Distributions of radionuclide sorption coefficients (Kd) in sub-surface sediments and the implications for transport calculations

The effect of the spatial variability of K_d on calculations of contaminant travel time in the vadose zone was determined. Depth discrete measurements of K_d were made for a suite of radionuclides (¹⁰⁹Cd, ⁵⁷Co, ⁶⁰Co, ⁸⁵Sr, ¹³⁷Cs, and ⁸⁸Y) utilizing a sediment core from the E-Area at the Savannah River Site. The K_d’s were ordered as ⁸⁵Sr²⁺ < ¹³⁷Cs⁺ < ¹⁰⁹Cd²⁺ < ⁵⁷Co²⁺ = ⁶⁰Co²⁺ << ⁸⁸Y³⁺ and the values generally fell below or near the lowest quartile of values reported in the literature. Correlations were generally weak between soil properties and K_d values. Most importantly, all of the K_d distributions could be reasonably approximated as log-normal. Deterministic and stochastic calculations of contaminant travel time to the water table were made. The deterministic calculations were based on each of three conceptual models of the vadose zone: complete stratification (17 strata, each with a different K_d), two strata (two sections of the vadose zone, each characterized by a single, average K_d), and unstratified (a single zone with an average K_d). Stochastic calculations were based on log-normal fits to the K_d data. The two strata model generally yielded travel times 2× greater than those in the completely stratified model. The unstratified model yielded travel times that were between 3 and 5 times greater than the completely stratified model. The stochastic mean travel times were comparable to those of the two strata model.     

Capturing market impacts of farm level policies: a statistical extrapolation approach using biophysical characteristics and farm resources

Technical change at the farm level or changes in input prices often have an impact on the firm's supply function, which in turn affect their economic and environmental performance. These changes can take place in numerous ways. This paper presents a methodology that increases the consistency of supply responses across various sets of agricultural products and most representative farm typologies in Europe, with a market model based on a statistical response function approach. Since most farm simulation models are limited to a subset of regions and farm types, the linkage to an aggregated model requires a procedure for expanding these results to non-sample regions to achieve full regional coverage. This paper addresses theoretical aspects related to the consistency between micro and market level models. The proposed approach is applied using a consistent set of simulation results from farm models in seven European regions. Our results show a fairly stable behaviour of the farm models considered for the analysis and quite good fit of the estimated response surface. As results are still preliminary we critically reflect on the applicability of this method in addressing further needs on up-scaling of other economic as well as environmental indicators.     

Long-range air pollution and its impact on heavy metal accumulation in dippers Cinclus cinclus in Norway

Heavy metals such as cadmium, lead and zinc are deposited in Norway as long-range transported air pollution, while copper deposition is of mainly local origin. This study examined whether the deposition influences the metal concentrations in dippers Cinclus cinclus. The lead concentration in dippers reflected the deposition pattern of long-range air pollution, with higher concentrations in Southern Norway than Central Norway and a significant decrease (>/=40%) between 1987 and 1994. For cadmium, copper and zinc there were no geographical or temporal variations in metal concentrations. For zinc, this lack of geographic and temporal variation probably reflects the fact that it is a homeostatically regulated metal. For both cadmium and copper, local sources are probably more important than long-range sources. Zinc and copper was at higher level in livers of females than in males during the egg laying period. The concentrations of zinc and copper in livers were positively correlated.     

Simultaneous CO2 injection and water production to optimise aquifer storage capacity

The estimates for geological CO₂ storage capacity worldwide vary, but it is generally believed that the capacity in saline aquifers will be sufficient for the amounts of CO₂ that will need to be stored. The effort required to select and qualify a geological storage site for safe storage will, however, be significant and storage capacity may be a limited resource regionally. Both from a economic and resource management perspective it is therefore important that potential storage sites are exploited to their full potential.In static capacity estimates, where the maximum stored amount of CO₂ is given as a fraction of the formation pore volume, typically arrive at efficiency factors in the range of a few per cents. Recent work has shown that when the dynamic behaviour of the injected CO₂ is taken into account, the efficiency factor will be reduced because of the increase in pore pressure in the region around the injection well(s). The increase in pore pressure will propagate much further than the CO₂. The EU directive on geological CO₂ storage specifically addresses the restriction that will apply when different storage sites are interacting due to pressure communication. Consequently, the pore pressure increase at the boundary of the storage license area will be an important limiting factor for the amount of CO₂ that can be injected.One obvious method to control the pore pressure is to produce water from the aquifer at some distance from the CO₂ injection wells. This paper discusses results from simulations of CO₂ injection in two aquifers on the Norwegian Continental Shelf; the Johansen aquifer and the southern part of the Utsira aquifer. These aquifers are candidates for injection of CO₂ shipped out via pipeline from the Norwegian West Coast. The injected amounts of CO₂ over a period of 50 years are 0.518 Gtonne for the Johansen aquifer and 1.04 Gtonne for the Utsira aquifer.Several design options for the injection operations are investigated: Injection of CO₂ without water production; injection into several wells to distribute the injected fluids and reduce the local pressure increase around each injection well; and injection with simultaneous production of water from one or more wells. The boundaries of the aquifer formations are assumed closed in all simulations. The possible consequences of other types of boundary conditions (semi-closed or open) are briefly discussed.     

