Decay Product Of Uranium Research Articles

Helium - Relationships to other reservoir gases and some implications for exploration: The New Mexico Example

Helium (He) is the second most abundant element in the universe after hydrogen but is relatively rare on earth. He occurs as two stable isotopes, 3He and 4He. 4He is the dominant isotope in crustal gases and is a radiogenic decay product of uranium and thorium mainly in granitic basement rocks. 3He is dominantly primordial and primarily originates from the earth’s mantle. 3He may also be formed by radiogenic decay of 6Li (Lithium) which may be found in argillaceous sediments deposited in evaporitic settings. Although He occurs in most natural gases, it almost always occurs in extremely low, subeconomic concentrations, less than 0.1%. It is rare in concentrations more than 1%. A very few small reservoirs have gases with more than 7% He. Other gases that constitute the dominant components of helium-bearing natural gases are nitrogen (N2), carbon dioxide (CO2), and methane (CH4). The highest He concentrations occur where the dominant gas is N2 but most He has historically been produced as a byproduct of gases that are hydrocarbons. Hydrocarbons are generated from petroleum source rocks. Their presence in a reservoir is dependent upon the presence of a mature source rock in the basin and a migration path between the source rock and the reservoir. Large accumulations of CO2 in the southwestern U.S. resulted from the degassing of rising Tertiary magmas and subsequent migration of the gases into crustal reservoirs. N2 appears to originate mostly from degassing of the mantle but may also be formed in some strata by the thermal maturation of kerogens or by diagenetic alteration of clays or organic compounds in red bed sequences. The presence of economic concentrations of He in reservoir gases is dependent not only on an adequate source of 4He generated from granitic basement rocks but also on accommodating flux rates of N2, CO2, and CH4. These gases differ in their origins, places of generation and rates of generation, migration and emplacement. While basement-derived 4He and N2 enter reservoirs at slow rates over long periods of geologic time, hydrocarbons and CO2 enter the reservoir over much shorter time periods and dilute the 4He and N2. Basement-derived gases may be characterized by differing N2:He ratios which may indicate greater rates of He production within the crust in some areas. Exploratory drilling for He on Chupadera Mesa in the late 1990’s and early 2000’s encountered He-rich gases in Lower Permian strata. Isotopic analyses suggest that 93% of Chupadera Mesa He originated from radiogenic decay in crustal rocks while 7% is derived from the mantle or with a possible contribution by evaporitic Permian shales. Marked differences in the CO2 concentrations in different strata indicate that some strata acted as carrier beds for magmatically-derived CO2 while strata with N2-rich and CO2-poor gases were isolated from CO2 sources.

Influence of the natural radon radiation on the spread of the COVID 19 pandemic

The statistics of COVID-19 accumulated in Ukraine show areas with a significantly lower incidence of diseases. The purpose of the study was to identify factors that could influence the pattern of the pandemic in a particular area. Within the study it was assumed that the level of health care is approximately the same throughout the country. Population density was considered the main factor influencing the dynamics of the spread of infection. To reduce the impact of changes in population density across regions, it was normalized by the average population density in the country. The normalization of statistics for the country resulted in a model in the form of a linear relationship between the normalized values of the number of COVID-19 cases in the region and the size of the region. Subsequent analysis of the graphical data made it possible to identify four regions with the lowest incidence of COVID-19. The geographical proximity of these regions Dnipro, Kherson, Vinnytsia and Kirovograd, indicates the presence of a common factor for them, not typical for the rest of Ukraine. Such a factor may be the location of 83% of Ukraine's uranium deposits in the territories around Kirovohrad. Radon is one of the decay products of uranium, so the population of these areas may experience increased exposure to radon. This noble gas has more than a century of medical use, in particular for pulmonary diseases, although there is still no consensus about its effectiveness and side effects. Considering that COVID-19 was often complicated by pulmonary diseases, it can be assumed that the geological specificity of these four regions of Ukraine had an impact on the course of the COVID-19 pandemic in their territories. The study findings are important in terms of further COVID-19 research and prevention strategies.

