Amount Of Radium Research Articles

ИССЛЕДОВАНИЕ ВЗАИМОДЕЙСТВИЯ СОЛЕЙ РАДИЯ С КОНСТРУКЦИОННЫМИ МАТЕРИАЛАМИ

Through calcination of barium salts (as a simulant of radium) on metal substrates interaction of barium nitrate and barium carbonate with some structural materials was examined: steel grade St3, stainless steel 12X18H10T, tantalum, nickel, zirconium and silver. The experiments were performed again for nickel and stainless steel using milligramme quantities of radium.

Assessing the Committed Effective Dose From 226Ra in Thermal Spring Water From San Diego De Alcala, Chihuahua, Mexico.

The oral administration of mineral-rich spring water is known as hydropinic treatment and is used to treat certain ailments. Health benefits are attributed to thermal spring water containing radioactive elements such as radium; this has popularized use of such radioactive water in various parts of the world, causing those who ingest it to increase their internal radiation dose. The goal of this study was to assess the activity concentrations of Ra present in the thermal spring waters of San Diego de Alcala, in the state of Chihuahua, Mexico, and to estimate the health risk posed to patients by the effective dose received from ingesting this water during hydropinic treatments. Water samples were taken from different areas of the San Diego de Alcala thermal springs, and pH, temperature, electrical conductivity, and total dissolved solids were measured. The Ra activity concentrations were measured with a liquid scintillation counter. The activity concentrations of Ra in sampled water varied from 125 to 452 mBq L with an average of 276 ± 40 mBq L. The committed effective dose from each of the Ra activity concentrations found in samples ranged from 9.80 × 10 to 4.0 × 10 mSv for hydropinic treatments being carried out in San Diego de Alcala thermal spring spas. Different treatments had different intake rates (200, 600, 1,000, and 1,500 mL d) and occurred over periods of 2 or 3 wk. According to the guidelines of the US Environmental Protection Agency, the maximum permissible amount of radium in drinking water is 185 mBq L; the Ra content in most of the collected samples exceeded this limit. The committed effective doses varied with Ra concentration and intake rate; none exceeded the World Health Organization's reference dose for drinking water of 0.1 mSv y, which is the maximum amount to which the population should be exposed.

Determining the radon exhalation rate from a gold mine tailings dump by measuring the gamma radiation

The mining activities taking place in Gauteng province, South Africa have caused millions of tons of rocks to be taken from underground to be milled and processed to extract gold. The uranium bearing tailings are placed in an estimated 250 dumps covering a total area of about 7000 ha. These tailings dumps contain considerable amounts of radium and have therefore been identified as large sources of radon. The size of these dumps make traditional radon exhalation measurements time consuming and it is difficult to get representative measurements for the whole dump.In this work radon exhalation measurements from the non-operational Kloof mine dump have been performed by measuring the gamma radiation from the dump fairly accurately over an area of more than 1 km2. Radon exhalation from the mine dump have been inferred from this by laboratory-based and in-situ gamma measurements. Thirty four soil samples were collected at depths of 30 cm and 50 cm. The weighted average activity concentrations in the soil samples were 308 ± 7 Bq kg−1, 255 ± 5 Bq kg−1 and 18 ± 1 Bq kg−1 for 238U, 40K and 232Th, respectively. The MEDUSA (Multi-Element Detector for Underwater Sediment Activity) γ-ray detection system was used for field measurements.The radium concentrations were then used with soil parameters to obtain the radon flux using different approaches such as the IAEA (International Atomic Energy Agency) formula. Another technique the MEDUSA Laboratory Technique (MELT) was developed to map radon exhalation based on (1) recognising that radon exhalation does not affect 40K and 232Th activity concentrations and (2) that the ratio of the activity concentration of the field (MEDUSA) to the laboratory (HPGe) for 238U and 40K or 238U and 232Th will give a measure of the radon exhalation at a particular location in the dump. The average, normalised radon flux was found to be 0.12 ± 0.02 Bq m−2 s−1 for the mine dump.

A simple method for calibration of Lucas scintillation cell counting system for measurement of 226Ra and 222Rn

Known quantity of radium from high grade ore solution was chemically separated and carefully kept inside the cavity of a Lucas Cell (LC). The 222Rn gradually builds up and attain secular equilibrium with its parent 226Ra. This gives a steady count after a suitable buildup period (>25 days). This secondary source was used to calibrate the radon counting system. The method is validated in by comparison with identical measurement with AlphaGuard Aquakit. The radon counting system was used to evaluate dissolved radon in ground water sample by gross alpha counting in LC. Radon counting system measures the collected radon after a delay of >180 min by gross alpha counting. Simultaneous measurement also carried out by AlphaGuard Aquakit in identical condition. AlphaGuard measures dissolved radon from water sample by constant aeration in a closed circuit without giving any delay. Both the methods are matching with a correlation coefficient of >0.9. This validates the calibration of Lucas scintillation cell counting system by designed encapsulated source. This study provides an alternative for calibration in absence of costly Radon source available in the market.

