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The areas around Homa and Ruri hills in Homa Bay County in Kenya are associated with high background radiation levels. The activity concentration of the natural radionuclides ( 226 Ra, 232 Th, and 40 K) in earthen building materials used in the areas of Homa and Ruri hills has been measured using a NaI (Tl) detector in this work. The measured values of radioactivity concentrations are used to estimate the associated radiological risk. The earthen building material samples from Ruri registered relatively high 232 Th concentration values averaging 1094 ± 55 Bq/kg, nearly three times those of the samples from Homa. 226 Ra level was not significantly different in both regions with Homa reporting 129 ± 10 Bq/kg and Ruri 111 ± 6 Bq/kg. 40 K was however higher in the samples from Homa by an approximate factor of 2 relative to those from Ruri where the activity concentration was 489 ± 24 Bq/kg. The radium equivalents for 226 Ra, 232 Th, and 40 K in the samples from Ruri were 111 ± 9, 1564 ± 125, and 38 ± 3 Bq/kg, while in Homa, the values were 129 ± 10, 570 ± 46, and 69 ± 5 Bq/kg, respectively. The calculated value of total radium equivalent in Ruri was 1713 ± 137 Bq/kg which was two times higher than that of Homa. 232 Th contributed about 74% and 91% to the total radium equivalent in Homa and Ruri, respectively; thus, it was the one with the largest contribution to radiation exposure in both regions. The average indoor annual effective dose rates were 1.74 ± 0.14 and 3.78 ± 0.30 mSv/y in Homa and Ruri, respectively, both of which were above the recommended safety limit of 1 mSv/y., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Willis Otieno Gor Odongo et al.)

The investigation of radioactivity in samples is an application of gamma-ray spectrometry dealing with low and very low level gamma-ray activities of different isotopes. Gamma-ray spectrometry performed in the framework of radiological environmental monitoring may be done after selective sampling processes or after a chemical purification of a sample. Both cases imply that only some specific radionuclides should contribute to the obtained spectrum. Gamma-ray spectrometry performed with medium energy resolution detectors may allow the possible distinction of their photopeaks. Therefore, a cerium bromide (CeBr 3 ) detector can be particularly attractive for routine tasks in radiological environmental monitoring as it has a high efficiency, medium energy resolution and it can work at room temperature. This study describes the conditions under which a CeBr 3 detector can serve for some routine analysis in radiological analysis of samples collected in the environment or collected by air-samplers in environmental radiological monitoring programmes., (Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Alpha spectrometry is one of the greatest nuclear techniques for identification and quantification of α-emitters in the environment due to nuclear fuel cycle operations, nuclear materials and geochemical studies or forensic medicine investigations. This study was conducted to re-evaluate and optimize the factors affecting the performance of a multi-chamber alpha spectrometer (EG&G Ortec) used in our laboratory using an aged α-source of 232 U in equilibrium with its decay products. The results shown that the energy calibration within energy window 4-9 MeV has been done using alpha particle emissions of 232 U (t 1/2 .70.6 y) and its decay products with good linear fitting (R 2  > 0.999). At a source to detector spacing of 10 mm, the efficiency of the detectors varied between 15 and 20%; while the better resolution (FWHM) was ~36 keV. These values are lower than those warranted when supplied before 20 years. The minimum detectable activity (MDA) of the detectors varies between 0.8 and 3.1 mBq for the chamber in use. The alpha spectrometer was also verified by certified reference samples to measure activity concentration of alpha emitters (e.g., 238 U, 232 Th, 226 Ra and 241 Am) with acceptable coefficient of variance (<10%), ζ-score (<3) and P-test (<25%). As a result, the optimized alpha spectrometer is valid and can be utilized for monitoring and assessment of natural and artificial α-emitters in different environmental compartments., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Alpha-particle spectrometry, gamma spectrometry and neutron activation analysis techniques for determination of Th and U in environmental samples have been compared. The analytical parameters studied include detection limit, accuracy, repeatability, reproducibility and surrogate recovery. The results show that neutron activation analysis technique has the best accuracy among the studied techniques; the other two techniques were assessed relative to it. The percentage difference between the three techniques results is about [-20, 20]. In addition, U and Th concentrations are generally overestimated by gamma spectrometry and alpha-particle spectrometry in all cases except Th concentration in the former technique, which is underestimated., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Effluents containing tritium (H) dispersed into the fresh water or marine environment from nuclear facilities can be taken up by biota. Aquatic and marine organisms are among the important pathways through which tritium can enter into the human body, and hence, assessment of the extent of pollution of these ecosystems is very important for radiation dose assessments. Tritium present in environmental matrices can be classified as tissue-free water tritium (TFWT) and organically bound tritium (OBT). Optimization of a method for the determination of OBT in fish, based on thermal oxidation of the sample, is discussed. Samples were subjected to thermal oxidation in a pyrolyser system, and the water produced from the combustion was analyzed by liquid scintillation spectrometry. Results show that a maximum of ~2 g of processed fish sample can be combusted efficiently in the pyrolyser. Using this method, a recovery of 84% was achieved, and minimum detectable activity (MDA) for the method was determined to be 8.5 Bq kg (sample weight = 2 g, counting time = 30,000 s, and detection efficiency = 20%).

The 2011 accident at Japan's Fukushima Daiichi Nuclear Power Plant released a considerable inventory of radioactive material into the local and global environments. While the vast majority of this contamination was in the form of gaseous and aerosol species, of which a large component was distributed out over the neighbouring Pacific Ocean (where it was subsequently deposited), a substantial portion of the radioactive release was in particulate form and was deposited across Fukushima Prefecture. To provide an underpinning understanding of the dynamics of this catastrophic accident, alongside assisting in the off-site remediation and eventual reactor decommissioning activities, the 'International Particle Analysis Database', or 'IPAD', was established to serve as an interactive repository for the continually expanding analysis dataset of the sub-mm ejecta particulate. In addition to a fully interrogatable database of analysis results for registered users (exploiting multiple search methods), the database also comprises an open-access front-end for members of the public to engage with the multi-national analysis activities by exploring a streamlined version of the data.

Internal dose assessment intercomparison exercises are useful tools: to verify the performance of an internal dosimetry service; to promote the harmonisation of dose assessments; and to identify weaknesses where further improvements are necessary. However, no such international intercomparisons have been performed for more than ten years. In the period May 2014-May 2016, the 'Technical Recommendations for Monitoring Individuals for Occupational Intakes of Radionuclides' were developed on the initiative of the European Commission, and later published within the EC Radiation Protection series, as RP188. In 2017 the Working Group 'Internal Dosimetry' of the European Radiation Dosimetry Group (EURADOS) organised a new intercomparison action, named ICIDOSE 2017, with the main aim of testing the practical applicability of these technical recommendations (RP188). Four case studies were proposed to participants: an artificially created case of inhalation of 60 Co to simulate a simple special monitoring case; a real case of inhalation of 125 I, with simple routine monitoring; a real and more complex case of incorporation of 234+235+238 U, featuring both confirmatory and special monitoring; and a complex real case of an accidental incorporation of 241 Am, including multiple administrations of diethylenetriamine pentaacetic acid (DTPA). Results were received from 66 participants from 26 countries; these were compared to reference or recommended solutions, developed for each case based on the application of RP188. In cases 1, 2 and 4 only a small number of results were identified as outliers, with the spread of all the results, expressed as the geometric standard deviation (GSD) of the values, assessed as 1.07, 1.04 and 1.43, respectively. This observed spread of the submitted results was improved from those obtained from similar cases in previous intercomparison exercises, showing that the availability of RP188 contributes to the harmonisation of the internal dose assessment process. There was a much wider spread of results for the uranium case: this case was characterised by an absence of any prior knowledge of the exposure scenario, and participants assumed a range of different exposure pathways and patterns.

