Health risks from radioactive particles on Cumbrian beaches near the Sellafield nuclear site.

A monitoring programme, in place since 2006, continues to recover radioactive particles (<2 mm diameter) and larger objects from the beaches of West Cumbria. The potential risks to members of the public using the beaches are mainly related to prolonged skin contact with or the inadvertent ingestion of small particles. Most particles are classified as either 'beta-rich' or 'alpha-rich' and are detected as a result of their caesium-137 or americium-241 content. Beta-rich particles generally also contain strontium-90, with90Sr:137Cs ratios of up to about 1:1, but typically <0.1:1. Alpha-rich particles contain plutonium isotopes, with Pu:241Amαratios usually around 0.5-0.6:1. 'Beta-rich' particles have the greatest potential to cause localised skin damage if held in stationary contact with the skin for prolonged periods. However, it is concluded that only particles of >106Bq of137Cs, with high90Sr:137Cs ratios, would pose a significant risk of causing acute skin ulceration. No particles of this level of activity have been found. Inadvertent ingestion of a particle will result in the absorption to blood of a small proportion of the radionuclide content of the particle. The subsequent retention of radionuclides in body organs and tissues presents a potential risk of the development of cancer. For 'beta-rich' particles with typical activities (mean 2 × 104Bq137Cs, Sr:Cs ratio of 0.1:1), the estimated committed effective doses are about 30µSv for adults and about 40µSv for 1 year old infants, with lower values for 'alpha-rich' particles of typical activities. The corresponding estimates of lifetime cancer incidence following ingestion for both particle types are of the order of 10-6for adults and up to 10-5for infants. These estimates are subject to substantial uncertainties but provide an indication of the low risks to members of the public.

EXPRESSION OF LIPOPROTEIN LIPASE AND c-MYC ONCOGENE IN PATIENTS WITH CHRONIC LYMPHOCYTIC LEUKEMIA AFFECTED BY THE CHORNOBYL ACCIDENT. / EKSPRESIIa GENA LIPOPROTEÏNLIPAZY I ONKOGENA c-MYC U KhVORYKh NA KhRONIChNU LIMFOTsYTARNU LEIKEMIIu, IaKI POSTRAZhDALY VNASLIDOK AVARIÏ NA ChORNOBYL'S'KII AES.

OBJECTIVE: to determine the association between the expression of lipoprotein lipase (LPL) and c-MYC genes inperipheral blood cells of chronic lymphocytic leukemia (CLL) patients affected by the Chornobyl catastrophedepending on the mutational status of IGHV genes. METHODS: Analysis was performed in the group of 69 CLL patients irradiated due to the Chornobyl NPP accident (58clean-up workers of 1986 year, 6 inhabitants of radionuclide contaminated areas, and 5 evacuees). The IGHV genemutational status was studied by polymerase chain reaction (PCR) followed by direct sequencing. LPL and c-MYCexpression was evaluated by Quantitative Real-time PCR. Data were analyzed with the SPSS software package, version 20.0. RESULTS: Relative LPL expression levels in CLL samples ranged from 0 to 1663.5 (mean 138.47 ± 30.69, median 26.1).A strong correlation between individual LPL expression levels and IGHV mutational status was found (r = 0.684;p < 0.0001). The average relative c-MYC expression level was 5.7 ± 0.87 (median 2.86; range 0-48.5). No association between c-MYC expression and IGHV mutational status was found. Among unmutated IGHV cases, a correlationbetween LPL and c-MYC gene expression levels was identified: r = 0.351; p = 0.013. CONCLUSIONS: Our data confirm the dominant concept that unmutated IGHV CLL cases are more sensitive to the actionof proliferative stimuli compared to mutated IGHV CLL cases. This is manifested by an increase in the expression ofa functionally significant LPL gene, is one for the strongest negative prognostic markers in CLL.

