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A comprehensive background radiological status in the surrounding environment of the Tummalapalle U mining and processing facilities was evaluated. Radioactivity in soil and rock was estimated by high-resolution gamma spectroscopy with a high-purity p-type germanium detector. The external gamma radiation level, outdoor 222Rn concentration, radioactivity in the groundwater, and water quality parameters around the Tummalapalle site were studied. The terrestrial radioactivity in soil was higher than the national and global averages in the study region. Radium equivalent activity (Raeq) in soil and rock was much lower than the safe limit of 370 Bq/kg and therefore safe to use as a construction material. Hydrogeochemical analysis indicated that the groundwater in the study region is neutral to medium basic, oxic, fresh to brackish, and predominantly Ca2+-Mg2+-HCO3− (62.5%) type. The hydrogeochemistry of groundwater was primarily governed by rock-aquifer interaction in this region. The data generated in this study can serve as the baseline for this region to understand the change in environmental conditions, if any, due to prolonged anthropogenic activities.

Nuclear power and modern agriculture are two crucial sectors for sustainable development in the United Arab Emirates (UAE). As these industries mature rapidly in the country, their long-term inter-compatibility needs monitoring with local data on transfer of radionuclides from arid sandy soils to farm products. Date palms, main crop from the Arabian Peninsula, remain largely unstudied for radioecological impact assessments. This paper reports the first measurement of soil to UAE date palms concentration ratios for natural radionuclides. Representative samples of soils, fruits, and leaves from seven palms in Abu Dhabi have been studied using gamma-spectrometry. Average activity concentrations in the soils are around 278.9 Bq kg−1 for 40K, 15.5 Bq kg−1 for 238U, and 8.3 Bq kg−1 for 232Th. The latter two decay chains, in the plant samples, are close to detection limits, signifying their lower levels in the UAE flora and the need for upgrading analytical techniques. The geometric means of soil to fruit concentration ratios are 1.12 for 40K, but negligibly low for the others—approximately 0.08 for 238U and 0.17 for 232Th chains. The respective ratios for the leaves are approximately 0.13, 0.36, and 0.77. Personal radiation doses due to soils and dates are very low, posing no danger to the public. [ABSTRACT FROM AUTHOR]

Ambient dose equivalent H *(10) is measured to assess general population exposure to ionising radiation. From its spatial and time variations it is possible to identify sources of exposure. In Slovenia, semi-annual H *(10) is measured routinely with thermoluminescence dosimeters at 66 locations around the Nuclear Power Plant (NPP) Krško and at 50 other locations covering the rest of Slovenian territory. Since the Chernobyl accident contamination had ceased to contribute to ambient dose equivalents, we have been calculating correlation coefficients between annual mean number of sunspots and annual H *(10). These correlation coefficients were calculated for five locations in western Slovenia and for five annual H *(10) extracted from measurements around NPP Krško. Their ranges between –0.64 and –0.38 suggest a clear negative correlation between solar activity and H *(10). Mean annual H *(10) averted by solar activity in the past two solar maxima reached 0.070 mSv around NPP Krško (155 m.a.s.l.) and 0.132 mSv and 0.180 mSv at Kredarica (2515 m.a.s.l.). Quantifying the influence of the solar activity on the ambient dose equivalent helps us to better understand exposure of the general population to ionising radiation.

The activity concentrations of the natural radionuclides, namely226Ra,232Th, and40K were measured from soil samples collected from different locations of Egbeda Local Government Area, Oyo state, Nigeria, with the aim of establishing radioactivity baseline data for the area. High-resolution gamma spectrometry detector was used to determine the activity concentration of these radionuclides in 45 soil samples taken at a depth of about 15 cm in various communities of Egbeda Local Government Area. The concentration of226Ra was in the range 5.9–61.3 Bq/kg with an average value of 30.5 Bq/kg,232Th in the range 4.0–116.5 Bq/kg with an average value of 50.8 Bq/kg, and40K in the range 27–798 Bq/kg with an average value of 200 Bq/kg. The results obtained in this study were compared with those of different countries in the world. Radiological index parameters were used for the assessment of radiological exposure of the natural radioactivity, and the absorbed dose rate, the radium equivalent activity, the annual effective dose, the external exposure index, and internal exposure index were calculated. There is no radiological risk from soil that may threat the residents around Egbeda Local Government Area. Hence, the probability of occurrence of any of the health effects of radiation is insignificant. Therefore, the radioactivity measurements taken represent the baseline data of the study area.