Soluble and insoluble radioactive cesium in municipal solid waste incineration fly ash were analyzed by X-ray diffraction and gamma-ray spectrometry. A total of 60% of soluble radioactive cesium was determined using the Tessier extraction method, and it was almost same extraction rate with Japanese leaching test No.13. In addition, chloride compounds such as halite (NaCl) and sylvite (KCl) showed same behavior with soluble radioactive cesium, therefore, soluble radioactive cesium existed as a chloride (CsCl) with water solubility characteristics. Almost insoluble radioactive cesium trapped into silicate of crystalline phase or amorphous phase was eluted by hydrogen fluoride treatment. Radioactive 137 Cs was released in three stages by heating treatment (untreated - 400 °C, 600 °C-800 °C, and 800 °C-1000 °C) according to decreasing amorphous content. The relationship between the concentrations of radioactive 137 Cs and amorphous phase exhibited good linearity (R = 0.9278). Insoluble radioactive 137 Cs was contained in inner part of the amorphous phase, and free radioactive cesium was determined from the concentration of the amorphous phase., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The abundance and distribution of highly radioactive cesium-rich microparticles (CsMPs) that were released from the Fukushima Daiichi Nuclear Power Plant (FDNPP) during the first stage of the nuclear disaster in March 2011 are described for 20 surface soils collected around the FDNPP. Based on the spatial distribution of the numbers (particles/g) and radioactive fraction (RF) of the CsMPs in surface soil, which is defined as the sum of the CsMP radioactivity (in Bq) divided by the total radioactivity (in Bq) of the soil sample, three regions of particular interest have been identified: i.) near-northwest (N-NW), ii.) far-northwest (F-NW), and iii.) southwest (SW). In these areas, the number and RF of CsMPs were determined to be 22.1-101 particles/g and 15.4-34.0%, 24.3-64.8 particles/g and 36.7-37.4%, and 0.869-8.00 particles/g and 27.6-80.2%, respectively. These distributions are consistent with the plume trajectories of material released from the FDNPP on March 14, 2011, in the late afternoon through to the late afternoon of March 15, 2011, indicating that the CsMPs formed only during this short period. Unit 3 is the most plausible source of the CsMPs at the beginning of the release based on an analysis of the sequence of release events. The lower RF values in the N-NW region indicate a larger influence from subsequent plumes that mainly consisted of soluble Cs species formed simultaneously with precipitation. The quantitative map of the distribution of CsMPs provides an important understanding of CsMP dispersion dynamics and can be used to assess risks in inhabited regions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Around former glass factories in south eastern Sweden, there are dozens of dumps whose radioactivity and physico-chemical properties were not investigated previously. Thus, radiometric and physico-chemical characteristics of waste at Madesjö glass dump were studied to evaluate pre-recycling storage requirements and potential radiological and environmental risks. The material was sieved, hand-sorted, leached and scanned with X-Ray Fluorescence (XRF). External dose rates and activity concentrations of Naturally Occurring Radioactive Materials from 238 U, 232 Th series and 40 K were also measured coupled with a radiological risk assessment. Results showed that the waste was 95% glass and dominated by fine fractions (<11.3 mm) at 43.6%. The fine fraction had pH 7.8, 2.6% moisture content, 123 mg kg -1 Total Dissolved Solids, 37.2 mg kg -1 Dissolved Organic Carbon and 10.5 mg kg -1 fluorides. Compared with Swedish EPA guidelines, the elements As, Cd, Pb and Zn were in hazardous concentrations while Pb leached more than the limits for inert and non-hazardous wastes. With 40 K activity concentration up to 3000 Bq kg -1 , enhanced external dose rates of 40 K were established (0.20 μSv h -1 ) although no radiological risk was found since both External Hazard Index (H ex ) and Gamma Index (I γ ) were <1. The glass dump needs remediation and storage of the waste materials under a safe hazardous waste class 'Bank Account' storage cell as a secondary resource for potential future recycling., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: To conduct a comparative analysis of the incidence of MM in the population of the Dnipropetrovsk region, taking into account the possible impact of various adverse environmental factors (air, water and soil con- tamination)., Materials and Methods: Epidemiological indicators of multiple myeloma (MM) morbidity in the 12-year observation period from 2006 to 2017 are analyzed in polluted and conventionally clean areas of the Dnipropetrovsk region., Results: In assessing the dynamics of morbidity in MM for years 2006-2017 there was an increase in the incidence in 2011, 2015 and quite stable indicators for 2006-2010. The analysis of morbidity in the industrial cities of the region showed consistently high rates for the entire period of observation. A marked increase in the incidence rate in the Zhovti Vody (2007, 2012, 2016), Nikopol (2016), Novomoskovsk (2016), Marganets (2008, 2009 and 2017), Pokrov (2016, 2017) from 4.35 to 6.25 was noted. This may indicate a fluctuation in the incidence of MM in sepa- rate large cities of Dnipropetrovsk. The analysis of the dynamics of morbidity in the most polluted cities showed a clear increase in the number of cases in the MM in Zhovti Vody, which is characterized by radiation pollution. According to the average annual morbidity rate among cities of Dnipropetrovsk region, Pokrov takes the first place, the second - Zhovti Vody., Conclusions: The obtained data testify to the fluctuation in the incidence of MM in the Dnipropetrovsk region during the period 2006-2017 and the negative environmental factors clearly affect the growth of morbidity in large industrialized cities contaminated with radioactive and chemical substances., (I. O. Selina, O. O. Yarchuk, P. Yu. Kaplan, G. V. Usenko, I. V.Sidorenko, I. S. Dyagil.)

Objective: to assess the naturally occurring radioactive materials (NORM) content in industrial waste in Ukraine and assess which industries should be a subject for the regulatory oversight., Methods: Sampling and analysis followed the same procedure in all cases. 250 samples were taken in total. High- resolution gamma spectrometry system ORTEK (US) with the high-purity germanium semiconductor detector (HPGe) were used for sample measurements. AMERSHAM (Germany) standard source was used for calibration of the gamma spectrometer. The estimated minimum detected activity for the measurement time of 3600 s was 0.5 Bq/kg for Thorium-232, and Radium-226 and 1.5 Bq/kg for Potassium-40., Results: Industries with the potential NORM content in their waste were approached in this research. 32 enterpris- es were the subject for investigation. It has been established average content of NORM in waste iron ore enterpris- es varies from 210 to 100 Bq/kg, 226Ra - from 14 to 45 Bq/kg, 40K - from 21 to 350 Bq/kg, 232Th - from 5 to 26 Bq/kg and 238U - from 19 to 48 Bq/kg. It was determined the content of NORM in waste is lower than the exemption lev- els. The average concentration of individual radionuclides does not exceed 10-20 Bq/kg. The assessment of the NORM average activity concentration in sludge and waste samples from different spots of the industrial site esti- mated that values may differ as much as 3 times, with average activity of 8,440 Bq/kg for 226Ra, 28,600 Bq/kg for 232Th, 11,000 Bq/kg for 210Pb. The NORM level in pipe sediments and silts of oil exceed the established exemption lev- els and range as follows: 210Pb 3-11 kBq/kg, 226Ra 2.9-8.4 kBq/kg, 232Th 0.8-2.8 kBq/kg, 226U 0.18-6.9 kBq/kg., Conclusion: Monitoring of the NORM levels in wastes has identified the need to establish regulatory control and oversight of the oil industry in the country., (T. Pavlenko, N. Aksenov, M. Fryziuk.)

