J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... 334 Nuclea r Technol ogy & Ra dia tion Protec tion: Year 2017, Vol. 32, No. 4, pp. 334-341

NAT U RAL AND AR TI FI CIAL RA DIO AC TIV ITY IN SOME PROTECTED AREA S OF SOUTH EAST EUROPE

by

Jovana A. DŽOLJI] 1, Svetlana M. STEVOVI] 2, Dragana J. TODOROVI] 3, Svetlana M. POLAVDER 4, Milica M. RAJA^I] 3, and Jelena D. KRNETA NIKOLI] 3

1 Fac ulty of Ecol ogy and En vi ron men tal Pro tec tion, Uni ver sity Un ion-Nikola Tesla, Bel grade, Ser bia 2 In no va tion Cen tre, Fac ulty of Me chan i cal En gi neer ing, Uni ver sity of Bel grade, Bel grade, Ser bia 3 De part ment of Ra di a tion and En vi ron men tal Pro tec tion, Vin~a In sti tute of Nu clear Sci ences, Uni ver sity of Bel grade, Bel grade, Ser bia 4 Min ing In sti tute, L.t.d., Bel grade, Ser bia

Sci en tific pa per http://doi.org/10.2298/NTRP1704334D

The pri mary aim of this re search is the in ves ti ga tion of nat u ral and ar ti fi cial ra dio ac tiv ity in pro tected ar eas of Kopaonik, Vlasina, and Rila Moun tains. Soil sam ples (in clud ing lake sed i - ment), drink able spring wa ter and co ni fers at men tioned lo ca tions of South east Eu rope, are cho sen as study ob jects due to their im por tance for peo ple and the en vi ron ment in global. Spe cific ac tiv i ties of 226Ra, 232Th, 40K, 238U, 235U, 137Cs, 210Pb, and 7Be are de ter mined us ing gamma spec trome try and the ob tained val ues compared with lit er a ture and mean world val - ues. Risk as sess ment pa ram eters and the soil-plant trans fer fac tor were de ter mined for 226Ra, 40K, 137Cs, and 210Pb. This is the first ra dio ac tiv ity study of high moun tain ar eas of Vlasina and Kopaonik in Serbia and Rila in Bul garia and as such a base line mea sure ment and foun da - tion for fu ture re search. Key words: gamma ray spec trom e try, risk as sess ment, soil, Nor way spruce, Kopaonik, Rila, Vlasina

