Determination of Activity Concentration of Natural Radionuclides and Radiation Hazards' Assessment of Building Materials in High Background Radiation Areas of Homa and Ruri, Kenya.

The areas around Homa and Ruri hills in Homa Bay County in Kenya are associated with high background radiation levels. The activity concentration of the natural radionuclides (226Ra, 232Th, and 40K) in earthen building materials used in the areas of Homa and Ruri hills has been measured using a NaI (Tl) detector in this work. The measured values of radioactivity concentrations are used to estimate the associated radiological risk. The earthen building material samples from Ruri registered relatively high 232Th concentration values averaging 1094 ± 55 Bq/kg, nearly three times those of the samples from Homa. 226Ra level was not significantly different in both regions with Homa reporting 129 ± 10 Bq/kg and Ruri 111 ± 6 Bq/kg. 40K was however higher in the samples from Homa by an approximate factor of 2 relative to those from Ruri where the activity concentration was 489 ± 24 Bq/kg. The radium equivalents for 226Ra, 232Th, and 40K in the samples from Ruri were 111 ± 9, 1564 ± 125, and 38 ± 3 Bq/kg, while in Homa, the values were 129 ± 10, 570 ± 46, and 69 ± 5 Bq/kg, respectively. The calculated value of total radium equivalent in Ruri was 1713 ± 137 Bq/kg which was two times higher than that of Homa. 232Th contributed about 74% and 91% to the total radium equivalent in Homa and Ruri, respectively; thus, it was the one with the largest contribution to radiation exposure in both regions. The average indoor annual effective dose rates were 1.74 ± 0.14 and 3.78 ± 0.30 mSv/y in Homa and Ruri, respectively, both of which were above the recommended safety limit of 1 mSv/y.

Uranium induces genomic instability and slows cell cycle progression in human lymphocytes in acute toxicity study.

In the situation of radiation triage, accidental exposure to uranium, or uranium contamination in food or water; haematopoietic decline or bone marrow sickness is observed in the aftermath followed by other systemic effects. Most studies done previously have been on cytogenetic analysis in blood lymphocytes of uranium miners wherein causal relationship was difficult to be established. This study provides new insights into the minimum risk level of uranium to human lymphocytes, DNA damage induced and alterations in the cell cycle progression through 96-h acute toxicity study. Cytotoxicity studies by MTT assay and flow cytometry showed that uranyl nitrate concentration of 1280 µM lead to 50% cell death, 640 µM caused 25% death, 250 µM caused 10% cell death and 5 µM was the NOAEL. Uranium caused DNA damages in a dose dependent manner as evident from comet and CBMN assays. A marked increase in G2/M phase cells was observed in the test culture groups. Halting of cell cycle at G2/M checkpoint also signified the extent of double strand breaks and genetic instability with increasing uranium dose in this study. Better cell cycle responses and lower genetic damage index observed in lower dosage of exposure, suggests adaptability and repair responses in human lymphocytes. Together these results advance our understanding of uranium effects on mammalian cells.

PROBLEMS OF RADIO SAFETY OF THE POPULATION OF THE ZAPORIZHZHIA REGION WHICH RELATES TO EXPOSURE TO BASIC SOURCES (by review of the literature). / PROBLEMY RADIATsIY̆NOÏ BEZPEKY NASELENNIa ZAPORIZ'KOÏ OBLASTI, IaKE ZAZNAIe OPROMINENNIa VID OSNOVNYKh DZhEREL (za ogliadom literatury).