Objective: analysis of some reproductive health disorders of female residents of radioactively contaminated (con- taminated) and clean territories of Ukraine., Materials and Methods: Data on disorders of the menstrual cycle (DMC), cancer of the body of the uterus (BU), inflammatory diseases of the uterus cervix (IDUC), which are taken from the statistical reports of the Ministry of Healthcare of Ukraine, from the State Statistics Service of Ukraine and the Kiev Regional Center for Maternal and Child Health Depending on Residence for the period 2007-2017, depending on the residence in the radioactively contaminated or clean settlement., Results: The prevalence and incidence of DMС increased from 2007 to 2017 from 17.79 ‰ and 10.66 ‰ to 18.50 ‰ and 11.66 ‰, the prevalence and incidence rates of IDUC (from 10.05 ‰ and 7.11 ‰ to 12.50 ‰ and 8.60 ‰), there was a negative tendency of incidence of malignant neoplasms of BU (an increase of 32.2 %) and UC (an increase of 5.1%). The incidence of BU cancer in 2014-2017 compared to Ukraine as a whole (0.14 ‰) in Kyiv region and Zhytomyr region increased (0.17 ‰, p <0.01 and 0.17 ‰, p < 0.01), and in Rivne region it was no diffe- rent from the national one (0.12 ‰). The lowest prevalence and incidence of DMC were found in Rivne region (10.41 ‰ and 6.85 ‰), which is almost twice lower than in Zhytomyr region (24.78 ‰ and 11.16 ‰). In Kyiv region, these figures are also significantly lower than in Ukraine (14.48 ‰ and 10.10 ‰). In the Kyiv region, there was no difference in the frequency of DMC (389.57 ‰, versus 405.99 ‰, p = 0.72), hyperplasia (67.48 ‰ vs. 59.95 ‰, p = 0.80), and BU polyps (46.01 ‰ against (57.22 ‰, p = 0.62) in contaminated and clean territory, with no such difference found for women from 1970-1987., Conclusions: Against the background of an increased incidence of BU cancer in the contaminated territories of the Zhytomyr region and Kyiv region, the prevalence and incidence of DMC was higher than the national level only in Zhytomyr region, whereas in Kyiv region and Rivne region, on the contrary, the indicators were lower. There is no dif- ference in the frequency of DMC, endometrial hyperplasia, BU polyps, both individually and in combination, among women who lived in the contaminated and clean territory of the Kyiv region., (Yu. G. Antypkin, N. Ye. Gorban, O. Yu. Borysiuk, O. V. Lynchak.)

Since the 1956 completion of nuclear testing at the Montebello Islands, Western Australia, this remote uninhabited island group has been relatively undisturbed (no major remediations) and currently functions as high-value marine and terrestrial habitat within the Montebello/Barrow Islands Marine Conservation Reserves. The former weapons testing sites, therefore, provide a unique opportunity for assessing the fate and behaviour of Anthropocene radionuclides subjected to natural processes across a range of shallow-marine to island-terrestrial ecological units (ecotopes). We collected soil, sediment and biota samples and analysed their radionuclide content using gamma and alpha spectrometry, photostimulated luminescence autoradiography and accelerator mass spectrometry. We found the activity levels of the fission and neutron-activation products have decreased by ~hundred-fold near the ground zero locations. However, Pu concentrations remain elevated, some of which are high relative to most other Australian and international sites (up to 25,050 Bq kg -1 of 239+240+241 Pu). Across ecotopes, Pu ranked from highest to lowest in the following order: island soils > dunes > foredunes > marine sediments > and beach intertidal zone. Low values of Pu and other radionuclides were detected in all local wildlife tested including endangered species. Activity concentrations ranked (highest to lowest) terrestrial arthropods > terrestrial mammal and reptile bones > algae > oyster flesh > whole crab > sea turtle bone > stingray and teleost fish livers > sea cucumber flesh > sea turtle skin > teleost fish muscle. The three detonations (one from within a ship and two from 30 m towers) resulted in differing contaminant forms, with the ship detonation producing the highest activity concentrations and finer more inhalable particulate forms. The three sites are distinct in their 240/239 Pu and 241/239 Pu atom ratios, including the Pu transported by natural process or within migratory living organisms., (Crown Copyright © 2019. Published by Elsevier B.V. All rights reserved.)

Increased uranium (U) concentrations are found in certain ground and surface waters of the Swiss Plateau. Analysis of more than 100 public fountains revealed that increased 238 U concentrations frequently occur close to the interface between the Lower Freshwater Molasse and the Upper Marine Molasse, cropping out in the western part of the Swiss Molasse Basin. Out of these locations, Mont Vully, situated ca. 20 km west of Berne, was studied in detail. As this hill consists of the two aforementioned stratigraphic Molasse units, it represents an ideal case study. Two springs at the northern slopes of Mont Vully exhibit the highest 238 U concentrations with more than 300 mBq/L and were thus monitored for almost two years in order to screen possible seasonal variations. Further water samples were collected from spring captures, creeks and drainage pipes. The pipes drain the farmland north of Mont Vully showing 238 U concentrations with more than 600 mBq/L. In order to discover the reason for the duplication in concentration, gamma dose rate measurements were accomplished on the farmland, revealing elevated dose rates of up to 160 nSv/h. These are located above ancient pathways of creeks that originated from Mont Vully. At these locations with elevated dose rates, three shallow sediment drill cores were taken and analyzed for their U content. The sediment cores can essentially be divided into three parts: (i) an upper soil with common U concentrations of about 30 Bq/kg 238 U, (ii) an U-rich peat horizon with concentrations of up to 500 Bq/kg 238 U, and (iii) an impermeable clay unit that acts as an aquitard with again minor 238 U concentrations. Radiocarbon dating of the U-rich peat horizon reveals ages younger than 8.1 kyrs. This study suggests that a wetland was formed on top of the impermeable clay layer after the last glaciation during the Holocene. The stream waters with 238 U concentrations of more than 300 mBq/L originating from Mont Vully contributed significantly to the water supply for the development of the wetland. Due to the reducing conditions that are present in wetlands, the dissolved U in the incoming streams was reduced and adsorbed onto organic matter. Accordingly, an entrapment for U was generated, persisting for at least 6 kyrs - a sufficient time to accumulate up to 500 Bq/kg. In the course of the last century, numerous wetlands in Switzerland were drained by capturing streams and installing drainage pipes to make the land suitable for agriculture. This kind of melioration was also done at the wetlands north of Mont Vully resulting in a subsequent change in redox conditions within the soil. The solubility of U depends on its oxidation state and U can be oxidized by oxygen-rich rainwater. The rainwater leached the U adsorbed on the peat yielding 238 U concentrations of more than 600 mBq/L. Consequently, the duplication of 238 U concentrations in the drainage water as compared to the original concentration that creeks brought into the ancient wetlands has been clarified during this study. Twenty of the analyzed public fountains in the Swiss Plateau exhibited a 238 U concentration of more than 50 mBq/L. All of them could have contributed to the formation of a wetland after the last glaciation, which leads to the assumption that the situation at Mont Vully is not a singularity in the Swiss Plateau., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

