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Today radioactivity monitoring in the environment is required not only around sites where the significant amounts of radioactive material are used or stored, but in a number of other processes as land remediation or decommissioning of nuclear plants. Since the end of the 20th century there has been an increasing awareness of the so-called technologically enhanced natural radioactivity and the need for its monitoring in a wide range of nonnuclear industries including oil and gas extraction, ceramic and glass industries, production of phosphoric acid, production of different phosphoric fertilizers and other chemical industries. Coal electric power plants as significant sources of ashes and other contaminants are included, too. Contrary to nuclear facilities or radioactive waste control these processes require measuring radionuclides at very low levels of radioactivity. This demands specific methodology and instrumentation and responding to the very real economic importance of classifying waste products from decommissioning and remediation processes. However, natural or man made, waste or industrial, environmental radioactivity monitoring requires adequate equipment calibrated in the full range of radionuclides likely to be encountered, as well as trained and experienced personnel. It is the task of national metrological institutions to provide radioactive reference materials and standards for calibration as pure isotopes, mixtures of isotopes or reference materials for particular applications and to supervise the processes of quality control and quality assurance. Besides primary standards and reference materials national metrological institutions should provide laboratory proficiency testing exercises to support radioactivity measurements within academic, industrial or research laboratories (Spasic, 1984; Spasic, 1985; Spasic, 1987a; Spasic et al. 1987).

This review paper discusses the content of natural ( 40K, 238U, 226Ra, and 232Th) and artificial (137Cs) radionuclides in the soil of the mountains of Maljen, Tara and Kopaonik in the Republic of Serbia over 2002-2015. In addition, the paper gives radiation hazard parameters, i.e., radium equivalent activity, absorbed dose rate, annual effective dose equivalent, external hazard index, annual gonadal dose equivalent, and excess lifetime cancer risk outdoors that we calculated from the obtained content of the natural radionuclides in the soil samples. We compared the parameters to previously published results for different parts of the country and looked into the radioecological status of the investigated areas. U radu su prikazani rezultati gamaspektrometrijskog određivanja sadržaja prirodnih (40K, 238U, 226Ra i 232Th) i proizvedenog (137Cs) radionuklida u zemljištu sa područja planina Maljen, Tara i Kopaonik. Uzorci zemljišta prikupljeni su u periodu od 2002. do 2015. godine na različitim nadmorskim visinama. Na osnovu sadržaja radionuklida u zemljištu odredili smo parametre radijacionog rizika: radijum ekvivalentnu aktivnost, jačinu doze, godišnju efektivnu dozu spoljašnjeg zračenja, indeks spoljašnjeg hazarda, godišnju gonadnu dozu i faktor rizika pojave kancera na području planinskih regiona Republike Srbije, i potom ih uporedili sa ranije objavljenim rezultatima za pojedine regione Republike Srbije.

Kaolins are used in a multiplicity of industries because of unique physical and chemical properties. Relationships between thermal and radioactivity properties are discussed in its application as a building material. Super-fine kaolin powder with particle sizes about 30 mu m was analyzed. Simultaneous TGA/DTA analysis was performed on powder samples at various heating rates in an argon atmosphere. Based on investigated thermal properties, it was concluded that dehydroxylation process can vary depending on the characteristics of starting material. The maximum degree of the dehydroxylation (D (T)) was obtained at the lowest rate of heating (D (T) = 60.79% for 10 A degrees C min(-1)). With an increase in the heating rate, decline in D (T) value was observed. Based on comprehensive testing, it was identified that the degree of dehydroxylation does not drop below 50%. It was concluded that appointed experimental conditions seem sufficient admissible for obtaining degree of dehydroxylation (D (T)) higher than 50%. In order to safe use of kaolin as a building material from the standpoint of radiological safety, content of natural radionuclides was determined by gamma spectrometry.

Significance A massive atmospheric release of radioactive 106Ru occurred in Eurasia in 2017, which must have been caused by a sizeable, yet undeclared nuclear accident. This work presents the most compelling monitoring dataset of this release, comprising 1,100 atmospheric and 200 deposition data points from the Eurasian region. The data suggest a release from a nuclear reprocessing facility located in the Southern Urals, possibly from the Mayak nuclear complex. A release from a crashed satellite as well as a release on Romanian territory (despite high activity concentrations) can be excluded. The model age of the radioruthenium supports the hypothesis that fuel was reprocessed ≤2 years after discharge, possibly for the production of a high-specific activity 144Ce source for a neutrino experiment in Italy., In October 2017, most European countries reported unique atmospheric detections of aerosol-bound radioruthenium (106Ru). The range of concentrations varied from some tenths of µBq·m−3 to more than 150 mBq·m−3. The widespread detection at such considerable (yet innocuous) levels suggested a considerable release. To compare activity reports of airborne 106Ru with different sampling periods, concentrations were reconstructed based on the most probable plume presence duration at each location. Based on airborne concentration spreading and chemical considerations, it is possible to assume that the release occurred in the Southern Urals region (Russian Federation). The 106Ru age was estimated to be about 2 years. It exhibited highly soluble and less soluble fractions in aqueous media, high radiopurity (lack of concomitant radionuclides), and volatility between 700 and 1,000 °C, thus suggesting a release at an advanced stage in the reprocessing of nuclear fuel. The amount and isotopic characteristics of the radioruthenium release may indicate a context with the production of a large 144Ce source for a neutrino experiment.