CHRONIC MYELOID LEUKEMIA COURSE IN PERSONS EXPOSED TO IONIZING RADIATION AS A RESULT OF THE CHORNOBYL ACCIDENT. / PEREBIG KhRONIChNOÏ MIIeLOÏDNOÏ LEIKEMIÏ U OSIB, IaKI ZAZNALY DIÏ IONIZUIuChOGO VYPROMINIuVANNIa VNASLIDOK ChORNOBYL'S'KOÏ AVARIÏ.

OBJECTIVE: Describe and characterize the peculiarities of the chronic myeloid leukemia (CML) course and responseto treatment in patients irradiated as a result of the Chornobyl nuclear power plant (ChNPP) accident based on theassessment of clinical-laboratory and clinical parameters. MATERIALS AND METHODS: The CML patients (n = 33) exposed to ionizing radiation as a result of the ChNPP accidentwere enrolled. The comparison group consisted of CML patients (n = 725) with no history of radiation exposure. Allpatients were in the chronic phase of the disease. Clinical, hematological and molecular genetic research methodswere applied. RESULTS: Patients exposed to ionizing radiation as a result of the ChNPP accident had no differences in CML manifestation, as well as in classical genetic markers at the onset of the disease compared with patients with no historyof radiation exposure. Reduction of tumor clone on imatinib therapy was significantly less effective in the patientsexposed to ionizing radiation than in cases of no history of radiation exposure. Cases of primary resistance were statistically significantly prevalent in the ChNPP accident consequences clean-up workers while in the residents ofradiologically contaminated areas a statistically significant increase in probability of loss of complete cytogeneticresponse (development of secondary resistance) to imatinib therapy was found. An association was found betweenthe radiation exposure and probability of loss of complete cytogenetic response to imatinib therapy in this group ofpatients. CONCLUSION: The radiation exposure in the history even many years before the onset of CML is an unfavorable exogenous factor responsible for the development of resistance to imatinib therapy.

CHANGES IN GENE EXPRESSION ASSOCIATED WITH NON-CANCER EFFECTS OF THE CHORNOBYL CLEAN-UP WORKERS IN THE REMOTE PERIOD AFTER EXPOSURE. / ZMINY GENNOÏ EKSPRESIÏ, ASOTsIIOVANI Z NEPUKhLYNNYMY EFEKTAMY VIDDALENOGO PERIODU PISLIa OPROMINENNIa V UChASNYKIV LIKVIDATsIÏ NASLIDKIV AVARIÏ NA ChAES.

OBJECTIVE: to establish the connection of radiation-induced changes in gene expression with the realized pathology of the broncho-pulmonary and cardiovascular systems in Chornobyl clean-up workers. MATERIALS AND METHODS: We examined 314 male Chornobyl clean-up workers (main group; age (58.94 ± 6.82) years(M ± SD); min 33, max 79 years; radiation dose (411.82 ± 625.41) mSv (M ± SD); min 1.74, max 3600 mSv) with various nosological forms of cardiovascular and broncho-pulmonary pathology (BPP) and 50 subjects of the controlgroup: age (50.50 ± 5.73) years (M ± SD); min 41, max 67 years. The relative level of BCL2, CDKN2A, CLSTN2, GSTM1,IFNG, IL1B, MCF2L, SERPINB9, STAT3, TERF1, TERF2, TERT, TNF, TP53, CCND1, CSF2, VEGFA genes expression was determined inperipheral blood leukocytes by real-time PCR (7900 HT Fast Real-Time PCR System (Applied Biosystems, USA)). The«gene-disease¼ association was determined on statistical models stratified separately for each disease and gene.Logistic regression was used to calculate the odds ratio. RESULTS: Increased GSTM1 gene expression and no changes in angiogenesis-related VEGFA gene expression werefound in the main group of patients with coronary heart disease (CHD). It was established overexpression of TP53,VEGF and IFNG genes in the group of patients with arterial hypertension (AH). At combination of these diseases anincrease of expression of СSF2, TERF1, TERF2 genes was established. The detected changes demonstrate an activationof the antioxidative defense system in patients with CHD, while AH is associated with the expression of genes ofangiogenesis and immune inflammation. It was shown an increase in the expression of genes associated with apoptosis and kinase activity (BCL2, CLSTN2, CDKN2), immune inflammation (CSF2, IL1B, TNF) in Chornobyl clean-upworkers with BPP. Expression of TP53 and GSTM1 (gene, associated with the glutathione system) was significantlyupregulated in the group of individuals with chronic bronchitis, whereas in patients with chronic obstructive pulmonary disease, no increase was detected; the expression of SERPINB9 and MCF2L genes was downregulated. CONCLUSIONS: Changes in the expression of genes, associated with the development of somatic pathology in theremote period after irradiation, in particular the genes of the immune response and inflammatory reactions CSF2,IFNG, IL1B, TNF; expression of genes that regulate cell proliferation, aging and apoptosis TP53, BCL2, MCF2L, CDKN2A,SERPINB9, TERF1, TERF2, TERT; genes that regulate cell adhesion and angiogenesis CLSTN2, VEGF.