Ambient dose equivalent H*(10) is measured to assess general population exposure to ionising radiation. From its spatial and time variations it is possible to identify sources of exposure. In Slovenia, semi-annual H*(10) is measured routinely with thermoluminescence dosimeters at 66 locations around the Nuclear Power Plant (NPP) Krško and at 50 other locations covering the rest of Slovenian territory. Since the Chernobyl accident contamination had ceased to contribute to ambient dose equivalents, we have been calculating correlation coefficients between annual mean number of sunspots and annual H*(10). These correlation coefficients were calculated for five locations in western Slovenia and for five annual H*(10) extracted from measurements around NPP Krško. Their ranges between –0.64 and –0.38 suggest a clear negative correlation between solar activity and H*(10). Mean annual H*(10) averted by solar activity in the past two solar maxima reached 0.070 mSv around NPP Krško (155 m.a.s.l.) and 0.132 mSv and 0.180 mSv at Kredarica (2515 m.a.s.l.). Quantifying the influence of the solar activity on the ambient dose equivalent helps us to better understand exposure of the general population to ionising radiation. [ABSTRACT FROM AUTHOR]

Due to heightening concern about radiation hazards protection, activity concentrations of 226Ra, 232Th, 40K in forty soil samples collected from Shoubra El Kheima in the South Nile Delta were measured using gamma-ray spectrometry. The mean activity concentrations of 226Ra and 40K were higher in 20% of the considered samples than the world average values. A comprehensive comparison with up-to-date data was carried out. Spatial distribution maps of the measured radionuclides and radiological parameters were generated. The distributions of natural radionuclides were influenced by the soil organic matter, clay content, and scavenger metals oxides, as well as differences in the physical and chemical attributes and solubility of these radionuclides. The results revealed that industrial activity and agricultural practices in the study area caused an incremental increase in 226Ra and 40K activity concentrations. It can be deduced that although there are intensive industrial activities in this area, the natural radiation that comes from the soil is normal and does not pose a significant radiological hazard to the public. The natural radioactivity of soil in this area needs to be monitored periodically to prevent unnecessary radiation exposure to inhabitants.

The activity concentrations of the natural radionuclides, namely226Ra,232Th, and40K were measured from soil samples collected from different locations of Egbeda Local Government Area, Oyo state, Nigeria, with the aim of establishing radioactivity baseline data for the area. High-resolution gamma spectrometry detector was used to determine the activity concentration of these radionuclides in 45 soil samples taken at a depth of about 15 cm in various communities of Egbeda Local Government Area. The concentration of226Ra was in the range 5.9–61.3 Bq/kg with an average value of 30.5 Bq/kg,232Th in the range 4.0–116.5 Bq/kg with an average value of 50.8 Bq/kg, and40K in the range 27–798 Bq/kg with an average value of 200 Bq/kg. The results obtained in this study were compared with those of different countries in the world. Radiological index parameters were used for the assessment of radiological exposure of the natural radioactivity, and the absorbed dose rate, the radium equivalent activity, the annual effective dose, the external exposure index, and internal exposure index were calculated. There is no radiological risk from soil that may threat the residents around Egbeda Local Government Area. Hence, the probability of occurrence of any of the health effects of radiation is insignificant. Therefore, the radioactivity measurements taken represent the baseline data of the study area. [ABSTRACT FROM AUTHOR]

The mineral extraction activities may disturb the natural radioactivity, therefore current study aims to generate baseline data of natural radionuclides and anthropogenic 137Cs before the start of industrial activities. Gamma spectrometry and gross alpha and beta counting systems were used for activity measurement in environmental samples. In soil, the mean activity of 232Th, 226Ra, 40K and 137Cs were determined as 79 (66-117), 47 (34-80), 823 (602-1159) and 1.3 (1.1-4.5) Bq kg−1, respectively. The average annual effective dose rate (128.7 µSv h−1) in the study area was twice higher than world's average value. Indoor hazard index was greater than unity at two places; therefore, proper ventilation is proposed during construction. [ABSTRACT FROM AUTHOR]