The gamma spectrometry of environmental samples poses a series of specific problems for the practitioner. The determination of full energy peak efficiencies is, in the case of environmental samples, one of the greatest challenges. In this paper, the calibration of two HPGe detectors for environmental samples in Marinelli beakers was performed using the newly developed MEFFTRAN software. The results obtained with MEFFTRAN were compared to the experimental efficiencies measured using the calibration sample produced at the Laboratory for Radiation and Environment Protection, Institute for Nuclear Sciences Vinca, Belgrade, in order to confirm the validity of the calculation. It is shown that calculated and experimental efficiencies are in good agreement with the discrepancies from -3.9% to +1.5%. The results were also validated by measuring secondary reference materials provided by the IAEA within several interlaboratory proficiency tests. The activity concentration of the radionuclides in the secondary reference materials was determined using the efficiency obtained by MEFFTRAN and compared with the target value given by the IAEA. All the results in materials provided by the IAEA were acceptable except one, proving, that MEFFTRAN produces satisfactory results. (C) 2016 Elsevier Ltd. All rights reserved.

This study of environmental radioactivity was carried out in the soils of an urban area. Naturally occurring gamma-emitting radionuclides and man-made Cs-137 were found in the soil profiles collected from four parks in the central Belgrade city area and the soil layer was examined every 10 cm and to a depth of 50 cm. Radioisotope activity concentrations (Bq kg(-1)) in the samples of urban soil using the gamma-ray spectrometry method were in the range of 14-46 for U-238, 33-50 for Ra-226, 29-63 for Pb-210, 1.2-3.4 for U-235, 28-50 for Th-232, 424-576 for K-40 and 0.7-35.8 for Cs-137. Some of the basic physicochemical soil properties (pH, organic matter content, calcium-carbonate content, particle size distribution) were determined to investigate the impact on the vertical distribution of radionuclides. The results of this investigation showed that variations of activity concentration ratios of radionuclides that belong to the same (U-238/Ra-226) or different radioactive series (Th-232/Ra-226; U-235/U-238), including Pb-210/Cs-137 ratios could well be explained by the properties of the soil. Alkaline pH reaction, the accumulation of organic matter in the uppermost and of carbonates in the deepest layers of urban soil had an effect on U-238/Ra-226, and Pb-210/Cs-137 activity concentration ratio values, while Th-232/Ra-226 and partially U-235/U-238 ratios were associated with the particle sizes vertical distribution. A study of radionuclides in the samples of leaves of two deciduous tree species common for these parks was also conducted and Pb-210 and K-40 were found concentrated in leaves rather than other investigated radionuclides.

The study of spatial distribution of activity concentration of 238U, 226Ra, 210Pb, 232Th, 40K, and 137Cs radionuclides in the surface soil samples (n = 42) collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg-1] in the range: 15-117 for 238U, 21-115 for 226Ra, 33-65 for 210Pb, 20-69 for 232Th, 324-736 for 40K, and 2-59 for 137Cs. Surface soil radio-activity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity (

Investigation of the natural radioactivity levels in water around power plants, as well as in plants, coal, ash, slag and soil, and to assess the associated radiation hazard is becoming an emerging and interesting topic. This paper is focused on the results of the radioactivity analysis in waste water samples from five coal fired power plants in Serbia (Nikola Tesla A, Nikola Tesla B, Kolubara, Morava and Kostolac), which were analyzed in period 2003–2015. River water samples taken upstream and downstream from the power plants, drain water as well as overflow water were analyzed. In the water samples gamma spectrometry analysis was performed as well as determination of gross alpha and beta activity. Natural radionuclide 40 K was detected by gamma spectrometry, while the concentrations of other radionuclides, 226 Ra, 235 U and 238 U usually were below the minimum detection activity (MDA). 232 Th and artificial radionuclide 137 Cs was not detected in these samples. Gross alpha and beta activity were determined by α / β low level proportional counter Thermo Eberline FHT 770 T. In the analyzed samples, gross alpha activity ranged from MDA to 0.47 Bq L − 1 , while the gross beta activity ranged from MDA to 1.55 Bq L − 1 .

The activity concentrations of natural radionuclides ((40)K, (210)Pb, (210)Po, (226)Ra and (228)Ra) in 17 most frequently used cigarette brands in Serbia and corresponding effective doses due to smoke inhalation are presented. The mean annual effective doses for (210)Pb and (210)Po were estimated to be 47.3 and 724 µSv y(-1) for (210)Pb and (210)Po, respectively. Serbia currently has the highest smoking rate in the world. The results of this study indicate the high contribution of the annual effective dose due to smoke inhalation to the total inhalation dose from natural radionuclides. The more effective implementation of actions for reducing smoking prevalence in Serbia is highly needed.

