Program Status Report to the Joint Committee on Atomic Energy, December, 31, 1957, Part Viii, Biology and Medicine (Partial)

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, Biology and Medicine Project SUNSHINE is the study of worldwide radioactive fallout from weapons testing &d , evaluation of its hazard to man: While these +dies are not qrectly concerned with evaluating the hazards of local fallout in the vicinity of an explosion, dab obtained. from local fallout studies are useful in the SUNSHINE studies. Project SUNSHINE includes worldwide sampling and monitoring activities and research projects on fallout problems and radiation effects. .' Some of these studies a r e made at teat sites; many otqers, in universities and laboratories throughout the country, are remote from any weapons testing activity. Studies of the occurrence and behavior of strontium 90 form an Important part of Project SUNSHINE. part of Project SUNSHINE but that xievertheless provides helpful data for the fallout studies. Table 1 summarizes the actual &d estimated expenditures for Project SONSHINE'and these ' related research projects for fiscal years 1957 and 1958, as compared with the estimate of The AEC sponsors considerable research on the biological hazards of radiation that is not Table 1-Expenditures for Studies and Research Projects on'lallout Problems and Related Research on the Biological Hazards of Radiation. . FY 1957 FY 1957 FY 1958 Sampling and analysis Research on the biological hazards of radioactive i i Related research on the . :I biological hazards of +Takenfrom page 1393 of the printed hearings.

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expenditures for fiscal year 1957 given in the hearings on “The Nature of Radioactive Fallout and Its Effects on Man,” held before the Special Subcommittee on Radiation of the Joint Committee on Atomic Energy during May and June 1957. The bulk of the added expenditure for Project SUNSHINE for fiscal year 1958 over f i s c a l year 1957 is the result of new programs for stratospheric air monitoring, coastal fallout surveys, and broad soil-climate-vegetation studies. Monitoring and Sampling , The scope of the strontium 90 monitoring and sampling program is as follows: , Stratosphere: United States and foreign Gummed film: United States and foreign Rainfall pots: United States and foreign Air filters: United States and foreign Soils: United States and foreign Pasture program (soil, vegetation, animal bone): United States and foreign Milk United States and foreign 1 Tap water: New York: Sea water: Pacific Food: United States and foreign Human bone: United States and foreign - ‘ .Some of these programs are discussed briefly below. Stratospheric monitoring. Samples of stratospheric particulate matter are being collected in an effort to determine the amount, -latitudinal distribution and movement, and rate of fallout of radioactive material retained in the stratosphere. Through contracts with General Mills, ’ Inc., and Nuclear Science and Engineering Corporation, and through a cooperative arrangement. with the Air Force, a schedule of routine stratospheric balloon flights has been established at‘ Minneapolis, Minnesota, San Angelo, Texas, the Panama Canal Zone, and a location in the southern hemisphere. At each station,,efforts are made to obtain one sample each month from each of four altitudes ranging from 50,000 to 90,000feet. The samples are obtained by filtering a determined volume(of air through a large filter paper mounted in a cylindrical housing which gives the program its title, “Project Ash Can.” A volume equivalent to at least 1,000 cubic feet of air, i f it were compressed to standard density, must be filtered in order to obtain a sample of particulate material large enough for radiochemical analysis; Because of the &eat expense and difficulty involved in obtaining these samples, an attempt is made to learn as much as possible about their origin and history by analyzing them for two long-lived fission products, strontium 90 and cesium 137; one relatively short-lived one, barium 140; and three with halflives of intermediate length, strontium 89, zirconium 95, and cerium 144. Samples for the . first six months of operation have been analyzed, but interpretation in terms of radioisotope concentrations in the stratosphere awaits the results of filter. efficiency tests in progress. Because of the difficulties of collecting particles of the extremely small size found in the. stratosphere at pressures of 1/100 to 1/10 atmosphere, it is necessary to conduct further rethe search for an accurate sampling method for calibration purposes, the Chicago Midway. Laboratories of the University of Chicago, under contract with the AEC, have developed, constructed, and ground-tested a cryogenic device for liquefying air at altitudes up to 60,000 feet. search and development leading toward more efficient and reliable methods of collection. In .