IN TRO DUC TION AND BACK GROUND lease of radionuclides, deplet ed uranium (DU), into the en vi ron ment of South east Eu rope, pre cisely Ser- Rapid in dus tri al iza tion and ur ban iza tion have bia, occurred in 1999. in creased the level of en vi ron men tal pol lu tion re- questing meta boli c adap t ati on of all ecos yst em func- tions [1]. Once ra dio ac tive ma te ri als are in cor po rated Ra dio ac tiv ity of soil, wa ter and plants into the ecosys tem, they can be taken up by food or in- gested by ani m als [2]. Levels of contam inants in envi - The im por tance of in ves ti gat ing the ra dio ac tiv- ron ment af fect the con cen tra tion and ex po sure to pri- ity of soil, wa ter and plants from se lected pro tected ar - mor dial radionuclides, enhanc ing the contac t with eas of high mountai n regions in Serbia and Bul garia is liv ing be ings and in creas ing over all ra dio ac tiv ity ex- based on their vicin it y to ter rains that were exposed to po sure. Some radionuclides, such as long-lived 40K, DU. These ar eas in clude places where peo ple live, or- 232Th, 238U, 90Sr, and 137Cs, are met a bol i cally in cor po - ga nized in dif fer ent com mu ni ties and mu nic i pal i ties. rated into plant specie s by absorp ti on from the soil Nor way spruce (Picea abies L.), is a peren nial plant through the root sys tem. Others, such as 210Pb and 7Be, can be depos it ed on plant leaves [1]. More over, foli ar specie s, com mon in high mountai n areas in this re gion, de po si tion rep re sents one way of radionuclide absorp - se lected for es ti mat ing the be gin ning of radionuclide tion from the air and is closely as so ci ated with the mor - absorp ti on by conif er ous trees. Along with the re- pho log i cal char ac ter is tics of leaves and the lo cal cli- search of spe cific ac tiv i ties and re lated am bi ent dose mate [3]. Mea sure ments of spe cific ac tiv i ties of 7Be in of radionucides, the soil-to-plant trans fer fac tor is also the envi ron m ent, espe cia lly in soil or plants, are novel. con sid ered. The amount of 137Cs in the envi ron m ent and its radio - Vari a tions in spe cific ac tiv i ties of pri mor dial logi cal im pact throughout Europe is the result of the radionuclides in soils around the world, re lated to geo - Chernobyl acci dent in 1986 [4]. The most re cent re- log i cal and geo graph ical con di tions, may vary the pub lic ex ter nal dose from ter res trial ra di a tion. The * Cor re spond ing au thor; e-mail: [email protected] mean world values of radionuclides in the soils are in J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... Nuclea r Technol ogy & Ra dia tion Pro tection: Year 2017, Vol. 32, No. 4, pp. 334-341 335 the range of 33-1000 Bqkg–1 for 238U, 32 Bqkg–1 for lish ing base line lev els of en vi ron men tal ra dio ac tiv ity 226Ra, 45-360Bqkg–1 for 232Th, and 420-3200 Bqkg–1 for detec ting any changes in future moni tor ing [12]. for 40K [5]. Many studies of radionuclides in soil and water and their transfer to plants were done around the Study area world, mostly for assess ing the dose and the risks re- sult ing from them [6, 7]. In terres tri al envi ron m ent, the The study area covers Rila Mountai n in Bulgari a soil to plant re la tion ship is con sid ered very sig nif i cant and Kopaonik and Vlasina in Serbia as places with re- and widely used for esti mating the amount of mineral cog nised nat u ral, eco log i cal, and cul tural fea tures. These mate ri als uptake from the soil by plants. are also tour ist des tina tions and spe cific world rare ar eas, The mean spe cific ac tiv i ties of 238U, 232Th, and 40K protec ted by the UN and nati onal author i ti es. The ter- in sur face soils in Ser bia are simi lar to equiv a lent val ues rains within them are used for agri cul ture , livestoc k reporte d for soils in regions with a sim ilar geolog i cal breeding, mushroom s and forest fruit collec tion, tra di- tional medi cal plant produc ti on and harvest ing, this in com posi ti on and geotectonic struc ture, as well as with part being the rea son for authors selec ting these sites for world wide av er age val ues. Ob tained re search re sults –1 238 –1 their study. The study area is pre sented in fig. 1. show mean values of 32.8 Bqkg for U, 37.8 Bqkg Kopaonik mountai n (NP Kopaonik) is the high- 232 –1 40 for Th, and 550 Bqkg for K in soils [8]. est moun tain in Cen tral Ser bia, di rec tion NW-SE, with During the UNEP DU mis sion, analyse d soil an east ern bor der between the Dinaric Alps and sam ples from the Pcinja Dis trict, South east Ser bia, Rhodope. Out stand ing nat u ral fea tures, di ver sity of and lo cations at Pljackovica, Vranje Gar ri son, ter rain ge ol ogy, geo mor phol ogy and biota, along with Bratoselce, Borovac, Bukarevac, and Reljan (fig. 1.) the im portanc e of the area for conser va ti on, result ed in confirme d the presence of vari ous amounts of DU [9]. desig nat ing it a Nati onal park in 1981. During the ac ci- The re ported mean specif ic acti vit y of radionuclides in dent 1999, Kopaonik was under heavy and prolonged the soil of southern Serbia, from loca ti ons where attac k result ing in the de struc tion of the ter rain and –1 226 –1 DU was used, are 45 Bqkg for Ra, 50 Bqkg disrup ti on of the forest ecosys tem [13, 14]. 232 –1 40 –1 137 for Th, 651 Bqkg for K, 10 Bqkg for Cs, Vlasina's pla teau is sit u ated in south east Ser bia, 3.4 Bqkg–1 for 235U, and 57 Bqkg–1 for 238U [10]. The near the border with Bulgari a. A Landsca pe of Out - im portanc e of radioanalysis is also emphasised by standing Feature s, Vlasina (LOF Vlasina) include s consid er ing the soil-cere als TF in the region of Pcinja, wetlands, a lake and the surround ing highland areas . Ser bia [11]. The nearest high re gion is the Rila mountai n range This is the first de tailed re search of ra dio ac tiv ity with the highest massif on the Balkans (Musala peak, levels in soil, spring wa ter and plants inside protec ted 2925 m), locat ed in Southwest ern Bulgari a. ar eas for pos si ble es tab lish ment of mon i tor ing points. Rila Mon as tery Nat u ral park (NP Rila Mon as - Es tab lish ing high qual ity state mon i tor ing of these ar- tery) is a protec ted area having one of the highest de- eas is of im portanc e. Risk assess ments within pro- grees of nat u ral ness, sta bil ity, typ i cal ity and rep re sen - tected areas of high mountai ns in this re gion are a pi o - ta tive val ues of eco sys tems in Bul garia. UNESCO neer research. The con trol of ra di ation lev els is World Cul tural and Nat u ral Her i tage Con ser va tion im por tant not only for eval u at ing the ef fec tive an nual con firmed the na tional valo ri sa tion, iden ti fy ing it as dose in the place where one lives, but also for estab - the second most visit ed protec ted area in Bul garia.

Fig ure 1. Map of ac ci dents and sam pling sitese J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... 336 Nuclea r Technol ogy & Ra dia tion Protec tion: Year 2017, Vol. 32, No. 4, pp. 334-341