Specific activity of tritium (H-3) in precipitation and specific activity of Cs-137 in ground-level air were monitored at three locations in Belgrade (Meteorological Station of Belgrade at Zeleno Brdo (ZB), Meteorological Station Usek (USEK), and Vina Institute of Nuclear Sciences (VINS)). Data presented cover the period 1985-1997 for Cs-137 for all locations and 1985-2009 (ZB), 1988-1997 (USEK), and 1988-2009 (VINS) for H-3. Concentrations of H-3 in precipitation have been determined using electrolytic enrichment and liquid scintillation spectrometer LKB-Wallac 1219 RackBeta. The activity of Cs-137 in air was determined on an HPGe detector (Canberra, relative efficiency 23 %). H-3 concentrations in precipitation ranged from 0.40 +/- 0.08 to 74.6 +/- 5.2 Bq l(-1) decreasing with distance from the nuclear facilities. Significantly higher tritium levels were measured in samples in VINS compared with those from an off-site location. The observed seasonal variations of tritium concentration indicate the stratospheric source of tritium. Increases in activity concentration of Cs-137 in the atmosphere were observed after the nuclear plant accident at Chernobyl in April 1986. The concentrations obtained for Cs-137 in 1986 were compared with the integrated air concentrations of Cs-137 in the region. The increases of Cs-137 air concentrations in 1987 and 1988 were attributed to local resuspensions from the ground. Since 1989, the activity level before the accident has been obtained. The average monthly concentrations of Cs-137 in ground-level air were shown spread maximum in spring-summer period and pronounced maximum during winter. The obtained results were statistically analyzed, i.e., the following parameters were determined: tritium deposition, monthly activities of H-3 and Cs-137, seasonal indices, radionuclide loading indices, and linear correlation coefficients.

Natural resources such as ores contain radioactive nuclides at various concentrations. Therefore it is important to investigate the radioactivity in these resources as well as in the soil at the locations of ore deposits. For that reason we conducted preliminary measurements in the soil samples taken from the locations of lead and zinc ore deposits in Bosilegrad and Raška and from the locations of phosphate ore deposits in Bosilegrad to estimate the environmental conditions prior to the ore excavation. The activity concentrations of radionuclides in soil, water and plant samples were determined by gamma spectrometry (HPGe detector, relative efficiency 23%). Results showed the presence of natural radionuclides (226)Ra, (232)Th, (40)K, (235)U, (238)U as well as the produced radionuclide (137)Cs (from the Chernobyl accident). Ambient gamma radiation dose rate in ground level air was also measured. In order to estimate the influence of subsequent mining on the working and living environment, radium equivalent (Ra(eq)), external hazard index (H(ex)), external gamma absorbed dose rate ([Formula: see text]) and annual effective dose (D(E)) were determined.

To assess the validity of the moss bag monitoring technique in the radioactivity control of ground level urban air, a study on radionuclide contents in moss was performed in the city of Belgrade, Serbia. From May 2006 to May 2007, moss (Sphagnum girgensohni, Dubna, Russia) was exposed to the aero pollution in a location in the central area of the city. The activity of 40K, 210Pb, and 137Cs was measured on an HPGe detector (Canberra, relative efficiency 23%) by standard gamma spectrometry. The activities 245 ± 25 Bq/kg for 40K, 315 ± 34 Bq/kg for 210Pb, and 28 ± 4 Bq/kg for 137Cs are in the range of values reported for the region; the differences are due to the moss species, local climate and measuring technique. Taking into consideration the time of the exposure and appropriate calibration procedure, moss bag biomonitoring could be used as a complementary method for determination of radionuclides in urban air. U cilju utvrđivanja valjanosti tehnike aktivnog monitoringa pomoću mahovina u kontroli radioaktivnosti prizemnog sloja atmosfere, na teritoriji grada Beograda sprovedena je studija sadržaja radionuklida u mahovinama. Od maja 2006. do maja 2007. godine, mahovina (Sphagnum girgensohni, Dubna, Rusija) izlagana je vazdušnom zagađenju na lokaciji u centru grada. Koncentracija aktivnosti 40K, 210Pb i 137Cs merena je HPGe detektorom (Canberra, relativne efikasnosti 23%) metodom standardne gama spektrometrije. Koncentracije aktivnosti od 245 ± ± 25 Bq/kg za 40K, 315 ± 34 Bq/kg za 210Pb i 28 ± 4 Bq/kg za 137Cs spadaju u opseg vrednosti izmerenih u regionu; razlike u rezultatima potiču od vrste mahovine, lokalne klime i tehnike merenja. Uzimajući u obzir vreme izlaganja i pravilnu proceduru kalibracije, aktivni monitoring mahovinama može da se primeni kao komplementarni metod za određivanje koncentracije radionuklida u vazduhu u urbanom području.

During 2005 and 2006, soil samples were collected from different regions in the Republic of Srpska, in order to evaluate their radioactivity. During the war that lasted from 1994 to 1995, it is known that some locations in the Republic of Srpska were imposed upon by NATO forces. Sampled locations were chosen far away from the bombed places in order to check whether the depleted uranium was dispersed over long distances. The activity concentrations of radionuclides in soil samples were determined by gamma spectrometry (HPGe detector, relative efficiency 23%). Results showed the presence of natural radionuclides 226 Ra , 232 Th , 40 K , 235 U , 238 U as well as the produced radionuclide 137 Cs (from the Chernobyl accident and nuclear probes). In order to evaluate the radiological hazard of the natural radioactivity, the radium equivalent activity, the gamma-absorbed dose rate, the annual effective dose rate and the external hazard index have been calculated.