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BIOLOGY AND MEDICINE Improvements in design of the "Ash Can" filter system to increase efficiency and reliability a r e being developed by General Mills, Inc. Proposals for the development of several other fundamentally different methods of collection a r e being reviewed. . - The cost of the entire stratospheric sampling program during fiscal year 1957 &s ap- ' proximately $300,000. In fisc'al year 1958 both sampling operations h d research were ex: panded. The total cost for fiscal year 1958 is expected to be approximately $1,000,000. Food collection. Representative samples of the foods that are the major sources ofAcium in the diet are being collected through the cooperation of teams of the Interdepar.$mental Committee on Nutrition for National Defense. Samples already received from Turkey, the Philippines, and Libya are being analyzed by the Health and Safety Laboratory of the New York Another food collection program is under way in Latin America. Arrangements-have been made with persons engaged in national nutrition and food programs in Argentina, Chile, and Peru for the collection of samples of the foods providing the major sources of calcium in the diet of people of those countries. The samples will be analyzed for strontium 90 content., total ' radioactivity, total strontium, and total calcium. In some instances, kp les will be taken, from locations where gummed-paper collection stations exist, and correlation of analytical results will be attempted. .Geological Observatory, Columbia University, will provide,' in addition to food samples,'samples of bone from the more primitive areas of Bolivia, Ecuador, Guatemala, and Venezuela. The low calcium content of the soils of these tropical and subtropical areas may res& in greater uptake of strontium 90 by vegetaqon and man. It is possible that the maximum concentration of.strontium 90 in humans may be determined from studies of samples from.these countries and that the high end of the distribution curve for strontium 90 in the world population may be estimated. - Soil sakpling. In the spring of 1958, representatives'of the Department of Agrickture will revisit most of the sites of earlier soil sampling in foreign countries to collect additlonal samples for analysis. A similar program w a s conducted in the United States in the f a l l of 1957 and the samples of soil collected at that time are being analyzed.. The AEC has had translated a report of the U.S.S.R. Academy of Science entitled, "On the Behavior of FissionProducts in Soil, Their Absorption by Plants and Their Accumulation in of the New York Operations Office on samples collected i n rainfall pots and on milk samples' show the following trends in strontium 90 levels: Strontium 90 monitoring results. Analyses performed at the Health and Safety.LaboiatorY 1. From the beginning of 1957 to the fall of 1957 the cumulative strontium 90 values for the rainfall collection pots in New York, Pittsburgh, and Chicago increased about 10, 6, and 7 millicuries per square mile respectively. By the f a l l of 1957 the . cumulative values for these pots were as follows: New York, 37-39 milliyries Per square mile (collection started i n February 1954); Pittsburgh, 23 millicuries per square mile (collection started in February 1955); collection in Chic,ago started in . 2. Monthly values for dried milk from Perry, New York, for the first eight monks of 1957 were between 3 and 4.75 strontium units (micromicrocuries of &Ontium 90 per gram of calcium). These values are lower than the peak values for..1956. .

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BIOLOGY AND MEDICINE 3. Values for powdered milk from Mandan, North Dakota, were from 4 to 17 strontium units in the first seven months of 1957. These values correspond to the range of values observed in 1956. U. S. Public Health Service milk monitoring program. The U. S. Public Health Service, which keeps in close contact with the mi& industry, has started a milk monitoring program, similar to the one conducted by the Commission, to keep informed regarding the contamination of milk by radioactive fallout. Care is being takes to obtain representative samples. Areas with predictable and constant dairy husbandry practices are selected for sampling. Only fluid mi& .samples are collected; these are composited from small herds and from areas cont?ining a predetermined number of farms. Samples a r e now being routinely received from areas in California, Missouri, New York, Ohio, and Utah; additional stations a r e expected to be sef up in the next few months. Analytical work is performed at the Public Health Service's Robert A. Taft Sanitary E n d - neering Center, Cincinn;)ti, Ohio. and the Food and Drug Administration at a meeting held on December 13, 1957. Soil and Plant Research The program of the Pubic Health Service was described representatives of the AEC ' The AEC sponsors a number'of research projects on the behavior of fission pr0duc.b in soils and plants. Such behavior is investigated in the field, in the greenhouse, in the growth chamber, and in the laboratory. . b . Experiments with different soils containing varying bouxits of exchangeable calcium' (Le., calcium replaceable by other cations and not fixed in the soil) show that the uptake of strontium by plants decreases somewhat with an increase in the amount of exchangeable calcium present. The same rde w a s found to apply to barium uptake. The uptake of cesium and rubidium, as would be e-qected from the periodic table of the elements, was more closely re- . lated to the amount of acid-soluble potassium, a commonly used index of available potassium. A distribution factor, defined as the ratio of strontium to calcium' in the plant, or plant ' . part, divided by the ratio of available (to the plant) strontium to available calcium in the soil or nutrient solution, was determined for certain situations. This factdr serves as a measure of the relative availability of strontium and calcium, and also can be applied to other pairs of chemically similar elements. The experiments with nutrient solutions yielded an average strontium-calcium distribution factor for the entire plant of slightly above^ 1, for roots much higher than 1, for stems, petioles, and leaves progressively less than the root values. cium i n wheat and alfalfa for a large number of sites in the United States was about 1. Ten crop plants grown on four soils in a greenhouse experiment had an average value of 0.7 f o r , the same factor. The average distribution factor for natural, stable (nonradioactive) strontium versus cal- . The effects of liming and tilling on the uptake of strontium 90 from an acid soil were investigated i n a field experiment. When four tons of lime per acre were applied to the surface of the soil there was no appreciable change Sn the ratio of strontium to calcium in either soybean plants or bluegrass. When the same amount of lime was rotary-tilled into the upper six inches of the soil, the uptake of strontium was reduced in soybean.plants bdt not in bluegrass., Burial of both the lime and the strontium to a depth of 15 inches reduced the uptake of stron- ' tium by soybeans even more effectively than rotary tilling. . -

