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Hu H, Ma P, Li H, You J. Determining buffering capacity of polydimethylsiloxane-based passive dosing for hydrophobic organic compounds in large-volume bioassays. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 914:169710. [PMID: 38184249 DOI: 10.1016/j.scitotenv.2023.169710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 12/25/2023] [Accepted: 12/25/2023] [Indexed: 01/08/2024]
Abstract
Polydimethylsiloxane (PDMS) is the most widely used material for passive dosing. However, the ability of PDMS to maintain constant water concentrations of chemicals in large-volume bioassays was insufficiently investigated. In this study, we proposed a kinetic-based method to determine the buffering capacity of PDMS for maintaining constant water concentrations of hydrophobic organic contaminants (HOCs) in large-volume bioassays. A good correlation between log Kow and PDMS-water partitioning coefficients (log KPW) was observed for HOCs with log Kow values ranging from 3.30 to 7.42. For low-molecular-weight HOCs, volatile loss was identified as the primary cause of unstable water concentrations in passive dosing systems. Slow desorption from PDMS resulted in a reduction of water concentrations for high-molecular-weight HOCs. The volume ratio of PDMS to water (RV) was the key factor controlling buffering capacity. As such, buffering capacity was defined as the minimum RV required to maintain 90% of the initial water concentration and was determined to be 0.0076-0.032 for six representative HOCs. Finally, passive dosing with an RV of 0.014 was validated to effectively maintain water concentrations of phenanthrene in 2-L and 96-h toxicity tests with adult mosquitofish. By determining buffering capacity of PDMS, this study recommended specific RV values for cost-efficient implementation of passive dosing approaches in aquatic toxicology, particularly in large-volume bioassays.
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Affiliation(s)
- Hao Hu
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
| | - Ping Ma
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China; Department of Eco-engineering, Guangdong Eco-Engineering Polytechnic, Guangzhou 510520, China
| | - Huizhen Li
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China.
| | - Jing You
- Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 511443, China
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2
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Ruan T, Li P, Wang H, Li T, Jiang G. Identification and Prioritization of Environmental Organic Pollutants: From an Analytical and Toxicological Perspective. Chem Rev 2023; 123:10584-10640. [PMID: 37531601 DOI: 10.1021/acs.chemrev.3c00056] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2023]
Abstract
Exposure to environmental organic pollutants has triggered significant ecological impacts and adverse health outcomes, which have been received substantial and increasing attention. The contribution of unidentified chemical components is considered as the most significant knowledge gap in understanding the combined effects of pollutant mixtures. To address this issue, remarkable analytical breakthroughs have recently been made. In this review, the basic principles on recognition of environmental organic pollutants are overviewed. Complementary analytical methodologies (i.e., quantitative structure-activity relationship prediction, mass spectrometric nontarget screening, and effect-directed analysis) and experimental platforms are briefly described. The stages of technique development and/or essential parts of the analytical workflow for each of the methodologies are then reviewed. Finally, plausible technique paths and applications of the future nontarget screening methods, interdisciplinary techniques for achieving toxicant identification, and burgeoning strategies on risk assessment of chemical cocktails are discussed.
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Affiliation(s)
- Ting Ruan
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pengyang Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haotian Wang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tingyu Li
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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3
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Frasat T, Tulain UR, Erum A, Saleem U, Sohail MF, Kausar R. Aloe vera and Artemisia vulgaris hydrogels : Exploring the toxic effects of structural transformation of the biocompatible materials. Drug Dev Ind Pharm 2022; 47:1753-1763. [PMID: 35282715 DOI: 10.1080/03639045.2022.2050751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES This study was aimed to evaluate the toxicity profile of hydrogels of plant-derived mucilage from Aloe vera and Artemisia vulgaris used for various drug delivery applications, yet no such toxicity study has been reported for the toxicity evaluation of 3D structures. New Drug carrier should be harmless for drug delivery applications. METHODS Acute and sub-acute (repeated dose) oral toxicity studies were conducted following OECD 407 and 425 guidelines. In vitro toxicity through hemolysis and MTT assay were checked against RBC's and human macrophages respectively. RESULTS The hemolysis and MTT assay showed good compatibility of hydrogels with blood components. Mutagenicity testing showed no genotoxic effects of hydrogels. In vivo toxicity evaluation was done in female albino rats and rabbits. General behavior, adverse effects, clinical signs and symptoms, and mortality were recorded for 14 days post-treatment which showed no significant (p < 005) abnormality. Hematological and biochemical parameters including LFTs and RFTs appeared to be normal with slight variations in the treated groups. Normal architecture of kidney, liver, heart, and intestine was evident upon histopathological analyses. CONCLUSION Hence, the results suggested that the 3D structure of Aloe vera and Artemisia vulgaris based hydrogels is safe upon ingestion and can be used for drug delivery science being cheap, natural and biocompatible.
