Characteristics of 210Po in Asian overbite clam (Potamocorbula laevis) from the coastal area at Thai Binh province, Vietnam.

210Po concentration in the edible muscle tissue and digestive diverticulum organs of Asian overbite clam at the near-shore Thai Binh, Vietnam was analyzed using alpha detectors. The 210Po activity in muscle tissue and digestive diverticulum organs ranged from 5 ± 1 to 178 ± 10 and from 118 ± 7 to 812 ± 12 Bq.kg-1 with the average value of 25 and 324 Bq.kg-1, respectively. Results showed that 210Po activity in the digestive diverticulum was significantly higher than in the muscle tissue. There was a slightly inverse correlation between 210Po activity in muscle tissue, digestive diverticulum, and clam weight and size. The annual committed effective dose was calculated from 210Po due to the consumption of Asian overbite clam for adults in the study area was higher than the guideline value of 0.2 - 1 mSv.y-1.

Allometric-kinetic model predictions of radionuclide dynamics across turtle taxa.

Chelonians (turtles, tortoises, and sea turtles; hereafter, turtles) inhabit a wide variety of ecosystems that are currently, or have the potential in the future to become, radioactively contaminated. Because they are long-lived, turtles may uniquely accumulate significant amounts of the radionuclides, especially those with long half-lives and are less environmentally mobile. Further, turtle shells are covered by scutes made of keratin. For many turtle taxa, each year, keratin grows sequentially creating annual growth rings or layers. Theoretically, analysis of these scute layers for radionuclides could provide a history of the radioactivity levels in the environment, yet there are few previously published studies focused on the dynamics of radionuclide intake in turtles. Using established biochemical and ecological principles, we developed an allometric-kinetic model to establish relationships between the radionuclide concentrations in turtles and the environment they inhabit. Specifically, we calculated Concentration Ratios (CRs - ratio of radionuclide concentration in the turtle divided by the concentration in the soil, sediment, or water) for long-lived radionuclides of uranium and plutonium for freshwater turtles, tortoises, and sea turtles. These CRs allowed prediction of environmental concentrations based on measured concentrations within turtles or vice-versa. We validated model-calculated CR values through comparison with published CR values for representative organisms, and the uncertainty in each of the model parameters was propagated through the CR calculation using Monte Carlo techniques. Results show an accuracy within a factor of three for most CR comparisons though the difference for plutonium was larger with a CR ratio of about 200 times for sea turtles, driven largely by the uncertainty of the solubility of plutonium in sea water.

Thyroid Doses to French Polynesians Resulting from Atmospheric Nuclear Weapons Tests: Estimates Based on Radiation Measurements and Population Lifestyle Data.

Thyroid doses were estimated for the subjects of a population-based case-control study of thyroid cancer in a population exposed to fallout after atmospheric nuclear weapons tests conducted in French Polynesia between 1966 and 1974. Thyroid doses due to (1) intake of I and of short-lived radioiodine isotopes (I, I, I) and Te, (2) external irradiation from gamma-emitting radionuclides deposited on the ground, and (3) ingestion of long-lived Cs with foodstuffs were reconstructed for each study subject. The dosimetry model that had been used in 2008 in Phase I of the study was substantially improved with (1) results of radiation monitoring of the environment and foodstuffs, which became available in 2013 for public access, and (2) historical data on population lifestyle related to the period of the tests, which were collected in 2016-2017 using focus-group discussions and key informant interviews. The mean thyroid dose among the study subjects was found to be around 5 mGy while the highest dose was estimated to be around 36 mGy. Doses from I intake ranged up to 27 mGy, while those from intake of short-lived iodine isotopes (I, I, I) and Te ranged up to 14 mGy. Thyroid doses from external exposure ranged up to 6 mGy, and those from internal exposure due to Cs ingestion did not exceed 1 mGy. Intake of I was found to be the main pathway for thyroid exposure accounting for 72% of the total dose. Results of this study are being used to evaluate the risk of thyroid cancer among the subjects of the epidemiologic study of thyroid cancer among French Polynesians.

A comprehensive probabilistic approach for integrating and separating natural variability and parametric uncertainty in the prediction of distribution coefficient of radionuclides in rivers.

