[en] Radiation protection as a part of radiation science today implies holistic approach to protection of human environment and biota. In Croatia radiation protection is among those areas that are quite satisfactory harmonized with European acquits. Institute for Medical Research and Occupational Health, Radiation Protection Unit is by Croatian competent authorities notified as well as accredited for radioecological monitoring that has been continuously carried on since 1959. This includes sampling, radiochemical analyses, measurements, and interpretation of results. Resulting databases are starting point for assessment of exposure of humans and biota to ionising radiation through different exposure pathways (e.g. ingestion, inhalation, external exposure etc). Although doses to Croatian public are minimal, this paper demonstrates the importance and need for individualization of dose assessment in the context of differences and variabilities in activity concentrations of various radionuclides in local foodstuffs. Consequently, dose assessment itself implies efficient radioecological monitoring on global and regional scales. (author)

[en] Laboratory for Nuclear and Plasma Physics, Institute ''Vinea'' is authorized and accredited in accordance with ISO/IEC 17025 for measurements of radionuclide content in environmental samples. In accordance with a standards request and international recommendations, TCS No. 24, Quality System Implementation for Nuclear Analytical Techniques, permanent internal quality control of semiconductor HPGe spectrometer has been conducted. Periodical testing of spectrometer characteristics and creation of control charts are included in internal quality control processes. The evaluation of the measuring system can be performed by periodical testing as follows: FWHM chart provides evaluation of the resolution of a detector. Variation of the FWHM could be caused by electronic noise inside the detector, or might indicate a vacuum problem; FWTM chart allows to monitor tailing due to damage of the detection crystal, bad P/Z ration may indicate a leakage current; The ratio FWHM/FWTM for different gamma ray energies allows to monitor the quality of the detector; Activity chart allows to monitor the stability of the whole method; Background chart might discover contamination; Peak position chart provide indications for electronic stability and the influence of environmental conditions such as temperature or humidity. Point sources 60Co and 137Cs were used as a control sources for FWHM, FWTM, FWHM/FWTM ratio and peak position testing. Presented control charts, for a period June - December 2010, were used for an analysis of spectrometer stability. These charts show that performances of analyzed HPGe spectrometer were stable, meaning that measurements results for environmental samples could be considered as reliable, i.e. that the practice of Laboratory fully consists with an international recommendations. (author)

[en] In this paper standards for measurements in the field of high frequency electromagnetic radiation are described with a view to protection from its hazardous action. Beside the standards which directly deal with high frequency electromagnetic radiation measurements, guidelines which describe hazardous influences of high frequency electromagnetic radiation on human body in the form of specific absorption rate (SAR) are given. Special attention is dedicated to standards and regulations, which are dealing with social responsibility, as well as with social responsibility in the field of high frequency radiation. This area is new and insufficiently known, rarely extended in everyday life. (author)

[en] Efficient interaction of technical legislation, metrology, standardization and accreditation within the system of quality infrastructure is precondition for assurance of safety of goods and services as well as protection of humans and environment. In the paper importance of quality infrastructure on national and international levels is presented while special interest is paid to accreditation. Current situation regarding the accreditation of laboratories in the field of radiation science is presented. Regarding this field, in Croatia three laboratories are accredited by Croatian Accreditation Agency: 1. Laboratory for Radioecology, Rudjer Boskovic Institute (Scope: Measurement of radionuclide content in environmental samples and commodities - Including foodstuffs and drinking water) 2. EKOTEH Dozimetrija Ltd., Department for Radiation Protection (Scope: Testing in the scope of ionizing and nonionizing radiation) 3. Radiation Protection Unit, Institute for Medical Research and Occupational Health (Scope: Determination of radioactivity). (author)