CONTRIBUTION OF THE G1691A ALLELE CARRYING OF THE COAGULATION FACTOR V GENE TO THE DEVELOPMENT OF THROMBOSES IN RADIATION-EXPOSED PATIENTS WITH REACTIVE CHANGES IN PERIPHERAL BLOOD. / VNESOK NOSIISTVA ALEL'NOGO VARIANTA G1691A GENA V FAKTORU KOAGULIaTsIÏ V ROZVYTOK TROMBOTYChNYKh USKLADNEN' V OSIB Z REAKTYVNYMY ZMINAMY U PERYFERIINII KROVI, ShchO ZAZNALY RADIATsIINOGO OPROMINENNIa.

Thrombosis triggers, in addition to «classic¼ risk factors (RFs) of cardiovascular events, includes the reactive changesof peripheral blood (RCPB), markers of the hereditary thrombophilia and radiation anamnesis. However, results ofmost studies suggest the «classic¼ RFs are able to neutralize the prothrombogenic potential of the hereditary thrombophilia and other, less powerful predictors of thrombosis. OBJECTIVE: to determine the influence of the G1691A allele of the proaccelerin gene carrying to the thrombosis development, taking into account the vascular type of their occurrence, the presence of RFs in individuals with RCPB (reactive leukocytosis and thrombocytosis, and secondary erythrocytosis), as well as with and without radiation anamnesis. MATERIAL AND METHODS: In general, it was analyzed the results of clinical and molecular-genetic data of 152 patientswith RCPB, 19 patients had radiation anamnesis, 133 - did not have. The thrombotic complications were detected in5 (26.31 %) of radiation-exposer patients and 25 (18.79 %) patients without radiation anamneses. The carrying ofthe G1691A allele proaccelerin gene (APG) (Leiden mutation (LM)) was detected using the allele-specific polymerasechain reaction. RESULTS: The LM was found in 5.9 % (9 carriers) of the general cohort (GC) of RPBC patients. There were no differencein the LM frequency between the groups of patients with and without radiation anamnesis (р = 0.312). In the groupof radiation-exposer patients (р = 0.017), as well as in the group without its (р = 0.031), venous thromboses only weremore frequently in the LM carriers. In the presence of a radiation anamnesis, G1691A APG carriers with RFs have thehigher frequency (р = 0.008) and the probability of the occurrence (relative risk [RR] = 25.00; CI 95 %: 1.56-399.68)of venous thrombosis. In the group without radiation anamnesis, the frequency of venues thrombosis in the LMcarriers is higher in the younger age subgroup (р = 0.001), without RFs (p = 0.044) and without RFs under 60 years(р = 0.023). The risk of venous thrombosis in the G1691A APG carriers of the group without radiation anamnesis is5.78 (95 % CI: 1.58-21.13). In LM carriers without radiation anamnesis and RFs, as well as under the 60 years of age,the probability of venous thrombosis was 6.85 (95 % CI: 1.86-25.22) and 19.40 (95 % CI: 4.64-81.09), respectively,and in the absence of both criteria - 9.57 (95 % CI: 2.49-36.73). CONCLUSIONS: In patients with and without radiation anamnesis, the risk of venues thrombosis are observed moreoften in carriers of LM. The carrying of the G1691A APG in patients with RPBC and without RA increased the risk ofvenues thrombosis development in subjects without FRs and below 60 years of age. In the radiation-exposure group,the frequency and the risk of venues thrombosis in the G1691A APG carriers was higher in the subgroup with RFs. It isprobably due to the peculiarity of the samples, or prothrombogenic interaction between LM and radiation-associated endothelial damage.

