Over the last 30 years there has been a reduction in the radioactive discharges from the UK’s Sellafield site. Radionuclide activity concentrations in the environment around Sellafield have declined as a result. However, routine monitoring results from the nearby Esk Estuary show a less clear trend, with fluctuations in gamma dose rate measurements being reported from year to year. A comprehensive survey (n = 576) of gamma dose rates in the Esk Estuary was undertaken in 2007 and the data compared to a similar survey carried out in 1989. There was a highly statistically significant decrease in the external gamma dose rates within the Esk Estuary between 1989 and 2007. The measured total gamma dose rate range in 2007 was 0.064 – 0.235 μGy h−1with a mean of 0.123 μGy h−1. This equates to a maximum exposure of 0.200 μSv h−1. There was no evidence of large-scale sediment redistribution under current conditions. However, there was limited evidence to suggest that part of the reason for the reduction in measured dose rates was the burial of contaminated sediment deposits by uncontaminated sediments transported by tidal processes.

Ukrainian Radiation Protection Institute has developed system for calculation of doses to the population living in the supervision zone of the NPP from atmospheric discharges of Nuclear Power Plants during normal operation. The system analyses daily meteorological data, and also daily and monthly atmospheric discharges of radionuclides. The developed system is applied for dose calculation for Ukrainian population and identification of radionuclides, which form considerable contribution to total doses (noble gases, H-3, I-131). A special attention has been given for variability of actual meteorological conditions and discharges. For example, it has been revealed the case when I-131 discharge from a Ukrainian NPP during 4 consecutive days has made 34 % of annual discharge (and 72% during 3 weeks). Variability of actual discharges is a result of changes in an operation mode of NPP unit and it is a typical situation for Ukrainian NPPs. Apparently, the similar situation can be typical for NPPs in another countries. Such results lead to necessity to consider possible variations of meteorological conditions and discharges for establishment of permissible levels (for example, by introduction of variability factor).

Annual intake of 90Sr trough foodstuffs and drinking water was assessed for eleven age categories of Finnish females and males in 1955–2010. Maximum intakes were received by young men in 1963–64. Cereals and milk contributed more than 80% to the dietary dose then. Per capita dose from ingestion of 90Sr corresponded to the dose for a boy 13 years of age and a man older than 65 years. Lifetime committed effective dose from ingestion of 90Sr for a newborn male was 0.49 mSv and for a 20 years old male 0.32 mSv, when the exposure of 70 and 50 years started in the beginning of 1955. For females the doses were 0.39 and 0.25 mSv, respectively. The activity concentrations of 90Sr in milk varied in the whole country by a factor of two in the years of maximum fallout and decreased towards the 1980s. Also other than soil related factors have contributed to the variation in human exposure to dietary 90Sr.

The understanding of the fate of the various pollutants and its mobility in the catchments of Nagarjun Sagar dam built on the Krishna river is of utmost important .As the Pedaguttu and Lambarpur catchments area has a proposed Uranium mining sites and Nagarjuna Sagar dam is the third largest man made dam which is the ultimate destination of all the rivulets in the Pedaguttu catchments. The concept of the distribution coefficient is invoked to understand the residence time of radionuclide on its nature. Expressions are derived to estimate the value of soil erosion constant using naturally occurring radionuclide. Based on 210Pb profile in the sediment core, the sedimentary load of 0.24 gm m−2y−1 was observed in the Pedaguttu and Lambarpur side of the Dam. The retention time and the transport coefficient of the pollutant were further obtained by using the appropriate modeling equation and was found 3776 and 2.7 × 10−5 respectively. The comparative exercise of the retention time and transport coefficient was done with the other studied catchments of the world for the further validation of the result.

In this study, we investigated the microbial community (bacteria and protozooplankton) of a Brazilian reservoir that receives neutralized acid mine drainage flowing from piles of earth produced during uranium extraction. Thus, this research represents an attempt to fill a gap in the information on the ecology of freshwater microorganisms in tropical oligotrophic habitats, in particular in systems affected by high levels of the uranium. During the study, we observed very low chlorophyll a contents and protozooplankton cell densities and biomass. These cell densities were between 0 and 89 cells L−1 and were lower than those frequently reported for oligotrophic freshwater lakes. In contrast, bacterial densities were normal or even slightly high, between 1.85 to 6.0 × 109 cells L−1. The present study has demonstrated very low protozooplankton cell densities and biomass in oligotrophic reservoir under the influence of acidic mining effuents and of high levels of ionizing radiation. It is likely that the ciliate cell densities and biomasses recorded in this study, which fall significantly below the previously published values, can be explained by the chronic fractionated exposure of these protozoa to the high levels of uranium to this system.