This work presents a comprehensive study of natural radioactivity in 720 building materials imported in Serbia in 2012. Radioactivity concentrations of Ra-226, Th-232 and K-40 in the studied samples range from LT 5 to 4,938, LT 3 to 763 and LT 10 to 3,192 Bq kg(-1), respectively. The maximum values of Ra-226 and Th-232 activity concentrations were found in zirconium mineral, while the highest K-40 activity concentration was in the feldspar. Based on the obtained radionuclide concentrations, radium equivalent activity, air absorbed dose rate, annual effective dose, external and internal hazard indices, gamma and alpha index due to radon inhalation were evaluated to assess the potential radiological hazard associated with these building materials.

Measurement of the gross alpha and beta activity concentrations in various matrices is suitable as a preliminary screening procedure to determine whether further analysis related to specific radionuclide is necessary. In Serbia, according to current regulations, radioactivity concentrations in drinking water for gross alpha and gross beta should be < 0.5 and < 1.0 Bq L−1, respectively. The generally accepted methods for gross alpha and beta activity analysis of drinking water in different countries are: EPA 900.0 and ISO methods (ISO 9696, water quality – measurement of gross alpha activity in non-saline water – thick source method, and ISO 9697, water quality – measurement of gross beta activity in non-saline water). This paper describes comparison of preparations and measurement gross alpha and beta activity in bottled mineral waters as well as in tap waters in Serbia using two methods: EPA 900.0 with and without ash, and ISO methods. Concentration of total dissolved solids (TDS) in investigated water samples was determined. Based on obtained TDS, certain volume was evaporated. The instrumentation used to count the gross alpha and gross beta activities for both methods is α/β low level proportional counter Thermo Eberline FHT 770 T.

The paper presents the results of indoor radon concentration survey in 201 homes and offices in Niska Banja (the Spa of Nis), a well-known health resort and a spa in the South-East of Serbia. Radon indoor concentrations were determined by active charcoal method, according to standard EPA procedure. The indoor radon concentrations were in the range of up to 200 Bq/m3 (47%), from 200–600 Bq/m3 (26%) and over 600 Bq/m3 (27%). Three areas of extremely high average radon concentrations were found (1340–4340 Bq/m3), with a maximum above 13,000 Bq/m3.The content of natural radionuclides (226Ra, 214Pb, 214Bi, 235U, 228Ac, 212Pb, 212Bi, 208Tl, 40K) and 137Cs, as well as the content of total uranium, thorium and potassium in mud used in peloidotherapy in the Health Institute “Niska Banja” was determined, too. The activities of the radionuclides were determined on an HPGe detector, by standard gamma spectroscopy. The results indicated considerably high amounts of total uranium and thorium (0.021 g/kg mud and 0.003 g/kg mud, respectively), due to the karsts origin of the soil. Keywords: Radon in air, Radionuclides, Soil, Spa, Gamma spectroscopy

The paper presents the results of radon indoor concentrations measurements in homes and public institutions (kindergardens) in Belgrade, as well as the results of the radionuclides content determination in building materials from Serbia, during the eighties and up to the mid-nineties of the 20th century. The activity of the radionuclides was determined on an HPGe detector (ORTEC relative efficiency 20%) by standard gamma spectrometry. Radon indoor concentrations on the grab samples of air were determined by alpha scintillation technique (Lucas scintilation cell with ZnS/Ag). Mean effective dose equivevalents of radon and its progenies in closed space were estimated at 0.074 mSv for radon and 1.22 mSv for its short-lived daughters, in total 1.3 mSv.

7Be to 210Pb concentration ratios in ground level air on two monitoring stations (MS1 and MS2) in Belgrade area were determined from 1996 to 2001. The average monthly concentrations of 7Be in ground level air were in the range of 0.6-18.3 mBq/m3 and exhibited one or two summer/early fall maxims and one minimum in winter. The maximum concentrations for 210Pb were generally observed in the fall, with the average concentrations in the range of 1.09 x 10(-4) to 30.9 x 10(-4) Bq/m3. The 7Be/210Pb ratios were in the range of 1.7-12.7 (MS1) and 1.8-11.3 (MS2), with summer maxims and late fall/winter minimums. The mean Radionuclides Loading Indices values approach zero except for 1996/1997 (MS1) and 2001 (MS2) due to higher concentrations of 7Be and 210Pb. The mean monthly concentrations of both radionuclides exhibited lognormal distributions. There is significant correlation between the 7Be/210Pb activities ratio and the air stability classes A + B + C for both monitoring stations (correlation coefficients 0.61-0.65), and no correlation with D class and E + F classes. Correlation was found between the activity of 7Be and air stability classes A + B + C (0.46-0.68), and E + F (0.38 for MS1), while for 210Pb, a moderate correlation (0.38-0.40) was found with the E + F air stability classes.

This study focuses on determination of soil to plant transfer factor (TF) of long lived radionuclides 90Sr and 137Cs. 90Sr and 137Cs activity concentration in agricultural soil samples was ranged between

In the 1999 bombing of the Federal Republic of Yugoslavia, NATO forces used ammunition containing depleted uranium. The cleaning of depleted uranium that followed was performed in southern Serbia by the Vinča Institute of Nuclear Sciences between 2002 and 2007 at the locations of Pljačkovica, Borovac, Bratoselce, and Reljan. This paper presents detailed results of radioactivity monitoring four years after cleaning (2011), which included the determination of gamma emitters in soil, water, and plant samples, as well as gross alpha and beta activities in water samples. The gamma spectrometry results showed the presence of natural radionuclides 226Ra, 232Th, 40K, 235U, 238U, and the produced radionuclide 137Cs (from the Chernobyl accident). In order to evaluate the radiological hazard from soil, the radium equivalent activity, the gamma dose rate, the external hazard index, and the annual effective dose were calculated. Considering that a significant number of people inhabit the studied locations, the periodical monitoring of radionuclide content is vital.

