo9C LOL 26 33 L14 27 0 93 36 L25 1 41 0 069 1 37 hl 20 38 18 39 0 62 1 35 1950 1951 24 o SJ 1947 R-2 1951 19h7 1951 AE-2 250 29 1948 1951 Ratliff Samples R-1 AE-1 d m g MJ crograms Pu239 sq ft Soil 0o87 LOO 1 63 Oo17 o 83 1950 1951 195'0 1951 1956 4 o 5 o 3h 67 22 6 5 3 0 22 12 20 O L1 r 0 095' lal8 lo20 0 76 0 0 22 0 10 Oo76 o 42 O 69 hese samples were collected from O - 1 2 inch all others were collected from O - 1 inch 19 appreciable decrease in plutonium content of the soils is occurring due to erosional factors except possibly in barren areas such as represented by the Ratliff samples • Plutonium was found in soil samples collected as far as 88 miles northeast of Trinity Site TABLE VIII and Fig 1 with the maximum contamination occurring on the Chupadera Mesa 20 to 30 miles northo Ai aly•- seLl were also carried out on soils collecte id south of Trinity Site from areas running southeast into Mockingbird Pass and west into the Jornada del Muerto from Observation Post T-3 This series of soil samples all assayed approximately 1 d m g which is considered normal soil backgroi _ndo Fu r ther J since the surface soil and b - 5 inch profile samples all assayed the same 1 j_t was concluded that this area was free of pluto lium contamination The results of the assay for plutor l um of soi1 profiles collected in 1951 are shown in TABLE IX Downward movement of plutonium was found in on iy the two cases where the surface cor tamination was relatively higho This was also found to be the case in 1949 and J 950 fer fission product isotopes P1uton ium Content of_ Plant Materials Collected in the Alamogordo_ Area Several samples o f juniper and pin'on pine trees from the Chupa dera Mesa collected in 1951 were analyzed for plutoniumo sented in TABLE X The data are pre Although the cortex or bark dat a are suggestive of possible uptake of plutonium by the trees 9 via the roots 9 these data are inconclusive The fact that soil activity was generally restricted to the surface inch of the profile coupled with negligible activity of wood suggests that external surface contamination was the source of the 20 TABIE VIII Plutonium Content of Surface Soil 0 1 2 Inch Collected at Various Locations North of the Chupadera Mesa in 1950 Miles from Ground Zero Trinity Site 30 33 36 40 39 41 Pu Content 7 8 8A 9 103 -11 39 43 6 o 12 13 14 62 70 76 82 87 86 Oo5 o 5 o o o 5 18 19 20 21 22 23 82 90 91 1 7 205' L3 0 1 l i J 2o 24 25 26 27 28 29 76 72 68 o 6 62 60 o o 59 58 o o 54 Oo2 Sample Location 1 2 3 4 5A 6 15 16 lr'° 30 31 32 33 34 35 36 Note 44 48 52 58 95 88 79 65 52 52 55 52 of Soil ' c m g 12 0 Micrograms Pu239 sq ft 1 2 ino Deep 0 22 24 13 Oo9 4 5 Oo8 2 8 Oo o 8 9 1 L7 1 2 405' Oo7 LO 3 5 L8 L9 o o 1 2 6 5 L6 1956 checks at locations 3 10 and 17 showed 11 and Oo8 d m g respectively Ooi i2 0 022 Oo02 Oo08 0 01 OolO Oo05 OoOl 0 01 Ool6 Oo03 0 01 OoOl o oo OoOl Oo02 0 08 0 03 0 04 Oo02 o oo 0 07 o oh 0 01 0 01 0 02 Oo06 Oo03 0 00 Oo03 0 00 o oo 0 00 Oo02 0 11 Oo03 5 3 21 measured activity of the bark The lc W activity associated w-lth the needles was very likely due to ext srnal contam natj en also ' ABIE IX PJJ rtoni·JJTI Content of Soils at Various Depths from the Surface 9 1951 0 P- ·ofile 21 A 2 _ B 2i C Harvey Gate Lateral 20 Note - _n o-5 l µg d mig Pu g 2808 21 1 408 llo2 3 5 802 19 8 lho5 ho0 2 9 d m g · 2 311 10-·S µg 2n 10- J g p _ g d m g Pu g 0 0 0 0 0 4 h 3o2 0 0 0 0 0 0 0 0 2o4 0 3o 0 l 3 d m g ·--- -24 and O 5 d m g A check on Profile 21B in 195'6 showed o L 11 depth incre ments respectively 0 •- 1 11 and 3 4vv 10-5 µg P g 0 0 0 0 0 0 0 0 0 for the o TABLE X Plutonium in NePdles Cortex and Wood from Juriiper and Pine from the Chupadera i esa New Mexico 9 Collected AugustP 1951 All results are expressed on basis of dry plant material o Needles 10-5 Lg Spec es d m g Harvey Gate Area 21 Pl Junirer Juniper lo34 0 49 Area 2ly Jm1iper Juniper 1o83 0 067 Ll4 