Studies that examine biological effects on non-human biota in natural settings provide a unique opportunity for obtaining information about the potential biological hazard associated with radioactive contamination. The results of long-term field study in the Bryansk Region, Russia, affected by the Chernobyl accident are discussed. Plant populations growing in areas with relatively low levels of pollution are characterized by the increased level of both cytogenetic alterations and genetic diversity. In particular, radioactive contamination of the plants’ environment activates genetic mechanisms, changing a population’s resistance to exposure. However, there are radioecological situations where enhanced radioresistance has not evolved or has not persisted. A development of a system for protection of the environment from ionizing radiation should be based on a clear understanding of these effects and their contribution to response of populations.

The effects of low-dose γ-irradiation on the crustacean Daphnia magna have been analyzed. Given that the LD50 for this species is approximately 100 Gy, one-day-old daphnids were exposed to 10, 100 and 1000 mGy of acute γ-rays. The survival of irradiated animals was evaluated over the maximum lifespan of 90 days. Increased mortality among irradiated at doses of 100 and 1000 mGy daphnids was found. Our data also showed that the observed decrease in survival of irradiated animals was attributed to their early aging, thus providing an important evidence for the effects of low-dose irradiation on early senescence. Overall, the results of our studies have shown that low-dose irradiation can result in a significant reduction in life span of exposed daphnids. As the majority of irradiated Daphnia showed reduced viability regardless the dose, our data therefore imply the presence of a threshold of dose of low-LET exposure capable of impairing the viability of this species. We have also found that parental irradiation significantly affected the survival of first-generation offspring, the magnitude of which cannot be attributed to the segregation of radiation-induced deleterious mutations. Potential implications of the results of our studies for the risk assessment of low-dose exposure have been discussed.

Original data of tritium (1H3HO, or HTO) studying (1959–2010) of both natural, and artificial (technogenic) origin in natural waters on the country territory and in the seas of the World Ocean are presented. Entry sources of cosmogenic and technogenic HTO in hydrosphere of the Earth from atmosphere and its carrying over to various links of hydrological cycle are considered. The basic laws of the space-temporal HTO distribution in surface water of the northern part of the Eurasian continent, in the seas washing Russia and in separate water areas of the World Ocean, and also in atmospheric precipitation and Antarctica’s firn snow are studied. Prevailing influence of a molecular exchange on the HTO content in the top layer of lakes, the seas and oceans and in atmospheric moisture over the ocean is shown. The theory of a multicomponent isotope balance method is developed for studying of dynamic characteristics of water objects. Priority results of tritium use in the industry (on oil deposits, collieries, mines etc.) and in researches under national and international programs (WESTPAK, SOUTHERN OCEAN, “Isotopes in deposits”, the Soviet Arctic and Antarctic expeditions) are given. Systems of national and Far East regional monitoring HTO pollution of natural waters are created. Complexes for HTO measuring with record levels of threshold sensitivity (in the late seventies sensitivity of complex POI equaled to 4 × 10−6 Bq/ml) have been developed.

The new technologies were developed for spent nuclear fuel (SNF) condition operative monitoring and search for the lost objects with SNF at the sea bottom using Kr-85. The new paradigm of sea radioecology based on extensive research was proposed. The investigations include a preliminary experimental study of kinetics of fission products (Kr-85 and Cs-137) release from SNF, a subsequent expedition to the Arctic, as well as modeling radionuclides transfer in a near-bottom layer by means of fractal formalism using hydrological data on the expedition area [1,2]. Series of original experimental studies on Kr-85 and Cs-137 release from SNF during corrosion in sea water were conducted in 2002–2010. Time dependence of fission products (FP) release was measured in laboratory under conditions typical of a near-bottom water layer in the Novaya Zemlya Basin. Another important result was received during the expedition to the Arctic in the fall of 2000. The H-3 anomaly was recognized in the surface layer of the Kara Sea in the Novaya Zemlya Basin (228 ± 9.1 TU vs.10–15 TU in the Arctic on average!). This anomaly is located 100 miles south from the dumped reactor of atomic icebreaker “Lenin”. So it can be caused by SNF from the reactors of icebreaker “Lenin” or nuclear submarine K-140.

Vertical distribution of uranium and its decay products (226Ra and 210Pb) in the uppermost layers of the oxidised brown coals was studied for some deposits and natural outcrops of the Western part of the Kansko-Achinsk brown-coal basin. Abnormal accumulation of the mentioned radioactive elements is observed in all studied sites. Several types of radioactive anomalies are differed by the ratio of activities of 238U and 226Ra: 1) Equilibrium; 2) Radium; 3) Uranium. The depletion of 210Pb in the radioactive horizons of some sites indicates an active emanation of 222Rn in the underlying coal layers. Uranium besides the form sorbed on coal is presented in poral solutions. It says about its potential mobility and is confirmed experimentally. Radium is actively absorbed by the plants growing on radioactive coals.