Low-Dose Radiation Exposure with 56MnO2 Powder Changes Gene Expressions in the Testes and the Prostate in Rats.

To investigate the biological effects of internal exposure of radioactive 56MnO2 powder, the major radioisotope dust in the soil after atomic bomb explosions, on male reproductive function, the gene expression of the testes and the prostate was examined. Ten-week-old male Wistar rats were exposed to three doses of radioactive 56MnO2 powder (41-100 mGy in whole body doses), stable MnO2 powder, or external 60Co γ-rays (2 Gy). Animals were necropsied on Days 3 and 61 postexposure. The mRNA expressions of testicular marker protein genes and prostatic secretory protein genes were quantified by Q-RT-PCR. On Day 3 postexposure, the testicular gene expressions of steroidogenesis-related enzymes, Cyp17a1 and Hsd3b1, decreased in 56MnO2-exposed groups. Germ cell-specific Spag4 and Zpbp mRNA levels were also reduced. On postexposure Day 61, the Cyp11a1 gene expression became significantly reduced in the testes in the group exposed to the highest dose of 56MnO2, while another steroidogenesis-related StAR gene mRNA level reduced in the 60Co γ-rays group. There were no differences in Spag4 and Zpbp mRNA levels among groups on Day 61. No histopathological changes were observed in the testes in any group following exposure. Expression in the prostatic protein genes, including CRP1, KS3, and PSP94, significantly decreased in 56MnO2-exposed groups as well as in the 60Co γ-rays group on Day 61 postexposure. These data suggest that the internal exposure to 56MnO2 powder, at doses of less than 100 mGy, affected the gene expressions in the testis and the prostate, while 2 Gy of external γ-irradiation was less effective.

External Cesium-137 doses to humans from soil influenced by the Fukushima and Chernobyl nuclear power plants accidents: a comparative study.

External exposure to gamma-photon irradiation from soil contamination due to nuclear power plant (NPP) accidents has significant contribution to human radiation exposure in the proximity of the NPP. Detailed absorbed doses in human organs are rarely reported in the literature. We applied the Monte Carlo Neutron Particle (MCNP) transport code to calculate and compare the absorbed doses in different human organs. The absorbed doses by gamma-photon radiation were from cesium-137 (137Cs) in soil contaminated by the two major NPP accidents. More serious and wide-spread impacts of the Chernobyl NPP accident on soil contamination in Ukraine, Belarus, Russia and countries as far as Sweden and Greece were due to the inland location, radiative plume transport pathway and high 137Cs emission strength (9 times the Fukushima emission). Based on our MCNP calculations, the largest absorbed dose was found in skin. The maximum calculated external 137Cs annual effective dose received from the Chernobyl accident was 10 times higher relative to the Fukushima accident. Our calculated effective doses at various influenced areas were comparable to those available in the literature. The calculated annual effective doses at areas near the Fukushima and Chernobyl NPPs exceeded the ICRP recommendation of 1 mSv yr-1.