The aim of this study is to determine the soil radioactivity levels and assess the possible relevant health hazards for the inhabitants of Ankara province. Total of 341 samples were collected from predetermined locations and outdoor gamma dose rate measurements were carried out. The mean activity of 40K, 226Ra, 232Th, and 137Cs with the ranges were determined as 454 (23-1355), 27 (6-186), 33 (2-181) and 3.3 (0.5-20.9) Bq kg−1, respectively. The average annual effective dose equivalent was found to be 71.8 µSv y−1 for public exposure and the average excess lifetime cancer risk value was calculated as 2.69E−04. [ABSTRACT FROM AUTHOR]

226Ra, 238U, 232Th, and 40K radionuclides have been determined using gamma-ray spectrometry in soil samples collected from urban areas in the southern governorates of Jordan and showed average concentrations of (39 ± 18), (45 ± 20), (23 ± 13), and (233 ± 128) Bq kg−1, respectively. The corresponding radio-elemental concentrations in the existing geological features were obtained and examined for the relative depletion/enrichment processes and state of equilibrium in soils. Radium equivalent activity, hazard indices, and annual gonadal dose equivalent do not exceed the permissible limits. Absorbed dose rates in air outdoor and external effective dose showed average values of 44.0 nGy h−1 and 54.4 μSv y−1, respectively. [ABSTRACT FROM AUTHOR]

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During the years 2001 and 2010, the content of 238 U, 226 Ra, 232 Th, 40 K and 137 Cs in agricultural soil and soil geochemical characteristics were measured on 50 locations in Northern Province of Serbia – Vojvodina. The locations for sampling were selected so that they proportionately represent all geomorphologic units in the region. The content of clay and humus varied within wide limits depending on soil type and influence the activity concentrations of radionuclides. In this paper we analyzed correlations between radionuclides content and geochemical characteristics of the soil. Possible influence of fertilizers on 238 U content in soil was discussed. The main conclusion is that measured maximal activity concentrations for 238 U (87 Bq/kg), 226 Ra (44.7 Bq/kg), 232 Th (55.5 Bq/kg) and 137 Cs (29 Bq/kg) at 30 cm depth could not endanger the safety of food production. The process of genesis of soil and cultivation mode plays a dominant role on the characteristics of the soil. The most significant correlation was found between the activity concentrations of 40 K and clay content in agricultural soil. [ABSTRACT FROM AUTHOR]

Some previous studies on radon concentration in dwellings of some areas of Kosovo and Metohija have revealed a high average radon concentration, even though the detectors were exposed for three months only. In order to better design a larger study in this region, the annual measurements in 25 houses were carried out as a pilot study. For each house, CR-39-based passive devices were exposed in two rooms for the two consecutive six-month periods to account for seasonal variations of radon concentration. Furthermore, in order to correlate the indoor radon with radium in nearby soil and to improve the knowledge of the natural radioactivity in the region, soil samples near each house were collected and 226Ra, 232Th, 40K activity concentration were measured. The indoor radon concentration resulted quite high from the average (163 Bq/m3) and generally it did not differ considerably between the two rooms and the two six-month periods. The natural radionuclides in soil resulted to be distributed quite uniformly. Moreover, the correlation between the226Ra content in soil and radon concentration in dwellings resulted to be low (R2=0.26). The annual effective dose from radon and its short-lived progeny (5.5 mSv, in average) was calculated by using the last ICRP dose conversion factors. In comparison, the contribution to the annual effective dose of outdoor gamma exposure from natural radionuclides in soil is nearly negligible (66 mSv). In conclusion, the observed high radon levels are only partially correlated with radium in soil; moreover, a good estimate of the annual average of radon concentration can be obtained from a six-month measurement with a proper choice of exposure period, which could be useful when designing large surveys.

The distribution of natural 238U, 232Th and 40K radionuclides in soil samples of Pompeiopolis Ancient City in Taşköprü-Kastamonu, Turkey has been carried out using a NaI(Tl) gamma ray spectrometric technique. The mean concentrations of radionuclides 238U, 232Th, and 40K were 31.12, 33.63, and 320.02Bq kg-1, respectively. The mean activity concentrations of measured radionuclides were compared with other literature and word's mean values. Using the activity concentrations of these radionuclides, radiological hazard parameters such as Radium equivalent activity (Raeq), External hazard index (Hex), Annual effective dose equivalent (AEDE), Absorbed dose rate (ADRA), Representative level index (Iγr) and Excess lifetime cancer risk (ELCR) were evaluated in order to determine the effects of the soils. Correlations between 238U, 232Th and 40K radionuclides and the radiological hazard parameters obtained from radioactivity were carried out to know the existing relations. The radiological maps of the Pompeiopolis/Turkey were composed using the results obtained from the study. [ABSTRACT FROM AUTHOR]