MATERIALS AND METHODS at 450 ºC and transferred to 120 ml cy lindri cal poly sty - rene con tain ers. The masses of the samples were about Sam pling sites from Nati onal park „Kopaonik”, 20-30 g. Upon this, they are sealed with bee wax and Land scape of Out stand ing Fea tures "Vlasina" in Ser - stored for 28 days to achieve radio ac ti ve equi librium bia and Nati onal park „Rila” in Bulgari a, alongside be tween ra don and its prog e nies. Spe cific ac tiv i ties of Chernobyl and NATO bombing sites in Soutest Ser bia, radionuclides 226Ra, 232Th, 40K, 238U, 235U, 210Pb, and are marked on the Map, fig. 1, as ac cident lo cations. 7Be were de ter mined by gamma spec trome try mea - Soil, wa ter and plants were se lected as samples sure ments us ing three HPGe spec trom e ters pro duced for in ves tiga tion since these are the media that first in - by CAN BERRA, with rel a tive effi cien cies of 18 %, di cate and trans fer ra dio ac tiv ity. 20 %, and 50 %.These spec trome ters are readily used A total of 5 soil sam ples from a depth of 0-10 cm in the Lab o ra tory for mea sure ment of en vi ron men tal were collected. Two samples were collected at Na tional samples. Time of measure ments for all samples was park "Kopaonik", at the lo cal ity of Suvo Rudiste, 1700 m 60 000 s. a. s. l.(E20°49'0.09", N43°17'33.24"), and at a lower al ti - De tec tor ef fi ciency cal i bra tion for dif fer ent ge - tude of 1100 m, near the village Brzece (E20°52'49.85", ome tries and dif fer ent matri ces was done in ac cor - N43°17'6.48"). One soil sam ple and one sam ple of river dance with the measured sample type [15]. sed i ment were ex tracted at LOF-Vlasina (E22°19'26.67", Cal ibra ti on for soil sam ples was perform ed using N42°44' 54.55"), at 1219 m of al ti tude and one soil sam ple ref er ent ra dio ac tive ma te rial, ma trix of sil i cone resin, was taken at Na ture park "Rila Monas ter y" (E23° 20' Czech Metrological In sti tute, Praha, 9031-OL-420/12, 241 109 20.59", N42°7'57.35"). At each sam pling site, about to tal ac tiv ity of 41.48 kBqat 31.08.2012 ( Am, Cd, 139 57 60 203 88 113 85 137 1.5-2 kg of soil was col lected from the surface of approx i - Ce, Co, Co, Hg, Y, Sn, Sr, Cs). mately 1 m2. For plant and water samples, sec ond ary ref er - Spring wa ter sam ples were taken from fountai ns ence ma te rial, pro duced by spik ing the min er al ized marked as a source of drinkable water . One spring water plant matrix with the pri mary ref er ent mate rial, Czech sample was taken at each lo cation, namely from the "Ma- Metrological In sti tute, Praha, 9031-OL-427/12, type rine vode" fountai n (E20°49'2.1", N43°17'30.48") at Na - ERX, to tal ac tiv ity of 72.40 kBq at 31.08.2012 241 109 139 57 60 203 88 113 tional park "Kopaonik", LOF Vlasina (E22°19'55.61", ( Am, Cd, Ce, Co, Co, Hg, Y, Sn, 85 137 210 N42°43'57.31"), and from Nature park "Rila Monas - Sr, Cs, Pb) was used. The sec ond ary ref er ence tery"(E23°20'25.72", N42°8'0.08"). At all sam pling ma te rial was placed in poly sty rene cy lin dri cal con - sites, 15 L of water were collected. tainers of 120 ml [15]. Twigs and needles of young spe cies of peren nial , co nif er ous trees of Nor way spruce, Picea abies L.,were Risk assessment sam pled. At each loca ti on, 1 kg of twigs and 1kg of nee- Absorbed dose rate (D&) dles were collected from the same local ity as the soil sam ples. Us ing re sults of radionuclide spe cific ac tiv ity measure m ents in the soil sam ples and fol lowing eq. (1), the inten sit y of the absorbed rate of gamma radi a - Sample preparation tion was cal cu lated & -1 Sam ple prep a ra tion and ra dio ac tiv ity anal y sis D(nGyh ) = 0.462CRa + 0.604CTh + 0.0417CK (1) were done at the Vin~a Institute of Nu clear Sci ences Ra di a tion and En vi ron men tal Pro tec tion De part ment. where CRa, CTh, and CK rep re sent the spe cific ac tiv ity After rem oving biota and stones, the soil sam ples were of the radionuclides [11]. dried at a tem pera ture of 105 ºC to a consta nt weight, An nual ef fec tive dose (DE) then hom oge nize d and approx i m ately 500 g of each sample were stored in Marinelli beak ers. The beak ers Also, the an nual effec tive dose of gamma ra di a - were sealed using bee wax and left in the labo ra tory for tion was calcu lat ed fol lowing eq. (2) 28 days to achieve radio ac ti ve equi librium betwee n -1 DE (mSv) = 0.7(SvGy ) 365 (d)× radon and its proge nies . ×24(h) ×D& (nGyh -1) 