The analysis of scientific literature is carried out in order to generalize the data of many years of research on radioe- cology of the environment of the population of the Zaporizhzhia region. The results of researches on the main sources of radioactive contamination of the territory, levels and structure of radiation doses of the population due to the natural radiation, diet, medical procedures, and the dose burden of the population are estimated. The main sources of radiation sources existing in the Zaporizhzhia region are considered, their characteristics are given, the rate of their influence on the environment and human is given. For this purpose a wide range of official literary sources and own researches were used.The Zaporizhzhia region is located in the south-eastern part of Ukraine and remarcable of the geomorphological structure, which is characterized by the presence of Ukrainian crystalline array enriched with minerals with an ele- vated level of natural radioactivity. This explains the large component of the radiation dose of the population due to the natural component. Total medieval efficiency of the population dosage of the Zaporizhzhia region at the expense of the natural component - 4,37 mSv, the main contribution to this dose is Radon-222 - 76 %. The level of radon-222 in the air of residential premises ranges from 37 to 112 Bq·m-3. Moreover, the percentage of exceeding the norm (100 Bq·m-3) is from 8% to 62%, depending on the administrative district. On average, 25 % of residential buildings in the region do not match the requirements of NRSU-97 regarding the content of radon in the air of the premises. Even more acute problem of the increased Radon radiation appears for the children's population. Due to the more stringent requirements of NRSU-97 regarding Radon content in the air of premises of preschool education- al institutions (PEI) (50 Bq·m-3), 99% of the premises of the PEI do not match the standards. Doses of children radi- ation because of Radon are higher than in adults and amounted to an average of 6.4 mSv per year with a spread of 4.3-9.7 mSv.The second place after Radon exposure to Zaporozhia region is a medical exposure. The analysis of patient dose loads in recent years suggests that the annual dose of irradiation of the population fluctuates in the range of 0.86-0.97 mSv·year-1, the average dose of irradiation is 0.9 mSv·year-1, which is almost 50 % more than the average Ukrainian rate and exceeds the average in the world twice.In the Zaporizhzhia region, the total annual radiation dose of the population due to the main sources of radiation is 5.0 mSv·year-1, with the main contribution of Radon-222 - 3.3 mSv and medical exposure - 0.9 mSv. Radon-222 in the air of the premises is the most important radiation factor for the population of Zaporizhzhia region, which creates an average risk level that is unacceptable for the population and requires careful regulatory control with the help of governmental and regional programs.

Advances on the toxicity of uranium to different organisms.

The extensive application of radioactive element uranium (U) and its compounds in the nuclear industry has significantly increased the risk of exposure to the environment. Therefore, research on the safety risks and toxicity mechanisms of U exposure has received increasing attention. This paper reviews the toxic effects of U on different species under different conditions, and summarizes the potential toxicity mechanisms. Under the exposure of U, reactive oxygen species (ROS) produced in cells will damage membrane structure in cells, and inhibit respiratory chain reaction by reducing the production of NADH and ATP. It also induce the expression of apoptosis factors such as Bcl-2, Bid, Bax, and caspase family to cause apoptosis cascade reaction, leading to DNA degradation and cell death. We innovatively list some methods to reduce the toxicity of U because some microorganisms can precipitate uranyl ions through biomineralization or reduction processes. Our work provides a solid foundation for further risk assessment of U.

Physiological effects of gamma irradiation in the honeybee, Apis mellifera.

Terrestrial ecosystems are exposed to various kinds of pollutants, including radionuclides. The honeybee, Apis mellifera, is commonly used in ecotoxicology as a model species for evaluating the effects of pollutants. In the present study, honeybees were irradiated right after birth for 14 days with gamma rays at dose rates ranging between 4.38 × 10-3 and 588 mGy/d. Biological tissues (head, intestine and abdomen) were sampled at D3, D10 and D14. Ten different physiological markers involved in nervous (acetylcholinesterase (AChE)), antioxidative (catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx) and glutathione-S-transferase (GST)), immune system (phenoloxidase (PO)) and metabolism (carboxylesterases (CaEs) and alkaline phosphatase (ALP)) were measured. Univariate analyses were conducted to determine whether each individual biomarker response was positively or negatively correlated with the dose rate. Then, multivariate analyses were applied to investigate the relationships between all the biomarker responses. Although no mortality occurred during the experiment, several biomarkers varied significantly in relation to the dose rate. Globally, the biomarkers of antioxidant and immune systems decreased as the dose rate increased. Reversible effects on the indicator of the neural system were found. Concerning indicators of metabolism (carboxylesterases), variations occurred but no clear pattern was found. Taken altogether, these results help better understand the effects of ionizing radiation on bees by identifying relevant physiological markers of effects. These results could improve the assessment of the environmental risk due to ionizing radiation in terrestrial ecosystems.

