Radiochemical characterization of mineral waters in the Eastern Black Sea Region, Turkey

This study has evaluated the levels of natural radionuclides and chemical components of mineral waters in the Eastern Black Sea Region (Turkey). The mean activity concentrations of (226)Ra, (232)Th, (137)Cs, (40)K, gross alpha and gross beta were found as 129, 33, 28, 714, 125 and 170 mBq L(-1), respectively. Due to consumption of mineral waters, the radiological impact of them on the inhabitants was calculated by taking the annual intake into account through ingestion of aforementioned radionuclides. The estimated effective doses from mineral water were found to be 13.20 μSv year(-1) ((226)Ra), 2.74 μSv year(-1) ((232)Th), 0.13 μSv year(-1) ((137)Cs) and 1.62 μSv year(-1) ((40)K). The overall contribution of these radionuclides to the committed effective dose from a year's consumption of mineral water in the region is therefore estimated to be only 17.69%, which is in concordance with the recommended WHO value (100 μSv year(-1)). The chemical analysis results showed that these waters contain Na, Al, P, Cl, K, Ca, V, Mn, Fe, Ni, Cu and Zn elements. These values were evaluated and compared with the internationally verified values. This study provides important information for consumers and authorities because of their internal radiochemical exposure risk from mineral water intake.     

226Ra in Tap and Mineral Water and Related Health Risk in the Republic of Croatia

The presence of 226Ra in drinking water may sometimes make important contribution to natural background radiation exposures. The paper describes the study of 226Ra content in drinking water of Croatia: tap water from the public supply system of several major towns and bottled mineral water from two selected mineral water springs. 226Ra was determined by alpha-spectrometric measurement after radiochemical separation. The radiation doses originating from drinking tap water and bottled mineral water were estimated. The annual dose from consumption of bottled mineral water was compared to that received from ingestion of public system tap water. The study showed that 226Ra content for investigated categories of waters is below the levels at which any unacceptable dose due to ingestion would arise.     

Radiological aspects of some Egyptian thermo-mineral springs

In Egypt, nineteen water springs with temperatures exceeding 35 degrees C, which can be considered thermal waters, were reported. The radiological aspects of thermal water in three northern regions of Egypt (Gulf of Suez, Cairo, and Bahariya Oasis) were investigated. The activity concentrations of natural radionuclides of 226Ra, 40K, total uranium and 210Pb (210Po) in water samples were determined using gamma spectrometry, laser fluorimetry and alpha spectrometry after chemical separation, respectively. The highest concentrations are detected in two locations, namely Sudr and Hammam Faroun springs, which are the hottest waters in Egypt (89 and 72 degrees C respectively). It seems that the presence of 226Ra is correlated to the water mineralization and the depth and the temperature of the reservoir's base. Also, these results seem evidence of uranium accumulation at depth in the mother bedrock and/or uranium immobilization due to uranium reduction to the immobile 4+-oxidation state in the reservoir base. The average activity concentrations of 40K are dependent on the water's origin, i.e. meteoric water mixed with sea water (Gulf of Suez springs) and meteoric water (Bahariya Oasis wells). There is no prescribed dose limit for short term and temporary exposure to thermal water. Workers at the thermal springs should be regularly monitored because of their continuous exposure to enhanced radiation levels over a long period of time. The hydrochemical characteristics, environmental isotopes aspects and water origin are briefly discussed based on published data.     

Estimation of uranium and radon concentration in some drinking water samples of Upper Siwaliks, India

Uranium and radon concentration was assessed in water samples taken from hand pumps, natural sources and wells collected from some areas of Upper Siwaliks, Northern India. Fission track registration technique was used to estimate the uranium content of water samples. The uranium concentration in water samples was found to vary from 1.08 +/- 0.03 to 19.68 +/- 0.12 microg l(-1). These values were compared with safe limit values recommended for drinking water. Most of the water samples were found to have uranium concentration below the safe limit of 15 microg l(-1) (WHO, World Health Organization, Guidelines for drinking-water quality (3rd ed.). Geneva, Switzerland: WHO, 2004). The radon estimation in these water samples was made using alpha-scintillometry to study its correlation with uranium. The radon concentration in these samples was found to vary from 0.87 +/- 0.29 to 32.10 +/- 1.79 Bq l(-1). The recorded values of radon concentration were within the recommended safe limit of 4 to 40 Bq l(-1) (UNSCEAR, United Nations Scientific Committee on the Effects of Atomic Radiations, Sources and effects of ionizing radiation. New York: United Nations, 1993). No direct correlation was found between uranium concentration and radon concentration in water samples belonging to Upper Siwaliks. The values of uranium and radon concentration in water were compared with that from the adjoining areas of Punjab state, India.     

