Substanzen mit endokriner Wirkung in Oberflaechengewaessern

The relevant scientific literature was surveyed to identify synthetic chemicals with estrogenic, antiestrogenic, androgenic and antiandrogenic activity. The various in vivo and in vitro methods used to assess these activities are discussed and whenever available the dose or concentration dependency of the effects (potency) is documented. To compile present levels of these compounds in surface waters in Germany responsible authorities of the Bundeslaender (federal states) were asked for timely data. These data are documented together with short summaries on use, sources and environmental fate of the respective chemicals. Adequate exposure-effect data which can be used to assess the relevance of the measured concentrations for aquatic organisms were available only for some alkylphenols and derivatives and tributyltin. Taking alkylphenols as example it is shown, that, at the moment, neither in vitro determined effective concentrations nor in vitro or in vivo determined relative potencies (equivalency factors) can be used for this purpose. (orig.)Available from TIB Hannover: RN 8908(97-068) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEUmweltbundesamt, Berlin (Germany); Bundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman

Tierische Zellen in vitro als Ersatz fuer Tierversuche: Evaluierung des prognostischen Wertes ausgewaehlter Testmodelle fuer die Abschaetzung der systemischen Toxizitaet von Chemikalien Abschlussbericht

The relevance and prognostic value of four in vitro test systems containing different mammalian cells (bovine spermatozoa, liver cells and skeletal muscular cells of rat, mouse-balb/c 3T3 cells) were investigated for assessment of the acute toxicity of chemicals. A fifth in vitro test model (cocultures of liver cells with balb/c 3T3 cells as target cells) was developed for metabolism-mediated cytotoxicity assessment. The response characteristics and informative value of the five test systems were characterized by testing model substances whose mechanisms of action were known. For assessment of the prognostic value the reference substances recommended within the framework of the international MEIC project were tested and were used as a measure for evaluation of the prognostic value of LD50 values and for the toxicity classifications based on these values. The effective in vitro concentrations (EC50 values) were converted into effective body doses (ED50 values) for a simple body model considering simple factors of toxicokinetic relevance. The ED50 values were found to be correlated significantly with the LD50 values. The correlation coefficients were in the range of 0.73 (sperm test) and 0.85 (3T3 test) in the case of oral, and 0.71 (sperm test) and 0.83 (muscular cell test) in the case of intraperitoneal application. A test strategy was proposed based on the results obtained evaluating the different test systems. After experimental verification and further development of the model with regard to toxicokinetic parameters of influence, the proposed strategy is expected to considerably reduce the number of bioassays which are needed for classification and characterization of chemicals in accordance with their acute lethal potency. (orig.)Available from TIB Hannover: F94B1186+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Forschung und Technologie (BMFT), Bonn (Germany)DEGerman

Endocrinically active chemicals and their occurrence in surface waters

Available from TIB Hannover: RN 8422(1998,66) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman

Einstufung von Schadstoffen als endokrin wirksame Substanzen. Kritische Ueberpruefung der Einstufung von ausgewaehlten Pestiziden und Industriechemikalien als endokrin wirksame Substanzen

Different authors have published lists of chemicals, especially pesticides and industrial chemicals, reported to have 'reproductive and endocrine disrupting activities' or 'estrogenic/antiestrogenic' activities. The objective of this study was to examine what is the basis for and whether it is justified to classify chemical compounds as 'endocrine disrupters' that are contained in frequently cited overviews, but have not been discussed in a previous report (UBA-TEXTE 46/97). Depending on the level of evidence derived from literature data, substances are classified either as (i) endocrinally active or (ii) potentially endocrinally active or (iii) without sufficient data on endocrine activity. The criteria used for the classification are based on the definitions by US-EPA and the Weybridge conference. (orig.)Von verschiedenen Autoren sind umfangreiche Listen mit Chemikalien, insbesondere Pestiziden und Industriechemikalien, veroeffentlicht worden, die als 'endokrin wirksam und reproduktionstoxisch' oder als 'oestrogen- bzw. 'antioestrogen wirksam' bezeichnet werden. Aufgabe der vorliegenden Studie ist es, zu untersuchen, auf welchen Grundlagen die Einstufung als 'endokrin wirksam' beruht, und zu ueberpruefen, ob sie gerechtfertigt ist. Je nach den Ergebnissen der Literaturrecherchen werden die Substanzen einer von drei Gruppen zugeordnet: 1. endokrin wirksam, 2. potentiell endokrin wirksam, 3. ohne ausreichende Hinweise auf endokrine Wirksamkeit. Die verwendeten Kritetien fuer die Zuordnung lehnen sich an die Definitionen der EPA und der Weybridge-Konferenz an. Schon in einem vorangegengenen Bericht (UBA-TEXTE 46/97) diskutierte Verbindungen werden nicht erneut behandelt. (orig.)SIGLEAvailable from TIB Hannover: RN 8422(1999,65) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman