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Nawaz T, Gu L, Fahad S, Saud S, Bleakley B, Zhou R. Exploring Sustainable Agriculture with Nitrogen-Fixing Cyanobacteria and Nanotechnology. Molecules 2024; 29:2534. [PMID: 38893411 PMCID: PMC11173783 DOI: 10.3390/molecules29112534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 06/21/2024] Open
Abstract
The symbiotic relationship between nitrogen-fixing cyanobacteria and plants offers a promising avenue for sustainable agricultural practices and environmental remediation. This review paper explores the molecular interactions between nitrogen-fixing cyanobacteria and nanoparticles, shedding light on their potential synergies in agricultural nanotechnology. Delving into the evolutionary history and specialized adaptations of cyanobacteria, this paper highlights their pivotal role in fixing atmospheric nitrogen, which is crucial for ecosystem productivity. The review discusses the unique characteristics of metal nanoparticles and their emerging applications in agriculture, including improved nutrient delivery, stress tolerance, and disease resistance. It delves into the complex mechanisms of nanoparticle entry into plant cells, intracellular transport, and localization, uncovering the impact on root-shoot translocation and systemic distribution. Furthermore, the paper elucidates cellular responses to nanoparticle exposure, emphasizing oxidative stress, signaling pathways, and enhanced nutrient uptake. The potential of metal nanoparticles as carriers of essential nutrients and their implications for nutrient-use efficiency and crop yield are also explored. Insights into the modulation of plant stress responses, disease resistance, and phytoremediation strategies demonstrate the multifaceted benefits of nanoparticles in agriculture. Current trends, prospects, and challenges in agricultural nanotechnology are discussed, underscoring the need for responsible and safe nanoparticle utilization. By harnessing the power of nitrogen-fixing cyanobacteria and leveraging the unique attributes of nanoparticles, this review paves the way for innovative, sustainable, and efficient agricultural practices.
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Affiliation(s)
- Taufiq Nawaz
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
| | - Liping Gu
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
| | - Shah Fahad
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
- Department of Agronomy, Abdul Wali Khan University Mardan, Mardan 23200, KP, Pakistan
| | - Shah Saud
- College of Life Science, Linyi University, Linyi 276000, China
| | - Bruce Bleakley
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
| | - Ruanbao Zhou
- Department of Biology/Microbiology, South Dakota State University, Brookings, SD 57007, USA
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2
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Oliveira Dos Anjos TB, Abel S, Lindehoff E, Bradshaw C, Sobek A. Assessing the effects of a mixture of hydrophobic contaminants on the algae Rhodomonas salina using the chemical activity concept. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2023; 265:106742. [PMID: 37977012 DOI: 10.1016/j.aquatox.2023.106742] [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: 04/05/2023] [Revised: 10/14/2023] [Accepted: 10/29/2023] [Indexed: 11/19/2023]
Abstract
The production and release of chemicals from human activities are on the rise. Understanding how the aquatic environment is affected by the presence of an unknown number of chemicals is lacking. We employed the chemical activity concept to assess the combined effects of hydrophobic organic contaminants on the phytoplankton species Rodomonas salina. Chemical activity is additive, and refers to the relative saturation of a chemical in the studied matrix. The growth of R. salina was affected by chemical activity, following a chemical activity-response curve, resulting in an Ea50 value of 0.078, which falls within the baseline toxicity range observed in earlier studies. The chlorophyll a content exhibited both increases and decreases with rising chemical activity, with the increase possibly linked to an antioxidant mechanism. Yet, growth inhibition provided more sensitive and robust responses compared to photosynthesis-related endpoints; all measured endpoints correlated with increased chemical activity. Growth inhibition is an ecologically relevant endpoint and integrates thermodynamic principles such as membrane disruption. Our study utilized passive dosing, enabling us to control exposure and determine activities in both the medium and the algae. The concept of chemical activity and our results can be extended to other neutral chemical groups as effects of chemical activity remain independent of the mixture composition.
