Determination of herbicides in stemflow and throughfall of beeches (Fagus sylvatica L.) and in rainfall

The pesticide contamination of water samples collected in and nearby a beech forest in northern Germany was evaluated. For this purpose, a method for the collection of water samples from stemflow and throughfall of beeches (Fagus sylvatica L.) and rainfall was developed in response to the demands for the analysis of organic contaminants in water samples. Furthermore a sensitive and selective multiresidue method was developed to determine 18 pesticides, frequently used in Germany, in aqueous samples. The samples collected were taken from the stemflow, the crown throughfall and the rainfall between May and November 2001. Analysis based on reversed-phase liquid chromatography with a pneumatically assisted electrospray mass spectrometer followed a solid phase extraction using C-18 extraction cartridges. Isoproturon, metolachlor, prosulfocarb and terbuthylazine were found during and shortly after their application period. In rainfall metolachlor, terbuthylazine and prosulfocarb were detectable in concentrations between 5 and 65 ng l(-1) and isoproturon in concentrations between 20 and 360 ng l(-1) respectively. In most of the samples, concentrations of those four pesticides were higher and detectable for a longer time in stemflow than in rainfall. Crown throughfall samples were collected from the end of August to November. Absolute deposition of isoproturon to forest soil were up to 70 times higher in comparison to rainwater samples.     

Partitioning of polychlorinated biphenyls and hexachlorobenzene into human faeces

The dietary absorption of persistent lipophilic organic pollutants (PLOPs) in humans is believed to occur via partitioning of the chemical between the lumen and the wall of the digestive tract. As such, the partitioning properties of the lumen contents are a key factor governing absorption. In this study, the partitioning properties of faeces were measured for 11 polychlorinated biphenyls and hexachlorobenzene (HCB). Four volunteers participated in the study, each of them providing faeces from a normal diet and a vegetarian diet. The faeces/gas equilibrium partition coefficient K(FG) varied by over three orders of magnitude between the different compounds. A linear relationship between log K(FG) and log KOA, the octanol/air partition coefficient, was observed. The slope of the relationship was > 1, indicating that the solvent properties of faeces were less polar than those of octanol. For a given compound, KFG varied up to a factor of 2.8 between the individuals on a normal diet. The influence of the vegetarian diet on K(FG) was negligible for the two volunteers who simply deleted fish and animal products from their normal diet, but K(FG) increased on average by a factor of 2 in the two individuals who increased their consumption of less readily digestible whole grains and vegetables in their vegetarian diet. On the basis of K(FG), the fugacities in the faeces were calculated. They were found to be much lower than the fugacities in blood. It is hypothesised that this is due to a temporary decrease in the fugacity in the wall of the jejunum caused by absorption of dietary lipids that results in equilibration between the lumen contents and the wall of the digestive tract at a fugacity below that present in the blood and the rest of the body.     

PIXE trace element analysis of an aquatic plant as indicator of heavy metal pollution

A new way of detecting trace elements in water is developed by using charged $\text{P}$article $\text{I}$nduced $\text{X}$-ray $\text{E}$mission (PIXE) analysis of cell walls of $\text{Chara corallina}$, a fresh water alga.     

Analysis of 2,3,7,8-Tetrachlorodibenzo-p-dioxin in Great Lakes fish

In fish samples from Lake Ontario and Lake Huron 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was found at concentrations from 2 to 162 pg/g (ppt) and from 2.5 to 29 ppt respectively. Fish from the other Great Lakes (Lake Superior, Lake Michigan and Lake Erie) generally had no detectable signals for TCDD although a few samples had < 3 ppt.     