After Fukushima accident, new approaches are found to be needed for the simulation of the absorbed dose-rate calculation due to different reasons; the large number of contaminated areas with different shapes, geometries, compositions, and densities. Furthermore, the effect of the depth profile of gamma-emitting isotopes. In this work, a new home made computer software was developed based on a simple model for dose-rate factors computation of radionuclides distribution in soil. The software used Monte Carlo simulation for model solution. The developed software was used for studying the main factors that affect the exposure dose rate; among those are the contaminated soil (source term) geometries, the shape, the composition, and the density. In addition, the effect of radioactivity depth profile was studied using the soil layers' model. The results of the dose-rate factors show that (a) the variation of shape and the density has a slight effect on the calculation. The effect of source term composition was up to 7.4% from the standard one. (b) 98% of the dose rate comes only from the first 5 m lateral distance from the source term around the studied point. (c) The most important parameter was the depth profile of gamma emitters in soil, because about 50% of the dose rate comes from the first 5 cm of soil depth, about 20% from the second 5 cm layer, about 10% from the third 5 cm layer, and only less than 2% comes from the eighth 5 cm layer. Finally, besides the model simplicity in this work, the associated software is fast, and the calculated results are compatible with the international models. [ABSTRACT FROM AUTHOR]

We developed an apparatus containing a NaI(Tl) scintillator to measure the 134 Cs and 137 Cs radioactivity of soil contaminated by the Fukushima Daiichi Nuclear Power Plant accident. The unfolding method with the least-squares technique was used to determine the radioactivity. Detector responses for each radionuclide in soil were calculated with EGS5 code for the unfolding method. The radionuclides that were measured were 40 K, 134 Cs, 137 Cs, 208 Tl, 214 Bi, and 228 Ac. The measured spectrum agreed well with the spectrum calculated from the response matrix and measured radioactivities. The unfolding method allows us to use the NaI(Tl) scintillator despite the overlap of peaks. [ABSTRACT FROM AUTHOR]

In the frame of establishing the radiological baseline of the Buenos Aires Province, Argentina, this work assesses the total outdoor external dose and the activity values of 40K, 226Ra, 232Th and 137Cs in superficial soils of La Plata and Lima cities. In the latter, the most important nuclear emplacement of the country is located. At La Plata, 49 sites were analyzed, which correspond to the green public spaces of the city while at Lima 6 sites around the nuclear power plants were studied. For La Plata, the external dose contribution and activity distribution maps of 40K, 226Ra, 232Th and 137Cs were obtained using the Kriging geo-statistical method. Activity values of 226Ra and 232Th resulted lower than their worldwide average ones, while the 40K levels were higher than the corresponding one. The activity dataset was analyzed together with the activity values determined previously in unperturbed soils of the region. The Pearson correlation coefficient was re-calculated, obtaining correlations more significant when all activity data were considered. No correlation between activity superficial distributions and the height above sea level or the geomorphological units was found. The activity values obtained in Lima soils lie in the range of the values determined for La Plata soils. Like in La Plata, 137Cs activity around the nuclear facility could be associated only with the nuclear power tests. The average total external annual dose for La Plata inhabitants are in the range of 0.19 to 0.25 mSv/year, similar to those determined for Lima residents. The present work complements previous reports contributing to the establishment of the radiological baseline for soils of Buenos Aires Province, Argentina, the province with the most important nuclear activities of the country. [ABSTRACT FROM AUTHOR]

The Northern Areas of Pakistan is known for its relatively higher radioactivity level. No study has been conducted for Nagar, which is located at 2,590 m above sea level (ASL) and Shigar at 2,300 m ASL. Soil samples were collected from the two cities and gamma-emitting radionuclides were assayed using gamma-ray spectrometry. The average activity concentrations, average air absorbed dose rate, average annual effective dose and three hazard indices namely the radium equivalent activity, external hazard index and internal hazard index were calculated. The risk to human was estimated using the excess life-time cancer risk for people living in the two cities. [ABSTRACT FROM AUTHOR]

