Simulating transport of 129I and idealized tracers in the northern North Atlantic Ocean

Transport of the radioactive tracer Iodine-129 (¹²⁹I, T _1/2 = 15.7 Myr) in the northern North Atlantic Ocean has been investigated using a global isopycnic Ocean General Circulation Model (OGCM) and observed data. ¹²⁹I originates mainly from the nuclear fuel reprocessing plants in Sellafield (UK) and La Hague (France), and is transported northwards along the Norwegian coast, and then into surface and intermediate layers in the Arctic Ocean through the Barents Sea and the Fram Strait, but also partly recirculating south along the eastern coast of Greenland. In the North Atlantic Subpolar Seas, ¹²⁹I is mainly found in dense overflow waters from the Nordic Seas being exported southwards in the Deep Western Boundary Current, and to a lesser extent in surface and intermediate layers circulating cyclonically within the Subpolar Gyre. Observed concentration of ¹²⁹I along a surface transect in the eastern Nordic Seas in 2001 is captured by the OGCM, while in the Nansen Basin of the Arctic Ocean the OGCM overestimates the observed values by a factor of two. The vertical profile of ¹²⁹I in the Labrador Sea, repeatedly observed since 1997 to present, is fairly realistically reproduced by the OGCM. This indicates that the applied model system has potential for predicting the magnitude and depth of overflow waters from the Nordic Seas into the North Atlantic Subpolar Seas. To supplement the information obtained from the ¹²⁹I distribution, we have conducted a number of idealized tracer experiments with the OGCM, including tracers mimicking pure water masses, and instantaneous pulse releases. New insight into time-scales of tracer transport in this region is obtained by utilizing a few recently developed methods based on the theory of Transit Time Distribution (TTD) and age of tracers. Implications for other types of “anomalies” in the northern North Atlantic Ocean, being anomalous hydrography or chemical tracers, and how they are interpreted, are discussed.     

The Czech Republic’s approach to the EU 2030 climate and energy framework

ABSTRACT

The East-West divide within the EU over climate policy has been frequently discussed. There is a tendency in the literature to focus on Poland and ignore the other countries in the central and eastern European region. Here it is argued that the institutionalised cooperation between the four countries in the Visegrad Group (the Czech Republic, Hungary, Poland and Slovakia) provides a crucial component for an understanding of how the participating countries approach EU climate negotiations. Here it is suggested that the group is important as a bargaining coalition but also as a reference point for the development of shared ‘Visegrad’ norms in the field. This is based on a case study of the Czech Republic’s approach to the 2014 negotiations on the 2030 climate and energy framework and the country’s cooperation with the other Visegrad countries on the issue.     

Ah Receptor Agonists in UV-exposed Toluene Solutions of Decabromodiphenyl Ether (decaBDE) and in Soils Contaminated with Polybrominated Diphenyl Ethers (PBDEs) (9 pp)

Goal, Scope and Background The use of polybrominated diphenyl ethers (PBDEs) as flame retardants increases the risk for emissions of other brominated compounds, such as polybrominated dibenzodioxins (PBDDs) and dibenzofurans (PBDFs). The large homology in structure of PBDD/Fs and mechanism of toxic action, i.e. the capacity to activate the Ah receptor (AhR) pathway, compared to their well-studied chlorinated analogues, justifies a raised concern to study the environmental levels and fate of these compounds. Decabromodiphenyl ether (decaBDE) is the most widely used PBDE today. Studies on photolytic debromination of decaBDE in organic solvents have shown debromination of decaBDE, as well as formation of PBDFs. However, little is known about the transformation mechanisms and there are only scarce data on photoproducts and PBDE transformation in environmentally relevant matrices. In this study, mechanism-specific dioxin bioassays were used to study photolytic formation of AhR agonists in toluene solutions of decaBDE. In addition, the influence of irradiation time and UV-light wavelength on the formation was studied. PBDE congener patterns and presence of PBDD/Fs were analysed. Further, AhR agonists were analysed in agricultural soils contaminated with PBDEs. Soils were also exposed to UV-light to study changes in AhR agonist levels. Methods Toluene solutions of decaBDE were irradiated using three different spectra of UV-light, simulating UV-A (320-400 nm), UV-AB (280-400 nm), and UV-ABC (250-400 nm). Additionally, decaBDE solutions were exposed to narrow wavelength intervals (10 nm bandwidth) with the central wavelengths 280, 290, 300, 310, 320, 330, 340, 350, 360 nm. AhR agonists in decaBDE solutions were analysed with two different bioassays, the chick embryo liver-cell assay for dioxins (Celcad) and the dioxin responsive, chemically activated luciferase expression assay (DR-Calux). Also, the decaBDE solutions were analysed with LRGC-LRMS to obtain PBDE congener patterns for breakdown of decaBDE, and with HRGC-HRMS, for presence of PBDD/Fs. Four soils were exposed to UV-AB light, under both dry and moist conditions. Levels of AhR agonists in soil extract fractions, before and after UV-exposure, were analysed with the DR-Calux. Results and Discussion Significant levels of photoproducts able to activate the AhR pathway, up to 31 ng bio-TEQ/ml, were formed in UV-exposed decaBDE solutions. The transformation yield of decaBDE into AhR agonists was estimated to be at the 0.1%-level, on a molar basis. The net formation was highly dependent on wavelength, with the sample irradiated at 330 nm showing the highest level of dioxin-like activity. No activity was detected in controls. PBDE analysis confirmed decaBDE degradation and a clear time-dependent pattern for debromination of PBDE congeners. AhR agonist effect in the recalcitrant fractions of the soils corresponded to the levels of chemically derived TEQs, based only on chlorinated dioxin-like compounds in an earlier study. It was concluded that no significant levels of other AhR agonists, e.g. PBDFs, were accumulated in the soil. UV-light caused changes in AhR-mediated activity in the more polar and less persistent fractions of the soils, but it is not known which compounds are responsible for this. Recommendations and Perspective . The laboratory experiments in this study show that high levels of AhR agonists can be formed as photoproducts of decaBDE and it is important to elucidate if and under which conditions this might occur in nature. However, soil analysis indicates that photoproducts of PBDE do not contribute to the accumulated levels of persistent dioxin-like compounds in agricultural soil. Still, more data is needed to fully estimate the environmental importance of PBDE photolysis and occurrence of its photoproducts in other environmental compartments. Analysis with dioxin bioassays enabled us to gather information about photoproducts formed from decaBDE even though the exact identities of these compounds were not known. Conclusion Bioassays are valuable for studying environmental transformation processes like this, where chemical analysis and subsequent toxicological evaluation requires available standard compounds and information on toxicological potency. The use of bioassays allows a rapid evaluation of toxicological relevance.     