An alpine ice core, extracted from the Adamello glacier (Central Italian Alps), was analyzed in its entire length through low background γ-spectroscopy, for the detection of 137 Cs. Our results show that in glacier ice 137 Cs is tightly bound to insoluble particulate matter inside the ice core, and it is therefore possible to restrict γ-spectroscopy analysis to particulate matter only. We show how the sensibility of the detection limit can be improved by almost one order of magnitude by using a well-type detector instead of a coaxial one. Hypothesis on the dating of some radioactive layers are also hereby presented., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

This study aims to identify the analytical and radiological characterization of scale TENORM waste produced from oil and natural gas productions in the western desert in Egypt and evaluates their radiological impacts. The mean activity concentration of 238 U, 226 Ra, 210 Pb, 228 Ra, 224 Ra, and 40 K measured in scale TENORM samples is 660 ± 63, 1979 ± 435, 1399 ± 211, 645 ± 104, 794 ± 116, and 556 ± 86 Bq/kg, respectively. Radiological hazard parameters (Ra eq , Hex, Hin, etc.) were estimated form the scale TENORM waste sample. All the calculated hazard parameters were found greater than the permissible and recommended safe levels. So the exposure to radiations released from the accumulation of the petroleum scale TENORM waste may cause health risks to the operators and who inhale radioactive radon gases and/or ingest contaminants by radiotoxic nuclides of U, Th, Ra, and Pb. Also, the risks may be extended to the near and/or the general environment.

Medical radionuclides are widely used in nuclear medicine practices today. Their production, handling and administration have different impacts on the environment and society due to the radioactive waste generated. Over recent years authors have taken an interest in the monitoring and safe disposal of this radiopharmaceutical waste, mainly in environmental and biological samples, and consequently a variety of radioanalytical methods for these matrices have been developed. The present review aims to outline the state of the art and the latest trends reported in the literature from 2007 to the present, focusing on the occurrence and determination of medical radionuclides in environmental and biological samples. Special attention is given to critically discussing the strengths and weaknesses of the different steps involved in determining medical radionuclides in these types of matrices. The methodologies presented are accompanied by examples., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Dose prediction tools making use of existing knowledge on the environmental behaviour of radiocontaminants are essential for justification and optimisation of recovery countermeasure strategies for contaminated inhabited areas. In this context, one necessary requirement is to estimate the relative initial contaminant distribution on different types of surfaces in the environment and the resultant initial dose rates to humans staying in the environment. This paper reports on the latest parametric refinements in this context for use in the ERMIN inhabited area dose model, which is an integral part of the European emergency management decision support systems ARGOS and RODOS., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

The occurrence of elevated uranium levels in post-war areas raise concerns among populations, especially in areas affected by heavy bombardment and potential use of depleted uranium weapons. The aim of this study was to assess public exposure to the uranium Water, soil, vegetables, urine, serum and hair samples were collected for the first time in eastern Croatia and analysed using an inductively coupled plasma mass spectrometry (ICP-MS) method, in order to try to explain the possible origins of uranium in the population and environment. Urine, serum and hair samples were collected from 389 inhabitants. A large variation of uranium concentrations in urine, serum and hair samples was found in this study. The majority of urine, serum and hair samples from our study had uranium concentrations below the reference literature values. A higher uranium concentration in the hair of 4% of inhabitants, mostly from rural areas, could not be explained at this stage of research. A further, extended epidemiological study should be made of uranium in the region., (Copyright © 2019. Published by Elsevier Ltd.)

The speciation of radioactive tritium (T) in a naturally-established subtropical loblolly pine forest that has been irrigated with highly-contaminated pond water for the last 20 years is reported. This irrigation project was created to limit the underground transport of a tritium-rich plume which also contains low levels of toxic organics, metals and radionuclides such as carbon-14 (14C) from a nearby low-level waste burial ground. The levels of tritiated water (HTO) in the wood cores were not influenced by recent irrigation activities. However, the tritium levels in the last 20 years of tree growth were more than 3-fold higher than that of tritium in the older growth. This was due to recent irrigation with organic-bound tritium (OBT)-rich water and subsequent accumulation of high levels tritium as OBT relative to tissue HTO. High levels of pond irrigation water OBT resulted from biogenic processes that converted HTO to OBT. Data for 14C that were acquired for some of the forest materials indicated that the processes controlling the movement and accumulation of 14C in this system are somewhat different than that of tritium. Spectroscopic characterization of tree core tissue of <20 years in age found no explanation for the unusually wide dark growth rings. It was concluded that the trees were over-irrigated based on results from other published studies with wood from severely-flooded areas. Although HTO is indeed toxic to biota, OBT represents a relatively greater hazard to biota because it can be bioaccumulated and retained for long periods of time in living tissues.

Terrestrial ecosystems are exposed to various kinds of pollutants, including radionuclides. The honeybee, Apis mellifera, is commonly used in ecotoxicology as a model species for evaluating the effects of pollutants. In the present study, honeybees were irradiated right after birth for 14 days with gamma rays at dose rates ranging between 4.38 × 10 -3 and 588 mGy/d. Biological tissues (head, intestine and abdomen) were sampled at D3, D10 and D14. Ten different physiological markers involved in nervous (acetylcholinesterase (AChE)), antioxidative (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)), immune system (phenoloxidase (PO)) and metabolism (carboxylesterases (CaEs) and alkaline phosphatase (ALP)) were measured. Univariate analyses were conducted to determine whether each individual biomarker response was positively or negatively correlated with the dose rate. Then, multivariate analyses were applied to investigate the relationships between all the biomarker responses. Although no mortality occurred during the experiment, several biomarkers varied significantly in relation to the dose rate. Globally, the biomarkers of antioxidant and immune systems decreased as the dose rate increased. Reversible effects on the indicator of the neural system were found. Concerning indicators of metabolism (carboxylesterases), variations occurred but no clear pattern was found. Taken altogether, these results help better understand the effects of ionizing radiation on bees by identifying relevant physiological markers of effects. These results could improve the assessment of the environmental risk due to ionizing radiation in terrestrial ecosystems., (Copyright © 2019 Elsevier Inc. All rights reserved.)

