The environmental behaviour of radium: revised edition (original) (raw)
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The Environmental Behaviour of Radium: Revised Edition. IAEA Technical Reports Series No 476
This publication aims to provide IAEA Member States with information for use in the radiological assessment of accidental releases and routine discharges of radium in the environment. It covers radium behaviour in the terrestrial, freshwater and marine environments. The information presented is relevant to the transfer of radionuclides through food chains to both humans and non-human biota. The corresponding remedial options and regulating aspects are also within the scope of this publication. Additionally, applications of radium isotopes to environmental issues are discussed in order to alert readers to studies that use radium isotopes as tracers of environmental processes. The information could also serve as a basis for remediation planning and identification of optimal remediation strategies in areas contaminated by radium.
Radionuclides in the Environment : Radium
Radium (chemical symbol Ra) is a radioactive element with chemical properties similar to calcium and barium. The isotopes of environmental concern are 226Ra with a half-life of 1600 years, and 228Ra with a half-life of 5.7 years; these isotopes are naturally occurring and are the decay products within the 238U and 232Th radioactive series, respectively (see Uranium; Thorium). Radium occurs in minute quantities in the environment, but is of concern due to its high radiotoxicity. Hence much public health attention has focused on its assessment and control in water and soil. Elevated radium concentrations in environmental media can be the result of natural processes (as in the case of some groundwater), or associated with either nuclear fuel cycle activities (such as uranium mining and milling) or nonnuclear industry activities (such as phosphoric acid production and oil-field brine disposal). Concerns regarding the biological uptake of radium, and its incorporation into human food cha...
Contamination caused by radium discharged with mine effluents into inland waters
Radioprotection, 2005
One of the most serious problems occurring during coal extraction in Upper Silesia in Poland is caused by waters with very high salinity. These waters often contain also high concentrations of natural radionuclides, mainly 226 Ra from uranium series and 228 Ra from thorium series. At least 70% of the total amount of radium carried by this waters remains nowadays in underground galleries as radioactive deposits. But, during the period of the most extensive coal extraction up to 225 MBq of 226 Ra and 400 MBq of 228 Ra were released daily into surface along with the other mine effluents. As a result of discharge of radium-bearing waters into settling ponds and later into rivers a significant increase of radium concentration in bottom sediments has been observed. Sometimes there is also a contamination of river beds, soils and biota. The paper describes results of investigation of waters and sediments with enhanced natural radioactivity, that occur in settling ponds, where mine waters have been dumped. Measurements of different factors of radiological hazard were made, such as radium content in the soil from ponds' banks, variations of gamma radiation background and radon exhalation. Additionally radium transfer to vegetation that had transgressed into the ponds has been calculated.
Radionuclide speciation and its relevance in environmental impact assessments
Journal of Environmental Radioactivity, 2004
To assess the long-term environmental impact of radioactive contamination of ecosystems, information on source terms including radionuclide speciation, mobility and biological uptake is needed. A major fraction of refractory radionuclides released from nuclear sources such as nuclear weapons tests and reactor accidents is present as radioactive particles, whilst radionuclides are also present as colloids or low molecular mass species in effluents from nuclear installations. Low molecular mass species are more mobile (lower apparent Kd) and bioavailable (higher apparent BCF) than colloids and particles. Soils and sediments act as sinks for particles and colloids. Due to particle weathering, associated radionuclides can be remobilised over time. Thus, information on particle characteristics such as composition, particle size, crystalline structures and oxidation states influencing weathering rates and subsequent mobilisation is essential. The present article summarises current knowledge on radioactive particles released from different sources, and the relevance of radionuclide speciation for mobility and biological uptake.
Lifetime risk assessment of Radium-226 in drinking water samples
Iranian Journal of Radiation Research, 2019
Background: One of the most significant radionuclides in natural drinking waters is Ra and its decay products. It is potential of health problems, including cancer risk. In this study, the effect of Ra concentration in 28 drinking water samples collected from the North Guilan province was investigated. Materials and Methods: The activity concentrations of Ra were measured by using of radon emanation method and Pylon AB-5 radon scintillation detector. The annual effective dose distribution by age groups, radiological risk and chemical toxicity risk were calculated in drinking water. Results: The activity concentration results range from a low limit of detection (LLD) 2.0±0.1 mBq l to 38.2±2.4 mBq l. Also, the annual effective dose distribution by age groups estimated results were from 1.8×10 Sv y for adults to 1.5×10 Sv y for infants. The radiological risk assessment results were 1.06×10 to 2.03×10 for morbidity risk, 7.32×10 to 1.40×10 for mortality risk. The chemical toxicity risk ...
Journal of Environmental Radioactivity, 2001
Saline waters from underground coal mines in Poland often contain natural radioactive isotopes, mainly 226 Ra from the uranium decay series and 228 Ra from the thorium series. Approximately 40% of the total amount of radium remains underground as radioactive deposits, but 225 MBq of 226 Ra and 400 MBq of 228 Ra are released daily into the rivers along with the other mine effluents from all Polish coal mines. Technical measures such as inducing the precipitation of radium in gobs, decreasing the amount of meteoric inflow water into underground workings, etc. have been undertaken in several coal mines, and as a result of these measures, the total amount of radium released to the surface waters has diminished by about 60% during the last 5-6 years. Mine water can have a severe impact on the natural environment, mainly due to its salinity. However, associated high levels of radium concentration in river waters, bottom sediments and vegetation have also been observed. Sometimes radium concentrations in rivers exceed 0.7 kBq/m 3 , which is the permitted level for waste waters under Polish law. The extensive investigations described here were carried out for all coal mines and on this basis the total radium balance in the effluents has been calculated. Measurements in the vicinity of mine settling ponds and in rivers have given us an opportunity to study radium behaviour in river waters and to assess the degree of contamination. Solid waste materials with enhanced natural radioactivity have been produced in huge amounts in the power and coal industries in Poland. As a result of the combustion of coal in power plants, low-radioactive waste materials are produced, with 226 Ra concentration seldom exceeding a few hundreds of Bq/kg. A different situation is observed in coal mines, where, as a result of precipitation of radium from radium-bearing waters, highly radioactive deposits are formed. Sometimes the radioactivity of such materials is extremely high; precipitates from coal mines
Radium-226 and radium-228 in shallow ground water, southern New Jersey
Fact Sheet
Concentrations of total radium (the sum of radium-226 and radium-228) and gross alpha-particle activities in drinking water that exceed the U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Levels (MCLs) are known to cause cancer. Results of investigations by the U.S. Geological Survey (USGS) in cooperation with the New Jersey Department of Environmental Protection (NJDEP) indicate that concentrations of total radium in water samples from 33 percent of 170 wells in the Kirkwood-Cohansey aquifer system in southern New Jersey exceeded the MCL of 5 pCi/L (picocuries per liter) (fig. 1). Wells containing water in which concentrations of total radium were greater than the MCL typically are found where the Bridgeton Formation crops out, in or near an agricultural area, where ground water is acidic (pH less than 5), and where nitrate concentrations generally exceed 5 mg/L (milligrams per liter). Leaching of nitrogen, calcium, and magnesium from agricultural chemicals (fertilizer, lime) applied to cropland may increase the mobility of radium in ground water. Gross alphaparticle activities exceeded the USEPA MCL of 15 pCi/L in water from 14 percent of 127 wells. A statistically significant 2:1 ratio between gross alpha-particle activity and concentration of total radium indicates that gross alpha-particle activity can be used as a screening tool to predict the presence of water that may have a high total-radium concentration.