First comprehensive studies of the radionuclides’ concentration and its composition in Estonian ground water began in 1990s. It was quickly realized that the activity concentration of 226Ra and 228Ra in Cambrian-Vendian (Cm-V) aquifer are the highest contributors to the total indicative dose (TID). About 22% of the population in Estonia uses Cm-V ground water for drinking water supply. In recent study [1], it was concluded, that about 91% of Cm-V aquifer consumers (20% of the Estonian population) obtain higher TID doses (TID exceeding 0.1 mSv/y) than set by European Commission and national regulations. Over the years, a good representation level by the number of measured samples for 226Ra and 228Ra from Cm-V aquifer has been obtained. However, for other widely used aquifers – Ordovician-Cambrian, Silurian-Ordovician and Devonian – only poor data is available. In several southern counties, only few percent of the water supplies have been surveyed. Data for other natural radionuclides (234,238U, 210Po and 210Pb) is also poor. Scarce data has been partly due to the lack of analysis techniques available in Estonian nuclear analysis laboratories. This has been the motivation in the development of gamma spectrometric and liquid scintillation (LSC) counting techniques for ground and drinking water applications.

The phosphogypsum is produced as a by-product of the manufacturing phosphoric acid or phosphate fertilizer from the phosphate rock on the wet process. In general, it contains relatively high concentrations of uranium series radionuclides such as 226Ra. This study surveyed overall radioactivity of the naturally occurring radionuclides in a facility using phosphate rock and evaluated the impact on the vicinity environment by the phosphogypsum.

The 137Cs activity has been measured in organisms from the Faroese terrestrial, aquatic and marine environments in the years 2002, 2003 and 2004. The aim of the study was to point out organisms that can be useful indicator organisms for radioactive contamination of the environment. Measurements are available back to the early 1960’s for some organisms, and the variation with time is considered for these organisms.

Gross alpha and beta measurements are common procedures for screening water samples in order to estimate the level of total indicative dose (TID) from the radionuclides in water. However, it has been pointed out that gross alpha and beta measurements are not suitable for waters containing high concentrations of natural radionuclides, especially Ra-226 and Ra-228. Cambrian-Vendian aquifer system is the major source of public water supply in northern and north-eastern Estonia. The aquifer is known for its high radionuclide concentrations. The main sources of TID are Ra-226 and Ra-228, but the water also contains K-40. Other nuclides from uranium and thorium series may be present as well. A set of Ra-226, Ra-228 and K-40 activity concentrations measured by gammaspectrometry are studied to analyze the applicability of gross alpha and beta measurements in case of Cambrian-Vendian ground water. The calculations indicate that the levels suggested by WHO guidelines are not suitable for the Cambrian-Vendian ground water. Results on the applicability analysis are given.

Seasonal indoor radon concentration was surveyed, and the annual effective dose was estimated for the residents in some dwellings near the registered uranium mining lot areas, considered as one of the potential radon-prone area. The range of indoor radon concentration in each dwelling was from 17.7 to 1,610 Bq⋅m−3. The range of annual effective dose due to inhaled radon of the resident in each dwelling was from 0.93 to 20.5 mSv.

Over the past few decades there has been some discussion concerning the increase of the natural background radiation originated by coal-fired power plants, due to the uranium and thorium content present in combustion ashes. The radioactive decay products of uranium and thorium, such as radium, radon, polonium, bismuth and lead, are also released in addition to a significant amount of 40K.

Since the measurement of radioactive elements released by the gaseous emissions of coal power plants is not compulsory, there is a gap of information concerning this situation. Consequently, the prediction of dispersion and mobility of these elements in the environment, after their release, is based on limited data and the radiological impact from the exposure to these radioactive elements is unknown. This paper describes the methodology that is being developed to assess the radiological impact due to the raise in the natural background radiation level originated by the release and dispersion of the emitted radionuclides. The current investigation is part of a research project that is undergoing in the vicinity of Sines coal-fired power plant (south of Portugal) until 2013. Data from preliminary stages are already available and possible of interpretation.