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Affiliation(s)
| | - Sebastian Abel
- Department of Environmental Science, Stockholm University, Stockholm, Sweden
| | - Elin Lindehoff
- Department of Biology and Environmental Science, Linnaeus University, Kalmar, Sweden
| | - Clare Bradshaw
- Department of Ecology, Environment and Plant Sciences, Stockholm University, Stockholm, Sweden
| | - Anna Sobek
- Department of Environmental Science, Stockholm University, Stockholm, Sweden
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3
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Brinkman DL, Flores F, Luter HM, Nordborg FM, Brooks M, Parkerton TF, Negri AP. Sensitivity of the Indo-Pacific coral Acropora millepora to aromatic hydrocarbons. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023:121963. [PMID: 37286027 DOI: 10.1016/j.envpol.2023.121963] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2022] [Revised: 05/22/2023] [Accepted: 06/03/2023] [Indexed: 06/09/2023]
Abstract
The risks posed by petroleum spills to coral reefs are poorly understood and quantifying acute toxicity thresholds for aromatic hydrocarbons to reef-building corals is required to assess their sensitivity relative to other taxa. In this study, we exposed Acropora millepora to toluene, naphthalene and 1-methylnaphthalene (1-MN) in a flow-through system and assessed survivorship and sublethal responses including growth, colour and the photosynthetic performance of symbionts. Median 50% lethal concentrations (LC50s) decreased over the 7-d exposure period, reaching asymptotic values of 22,921, 5,268, 1167 μg L-1 for toluene, naphthalene and 1-MN, respectively. Corresponding toxicokinetic parameters (εLC50) defining the time progression of toxicity were 0.830, 0.692, and 0.256 d-1, respectively. Latent effects after an additional 7-d recovery in uncontaminated seawater were not observed. Effect concentrations (EC50s) for 50% growth inhibition were 1.9- to 3.6-fold lower than the LC50s for each aromatic hydrocarbon. There were no observed effects of aromatic hydrocarbon exposure on colour score (a proxy for bleaching) or photosynthetic efficiency. Acute and chronic critical target lipid body burdens (CTLBBs) of 70.3 ± 16.3 and 13.6 ± 18.4 μmol g-1 octanol (± standard error) were calculated for survival and growth inhibition based on 7-d LC50 and EC10 values, respectively. These species-specific constants indicate adult A. millepora is more sensitive than other corals reported so far but is of average sensitivity in comparison with other aquatic taxa in the target lipid model database. These results advance our understanding of acute hazards of petroleum contaminants to key habitat-building tropical coral reef species.
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Affiliation(s)
- Diane L Brinkman
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia.
| | - Florita Flores
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia
| | - Heidi M Luter
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia
| | - F Mikaela Nordborg
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University and Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia; James Cook University, College of Science & Engineering, Townsville, Queensland 4810, Australia
| | - Maxime Brooks
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University and Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia; James Cook University, College of Science & Engineering, Townsville, Queensland 4810, Australia
| | | | - Andrew P Negri
- Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia; AIMS@JCU, Division of Research & Innovation, James Cook University and Australian Institute of Marine Science, Townsville, Queensland, 4810, Australia
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Li JJ, Yue YX, Jiang JF, Shi SJ, Wu HX, Zhao YH, Che FF. Assessment of toxic mechanisms and mode of action to three different levels of species for 14 antibiotics based on interspecies correlation, excess toxicity, and QSAR. CHEMOSPHERE 2023; 317:137795. [PMID: 36632953 DOI: 10.1016/j.chemosphere.2023.137795] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Revised: 01/06/2023] [Accepted: 01/06/2023] [Indexed: 06/17/2023]
Abstract
Antibiotics have received much attention owing to their ecotoxicity toward nontarget aquatic creatures. However, the mode of action (MOA) of toxicity against nontarget organisms is unclear in some aquatic organisms. In this study, the comparison of toxicities through interspecies correlations, excess toxicity calculated from toxicity ratio, and quantitative structure-activity relationship (QSAR) was carried out to investigate the MOAs for 14 antibiotics among Daphnia magna, Vibrio fischeri, and Pseudokirchneriella subcapitata. The results showed that interspecies toxicity correlations were very poor between any two of the three species for the 14 antibiotics. The toxicity ratio revealed that most antibiotics exhibited excess toxicity to algae and Daphnia magna but not to V. fischeri, demonstrating that some antibiotics share the same MOA, but some antibiotics share different MOAs among the three different levels of species. P. subcapitata was the most sensitive species, and V. fischeri was the least sensitive species. This is because of the differences in the biouptake and interactions of antibiotics with the target receptors between the three different trophic levels of the species. Molecular docking simulations suggested that the toxicity of antibiotics depends highly on their interactions with target receptors through hydrogen bonds, electrostatic or polar interactions, π bond interactions, and van der Waals forces. QSAR models demonstrated that hydrogen bonding and electrophilicity/nucleophilicity play key roles in the interaction of antibiotics with different receptors in the three species. The toxic mechanisms of antibiotics are attributed to the interactions between electrophilic antibiotics and biological nucleophiles, and hydrogen-bond interactions. These results are valuable for understanding the toxic mechanisms and MOA of the three different levels of species.