Cancer incidence surrounding the former Apollo nuclear facility 1990-2010.

Environmental radiation releases from a nuclear fuel fabrication facility in Apollo, Pennsylvania may have exposed the surrounding population to ionizing radiation. This study characterizes cancer incidence in the population living near the nuclear facility between 1990 and 2010. Cancer incidence in the minor civil divisions surrounding the Apollo facility was compared to a standard population of the state of Pennsylvania adjusted for calendar year, age, sex, and race. Bias due to residential misclassification was considered by adjustment of case count. We also evaluated whether birth cohort effects or changes in population distribution over time affected the standardized incidence rate ratio (SIR). From 1990 to 2010, the observed rate of cancer incidence among males in the Apollo area was 1.56 (95% CI 1.47-1.66) times the expected cancer rate, and among females was 1.38 (95% CI 1.30-1.47) times the expected cancer rate. Accounting for residential misclassification, the SIR for males and females combined was 1.16 (95% CI 1.10-1.21). Residents who were members of earlier birth cohorts had similar SIRs to those born later. This research suggests that cancer incidence among the population surrounding the former Apollo nuclear facility is greater than expected based on statewide rates.

Elevated serum chemokines are independently associated with both endometriosis and uranium exposure.

Endometriosis is a complex disease impacted by the hormonal and immune systems. Cytokines and chemokines are serum biomarkers that maybe useful to develop a noninvasive disease diagnosis. Individuals in the Fernald Community Cohort were exposed to uranium, a heavy metal with radioactive properties and estrogenic potential; therefore, serum samples from women in this cohort with or without uranium and with or without endometriosis were compared for alterations in chemokine, cytokine, and matrix metalloproteinase (MMP) levels. Control women were matched to endometriosis cases by uranium exposure, age, and body mass index. MMP levels were not altered. Five chemokines and one cytokine significantly increased in endometriosis cases versus controls irrespective of uranium exposure. Uranium exposure alone was associated with an increase in inflammatory chemokines. The majority of the elevated chemokines in endometriosis cases play important roles in attracting T helper-2 cells, which may be vital to understanding the immune response in endometriosis.

Metal-organic framework-based materials: superior adsorbents for the capture of toxic and radioactive metal ions.

Highly efficient removal of metal ion pollutants, such as toxic and nuclear waste-related metal ions, remains a serious task from the biological and environmental standpoint because of their harmful effects on human health and the environment. Recently, highly porous metal-organic frameworks (MOFs), with excellent chemical stability and abundant functional groups, have represented a new addition to the area of capturing various types of hazardous metal ion pollutants. This review focuses on recent progress in reported MOFs and MOF-based composites as superior adsorbents for the efficient removal of toxic and nuclear waste-related metal ions. Aspects related to the interaction mechanisms between metal ions and MOF-based materials are systematically summarized, including macroscopic batch experiments, microscopic spectroscopy analysis, and theoretical calculations. The adsorption properties of various MOF-based materials are assessed and compared with those of other widely used adsorbents. Finally, we propose our personal insights into future research opportunities and challenges in the hope of stimulating more researchers to engage in this new field of MOF-based materials for environmental pollution management.

Progress Toward Rice Seed OMICS in Low-Level Gamma Radiation Environment in Iitate Village, Fukushima.

Here, we present an update on the next level of experiments studying the impact of the gamma radiation environment, created post-March, 2011 nuclear accident at Fukushima Daiichi nuclear power plant, on rice plant and its next generation-the seed. Japonica-type rice (Oryza sativa L. cv. Koshihikari) plant was exposed to low-level gamma radiation (~4 µSv/h) in the contaminated Iitate Farm field in Iitate village (Fukushima). Seeds were harvested from these plants at maturity, and serve as the treated group. For control group, seeds (cv. Koshihikari) were harvested from rice grown in clean soil in Soma city, adjacent to Iitate village, in Fukushima. Focusing on the multi-omics approach, we have investigated the dry mature rice seed transcriptome, proteome, and metabolome following cultivation of rice in the radionuclide contaminated soil and compared it with the control group seed (non-radioactive field-soil environment). This update article presents an overview of both the multi-omics approach/technologies and the first findings on how rice seed has changed or adapted its biology to the low-level radioactive environment.