Radon concentration in hydrogeothermal deposit and spas of Boyacá, Colombia.

Inhaled radon and its progenies induce health concern due to high activity-concentration in selected thermal spas of Boyacá region. Hydrogeothermal water sources in a high risk seismic area, are studied to determine by water bubbling method radon concentration values; their occurrence is between few hundreds and 2000 Bq dm-3. Deposits, existing in this area, reach at the surface soil gas radon concentration up to 210 kBq m-3. Maintenance workers, health tourists and visitor's possible detrimental health effects, are discussed in relation to radon balneotherapy beneficial aspects.

Risk assessment due to various terrestrial radionuclides concentrations scenarios.

PURPOSE: The purpose of this paper is to evaluate the morbidity excess cancer risk (ECR) due to internal and external exposure to three category levels of natural radionuclides in soil like 238U, 232Th and 40K. Although the exposure rate in soil is low but effect this radiation over time can lead to cancer risk and this risk can be calculated. MATERIALS AND METHODS: Natural activity concentration levels of 40K, 238U and 232Th in soil were selected from last reports in three concentration categories including: low, medium and high levels. The excess cancer risks of three concentration levels were calculated by means of RESidual-RADioactivity (RESRAD) code. RESULTS AND CONCLUSIONS: The calculated average morbidity ECR from 40K, 238U and 232Th in three concentration categories levels in soil were 1.40 × 10-4, 8.56 × 10-4 and 1.35 × 10-3, respectively. This calculation shows that the excess cancer risk value is the highest value in 100 years' time in all categories. Overall ECR from 40K radionuclide was maximal and the highest exposure pathways was through plant pathway; however, these pathway changes over 60 years to the drinking water pathway. The results of this study may be useful to risk assessment and for decision making for public health protection against high-level radiation.

Estimation of the cumulative cancer risk of female children attributable to radiocaesium in soil in an evacuation zone, prior to their return.

The Fukushima Daiichi accident highlighted the difficulty in making good decisions regarding post-accident actions for the protection of members of the public. Discussions are continuing between the authorities and the residents about 'how safe is safe'. Although governmental officials have argued that 20 mSv per year is a safe level of exposure, many residents have expressed strong doubts, and one of their major concerns is the greater health risk of radiation exposure for children. For settling this controversy, the author has demonstrated risk projections for cancer mortality of female children (0 to 18 years old) resulting from four different levels of radiocaesium deposits on the ground. The results showed that, for female children, the cumulative lifetime attributable risk of cancer mortality due to 18-years external radiation exposure from radiocaesium in soil would be 0.9% for 134Cs and 2.4% for 137Cs for an initial annual dose of 20 mGy/year; when the initial dose was 5 mGy/year, the cumulative lifetime cancer risk would be 0.2% and 0.6% for 134Cs and 137Cs, respectively. These results indicate the critical importance of accurate information about the composition and behavior of major radionuclides released to the environment, as well as precise dose monitoring and risk coefficients, for proper decision-making regarding protective actions for members of the public.

Natural radioactivity levels and associated health hazards from the terrestrial ecosystem in Rosetta branch of the River Nile, Egypt.

Twenty soil and 25 sediment samples were collected from the banks and bottom of the River Nile in the surroundings of biggest cities located close to it. Natural radioactivity concentrations of 226Ra, 232Th and 40K have been evaluated for all samples by means of γ spectrometric analysis. The radioactivity levels of soil and sediment samples fall within the internationally recommended values. Nevertheless, high natural background radiation zones are detected in the Kafr El-Zayat region due to the presence of a fertilizer factory, and in the Rosetta region due to the presence of black sand deposits. The absorbed dose rate, the γ index and excess life time cancer risk are calculated. High values for some of the radiation health parameters are detected in the Kafr El-Zayat and Rosetta regions representing a serious problem to public health because the soil and sediment are used as constructing material for buildings. Furthermore, the isotope analysis of uranium for representative collected sediment samples via α spectrometry showed average specific activities of 18.7 ± 3.6, 0.087 ± 0.0038 and 18.6 ± 3.8 Bq kg-1 for 234U, 235U and 238U, respectively. In general, these values confirm the balance in the isotopic abundance of U isotopes.