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BIOLOGY AND MEDICINE Experiments have been conducted to find out what happens when'strontium is appUed to various leaves of a plant. Strontium appears in other aboveground parts ot the plant, 'and measurements can be made of the relative amounts. The extent to which strontium 90 is fixed (made relatively unawilable to plantSj in nonexchangeable forms is under investigation. Samples taken in 1955 of one so4 from Ohio exhibited fixation values ranging from zero to 20 percent of the total strontium 90 conteot. Comparable samples of a different soil collected nearby showed values ranging up to about 10 percent. Incomplete data on soil samples from North Carolina indicate a maximum @ue of 35 percent, higher than the Ohio values. A leaching experiment with five soilsshowed that dilute solutions of calcium $&'&e much more effective in the leachlng of radiostrontium than are sodium salt-solutions (common table salt is one sodium, salt) or plain water alone. In general, the coarser the soil, the greater the downward movement of strontium whep the rate of flow of the water and solutions h not excessive. For neither strontium or cesium, on which experiments were also conducted, is the rate of. movement f a s t enough to suggest leaching with dilute solutions as a rapid method for Experhnehts with a fine sandy soil show that relatively large amounts of hydrochloric acid applied to the rmftace of q e soil are effective in leaching out strontium. Other chemicals applied in equivalent amounts, ferric chloride, calcium chloride, .and strontium chloride, were noi so effective, and sulfuric acid, aluminum chloride, and sodium chloride w-ere even less effective. In all cases except hydrochloric acid, an appreciable fraction of the str on tib remained in the soil where the chemicals were applied, indikating that some of the str Field studies bn soil decontamination have been carried out using some of h e c listed above. The chemicals were applied to the soils which were then irrigated with waterto a depth of five feet; the distribution of strontiuni 90 and salt to a depth of three feet was then determined. Hydrochloric acid again f a 8 most effective, and ferric chloride also was effective in removing strontium from surface layers. It was concluded that decontamination of soils by any of these treatplents would be expensive. One method involves spraying the soil first with a material to enclose and hold onto the contaminants and surface soil. It was found that 97 percent of the radioactivity could be removed by spraying the soil surface with asphalt emulsion and peeling off the resulting crust. When the crust was mixed throughout the soil, a s plowing would do, the strontium 90 evenhially became more available to barley plants. In another e*rhnent, the crust was mixed with the top six inches of soil, and the soil was irrigated and planted to barley. At the time of'harvest, . three months later, it was found that this treatment had effected a 30 percent reduction in For this reason, physical removal of surface deposits of fission products has been studied. strontium uptake as compared with the untreated soil. . , RADIOBIOLOGICAL SURVEYS OF, THE MARSHALL ISLANDS AND WESTERN PACIFIC Radiobiological surveys have been made in the Marshall Islands 'since the initiation 6f ihe Pacific testipg program in 1946. In March 1954 the fallout on several atolls in the Marshall Islands, including Rongelap, was greater than had occurred from previous tests. For this reason …