Fate of hexachlorobenzene-14C in wheat plants and soil under outdoor conditions

Residues of hexachlorobenzene-¹⁴C were found in all parts of wheat plants grown from treated seeds or in contaminated soil. Besides the parent compound and bound residues in plants and soil, very small amounts of soluble acidic metabolites were present in plants, which were characterized and determined quantitatively.     

Long-term sampling method for polychlorinated dibenzofurans (PCDFs) and dibenzo(p)dioxins (PCDDs) in flue gas of combustion facilities

A long-term sampling method for PCDF/D in emissions from combustion facilities is presented. The sampling of PCDF/D was performed over a four week period. The results are compared to results of four one-week measurements.     

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.     

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