Investigations in the post-Chernobyl period (1986-2009) of radiocaesium activity concentrations i... more Investigations in the post-Chernobyl period (1986-2009) of radiocaesium activity concentrations in Adriatic pilchards are presented. Compared with pre-Chernobyl period, the Chernobyl nuclear accident caused increase of 137 Cs activity concentrations in pilchards. By fitting the measured 137 Cs activity concentrations to the theoretical curve was estimated to be 1.5+ + + + +0.4 y for 1986-90 and 5.8+ + + + +0.4 y for 1991-2009 and the bimodal behaviour for the ecological half-life of 137 Cs in pilchards has been observed. Estimated annual effective doses received by 134 Cs and 137 Cs intake due to consumption for an adult member of Croatian population are small. Collective dose for the 1986-2009 period was 4.910.3 person-Sv. The observed 134 Cs/ 137 Cs activity ratio in pilchards was similar to the ratio that has been found in other environmental samples. The concentration factor for pilchards was roughly estimated to be 93.7+ + + + +39.2 l kg 21 , which is consistent with the values observed elsewhere.
Mosses, lichens, mushrooms are able to efficiently accumulate different radioactive elements from... more 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 137 Cs activities in mosses and in some edible mushroom species in North Croatia for the post-Chernobyl period 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 137 Cs deposited by fallout has been recorded in 1986, which is the year of Chernobyl accident, causing peak 137 Cs activity concentration in moss of 8800 Bq/kg in May 1986. In the same period mean 137 Cs activity concentration in grass was 390 Bq/kg. The highest value of 137 Cs activity concentration in Cortinarius caperatus mushrooms of 1351 Bq/kg has been recorded in 1989. Fitting the measured 137 Cs activity concentrations to the theoretical curve the ecological half-life of 137 Cs in moss was found to be around 978 days, in grass around 126 days in the period . 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.
Primljeno u kolovozu 2010. Prihvaćeno u rujnu 2010. Od vremena otkrića radioaktivnosti i postepen... more Primljeno u kolovozu 2010. Prihvaćeno u rujnu 2010. Od vremena otkrića radioaktivnosti i postepenog ovladavanja i iskorištavanja pojava vezanih uz radioaktivnost razvijala se i ideja o potrebi zaštite od ionizirajućeg zračenja. Zaštita od zračenja razvila se u sustavnu djelatnost, a danas je to razvijena doktrina i znanstvena disciplina koja holističkim pristupom vodi brigu o zračenju, o ljudima izloženima zračenju, ali istodobno i o ljudskom okruženju i o okolini. Razvojni trendovi znanosti o zračenju, zaštite od zračenja i tehnološkog područja koje se njima bavi, neprestano unose nove sastavnice u doktrinu zaštite od zračenja, što novim preporukama dovodi do minimiziranja izlaganja zračenju. Radiološke nesreće dodatno senzibiliziraju ljude na opasnosti od ionizirajućeg zračenja. Nuklearne nesreće, kao ona u Černobilu 1986. godine, postavljaju pred cjelokupnu zajednicu pitanja o granicama doza ionizirajućeg zračenja, kako na lokalnoj tako i na međunarodnoj razini. Svakodnevni intenzivni promet robe, ljudi i usluga dodatno otkriva probleme vezane uz ograničavanja koja su nužna u slučaju mogućih nuklearnih nesreća većih razmjera. No, istodobno postavlja se pitanje i o uspostavi i održavanju jednako vrijednih standarda radiološke zaštite.
This paper gives a review of marine radioecology research in the Adriatic area carried out by the... more This paper gives a review of marine radioecology research in the Adriatic area carried out by the Radiation Protection Unit of the Institute for Medical Research and Occupational Health. Measurements of radioactivity in the Adriatic started in 1963 as a part of an extended monitoring programme of radioactivity in Croatian environment. The main sources of radioactive contamination of the Adriatic Sea are the fallout from past nuclear weapon testing conducted in the atmosphere and the Chernobyl accident. In 2005, the activity concentrations of fission radionuclides were detectable at very low levels in all environmental samples collected on the Adriatic. The 90 Sr data obtained from long-term monitoring were used to estimate the upper limit of the Adriatic seawater turnover time, which turned out to be (3.4±0.4) years. Detailed knowledge about seawater circulation, including the turnover time is essential for planning an overall communal and other wastewater management on the Adriatic coast. The paper concludes with the prospects for future marine radioecological investigations.