Behaviour of the Alkaline Earth Elements (Beryllium to Radium) During the Precipitation of Jarosite-Type Compounds

The behaviour of the alkaline earth elements (beryllium, magnesium, calcium, strontium, barium and radium) during the precipitation of jarosite-type compounds was investigated over the range of conditions likely to be encountered in hydrometallurgical processes. Negligible amounts (< 0.05 wt%) of beryllium were incorporated in the structure of either potassium jarosite or sodium jarosite; this was a consequence of the small size of the divalent beryllium ion. In contrast, limited magnesium incorporation seemed to occur in the jarosite structure. Up to 0.20 wt% Mg was incorporated in sodium jarosite and up to 0.38 wt% Mg was detected in potassium jarosite; in both species, the amount increased as the magnesium concentration of the synthesis solution increased. Increasing temperatures, ferric ion concentrations and solution pH had only a minor effect on the extent of magnesium incorporation in the jarosite precipitates. In contrast, increasing concentrations of CuSO4 or ZnSO4 significantly reduced the level of Mg incorporation. Regardless of the calcium concentration of the solution, the calcium contents of the well-washed hydronium jarosite, sodium jarosite, potassium jarosite and lead jarosite precipitates were consistently less than 0.05 wt%Ca. The addition of soluble salts of strontiumand bariumto sulphate processing solutions resulted in the extensive precipitation of SrSO4 and BaSO4. However, electron microprobe analyses detected trace amounts of these elements in the potassium jarosite precipitates, suggesting a modest degree of Sr and Ba solid solubility. Picogram quantities of radium are soluble in sulphate media and 60-90% of the dissolved Ra precipitated with the jarosite-type compounds. However, it is not clear whether the radium was incorporated in the structure of the jarosite or whether it was adsorbed on the jarosite particles.

Distribution of natural radionuclides throughout intermediate products from chlorination of loparite concentrate

Distribution of radionuclides throughout intermediate products and wastes from high-temperature chlorination of loparite concentrate is studied by γ-ray spectrometry. The major fraction (about 80%) of natural radionuclides remains in the REE chloride melt, the residual activity being distributed between the salt trickling filter (STF) melt and crude niobium and tantalum chlorides. Thorium and uranium chlorides sublime and are concentrated in spent STF melt, whereas the radium chlorides remain essentially in the REE melt. However, a remarkable amount of radium (228Ra and 226Ra) is found in spent STF melt, which should be taken into account in developing and introducing an advanced process for treatment and deactivation of the salt solutions formed in hydrowashing of STF melt.

NATURAL RADIONUCLIDE DISTRIBUTION AND RADON EXHALATION RATE FROM THE SOIL IN VILNIUS CITY

In the territory of Vilnius city radioisotopic composition of different soils was experimentally determined and radon exhalation rate from the soil was evaluated using these data. Specific activitys of natural radionuclides 226Ra, 232Th and 40K were measured. From identified natural radionuclides the biggest quantities were for 40K (263 Bq/kg), the smallest values ‐ for 232Th (5 Bq/kg), average 226Ra values reached 13 Bq/kg. Radon exhalation rate from the soil in Vilnius city was calculated and evaluated. Distribution of radon exhalation rate values in the whole territory of the city is stated. The received values vary from 15 Bq/m2·h (in clay loam) to 23 Bq/m2·h (in sand). It is assessed that of the most important parameters, which determine radon exhalation rate from the soil, are the quantity of radium and the porosity of the soil. It is observed that radon exhalation rate from the soil is bigger than that from building materials. This difference is determined by a bigger porosity of the soil.

Contribution of the industrial chemical processing of pitchblende in Jáchymov to the first isolation of radium

The uranium ore chemical processing plant in Jachymov (St. Joachimstal) started the industrial production of uranium yellow (sodium diuranate) in 1853. This technology was developed by a talented metallurgical chemist Adolf Patera. The insoluble residue from uranium leaching was enriched by radium226Ra. During more than forty years before discovery of radioactivity, a worthless waste was accumulated in this uranium plant. This waste as radium preconcentrate was present in a suitable chemical form for the subsequent separation of radium. The occurence of this material significantly facilitated the separation and isolation of the first pure weighable amount of radium, necessary to prove the existence of a new chemical element, discovered in 1898 by M. and P. Curie and G. Bemont.