[en] A lack of primary standards for HDR 192Ir brachytherapy has been known for years to cause the largest problem in obtaining lower uncertainties in RAKR measurements. The currently used calibration techniques where chambers are calibrated against interim standards, based on interpolation techniques, provide typically an uncertainty of @ 2.5 % (k = 2) in the calibration factor. It constitutes the largest contribution to the total uncertainty in RAKR and may be significantly reduced through the on-going development of primary standards. In this work, RAKR values of 23 HDR 192Ir sources were measured in the department in the past 10 years of clinical HDRBT application. All differences between the measured RAKR and manufacturer's specification were lower than @ 3.5 %. Upon the acceptance of a more rigorous protocol, through which the different variables, such as thermal stability and geometrical reproducibility, have been better controlled during the measurement, these differences dropped to less than @ 2 %. Two ionisation chambers tested in this work showed very good precision, long term stability, small polarity effect and recombination equal to the manufacturer's specification. Differences in repeated measurements of RAKR during the 6 weeks period, in which a source was also changed, were minimal; RAKR-s stayed within 1 %. The calibration technique based on the re-entrant well type chamber is due to its simplicity, speed, accuracy and long term stability a highly recommended option for an institution performing HDR brachytherapy. (author)

[en] The production of phosphate fertilizers and its effects on human health and the environment are the subject of systematic investigation conducted by Radiation protection unit of the Institute for Medical Research and Occupational Health. During phosphate ore processing, practically all 226Ra gets incorporated into phosphogypsum, which classifies it as technologically-enhanced NORM - Naturally Occurring Radioactive Material. In this paper natural radionuclides (40K, 232Th and 226Ra) were measured gamma-spectrometricaly and the activity concentrations were calculated. Due to recent investigations which are focused on phosphogypsum usage in road construction, mine remediation, agriculture etc., radium equivalent (Ra_eq) and external hazard index (H_ex) were calculated. (author)

[en] Regulatory framework for the radiation protection has been fully harmonised with the EU acquis communautaire by the Act on Radiological and Nuclear Safety passed in 2010. Pursuant to the Act, a unique regulatory body, the State Office for Radiological and Nuclear Safety is established and its independence, administrative and expert capacities ensured. Provisions of the Act regulate measures for the safety, protection against ionising radiation and physical security related to nuclear practices and practices involving sources of ionising radiation with the aim to provide appropriate protection of the individuals, society and environment for present and future generations. Legal provisions constitute the basis for implementation of the radiation protection measures. Their compliance with EU and international norms guarantees implementation of those norms, providing effective protection of individuals and the environment. Effectiveness of the radiation protection can be assessed through various indicators, of which one of the most direct is exposure of individuals. In this paper, exposure to ionising radiation of exposed workers through the period of ten years is analysed. The level of exposure to external radiation is based on recorded results of measurements performed by film or thermoluminescent dosimeters. For each exposed worker, monthly effective doses, estimated using H_p(10) personal dose equivalent and regularly recorded, were used. The results indicate that the improvement of protection, when observed through decrease of the collective dose, is coincident with and can reasonably be attributed to the development of the radiation protection legislative, its harmonisation with EU and international standards and establishing of more effective administrative measures. (author)

[en] Radon monitoring at potentially highly radioactive location such as caves is important to assess the radiological hazards to occupational workers and occasional visitors. In its Publication 65 the ICRP has produced recommendations dealing with exposure to elevated background radiation, in particular, the risk associated with the inhalation of radon and radon progeny. Recommended annual effective dose from radon 222Rn and its short-lived progeny for workers should not exceed 20 mSv and for occasional users (visitors) the same recommendation is 1 mSv. Measurements were performed with series of track etched detectors (LR115 - type II) in several caves in Croatia. The obtained values for the radon concentration ranged from ambient values up to several thousand Bq m^-3. Radon concentration was measured in about 20 caves of Velebit and Zumberak mountains and the highest radon concentration was in Lubuska jama (3.8 kBq m^-3) and cave Dolaca (21.8 kBq m^-3), respectively. Djurovica cave is especially interesting because of its huge tourist potential due to its location bellow Dubrovnik airport. Its mean annual radon concentration of 17.6 kBq m^-3 classifies Djurovica cave among caves with high radon concentration. A visitor during half an hour visit at summer time would receive an effective dose of 30.6 μSv. Calculated mean dose rate of 44 μSv/h means that workers (mainly tourist guides) should limit their time inside cave to 454 hours per year. Manita pec is the only cave open for tourists on the territory of Paklenica National Park. The preliminary radon measurements performed during summer 2010, gave an average radon concentration of 1.1 kBq m^-3. An exposure to average dose rate of 3.7 μSv/h means that the tourist guides would receive an effective dose of 0.42 mSv during summer period according to their working schedule. A visitor during half an hour visits would receive an effective dose of 1.86 μSv. (author)

