Elevated Levels Of Radioactivity Research Articles

Determine the hazards of radioactive elements and radon gas manufacturing processes in an Egyptian fertilizer factory

This study investigated the levels of radioactivity in soil surrounding a phosphate fertilizer factory in Egypt, aiming to assess potential risks to the population exposed to radiation. Concentrations of 238U, 226Ra, 232Th, and 40K were measured in soil samples collected from two subsites: one near the factory (subsite 1) and another further away (subsite 2). Two different systems were used for measuring radioactivity, a high-purity gamma ray spectroscopy system with an HPGe detector for gamma-emitting isotopes and a CR-39 solid nuclear track detector for alpha-emitting radon gas. Subsite 1, located close to the factory, displayed significantly elevated levels of 226Ra compared to global background levels (514 and 456 Bq/kg vs. 35 Bq/kg). Additionally, the concentrations of 238U (241.06 Bq/kg vs. global average 35 Bq/kg), 232Th (16.15 Bq/kg vs. global average 30 Bq/kg), and 40K (146.36 Bq/kg vs. global average 400 Bq/kg) were all above global averages. Furthermore, a high concentration of radon gas (337.06 μSv/y) was measured at subsite 1. The strong positive correlation observed between 226Ra and 238U (0.96256) provides further evidence of potentially elevated radioactivity levels near the factory. In contrast, subsite 2, situated farther from the factory, exhibited natural radioactive background levels within international limits. Quantitative analysis revealed that gamma ray absorbed doses for 226Ra and 232Th exceeded global averages in some samples. Specifically, 226Ra doses ranged from 7.8 to 46.26 ppm (exceeding the 20 ppm global average in some cases), and 232Th doses ranged from 1.98 to 9.14 ppm (exceeding the 10 ppm global average in some cases). The concentration of 40K, however, remained within the global range (0.07%–0.69 %). The observed imbalances in the ratios of Th/U (0.17–0.24 Bq/kg and 0.73–0.24 ppm) and U/Ra (0.81–0.73 Bq/kg and 0.73–0.17 ppm), both of which are significantly lower than their respective global averages of 4 and 2.4, point towards the presence of fertilizer-derived contamination. This conclusion is further supported by the high phosphate concentrations detected in the samples. Overall, this study suggests that radioactive contamination near the phosphate fertilizer factory significantly exceeds global background levels and international limits in some cases. This raises concerns about potential risks posed to surrounding agricultural land and crops.

Assessment of radionuclides from coal-fired brick kilns on the outskirts of Dhaka city and the consequent hazards on human health and the environment

In a first-of-its-kind study, terrestrial radionuclide concentrations were measured in 35 topsoil samples from the outskirts of Dhaka using HPGe gamma-ray spectrometry to assess the radiological consequences of such a vast number of brick kilns on the plant workers, general as well as dwelling environment. The range of activity concentrations of 226Ra, 232Th, and 40K is found at 19 ± 3.04 to 38 ± 4.94, 39 ± 5.85 to 57 ± 7.41, and (430 ± 51.60 to 570 ± 68.40) Bq/kg, respectively. 232Th and 40K concentrations were higher than the global averages. Bottom ash deposition in lowlands, fly ash buildup in soils, and the fallout of micro-particles are all probable causes of the elevated radioactivity levels. 137Cs was found in the sample, which indicates the migration of 137Cs from nuclear accidents or nuclear fallout, or the contamination of feed coal. Although the effective dose received by the general public was below the recommended dose limit but, most estimates of hazard parameters surpass their respective population weighted global averages, indicating that brick kiln workers and nearby residents are not safe due to prolonged exposures to terrestrial radiation. In addition, the soil around sampling sites is found to be unsuitable for agricultural purposes.