There is widespread degradation of the environment of the Niger Delta region of Nigeria such that the United Nations Environment Program described it as an ecological wasteland. The contamination is due mainly to unregulated oil and gas production activities leading to oil spills and illegal disposal of contaminated materials, indiscriminate industrial and domestic discharges into water bodies. This widespread contamination includes naturally occurring radioactive materials (NORM) and technologically enhanced radioactive materials (TENORM). NORMs are naturally associated with every mineral in the earth crust, thus the exploitation of such minerals may transport NORM to the surface as TENORM. If uncontrolled by operators and unregulated by government agencies, NORM can find its way into surface and ground water, seafood and even crops consumed by humans. The Niger Delta region is the hub of oil and gas activities providing huge employment and socioeconomic benefits to its indigenes and accounting for more than 90% of foreign exchange earnings for the country. However, uncontrolled spills and discharges from these activities have left the land desolate, degrading most of its aquifers and surface waters, leaving the indigenes with a Hobson choice, eating and drinking contaminated substances everyday of their lives. It is expedient that attention be drawn to this area as radionuclides such as Po-210, Pb-210 and Ra-226 have been confirmed as radiotoxic and may be responsible for several new cases of health challenges reported in the study area over the years., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Amanita muscaria collected from a forested area in northern Poland in 2015 were analysed for activity concentrations of 137 Cs and 40 K. Total K concentration values were calculated from 40 K data. Mushrooms were grouped in six fruiting bodies size classes regarding to their developmental stage. The 137 Cs activity concentrations declined in A. muscaria as the fruiting bodies maturated. The contents of 40 K/K activity remained constant in caps at different developmental stage, while for stipes an increase was around twofold ( 40 K from 925 ± 55 Bq kg -1 dry biomass in the baby individuals and 1600 ± 63-1700 ± 53 Bq kg -1 dry biomass in two oldest classes). A. muscaria is a weak accumulator of 137 Cs, while a steep drop in activity concentrations of this nuclide in the fruiting bodies as they maturate has not been reported earlier for mushrooms. Clearly, a fate of 137 Cs in A. muscaria is highly different from that of 40 K/K that is an essential element to fungi. In parallel, an observed increase in the content of 40 K/K in stipes of fruiting bodies with developmental state can be related to its 'hardening' and more fibrous nature with age and basic function to support the cap, but this has not been studied.

Environmental radiation monitoring networks have been established in Europe and world-wide for the purpose of protecting population and environment against ionizing radiation. Some of these networks had been established during the cold war period and were improved after the Chernobyl accident in 1986. Today, the German Federal Office for Radiation Protection (BfS) operates an early warning network with roughly 1800 ambient dose equivalent rate (ADER) stations equally distributed over the German territory. The hardware and software of all network components are developed in-house allowing the continuous optimization of all relevant components. A probe characterization and quality assurance and control program are in place. Operational and technical aspects of the network and data harmonization techniques are described. The latter allows for calculating of the terrestrial and net ADER combined with uncertainties mainly from site specific effects. Harmonized data are finally used as input to the German emergency management system and the European radiological data exchange platform., (© The Author(s) 2018. Published by Oxford University Press.)

The bioassay of urine and fecal samples has been used since the 1940s to determine an individual's uptake of uranium and actinide elements such as americium and plutonium. Over the years, several analytical separation methods and techniques have been employed for these types of analyses. Analytical separations, ranging from solvent extraction and anion exchange to chromatography, and analytical techniques, ranging from autoradiography to kinetic phosphorescence to fission-track analysis and high-resolution solid-state alpha spectroscopy, have been used at one time or another. Over the last few decades, there have been significant advances in radiochemical separations, as well as an increased use of mass spectroscopy, to determine trace and ultratrace levels of actinides in urine and fecal samples. This review summarizes and discusses developments in radiochemical separation methods and advancements in analytical techniques for actinide bioassay since the early 1940s to the present, followed by a recent development and trend in the bioassay of actinides-particularly in urine and fecal samples.

As a response to the Tokyo Electric Power Company's Fukushima Daiichi nuclear power plant accident in 2011, seven TEPCO workers whose exposure doses were expected to be >250 mSv (a tentative dose limit stipulated by the Japanese central authority) attended Japan's National Institute for Radiological Sciences for additional internal dose measurements. The National Institute for Radiological Sciences examination revealed that these workers' internal doses came mainly from their intake of the radionuclide I during emergency operations. In this study, we performed numerical simulations based on individual volume-pixel (voxel) phantoms of six of the seven workers for a more sophisticated evaluation of their internal doses, taking into account the individual thyroid size and other specific parameters. The voxel phantoms were created from magnetic resonance imaging scan images. As a result, the individual thyroid volumes ranged from 6.5 to 28.2 cm and were considerably smaller than the reference value (~20 cm) adopted in the International Commission on Radiation Protection's dosimetric model for four of the six subjects. Compared to the original estimates of the thyroid absorbed dose, our preliminary evaluation revealed values that were increased by approximately 3-fold or decreased by 30% at maximum. A wide difference in the individual thyroid size would be one of the significant modifiers in the current dose estimation of subjects of the ongoing epidemiological study project. The present simulations also provided evidence that the direct thyroid measurements by the National Institute for Radiological Sciences to determine the workers' I thyroid contents were sufficiently accurate.

Bio-indicator of long time exposure to pollutants, human hair is studied in contaminated areas. The number of studies on background environments remains small, and factors impacting human hair radioactivity in contaminated and background areas remain poorly known. Radon-222, a radioactive noble gas of half-life 3.8 days, is the alpha decay daughter of radium-226 in the uranium-238 chain. Radon emission depends on radium concentration (C Ra ) and probability of decaying radium to liberate radon (i.e., the emanation coefficient E). The radon-222 emanating power (i.e., radon emanation or effective radium-226 concentration, EC Ra ) is measured in the laboratory from human hair of a cohort of 93 individuals living in uranium non-contaminated areas using a high-sensitivity method based on 371 long accumulation sessions. E of human hair is also determined. EC Ra values from human hair are heterogeneous, ranging from 0.059 ± 0.008 to 3.7 ± 0.1 Bq kg -1 (mean: 0.484 ± 0.006 Bq kg -1 ). We find 2.6 ± 0.1 and 2.5 ± 0.1 times larger values for females than males and for color-treated than natural hair, respectively. By contrast, E is homogeneous (mean: 0.33 ± 0.11; n = 9). Our data suggest a different behavior of accumulation/elimination processes of heavy elements in females and non-negligible radium concentration in hair dye products. Our results demonstrate 226 Ra- 238 U disequilibrium in human hair, indicating secondary radium intake, and that EC Ra mainly depends on C Ra . Other factors such as age and sampling time are also studied. The impact of factors on EC Ra from human hair in uranium non-contaminated areas is ordered as follows: (body site?) > sex > hair dyeing > dietary/drinking habits > natural color > time period > geographical location > age. Any human hair-based study should take into consideration these factors. Our method, cost-effective and easy to implement, may be applied to large numbers of samples for large-scale epidemiological studies, and may also be useful for criminal investigations., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Effective decontamination of large-scale areas such as roads and parking lots after an accidental or intentional radiological incident is important in order to contain the spread of contamination and avoid the need for long-term evacuation of urban areas. As a simulation, large coupons (surface area 3600 cm 2 ) made of concrete patio stone and aged asphalt (from a parking lot) were contaminated with either 60 Co or 137 Cs solutions and then decontaminated. The decontamination process consisted of a six-component water-based chemical formulation applied using a common house-hold carpet cleaner. Tests were carried out to compare the effectiveness of decontamination using deionized water (simulating rain fall) and chemical formulation. Test results showed that rain fall prior to decontamination lowered the effectiveness of a subsequent decontamination regardless of the surface type or radionuclide. Tests were also carried out to determine if the decontamination effectiveness increased with multiple applications. Using multiple applications of the chemical formulation, the removal of 60 Co from concrete patio stone and aged asphalt were 65 ± 2% and 70 ± 3%, respectively, while the removal of 137 Cs was 53 ± 3% from asphalt surfaces and 21 ± 8% from concrete patio stone. This paper summarizes the work carried out to prepare for the tests, presents the test results and compares the process to several other processes in terms of effectiveness and suitability for application on a large scale., (Copyright © 2019. Published by Elsevier Ltd.)

