S. Forkapic

Public exposure to radon in drinking water in Serbia.

Radon is the main source of natural radiation that is received by population. The results of radon activity measurements in water from public drinking fountain, from bottled drinking water and from tap water in the city of Novi Sad, Serbia, are presented in this paper. The measurements were performed by RAD 7 radon detector manufactured by DURRIDGE COMPANY Inc. The corrected value of radon concentration in one sample exceeded the European Commission recommendation reference level for radon in drinking water of 100 Bql(-1). In order to make the correlation between radon and radium concentrations in the tap water and in the water from public drinking fountain, the gamma-spectrometric measurements were performed. The results of (222)Rn activity concentration measurements from soil in the city of Novi Sad using RAD 7 detector are presented.

Airborne radioiodine in northern Serbia from Fukushima

The results obtained with the monitoring system set up to assess the impact of the Fukushima accident on the environment of Vojvodina (Northern Province of Serbia) are presented and discussed. Aerosol, rain, fresh milk and spinach samples were collected daily in the weeks following the accident. In the aerosol samples, (131)I activity concentrations of several mBq m(-3) were measured, while in rain, milk and spinach samples, (131)I levels had values in a range of (0.3-1.7) Bq kg(-1). These are the first results on the impact of the Fukushima accident on the Pannonian basin region. Our results are compared with the reported values from other parts of the world.

Monitoring for exposures to TENORM sources in Vojvodina region

TENORM are found in a wide variety of waste materials, some raw mineral ores and in some consumer products (in trace amounts) where molecules of radionuclides may be bound to specific minerals used in the manufacturing process and can result in increases in radiation exposures to workers and the public. The aim of this paper is to understand this problem and to develop effective ways to protect humans and the environment from harmful exposure to the radiation in TENORM materials in the Vojvodina region. The results of measurement of indoor radon concentration in schools and kindergartens and dose-rate and gamma-spectrometry measurements of the workplace with TENORM materials are presented.

NATURAL RADIOACTIVITY IN RAW MATERIALS USED IN BUILDING INDUSTRY IN SERBIA

Natural radioactivity is responsible for most of the total radiation dose received by human population. Geological materials used in building industry usually become contaminated with naturally occurring radioactive materials. They are used as mixtures in building industry (kaolin, zircon, frit, feldspar) or mechanically processed and used for covering floors and walls of the rooms (granite). In this paper, activity concentrations of 226Ra, 232Th and 40K in 6 kaolin, 11 zircon, 18 granite, 3 marble, 6 sand, 4 perlite, 4 feldspar, 5 korund and 1 frit samples imported in Serbia were determined by gamma-ray spectrometry. Activity concentration index, dose rate and annual effective dose were calculated for each of the investigated samples. Measurement of an external gamma dose rate by using a commonly available radiation survey meter can give some indication of the need for further investigations. The absorbed dose rate and annual effective doses for workers in the ceramic industry “Keramika Kanjiza Plus” in Serbia working with granite are determined.

Possibility of Prompt 238U Activity Concentration Determination by Gamma-Ray Spectroscopy

Recent results on 238U/234Th disequilibria in marine studies seriously challenge the possibility of the prompt gamma-ray spectroscopic determination of 238U activity concentration in environmental samples from the gamma-ray lines of the first daughter of 238U, the nucleus 234Th. In this paper we present the results of the gamma-ray spectrometric measurements of 234Th, which were repeated using the same soil and sediment samples at least one year after the first measurement. We did not find any indication of Th activity variation due to 238U/234Th disequilibria. All the obtained results prove that the 238U and depleted uranium determination in soil and sediment samples using 234Th gamma-ray lines introduces at most a systematic error of 3% into the obtained results.

Radioactivity in the indoor building environment in Serbia

Measurement of activity concentrations of radionuclides in building materials and radon in indoor space is important in the assessment of population exposures, as most individuals spend 80 % of their time indoors. This paper presents the results of activity concentration measurements of: radon emanated from the soil, radionuclides (226)Ra, (232)Th and (40)K in the soil, indoor radon in the city of Novi Sad (the capital city of Vojvodina) using charcoal canisters and indoor radon in the Vojvodina region using alpha-track detectors and the radioactivity of some building materials. Influences of floor level, space under the rooms, boarding, and the heating system on indoor radon accumulation in the Vojvodina province, situated in the northern part of Serbia, are also presented in this paper. The total effective dose and the activity concentration index are calculated applying the dose criteria recommended by the European Union for building materials.

Radon in thermal waters in south-east part of Serbia.

There are several occurrences of thermal waters in the south-eastern part of Serbia, which are originating from igneous and metamorphic rocks. These waters are mainly used in balneology, but some of them are used for drinking purposes and in water supply to heat buildings, for greenhouses and to irrigate land. In this region, there is the well-known Niška banja spa, which has elevated levels of radon. Water samples were examined from other spas in the south-eastern part of Serbia in order to determine radon activity concentration. A detailed discussion of a possible correlation between determined radon activity concentration and the geology of this area is also given.

Radioactivity in fertilizers and radiological impact

The contents of natural radionuclides (226Ra, 232Th and 40K) in 33 fertilizers and 50 soil samples from Vojvodina region, Serbia, were measured by low level gamma spectrometry. The obtained results showed that the averages of radiation hazard parameters for the fertilizers are higher than acceptable level for radium equivalent activity (Raeq), representative level index (Iγ), external hazard index (Hex) and absorbed dose rate (D) [1]. Based on the measured values of the activity concentration of radionuclides in soils, the activity concentrations of radionuclides for most commonly grown crops in Vojvodina were calculated.

Results of the 2015 national indoor radon intercomparison measurements in Serbia

Abstract Results and conclusions of interlaboratory comparison of indoor radon in 2015 in Serbia are presented. The participants were three accredited laboratories from Serbia: Serbian Institute of Occupational Health “Dr Dragomir Karajović”, Laboratory for Radioactivity and Dose Measurements at the Faculty of Sciences, University of Novi Sad and Radiation and Environmental Protection Department, Vinča Institute of Nuclear Science. The laboratories make use of the same method for radon measurement, using charcoal canisters according to US Environmental Protection Agency (EPA) protocol 520/5-87-005. Calibration of detection efficiency was performed using EPA radium standard. Radon activity concentrations were determined on the basis of the intensity of short-living radon daughters, 214Bi and 214Pb, gamma lines. The results of intercomparison were evaluated by using the u-test, which was calculated according to the International Atomic Energy Agency criteria. In this paper, not only limitations but also the advantages and possibilities of application of this method for measuring levels of human exposure to radon are discussed.

The MIREDO Facility in Novi Sad

The MIREDO (Muon Induced Rare Event Dynamic Observatory) spectrometer system will be mainly devoted for the study of cosmic muon induced nuclear reactions. The system will be developed around the 100% nominal efficiency ultra low‐background HPGe spectrometer. Our previous detection system enabled only the detection of secondary muon induced events mostly from the interaction of cosmic muons with the shielding materials [1, 2]. The improved geometry of the MIREDO scintillation detection system will enable the direct measurement of the cross section of the muon induced reactions with the sample material.