[Spatial Distribution of ¹³7Cs in Soil of Spruce Forest in the Distant Zone of Chernobyl Fallout].

The vertical distribution of ¹³7Cs in Albeluvisols of the spruce forest in the Roslavl district of Smolensk region was investigated. The statistical characteristics of spatial variability and distribution laws for the activity con- centrations and activity depositions of ¹³7Cs in upper soil layers (forest litter, 0-5, 5-10, 10-19 cm) were de- termined. Positive correlations between the height, crown length of spruce trees and the content of ¹³7Cs in the soil under them were revealed. The regularities of spatial configuration of ¹³7Cs contamination in soil were related to the parcel structure of spruce forest. The lateral trends for distribution of 137Cs along the tessers un- der spruce and during the transfer to the open positions between the trees were recorded.

[Current Activity Levels of Artificial Radionuclides in Water Facilities Located at the Semipalatinsk Test Site].

The current data of radioecological research within the Semipalatinsk test site (STS) are presented in the pa- per. It has been shown that almost 90% of polygon lands can be returned to the national economy. Waters of water facilities located at conditionally "background" territories of the STS do not present a radiation hazard to population. Waters of the potential water facilities located close to the radiation hazardous facilities have an increased level of the specific activity of individual radionuclides. Recommendations for the radiological assessment of the quality of waters in water facilities located near radiation hazardous facilities and adjacent territories of STS are offered in the article.

[Ecological-hygienic evaluation of the environment of territories being adjacent to decultivated uranium mines].

On the territory of Kazakhstan there are uranium deposits, many ofwhich are in mothballed since times of perestroika. Often, the mines are flooded and represent a "time-delay bomb". Inside of mines various there are accumulated gases of both organic and inorganic nature, periodically thrown out and adversely affecting on the health of local populations. The aim of the study was the investigation of the state of the environment of Esilsky district of the Akmola region by common pollutants and chemicals. As the basic variable for the investigation of ambient air there was accepted the maximum one-time concentration of suspended substances, phenol, nitrogen dioxide, sulfur dioxide. The results were evaluated in relation to the MPC for the analyzed substance in the air according to maximal single MPC (MPCms) and daily average MPC (MPCda). The content of metals in the water was determined with the use of spectrophotometer PD-303S. Evaluation of the results was executed in relation of the MPC of substances in water, by means of the comparison with the requirements of Federal standards for drinking water, samples from drinking water sources. There were executed calculations of the overall index of water pollution (IWVgen), the index of water pollution by heavy metals (IWVhm). Chemical analysis of soil was carried out with the use of spectrophotometer PD- 303S (Japan), the photometer expert-003 "Ekoniks". Evaluation of the results was carried out with the respect to the MPC in the soil, the toxicity of all components. Summarizing soil pollution index was evaluated for metals contained in the soil at the level of more than or equal to 1 MAC. The settlement Krasnogorskiy and the village of Kalachi were found to be characterized by a low level of air pollution, increased rigidity of drinking water exceeded the maximum permissible concentrations of copper by 3.45 times and chloride by 1.17 times in the soil cover.

Influence of soil structure on the "Fv approach" applied to 238U and 226Ra.