Screening for Stockholm Convention persistent organic pollutants in the Bosna River (Bosnia and Herzogovina)

The Stockholm Convention, which aspires to manage persistent organic pollutants (POPs) at the international level, was recently ratified in Bosnia and Herzegovina (BiH). Despite this fact, there is in general a paucity of data regarding the levels of POPs in the environment in BiH. In the present study, screening for POPs was conducted in one of the country’s major rivers, the Bosna. A two-pronged approach was applied using passive samplers to detect the freely dissolved and bioavailable concentrations in the water phase and sediment analysis to provide an integrated measure of historical contamination. At several places along the river, the concentrations of polycyclic aromatic hydrocarbons (PAH) were high and exhibited potential for both chronic and acute effects to biota. River water also showed elevated concentrations of PAH, up to 480 ng L^?1 near the city of Doboj, and diagnostic ratios suggested combustion sources for the contamination present in both types of sample. The levels of the other contaminants measured—polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers—were generally low in the water phase. However, PCBs and some OCPs were present in river sediments at levels which breach the international criteria and thus suggest potential for ecological damage. Additionally, the levels of heptachlor breached these criteria in many of the sites investigated. This study presents the first screening data for some of these Stockholm Convention relevant compounds in BiH and reveals both low concentrations of some chemical groups, but significant point sources and historic contamination for others.     

The use of extraction chromatography resins to concentrate actinides and strontium from soil for radiochromatographic analyses

An analytical technique utilizing selective extractant resins to concentrate strontium and actinides from soil followed by separation with radiochromatography was evaluated. The technique was tested using uncontaminated soil samples spiked with a radionuclide tracer solution that were either microwave-aided acid digested or leached with a strong acid. Extraction of the strontium and actinides from the acidified solution was accomplished using a serial arrangement of Sr-Resin and TRU-Resin columns. The combined eluate solutions from the extraction resins were treated with HNO(3) and H(2)O(2) to oxidize residual extractant and eluates prior to separation and analysis of the radionuclides by radiochromatography. Chromatograms obtained with larger soil mass loadings resulted in either incomplete peak resolution of the tracers or had highly variable peak elution times, indicative of an ionic interfering constituent(s). Better separations (e.g., chromatograms that resolved all radioactive constituents) were obtained when the sample mass loading was decreased, but with a concurrent decreased sensitivity for the radionuclides. Elemental analyses of the soil were conducted to provide data on the ionic constituents in unprocessed soil and post-processed soil samples. These results identified aluminum as an interfering contributor to the poor performance exhibited by the radiochromatographic separations.     

Radiation Charging: A Novel Way to Charge Fine Particles Electrically

The purpose of this paper is to describe a scheme to electrically charge fine particles using electric and magnetic fields in conjunction with ionizing radiation. Once charged, particulate matter can be removed from the air stream by directly applying a transverse electric field. In addition, since electrostatic forces can assist filtration and wet collection systems, it may be possible to design new and improved filtration and wet scrubber systems using radiation charging. The objectives of this paper are: (1) to present expressions that predict the charge acquired by particles and (2) to present the results of preliminary experiments.     

Acute impairing effects of morphine related to driving: A systematic review of experimental studies to define blood morphine concentrations related to impairment in opioid-naïve subjects

Objective: The objective of this study was to look for dose– and concentration–effect relationships in experimental studies on single-dose administration of morphine on traffic-relevant behavioral tests by a systematic literature review and possibly to see whether a dose/concentration could be defined below which few or no tests would be affected.

Methods: Searches for corresponding literature were conducted using MEDLINE, EMBASE, and PsycINFO, throughout March of 2016. The search strategy consisted of words colligated to cognitive and psychomotor functions of relevance to driving, in relation to morphine administration. The tests were arranged in main groups, and tests showing impairment were categorized by doses as well as calculated plasma concentrations.

Results: Fifteen studies were included in the review. Impairment after the administration of a single intravenously dose of morphine was found in some of the tests on reaction time, attention, and visual functions. No impairment was observed in tests on psychomotor skills and en-/decoding. Tests on reaction time appeared to be less sensitive to the morphine administration, whereas tests on visual functions and attention appeared to be the most sensitive to the morphine administration. Single-dose administration of morphine with dosages up to 5 mg appeared to cause very few effects on traffic-relevant performance tasks. At higher dosages, impairment was found on various tasks but with no clear dose–effect relationship. Plasma morphine concentrations less than 50 nmol/L are most probably accompanied by few effects on traffic-relevant performance tasks.

Conclusions: A plasma morphine concentration of 50 nmol/L (approximately 14.3 ng/mL) could represent an upper level, under which there is little accompanying road traffic risk. A single dose of 5 mg morphine IV and analgetic equivalence doses of fentanyl, hydromorphone, oxycodone, and oxymorphone are presented with the suggestion that few traffic-relevant effects will appear after such doses.     

Spatial Trends of Trace-Element Contamination in Recently Deposited Lake Sediment Around the Ni–Cu Smelter at Nikel, Kola Peninsula, Russian Arctic

A large copper–nickel smelter complex is located at the Kole Penninsula, Russia, close to the Norwegian border. Trace-element concentrations in surface sediments (0–0.5 cm) and pre-industrial sediments from 45 lakes in the region were used to uncover spatial deposition patterns and contamination factor of sediments. Elevated concentrations were found, especially for Ni and Cu, but also for Pb, Co, Hg, As, and Cd. Highest concentrations were found up to 20 km from the smelter, but the concentrations decreased exponentially with distance from the smelter. Increasing Ni, Cu, As, and Hg concentrations from sub-surface to surface sediments were found for lakes at intermediate distances (20–60 km). This may reflect recent changes in atmospheric depositions, as shown in nearby Norwegian areas. However, we cannot rule out that this also may have been caused by diagenetic processes, especially for the most redox-sensitive elements such as As.