Evaluation of Internal Alpha-Particle Radiation Exposure and Subsequent Fertility among a Cohort of Women Formerly Employed in the Radium Dial Industry

This study examined the effect of internal exposure to alpha-particle radiation on subsequent fertility among women employed in the radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips. The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n = 603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of alpha particles emitted, fraction of energy absorbed within the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of gamma-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility.

Measurement of Activity in Anthropomorphic Organ Phantoms

This paper describes two nondestructive measurement techniques for determining the radioactivity in a homogeneous organ phantom with an acceptable error and the capability of being traceable to the National Institute of Standards and Technology. These two techniques are based on a method developed by Robley D. Evans in 1937 for measuring the amount of radium deposited in a living person. There are two significant improvements in the new techniques: 1) the radially-dependent error is eliminated, and 2) the effect of self absorption in the unknown body is measured and taken into account. The first assay method is a single-source technique involving four measurements and requiring only one standard source, the second one is a double-source technique involving six measurements and requiring two unequal standard sources. Three pairs of lung phantoms radiolabeled with 241Am, 137Cs, and 154Eu were measured with both the single- and double-source techniques. The results imply that the self-attenuation of photons within the organ phantom cannot be neglected, especially at low energies. Finally, potential applications (other than the calibration of bioassay phantoms of the single- and double-source techniques) and their limitations are discussed.

Radithor and the Era of Mild Radium Therapy

Soon after the discovery of radium, a school of practitioners arose who were interested primarily in the physiological rather than the tumoricidal powers of this new radioactive element. This treatment philosophy was called "mild radium therapy" and involved the oral or parenteral administration of microgram quantities of radium and its daughter isotopes, often as cures for rheumatic diseases, hypertension, and metabolic disorders. Manufacturers of patent medicines responded to this market by producing a variety of over-the-counter radioactive preparations including pills, elixirs, and salves. One such nostrum was Radithor, a popular and expensive mixture of radium 226 and radium 228 in distilled water. Radithor was advertised as an effective treatment for over 150 "endocrinologic" diseases, especially lassitude and sexual impotence. Over 400,000 bottles, each containing over 2 muCi (74 kBq) of radium, were apparently marketed and sold worldwide between 1925 and 1930. The death of the Pittsburgh millionaire sportsman Eben M. Byers, who was an avid Radithor user, by radium poisoning in 1932 brought an end to this era and prompted the development of regulatory controls for all radiopharmaceuticals.

Effects of calcium silicate slag application on radium‐226 concentrations in plant tissues

Abstract Calcium silicate slag is a by‐product of the electric furnace reduction process for producing phosphoric acid from phosphate rock (PR). Since slag contains trace amounts of radium (Ra), and uranium (U) as contaminants from the PR, a greenhouse pot experiment was conducted to determine if plants absorb Ra from slag applied to soil. Slag at rates equivalent to 0 and 22 mt/ha was mixed with Mountview silt loam (Typic Paleudults) limed to pH 5.8 and 7.2. Three clippings each of fescue (Festuca arundinacea Schreb.), and Swiss chard (Beta vulgaris L.), and one harvest of wheat (Triticum aestivum L.) for grain and straw were grown on separate series of treated soil, and plant samples were analyzed for radioactivity due to Ra uptake. Samples of sugarcane (Saccharum officinarum L.) forage and extracted juice from field experiments in Florida testing this slag as a Si source also were analyzed for radioactivity. Dry forage yields of fescue and wheat were not affected by slag applications, but those of Swis...

A new explanation of the presence of excessive amount of radon in mineral spring by the δRn term calculated from the amounts of radium and radon

A new explanation of the presence of excessive amount of radon in mineral spring by the δRn term calculated from the amounts of radium and radon

Comment: Radionuclide Carcinogenesis and Sinus Carcinoma

Radiation-induced tumors (ie, osteogenic sarcomas or leukemias) relate more to the ingestion or injection of radioactive materials than they do to exposure to external radiation sources. However, the most common cancers induced by radionuclides are cancers about the paranasal sinuses. Human experience with radionuclide carcinogenesis is popularly related to radium dial painters who unwittingly ingested significant amounts of radium while wetting their brushes with the luminescent radium paint. Now, patients receiving radium salts, intravenously, persons drinking various radioactive nostrums, and chemists inhaling compounds during work are also included in this category. With the advent of the atomic era, concern with late induction neoplasms after exposure to radioactive materials has understandably increased. A large number of experimental and practical investigations into the neoplastic effects of bone seeking radionuclides have been carefully recorded. 45 The dosimetry of radionuclides deposited in bones is a complex problem. Calculation of various concentrations of radium and