0.2 (2) Water samples were acid ified and then evap o - rated to dry resi due under a IR lamp. The resi due The es ti ma tion of an nual ef fec tive doses in- was col lected and miner alized at a tem per ature of cludes the con ver sion co ef fi cient from ab sorbed dose –1 450 ºC. The whole amount of min er al ised res i due in the air to ef fecti ve dose (0,7 SvGy ) and the out- (1-2 g) is then transferred to cyli ndri cal poly sty rene door occu pancy factor , 0.2 [16]. contai ners of 120 ml cover ing only the bottom with a Cal cu la tion of soil-to-plant trans fer fac tor (TF) thin layer of sam ple. Af ter clean ing off soil and lit ter, the plant The soil-to-plant trans fer fac tor (TF) was cal cu - samples are dried at room tem per ature, miner alized lated for 226Ra, 40K, 137Cs, and 210Pb using eq. (3) J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... Nuclea r Technol ogy & Ra dia tion Pro tection: Year 2017, Vol. 32, No. 4, pp. 334-341 337 given by the Inter nati onal Atomic Ener gy Agency South Serbia [18] and global values (tab. 2) and corre - (1994) spond to the nat ural radionuclide dis tri bu tion [16]. 235 238 -1 The in ves ti ga tion of U and U spe cific ac tiv i ties in radionuclide activity per unit of plant dry mass [Bgkg ] TF = soils and their rati o is used to indi cat e the presence of -1 radionuclide activity per mass unit of dry soil [Bqkg ] (3) DU. The dif fer ence be tween nat u ral and depleted ura - nium is in isoto pic com posi ti on which, in DU, changes by re mov ing 234U and 235U fracti ons, leading to an in- RESULTS AND DISCUSSION cre ment of 238U. The value of the ac tiv ity ra tio of 235U 238 Re sults of radionuclide spe cific ac tiv ity mea - and U of 0.045 no ticed at this lo ca tion is simi lar to surem ents in sam ples of soil, plant and water are pre - the rati o in nat ural uranium of 0.047. sented in tabs. 1, 3, and 4.The result s are present ed The geo log i cal back ground of Na tional park with ex panded un cer tainty with cov er age fac tor k = 2, „Kopaonik”, Ser bia, is rep re sented by con tact-meta- giving a confi dence level of 95 % for norm al distri bu - mor phic rocks and oc cur rences and, spe cif i cally, in tion. the case of site ''Suvo Rudiste'' deter mined as The un cer tainty bud get in cludes un cer tainty granodiorite transi ti on to quartz monzonite [19]. aris ing from count ing sta tis tics, mea sure ment of mass Wher ever the geol ogy of the terrai n is repre sent ed by and ef fi ciency cal i bra tion. The un cer tainty bud get of granit e, higher spe cific acti vit y of U and Th is ex- ef fi ciency cal i bra tion cov ers the un cer tain ties of the pected. Com par ing radionuclide spe cific ac tiv i ties in count ing sta tis tics from ref er ence ma te rial mea sure - the soil of ''Suvo Rudiste'' and Borovac in southern ments, un cer tainty of ref er ence ma te rial ac tiv ity and Serbia, the terrai n contam inate d by DU [18] shows sim i lar radionuclide distri buti on. The same val ues of the un cer tainty of the co in ci dence sum ming cor rec tion 235 238 fac tors [15]. spe cific ac tiv i ties of U and U rati o are found at Radionuclide spe cific ac tiv ities in soil sam ples Kopaonik and the previ ously menti oned loca ti on, re- from all loca ti ons are present ed in tab. 1. It should be cording val ues of 0.055 at ''Suvo Rudiste'' and 0.056 at noted that the spe cific ac tiv ity of 137Cs de tected in all Borovac[18], which is slightly higher than the rati o in sam ples is a result of the nucle ar ac cident in Chernobyl in natu r al urani um. The obtai ned resul ts of radionuclide 1986. spe cific ac tiv i ties are in agree ment with lit er a ture val - The lithological com po si tion of LOF Vlasina is ues re ported for Kopaonik, and are a comm on char ac - de ter mined as a metam or phic complex of shale and, ter istic for the area [14]. spe cif ically , at the samplin g site of the "Vlasina" com- At lower al titud es of NP Kopaonik, at samplin g plex, as al bite-chlorite mus co vite schists and (dot ted) site "Brzece", lower val ues of all radionuclide spe cific gneiss es [17]. Soil sam ples from the Vlasina site have ac tiv i ties ex cept for 137Cs are de tected, compared to lower spe cific ac tiv i ties of mea sured radionuclides the samplin g site "Suvo Rudiste". A dif fer ent geo log i - than val ues measured at Borovac in the Pcinja Dis trict, cal background for this site is deter mined, repre sent ed

