[en] In this paper is presented that accreditation in our days is a strict requirement for a lab for its results could be accepted on international level. Accreditation itself brings to new requirements, among them some are related to the calibration of the radiological measuring equipment

[en] Dose-effect curve for X-radiation was made based on the analysis of chromosome aberrations in lympocytes of goats. Blood samples from seven goats were irradiated using MOORHEAD method, slightly modified and adapted to our conditions. Linear-square model was used, and the dose-effect curves were fitted by the smallest squares method. Dose-effect curve (collective) for goats is displayed as the following expression: y(D)= 8,6639·10^-3 D + 2,9748·10^-2 D²+2,9475·10^-3. Comparison with some domestic animals such as sheep and pigs showed differences not only with respect to linear-square model, but to other mathematical presentations as well. (author)

[en] Safety assessments are usually performed to gain acceptance or approval for disposal of accumulated waste, demonstrating compliance with national regulations for a particular facility. However, the preliminary assessment for Croatian LILW repository should generally focus on providing reasonable assurance both to the public and to decision makers that the Croatian share of LILW from NPP Krsko - which is still in Slovenia - can be admitted and safely disposed of in Croatia. More specifically, the assessment should clearly present all realistic options and compare the associated long term repository performances, demonstrating that desirable safety goals can be achieved by an appropriate choice of (a) location, (b) facility design, (c) institutional control period and (d) waste acceptance criteria. As relevant national legislation does not require any safety analyses at this early phase of repository planning, generally recognized international safety standards, practices and recommendations (e.g. as presented in the recent IAEA publications) can provide guidance through the assessment process, while the results should be evaluated against national regulations. (author)

[en] Hungary has a countrywide early warning radiation monitoring network which consist of about 70 stations in an on-line connection with the Emergency Information Center of the National System for Nuclear Emergency Preparedness. The system consists of a variety of stations and organizations including Hungarian Meteorological Service, Ministry of Environment and Regional Policy operate their own networks which are not connected with the central system, but could in certain cases exchange the data. The overall impression of the early warning for the radiation emergency is very good, as the system is in the 24 hours on-line mode and raise alarm immediately if the measured values exceed the preset limit. It this respect, the organization appears very good and capable (together with laboratory services) to assure reasonable protection of the population. The possibility to measure the radioactivity in the environment, food and water exist through a series of laboratories, which operate throughout the country. Those appear to be reasonably well equipped and both the knowledge and the experience of their staff appear very high. The same applies for the tools and methods used to forecast the impact and the consequences. (author)

[en] The knowledge of the concentration of natural radioactive isotope ¹⁴C in the atmosphere and its global and local distribution in of great importance for ecology, climatology and hydrogeology, as well as for the monitoring of the carbon cycle in the environment. A significant increase of the concentration of ¹⁴C in the atmospheric CO₂ in the whole atmosphere and biosphere during the sixties was caused by intensive thermonuclear bomb tests in the atmosphere. Various nuclear facilities may also contribute to the increase of ¹⁴C in the atmosphere, while the use of great amounts of fossil fuels causes a dillution of ¹⁴C, i.e., a decrease of its concentration. In the Radiocarbon and Tritium Laboratory of the Rudjer Boskovic Institute we have monitored the ¹⁴C activity of the atmospheric CO₂ since 1978. Our results show a continuous decrease of the atmospheric ¹⁴C activity in this period (Fig. 1), in accordance with the global trend of ¹⁴C decrease. Between 1995 and 1997 we measured ¹⁴C concentration in monthly samples collected at station Puntijarka, Mt. Medvednica. ¹⁴C concentration at this station is mostly higher than in the Zagreb city area (Fig. 2), and the difference is significant during the winter months due to fossil fuel combustion in the Zagreb area. The average ¹⁴C activity for period 1995 - 1997 in the Zagreb area is Δ¹⁴C = (70±30)promil, while at the Puntijarka station Δ¹⁴C = (86±20)promil. Monthly samples of atmospheric CO₂ were also collected outside and inside the Postojna Cave, Slovenia (Fig. 3). D14C values measured inside the cave range from -3promil to 55promil, with the mean value (26±16)promil. Outside the cave the mean value was (95±11)promil, and the monthly ¹⁴C activities ranged from 76promil to 113promil. (author)

[en] Preliminary investigation of the ²²⁶Ra activity concentration in drinking water in central region of Bosnia and Herzegovina have been performed. The results show that the activity concentrations of the samples vary between 33.3 - 48.8 Bq m^-3. According to the legal stipulation as given by the Official Bulletin of Bosnia and Herzegovina (2/.92), it can be concluded that the results are within given regulations. (author)