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Affiliation(s)
- Jin J Li
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201306, PR China
| | - Ya X Yue
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201306, PR China
| | - Jie F Jiang
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201306, PR China
| | - Sheng J Shi
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201306, PR China
| | - Hui X Wu
- College of Marine Ecology and Environment, Shanghai Ocean University, Shanghai, 201306, PR China.
| | - Yuan H Zhao
- State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun, Jilin 130117, PR China
| | - Fei F Che
- National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, Chinese Research Academy of Environmental Sciences, Beijing, 100012, PR China
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5
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Birch H, Sjøholm KK, Dechesne A, Sparham C, van Egmond R, Mayer P. Biodegradation Kinetics of Fragrances, Plasticizers, UV Filters, and PAHs in a Mixture─Changing Test Concentrations over 5 Orders of Magnitude. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:293-301. [PMID: 34936331 DOI: 10.1021/acs.est.1c05583] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Biodegradation of organic chemicals emitted to the environment is carried out by mixed microbial communities growing on multiple natural and xenobiotic substrates at low concentrations. This study aims to (1) perform simulation type biodegradation tests at a wide range of mixture concentrations, (2) determine the concentration effect on the biodegradation kinetics of individual chemicals, and (3) link the mixture concentration and degradation to microbial community dynamics. Two hundred ninety-four parallel test systems were prepared using wastewater treatment plant effluent as inoculum and passive dosing to add a mixture of 19 chemicals at 6 initial concentration levels (ng/L to mg/L). After 1-30 days of incubation at 12 °C, abiotic and biotic test systems were analyzed using arrow solid phase microextraction and GC-MS/MS. Biodegradation kinetics at the highest test concentrations were delayed for several test substances but enhanced for the reference chemical naphthalene. Test concentration thus shifted the order in which chemicals were degraded. 16S rRNA gene amplicon sequencing indicated that the highest test concentration (17 mg C/L added) supported the growth of the genera Acidovorax, Novosphingobium, and Hydrogenophaga, whereas no such effect was observed at lower concentrations. The chemical and microbial results confirm that too high mixture concentrations should be avoided when aiming at determining environmentally relevant biodegradation data.
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Affiliation(s)
- Heidi Birch
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark
| | - Karina Knudsmark Sjøholm
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark
| | - Arnaud Dechesne
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark
| | - Chris Sparham
- Safety & Environmental Assurance Centre, Unilever, Bedford MK44 1LQ, U.K
| | - Roger van Egmond
- Safety & Environmental Assurance Centre, Unilever, Bedford MK44 1LQ, U.K
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark
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6
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Bicherel P, Thomas PC. Aquatic Toxicity Calculation of Mixtures: A Chemical Activity Approach Incorporating a Bioavailability Reduction Concept. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:11183-11191. [PMID: 34338513 DOI: 10.1021/acs.est.1c04389] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A calculation estimating the effect concentration (EL/LL50) of a water-accommodated fraction (WAF) for mixture toxicity is proposed. The method is based on chemical activity where the activity of a molecule is its effective concentration taking into account intermolecular interactions. First, the thermodynamic influence of each constituent on the solubility of the others within the mixture (i.e. the concentration of each constituent in the "loading rate") is determined. Then, the non-bioavailable fraction is determined and removed to calculate the true concentration of each constituent exerting toxicity. Finally, the loading rate is adjusted until the sum of activities of the bioavailable fractions is equal to the fraction-weighted average of toxic activity of each constituent. This process is a mechanistic interpretation of experimental WAF tests. The methodology has been validated comparing toxic loading rates of 13 reliable experimental WAF studies on fish, daphnids, and algae. The predictions were all within a factor of 2 of the study outcomes and can be considered as accurate as the laboratory studies. This is in contrast to the standard additivity method which consistently overestimates the toxicity of these mixtures by at least a factor of 2 up to over an order of magnitude or even more.