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Affiliation(s)
- Taskeen Frasat
- Faculty of Pharmacy, University of Sargodha, Sargodha, Pakistan
| | | | - Alia Erum
- Faculty of Pharmacy, University of Sargodha, Sargodha, Pakistan
| | - Uzma Saleem
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, GC University, Faisalabad, Pakistan
| | - Muhammad Farhan Sohail
- Riphah Institute of Pharmaceutical Sciences, Riphah International University, Lahore Campus, Lahore, Pakistan
| | - Rizwana Kausar
- ILM College of Pharmaceutical Sciences, Sargodha, Pakistan
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4
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Smith KEC, Jeong Y. Passive Sampling and Dosing of Aquatic Organic Contaminant Mixtures for Ecotoxicological Analyses. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:9538-9547. [PMID: 33749267 DOI: 10.1021/acs.est.0c08067] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Toxicity results from exposure to mixtures of organic contaminants. Assessing this using ecotoxicity bioassays involves sampling of the environmental mixture and then introducing this into the test. The first step is accounting for the bioavailable levels of all mixture constituents. Passive sampling specifically targets these bioavailable fractions but the sampler-accumulated mixture varies with the compound and sampler properties as well as time. The second step involves reproducing and maintaining the sampled mixture constituents in the bioassay. Passive sampler extraction and spiking always leads to a skewed mixture profile in the test. Alternatively, the recovered passive samplers might be directly used in passive dosing mode. Here, the reproduced contaminant mixture depends on whether kinetic or equilibrium sampling applies. These concepts were tested for determining the combined toxicity of laboratory and field mixtures of aquatic contaminants in the Microtox and ER-Calux bioassays. Aqueous sample extraction and spiking, passive sampler extraction and spiking, and passive sampling and dosing were compared for first sampling and then introducing mixtures in toxicity bioassays. The analytical and toxicity results show that the correct way to first sample the bioavailable mixture profile, and then to reproduce and maintain this in the toxicity test, is by combining equilibrium passive sampling and dosing.
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Affiliation(s)
- Kilian E C Smith
- Environmental Safety Group, KIST Europe, Korea Institute of Science and Technology, Campus E 7.1, Saarbrücken, Germany
| | - Yoonah Jeong
- Environmental Safety Group, KIST Europe, Korea Institute of Science and Technology, Campus E 7.1, Saarbrücken, Germany
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5
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Chapman FM, Sparham C, Hastie C, Sanders DJ, van Egmond R, Chapman KE, Doak SH, Scott AD, Jenkins GJS. Comparison of passive-dosed and solvent spiked exposures of pro-carcinogen, benzo[a]pyrene, to human lymphoblastoid cell line, MCL-5. Toxicol In Vitro 2020; 67:104905. [PMID: 32497684 DOI: 10.1016/j.tiv.2020.104905] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 02/26/2020] [Accepted: 05/28/2020] [Indexed: 11/17/2022]
Abstract
Genotoxicity testing methods in vitro provide a means to predict the DNA damaging effects of chemicals on human cells. This is hindered in the case of hydrophobic test compounds, however, which will partition to in vitro components such as plastic-ware and medium proteins, in preference to the aqueous phase of the exposure medium. This affects the freely available test chemical concentration, and as this freely dissolved aqueous concentration is that bioavailable to cells, it is important to define and maintain this exposure. Passive dosing promises to have an advantage over traditional 'solvent spiking' exposure methods and involves the establishment and maintenance of known chemical concentrations in the in vitro medium, and therefore aqueous phase. Passive dosing was applied in a novel format to expose the MCL-5 human lymphoblastoid cell line to the pro-carcinogen, benzo[a]pyrene (B[a]P) and was compared to solvent (dimethyl sulphoxide) spiked B[a]P exposures over 48 h. Passive dosing induced greater changes, at lower concentrations, to micronucleus frequency, p21 mRNA expression, cell cycle abnormalities, and cell and nuclear morphology. This was attributed to a maintained, definable, free chemical concentration using passive dosing and the presence or absence of solvent, and highlights the influence of exposure choice on genotoxic outcomes.
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Affiliation(s)
- Fiona M Chapman
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK.
| | - Chris Sparham
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Colin Hastie
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - David J Sanders
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Roger van Egmond
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Katherine E Chapman
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK
| | - Shareen H Doak
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK
| | - Andrew D Scott
- Safety and Environmental Assurance Centre, Unilever, Colworth House, Sharnbrook, Bedford MK44 1LQ, UK
| | - Gareth J S Jenkins
- In Vitro Toxicology Group, Institute of Life Science 1, Swansea University Medical School, Singleton Campus, Swansea SA2 8PP, UK
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6
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Hammershøj R, Birch H, Sjøholm KK, Mayer P. Accelerated Passive Dosing of Hydrophobic Complex Mixtures-Controlling the Level and Composition in Aquatic Tests. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2020; 54:4974-4983. [PMID: 32142613 DOI: 10.1021/acs.est.9b06062] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Petroleum products and essential oils are complex mixtures of hydrophobic and volatile chemicals and are categorized as substances of unknown or variable composition, complex reaction products, or biological materials (UVCBs). In aquatic testing and research of such mixtures, it is challenging to establish initial concentrations without the addition of cosolvents, to maintain constant concentrations during the test, and to keep a constant mixture composition in dilution series and throughout test duration. Passive dosing was here designed to meet these challenges by maximizing the surface area (Adonor/Vmedium = 3.8 cm2/mL) and volume (Vdonor/Vmedium > 0.1 L/L) of the passive dosing donor in order to ensure rapid mass transfer and avoid donor depletion for all mixture constituents. Cracked gas oil, cedarwood Virginia oil, and lavender oil served as model mixtures. This study advances the field by (i) showing accelerated passive dosing kinetics for 68 cracked gas oil constituents with typical equilibration times of 5-10 min and for 21 cederwood Virginia oil constituents with typical equilibration times < 1 h, (ii) demonstrating how to control mixture concentration and composition in aquatic tests, and (iii) discussing the fundamental differences between solvent spiking, water-accommodated fractions, and passive dosing.