Soil is a basic component of biosphere and its important natural resource. The article deals with the analysis of soil radioactivity in Chinese province Guangdong. In the course of the analysis, it was stated that highly radioactive soil of China had been formed due to deep chemical weathering of highly radioactive potassium granites. High uranium and thorium contents in them are caused by specific conditions of weathering crust formation and subsequent pedogenesis. High dose loads for a man are formed in the development fields of such rock types. [ABSTRACT FROM AUTHOR]

Abstract: This study is aimed at the determination of the activity concentrations of naturally occuring and technologically enhanced levels of radiation in 34 representative soil samples that have been collected from an inshore oil field area which was found to have, in a previous study, the highest observed value of 226Ra concentration among 129 soil samples. The activity concentrations of 238U and 226Ra have been inferred from gamma-ray transitions associated with their decay progenies and measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the values of the activity concentrations associated with the naturally occuring radionuclide chains for all the samples collected from NW Dukhan. Discrete-line, gamma-ray energy transitions from spectral lines ranging in energy from ∼100keV up to 2.6MeV have been associated with characteristic decays of the various decay products within the 235.8U and 232Th radioactive decay chains. These data have been analyzed, under the assumption of secular equilibrium for the U and Th decay chains. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented. The weighted mean value of the activity concentrations of 226Ra in one of the samples was found to be around a factor of 2 higher than the values obtained in the previous study and approximately a factor of 10 higher than the accepted worldwide average value of 35Bq/kg. The weighted mean values of the activity concentrations of 232Th and 40K were also deduced and found to be within the worldwide average values of 30 and 400Bq/kg, respectively. Our previous study reported a value of 201.9±1.5Stat.±13Syst. Bq/kg for 226Ra in one sample and further investigation in the current work determined a measured value for 226Ra of 342.00±1.9Stat.±25Syst. Bq/kg in a sample taken from the same locality. This is significantly higher than all the other investigated soil samples in the current and previous works. Notably, the Th levels in the same sample are within the worldwide average expectations, implying that the increased 226Ra concentration arises from TENORM processes. [Copyright &y& Elsevier]

The present work reports the results of a study performed by gamma spectral analysis, on different soil samples collected from Petrosani - Romanian city placed in an important coal mining area. The purpose of this research is to estimate the gamma dose rate in the out-door air (at a height of 1 m above the ground), in order to compare the results obtained to the annual effective limit dose value received by the population, which is 1 mSv/year. A modern statistical method -- Monte Carlo simulation -- was used to perform the study. By estimating the mean activity concentrations for the primordial decay chains (those of Radium-226 and Thorium-232), as well as the mean activity concentration for the Potassium-40 radioisotope, the gamma dose rate received by the public in Petrosani was evaluated; this is proved to be lower than the maximum admitted value, so the study leads to the conclusion that the inhabitants are not dangerously exposed to gamma radiation caused by radioisotopes present in soil. [ABSTRACT FROM AUTHOR]

This paper aims to present the results of a study performed - by using gamma spectral analysis - on different soil samples collected from Petrosani - a Romanian city situated on the Jiu Valley, in a coal mining zone. The purpose of this research is to estimate the gamma dose rate in out-door air (at a height of 1 m above the ground), in order to compare the result thus obtained to the annual effective dose value which is recommended not to be exceeded for the population. By calculating the mean activity concentrations for the primordial decay chains (those of Uranium-238 and Thorium- 232), as well as the mean activity concentration for the Potassium-40 radioisotope, one may evaluate the gamma dose rate received by the public in Petrosani, which is proved to be lower than the maximum admitted value, so the study leads to the conclusion that the inhabitants are not dangerously exposed to gamma radiation. [ABSTRACT FROM AUTHOR]

This paper aims to present the results of a study performed - by using gamma spectral analysis - on different soil samples collected from Petrosani - a Romanian city situated on the Jiu Valley, in a coal mining zone. The purpose of this research is to estimate the gamma dose rate in out-door air (at a height of 1 m above the ground), in order to compare the result thus obtained to the annual effective dose value which is recommended not to be exceeded for the population. By calculating the mean activity concentrations for the primordial decay chains (those of Uranium-238 and Thorium- 232), as well as the mean activity concentration for the Potassium-40 radioisotope, one may evaluate the gamma dose rate received by the public in Petrosani, which is proved to be lower than the maximum admitted value, so the study leads to the conclusion that the inhabitants are not dangerously exposed to gamma radiation. [ABSTRACT FROM AUTHOR]