Study on transfers of uranium, thorium and decay products from grain, water and soil to chicken meat and egg contents

Activity concentrations of the uranium and thorium series radionuclides were determined in chicken meat and eggs as well as in soil, water and other dietary intakes of poultry at five sites of the French territory. These data allow the calculation of transfer coefficients which enrich the database given by the technical report series no. 472 of the IAEA. In egg contents, the highest activity concentrations (in mBq kg(-1) fresh weight) are for (226)Ra, ranging between 136 and 190 and are much lower for uranium (between 0.51 and 1.30 for (238)U). In chicken meat, (238)U activity concentration is higher than in egg contents and ranges between 1.7 and 9.7. Concerning (232)Th, its activity concentration is lower than uranium and ranges between 0.5 and 4.9. Daily ingested activity concentration by the animals was assessed taking into account the activity concentrations measured in the grains, in the soil and in the drinking water. The activity concentration in grains and the daily intakes allow the calculation of concentration ratios and transfer coefficients for chicken meat and egg contents. In chicken meat the transfer coefficients (d kg(-1)) range between 0.0018 and 0.0073 for (238)U and between 0.0008 and 0.0028 for (232)Th. In egg contents they range from 0.00018 to 0.0018 for (238)U and are much higher for radium isotopes (0.10-0.23 for (226)Ra and 0.07-0.11 for (228)Ra).     

Risk assessment due to ingestion of natural radionuclides and heavy metals in the milk samples: a case study from a proposed uranium mining area, Jharkhand

Ingestion of radionuclides and heavy metals through drinking water and food intake represents one of the important pathways for long-term health considerations. Milk and milk products are main constituents of the daily diet. Radionuclides and heavy metals can be apprehended in the ecosystem of the East Singhbhum region which is known for its viable grades of uranium, copper and other minerals. For the risk assessment studies, samples of milk were collected from twelve villages around Bagjata mining area and analysed for U(nat), ²²⁶Ra, ²³⁰Th, ²¹⁰Po, Fe, Mn, Zn, Pb, Cu and Ni. Analysis of the results of the study reveals that the geometric mean of U(nat), ²²⁶Ra, ²³⁰Th and ²¹⁰Po was 0.021, 0.24, 0.23 and 1.08 Bq l^???1, respectively. The ingestion dose was calculated to be 12.34 ??SvY^???1 which is reflecting the natural background dose via the route of ingestion, and much below the 1 mSv limit set in the new ICRP recommendations. The excess lifetime cancer risk was estimated to be 1.72 × 10^???4 which is within the acceptable excess individual lifetime cancer risk value of 1 × 10^???4. The geometric mean of Fe, Mn, Zn, Cu and Ni was 4.91, 0.29, 4.77, 0.56 and 0.48 mgl^???1, respectively; whereas the daily intake was computed to be 0.44, 0.03, 0.43, 0.05 and 0.04 mg/day, respectively. Pb was not detected in any of the samples. The hazard quotient revealed that the intake of the heavy metals through the ingestion of milk does not pose any apparent threat to the local people as none of the HQ of the heavy metals exceeds the limit of 1.     

