Assessment of radiation exposure in the uranium mining and milling area of Mailuu Suu, Kyrgyzstan
TL;DR: Radiological assessment was performed for critical group members living in the city of Mailuu Suu, located downstream the tailings, or in the village of Kara Agach, partially located on a uranium mine waste dump.
About: This article is published in Journal of Environmental Radioactivity.The article was published on 2006-01-01. It has received 62 citations till now.
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01 Dec 2020
TL;DR: In this paper, the impact and mechanism of mine damage to the environment was discussed together with the remediation principles, and the enforcement of environmental laws, regulations, and standards were highlighted.
Abstract: Mining is very vital to the production of goods, services and infrastructure; it advances the quality of lives in the society. However, the possible hazard of waste and radioactivity generated by mining, dumping and tailing, has called on the society to find ways of seeking remedy that will adequately treat mining waste from mine dump, tailing and abandoned mine. Mine waste reuse and recycling in mining industries could offer cost-effective benefits through offsetting raw material requirements and decreasing the volumes of waste to be managed. This review discussed mine dump pollution monitoring and mine dump management strategies for some selected countries. Impact and mechanism of mine damage to the environment was discussed together with the remediation principles. It further examines the mining Act and regulations of the same selected countries. Emphasised was placed on the enforcement of environmental laws, regulations, and standards. Practical ways in which country’s state authority and civil society can keep a close watch and enhance the enforcement of laws and regulations were highlighted. The prediction for the control of mineral exploration and environmental assessment was also discussed for executing a specific control to take preventive measures. Management techniques used in combating the impact of mine dump, stockpiles and tailing on the environment were discussed. In addition, radioactivity in mine and its monitoring and control was discussed.
72 citations
TL;DR: In this article, the concentration of natural radionuclide uranium (U) in surface and groundwater resources has been examined on routine bases and a summary of available analytical techniques for U determination has also been presented.
Abstract: Keeping in view the toxicity of uranium and to reduce exposure to uranium and avoid high doses, it is essential to examine on routine bases the concentration of natural radionuclide uranium (U) in surface and groundwater resources. In this approach, the concentrations of U (total U) were summarized in worldwide surface and groundwater resources. U(+6) is the major form of U in oxic surface waters, while U(+4) is the major form in anoxic waters. An efficient way of uranium measurement in all water sources must be utilized to obtain reliable results. For this purpose a summary of available analytical techniques for U determination has also been presented. On the basis of the available data, the chemical exposures from these contaminated water sources were specified and some important epidemiological cross-sectional, ecological, and case-control studies and influence of heavy metal mining on water quality were also included. The literature review results revealed that the concentrations of natural U are high...
70 citations
TL;DR: NORM and TENORM have the potential to cause important human health effects and it is important that these adverse health effects are evaluated using the basic principles of toxicology, including the magnitude and type of exposure, as well as threshold and dose response.
Abstract: Introduction. Naturally occurring radioactive materials (NORM) are ubiquitous throughout the earth's crust. Human manipulation of NORM for economic ends, such as mining, ore processing, fossil fuel extraction, and commercial aviation, may lead to what is known as “technologically enhanced naturally occurring radioactive materials,” often called TENORM. The existence of TENORM results in an increased risk for human exposure to radioactivity. Workers in TENORM-producing industries may be occupationally exposed to ionizing radiation. TENORM industries may release significant amounts of radioactive material into the environment resulting in the potential for widespread exposure to ionizing radiation. These industries include mining, phosphate processing, metal ore processing, heavy mineral sand processing, titanium pigment production, fossil fuel extraction and combustion, manufacture of building materials, thorium compounds, aviation, and scrap metal processing. Methods. A search of the PubMed database (www....
64 citations
Cites background from "Assessment of radiation exposure in..."
...2 mSv/year of radiation with an additional 10–30 mSv annually from local crops and livestock.(55) Estimation of health risks...
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TL;DR: Overall, it is concluded that measures such as restricted access to the Pit Lake as well as dietary restrictions with respect to drinking water and intake of fish should be taken to reduce the environmental risk to man and biota.
47 citations
Cites background from "Assessment of radiation exposure in..."
...…varied from 11.3 to 33.0 mg/L with a mean concentration of 26 mg/L, which is higher than reported for drinking water at a number of mining sites in other countries, for example in the Mailuu Suu area in Kyrgyzstan, ranging from 1.9 to 7.1 mg/L and 0.37 to 3.1 mg/L (Vandenhove et al., 2006)....
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TL;DR: The results from in situ size fractionation of water demonstrated radionuclides predominately present as colloids and low molecular mass (LMM) species, being potentially mobile and available for uptake in aquatic organisms of Norsjø Lake.