Experience and the results of emergency management of the 1957 accident at the Mayak Production Association.

The experience accumulated while dealing with the aftermath of a major nuclear accident (the 'Kyshtym Accident') in 1957 at the Mayak complex in the Southern Urals of Russia is summarised. Information is presented on the causes of the accident, on the radiation environment and radioactive contamination of the affected territory in the critical period, and on the system of emergency management and decision-making adopted when dealing with the accident and its aftermath. The technical and organisational approaches applied and methods used are described, as well as remediation results and the current situation 60 years after the accident. It is demonstrated that the implementation of fairly simple and self-evident organisational and technical solutions gave good results, and that appropriate timely and task-oriented measures were applied. Safety relevant conclusions and recommendations are presented.

Proteogenomic insights into uranium tolerance of a Chernobyl's Microbacterium bacterial isolate.

Microbacterium oleivorans A9 is a uranium-tolerant actinobacteria isolated from the trench T22 located near the Chernobyl nuclear power plant. This site is contaminated with different radionuclides including uranium. To observe the molecular changes at the proteome level occurring in this strain upon uranyl exposure and understand molecular mechanisms explaining its uranium tolerance, we established its draft genome and used this raw information to perform an in-depth proteogenomics study. High-throughput proteomics were performed on cells exposed or not to 10µM uranyl nitrate sampled at three previously identified phases of uranyl tolerance. We experimentally detected and annotated 1532 proteins and highlighted a total of 591 proteins for which abundances were significantly differing between conditions. Notably, proteins involved in phosphate and iron metabolisms show high dynamics. A large ratio of proteins more abundant upon uranyl stress, are distant from functionally-annotated known proteins, highlighting the lack of fundamental knowledge regarding numerous key molecular players from soil bacteria. BIOLOGICAL SIGNIFICANCE: Microbacterium oleivorans A9 is an interesting environmental model to understand biological processes engaged in tolerance to radionuclides. Using an innovative proteogenomics approach, we explored its molecular mechanisms involved in uranium tolerance. We sequenced its genome, interpreted high-throughput proteomic data against a six-reading frame ORF database deduced from the draft genome, annotated the identified proteins and compared protein abundances from cells exposed or not to uranyl stress after a cascade search. These data show that a complex cellular response to uranium occurs in Microbacterium oleivorans A9, where one third of the experimental proteome is modified. In particular, the uranyl stress perturbed the phosphate and iron metabolic pathways. Furthermore, several transporters have been identified to be specifically associated to uranyl stress, paving the way to the development of biotechnological tools for uranium decontamination.

[Frequency of Lymphocytes with Mutations at the Locus of T-Cell Receptor in Residents of Radiation Polluted Bryansk Region 28 Years after the Chernobyl Nuclear Power Plant Accident].

The aim of this study is to assess the level of somatic mutagenesis according to the frequency of lymphocytes bearing mutations at the locus of T-cell receptor (TCR) in the residents of the Bryansk region contaminated with radionuclides as a result of the Chernobyl accident. The study was :conducted in 2014 in two regional centers - Klintsy and Novozybkov (average¹³7Cs pollution density of 322 and 708 kBq/m²,.respectively). The average frequency of the TCR-mutant cells in the total group of examined residents of the Bryansk region (n = 237) was not significantly different from that in the group of agematched control persons living in un- contaminated areas (n = 146): 3.8 x 10⁻4 vs 3.5 x 10⁻4, respectively (p = 0.84). However, after separation of examinees into 3 groups depending on age at the start of irradiation (at.the moment of the Chernobyl acci- dent) it was found that the average frequency of the TCR-mutant cells in the persons exposed in utero was 1.6 higher than that in the control group (p = 0.04). Proportion of persons with an increased frequency of the mutant cells (more than the age norm of this indicator) among prenatally exposed population reached 23.8%; which was about.4 times higher than in the control group (p = 0.04). Proportion of persons with an increased frequency of the TCR-mutant cells in group "0-17 years at the start of irradiation", was about 2 times higher than in controls, but this difference was not statistically significant (8.0% vs 4.3%, respectively, p = 0.33). In the third group "18 or more years old at the start of irradiation" we could not register the difference in the average frequency of theTCR mutant cells or the proportion of persons with an increased frequency of these cells in comparison with the age-matched control group. In general, comparison with earlier data shows that age-related regularities of somatic mutagenesis established 15-18 years after the Chernobyl accident persist at a later date (after 28 years in this study).

Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) in the Oil and Gas Industry: A Review.

Radiation is part of the natural environment: it is estimated that approximately 80 % of all human exposure comes from naturally occurring or background radiation. Certain extractive industries such as mining and oil logging have the potential to increase the risk of radiation exposure to the environment and humans by concentrating the quantities of naturally occurring radiation beyond normal background levels (Azeri-Chirag-Gunashli 2004).

Urine uranium concentrations and renal function in residents of the United States--2001 to 2010.

CONTEXT: Animal model studies have demonstrated that subchronic oral uranium exposure is associated with renal dysfunction. Little is known about the effects of environmental exposure to uranium in humans. OBJECTIVE: To determine whether environmental exposure to uranium is associated with alterations in renal function among residents of the United States. METHODS: We analyzed data from the National Health and Nutrition Examination Survey (NHANES) 2001-2010. Inclusion criteria included the measurement of urine uranium concentration, serum creatinine (sCr), and urine albumin-creatinine ratio. Exclusion criteria included a reported history of diabetes mellitus. Urine uranium concentrations were normalized to urinary creatinine. Respondents with and without detectable urine uranium concentrations were compared using Welch's t-test for urine albumin-creatinine ratio and sCr and using Fisher's exact test for a reported history of renal disease. Regression analysis was performed to assess for an association between urine uranium concentration and urine albumin-creatinine ratio, sCr, or a reported history of renal disease. RESULTS: Uranium was detectable in the urine of 74.1% (n = 9025) of respondents. Urine albumin-creatinine ratio was significantly greater in respondents with detectable urine uranium concentrations (mean 4.84 ± 45.8 mg/g) compared to respondents without detectable urine uranium concentrations (mean 0.77 ± 3.7 mg/g) (p < 0.001). There was no significant difference between the groups with respect to sCr or a reported history of renal disease. Regression analysis did not show a statistically significant association between urine uranium concentration and urine albumin-creatinine ratio (p = 0.45), sCr (p = 0.71), or a reported history of renal disease (p = 0.05). CONCLUSIONS: In this study, a high proportion of the U.S. population had exposure to uranium. We demonstrated an association between detectable urine uranium concentrations and microalbuminuria in residents of the United States but no association with clinical renal disease.

[Evaluation of Reproductive Health of Chickens and Their Progeny at a Chronic Effect of 131I].

A reproductive health of hens exposed to 131I in a 30-day period with daily quantities ranging from 0.11 to 4.6 MBq/kg and 6 progenies of their offspring was evaluated. We determined that 131I did not change significantly the reproductive potential of hens if administered at a dose of 0.11 MBq, while it raised at 1.1 MBq, progressively decreased after a short-time increase at 2.1 MBq and was inhabited up to its irreversible extinction at 4.6 MBq. Irrespective of the isotope quantity administered, a decline occurred in the birth rate of the progeny where hens dominated in the sex composition. The reproductive potential (i.e., laying capacity) of the offspring of three chicken progenies that had been administered 131I at 0.11 MBq/kg, progenies 3 and 5 that had been administered 1.1 MBq/kg and progeny 1 affected with 2.1 MBq/kg increased, while for chicken progenies 1, 2, 4 and 6 that had been given 131I at 1.1. MBq/kg the reproductive capacity was within the normal range or decreased.

Monitoring free-living Japanese Bush Warblers (Cettia diphone) in a most highly radiocontaminated area of Fukushima Prefecture, Japan.

The Fukushima-Daiichi Nuclear Power Plant (F1NPP) accident is an IAEA level 7 event, the same as that of Chernobyl, while the amount of radionuclides released is not comparable. Radioactivity attributed to the F1NPP accident was detected 250 km away from the F1NPP. Although we have not yet systematically studied the effect of radionuclides on the environment and wildlife, one of three Japanese Bush Warblers (Cettia diphone), captured in Akaugi district in August 2011, was observed to have a conspicuous lesion near the cloaca, which is rare in Japan. All of the birds' feathers were strongly contaminated. Further study is needed to determine the significance of this result. We emphasize the importance of continuing assessment of the effects of the F1NPP accident on wildlife.