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Affiliation(s)
- Pascal Bicherel
- KREATiS, Knowledge & Research in Environment and Toxicology in Silico KREATiS SAS, 23 rue du Creuzatt, 38090 L'Isle d'Abeau, France
| | - Paul C Thomas
- KREATiS, Knowledge & Research in Environment and Toxicology in Silico KREATiS SAS, 23 rue du Creuzatt, 38090 L'Isle d'Abeau, France
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7
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Philibert D, Parkerton T, Marteinson S, de Jourdan B. Assessing the Toxicity of Individual Aromatic Compounds and Mixtures to American Lobster (Homarus americanus) Larvae Using a Passive Dosing System. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:1379-1388. [PMID: 33465259 PMCID: PMC8252573 DOI: 10.1002/etc.4988] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 11/15/2020] [Accepted: 01/14/2021] [Indexed: 05/16/2023]
Abstract
Aquatic exposures to aromatic compounds (ACs) may be important contributors to biological effects of oil spills. The present study examined the acute toxicity of 11 ACs and 3 binary AC mixtures on stage 1 American lobster larvae using a passive dosing test design. The ACs investigated covered a range of classes and log octanol-water partition coefficient values (KOW ; 2.5-5.5). Silicone O-rings were used to partition ACs into seawater and maintain stable exposures. Exposed lobster larvae were assessed for mobility and survival at 3, 6, 12, 24, 36, and 48 h. Fluorometry and gas chromatography-mass spectrometry measurements confirmed well-defined substance exposures. Expressing lethality in terms of chemical activities yielded values between 0.01 and 0.1, consistent with a baseline mode of action. Analysis of time-dependent median lethal/effect concentration (L/EC50) values were used to determine incipient values. An expected linear relationship between the incipient log L/EC50 and log KOW was fit to the empirical toxicity data to derive critical target lipid body burdens for immobilization and lethality endpoints. These values indicate that American lobster larvae fall on the sensitive end of the acute species sensitivity distribution. We used AC toxicity data to successfully predict toxicity of binary mixtures assuming additive toxicity. The observed time-dependent toxicity was inversely related to log KOW and occurred more quickly than reported previously. The results contribute to improving models for predicting oil spill impacts on American lobster larvae populations. Environ Toxicol Chem 2021;40:1379-1388. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Affiliation(s)
| | | | - Sarah Marteinson
- National Contaminants Advisory Group, Department of Fisheries and Oceans, OttawaOntarioCanada
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8
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Hammershøj R, Sjøholm KK, Birch H, Brandt KK, Mayer P. Biodegradation kinetics testing of two hydrophobic UVCBs - potential for substrate toxicity supports testing at low concentrations. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:2172-2180. [PMID: 33000828 DOI: 10.1039/d0em00288g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
The biodegradation kinetics of UVCB substances (unknown or variable composition, complex reaction products or biological materials) should be determined below the solubility limit to avoid experimental artefacts by the non-dissolved mixture. Recently, we reported delayed biodegradation kinetics of single petroleum hydrocarbons even at concentrations just below the solubility limit and attributed this to toxicity. The present study aimed to determine the concentration effect on biodegradation kinetics for constituents in two UVCBs, using surface water from a rural stream as the inoculum. Parallel biodegradation tests of diesel and lavender oil were conducted at concentrations just below the solubility limit and two orders of magnitude lower. The biodegradation kinetics of diesel oil constituents were generally similar at the two concentrations, which coincided with the stimulation of bacterial productivity (growth) at both concentrations, determined by [3H]leucine incorporation. By contrast, the biodegradation of lavender oil constituents was significantly delayed or even halted at the high test concentration. This was consistent with lavender oil stimulating bacterial growth at low concentration but inhibiting it at high concentration. The delayed biodegradation kinetics of lavender oil constituents at high concentration was best explained by mixture toxicity near the solubility limit. Consequently, biodegradation testing of hydrophobic UVCBs should be conducted at low, environmentally relevant concentrations ensuring that mixture toxicity does not affect the biodegradation kinetics.