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Affiliation(s)
- Rikke Hammershøj
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kongens Lyngby, Denmark
| | - Heidi Birch
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kongens Lyngby, Denmark
| | - Karina K Sjøholm
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kongens Lyngby, Denmark
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kongens Lyngby, Denmark
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7
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Bluhm K, Heger S, Redelstein R, Brendt J, Anders N, Mayer P, Schaeffer A, Hollert H. Genotoxicity of three biofuel candidates compared to reference fuels. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2018; 64:131-138. [PMID: 30391874 DOI: 10.1016/j.etap.2018.10.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 10/13/2018] [Indexed: 06/08/2023]
Abstract
Global demand for alternative energy sources increases due to concerns regarding energy security and greenhouse gas emissions. However, little is known regarding the impacts of biofuels to the environment and human health even though the identification of such impacts is important to avoid biofuels leading to undesired effects. In this study mutagenicity and genotoxicity of the three biofuel candidates ethyl levulinate (EL), 2-methyltetrahydrofuran (2-MTHF) and 2-methylfuran (2-MF) were investigated in comparison to two petroleum-derived fuels and a biodiesel. None of the samples induced mutagenicity in the Ames fluctuation test. However, the Micronucleus assay revealed significant effects in Chinese hamster (Cricetulus griseus) V79 cells caused by the potential biofuels. 2-MF revealed the highest toxic potential with significant induction of micronuclei below 20.0 mg/L. EL and 2-MTHF induced micronuclei only at very high concentrations (>1000.0 mg/L). In regard to the genotoxic potential of 2-MF, its usage as biofuel should be critically discussed.
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Affiliation(s)
- Kerstin Bluhm
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany
| | - Sebastian Heger
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany
| | - Regine Redelstein
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany
| | - Julia Brendt
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany
| | - Nico Anders
- RWTH Aachen University, Aachener Verfahrenstechnik - Enzyme Process Technology, Worringerweg 1, 52074 Aachen, Germany
| | - Philipp Mayer
- Technical University of Denmark, Department of Environmental Engineering, Kongens Lyngby, Denmark
| | - Andreas Schaeffer
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany; Chongqing University, College of Resources and Environmental Science, Chongqing, 400715, China; Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing, 210093, China
| | - Henner Hollert
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany; Chongqing University, College of Resources and Environmental Science, Chongqing, 400715, China; Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing, 210093, China; Tongji University, College of Environmental Science and Engineering and State Key Laboratory of Pollution Control and Resource Reuse, Shanghai, 200092, China.
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8
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Castro M, Breitholtz M, Yuan B, Athanassiadis I, Asplund L, Sobek A. Partitioning of Chlorinated Paraffins (CPs) to Daphnia magna Overlaps between Restricted and in-Use Categories. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9713-9721. [PMID: 30074385 DOI: 10.1021/acs.est.8b00865] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Chlorinated paraffins (CPs) are high-production volume industrial chemicals consisting of n-alkanes (with 10 to 30 carbon atoms in the chain) with chlorine content from 30 to 70% of weight. In Europe, the use of short chain chlorinated paraffins (SCCPs) has been restricted by the Stockholm Convention on POPs due to their PBT (persistent, bioaccumulative and toxic) properties. Medium (MCCPs) and long chain (LCCPs) chlorinated paraffins are used as substitution products. In this work we studied the partitioning behavior of five different CP technical mixtures from the established categories (2 SCCPs, 1 MCCP, 1 LCCP and 1 CP technical mixture covering all categories) using passive dosing, by determining the partitioning coefficient of CP technical mixtures between silicone and water ( Ksilicone-water) as well as between organic matter and water ( Koc-water). We show that both silicone-water and organic carbon-water partition coefficients overlap between different categories of CP technical mixtures. These results indicate that in-use MCCPs and LCCPs may be equally or more bioaccumulative than restricted SCCPs. For the tested mixtures, both chlorine content and carbon chain length showed a significant correlation with both Ksilicone-water and Koc-water.
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Affiliation(s)
- Mafalda Castro
- Department of Environmental Science and Analytical Chemistry (ACES) , Stockholm University , 106-91 Stockholm , Sweden
| | - Magnus Breitholtz
- Department of Environmental Science and Analytical Chemistry (ACES) , Stockholm University , 106-91 Stockholm , Sweden
| | - Bo Yuan
- Department of Environmental Science and Analytical Chemistry (ACES) , Stockholm University , 106-91 Stockholm , Sweden
| | - Ioannis Athanassiadis
- Department of Environmental Science and Analytical Chemistry (ACES) , Stockholm University , 106-91 Stockholm , Sweden
| | - Lillemor Asplund
- Department of Environmental Science and Analytical Chemistry (ACES) , Stockholm University , 106-91 Stockholm , Sweden
| | - Anna Sobek
- Department of Environmental Science and Analytical Chemistry (ACES) , Stockholm University , 106-91 Stockholm , Sweden
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9
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Niehus NC, Floeter C, Hollert H, Witt G. Miniaturised Marine Algae Test with Polycyclic Aromatic Hydrocarbons - Comparing Equilibrium Passive Dosing and Nominal Spiking. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2018; 198:190-197. [PMID: 29554635 DOI: 10.1016/j.aquatox.2018.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 01/05/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
In this study the miniaturised Marine Algae Test (mMAT) using passive dosing was developed based on the ISO EN DIN10253 to investigate the growth inhibition of the marine diatom Phaeodactylum tricornutum caused by polycyclic aromatic hydrocarbons (PAHs). Risk assessment of hydrophobic organic compounds (HOCs) like PAHs in aquatic toxicity tests is very difficult due to their low aqueous solubilities, losses via sorption to the wells and volatilisation. However, passive dosing can overcome these challenges. In this study biocompatible silicone O-rings were used as PAH reservoir. Individual PAHs at saturation were tested using passive dosing and in comparison with nominal spiking. Additionally, a recreated mixture of PAHs reflecting the field composition of the sediment pore water was tested with passive dosing. PAHs revealed strong growth inhibiting effects on algal growth in passive dosing tests, while nominal spiking had only slightly growth inhibiting effects in the highest concentration. The recreated PAH mixture revealed slightly inhibiting effects using passive dosing when tested with a factor of 5000 of the field concentration. This study demonstrates the superiority of passive dosing to spiking and further the successful implementation of passive dosing in the marine algae test maintaining a constant concentration for HOCs with a log KOW > 4.6.