0 37 1 66 LOO o J O J4 0 74 Oo1 d Location Pu Area 219 P Area 21 P13 Area 21s NS-1 Area 21 NS-2 Area 21 Pl Area 21 Ph Area 2lj TS-1 Area 21 N -2 Juniper Juniper Juniper Pinon Pinon Pinon Pinon 0 31 0 12 o 43 C' rtex Pu g' d m g 1o07 Oo83 O 2 7 1 20 0 25 O 23 0 09 0 _ L 10 9 i ho2o 3060 i_o-5 Wood µg Pu g d m g 0 080 0 23 0 07 0 02 0 04 0 02 s oo 3o07 2o67 10·- µg Pu g 0 o L -- ' 0 005 0•14 0 03 0 02 4 5'3 5006 3 33 ho 73 1 80 L8o 0 27 3 i i 6 OoOS 0 03 0 02 L33 L33 0ol9 0 02 0 02 lo20 Jo J o 87 o o5 22 The results of a limited number of analysis of grass samples from the Chupa dera Mesa are given in TABIE XI Although some of these data are suggestive of plant uptake they are rtot conclusive In view of the soil contamination levels the observed activities could all be due to external contamination TABIE XI Plutonium Content of Grass Samples from the Chupadera Mesa 1957 and 1950 Pu Content Location Year Collected AE-3 AE-3 Ratliff-1 Ratliff-2 Harvey Gate Lateral 20 Area 21 P-1 Area 21 P-4 Area 21 P-7 Area 21 P-13 Area 21 P-B Area 21 P-C 1947 1947 1947 1947 19 0 1950 1950 1950 1950 1950 1950 1950 Plant d m g 40 12 13 29 o 5 o 5 2 oO 1 1 0 7 o 4 Ool 0 4 Soil d m g 55 67 41 24 23 24 26 33 47 26 SUMMARY The soils and plants from the area of central and northeastern New Mexico which were contaminated by the atomic bomb detonation of July 16 1945 were analyzed for plutonium Plutonium was found in amounts up to 0 07 micrograms per square foot one-half inch deep at a distance of 88 miles northeast of Trinity Site The greatest concentration of plutonium 1 47 micrograms per square foot one-half inch deep was found on the Chupa dera Mesa at a distance of 28 miles northeast of Trinity Site No 23 plutor ium was found in soil S llplea collected 3 mLi es south of the Site The evidence obtained suggests a minimum of redistrib'ation of plutonium due to the action of erosional fae tor so A limited nmnber of analyses of plant materials did not show any conclusive evidence of the uptake p utonium by plants In assaying r f C foT plutcniwn 9 the method of Eisena her 2 was adapted to soil and plant samples An estimated precision of o obtained when the method was applied to field ample 15 per cent vrns A recovery of 98oO • 3o0 per cent was obtained when the methcd was appllea to a 11 standard 11 aoiL U ra ni'Wll 2 thorium9 or other alpha emit-t ing elements 10 not interfere in thj_s method even when they are present in qua ntiH8 s much greater than the ma rlnrwr normaliy fcund in soils a ACKNOWLEDG'EMENT 'fhe authors would like to gj_ve recogr iti on to the many members of our group 9 both pa st and pr esent 9 who have contriht ted imrumerable hours 0 of ef'fort in carrying out the work we have describedo Especially du we wish to recognize the efforts of Wo F o D mn and no Mo Mork in perf rm ng the analyses and evaluation e f rneth J cl igy 9 a nd cf Jo Wo Nee Lo Baurmash 9 and A Wo Bellamy who 1a ve in vari- iu s ways towards making this report p ssible a ontribt t ed sig i HicantJ y 24 REFERENCES 1 Bellamy Ao Wo et al 2 Eisenacher P L 3 Farabee L B 1947 Procedure for the Determination of Plutonium in Human Urine Report Mon H 218 4 Healy J W 5 Jarrett A A 1946 Statistical methods used in the measurement of radioactivity Report Mon P-126 6 Larson K H et al 7 Larson K H et al 1951 The 1949 and 1950 radiological soil survey of fission product contamination and some soil-plant interrelationships of areas in New Mexico affected by the first atomic bomb detonation Repart UCLA-140 8 Rankama K and F G Sahama Chicago press 9 Reed C 1950 Operation and design of an end-window alpha scintillation counter for low counting rates Report UCLA 85 10 Schubert J 1948 1949 1949 Report UCIA-32 Classified 1946 Manual of standard procedures Bioassay at Hanford Report HW 10522 1951 Report UCLA-108 19 50 M-420L Classified Geochemistry University of Private connnunication to Ro J Buettner