MJERENJE RADIOAKTIVNOSTI U ŽIVOTNOJ SREDINI NA TERITORIJI REPUBLIKE SRBIJE U PERIODU 1986-2002. GODINA
Pantelić G, Tanasković I, Vuletić V, Javorina Lj, Eremić- Savković M.
Institut za medicinu rada i radiološku zaštitu "Dr Dragomir Karajović", Beograd, Srbija i Crna Gora

CILJ: Cilj je dati prikaz rezultata merenja radioaktivnosti u životnoj sredini na teritoriji republike Srbije od 1986- 2002.godine.

MATERIJAL I METODE: U Institutu za medicinu rada i radiološku zaštitu " Dr Dragomir Karajović" već 40 g?dina s? prati radioaktivnost životne sredine metodologijom vertikalne analize uzoraka na teritoriji Republike Srbije. Uzorkovanje se vrši u vazduhu, padavinama, tlu, rečnoj i pitkoj vodi, vegetaciji i prehrambenim proizvodima. Preporučena granica iznosi 1 mSv/god i odnosi se na zbir odgovarajućih doza od spoljašnjeg izlaganja i očekivane efektivne doze unutrašnjeg izlaganja za period od godinu dana (Pravilnik o granicama izlaganja jonizujućim zračenjima, Sl. list SRJ br. 32/98).

REZULTATI: Rezultati merenja aktivnosti 137Cs i 90Sr u prehrambenim proizvodima i dnevni unos ovih radionukleotida ishranom za stanovništvo Beograda, Niša, Novog Sada, Subotice, Zaječara i Užica u periodu 1986.-2002. godine pokazuju značajno i kontinuirano opadanje aktivnosti 137Cs i 90Sr u ciklusu ishrane. ?fektivna doza zračenja za stanovništvo od tih radionukleotida unetih ingestijom je značajno ispod preporučene godišnje granice primljene doze za pojedinca. Aktivnosti prirodnih radionuklida bile su u granicama prosečnih vrednosti u ispitivanim regionima u Srbiji. Odnos aktivnosti 238U i 235 U u merenim uzorcima odgovara njihovom odnosu u prirodnom uranu (21.4). Prisustvo osiromašenog uranijuma na teritoriji Beograda, Niša, Zaječara, Zlatibora, Kragujevca, Kraljeva, Novog Sada i Subotice nije utvrđeno. Lokacije na kojima je dokazana kontaminacija municijom osiromašenog uranijuma su u regionu Vrava. Rezultati merenja ukupne alfa i beta aktivnosti, kao i gamaspektrometrijska ispitivanja voda za piće iz lokalnog vodozahvata na Pljačkovici i bunara u Borovcu, Bratoselcu i Bukurevcu pokazali su da ove vode zadovoljavaju kriterije o radiološkoj ispravnosti i mogu se koristiti za piće. Rezultati gamaspektrometrijskih mjerenja u prehrambenim proizvodima sa lokaliteta Pljačkovica i Borovac pokazali su značajno niske vrednosti prirodnih radionuklida i niske aktivnosti 137Cs. U ovim uzorcima za sada nije dokazano prisustvo osiromašenog uranijuma. ?d skoro svih prikupljenih uzoraka zemljišta, rezultati su pokazali dobro slaganje aktivnosti prirodnih radionuklida 40?, 232?h, 226R? i njihovu homogenu raspoređenost na ispitivanim mikrolokacijama. Kontaminacija koja potiče od osiromašenog uranijuma nije homogena (rezultati merenja aktivnosti 238U i 235U). Visoka kontaminacija tla otkrivena je na mestima gde su pronađena zrna od osiromašenog uranijuma. Aktivnost 238U u uzorcima tla kretala se od 35 - 216721 Bq/kg.

ZAKLJUČAK: Može se zaključiti da se aktivnost kako prirodnih tako i dugoživećih radionuklida veštačkog porekla (uglavnom padavine nakon akcidenta u Černobilju), u različitim vrstama uzoraka kretala u niskim nivoima. Treba naglasiti da je veoma važno prikupljanje uzoraka na terenu ugroženih mikrolokacija gde se može naći visoka kontaminacija tla.

RADIOACTIVITY MEASUREMENT IN THE LIVING ENVIRONMENT ON THE TERRITORY OF THE REPUBLIC OF SERBIA BETWEEN 1986-2002
Pantelić G, Tanasković I, Eremić Savković M, Javorina Lj, Vuletić V.
Institute of Occupational Medicine and Radiological Protection "Dr Dragomir Karajović", Belgrade, Serbia and Montenegro

AIM: The goal is to present results of the measuring radioactivity in environment on the territory of the Republic of Serbia between 1986- 2002.

MATERIAL AND METHODS: The monitoring of radioactivity level in the living environment has been carried out at the Institute of Occupational Medicine and Radiological protection for 40 years, by methodology of vertical analysis on the territory of the Republic of Serbia. On the basis of the overall measurements, it was concluded that the activity of both natural and long-lived radio -nuclides of artificial origin (mostly resulting from precipitation after Chernobyl accident), ranged within low levels in different types of samples (air, fall-out, soil, river and drinking water, vegetation, foodstuffs). Recommended limit is 1 mSv/year and it represents the sum of the appropriate dose of the external exposure and the expected effective dose of internal exposure for the period of one-year (Regulations on limits of exposure to ionising radiation, Official Gazette of FRY, No 32/98).

RESULTS: The results of measurements of 137Cs and 90Sr activity in foodstuffs and daily intake of these radio-nuclides in food for population (the regions of Belgrade, Niš, Novi Sad, Subotica, Zaječar and Užice) showed significant and continuous decrease of 137Cs and 90Sr activity in nutrition cycle between 1986-2002. The effective dose of radiation by those ingested radio -nuclides in population was significantly below the recommended annual limit of administered dose/individual. The activity of natural radio -nuclides is within normal limits of mean values for the tested regions in Serbia. The ratio of 238U and 235U activities in measured samples corresponds to their ratio in natural uranium (21.4). The presence of depleted uranium on the territory of Belgrade, Niš, Zaječar, Zlatibor, Kragujevac, Kraljevo, Novi Sad and Subotica has not been found in recent measurements. The locations with verified contamination by depleted uranium ammunition have been identified and marked, while local population has been warned against the hazard from contaminated soil and longer stay in that region. The results of measurements of total alpha and beta activities as well as gamma-spectrometric examination of drinking water from local water intake on Pljačkovica and wells in Borovec, Bratoselce and Bukurevac showed that these waters met the criteria on radiological correctness in compliance with legal regulations. The results of gamma-spectrometric measurements of foodstuffs from the locations of Pljačkovica and Borovac revealed significantly lower levels of natural radio -nuclides, as well as low activity of 137Cs. So far, the presence of depleted uranium has not been confirmed in these samples. Out of almost all collected soil samples were assumed as contaminated, two samples were taken for measurement, respectively. The results of measurement showed good congruence of activities of natural radio -nuclides 40K, 232Th and 226Ra, and their homogenous distribution in the tested micro-locations. The contamination derived from depleted uranium was not homogenous, what was evident by the results of measurements of 238U and 235U activities. The activity of 238U in the soil samples ranged from 35 to 216721 Bq/kg.

CONCLUSION: Only following longer monitoring and examination of all jeopardised territories, and after longer periodical examinations of all segments of living environment, the evaluation of its imperilment and actual health risk for population can be assessed.