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[en] The paper reports on the study of the radiation situation and the degree of contamination with natural radionuclides and toxic elements of 11 transboundary rivers and the Big Chu Channel at the points of their inflow into Kazakhstan from Kyrgyzstan. The methods of radiometry, IGS, XRF, MS-ICP, OES-ICP, RChA were used. It was established that the radiation background in the examined areas is high, but does not pose a risk to human health. In the majority of the transboundary watercourses, the chemical toxicity of waters exceeds for 2-12 times the regulatory value set in the Republic of Kazakhstan for drinking water. Uranium contributes 37% to this indicator. (author)
[en] This report supplies emissions data, for France, concerning all the substances covered by the different protocols adopted under the Convention on Long Range Transboundary Air Pollution (LRTAP), under the aegis of the United Nations Economic Commission for Europe (UNECE) and by the European Directive on national emission ceilings (NEC). The substances covered are sulphur dioxide (SO2), nitrogen oxides (NOx), non-methane volatile organic compounds (NMVOCs), ammonia (NH3), carbon monoxide (CO), total suspended particles (TSP), fine particles (PM10 and PM2.5), and black carbon (BC), heavy metals (As, Cd, Cr, Cu, Hg, Ni, Pb, Se, Zn) and persistent organic pollutants (POPs) such as dioxins and furans (PCDD/F), specified polycyclic aromatic hydrocarbons (PAHs) compounds (BaP, BbF, BkF, IndPy), polychlorobiphenyls (PCBs) and hexa-chlorobenzene (HCB). Parties to the Convention have to report emissions of these substances annually. Since the March 2016 edition, results are reported in the format UNECE/NFR in accordance with the new specifications set out in the guidelines relative on guidelines for reporting emission data under the Convention on LRTAP (ECE/EB.AIR/125 Advanced version adopted in December 2014) defined by the United Nations Economic Commission for Europe. The results are presented at the national level with the updated 2014 NFR nomenclature using 5 sectors and 127 sub-sectors. Conversely, the nomenclature used in the national inventory system to conduct inventories is the CORINAIR/ SNAP 97c nomenclature. A table of correspondence NFR/SNAP 97c is included in this report. For the entire period (going back as far as 1980) concerning each substance, estimates provided in the previous inventories have been reviewed and corrected to take into account updated statistics, improved knowledge and possible changes in methodology. As indicated in the table below, emission trends between the reference year and 2017 show a decline for most substances. These trends, on the decrease, give an indication of measures taken to reduce emissions in order to comply with the ceilings set by the Gothenburg Protocol and the EU NEC Directive (most of the targets have been reached) and in anticipation of future targets. The amended Gothenburg Protocol was just adopted on May 4, 2012 in Geneva and set new reduction commitments for 2020 and introduced a commitment for the PM2.5 in addition to those for the SO2, NOx, NH3 and NMVOCs. These ceilings are not any more set in absolute values (ceilings) but in relative values. The same is true for the new and more stringent targets set by the revise NEC Directive (EU) 2016/2284. Future reviews of these data are always possible, if not probable, to take into account both changes in methodology and work underway at international level in order to improve knowledge and rules on compiling and presenting emissions
[en] ASEAN Network on Nuclear Power Safety Research (ASEAN NPSR) has been working since 2017 on the atmospheric dispersion benchmark problem to support capacity building in emergency preparedness and response (EPR) in ASEAN. Its project named Enhancing ASEAN Research Competency in Nuclear Emergency Preparedness and Response is being funded under the ASEAN Science, Technology and Innovation Funds (ASTIF). Atmospheric dispersion characteristics of a hypothetical release from nuclear power plants (NPP) are assessed with different meteorological conditions, calculation codes and assessors, and the results are compared and discussed. The project started with the assessment of the proposed Ninh Thuan 1 Nuclear Power Plant, and later shifted to Fangchenggang Nuclear Power Plant. Source term data is adopted from the station blackout scenario in the SOARCA report. Three different sets of meteorological data are used for the calculation to cover dry and wet conditions. The benchmark problem is assessed by three member states: Singapore, Vietnam and Thailand, using four calculation codes: ARGOS, Flexpart, JRODOS and NACAC. The dispersion patterns of ARGOS and JRODOS are almost identical, while those of Flexpart and NACAC are quite different. It was found that air concentration and ground concentration calculated by ARGOS and JRODOS are within the same ranges (differences are less than an order of magnitude), though ARGOS delivers much smaller total effective dose equivalents (TEDEs) for dry deposition, and much larger TEDEs for wet deposition. The results are being investigated to find the root causes to these differences, and to summarize recommendations to the users of these calculation codes when the codes are applied to transboundary atmospheric dispersion calculation. (author)
[en] Highlights: • 85Kr from a fuel reprocessing plant occasionally is detected at 750 km distance. • Atmospheric transport modeling results are correlated with observations. • About 50% of the results are within a factor of two of the measurements. - Abstract: Due to its half-life, chemical inertness and low solubility in water, radioactive 85Kr is a valuable tracer for testing the performance of atmospheric dispersion models in simulating long-range transport of pollutants. This paper evaluates the capability of simulating the dispersion of radiokrypton emitted by a nuclear fuel reprocessing plant in north-west France. Three time periods during which elevated activity concentrations of 85Kr in ground level air were detected in south-west Germany are chosen. Simulations have been performed using the HYSPLIT code and the European Centre for Median-Range Weather Forecasts (ECMWF) data base. Although their results show a slight trend of underestimating the measured 85Kr concentrations, there is a significant correlation and moderate scatter between observations and simulations with about 50% of the results being within a factor of two of the measured concentrations. The simulated travel time distributions provided a valuable tool for providing additional insight into the dispersion of the tracer radionuclides and for identifying potential causes of deviations between measured and calculated concentrations.