Abstract: The Fen Central Complex in southern Norway, a geologically well investigated area of magmatic carbonatite rocks, is assumed to be among the world largest natural reservoirs of thorium (232Th). These rocks, also rich in iron (Fe), niobium (Nb), uranium (238U) and rare earth elements (REE), were mined in several past centuries. Waste locations, giving rise to enhanced levels of both radionuclides and metals, are now situated in the area. Estimation of radionuclide and metal contamination of the environment and radiological risk assessment were done in this study. The average outdoor gamma dose rate measured in Fen, 2.71 μGy h−1, was significantly higher than the world average dose rate of 0.059 μGy h−1. The annual exposure dose from terrestrial gamma radiation, related to outdoor occupancy, was in the range 0.18–9.82 mSv. The total activity concentrations of 232Th and 238U in soil ranged from 69 to 6581 and from 49 to 130 Bq kg−1, respectively. Enhanced concentrations were also identified for metals, arsenic (As), lead (Pb), chromium (Cr) and zinc (Zn), in the vicinity of former mining sites. Both radionuclide and heavy metal concentrations suggested leaching, mobilization and distribution from rocks into the soil. Correlation analysis indicated different origins for 232Th and 238U, but same or similar for 232Th and metals As, Cr, Zn, nickel (Ni) and cadmium (Cd). The results from in situ size fractionation of water demonstrated radionuclides predominately present as colloids and low molecular mass (LMM) species, being potentially mobile and available for uptake in aquatic organisms of Norsjo Lake. Transfer factors, calculated for different plant species, showed the highest radionuclide accumulation in mosses and lichens. Uptake in trees was, as expected, lower. Relationship analysis of 232Th and 238U concentrations in moss and soil samples showed a significant positive linear correlation.
36 citations
References
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TL;DR: Van Genuchten et al. as mentioned in this paper proposed a closed-form analytical expression for predicting the hydraulic conductivity of unsaturated soils based on the Mualem theory, which can be used to predict the unsaturated hydraulic flow and mass transport in unsaturated zone.
Abstract: A new and relatively simple equation for the soil-water content-pressure head curve, 8(h), is described in this paper. The particular form of the equation enables one to derive closedform analytical expressions for the relative hydraulic conductivity, Kr, when substituted in the predictive conductivity models of N.T. Burdine or Y. Mualem. The resulting expressions for Kr(h) contain three independent parameters which may be obtained by fitting the proposed soil-water retention model to experimental data. Results obtained with the closed-form analytical expressions based on the Mualem theory are compared with observed hydraulic conductivity data for five soils with a wide range of hydraulic properties. The unsaturated hydraulic conductivity is predicted well in four out of five cases. It is found that a reasonable description of the soil-water retention curve at low water contents is important for an accurate prediction of the unsaturated hydraulic conductivity. Additional Index Words: soil-water diffusivity, soil-water retention curve. van Genuchten, M. Th. 1980. A closed-form equation for predicting the hydraulic conductivity of unsaturated soils. Soil Sci. Soc. Am. J. 44:892-898. T USE OF NUMERICAL MODELS for simulating fluid flow and mass transport in the unsaturated zone has become increasingly popular the last few years. Recent literature indeed demonstrates that much effort is put into the development of such models (Reeves and Duguid, 1975; Segol, 1976; Vauclin et al., 1979). Unfortunately, it appears that the ability to fully characterize the simulated system has not kept pace with the numerical and modeling expertise. Probably the single most important factor limiting the successful application of unsaturated flow theory to actual field problems is the lack of information regarding the parameters entering the governing transfer equations. Reliable estimates of the unsaturated hydraulic conductivity are especially difficult to obtain, partly because of its extensive variability in the field, and partly because measuring this parameter is time-consuming and expensive. Several investigators have, for these reasons, used models for calculating the unsaturated conductivity from the more easily measured soil-water retention curve. Very popular among these models has been the Millington-Quirk method (Millington and Quirk, 1961), various forms of which have been applied with some success in a number of studies (cf. Jackson et al., 1965; Jackson, 1972; Green and Corey, 1971; Bruce, 1972). Unfortunately, this method has the disadvantage of producing tabular results which, for example when applied to nonhomogeneous soils in multidimensional unsaturated flow models, are quite tedious to use. Closed-form analytical expressions for predicting 1 Contribution from the U. S. Salinity Laboratory, AR-SEA, USDA, Riverside, CA 92501. Received 29 June 1979. Approved 19 May I960. 