Modeling and predicting mean indoor radon concentrations in Austria by generalized additive mixed models

Radon is a noble gas that occurs naturally as a decay product of uranium. Aside from smoking, radon is considered to be one of the major causes of lung cancer. Indoor environments, where radon can accumulate and potentially reach high concentrations, are of a particular concern. A mixed effects additive model along with a data-driven cross validation model selection method is applied to model the mean indoor radon concentration of dwellings in Austria. For this model a prediction approach is introduced, which enables the mapping of indoor radon potential to identify radon areas in Austria. The data used for modeling was collected in monitoring campaigns for private dwellings in Austria from 2013 to 2019. The proposed method allows policy makers to identify regions with high indoor radon concentrations and enables them to meet regulatory requirements or prioritize radon protection measures. The currently published Austrian radon map and the delineation of radon areas in Austria is based on this proposed method.

DEVELOPMENT OF EMERGENCY MONITORING SYSTEM FOR ALPHA-PARTICLE-EMITTING RADIONUCLIDES IN THE AIR.

During the early phase of a nuclear accident, major radioactive materials are released into the environment, necessitating the prompt deployment of various protective actions to avoid or reduce radiation exposure. To implement these actions, the levels of radioactivity in the environment should be determined. However, the radioactivity concentrations of artificial alpha-particle-emitting radionuclides such as plutonium are difficult to measure in airborne samples, because they are interfered with natural radionuclides such as uranium decay products. Therefore, chemical separation is required to measure the concentrations. This study presents a new emergency monitoring system for airborne samples, which performs multiple-pulse time-interval analysis (MTA) without chemical separation. The system is used in conjunction with an alpha/beta-particle survey meter and adopted an analysis method focusing on the detected time interval of each particle. Its features are that a short time to output measurement result, easy handling and nondestructive. The estimated detection limit of the system was 9.5×10-2Bqm-3. The MTA-based monitoring system could be useful in situations requiring prompt measurement and screening of samples.

Assessing the natural and anthropogenic radionuclide activities of the Pechora River estuary: Bottom sediments and water (Arctic Ocean Basin)

This paper studies the activity of natural and technogenic radionuclides in bottom sediments and surface water of the Pechora River estuary, which is the largest Arctic river within the European part of Russia. The relevance of conducting radioecological studies of this region is associated with active oil and gas activities in the Pechora basin and the presence of potential sources of radiation hazard. The average activities of 137Cs, 226Ra, 232Th, and 40K in bottom sediments were 0.16, 18.72, 13.36, and 373.59 Bq·kg-1, respectively. The average activity of 226Ra in the bottom sediments of the Pechora delta was two times higher than in other rivers of the Arctic basin of the European part of Russia, which is associated with oil and gas activities that are carried out in the Pechora basin. This is due to the fact that the decay products of uranium are the main by-products of oil and gas production. The specific activity of technogenic 137Cs in bottom sediments of the Pechora River delta was low and did not exceed 2.2 Bq·kg-1. We did not detect any radioactive 90Sr in bottom sediments. The low 137Cs activity in the bottom sediments of the Pechora delta was associated with both the larger granulometric composition of the sediments in comparison with the estuaries of the Siberian rivers, and with low concentrations of 137Cs in the terrigenous material (soil) entering the river from the catchment area. This was due to the low levels of 137Cs contamination in the soil of the Pechora river basin. We did not find any negative radiation effects of the underground nuclear explosion “Pyrite” carried out in the northern part of the delta, since there were no other technogenic radionuclides. The values of the radionuclides 3H, 137Cs, 226Ra, 232Th and 40K, as well as the total alpha activity in the surface waters of the Pechora River delta, turned out to be below the detection limit. In surface waters, we were able to determine only the total beta activity, which varied over a range from 19.6 to 59.6 Bq·m-3 with an average value of 33.9 Bq·m-3, which was significantly lower than the radiation safety standards. The values of the radiation hazard parameters were below the world average levels and were not significantly hazardous to the health of people living in the area of the Pechora River delta. We concluded that at present, in the Pechora River delta, there are pastures for reindeer with low levels of natural and man-made radioactivity. These conducted studies are the source material in a series of comprehensive studies of the current radioecological state of the tundra territories of the European part of Russia.

