Iskustva akreditacije Instituta za medicinska istraživanja i medicinu rada

Accreditation in accordance with the international General Requirements for the Competence of Testing and Calibration Laboratories (HRN EN ISO/IEC 17025 standard) has become a widely accepted method of quality management and objective evidence of technical competence, knowledge, and skills of testing and calibration laboratories. In 2010, the Institute for Medical Research and Occupational Health (IMROH) had its management system accredited against the HRN EN ISO/IEC 17025 standard for the following scopes: determination of radioactivity, testing of ambient air quality, and testing in the scope of ionising radiation protection. This accreditation encompassed three laboratories: Radiation Protection Unit, Environmental Hygiene Unit, and the Radiation Dosimetry and Radiobiology Unit. In accordance with the rules of the Croatian Accreditation Agency, the second re-accreditation is due in 2020. This paper describes and discusses the quality management system at IMROH over the ten years of its implementation. We share our experiences about non-conformities discovered during regular work, internal audits, and external audits performed by the Croatian Accreditation Agency. The accredited management system significantly improved the performance of the accredited units, and the Institute increased its visibility and marketing advantage, consequently improving its market position.Akreditacija u skladu sa zahtjevima međunarodnog standarda HRN EN ISO / IEC 17025 (Opći zahtjevi za osposobljenost ispitnih i umjernih laboratorija) postala je praktična i široko prihvaćena metoda upravljanja kvalitetom i objektivni dokaz tehničke osposobljenosti, znanja i vještina u ispitnim i umjernim laboratorijima. Institut za medicinska istraživanja I medicinu rada (IMROH) akreditirao je 2010. godine svoj sustav upravljanja u skladu sa zahtjevima HRN EN ISO / IEC 17025 norme za sljedeća područja primjene: određivanje radioaktivnosti, ispitivanja kvalitete zraka te ispitivanja u području zaštite od ionizirajućega zračenja. Akreditacija je obuhvaćala tri laboratorija: Jedinicu za zaštitu od zračenja, Jedinicu za higijenu okoline i Jedinicu za dozimetriju zračenja i radiobiologiju. U skladu s pravilima Hrvatske akreditacijske agencije, u 2020. godini planira se druga reakreditacija Instituta. U radu je opisan sustav upravljanja kvalitetom u IMROH-u i iskustva stečena tijekom desetogodišnjeg razdoblja. Analizirane su nesukladnosti otkrivene tijekom redovitog rada, u internim auditima te u vanjskim auditima koje je provodila Hrvatska akreditacijska agencija, tj. nacionalno akreditacijsko tijelo u Hrvatskoj. Može se zaključiti da je akreditirani sustav upravljanja značajno poboljšao rad uključenih akreditiranih jedinica, a Institut je povećao vidljivost na tržištu i marketinšku prednost te posljedično poboljšao svoju tržišnu poziciju

226Ra and 228Ra in Croatian Rivers

The presence of natural radionuclides in Croatian rivers emphasizes the need for its continuous monitoring. Therefore results of 226Ra and 228Ra determination in Croatian river waters are presented in this paper. 226Ra and 228Ra were chosen as a possible source of human exposure due to their high radio-toxicity. Fifty liters of river water samples were collected from the Danube, Drava, Sava, Krka and Neretva rivers twice a year from 2002 to 2006. It is showed that activity concentrations of 226Ra ranged from 6.54 mBq/L to 59.44 mBq/L and 228Ra activity concentrations ranged from 2.57 mBq/L to 20.76 mBq/L. The highest values of both 226Ra and 228Ra were measured in the river Drava, and the lowest values in the river Sava. Statistically significant differences were not observed between radium concentrations from two watersheds (the Black Sea and the Adriatic Sea watershed), nor between 226Ra/228Ra ratio in rivers individually. The number of collected samples is insufficient to make more statistically significant conclusions. However the data obtained in this study could be the baseline for evaluating possible future changes

Mosses and Some Mushroom Species as Bioindicators of Radiocaesium Contamination and Risk Assessment

