Bleiverunreinigung von trinkwasser durch leitungssysteme in Berlin

There are many acute and chronic adverse effects of lead on human beings. This is especially true for infants and children. In Germany, the intake of lead through drinking water is commonly due to metal corrosion of the user’s plumbing. In the last years and decades, many lead pipes in Germany were replaced by pipes made of alternative materials. The aim of this study was to assess the present state of drinking water contamination and the resulting lead exposure in infants, the most sensitive population group. For this purpose, mothers of newborn babies were offered a free examination of their drinking water. After a written declaration of consent had been received, two composite samples collected during the day were obtained from the families. The samples were analyzed for their lead concentration using atomic absorption spectrometry. A total of 2109 samples from house holds in the area of Berlin, Germany were collected. From the first composite samples 5.6% and 7.0% of the second composite samples demonstrated lead concentrations higher than 0.01 mg/l (recommended limit of the WHO). 0.95% of the first composite samples and 1.3% of the second composite samples had concentrations above the limit of the German drinking water regulation (0.04 mg/l). The highest measured lead concentrations is the first and second composite samples were 0.19 and 0.13 mg/l, respectively. By region, the suburbs of Charlottenburg, Neukölln, Schöneberg, Wilmersdorf and Zehlendorf were particularly severley affected with more than 10% and their samples being elevated above 0.01 mg/l.     

A New and Sound Technology for Biogas from Solid Waste and Biomass

Organic waste, as a main constituent of municipal solid waste, has as well as solid biomass a high potential for biogas generation. Despite the importance of biogas generation from these materials, the availability of large-scale biogas processes lacks behind the demand. A newly developed double-stage solid–liquid biogas process, consisting of an open hydrolysis stage and a fixed-bed methane reactor, allows the biogas production from almost all biodegradable solid waste and renewable resources like maize, grass, sugar cane, etc. Furthermore, residues from industrial processes, like the glycerine waste water from biodiesel production, can also be converted into biogas successfully. Due to the strong separation of hydrolysis and methanation, the process is extremely stable. No malfunction has been detected so far. The open hydrolysis releases CO₂ and allows oxidation of sulfur. Consequently, the biogas has a high methane (>72%) and low H₂S concentration (<100 ppm). Stirrers or other agitation equipment are not necessary; only liquids are pumped. The biogas generation becomes controllable for the first time; thus, the actual generation can be easily adapted to the consumption.     

Are you an ambitious cyclist? Results of the cyclist profile questionnaire in Germany

Abstract

Objective: A number of studies have already grouped cyclists according to different aspects of their mobility behavior. This could be used e.g., to improve the bicycle infrastructure planning, to detect critical spots and, to reduce obstacles for cycling. This wide, preexisting, range of cyclist typologies usually concentrates on one or two influence factors and differs, content-wise, in both factors used, as well as, methodically. Based on existing cyclist typologies we extracted all possible influence factors to integrate them in one single questionnaire. The objective of this study, using an empirical, based approach, is to compare this typology of cyclists with existing ones, integrating all known influence factors of recent studies.

Methods: To address these issues, we conducted a Germany-wide online survey on cycling behavior, covering all relevant aspects we derived from both literature and especially, former cyclist typology studies including: social factors; the impact of environmental, individual; and route factors; as well as motives. The main goal was to identify distinct types of cyclists, and describe them as detailed as possible. The heterogeneous sample included a total of 10,294 responses.

Results: Using factor and cluster analyses, a multidimensional typology with four groups of cyclists was derived which were interpreted as: ambitious, functional, pragmatic, and passionate cyclists. In addition, socio-economic factors, cyclist’s motivation, and crash history were analyzed.

Conclusion: The results produced by grouping different characteristics of cyclists can lead to policy recommendations or communal bicycle traffic planning. Policy planners can estimate reactions of the different types on interventions and adjust their decisions which can serve to support already passionate cyclists or, encourage normally under-represented infrequent cyclists to cycle more. The extent of perceived safety plays here an important role in the classification, e.g., the handling of high-risk areas for crashes.     

Scenarios of bioenergy provision: technological developments in a landscape context and their social effects

While it is developing rapidly throughout Germany, bioenergy provision is open to different development opportunities. To understand the cause–effect relationships that drive bioenergy development and explore different development options and their effects on regional development, qualitative scenarios have been drafted using the Görlitz district as an example. The paper introduces the scenario method, with scenarios that are expressed in storylines. Driving forces and their relationships are thereupon reflected. The results show that the relation of the Common Agricultural Policy and Renewable Energy Act is of particular importance for future development in general. For the specific type of development in particular in rural regions, technologies are equally important, as they allow for both strongly central and highly decentralised developments. Due to an increasing diversity of options, the decision between central and decentral developments is, however, less technologically determined, but rather dependent on stakeholders’ decisions. Such stakeholders not only include stakeholders from the production sector, but also include consumers and affected parties, particularly the inhabitants whose living environment is changing rapidly. Both the landscape and society are subject to change. As a major driving force and an impacted system under change itself, social constellations must be taken into account to ensure a sustainable development under the signs of renewable energy expansion. Management tools should consider the interlinkage between landscape, energy, and social systems.     

III. Ökotoxikologische Charakterisierung der Schwermetall-Immissionsmuster

The spatial variation of the immission patterns of Cr, Fe, Pb and V in the region Leipzig-Halle is dicussed in terms of similarities as well as dissimilarities. The representation by isopleths enables the identification of areas with high and low air pollution. The immission patterns can be used as criteria to select areas suitable for in-field testing so that possible effects on fauna und flora and xenobiotic fluxes can be studied at representative sites. The comparison with literature data yields a first characterization of the ecotoxic potential of the heavy-metal immission for the region. By the principal component analysis a comparative evaluation of the spatial structure of all element contents is performed, which leads to conclusions about emission sources and the physicochemical behaviour of the elements.     

Not Only Single Mating in Stingless Bees

Queens of the large, pantropical and fully eusocial taxon Meliponinae (stingless bees) are generally considered to be singly mated. We indirectly estimated queen mating frequency in two meliponids, Melipona beecheii and Scaptotrigona postica, by examining genotypes of workers at microsatellite DNA loci. Microsatellites were highly variable, providing suitable markers with which to assign patrilinial origin of workers within colonies headed by single queens. Queen mating frequency varied between 1 and 3 (M. beecheii) and 1 and 6 (S. postica), representing the first clear documentation of polyandry in the Meliponinae. Effective paternity frequency, m _e , was lower, although above 2 for S. postica. Stingless bees may provide suitable subjects for the testing of recent inclusive fitness arguments describing intracolony kin conflict in social Hymenoptera. Received: 26 August 1998 / Accepted in revised form: 18 November 1998