This article brings the results of a method for quality assurance in gamma-ray spectrometry of se... more This article brings the results of a method for quality assurance in gamma-ray spectrometry of seabed sediments. Sediments were collected in selected locations of the South and Middle Adriatic Sea using grab and corer tools. Using our own experimental design, we determined the self-attenuation factors of selected samples. The article also discusses sources of uncertainty in gamma-ray spectrometry, which is another important issue in quality assurance. Together with self-attenuation correction sources of uncertainty are used to calculate the activity concentration for a given sample. The presented procedure demonstrates how a gamma-ray spectrometry experiment should be approached in order to properly account for errors and uncertainties specifi c to a particular sample.
Archives of Industrial Hygiene and Toxicology, 1994
The biological concentration factors for the system pilchard/sea-water for 90Sr and 137Cs are pre... more The biological concentration factors for the system pilchard/sea-water for 90Sr and 137Cs are presented and discussed. The 90Sr concentration factor was constant, whereas the concentration factor for 137Cs steadily increased after the Chernobyl accident. An UNSCEAR model was used to describe 90Sr transfer from fallout deposition to pilchards. The transfer coefficient was calculated to be 1.85 x 10(-3) Bq yr kg-1/(Bq m-2). The dose incurred by pilchard consumption was estimated for the Croatian population, the annual collective equivalent dose being less than 0.1 Sv.
Archives of Industrial Hygiene and Toxicology, Sep 28, 2006
This paper gives a review of marine radioecology research in the Adriatic area carried out by the... more This paper gives a review of marine radioecology research in the Adriatic area carried out by the Radiation Protection Unit of the Institute for Medical Research and Occupational Health. Measurements of radioactivity in the Adriatic started in 1963 as a part of an extended monitoring programme of radioactivity in Croatian environment. The main sources of radioactive contamination of the Adriatic Sea are the fallout from past nuclear weapon testing conducted in the atmosphere and the Chernobyl accident. In 2005, the activity concentrations of fission radionuclides were detectable at very low levels in all environmental samples collected on the Adriatic. The 90 Sr data obtained from long-term monitoring were used to estimate the upper limit of the Adriatic seawater turnover time, which turned out to be (3.4±0.4) years. Detailed knowledge about seawater circulation, including the turnover time is essential for planning an overall communal and other wastewater management on the Adriatic coast. The paper concludes with the prospects for future marine radioecological investigations.
Radiation doses due to human exposure to cosmic radiation in the Republic of Croatia
Archives of Industrial Hygiene and Toxicology
The annual per caput whole body equivalent dose for the world's population on ground leve... more The annual per caput whole body equivalent dose for the world's population on ground level in areas on normal background from natural sources of radiation is approximately 2.4 mSv, 0.3 mSv of which is due to cosmic rays. As the intensity of cosmic radiation increases with altitude, the subpopulation of aircraft flight crews and frequent flyers may receive an additional equivalent dose of up to 1 mSv during commercial flights. The estimated annual collective equivalent dose from aircraft flights for the Republic of Croatia is about 4 man Sv, whereas the annual collective effective dose due to the cosmic radiation component of normal background radiation is approximately 1200 man Sv. Future development of hypersonic aircraft, which would fly orbital trajectories above the Earth's atmosphere would cause a significant increase of doses. Also, future utilization of extended space missions might be limited by high equivalent doses to space travellers.