Mosses, lichens, mushrooms are able to efficiently accumulate different radioactive elements from their environment to a much higher degree than other vegetation. They are sensitive bioindicators of radioactive contamination for various ecosystems, particularly in the event of a nuclear accident and uncontrolled emission oh fission products. Results of systematic, long-term measurements of 137Cs activities in mosses and in some edible mushroom species in North Croatia for the post-Chernobyl period (1986–2007) are summarized. The study was conducted in the Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb, as a part of an extensive monitoring program of the Croatian environment. In the overall observed period the highest activity concentration of 137Cs deposited by fallout has been recorded in 1986, which is the year of Chernobyl accident, causing peak 137Cs activity concentration in moss of 8800 Bq/kg in May 1986. In the same period mean 137Cs activity concentration in grass was 390 Bq/kg. The highest value of 137Cs activity concentration in Cortinarius caperatus mushrooms of 1351 Bq/kg has been recorded in 1989. Fitting the measured 137Cs activity concentrations to the theoretical curve the ecological half-life of 137Cs in moss was found to be around 978 days, in grass around 126 days in the period 1986–1990, in Cortinarius caperatus mushroom around 5865 days (16.1 years). Regarding the risk assessment to Croatian population, due to consumption of mushrooms, the collective effective dose for Croatian population, estimated to be about 35 mSv per year, was found to be quite low. Therefore, it can be concluded that mushroom consumption was not a critical pathway for the transfer of radiocaesium from fallout to humans after the Chernobyl accident

Fosfogips i njegovo potencijalno korištenje u Republici Hrvatskoj ‒ izazovi i prilike

Phosphogypsum (PG) is a waste by-product (residue) originating from the production of phosphoric acid and phosphate fertilisers. PG contains chemical and radioactive impurities, which is why it is mostly stockpiled in controlled areas. Worldwide, only about 15 % of PG is recycled or reused. Today, policies and business strategies prioritise sustainable development through circular economy, which certainly includes PG. This provides new opportunities for Croatia to manage its PG and make an effort to use it as an additive in different industries, such as agriculture and construction. Due to its chemical and radiological properties, PG can potentially cause problems for the environment and human health. Hence, before using PG, detailed knowledge of potential hazards is necessary to protect people and the environment. The aim of this review is to summarise available data on Croatian PG, compare them with other countries, and to identify knowledge gaps and the lack of data on potential hazardous substances in PG in order to assess the opportunities of using PG in Croatia.Fosfogips (FG) otpadni je nusproizvod (rezidua) koji potječe iz proizvodnje fosforne kiseline i fosfatnih mineralnih gnojiva. FG je kontaminiran kemijskim i radioaktivnim tvarima, stoga se uglavnom odlaže na kontroliranim odlagalištima. U svijetu se samo oko 15 % FG-a reciklira i ponovno koristi. U današnje vrijeme, političke i poslovne strategije stavljaju na prvo mjesto održivi razvoj kroz kružno gospodarstvo, a tu svoje mjesto može pronaći i FG. Time se stvaraju nove prilike u Republici Hrvatskoj za korištenje FG-a kao aditiva u različitim industrijama, od poljoprivrede do građevinske industrije. Zbog svojih kemijskih i radioloških svojstava, korištenje FG-a može potencijalno prouzročiti probleme za okoliš i ljudsko zdravlje. Stoga je prije korištenja nužno detaljno znanje o potencijalnim opasnostima FG-a kako bismo zaštitili ljude i okoliš. Cilj je ovoga preglednog rada sažeti dostupne podatke o FG-u u Republici Hrvatskoj, usporediti ih sa svjetskim podatcima i prepoznati nedostatke i manjak podataka o riziku koji nose potencijalno opasne tvari u FG-u