Assessing the Impact of Housing Features and Environmental Factors on Home Indoor Radon Concentration Levels on the Navajo Nation.

Uranium is naturally found in the environment as a radioactive metal element with high concentrations in the Southwestern US. In this region is the Navajo Nation, which spans approximately 69,930 square kilometers. A decay product of uranium is radon gas, a lung carcinogen that has no color, odor, or taste. Radon gas may pass from soil into homes; and, indoor accumulation has been associated with geographical location, seasonality, home construction materials, and home ventilation. A home and indoor radon survey was conducted from November 2014 through May 2015, with volunteers who reported residence on the Navajo Nation. Home geolocation, structural characteristics, temperature (°C) during radon testing, and elevation (meters) were recorded. Short-term indoor radon kits were used to measure indoor radon levels. 51 homes were measured for indoor radon levels, with an arithmetic mean concentration of 60.5 Becquerels per cubic meter (Bq/m3) (SD = 42.7). The mean indoor radon concentrations (Bq/m3) by house type were: mobile, 29.0 (SD = 22.9); wood, 58.6 (SD = 36.0); hogan, 74.0 (SD = 0.0); homes constructed of cement and wood, 82.6 (SD = 3.5); and homes constructed of concrete and cement, 105.7 (SD = 55.8). A key observation is that house construction type appears to be associated with the mean home indoor radon concentration. This observation has been published in that the basic structural make-up of the home may affect home ventilation and therefore indoor radon concentration levels.

Risk assessment of radon in some bottled water on the Ghanaian market

The demand for bottled drinking water on the Ghanaian market has increased despite being expensive. This can be attributed to the public perception that is of higher quality relative to other water sources. Radon (222Rn) is a noble gas formed from radium (226Ra) which is the decay product of Uranium (238U). Radon concentration and annual effective doses were measured in fifteen popular bottled water samples on the Ghanaian market at the Greater Accra, Region. Measurements were made using RAD -H20. The range and mean radon concentration of 222Rn in all sampled water were 0.03–0.09 Bql−1 and 0.06 ± 0.01 Bql−1 respectively. The annual effective dose due to ingestion in the various age groups had a range and mean of 6.79E-01-1.90E-01 μSvy−1 and 4.66E-01 ± 3.77E-02 μSvy−1 for adults, 3.80E-01-1.36 E-01 μSvy−1 and 9.33E-01 ± 7.55E-02 μSvy−1 for children and 1.33–4.75 μSvy−1 and 3.26 μSvy−1 ± 2.64E-01 for infants. The measured values of radon concentration as well as the annual effective dose were found within the United States Environmental Protection Agency (US-EPA), European Union (EU) and World Health Organization (WHO) recommended limits. It can be concluded that the radiation dose from radon in the bottled water analysed is low and pose no risk to the public.

Radiation in different types of building, human health

Radon is a radioactive gas permanently produced in rocks, soils, building materials as an indirect decay product of uranium and thorium. According to EPA, radon is the second most frequent cause of lung cancer, after cigarette smoking.The aim of survey was to measure radon levels and ambient gamma dose rates in dwellings in various types of buildings situated on various ground and to evaluate health parameters depended on indoor radiation such as lung cancer risk and total annual effective dose rate. Moreover, we wanted to verify the possibility to predict indoor radon concentration in specific dwelling knowing types of soil, building construction, building materials and floor number.The measurements of radon concentrations were carried out using SSNTDs Kodak LR-115 which were exchanged seasonally. The ambient gamma dose rates were measured using Geiger counter.Radon concentrations in all dwellings were lower than 300 Bq m−3 (recommended by EU action level). In some dwellings during some seasons radon concentrations were above 100 Bq m−3. Prolonged exposure to indoor radon at the levels of 100 Bq m−3 causes statistically significant increase of lung cancer. The average indoor radon concentration in Wroclaw's dwellings was 46 Bq m−3. The annual risk of lung cancer was lower than 0.0005%. The total annual effective dose rates ranged from 1.36 mSv y−1 to 3.3 mSv y−1. We observed seasonal, vertical, spatial variations of radon concentrations. We did not notice significant drop of ambient gamma dose rates between the ground floor and floors 2nd to 5th as we did for radon concentrations. We noticed that indoor radon concentrations differed 4 to 6 times even among dwellings located in these same types of buildings, on these same soil types or these same floors.