Concentrations of 210 Pb in ground level air in the city area (Belgrade, Central Serbia) were measured in the period from 1985 to 1996. The activity of 210 Pb in air filters was determined on a HPGe detector by standard gamma spectrometry. Total standard error of the method was estimated to be below 25%. The average monthly concentrations of 210 Pb in the ground level air in the period from 1985 to 1996 were in the range of 0.30–3.17 mBq m−3 with the maxima in fall–winter periods and minimums in springs and early summers. The seasonal indices were 1.12–1.59 for fall–winter and 0.77–0.92 for spring–summer periods. The ratios of maximum-to-minimum concentrations in each year were relatively stable over the period, with slight increase in 1985, 1989 and 1995. The investigations are part of the long-term measurements of natural and man-made radionuclides in the ground-level air in the region.

The effect of tropopause height on the content of Cs-137 and total beta activity in surface atmosphere was considered for the period of intensive nuclear weapon tests, from 1968-1971. The activity of Cs-137 in monthly air filter samples was measured by gamma spectrometry and total beta activity was determined by 2 pi proportional counters. The results were correlated with data on tropopause height. The results indicate that the movement of radioactive debris from the stratosphere into the troposphere occurs simultaneously with the changes in tropopause height. The content of long lived radionuclides in the troposphere follows the changes with a certain delay due to meteorological conditions in surface air and due to the location of sampling. (C) 1997 Elsevier Science Ltd.

This is a preliminary study of the depth distribution of 137Cs radionuclides in cultivated anthrosol soil of a 15-year old peach tree plantation at the experimental field “Radmilovac” near Belgrade. Before planting, the soil was ploughed at the depth of 1 m. The soil had not been annually ploughed, irrigated and treated with mineral fertilizers for three years before sampling. Activity concentration for 137Cs ranged from 1.8 Bq kg-1 to 35 Bq kg-1. Along the soil depth it varied highly, reaching as high a total variation coefficient as 83 %. Radiocaesium distribution patterns depended on the extent of soil mixing in the plough layer, as it was mechanically transferred from the surface to the lower soil layers during cultivation. 137Cs was associated with humus content and fixation to clay fractions in the soil. Our results single out soil’s hygroscopic water as a valuable parameter for 137Cs behaviour that could be used commonly if the measurement is standardised.

Leaves of linden (Tilia tomentosa L. and Tilia cordata Mill.) and horse chestnut (Aesculus hippocastanum L.) were analysed as biomonitors of radionuclides in urban air. Samples of soils, leaves and aerosols were collected in Belgrade, Serbia. Activities of (137)Cs, (40)K, (210)Pb and (7)Be in the samples were measured on an HPGe detector by standard gamma spectrometry. "Soil-to-leaves" transfer factors were calculated. Student's t test and linear Pearson correlation coefficients were used for statistical analysis. Differences in local conditions at the sampling sites were not significant, and the mechanisms of the radionuclides' accumulation in both plant species are similar. Ceasium-137 was detected in some of the leaf samples only. Transfer factors for (137)Cs and (40)K were (0.03-0.08) and 1.3, respectively. The concentrations of (210)Pb and (7)Be in leaves were higher in autumn than in spring, and there were some similarities in their seasonal patterns in leaves and in air. Weak to medium correlation was obtained for the (210)Pb and (7)Be activities in leaves and aerosols. Large positive correlation was obtained for the (210)Pb activities in linden leaves and the mean activity in aerosols for the preceding months. Different primary modes of radionuclides accumulation in leaves were observed. Since large positive correlation was obtained for the (210)Pb activity in linden leaves and the mean in aerosols for the preceding months, mature linden leaves could be used as biomonitors of recent (210)Pb activity in air.

This work presents the first estimate of the radioactivity and sediment deposition rate of the Drenova reservoir. The radioactivity and sedimentation rate were computed applying the 210Pb and 137Cs methods. Samples of 210Pb and 137Cs were taken from four boreholes drilled in the Drenova reservoir in June 2010. Vertical distribution of the natural and artificial radionuclides in four boreholes was examined using a gamma spectrometry measurement with HpGe detectors, Gamma X type (10 keV-3 MeV). Activities ranging from 122-8 Bq/kg were found for 210Pb, and from 140-0.8 Bq/kg for 137Cs. The sedimentation rate in the Drenova reservoir varied from 1.96 to 2.90 cm per year for unsupported 210Pb and 0.47 to 5.33 cm per year for 137Cs. U ovom radu date su prve procene radioaktivnosti i sedimentne brzine u akumulaciji Drenova. Radioaktivnost i sedimentna brzina određene su korišćenjem takozvane 210Pb i 137Cs metode. Uzorci su sakupljeni iz četiri bušotine iz akumulacije Drenova u toku 2010. godine. Spektrometrijom gama emitera korišćenjem HPGe detektora, GMX tipa (10 keV-3 MeV), određena je vertikalna distribucija prirodnih i veštačkih radionuklida u svim bušotinama. Dobijene vrednosti koncentracije su u intervalu 8-122 Bq/kg za 210Pb, i 0,8-140 Bq/kg za 137Cs. Sedimentna brzina u akumulaciji Drenova je u opsegu 1,96-2,90 cm po godini za korigovan 210Pb i 0,47-5,33 cm po godini za 137Cs.