Dose-dependent hepatic transcriptional responses in Atlantic salmon (Salmo salar) exposed to sublethal doses of gamma radiation.

Due to the production of free radicals, gamma radiation may pose a hazard to living organisms. The high-dose radiation effects have been extensively studied, whereas the ecotoxicity data on low-dose gamma radiation is still limited. The present study was therefore performed using Atlantic salmon (Salmo salar) to characterize effects of low-dose (15, 70 and 280 mGy) gamma radiation after short-term (48h) exposure. Global transcriptional changes were studied using a combination of high-density oligonucleotide microarrays and quantitative real-time reverse transcription polymerase chain reaction (qPCR). Differentially expressed genes (DEGs; in this article the phrase gene expression is taken as a synonym of gene transcription, although it is acknowledged that gene expression can also be regulated, e.g., at protein stability and translational level) were determined and linked to their biological meanings predicted using both Gene Ontology (GO) and mammalian ortholog-based functional analyses. The plasma glucose level was also measured as a general stress biomarker at the organism level. Results from the microarray analysis revealed a dose-dependent pattern of global transcriptional responses, with 222, 495 and 909 DEGs regulated by 15, 70 and 280 mGy gamma radiation, respectively. Among these DEGs, only 34 were commonly regulated by all radiation doses, whereas the majority of differences were dose-specific. No GO functions were identified at low or medium doses, but repression of DEGs associated with GO functions such as DNA replication, cell cycle regulation and response to reactive oxygen species (ROS) were observed after 280mGy gamma exposure. Ortholog-based toxicity pathway analysis further showed that 15mGy radiation affected DEGs associated with cellular signaling and immune response; 70mGy radiation affected cell cycle regulation and DNA damage repair, cellular energy production; and 280mGy radiation affected pathways related to cell cycle regulation and DNA repair, mitochondrial dysfunction and immune functions. Twelve genes representative of key pathways found in this study were verified by qPCR. Potential common MoAs of low-dose gamma radiation may include induction of oxidative stress, DNA damage and disturbance of oxidative phosphorylation (OXPHOS). Although common MoAs were proposed, a number of DEGs and pathways were still found to be dose-specific, potentially indicating multiple mechanisms of action (MOAs) of low-dose gamma radiation in fish. In addition, plasma glucose displayed an apparent increase with increasing radiation doses, although the results were not significantly different from the control. These findings suggested that sublethal doses of gamma radiation may cause dose-dependent transcriptional changes in the liver of Atlantic salmon after short-term exposure. The current study predicted multiple MoA for gamma radiation and may aid future impact assessment of environmental radioactivity in fish.

Fukushima's biological impacts: the case of the pale grass blue butterfly.

To evaluate the effects of the Fukushima nuclear accident on the surrounding area, we studied the pale grass blue butterfly Zizeeria maha, the most common butterfly in Japan. We here review our important findings and their implications. We found forewing size reduction, growth retardation, high mortality rates, and high abnormality rates in the field and reared samples. The abnormality rates observed in September 2011 were higher than those observed in May 2011 in almost all localities, implying transgenerational accumulation of genetic damage. Some of the abnormal traits in the F1 generation were inherited by the F2 generation. In a particular cross, the F2 abnormality rate scored 57%. The forewing size reduction and high mortality and abnormality rates were reproduced in external and internal exposure experiments conducted in our laboratory using Okinawa larvae. We observed the possible real-time evolution of radiation resistance in the Fukushima butterflies, which, in retrospect, indicates that field sampling attempts at the very early stages of such accidents are required to understand the ecodynamics of polluted regions. We propose, as the postulates of pollutant-induced biological impacts, that the collection of phenotypic data from the field and their relevant reproduction in the laboratory should be the basis of experimental design to demonstrate the biological effects of environmental pollutants and to investigate the molecular mechanisms responsible for these effects.