Auf zu neuen Ufern — Postgraduale Weiterbildung mit dem zertifizierten Abschluss Fach?kotoxikologin/e SETAC/GDCh beginnt 2005

Ohne Zusammenfassung     

Effect of agricultural antibiotics on the persistence and transformation of 17beta-estradiol in a Sequatchie loam

A laboratory incubation study was conducted to investigate the effect of agricultural antibiotics (sulfamethazine, tylosin, and chlortetracycline) on the persistence and transformation of 17beta-estradiol in Sequatchie loam. We measured concentrations of 17beta-estradiol and its primary metabolite (estrone) in soils spiked with antibiotics and 17beta-estradiol. Dehydrogenase activity (DHA) was also measured as an indicator of the total microbial activity of the soils. The presence of antibiotics significantly decreased transformation of 17beta-estradiol to estrone. There was a positive correlation between the DHA and the concentrations of estrone in soil spiked with 17beta-estradiol only, implying that the reaction is mainly catalyzed by dehydrogenases. However, the positive correlation was weakened in soil spiked with 17beta-estradiol and antibiotics together. We recommend that any study evaluating the fate and transport of estrogenic hormones in soil should include the effect of agricultural antibiotics because antibiotics and estrogenic hormones are commonly excreted together in environmental samples.     

Genetic effects of air pollution on forest tree species of the Carpathian Mountains

The effects of air pollution on the genetic structure of Norway spruce, European silver fir and European beech were studied at four polluted sites in Slovakia, Romania and Czech Republic. In order to reduce potential effects of site heterogeneity on the health condition, pair-wise sampling of pollution-tolerant and sensitive trees was applied. Genotypes of sampled trees were determined at 21 isozyme gene loci of spruce, 18 loci of fir and 15 loci of beech. In comparison with Norway spruce, fewer genetic differences were revealed in beech and almost no differentiation between pollution-tolerant and sensitive trees was observed in fir. In adult stands of Norway spruce, sensitive trees exhibited higher genetic multiplicity and diversity. The decline of pollution-sensitive trees may result thus in a gradual genetic depletion of pollution-exposed populations of Norway spruce through the loss of less frequent alleles with potential adaptive significance to altered stressing regimes in the future. Comparison of the subsets of sensitive and tolerant Norway spruce individuals as determined by presence or absence of discolorations ("spruce yellowing") revealed different heterozygosity at 3 out of 11 polymorphic loci.     

Artificial indoor streams as a method to investigate the impact of chemicals on lotic communities

The potential hazard of chemicals on aquatic communities are generally evaluated by standardised single-species bioassays. Safety assessment is based on results gained from organisms adapted to lentic systems and biological interactions in ecosystems are neglected. While lotic communities are often at first in contact with chemicals, it is astonishing that microcosms with lentic communities are mainly used as a bridge between laboratory bioassays and outdoor aquatic systems. Hence, we established five artificial indoor streams to simulate abiotic factors of small rivers. The closed-circuit system was filled with nutrients added to tap water. Washed pebbles were used as sediment. The dynamics of a simple biocoenoses consisting of aufwuchs, Lumbriculus variegatus Asellus aquaticus and Gammarus fossarum was investigated. The dynamic of aufwuchs and periphyton was determined as dry weight and chlorophyll-a, respectively and qualitatively by pigment pattern. The abundance of different developmental stages of L. variegatus was determined at the end of the experiment as well as the population dynamics of G. fossarum and A. aquaticus. Survival rates of gammarids and juveniles per female were investigated and data were used for modelling the population dynamics. The experiment was carried out to investigate the performance of the established artificial streams and the developed approaches to investigate effects of chemicals on a basic lotic community. The prime reason to establish this approach was to close a gap between complex artificial stream systems and laboratory single species tests to assess the impact of chemicals on the aquatic environment.     

