Health and Safety Laboratory Program Presentation for the 97TH Advisory Committee for Biology and Medicine Meeting March 8-9, 1963

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MEETING OF THE ACBM AT HASL John H. Harley, Director, HASL 9: 30 Health Protection Engineering 3 . Measurement of Weapons Debris i n the Stratosphere - Air Filter Testing - Jess Thomas 1. General Program - Edward Hardy, Director Fallout i n t h e United State6 during 1961 and 1962 - Sr9’ i n Human Diet and Bone - Joseph Rivera 1. General Program - James McLaughlin, Director 3. Determination of External Environmental Dose Rates - c 1. General Program - John H. Harley, Acting Director. Ra226 i n Human Diet and Bone - Naomi Hallden 1. General Program - Robert Graveson, Director 2. Gamma Intensity Measurements a t High Altitudes - 3 . Development and Application of Photomultipliers -

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MEETING OF THE ACBM AT HASL 9: 00 A.M., General Discuss-ion of Future HASL Program 9: 30 Tour of Laboratory (coffee along the way)

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I * REALTH PROTECTION ENGINEERING DIVISION PROJECTS INDUSTRIAL DUST EVALUATION AND CONTROL Aerodynamic Characteristics of Industrial Air Contaminants - Measurements of respirable fractions , particle size distribution, and particle shapes of air contaminants are being obtained routinely a t AEC facilities. structed in basic aerosol physics and methods of testing high efficiency filters installed in ventilation systems. Air Cleaninq Filter Studies - The characteristics of high efficiency filters will be investigated to develop practical engineering data and to provide a basis for improving filter quality. Inter-Laboratory Comparison of Particle Measuring Techniques - Aerosol particle s i z e measurements by three laboratories are being compared to determine the 11 validity of techniques. Air Sampling Filter Characterjstics - A systematic study is being conducted of the collection efficiencies and resistances of approximately 35 types of sample filters Aerosol Generator Development - Aerosol generators a r e developed to meet the special requirements of filter testing, air sampler calibration, and the high altitude sampler evaluation program HIGH ALTITUDE SAMPLER EVALUATION AND DEVELOPMENT Evaluation of Sampling Devices - The performance characteristics of existing s tratospheric sampling devices i n simulated stratospheric environments are being evaluated inan altitude chamber. Study of Stratospheric Particle Samples - Particles collected i n stratospheric sampling flights a r e being examined to augment knowledge of particle properties for general scientific information and so that sampler performance may be realSampler Development - High altitude samplers for specific programmatic needs ! is tic ally evaluated.

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Fallout in the United States During 1961 and 1962 From January 1961 through August 1961, strontium-90 analyses af monthly fallout collections were routinely performed at 43 sites in the United States, and strontium-90 and cerium-144 analyses at five additional contractor stations. After the resumption of nuclear testing in September 1961, these analyses were augmented by strontium-89 analyses in the larger sampling network and by strontium-89, zirconium-95, the contractor program. Results from these analyses are used to show that an average of 18 mc/mi2 of strontium-90 was deposited in the United States from January 1961 through-September1962. About 10% of this debris appears to have originated from nuclear tests conducted in 1958. The remainder of the debris is attributed to polar tests started by the Soviet Union in September 1961 with some contributions from the 1962 United States tests arriving in the latter half of 1962. Sufficient data are presently available also to compare early deposition profiles from the 1961 Polar tests to profiles previously obtained for 1958 Polar and equatorial test series and to estimate to some extent what future deposition rates will be.

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-. In Diet and Bone sation inthe Environmental Studies 1 strontium-90 dietary intake and Estimates of the dietary intake of :k City, Chicago, and San Francisco, IO different foods cornposited into three months since March 1960. Iertebrae have also been made from each of the three cities. Most : victims or from people where metat o have been normal prior to death. ling investigation will be presented