[en] Here, the Arctic is warming at an alarming rate, yet the processes that contribute to the enhanced warming are not well understood. Arctic aerosols have been targeted in studies for decades due to their consequential impacts on the energy budget, both directly and indirectly through their ability to modulate cloud microphysics. Even with the breadth of knowledge afforded from these previous studies, aerosols and their effects remain poorly quantified, especially in the rapidly changing Arctic. Additionally, many previous studies involved use of ground-based measurements, and due to the frequent stratified nature of the Arctic atmosphere, brings into question the representativeness of these datasets aloft. Here, we report on airborne observations from the US Department of Energy Atmospheric Radiation Measurement (ARM) program's Fifth Airborne Carbon Measurements (ACME-V) field campaign along the North Slope of Alaska during the summer of 2015. Contrary to previous evidence that the Alaskan Arctic summertime air is relatively pristine, we show how local oil extraction activities, 2015's central Alaskan wildfires, and, to a lesser extent, long-range transport introduce aerosols and trace gases higher in concentration than previously reported in Arctic haze measurements to the North Slope. Although these sources were either episodic or localized, they serve as abundant aerosol sources that have the potential to impact a larger spatial scale after emission.
[en] After performing a first multi-model exercise in 2015 a comprehensive and technically more demanding atmospheric transport modelling challenge was organized in 2016. Release data were provided by the Australian Nuclear Science and Technology Organization radiopharmaceutical facility in Sydney (Australia) for a one month period. Measured samples for the same time frame were gathered from six International Monitoring System stations in the Southern Hemisphere with distances to the source ranging between 680 (Melbourne) and about 17,000 km (Tristan da Cunha). Participants were prompted to work with unit emissions in pre-defined emission intervals (daily, half-daily, 3-hourly and hourly emission segment lengths) and in order to perform a blind test actual emission values were not provided to them. Despite the quite different settings of the two atmospheric transport modelling challenges there is common evidence that for long-range atmospheric transport using temporally highly resolved emissions and highly space-resolved meteorological input fields has no significant advantage compared to using lower resolved ones. As well an uncertainty of up to 20% in the daily stack emission data turns out to be acceptable for the purpose of a study like this. Model performance at individual stations is quite diverse depending largely on successfully capturing boundary layer processes. No single model-meteorology combination performs best for all stations. Moreover, the stations statistics do not depend on the distance between the source and the individual stations. Finally, it became more evident how future exercises need to be designed. Set-up parameters like the meteorological driver or the output grid resolution should be pre-scribed in order to enhance diversity as well as comparability among model runs.
[en] Highlights: • Radioactive charging can significantly affect the coagulation rate and atmospheric transport of radioactive aerosols. • An increase of particle concentrations remaining in the atmosphere after 5 days up to a factor of 30 was simulated for iodine, and up to a factor of 3 for cesium, when radioactive charging is accounted for. -- Abstract: Radioactive charging can significantly impact the way radioactive aerosols behave, and as a result their lifetime, but such effects are neglected in predictive model studies of radioactive plumes. The objective of this work is to determine the influence of radioactive charging on the vertical transport of radioactive aerosols in the atmosphere, through its effect on coagulation and deposition, as well as quantifying the impact of this charging on aerosol lifetime. The TwO-Moment Aerosol Sectional (TOMAS) microphysical model was extended to account for radioactive charging effects on coagulation in a computationally efficient way. The expanded model, TOMAS-RC (TOMAS with Radioactive Charging effects), was then used to simulate the microphysical evolution and deposition of radioactive aerosol (containing the isotopes 131I and 137Cs) in a number of idealized atmospheric transport experiments. Results indicate that radioactive charging can facilitate or suppress coagulation of radioactive aerosols, thus influencing the deposition patterns and total amount of radioactive aerosol mass available for long-range transport. Sensitivity simulations to uncertain parameters affirm the potential importance of radioactive charging effects. An important finding is that charging of neutral, coarse mode aerosol from background radiation can reduce coagulation rates and extend its lifetime in the atmosphere by up to a factor of 2.
