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New Test Strategy for Dung Beetles During the Authorization Process of Parasiticides

According to European legislation, an environmental risk assessment (ERA) of veterinary medicinal products (VMPs) for dung fauna is required in the authorization process, if the substance acts as a parasiticide for the treatment of pasture animals. In the past, however, the demonstration of the environmental safety of those VMPs for dung fauna was strongly hampered by the fact that no standardized tests were available. Therefore, starting with recommendations from the Society of Environmental Toxicology and Chemistry (SETAC) advisory group, dung organism toxicity test standardization (DOTTS) test systems for phase II Tier A standardized tests on the mortality of dung fly and dung beetle larvae were developed and published by the Organisation for Economic Co-operation and Development (OECD) in 2008 and 2010. If a risk is identified for dung organisms in phase II Tier A of the ERA process, further tests are required for Tier B. So far, however, no advice is given for such studies in the existing guidelines. Therefore, 4 workshops took place between 2007 and 2009 with international dung fauna experts (Aveiro-Group) to find an appropriate test strategy for dung fauna organisms beyond Tier A mortality testing. For the first time, 2 different Tier B extended laboratory test approaches for dung beetles and test strategies for scenarios beyond Tier B are described in more detail. In case the risk assessment is still not clear, further options for Tier C (i.e., field studies) or Tier D (modeling) are briefly presented. Finally, the role of uncertainty and variability of test results is discussed, including recommendations for assessment factors for the different tiers to be used when assessing the risk of VMPs on dung organisms. The approach, especially the test strategy, will help industry, consultants, and assessors appropriately assess the environmental risk assessments during the authorization procedure of parasiticides. Integr Environ Assess Manag 2013;9:524-530. © 2013 SETAC

Four selected high molecular weight heterocyclic aromatic hydrocarbons: Ecotoxicological hazard assessment, environmental relevance and regulatory needs under REACH

Little 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.

Alge des Jahres 2015: Meersalat (Ulva lactuca)

Algenforscher wählten den in allen Weltmeeren vorkommenden Meersalat (Ulva lactuca) zur Alge des Jahres 2015. Er wächst bandförmig oder wie ein Salatblatt, aber nur wenn Bakterien die Differenzierungs- und Entwicklungsprogramme der Grünalge anwerfen. Weil Ulva ohne die Bakterien kaum wachsen kann, locken die etwa 20 bis 30 Zentimeter langen Algen die richtigen Mikroorganismen in ihre Nähe. Wie Makroalgen und Bakterien, zwei Lebewesen aus völlig verschiedenen Organismengruppen, Informationen miteinander austauschen, fasziniert Chemiker, Biologen und Algenforscher, die derzeit die Art Ulva mutabilis als zukünftigen Modellorganismus etablieren möchten.

From theory to reality – Evaluation of suitable organisms and test systems for the biomitoring of pharmaceuticals

In order to identify sensitive organisms, biological endpoints in vivo and suitable in vitro test systems for the biomonitoring of pharmaceuticals, a two-part literature search was conducted. Veröffentlicht in Texte | 64/2014.

Comparison of dung and soil fauna from pastures treated with and without ivermectin as an example of the effects of a veterinary pharmaceutical

Soil organisms in manure or organisms that colonize dung pats can be impacted by the application of veterinary medical products, especially parasiticides, to livestock. For this reason, the authorization process for veterinary medicinal products in the European Union and other countries includes a requirement for “higher-tier” tests when adverse effects on dung organisms can be detected in single-species toxicity tests. However, no guidance documents for the performance of higher-tier tests are available, so far. Therefore, an international research project was undertaken to develop and validate a proposed test method under varying field conditions of climate, soil, and endemic coprophilous fauna. The test took place at Lethbridge (Canada), Montpellier (France), Zurich (Switzerland), and Wageningen (The Netherlands). The aim of the project was to determine if fecal residues of a parasitide with known insecticidal activity (ivermectin) showed similar effects on insects breeding in dung of treated animals, coprophilous organisms in the soil beneath the dung, and rates of dung degradation. Veröffentlicht in Texte | 54/2017.