Radioactive emissions into the atmosphere from the damaged reactors of the Fukushima Dai-ichi nuclear power plant (NPP) started on March 12th, 2011. Among the various radionuclides released, iodine-131 ( 131I) and cesium isotopes ( 137Cs and 134Cs) were transported across the Pacific toward the North American continent and reached Europe despite dispersion and washout along the route of the contaminated air masses. In Europe, the first signs of the releases were detected 7 days later while the first peak of activity level was observed between March 28th and March 30th. Time variations over a 20-day period and spatial variations across more than 150 sampling locations in Europe made it possible to characterize the contaminated air masses. After the Chernobyl accident, only a few measurements of the gaseous 131I fraction were conducted compared to the number of measurements for the particulate fraction. Several studies had already pointed out the importance of the gaseous 131I and the large underestimation of the total 131I airborne activity level, and subsequent calculations of inhalation dose, if neglected. The measurements made across Europe following the releases from the Fukushima NPP reactors have provided a significant amount of new data on the ratio of the gaseous 131I fraction to total 131I, both on a spatial scale and its temporal variation. It can be pointed out that during the Fukushima event, the 134Cs to 137Cs ratio proved to be different from that observed after the Chernobyl accident. The data set provided in this paper is the most comprehensive survey of the main relevant airborne radionuclides from the Fukushima reactors, measured across Europe. A rough estimate of the total 131I inventory that has passed over Europe during this period was \textless1% of the released amount. According to the measurements, airborne activity levels remain of no concern for public health in Europe. © 2011 American Chemical Society.

The radioactivity monitoring in the ?Nikola Tesla?, ?Kolubara?, ?Morava? and ?Kostolac? coal-fired power plants was performed by the Radiation and Environmental Protection Laboratory, Vinca Institute of nuclear sciences in the period 2003-2010. Monitoring included the analysis of soil, water, flying ash, slag, coal and plants. This paper presents the results of the radioactivity analysis of coal, ash and slag samples. Naturally occurring radionuclides 226Ra, 232Th, 40K, 235U, 238U, and 210Pb as well as the man-made radionuclide 137Cs were determined by gamma spectrometry using HPGe detector. The concentrations of pairs of radionuclides were statistically tested to determine the correlation between them. Based on the obtained results, health effect due to the activity of these radionuclides was estimated via radium equivalent (Raeq), external hazard index (Hex), external gamma absorbed dose rate () and annual effective dose.

3.1 Trace elements in moss bags The initial (background) content of elements plays a crucial role in obtaining the relative accumulation level in biomonitoring studies. For most of the examined elements, the initial values in S. girgensohnii, used for active biomonitoring in Belgrade (Aničić et al., 2009a,b), were significantly lower than those from other sites (Adamo et al., 2003; Djingova et al., 2004; Culicov & Yurukova, 2006) or in other Sphagnum spp. (Djingova et al., 2004). The initial element concentrations in S. girgensohnii were even lower than the values proposed by Markert (1992) as “reference plant values” used to compare elements accumulation among the different species. This points to the variation in natural Sphagnum element content from different areas and, consequently, to a necessity to determine the background (control) levels prior to each biomonitoring study. The advantage of low background levels is the higher method sensitivity in areas with low atmospheric deposition (Culicov et al., 2005). Significant accumulation of the majority of examined elements in the S. girgensohnii moss bags were observed over the 3-month exposure periods (Table 1) indicating that this species is an efficient trace element accumulator (Aničić et al., 2009a). Higher element content was

Concentrations of beryllium-7 ((7)Be), lead-210 ((210)Pb) and caesium-137 ((137)Cs) were measured at two sites in the city of Belgrade (Serbia). One monitoring site was located in the central city area with heavy traffic and the other within the Institute of Nuclear Sciences Vinca, in the suburbs. Presented data cover the period 2004-9. Activity of the radionuclides was determined on an HPGe detector (Canberra, relative efficiency 23 %) by standard gamma spectrometry. Activities of (7)Be and (210)Pb exhibit a similar seasonal pattern. The mean monthly concentrations of (7)Be did not exceed 7 mBq m(-3). The maxima are correlated with the seasonal increase in temperature, whereas the minima are linearly correlated with the amount of precipitation. The activity of (210)Pb was below 0.9 mBq m(-3). The activities of both radionuclides were very low in winters and were largely affected by precipitation and snow coverage. Concentrations of (137)Cs were mainly below the limit of detection.