Foreign direct investment and institutional obstacles: The case of Russian forestry

This article examines why, in spite of vast forest resources, Russia has been unable to attract foreign investors into its forest industry. A survey of 32 influential Western European forest companies indicates that purely economic factors, such as labour or raw material costs, are not the main reasons these companies refrain from investing. Instead, the companies identify a number of institutional factors: ambiguous legal systems; difficulties in negotiating with local authorities; unfair tax enforcement; and general political instability as the main impediments to FDI in the sector. These factors have led many companies to abandon previously considered investments in Russia, and also to terminate existing business relationships with Russian partners. The survey results also indicate that, while many investors in forestry were attracted by the potential for a growing Russian market in the early days of the transition period, they have become more and more aware of the many institutional obstacles challenging growth in the sector. The article concludes, therefore, that FDI in the Russian forestry sector is likely to remain low until a fundamental change takes place in the legal and political systems.     

The Impact of Traffic Noise on the Values of Single-family Houses

The objective of this paper is to provide an empirical analysis of the impact traffic noise has on the values of single-family houses. Under the assumption that negative externalities are capitalized into house values, the hedonic price method is used. Issues of asymmetric information and disequilibrium are discussed and tested. Furthermore, the cost-benefit valuation has been corrected for the existence of property tax. Noise pollution was found to have a substantial negative effect on housing values. A single-family house of SEK975 000 would sell for SEK650 000 if located near a road where noise is loud, equivalent to a total discount of 30%.     

Predictors of telomere content in dragon lizards

Telomeres shorten as a consequence of DNA replication, in particular in cells with low production of telomerase and perhaps in response to physiological stress from exposure to reactive oxygen species, such as superoxide. This process of telomere attrition is countered by innate antioxidation, such as via the production of superoxide dismutase. We studied the inheritance of telomere length in the Australian painted dragon lizard (Ctenophorus pictus) and the extent to which telomere length covaries with mass-corrected maternal reproductive investment, which reflects the level of circulating yolk precursor and antioxidant, vitellogenin. Our predictors of offspring telomere length explained 72?% of telomere variation (including interstitial telomeres if such are present). Maternal telomere length and reproductive investment were positively influencing offspring telomere length in our analyses, whereas flow cytometry-estimated superoxide level was negatively impacting offspring telomere length. We suggest that the effects of superoxide on hatchling telomere shortening may be partly balanced by transgenerational effects of vitellogenin antioxidation.     

Relative Abundance of Human Bocaviruses in Urban Sewage in Greater Cairo,Egypt

Human bocavirus (HBoV) is predominantly found in the respiratory tract infections and in the stool of patients with gastroenteritis symptoms. However, data on the prevalence of HBoV genotypes in environmental samples are limited. Here we addressed the prevalence of HBoV in sewage collected from three different wastewater treatment plants in Egypt. HBoV-1, HBoV-2, and HBoV-3 were detected, whereas none of the samples were positive for HBoV-4. The median concentration of HBoV in influent samples was 8.5 × 10³ GC/l for HBoV-1, 3.0 × 10⁴ GC/l for HBoV-2, and 2.5 × 10⁴ GC/l for HBoV-3. The concentration was reduced but not completely removed in the effluent samples. The median concentration in the outlet samples was 2.9 × 10³ GC/l for HBoV-1, 4.1 × 10³ GC/l for HBoV-2, and 2.1 × 10³ GC/l for HBoV-3. Moreover, no seasonality pattern of HBoVs was found. The high incidence of HBoV in sewage samples provided an evidence of its circulation in the local population. Although the role of HBoV in respiratory or gastro-intestinal infections still remains to be fully elucidated, the risk of infection via contaminated water should be taken into consideration.