Assessing the Impacts of Long-Range Sulfur and Nitrogen Deposition on Arctic and Sub-Arctic Ecosystems

For more than a decade, anthropogenic sulfur (S) and nitrogen (N) deposition has been identified as a key pollutant in the Arctic. In this study new critical loads of acidity (S and N) were estimated for terrestrial ecosystems north of 60° latitude by applying the Simple Mass Balance (SMB) model using two critical chemical criteria (Al/Bc = 1 and ANC_le = 0). Critical loads were exceeded in large areas of northern Europe and the Norilsk region in western Siberia during the 1990s, with the more stringent criterion (ANC_le = 0) showing the larger area of exceedance. However, modeled deposition estimates indicate that mean concentrations of sulfur oxides and total S deposition within the Arctic almost halved between 1990 and 2000. The modeled exceeded area is much reduced when currently agreed emission reductions are applied, and almost disappears under the implementation of maximum technically feasible reductions by 2020. In northern North America there was no exceedance under any of the deposition scenarios applied. Modeled N deposition was less than 5 kg ha⁻¹ y⁻¹ almost across the entire study area for all scenarios; and therefore empirical critical loads for the eutrophying impact of nitrogen are unlikely to be exceeded. The reduction in critical load exceedances is supported by observed improvements in surface water quality, whereas the observed extensive damage of terrestrial vegetation around the mining and smelter complexes in the area is mainly caused by direct impacts of air pollution and metals.     

The intercoder agreement when using the Driving Reliability and Error Analysis Method in road traffic accident investigations

Many different classification schemes have been used in the analysis of road traffic accidents but the agreement between coders using the same classification scheme is rarely tested and/or reported. As a high intercoder agreement is a prerequisite for a study’s validity, this is a serious shortcoming. The aim of the present study was, therefore, to test the intercoder agreement of the Driving Reliability and Error Analysis Method (DREAM) version 3.0 by letting seven coders from different European countries analyse and classify the causes of the same four accident scenarios. The results showed that the intercoder agreement for genotypes (contributing factors) ranges from 74% to 94% with an average of 83%, while for phenotypes (observable effects) it ranges from 57% to 100% with an average of 78%. The results also showed that weaknesses in classification schemes, methods, training of coders as well as in presentation of accident information can be identified by testing the intercoder agreement.     

Synthesis of substituted diphenylamines and carbazoles: phototransformation products of diclofenac

The formation of stable and potentially hazardous compounds as a result of photochemical transformation of pharmaceutical substances in the aquatic environment implies a demand for standard compounds within environmental analysis. The major phototransformation products of diclofenac are comprised of substituted diphenylamines and carbazoles. Substituted diphenylamines were synthesized by Ullmann condensation reactions between anilines and halobenzenes. Monochlorocarbazoles were obtained from palladium-catalyzed intramolecular coupling reactions of monochlorinated diphenylamines, photocyclization of dichlorinated diphenylamines or by direct chlorination of carbazole. The availability of synthetic photoproducts of diclofenac is of critical importance for further studies on the environmental fate as well as the ecotoxicological effects of the drug in the environment.     

Exploring possibly increasing trend of hurricane activity by a SiZer approach

Statistical studies of hurricane activity in the North Atlantic basin are of current interest, not the least after the year of 2005 when many records were broken. An exploratory analysis of possibly increasing trend of the yearly number of hurricanes can be carried out by employing a graphic device, the SiZer map. Use of this method provides a useful complement to other statistical techniques for detection of trends or shifts in time series.     

Identification of acetylcholinesterase and cholinesterase in amniotic fluid by immune absorption technique

A method for immunological detection of acetylcholinesterase (AChE) and cholinesterase (ChE) in amniotic fluid is described. By addition of a small amount of antihuman-erythrocyte membrane antibody or anti-pseudocholinesterase antibody to the sample before electrophoresis the two esterase bands on polyacrylamide gel (PAG) can be absorbed away. Similar staining results can also be obtained by specific inhibition of the two esterases with either BW 284C51 (AChE inhibitor) or Lysivane (ChE inhibitor). In cases with a faint AChE band and in cases with blood contamination the immune absorption technique makes interpretation easier. Nearly identical staining results have been obtained by the immune absorption technique and the inhibition technique in the following samples with an AChE band: 34 samples from pregnancies with severe fetal malformation or intrauterine death (2 cases), 4 fetal serum samples, 4 samples of cerebrospinal fluid, 4 samples of fetal erythrolysate and 4 samples of adult erythrolysate. It can be concluded that an antibody prepared against erythrocyte AChE cross-reacts with AChE in cerebrospinal fluid, and that this antibody can be used for demonstration of AChE in amniotic fluid.     

Occurrence of organophosphorus compounds in polluted marine sediments near a pesticide manufacturing plant

Sediment samples from 23 sampling stations in Nissum Broad (Jutland, Denmark) have been analysed for their contents of 8 organophosphorus compounds: 4 pesticides and 4 related triesters.Only in a few samples, all collected within a short distance from a pesticide manufacturing plant, detectable levels of organophosphates have been observed. The levels ranged from less than 1 μg/kg (ppb) up to 3, 8 mg/kg (ppm) for single compounds.One compound, triethylphosphate, occurred at low concentrations (<1 ppb) in many sediment samples independently of the distance from the chemical plant. Assumably, for this compound, other sources of pollution than the chemical plant may be considered.