Mjerenje i modeliranje radiološkog utjecaja odlagališta fosfogipsa na okoliš

Phosphogypsum (PG) is a waste product (residue) from the production of phosphoric acid characterized by technologically enhanced natural radioactivity. Croatia’s largest PG deposition site is situated at the edge of Lonjsko Polje Nature Park, a sensitive ecosystem possibly endangered by PG particles. This field study investigates two aspects relevant for the general radiological impact of PG: risk assessment for the environment and risk assessment for occupationally exposed workers and local inhabitants. Activity concentrations of natural radionuclides (238U, 235U, 232Th, 226Ra, 210Pb, and 40K) were measured in the PG (at the deposition site), soil, and grass samples (in the vicinity of the site). The ERICA Assessment Tool was used to estimate the radiological impact of PG particles on non-human biota of the Lonjsko Polje Nature Park. The average annual effective dose for occupationally exposed workers was 0.4 mSv which was within the worldwide range.Fosfogips je nusproizvod koji nastaje tijekom proizvodnje fosforne kiseline, a karakteriziran je tehnološki povišenom prirodnom radioaktivnošću. Odlagalište fosfogipsa u Hrvatskoj nalazi se na rubu Parka prirode Lonjsko polje, osjetljivom ekosustavu potencijalno ugroženom od čestica fosfogipsa. Istraživanje opisano u ovom radu sagledava dva aspekta značajna za radiološki utjecaj fosfogipsa: procjenu rizika za okoliš te procjenu rizika za profesionalno izložene radnike i lokalno stanovništvo. Koncentracije aktivnosti prirodnih radionuklida (238U, 235U, 232Th, 226Ra, 210Pb i 40K) izmjerene su u uzorcima fosfogipsa uzetima s odlagališta te u uzorcima tla i trave uzetima u blizini odlagališta. Za modeliranje utjecaja fosfogipsa na okoliš (biotu) korišten je program ERICA Assessment Tool. Prosječna godišnja efektivna doza za profesionalno izložene radnike iznosila je 0,4 mSv, što je na razini svjetskog prosjeka

RAZINE SUMPORA, METALA, POLUMETALA, RADIOAKTIVNOSTI I CITOTOKSIČNOSTI U KRŠKIM ISPUSTIMA VODE IZ NAPUŠTENIH RAŠKIH UGLJENOKOPA (SJEVERNI DIO JADRANSKOGA MORA)