Table 1. Specific activities of natural and artificial radionuclides in samples of soil from protected areas 226Ra 232Th 40K 238U 235U 137Cs 210Pb Samples [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] "Rila monastery" Natural park 1 Mountain soil 29 ± 2 35 ± 3 370 ± 25 30 ± 6 1.5 ± 0.2 49 ± 3 50 ± 10 Mountain soil National park 2 Suvo Rudište 88 ± 6 111 ± 7 780 ± 50 93 ± 8 5.1 ± 0.4 9.8 ± 0.8 64 ± 7 "Kopaonik" 3 Mountain soil Brzece 30 ± 3 41 ± 3 650 ± 40 37 ± 5 1.8 ± 0.2 89 ± 5 52 ± 5 Landscape of 4 Mountain soil 19 ± 2 16 ± 1 300 ± 20 25 ± 6 1.2 ± 0.1 30 ± 2 37 ± 9 outstanding Sediment from features "Vlasina" 5 Vlasina lake 34 ± 3 36 ± 3 510 ± 30 50 ± 10 2.3 ± 0.2 1.0 ± 0.2 50 ± 20

Table 2. Mean radionuclide specific activities in the world and some countries in the region, (UNSCEAR, 2000) Specific activities of radionuclides 40K 238U 226Ra 232Th Countries [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] Mean Range Mean Range Mean Range Mean Range Albania 360 15-1150 23 6-96 – – 24 4-160 Bulgaria 400 40-800 40 8-190 48 12-210 30 7-160 Greece 360 12-1570 25 1-240 25 1-240 21 1-190 Croatia 490 140-710 110 83-180 54 21-77 45 12-65 Hungary 370 79-570 29 16-66 33 14-76 28 12-45 Global value 400 140-850 35 16-110 35 17-60 30 11-64 J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... 338 Nuclea r Technol ogy & Ra dia tion Protec tion: Year 2017, Vol. 32, No. 4, pp. 334-341 by sandstone , marl and alveolite of the Fleece mid dle LOF-Vlasina site. De tected spe cific ac tiv i ties of 238U part [19]. The maxi m al value of 137Cs -spe cific activ - and 235U in spruce needles at all sam pling sites are ity, 89 Bqkg–1, can be explai ned by ter rain geol ogy and lower than the min i mal de tect able ac tiv ity (MDA), higher soil erosion. (tab. 3). In the nee dles from „Suvo Rudište” the de - 232 –1 Re search re sults of ra dio ac tiv ity in soil sam ples tected spe cific ac tiv ity of Th is 4.5 Bqkg , repre - from Central Serbia, NP Kopaonik, "Suvo Rudiste", sent ing the maxi m al value. A maxi m al value of 8.8 –1 226 even though higher than the global aver age (tab. 2), Bqkg for Ra was de tected at NP Kopaonik, a max - –1 40 are con sid ered a gen eral char ac ter is tic for the area. im al value of 22 Bqkg for K has been de tected at Sim i lar re sults of radionuclide spe cific ac tiv i ties in the NP-Rila Monas ter y, while the maxi m al value of 6.9 Bqkg–1 for 137Cs has been ob served at sam ples from soil of Kopaonik, es pe cially at Pancic's peak, are noted NP Kopaonik. The high est value for 210Pb was found by other authors [14]. At lower al ti tudes of the same in sam ples from NP Kopaonik, with a sim ilar value mountai n, at sam pling site "Brzece", ex cept for 40K, found in needles from NP Rila Monas ter y. all other nat u ral radionuclides show a lower value than The spe cific ac tiv ity of 40K in spruce nee dles at "Suvo Rudiste" (tab. 1). from LOF-Vlasina and NP-Rila Mon as tery is lower Rila Mountai n and its surround ings are largely than pre vi ously men tioned re sults found in lit er a ture made up of var i ous am phi bo lite-fa cies gneiss es in - [21, 22]. truded by gra nitic bodies . The geolog i cal background Re search re sults show var i ous spe cific ac tiv i ties of the samplin g site in side the Nat u ral Park is rep re - of 226Ra in spruce needles . The amount of 226Ra in sented by bi o tite and am phi bole-bi o tite gneiss es [20]. spruce needles depends on the age of the plant, with Ob tained re sults of radionuclide spe cific ac tiv i ties are the lowest amount found in the younger spe cies [23]. char ac ter is tic for ter rain formed of gneiss es. At this 137 –1 The re sults obtai ned in this re search also show a very samplin g site, the spe cific ac tiv ity of Cs, 50 Bqkg , low value of 226Ra in spruce twigs (tab. 3). is in ac cor dance with data cited in lit er ature [16]. Spe cific ac tiv i ties of 137Cs in nee dles are sim ilar In soil sam ples from Nature park "Rila Monas - to data previ ously cited in lit era ture [22, 24]. tery", the de tected spe cific ac tiv i ties of radionuclides In cor po ra tion of 210Pb into plants through the root cor re spond to the global av er age and are char ac ter is tic sys tem shows that alm ost 98 % of lead is atm ospheri c in for the terrain. or i gin [25]. The max i mal de tected spe cific ac tiv ity of this The highest values of all natu ral radionuclides in radionuclide was noti ced in the sam ples of the older the dif fer ent soil samples are detected at site "Suvo plants (45 Bqkg–1), confirm ing that the at mosphere is the Rudiste" in NP Kopaonik (tab. 1). The rati o of specif ic 235 238 ori gin of de posi ti on [23]. In this re search, the maxi m al ac tiv ity of U and U in soil sam ples from dif ferent 210 –1 loca ti ons is in the range of 0.045 to 0.055 which corre - de tected spe cific ac tiv ity of Pb was 90 Bqkg , found sponds to the rati o in nat ural uranium , indi cat ing its in sam ples from NP-Kopaonik „Suvo Rudište”. This lo - natu r al ori gi n. cal ity is a very pop u lar tour ist des tina tion in Ser bia with a 210 Re sults of radionuclide spe cific ac tiv i ties in the well-de vel oped in fra struc ture. Higher val ues of Pb in pe ren nial spruce spe cies Picea abies L., presented in the spruce may be a re sult of air pollu ti on from the traf fic tab. 3, show dif fer ent ac cu mu la tion val ues in twigs and fo liar de po si tion. (di am eter less than 1 mm) and nee dles, with spa tial Except for the sam ples of spruce needles from vari a tion ob served as well. Rila and Kopaonik and twig sam ples from Vlasina, the 7 Com par ing radionuclide spe cific ac tiv i ties in spe cific ac tiv ity of Be at all other lo ca tions was be low spruce nee dles from Kopaonik mountai n, Vlasina, and min i mum de tect able ac tiv ity. 7Be con cen tra tions in Rila, the mini m al values noted are 2.2 Bqkg–1 for the veg e ta tion re flected the chang ing at mo spheric 226Ra at NP Rila Mon as tery and 86 Bqkg–1 for 40K at con di tions, mainly pre cip i ta tion [26] that, along with