Assessments of natural gamma radiation were done for urban sites in the city of Ribeirão Preto – SP – Brazil, allowing to infer the average annual effective dose value for the population in these areas. The measurements were done using a vehicle with a mobile radioactivity measurement system, Eberline, with a plastic scintillation detector and a Global Position System (GPS), to collect measurements of gamma dose rate and its spatial distribution. Using the national census information, the stored data allowed mapping the radiometric measurements through the ArcGIS software, correlating the geographical coordinates with their respective dose rates. These maps illustrate how effective dose values are distributed within the selected areas and also correlate the collective dose values for these populations. Around 45,000 georeferenced effective dose values, ranging from 12.2 up to 59.8 nSv/h raised an average value of 0.034 ± 0.004 mSv/year, which is less than the worldwide average effective dose value of 0.07 mSv/year [12] (for outdoor exposures from terrestrial radiation sources) and less than the previous average values found in Brazil for the regions of Poços de Caldas, Guarapari, Andradas, Caldas and Meaípe [2,10].

Concentrations of natural radionuclides 238U, 208Tl (232Th), 226Ra, 210Po, 210Pb and 40K, and fallout 137Cs were determined in pelagic and demersal fishes which are of economic importance. Pelagic fishes concentrated more radionuclides in the muscle tissue when compared to benthic species. Similarly, teleosts registered more activity than elasmobranchs. Based on the activity levels in muscle, the intake, effective dose and lifetime risks to humans were estimated. The internal radiation doses received by fishes and human beings seem to be mainly due to 210Po and 40K. The fishes were found to be safe for consumption.

The environmental monitoring of waste heaps, sludge reservoirs is an important task. The Pb(Po) accumulation of tobacco has been known for long. Knowing familiar with the accumulation capability can be suitable for bio-monitoring the tailing ponds of the remedied uranium mine, as isotopes may be bound on the skin surfaces or may be absorbed via the roots.

Our research investigates the Pb(Po)-210 concentration values of tobacco plants grown for experimental purposes in the remedied uranium-mine area. During the work the Pb(Po)-210 concentration values of 73 tobacco and soil samples, grown between 2002-2009 were determined using a semi-conductor (PIPS) detector alpha-spectrometer. The source for measurement was prepared using spontaneous deposition process following the combined acidic leaching using Po-209 tracers. Based on the results it can be stated that the Pb(Po)-210 activity concentration values of tobacco and soil samples altered between 2.12 ± 0.8 – 1866 ± 98 mBq/g. Processing the measurement data of the previous years it was apparent that with the changes of the Pb(Po) concentration values of the soil samples the activity concentration values of the tobacco samples also changed proportionally. Therefore, later the migration of radioisotopes disengaged from the tailings dump can also be traced.

An investigation on the distribution of Radium activity levels in the entire south-eastern coast of Tamilnadu, India, from Chennai to Kanyakumari was carried out. Insitu preconcentration technique was adopted by passing 1000 liters of seawater through MnO2 impregnated cartridge filters at all the locations. In the coastal waters, 226Ra and 228Ra concentration was observed to be in the range of 1 to 1.81 mBq/l and 3.1 to 7.5 mBq/l respectively with an average of 1.52 and 4.53 mBq/l respectively, while the sediment samples showed 226Ra activity levels from 8.1 to 129.0 Bq/kg and 228Ra varied from 14.7 to 430.01 Bq/kg. The concentration of 228Ra was observed to be more than 226Ra in all the locations. The activity ratio of 228Ra/ 226Ra in the Bay of Bengal showed a ratio varying from 0.8 to 2.4 with a mean of 2.1. In the present study, activity ratio varies from 1.9 to 2.4 at Karaikkal. But the regions of Rameswaram and Kanyakumari which comprises the high natural background region reflects different ratio varying from 3.5 to 6.9, reflecting different sources of weathered material for 228Ra. The findings supported the fact that the area also comes under natural high radiation background at the south west of Indian peninsula due to the presence of heavy mineral containing monazite. The spatial distribution of the activity with respect to location is discussed in the paper. The radioactive database obtained represents reference values for coastal environment of Tamil Nadu.