The soil-to-plant transfer factors were determined in a granitic area for the two long-lived uranium series radionuclides 238U and 226Ra. With the aim to identify a physical fraction of soil whose concentration correlates linearly with the plant concentration, the soil compartment was analyzed in various stages. An initial study identified the soil compartments as being either bulk soil or its labile fraction. The bulk soil was subsequently divided into three granulometric fractions consisting of: coarse sand, fine sand, and silt and clay. The soil-to-plant transfer of radionuclides for each of these three texture fractions was analyzed. Lastly, the labile fraction was extracted from each textural part, and the activity concentration of the radionuclides 238U and 226Ra was measured. In order to assess the influence of soil texture on the soil-to-plant transfer process, we sought to identify possible correlations between the activity concentration in the plant compartment and those found in the different fractions within each soil compartment. The results showed that the soil-to-plant transfer process for uranium and radium depends on soil grain size, where the results for uranium showed a linear relationship between the activity concentration of uranium in the plant and the fine soil fraction. In contrast, a linear relation between the activity concentration of radium in the plant and the soil coarse-sand fraction was observed. Additionally, the presence of phosphate and calcium in the soil of all of the compartments studied affected the soil-to-plant transfer of uranium and radium, respectively.

Estimated association between dwelling soil contamination and internal radiation contamination levels after the 2011 Fukushima Daiichi nuclear accident in Japan.

OBJECTIVES: Measurement of soil contamination levels has been considered a feasible method for dose estimation of internal radiation exposure following the Chernobyl disaster by means of aggregate transfer factors; however, it is still unclear whether the estimation of internal contamination based on soil contamination levels is universally valid or incident specific. METHODS: To address this issue, we evaluated relationships between in vivo and soil cesium-137 (Cs-137) contamination using data on internal contamination levels among Minamisoma (10-40 km north from the Fukushima Daiichi nuclear power plant), Fukushima residents 2-3 years following the disaster, and constructed three models for statistical analysis based on continuous and categorical (equal intervals and quantiles) soil contamination levels. RESULTS: A total of 7987 people with a mean age of 55.4 years underwent screening of in vivo Cs-137 whole-body counting. A statistically significant association was noted between internal and continuous Cs-137 soil contamination levels (model 1, p value <0.001), although the association was slight (relative risk (RR): 1.03 per 10 kBq/m(2) increase in soil contamination). Analysis of categorical soil contamination levels showed statistical (but not clinical) significance only in relatively higher soil contamination levels (model 2: Cs-137 levels above 100 kBq/m(2) compared to those <25 kBq/m(2), RR=1.75, p value <0.01; model 3: levels above 63 kBq/m(2) compared to those <11 kBq/m(2), RR=1.45, p value <0.05). CONCLUSIONS: Low levels of internal and soil contamination were not associated, and only loose/small associations were observed in areas with slightly higher levels of soil contamination in Fukushima, representing a clear difference from the strong associations found in post-disaster Chernobyl. These results indicate that soil contamination levels generally do not contribute to the internal contamination of residents in Fukushima; thus, individual measurements are essential for the precise evaluation of chronic internal radiation contamination.

[Tritium in the Water System of the Techa River].

The aim of the paper is to study modern tritium levels in various sources of the drinking water supply in the settlements situated in the riverside zone of the Techa. Almost everywhere the water entering water-conduit wells from deep slits (100-180 m) contains averagely 2-3 times higher tritium concentrations than the water from less deep personal wells, slits and springs. Tritium levels in the drinking water supply decrease with the distance from the dam; while in wells, springs and personal wells they are constant all along the river. The observed phenomenon can be explained by the fact that the river bed of the Techa is situated at a break zone of the earth crust, where the contaminated deep water penetrates from the reservoirs of the "Mayak" enterprise situated in the upper part of the regulated river bed. Less deep water sources (personal wells, slits and springs) receive predominantly flood, atmospheric and subsoil waters and are not connected with the reservoirs.

Radon levels in drinking water and soil samples of Jodhpur and Nagaur districts of Rajasthan, India.