[en] Regarding radiation protection regulations in Slovenia measurements of natural radiation in public institutions have to be done by accredited laboratory to determine those with elevated radon concentrations. Ministry of Health started measurements of radon concentrations in schools and kindergartens twenty years ago. Almost all kindergartens and schools were included in monitoring. In kindergartens and schools with very high radon concentrations measurements were repeated and remediate if needed. Monitoring is continuing and in last five years 330 measurements of radon concentrations in public buildings by track each detectors were done. Radon concentrations in thirty five kindergartens and schools and twelve other public institutions were higher than proposed by regulations, 400 Bq/m³ for schools and kindergartens and 1000 Bq/m³ for other institutions. For those institutions special monitoring was carried out. We did thirty five measurements by electronic devices in the period of one week to determine radon and radon progeny concentrations. In case of high radon concentration in rooms also radon concentrations in cracks and water or electricity installations in the basement were measured. In special cases radon concentration in soil near building was measured. After measurements dose assessment was done and remediation actions proposed. Concerning results of radon concentration measurements we can conclude, (i) karst area and central southern part of Slovenia with limestone, marl and conglomerate as a main geological structure represent a strong radon source, (ii) old buildings with cracks in the floor make a great possibility to radon entering the rooms, and finally (iii) remediation actions are urgent in almost all old schools and kindergartens on the area presented. (author)

[en] It is now generally recognised that there needs to be a system to demonstrate that the environment is protected from ionising radiation. In its latest recommendations, the International Commission on Radiological Protection (ICRP) acknowledged the need for radiological protection of the environment. The International Atomic Energy Agency (IAEA) is also revising the international Basic Safety Standards (BSS) to incorporate the IAEAs fundamental safety objective: ''to protect people and the environment from harmful effects of ionizing radiation''. The European Basic Safety Standards are also being revised and chapter X describes the requirements for environmental protection. There has been considerable international and national effort over the last decade on how to conduct environmental assessments. These have focused on collating relevant information and developing assessment approaches for regulatory purposes. Validation and comparison of the radioecological and dosimetric components of various approaches has also begun. It is important that the approaches used are practicable, credible to stakeholders and fit for purpose. This paper describes the results of the habitats assessments conducted for 429 Natura sites of conservation value in England and Wales and highlight some of the assumptions, limitations and issues identified. The assessment involves the calculation of dose rates to reference organisms and feature species from exposure to permitted discharges of radioactive substances at Natura 2000 sites in England and Wales. The calculated dose rates can then be related to biological effects data (e.g. mortality, morbidity, reproductive effects) to determine the likely risk of impact at the Natura 2000 site. A number of assumptions were included in the assessment process: 1) Discharges were assumed to be at the Radioactive Substances Act 1993 authorization limits (now Environmental Permit Limits) but in reality actual discharges are likely to be significantly lower than the discharge limit. 2) The calculated dose rate per unit concentration data used to calculate the dose rate to the reference or feature species are based on our earlier work. 3) The dispersion modelling conducted was for current discharges and the assessments do not include concentrations of radionuclides which may have been discharged when historical limits were significantly higher. 4) The total dose rate from releases to air and water to the worst affected organism has been calculated from the terrestrial dose rate and water environment dose rate for the worst affected organism. The total dose rates to the worst affected organism are less than the agreed threshold of 40 Gy h^-1 for all but two Natura 2000 sites. This threshold represents the level below which it is accepted that there will be no adverse affect on the integrity of a Natura 2000 site. The assessment process followed a staged approach to identify those sites most at risk from the discharges of radioactive substances and effort to completely assess the risk was targeted at those sites (i.e. the Drigg coastal SAC and the Ribble and Alt Estuaries SPA). This is considered to be an approach consistent with the likely level of risk of impact from ionising radiation to wildlife. (author)