Trace Elements and Radionuclides in Urban Air Monitored by Moss and Tree Leaves

In urban areas, air quality is strongly influenced by numerous anthropogenic activities. High population density, heavy traffic and domestic heating in winters in the centre, and various industrial activities at the outskirts, influence atmospheric concentrations of trace elements and radionuclides. Consequently, large population is exposed to possible adverse effects arising from the altered urban air composition. Therefore, air quality monitoring has become one of the standard quality control procedures in urban areas

Natural radionuclides and 137Cs in moss and lichen in eastern Serbia

The paper presents the results of radionuclides determination in moss (Homolothecium sp., Hypnum Cupressiforme sp., and Brachythecium sp.) and lichen (Cladonia sp.) sampled in the region of Eastern Serbia during 1996-2010. The activities in moss are in the range of 100-500 Bq/kg d. w. for 40K, and 5-50 Bq/kg d. w. for 226Ra and 232Th, while the “soil-to-moss” transfer factors are 0.45 for 40K, 3 for 226Ra, and 0.3 for 232Th. The spatial distribution of the 137Cs activities is highly non-uniform; some values reach 500 Bq/kg d. w., with less than 10% of the samples, mainly the ones taken prior to 2000, with the activity above 1000 Bq/kg d. w. The variations in the content of natural radionuclides among the moss species are not significant. The frequency pattern of the activities of natural radionuclides in lichen is similar to the one in moss, but the activities in lichen are to some extent lower. The mean activity of 137Cs in lichen is below 400 Bq/kg d. w. The mean activities of 7Be in moss and lichen sampled in 2006 and 2008 are in the range of 41-122 Bq/kg d. w., with pronounced variations between the sampling sites

Natural and artificial radionuclides in herbal teas from Serbia

Due to their therapeutic and pharmacologic properties, medicinal herbs have a long history of use around the world. The objective of this study is to determine the activity concentration of natural ( 40K, 226Ra, 232Th, and 238U) and artificial ( 137Cs) radionuclides in samples of herbal teas from Serbia. The samples of the following commercially available teas: dandelion leaf (Taraxaci folium), mulberry leaf (Mori nigrae folium), ground ivy (Glechoma hederacea), sweet wormwood (Artemisia annua), rose hip (Cynosbati fructus), wall germander (Teucrium chamaedrys), and thyme (Thymus vulgaris), were collected in Serbia in 2021. The radionuclides’ activity concentrations were determined using gamma spectrometry. The results show that among the natural radionuclides, 40K is dominant (316–1616 Bq/kg), while the activity concentration of 226Ra and 232Th ranges from below the minimum detectable activity (MDA) to 12.3 Bq/kg, and below the MDA to 13.4 Bq/kg, respectively. In all investigated samples, the 238U activity concentration is below the MDA. Cesium-137 is detected in five out of seven analysed samples (0.3–2.9 Bq/kg). The results indicate that 137Cs, released into the atmosphere after the Chernobyl accident in 1986, is still present in the environment of Serbia. Nevertheless, according to the Serbian legislation regulating the maximum permitted levels of radionuclides in foodstuffs, all of the investigated samples of herbal teas are safe for human consumption

Prirodni i proizvedeni radionuklidi u zemljištu planinskih regiona Republike Srbije i parametri radijacionog rizika

