Ernest C. Anderson

Average Potassium Concentration of the Human Body as a Function of Age

Potassium-40 measurements on 1590 males and females ranging in age from less than 1 year to 79 years show sex differences and age trends in the ratio of muscle mass to the mass of other body constituents. A difference first at approximately 12 years of age. While females show a continuous decrease in potassium concentration, males show a rapid increase between the ages of 14 and 16. During adult life both sexes show a persistent and parallel decrease, which may be related to physiologic aging.

RADIOACTIVITY OF PEOPLE AND FOODS

Measurements of the cesium-137 content of people and of foodstuffs indicate that this nuclide is unlikely to be a decisive factor in the long-term hazards from weapons testing and reactor waste disposal. The amount of cesium-137 now present in the population of the United States averages 0.006 microcurie and shows no marked dependence on geographic location. The average radiation dose received from cesium-137 is one-twentieth of that received from natural radiopotassium and 1 percent of the average total dose from all natural sources. Because of the short biological half-life of cesium of about 140 days, it does not accumulate in the body as does strontium-90. The study of the distribution of cesium-137 is being continued to furnish information on the mechanisms of the fallout process and provide a measure of the rate of fallout and of stratospheric storage.

On the radioactivity of stone meteorites

Abstract The γ-ray spectra of 37 samples of 25 chondrites, 3 carbonaceous chondrites, and 9 achondrites have been investigated using a large NaI(Tl) scintillation spectrometer. An extensive set of measurements are presented here. Long lived K 40 and Al 26 were the predominant radioactivities detected; more unusual γ-ray emitters detected were 308-day Mn 54 , 2.6-year Na 22 , and probably a mixture of Sc 46 and Co 56+58 (half-lives approximately 80 days). These nuclides were detected in relatively recent falls (the youngest, the Harleton, Texas, chondrite was measured 21 days after fall). Furthermore, thorium was detected and measured in 5 of the 9 achondrites. The average potassium content in chondrites was found to be 0.081 per cent, in excellent agreement with Edwards and Urey. Chondritic potassium concentrations vary ±10 per cent from this average value. The average Al 26 concentration in stone meteorites was 245 ± 42 disintegrations/min/kg (silicon and aluminum). The variation from the mean of both potassium and Al 26 concentrations is real, not analytical.

Three-Component Body Composition Analysis Based on Potassium and Water Determinations

At least one obvious fact is becoming better appreciated as further studies of body composition provide us with an increasing number of parameters measured to a constantly improving precision: that is, the human body is a very complex mixture of many components. The history of methods of estimating body composition is basically one of finding a satisfactory and useful compromise between the implications of this complexity, on the one hand, and the requirements of a practicable method, on the other. It is a fundamental principle that, in order to specify completely a multicomponent system, one must determine at least as many parameters as there are components. A number of considerations prevent carrying this logic to its extreme, not the least of which is the desirability of nondestructive methods of measurements and the requirements of practicality, especially when large numbers of subjects must be measured. It may also be noted that the fewer components which are used in specifying body composition, the better chance there is of “overdetermining” the system (that is, of measuring more parameters than there are components and thus being able to check the hypothesis of uniform composition on the basis of internal evidence ) . A variety of attempts have been made, therefore, to demonstrate constant proportionality between various components of the body so that a determination of one component would permit the inference of the amounts of the related components. In its extreme form, this approach reduces the normal body to two components only (for example, “fat” and “lean,” “obesity” and “nonobesity” tissue) so that, in principle, a single determination of one component (e.g. , body water, total or exchangeable potassium, or density), in addition to gross weight, would uniquely define body composition. While such methods have had varying degrees of success, particularly with “normal” subjects (perhaps best defined in this connection as subjects who give reasonable and consistent results under the chosen method of analysis ), they are clearly inapplicable to abnormal situations. They will also fail when the precision of the investigation exceeds the limitations of the fundamental assumptions of the method. The present paper discusses the limitations of the two-component system and investigates a three-component system of body composition analysis, similar to that proposed by von Dobeln (W. von Dobeln, 1962) but based on different measured parameters, which may offer an increase in