Leachable 226Ra in Philippine phosphogypsum and its implication in groundwater contamination in Isabel, Leyte, Philippines

Phosphogypsum (PG), the major waste material in phosphate fertilizer processing, has been known to contain enhanced levels of naturally-occurring radionuclides especially (226)Ra.The lack of radioactivity data regarding Philippine phosphogypsum and its environmental behavior in the Philippine setting has brought concern on possible contamination of groundwater beneath the phosphogypsum ponds in Isabel, Leyte, Philippines. The radioactivity of Philippine phosphogypsum was determined and the leaching of (226)Ra from phosphogypsum and through local soil was quantified. Level of (226)Ra in groundwater samples in Isabel, Leyte, Philippines was also quantified to address the primary concern. It was found that the (226)Ra activity in Philippine phosphogypsum is distributed in a wide range from 91.5 to 935 Bq/kg. As much as 5% of (226)Ra can be leached from Philippine PG with deionized water. In vitro soil leach experiments suggest that the soil in the phosphate fertilizer plant area would be able to deter the intrusion of (226)Ra into the water table. Compared to reported values of natural groundwater levels of (226)Ra, the concentration of this radionuclide in Isabel, Leyte groundwater suggest that there is no (226)Ra intrusion brought about by the presence of phosphogypsum ponds in the area.     

Distributions of 210Pb around a uraniferous coal-fired power plant in Western Turkey

In the present study the spatial and the vertical distributions of 210Pb were investigated in the soils around a uranifereous coal fired power plant (CPP) in Yatagan Basin, in Western Turkey. The variation of 226Ra activity along the soil profiles was studied to assess the unsupported 210Pb distribution in the same samples. 226Ra was measured by gamma spectroscopy and 210Pb activities were determined from 210Po activities using radiochemical deposition and alpha spectroscopy. The total 210Pb activity concentrations in bulk core samples varied in the range of 38-250 Bq kg(-1) in the study sites and of 22-78 Bq kg(-1) in reference site. In the sectioned cores sampled from the study areas the ranges for activity concentrations of 226Ra, total 210Pb and unsupported 210Pb are 24-77; 39-344 and 4-313 Bq kg(-1), respectively. Corresponding ranges for reference site are 37-39; 39-122 and 1-83 Bq kg(-1).     

Total effective dose equivalent assessment after exposure to high-level natural radiation using the RESRAD code

The current work reports the activity concentrations of several natural radionuclides (²²⁶Ra, ²³²Th, and ⁴⁰K) in Khak-Sefid area of Ramsar, Iran. An evaluation of total effective dose equivalent (TEDE) from exposure to high-level natural radiations is also presented. Soil samples were analyzed using a high-purity germanium detector with 80 % relative efficiency. The TEDE was calculated on a land area of 40,000 m² with 1.5-m thickness of contaminated zone for the member of three critical groups of farmer, construction worker, and resident using Residual Radioactive Material Guidelines (RESRAD) modeling program. It was found that the mean activity concentrations (in Bq/kg) were 23,118?±?468, 25.8?±?2.3, and 402.6?±?16.5 for ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively. The maximum calculated TEDE during 1,000 years was 107.1 mSv/year at year 90, 92.42 mSv/year at year 88, and 22.09 mSv/year at year 46 for farmer, resident, and construction worker scenarios, respectively. The maximum TEDE in farmer scenario can be reduced to the level below the dose limit of 1 mSv/year which is safe for public health using soil cover with thickness of 50 cm or more on the contaminated zone. According to RESRAD prediction, the TEDE received by individuals for all exposure scenarios considerably exceed the set dose limit, and it is mainly due to ²²⁶Ra.     

The impact of a disused mine on uranium transport in the River Fal, South West England

Unfiltered and filtered (0.45 and 0.2 microm) water samples and sediment samples (sieved to <180 microm and 180-1000 microm) were collected along an approximately 15 km transect of the River Fal, Cornwall, UK, to examine the impact of the disused South Terras uranium mine on the uranium concentrations of the river water and underlying sediments. The uranium concentration of the water samples fluctuated along the river, with the 0.45 microm filtered water showing the largest, seven-fold, difference between minimum (0.19 microg L(-1)) and maximum (1.34 microg L(-1)) concentrations. The historical uranium mine and spoil heaps were not a significant source of uranium to the river water, as water concentrations were low next to the site, but a highly elevated uranium concentration (1000 mg kg(-1)) was found in sediment below an outflow pipe from this mine. Operationally defined "colloidal" (0.2-0.45 microm) and "dissolved" (<0.2 microm) uranium were the predominant forms of the element in the river water (35 and 45% respectively). The uranium concentration in the dissolved phase showed a correlation coefficient of 0.83 (n= 9) with the total cation concentration, suggesting that the uranium concentration in this fraction is directly linked to weathering of rocks and minerals. The observation that weathering is the dominant mechanism delivering uranium to the river water explains the low uranium concentrations in the river water close to South Terras mine, despite the proximity of the spoil heaps, and the maximum uranium concentrations close to a china clay mining area.     