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RADIATION PKYSICS DIVISION "he technical activities of the Radiation Physics 'Division are divisible into three classes, each of which isthe technical responsibility of a senior member of t h e Division. Each activity includes various projects which may vary as the short term projects,are concluded and new ones begin. projects, can be identified as follows. Recent short term and continuing 1. External Environmental Radiation Studies a. Instrumentation - Recent effort has been concentrated on developing 7-ray spectrometry techniques for field use, and on transportable b. Surveys - Over past years, detailed background dose rates, and estimates of t h e important contributors, have been made i n New England, New York State, and the Western U. S. c. Dosimetry - As a result of the instrumentation evaluations and the surveys, analyses are carried out-on t h e variations i n and components of "background dose". This work will be reported atthe Symposium on Natural'Radiation Environment i n Houston in April, and is summarized a. Nuclear Track Studies - As part of our efforts to measure and analyze stray radiations produced by particle accelerators, time-integrated estimates of neutron fluxes and spectra are obtained. The techniques t o measure neutron spectra with nuclear track emulsions have been developed and reported and will be improved. developed by L.R.L. has been used in conjuction w i t h N. T. emulsions. The use of devices t o detect high energy neutrons, f o r example by means of the C12(n, 2n)Cu reaction and Cerenkov radiation, are also c. Neutron Dose Estimates - The above measurements should enable us t o calculate dose, though the Failla-Rossi tissue-equivalent chamber will continue i n use. la tion chambers, work i s now being concluded on the dose rate effect of various atomic number materials near a uranium disk.

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computer has been employed to devise analytical techniques Several reports have been and are of criticality parameters of accumulations of sionable materials- Other computations involve the problem of g published, which compare analytical results with experiments chine program is being prepared to analyze the diffusion'and of fission products from a malf'unctioning reactor. be useful within the AEC in examining contractor :yses and will be published. 5 gent the Division includes 12 physicists and engineers, plus another ier on assignment from NYOO, a laboratory technician, and a part-time jcs graduate student. A l l personnel, except three, one of whom is the nt, have at least one year of appropriate graduate study, and such 'cluding the N y engineer) to numerous technical advisory semices for continue. Of this available effort, 14 1/2 man-years, about TO$ I( to the research activities mentioned here, and the balance ious AEC groups. The current division of personnel is as follows. External Environmental Radiation Studies Nuclear and Reactor Safety It should be noted that these divisions are informal and considerable interaction occurs among the various Division personnel.

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MAY'PROFAGATION AT THE AIR-GROUND INTERFACE, BY KERAN o ~ m m During the Summer of 1962, measurements were made of the dose rates from two large point sources on the air-ground interface. The .purpose was to compare these values with those expected in the medium, and so to estimate the dose rate from distributions of point sources, such as fallout. hitherto associated with ground roughness may be due to the nearby interface. case of an infinite homogeneous We also hoped to resolve the problem that the effects m e site of the experiment was a 150 meter tower at the Nevada Test Site. Extending from the base of -the tower, a 25 meter wide by 1000 meter long area was cleared, and surveyed. A 500 curie Co60 source and a 300 curie Cs137 source were successively sources were-moved through plastic tubing until an appropriate magnetic actuator located them at previously determined spots. The instrumentation package was placed successively at six elevations for the measurements, F e l y 0, 15, 38, 76, 114 and 148 meters, The detectors were Victoreen condenser ionization chambers and a pressurized, argon filled, ionization chamber used Fn conjunction with a vibrating capacitor electrometer modified to be operated remotely. Calibrations were made with :a. NBS standardized radium source. response of the chambers was obtained using a combination of heavily Instrument heights, source-detector distances, and distances along the ground were corrected for a 5% slope of the ground. The dose rate measurements obtained show marked deviations from those predicted on the basis of infinite homogeneous theory. values increase with increasing instrument height above ground, to a maximum, and then decrease. The maximum dose rate values occur at greater instrument heights as the tower-source distance increases. behavior discovered by other experimenters at the N.T.S.,:the N.B.S. and For instance, the dose rate This is consonant with the