Radium in Aquatic Food Chains: Radium Uptake by Fresh Water Algae

Accumulation of226 Ra was studied in four species of green algae; Ankistrodesmus falcatus var. acicularis, Chlorella vulgaris, Coelastrum cambricum, Chlamydomonas simplex and two species of blue-green algae, Microcystis pulverea and Anacystis nidulans. Algae were cultivated in inorganic culture. Radium was added in amounts of 1 μCi/l., 0.1 μCi/l. and 0.01 μCi/l. After 14 days the amount of radium in the medium in dead and living algal cells, and in washes from the algae, was determined at intervals using a liquid scintillation counter. There were two characteristic types of response to radium. The first was shown by Ankistrodesmus falcatus var. acicularis and Coelastrum cambricum. From 50 to 80% of the radium was absorbed within the cells and the amount absorbed was proportional to the length of exposure. In the second type of response, typical of the other four species of algae, radium was mostly adsorbed on the cell surface (25-50%) and only 1-8% was present within the cells. The highest accumulative fa...

In-safe threading and sterilization of radium needles.

Radium needles must be threaded, sterilized, and, unless storage facilities are available in the operating room, they must be transported there for use. Exposure to personnel may be reduced if these operations are conducted without removing the needles from storage. A safe designed for this purpose will be described. It consists of three parts: (a) a lead box (with lid), inside which there fit (b) a central core of lead with holes to contain the needles, and (c) a lead brick wall attached to the side of the box behind which the operator stands. The lead box is water-tight, permitting flooding with sterilizing solution for cold sterilization of the needles. It may be drained through a valve near its bottom so the needles may be stored dry. Since the lid and walls are only 2 cm thick, this box alone cannot provide adequate protection from the amount of radium it was designed to contain (130 mg). Providing additional protection is one of the functions of the lead core that fits inside the box. This lead core...

An apparatus for loading and unloading ovoids.

The quantities of radium or radon in use for intrauterine work are usually fairly large and consequently poor techniques of loading the applicators result in relatively high radiation exposure to the hands and fingers of the operators involved. The ovoids in use in this Institute are cast from P.V.C. (Hunt, 1954), the surfaces being dimpled to provide better adhesion when in position. Colpostats using the ovoids have the ovoids cast on to stainless-steel springs so that the separate ovoids and the colpostat are both sterilisable and can be re-used. The sources used are a snug fit in the ovoids.

A radium applicator for treatment of the penis.

An applicator of the cylindrical mould type can be used to deliver a reasonably homogeneous γ-ray dose to the glans and major part of the shaft of the penis. In the applicator now described special attention has been given to overcoming two difficulties which are frequently encountered in using this technique. The first difficulty is the high dose which may be delivered to the suprapubic skin and scrotum when a satisfactory length is treated and the diameter of the radium cylinder is sufficiently large to give a reasonably homogeneous dose. Secondly, the applicator must be applied and removed many times, and since it may contain a relatively large amount of radium, there is an appreciable radiation hazard to staff. In this applicator, unwanted irradiation of skin is reduced by lead shielding. Staff dosage is minimised by mounting the radium on a detachable holder which can be rapidly attached after the shielding and locating devices have been carefully positioned. The dimensions were chosen to suit an ind...

LATE EFFECTS (TWENTY-FIVE TO FORTY YEARS) OF THE EARLY MEDICAL AND INDUSTRIAL USE OF RADIO-ACTIVE MATERIALS

LATE EFFECTS (TWENTY-FIVE TO FORTY YEARS) OF THE EARLY MEDICAL AND INDUSTRIAL USE OF RADIO-ACTIVE MATERIALS

A radium alarm system.

A Careful daily record is kept in this Department to indicate the number of radium containers in use on the wards and those held in the radium safe. This record is a valuable safeguard against the loss of radium, but in itself is not sufficient. There is always a possibility that radium may be accidentally removed from the ward in soiled linen in transit to the laundry or in the bins containing used dressings. It is our policy to monitor all the bags of soiled linen and dressing bins leaving the ward. Up to the present, this has been done manually by means of a pistol radiation monitor or a portable Geiger counter. The first of these instruments suffers from two faults from our point of view: (i) it is battery operated, and batteries need continual replacement, and (ii) it is rather sluggish, relying on an ionization chamber for its operation. As a result of this, it might fail to detect a small quantity of radium if handled by an inexperienced operator. The second instrument is very suitable for the purp...