Raša coal, mined on the Istrian Peninsula (NW Croatia) for nearly 400 years up to 1999, is notable for having superhigh organic sulfur, and high levels of selenium, uranium, vanadium, and molybdenum. Selenium is the poison responsible for the widespread loss of cattle and sheep. It is essential to human health in trace amounts, but higher concentrations can be harmful. An estimated 4.4Mt. of coal remains underground within marine carbonate rocks. The study area belongs to the coastal karst of the Adriatic Sea. Several abandoned coal-mine discharges (CMDs) were released into local streams and the Raša Bay for decades. Therefore, the water quality of a natural karst spring (Fonte Gaja), the Raša Bay seawater, municipal wastewater, and the Raša CMDs were investigated, focusing on sulfur, selected metal(loid)s (major, minor, and trace), radioactivity, and cytotoxicity. The Fonte Gaja spring water, unrelated to the Raša CMD, served as a reference. Its values of Se, U, V, and Mo (µg/L) were as follows: 1.09, 0.75, 1.37, and 2.04, respectively. However, the respective levels (µg/L) were increased in the rest of the water samples as follows: 10.9, 10.8, 4.60, and 33.1. Water sulfate levels were low though. Total beta activities of the CMDs and Raša Bay water were 235 and 1320 Bq/m3, respectively, below the guideline level of 2000 Bq/m3. The cytotoxicity of water samples on the RTG-2 fish cells was not statistically significant. The large volumes of water involved mean the transport of rather large amounts of Se and U, and their deposition in the Adriatic Sea. Due to the complexity of the karst hydrogeology, knowledge of Se and U circulation patterns is highly needed.Pridobivanje raškoga ugljena u Istri (SZ Hrvatska) trajalo je gotovo 400 godina, sve do 1999. godine. Raški ugljen poznat je po iznimno visokim koncentracijama organskoga sumpora te visokim razinama selena, urana, vanadija i molibdena. Otprije je poznata toksičnost selena na primjerima goveda i ovaca. Za ljudsko zdravlje selen je od presudne važnosti, ali u povišenim je količinama štetan. Procjenjuje se da je još 4,4 milijuna tona raškoga ugljena ostalo pod površinom, unutar marinskih karbonatnih stijena. Područje istraživanja pripada obalnome krškom pojasu Jadranskoga mora. Na nekoliko mjesta nalaze se ispusti podzemne vode iz napuštenih rudnika ugljena (engl. CMD), gdje ta voda desetljećima izbija van na površinu te se izravno ulijeva u lokalne vodotoke i na kraju u Raški zaljev. Stoga su uzeti uzorci vode prirodnoga krškog izvora, morske vode Raškoga zaljeva, komunalne otpadne vode te CMD. U uzorcima su izmjerene koncentracije sumpora, odabranih metala i polumetala (glavnih, sporednih i u tragovima), radioaktivnost te citotoksičnost. Izvorska voda, koja nije u dodiru s CMD-om, poslužila je u referentne svrhe. Njezine odgovarajuće vrijednosti Se, U, V i Mo (μg/L) bile su sljedeće: 1,09, 0,75, 1,37 i 2,04. Međutim, odgovarajuće razine tih četiriju elemenata (μg/L) bile su povišene u ostatku uzoraka vode: 10,9, 10,8, 4,60 i 33,1. Razina sumpora u vodi bila je niska. Ukupne beta aktivnosti CMD-a i vode Raškoga zaljeva iznosile su 235 i 1320 Bq/m3, čime nije bila premašena dopuštena vrijednost od 2000 Bq/m3. Citotoksičnost nekoliko odabranih uzoraka vode nije se pokazala statistički značajnom. Velike količine vode podrazumijevaju transport prilično velikih količina Se i U te njihovo taloženje u Jadranskome podmorju. Zbog složenosti krške hidrogeologije nužno je istražiti obrasce cirkuliranja selena i urana na spomenutome području

Radioaktivnost tla u Hrvatskoj I. – prirodnopojavni lanci raspada

The assessment of environmental radioactivity much relies on radionuclide content in soil. This stems from the significant contribution of soil to both external and internal exposure to ionising radiation via direct emission of gamma radiation and soil-to-plant radionuclide transfer, respectively. This motivated us to carry out a systematic research on the radioactivity of soil in Croatia to obtain relevant data that can be used as a basis for understanding the related effects of geomorphological, biogeographical, and climatological properties of the environment. We collected samples of the surface layer of uncultivated soil (0–10 cm) at 138 sites from all over the country and measured them for radionuclide activity concentrations by means of high-resolution gamma-ray spectrometry. This resulted in radioactivity maps containing data on activity concentrations of representative radionuclides in the environment. In this paper, which is the first in our two-part presentation, we focus on the naturally occurring 232Th and 238U decay chains and their correlations with the diversity of Croatian regions. For both of the chains, activity concentrations were the highest in the Dinaric region, the lowest in the Pannonian region, and intermediate in the Adriatic region. Relatively high concentrations of 226Ra in the soil of the Dinaric region implied a possibility of an enhanced emanation of its progeny 222Rn into the air. Activity concentrations of 210Pb were additionally elevated in areas with dense vegetation, most probably due to an atmospheric deposition of airborne 210Pb onto the surface of plants and their eventual decomposition on the ground.U radioaktivnosti okoliša velika se pažnja posvećuje radionuklidima u tlu. Taj interes slijedi iz značajnih doprinosa tla I vanjske i unutarnje izloženosti ionizirajućem zračenju izravnom emisijom gama-zračenja i transferom radionuklida iz tla u biljke. To nas je motiviralo da provedemo sustavno istraživanje radioaktivnosti tla u Hrvatskoj kako bismo dobili relevantne podatke kao osnovu za razumijevanje pripadnih učinaka geomorfoloških, biogeografskih i klimatoloških svojstava okoliša. Prikupili smo uzorke površinskoga sloja (0–10 cm) nekultiviranoga tla s 138 lokacija diljem zemlje te smo mjerili koncentracije aktivnosti u njima koristeći se visokorezolucijskom gamaspektrometrijom. To je rezultiralo mapama radioaktivnosti hrvatskoga tla, koje sadržavaju podatke o koncentracijama aktivnosti reprezentativnih radionuklida u okolišu. U ovom radu, koji je prvi u našoj dvodijelnoj prezentaciji, fokusirali smo se na prirodnopojavne 232Th i 238U lance raspada i njihove korelacije s raznolikošću hrvatskih regija. Za oba su lanca koncentracije aktivnosti bile najviše u dinarskom području, najniže u panonskom području i srednje u jadranskom području. Posebice, relativno visoke koncentracije 226Ra u tlu dinarskoga područja impliciraju mogućnost povišene emanacije njegova potomka 222Rn u zrak. Koncentracije aktivnosti 210Pb bile su dodatno povišene u područjima s gustom vegetacijom, vrlo vjerojatno zbog atmosferske depozicije iz zraka na biljke te na njihovu konačnu dekompoziciju na tlu