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

The uniqueness of the beryllium-7 time series in Kista and Vienna over 1987–2014

Activity concentration of beryllium-7 (Be-7) in the surface air is considered a good tracer of atmospheric processes. Promptly after its production, this radionuclide attaches to aerosols and then subsides to the surface where its concentrations depend on the aerosol removal processes, e.g. precipitation, and atmospheric transport drivers, e.g. temperature and pressure. Our study investigates whether a set of five variables: mean temperature, minimum temperature, maximum temperature, precipitation and atmospheric pressure can account for the Be-7 concentration variability at the surface. We use the Be-7 activity concentration from the Radioactivity Environmental Monitoring data bank maintained by the Joint Research Centre in Ispra, Italy. We look into two locations, Kista (59.40 °N; 17.93 °E; 16 m a.s.l.) in Sweden and Vienna (48.22 °N; 16.35 °E; 193 m a.s.l.) in Austria, between February 1987 and December 2014, when the sampling was performed on a weekly basis. The meteorological parameters are extracted from the E-OBS gridded climatology, version 15, using bilinear interpolation. For each location, we perform Factor Analysis. The calculations are done in R, an open-source software for statistical computing and graphics. Factor Analysis assumes that a given set can be modelled as a linear combination of unobserved uncorrelated factors. Loadings are contributions of each original variable to a factor; variables with high loadings are well explained by the factor. The total data variability has two terms: communality arising from the linear combinations of the factors, and uniqueness not explained by the factors. The model is appropriate if the uniqueness is low. The null hypothesis in Factor Analysis is that the chosen number of factors is sufficient to explain the variability of the data; the hypothesis is rejected if the calculated p-value is less than 0.05. We perform Factor Analysis by choosing 1, 2 and 3 factors. Results for both locations give similar results. One factor (F1): Temperatures show very high loadings (greater than 0.98) making F1 identical to a temperature variable in the set. The loading of the Be-7 concentration is 0.39 and 0.68 for Kista and Vienna, respectively. The loadings of precipitation and atmospheric pressure are less than 0.4. With the low Be-7 concentration loading, its uniqueness is large, giving temperature, as a single contributing factor, insufficient to explain well the data’s features. This is corroborated by the p-value=0. Two factors (F1 and F2): The sum of square loadings for F1 is greater than 3 making it significant, unlike F2 (a factor is significant if the sum of square loadings is greater than 1). The Be-7 concentration and temperatures have high loadings for F1, but precipitation has a negligible F1-loading; precipitation has a significant loading for F2, while the pressure has similar loadings for F1 and F2. Although the uniqueness of the Be-7 concentration decreases with two factors, p-value is again very low, essentially zero. Three factors (F1, F2 and F3): Again, F1 with the highest temperature loadings can be identified as a temperature variable. The loading of atmospheric pressure is the highest for F2. Both F1 and F2 are significant, while F3 is insignificant. Also, we cannot assess the validity of the null hypothesis regarding the use of the 3-factor model, because this model has zero degrees of freedom, thus no p-value can be calculated. Nevertheless, if we look into the uniqueness of the Be-7 concentration, its lowest values are given by this model. In conclusion, all variables exhibit a variance that cannot be captured by up to 3 factors. Still, the Be-7 concentration seems to be strongly correlated with the temperature variables in all the investigated models. But, the uniqueness of the Be-7 concentration remains high, implying that the chosen set of variables lacks an important observable that could help explain the behaviour of the Be-7 concentration at the surface.Book of Abstract

Elemental composition of moss and lichen species in eastern Serbia

Instrumental neutron activation analysis is used to determine a content of 47 elements (Na, Mg, Al, Cl, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Ni, Co, Cu, Zn, As, Se, Br, Rb, Sr, Zr, Mo, Ag, Cd, Sb, I, Ba, Cs, La, Ce, Nd, Sm, Eu, Gd, Tb, Dy, Tm, Yb, Lu, Hf, Ta, W, Au, Hg, Th, and U) in mosses (Homolothecium sp., Hypnum cupressiforme Hedw., and Brachythecium mildeanum (Schimp.) Schimp.) and lichen (Cladonia fimbriata (L.) Fr.) collected in three locations in Eastern Serbia over years 2006-2010. Concentrations of six elements (Zr, Nd, Gd, Tm, Yb, and Lu) in mosses in Serbia are measured for the first time. For other elements, the obtained concentrations fall within the ranges reported for mosses and lichens in Europe, but no declining trend in concentrations of V, Cd, Cr, Zn, Ni, Fe, and Cu, that has been described in the literature, can be inferred from our results. Factor analysis shows that terrigenous and industrial components are the highest contributing factors to the elemental composition and that the most polluted measurement site is in the vicinity of a copper mining and smelting complex