Investigating missing sources of glyoxal over China using a regional air quality model (RAMS-CMAQ)

Currently, modeling studies tend to significantly underestimate observed space-based glyoxal(CHOCHO) vertical column densities(VCDs), implying the existence of missing sources of glyoxal. Several recent studies suggest that the emissions of aromatic compounds and molar yields of glyoxal in the chemical mechanisms may both be underestimated, which can affect the simulated glyoxal concentrations. In this study, the influences of these two factors on glyoxal amounts over China were investigated using the RAMS-CMAQ modeling system for January and July 2014. Four sensitivity simulations were performed, and the results were compared to satellite observations. These results demonstrated significant impacts on glyoxal concentrations from these two factors.In case 1, where the emissions of aromatic compounds were increased three-fold,improvements to glyoxal VCDs were seen in high anthropogenic emissions regions. In case 2, where molar yields of glyoxal from isoprene were increased five-fold, the resulted concentrations in July were 3–5-fold higher, achieving closer agreement between the modeled and measured glyoxal VCDs. The combined changes from both cases 1 and 2 were applied in case 3, and the model succeeded in further reducing the underestimations of glyoxal VCDs. However, the results over most of the regions with pronounced anthropogenic emissions were still underestimated. So the molar yields of glyoxal from anthropogenic precursors were considered in case 4. With these additional mole yield changes(a two-fold increase), the improved concentrations agreed better with the measurements in regions of the lower reaches of the Yangtze River and Yellow River in January but not in July.     

Die Wirkung des Isonikotinsäurehydrazids auf die Zellmorphologie von Mykobakterien

The Science of Nature -     

Implementation of the ecosystem services approach in Swedish municipal planning

While ecosystem-based planning approaches are increasingly promoted through international and national policies, municipalities are still struggling with translating them into practice. Against this background, this paper aims to increase the knowledge of current advances and possible ways to support the implementation of the ecosystem services (ES) approach at the municipal level. More specifically, we analyze how ES have been integrated into comprehensive planning within the municipality of Malmö in Sweden over the last 60 years, a declared forerunner in local environmental governance. Based on a content analysis of comprehensive plans over the period 1956–2014 and interviews with municipal stakeholders, this paper demonstrates how planning has shifted over time toward a more holistic view of ES and their significance for human well-being and urban sustainability. Both explicit and implicit applications of the ES concept were found in the analyzed comprehensive plans and associated programs and projects. Our study shows how these applications reflect international, national, and local policy changes, and indicates how municipalities can gradually integrate the ES approach into comprehensive planning and facilitate the transition from implicit to more explicit knowledge use.     

Evaluation of trajectories calculated from ecmwf data against constant volume balloon flights during etex

This paper validates trajectories calculated from ECMWF analyses against the tracks of constant volume balloons (CVBs) released during the European tracer experiment (ETEX). The altitudes of the calculated trajectories were adjusted to the altitudes of the respective balloons in short intervals to allow direct comparisons. The agreement between the calculated trajectories and the balloon tracks was very good for the first experiment (individual errors from 1 to 26%, average 15%), and excellent (errors from 2 to 11%, average 6%) for the second one. The agreement for the second experiment was probably partly better because the CVBs travelled above the planetary boundary layer, but the small errors also indicate that the ECMWF fields of the horizontal wind were of exceptionally good quality in the second experiment. This is in sharp contrast to the results of the dispersion models which all failed in the prediction of the perfluorocarbon tracer dispersion for the second experiment. A likely explanation for this is that vertical motions, possibly on small scales, were not correctly captured by the ECMWF analyses, but it is not possible to clarify this with the CVB data.     

Experimental evidence for the effects of task repetitiveness on mental strain and objective work performance

People frequently have to work in high repetitive jobs. Previous research has focused exclusively on the effects of task repetitiveness on well‐being, while neglecting effects on work performance. In the present study, we aimed to fill this void by conducting two workplace simulations with experimental manipulations of task repetitiveness. Participants worked for about 5 hours at either a computer workstation, compiling computer hardware packages according to customer requests (Experiment 1, N = 160), or at an assembly line, piecing together equipment sets for furniture (Experiment 2, N = 213). Both experiments provide consistent evidence that high repetitiveness has a detrimental effect on well‐being, whereas work performance increases under conditions of high repetitiveness. On a practical level, our study hence shows that high task repetitiveness is a double‐edged sword for both employees and organizations. On a conceptual level, our findings emphasize the necessity to account for both mental strain and work performance when examining the effects of task repetitiveness. Copyright © 2014 John Wiley & Sons, Ltd.