Radium distribution

Morawska L, Philhps CR (1992) Dependence of the radon emanation coefficient on radium distribution and internal stractnre of the mineral. Geochim Cosmochim Acta 57 1783-1797 Neretnieks I (1980) Diffusion in the rock matrix an important factor in radionuclide retardation J Geophys Res 88 4379-4397... 

Semkow, T. M., and P. P. Parekh. 1990. The role of radium distribution and porosity in radon emanation from solids. Geophys. Res. Letters l7(6) 837-40. 

Barium [7440-39-3] Ba, is a member of Group 2 (IIA) of the periodic table where it Hes between strontium and radium. Along with calcium and strontium, barium is classed as an alkaline earth metal, and is the densest of the three. Barium metal does not occur free in nature however, its compounds occur in small but widely distributed amounts in the earth s cmst, especially in igneous rocks, sandstone, and shale. The principal barium minerals are barytes [13462-86-7] (barium sulfate) and witherite [14941-39-0] (barium carbonate) which is also known as heavy spar. The latter mineral can be readily decomposed via calcination to form barium oxide [1304-28-5] BaO, which is the ore used commercially for the preparation of barium metal. 

Joly observed elevated "Ra activities in deep-sea sediments that he attributed to water column scavenging and removal processes. This hypothesis was later challenged with the hrst seawater °Th measurements (parent of "Ra), and these new results conhrmed that radium was instead actively migrating across the marine sediment-water interface. This seabed source stimulated much activity to use radium as a tracer for ocean circulation. Unfortunately, the utility of Ra as a deep ocean circulation tracer never came to full fruition as biological cycling has been repeatedly shown to have a strong and unpredictable effect on the vertical distribution of this isotope. 

Figure 1. Schematic illustration of factors influencing the production and migration of radon in soils and into buildings. Geochemical processes affect the radium concentration in the soil. The emanating fraction is principally dependent upon soil moisture (1 0) and the size distribution of the soil grains (d). Diffusion of radon through the soil is affected primarily by soil porosity ( ) and moisture content, while convective flow of radon-bearing soil gas depends mainly upon the air permeability (k) of the soil and the pressure gradient (VP) established by the building.

Data on the geographic distribution of surficial radium concentrations were acquired by the National Airborne Radiometric Reconnaissance (NARR) survey, part of the National Uranium Resource Evaluation (NURE) program conducted by the U.S. Department of Energy in the mid-1970s. The data were originally collected and tabulated by 1° by 2° quadrangle map area, and the data cover approximately 450 out of a total of 474 such quadrangles... 

Data on surface radium concentrations has been compiled for 394 of the 474 quadrangles covering the conterminous 48 states. The resulting distribution is illustrated in Figure 2, where the parameters shown for the distribution are calculated from the binned data. This distribution has a GM of 25 Bq kg and geometric standard deviation (GSD) of 1.75. Based on this distribution, approximately 20% of the surface radium concentration data are above 40 Bq kg and 0.7% are above 100 Bq kg... 

Figure 2. Distribution of the surface radium concentration data from the National Airborne Radiometric Reconnaissance survey for 394 1° by 2° quadrangles covering most of the contiguous 48 states. The distribution parameters are calculated from the data and the lognormal distribution based on the geometric mean., and standard deviation from the data is shown as a solid curve.

Figure 3. Distribution of surface radium concentrations for a quadrangle (a) with a GM < 20 Bq kg and for a quadrangle (b) with a GM > 40 Bq kg. The curves represent lognormal distributions based on the distribution parameters calculated from the data.

As noted in Table I, average surface radium concentrations appear to vary by about a factor of 20. This can also be seen from the distributions from the NARR data. Soil permeabilities, on the other hand, have much larger variations, and thus, in principle, may have a greater influence on the spatial variations in average indoor radon concentrations that have been observed. As with the case of surface radium concentrations, the spatial variability of air permeabilities of soils is an important element in developing a predictive capability. 

Briggs, G.H., Distribution of the Active Deposits of Radium, Thorium and Actinium in Electric Fields, Phil. Mag. 41, 357, 1921. 

Wellisch, E.M. The Distribution of Active Deposit of Radium in an Electric Field, Philosophical Magazine 26 623-635 (1913). 

The air circulation must continue at least three hours. It is not only necessary to distribute the radon accumulated in the radium solution bottle into the entire system (for this purpose a shorter time would be sufficient) but it takes three hours to establish the equilibrium between radon and its short-lived daughters in the medium. 

Lloyd, R.D., F.W. Bruenger, S.C. Miller, W. Angus, G.N. Taylor, W.S.S. Jee, and E. Polig. 1991. Distribution of radium-induced bone cancers in beagles and comparison with humans. Health Phys. 60 435-438. 

Uranium, thorium, radium, and strontium spatial distribution within studied area turn out to be different 1) a relatively similar pictures of U, Th, and Ra distributions (Fig. 2 - 4), and 2) a clear difference of distribution for Sr (Fig. 5). The greatest features in the spatial distributions of U, Th, and Ra appear in the northern-western and southern-eastern parts of the region (see Fig. 2 - 4). 

Radon is another example of a very curious and toxic compound that many of us regularly inhale, hopefully in small amounts. For those regularly exposed to radon, there is an increased risk for lung cancer and, for those that smoke, radon exposure results in a three-fold increase in the incidence of lung cancer. In the United States it is estimated that indoor radon exposure causes between 7000 and 30,000 lung cancer-related deaths each year, second only to tobacco smoking. Radon-222 is a colorless and odorless radioactive gas that results from the decay of radium-226, which is widely distributed in the earth s crust. Radon decays with a half-life of 3.8 days into solid particles of polonium. It is actually the breakdown of... 

Yang HS, Nozaki Y, Sakai H, et al. 1986. Natural and man made radionuclide distributions in Northwest Pacific deep sea sediments Rates of sedimentation, bioturbation and radium-226 migration. Geochem J 20 29-40. 

At the time of the discovery of radio-activity, about seventy-five substances were called elements in other words, about seventy-five different substances were known to chemists, none of which had been separated into unlike parts, none of which had been made by the coalescence of unlike substances. Compounds of only two of these substances, uranium and thorium, are radio-active. Radio-activity is a very remarkable phenomenon. So far as we know at present, radio-activity is not a property of the substances which form almost the whole of the rocks, the waters, and the atmosphere of the earth it is not a property of the materials which constitute living organisms. It is a property of some thirty substances—of course, the number may be increased—a few of which are found widely distributed in rocks and waters, but none of which is found anywhere except in extraordinarily minute quantity. Radium is the most abundant of these substances but only a very few grains of radium chloride can be obtained from a couple of tons of pitchblende. 

Friedrich O. Giesel (bom 1852) was for many years a chemist at the quinine works of Braunschweig Buchler and Company, and in the early days he worked up large quantities of radioactive minerals and generously distributed his radium among investigators in all parts of the world (56). 

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