Letter to T Mccraw, Subject: Evaluating the Pu Concentrations Observed in Urine Samples from Bikini and New York

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Division of Safety, Standards and Compliance concentrations observed i n urine samples from Bikini and New York. Ne plan t o publish the report as a UC RL and would appreciate any comments you may have, I am also sending information copies t o Bob Idatters and Bill Forster of D B E R and Nat Barr of DTO. Enclosed is a draft copy of our paper evaluating the Pu It is interesting that the relative difference in observed Pu concentrations at Bikini and New York can be accounted for by the difference i n intake of Pu via the various pathways. However, a very significant point is the inability to zccount for the absolute magnitude ofthe Pu brine concentrat.ions o b - served. Ne feel the Bikini data indicate that perhaps for humans, and for Pu incorporated in food products, that the transfer across the gut via11 may be considerably greater than that predicted froni animal studies, Ne feel this is a very significant point and we ~ hope that support for follow-up research, for which we have several proposal s , would be supported by EKDA. We would greatly appreciate any comments you have inthe ‘analysis presented i n the paper and also on the potential for pur - ,’ suing the metabolism of P u ingested i n food products by human

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COMPARISON OF PLUTONIUPI CONCENTRATIONS IN DIETARY ‘AND INHALATION PATHWAYS AT BIKINI AND NEW YORK AND THEIR RELEVANCE TO Pu URINE CONCENTRATIONS AND BODY BURDENS I n 1970 analyses for plutonium 239 and 240 i n pooled urine samples from Bikini by the HASL-ERDA Laboratory (Health and Safety Laboratory, 1971 the average 239y240Pu concentration of 3urine samples from Bikini 0.013 pCi/k.’ (No errors are attached t o the values reported i n Ref. 1. ’ The average value for any year was obtained by multiplying thePu concentration o f each sample by its volume, summing these products, and dividing by the total sample from Bikini was reported2 a s 0.011 pCi / a . This concentration i s similar to the value found i n 1974 butis 10 tims higher than the In 1975 t h e average 239’240Pu concentration ‘in a pooled 9-& urine concentration (0.001 pCi / a ) reported fora 1975 representative population sample from New York. concentrations area direct indicator of plutoniim burdens i n the body, the increase in Bikini plutonium levels from early to mid 1970’s and the large difference between the concentration found i n samples from’ New York and Bikini is cause for concern. . 5) - Because of the toxicity of plutonium and the belief that urine

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. . The purpose of this report 'is t o presekt comparative data on Bikini and New York plutonium pathways t o man now available from the recent LLL 1975 Bikini survey 3 ' 4 y 'and other studies. Although a comparison of the , pathways is not sufficient to clarify issues on plutonium concentrations i n body tissues or excretions,it does show that a Bikini population i s exposed t o higher plutonium levels through dietary and inhalation pathways thana New York population. We acknowledge ;hat the excretion rates of plutonium and the quaritities excreted may differ significantly depending upon routes of entry into the body and that the assessment of these rates and quantities is further complicated by dissimilar physico-chemical -forins of plutonium i n the , environment. We suggest that.differences in concentrations i n various pathways could account for the relative difference in urinary levels presently found for the two populations. Computed annual plutonium urinary concentrat'ons, \ ' however, are very different than reported values2 from New York and Bikini. Several interpretations are proposed for this noted discrepancy. the concentrations found in pathways are directly related to the concentrations excreted, then the urine plutonium levels will,with time, become increasingiy higher and differ even more Bikiniaris rely increasingly from future control samples from New York a s the oh dietary components from their atoll. I n ha 1a t i on Pa t hwa y * The contribution from the inhalation pathway t o plutonium concentration in urine, especially a t Bikini, i s very hard to quantify. different activity levels from fallout present In the air at Bikini and New York, resuspension processes that contrib ut e.-, airborne plutonium a t New In addition tothe