Analysing radon accumulation in the home by flexible M-quantile mixed effect regression

Radon is a noble gas that occurs in nature as a decay product of uranium. Radon is the principal contributor to natural background radiation and is considered to be one of the major leading causes of lung cancer. The main concern revolves around indoor environments where radon accumulates and reaches high concentrations. In this paper, a semiparametric random-effect M-quantile model is introduced to model radon concentration inside a building, and a way to estimate the model within the framework of robust maximum likelihood is presented. Using data collected in a monitoring survey carried out in the Lombardy Region (Italy) in 2003–2004, we investigate the impact of a number of factors, such as geological typologies of the soil and building characteristics, on indoor concentration. The proposed methodology permits the identification of building typologies prone to a high concentration of the pollutant. It is shown how these effects are largely not constant across the entire distribution of indoor radon concentration, making the suggested approach preferable to ordinary regression techniques since high concentrations are usually of concern. Furthermore, we demonstrate how our model provides a natural way of identifying those areas more prone to high concentration, displaying them by thematic maps. Understanding how buildings’ characteristics affect indoor concentration is fundamental both for preventing the gas from accumulating in new buildings and for mitigating those situations where the amount of radon detected inside a building is too high and has to be reduced.

Health Effects of Radon Exposure.

Radon is a naturally occurring radioactive material that is formed as the decay product of uranium and thorium, and is estimated to contribute to approximately half of the average annual natural background radiation. When inhaled, it damages the lungs during radioactive decay and affects the human body. Through many epidemiological studies regarding occupational exposure among miners and residential exposure among the general population, radon has been scientifically proven to cause lung cancer, and radon exposure is the second most common cause of lung cancer after cigarette smoking. However, it is unclear whether radon exposure causes diseases other than lung cancer. Media reports have often dealt with radon exposure in relation to health problems, although public attention has been limited to a one-off period. However, recently in Korea, social interest and concern about radon exposure and its health effects have increased greatly due to mass media reports of high concentrations of radon being released from various close-to-life products, such as mattresses and beauty masks. Accordingly, this review article is intended to provide comprehensive scientific information regarding the health effects of radon exposure.

Estimation of uranium concentration in Indian monazite samples by using HPGe semiconductor detector

Various techniques are available for the estimation of uranium concentration in geological rock samples. In the uranium exploration program in India, the beta–gamma technique is widely used by the Atomic Minerals Directorate for Exploration and Research (Department of Atomic Energy) to estimate uranium concentration in natural rock or soil samples. Uranium concentration cannot be estimated accurately by the beta–gamma technique if the sample has high concentrations of thorium. Because the ratio of thorium to uranium concentration varies between 15 and 30 in monazite samples, uranium concentration in monazite samples cannot be estimated accurately by the conventional beta–gamma technique. Uranium concentration in monazite samples can be estimated by measuring the 1.001 MeV gamma ray peak of Pa-234 (which is a decay product of uranium having a half-life of 1.17 min) using a P-type HPGe semiconductor detector. In this paper, uranium concentrations in 10 samples of Indian monazites were estimated using the P-type HPGe semiconductor detector, in which the average thorium concentration was 9.5%.

Construction of a naturally occurring radioactive material project in the BeAAT hazardous waste facilities.

This paper does not necessarily reflect the views of the International Commission on Radiological Protection. Naturally occurring radioactive material (NORM) is produced during exploration and production operations of subsidiaries of the Abu Dhabi National Oil Company (ADNOC) in the United Arab Emirates, and accumulates in drilling tubulars, plant equipment, and components. These NORM hazardous wastes need to be managed in such a way that they do not damage human health and the environment. The primary radionuclides of concern in the oil and gas industries are radium-226 and radium-228. These radioisotopes are the decay products of uranium and thorium isotopes that are present in subsurface formations from which hydrocarbons are produced. While uranium and thorium are largely immobile, radium is slightly more soluble and may become mobilised in the fluid phases of the formation (International Association of Oil & Gas Producers, 2008). In order to treat and dispose of NORM waste products safely, ADNOC's subsidiary 'TAKREER' is developing a new facility, on behalf of all ADNOC subsidiaries, within the existing Central Environmental Protection Facilities (BeAAT) in Ruwais city. The NORM plant is envisaged to treat, handle, and dispose of NORM waste in the forms of scale, sludge, and contaminated equipment. The NORM treatment facility will cover activities such as decontamination, volume reduction, NORM handling, and concrete immobilisation of NORM waste into packages for designated landfilling.

