99Tc in seawater in the West Spitsbergen Current and adjacent areas

99Tc levels were measured in seawater samples collected between 2000 and 2002 in the West Spitsbergen Current (WSC) and along the western coast of Svalbard or Spitzbergen and compared with available oceanographic 3-D modelling results for the late 1990s. Additional data from related regions are also presented in order to support the data interpretation. The seawater in the Arctic fjord Kongsfjorden on the western coast of Svalbard is influenced by the WSC, as shown by the 99Tc levels in surface water. By means of the WSC, 99Tc reaches the Eastern Fram Strait, where one branch of the WSC turns west into the East Greenland Current (EGC), and another branch continues northwards into the Arctic Ocean. Surface seawater collected in the central part of the WSC during a cruise on board the R/V "Polarstern" in the summer of 2000, showed higher levels of (99)Tc than samples measured in Kongsfjorden in the spring of 2000. However, all levels measured in surface water are of the same order of magnitude. Data from sampling of deeper water in the WSC and EGC provide information pertaining to the lateral distribution of 99Tc. In all vertical profiling surveys (conducted in spring and summer), the highest levels of 99Tc were found in surface water. Comparison with oceanographic 3-D modelling indicates both significant seasonal variations in the lateral stratification of the WSC and variations with depth over shorter vertical distances. This information can be applied in sampling strategies, environmental monitoring, long-range transport of pollutants and physical oceanography.     

Toxicity testing of heavy metals with theRhizobium-legume symbiosis: High sensitivity to cadmium and arsenic compounds

Legume root nodules are the site of biological nitrogen fixation in theRhizobium-legame symbiosis. Nodules are structures unique to this symbiosis and they are morphologically as well as physiologically distinct from other plant organs. Organic substances affecting the macro- or microsymbionts vitality, such as PAHs (Wetzel et al., 1991), reduce nodulation even before visible damage to the plant can be detected. We present data that the formation of nodules (nodulation) may also serve for ecotoxicological evaluation of heavy metals in different binding states. Tests were performed in petri dishes with alfalfa (lucerne) seedlings inoculated withRhizobium meliloti. Cultivation took place in growth cabinets with carefully standardized and documented growth conditions. Data from stressed plants was recorded after 14 days of cultivation on contaminated substrate. A dose responsive decrease in nodulation was found after application of cadmium acetate, cadmium iodide, cadmium chloride, sodium salts of arsenate and arsenite, arsenic pentoxide, and lead nitrate, whereas lead acetate showed no effect up to a concentration of 3 μM. The dose response curves were used to calculate EC10, EC50 and EC90 values. EC50 values for cadmium compounds range from 1.5 to9.5 pM. Testing different arsenic compounds results in EC50 from 2.6 to 20.1 μM. EC50 of lead nitrate is 2.2 μM. The sensitivity, reproducibility and reliability of this test system is discussed compared to established biotests.     

Promoting safety by training supervisors and safety representatives for daily safety work

Safety at Finnish work places is mainly considered to be the task of a separate safety organization, e.g., a safety manager and safety delegates. However, it is the supervisor who is responsible for the daily safety in the departments. The Finnish paper industry has developed a supplementary system for the safety organization to carry out safety work in the factories. The monitoring and improving of the daily safety has been delegated to small groups in the production departments. These small groups consist of the supervisor and the safety representative (worker member) of the work area. Sometimes also a department manager or a member of the maintenance department may participate in the work group. A training program was designed to give basic knowledge and skills for the groups. The course has helped the participants to better outline their duties and activities within the safety field.     