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and BI1.fn-I are very difficult but important processes t o assess t o estimate the cumula.tive exposure t o plutonium from inhalation. Bennett 7 has recently concluded that plutonium from resuspended fallout at New York presently contributes 0.3% and will ultimately contribute an additional 0.22 of the in take that occurs during the original deposition of the fallout debris during any time period. The soil plutonium levels on Bikini Island 5are certainly, on the average, higher than fallout levels deposited inthe United resu.spension of surface materials by,people o r vehicles at Bikini is slight even during very long dry spells. However the available comparative aerosol data shows that some locations on Bikini Island have higher levels of plutonium i n the air than expected from world wide fallout and higher levels 8 Visual observations indicate that the formation of du'st clouds or than those encountered i n New York City during 'comparable periods. show ina following section that resuspension may also contribute elevated plutonium levels to the ingestion pathway at Bikini. Comparable data on plutonium concentrations i n the air exists only for the peribds of late May to early June 19709 and May 1972". During the five locations on Bikini Island. o f 29 May to2 June 1970 ranged from 60 t o 540 aCi/m3 (aCi = at to curie). ' The The aeolian concentrations during this period mean air concentration at4sites on the island of Eneu (Bikini Atoll) was only 40 aCi/nr3 during a comparable period.' Plotted inFig.1asa function o f latitude,are the average plutonium concentrations at ground lev21 atair sampling stations of the HASL sampling network d u r i n g June 1970.11 The ~

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concentration-lat-itude profile was obtained by simply drawing a continuous curve through the available data points. From this curve the average fallout concentration expected i n ground level airat the latitude of Bikini Island (11’ 37‘ N ) should be approximately 32 aCi/m .3 This value cannot be considered t o be i n disagreement with the plutonium levels in air levels for the latitude these 1eve1 s coul d have t h e Island. The median mean concentration detected on the lesser contaminated island of Eneu. 4,5 However, i t is not only well below the log normal median (134 aCi/m ) or mean (186 aCi/m ) concentrations on Bikini Island b u t i s well below the range found over the entire Island. There is little question that the during June 1970 were above fallout background of Bikini Island. The only mechanism by which been attained was thr qu gh resuspension processes on value at Bikini is vet-y nearly equivalent t o the mean air concentration a t New York dhng this period. remembered that during 1970 the urine concectrations from Bikini and New York were also comparable. Except for water,’no other indigenous material was consumed at Bikini during the two years before 1970. comparison of New York and Bikini, the 1970 data strongly suggests there was a close correlation between aeolian plutonium levels and urine v In May 1972, air samplers were again operated on Bikini Island a t four different locations. The 239’240Pu air concentration during this concentration over t h e Island was 22 4 C i / n i and the mean concentration was 34 aCl/m . In Fig.2are plotted the QASL plutonium air concentrations durlng May 1972 as a function of latitude. ” A‘smooth continuous curve

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wds again drawn' through the data points. The air fallout concentration expected.at the latitude of Bikini during Play 1972 is approximately found and only half the mean plutonium air concentration detected at Bikini during this period. 3 This concentration i s only slightly less than the median value I n Nay 1972, 37 aCi/m were detected i n the air over New York. Again we finda similarity..between the plutonium i n Bikini and New York air,and the Bikini mean concentration is still higher than world wide fallout concentrations predicted for this latitude. The' 1972 data on air concentration at Bikini also showed a strong geographical correlation. 10 . The plutonium air concentrations increased i n the samplers from the N.W. t o S.E. along the length of the Island. There are,therefore, regions of island that have higher plutonium aerosol concentrations than others. The individual inhalation exposure then must a l s o depend on the time spent working or living in a specific regibn of the Island. In summary,without more ' detailed data from Bikini and without any knowledgeI . on the differ e rce between concentrations froin large volumes of open air and the concentrations i n an individual ' s immediate environment resulting from resuspension by a person during his daily routine, we can atleast safely aszume that the inhalation pathway fdr plutonium i s comparable t o New York. The avail abl e. . data strongly suggests that over certain regions o f the Island the aeolian concentrations are significantly higher than New York. ' If resuspension by human activity is also important, there is a much-.-<_. greater chance of higher exposure at Bikini through the inhalation pathway.

