カテゴリー「ecology・environment」
Title: MUD: a Model to investigate the migration of 137Cs in the Urban environment and Drainage and sewage treatment systems
Author: Gallego, E.
Reference: Journal of Environmental Radioactivity, 2006, vol.85, no.2-3, pp. 247-64
doi: 10.1016/j.jenvrad.2004.10.017
Keywords: Urban environment; 137Cs; Sewage water; Water treatment
Abstract: A model is presented for the migration of 137Cs in the urban environment, including the drainage systems and the sewage treatment plants, with flexibility to be adapted to different configurations common in urban areas. The dynamics of 137Cs is simulated both under natural evolution and in case of forced decontamination, which can have a direct impact on the radioactivity going to sewers. The model assesses the activity concentrated in sewage sludge and that discharged with the treated or untreated effluent to the receiving watercourse. Tests made for two post-Chernobyl contamination scenarios in Sweden show differences between model predictions and observed results within the range of the experimental uncertainties. An uncertainty and sensitivity analysis of the main model parameters indicates that some parameters may have a significant influence on the results of the model. Moreover, the model uncertainty is driven by a few parameters; therefore, additional research could be necessary into these parameters, aiming at simplifying the model without losing its predictive power.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X05002201
Title: Aquatic Assessment of the Chernobyl Nuclear Accident and Its Remediation
Author: Onishi, Y.; Kivva, S. L.; Zheleznyak, M. J.; Voitsekhovich, O. V.
Reference: Journal of Environmental Engineering. Nov2007, Vol. 133 Issue 11, p1015-1023. 9p. 1
doi: 10.1061/(ASCE)0733-9372(2007)133:11(1015)
Keywords: Accidents; Aquatic habitats; Nuclear powerplants; Radioactive materials; Remedial action;Simulation models; Transport phenomena; Ukraine.
Abstract: This modeling study evaluated the aquatic environment affected by the Chernobyl nuclear accident and the effectiveness of remediation efforts. The study results indicate that radionuclide concentrations in the Pripyat and Dnieper rivers were well above the drinking water limits immediately after the Chernobyl accident but have decreased significantly in subsequent years due to flushing, burying, and decaying. Because high concentrations of 90Sr and 137Cs, the major radionuclides affecting human health through the aquatic pathways, are associated with flooding, two earthen dikes were constructed along the Pripyat River. The left-bank dike alone was successful in reducing the 90Sr concentration in the river by half. The 100-m-high, movable New Safe Confinement (NSC), which will cover the current Chernobyl Shelter, will reduce radionuclide contamination further in these rivers and nearby groundwater. If the Chernobyl Shelter should collapse before the NSC is built, the resulting peak radionuclide concentrations in the Dnieper River are expected to still remain below the drinking water limits. The radionuclide influx to groundwater through the NSC should not have any effect on concentrations in the Pripyat River.
URL: http://ascelibrary.org/doi/abs/10.1061/(ASCE)0733-9372(2007)133%3A11(1015)
Title: Long-term environment monitoring based on MTS-N (LiF:Mg, Ti) and MCP-N (LiF:Mg, Cu, P) thermoluminescent detectors
Author: Budzanowski, M.; Olko, P.; Obryk, B.; Ryba, E.; Nowak, A.
Reference: Radiation Measurements, Aug.-Dec. 2004, vol.38, no.4-6, pp. 821-4
doi: 10.1016/j.radmeas.2004.01.023
Keywords: Thermoluminescence; TLD; LiF; Environmental measurements
Abstract: An environmental radiation monitoring system using standard MTS-N (LiF:Mg, Ti) and high-sensitive thermoluminescent LiF:Mg,Cu,P (MCP-N) detectors was applied to control the radiation exposure over the area of the Institute of Nuclear Physics (INP) in Kraków. First environmental measurements using MTS-N detectors began in 1970 at five locations and were continued during the Chernobyl accident at six sites. In March 1987 high-sensitive MCP-N detectors read out in a manual TL reader were first introduced into service at the INP. Since 1992 about 60 locations over an area of the INP were selected for quarterly dose rate measurements, using an automatic TLD system based on MTS-N detectors placed in cards. In 2002 MTS-N detectors were replaced by high-sensitive MCP-N pellets.
