Person: Hassold, Enken
Lade...
E-Mail-Adresse
Geburtsdatum
1975
Forschungsvorhaben
Organisationseinheiten
Berufsbeschreibung
Biologe
Nachname
Hassold
Vorname
Enken
Name
4 Ergebnisse
Suchergebnisse
Gerade angezeigt 1 - 4 von 4
Veröffentlichung Options for an environmental risk assessment of intentional and unintentional chemical mixtures under REACH(2021) Galert, Wiebke; Hassold, Enken; Schulze, JonaIt is acknowledged that a variety of chemicals enter the environment and may cause joint effects. Chemicals regulated under the European Chemicals Regulation REACH are often part of formulated mixtures and during their processing and use in various products they can be jointly released via sewage treatment plants or diffuse sources, and may combine in the environment. One can differentiate between intentional mixtures, and unintentional mixtures. In contrast to other substance-oriented legislations, REACH contains no explicit requirements for an assessment of combined effects, exposures and risks of several components. Still, it requires ensuring the safe use of substances on their own, in mixtures, and in articles. The available options to address intentional as well as unintentional mixtures are presented and discussed with respect to their feasibility under REACH, considering the responsibilities, communication tasks and information availability of the different actors (registrants, downstream-user and authorities). Specific mixture assessments via component-based approaches require a comprehensive knowledge on substances properties, uses, fate and behaviour, and the composition of the mixture under consideration. This information is often not available to the responsible actor. In principle, intentional mixtures of known composition can be assessed by the downstream-user. But approaches have to be improved to ensure a transparent communication and sound mixture assessment. In contrast, unintentional mixtures appear to be better addressable via generic approaches such as a mixture allocation factor during the chemical safety assessment, although questions on the magnitude, implementation and legal mandates remain. Authorities can conduct specific mixture risk assessments in well-defined and prioritized cases, followed by subsequent regulatory measures. In order to address intentional and unintentional mixtures within the current REACH framework, legal mandates together with guidance for the different actors are needed. Furthermore, further data on mixture compositions, uses and co-exposures need to be made accessible via shared databases. © The Author(s) 2021.Veröffentlichung Environmental Risk Assessment of Technical Mixtures Under the European Registration, Evaluation, Authorisation and Restriction of Chemicals(2021) Galert, Wiebke; Hassold, EnkenThe European Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH) regulation has been in force since 2007 and is intended to ensure a high level of protection for human health and the environment. The REACH regulation is based on the principle that manufacturers, importers, and downstream users take responsibility for their chemicals. Currently about 23 000 single chemicals are registered within the REACH legislation. A large proportion of substances registered under REACH end up in technical mixtures, intentionally manufactured as such, or generated mixtures containing byproducts of processes. Such mixtures that contain a number of different components are, for example, ink, paint, lacquer, mortar, or cleaning agents. However, REACH focuses on single substances and addresses the safe use of substances as such (e.g., bisphenol A) or substances in mixtures (e.g., bisphenol A used as an antioxidant in mixtures) and in articles (e.g., bisphenol A used as a monomer for polycarbonate production from which greenhouse sheets may be made). In contrast to other substance regulations, under REACH the registrants and downstream users of chemicals are responsible for the risk assessment. According to the REACH regulation, they also have the obligation to derive and communicate safe use conditions for their technical mixtures. Currently, no guidance document and no distinct obligations for an assessment of technical mixtures exist. In light of the available evidence for the joint exposures and effects of chemicals due to co-exposures, the need for approaches for a mixture assessment and improved data communications were highlighted by various stakeholders from industry, European member states, and the European Chemicals Agency (ECHA). The lead component identification (LCID) methodology and the safe use of mixtures information (SUMI) tool were proposed by the European Chemical Industry Council (Cefic) as working tools for the evaluation of the hazard potential, derivation of safe use conditions, and data communication for mixtures along the supply chain. The present paper analyzes the workability and pitfalls of these proposed methodologies from a regulatory perspective, aiming at a safe use of technical mixtures which considers the joint effects and exposures of its components. Integr Environ Assess Manag 2021;17:498-506. © 2021 UmweltbundesamtVeröffentlichung Four selected high molecular weight heterocyclic aromatic hydrocarbons: Ecotoxicological