Ramsar, in the north of Iran by the Caspian Sea, has been known for the highest natural radiation background on Earth due to the local geology and hydrogeology. The residents and visitors use the hot springs that distribute the natural radionuclides especially 226 Ra and its decay products in the areas. Many studies have been undertaken to measure the absorbed dose rate in Ramsar's air, however, no survey has been done to assess public internal exposure from ingestion of natural radionuclides, such as, a broad survey for 226 Ra was conducted in foodstuffs and drinking water. This study presents the results of public annual activity intake (Bq) and effective dose (μSv) from ingestion of 226 Ra in foodstuffs and drinking water in Ramsar city. The total mean annual intake for adults was found to be 24.8 Bq. The annual average effective dose due to ingestion exposure to 226 Ra was found to be 6.9 μSv for adults that were slightly more than the estimated global averages reported by UNSCEAR, 2000 (6.3 μSv). The contribution of drinking water and foodstuffs represent respectively about 30% and 70% of the total mean annual effective dose due to 226 Ra. The highest effective dose from ingestion of 226 Ra for adults was estimated to be 80.6 μSv y -1 . Based on the results of this study, even with the largest 226 Ra value in our survey, maximum annual effective dose due to consumption of foodstuffs and drinking water for children was 164.2 μ b Sv y -1 ., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This study entails the measurement of the specific activity of natural radionuclides ( 226 Ra, 40 K and 232 Th) in 18 tooth samples obtained from the clinic of the Universiti Sains Malaysia (USM), Penang, by using an HPGe detector. The specific activity of 226 Ra, 40 K and 232 Th was measured to estimate the hazard index of the radionuclides, radium equivalent activities (Ra eq ), external, internal hazard indices (H ex , H in ), and absorbed dose (D out , D in ). The maximum values of concentration of 226 Ra, 232 Th and 40 K in the tooth samples were found to be 60.82, 60.29 and 594.22 Bq kg -1 , respectively. Maximum values of Ra eq , H ex , H in , D out and D in were found to be 192.78 Bq kg -1 , 0.520, 0.685, 89.29 and 169.81 nGy h -1 , Iγ and Iα as 0.702 and 0.304, respectively. The results were lower than the average world value (UNSCEAR). In addition, a strong correlation was found between the concentrations of 226 Ra and Ra eq , between energy and net area, as well as between radionuclides ( 226 Ra, 40 K and 232 Th) in tooth samples and age of volunteers. This study showed that the concentrations and hazard indices of tooth samples are below the recommended safe levels; therefore, the study area is considered safe in terms of radiological health hazards.

An altitude-based background correction strategy was developed for use in the application of pattern recognition methods to the classification of gamma-ray spectra collected during airborne surveys. Application of this methodology helped to suppress the background spectral variation that serves to obscure the photopeaks associated with low levels of gamma-ray emission. The correction method was implemented by optimizing a database of background gamma-ray spectra collected at various locations and altitudes. Given this background database, a field-collected spectrum was corrected by performing linear regression onto a background spectrum from the database at a matching altitude. The residuals about the regression fit were then digitally filtered and submitted to nonparametric linear discriminant analysis for the purpose of computing classification models for targeted radioisotopes. The resulting classifiers were applied to predict the presence or absence of specific radioisotope signatures in data acquired during airborne surveys. Employing data provided by the U.S Environmental Protection Agency Airborne Spectral Photometric Environmental Collection Technology (ASPECT) program, classification models were computed to detect the presence of cesium-137 ( 137 Cs) and cobalt-60 ( 60 Co). The optimized classifiers were tested over 12 diverse locations, with nine of these data sets containing the target radioisotopes. Correct classification percentages of 99.4% and 99.8% were obtained for the 137 Cs and 60 Co classifiers, respectively, on the basis of comparisons to visual inspections of the corresponding spectra., (Copyright © 2018. Published by Elsevier Ltd.)

Accurate and precise analyses of oil and gas (O&G) wastewaters and solids (e.g., sediments and sludge) are important for the regulatory monitoring of O&G development and tracing potential O&G contamination in the environment. In this study, 15 laboratories participated in an inter-laboratory comparison on the chemical characterization of three O&G wastewaters from the Appalachian Basin and four solids impacted by O&G development, with the goal of evaluating the quality of data and the accuracy of measurements for various analytes of concern. Using a variety of different methods, analytes in the wastewaters with high concentrations (i.e., >5 mg L-1) were easily detectable with relatively high accuracy, often within ±10% of the most probable value (MPV). In contrast, often less than 7 of the 15 labs were able to report detectable trace metal(loid) concentrations (i.e., Cr, Ni, Cu, Zn, As, and Pb) with accuracies of approximately ±40%. Despite most labs using inductively coupled plasma mass spectrometry (ICP-MS) with low instrument detection capabilities for trace metal analyses, large dilution factors during sample preparation and low trace metal concentrations in the wastewaters limited the number of quantifiable determinations and likely influenced analytical accuracy. In contrast, all the labs measuring Ra in the wastewaters were able to report detectable concentrations using a variety of methods including gamma spectroscopy and wet chemical approaches following Environmental Protection Agency (EPA) standard methods. However, the reported radium activities were often greater than ±30% different to the MPV possibly due to calibration inconsistencies among labs, radon leakage, or failing to correct for self-attenuation. Reported radium activities in solid materials had less variability (±20% from MPV) but accuracy could likely be improved by using certified radium standards and accounting for self-attenuation that results from matrix interferences or a density difference between the calibration standard and the unknown sample. This inter-laboratory comparison illustrates that numerous methods can be used to measure major cation, minor cation, and anion concentrations in O&G wastewaters with relatively high accuracy while trace metal(loid) and radioactivity analyses in liquids may often be over ±20% different from the MPV.

A new method for the determination of radium quartet ( 223,224,226,228 Ra) in environmental samples by alpha-particle spectrometry with PIPS detectors is described. This uses 225 Ra as yield tracer, in equilibrium at the beginning with 229 Th. Thorium is removed from the sample by using AG1X8 anion-resin, and then radium isotopes are isolated and purified with a cation-exchange column Biorad AG50X8, verifying that Ac has been fully removed from the sample to ensure the good evaluation of the Ra yield (average decontamination factor > 92%). Finally, the counting source of radium is obtained by micro-precipitation with BaSO 4 . This method produces high spectral resolution (<35 keV), and quantitative Ra recoveries (>70%). In this new method, NH 4 Ac in 0.1 M HNO 3 is used to remove the 225 Ac contained in the sample in order to avoid its future spectral interference in the yield calculation. The method has been validated by using certified reference samples with known concentrations of radium isotopes., (Copyright © 2018. Published by Elsevier Ltd.)

During the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, large amounts of radioactive materials were released into the environment. Among them, a large proportion of the radionuclides, such as Cs, entered into the environment as radioactive microparticles (RMs). In recent years, the characterization of RMs based on synchrotron radiation (SR) techniques has been reported, since their physical and chemical properties played an important role in evaluating the chemical reactions and physical changes that occurred when the nuclear material meltdowns took place. In this review, we summarize separation and measurement technologies used in studies of RMs, and we emphasize the application of SR-based techniques in the characterization of RMs. We report research progress, including information for elemental composition, isotopic distribution, radioactivity, and formation processes. Also, we compare the RMs from the FDNPP and the Chernobyl Nuclear Power Plant accidents. The SR-based technologies offer great improvement in the resolution and precision compared to conventional technologies, such as X-ray fluorescence and X-ray diffraction., (Copyright © 2018. Published by Elsevier Ltd.)