Spectrometric measurement of natural and cosmic-ray induced radioactivity in meteorites

Abstract A nondestructive method of analysis of meteorites for natural and cosmic-ray induced radioactivity using low-level γ-ray spectrometry of kilogram samples is reported. Results so far obtained are essentially qualitative but appear to be in agreement with previous chemical measurements of K and Al 26 in chondrites and achondrites. Cobalt 60 was detected in the Ussuri (Sikhote-Alin) siderite (fell 1947) but not in old falls such as Odessa and Canyon Diablo. The rate of production of some interesting cosmic-ray induced activities is discussed.

Radioactivity of people and milk: 1957. Measurements of 2200 samples for cesium-137 and potassium-40 levels reveal interesting correlations.

The routine determination of cesium-137 and potassium-40 content of over 2200 samples was accomplished through utilization of one-fifth of the potential capacity of the Los Alamos human counter. Little change in the cesium-137 concentration in people was observed from 1956 to 1957, in spite of the increase in both the rate and the integrated levels of fallout. The correlation of levels in human beings with cesium levels in milk indicates a discrimination factor of 1.8 in this step of the ecological transfer. Precipitation is shown to be an important factor determining the cesium content of milk, but the lack of complete correlation indicates that a more detailed analysis is necessary. Contamination of the troposphere during periods of weapon testing complicates the interpretation, as do seasonal variations.

Strontium-90 and Cesium-137 in North American Milk

The strontium-90 and cesium-137 concentrations in powdered milk in North America vary roughly with the specific activity of rain. The Sr90/Cs137. ratios in over 800 powdered milk samples taken from 60 stations in North America from 1957-60 have a standard deviation of only 44 percent.

The relative biological effectiveness of tritium beta-radiation with the broad bean root (Vicia faba) as a test system.

Beans used in this study were Suttons Exhibition Longpod broad beans. They were obtained from Sutton and Sons, Ltd., Reading, England, and were genetically the same as those used by Gray. With three exceptions, the methods used for bean root culture in the present study were the same as those described by Gray and Read (2). Two culture tanks with bean capacities of 80 and 96 beans, respectively, were used. The tanks were provided with a constant flow of water at a temperature of 20 + 3oC throughout the year, and each tank was covered with a Lucite lid to keep the relative humidity directly over the beans constant and somewhat higher than that of the laboratory. The indicator of radiation effect on the apical cell mass of the primary root was reduction or cessation of root elongation, and the criterion for death was cessation of root elongation for 4 consecutive days. A preliminary study was desirable to determine the sensitivity of the bean root to

Lunar Composition by Scintillation Spectroscopy

Information on the composition of the moon and its past history is being sought through measurements of the spectrum of the gamma rays emerging from the lunar surface. The detector is a 3 × 3 in. CsI-plastic scintillator phoswich feeding a 32-channel analyzer weighing 5 pounds. Energy range is to 3 Mev; in-flight calibration is provided by a small Co-57 and Hg-203 source fixed to the detector. Energy resolution is 12 ± 2 per cent at 0.66 Mev. The spectrometer, and indeed the entire spacecraft, is biologically sterile. The spectrometer aboard Ranger 3 (launched January 26, 1962; missed the moon by about 20,000 miles) transmitted back spectra currently being studied; Rangers 4 and 5 are repeats scheduled for later in 1962.

Tumorigenic hazard of particulate alpha activity in Syrian hamster lungs.

Syrian hamsters were exposed to lung irradiation by three modalities that differed in degree of localization of the radiation dose and in the fraction of lung exposed. Intratracheal instillation of210 Po solution gave nearly uniform α irradiation of the entire lung, intravenous injection of large numbers of