Steps towards environmental hazard assessment of new chemicals (including a hazard ranking scheme,based upon directive 79/831/EEC)

Directive 79/831/EEC came into force on 18th September 1981, enabling all the Member States of the EEC to classify so-called “new chemicals” with respect to their potential hazard to the environment and to human health on a standardized basis (Directive 79/831/EEC, Annex VII). The authors are of the opinion that the assessment of the “environmental hazard” of new chemicals before they are placed on the market, represents, in the present critical economic /ecological situation, which practically all the Member States have in common, a particular challenge to the scientific community and the competent authorities. The comments aim to achieve the following - to provide a more precise definition of certain key terms and to point out a way of selecting from the bundle of new chemicals those (few) which are potentially hazardous; a way which is clear to the administration, the scientific community, industry and, not least of all, to the individual as taxpayer and consumer.     

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.      

Modellierung von Stoffausbreitungen

Die Modellierung des Ausbreitungsverhaltens von Stoffen unterschiedlicher Eigenschaften in der Umwelt stellt eine Herausforderung dar, da die zugrundeliegenden physikalischen Transport-, chemischen Reaktions- und biologischen An- oder Abreicherungsprozesse zeitlich variabel in r?umlich heterogen strukturierten Umweltsystemen wirken. Durch geschickt gew?hlte Vereinfachungen, Abgrenzungen und Mittelungen sind bemerkenswerte Erfolge bis hin zur bedingt-prognostischen Simulation ausgew?hlter Stoffe und Stoffgruppen erzielt worden. Forschungsbedarf besteht vor allem in der Modellierung der kleinr?umigen, medienübergreifenden Ausbreitung von Stoffen in komplexen ?kosystemaren Zusammenh?ngen, einschlie?lich der Austausch- und Transfervorg?nge und der chemisch-biologischen Transformationen. Bericht vom 32. Tutzing-Symposium der DECHEMA e.V., 7. bis 10. M?rz 1994     

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.