Targeting HER2-receptors with 177Lu-labeled triazole stapled cyclic peptidomimetic

In this study on-resin Cu(I)-catalyzed click reaction was performed to synthesize triazole-stapled cyclic peptidomimetic, DOTA-c[TZ]A9 targeting HER2 receptor expression in breast cancers. Spectroscopic (circular dichroism) and docking analysis provided evidence of enhanced helicity and secondary structure stabilization along with improved HER2 affinity in comparison to the corresponding linear peptide, DOTA-[Pra1, Aza7]A9. 177Lu-labeled cyclic peptide, 177Lu-DOTA-c[TZ]A9 displayed higher in vitro serum stability and in vivo metabolic stability and better HER2 binding affinity {Kd of 16.93 ± 3.02 nM} than the linear counterpart, [177Lu]DOTA-[Pra1, Aza7]A9 {Kd of 26.28 ± 2.87 nM}. Biodistribution profile in SKBR3 tumor bearing SCID mice demonstrated elevated radioactivity levels and prolonged retention of cyclic peptide in the tumor compared to the linear peptide. Thus, solid phase click cyclization technique can be extended towards preparation of triazole-stapled peptides targeting different receptors with improved stability and efficacy.

Investigations of environmental radioactivity in the northern state of Sudan

Investigations have been carried out for naturally occurring radionuclides in surface soils in selected regions of the Northern State of Sudan, in response to widely spread rumours of elevated levels of radioactivity causing higher than normal incidence of cancer in that area. Eighty surface soil samples were collected from different regions in the Northern State and their activity concentrations were measured by a high-purity germanium detector gamma spectrometer system. From the data obtained the mean values and standard deviations of the radionuclide activities were calculated. From the activity concentrations of 226Ra, 232Th and 40K radionuclides the external absorbed dose rate in air and the annual effective dose were calculated.The radium equivalent activity and the external hazard index were applied for estimating the radiation hazards of soil used as building material. The mean activity concentrations of 226Ra, 232Th and 40K in different regions of the Northern State were found to be 82.6 + 6.8, 26.0 + 2.9 and 726.4 + 72.0 Bq/kg, respectively.The average outdoor gamma absorbed dose rate in air at 1meter above ground was calculated as 84.6 + 7.1 nGy/h. The average annual effective dose equivalent for population in the regions under study was found to be 103.7 + 8.7 Sv/y. The external hazard index was found to be 0.48 + 0.04.

Feasibility of ZrSiO4 as reference signature in naturally-occurring radioactive elements for the application of radioactivity monitoring

Radioactivity monitoring post-cold war has become more complex due to the nuclear fallout and the surge in use of radioactive materials. This requires novel methods to detect, trace and distinguish natural and anthropogenic radioactive sources in the environment. We explored the feasibility of using ZrSiO4 (Zircon), as a reference signature for radioactivity monitoring due to the unique phenomenon of metamictization. We investigated the variations in microstructural properties of Zircon samples collected from a proposed Uranium site to identify these signatures using analytical techniques such as Gamma-ray Spectroscopy, XRD and Raman spectrum analysis. Besides elevated levels of radioactivity, the samples exhibited distinct properties such as increased lattice parameters observed from the XRD analysis and dramatic broadening of A1g (439 cm−1) and B1g (1008 cm−1) vibrational modes in the Raman spectrum. Structural parameters were further analyzed by modeling the crystal from experimentally observed lattice parameters. Ab-initio calculations were then performed on the modeled structure providing more insight into the microstructural variations. Samples collected from proposed Uranium mines indicate an increase of 1.226% and 0.9389% in Si–O and Zr–O bond lengths of the Zircon crystal signifying the ongoing process of metamictization from radiation damage. By correlating radioactivity levels with the lattice parameters variations of the collected samples, the study establishes a linear relation between the degree of damage to a mineral's crystal structure and the amount of radioactivity. We propose to use the variations in damage found in a mineral's structure as a nuclear forensic signature for advanced assessment of accumulated radioactivity in a particular geographical location.