A geochemical speciation model was developed to predict Distribution coefficients (Kds) of radionuclides (RNs) in rivers. The model takes into account complexation of RNs with inorganic ligands, sorption of RNs with hydrous ferric oxides, complexation of RNs with dissolved and particulate organic carbon (DOC and POC) and sorption and/or co-precipitation of RNs to carbonates. A sorption model of Cs onto clay was also integrated. The tool is also designed to conduct uncertainty and sensitivity analysis. Sensitivity analysis follows a stepwise structured approach, starting from computationally 'inexpensive' Morris method to most costly variance-based EFAST method. A nested Monte Carlo approach was also implemented to separate natural variability and lack of knowledge in global uncertainty assessment. As case studies, Kd distributions were estimated for Co, Mn, Ag and Cs in seven French rivers. Uncertainty analysis allowed to quantify Kd ranges that can be expected when considering all the sensitive parameters together.

Uranium in drinking water: a public health threat.

Uranium (U) has no known essential biological functions. Furthermore, it is well known for its toxicity, radioactivity, and carcinogenic potency. Impacts on human health due to U exposure have been studied extensively by many researchers. Chronic exposure to low-level U isotopes (radionuclides) may be interlinked with cancer etiology and at high exposure levels, also kidney disease. Other important issues covered U and fertilizers, and also U in soils or human tissues as an easily measurable indicator element in a pathophysiological examination. Furthermore, phosphate fertilization is known as the important source of contamination with U in the agricultural land, mainly due to contamination in the phosphate rock applied for fertilizer manufacture. Therefore, long-term usage of U-bearing fertilizers can substantially increase the concentration of U in fertilized soils. It should also be noted that U is an active redox catalyst for the reaction between DNA and H2O2. This review is aimed to highlight a series on various hydro-geochemical aspects in different water sources and focused on the comparison of different U contents in the drinking water sources and presentation of data in relation to health issues.

A 40-year marine record of 137Cs and 99Tc transported into the Danish Straits: Significance for oceanic tracer studies.

This work reports comprehensive time-series datasets for 137Cs and 99Tc in marine samples from the Danish Straits over the past 40 years, where dynamic inputs from the two European nuclear reprocessing plants Sellafield (SF) and La Hague (LH) and Chernobyl accident are clearly archived. Distinct seasonal variations between 137Cs and 99Tc are observed in Fucus vesiculosus (F. vesiculosus), which needs to be taken into account when using F. vesiculosus as a bio-monitor to represent the concentration of radionuclides in seawater. Comparable transfer factor (TF) for 99Tc from SF to Kattegat between our calculation and earlier studies indicates a relatively steady water mass transport over the past decades. Three distinct events are observed in the temporal evolution of 99Tc/137Cs activity ratio in F. vesiculosu with the first event corresponding with the increased 99Tc discharge from SF, while the other two are very likely related to the major Baltic inflow (MBI) events. The correlation between the 99Tc/137Cs activity ratio and salinity fits well into the binary mixing line with the North Sea (NS) and the Baltic Sea (BS) as end members. A model simulation indicates that water mass from NS constitutes less than 50% in the surface water and 50-100% for most locations in the bottom water of the Danish Straits. Overall observations show that 137Cs and 99Tc in marine samples, especially 99Tc/137Cs isotope ratios, serve as useful oceanic tracers to study different natural processes, such as water mixing and transport dynamics.

Specific Recognition of Uranyl Ion Employing a Functionalized Nanochannel Platform for Dealing with Radioactive Contamination.

Radioactive contamination is a highly concerning global environmental issue along with the development of the nuclear industry. On account of sophisticated operations and high cost of instrument detection methods, numerous efforts have been focused on rapid and simple detection of pollution elements and uranium is the most common one. It is an enormous challenge to push the limit of determination as low as possible while carrying out ultrasensitive detection. Here, we report an intelligent platform based on functionalized solid nanochannels to monitor ultratrace uranyl ions. The platform has a detection limit of 1 fM, which is far below the value that traditional instrumental methods can reach. What is more, the system also exhibits uranyl removal property. The mesenchymal stem cells cultivated in media containing uranyl can achieve excellent viability in the presence of the membranes. This work provides a new choice for handling global radioactive contamination of water.