Optimization of sampling for the determination of mean radium-226 concentration in surface soil

There are thousands of properties in the United States on which the soil has been contaminated to some degree with uranium mill tailings. An effort is now underway by the United States Department of Energy to identify sites contaminated with tailings and to perform remedial action when ²²⁶Ra levels exceed current guidelines. Because of the large number of sites involved, it is imperative that sample collection be performed in a cost-effective manner. In this paper we describe the results of a study in which we compared the efficiencies of different methods of sample collection in order to determine an optimal method for estimating the mean ²²⁶Ra concentration in soil. The study involved a field experiment in which extensive sampling was performed on sites known to be contaminated with uranium tailings. The experiment was designed to identify the advantages and limitations of composite sampling, the relative merits of random and uniformly spaced sample collection, the use of field gamma measurements for supplementing and reducing soil sample collection, and practical levels of accuracy and precision that can be obtained. Conclusions regarding gamma measurements are unique to ²²⁶Ra contamination. On the other hand, conclusions concerning composite sampling and random versus uniformly spaced sampling may depend primarily on the way the contamination was spread by man and hence may not be unique to ²²⁶Ra.Research sponsored by the Department of Remedial Action Projects, Office of Terminal Waste Disposal, U. S. Department of Energy under contract DE-AC05-84OR21400 with the Martin Marietta Energy Systems, Inc.ORNL—Grand Junction Office, Grand Junction, Colorado.     

我国内陆流域各类水体中天然放射性核素浓度

1985年～1989年由新疆、甘肃、青海、西藏、内蒙古、陕西、宁夏等省、自治区环境监测站(研究所)对内陆流域各类水体中U、Th、~(226)Ra、~(40)K浓度进行调查,由调查的29条内陆河、23个湖泊、15座水库、55处井泉和34个自来水的统计结果表明,流域内各水体中U和~(40)K浓度的平均值与同期调查的黄河水系同类水体的浓度相近,明显高于长江水系,与全国同类水体相比亦属偏高。Th和~(226)Ra的平均浓度与全国同类水体的浓度相近,甘、新内陆区浓度较低。调查发现,一些咸水湖、井水和自来水中U、~(226)Ra,或~(40)K浓度异常偏高。     

Solid phase extraction of Cu(II), Ni(II), Pb(II), Cd(II) and Mn(II) ions with 1-(2-thiazolylazo)-2-naphthol loaded Amberlite XAD-1180

A new method for separation and preconcentration of trace amounts of Cu(II), Ni(II), Pb(II), Cd(II) and Mn(II) ions in various matrices was proposed. The method is based on the adsorption and chelation of the metal ions on a column containing Amberlite XAD-1180 resin impregnated with 1-(2-thiazolylazo)-2-naphthol (TAN) reagent prior to their determination by flame atomic absorption spectrometry (FAAS). The effect of pH, type, concentration and volume of eluent, sample volume, flow rates of sample and elution solutions, and interfering ions have been investigated. The optimum pH for simultaneous retention of all the metal ions was 9. Eluent for quantitative elution was 20 ml of 2 mol l(-1) HNO(3). The optimum sample and eluent flow rates were found as 4 ml min(-1), and also sample volume was 500 ml, except for Mn (87% recovery). The sorption capacity of the resin was found to be 0.77, 0.41, 0.57, and 0.30 mg g(-1) for Cu(II), Ni(II), Cd(II), and Mn(II), respectively. The preconcentration factor of the method was 200 for Cu(II), 150 for Pb(II), 100 for Cd(II) and Ni(II), and 50 for Mn(II). The recovery values for all of the metal ions were > or = 95% and relative standard deviations (RSDs) were < or = 5.1%. The detection limit values were in the range of 0.03 and 1.19 microg l(-1). The accuracy of the method was confirmed by analysing the certified reference materials (TMDA 54.4 fortified lake water and GBW 07605 tea samples) and the recovery studies. This procedure was applied to the determination of Cu(II), Ni(II), Pb(II), Cd(II) and Mn(II) in waste water and lake water samples.     

