Einfluss organischer Substanz auf die Reproduktion, Biomasse und Akkumulation hydrophober Schadstoffe in Lumbriculus variegatus

Background, aim, and scope Sediment-Water Toxicity Tests are an important instrument for the environmental risk assessment of native, contaminated sediments within the European Water Framework Directive. Thus, it must be guaranteed to distinguish between natural and anthropogenic adverse effects. The content of particulate (POC) and dissolved (DOC) organic carbon can affect the mobility of sediment pollutants. Different studies demonstrated that the DOC-content can influence the bioavailability of contaminants and can directly affect aquatic organisms. The aim of this study was to investigate the influence of increasing sediment organic matter on reproduction and growth of the benthic oligochaete Lumbriculus variegatus. Furthermore, the accumulation factors of the hydrophobic substances 1,1-dichloro-2,2-bis(p-chlorphenyl)ethylene (p,p'-DDE), 2´, 3, 4, 4´, 5´-Hexachlorbiphenyl (PCB 138) und 2, 2´, 4, 4´, 5, 5´-Hexachlorbiphenyl (PCB 153) were calculated considering the TOC-content and the uptake route (water-only exposure or sediment ingestion). Materials and methods The test was performed according to the OECD Guideline 225 (2007) using artificial sediment with different peat concentrations. The effect of an increasing TOC-concentration was studied in three different testmodifications with and without spiked sediment. The nominal concentration of the contaminants in spiked sediment was 50?µg/kg. Results The results showed maximum accumulation factors of 13 for both, PCB 138 and 153 and 11 for p,p'-DDE in sediments with low organic carbon content. With increasing peat content accumulation factors decreased. Thereby the ingestion of sediment was the main exposure route. Moreover preponderantly negative correlations between the organic carbon content in unspiked sediments and reproduction as well as growth of the testorganisms were detected. In combination with the test substances reproduction and growth increased with increasing organic carbon content. Discussion Hence it can be assumed that organic matter, especially humic substances, directly effected the testorganisms in the tests without spiked sediment. Due to the decrease of accumulation factors in spiked sediment with increasing TOC-content it might be possible that the availability of humic substances was reduced by conglomeration with the tested chemicals. Conclusions Therefore the possible influence of dissolved organic matter on the testorganism should be considered when assessing the results of toxicity tests and bioaccumulation studies with Lumbriculus variegatus. Recommendations and perspectives To receive detailed information about a critical DOC-concentration influencing the testorganisms further investigations about the amount of organic matter in the sediment and the DOC-concentration in the overlaying water are recommended.     

Land Consumption by Urban Sprawl—A New Approach to Deduce Urban Development Scenarios from Actors’ Preferences

A new modelling approach to urban sprawl dynamics is introduced which allows representing qualitative knowledge on relations between moving actor populations and properties of locations. The results of this Qualitative Attractiveness Migration (QuAM) Model are scenario-like sets of possible future developments of the urban system, much in contrast to quantitative forecasts gained by traditional modelling approaches. QuAM models allow for the interaction between internal dynamics and external influences. The application of the new approach is exemplified by the case of urban sprawl in Leipzig since 1990. It was possible to reproduce the observed qualitative development and to calculate future scenarios. The scenario runs project a new wave of middle class driven residential sprawl and suggest implications for sprawl reducing policy interventions.     

Organochlorverbindungen in Eiern von Wanderfalken und anderen wild lebenden Vogelarten in Baden-Württemberg

Goal and Scope

Organochlorine pollutants such as some pesticides and polychlorinated biphenyls (PCBs), dioxins and furans (PCDD/F) are highly persistent compounds in the environment. As synthetic, man-made products they are not encountered in natural ecosystems. Due to their high lipid solubility these compounds can accumulate in animals and humans, where they may exert chronically toxic and carcinogenic effects or disrupt endocrine functions and/or interfere with reproduction. Sound environmental stewardship demands continuous monitoring of such substances, assessment of their ecotoxicological risk, and reduction of excessive risk by setting appropriate standards.