Untersuchungen zur Charakterisierung von Brandrauch

Zusammenfassung  Ziel dieser Arbeit ist, zu kl?ren, ob ein Zusammenhang zwischen den organischen Brandzersetzungsprodukten und dem Brandgut besteht. Aus Gründen der Homogenit?t des Datenmaterials werden ausschlie?lich Untersuchungen der Forschungsstelle für Brandschutztechnik an der Universit?t Karlsruhe statistisch ausgewertet. Die Zusammenfassung strukturell ?hnlicher Verbindungen sowie die Zuordnung von Strukturindices erm?glicht Aussagen über die H?ufigkeit des Vorkommens bestimmter Stoffklassen im Brandrauch. Dabei steht die Ermittlung von Leitsubstanzen im Vordergrund, wobei anorganische Brandzersetzungsprodukte nicht, besonders leichtflüchtige (z.B. Acrolein oder Vinylchlorid) ebenso wie besonders schwerflüchtige organische Substanzen (z.B. h?here PAKs) aufgrund des analytischen Verfahrens nicht oder nur unvollst?ndig Berücksichtigung finden. Im Rahmen des vorhandenen Datenmaterials sind Benzol, Methylbenzol, Ethenylbenzol und Ethylbenzol immer im Brandrauch enthalten. Die Bildung dieser Stoffe wird modellhaft beschrieben. Neben solchen brandrauchtypischen Substanzen treten weitere organische Verbindungen auf, die für ein bestimmtes Brandgut typisch sind. Viele der Brandzersetzungsprodukte haben ein krebserregendes Potential. Aus diesen Ergebnissen ist abzuleiten, da? h?ufig exponierte Personen konsequenten Arbeitsschutz betreiben sollten. Um eine bessere Gefahrenabsch?tzung hinsichtlich der gesundheitlichen Risiken zu erm?glichen sind toxikologische Untersuchungen erforderlich.      

Verglaste Filterstäube aus Müllverbrennungsanlagen

Solid waste residues from municipal solid waste incinerator flue gas cleaning systems basically consists of Al, Ca-silicates and metal oxides. At lower concentrations, environmentally harmful compounds such as alkali halide salts, heavy metals and traces of organic pollutants, e.g. PCDD, PCDF and PCB, are also present. For the reuse of the valuable materials (Al, Ca and metal oxides), an effective treatment technique for destroying the organic contaminants and separating the anorganic toxins from the non-toxic components has to be applied, which can only be achieved through thermal processing. Detailed investigations on vitrified electrostatic precipitator ash from municipal solid waste incinerator plants have shown promising results in regard to the mass balances, the chemical composition and the quality of the glass phase obtained.     

Modeling the Effects of Habitat Fragmentation on Source and Sink Demography of Neotropical Migrant Birds

Many songbird populations in the midwestem United States are structured as a network of sources and sinks that are linked by dispersal. We used a modeling approach to examine explicitly how populations respond to incremental fragmentation of source habitat and how this response may vary depending upon two life-history attributes: fidelity to natal habitat type and reproductive strength of the source. Fragmentation of source habitat led to a predictable decline in population for both attributes examined, but the manner in which populations declined varied depending upon the reproductive strength of the source and the level of fidelity. When the source was weak and produced few excess individuals, fragmentation of source habitats resulted in a predictable and parallel population decline of adults in both the source and the sink. In this situation high fidelity to natal habitats was important for maintenance of population size and structure. Low fidelity to weak sources resulted in population extinction; populations experienced a demographic cost by dispersing from high quality source habitat to low quality sink habitat. In contrast, when the source was strong and produced many excess individuals, fragmentation of the source led to population declines in both the source and the sink, but this decline was more abrupt in sink habitats. When the source was strong and produced a large excess of individuals, nonfidelity to natal habitats had little effect on metapopulation size and structure.     

Altai pika (<Emphasis Type="Italic">Ochotona alpina</Emphasis>) alarm calls: individual acoustic variation and the phenomenon of call-synchronous ear folding behavior

Non-hibernating pikas collect winter food reserves and store them in hay piles. Individualization of alarm calls might allow discrimination between colony members and conspecifics trying to steal food items from a colony pile. We investigated vocal posture, vocal tract length, and individual acoustic variation of alarm calls, emitted by wild-living Altai pikas Ochotona alpina toward a researcher. Recording started when a pika started calling and lasted as long as possible. The alarm call series of 442 individual callers from different colonies consisted of discrete short (0.073–0.157 s), high-frequency (7.31–15.46 kHz), and frequency-modulated calls separated by irregular intervals. Analysis of 442 discrete calls, the second of each series, revealed that 44.34% calls lacked nonlinear phenomena, in 7.02% nonlinear phenomena covered less than half of call duration, and in 48.64% nonlinear phenomena covered more than half of call duration. Peak frequencies varied among individuals but always fitted one of three maxima corresponding to the vocal tract resonance frequencies (formants) calculated for an estimated 45-mm oral vocal tract. Discriminant analysis using variables of 8 calls per series of 36 different callers, each from a different colony, correctly assigned over 90% of the calls to individuals. Consequently, Altai pika alarm calls are individualistic and nonlinear phenomena might further increase this acoustic individualization. Additionally, video analysis revealed a call-synchronous, very fast (0.13–0.23 s) folding, depression, and subsequent re-expansion of the pinna confirming an earlier report of this behavior that apparently contributes to protecting the hearing apparatus from damage by the self-generated high-intensity alarm calls.