hazard assessment, environmental relevance and regulatory needs under REACH(2018) Brendel, Stephan; Einhenkel-Arle, Doreen; Hassold, Enken; Polleichtner, ChristianLittle is known about the ecotoxicity of heterocyclic aromatic hydrocarbons (NSO-HETs) to aquatic organisms. In the environment, NSO-HETs have been shown to occur in a strong association with their unsubstituted carbocyclic analogues, the polycyclic aromatic hydrocarbons (PAH), for which much more information is available. The present study addressed this issue by investigating the toxicity of four selected NSO-HETs in green algae (Desmodesmus subspicatus), daphnids (Daphnia magna) and fish embryos (Danio rerio). The four high molecular weight NSO-HETs dibenz[a,j]acridine (DBA), 7H-dibenzo[c,g]carbazole (DBC), benzo[b]naphtho[2,1-d]thiophene (BNT) and benzo[b]naphtho[1,2-d]furan (BNF) were selected, based on the results of a previous research project, indicating a lack of toxicity data and a high potential for persistence and bioaccumulation. The solubilities of the NSO-HETs in the test media were determined and turned out to be comparatively low (2.7-317ng/L) increasing in the following order: DBA < BNT " DBC " BNF. Exposure concentrations during the toxicity tests were quantified with GC-MS and decreased strongly possibly due to sorption or metabolising during the test periods (48-96 h). Therefore, the estimated effect concentrations were related to the mean measured concentrations, as endpoints related to nominal concentrations would have underestimated the toxicity many times over. Within the range of the substance solubilities, BNF affected all test organisms with fish embryos being the most sensitive (fish: EC50 6.7 ng/L, algae: EC10 17.8 ng/L, daphnids: EC50 55.8 ng/L). DBC affected daphnids (EC50 2.5 ng/L,) and algae (EC10 3.1 ng/L), but not fish embryos. The lowest toxicity endpoint was observed for BNT affecting only algae (NOEC 0.556 ng/L) and neither daphnids nor fish embryos. DBA did not show any effects on the tested organisms in the range of the water solubility. However, we would expect effects in long-term toxicity studies to fish and aquatic invertebrates for all substances at lower concentrations, which needs further investigation. All four NSO-HETs were identified in mussels (Mytilus edulis) from the German coasts, in green kale (Brassica oleracea var. acephala) and in freshwater harbor sediment in concentrations between 0.07 and 2 ng/kg, highlighting their relevance as environmental contaminants. There is a need to regulate the four NSO-HETs within the REACH regulation due to their intrinsic properties and their environmental relevance. However, acquisition of additional experimental data appears to be pivotal for a regulation under REACH. © 2018 The Authors. Published by Elsevier Inc.Veröffentlichung Prospective environmental risk assessment of mixtures in wastewater(2018) Coors, Anja; Vollmar, Pia; Sacher, Frank; Hassold, Enken; Polleichtner, Christian; Gildemeister, Daniela; Kühnen, UteThe aquatic environment is continually exposed to a complex mixture of chemicals, whereby effluents of wastewater treatment plants (WWTPs) are one key source. The aim of the present study was to investigate whether environmental risk assessments (ERAs) addressing individual substances are sufficiently protective for such coincidental mixtures. Based on a literature review of chemicals reported to occur in municipal WWTP effluents and mode-of-action considerations, four different types of mixtures were composed containing human pharmaceuticals, pesticides, and chemicals regulated under REACH. The experimentally determined chronic aquatic toxicity of these mixtures towards primary producers and the invertebrate Daphnia magna could be adequately predicted by the concept of concentration addition, with up to 5-fold overestimation and less than 3-fold underestimation of mixture toxicity. Effluents of a municipal WWTP had no impact on the predictability of mixture toxicity and showed no adverse effects on the test organisms. Predictive ERAs for the individual mixture components based on here derived predicted no effect concentrations (PNECs) and median measured concentrations in WWTP effluents (MCeff) indicated no unacceptable risk for any of the individual chemicals, while MCeff/PNEC summation indicated a possible risk for multi-component mixtures. However, a refined mixture assessment based on the sum of toxic units at species level indicated no unacceptable risks, and allowed for a safety margin of more than factor 10, not taking into account any dilution of WWTP effluents by surface waters. Individual substances, namely climbazole, fenofibric acid and fluoxetine, were dominating the risks of the investigated mixtures, while added risk due to the mixture was found to be low with the risk quotient being increased by less than factor 2. Yet, uncertainty remains regarding chronic mixture toxicity in fish, which was not included in the present study. The number and identity of substances composing environmental mixtures such as WWTP effluents is typically unknown. Therefore, a mixture assessment factor is discussed as an option for a prospective ERA of mixtures of unknown composition. © 2018 Elsevier Ltd. All rights reserved.