Coal, bottom ash and fly ash samples were collected from three different coal-fired thermal power plants in India and subjected to gamma spectrometry analysis for natural radioactivity contents. The results of present study show that fly ash and bottom ash contains two to five times more natural radionuclides than feed coal. None of the fly-ash and bottom ash samples had radium equivalent activities and external hazard index values more than 370 Bq kg–1 and unity respectively. However the absorbed dose rate at 1 m above the ash pond was 79.19n Gy h–1 (average of 3 plants) higher than the global average value of 55 nGy h–1. The corresponding annual external effective dose is estimated to be 0.68 mSv y–1, which is also more than that (0.46 mSv y–1) in areas of natural background radiation. The 5th percentile, 95th percentile and mean values for total inhalation risk arising from radionuclides (Ra226, Th228, Pb210 and Nat-U) were found to be 3.83 × 10−9, 6.50 × 10−8 and 2.08 × 10−8 respectively.

Traces of short- and long-lived fallout isotopes (131I, 134Cs and 137Cs) were found in environmental samples obtained in northwest Germany (river sediment, rainwater, grass and milk) from March to May 2011, following the radioactivity releases after the nuclear accident in Fukushima, Japan. The found concentration values are consistent with reported concentrations in air, amount of rainfall and expected values applying simple radioecological models. The [134Cs]/[137Cs] ratio reported for air (about 1:1) allows for discrimination between “recent” and “old” 137Cs. Expected 136Cs values fell below the detection limits of the instrumentation, despite large sample masses and long counting times.

An evaluation of the radioecological sensitivity of the coastal marine regions can be used to improve risk management and decision-making systems, especially the development of response strategies, by defining the most sensitive areas. Environmental sensitivity analysis has been carried out for six marine coastal regions for a single deposition of 1000 Bq/m2 for radionuclides 137Cs, 90Sr, 131I and 239Pu. The analysis has been based on dose calculations during the 1st year, 2nd year and 10th year after releases of radionuclides for adults and children of 1 and 10 years of age. The calculations have been carried out by the compartment model, which includes the processes of dispersion of radioactivity in water - sediment environment and accumulation of radionuclides by marine organisms. Doses to man are calculated on the basis of seafood consumption. Results show that for all regions the radiation doses for adults are significantly higher than doses calculated for children. Further, the doses calculated for the first year dominate the doses of the second and tenth year following the releases of radionuclides. Calculations also indicate that doses vary greatly for different radionuclides; and the dose levels for the same radionuclide vary greatly in different marine environments.

The examination of sediment samples collected from the Yenisei River revealed the presence of artificial radionuclides characteristic of radioactive discharges from the MCC facility: isotopes of europium (152Eu, 154Eu, and 155Eu), cesium (137Cs and 134Cs), 60Co,90Sr, and transuranium elements. Radionuclide concentrations in sediment layers remained high as far as 240 km downstream of the MCC. The vertical distribution of radionuclides in sediment cores was very complex, and down-core variations were due to different amounts of radionuclides released by the MCC and due to variations in the hydrologic conditions in the river. Sequential extraction performed on samples of the upper layers of the sediment core showed different degrees of potential environmental availability of artificial radionuclides: the amounts of extracted 90Sr, 152Eu and 241Am were the largest (60–80% of initial activity), then followed 60Co (30%), 238,239,240Pu (15–30%), and, last, 137Cs (5–15%). The distribution of 238U among chemical fractions of sediments was similar to that of 60Co and 238,239,240Pu: 30–40% of 238U initial activity was extracted. In a few samples, 241Am was present in the unextractable form, which may be accounted for by the presence of microparticles of the reactor fuel.

In Finland, Olkiluoto Island on the western coast has been selected as a repository site for spent nuclear fuel disposal. A safety criterion is that typical exposures (dose rates) to flora and fauna should be demonstrated to be lower than those that according to best available knowledge could cause detrimental effect. To increase the confidence of dose assessment to flora, some selected plant species were measured in field conditions. This paper presents the results of the field campaign and discusses on the realism of the common assumption of ellipsoidal geometry applied to the plants in dose assessments of the other biota.

The Søve site is a disused mining complex in Telemark County, Norway, exhibiting enhanced levels of naturally occurring radionuclides from the 238U and 232Th decay series. The nascent General Assessment Methodology Process (‘GAMP’), developed under IAEA’s EMRAS II programme, has been applied at the site. The a priori fixed screening criteria were exceeded in the scenario, precipitating the requirement to undertake a more detailed assessment. The USDOE’s RESRAD-OFFSITE code was employed to investigate potential changes in activity concentrations in various environmental compartments over time and the contribution of various exposure pathways to effective doses. Owing to problems associated with model parameterisation and results interpretation a simple leaching and groundwater migration compartmental model was also applied. This allowed activity concentrations in three waste compartments to be calculated with time. Furthermore, an existing external dose-rate model that correlates information on activity concentrations with depth in soil to dose rates in air above ground has been used to estimate prospective external dose-rates to humans and evaluate the efficacy of applying various remediation options.