Seasonality of 7 Be concentrations in Europe and influence of tropopause height

This study aims at analysing the latitudinal variability of both the yearly and seasonal pattern of Be-7 surface activity concentrations, at addressing the impact of tropopause height (TPH) on Be-7 distribution and at evaluating the time lag between TPH and Be-7 at European level. With this aim, weekly Be-7 and daily TPH data at 17 sampling stations during 10 yr (2001-2010) are analysed. Be-7 shows a clear increasing tendency in the period and generally tends to increase with decreasing latitude. The seasonal pattern generally shows maxima during the warm period and minima during the cold one. The seasonal variogram analysis points out a good spatial correlation for TPH data while a weaker one is observed for Be-7, having TPH a larger influence on Be-7 during summer. The influence of TPH on Be-7 exhibits a large spatial variability, with a clear gap between south and north in the area of the polar front jet. The results identify the presence of two main groups, in particular separating between stations located in northern Europe (50 degrees N and higher) and stations in southern Europe (south of 50 degrees N). A similar behaviour for stations located in the same geographical area is also observed when looking at the day of maximum impact of TPH on Be-7 concentrations. The results suggest that Be-7 concentrations respond in different time ranges to changes in the TPH, observing seasonal differences in each group. These results represent the first European approach to the understanding of the TPH impact on Be-7 concentrations at surface levels

Determination of the activity concentration of 137Cs and 40K in blueberry-based products consumed in Serbia

The aim of the study is the investigation of the activity concentration of 137Cs and 40K in blueberry-based products that are available on the market in the Republic of Serbia. Samples were bought in stores during September 2017 and in total, ten packaged juices, two jams, two sweets and a fresh wild blueberry were measured. The activity concentrations of 137Cs in blueberry-based juices, jams and sweets varied from <MDA to 4.1 Bq/kg, <MDA to 21 Bq/kg and 0.6 Bq/kg to 28 Bq/kg, respectively. The average activity concentration of 137Cs in fresh wild blueberry was 4.1 Bq/kg. In Serbia, the recommended activity concentration of 137Cs in juices and sweets is 15 Bq/kg and 150 Bq/kg in fresh blueberries. The tested samples of juices, jams, fresh wild blueberry and one of the sweets meet the set criteria for 137Cs while one sweets sample exceeds the limit. The activity concentrations of 40K in juices, jams and sweets varied from 3.5 to 55 Bq/kg, 13.9 to 19.2 Bq/kg and 17.2 to 227 Bq/kg, respectively. The average activity concentration of 40K in fresh wild blueberry was 32 Bq/kg. With the obtained result the annual effective dose equivalent due to ingestion of blueberry-based products for adults was calculated, and for 137Cs in blueberry-based juices, jams, sweets and fresh wild blueberry varied from 0.2 to 2.5 Sv, 2.8 Sv, 0.4 to 17.0 Sv and 2.5 Sv, respectively. The annual effective dose equivalent for 40K in blueberry-based juices, jams, sweets and fresh wild blueberry varied from 1.0 to 16.0 Sv, 1.2 Sv, 5.0 to 66.0 Sv, and 9.3 Sv, respectively. © 2019 RAD Association. All rights reserved.Conference of 6th International Conference on Radiation and Applications in Various Fields of Research, RAD 2018 ; Conference Date: 18 June 2018 Through 22 June 2018; Conference Code:14955

Seasonal changes of naturally occurring radionuclides and fallout 137-Cs in the samples of leaves of deciduous trees