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The primary source of d riG king and cooking water for Bikini inhabitants i s unprocessed rain mter obtained from cisterns attached t o the newly constructed buildings along lagoon road. drained from the windward roof of each building. The cisterns collect water Ground water has also been used for drinking purposes i n periods of drought and will be used i n the future when ever cistern water i s unavailable. There i s presently a high demand for the ground water for agriculture on Bikini Island. Three of the cisterns were first sampled i n June 1975, and analyzed for. shown i n Table 1 , From an examination of the fallout in rainfall at other Pacific Islands over ' the period of 1968 t o 1974, it was concluded4 that the water did not result solely from world wide fallout. The cisterns contained levels o f radfonuclidos that were locally derived. In support of this contention, two water samples collected in October 1975 from the drinking water tanks on the ERGA supported Marshall Island Research collected at Kwajalein Atoll. Marshall Island rainfall are then approximately 1/20 of the concentrations This water comes from t h e rain water supply The 239y240Pu and 137Cs concentrations i n in the Bikini ' cisterns. Ne therefore conclude that the Bikini cistern plutonium radionuclides above those expected from world wide fallout. higher concentrations could originate5from 1 eaching o f the concrete cisterns

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(the concrete used for the cistern construction was locally derived) or, a7 ter natively, from resuspended airborne 1 abeled particles accumulated on the drainage surface of the roofs and washed into the cisterns with the next rain. If the latter mechanism is correct, resuspension processes contribute plutonium not only to the inhalation pathway but to the ingestion pathway as well. . I Bennett 7 has recently pub1 ished *'data on fa1 lout 239y240Pu i n 1972 dietary components i n New York that included from 1973 a mean tap water concentration levels i n untreated surface water of t h e Great Lakes. 12' '3 Other data appropriate for comparative purposes are fallout summarized i n Table 2 along with the mean and range of plutonium concentratioris I n cistern and ground water from Bikini. rates for individuals at Bikini and New York are similar,there can be little Assuming that water consumption . question that Eikinians experience . a higher plutonium body burden from cistern o r ground water ingestion than populations i n New York. Ne assume here, of course, that Bikini Island water is the only available source for the present popuiation. I t follows that urine levels in the Bikini population would exceed those ina New York population even i f this were the only pathway involved with all other pathways contributing similar levels of Puto the bl'ood stream a t both locations. Terrestrial Food Products The diet for the peop-le on Bikini Island consists of foods imported from the United States and foods grown and obtained locally from Bikini Atoll. The imported foods, on the av&rage, should conta_in fallout levels

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. of plutonium similar to those consumed by New Yorkers. concentrations i n the New York diet are abstracted from a report by Some recent plutonium data from the June 1975 Bikini Survey' and earlier 6data obtained for terrestrial food items are given i n Table 4. Only upper plutonium detection limits (with 95% confidence) were available for some saniples because o f the limited sample=size t h a t could be obtained from the existing inventory of food products on the Island. However, from those samples where there was sufficient material t o obtain a real number (papaya, . pig muscle), it is clear that the Pu concentrations are twice as high as any values reported for terrestrial ly derived food products inthe New York diet. It is not yet clear just how much of the different food products grown on Bikini Island are actually used i n the diet. However, whatever the use . . (and there is undoubtedly some) and bhatever increased future use there may be would lead ,to higher body burdens and therefore 'higher urine concentrations of Pu in the Bikini population over the New York population from th k food pathway. : For example, i f one assumes an average P u concentration of 0.6 pCi / k g fresh weight inall the food products on Bikini Island and a combined intake of a17 foods of 100 g/d o r 36.5 kg/y, then the y e a r l y plutonium intake would ,be 21.9 pCi compared t o the 1.46 pCi (1.6 pCi minus the shellfish and water) estimated by Bennett for New York. Plutonium levels in a diet entirely derived from Bikini terrestrial foods are 15 times the levels in a terrestrial diet from New York.

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Marine Food Products Marine food products from Bikini Atoll supply a substantial portion of plutonium to the diet for Bikinians. Atoll have been published by Nevissi and S ~ he1l.l ~These data are abstracted Some P u concentrations in fish at Bikini and given i n Table 5 along with some data on marine invertebrates.'* Using both data for fish muscle o r eviscerated whole fish and real numbers 'and weighting by the numb-er of fish in a sample, the mean P u the detection limits as concentration for fish at Bikini Atoll is2.2pCi / k g wet weight. Concentrations in invertebrate muscle average 1pCi / kg. Assuming an average …