Natural radioactivity and chemical concentrations in Egyptian groundwater

Measurements of natural radioactivity in drinking water have been performed in many parts of the world, mostly for assessment of the doses and risk resulting from consuming water. A study of the radionuclide and chemical components in groundwater from Beni Suef Governate, Egypt has been carried out. Fifty water samples were analyzed by gamma ray spectroscopy to determine the ²²⁶Ra, ²³²Th, and ⁴⁰K concentrations; major elements, pH, alkalinity, and conductivity were also measured. The specific activity values ranged from 0.008 to 0.040 Bq/l for ²²⁶Ra, from 0.003 to 0.019 Bq/l for ²³²Th, and from 0.025 to 0.344 Bq/l for ⁴⁰K. The annual ingestions of these radionuclides, using local consumption rates (average over the whole population) of 1.5 l day^???1, were estimated to be 8.59, 4.86, and 83.47 Bq year^???1 for ²²⁶Ra, ²³²Th, and ⁴⁰K, respectively. The estimated values and weighted means of these radionuclides compare well with the world average. The estimated effective doses from drinking water were found to be 2.4 ??Sv year^???1 (²²⁶Ra), 1.1 ??Sv year^???1 (²³²Th), and 0.51 ??Sv year^???1 (⁴⁰K). Contribution of these radionuclides to the committed effective dose from 1 year consumption of drinking water is estimated to be only 4%.     

Assessment of public exposure to naturally occurring radioactive materials from mining and mineral processing activities of Tarkwa Goldmine in Ghana

Studies have been carried out in a Goldmine in Ghana to determine the exposure of the public to naturally occurring radioactive materials from processing of gold ore. Direct gamma spectrometry and neutron activation analysis techniques were used to analyse soil, rock, water and dust samples from the mining environment. The mean activity concentrations measured for (238)U, (232)Th and (40)K in the soil/rock samples were 15.2, 26.9 and 157.1 Bq kg(?-?1), respectively. For the water samples, the mean activity concentrations were 0.54 and 0.41 Bq l(?-?1)) and 7.76 Bq l(?-?1) for (226)Ra, (232)Th and (40)K, respectively. The mean activity concentrations measured in the dust samples were 4.90 and 2.75 μBq m(?-?3) for (238)U and (232)Th, respectively. The total annual effective dose to the public was estimated to be 0.69 mSv. The results in this study compared well with typical world average values. The results indicate an insignificant exposure of the public from the activities of the Goldmine.     

Radiological study of exposure levels in El Maghara underground coal mine

Coal is largely composed of organic matter, but it is the inorganic matter in coal minerals and trace elements that have been cited as possible causes of health, environmental and technological problems associated with the use of coal. Some trace elements in coal are naturally radioactive. These radioactive elements include uranium (U), thorium (Th) and their numerous decay products, including radium (Ra) and radon (Rn). Although these elements are less chemically toxic than other coal constituents, such as arsenic, selenium or mercury, questions have been raised concerning the possible risk from radiation. In order to accurately address these questions and to predict the mobility of radioactive elements during the coal fuel cycle, it is important to determine the specific activity, distribution and form of radioactive elements in coal. The assessment of the radiation exposure from coal burning is critically dependent on the specific activity of radioactive elements in coal and in the fly ash that remains after combustion. The El-Maghara coal mine is the only producing coal mine in Egypt. It is located in the middle of the Sinai desert about 250 km north-east of Cairo, where a coal-fired power plant is intended to be built. In this study, a pre-operational radiological baseline of the site and the occupational radiation exposures due to radon progeny in the mine were determined. The specific activities of 226Ra, 232Th and 40K in soil and coal dust samples collected along the main gallery ranges were found to be 6-22.9, 9.6-47.3 and 77-489 Bq kg-1, respectively. Soil samples collected around the mine showed concentrations of 226Ra, 232Th and 40K in the ranges 2.7-20.2, 3.2-12.6 and 14.6-201 Bq kg-1, respectively. All of the mean values of radon progeny were lower than the action levels for working places recommended in the International Commission on Radiological Protection (ICRP) 65.     