URL: http://www.sciencedirect.com/science/article/pii/S1350448704000290
Title: Long-term investigations of radioactive matter in the air of Zagreb, Croatia
Author: Franic, Z.; Marovic, G.; Sencar, J.
Reference: Atmospheric Research, Sept. 2008, vol.89, no.4, pp. 391-5
doi: 10.1016/j.atmosres.2008.03.005
Keywords: Radioactivity; 137Cs; 7Be; Chernobyl accident; Effective dose
Abstract: Investigations on the distribution and fate of naturally occurring, nuclear-weapons-produced, and reactor-released radionuclides in the city of Zagreb, Coatia, have been conducted as part of the monitoring program for radioactive contamination of the human environment in Croatia since the early 1960s. This paper describes long-term investigations of man-made 137Cs and naturally occurring 7Be in the city of Zagreb after the Chernobyl accident. The Chernobyl nuclear accident caused a major increase in 137Cs activity concentrations only in 1986, which quickly decreased over the next few years to pre-Chernobyl values. The observed mean residence time for 137Cs in the air during the post-Chernobyl period from January 1987 to December 1990 was estimated to be 1.0 year. During this period, the observed mean residence time for 137Cs in fallout was estimated to be 0.9 years. The mean 7Be activity concentration in the air from 1987 to 2004 was (5.4 ± 2.8) × 10− 3 Bq m− 3. The measured 7Be activity concentrations showed seasonal behavior with the highest usually measured in July.
URL: http://www.sciencedirect.com/science/article/pii/S0169809508000689
Title: Testicular steroidogenesis is not altered by 137 cesium Chernobyl fallout, following in utero or post-natal chronic exposure.
Author: Grignard, Elise; Guéguen, Yann; Grison, Stéphane; Dublineau, Isabelle; Gourmelon, Patrick; Souidi, Maâmar.
Reference: Comptes Rendus Biologies. May2010, Vol. 333 Issue 5, p416-423. 8p.
doi: 10.1016/j.crvi.2010.02.003.
Keywords: TESTIS — Physiology; CESIUM — Isotopes; STEROID hormones — Synthesis; CHERNOBYL Nuclear Accident, Chornobyl, Ukraine, 1986; GENE expression; CONTAMINATION (Technology); RATS as laboratory animals
Abstract: The testis is especially sensitive to pollutants, including radionuclides. Following the Chernobyl nuclear power plant accident, several of these radionuclides were emitted and spread in the environment. Subsequently, children presented some disruptions of the endocrine system. To determine whether these disruptions were due to 137 cesium (137Cs) exposure, the effects of chronic contamination with low doses of 137Cs in utero or from birth on testicular steroidogenesis in rats were studied. Contamination was continued for 9 months. No modification was observed in circulating level of hormones (17β-estradiol, testosterone, follicle-stimulating hormone, luteinizing hormone) following in utero or post-natal contamination. Expression of several genes involved in testicular steroidogenesis was affected (cyp19a1, fxr, sf-1), without modification of protein expression or activity. Our results suggest that growing organisms may be affected at the molecular level by 137Cs contamination at this post-accidental dose.
URL: http://www.sciencedirect.com/science/article/pii/S1631069110000466
Title: VARIATION IN MITOCHONDRIAL DNA CONTROL REGION HAPLOTYPES IN POPULATIONS OF THE BANK VOLE, CLETHRIONOMYS GLAREOLUS, LIVING IN THE CHERNOBYL ENVIRONMENT, UKRAINE
Author: Wickliffe, Jeffrey K.; Dunina-Barkovskaya, Yelena V.; Gaschak, Sergey P.; Rodgers, Brenda E.; Chesser, Ronald K.; Bondarkov, Mikhail; Baker, Robert J.