Controlled Conversion of Sodium Metal From Nuclear Systems to Sodium Chloride

A series of three bench-scale experiments was performed to investigate the conversion of sodium metal to sodium chloride via reactions with non-metal and metal chlorides. Specifically, batches of molten sodium metal were separately contacted with ammonium chloride and ferrous chloride to form sodium chloride in both cases along with iron in the latter case. Additional ferrous chloride was added to two of the three batches to form low melting point consolidated mixtures of sodium chloride and ferrous chloride, whereas consolidation of a sodium-chloride product was performed in a separate batch. Samples of the products were characterized via X-ray diffraction to identify attendant compounds. The reaction of sodium metal with metered ammonium chloride particulate feeds proceeded without reaction excursions and produced pure colorless sodium chloride. The reaction of sodium metal with ferrous chloride yielded occasional reaction excursions as evidenced by temperature spikes and fuming ferrous chloride, producing a dark salt-metal mixture. This investigation into a method for controlled conversion of sodium metal to sodium chloride is particularly applicable to sodium containing elevated levels of radioactivity—including bond sodium from nuclear fuels—in remote-handled inert-atmosphere environments.

Enhancing Radiation Detection by Drones through Numerical Fluid Dynamics Simulations.

This study addresses the optimization of the location of a radioactive-particle sensor on a drone. Based on the analysis of the physical process and of the boundary conditions introduced in the model, computational fluid dynamics simulations were performed to analyze how the turbulence caused by drone propellers may influence the response of the sensors. Our initial focus was the detection of a small amount of radioactivity, such as that associated with a release of medical waste. Drones equipped with selective low-cost sensors could be quickly sent to dangerous areas that first responders might not have access to and be able to assess the level of danger in a few seconds, providing details about the source terms to Radiological-Nuclear (RN) advisors and decision-makers. Our ultimate application is the simulation of complex scenarios where fluid-dynamic instabilities are combined with elevated levels of radioactivity, as was the case during the Chernobyl and Fukushima nuclear power plant accidents. In similar circumstances, accurate mapping of the radioactive plume would provide invaluable input-data for the mathematical models that can predict the dispersion of radioactivity in time and space. This information could be used as input for predictive models and decision support systems (DSS) to get a full situational awareness. In particular, these models may be used either to guide the safe intervention of first responders or the later need to evacuate affected regions.

Distribution of naturally occurring radionuclides in soil around a coal-based power plant and their potential radiological risk assessment

Abstract Coal-fly-ash is one of the major byproducts of coal-based power plant in which naturally occurring radioactive materials (NORMs) are drastically enriched compared to those of feed coals. Thus, improper management of fly-ash may introduce additional radioactivity to the surrounding environment and cause radiological risk. So, in order to study the distribution of radionuclides in soil around a coal-based power plant and to evaluate their radiological risk, soil, coal and fly-ash samples were analyzed by using a HPGe detector for U-238, Ra-226, Th-232 and K-40 radioactivity concentrations. Furthermore, soil minerals were also studied by X-ray diffractometer to assess the mineralogical provenance of the radionuclides. Mean radioactivity concentrations (in Bq·kg−1) of U-238, Ra-226, Th-232 and K-40 in soil samples are 102.9±41.4, 63.6±7.4, 103.4±13.9 and 494.2±107.5, respectively which are comparatively higher than the typical world mean value. Elevated levels of radioactivity are likely due to the presence of illite, kaolinite, monazite, rutile and zircon minerals in the soil samples rather than technogenic contributions from the power plant. Furthermore, mean soil contamination factor (CF) are close to unity and mean pollution load index (PLI) is below unity while the average radium equivalent activity (Raeq in Bq·kg−1), external hazard index (Hex), absorbed γ dose rate (D in nGyh−1), annual effective dose rate (E in mSv·y−1) and excess lifetime cancer risk (ELCR in Sv−1) are 249.5±21.7, 0.67±0.06, 114.2±9.4, 0.20±0.02, 4.9×10−4±0.4×10−4, respectively, which are within the permissible limit. Thus, in terms of radioactivity concentrations and associated environmental and radiological indices, the effect of the power plant is insignificant.