Joint effects of pharmaceuticals and chemicals regulated under REACH in wastewater treatment plant effluents – Evaluating concepts for a risk assessment by means of experimental scenarios

Non-target organisms in the environment are exposed simultaneously to a multitude of substances from various sources. In the aquatic environment, effluents of wastewater treatment plants (WWTPs) represent a key source for co-incidental mixtures of chemicals from various uses. The aim of the present project was to explore the consideration of mixtures of chemicals released via WWTPs in an Environmental Risk Assessment. Different organisms were exposed in chronic toxicity tests to single substances and various mixtures of them. The results show that the concept of concentration addition (CA) predicts mixture toxicity in effluents sufficiently and for a prospective risk assessment the use of a mixture assessment factor (MAF) could be helpful. Veröffentlicht in Texte | 61/2017.

Do new generations of active pharmaceuticals for human use require an adaption of the environmental risk assessment?, Part I: Literature review

Since 2006, various new active pharmaceutical ingredients have been developed with highly specific mechanisms of action. That raise the question of whether current environmental risk assessment within the scope of the authorization is still sufficient to appropriately assess relevant effects on environmental organisms. In this literature review the scientific basis for a tailored risk assessment was developed and discussed for 3 substance classes (oncology, neurology, cardiology). The proposed assessment includes additional test methods, groups of organisms and alternative endpoints. The practical review of the proposed test approaches is to be carried out using case studies in subproject 2. Veröffentlicht in Texte | 150/2020.

Environmental hazard of selected TiO2 nanomaterials under consideration of relevant exposure scenarios

This project investigated the ecotoxicological hazard of two different sized TiO2 nanomaterials and one non-nano sized TiO2 reference material to organisms inhabiting different environmental compartments. Following standardized tests (⁠ OECD ⁠ guidelines) were used to investigate the influence of these materials on several test organisms:  Daphnia sp. acute immobilization test (Test No. 202), Fish embryo acute toxicity (FET) test (Test No. 236), Activated sludge, respiration inhibition test (Test No. 209), Earthworm, acute toxicity test (Test No. 207), Earthworm, reproduction test, (Test No. 222). Thereby, different organisms and effect levels (respiration, mobility, mortality, reproduction, embryonic development) were considered. Main focuses of the study were tests under relevant exposure scenarios. Therefore, Daphnia sp. acute immobilization tests and activated sludge tests were performed with solar radiation. Mixture experiments with nano-TiO2 and an organic contaminant were conducted with the acute and chronic earthworm and activated sludge respiration tests. Veröffentlicht in Texte | 72/2014.

Prüfungslücke bei der Biozidbewertung: Wirkungsrelevanz von Repellentien
(Produktart 19) für Nichtzielorganismen (Insektenlarven, Krebse) in Oberflächengewässern, Teil 2: Laborstudie