A modeling approach to estimate the 137Cs discharge in rivers from immediately after the Fukushima accident until 2017.

We developed a simple model to evaluate and predict the 137Cs discharge from catchments using a tank model and the L-Q equation. Using this model, the 137Cs discharge and discharge ratio from the Abukuma River and 13 other rivers in the Fukushima coastal region were estimated from immediately after the Fukushima accident up to 2017. The 137Cs discharge (and discharge ratio to the deposition inventory in the catchment) of the Abukuma River and 13 other rivers in the Fukushima coastal region during the initial six months after the accident were estimated to be 18 TBq (3.1%) and 11 TBq (0.79%), respectively. These values of 137Cs discharge ratio were 1-2 orders of magnitude higher than those observed after June 2011 in previous studies (Ueda et al., 2013; Tsuji et al., 2016; Iwagami et al., 2017a), indicating that the initial 137Cs discharge from the catchments through the rivers was significant. The simulated initial 137Cs discharge rates for the initial six months after the Fukushima accident were about 9-30 times larger in each catchment than those after that point until 2017, though initial 137Cs concentration in river water was derived from an extrapolation of data based on a two exponentially decreasing fitting. However, it was found that the impact on the ocean from the initial 137Cs discharge through the rivers can be limited because the 137Cs discharge from the Abukuma River and the 13 other rivers in the Fukushima coastal region (29 TBq) was two orders of magnitude smaller than the direct release from Fukushima Dai-ichi Nuclear Power Plant (FDNPP) into the ocean (3.5 PBq) and from atmospheric deposition into the ocean (7.6 PBq) (Kobayashi et al., 2013). This model is expected to be useful to evaluate and predict 137Cs discharge from catchments in future water management and in the estimation of 137Cs discharge into reservoirs and the ocean.

Transport and fate of 137Cs in the Mediterranean and Black Seas system during 1945-2020 period: A modelling study.

The compartment model POSEIDON-R with an embedded dynamic food web model was used to assess 137Cs distributions in the Mediterranean and Black Seas during 1945-2020 due to the weapon testing and accident at the Chernobyl nuclear power plant. Three maximums of contamination of surface waters can be identified from 1950 in the Mediterranean Sea system. Two of them (in 1959 and 1963) were caused by atmospheric deposition due to the nuclear weapon testing. Third maximum in 1986 was related with the Chernobyl accident. Maximum of inventory of 137Cs in the Mediterranean Sea (11461 TBq) was achieved in 1968, whereas secondary maximum caused by Chernobyl accident in 1986 was almost the same (11460 TBq). The corresponding maximum in the Black Sea (3703 TBq) was reached in 1986. It is approximately two times larger than nuclear weapon tests maximum. The results of simulations conducted with generic parameters agreed well with measurements of 137Cs concentrations in the water, bottom sediments, and in marine organisms. The inventory in the Mediterranean Sea is most sensitive to the global deposition, whereas water exchange with Atlantic Ocean and the Black Sea plays minor role. The cumulative individual dose for the period 1945-2020 from consumption of marine products contaminated by 137Cs was in the range 41-130 µSv in the Mediterranean Sea and 213-274 µSv in the Black Sea. The dose increased up to 40% due to Chernobyl accident in the Mediterranean countries and 66-103% in the Black Sea countries comparatively with dose from the global deposition. A useful application of the modelling for monitoring purposes was selection of representative regions in the Mediterranean Sea (5 regions) and in the Black Sea (4 regions) using "etalon" method for classification.

Elevated autoimmunity in residents living near abandoned uranium mine sites on the Navajo Nation.