Specifična aktivnost prirodnih radionuklida 238U, 235U, 226Ra, 210Pb, 232Th i 40K i proizvedenog 137Cs je merena u uzorcima lišća dve vrste listopadnog drveća, kestena (Aesculus hippocastanum) i lipe (Tilia spp) koji potiču iz tri gradska parka na užem području Beograda. Uzorci su sakupljani u vreme prolećne (n=7), letnje (n=2) i jesenje (n=8) sezone u periodu od 2002-2012. godine. Iz svake pojedinačne sezone uzorci lišća su spojeni po vrstama pri čemu je dobijen jedan integralni (sezonski) uzorak za svaki ispitivani park čime je postignuta veća efikasnost detekcije niskog nivoa gama zračenja. Za određivanje aktivnosti primenjen je metod spektrometrije gama emitera. U svim pojedinačnim uzorcima suve materije lišća detekcija radionuklida 210Pb i 40K je bila moguća i njihova specifična aktivnost se nalazila intervalu 15-52 Bq/kg i 310-650 Bq/kg, respektivno. Iako je aktivnost 226Ra bila veoma niska, u intervalu 0,5-5,6 Bq/kg, ovaj radionuklid je bio izmeren u svim uzorcima (osim u dva) i svim sezonama. Aktivnost 210Pb i 226Ra se povećavala tokom godine, pri čemu su njihove najveće vrednosti izmerene u lišću kestena u letnjoj sezoni. Suprotno, aktivnost 40K u lišću lipe i kestena je opadala tokom godine. Za razliku od prethodno navedenih, radionuklidi 238U, 235U i 232Th su retko detektovani samo u letnjem i/ili jesenjem periodu i po četiri uzorka lišća su sadržali 238U (2,7-11,7 Bq/kg) i 235U (0,13-1,0 Bq/kg), a tri 232Th (1,8-3,3 Bq/kg). Proizvedeni radionuklid 137Cs detektovan je u svim uzorcima lišća (osim u dva), a bez jasnog trenda ponašanja po sezonama i nalazio se u intervalu 0,3-1,2 Bq/kg. Cilj rada bio je ispitivanje akumulacije prirodnih radionuklida i njihovog potencijalnog variranja tokom godine u lišću listopadnog drveća.The specific activity of naturally occurring radionuclides 238U, 235U, 226Ra, 210Pb, 232Th, and 40K and fallout 137Cs was measured in the samples of leaves of two deciduous tree species, chestnut (Aesculus hippocastanum) and linden (Tilia spp.) common for the Belgrade urban area. Samples were collected in the spring (n = 7), summer (n = 2) and autumn (n = 8) during the vegetation period from 2002 to 2012. From each season, samples of leaves were combined according to two species and one single integral (seasonal) sample was obtained in order to improve detection efficiency of low gamma radiation level. Specific activities were determined using the gamma-ray spectrometry method. 210Pb and 40K radionuclides were detected in all the samples of leaves and their specific activity was in the range (Bq/kg dry weight): 15 - 52 and 310 - 650, respectively. Although the 226Ra level was very low and in the range from 0.5 - 5.6 Bq/kg, this radionuclide has been measured in all samples (except in the two) and each season. 210Pb and 226Ra activity increased during the vegetation period and their highest values were found in the leaves of chestnut trees in the summer season. In contrast, the activity of 40K in the leaves of linden and chestnut has decreased. Detection 238U, 235U and 232Th radionuclides was scarce and only in the summer and/or autumn. Four samples of leaves contained 238U (2.7 - 11.7 Bq/kg dry wt) and 235U (0,13 - 1.0 Bq/kg dry wt) and three of them 232Th (1.8 - 3.3 Bq/kg dry wt). Man-made radionuclide 137Cs (0.3-1.2 Bq/kg dry wt) was detected in all samples of leaves (except in two) and no clear trend according to seasons was found. The aim was to investigate the accumulation of naturally occurring radionuclides and fallout 137Cs in the leaves of deciduous trees and their potential variations during the vegetation period

Seasonal changes of naturally occurring radionuclides and fallout 137-Cs in the samples of leaves of deciduous trees