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Affiliation(s)
- Nora Claire Niehus
- Hamburg University of Applied Sciences, Department Environmental Engineering, Ulmenliet 20 21033 Hamburg, Germany; RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany.
| | - Carolin Floeter
- Hamburg University of Applied Sciences, Department Environmental Engineering, Ulmenliet 20 21033 Hamburg, Germany.
| | - Henner Hollert
- RWTH Aachen University, Institute for Environmental Research, Worringerweg 1, 52074 Aachen, Germany.
| | - Gesine Witt
- Hamburg University of Applied Sciences, Department Environmental Engineering, Ulmenliet 20 21033 Hamburg, Germany.
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10
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Stibany F, Ewald F, Miller I, Hollert H, Schäffer A. Improving the reliability of aquatic toxicity testing of hydrophobic chemicals via equilibrium passive dosing - A multiple trophic level case study on bromochlorophene. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 584-585:96-104. [PMID: 28142058 DOI: 10.1016/j.scitotenv.2017.01.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/13/2017] [Accepted: 01/13/2017] [Indexed: 04/15/2023]
Abstract
The main objective of the present study was to improve the reliability and practicability of aquatic toxicity testing of hydrophobic chemicals based upon the model substance bromochlorophene (BCP). Therefore, we adapted a passive dosing format to test the toxicity of BCP at different concentrations and in multiple test systems with aquatic organisms of various trophic levels. At the same time, the method allowed for the accurate determination of exposure concentrations (i.e., in the presence of exposed organisms; Ctest) and freely dissolved concentrations (i.e., without organisms present; Cfree) of BCP in all tested media. We report on the joint adaptation of three ecotoxicity tests - algal growth inhibition, Daphnia magna immobilization, and fish-embryo toxicity - to a silicone O-ring based equilibrium passive dosing format. Effect concentrations derived by passive dosing methods were compared with corresponding effect concentrations derived by standard co-solvent setups. The passive dosing format led to EC50-values in the lower μgL-1 range for algae, daphnids, and fish embryos, whereas increased effect concentrations were measured in the co-solvent setups for algae and daphnids. This effect once more shows that passive dosing might offer advantages over standard methods like co-solvent setups when it comes to a reliable risk assessment of hydrophobic substances. The presented passive dosing setup offers a facilitated, practical, and repeatable way to test hydrophobic chemicals on their toxicity to aquatic organisms, and is an ideal basis for the detailed investigation of this important group of chemicals.
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Affiliation(s)
- Felix Stibany
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.
| | - Franziska Ewald
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Ina Miller
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Henner Hollert
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Andreas Schäffer
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
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11
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Stibany F, Schmidt SN, Schäffer A, Mayer P. Aquatic toxicity testing of liquid hydrophobic chemicals - Passive dosing exactly at the saturation limit. CHEMOSPHERE 2017; 167:551-558. [PMID: 27770722 DOI: 10.1016/j.chemosphere.2016.10.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 09/30/2016] [Accepted: 10/03/2016] [Indexed: 06/06/2023]
Abstract
The aims of the present study were (1) to develop a passive dosing approach for aquatic toxicity testing of liquid substances with very high Kow values and (2) to apply this approach to the model substance dodecylbenzene (DDB, Log Kow = 8.65). The first step was to design a new passive dosing format for testing DDB exactly at its saturation limit. Silicone O-rings were saturated by direct immersion in pure liquid DDB, which resulted in swelling of >14%. These saturated O-rings were used to establish and maintain DDB exposure exactly at the saturation limit throughout 72-h algal growth inhibition tests with green algae Raphidocelis subcapitata. Growth rate inhibition at DDB solubility was 13 ± 5% (95% CI) in a first and 8 ± 3% (95% CI) in a repeated test, which demonstrated that improved exposure control can lead to good precision and repeatability of toxicity tests. This moderate toxicity at chemical activity of unity was higher than expected relative to a reported hydrophobicity cut-off in toxicity, but lower than expected relative to a reported chemical activity range for baseline toxicity. The present study introduces a new effective approach for toxicity testing of an important group of challenging chemicals, while providing a basis for investigating toxicity cut-off theories.
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Affiliation(s)
- Felix Stibany
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany; Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, DK-2800 Kongens Lyngby, Denmark.
| | - Stine Nørgaard Schmidt
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, DK-2800 Kongens Lyngby, Denmark
| | - Andreas Schäffer
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, DK-2800 Kongens Lyngby, Denmark
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12
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Fischer F, Böhm L, Höss S, Möhlenkamp C, Claus E, Düring RA, Schäfer S. Passive Dosing in Chronic Toxicity Tests with the Nematode Caenorhabditis elegans. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:9708-9716. [PMID: 27494096 DOI: 10.1021/acs.est.6b02956] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In chronic toxicity tests with Caenorhabditis elegans, it is necessary to feed the nematode with bacteria, which reduces the freely dissolved concentration (Cfree) of hydrophobic organic chemicals (HOCs), leading to poorly defined exposure with conventional dosing procedures. We examined the efficacy of passive dosing of polycyclic aromatic hydrocarbons (PAHs) using silicone O-rings to control exposure during C. elegans toxicity testing and compared the results to those obtained with solvent spiking. Solid-phase microextraction and liquid-liquid extraction were used to measure Cfree and the chemicals taken up via ingestion. During toxicity testing, Cfree decreased by up to 89% after solvent spiking but remained constant with passive dosing. This led to a higher apparent toxicity on C. elegans exposed by passive dosing than by solvent spiking. With increasing bacterial cell densities, Cfree of solvent-spiked PAHs decreased while being maintained constant with passive dosing. This resulted in lower apparent toxicity under solvent spiking but an increased apparent toxicity with passive dosing, probably as a result of the higher chemical uptake rate via food (CUfood). Our results demonstrate the utility of passive dosing to control Cfree in routine chronic toxicity testing of HOCs. Moreover, both chemical uptake from water or via food ingestion can be controlled, thus enabling the discrimination of different uptake routes in chronic toxicity studies.