[en] Among artificial sources of ionic radiation people are most often exposed to those emanating from X-ray diagnostic equipment. However, responsible usage of X-ray diagnostic methods may considerably reduce the general exposure to radiation. A research on rational access to X-ray diagnostic methods conducted at the X-ray Cabinet of the Tresnjevka Health Center was followed by a control survey eight years later of the rational methods applied, which showed that the number of unnecessary diagnostic examining was reduced for 34 % and the diagnostic indications were 10-40 $ more precise. The results therefore proved that radiation problems were reduced accordingly. The measures applied consisted of additional training organized for health care workers and a better education of the population. The basic element was then the awareness of both health care workers and the patients that excessive radiation should be avoided. The condition for achieving this lies in the moral responsibility of protecting the patients' health. A radiologist, being the person that promotes and carries out this moral responsibility, should organize and hold continual additional training of medical doctors, as well as education for the patients, and apply modern equipment. The basis of such an approach should be established by implementing medical ethics at all medical schools and faculties, together with the promotion of a wider intellectual and moral integrity of each medical doctor. (author)

[en] Iodine is a highly volatile element therefore being very mobile in the environment. It enters the metabolism of living organisms and is selectively taken up and concentrated in the thyroid gland. The plume (cloud-like formation) of radioactive material that might be released in the environment in the case of a serious nuclear accident, primarily consists of the radioactive isotopes of iodine. Among those, due to its decay properties, is the most important ¹³¹I. The effective means of protecting the thyroid gland against exposure to radioactive iodine is an intake of stable iodine. Therefore, one of the central issues in the emergency planning is to determine whether and at which projected thyroid radiation dose stable iodine should be given to the population. The International Atomic Energy Agency (IAEA) set the generic optimized intervention value for iodine prophylaxis to 100 mGy of avertable committed dose to a thyroid.The prophylaxis is implemented by utilizing the pills of pills of potassium iodine (KI). The efficacy of KI in protecting the thyroid gland depends upon the time of intake relative to the start of exposure to radioactive iodine. The best results are obtained if KI is taken 1-2 hours before or immediately after the start of exposure. The recommended dosage, based upon the study performed by Il'in et.al. is 130 mg/day. KI should be taken at least three days after the acute exposure to radioiodine, to prevent accumulation in a thyroid gland of radioiodine excreted from the other compartments of the body. The largest epidemiological study on the effects of KI prophylaxis ever performed was the one in Poland after the Chernobyl accident. Stable iodine was given as single dose of KI solution to 10.5 million of children and 7 millions of adults. Among children no serious side effects were seen while only two adults (with previously recorded iodine sensitivity) had severe respiratory distresses. Polish experiences showed that rapid response to such widespread nuclear accident is as much a social problem as well as a medical or scientific one, requiring rapid organization of large number of people and facilities. In USA, Nuclear Regulatory Commission (NRC) recently decided (summer 1998) that NRC would financially support the stockpiling of the KI pills, if federal states decide to stockpile them. Previously, NRC recommended that potassium iodine be available mainly for emergency workers, but not stored for general public. In order to protect the general public in the case of a nuclear accident, The Republic of Croatia should consider the optimal way of KI prophylaxis and implement the detailed procedure in emergency plans. It would be recommended to identify those persons with iodine sensitivity, which could be achieved through a public health care system. (author)

[en] Computed tomography (CT) has become a major source of the population exposure to diagnostic X-rays, and acknowledge of the doses delivered by the CT equipment has become very important. Considerable efforts should be made to keep these doses to a reasonable minimum, without sacrificing the image quality. The conditions of exposure in CT are quite different from dose in conventional X-ray imaging. This has required the development of specific techniques for assessing patient dose from CT. The aims of this work were to determine the dose delivered to various organs of patients undergoing computed tomography of abdomen as measured on the surface of the body and to estimate the risk to the patients. Dosimetric measurements were performed at CT scanner Hitachi W 450 in General Hospital Karlovac. The doses absorbed by different organs (gonads, chest, thyroid and eye lens) and by the examined part of the body of 11 patients were measured with TLD-700. The doses absorbed by different organs during the diagnostic CT examination of the body depend on the technical parameters, such as the number of scans, mAs, the thickness of scans, scanning times, tube voltage and other characteristics. The type and severity of illness influence the choice of technical parameters. Clinical parameters, such as patient size and composition, and patient cooperation with regard to the control and motion, also influence the dose and the image quality. The highest dose measured in this study (112.5 mGy) was delivered to front surface of the body during CT examination of abdomen. (author)

[en] Many would argue that sustainable development is a very simple idea. It is about ensuring a better quality of life for everyone, now and for generations to come. Deeply embedded in the whole concept is the prudent use of natural resources and this very much includes consideration of renewable forms of energy. Historically, in the UK and some other parts of europe the emphasis on development has been towards large scale energy production facilities. This has been seen as a logical progression within an energy industry which has evolved around the centralised, 'big is beautiful' model. Such thinking has lead to renewables being disadvantaged in many ways. Renewables are a disparate resource and often at their peak in rural, isolated and environmentally sensitive areas. Harnessing them may more easily fit with a local community based approach. This airflow's the greater involvement of the local communities themselves, their local Government and industry. It also presents the best opportunity for the protection of the environment and for the change to focus on local agendas. In terms of 'living within a sustainable world' following Kyoto such a community based strategy for the future is more likely to yield success, turning as it must on achieving a fundamental change of attitude within the wider population to energy provision and use. Noteworthy in this respect is the recent White Paper from the European Commission (entitled 'Energy for the Future: Renewable Sources of Energy') which champions the idea of 100 communities in the EU which might be self sufficient in the use of renewable sources of energy. (author)