Specific autoantibodies were assessed among residents of the Navajo Nation in New Mexico chronically exposed to metal mixtures from uranium mine wastes and in drinking water supplies. Age and the extent of exposure to legacy waste from 100 abandoned uranium mine and mill sites were associated with antibodies to denatured DNA, previously known to be an early indicator of medication-induced autoimmunity. Surprisingly, autoantibodies to native DNA and/or chromatin were also linked to environmental exposure, specifically uranium consumption through drinking water for both men and women, while urinary arsenic was negatively associated with these autoantibodies in women. These findings suggest that contaminants derived from uranium mine waste enhanced development of autoantibodies in some individuals, while arsenic may be globally immunosuppressive with gender-specific effects. Specific autoantibodies may be a sensitive indicator of immune perturbation by environmental toxicants, an adverse effect not considered in current drinking water standards or regulatory risk assessment evaluations.

Fukushima 137Cs releases dispersion modelling over the Pacific Ocean. Comparisons of models with water, sediment and biota data.

A number of marine radionuclide dispersion models (both Eulerian and Lagrangian) were applied to simulate 137Cs releases from Fukushima Daiichi nuclear power plant accident in 2011 over the Pacific at oceanic scale. Simulations extended over two years and both direct releases into the ocean and deposition of atmospheric releases on the ocean surface were considered. Dispersion models included an embedded biological uptake model (BUM). Three types of BUMs were used: equilibrium, dynamic and allometric. Model results were compared with 137Cs measurements in water (surface, intermediate and deep layers), sediment and biota (zooplankton, non-piscivorous and piscivorous fish). A reasonable agreement in model/model and model/data comparisons was obtained.

INTEGRAL ESTIMATION OF QUALITY OF THE DNIPRO RIVER WATER INCLUDING RADIATION INDEXES AT PLACES OF WATER INTAKE AND POTABLE WATER SUPPLY STATIONS. / INTEGRAL'NA OTsINKA IaKOSTI VOD RIChKY DNIPRO Z VYZNAChENNIaM RADIATsIINOÏ AKTYVNOSTI U MISTsIaKh PYTNYKh VODOZABORIV TA PYTNYKh VODOPROVIDNYKh STANTsII.

OBJECTIVE: To develop an methodology for integral estimation of natural and potable water and to conduct relevant estimation of the Dnipro River water including radiation indexes at locations of potable water intake and potable water supply stations. MATERIALS AND METHODS: Materials of Cherkasyvodokanal ME, Dniprovodokanal ME, Vodokanal ME, Berdyansk-vodokanal ME, and Oblvodokanal ME were analyzed. Along the period of 3 years (2015-2017), 468 water samplesfrom 7 water supply stations which use the Dnipro River water for intake were examined, upon 25 sanitary-chemical and 2 radiation (α activity and ß activity) parameters. When carrying out the research, the following methods were used: bibliographic, sanitary-chemical, experts' and integral estimations. RESULTS: In order to carry out integral estimation of the quality of intake and potable water of water supply stations, for the first time the method of hierarchic folding of variables in the method of hierarchy analysis of T. Saati was used, by way of stage-by-stage expert comparison of different groups of parameters and of parameters in groups.Herewith, the groups of parameters were classified according to requirements of State Sanitary Rules and Standards (DSanPiN) 2.2.4-171-10 «Hygienic Requirements to Potable Water Intended for Consumption by Humans¼ asorganoleptic, integral, physical-chemical with organoleptic and general sanitary, as well as sanitary-toxicological characteristics of health hazards. Weight coefficients for parameters of quality of water are calculated as the superposition of expert weights for each group with taking into account relative estimations of significance for a complex parameter of groups between each other. It was educed that the average complex parameter for all stations in intake water in spring, in summer, and in autumn is statistically (p < 0.001) greater than in winter, and after treatment it doesn't vary along seasons of the year. If complex parameters for water from all stations are compared, their minimum values were for water of Cherkasyvodokanal ME (0.177 ± 0.005 and 0.167 ± 0.005 - of intake and potable water respectively) and Kaydatska Pumping and Filtration Station of Dniprovodokanal ME (0.156 ± 0.006 of intake water). Maximum values were detected in intake water of Blocks No. 1 and No. 2 of DWSS-1 of the town of Zaporizhzhia (0.267 ± 0.008 for each) and of Oblvodokanal ME (0.273 ± 0.004); of potable: DWSS-1 of the town of Zaporizhzhia (0.260 ± 0.008 and 0.265 ± 0.008 respectively) and Berdyanskvodokanal ME (0.282 ± 0.009). At several stations, after treatment, the increase of the value of the complex parameter was observed, and at other, the decrease or the stability of that value was observed. CONCLUSIONS: 1. An methodology for assessing the quality of natural and drinking water including radiation indexes is developed, which will allow processing of large massifs of indicators through their step-by-step expert comparison with a significant simplification of the work of experts and without losing the accuracy of the evaluation results. 2. The integral estimation of the ecological state of water of the Dnipro River at places of potable water intakes allowed to determine that the complex parameter of the quality of above mentioned water has a minimum value in winter, and after treatment at water supply stations the parameter is stable along the year. The dynamics of changes in the integral parameter by years (2015-2017) was educed, and along the river bed. Minimum values of complex parameters of quality of intake water was detected for the following stations: Cherkasyvodokanal ME and Kaydatska Pumping and Filtration Station of Dniprovodokanal ME, and maximum values were detected at Blocks No. 1 and No. 2 of DWSS-1 of the town of Zaporizhzhia and at Oblvodokanal ME. It was confirmed that with the purpose of carrying out efficient state monitoring of the quality of natural and potable water in the spatial-temporal aspect, it is expedient to use the method of integral estimation.