Abstract: This study is aimed at the determination of the activity concentrations of naturally occuring and technically enhanced levels of radiation in soil samples collected across the landscape of Qatar. Representative soil samples from various locations across the Qatarian peninsula have been collected and analyzed in order to establish activity concentrations associated with the 235,8U and 232Th natural decay chains and also the long-lived naturally occurring radionuclide 40K. The activity concentrations have been measured using a hyper-pure germanium detector. Details of the sample preparation and the gamma-ray spectroscopic analysis techniques are presented, together with the preliminary values of the activity concentrations associated with the naturally occuring radionuclide chains for six soil samples collected from the Qatarian peninsula. Sample 228, which has been collected from an inshore oil-field area, was observed to have the highest observed value of 226Ra concentration among the six samples. The weighted mean values of the activity concentrations of the radionuclides 238U, 232Th and 40K in one particular sample (sample 228) were, respectively, found to be 213.9±1.4, 4.55±0.11 and 111.4±3.6Bq/kg, which compare with the worldwide weighted mean values in soil samples, 33, 45 and 420Bq/kg, respectively. The deduced activity concentration of 238U in sample 228 in the current work was found to be significantly higher than the worldwide average value and was also significantly higher than the values determined for the five other initial samples discussed here. The mean values of the activity concentration of the 232Th series, 40K and 137Cs in Bq/kg from the six investigated soil samples were found to be 9.4±1.3, 204±22 and 5.8±5.6, respectively, with the quoted uncertainty referring to the standard deviation among these measurements. [Copyright &y& Elsevier]

Due to heightening concern about radiation hazards protection, activity concentrations of 226Ra, 232Th, 40K in forty soil samples collected from Shoubra El Kheima in the South Nile Delta were measured using gamma-ray spectrometry. The mean activity concentrations of 226Ra and 40K were higher in 20% of the considered samples than the world average values. A comprehensive comparison with up-to-date data was carried out. Spatial distribution maps of the measured radionuclides and radiological parameters were generated. The distributions of natural radionuclides were influenced by the soil organic matter, clay content, and scavenger metals oxides, as well as differences in the physical and chemical attributes and solubility of these radionuclides. The results revealed that industrial activity and agricultural practices in the study area caused an incremental increase in 226Ra and 40K activity concentrations. It can be deduced that although there are intensive industrial activities in this area, the natural radiation that comes from the soil is normal and does not pose a significant radiological hazard to the public. The natural radioactivity of soil in this area needs to be monitored periodically to prevent unnecessary radiation exposure to inhabitants. [ABSTRACT FROM AUTHOR]

Abstract: Determination of the natural radioactivity has been carried out, by means of gamma-ray spectrometry system, in surface soil samples collected from various geological formations in urban areas of the northern highlands of Jordan. These highlands, extending from Yarmouk River in the north to Wadi Wala in the south, form the agriculturally important regions of Jordan. Soils of the study region, at which about 70% of the total population of the country are living, mainly originated from limestones that are locally used in construction materials, making the evaluation of environmental radioactivity and estimating the current radiation hazards to the population an interesting issue. The total average concentrations of radionuclides 226Ra, 238U, 232Th, and 40K were 42.5, 49.9, 26.7, and 291.1Bqkg−1, respectively. Correlations made among these radionuclides prove the existence of secular equilibrium in the investigated soils. The total average absorbed dose rate in the study areas is found to be 51.5nGyh−1, whereas the annual effective dose equivalent has an average value of 63.2μSvy−1. The external and internal hazard indices, the radium equivalent activity, and the annual gonadal dose equivalent associated with the investigated soils do not exceed the permissible limits except for soils originated from phosphate rocks. Moreover, the radio-elemental concentrations of uranium, thorium and potassium, evaluated for the various geological features in the study areas were calculated to indicate whether relative depletion/enrichment of radioisotopes had occurred. The results of the present study were discussed and compared with internationally recommended values. [Copyright &y& Elsevier]