Table 3. Natural and artificial specific activities of radionuclides in the samples of spruce* from protected areas 226Ra 232Th 40K 238U 235U 137Cs 210Pb 7Be Samples [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] [Bqkg–1] Spruce needles 1 (Piceaabies) 2.2 ± 0.3 <0.5 220 ± 10 <3 <0.2 1.0 ± 0.2 82 ± 8 4.1 ± 0.9 "Rila "Suvo Rudiste" monastery" Natural park Spruce twigs 2 (Piceaabies) <1 <1 45 ± 6 <5 <0.4 <0.3 200 ± 10 <2 "Suvo Rudiste" National park Spruce needles "Kopaonik" 3 (Piceaabies) 8.8 ± 0.9 4.5 ± 0.7 140 ± 10 <2 <0.1 6.9 ± 0.5 90 ± 10 3.0 ± 0.7 Spruce needles Landscape of 8 4 ± 1 <2 80 ± 9 <10 <0.4 <0.4 <12 <2 outstanding (Piceaabies) features Spruce twigs "Vlasina" 9 (Piceaabies) <5 <2 110 ± 10 <10 <0.7 0.5 ± 0.2 130 ± 20 30 ± 10 *Spe cific ac tiv ity in plant sam ples ex pressed as [Bqkg–1] of plant mass dried at room temper a ture J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... Nuclea r Technol ogy & Ra dia tion Pro tection: Year 2017, Vol. 32, No. 4, pp. 334-341 339

Table 4. Radionuclide activity concentration in spring water 226Ra 232Th 40K 238U 235U 137Cs 210Pb Samples [mBqL–1] [mBqL–1] [mBqL–1] [mBqL–1] [mBqL–1] [mBqL–1] [mBqL–1] 1 Spring water Rila Monastery fountain 12 ± 2 <3 70 ± 10 60 ± 10 2.5 ± 0.5 <0.5 <50 Spring water "Marine vode", Kopaonik 2 "Suvo Rudiste" 46 ± 6 <5 <30 <30 <2 <2 <20 3 Spring water LOF "Vlasina" <30 <10 <70 <70 <4 <4 <40

7 its short half-life, can explai n lower val ues of Be in a Table 5. Risk assessment results from different localities tem per ate cli mate. & –1 Sampling sites Altitude [m] D [nGyh ] DE [mSv] Re sults of radionuclides in wa ter samples from NP Rila monastery 1147 50 0.06 all loctions are presented in tab. 4. NP Kopaonik "Suvo Var i ous con cen tra tions of radionuclide ac tiv ity were Rudiste" 1735 140 0.17 NP Kopaonik found in spring wa ter sam ples. Re search result s show that 1100 66 0.08 in sam ples from LOF Vlasina all radionuclides show a "Brzece" value of acti vit y concen tra tion lower than MDA. LOF Vlasina 1242 31 0.04 Radio anal ysis of water samples from all sam - pling sites showed that ac tivit y con centra tions of Rudiste", NP Kopaonik (tab. 5). The annual dose at NP 226 232 238 137 Ra, Th, U, and Cs (tab. 4) are sig nif icantly ''Rila Mon as tery'' and LOF Vlasina is lower than the lower than the guidance level [2]. Acti vit y con centra - global aver age value of 0.07 mSv given for outdoor 137 210 tions of Cs and Pb in spring wa ter were be low envi ron m ent [5], while site "Suvo Rudiste" at min i mum de tect able ac tiv ity. Kopaonik has higher val ues (tab. 5). Pre vi ous stud ies of ra dio ac tiv ity in wa ter were car - The quan ti fi ca tion of radionuclide uptake from ried out for sam ples of water of dif ferent or igin [27]. soil-to-leaf using transfer factors (TF) was deter mined –1 Drinking wa ter in Serbia contai ns less than 70 mBqL for radionuclides 226Ra, 40K, 137Cs, and 210Pb and the 226 –1 40 of Ra, less than 250 mBqL of K and less than result s present ed in tab. 6. –1 232 50 mBqL of Th [27]. Re sults obtai ned in this study Research results of the trans fer fac tor for 40K are show signi fi c antly lower value s than previ ously pre- higher than for 226Ra and corre spond to values in liter - sented. At the same time, ac tiv ity con cen tra tions of the ature. The max im al value for TF-40K is found in sam - studied sam ples are nota bly lower than the maxi m al al- ples from NP Rila Mon as tery, for TF-226Ra in sam ples 226 232 lowed ac tiv ity con cen tra tion for Ra and Th in from LOF Vlasina, and for TF-137Cs in spruce sam ples –1 –1 drinking wa ter of 490 mBqL and 590 mBqL re spec - from NP Kopaonik "Suvo Rudiste". tively, define d by the nati onal legis la ti on [28]. Obtai ned higher val ues for the 210Pb trans fer fac- Based on the result s of nat ural and arti ficia l tor corre spond to the fact that be sides root absorp ti on, radionuclide spe cific ac tiv ities in the soil (tab. 1), risk these radionuclides can be absorbed through foli ar de- as sess ment re sults are presented in the tab. 5. posi ti on. In spruce needles from NP Kopaonik and NP The absorbed dose rate is found to be in the range Rila Mon as tery a simi lar value of TF-210Pb,that of –1 –1 of 31 nGyh at LOF Vlasina to 140 nGyh at NP 1.42 and 1.67, re spec tively, is de tected, while the Kopaonik "Suvo Rudište". An al most twice higher TF-210Pb for twigs shows a value higher than 3.51 in –1 value, com pared to that of LOF Vlasina (66 nGyh ), the samples from LOF Vlasina and that of 4.08 at NP was de ter mined at site "Brzece" NP Kopaonik, which Rila Mon as tery. is to be expect ed regard ing the result s of radionuclide spe cific ac tiv ities. At the same moun tain, at higher al - titud es and that of site "Suvo Rudiste", the absorbed CONCLUSIONS dose rate shows a maxi m al value that is higher than the global aver age of 58 nGyh–1 [5], due to the geolog i cal The main conclu sion of this re search is that ac ci- background in the form of granodiorite. dent sit u a tions in the im me di ate vi cin ity of in ves ti - The mini m al value of the annual ef fecti ve dose gated areas in Southeas t Europe did not af fect the natu - of 0.04 mSv was obtai ned at LOF Vlasina, while the ral spa tial dis tri bu tion of radionuclides. As the first maxi m al value of 0.17 mSv was de ter mined at "Suvo ra dio ac tiv ity in ves ti ga tion of men tioned ar eas, it