Methods

The analysis of birds’ eggs is one method for the detection of organochlorine pollutants in ecosystems. In the German state of Baden-Wuerttemberg eggs of some bird species, especially Peregrine falcons, have been collected and analysed for selected persistent organic pollutants [total DDT (dichlorodiphenyl-trichloroethane), HCB (hexachlorobenzene), HCEP (heptachloroepoxide), HCH (hexachlorocyclohexane), PCBs] since the 1970s. Long-term continuous investigations yield data concerning temporal changes and regional differences in the pollution of the bio-indicators.

Results and Conclusion

Dioxin-like PCBs and total DDT were the most prominent pollutants. The Peregrine falcon (Falco peregrinus) was the most polluted bird species within the project. During the 1970s and 1980s all of the mentioned substances showed an encouraging decrease, undoubtedly because their use was banned in Germany. Analyses for PCDD/F in a small number of Peregrine falcon eggs from the period of 2000 to 2003 revealed the high level of pollution of these samples with dioxin toxicity equivalents (WHO-TEQ) from PCB and PCDD/F, which in all eggs reached the no observed effect level (NOEL) determined in osprey chicks and surpassed this threshold fivefold in the most polluted one.. Because of their great variability the pollutant concentrations in the eggs were difficult to interprete in some cases. Based on the results for the Peregrine falcon eggs of the years 2001 to 2003 a statement concerning the regional distribution of DDT and PCBs in Baden-Wuerttemberg could be made and depicted on the map. Because of their high lipid content, birds’ eggs are generally well suited as bio-indicators for the accumulation of persistent and lipophilic compounds.

Recommendations and Perspective

In spite of the significant decline of the organochlorine concentrations in the eggs of the birds investigated, the present situation is still alarming. Too many of the analytical data continue to exceed the respective national and EU-wide limit values for food and feed, and in the case of dioxin equivalents even lie above the assumed action threshold in the indicator organism. Therefore it is necessary to continue the bio-monitoring in Baden-Wuerttemberg in order to be able to recommend reduction measures where appropriate.     

Polybrominated diphenyl ether exposure to electronics recycling workers--a follow up study

Workers at an electronics recycling plant have previously been shown to have elevated serum levels of polybrominated diphenyl ethers (PBDEs) compared to referents without occupational PBDE exposure. Subsequent structural changes and industrial hygiene measures at the plant were applied to improve the work environment. The present study aims to assess the impact of these work environment changes on the occupational exposure to PBDEs.

Blood were drawn from the workers and analyzed at two different laboratories, and serum concentrations of several PBDE congeners were determined by GC/MS or GC/HRMS. Cross-sectional studies were performed prior to (in 1997; N = 19) and after (in 2000; N = 27) workplace improvements. Longitudinal studies were performed on twelve of the workers that were sampled at both occasions.

Even though the amount of processed goods had doubled in 2000 as compared to 1997, there was a significant decrease in the serum levels of BDE-183 and BDE-209. For BDE-209 the levels observed in year 2000 were even lower than in referents with no occupational exposure. In contrast to the decrease of higher brominated diphenyl ethers, the concentrations of BDE-47 did not significantly change. For BDE-153, the cross-sectional study indicated no change, whereas the longitudinal follow up indicated a significant increase.

This study shows that the industrial hygiene improvements clearly reduced the occupational exposure to BDE-183 and BDE-209 at the plant. Still, the levels of hexa- to nonaBDEs but not BDE-209 were elevated, compared to referents with no occupational exposure.     

Visual targeting of components of floral colour patterns in flower-naïve bumblebees (Bombus terrestris; Apidae)