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DETERMINATION OF EXTERNAL ENv7RONMENTAL RADIATION DOSE RATES, BY WAYNE M. LOWDER We haiTe been developing instruments and techniques f o r estimating .environmental radiation dose rates in populated areas i n the United States. chambers, filled with airat atmospheric pressure, and argon o r nitrogen gas at,high pressure, have been utilized for total dose rate measurements of the ionizing component of cosmic radiation and 7 radiation from terrestrial sources. 7-ray spectrometry has been employed i n the field to separate the fallout from The spectra obtained in the fie d consistently show three major photopeaks, a t 1.46 Mev and 2 -62 Mev from Kb and T1208 ( ThC1I), respectively, and a t 0.75 Mev from Zr95-Nb95. Minor peaks a r e observed a t 0.5 Mev, probably due eter with various monoenergetic 7 sources relate photopeak area t o incoming primary flux. Calculations from theory give the dose rate per unit primary f l ~a t the detector. By measuring the photopeak areas in the field spectra, the individual dose contributions fram K, U, Th, and f a l l o u t can be obtained and compared with the ion chamber readings. In New England, HASLconducted f i e l d measurements with the Harvard University School of Public Health i n an attempt t o develop adequate methods for future epidemiological studies of the effects of chronic low level radiation exposure on large populations. The areas chosen included relatively high background areas i n central and southern New Hampshire, influenced by t h e thorium-rich Conway granite formations, and low backgr&nd regions in central Vermont. A recent Western United States survey included measurements on the Olympic peninsula i n cooperation with the U. S. Department of Agriculture and the University of California Radiation Laboratory. Francisco and the Denver areas were also examined. Selected locations i n the San The following conclusions can be drawn from these surveys. Fallout 7 dose rates inthe United States during the late Summer of 1962, primarily due t o Zr95-Nb95, were generally 10 t o 2076 of the total The Zr95-Nb95 present a t t h e Olympic peninsual locations correlated well with the mean annual rainfall levels. The fallout levels i n the San Francisco Bay area were uniformly low. Dose rates encountered i n New Hampshire areas were generally 50% higher than i n Vermont, primarily due t o the presence of thori ~and potassium. The total7 and cosmic radiation dose rates in the Deenver-Colorado Springs area averaged over 20 p r / hr. I n general, the dose contribution from the uranium series appears t o be substantially less than that calculated from the uranium concentrations i n the soil, because of the migration of radon and its daughters from the upper layers.

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A program of the Radiochemistry Division is outlined below under the separate working groups. 1. Balloon Filter Program Samples of airborne dust from the stratosphere a r e collected by balloons a t San Angelo, Texas, Mildura, Australia and Rapid City, South Dakota. AnalysZs of these samples is important i n determining the stratospheric inventory and i n alerting fallout measuring stations of the appearance of individual nuclides, particularly tracers. Much of the analytical work is done under contract but t h i s group is responsible for initial gamma counting and spectroscopy, analytical quality control and atleast primary data interpretation. I n addition, some time is devoted t o radiochemical method development, particularly for tracer nuclides. This group is responsible f o r the analysis of samples collected i n connection with surveys a t NYO Contractors and by Region I Compliance chemical methods related to their operations. They also have a modes-kdevelopment program i n radioThis i s a program intended t o provide long range radiochemical method required for the balloon filter program. methods involving a combination f radiochemistry and gamma spectroscopy. During the -Last year the effort was devoted t o methods Future work should emphasize This group is responsible f o r the preparation of primary and secondary radionuclide standards f o r the laboratory, as well as development work i n new techniques of counting and counter data handling. project has been development of methods f o r measuring Radium-226 .. .. and Radon-222 f o r application t o samples of diet, bone and other matrices, a s well as a study of upper air radon levels.

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Balloon Sampling Program - Analytical Effort Participation in the analytical phase of the High Altitude Balloon Sampling Program has been intensified since the Spring of 1962, with resultant 'alteration in the nature and scope of the Laboratory's effort in the program. Emphasis has been given to providing methods for obtaining pertinent and high quality data. The current operations are summarized in the following list: Gamma scanning all incoming filter samples to obtain preliminary information on the quantity and radionuclide content of debris; Directing contract effort in routine analyses and applied research projects; Conducting a quality control program to evaluate (a) contamination problems related to sample collection, and (b) the accuracy, precision, and sensitivity of radionuclide analyses; Performing "in house" analyses as aCadjunct to the quality control program, developing analytical methods, and engaging in applied research studies; Evaluating, assembling, and reporting radioanalytical data and the results of pertinent research studies. Some of the information obtained as a consequence of the use of the g a m scanning technique include: Indication of a small contribution of debris from the Fall 1961 Russian tests to the activity levels in February 1962 samples collected from the lower stratosphere (60 kilofeet and below) at Mildura, Australia (34OS) ; Observations of stratification of gross gamma activity concentration levels at San Angelo, Texas (310N) with peaks often appearing at 90 kilofeet or above as well as in the lower stratosphere; Sudden appearance of detectable quantities of barium-140 at 60 kilofeet, 310N in June 1962; 62 kilofeet, 340s in August 1962; and above 110 kilofeet, 310N in October 1962; Presence of manganese-54 and antimony-124 at 88 kilofeet, 310N in February 1962 and at lower altitudes in subsequent months; First appearance at 79 kilofeet, 310N in January 1963 of an unidentified 1.8 MeV photon emitter with a half-life greater than 30 days; Evaluation of the precision of sampling volume measurements. A number of these findings have been confirmed by later radiochemical analysis.

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Radium-226 in the Diet and Human Bone A …