Reference: Environmental Toxicology & Chemistry. Feb2006, Vol. 25 Issue 2, p23-23. 1p.
doi: 10.1897/05-327R.1
Keywords: Chernobyl; Vole; Mitochondrial; DNA diversity; Radiation
Abstract: Bank vole, Clethrionomys glareolus, specimens have been annually sampled from the radioactive Chernobyl, Ukraine, environment and nonradioactive reference sites since 1997. Exposed voles continually exhibit increased mitochondrial DNA hap-lotype (h) and nucleotide diversity (ND), observed in the hypervariable control region (1997–1999). Increased maternal mutation rates, source–sink relationships, or both are proposed as hypotheses for these differences. Samples from additional years (2000 and 2001) have been incorporated into this temporal study. To evaluate the hypothesis that an increased mutation rate is associated with increased h, DNA sequences were examined in a phylogenetic context for novel substitutions not observed in haplotypes from bank voles from outside Ukraine or in other species of Clethrionomys. Such novel substitutions might result from in situ mutation events and, if largely restricted to samples from radioactive environments, support an increased maternal mutation rate in these areas. The only unique substitution meeting this criterion was found in an uncontaminated reference site. All other substitutions are found in other haplotypes of the bank vole or in other species. Increased maternal mutation rates do not appear to explain trends in h and ND observed in northern Ukraine. Studies examining ecological dynamics will clarify the reasons behind, and significance of, increased levels of h in contaminated areas.
URL: http://onlinelibrary.wiley.com/doi/10.1897/05-327R.1/abstract
Title: Radioactivity in the environment (including the Arctic and Antarctic). The International Conference in Nice, France, 2-6 October 2005
Author: Strand, P.; Brown, J.
Reference: Journal of Environmental Radioactivity, July-Sept. 2007, vol.96, no.1-3, pp. 1-5
doi: 10.1016/j.jenvrad.2007.01.014
Keywords: radiation monitoring; radioactive pollution; radioactivity measurement; risk management; Arctic region; Antarctic region; radioecology; environmental radioactivity; ecosystems; empirical data; modelling tools; Chernobyl Accident; technologically enhanced naturally occurring radioactive materials; TENORM; environment protection; radioactivity measurement; radioactivity monitoring; risk assessment; risk management
Abstract: Understanding the behaviour of radionuclides in ecosystems and studying the subsequent consequences of exposure to radiation on man and the environment, through analyses of empirical data and use of modelling tools, has traditionally been a mainstay of radioecological sciences. Following a period of intense atmospheric nuclear weapons tests in the late 1950s and early 1960s, scientists were provided with the first insights into the consequences of global contamination by radioactivity and the transfer and fate of radionuclides in the environment. It became clear during these early studies that some radionuclides, notably 137Cs and 90Sr, could be relatively easily transferred through terrestrial and aquatic food-chains resulting in potential exposure of radioactivity to human populations via ingestion.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X0700063X
Title: Model testing using data on 137Cs from Chernobyl fallout in the Iput River catchment area of Russia
Author: Thiessen, K.M.; Sazykina, T.G.; Apostoaei, A.I.; Balonov, M.I.; Crawford, J.; Domel, R.; Fesenko, S.V.; Filistovic, V.; Galeriu, D.; Homma, T.; Kanyar, B.; Krajewski, P.; Kryshev, A.I.; Kryshev, I.I.; Nedveckaite, T.; Ould-Dada, Z.; Sanzharova, N.I.; Robinson, C.; Sjoblom, K.-L.