Analysis of uranium and its correlation with some physico-chemical properties of drinking water samples from Amritsar, Punjab

Fission track technique has been used for uranium estimation in drinking water samples collected from some areas of Amritsar District, Punjab, India. The uranium concentration in water samples is found to vary from 3.19 to 45.59 microg l(-1). Some of the physico-chemical properties such as pH, conductance and hardness and the content of calcium, magnesium, total dissolved solids (TDS), sodium, potassium, chloride, nitrate and heavy metals viz. zinc, cadmium, lead and copper have been determined in water samples. An attempt has been made to correlate uranium concentration with these water quality parameters. A positive correlation of conductance, nitrate, chloride, sodium, potassium, magnesium, TDS, calcium and hardness with uranium concentration has been observed. However, no correlation has been observed between the concentration of uranium and the heavy metals analysed.     

Radioactivities related to coal mining

Natural radioactivity concentrations due to the coal mining in Gabal El-Maghara, North Sinai, Egypt, were determined using gamma-ray spectroscopy. Coal, water and soil samples were investigated in this study. The (226)Ra, (232)Th and (40)K activity concentrations in coal before extraction were 18.5 +/- 0.5, 29.5 +/- 1.2 and 149.0 +/- 8.4 Bq kg(-1), respectively. These concentrations were reduced to 18-22% after extraction due to the clay removal of the coal ore. The activity contents of the water and soil samples collected from the surrounding area did not show any evidence of enhancement due to the mining activities. Absorbed dose rate and effective dose equivalent in the mine environment were 29.4 nGy h(-1) and 128.0 microSv a(-1), respectively. The measured activity concentrations in the mine environment and the surrounding areas (5 km away from the mine) are similar to that found in other regions in North and South Sinai. Based on the measurements of gamma-ray emitting radionuclides, the mine activity does not lead to any enhancement in the local area nor represents any human risk.     

Assessment of the radiological impacts of utilizing coal combustion fly ash as main constituent in the production of cement

The purpose of this study is to assess potential radiological impacts of utilizing pulverized fly ash (PFA) as a constituent in ordinary Portland cement. For this purpose, the activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K in samples of PFA and Portland cement containing 15%, 20%, and 25% by mass PFA were measured using gamma-ray spectrometry with HPGe detector. The mean activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K were found as 366.6, 113.7, and 460.2 Bq kg^???1, 94.2, 25.9, and 215.3 Bq kg^???1, 113.7, 34.3, and 238.3 Bq kg^???1, and 124.2, 41.8, and 279.3 Bq kg^???1 for the examined samples of PFA, Portland cement with 15%, 20%, and 25% by mass PFA, respectively. Radiological parameters such as radium equivalent activity, external exposure index (activity concentration index), internal dose index (alpha index), indoor absorbed gamma dose rate, and the corresponding the annually effective dose were assessed for Portland cement samples containing three percentages (15%, 20%, and 25%) by mass PFA. The results of assessment show that all Portland cement samples are within the safe limits recommended for building materials for dwellings.     

Development of an efficient and sensitive analytical method for the determination of copper at trace levels by slotted quartz tube atomic absorption spectrometry after vortex-assisted dispersive liquid-liquid microextraction in biota and water samples using a novel ligand

This study describes the determination of trace levels of copper by slotted quartz tube atomic absorption spectrometry after dispersive liquid-liquid microextraction. A ligand synthesized from the reaction of salicylaldehyde and 1-naphthylamine was used to form coordinate copper complex prior to extraction. All parameters that influence the output of complex formation, extraction, and instrumental measurement were optimized to enhance the absorbance signal of copper. Under the optimum conditions, about 104-fold enhancement in sensitivity was recorded over the conventional flame atomic absorption spectrometer, corresponding to a 0.51 ng/mL detection limit. The percent relative standard deviation calculated for the lowest concentration (4.8%) indicated high precision for the experimental procedure. Accuracy and applicability of the optimum method were determined by performing spiked recovery tests on urine, lake water, and mineral water samples. Satisfactory recovery results were obtained between 82.2 and 106.3% at four different concentrations. Matrix matching method was also performed to increase the accuracy of quantification, and the percent recovery calculated for 175 ng/mL was 105.14%.