EFFECT OF SOMEUNFAVORABLE FACTORS OF ENVIRONMENT ON THE SURVIVAL OF CHILDREN WITH ACUTE LEUKEMIA IN A LONG6TERM PERIOD AFTER ACCIDENT ON THE CHORNOBYL NPP. / VPLYV DEIaKYKh NESPRYIaTLYVYKh ChYNNYKIV DOVKILLIa NA VYZhYVANIST' DITEI Z GOSTRYMY LEIKEMIIaMY U VIDDALENYI PERIOD PISLIa AVARIÏ NA ChORNOBYL'S'KII AES.

OBJECTIVE: Determine of the influence of adverse environmental factors, including irradiation, on the survival ofchildren with acute leukemia in the long-term period after the Chornobyl accident (2008-2017). MATERIALS AND METHODS: Examined 74 children with acute leukemia (АL): 64 with acute lymphoblastic leukemia(ALL); 10 - acute myeloblastic leukemia (AML). The influence of negative environmental factors was assessed bythe degree of integrated pollution of the atmospheric air, surface waters and soils with pesticides, heavy metals (Pb,Cu, Ni, Cr, Mn, Zn, Fe) and cesium isotope 137Cs. These regions were ranked on a moderately polluted (1), polluted (2),very (3) and extremely (4) polluted territories. Took into account the age of children, blood test, immunophenotyp-ic of variant the acute leukemia, survival of patients and place of residence (city / village), serum ferritin level (SF). RESULTS: Exposure doses of children were in the range from 0.4 mSv to 35.0 mSv (average values were (4.25 ± 0.63 mSv)and did not affect the prognosis and variants of AL. 52 children lived in moderately and polluted territories (30 wereresidents of cities, 22 - villages). 22 patients were lived in very and extremely polluted territories (4 were residentsof cities, 18 - villages). Of 74 patients with ALL and AML 24 children died (32.4 %). The smallest number ofchildren, who died, were patients with «general type¼ В-ALL (18.7 %), most of all children with pro-В-ALL (8 out of10) and Т-ALL (3 of 4). Of the 52 patients, the inhabitants of moderately and polluted regions, 13 patients died (25%), while out of 22 patients, who lived in very and extremely polluted areas, 11 children died (50 % share)(rs = 0.39; p < 0.05). Of the 10 patients with AML, 4 children died. Most often, children died, who were residents ofvillages. Moreover, the level of SF was significantly higher in children over 6 years, the inhabitants of villages -(406.8 ± 40.6) ng/ml, compared to younger patients - (211.2 ± 32.1) ng/ml) and residents of of cities: up to 6years - (297.4 ± 52.3) ng/ml; over 6 years - (275.6 ± 29.8) ng/ml. CONCLUSIONS: The obtained data testify to the negative influence of environmental factors, including iron, and canbe the basis for understanding the mechanisms of potentiating influence of metals and their compounds on thedevelopment of malignant diseases of the blood system in children.

