| 1. |
- Hunka, Agnieszka D., 1978-, et al.
(author)
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Stakeholders' Perspective on Ecological Modeling in Environmental Risk Assessment of Pesticides : Challenges and Opportunities
- 2013
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In: Risk Analysis. - Hoboken : Wiley-Blackwell. - 0272-4332 .- 1539-6924. ; 33:1, s. 68-79
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Journal article (peer-reviewed)abstract
- The article closely examines the role of mechanistic effect models (e.g., population models) in the European environmental risk assessment (ERA) of pesticides. We studied perspectives of three stakeholder groups on population modeling in ERA of pesticides. Forty-three in-depth, semi-structured interviews were conducted with stakeholders from regulatory authorities, industry, and academia all over Europe. The key informant approach was employed in recruiting our participants. They were first identified as key stakeholders in the field and then sampled by means of a purposive sampling, where each stakeholder identified as important by others was interviewed and asked to suggest another potential participant for our study. Our results show that participants, although having different institutional backgrounds often presented similar perspectives and concerns about modeling. Analysis of repeating ideas and keywords revealed that all stakeholders had very high and often contradicting expectations from models. Still, all three groups expected effect models to become integrated in future ERA of pesticides. Main hopes associated with effect models were to reduce the amount of expensive and complex testing and field monitoring, both at the product development stage, and as an aid to develop mitigation measures. Our analysis suggests that, although the needs of stakeholders often overlapped, subtle differences and lack of trust hinder the process of introducing mechanistic effect models into ERA. © 2012 Society for Risk Analysis.
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| 2. |
- Lammel, Tobias, et al.
(author)
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Dietary uptake and effects of copper in Sticklebacks at environmentally relevant exposures utilizing stable isotope-labeled 65CuCl2 and 65CuO NPs
- 2021
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In: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 757
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Journal article (peer-reviewed)abstract
- © 2020 Elsevier B.V. Copper oxide nanoparticles (CuO NPs) accumulating in sediment can be taken up by invertebrates that serve as prey for fish. Thus, it is likely that the latter are exposed to CuO NPs via the gut. However, to this day it is unknown if CuO NPs can be taken up via the gastrointestinal tract and if and in which tissues/organs they accumulate. To address this knowledge gap, we synthesized CuO NPs enriched in the stable isotope 65Cu and incorporated them at low concentration (5 μg 65Cu g−1 ww food) into a practical diet prepared from worm homogenate, which was then fed to Three-spined Stickleback (Gasterosteus aculeatus) for 16 days. For comparison, fish were exposed to a diet spiked with a 65CuCl2 solution. Background Cu and newly taken up 65Cu in fish tissues/organs including gill, stomach, intestine, liver, spleen, gonad and carcass and feces were quantified by ICP-MS. In addition, expression levels of genes encoding for proteins related to Cu uptake, detoxification and toxicity (ctr-1, gcl, gr, gpx, sod-1, cat, mta and zo-1) were measured in selected tissues using RT-qPCR. The obtained results showed that feces of fish fed 65CuO NP-spiked diet contained important amounts of 65Cu. Furthermore, there was no significant accumulation of 65Cu in any of the analyzed internal organs, though 65Cu levels were slightly elevated in liver. No significant modulation in gene expression was measured in fish exposed to 65CuO NP-spiked diet, except for metallothionein, which was significantly upregulated in intestinal tissue compared to control fish. Altogether, our results suggests that dietary absorption efficiency of CuO NPs, their uptake across the gastrointestinal barrier into the organism, and effects on Cu-related genes is limited at low, environmentally relevant exposure doses (0.2 μg 65Cu −1 fish ww day−1).
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| 3. |
- Nielsen, Maria, et al.