Reference: Journal of Environmental Radioactivity, 2005, vol.84, no.2, pp. 225-44
doi: 10.1016/j.jenvrad.2004.10.016
Keywords: Cesium-137; Model testing; Dose reconstruction; Chernobyl
Abstract: Data collected for 10 years following the Chernobyl accident in 1986 have provided a unique opportunity to test the reliability of computer models for contamination of terrestrial and aquatic environments. The Iput River scenario was used by the Dose Reconstruction Working Group of the BIOMASS (Biosphere Modelling and Assessment Methods) programme. The test area was one of the most highly contaminated areas in Russia following the accident, with an average contamination density of 137Cs of 800,000 Bq m−2 and localized contamination up to 1,500,000 Bq m−2, and a variety of countermeasures that were implemented in the test area had to be considered in the modelling exercise. Difficulties encountered during the exercise included averaging of data to account for uneven contamination of the test area, simulating the downward migration and changes in bioavailability of 137Cs in soil, and modelling the effectiveness of countermeasures. The accuracy of model predictions is dependent at least in part on the experience and judgment of the participant in interpretation of input information, selection of parameter values, and treatment of uncertainties.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X05001499
Title: Application of in-situ measurement to determine 137Cs in the Swiss Alps
Author: Schaub, M.; Konz, N.; Meusburger, K.; Alewell, C.
Reference: Journal of Environmental Radioactivity, May 2010, vol.101, no.5, pp. 369-76.
doi: 10.1016/j.jenvrad.2010.02.005
Keywords: NaI detector; GeLi detector; Alps; In-situ measurements; Field application
Abstract: Establishment of 137Cs inventories is often used to gain information on soil stability. The latter is crucial in mountain systems, where ecosystem stability is tightly connected to soil stability. In-situ measurements of 137Cs in steep alpine environments are scarce. Most studies have been carried out in arable lands and with Germanium (Ge) detectors. Sodium Iodide (NaI) detector system is an inexpensive and easy to handle field instrument, but its validity on steep alpine environments has not been tested yet. In this study, a comparison of laboratory measurements with GeLi detector and in-situ measurements with NaI detector of 137Cs gamma soil radiation has been done in an alpine catchment with high 137Cs concentration
URL: http://www.sciencedirect.com/science/article/pii/S0265931X10000354
Title: Regional-scale application of the decision support system MOIRA-PLUS: an example of assessment of the radiological impact of the Chernobyl accident on the fresh water ecosystem in Italy.
Author: Luigi Monte
Reference: Journal of Environmental Radioactivity. Feb2011, Vol. 102 Issue 2, p73-83. 11p.
doi: 10.1016/j.jenvrad.2010.10.002
Keywords: Decision support systems; Fresh water environment; Radionuclide migration models; Lakes; Rivers; MOIRA-PLUS
Abstract: ► MOIRA-PLUS is a computerised decision support system aimed at evaluating the behaviour of radiocaesium and radiostrontium in fresh water ecosystems and at assessing the appropriateness of suitable strategies for the management of the contaminated aquatic environment by the application of advanced multi-attribute analysis techniques. ► MOIRA-PLUS (release 4.1.2) allows the user to customise the migration model for the assessment of the behaviour of radionuclides in complex networks of water systems including, for instance, a main watercourse and several tributaries of different order. ► The test and the calibration of MOIRA-PLUS migration models applied to 18 rivers and 10 lakes in Italy gave the opportunity of customising MOIRA for practical applications to the fresh water environment in the Italian territory. ► The calibrations of the MOIRA-PLUS environmental models offered the opportunity of assessing site-specific values of several migration parameters of importance for predicting the dynamics of radiocaesium in the selected water bodies (radionuclide sedimentation velocity, radionuclide transfer coefficient from catchments, radionuclide burial rate to deep sediment). ► Conclusions: MOIRA-PLUS can be easily customised to complex freshwater systems at regional scale. Information and data obtained from independent empirical studies can be promptly exploited for testing and calibrating the models. MOIRA-PLUS can be used for quick evaluations of radionuclide fluxes through the aquatic compartments and of the doses released to humans.
URL: http://www.sciencedirect.com/science/article/pii/S0265931X10002250