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Affiliation(s)
- Fabian Fischer
- German Federal Institute of Hydrology (BfG) , Am Mainzer Tor 1, 56068 Koblenz, Germany
- Institute of Soil Science and Soil Conservation, Research Center for BioSystems, Land Use, and Nutrition (iFZ), Justus Liebig University Giessen , Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Leonard Böhm
- Institute of Soil Science and Soil Conservation, Research Center for BioSystems, Land Use, and Nutrition (iFZ), Justus Liebig University Giessen , Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | | | - Christel Möhlenkamp
- German Federal Institute of Hydrology (BfG) , Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Evelyn Claus
- German Federal Institute of Hydrology (BfG) , Am Mainzer Tor 1, 56068 Koblenz, Germany
| | - Rolf-Alexander Düring
- Institute of Soil Science and Soil Conservation, Research Center for BioSystems, Land Use, and Nutrition (iFZ), Justus Liebig University Giessen , Heinrich-Buff-Ring 26-32, 35392 Giessen, Germany
| | - Sabine Schäfer
- German Federal Institute of Hydrology (BfG) , Am Mainzer Tor 1, 56068 Koblenz, Germany
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13
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Brack W, Ait-Aissa S, Burgess RM, Busch W, Creusot N, Di Paolo C, Escher BI, Mark Hewitt L, Hilscherova K, Hollender J, Hollert H, Jonker W, Kool J, Lamoree M, Muschket M, Neumann S, Rostkowski P, Ruttkies C, Schollee J, Schymanski EL, Schulze T, Seiler TB, Tindall AJ, De Aragão Umbuzeiro G, Vrana B, Krauss M. Effect-directed analysis supporting monitoring of aquatic environments--An in-depth overview. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 544:1073-118. [PMID: 26779957 DOI: 10.1016/j.scitotenv.2015.11.102] [Citation(s) in RCA: 237] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 11/20/2015] [Accepted: 11/20/2015] [Indexed: 05/18/2023]
Abstract
Aquatic environments are often contaminated with complex mixtures of chemicals that may pose a risk to ecosystems and human health. This contamination cannot be addressed with target analysis alone but tools are required to reduce this complexity and identify those chemicals that might cause adverse effects. Effect-directed analysis (EDA) is designed to meet this challenge and faces increasing interest in water and sediment quality monitoring. Thus, the present paper summarizes current experience with the EDA approach and the tools required, and provides practical advice on their application. The paper highlights the need for proper problem formulation and gives general advice for study design. As the EDA approach is directed by toxicity, basic principles for the selection of bioassays are given as well as a comprehensive compilation of appropriate assays, including their strengths and weaknesses. A specific focus is given to strategies for sampling, extraction and bioassay dosing since they strongly impact prioritization of toxicants in EDA. Reduction of sample complexity mainly relies on fractionation procedures, which are discussed in this paper, including quality assurance and quality control. Automated combinations of fractionation, biotesting and chemical analysis using so-called hyphenated tools can enhance the throughput and might reduce the risk of artifacts in laboratory work. The key to determining the chemical structures causing effects is analytical toxicant identification. The latest approaches, tools, software and databases for target-, suspect and non-target screening as well as unknown identification are discussed together with analytical and toxicological confirmation approaches. A better understanding of optimal use and combination of EDA tools will help to design efficient and successful toxicant identification studies in the context of quality monitoring in multiply stressed environments.
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Affiliation(s)
- Werner Brack
- UFZ Helmholtz Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany; RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Selim Ait-Aissa
- Institut National de l'Environnement Industriel et des Risques INERIS, BP2, 60550 Verneuil-en-Halatte, France
| | - Robert M Burgess
- US Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, Narragansett, RI, USA
| | - Wibke Busch
- UFZ Helmholtz Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany
| | - Nicolas Creusot
- Institut National de l'Environnement Industriel et des Risques INERIS, BP2, 60550 Verneuil-en-Halatte, France
| | | | - Beate I Escher
- UFZ Helmholtz Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany; Eberhard Karls University Tübingen, 72074 Tübingen, Germany
| | - L Mark Hewitt
- Water Science and Technology Directorate, Environment Canada, 867 Lakeshore Road, Burlington, Ontario L7S 1A1, Canada
| | - Klara Hilscherova
- Masaryk University, Research Centre for Toxic Compounds in the Environment (RECETOX), Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Juliane Hollender
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Henner Hollert
- RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany
| | - Willem Jonker
- VU University, BioMolecular Analysis Group, Amsterdam, The Netherlands
| | - Jeroen Kool
- VU University, BioMolecular Analysis Group, Amsterdam, The Netherlands
| | - Marja Lamoree
- VU Amsterdam, Institute for Environmental Studies, Amsterdam, The Netherlands
| | - Matthias Muschket
- UFZ Helmholtz Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany
| | - Steffen Neumann
- Leibniz Institute of Plant Biochemistry, Halle (Saale), Germany
| | - Pawel Rostkowski
- NILU - Norwegian Institute for Air Research, Instituttveien 18, 2007 Kjeller, Norway
| | | | - Jennifer Schollee
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Emma L Schymanski
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Tobias Schulze
- UFZ Helmholtz Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany
| | | | - Andrew J Tindall
- WatchFrag, Bâtiment Genavenir 3, 1 Rue Pierre Fontaine, 91000 Evry, France
| | | | - Branislav Vrana
- Masaryk University, Research Centre for Toxic Compounds in the Environment (RECETOX), Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Martin Krauss
- UFZ Helmholtz Centre for Environmental Research, Permoserstraße 15, 04318 Leipzig, Germany
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14