Tuzla geothermal basin is situated in north-western Turkey on the Biga Peninsula, which is located at the west end of the Northern Anatolian Fault system. Soil and water samples were collected between August 2003 and June 2004 to initiate development of a geochemical profile of surface and subsurface waters in the geothermal basin and radionuclide concentrations in soils. All water samples were found to fall within Turkish Water Quality Class 4, meaning they were remarkably contaminated for any water consumption sector (industrial, human use or agricultural) based on sodium and chloride ions. Such waters could be used only after appropriate water treatment. The water samples are of the chloride type in terms of geochemical evaluation. Preliminary geochemical evidence shows that the N–S flowing part of the Tuzla River acts as a natural barrier within the basin. Heavy metal concentrations in the soil samples show slight elevations, especially those obtained from the east part of the basin where thermal springs are dominant. Geochemical calculations were carried out with PHREEQC® software to determine equilibrium concentration of chemical species and saturation indices, by which it is suggested that chloride is the most important ligand to mobilize the heavy metals in the studied system. In addition, the activity concentration and gamma-absorbed dose rates of the terrestrial naturally occurring radionuclides were determined in the soil using gamma-ray spectrometry. The soil activity ranged from 42.77 to 988.66 Bq kg−1 (averaging 138 Bq kg−1) for 238 U, 13.27 to 106.31 Bq kg−1 (averaging 32.42 Bq kg−1) for 232 Th, and 99.28 to 935.36 Bq kg−1 (averaging 515.44 Bq kg−1) for 40 K. The highest value of 238 U was found in the soil samples obtained from an area close to the hot spring. [ABSTRACT FROM AUTHOR]

Abstract: The significance of exposure from natural radioactivity in soil and the potential risk for causing health detriment have not received adequate attention in Nigeria. Cancer has become a major cause of mortality in the recent times and now the public interest in the long-term effects of radiation on humans has assumed great prominence following the establishment of a nuclear regulatory body in Nigeria. This study is an effort to investigate a possible relationship between reported cancer incidence and external terrestrial radiation dose level across the six geo-political zones of the country. Data from the national cancer registries across the zones were compared with expected cancer incidences due to soil radioactivity based on the linear no-threshold model (LNT). A regression equation that best describe the reported cancer incidence and the expected cancer incidence was developed. It was observed that cancer cases attributable to radiation exposure due to soil radioactivity is low, constituting only between 1.3% and 9.2% of the total reported cases. [Copyright &y& Elsevier]

A sample study of the profiles of radiation exposures to the populations living in the high background radiation areas (HBRAs) of the monazite-bearing region in Kerala, India, has been conducted by monitoring 200 dwellings selected from two villages in this region. Each of these dwellings was monitored for 1 year and the study lasted for a period of 2 years. The indoor gamma ray dose measurements were carried out using thermo luminescent dosimeters (TLDs) and the inhalation doses due to radon, thoron and their progenies were monitored using solid-state nuclear track detector (SSNTD) based twin-cup dosimeters. Outdoor gamma ray dose measurements were carried out using Geiger Muller (GM) tube based survey meters. Annual effective doses were computed, using occupancy factors of 0.8 and 0.2, respectively, for indoor and outdoor, by adding the three components. Occupants of 41.6% of the houses surveyed were observed to receive the annual effective doses ranging between 0.5 and 5 mSv/a, 41.6% between 5 and 10 mSv/a, 10.2% between 10 and 15 mSv/a and 6.6% greater than 15 mSv/a. The inhalation component was generally smaller than the external gamma ray component and on an average it was found to constitute about 30% of the total dose. The paper presents the details of the methodology adopted and the analysis of the results. [Copyright &y& Elsevier]