Background, aim and scope The paper presents concentrations of trace elements in blood of homebred animals (cows and sheep) from Southern Serbia (Bujanovac) and the contents of natural and anthropogenic radionuclides and some heavy metals in feed. The region of Southern Serbia was exposed to contamination by depleted uranium ammunition during NATO attacks in 1999 and therefore, is of great concern to environmental pollution and human and animal health. Materials and methods Conventional instrumental and epithermal neutron activation analyses are used to measure trace elements in cow and sheep blood samples collected randomly at six locations in the region of Bujanovac (village of Borovac) in the spring of 2005. Samples of feed (grass and crops: corn, wheat and oats), collected on the same locations (households), are analysed for the contents of radionuclides on an HPGe detector (Ortec, relative efficiency 23%) by standard gamma spectrometry. The content of Hg, Pb and Cd in feed is determined by standard atomic absorption spectrometry on the VarianSpectra220/ThermoSolar GFS97 spectrometer. Results Concentrations of 29 elements (Na, Al (P), Cl, K, Sc, Cr, Mn, Ni, Fe, Co, Zn, Se, As, Br, Sr, Rb, Sb, In, I, Ba, Cs, La, Nd, Eu, Sm, Tb, Hf, Ta and Th) are determined in blood of the examined animals. In feeds, natural 40K is found in all of the samples, cosmogenic Be-7 and fission product Cs-137 are detected only in the grass samples, while heavy metals Hg, Cd and Pb are found in the range of 0.01-0.02, 0.84-1.15 and 0.74-7.34 mg/kg, respectively. Calculated soil-to-blood transfer factors are in a wide range of 8.10(-6) to 64, as a result of varying significance of the elements in animal metabolism and feeding habits. Discussion The results of trace elements concentrations in animal blood are in good agreement with available data for K, Ni, Zn, Se and Rb. Higher Br concentrations in animal blood are most probably caused by large biomass burning events during blood sampling. Very low concentration of Fe in cows and sheep confirms the results of previous biochemical studies on animal anaemia in the region. High concentration of As correlates with geochemical peculiarities of the Balkans and is also likely influenced by the use of pesticides in the agricultural production. For some of the elements (La, Nd, Eu, Sm, Tb, Sb, Hf, Ta, Th, In, Ba, Sr, Sc and Cs), there are few or no literature data. Therefore, some of the presented data are significant not only for the country and the region, but on a wider scale. Activities of natural radionuclides in feeds are within the average values reported for the region, while the activities of Pb-210 and U-235/238 are below the limit of detection. This is in accordance with previous investigations showing no widespread contamination by depleted uranium in the area. Contents of Hg and Pb in feeds are below the nationally permissible levels, unlike the content of Cd which exceeds it, probably caused by the use of phosphate fertilisers and fossil fuel combustion in the area. Conclusions In general, the concentrations of trace elements in blood of homebred cows and sheep are in good agreement with reference materials, available literature data and the results of previous studies in the area. The exceptions are Fe, As and Br. The contents of natural and anthropogenic radionuclides in feeds are within the expected levels, and there are no signs of contamination by depleted uranium or other fission products. Apart from Cd, there are no signs of pollution by heavy metals in feeds. The highly sensitive method of instrumental neutron activation analysis provides data on the concentration of some elements in animal blood not previously reported for the region and elsewhere. Recommendations and perspectives The presented study is a part of the long term ongoing project on the health risk assessment on animals and humans in the region. The collected data is intended to provide a base for the animal and human risk assessment as well as an estimate of the general pollution status of the environment in the region. Since some of the investigated elements are classified as important trace elements for livestock, the results could also be used to balance and improve the animal diet and thus, improve the growth and reproduction rate.

Distribution of natural gamma-emitting radionuclides 238U and 40K were determined in the soil profiles from the peach-trees field on experimental farm Radmilovac, southeast Belgrade. Internal soil morphology has been changed in 1992. when soil rigosol type with deep Ap-horizon (0-80 cm) has been formed by special treatment of parent soil, chernozem type. Gamma-spectrometry method is applied in measurement of radionuclide activities in soil samples by using hyperpure coaxial gamma-ray detector, Canberra type. Investigation results has been shown that the natural activity contents obtained in the experiment are within the range of normal BACKGROUND: activity according to UNSCEAR (2000) and that radionuclide activity decreased in the plant root zone. Distribucija prirodnih radionuklida gama-emitera 238U i 40K je određena u profilima zemljišta sakupljenih sa voćnjaka pod zasadom breskvi na Oglednom školskom poljoprivrednom dobru 'Radmilovac', Poljoprivrednog fakulteta, Beograd-Zemun. Unutrašnja morfologija zemljišta je izmenjena 1992. godine kada je zemljište rigosol tipa sa dubokim Ap-horizontom (0-80 cm) formirano rigolovanjem osnovnog zemljišta černozem tipa. Aktivnost radionuklida u uzorcima zemljišta određena je metodom gama-spektrometrije korišćenjem koaksijalnog HPGe-detektora (Canberra). Rezultati ispitivanja su pokazala da je eksperimentalno određena prirodna aktivnost u granicama normalne osnovne aktivnosti preporučene od strane UNSCEAR (2000) i da aktivnost radionuklida opada u zoni korenovog sistema.