Results of systematic, long-term measurements of 137Cs activities in wheat are summarized. 137Cs ... more Results of systematic, long-term measurements of 137Cs activities in wheat are summarized. 137Cs fallout activity affected wheat activity the coefficient of correlation being 0.91. A model used by UNSCEAR was used to describe 137Cs transfer from fallout deposition to wheat. The transfer coefficient was calculated to be 6.1 x 10(-3) Bq yr kg-1/(Bq m-2). The dose incurred by wheat consumption was estimated for the Croatian population, the annual collective equivalent dose being approximately 550 man Sv for the 1965-1992 period. After the Chernobyl nuclear accident the 134Cs: 137Cs activity ratio in wheat was approximately 0.5, and did not differ from that for other environmental samples.
Otpad vezan uz proizvodnju električne energije i proizvodnju mineralnih gnojiva
Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb... more Radiation Protection Unit of the Institute for Medical Research and Occupational Health in Zagreb has been conducting systematic investigations of radioactive contamination of the Croatian environment by anthropogenic fission products as well as by naturally occurring radioactive material (NORM) since 1963. Several critical sites in Croatia were identified for NORM, that is, for slag and ash repositories from coalfired power plants and phosphogypsum repository from a mineral fertilizer production plant. As the coals and phosphate ores contain naturally occurring radionuclides, especially the members of the uranium and thorium radioactive chains, utilising these materials in various industries only enhances their natural radioactivity in residual waste. Consequently, the resulting activity concentrations of natural radionuclides in waste material could be several times higher than in the adjacent soil. These deposited materials pose permanent risk of radiation exposure due to the lon...
This paper gives a review of marine radioecology research in the Adriatic area carried out by the... more This paper gives a review of marine radioecology research in the Adriatic area carried out by the Radiation Protection Unit of the Institute for Medical Research and Occupational Health. Measurements of radioactivity in the Adriatic started in 1963 as a part of an extended monitoring programme of radioactivity in Croatian environment. The main sources of radioactive contamination of the Adriatic Sea are the fallout from past nuclear weapon testing conducted in the atmosphere and the Chernobyl accident. In 2005, the activity concentrations of fission radionuclides were detectable at very low levels in all environmental samples collected on the Adriatic. The 90Sr data obtained from long-term monitoring were used to estimate the upper limit of the Adriatic seawater turnover time, which turned out to be (3.4±0.4) years. Detailed knowledge about seawater circulation, including the turnover time is essential for planning an overall communal and other wastewater management on the Adriatic ...
Radiotoxicity of tritiated water and tritiated hydrogen
Archives of Industrial Hygiene and Toxicology
Tritium in the form of tritiated water is much more radiotoxic than tritiated hydrogen. The effec... more Tritium in the form of tritiated water is much more radiotoxic than tritiated hydrogen. The effective dose which results from tritiated water as the oxidation product of Inhaled tritiated hydrogen gas makes about 55 per cent of the effective dose due to direct irradiation of the lungs by tritiated hydrogen only. The inclusion of the dose due to the production of tritiated water would tower the relative toxicity ratio as well as the value of derived air concentration for tritiated hydrogen. Therefore, to assess the health hazard from tritium exposure, for the two species the relative significance of 1:12,000 should be used, instead of the relative radiotoxicity ratio of 1:25,000 as given by the International Commission on Radiological Protection.
Due to high volatility and environmental mobility, radioactive isotopes of iodine pose a serious ... more Due to high volatility and environmental mobility, radioactive isotopes of iodine pose a serious risk in the acute phases of a nuclear accident. The critical organ for iodine is the thyroid. A number of studies dealing with thyroid protection from exposure to radioiodine have shown that radioiodine uptake by the thyroid can be effectively blocked by administration of stable iodine, usually in the form of potassium iodide (KI) pills. However, unless perfectly timed, this protective action may be counterproductive. The International Atomic Energy Agency recommends potassium iodide prophylaxis in cases when an avertable thyroid dose by protective action exceeds 100 mGy. This paper reviews experiences and practices with potassium iodide in the thyroid protection. This kind of information should serve as the basis for discussion and decision making on KI prophylactic programmes in nuclear emergency situations in Croatia. If Croatia adopts such programme, it will still have to develop the...
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