The decommissioning of nuclear installations represents a complex process resulting in the generation of large amounts of waste materials containing various concentrations of radionuclides. Selection of an appropriate strategy of management of the mentioned materials strongly influences the effectiveness of decommissioning process keeping in mind safety, financial and other relevant aspects. In line with international incentives for optimization of radioactive material management, concepts of recycling and reuse of materials are widely discussed and applications of these concepts are analysed. Recycling of some portion of these materials within nuclear sector (e.g. scrap metals or concrete rubble) seems to be highly desirable from economical point of view and may lead to conserve some disposal capacity. However, detailed safety assessment along with cost/benefit calculations and feasibility study should be developed in order to prove the safety, practicality and cost effectiveness of possible recycling scenarios. Paper discussed the potential for recycling of slightly radioactive metals arising from decommissioning of NPPs within nuclear sector in Slovakia. Various available recycling scenarios are introduced and method for overall assessment of various recycling scenarios is outlined including the preliminary assessment of safety and financial aspects., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Buffer materials such as bentonite are vital for absorbing radionuclide leakage and retarding migration from radioactive waste canisters. The diffusion coefficient and the retardation factor are the predominant properties controlling the diffusion-reaction process in a buffer material. Diffusion experiments combined with Crank's graphical method are a well-established process for determining asymptotic diffusion coefficients. However, the inaccuracy of the diffusion coefficient that results from the subjective judgement of the late-time linear part of the cumulative concentration data in Crank's graphical method will deteriorate the estimate of the retardation factor. A novel parameter identification process based on an iterative and analytical method (PIPIAM) is proposed here to obtain the diffusion coefficients and porosity of bentonite using concentration data. The results of PIPIAM and the graphical method are compared through an error analysis of concentration. The results show that PIPIAM outperforms the graphical method in terms of the error reduction of the concentration and the uncertainty decrease of the estimated parameters. The proposed method is thus a good alternative for acquiring transport parameters for use in safety assessments of nuclear waste repositories., (Copyright © 2018. Published by Elsevier Ltd.)

The European Atlas of Natural Radiation is a collection of maps displaying the levels of natural radioactivity caused by different sources. It has been developed and is being maintained by the Joint Research Centre (JRC) of the European Commission, in line with its mission, based on the Euratom Treaty: to collect, validate and report information on radioactivity levels in the environment of the EU Member States. This work describes the first version of the European Atlas of Natural Radiation, available in digital format through a web portal, as well as the methodology and results for the maps already developed. So far the digital Atlas contains: an annual cosmic-ray dose map; a map of indoor radon concentration; maps of uranium, thorium and potassium concentration in soil and in bedrock; a terrestrial gamma dose rate map; and a map of soil permeability. Through these maps, the public will be able to: familiarize itself with natural environmental radioactivity; be informed about the levels of natural radioactivity caused by different sources; have a more balanced view of the annual dose received by the European population, to which natural radioactivity is the largest contributor; and make direct comparisons between doses from natural sources of ionizing radiation and those from man-made (artificial) ones, hence, to better assess the latter. Work will continue on the European Geogenic Radon Map and on estimating the annual dose that the public may receive from natural radioactivity, by combining all the information from the different maps. More maps could be added to the Atlas, such us radon in outdoor air and in water and concentration of radionuclides in water, even if these sources usually contribute less to the total exposure., (Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident has caused significant radionuclide contamination. Pu isotopes at the level of GBq were released from the damaged reactors to terrestrial and marine ecosystems. In this work, 35 samples were collected at different locations of Fukushima. Samples consisted of three types, soil, forest litter and alluvial dust (road dust, sludges from drainage systems and below gutter pipe outflows). The obtained activity ratios of 238 Pu/ (239+240) Pu ranged from 0.030 to 1.86. 14 of our samples contained trace amounts of Pu originating from the damaged reactors (2SM verification). Our study identified a few previously unknown "hot spots" of 238 Pu/ (239+240) Pu activity ratio localized in an area between 15 and 30 km in the northwest direction from the FDNPP. Additionally, results obtained in this study combined with previously published data allowed us to prepare a map of spatial distribution of the Pu isotope fingerprints ( 238 Pu/ (239+240) Pu) in Fukushima Prefecture., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The first nationwide indoor radon survey in Montenegro started in 2002 and year-long radon measurements with CR-39 track-etch detectors, within the national grid of 5 km × 5 km and local grids in urban areas of 0.5 km × 0.5 km, were performed in homes in half of the country's territory. The survey continued in 2014 and measurements in the rest of the country were completed at the end of 2015. The 953 valid results, obtained in the national radon survey, give an average radon activity concentration in Montenegrin homes of 110 Bq/m 3 . Assuming a log-normal distribution of the experimental results, geometric mean GM = 58.3 Bq/m 3 and geometric standard deviation GSD = 2.91 are calculated. However, normality tests show that the experimental data are not log-normal, and that they become closest to a log-normal distribution after subtracting from them radon concentration in the outdoor air of 7 Bq/m 3 , which is theoretically calculated. Such a transformed distribution has GM tr  = 46.7 Bq/m 3 and GSD tr  = 3.54. The estimations derived from positing a priory that the experimental results conform to a log-normal distribution underestimate the percentage of homes with radon concentrations at the thresholds of 300 Bq/m 3 and above, which is better estimated by using GM tr and GSD tr . Based on the results of radon survey, a new national radon reference level of 300 Bq/m 3 and an "urgent action level" of 1000 Bq/m 3 are suggested, with estimated fractions of the national dwelling stock above these levels of 7.4% and 0.8% respectively. Fractions of homes with radon concentrations above the suggested levels are also estimated for each of the 23 municipalities in Montenegro, using appropriate GM tr and GSD tr . The six municipalities which have more than 10% of homes with radon concentration above 300 Bq/m 3 are recommended as radon priority areas., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

To study the level of radioactivity concentrations from a coal-based power plant (Barapukuria, Bangladesh) and to estimate the associated radiological hazards, coal and associated combustion residuals from the power plant were analyzed by gamma-ray spectrometry with high-purity germanium (HPGe) detector. The results reveal that the mean radioactivity (Bq kg -1 ) concentrations in feed coal samples are 66.5 ± 24.2, 41.7 ± 18.2, 62.5 ± 26.3, and 232.4 ± 227.2 for U-238, Ra-226, Th-232, and K-40, respectively, while in coal combustion residuals (CCRs), they are 206.3 ± 72.4, 140.5 ± 28.4, 201.7 ± 44.7, and 232.5 ± 43.8, respectively. With the exception of K-40, all the determined natural radionuclides are considerably higher in the investigated feed coal and associated combustion residues as compared with the world soil and world coal mean activities. On the average, CCRs contains 3.10-3.37 times more natural radionuclides than the feed coal, except for K-40. The radioactivity of fly ash and bottom ash is fractionated, and ratio ranges from 1.40 to 1.57. The mean values of the radiological hazard indices in the coal and their associated residuals are 153.1 and 446.8 Bq kg -1 for radium equivalent activity, 0.41 and 1.21 for the external hazard index, 70 and 200.1 nGy h -1 for the absorbed gamma dose rate, 0.09 and 0.25 mSv year -1 for the annual effective dose rate, and 3.0 × 10 -4 and 8.6 × 10 -4  Sv -1 for the excess lifetime cancer risk, respectively, most of which exceed the UNSCEAR-recommended respective threshold limits. The outcome of this study suggests a potential radiological threat to the environment as well as to the health of occupational workers and nearby inhabitants from the examined samples.