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Affiliation(s)
- Rikke Hammershøj
- Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark.
| | - Karina K Sjøholm
- Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark.
| | - Heidi Birch
- Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark.
| | - Kristian K Brandt
- University of Copenhagen, Department of Plant and Environmental Sciences, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark
| | - Philipp Mayer
- Technical University of Denmark, Department of Environmental Engineering, Bygningstorvet, Building 115, 2800 Kgs. Lyngby, Denmark.
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9
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Stibany F, Schmidt SN, Mayer P, Schäffer A. Toxicity of dodecylbenzene to algae, crustacean, and fish - Passive dosing of highly hydrophobic liquids at the solubility limit. CHEMOSPHERE 2020; 251:126396. [PMID: 32163782 DOI: 10.1016/j.chemosphere.2020.126396] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/28/2020] [Accepted: 02/29/2020] [Indexed: 06/10/2023]
Abstract
In the current study, improved exposure control and measurements were applied for the aquatic toxicity testing of a highly hydrophobic organic compound. The aim was to reliably determine the ecotoxicity of the model compound dodecylbenzene (DDB, Log KOW = 8.65) by applying passive dosing for aquatic toxicity testing exactly at the solubility limit. Methodologically, silicone O-rings were saturated by immersion in pure liquid DDB (i.e., "loading by swelling") and then used as passive dosing donors. Daphnia immobilization and fish embryo toxicity tests were successfully conducted and provide, together with recently reported algal growth inhibition data, a full base-set of ecotoxicological data according to REACH. All tests were conducted in closed test systems to avoid evaporative losses, and exposure concentrations were measured throughout test durations. The Daphnia test was optimized by placing the O-rings in cages to prevent direct contact between daphnids and the passive dosing donor. Toxicologically, Daphnia magna immobilization was 19.3 ± 8% (mean ± 95% CI; 6 tests) within 72 h, whereas Danio rerio fish embryos did not show any significant lethal or sublethal toxic responses within 96 h. Growth rate inhibition for the algae Raphidocelis subcapitata was previously reported to be 13 ± 5% in a first and 8 ± 3% in a repeated test. These results for aquatic organisms, spanning three trophic levels, demonstrate toxicity of a highly hydrophobic compound and suggest that improvements of the current ecotoxicological standard tests are needed for these "difficult-to-test" chemicals. Furthermore, the obtained toxicity results significantly question the existence of a generic Log KOW cut-off in baseline toxicity.
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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, 2800, Kgs. Lyngby, Denmark.
| | - Stine Nørgaard Schmidt
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, 2800, Kgs. Lyngby, Denmark
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Bygningstorvet B115, 2800, Kgs. Lyngby, Denmark
| | - Andreas Schäffer
- Institute for Environmental Research (Biology V), RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany
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10
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Mackay D, Celsie AKD, Parnis JM, Arnot JA. A perspective on the role of fugacity and activity for evaluating the PBT properties of organic chemicals and providing a multi-media synoptic indicator of environmental contamination. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2020; 22:518-527. [PMID: 31993610 DOI: 10.1039/c9em00496c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The hazard and risk from organic chemicals present in the environment are routinely evaluated using P (persistence), B (bioaccumulation) and T (toxicity) criteria. We present a perspective on how models based on the equilibrium criteria of fugacity and chemical activity can contribute to all three evaluations, thus providing a consistent and seamless assessment process. Persistence and its closely related, but fundamentally different property, chemical residence time can be determined from degradation half-lives (typically obtained from monitoring data) and multi-media mass balance models describing chemical fate and transport in real or evaluative environments. Bioaccumulation is driven by equilibrium partitioning processes that can be estimated from fugacity models treating uptake by respiration and diet in single organisms and in food webs, most commonly for aquatic systems for which confirmatory monitoring data can be obtained. Biomagnification is readily evaluated both experimentally and as a fugacity (or activity) increase from prey to predator. Toxicokinetic evaluations of chemical uptake and disposition in a variety of organisms, including humans, can be obtained using fugacity- and physiologically-based pharmacokinetic models. Toxicodynamic processes of chemical interactions with organisms leading to adverse toxic outcomes are less obviously amenable to fugacity assessment with the notable exception of baseline toxicity (narcosis), the most common mode of action of commercial chemicals. It is shown that a range of fugacities can be defined and correlated for specific species thus enabling direct comparison of fugacities estimated or monitored in the environment with fugacities resulting in baseline toxicity. Finally, it is shown that fugacity and activity can serve as multi-media metrics of chemical contamination in ecosystems, thus enabling identification of specific regions and species at greatest risk in a pictorial format that is readily understandable to scientific and regulatory communities and to the general public.