Specifična aktivnost prirodnih radionuklida 238U, 235U, 226Ra, 210Pb, 232Th i 40K i proizvedenog 137Cs je merena u uzorcima lišća dve vrste listopadnog drveća, kestena (Aesculus hippocastanum) i lipe (Tilia spp) koji potiču iz tri gradska parka na užem području Beograda. Uzorci su sakupljani u vreme prolećne (n=7), letnje (n=2) i jesenje (n=8) sezone u periodu od 2002-2012. godine. Iz svake pojedinačne sezone uzorci lišća su spojeni po vrstama pri čemu je dobijen jedan integralni (sezonski) uzorak za svaki ispitivani park čime je postignuta veća efikasnost detekcije niskog nivoa gama zračenja. Za određivanje aktivnosti primenjen je metod spektrometrije gama emitera. U svim pojedinačnim uzorcima suve materije lišća detekcija radionuklida 210Pb i 40K je bila moguća i njihova specifična aktivnost se nalazila intervalu 15-52 Bq/kg i 310-650 Bq/kg, respektivno. Iako je aktivnost 226Ra bila veoma niska, u intervalu 0,5-5,6 Bq/kg, ovaj radionuklid je bio izmeren u svim uzorcima (osim u dva) i svim sezonama. Aktivnost 210Pb i 226Ra se povećavala tokom godine, pri čemu su njihove najveće vrednosti izmerene u lišću kestena u letnjoj sezoni. Suprotno, aktivnost 40K u lišću lipe i kestena je opadala tokom godine. Za razliku od prethodno navedenih, radionuklidi 238U, 235U i 232Th su retko detektovani samo u letnjem i/ili jesenjem periodu i po četiri uzorka lišća su sadržali 238U (2,7-11,7 Bq/kg) i 235U (0,13-1,0 Bq/kg), a tri 232Th (1,8-3,3 Bq/kg). Proizvedeni radionuklid 137Cs detektovan je u svim uzorcima lišća (osim u dva), a bez jasnog trenda ponašanja po sezonama i nalazio se u intervalu 0,3-1,2 Bq/kg. Cilj rada bio je ispitivanje akumulacije prirodnih radionuklida i njihovog potencijalnog variranja tokom godine u lišću listopadnog drveća.The specific activity of naturally occurring radionuclides 238U, 235U, 226Ra, 210Pb, 232Th, and 40K and fallout 137Cs was measured in the samples of leaves of two deciduous tree species, chestnut (Aesculus hippocastanum) and linden (Tilia spp.) common for the Belgrade urban area. Samples were collected in the spring (n = 7), summer (n = 2) and autumn (n = 8) during the vegetation period from 2002 to 2012. From each season, samples of leaves were combined according to two species and one single integral (seasonal) sample was obtained in order to improve detection efficiency of low gamma radiation level. Specific activities were determined using the gamma-ray spectrometry method. 210Pb and 40K radionuclides were detected in all the samples of leaves and their specific activity was in the range (Bq/kg dry weight): 15 - 52 and 310 - 650, respectively. Although the 226Ra level was very low and in the range from 0.5 - 5.6 Bq/kg, this radionuclide has been measured in all samples (except in the two) and each season. 210Pb and 226Ra activity increased during the vegetation period and their highest values were found in the leaves of chestnut trees in the summer season. In contrast, the activity of 40K in the leaves of linden and chestnut has decreased. Detection 238U, 235U and 232Th radionuclides was scarce and only in the summer and/or autumn. Four samples of leaves contained 238U (2.7 - 11.7 Bq/kg dry wt) and 235U (0,13 - 1.0 Bq/kg dry wt) and three of them 232Th (1.8 - 3.3 Bq/kg dry wt). Man-made radionuclide 137Cs (0.3-1.2 Bq/kg dry wt) was detected in all samples of leaves (except in two) and no clear trend according to seasons was found. The aim was to investigate the accumulation of naturally occurring radionuclides and fallout 137Cs in the leaves of deciduous trees and their potential variations during the vegetation period