Hazardous radioactivity levels and heavy mineral concentrations in beach sediments of Lake Peipsi, northeastern Estonia

Abstract The present study discusses results of heavy mineral analyses and radioactivity of beach sediments of Lake Peipsi. Such analyses are commonly done globally, but had not yet been conducted for the fourth largest lake in Europe. The average heavy mineral content in Lake Peipsi beach sediments along the northern and western coast is higher than usual for Estonian coastal and Quaternary sediments. Concomitantly, elevated radioactivity levels have been measured in several places, with the highest concentrations observed at Alajõe (1885.5 Bq/kg), which is over five times more than the recommended limit. The aim of the present study is to find sites with higher radioactivity levels, because the northern coast of Lake Peipsi is a well-known recreational area.

Intravenous and intratumoral injection of Pluronic P94: The effect of administration route on biodistribution and tumor retention

Pluronics P94 are block-copolymer showing prolonged circulation time and tumor-cell internalization in vitro, suggesting a potential for tumor accumulation and as a drug carrier. Here we report the results of the radiolabeled-P94 unimers (P94-111In-DTPA) on tumor uptake/retention and biodistribution after intravenous and intratumoral injection to tumor-bearing mice. Intravenous administration results in a high radioactive signal in the liver; while in tumor and other healthy tissues only low levels of radioactivity could be measured. In contrast, the intratumoral injection of P94 resulted in elevated levels of radioactivity in the tumor and low levels in other organs, including the liver. Independently from the injection route, the tumor tissue presented long retention of radioactivity. The minimal involvement of off-target tissues of P94, together with the excellent tracer retention over-time in the tumor designates Pluronic P94 copolymer as a highly promising carrier for anti-tumor drugs.

Natural radioactivity around former uranium mine, Gabrovnica in Eastern Serbia

Gabrovnica near Kalna village was the first uranium mine established in Yugoslavia. In 1963, the Nuclear Energy Commission began operating the mine and mill. Between 1964 and 1966, the staff at Kalna extracted and produced an estimated 900 kg of UO2 and 400 kg of uranium metal. The Kalna ore was of poor quality, containing very low uranium content, which required higher-cost mining and refining methods. That was the main reason for closing this mine. This paper presents results obtained by measuring the activity concentration of soil samples measured by gamma spectrometry and also indoor 222Rn activity concentrations in houses in the nearby village Kalna. There is a presence of elevated radioactivity levels in the most of the measured samples. The mine was never officially decommissioned. The results obtained might be useful for the future decommissioning procedure.

Anomalous radioactivity level and high concentrations of heavy minerals in Lemme area, South-West Estonia

Abstract As early as in the 1960s, extensive heavy-mineral concentrations containing zircon, monazite, and xenotime were discovered in the Lemme region of south-western Estonia. These concentrations contribute to the elevated radioactivity levels of the enclosing sediments. The near shore sands of the Litorina Sea contain up to 10-cm-thick interlayers with a heavy mineral content of up to 80%. These anomalous layers were formed during the transgressive phase and result from a complicated cross- and alongshore migration of sedimentary material, derived mainly from local Devonian bedrock. Radioactivity level in the study area is higher relative to the majority of the Devonian plateau. The Lemmeoja buried soil has 13 radiocarbon dates in an area of renewed interest for the investigation of the Baltic Sea history.

Environmental impact assessment of radionuclide and metal contamination at the former U site at Kadji Sai, Kyrgyzstan