Radiocesium in seawater, sediments, and marine megabenthic species in coastal waters off Fukushima in 2012-2016, after the 2011 nuclear disaster.

In bottom-sediment samples collected in 2012 from a coastal strip (∼30 km × 120 km) off the Fukushima Daiichi Nuclear Power Plant (FDNPP), radiocesium activity concentrations were generally higher south of the FDNPP, with high activity concentration patches in the north. In periodic surveys conducted at nearshore sites during 2012-2016, no clear temporal trends were observed in radiocesium activity concentrations in seawater or bottom sediment, and activity concentrations were higher in fish than in invertebrates. During 2012-2014, radiocesium activity concentrations tended to decrease in fish, but during 2012-2013 in the south, some increases were observed. Radiocesium activity concentrations were significantly higher in some fish (e.g., Okamejei kenojei) directly offshore and south of the FDNPP than in the north. Activity concentrations in fish stomach contents were significantly correlated with those in muscle tissue, suggesting that the consumption of contaminated prey contributed greatly to radiocesium contamination in demersal fish.

A laboratory information management system for the analysis of tritium (3H) in environmental waters.

Accurate and precise measurements of low levels of tritium (3H) in environmental waters are difficult to attain due to complex steps of sample preparation, electrolytic enrichment, liquid scintillation decay counting, and extensive data processing. We present a Microsoft Access™ relational database application, TRIMS (Tritium Information Management System) to assist with sample and data processing of tritium analysis by managing the processes from sample registration and analysis to reporting and archiving. A complete uncertainty propagation algorithm ensures tritium results are reported with robust uncertainty metrics. TRIMS will help to increase laboratory productivity and improve the accuracy and precision of 3H assays. The software supports several enrichment protocols and LSC counter types. TRIMS is available for download at no cost from the IAEA at www.iaea.org/water.

Gross beta determination in drinking water using scintillating fiber array detector.

A scintillating fiber array detector for measuring gross beta counting is developed to monitor the real-time radioactivity in drinking water. The detector, placed in a stainless-steel tank, consists of 1096 scintillating fibers, both sides of which are connected to a photomultiplier tube. The detector parameters, including working voltage, background counting rate and stability, are tested, and the detection efficiency is calibrated using standard potassium chloride solution. Water samples are measured with the detector and the results are compared with those by evaporation method. The results show consistency with those by evaporation method. The background counting rate of the detector is 38.131 ±â€¯0.005 cps, and the detection efficiency for ß particles is 0.37 ±â€¯0.01 cps/(Bq/l). The MDAC of this system can be less than 1.0 Bq/l for ß particles in 120 min without pre-concentration.

Bio accumulation of radioactive caesium in marine mammals in the Baltic Sea - Reconstruction of a historical time series.

Radionuclides from the Chernobyl accident in 1986 still circulate in the Baltic marine ecosystem and activity levels in water, sediments and fish species such as herring and perch are monitored annually. However, the activity levels of radionuclides in marine mammals have only been sporadically reported. Tissue samples from a museum collection were analysed in two species of seals, and the trends over time in activity level of radioactive caesium (Cs-137) after the Chernobyl accident were reconstructed. We also performed a literature review summarizing activity levels in marine mammals world-wide. We found activity concentrations of Cs-137 in Baltic ringed seals and grey seals to be elevated also in the most recent samples, and during the entire study period measurements ranged between 19 and 248 Bq/kg wet weight. A declining trend in time over the last 30 years follow the general trend of decline in activity levels in other Baltic biota. Accumulation was found to be species specific in the two seal species studied, with 9 times higher activity concentration in grey seals compared to herring, and 3.5 times higher in ringed seals compared to herring. We discuss potential paths and rates of bioaccumulation of radioactive caesium in the Baltic Sea including species specific prey choice of the two seal species and estimate life time exposure. The study contributes one important piece of information to predictive models in risk assessments for nuclear accidents.

Measurement of the 100 MHz EMF radiation in vivo effects on zebrafish D. rerio embryonic development: A multidisciplinary study.

