Spatially valid data of atmospheric deposition of heavy metals and nitrogen derived by moss surveys for pollution risk assessments of ecosystems

For analysing element input into ecosystems and associated risks due to atmospheric deposition, element concentrations in moss provide complementary and time-integrated data at high spatial resolution every 5 years since 1990. The paper reviews (1) minimum sample sizes needed for reliable, statistical estimation of mean values at four different spatial scales (European and national level as well as landscape-specific level covering Europe and single countries); (2) trends of heavy metal (HM) and nitrogen (N) concentrations in moss in Europe (1990–2010); (3) correlations between concentrations of HM in moss and soil specimens collected across Norway (1990–2010); and (4) canopy drip-induced site-specific variation of N concentration in moss sampled in seven European countries (1990–2013). While the minimum sample sizes on the European and national level were achieved without exception, for some ecological land classes and elements, the coverage with sampling sites should be improved. The decline in emission and subsequent atmospheric deposition of HM across Europe has resulted in decreasing HM concentrations in moss between 1990 and 2010. In contrast, hardly any changes were observed for N in moss between 2005, when N was included into the survey for the first time, and 2010. In Norway, both, the moss and the soil survey data sets, were correlated, indicating a decrease of HM concentrations in moss and soil. At the site level, the average N deposition inside of forests was almost three times higher than the average N deposition outside of forests.     

Neutral poly- and perfluoroalkyl substances in air and seawater of the North Sea

Concentrations of neutral poly- and perfluoroalkyl substances (PFASs), such as fluorotelomer alcohols (FTOHs), perfluoroalkane sulfonamides (FASAs), perfluoroalkane sufonamidoethanols (FASEs), and fluorotelomer acrylates (FTACs), have been simultaneously determined in surface seawater and the atmosphere of the North Sea. Seawater and air samples were taken aboard the German research vessel Heincke on the cruise 303 from 15 to 24 May 2009. The concentrations of FTOHs, FASAs, FASEs, and FTACs in the dissolved phase were 2.6–74, <0.1–19, <0.1–63, and <1.0–9.0 pg L^?1, respectively. The highest concentrations were determined in the estuary of the Weser and Elbe rivers and a decreasing concentration profile appeared with increasing distance from the coast toward the central part of the North Sea. Gaseous FTOHs, FASAs, FASEs, and FTACs were in the range of 36–126, 3.1–26, 3.7–19, and 0.8–5.6 pg m^?3, which were consistent with the concentrations determined in 2007 in the North Sea, and approximately five times lower than those reported for an urban area of Northern Germany. These results suggested continuous continental emissions of neutral PFASs followed by transport toward the marine environment. Air–seawater gas exchanges of neutral PFASs were estimated using fugacity ratios and the two-film resistance model based upon paired air–seawater concentrations and estimated Henry's law constant values. Volatilization dominated for all neutral PFASs in the North Sea. The air–seawater gas exchange fluxes were in the range of 2.5?×?10³–3.6?×?10⁵ pg m^?2 for FTOHs, 1.8?×?10²–1.0?×?10⁵ pg m^?2 for FASAs, 1.1?×?10²–3.0?×?10⁵ pg m^?2 for FASEs and 6.3?×?10²–2.0?×?10⁴ pg m^?2 for FTACs, respectively. These results suggest that the air–seawater gas exchange is an important process that intervenes in the transport and fate for neutral PFASs in the marine environment.     

Alkoxy-silyl Induced Agglomeration: A New Approach for the Sustainable Removal of Microplastic from Aquatic Systems

The substance class of inert organic-chemical stressors (IOCS) describes organic-chemical (macro-) molecules, which demonstrate a high level of persistence upon entry in the ecosystem, and whose degradation is limited. These synthetically produced organic-chemical macromolecules, which are often derived from the polymerization of different monomers, are, in the form of plastics, indispensable in the everyday world. They enter the environmental compartments and cause great damage due to primary (industry, cosmetic, washing of textile), and secondary (degradation) entry. If these particles get into aquatic systems, this has fatal consequences for the ecosystem such as the death of marine animals, or bioaccumulation. Wastewater treatment plants are reaching their limits and require innovative ideas for the sustainable removal of microplastic. This article examines a new approach to the removal of polymers from aquatic systems (lab scale) by using sol–gel induced agglomeration reactions to form larger particle agglomerates. These enlarged agglomerates can be separated much more easily from the wastewater, since they float on the water surface. Separation systems, e.g. sand trap can easily be used. A further advantage is that the agglomeration can be carried out completely independently of the type, size, and amount of the trace substance concentration as well as of the external influences (pH value, temperature, pressure). Thus, this new type of particle separation can not only be used in sewage treatment plants, but can also be transferred to decentralized systems (e.g. implementation in industrial processes).