During 1949–1967, a U mine, a coal-fired thermal power plant and a processing plant for the extraction of U from the produced ash were operated at the Kadji Sai U mining site in Tonsk district, Issyk-Kul County, Kyrgyzstan. The Kadji Sai U legacy site represents a source of contamination of the local environment by naturally occurring radionuclides and associated trace elements. To assess the environmental impact of radionuclides and trace metals at the site, field expeditions were performed in 2007 and 2008 by the Joint collaboration between Norway, Kazakhstan, Kyrgyzstan, Tajikistan (JNKKT) project and the NATO SfP RESCA project. In addition to in situ gamma and Rn dose rate measurements, sampling included at site fractionation of water and sampling of water, fish, sediment, soils and vegetation. The concentrations of radionuclides and trace metals in water from Issyk-Kul Lake were in general low, but surprisingly high for As. Uptake of U and As was also observed in fish from the lake with maximum bioconcentration factors for liver of 1.6 and 75, respectively. The concentrations of U in water within the Kadji Sai area varied from 0.01 to 0.05 mg/L, except for downstream from the mining area where U reached a factor of 10 higher, 0.2 mg/L. Uranium concentrations in the drinking water of Kadji Sai village were about the level recommended by the WHO for drinking water. The 234U/238U activity ratio reflected equilibrium conditions in the mining pond, but far from equilibrium outside this area (reaching 2.3 for an artesian well). Uranium, As and Ni were mainly present as low molecular mass (LMM, less than 10 kDa) species in all samples, indicating that these elemental species are mobile and potentially bioavailable.The soils from the mining sites were enriched in U, As and trace metals. Hot spots with elevated radioactivity levels were easily detected in Kadji Sai and radioactive particles were observed. The presence of particles carrying significant amount of radioactivity and toxic trace elements may represent a hazard during strong wind events (wind erosion). Based on sequential extractions, most of the elements were strongly associated with mineral matter, except for U and As having a relatively high remobilization potential. Low Kd was obtained for U (3.5 × 102 L/kg d.w.), intermediate Kds (∼3 × 103 L/kg d.w.) were obtained for 226Ra, As and Ni, while a high Kd (2.2 × 105 L/kg d.w.) were obtained for Pb. The accumulation of metals in fish gills reflected the LMM species in the Issyk-Kul water, and did not show any bioaccumulation. The muscle Hg concentrations in all fish species were low and did not represent any health risk even for groups at risk.Total gamma and Rn dose rate to man amounted to about 12 mSv/y, while the highest calculated dose rate for non-human species based on the ERICA Assessment Tool were obtained in terrestrial plants (164 μGy/h) due to the Ra exposure. The results obtained showed that radiation doses to resident public at all of the investigated sites in the Kadji Sai area were in general relatively low. Low radiological risk and no detrimental health impact on resident public can be expected at these sites. However, exposure to Rn and Tn in the living environment can be further reduced by implementing simple countermeasures such as ventilation of dwelling cellars. More focus in the Kadji Sai area should probably be put on trace elements, especially the As uptake in fish in Lake Issyk-Kul.

Radioactivity in the environment around past radium and uranium mining sites of Portugal

Measurements of ambient radiation doses and determination of radionuclide concentrations in mining waste and soils were performed in 60 areas of former radium and uranium mining. In several places, mining waste and low-grade uranium ore left on the surface contain radioactivity above regional background. Most of the former mining sites present no enhanced radionuclide concentrations. However, in the mining facilities where the radioactive ore was chemically extracted, mill tailings contain materials with elevated levels of radioactivity, up to 200 times the levels in unaffected soils of the region. Mud from neutralization ponds used to treat acid mine waters contains also elevated radionuclide concentrations. Furthermore, depending on the type of waste, the radioelement composition varies. Environmental rehabilitation measures shall take these differences into account in order to prevent in the long term the radioactive contamination of agriculture soils and water resources, and to ensure adequate radiological protection to the public and to the environment.

Occurrence of natural radionuclides and fallout cesium-137 in dry-season agricultural land of South Western Nigeria

The radioactivity of the Opa river — irrigated farmlands in the south western Nigeria was determined using an HpGe based, low-level passive gamma-counting system. With the exception of two isotopes, the main radionuclides analysed in the sample were the progenies of238U and232Th. The other two isotopes were the naturally occurring40K and the anthropogenic137Cs. The result obtained showed elevated levels of radioactivity from all detected radionuclides compared to the published data for this area. Enhanced levels of naturally occurring radionuclides is attributed to the use of phosphatic fertilizers for dry season vegetable cultivation along this river banks. The presence of the fission product137Cs could be traced to the fallouts occasioned by the various French nuclear tests in the Sahara desert, and probably, some effect of the more recent nuclear reactor accident at Chernobyl in 1986.