Natural radioactivity is associated with the vast mineral resources in South Africa in such concentrations that the radionuclides from the natural uranium and thorium decay series are found to pose concern for public exposure to communities living around these areas. Consumption of water and food is usually the most important route by which natural radionuclides can enter the human body and assessment of natural radionuclide levels in different foods and diets is therefore important to estimate the intake of these radionuclides by man. Sensitive measurement of three major radionuclides (in addition to 238U, 234U, 232Th, 226Ra, 224Ra and 223Ra) is necessary to calculate the estimated annual dose with a high degree of certainty i.e. 230Th, 210Pb and 210Po, while 231Pa, 227Ac and 228Ra also require improved sensitivity. In order to evaluate the yearly dose due to an individual source at a screening level of 25 μSv/a, one is faced with a required lower limit of determination (LLD) of 0.1 to 0.5 Bq/kg for certain foodstuffs. In this study the potential radiological impact of foodstuffs grown in a catchment area influenced by mining and mineral processing industries in South Africa, was determined by measuring the natural radionuclides in a number of foodstuffs collected from the area. The radionuclides were measured by non-destructive techniques such as Instrumental Neutron Activation Analysis (INAA) and low background gamma spectrometry. The assessment of natural radionuclides in foods allowed us to evaluate the items that present the highest risk to the population, and compare this to the limits established by the National Nuclear Regulator (NNR). From the public’s point of view it is important to ensure the population that the contaminant levels in specific food as a result of mining activities, do not exceed the permissible limits. For the majority of the analysed foodstuffs, the estimated dose was less than 250 μSv/a. Overestimation of dose, due to poor measurement detection limits, was clearly indicated for some of the samples. For most of the analysed nuclides, suitable data for evaluation of the yearly dose at the screening level of 25 μSv/a was obtained by broad energy gamma analysis of ashed samples. However, nuclides such as 230Th, 210Po and 231Pa has to be analysed by radiochemical separation through acid destruction of dried foodstuffs followed by individual element separations to provide suitable data with a low enough LLD not to result in an overestimation of the calculated dose.

The European decision support systems ARGOS and RODOS rely on the ECOSYS model for prognoses of ingestion doses. ECOSYS needs an update of various parameter values to provide reliable estimates. This paper reports on some results of a Nordic initiative to derive parameter values that are specific to Nordic conditions, as well as to improve generic parameter values in ECOSYS, taking into account the host of useful measurement data accumulated since ECOSYS was created.

Members of the public are exposed to radiation because of where they live and their habits bring them into contact with sources of radiation. They may be exposed directly by the source, by direct irradiation or inhalation of released activity or indirectly by exposure to contaminated environmental materials such as food. Consequently habit data are an essential part of dose assessment for members of the public [1]. Previously no detailed surveys had been undertaken in Ireland of habit data relevant to the assessment of doses to the population from radioactivity in the marine environment. Instead RPII dose assessments were made on the basis of assumed or notional data inferred from habit surveys undertaken elsewhere and from national average consumption figures. Following a tender process the Centre for Environment, Fisheries & Aquaculture Science, Cefas, UK, were commissioned to undertake a Habits Survey. Its report [2] provides an assessment of aquatic radiation exposure pathways in Ireland relating to anthropogenic radioactivity in the Irish Sea.

In Finland, Olkiluoto Island has been selected for constructing a spent nuclear fuel disposal facility. With the approaching licensing step, submitting the application for nuclear construction licence in 2012, all components of the safety case are becoming more site-specific. In order to assess compliance with regulatory requirements, a prospective deterministic dose assessment methodology based on the ICRP concept of assessing doses to the representative person was developed and implemented in the interim safety case 2009, to be further refined for the safety case 2012. To facilitate the assessment of doses to the most exposed people and other people at the evolving site, full dose distributions are derived, comprising the dose to each potentially exposed person in each generation.