'Soil Scientist, Dep. of Soil and Environmental Sciences, University of California, Riverside, CA 92521. The author is located at the U. S. Salinity Lab., 4500 Glenwood Dr., Riverside, CA 92502. the unsaturated hydraulic conductivity have also been developed. For example, Brooks and Corey (1964) and Jeppson (1974) each used an analytical expression for the conductivity based on the Burdine theory (Burdine, 1953). Brooks and Corey (1964, 1966) obtained fairly accurate predictions with their equations, even though a discontinuity is present in the slope of both the soil-water retention curve and the unsaturated hydraulic conductivity curve at some negative value of the pressure head (this point is often referred to as the bubbling pressure). Such a discontinuity sometimes prevents rapid convergence in numerical saturated-unsaturated flow problems. It also appears that predictions based on the Brooks and Corey equations are somewhat less accurate than those obtained with various forms of the (modified) Millington-Quirk method. Recently Mualem (1976a) derived a new model for predicting the hydraulic conductivity from knowledge of the soil-water retention curve and the conductivity at saturation. Mualem's derivation leads to a simple integral formula for the unsaturated hydraulic conductivity which enables one to derive closed-form analytical expressions, provided suitable equations for the soil-water retention curves are available. It is the purpose of this paper to derive such expressions using an equation for the soil-water retention curve which is both continuous and has a continuous slope. The resulting conductivity models generally contain three independent parameters which may be obtained by matching the proposed soil-water retention curve to experimental data. Results obtained with the closedform equations based on the Mualem theory will be compared with observed data for a few soils having widely varying hydraulic properties. THEORETICAL Equations Based on Mualem's Model The following equation was derived by Mualem (1976a) for predicting the relative hydraulic conductivity (Kr) from knowledge of the soil-water retention curve
22,781 citations
TL;DR: PHREEQC as discussed by the authors is a C program written in the C programming language that is designed to perform a wide variety of low-temperature aqueous geochemical calculations.
Abstract: PHREEQC version 2 is a computer program written in the C programming language that is designed to perform a wide variety of low-temperature aqueous geochemical calculations. PHREEQC is based on an ion-association aqueous model and has capabilities for (1) speciation and saturation-index calculations; (2) batch-reaction and onedimensional (1D) transport calculations involving reversible reactions, which include aqueous, mineral, gas, solidsolution, surface-complexation, and ion-exchange equilibria, and irreversible reactions, which include specified mole transfers of reactants, kinetically controlled reactions, mixing of solutions, and temperature changes; and (3) inverse modeling, which finds sets of mineral and gas mole transfers that account for differences in composition between waters, within specified compositional uncertainty limits. New features in PHREEQC version 2 relative to version 1 include capabilities to simulate dispersion (or diffusion) and stagnant zones in 1D-transport calculations, to model kinetic reactions with user-defined rate expressions, to model the formation or dissolution of ideal, multicomponent or nonideal, binary solid solutions, to model fixed-volume gas phases in addition to fixed-pressure gas phases, to allow the number of surface or exchange sites to vary with the dissolution or precipitation of minerals or kinetic reactants, to include isotope mole balances in inverse modeling calculations, to automatically use multiple sets of convergence parameters, to print user-defined quantities to the primary output file and (or) to a file suitable for importation into a spreadsheet, and to define solution compositions in a format more compatible with spreadsheet programs. This report presents the equations that are the basis for chemical equilibrium, kinetic, transport, and inverse modeling calculations in PHREEQC; describes the input for the program; and presents examples that demonstrate most of the program's capabilities.
7,654 citations
TL;DR: The information contained in the report is mostly tabulated and drawn from a wide variety of ICRP reports, providing a compilation of age-dependent committed effective-dose coefficients for members of the general public due to inhalation or ingestion of a variety of radionuclides.
Abstract: This report is yet another valuable reference text in the series of International Commission on Radiological Protection (ICRP) publications. The information contained in the report is mostly tabulated and drawn from a wide variety of ICRP reports (numbers 56, 67, 69 and 71), providing a compilation of age-dependent committed effective-dose coefficients for members of the general public due to inhalation or ingestion of a variety of radionuclides. The information is likely to be of direct benefit to those involved in radiation protection for the nuclear, environmental and health-care industries. It is unlikely to be of use to those interested in medical research since the chemical/pharmaceutical form is not considered in detail. It is a report for use by a specialist and not for casual reading: in short, a key text for any institution that already makes use of ICRP publications.
273 citations
110 citations
TL;DR: In this article, the effect of pH, ionic strength and carbonate alkalinity on Th adsorption on goethite was evaluated in Soap Lake, an alkaline lake in Eastern Washington.
85 citations