Since the first widespread use of depleted uranium in military in the 1991 Gulf War, the so-called "Gulf War Syndrome" has been a topic of ongoing debate. However, a low number of reliable scientific papers demonstrating the extent of possible contamination as well as its connection to the health status of residents and deployed veterans has been published. The authors of this study have therefore aimed to make a selection of data based on strict inclusion and exclusion criteria. With the goal of clarifying the extent of DU contamination after the Gulf Wars, previously published data regarding the levels of DU in the Middle East region were analyzed and presented in the form of a meta-analysis. In addition, the authors attempted to make a correlation between the DU levels and their possible effects on afflicted populations. According to results observed by comparing 234 U/ 238 U and 235 U/ 238 U isotopic activity ratios, as well as 235 U/ 238 U mass ratios in air, water, soil and food samples among the countries in the Middle East region, areas indicating contamination with DU were Al Doha, Manageesh and Um Al Kwaty in Kuwait, Al-Salman, Al-Nukhaib and Karbala in Iraq, Beirut in Lebanon and Sinai in Egypt. According to these data, no DU contamination was observed in Algeria, Israel, Afghanistan, Oman, Qatar, Iran, and Yemen. Due to the limited number of reliable data on the health status of afflicted populations, it was not possible to make a correlation between DU levels and health effects in the Middle East region., (Copyright © 2018. Published by Elsevier Ltd.)

Water can become contaminated as a result of a leak from a nuclear facility, such as a waste facility, or from clandestine nuclear activity. Low-level on-line radiation monitoring is needed to detect these events in real time. A Bayesian control chart method, Shiryaev-Roberts (SR) procedure, was compared with classical methods, 3-σ and cumulative sum (CUSUM), for quantifying an accumulating signal from an extractive scintillating resin flow-cell detection system. Solutions containing 0.10-5.0 Bq/L of 99 Tc, as T99cO 4 - were pumped through a flow cell packed with extractive scintillating resin used in conjunction with a Beta-RAM Model 5 HPLC detector. While T99cO 4 - accumulated on the resin, time series data were collected. Control chart methods were applied to the data using statistical algorithms developed in MATLAB. SR charts were constructed using Poisson (Poisson SR) and Gaussian (Gaussian SR) probability distributions of count data to estimate the likelihood ratio. Poisson and Gaussian SR charts required less volume of radioactive solution at a fixed concentration to exceed the control limit in most cases than 3-σ and CUSUM control charts, particularly solutions with lower activity. SR is thus the ideal control chart for low-level on-line radiation monitoring. Once the control limit was exceeded, activity concentrations were estimated from the SR control chart using the control chart slope on a semi-logarithmic plot. A linear regression fit was applied to averaged slope data for five activity concentration groupings for Poisson and Gaussian SR control charts. A correlation coefficient (R 2 ) of 0.77 for Poisson SR and 0.90 for Gaussian SR suggest this method will adequately estimate activity concentration for an unknown solution., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Rapid determination of selected gross alpha and beta emitters in environmental matrices by solid-state scintillation technique is discussed. This method is based on sample treatment using microwave reactor and direct measurement of digested products using powder scintillator and alkaline solution as a substitute for traditional liquid scintillation cocktail. The selected group of radionuclides was chosen with respect to their use in nuclear industry, high radiotoxicity, and the possibility of potential misuse. The work aimed at verifying the connection of microwave decomposition using alkaline solution with solid-state scintillation using a powder scintillator YAP:Ce together with an alkaline medium., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

The high fission yield product 90 Sr has been released into the environment in large amounts due to nuclear weapon tests, nuclear power plant accidents, and nuclear fuel reprocessing industries. It is a long half-life radionuclide (28.9 y), with serious consequences to human health; hence, it is desirable to perform routine monitoring of 90 Sr in environmental samples. Many 90 Sr radiometric methods have been developed in the past decades, which generally require complicated separation and purification steps with a relatively long analytical time. Moreover, some nominally rapid methods usually have high method detection limits, making them unsuitable for the environmental samples with ultra-low 90 Sr levels. In this review, some rapid and practical methods for 90 Sr routine monitoring are summarized. Different sample pretreatments and major purification procedures for 90 Sr developed in recent years, such as variable digestion methods and extraction chromatography using Sr resin or DGA resin, are especially described. Additionally, four conventional and widely used β spectrometric and mass spectrometric methods are demonstrated. Finally, 90 Sr evaluations focusing on contaminated soil and seawater samples collected after the Fukushima Daiichi Nuclear Power Plant accident, and 90 Sr application as tracers for environmental behavior are also reviewed., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

During the last days of September to the first days of October in 2017, a unique detection of 106 Ru was observed in air filters sampled at different locations in Sweden via the national air monitoring network. Furthermore, measurements of precipitation also showed the presence of 106 Ru. This initiated soil sampling and in situ gamma-ray spectrometry at one of the locations., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

A simple, rapid and cost-efficient method for determination of activity concentration of 90 Sr in biological samples with an extraction chromatographic column (crown ether on teflon powder) and following counted by liquid scintillation counting was developed in this paper. The column retained most of 90 Sr while almost all of matrix ions were removed during rinsing steps with 8M nitric acid and finally 90 Sr was eluted with deionized water, the chemical recovery of strontium is greater than 60%, almost all of matrix ions were removed by the procedure we reported. Finally the uncertainty was evaluated and minimum detectable activity of this method is 1.28Bq/kg., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Mapping the radiation distribution on ground during a radiological emergency monitoring, or decontamination mission is an important task. Accurate knowledge of the radioactivity distribution can help radiation workers locate the contamination, which reduces unnecessary radiation exposure to personnel and perhaps to some extent also the exposure to the public. Recently, radiation monitoring systems based on unmanned aerial vehicles (UAV) have been widely studied and employed. However, development of algorithms for mapping the contamination from measured data obtained by the detection system mounted on an UAV is still lacking. In this work, we implemented an advanced statistical reconstruction algorithm for mapping spread and point radiation contamination. The algorithm significantly improves accuracy in the scope and location of radiation contamination., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

This paper summarizes the results of the decontamination of the infrastructure materials concrete, limestone, brick and asphalt contaminated with 60 Co, 85 Sr, 137 Cs and 241 Am. The paper focuses on the effect of differences in substrate properties and of the pH of the radionuclide solution used for surface contamination on adsorption or ion exchange of the radionuclides and how these factors affect the decontamination effectiveness. A six-component chemical formulation was used and a process effectiveness of up to 76% was obtained depending on the substrate and radionuclide. Asphalt was the easiest material to decontaminate because of its more hydrophobic nature. Concrete and limestone (and to some extent brick) were less effectively decontaminated as their porous surfaces allowed penetration of radionuclides into water-filled pores in the substrate facilitating adsorption or ion exchange and making them difficult to remove. Brick was the most difficult material to decontaminate because the major component of brick is clay which retains most mono- and divalent ions. The removal of 60 Co, 85 Sr and 137 Cs from the surfaces of concrete, limestone and brick increased when the pH of the radionuclide solutions was moderately acidic to neutral compared to when they were highly acidic. The variability in the test results was similar to that observed in other studies using other decontamination methods, attributed to the inhomogeneity of the substrates used and considered representative of real infrastructure materials., (Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.)