230Th and 231Pa on GEOTRACES GA03, the U.S. GEOTRACES North Atlantic transect, and implications for modern and paleoceanographic chemical fluxes

The long-lived uranium decay products 230Th and 231Pa are widely used as quantitative tracers of adsorption to sinking particles (scavenging) in the ocean by exploiting the principles of radioactive disequilibria. Because of their preservation in the Pleistocene sediment record and through largely untested assumptions about their chemical behavior in the water column, the two radionuclides have also been used as proxies for a variety of chemical fluxes in the past ocean. This includes the vertical flux of particulate matter to the seafloor, the lateral flux of insoluble elements to continental margins (boundary scavenging), and the southward flux of water out of the deep North Atlantic. In a section of unprecedented vertical and zonal resolution, the distributions of 230Th and 231Pa across the North Atlantic shed light on the marine cycling of these radionuclides and further inform their use as tracers of chemical flux. Enhanced scavenging intensities are observed in benthic layers of resuspended sediments on the eastern and western margins and in a hydrothermal plume emanating from the Mid-Atlantic Ridge. Boundary scavenging is clearly expressed in the water column along a transect between Mauritania and Cape Verde which is used to quantify a bias in sediment fluxes calculated using 230Th-normalization and to demonstrate enhanced 231Pa removal from the deep North Atlantic by this mechanism. The influence of deep ocean ventilation that leads to the southward export of 231Pa is apparent. The 231Pa/230Th ratio, however, predominantly reflects spatial variability in scavenging intensity, complicating its applicability as a proxy for the Atlantic meridional overturning circulation.

Selenium Content and Uptake in Crops as Affected by Soil Selenium Content and Implications on Human Health

The selenium contents of soil and its uptake by a wide variety of crops are analyzed along a transect, with the sampling stations located at Mawkyrwat, Upper Shillong, Pynthormukrah, and Nongpoh. Each site is successively farther away from uranium deposits, with the closest being Mawkyrwat (50 km). Leafy vegetables had greater selenium content than tubers and fruits. The concentrations of selenium in soil ranged from 70 μg g−1 to 296 μg g−1 and in vegetables varied from 26 μg g−1 to 225 μg g−1. Selenium is known to be a decay product of uranium, and the results indicate that the selenium content of soil and vegetables of Mawkrywat is greater than the other three sampling sites. This can be attributed to the proximity of this site to uranium deposits of Domiasat. The possible implications of selenium on human health are discussed.

Radionuclides in Fracking Wastewater: Managing a ToxicBlend

Naturally occurring radionuclides are widely distributed in the earth’s crust, so it’s no surprise that mineral and hydrocarbon extraction processes, conventional and unconventional alike, often produce some radioactive waste.1 Radioactive drilling waste is a form of TENORM (short for “technologically enhanced naturally occurring radioactive material”)—that is, naturally occurring radioactive material (NORM) that has been concentrated or otherwise made more available for human exposure through anthropogenic means.2 Both the rapidity and the extent of the U.S. natural gas drilling boom have brought heightened scrutiny to the issues of radioactive exposure and waste management. Perhaps nowhere is the question of drilling waste more salient than in Pennsylvania, where gas extraction from the Marcellus Shale using hydraulic fracturing (fracking) made the state the fastest-growing U.S. producer between 2011 and 2012.3 The Marcellus is known to have high uranium content, says U.S. Geological Survey research geologist Mark Engle. He says concentrations of radium-226—a decay product of uranium—can exceed 10,000 picocuries per liter (pCi/L) in the concentrated brine trapped in the shale’s depths. A lined impoundment receives waste at a fracking site in Dimock, Pennsylvania. To date the drilling industry and regulators have considered the risk posed to workers and the public by radioactive waste to be minor. In Pennsylvania, Lisa Kasianowitz, an information specialist with the state Department of Environmental Protection (PADEP), says there is currently nothing to “indicate the public or workers face any health risk from exposure to radiation from these materials.” But given the wide gaps in the data, this is cold comfort to many in the public health community.