Table 6. Transfer factor soil-to-leaf in plants from the analysed study area Sample TF-226Ra TF-40K TF-137Cs TF-210Pb NP Rila Norway spruce twigs – 0.12 – 4.08 monastery Norway spruce needles 0.08 0.60 0.02 1.67 NP Kopaonik Norway spruce needles "Suvo Rudiste" 0.10 0.18 0.70 1.42 Norway spruce twigs – 0.37 0.02 3.51 LOF Vlasina Norway spruce needles 0.21 0.27 – – J. A. D`olji}, et al.: Natu ral and Arti fi cial Radio ac tiv ity in Some Protected Areas ... 340 Nuclea r Technol ogy & Ra dia tion Protec tion: Year 2017, Vol. 32, No. 4, pp. 334-341 should be viewed as a start ing point and ba sis for fu- Krneta-Nikoli}, and J. A. Džolji}. The credit for the ture in ves ti ga tion. con cept of the re search goes to S. M. Stevovi}. All au - In com pari son to other sam pling loca ti ons, thors were include d into result anal ysis and dis cussion, higher spe cific ac tiv i ties of all radionuclides were while manuscri pt and figures' prepa ra ti on was done by found at both sam pling sites on Kopaonik. The con- J. A. Džolji}. clu sion is that the ob tained spe cific ac tiv ities of radionuclides from these sampling sites are typ ical and expect ed for said soil sam ples, due to the geolog i cal REFERENCES char acter istics of the ter rain. They are within [1] Nikoli}, M., Stevovi}, S., Family Asteraceae as a Sus- UNSCEAR reporte d values of natu ral radionuclide tain able Plan ning Tool in Phytoremediation and its 137 dis tri bu tion. 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This resea rch did not re - [12] ***, IAEA, Safety Re ports Series 64: Programmes ceive any spe cific grants from pub lic or comm er cial and Sys tems for Source and En vi ron men tal Ra di a tion Mon i tor ing,In ter na tional Atomic En ergy Agency, Vi - funds or the non-profit sec tor, but The Minis try of Sci - enna, USA, 2010, p. 248 ence and Tech no log i cal De vel op ment of the Re pub lic [13] ***, UNEP/UNCHS Bal kans Task Force (BTF), As - of Serbia supporte d this work under Project III43009. sess ment of the Damage to Biodiversity in Protected Ar eas of the Fed eral Re pub lic of Yu go sla via (1999), Tech ni cal mis sion. Avail able on line.http://www.grid. unep.ch/btf/mis sions/sep tem ber/biodiversity.pdf AUTHORS' CONTRIBUTIONS (last ac cessed 17.12.2016.) [14] Mitrovi}, B., et al., Nat u ral and Anthropogenic Ra - The the o ret ical anal y sis was car ried out by J. A. dioac ti vity in the Envi ron ment of Kopaonik Moun- Džolji}, S. M. Stevovi}, D. J. Todorovi}, and S. 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[15] Nikoli}, J., et al., Ap pli ca tion of GEANT4 Sim u la tion [23] Seidel, C., Ar ti fi cial and Nat u ral Radionuclides in on Cal i bra tion of HPGe De tec tors for Cy lin dri cal En- Spruce Nee dles in Up per Austria from 1983 to 2008 - vi ron men tal Sam ples, Jour nal of Ra dio log i cal Pro - an Ap pli ca tion for Radioecological Mon i tor ing, tec tion, 34 (2014), 2, pp. 47-55 Universität für Bodenkultur Wien, Dis ser ta tion, 2010 [16] ***, United Nations Sci entific Commit tee on the Ef - [24] Jasinska, M., et al., Ra dio ac tive Con tam i na tion of the fects of Atomic Radi a tion,UNSCEAR 2000 Re port Forest of South ern Po land and Fin land, Jour nal of vol. I: Sources, UN, New York, 2000, p. 654 Radioanalytical and Nuclear Chem istry , 146 (1990), [17] Petrovi}, B., et al., Ba sic Geo log i cal Map of SFRY 1, pp. 1-13 1:100000, the Vlasotince Sheet (in Serbian), Federal [25] Hovmand, M. F., et al., Root Up take of Lead by Nor - Geo log i cal In sti tute, Beograd, 1966 way Spruce Grown on 210Pb Spiked Soils, En vi ron - [18] Popovi}, D., et al., Radionuclides and Heavy Metals men tal Pol lu tion, 157 (2009), 2, pp. 404-409 in Borovac, South ern Ser bia, En vi ron men tal Sci ence [26] Poschl, M., et al., Sea sonal and Inter-Annual Vari a - and Pol lu tion Re search, 15 (2008), 6, pp. 509-520 tion of Be ryl lium-7 De po sition in Birch-Tree Leaves [19] Uroševi}, M., et al., Ba sic Geo log i cal Map of SFRY and Grass in the North east Up land Area of the Czech 1:100000, the Novi Pazar Sheet (in Serbian), Federal Re pub lic, Jour nal of En vi ron men tal Ra dio ac tiv ity, Geo log i cal In sti tute, Beograd, 1970 101 (2010), 9, pp. 744-750 [20] Sarov, S., et al., Geo log i cal Map of the Re public of [27] Jankovi}, M. M., et al., Nat u ral Radionuclides in Bul garia 1:50000, the Rila Monas tery Sheet (in Bul - Drink ing Wa ters (in Ser bia), Ap plied Ra di a tion and gar ian), Min is try of En vi ron ment and Wa ter, Bul gar - Iso topes, 70 (2012), 12, pp. 2703-2710 ian Na tional Geo log i cal Sur vey, Sofiya, 2010 [28] ***, Of fi cial Ga zette of the Re pub lic of Ser bia, 2011, [21] Mietelski, J. W, et al., 137Cs, 40K, 90Sr, 238, 239+240Pu, Reg u la tion on Lim its of Radionuclide Content in 241Am and 243+244Cm in For est Litter and Their Trans- Drink ing Wa ter, Food stuffs, Feed ing Stuffs, Drugs, fer to Some Spe cies of In sects and Plants in Bo real Items of General Use, Building Mate rials and Other Forests: Three Cases Study, Jour nal of Goods to be Placed on the Mar ket, Ser bia, no. 86. Radioanalytical and Nuclear Chem istry , 262 (2004), Andno. 97 from 2013 3, pp. 645-660 [22] Tomankiewicz, E., et al., Ac cu mu la tion Prop er ties of Norway Spruce (Piceaabies) for Dif fer ent Recei ved on Janu ary 9, 2017 Radionuclides, Nukleonika, 51 (2006), Suppl. 2, pp. 59-67 Accept ed on August 28, 2017

