Daphnia magna as an Alternative Model for (Simultaneous) Bioaccumulation and Chronic Toxicity Assessment─Controlled Exposure Study Indicates High Hazard of Heterocyclic PAHs
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| Názov: | Daphnia magna as an Alternative Model for (Simultaneous) Bioaccumulation and Chronic Toxicity Assessment─Controlled Exposure Study Indicates High Hazard of Heterocyclic PAHs |
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| Autori: | Göksu Çelik, Schylar Alexandra Healy, Stefan Stolte, Philipp Mayer, Marta Markiewicz |
| Zdroj: | Environ Sci Technol |
| Informácie o vydavateľovi: | American Chemical Society (ACS), 2025. |
| Rok vydania: | 2025 |
| Predmety: | Daphnia magna, NSO-PAHs, 106027 Ökotoxikologie, depuration rate constant, Bioaccumulation, bioaccumulation, Daphnia, passive dosing, Animals, 106027 Ecotoxicology, Polycyclic Aromatic Hydrocarbons, Toxicity Tests, Chronic, chronic toxicity, Water Pollutants, Chemical |
| Popis: | Testing the bioaccumulation and chronic toxicity of (highly) hydrophobic compounds is extremely challenging, but crucial for hazard assessment. Fish are used as a model organism in these tests, but have many limitations, including a long time to reach steady-state, difficulty in maintaining constant exposure, and ethical concerns. We developed a method for the (simultaneous) assessment of chronic reproductive toxicity and bioaccumulation using Daphnia magna as a model organism. As test chemicals, we selected heterocyclic polyaromatic hydrocarbons (heterocyclic PAHs), which are often persistent and show high acute aquatic toxicity, raising concerns about their long-term effects. In this study, we developed a robust passive dosing method to maintain constant exposure in chronic toxicity and bioaccumulation tests of four heterocyclic PAHs in Daphnia magna. Passive dosing maintained stable exposure concentrations in the ng to μg L-1 range, even after reusing disks up to three times. All chemicals were toxic to Daphnia magna with EC10 values between 0.1 and 15 μg L-1. Bioaccumulation tests showed that steady-state was not reached, and the uptake rate constant (k1) could not be reliably determined due to complex exposure routes (both via water and diet). However, depuration rates in Daphnia magna were about 2 orders of magnitude higher than in fish, which is advantageous in the assessment of highly hydrophobic compounds. We propose to use the depuration rate constant (k2), which is independent of the uptake route, as an indicator of bioaccumulation potential. The k2 thresholds for Daphnia magna were estimated to identify (very) bioaccumulative compounds by correlating k2 values with bioconcentration factors (BCFs) for Daphnia magna and applying fish BCF thresholds. We suggest that a Daphnia magna bioaccumulation test can be used as a screening tool to trigger further bioaccumulation testing in fish, as it offers higher throughput, is more ethical, and reaches steady-state faster. However, further validation with reference test protocols and substances is essential. |
| Druh dokumentu: | Article Other literature type |
| Jazyk: | English |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/acs.est.5c00384 |
| Prístupová URL adresa: | https://pubmed.ncbi.nlm.nih.gov/40305857 https://ucrisportal.univie.ac.at/de/publications/15b6784d-82a6-4ab9-98ee-5b8d76330b3d https://doi.org/10.1021/acs.est.5c00384 |
| Rights: | CC BY URL: http://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (http://creativecommons.org/licenses/by/4.0/). |
| Prístupové číslo: | edsair.doi.dedup.....318c9d4efc216fd18ea5e7fbbfb4083b |
| Databáza: | OpenAIRE |
Nájsť tento článok vo Web of Science | Abstrakt: | Testing the bioaccumulation and chronic toxicity of (highly) hydrophobic compounds is extremely challenging, but crucial for hazard assessment. Fish are used as a model organism in these tests, but have many limitations, including a long time to reach steady-state, difficulty in maintaining constant exposure, and ethical concerns. We developed a method for the (simultaneous) assessment of chronic reproductive toxicity and bioaccumulation using Daphnia magna as a model organism. As test chemicals, we selected heterocyclic polyaromatic hydrocarbons (heterocyclic PAHs), which are often persistent and show high acute aquatic toxicity, raising concerns about their long-term effects. In this study, we developed a robust passive dosing method to maintain constant exposure in chronic toxicity and bioaccumulation tests of four heterocyclic PAHs in Daphnia magna. Passive dosing maintained stable exposure concentrations in the ng to μg L-1 range, even after reusing disks up to three times. All chemicals were toxic to Daphnia magna with EC10 values between 0.1 and 15 μg L-1. Bioaccumulation tests showed that steady-state was not reached, and the uptake rate constant (k1) could not be reliably determined due to complex exposure routes (both via water and diet). However, depuration rates in Daphnia magna were about 2 orders of magnitude higher than in fish, which is advantageous in the assessment of highly hydrophobic compounds. We propose to use the depuration rate constant (k2), which is independent of the uptake route, as an indicator of bioaccumulation potential. The k2 thresholds for Daphnia magna were estimated to identify (very) bioaccumulative compounds by correlating k2 values with bioconcentration factors (BCFs) for Daphnia magna and applying fish BCF thresholds. We suggest that a Daphnia magna bioaccumulation test can be used as a screening tool to trigger further bioaccumulation testing in fish, as it offers higher throughput, is more ethical, and reaches steady-state faster. However, further validation with reference test protocols and substances is essential. |
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| ISSN: | 15205851 0013936X |
| DOI: | 10.1021/acs.est.5c00384 |