Of the radiation types, alpha-(α) particles are of particular interest as they are an environmental concern, predominately due to inhalation of radon and its daughter progeny. Furthermore, α-particle emitters like Americium-241, Plutonium-238 and Polonium-210 have been identified as probable isotopes to be used in radiological dispersal devices. Thus, the identification of potential biomarkers to α-particle radiation exposure would be useful for the development of field deployable bioassays which could be used for human risk assessment and public health protection. Human lung cells were exposed to α-particle radiation and assessed for modulations in protein expression using two-dimensional gel electrophoresis (2D-GE). Concurrently, cell culture supernatants were analyzed for cytokine secretion using a multiplex-27 bead array assay. Cell culture supernatants assessed for cytokine secretion expressed 8 statistically significant cytokines following α-particle exposure, among which VEGF was confirmed to be dose-responsive and not modulated in X-irradiated cells. Analysis of whole cell lysates using 2-D gel electrophoresis showed 15 upregulated and 1 downregulated protein spot, of which 4 were identified by mass spectrometry. These data suggest that α-particle exposure results in the alterations in expression-levels of specific proteins which may be potential biomarkers used further for the development of fast and reliable bioassays.

With the development of nuclear power programme, an additional consideration outside the existing radiation protection framework appeared: the need to assess not only the level of exposure, but also to take into consideration the accidents which could release large inventories of radioactivity. With the expansion of nuclear commitments, the inventories of Tritium are bound to increase. The possible use of tritium as the fuel for fusion reactors in the near future may result in an additional source of tritium. Swiss albino mice of 1, 2, 3, 4 & 6 weeks of age were injected with tritiated water (HTO) at the dose 111 kBq/gram body weight and the animals from each age group autopsied on 1, 7 and 30 days post- injection. The mouse show radiovulnerability with a capability to repair and recover from the rendered damage during the first half (1 week to 3 week) of postnatal development, whereas during the second half (4 week to 6 week of age) a tendency towards radioresistance is achieved. The presentation is an attempt to revisit the behaviour of tritium with its possible implications on the environment in accordance with the presently projected radiation protection framework.

In 1986–2009 the dynamics of the radionuclide contamination of the Pripyat inlet ánd Perstok Lake and their biota as well as the set of biological test criteria reflecting impact of ionizing radiation on pulmonate mollusk Lymnaea stagnalis from these reservoirs have been investigated. The γ-activity of biota after the highest level in 1987 (up to 1100 kBq kg−1 wet mass) quickly decreasing. In 2005–2008 the activities of biota in the Pripyat inlet dropped to the natural level, but in the Perstok Lake they remained a rather high – up to 4000 Bq kg−1. Alongside the increase of activity of transuranium α-isotope 241Ám in bottom sediments of the Perstok Lake has been observed since 2006. In the L. stagnalis population in the Perstok Lake the obvious negative effect of chronic impact of radiation was noted. The share of cells with the micronuclei has considerably grown there if compared with the mollusks from the Pripyat inlet. The negative effects mentioned above did not influenced seriously on the viability on organism and populations levels. So, the embryonic mortality in both populations is low and they are capable to maintain sufficient level of reproduction despite the chronic radioactive impact.

This study aimed at investigating biological effects in Arabidopsis thalianaleaves and roots irradiated for 72 h with 3.5 Gy or 30 Gy of gamma radiation, and to unravel oxidative stress related responses to achieve a better understanding of the importance of the cellular redox balance as a modulator in gamma radiation stress. A. thaliana performs like a rather radioresistant plant species as no alterations on growth and only minor alterations in the nutrient profile were observed. Gamma irradiation did not seem to induce an NADPH mediated oxidative burst and lipid peroxidation appeared to be directly induced by ionizing radiation rather than mediated through LOX activity. As ionizing radiation can cause indirect damage via water radiolysis, H2O2 is hypothesized to be an important reactive oxygen species under radiation stress. Although most H2O2-scavenging enzymes remained unchanged, important alterations were observed for CAT1, CAT2 and CAT3expression.

The LLW Repository Limited has recognised the potential importance of the processes being considered in the BIOPROTA 14C working group and funded the development a new 14C model that addresses the exchange of gas in a soil-plant-atmosphere system. This model considers two regions in the above-ground atmosphere and utilises concepts from the field of micrometeorology to describe the exchange of air between these regions and losses from the area of interest. The lower layer only experiences molecular diffusion processes in relation to the movement of molecules of CO2, whereas the upper layer experiences some degree of turbulent mixing as a result of winds which flow over the area of interest. The thicknesses of these layers depend upon the canopy density, which will affect the light intensity and thus the rate of photosynthetic uptake of carbon in the canopy profile. Model results demonstrate the impacts of 14C-labelled gas from the soil upon the calculated 14C concentration in plants for a variety of plant species (pasture and garden crops) and subsequent doses to human exposure groups. The technical modelling work described has been funded by the LLW Repository Ltd in support of its 2011 Environmental Safety Case.