(author)
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Nanomaterials in the European chemicals legislation-methodological challenges for registration and environmental safety assessment
- 2021
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In: Environmental Science: Nano. - : Royal Society of Chemistry. - 2051-8153 .- 2051-8161. ; 8:3, s. 731-747
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Journal article (peer-reviewed)abstract
- In the European Union the Annexes of its chemical legislation (REACH) were revised and now clarify the technical data requirements for nanomaterials (NMs). These new provisions, effective from January 1, 2020, introduce requirements for manufacturers, importers and downstream users regarding registration and safety assessment of NMs. This study aims to assess the availability and suitability of methods needed to comply with the new regulatory provisions on NMs for physico-chemical characterisation and environmental fate and effects. The scientific literature and relevant test guideline frameworks were reviewed to identify applicable methods. These were subsequently evaluated and categorised as either: 'internationally accepted test guideline or standard (TGS)', 'internationally accepted test guideline or standard under development (TGSUD)', 'established as standard methods in scientific literature (SCI)', 'other methods and/or more research needed (O)' or 'no method (N)'. We find that 80% of the information requirements and a bit more than 40% of the waiving criteria in the new REACH Annexes are supported by methods that are available as TGS, TGSUD or SCI. Most of the relevant methods in the scientific literature are included in recent OECD guidance documents or ECHA guidance. We recommend that a targeted effort is made to develop protocols and guidelines for methods to determine NM adsorption/desorption, degradation, exposure scenarios and ability to cross biological membranes. Here methods to fulfil the information requirements and waiving criteria are currently lacking. Furthermore, we recommend that increasing attention is directed towards regulatory reliability and relevance of the information that is submitted by the registrants.
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| 4. |
- Thit, Amalie, et al.
(author)
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Influence of Aging on Bioaccumulation and Toxicity of Copper Oxide Nanoparticles and Dissolved Copper in the Sediment-Dwelling Oligochaete Tubifex tubifex: A Long-Term Study Using a Stable Copper Isotope
- 2021
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In: FRONTIERS IN TOXICOLOGY. - : Frontiers Media SA. - 2673-3080. ; 3
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Journal article (peer-reviewed)abstract
- For engineered metal nanoparticles (NPs), such as copper oxide (CuO) NPs, the sediment is recognized as a major compartment for NP accumulation. Sediment-dwelling organisms, such as the worm Tubifex tubifex, will be at particular risk of metal and metal NP exposure. However, a range of complex transformation processes in the sediment affects NP bioavailability and toxicity as the contamination ages. The objective of this study was to examine bioaccumulation and adverse effects of CuO NPs in T. tubifex compared to dissolved Cu (administered as CuCl2) and the influence of aging of spiked sediment. This was done in a 28-day exposure experiment with T. tubifex incubated in clean sediment or freshly spiked sediment with different concentrations of dissolved Cu (up to 230 mu g g(-1) dw) or CuO NPs (up to 40 mu g g(-1) dw). The experiment was repeated with the same sediments after it had been aged for 2 years. To obtain a distinct isotopic signature compared to background Cu, both Cu forms were based on the stable isotope Cu-65 (>99%). The 28-day exposure to sediment-associated dissolved Cu-65 and (CuO)-Cu-65 NPs resulted in a clear concentration-dependent increase in the T. tubifex Cu-65 body burden. However, despite the elevated Cu-65 body burdens in exposed worms, limited adverse effects were observed in either of the two experiments (e.g., above 80% survival in all treatments, low or no effects on the growth rate, feeding rate, and reproduction). Organisms exposed to aged sediments had lower body burdens of Cu-65 than those exposed to freshly spiked sediments and we suggest that aging decreases the bioavailability of both Cu-65 forms. In this study, the use of a stable isotope made it possible to use environmentally realistic Cu concentrations and, at the same time, differentiate between newly accumulated Cu-65 and background Cu in experimental samples despite the high background Cu concentrations in sediment and T. tubifex tissue. Realistic exposure concentrations and aging of NPs should preferably be included in future studies to increase environmental realism to accurately predict the environmental risk of metal NPs.
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| 5. |
- Waldschläger, Kryss, et al.
(author)
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Microplastics: What Can We Learn from Clastic Sediments?
- 2023
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In: Springer Water. - : Springer Nature. - 2364-6934 .- 2364-8198. ; , s. 105-116
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Book chapter (other academic/artistic)abstract
- Microplastics research has gained momentum in the 21st century but lags behind the long-standing research on clastic sediment.An interdisciplinary review paper was conducted, comparing microplastics with natural sediments in terms of particle properties, transport processes, sampling techniques, and ecotoxicology. The paper identifies seven research goals to enhance our understanding of microplastics in freshwater environments while learning from sediment research. This extended abstract presents the core message of the review paper, emphasizing the need to improve descriptions of microplastic particles, understand their transport processes, develop standardized sampling methods, and study their ecotoxicological effects. The research goals outline specific tasks to achieve these objectives and emphasize the importance of comparing microplastics to sediments to gain insights into their toxicity. Addressing these research goals will contribute to a comprehensive understanding of microplastics and their impact on freshwater ecosystems. For detailed insights, the original paper should be consulted.
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