Floral colour patterns are contrasting colour patches on flowers, a part of the signalling apparatus that was considered to display shape and colour signals used by flower-visitors to detect flowers and locate the site of floral reward. Here, we show that flower-naïve bumblebees (Bombus terrestris) spontaneously direct their approach towards the outside margin of artificial flowers, which provides contrast between these dummy flowers and the background. If no floral guides are present, the bumblebees continue to approach the margin and finally touch the marginal area of the dummy flower with the tips of their antennae. Whilst approaching dummy flowers that also have a central floral guide, the bumblebees change their direction of flight: Initially, they approach the margin, later they switch to approaching the colour guide, and finally they precisely touch the floral guide with their antennae. Variation of the shape of equally sized dummy flowers did not alter the bumblebees’ preferential orientation towards the guide. Using reciprocal combinations of guide colour and surrounding colour, we showed that the approach from a distance towards the corolla and the antennal contact with the guide are elicited by the same colour parameter: spectral purity. As a consequence, the dummy flowers eliciting the greatest frequency of antennal reactions at the guide are those that combine a floral guide of high spectral purity with a corolla of less spectral purity. Our results support the hypothesis that floral guides direct bumblebees’ approaches to the site of first contact with the flower, which is achieved by the tips of the antennae.Electronic Supplementary Material  Supplementary material is available for this article at     

Modelling land use change across elevation gradients in district Swat, Pakistan

District Swat is part of the high mountain Hindu-Kush Himalayan region of Pakistan. Documentation and analysis of land use change in this region is challenging due to very disparate accounts of the state of forest resources and limited accessible data. Such analysis is, however, important due to concerns over the degradation of forest land leading to deterioration of the protection of water catchments and exposure of highly erodible soils. Furthermore, the area is identified as hotspot for biodiversity loss. The aim of this paper is to identify geophysical and geographical factors related to land use change and model how these relationships vary across the district. For three selected zones across the elevation gradient of the district, we analyse land use change by studying land use maps for the years 1968, 1990 and 2007. In the high-altitude zone, the forest area decreased by 30.5 %, a third of which was caused by agricultural expansion. In the mid-elevation zone, agriculture expanded by 70.3 % and forests decreased by 49.7 %. In the lower altitudes, agriculture expansion was 129.9 % consuming 31.7 % of the forest area over the forty-year time period. Annual deforestation rates observed were 0.80, 1.28 and 1.86 % in high, mid and low altitudes, respectively. In the high-altitude ecosystems, accessibility (distance to nearest road and city) had no significant role in agriculture expansion; rather land use change appears significantly related to geophysical factors such as slope, aspect and altitude. In the low-elevation zone, accessibility was the factor showing the closest association with agriculture expansion and abandonment. The analysis illustrates that land use change processes vary quite considerably between different altitudinal and vegetation cover zones of the same district and that environmental constraints and stage of economic development provide important contextual information.     

Arzneimittel, Diagnostika und Desinfektionsmittel in der Umwelt

Zusammenfassung  Ein Eintrag von Arzneimitteln, Diagnostika und Desinfektionsmitteln in die Umweltbereiche Wasser und Boden kann aus Krankenh?usern, anderen medizinischen Einrichtungen, Haushalten (Verschreibungen durch niedergelassene ?rzte) und der Tierhaltung bzw.-mast oder-zucht einschlie?lich der Aquakultur (Arzneimittel zur Therapie und Prophylaxe sowie Futtermittelzusatzstoffe) sowie durch den Gebrauch bei Heimtieren resultieren. Im Folgenden sollen grunds?tzliche Erw?gungen und übergeordnete Gesichtspunkte zum Eintrag von Pharmaka, Diagnostika und Desinfektionsmitteln ausführlicher er?rtert werden. Im Mittelpunkt stehen dabei neben den gesetzlichen Regelungen die Eigenschaften der Stoffe, ihr daraus abzuleitendes Umweltverhalten, die damit verbundene Risikoabsch?tzung sowie notwendige Ma?nahmen zur L?sung des Problemkreises ‘Arzneimittel in der Umwelt’. Neben den eigentlichen Arzneimitteln werden in der Human- und Tiermedizin eine Vielzahl weiterer Stoffe z.B. für die Diagnostik und aus hygienischen Gründen verwendet. Sie werden in die Betrachtungen eingeschlossen. Dieser Beitrag ist Prof. Dr. Fritz Frimmel zum 60. Geburtstag gewidmet.     

Persistente Organische Schadstoffe Persistent Organic Pollutants, POPs

Einführung Beitragsserie POPs

Persistente Organische Schadstoffe Persistent Organic Pollutants, POPs