A multiresidue method for the analysis of phenols and nitrophenols in the atmosphere

A method using GC-MS and derivatization with N-(t-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA) was developed for the analysis of 20 phenolic compounds in atmospheric samples (gas and particles). Air sampling was carried out using a Hi-Vol sampler with glass fibre filter and XAD-2 resin at a flow rate of 60 m(3) h(-1). The particle and gas phases were collected separately over a period of 4 h. Samples were Soxhlet extracted, evaporated to dryness under nitrogen and refilled with acetonitrile. 100 microl of these extracts were derivatized with 100 microl of MTBSTFA at 80 degrees C for 1 h under strong stirring. Phenolic compounds were injected into a GC-MS in splitless mode and quantified as their TBDMS derivatives in the SIM mode. Mass spectral analysis of the derivatives of the 20 compounds studied indicates that the spectra are highly specific showing an ion at [M - 57]+ which is useful for structure confirmation or analysis at low levels using selected ion monitoring. Quantification limits varied between 5 microg l(-1) and 10 microg l(-1) which correspond to 20 pg m(-3) and 40 pg m(-3) for 250 m(3) of air sampled. This method was successfully applied to atmospheric samples.     

Monitoring ammonia in urban, inner alpine and pre-alpine ambient air

Passive samplers were used to monitor ammonia concentrations at rural inner alpine and pre-alpine, as well as urban, sites in Austria and Bavaria. Elevated concentrations were measured both at farms (up to 36 microg NH3 m(-3)) and at urban locations (up to 28 microg NH3 m(-3)). At urban locations a linear relationship between the traffic density and the NH3 concentration was found, but there was no marked seasonal trend. The highest ammonia concentrations were measured in a traffic tunnel (up to 78 microg NH3 m(-3)). The presence of livestock breeding or small scale alpine pastures resulted in elevated concentrations at the rural sites (8.1-12 and 2.5-4.6 microg NH3 m(-3), respectively), compared to the surrounding areas (3.1 and 0.9 microg NH3 m(-3)). Agriculture related sources are usually limited either spatially or seasonally. As the emissions were moderate in our case, a rapid removal and dilution of ammonia was possible and therefore the NH3 burden was only local. Sources related to traffic are more evenly distributed both geographically and seasonally. The WHO guideline, annual average concentration of 8 microg m(-3) for the protection of vegetation, was only exceeded at farms, at the urban station with the heaviest traffic and in the Tauerntunnel.     

Influence of ripening on pHstat leaching behaviour of heavy metals from dredged sediments

The influence of oxidation and ripening on the kinetics of heavy metal release from anoxic sediments was investigated by means of porewater analysis and pH(stat) leaching tests. During simulated land disposal of an anoxic river sediment, a considerable heavy metal (Cd, Zn and Ni) release into the porewater was observed after 25 days of exposure of the sediment to the air. The release kinetics of Cd and Zn during pH(stat) leaching indicated that their release was related to the oxidation of Cd- and Zn-sulfides. It was not completely clear whether the release of Ni was due to the oxidation of Ni-sulfides or to the introduction of H(+)(generated by the oxidation of sulfides or introduced by titration). The release of Cu seemed to be explained by the oxidation of both Fe-sulfides and Cu-sulfides. As such, pH(stat) experiments provided an indirect way to assess the mineralogy of the anoxic sediment. During ripening of the sediment, the release rate of Zn and Cd in pH(stat) leaching tests increased. For Ni, however, a similar release pattern was observed in the anoxic sediment and in the ripened sediments. Two weeks' drying at 100 degrees C resulted in an increase in the leachability of Cu. Nevertheless, at pH 4 and 6, the thermally treated sediment displayed a slower leaching of Cd and Zn than the ripened sediment. Although thermal treatment is often used to simulate ageing in soils, it cannot be used to simulate ripening of anoxic sediments.     