Terrestrial radioactivity monitoring of 238U and 232Th series, and 40K in soil is an essential practice for radioactivity and radiation measurement of a place. In conventional practice, only basic data can be in-situ measured using a survey instrument, for example radioactivity concentration in soil and ambient dose equivalent rate. For other physical quantities, for example organ absorbed dose and organ equivalent dose, the measurement is impossible to be performed and can only be computed using Monte Carlo radiation transport simulations. In the past, most of the works only focused on calculating air-kerma-to-effective dose conversion factors. However, the information on organ dose conversion factors is scarcely documented and reported. This study was conducted to calculate organ absorbed and tissue-weighted equivalent dose conversion factors as a result of exposure from terrestrial gamma radiation. Series of organ dose conversion factors is produced based on computations from Monte Carlo MCNP5 simulations using modelled gamma irradiation geometry and established adult MIRD phantom. The study found out that most of the radiation exposed organs absorb energy at comparable rates, except for dense and superficial tissues i.e., skeleton and skin, which indicated slightly higher values. The good agreement between this work and previous studies demonstrated that our gamma irradiation geometry and modelling of gamma radiation sources are adequate. Therefore, the proposed organ dose conversion factors from this study are reasonably acceptable for dose estimation in environmental radioactivity monitoring practices. • Organ dose conversion factors for 238U and 232Th series, 40K and 137Cs in soil. • The calculations were performed using MCNP5 simulation and MIRD phantom. • The exposed organs absorb at rate 0.6–0.8 of free-air kerma. • The tabulated conversion factors are applicable for radioactivity monitoring practices. [ABSTRACT FROM AUTHOR]

• NPK fertilisation suppressed the uptake of several radionuclides by maize. • No suppression for radionuclides which are or can mimic biogenic elements. • No suppression for radionuclides which accumulated on stem from air. • Low radionuclide concentrations in grain. • Fertilisation did not change the radiological properties of the soil. The goal of this study is to shed more light on the influence of fertilisation on radionuclide transfer from soil to crops, which is a significant ecological issue in present-day agriculture due to the intensive use of soil amendments. Research on this subject has not been extensive, hence there are still numerous open questions that require an interdisciplinary approach involving agroecology and radioecology. Maize was chosen for our investigation because it has been used, in considerable quantities and worldwide, as both food and feed, which makes it part of numerous food chains with humans as final consumers. The agricultural part of the experiment was carried out on an acidic soil in northwestern Croatia, and it was based on seven treatments with different levels of NPK fertilisation. Radionuclide activity concentrations in sampled soil, stem, and grain were measured by means of high-resolution γ-ray spectrometry. We found that the radiological properties of the soil were not affected by the addition of the fertiliser. Soil-to-stem uptake for radionuclides of the whole 232Th decay chain was first suppressed by mild fertilisation, and then, at higher fertiliser concentrations, it stayed low and became independent of fertilisation level. The same effect was observed for the 238U decay chain before gaseous 222Rn. We present arguments in favour of the cause of the observed suppression being radionuclide complexation with constituents of the fertiliser. However, the concentration of 210Pb in stem did not depend on fertilisation, which was most probably a consequence of the decay of airborne 222Rn and the deposition of its progenies onto stem. Radionuclide translocation from stem to grain did not depend on fertilisation either, and it was appreciable only for 40K and 137Cs. In grain, radionuclide concentrations were lower than in stem. Overall, in our case, fertilisation had positive effects, reducing the presence of radionuclides in the maize while having no detectable impact on the radiological properties of the soil. This finding may have implications for future work, especially regarding concerns about the impact of soil amendments on food production. [ABSTRACT FROM AUTHOR]

The present study was conducted in mountain regions of Armenia with the aim to assess the activity concentrations of natural K-40 and artificial Cs-137 in soil and mosses and reveal the distribution similarities and differences. Most widespread moss species and surface soils were sampled concurrently from eight mountain ridges and massifs by different altitudinal belts. Statistical analysis revealed significant differences and opposite characteristics for K-40 and Cs-137. In case of K-40 the activity concentrations decreased in mosses by altitude but with no significant correlation. The mean activity concentrations of K-40 in the soils of different altitudinal belts are close, nevertheless, the higher activity concentrations are common for soils derived from ingenious rocks. For Cs-137 in mosses, the correlation with altitude is statistically insignificant, but the altitudinal dependence is noticeable within separate ridges and massifs. A significant correlation was identified between Cs-137 in soil, altitude and precipitation rate. Studying natural K-40 and artificial Cs-137 radionuclides together yielded interesting contrasting results confirming the dissimilar behaviour of radionuclides with different origins in the environment. • K-40 and Cs-137 were investigated in mosses and soil in highlands of Armenia. • Characterization of K-40 and Cs-137 distribution by altitude were identified. • Dissimilar behaviour of K-40 and Cs-137 with different origin was confirmed. • The trend of decrease K-40 activity with the altitude identified for mosses. • Cs-137 activity increases in soil and moss and the altitude. [ABSTRACT FROM AUTHOR]