Jovana A. XOQI], Svetlana M. STEVOVI], Dragana J. TODOROVI], Svetlana M. POLAVDER, Milica M. RAJA^I], Jelena D. KRNETA NIKOLI]

PRIRODNA I VE[TA^KA RADIOAKTIVNOST U ZA[TI]ENIM PODRU^JIMA JUGOISTO^NE EVROPE

Ciq istra`ivawa bio je da se ispita prirodna i ve{ta~ka radioaktivnost u uzorcima iz za{ti}enih podru~ja Kopaonika, Vlasine i Rile. Za predmet istra`ivawa izabrani su zemqi{te (ukqu~uju}i jezerski sed i ment), pija}a izvorska voda i ~etinari na navedenim lokacijama Jugoisto~ne Evrope, zbog wihovog zna~aja za qude i `ivotnu sredinu u globalu. Metodom gamaspektrometrije laboratorijski su odre|ene specifi~ne aktivnosti 226Ra, 232Th, 40K, 238U, 235U, 137Cs, 210Pb i 7Be koje su upore|ene sa prose~nim vrednostima u svetu. Ura|ena je procena rizika i odre|en je transfer faktor zemqi{te – biqka za 226Ra, 40K, 137Cs i 210Pb. Ovo je prvo istra`ivawe radioaktivnosti visokoplaninskih podru~ja Vlasine i Kopaonika u Srbiji i Rile u Bugarskoj i mo`e se smatrati nultim stawem i osnovom za daqa istra`ivawa.

Kqu~ne re~i: gamaspektrometrija, procena rizika, smr~a, Kopaonik, Rila, Vlasina