The augmented exposure of both environment and human being to electromagnetic waves and the concomitant lack of an unequivocal knowledge about biological consequences of these radiations, raised public interest on electromagnetic pollution. In this context, the present study aims to evaluate the biological effects on zebrafish (ZF) embryos of 100 MHz radiofrequency electromagnetic field (RF-EMF) exposure through a multidisciplinary protocol. Because of the shared synteny between human and ZF genomes that validated its use in biomedical research, toxicology and developmental biology studies, ZF was here selected as experimental model and a measurement protocol and biological analyses have been set up to clearly discriminate between RF-EMF biological and thermal effects. The results showed that a 100 MHz EMF was able to affect ZF embryonic development, from 24 to 72 h post fertilization (hpf) in all the analyzed pathways. Particularly, at the 48 hpf stage, a reduced growth, an increased transcription of oxidative stress genes, the onset of apoptotic/autophagic processes and a modification in cholesterol metabolism were detected. ZF embryos faced stress induced by EMF radiation by triggering detoxification mechanisms and at 72 hpf they partially recovered from stress reaching the hatching time in a comparable way respect to the control group. Data here obtained showed unequivocally the in vivo effects of RF-EMF on an animal model, excluding thermal outcomes and thus represents the starting point for more comprehensive studies on dose response effects of electromagnetic fields radiations consequences.

Applicability of Kd for modelling dissolved 137Cs concentrations in Fukushima river water: Case study of the upstream Ota River.

A study is presented on the applicability of the distribution coefficient (Kd) absorption/desorption model to simulate dissolved 137Cs concentrations in Fukushima river water. The upstream Ota River basin was simulated using GEneral-purpose Terrestrial Fluid-flow Simulator (GETFLOWS) for the period 1 January 2014 to 31 December 2015. Good agreement was obtained between the simulations and observations on water and suspended sediment fluxes, and on particulate bound 137Cs concentrations under both base and high flow conditions. By contrast the measured concentrations of dissolved 137Cs in the river water were much harder to reproduce with the simulations. By tuning the Kd values for large particles, it was possible to reproduce the mean dissolved 137Cs concentrations during base flow periods (observation: 0.32 Bq/L, simulation: 0.36 Bq/L). However neither the seasonal variability in the base flow dissolved 137Cs concentrations (0.14-0.53 Bq/L), nor the peaks in concentration that occurred during storms (0.18-0.88 Bq/L, mean: 0.55 Bq/L), could be reproduced with realistic simulation parameters. These discrepancies may be explained by microbial action and leaching from organic matter in forest litter providing an additional input of dissolved 137Cs to rivers, particularly over summer, and limitations of the Kd absorption/desorption model. It is recommended that future studies investigate these issues in order to improve simulations of dissolved 137Cs concentrations in Fukushima rivers.

Temporal and spatial variations of 134Cs and 137Cs levels in the Sea of Japan and Pacific coastal region: Implications for dispersion of FDNPP-derived radiocesium.

To investigate the dispersion of Fukushima Dai-ichi Nuclear Power Plant (FDNPP)-derived radiocesium in the Sea of Japan and western Pacific coastal region and determine the sources of radiocesium in these areas, we examined the temporal and spatial variations of 134Cs and 137Cs concentrations (activities) during 2011-2016 in seawaters around the western Japanese Archipelago, particularly in the Sea of Japan. In May 2013, the surface concentration of 134Cs was ∼0.5 mBq/L (decay-corrected to March 11, 2011), and that of 137Cs exceeded the pre-accident level in this study area, where the effects of radiocesium depositions just after the FDNPP accident disappeared in surface waters in October 2011. Subsequently, radiocesium concentrations gradually increased during 2013-2016 (∼0.5-1 mBq/L for 134Cs), exhibiting approximately homogeneous distributions in each year. The temporal and spatial variations of 134Cs and 137Cs concentrations indicated that FDNPP-derived radiocesium around the western Japanese Archipelago, including the Sea of Japan, has been supported by the Kuroshio Current and its branch, Tsushima Warm Current, during 2013-2016. However, in the Sea of Japan, the penetration of 134Cs was limited to depths of less than ∼200 m during three years following the re-delivery of FDNPP-derived radiocesium.