A recent drilling program to investigate radionuclide migration at the Nevada Test Site

Recent drilling affords new opportunities to investigate the occurrence, distribution, and transport of radionuclides above and below the water table at the Nevada Test Site (NTS), Nye County, Nevada. This program is unique because of elevated levels of radioactivity encountered during drilling (>3.7E+6Bq/l3H), extreme completion depths (>950 m), and the expense of constructing new wells (>$1E+6/borehole). Sites of five nuclear tests have been drilled. Three of the events were fired in Yucca Flat which is a hydrologically closed basin and two were fired in fractured volcanics of Pahute Mesa. Results from Yucca Flat indicate that volatile and refractory radionuclides fractionated at zero time, are not highly mobile under saturated conditions. In contrast, boreholes completed on Pahute Mesa intercept high concentrations of tritium (>3.7E+6Bq/l3H) and other radionuclides transported more than 300 m from event cavities as dissolved species or as colloids.

Radiation exposure modeling for apartment living spaces with multiple radioactive sources.

Since late 1992, over 100 building complexes in Taiwan, including both public and private schools, and 1,000 apartments have been identified as emitting elevated levels of gamma-radiation. These high levels of gamma-radiation have been traced to construction steel contaminated with 60Co. Accurate reconstruction of the radiation exposure dosage among residents is complicated by the discovery of multiple radioactive sources within the living spaces and by the lack of comprehensive information about resident life-style and occupancy patterns within these contaminated spaces. The objective of this study was to evaluate the sensitivity of current dose reconstruction approach employed in an epidemiological study for the health effects of these occupants. We apply a statistical method of local smoothing in dose rate estimation and examine factors that are closely associated with radiation exposure from multiple radioactive sources in the apartment. Two examples are used, a simulated measurement in a hypothetical room with three radioactive sources and a real apartment in Ming-Shan Villa, one of the contaminated buildings. The simulated and estimated means are compared along 5-10 selected points of measurement: by local smoothing approach, with the furniture-adjusted space, and with the occupancy time-weighted mean. We found that the local smoothing approach came much closer to theoretical values. The local smoothing approach may serve as a refined method of radiation dose distribution modeling in exposure estimation. Before environmental exposure assessment, "highly occupied zones" (HOZs) in the contaminated spaces must be identified. Estimates of the time spent in these HOZs are essential to obtain accurate dosage values. These results will facilitate a more accurate dose reconstruction in the assessment of residential exposure in apartments with elevated levels of radioactivity.

Radon, radium, and other radioactivity in ground water: hydrogeologic impact and application to indoor airborne contamination: proceedings of the NWWA Conference, April 7-9, 1987, Somerset, New Jersey