Graphical Abstract

Open image in new window

     

Factors affecting adolescents’ use of urban public spaces in their leisure time: an exploratory study from the city of Vienna

Urban public spaces are important areas for leisure, recreation and physical activity and therefore contribute to the quality of life in cities. In particular, for adolescents they provide important spaces to meet with their peers, away from parental or school control. In many cities worldwide, public spaces have undergone severe developmental processes, and often a withdrawal from public space is noted. With regard to the opportunities those spaces provide for adolescents, it is necessary to investigate their current meaning for adolescents in a leisure context. In this article, qualitative research methods were used to investigate factors affecting adolescents’ use of public spaces in Vienna, Austria. In total 45 adolescents were interviewed. Results show that public open spaces are not regarded as important leisure spaces, and data reveal a strong retreat to private areas for leisure purposes. Perceived insecurities and fears support these processes and often result in avoidance of public spaces but also the wish for more control by authorities.     

How is a giant sperm ejaculated? Anatomy and function of the sperm pump, or “Zenker organ,” in Pseudocandona marchica (Crustacea, Ostracoda, Candonidae)

‘Giant sperm’, in terms of exceptionally long spermatozoa, occur in a variety of taxa in the animal kingdom, predominantly in arthropod groups, but also in flatworms, mollusks, and others. In some freshwater ostracods (Cypridoidea), filamentous sperm cells reach up to ten times the animal’s body length; nonetheless, during a single copulation several dozen sperm cells can be transferred to the female’s seminal receptacle. This highly effective ejaculation has traditionally been credited to a chitinous-muscular structure within the seminal duct, which has been interpreted as a sperm pump. We investigated this organ, also known as the Zenker organ, of a cypridoid ostracod, Pseudocandona marchica, utilizing light and electron microscope techniques and produced a three-dimensional reconstruction based on serial semi-thin histological sections. This paper shows that numerous muscle fibers surround the central tube of the Zenker organ, running in parallel with the central tube and that a thin cellular layer underlies the muscular layer. A cellular inner tube exists inside the central tube. A chitinous-cellular structure at the entrance of the organ has been recognized as an ejaculatory valve. In male specimens during copulation, we confirmed a small hole derived from the passage of a single spermatozoon through the valve. The new data allowed for proposing a detailed course of operation of the Zenker organ during giant sperm ejaculation.     

Modelling visitor groups' intentions to displace from an urban trail: a combined stated preference and video monitoring approach

Depending on gender and activity, overcrowding and safety concerns may detract from urban green space use. Differences in use displacement intentions from a recreational trail in a forest in Vienna were investigated for male and female walkers as well as male and female dog-walkers (N = 425) using an image-based stated preference model. The trail scenarios were depicted as digitally calibrated images that systematically displayed combinations of levels of crowding with different mixes of user types and visitor behaviour. Visitors were asked whether the presented recreation scenario was so unacceptable that they would shift their use away from the presented trail. Hours and days of stated non-use of the recreation trail by various user groups are estimated by integrating the results of the behavioural model with annual visitation data. Use displacement intentions differed by gender and activity. High use levels were a greater concern for all respondents than very low use levels, particularly for female dog-walkers. However, only a small proportion of the recorded hours were heavily used. Safety concerns about very low use levels reduced the potential times of forest use for female walkers without a dog.     

Chlorinated hydrocarbons in sediments of the Elbe River and the Elbe Estuary

Eight sediment samples collected between Hamburg and Cuxhaven were analysed for organic micropollutants. Using three different methods the following compounds were determined: α-HCH, γ-HCH, HCB, PCB, DDT-family, pentachlorobenzene and octachlorostyrene.     

Die organisation der Früherkennung von Umweltproblemen im Rahmen der wissenschaftlichen Beratung der Umweltpolitik

This study is based on the theses that

1. early diagnosis is indispensable in the context of precautionary policy for the management of environmental problems which have the character of a “creeping disaster”, and that
2. the public must play the active role that is adequate within a democratic society.

In the context of the study, three existing advisory committees for environmental policy as well as two concepts which have not been put into effect are investigated. The third part deals with the critique of these committees and an alternative concept of early diagnosis “General Ecological Monitoring” which has not yet been put into effect. In part I, the concept of the Picht commission from 1972, which has never been realized in this form has been introduced. In part II, the concepts and the working method of the three existing advisory committees (SRU, WBGU, TAB) have been presented. In part IV, the work of the oldest of the committees, the SRU, is examined with respect to the three most important environmental problems of the last 15 years.