[en] Highlights: • Comparison of production-based and consumption-based accounting of CO2 emissions. • Longitudinal analysis of the newest data for 110 countries for the last 15 years. • Results show only small differences between PBA and CBA. • Countries with large imports have higher CBA/PBA ratios. • The CBA/PBA ratio is positive for countries with high energy efficiency. - Abstract: Lately, a controversial debate has evolved regarding consumption-based accounting (CBA) versus production-based accounting (PBA) of CO2 emissions. So far, the debate has been predominately theoretical and has inspired only a few empirical studies. In this article, we compare production-based versus consumption-based emissions, and for the first time analyze reasons for the differences. In particular, we focus on whether there is evidence for carbon leakage from developed to developing countries. We use the newest available data for 110 countries and analyze whether there are differences between OECD and non-OECD members. Furthermore, we compare the within-country differences for the time span of 1997 to 2011 via fixed effects panel regression models in order to investigate whether increases in GDP per capita result in higher imported emissions. The results suggest that for most countries the differences depending on accounting schemes are small. Furthermore, we find no evidence for carbon leakages. In particular, the ratio of CBA to PBA is not driven by OECD membership or GDP per capita. Instead, the ratio is greater for countries with high energy efficiency and high import rates. Given the small differences between PBA and CBA, we suggest keeping the production-based accounting of CO2 emissions.
[en] Arctic-alpine tundra habitats are very vulnerable to the input of relatively small amounts of xenobiotics, and thus their level in such areas must be carefully controlled. Therefore, we collected the terrestrial widespread moss Racomitrium lanuginosum (Hedw.) Brid. in Spitsbergen in the Arctic moss lichen tundra and, for comparison, in the Arctic-alpine tundra in the Karkonosze (SW Poland). Concentrations of the elements Cd, Co, Cr, Cu, Fe, Hg, Li, Mn, Mo, Na, Ni, Pb, V, and Zn in this species and in the parent rock material were measured. We tested the following hypothesis: R. lanuginosum from Spitsbergen contains lower metal levels than the species from the Karkonosze collected at altitudes influenced by long-range transport from former Black Triangle industry. Principal component and classification analysis (PCCA) ordination revealed that mosses of Spitsbergen were distinguished by a significantly higher Na concentration of marine spray origin and mosses of Karkonosze were distinguished by significantly higher concentrations of Cd, Cr, Cu, Fe, Hg, Li, Mn, Pb, V, and Zn probably from long-range atmospheric transport. The influence of the polar station with a waste incinerator resulted in significantly higher Co, Li, and Ni concentrations in neighbouring mosses in comparison with this species from other sites. This investigation contributes to the use of R. lanuginosum as a bioindicator for metal contamination in Arctic and alpine tundra regions characterised by severe climate habitats with a restricted number of species. This moss enables the control of pollution usually brought solely by long-range atmospheric transport in high mountains as well as in Arctic areas.
[en] Antibiotic resistance is a worsening global concern, and the environmental behaviors and migration patterns of antibiotic resistance genes (ARGs) have attracted considerable interest. Understanding the long-range transport of ARG pollution is crucial. In this study, we characterized the dynamics of ARG changes after their release into aquatic environments and demonstrated the importance of traditional chemical contaminants in the transmission mechanisms of ARGs. We hypothesized that the main route of ARG proliferation switches from active transmission to passive transmission. This antibiotic-dominated switch is motivated and affected by non-corresponding contaminants. The effect of anthropogenic activities gradually weakens from inland aquatic environments to ocean environments; however, the effect of changes in environmental conditions is enhanced along this gradient. The insights discussed in this study will help to improve the understanding of the distribution and migration of ARG pollution in various aquatic environments, and provide a modern perspective to reveal the effect of corresponding contaminants and non-corresponding contaminants in the process of antibiotic resistance proliferation. - Highlights: • Process of ARGs flow through WWTPs, rivers, estuaries and ocean to implement global proliferation and commutation. • The diversity and concentrations of ARGs progressively decrease during dynamic long-range migration processes. • The main route of ARG proliferation switches from active transmission to passive transmission from inland to ocean. - The diversity and concentrations of antibiotic resistance genes progressively decrease during dynamic long-range migration processes.