Lock- und Schreckstoffe (Attraktanzien & Repellentien) werden gezielt gegen Organismen eingesetzt und gelangen auch in die aquatische Umwelt, wo sie Verhaltensänderungen auslösen können. Sie gehören zu den vom Menschen gemachten Chemikalien, die Wasserorganismen so beeinflussen können, dass sie ihre Umgebung anders wahrnehmen. Man spricht in diesem Fall vom Infochemikalien-Effekt. Viele über ihren Geruch wirkenden Stoffe, wie das auf unserer Haut anzuwendende Mückenmittel DEET(Diethyltoluamid), werden bereits in unseren Oberflächengewässern nachgewiesen und ziehen dort möglicherweise Infochemikalien-Effekte nach sich. Am Beispiel von Humanarzneimitteln wie dem Tranquilizer Oxazepam konnte gezeigt werden, dass Stoffe unterhalb der Toxizitätsschwelle zum Beispiel das Schwarmverhalten von Flußbarschen verändern. Auch Neonicotinoide, die in geringen Konzentrationen (unterhalb der Toxizitätsschwelle) kurzzeitig in Fließgewässer eingetragen werden, können dort eine aktive, massenhafte Drift von Wasserorganismen auslösen und damit einen nachteiligen Einfluss auf lokale Populationen ausüben. Repellentien werden in der praktischen Anwendung vor allem gegen Blut saugende ⁠ Gliederfüßer ⁠ wie Stechmücken, Bremsen oder Zecken eingesetzt. Künstliche Repellentien gegen Gliederfüßer sind beispielsweise Diethyltoluamid (DEET), Icaridin (Picaridin) oder IR3535 (Ethylbutylacetylaminopropionat, EBAAP). Auch bei bestimmungsgemäßem Einsatz könnten von Repellentien bisher nicht beachtete Wirkungen auf Nicht-Zielorganismen ausgehen. Um Stoffe mit solchen Effekten aufzuspüren, sind daher neue Teststrategien zu entwickeln und geeignete Testsysteme im Labormaßstab zu etablieren. Das hier durchgeführte Vorhaben leistet dabei einen wichtigen Beitrag, in dem es Testsysteme für ökotoxikologische Fragestellungen anpasst und auf ihre Eignung prüft. Die Ergebnisse des Vorhabens sind für die Umweltbewertung von bioziden Wirkstoffen von großem Interesse. Bisher wurden nur akute und langfristige Effekte auf Nicht-Zielorganismen bewertet, weil das EU-Bewertungs¬konzept für Biozide und Chemikalien keine Bewertung repellenter Wirkungen vorsieht (Bewertungslücke). Bei den drei Repellentien wurden hier keine nachteiligen Umweltwirkungen im Verhalten der Testorganismen und unter den hier eingesetzten Testbedingungen ausgelöst. Dies ist zum Beispiel für den repellenten Wirkstoff DEET wichtig, der aktuell in vielen Haushaltsprodukten enthalten ist. Damit stehen nun erste Testsysteme zur Verfügung, um derartige Wirkungen künftig zuerkennen und gegebenenfalls bei der Bewertung, insbesondere bei Wirkungen auf das Schutzgut ⁠ Biodiversität ⁠, einbeziehen zu können. Veröffentlicht in Texte | 57/2016.

Cold atmospheric pressure plasma comb - a physical approach for pediculosis treatment

Pediculosis, that is the infestation of humans with Pediculus humanus capitis (head lice), poses a worldwide problem that is as old as mankind itself. Over the centuries, man has developed a variety of remedies, all of which have ultimately culminated in the use of chemical agents. Some of these remedies are known to produce successful results. A large portion of the effective remedies used to kill lice and their eggs contain insecticides, but there is an increasing number of reports of head lice populations revealing an increased resistance. This study presents an alternative treatment approach, the efficacy of which is based on physical effects. Cold atmospheric pressure plasmas have successfully shown their formidably wide application range within the field of plasma medicine. This study presents a plasma device in its current stage of development that is engineered as a consumer product to enable an alternative physical and insecticide-free option for the treatment of pediculosis. An efficacy study concerning different developmental stages of P. humanus humanus is presented. P. humanus humanus was chosen as a substitute test organism for P. humanus capitis due to possible laboratory rearing and high anatomic similarity. The study shows how a single stroke of the plasma device over a hair strand (approximately 22 cm in length with a weight of 1.5 g) led to mortality rates of 68.3% (50.0; 79.7) (95% CI) in the juvenile test group, a mortality rate of approx. 67.7% (54.9; 78.8) (95% CI) in the female test group, and approx. 46.7% (28.3; 65.7) (95% CI) in the male test group. When single eggs were introduced directly into the plasma for approx. 1 s, younger eggs (0-2 d) showed a higher mortality of 66.7% (42.7; 82.7) than the older (4-6 d) eggs, with 16.7% (5.6; 34.7) (CI). Furthermore, the results of a risk assessment of the device are described. The article concludes with necessary handling instructions as well as further developmental steps, derived from the results of the efficacy and the risk assessment study. Quelle: https://www.mdpi.com

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