Differences in lung cancer mortality trends from 1986-2011 by radon risk areas in British Columbia, Canada

Background: Radon gas is a decay product of uranium. Residential exposure is associated with increased lung cancer risk, especially in smokers. Most evidence about the health effects comes from int...

Identifying radon-prone building typologies by marginal modelling

Radon is a naturally occurring decay product of uranium known to be the main contributor to natural background radiation exposure. It has been established that the health risk related to radon exposure is lung cancer. In fact, radon is considered to be a major leading cause of lung cancer, second only to smoking. In this paper, we identified building typologies that affect the probability of detecting indoor radon concentration above reference values, using the data collected within two monitoring campaigns recently conducted in Northern Italy. This information is fundamental both in prevention, i.e. when the construction of a new building is planned and in mitigation, i.e. when a high concentration detected inside buildings has to be reduced. A spatial regression approach for binary data was adopted for this goal where some relevant covariates on the soil were retrieved by linking external spatial databases.

Assessment of direct radiological risk and indirect associated toxic risks originated by Coal-Fired Power Plants

Over the past few decades there has been some discussion concerning the increase of the natural background radiation originated by coal-fired power plants, due to the uranium and thorium content present in combustion ashes. The radioactive decay products of uranium and thorium, such as radium, radon, polonium, bismuth and lead, are also released in addition to a significant amount of 40 K.Since the measurement of radioactive elements released by the gaseous emissions of coal power plants is not compulsory, there is a gap of information concerning this situation. Consequently, the prediction of dispersion and mobility of these elements in the environment, after their release, is based on limited data and the radiological impact from the exposure to these radioactive elements is unknown. This paper describes the methodology that is being developed to assess the radiological impact due to the raise in the natural background radiation level originated by the release and dispersion of the emitted radionuclides. The current investigation is part of a research project that is undergoing in the vicinity of Sines coal-fired power plant (south of Portugal) until 2013. Data from preliminary stages are already available and possible of interpretation.

서울지역 라돈농도의 분포예측을 위한 공간분석법 연구

Radon is an invisible, odorless, and radioactive gas. It is formed by the disintegration of radium, which is a decay product of uranium. Some amounts of radon gas and its products are present ubiquitously in the soil, water, and air. Particularly high radon levels occur in regions of high uranium content. Although radon is permeable into indoor environment not only through geological features (bed rock and permeability) but also through the construction materials and underground water, the radiation from the geological features is generally main exposure factor. So there can be a problem in a certain space such as the underground and/or relatively poor ventilation condition. In this study, a GIS technique was used in order to investigate spatial distribution of radon measured from sub- way stations of 1 thru 8 in Seoul, Korea in 1991, 1998, 2001, and 2006. Spatial analysis was applied to reproduce the radon distribution. We utilized spatial analysis techniques such as inverse distance weighted averaging (IDW) and kriging techniques which are widely used to relate between different spatial points. To validate the results from the analyses, the jackknife technique for an uncertainty test was performed. When the number of measuring sites was less than 100 and also when the number of omitted sites increased, the kriging technique was better than IDW. On the other hand, when the number of sites was over 100, IDW technique was better than kriging technique. Thus the selection of analytical tool was affected sensitives by the analysis based on the number of measuring sites.

Atlantic Meridional Overturning Circulation During the Last Glacial Maximum

The circulation of the deep Atlantic Ocean during the height of the last ice age appears to have been quite different from today. We review observations implying that Atlantic meridional overturning circulation during the Last Glacial Maximum was neither extremely sluggish nor an enhanced version of present-day circulation. The distribution of the decay products of uranium in sediments is consistent with a residence time for deep waters in the Atlantic only slightly greater than today. However, evidence from multiple water-mass tracers supports a different distribution of deep-water properties, including density, which is dynamically linked to circulation.