Geostatistical analysis as applied to two environmental radiometric time series

This article details the results of an investigation into the application of geostatistical data analysis to two environmentalradiometric time series. The data series employed consist of ⁹⁹Tc values for seaweed (Fucus vesiculosus) and seawater samples taken as part of a marine monitoring program conducted on the coast of northern Norway by the Norwegian Radiation Protection Authority. Geostatistical methods were selected in order to provide information on values of the variables at unsampled times and to investigate the temporalcorrelation exhibited by the data sets. This information is ofuse in the optimisation of future sampling schemes and for providing information on the temporal behaviour of the variablesin question that may not be obtained during a cursory analysis.The results indicate a high degree of temporal correlation withinthe data sets, the correlation for the seawater and seaweed databeing modelled with an exponential and linear function,respectively. The semi-variogram for the seawater data indicatesa temporal range of correlation of approximately 395 days with noapparent random component to the overall variance structure and was described best by an exponential function. The temporal structure of the seaweed data was best modelled by a linear function with a small nugget component. Evidence of drift was present in both semi-variograms. Interpolation of the data setsusing the fitted models and a simple kriging procedure were compared, using a cross-validation procedure, with simple linearinterpolation. Results of this exercise indicate that, for theseawater data, the kriging procedure outperformed the simpleinterpolation with respect to error distribution andcorrelation of estimates with actual values. Using theunbounded linear model with the seaweed data produced estimatesthat were only marginally better than those produced by thesimple interpolation.     

A comparison of Lowry,Bradford and Smith protein assays using different protein standards and protein isolated from the marine diatom Thalassiosira pseudonana

Two spectrophotometric assays for protein commonly used in marine research (Coomassie stain, Bradford; alkaline copper, Lowry) and a more recent assay which has not been applied in this field (bicinchoninic acid, Smith) were compared for homogenates of the marine diatom Thalassiosira pseudonona using bovine serum albumin (BSA) as a standard. When homogenates were prepared by precipitating protein with trichloroacetic acid (TCA) and redissolving in 1 N NaOH, the protein content estimated by the Lowry and Smith assays agreed closely, but was consistently 20% higher than that indicated by the Bradford assay. To determine if this difference was due to the choice of a protein standard, protein from T. pseudonana was purified and compared to BSA, bovine gamma-globulin (BGG), and casein. The reactivity of the purified protein (expressed as the slope of the absorbance vs protein concentration curve) did not differ between cultures grown at high or low irradiance. For the Smith and Bradford assays the reactivity of BSA was not significantly different from algal protein, but for the Lowry assay, algal protein was significantly higher in reactivity than BSA. BGG was not significantly different in reactivity from algal protein for the Lowry and Smith assays, but BGG gave significantly lower absorbances than algal protein in the Bradford assay. These results suggest that BSA is a suitable standard for algal protein in the Bradford assays, while BGG is preferable for the Lowry assay. Either protein standard could be used for the Smith assay. Differences in purified algal protein reactivity compared to BSA could not account for the differences among the assays, nor could interference by chlorophyll a. Precipitating protein with TCA prior to analyses gave lower protein than direct analyses of homogenates for the Lowry and Smith assays, but no differences were found for the Bradford assay. As a result, the Lowry and Smith assays indicated up to 60% greater protein than the Bradford if TCA precipitation was not performed. This may be due to removal of free amino acids and small peptides which are less reactive in the Bradford assay. The 20% higher protein found in the Lowry or Smith vs Bradford assays may be due to different assay sensitivity to small peptides or other compounds which are precipitated along with proteins by TCA. Although the Smith assay is substantially simpler to perform than the Lowry, there appear to be no quantitative differences in the results. It remains unclear which spectrophotometric assay is most accurate, but the Bradford assay is faster and simpler, and is less likely to be affected by non-protein compounds found in marine phytoplankton.     

Liquid crystallinity of levan/water/starch solutions

Transmitted light measurements performed with a UV-visible spectrophotometer were used to characterize how starch affects the position of boundaries on the phase diagram for dilute aqueous solutions of levan (a branched polymer of fructose). Data were collected in the range 15 to 70°C; the minimum concentrations required for separation of a nematic phase and the minimum concentration required for a fully nematic solution were identified within this range. While hard interactions (repulsion between rod-like molecular segments) dictate the formation of a liquid crystalline phase at and above ambient temperature in the absence of starch, soft interactions become more significant as solutions are cooled toward ambient when starch is present. Small amounts of starch might be used as a filler to modify the mechanical properties (while retaining the process-related benefits) of levan films cast from liquid crystalline solution.