Radon causes lung cancer when it is trapped inside the lungs. Therefore it is very important to analyze the radon concentration in water and soil samples. In the present investigation, water and soil samples collected from 20 different locations of Jodhpur and Nagaur districts of Northern Rajasthan, India have been studied by using RAD7. The measured radon concentration in water samples varies from 0.5 to 15Bql(-1). The observed values lie within the safe limit as set by UNSCEAR, 2008. The total annual effective dose due to radon in water corresponding to all studied locations has been found to be well within the safe limit of 0.1mSvy(-1) as recommended by World Health Organization (WHO, 2004) and European Council (EU, 1998). The measurements carried out on radon concentration in soil samples reveal a variation from 1750 to 9850Bqm(-3). These results explore that the water of Jodhpur and Nagaur districts is suitable for drinking purpose without posing any health hazard but soil hazards depend upon its permeability and radon concentration.

The impact of low and intermediate-level radioactive waste on humans and the environment over the next one hundred thousand years.

In order to assess the potential radiological risk to humans and the environment from a geological repository for radioactive waste, a safety assessment must be performed. This implies that the release and transfer of radionuclides from the repository into the surface environment are calculated and that the effects in the biosphere are evaluated for an assessment period up to one hundred thousand years according to Swedish regulations. This paper discusses the challenges associated with the modelling of surface ecosystems over such long time scales, using the recently completed assessment for the extension of the existing repository for the low- and intermediate-level nuclear waste (called SFR) in Forsmark, Sweden as an applied example. In the assessment, natural variation and uncertainties in climate during the assessment period were captured by using a set of climate cases, primarily reflecting different expectations on the effects of global warming. Development of the landscape at the site, due to post-glacial isostatic rebound, was modelled, and areas where modelling indicated that radionuclides could discharge into the biosphere were identified. Transfers of surface water and groundwater were described with spatially distributed hydrological models. The projected release of radionuclides from the bedrock was then fed into a biosphere radionuclide transport model, simulating the transport and fate of radionuclides within and between ecosystems in the landscape. Annual doses for human inhabitants were calculated by combining activity concentrations in environmental media (soil, water, air and plants) with assumptions on habits and land-use of future human inhabitants. Similarly, dose rates to representative organisms of non-human biota were calculated from activity concentrations in relevant habitats, following the ERICA methodology. In the main scenario, the calculated risk for humans did not exceed the risk criteria or the screening dose rate for non-human biota, indicating that the repository design is sufficient to protect future populations and the environment. Although the combination of radionuclides, land-uses/habitats, type of most exposed population and area of exposure that contribute most to the total dose shifts over time, the total calculated dose shows limited variability. Significant reductions in the dose only occur during submerged periods and under periglacial climate conditions. As several different water and food pathways were equally important for endpoint results, it is concluded that it would be difficult to represent the biosphere with one or a set of simplified models. Instead, we found that it is important to maintain a diversity of food and water pathways, as key pathways for radionuclide accumulation and exposure partly worked in parallel.

Radioecological impacts of tin mining.

The tin mining activities in the suburbs of Jos, Plateau State, Nigeria, have resulted in technical enhancement of the natural background radiation as well as higher activity concentrations of primordial radionuclides in the topsoil of mining sites and their environs. Several studies have considered the radiological human health risks of the mining activity; however, to our knowledge no documented study has investigated the radiological impacts on biota. Hence, an attempt is made to assess potential hazards using published data from the literature and the ERICA Tool. This paper considers the effects of mining and milling on terrestrial organisms like shrubs, large mammals, small burrowing mammals, birds (duck), arthropods (earth worm), grasses, and herbs. The dose rates and risk quotients to these organisms are computed using conservative values for activity concentrations of natural radionuclides reported in Bitsichi and Bukuru mining areas. The results suggest that grasses, herbs, lichens, bryophytes and shrubs receive total dose rates that are of potential concern. The effects of dose rates to specific indicator species of interest are highlighted and discussed. We conclude that further investigation and proper regulations should be set in place in order to reduce the risk posed by the tin mining activity on biota. This paper also presents a brief overview of the impact of mineral mining on biota based on documented literature for other countries.