Auflistung nach Schlagwort "Abbau"

Gerade angezeigt 1 - 6 von 6

A blind spot in the assessment of POP/PBT/vPvB properties
(2018) Priegnitz, Jan; Deutschland. Umweltbundesamt
This paper relates to the assessment of transformation products (i.e. metabolites, degradation or reaction products), which are formed from plant protection products. It addresses a detail in Regulation (EC) No. 1107/2009 which is not in line with other substance regulations for ⁠REACH⁠, medicinal products, and biocides.Our concern: Also transformation products can be hazardous substances. Meanwhile, they are not yet covered within the ⁠POP⁠/⁠PBT⁠/vPvB assessment and the approval criteria for active substances.Our proposal: At least transformation products occurring in a relevant amount should be included in the assessment and the approval criteria in the same way as active substances.
Application of nonlinear hierarchical models to the kinetic evaluation of chemical degradation data
(Umweltbundesamt, 2023) Ranke, Johannes; Deutschland. Umweltbundesamt; Wöltjen, Janina; Meinecke, Stefan
Derzeit werden chemische Abbaudaten ausgewertet, indem verschiedene nichtlineare Regressionsmodelle einzeln auf die verfügbaren Datensätze angewandt werden. In vielen Fällen können dabei einige der Abbauparameter nicht für alle Datensätze verlässlich bestimmt werden. Die aktuell gültigen regulatorischen Leitlinien empfehlen in solchen Fällen die Verwendung von mehr oder weniger willkürlich gewählten Standardwerten für diese Parameter. Des Weiteren ergeben oft unterschiedliche Modelle die beste Anpassung in den verschiedenen Datensätzen, so dass mittlere Modellparameter mit Hilfe von Behelfslösungen mit schwacher wissenschaftlicher Grundlage bestimmt werden müssen. Beide Probleme können vermieden werden, wenn hierarchische nichtlineare Modelle verwendet werden, bei denen Parameterverteilungen an die Gesamtheit der Daten angepasst werden. In diesem Bericht wird eine kurze Einführung in diesen Modelltyp gegeben. Weiterhin wird die Verwendung einer R markdown Vorlage und einer Tabellenkalkulationsdatei für die Eingabe von Daten beschrieben. Beide Dateien wurden kürzlich in das R-Paket mkin integriert und erleichtern damit die Anwendung dieser Methode auf neue Daten. Um hierarchische kinetische Modelle in der regulatorischen Auswertung von Abbaudaten zu etablieren, müsste ein Leitfaden erarbeitet werden, in dem erläutert wird, wie die Ergebnisse der hierarchischen Abbaukinetiken in den verschiedenen regulatorischen Anwendungsbereichen verwendet werden sollten. Quelle: Forschungsbericht
Development of a test method for transformation of veterinary pharmaceuticals and biocides in anaerobic liquid manure
(2020) Junker, Thomas; Atorf, Cornelia; Berkner, Silvia; Konradi, Sabine
Background Spreading of manure on agricultural soils represents an important pathway by which veterinary medicinal and biocidal products enter the environment. To assess their environmental impact in the context of authorization processes, experimental testing of transformation of these compounds in manure is considered in regulatory guidance documents. However, there is no standardized experimental test method available so far. To fill this gap, an experimental test method was developed to examine transformation in liquid cattle and pig manure. Results To account for manure specifics and for a possible influence of manure parameters on transformation rates, a comprehensive data acquisition and statistical analysis were performed. To address the variability of liquid manure of different type and origin, 30 manures were sampled and characterized. Thereof, three cattle and three pig manures were selected to perform anaerobic transformation studies with two radiolabeled veterinary medicinal active substances (14C-salicylic acid and 14C-paracetamol) and a confidential radiolabeled "14C-biocide B" serving as test compounds. Spatial and seasonal variability of manure parameters was quantified, and a sampling technique to obtain homogenous manure samples was developed. Transformation studies with six replicates per sampling point were conducted to examine the influence of test setup, of manure storage conditions, and of parameter variations between manure of the same species and of different species on half-lives, formation of extractable and non-extractable residues and mineralization rates. Finally, a test design was established that yields reproducible results for transformation studies in liquid cattle and pig manure under anaerobic conditions. Conclusions Results give a reliable basis for an experimental test method to perform anaerobic transformation studies in liquid cattle and pig manure. The developed test method comprises detailed guidance on selection of sampling date and site, collection from manure tank, storage duration and temperature in the laboratory, duration of manure acclimation period, and the incubation system design. It proved to give reproducible results in a validation ring test performed in a follow-up project and is planned to be submitted as draft test guideline for approval by the OECD. © The Author(s) 2020.
Soil governance at the international, regional and national level
(2022) Ginzky, Harald
The chapter first analyses what is meant by the term soil governance and what the particular challenges are. It addresses the national and regional levels of soil governance, together with an explanation of the existing regulatory structure at the international level. As sustainable management of soils is inextricably linked to and carried out based on the conditions specific to a location, national regulation is most essential. To provide more specific insights, this chapter also explores - in an excursus - soil governance in Germany and an assessment of the tools and sources of information, including databases. The interlinkage of international trade law and sustainable soil management is also explained. © 2022 Elsevier
Understanding the role of agricultural management effects on global soil degradation utilizing biophysical modeling
(Lebenswissenschaftliche Fakultät der Humboldt-Universität zu Berlin, 2022) Herzfeld, Tobias
Using environmental simulations to test the release of hazardous substances from polymer-based products: Are Rrealism and pragmatism mutually exclusive objectives?
(2020) Aitken, Michael D.; Bandow, Nicole; Geburtig, Anja
The potential release of hazardous substances from polymer-based products is currently in the focus of environmental policy. Environmental simulations are applied to expose such products to selected aging conditions and to investigate release processes. Commonly applied aging exposure types such as solar and UV radiation in combination with water contact, corrosive gases, and soil contact as well as expected general effects on polymers and additional ingredients of polymer-based products are described. The release of substances is based on mass-transfer processes to the material surfaces. Experimental approaches to investigate transport processes that are caused by water contact are presented. For tailoring the tests, relevant aging exposure types and release quantification methods must be combined appropriately. Several studies on the release of hazardous substances such as metals, polyaromatic hydrocarbons, flame retardants, antioxidants, and carbon nanotubes from polymers are summarized exemplarily. Differences between natural and artificial exposure tests are discussed and demonstrated for the release of flame retardants from several polymers and for biocides from paints. Requirements and limitations to apply results from short-term artificial environmental exposure tests to predict long-term environmental behavior of polymers are presented. Source: https://www.mdpi.com