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Defining and Controlling Exposure During In Vitro Toxicity Testing and the Potential of Passive Dosing. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2016; 157:263-292. [DOI: 10.1007/10_2015_5017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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15
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Assessment of the Mutagenicity of Sediments from Yangtze River Estuary Using Salmonella Typhimurium/Microsome Assay. PLoS One 2015; 10:e0143522. [PMID: 26606056 PMCID: PMC4659643 DOI: 10.1371/journal.pone.0143522] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 10/07/2015] [Indexed: 02/01/2023] Open
Abstract
Sediments in estuaries are of important environmental concern because they may act as pollution sinks and sources to the overlying water body. These sediments can be accumulated by benthic organisms. This study assessed the mutagenic potential of sediment extracts from the Yangtze River estuary by using the Ames fluctuation assay with the Salmonella typhimurium his (-) strain TA98 (frameshift mutagen indicator) and TA100 (baseshift mutagen indicator). Most of the sediment samples were mutagenic to the strain TA98, regardless of the presence or absence of exogenous metabolic activation (S9 induction by β-naphthoflavone/phenobarbital). However, none of the samples were mutagenic to the strain TA100. Thus, the mutagenicity pattern was mainly frameshift mutation, and the responsible toxicants were both direct (without S9 mix) and indirect (with S9 mix) mutagens. The mutagenicity of the sediment extracts increased when S9 was added. Chemical analysis showed a poor correlation between the content of priority polycyclic aromatic hydrocarbons and the detected mutagenicity in each sample. The concept of effect-directed analysis was used to analyze possible compounds responsible for the detected mutagenic effects. With regard to the mutagenicity of sediment fractions, non-polar compounds as well as weakly and moderately polar compounds played a main role. Further investigations should be conducted to identify the responsible components.
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16
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Kurth D, Brack W, Luckenbach T. Is chemosensitisation by environmental pollutants ecotoxicologically relevant? AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2015; 167:134-42. [PMID: 26281775 DOI: 10.1016/j.aquatox.2015.07.017] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 07/28/2015] [Accepted: 07/28/2015] [Indexed: 05/11/2023]
Abstract
The active cellular efflux of toxicants is an efficient biological defense mode present in all organisms. By blocking this so-called multixenobiotic resistance transport-a process also referred to as chemosensitisation-, cellular bioaccumulation and the sensitivity of organisms towards environmental pollutants can increase. So far, a wide range of compounds, including pesticides, pharmaceuticals, fragrances, and surfactants, have been identified as chemosensitisers. Although, significant on a cellular level, the environmental impact of chemosensitisation on the organism level is not yet understood. Critically evaluating existing data, this paper identifies research needs to support our tentative conclusion that chemosensitisation may well enhance the risks of chemical exposure to aquatic organisms. Our conclusion is based on studies investigating the impact of individual chemicals and complex environmental mixtures on aquatic wildlife and a chemosensitiser mixture toxicity model which, however, is subject to great uncertainty due to substantial knowledge gaps. Those uncertainties include the inconsistent reporting of effect data, the lack of representative environmental contaminants tested for chemosensitisation, and the publishing of highly unreliable nominal exposure concentrations. In order to confirm the tentative conclusion of this paper, we require the significant and systematic investigation of a broader set of chemicals and environmental samples with a harmonised set of bioassays and rigorously controlled freely dissolved effect concentrations.
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Affiliation(s)
- Denise Kurth
- UFZ-Helmholtz Centre for Environmental Research, Department of Effect-Directed Analysis, Permoserstr. 15, 04318 Leipzig, Germany; RWTH Aachen University, Department of Ecosystem Analyses, Institute for Environmental Research, Worringerweg 1, 52074, Aachen, Germany
| | - Werner Brack
- UFZ-Helmholtz Centre for Environmental Research, Department of Effect-Directed Analysis, Permoserstr. 15, 04318 Leipzig, Germany; RWTH Aachen University, Department of Ecosystem Analyses, Institute for Environmental Research, Worringerweg 1, 52074, Aachen, Germany.
| | - Till Luckenbach
- UFZ-Helmholtz Centre for Environmental Research, Department of Bioanalytical Ecotoxicology, Permoserstr. 15, 04318 Leipzig, Germany
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17
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Claessens M, Monteyne E, Wille K, Vanhaecke L, Roose P, Janssen CR. Passive sampling reversed: coupling passive field sampling with passive lab dosing to assess the ecotoxicity of mixtures present in the marine environment. MARINE POLLUTION BULLETIN 2015; 93:9-19. [PMID: 25752535 DOI: 10.1016/j.marpolbul.2015.02.028] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 02/16/2015] [Accepted: 02/19/2015] [Indexed: 06/04/2023]
Abstract
This study presents a new approach in aquatic toxicity testing combining passive sampling and passive dosing. Polydimethylsiloxane sheets were used to sample contaminant mixtures in the marine environment. These sheets were subsequently transferred to ecotoxicological test medium in which the sampled contaminant mixtures were released through passive dosing. 4 out of 17 of these mixtures caused severe effects in a growth inhibition assay with a marine diatom. These effects could not be explained by the presence of compounds detected in the sampling area and were most likely attributable to unmeasured compounds absorbed to the passive samplers during field deployment. The findings of this study indicate that linking passive sampling in the field to passive dosing in laboratory ecotoxicity tests provides a practical and complimentary approach for assessing the toxicity of hydrophobic contaminant mixtures that mimics realistic environmental exposures. Limitations and opportunities for future improvements are presented.