To quantitatively evaluate OBT production after a nighttime wet deposition of atmospheric HTO onto land surface, numerical experiments using a sophisticated tritium transport model (SOLVEG-II) were conducted. For a nighttime rain actually observed at a grassland site, two hypothetical scenarios for wet deposition of HTO were made; 0.1-folded and 10-folded case, each having rain HTO concentration at 0.1 folds and 10 folds of equilibrium concentration of ground-level air HTO concentration. Calculation results showed atmospheric HTO concentration after the rain at 10-folded case was more than an order of magnitude larger than that at 0.1-folded case, affected by interception and evaporation of rain HTO with leaves, and, by a larger HTO re-emission from soil. After the rain, due to these heightened atmospheric HTO, TFWT concentration in leaf cellular water at 10-folded case kept an order, or more, larger than that at 0.1-folded case. As a result, OBT produced in leaves over nine-day after the rain at 10-folded case was 18 times larger than that at 0.1-folded case. We therefore concluded that nighttime wet deposition of HTO pronouncedly increases OBT formation if rain HTO concentration exceeds equilibrium concentration for the air HTO near the ground.

The Institut de Radioprotection et de Sureté Nucléaire (IRSN) performed a series of air sampling campaigns at mesoscale distances (10–80 km) from the AREVA La Hague reprocessing plant (north west of France) between 2007 and 2009. These samples were collected in order to test and optimise a technique to measure low krypton-85 (85Kr) air concentrations, and to investigate the performance of three atmospheric dispersion models (RIMPUFF, HySplit, and ADMS). This paper presents 85Kr air concentrations measured at both land and sea locations. In addition, this paper compares the measured 85Kr air concentrations, which varied from 2 to 8000 Bq m−3, with the predictions from the atmospheric dispersion models. During stable wind conditions, the dispersion models make reasonable estimates of the 85Kr field measurements. In contrast, the models fail to accurately predict temporal peaks in concentration during periods of rapid and large changes in wind speed and/or wind direction.

Tritium can represent a key radionuclide in the aquatic environment, in some cases, contributing significantly to the doses received by aquatic non-human biota and by humans due to aquatic releases. Recently, the necessity to have a robust assessment of tritium routine and accidental risk emissions for large nuclear installations increased the interest in the topic. In the present study, the recent experiments concerning tritium transfer in adult rainbow trout are described. The updated model concerning the dynamics of tritium transfer in aquatic food chain (AQUATRIT model) developed by the authors is applied and tested for these experimental data. The model predicts the experimental data with a factor of 2 to 3 and the potential improvements of the model are discussed. The present model results emphasize that in the field conditions, the major factors influencing the OBT biological loss rate are the temperature and the prey availability while, the OBT uptake is mainly influenced by the fish growth rates. The main goals of this study are to enhance the robustness of aquatic models for tritium risk assessment and to fulfil a gap for aquatic pathways in environment.

Population of small rodents in radiocontaminated environment is compelled to include more energy-intensive way of maintenance its ability to live — increasing of the proportion of mature young of the year (first pathway of ontogeny). Their reproductive characteristics — actual fecundity was higher, whereas embryonic mortality and the proportion of females with embryonic losses were significantly lower compared with neighboring areas. Abundance of mice in the impact zone was higher, age cross was revealed, which improves the adaptive possibility of the population. Preconditions for acceleration of evolutionary transformations of a population are created, but this process is restrained by both the local configuration of the polluted territory and migration of murine rodents. As a consequence, the population decreases the probability that certain changes will be fixed and inherited in a series of generations. Chronic low-dose radiation (stress) can be considered as the mechanism of switching of life history of cyclomorphic mammals. Thus, ontogenetic multiversality of small mammals is an important mechanism of protection strategy of population and decreasing the damaging action on biota in radiocontaminated environment. Functional approach makes it possible to reduce errors in assessing the radiological consequences and hence, can provide a reliable methodological basis for organization of biological monitoring.

Tritium (3H) transfer into environment must be modelled differently than the transfer of other radionuclides released from nuclear reactors because hydrogen represents the building blocks of life. A solid understanding of 3H behaviour is essential because 3H may be released in large quantities from CANDU (CANada Deuterium Uranium) reactors and from future thermonuclear reactors. Recently, the authors published a complex dynamic metabolic model for 3H and 14C transfer in farm and wild animals, but the model applications for wild biota were restricted to too few examples and mostly for 14C transfer. In this study, the model is applied to few selected wild animals for 3H uptake. Despite the lack of any experimental data for wild animals, the results presented in this study are less uncertain than for many other radionuclides and can provide a useful estimation for biota radioprotection.