Background, aim, and scope The paper presents the complex approach to the assessment of the state of the environment in Southern Serbia, surroundings of Bujanovac, the region which is of great concern as being exposed to contamination by depleted uranium (DU) ammunition during the North Atlantic Treaty Organization (NATO) attacks in 1999. It includes studies on concentrations of radionuclides and heavy metals in different environmental samples 5 years after the military actions. Materials and methods In October 2004, samples of soil, grass, lichen, moss, honey, and water were collected at two sites, in the immediate vicinity of the targeted area and 5 km away from it. Radionuclide (Be-7, K-40, Cs-137, Pb-210, Ra-226, Th-232, U-235, U-238) activities in solid samples were determined by standard gamma spectrometry and total alpha and beta activity in water was determined by proportional alpha-beta counting. Concentrations of 35 elements were determined in the samples of soil, moss, grass, and lichen by instrumental neutron activation analysis (INAA). Results The results are discussed in the context of a possible contamination by DU that reached the environment during the attacks as well as in the context of an environmental pollution by radionuclides and heavy metals in Southern Serbia. The results are compared to the state of environment in the region and other parts of the country both prior to and following the attacks. Discussion This is the first comprehensive study of the contents of radionuclides and heavy metals in Southern Serbia and consequently highly important for the assessment of the state of environment in this part of the country concerning possible effects of DU ammunition on the environment, as well as anthropogenic source of pollution by radionuclides and heavy metals and other elements. Also, the highly sensitive method of INAA was used for the first time to analyze the environmental samples from this area. Conclusions The results of the study of radionuclides in the samples of soils, leaves, grass, moss, lichen, honey, and water in Southern Serbia (Bujanovac) gave no evidence of the DU contamination of the environment 5 years after the military actions in 1999. Activities of radionuclides in soils were within the range of the values obtained in the other parts of the country and within the global average. The ratio of uranium isotopes confirmed the natural origin of uranium. In general, concentrations of heavy metals in the samples of soils, plant leaves, mosses, and lichen are found to be less or in the lower range of values found in other parts of the country, in spite of the differences in plant and moss species or soil characteristics. Possible sources of heavy metal contamination were identified as a power coal plant in the vicinity of the sampling sites and wood and waste burning processes. Recommendations and perspectives The collected data should provide a base for the health risk assessments on animals and humans in the near future. It should be emphasized that the sampling was carried out 5 years after the military action and that the number of samples was limited; therefore, the conclusions should be accepted only as observed tendencies and a detailed study should be recommended in the future.

The radioactivity of water and sediments from the Sava river in the course through Serbia during 2001-2003 has been examined by alpha- and gamma-ray spectrometry. Except for cesium originating from Chernobyl, the radioactivity level of water and sediment coincide with the content of natural radionuclides in the environment of the river basin. Distribution coefficients as well as the runoff coefficient were determined for (137)pCs.

Radioactivity of water and sediments from the Danube river in its course through Serbia during 2001-2003 years has been tested by alpha- and gamma-ray spectrometry. Except for cesium originating from Chernobyl, the radioactivity level of water and sediment coincide with the content of natural radionuclides in the environment of rivers basin. No increase in the radioactivity of sediments, due to slowing down of the water flow, was observed. The obtained results were analyzed in accordance with the model which considers only naturally occurring radionuclides originating in river sediment. The distribution coefficients for natural radionuclides are determined.

Uranium series disequilibria in the hydrosphere occur due to geochemical differentiation processes resulting with different mobility of the radionuclides from the same series. Radioactive equilibrium in the mineral waters Cibutkovica and Studenica, originated from metamorphic rock area of the South Serbia was the object of investigation. Enhanced total alpha/beta activity found in examined natural mineral waters with similar chemical composite and origin indicated high content of naturally occurring radionuclides, members of 238 U and 232 Th series. Gamma and alpha spectrometry analysis have been undertaken and present natural radionuclides quantified. It was found that content of 226 Ra exceeds the value that expected from content of 238 U, in Studenica water. Rise in the activity level coresponds to the 226 Ra. In Cibutkovica mineral water disequilibria exist, both in the uranium-238 and thorium-232 series. Content of 226 Ra, that should be in equilibrium with 238 U, much exceeds the value which is expected. In thorium-232 series there exists a disequilibrium and concentrations of 228 Th, 228 Ac and 228 Ra are much higher than expected from present 232 Th. High content of radium isotopes in analysed natural mineral waters indicates contribution from other sources than water, probably environmental sediment.

Radon concentrations in air and gamma dose rates were measured in a hundred and sixty-seven houses in Belgrade. Indoor radon concentrations determined by alpha scintillation counting were in the range from 10 to 200 Bq.m 3 and were roughly correlated with building materials corresponding to the age of the house. The vertical distribution of the mean radon indoor concentrations was also estimated. The annual effective equivalent dose for indoor radon and its short-lived daughters estimated for the mean radon in air concentration (58 Bq.m -3 ) was 1.3 mSv. The contents of natural radionuclides ( 232 Th, 226 Ra, 40 K) in raw building materials (gravel, quartz sand, cement, unhydrated lime) and final products (Siporex expanded concrete) were determined by standard gamma spectrometry.

The activity of natural radionuclides (226Ra, 238U, 235U, 232Th, and 40K) was measured in soils, meadow flowers, and honey from a mountain region in West Serbia. No statistically significant differences in the contents of natural radionuclides in soil or meadow flora from different soils (shale or limestone) were obtained, although concentrations were generally higher in shale soils than in soils mainly composed of limestone rocks. Activity of 226Ra, 238U, and 235U in plants was below minimal detectable concentrations (0.4 - 0.1 Bq/kg). The content of 232Th was higher in meadow flora from shale soils. For 40K, there were no significant differences in its concentrations in plants from different soils. The activity of natural radionuclides in honey did not depend on the type of soil or meadow flora, but the variations for 238U and 235U concentrations were high. Concentration factors for “soil-honey” phase were in the range 0.01-0.07, while for “soil-plant” and “plant-honey” phase they could be calculated only for 232Th and 40K and were in the range 0.1–3.0 and 0.09-0.02, respectively.