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Affiliation(s)
- Michiel Claessens
- Ghent University, Faculty of Bioscience Engineering, Laboratory of Environmental Toxicology and Aquatic Ecology, J. Plateaustraat 22, B-9000 Ghent, Belgium.
| | - Els Monteyne
- Royal Belgian Institute of Natural Sciences, Management Unit of the North Sea Mathematical Model, 2e en 23e Linieregimentsplein, B-8400 Oostende, Belgium
| | - Klaas Wille
- Ghent University, Faculty of Veterinary Medicine, Research Group of Veterinary Public Health and Zoonoses, Laboratory of Chemical Analysis, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Lynn Vanhaecke
- Ghent University, Faculty of Veterinary Medicine, Research Group of Veterinary Public Health and Zoonoses, Laboratory of Chemical Analysis, Salisburylaan 133, 9820 Merelbeke, Belgium
| | - Patrick Roose
- Royal Belgian Institute of Natural Sciences, Management Unit of the North Sea Mathematical Model, 2e en 23e Linieregimentsplein, B-8400 Oostende, Belgium
| | - Colin R Janssen
- Ghent University, Faculty of Bioscience Engineering, Laboratory of Environmental Toxicology and Aquatic Ecology, J. Plateaustraat 22, B-9000 Ghent, Belgium
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18
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Gallampois CMJ, Schymanski EL, Krauss M, Ulrich N, Bataineh M, Brack W. Multicriteria approach to select polyaromatic river mutagen candidates. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:2959-68. [PMID: 25635928 DOI: 10.1021/es503640k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
The identification of unknown compounds remains one of the most challenging tasks to link observed toxic effects in complex environmental mixtures to responsible toxicants in effect-directed analysis (EDA). Here, a workflow is presented based on nontarget liquid chromatography-high resolution mass spectrometry (LC-HRMS) starting with molecular formulas determined in a previous study. A compound database search (ChemSpider) was performed to retrieve candidates for each formula. Subsequently, the number of candidates was reduced by applying MS-, physical-chemical, and chromatography-based selection criteria including HRMS/MS fragmentation and plausibility, ionization efficiency with different ion sources and detection modes, acid/base behavior, octanol/water partitioning, retention time prediction and finally toxic effects (mutagenicity caused by aromatic amines). The workflow strongly decreased the number of possible candidates and resulted in the tentative identification of possible mutagens and the positive identification of the nonmutagen benzyl(diphenyl) phosphine oxide in a mutagenic fraction. The positive identification of mutagens was hampered by a lack of commercially available standards. The workflow is an innovative and promising approach and forms an excellent basis for possible further advancements.
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Affiliation(s)
- Christine M J Gallampois
- UFZ - Helmholtz Centre for Environmental Research , Department of Effect-Directed Analysis, Permoserstr. 15, D-04318 Leipzig, Germany
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19
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Differential immunomodulatory responses to nine polycyclic aromatic hydrocarbons applied by passive dosing. Toxicol In Vitro 2015; 29:345-51. [DOI: 10.1016/j.tiv.2014.11.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 11/09/2014] [Accepted: 11/18/2014] [Indexed: 01/02/2023]
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20
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Yao J, Gao Q, Li X, Hu M, Miao M, Pan B. Investigating river pollution flowing into Dianchi Lake using a combination of GC-MS analysis and toxicological tests. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2014; 92:67-70. [PMID: 24162646 DOI: 10.1007/s00128-013-1132-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Accepted: 10/17/2013] [Indexed: 06/02/2023]
Abstract
Due to the presence of various harmful compounds in polluted water, toxicological tests should be combined to evaluate whether a body of water is polluted. The water quality of four rivers flowing into Dianchi Lake, which is well known for its heavy and lasting pollution, was investigated in this study using a combination of GC-MS analysis and cytotoxicity and mutagenicity tests. GC-MS analysis showed that the rivers investigated contained a variety of chemicals and suggested that severe water pollution existed. In addition, the water obtained from the four rivers induced acute cytotoxicity in CHO cells and dose-dependent mutagenicity in four Salmonella typhimurium strains (TA97, TA98, TA100 and TA102). The integration of GC-MS analysis and short-term in vitro toxicological tests might be a valuable approach that can be used to monitor the health hazards that may result from water pollution.
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Affiliation(s)
- Jianhua Yao
- Faculty of Environmental Science and Engineering, Kunming University of Science and Technology, Kunming, 650500, China
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21
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Groothuis FA, Heringa MB, Nicol B, Hermens JLM, Blaauboer BJ, Kramer NI. Dose metric considerations in in vitro assays to improve quantitative in vitro-in vivo dose extrapolations. Toxicology 2013; 332:30-40. [PMID: 23978460 DOI: 10.1016/j.tox.2013.08.012] [Citation(s) in RCA: 139] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 07/17/2013] [Accepted: 08/14/2013] [Indexed: 12/17/2022]
Abstract
Challenges to improve toxicological risk assessment to meet the demands of the EU chemical's legislation, REACH, and the EU 7th Amendment of the Cosmetics Directive have accelerated the development of non-animal based methods. Unfortunately, uncertainties remain surrounding the power of alternative methods such as in vitro assays to predict in vivo dose-response relationships, which impedes their use in regulatory toxicology. One issue reviewed here, is the lack of a well-defined dose metric for use in concentration-effect relationships obtained from in vitro cell assays. Traditionally, the nominal concentration has been used to define in vitro concentration-effect relationships. However, chemicals may differentially and non-specifically bind to medium constituents, well plate plastic and cells. They may also evaporate, degrade or be metabolized over the exposure period at different rates. Studies have shown that these processes may reduce the bioavailable and biologically effective dose of test chemicals in in vitro assays to levels far below their nominal concentration. This subsequently hampers the interpretation of in vitro data to predict and compare the true toxic potency of test chemicals. Therefore, this review discusses a number of dose metrics and their dependency on in vitro assay setup. Recommendations are given on when to consider alternative dose metrics instead of nominal concentrations, in order to reduce effect concentration variability between in vitro assays and between in vitro and in vivo assays in toxicology.
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Affiliation(s)
- Floris A Groothuis
- Institute for Risk Assessment Sciences, Utrecht University, PO Box 80177, 3508 TD Utrecht, The Netherlands.
| | - Minne B Heringa
- National Institute of Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands.
| | - Beate Nicol
- Unilever U.K., Safety & Environmental Assurance Centre, Colworth Science Park, Sharnbrook, Bedford MK44 1LQ, United Kingdom.
| | - Joop L M Hermens
- Institute for Risk Assessment Sciences, Utrecht University, PO Box 80177, 3508 TD Utrecht, The Netherlands.
| | - Bas J Blaauboer
- Institute for Risk Assessment Sciences, Utrecht University, PO Box 80177, 3508 TD Utrecht, The Netherlands.
| | - Nynke I Kramer
- Institute for Risk Assessment Sciences, Utrecht University, PO Box 80177, 3508 TD Utrecht, The Netherlands.
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22
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Marchal G, Smith KEC, Rein A, Winding A, Trapp S, Karlson UG. Comparing the desorption and biodegradation of low concentrations of phenanthrene sorbed to activated carbon, biochar and compost. CHEMOSPHERE 2013; 90:1767-1778. [PMID: 22921652 DOI: 10.1016/j.chemosphere.2012.07.048] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Revised: 07/17/2012] [Accepted: 07/24/2012] [Indexed: 06/01/2023]
Abstract
Carbonaceous soil amendments are applied to contaminated soils and sediments to strongly sorb hydrophobic organic contaminants (HOCs) and reduce their freely dissolved concentrations. This limits biouptake and toxicity, but also biodegradation. To investigate whether HOCs sorbed to such amendments can be degraded at all, the desorption and biodegradation of low concentrations of (14)C-labelled phenanthrene (≤5 μg L(-1)) freshly sorbed to suspensions of the pure soil amendments activated carbon (AC), biochar (charcoal) and compost were compared. Firstly, the maximum abiotic desorption of phenanthrene from soil amendment suspensions in water, minimal salts medium (MSM) or tryptic soy broth (TSB) into a dominating silicone sink were measured. Highest fractions remained sorbed to AC (84±2.3%, 87±4.1%, and 53±1.2% for water, MSM and TSB, respectively), followed by charcoal (35±2.2%, 32±1.7%, and 12±0.3%, respectively) and compost (1.3±0.21%, similar for all media). Secondly, the mineralization of phenanthrene sorbed to AC, charcoal and compost by Sphingomonas sp. 10-1 (DSM 12247) was determined. In contrast to the amounts desorbed, phenanthrene mineralization was similar for all the soil amendments at about 56±11% of the initially applied radioactivity. Furthermore, HPLC analyses showed only minor amounts (<5%) of residual phenanthrene remaining in the suspensions, indicating almost complete biodegradation. Fitting the data to a coupled desorption and biodegradation model revealed that desorption did not limit biodegradation for any of the amendments, and that degradation could proceed due to the high numbers of bacteria and/or the production of biosurfactants or biofilms. Therefore, reduced desorption of phenanthrene from AC or charcoal did not inhibit its biodegradation, which implies that under the experimental conditions these amendments can reduce freely dissolved concentration without hindering biodegradation. In contrast, phenanthrene sorbed to compost was fully desorbed and biodegraded.
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Affiliation(s)
- Geoffrey Marchal
- Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000 Roskilde, Denmark
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23
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Smith KEC, Heringa MB, Uytewaal M, Mayer P. The dosing determines mutagenicity of hydrophobic compounds in the Ames II assay with metabolic transformation: passive dosing versus solvent spiking. Mutat Res 2012; 750:12-8. [PMID: 22989744 DOI: 10.1016/j.mrgentox.2012.07.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 06/15/2012] [Accepted: 07/25/2012] [Indexed: 11/20/2022]
Abstract
The Ames II bacterial mutagenicity assay is a new version of the standard Ames test for screening chemicals for genotoxic activity. However, the use of plastic micro-titer plates has drawbacks in the case of testing hydrophobic mutagens, since sorptive and other losses make it difficult to control and define the exposure concentrations, and they reduce availability for bacterial uptake or to the S9 enzymes. With passive dosing, a biocompatible polymer such as silicone is loaded with the test compound and acts as a partitioning source. It compensates for any losses and results in stable freely dissolved concentrations. Passive dosing using silicone O-rings was applied in the Ames II assay to measure PAH mutagenicity in strains TA98 and TAMix - a mixture of six different bacterial strains detecting six different base-pair substitutions - after metabolic activation by S9. Initially, 10 PAHs were tested with passive dosing from saturated O-rings, aiming at levels in the test medium close to aqueous solubility. Fluoranthene, pyrene and benzo(a)pyrene were mutagenic in both TA98 and TAMix, whereas benz(a)anthracene was mutagenic in TA98 only. The concentration-dependent mutagenic activity of benzo(a)pyrene was then compared for passive dosing and solvent spiking. With spiking, nominal concentrations greatly exceeded aqueous solubility before mutagenicity was observed, due to sorptive losses and limiting dissolution kinetics. In contrast, the passive dosing concentration-response curves were more reproducible, and shifted towards lower concentrations by several orders of magnitude. This study raises fundamental questions about how to introduce hydrophobic test substances in the Ames II assay with biotransformation, since the measured mutagenicity not only depends on the compound potency but also on its supply, sorption and consumption during the assay.
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Affiliation(s)
- Kilian E C Smith
- Department of Environmental Science, Aarhus University, Roskilde, Denmark.
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