Radioaktivnost tla u Hrvatskoj II.: 137Cs, 40K i brzina apsorbirane doze

We took samples of uncultivated soil from the surface layer (0–10 cm) at 138 sites from all over Croatia and measured their radionuclide activity concentrations with high-resolution gamma-ray spectrometry. This second part of our report brings the results on 40K and 137Cs to complement those on the 232Th and 238U decay chains addressed in the first part. Together they give the most complete picture of radioactivity of Croatian soil so far. Activity concentrations of 40K were the highest in the Pannonian region, and there was an opposite trend for 137Cs. We found that the concentrations of 137Cs tended to increase with altitude, annual precipitation, and vegetation density. The concentration ratio of 137Cs and K in soil, which indicates the potential for 137Cs entering food chains via uptake by plants, was the lowest in agriculturally important areas in the east of the Pannonian region. In addition, we used the obtained results on activity concentrations to calculate the related absorbed dose rate as a measure of external exposure to ionising radiation from soil. The sum of the absorbed dose rates for naturally occurring radionuclides and 137Cs showed that external exposure was generally the highest in the Dinaric region and Istrian Peninsula.Uzorkovali smo površinski sloj (0–10 cm) nekultiviranog tla na 138 mjesta diljem Hrvatske i mjerili koncentracije aktivnosti radionuklida u prikupljenim uzorcima visokorezolucijskom gamaspektrometrijom. U ovom radu, koji je drugi dio naše dvodijelne prezentacije, fokus je na 40K, 137Cs i brzini apsorbirane doze zbog prisutnosti radionuklida u tlu. Ti rezultati dopunjuju one vezane uz 232Th i 238U lance raspada, što vodi do dosad najcjelovitije slike radioaktivnosti tla u Hrvatskoj. Koncentracije aktivnosti 40K bile su najviše u hrvatskom panonskom području, a trend za 137Cs bio je suprotan. Našli smo da su koncentracije 137Cs pokazivale tendenciju porasta s nadmorskom visinom, količinom oborine i gustoćom vegetacije. Omjer koncentracija 137Cs i K u tlu, a koji predstavlja potencijal za ulaz 137Cs u hranidbene lance apsorpcijom putem biljaka, bio je najmanji na istoku panonskoga područja gdje se nalaze poljoprivredno važne površine. Rezultate za koncentracije aktivnosti iskoristili smo za izračun posljedične brzine apsorbirane doze kao mjere vanjske izloženosti ionizirajućem zračenju iz tla. Zbroj brzina apsorbirane doze za prirodnopojavne radionuklide i 137Cs pokazao je da je vanjska izloženost općenito bila najveća u dinarskom području i na istarskom poluotoku