KEYNOTE. Development of Regulations for Radionuclides in Drinking Water. GEOLOGIC AND HYDROGEOLOGIC CONTROLS INFLUENCING RADON OCCURRENCE. Geologic Controls and Radon Occurrence in New England. The Effect of Uranium Siting in Two-Mica Granites on Uranium Concentrations and Radon Activity in Ground Water. Source and Distribution of Natural Radioactivity in Ground Water of the Newark Basin, New Jersey. MONITORING RADON, RADIUM AND OTHER RADIOACTIVITY FROM GEOLOGIC AND HYDROGEOLOGIC SOURCES. Elevated Levels of Radioactivity in Water Wells in Los Angeles and Orange Counties, California. A Preliminary Assessment of Factors Affecting Radon Levels in Idaho. Natural Radioactivity in Some Ground Waters of the Canadian Shield. Determination of Bulk Radon Emanation Rates by High Resolution Gamma-Ray Spectroscopy. Radon in Ground Water of the Long Valley Caldera, California. MINING IMPACTS ON THE OCCURRENCE OF RADON, RADIUM AND OTHER RADIOACTIVITY IN GROUND WATER. Radioactivity in Hocking River Basin. Factors Controlling Uranium and Radium Isotopic Distributions in Ground Waters of the West Central Florida Phosphate District. SAMPLING AND ANALYSIS OF RADON, RADIUM AND OTHER RADIOACTIVITY IN GROUND WATER. Sampling and Analysis of Dissolved Radon-222 in Surface and Ground Water. Radon-222 Concentrations of Ground Water from a Test Zone in a Shallow Alluvial Aquifer in the Santa Clara Valley, California. An Improved Method for the Simultaneous Determination of Radium-224, Radium-226, and Radium-228 in Water, Soils, and Sediments. Nationwide Distribution of Radium-228, Radium-226, Radon-222, and Uranium in Ground Water. Radon Measurement in Streams to Determine Location and Magnitude of Ground Water Seepage. Polonium in the Surficial Aquifer of West Central Florida. A Technique for the Rapid Extraction of Radon-222 from Water Samples and a Case Study. Relation Between Natural Radionuclide Activities and Chemical Constituents in Ground Water of the Newark Basin, New Jersey. RADON AND RADIUM IN WATER SUPPLY WELLS. Radon Survey of the American Water Works System. A Connecticut Radon Study-Using Limited Water Sampling and a Statewide Ground Gamma Radiation Survey to Help Guide an Indoor Air Testing Program: A Progress Report. Extreme Levels of Radon-222 and Uranium in a Private Water Supply. Radium-226 and Radon-222 in Domestic Water of Houston-Harris County, Texas. Radium, Radon, and Uranium Isotopes in Ground Water from Cambrian-Ordovician Sandstone Aquifers in Illinois. Radon Production in Pumping Wells. Radium-228 and Radon-226 in the Ground Water of the Chickies Formation, Southeastern Pennsylvania. Hydrogeologic Controls on the Occurrence of Radionuclides in Ground Water of Southern Ontario. PREDICTIVE MODELS FOR THE OCCURRENCE OF RADON AND OTHER RADIOACTIVITY. A Predictive Model for Indoor Radon Occurrences-A First Approximation. REMEDIAL ACTIONS FOR RADON, RADIUM AND OTHER RADIOACTIVITY. A Method of Radon Reduction for New Buildings. Treatment Scheme for Controlling the Migration of Radium from a Tailings Impoundment. Assessing the Potential Water Quality Hazards Caused by Disposal of Radium-Containing Waste Solids by Soil Blending. Radon in Water Supply Wells: Treatment Facility Requirements and Costs. Occurrence and Treatment of Uranium in Point of Use Systems in Colorado.

β-Diethylaminoethyl-diphenylpropylacetate (SKF 525-A) enhancement of tissue accumulation of aldrin in mice

Pretreatment of male Swiss-Webster mice given acutely toxic doses of [ 14C]aldrin (150 mg/kg ip) with SKF 525-A (50 mg/kg ip) resulted in significant increases in the accumulation of radioactivity in blood, brain, kidney, and liver. Elevated levels of radioactivity were seen whether aldrin was injected in dimethylsulfoxide or methoxytriglycol. This effect was not seen at 5 mg/kg SKF 525-A but was dose-related in blood, kidney, and liver at 50 and 100 mg/kg. Whole body measurements of the extent of aldrin biotransformation in mice pretreated with 50 mg/kg SKF 525-A indicate that the effect is probably not related to differences in metabolite formation or excretion. Both the alteration of tissue accumulation and metabolism may be dependent on the route of administration, dose, and pretreatment interval of SKF 525-A, as well as the route of administration and dose of the compound being tested.

Oral I 131 triolein tolerance curves in elderly subjects with coronary artery disease

1. 1. Oral I 131 triolein tolerance curves were performed on ten subjects with coronary artery disease, sixty years of age or older, and on sixteen subjects who were less than sixty years old. 2. 2. Elevated levels of radioactivity were found in the whole blood and circulating lipoprotein fraction of the younger group. 3. 3. Values similar to those in normal control subjects were found in the older subjects. 4. 4. The results were attributed to a difference in lipid absorption between the older and younger groups.