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Affiliation(s)
- Donald Mackay
- Chemical Properties Research Group, Canadian Environmental Modelling Centre (CEMC), Department of Chemistry, Trent University, Peterborough, ON K9L OG2, Canada.
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11
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Trac LN, Schmidt SN, Holmstrup M, Mayer P. Headspace Passive Dosing of Volatile Hydrophobic Organic Chemicals from a Lipid Donor-Linking Their Toxicity to Well-Defined Exposure for an Improved Risk Assessment. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:13468-13476. [PMID: 31612707 DOI: 10.1021/acs.est.9b04681] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
High hydrophobicity and volatility of chemicals often lead to substantial experimental challenges but were here utilized in headspace passive dosing (HS-PD) to establish and maintain exposure: the pure chemical served as a passive dosing donor for controlling exposure at saturation, whereas triglyceride oil containing the chemical was used to control lower exposure levels. These donor solutions were added to glass inserts placed in the closed test systems. Mass balance calculations confirmed a dominant donor capacity for all chemicals except isooctane. This HS-PD method was applied to algal growth inhibition and springtail lethality tests with terpenes, alkanes, and cyclic siloxanes. Headspace concentrations above the lipid donors were measured for three chemicals to determine their chemical activity, using saturated vapor as the analytical standard and thermodynamic reference. Toxicity was related to chemical activity and calculated concentrations in membranes at equilibrium with the lipid donor. For both tests and all chemicals, toxic effects were observed within or above the reported range for baseline toxicity, meaning that no excess toxicity was observed. The toxicity of siloxanes was markedly higher to the terrestrial springtail than the aquatic algae, which is consistent with a more efficient mass transfer of these volatile hydrophobic chemicals in air compared to water.
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Affiliation(s)
- Lam Ngoc Trac
- Department of Environmental Engineering , Technical University of Denmark , DK-2800 Kgs Lyngby , Denmark
| | - Stine Nørgaard Schmidt
- Department of Environmental Engineering , Technical University of Denmark , DK-2800 Kgs Lyngby , Denmark
| | - Martin Holmstrup
- Department of Bioscience , Aarhus University , DK-8600 Silkeborg , Denmark
| | - Philipp Mayer
- Department of Environmental Engineering , Technical University of Denmark , DK-2800 Kgs Lyngby , Denmark
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12
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Hammershøj R, Birch H, Redman AD, Mayer P. Mixture Effects on Biodegradation Kinetics of Hydrocarbons in Surface Water: Increasing Concentrations Inhibited Degradation whereas Multiple Substrates Did Not. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:3087-3094. [PMID: 30801186 DOI: 10.1021/acs.est.9b00638] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Most biodegradation tests are conducted using single chemicals at high concentrations, although these chemicals are present in the environment as mixtures at low concentrations. A partitioning-based platform was recently developed for biodegradation testing of composed mixtures of hydrophobic chemicals at ng/L to μg/L concentrations. We used this platform to study the concentration and mixture effect on biodegradation kinetics. Biodegradation tests were conducted in 20 mL vials using environmental water samples as inocula. Passive dosing was applied (1) to vary initial test concentrations of individual test compounds and (2) to vary the number of mixture components between 1 and 16. Automated solid-phase microextraction coupled to gas chromatography-mass spectrometry was used to measure substrate depletion relative to abiotic controls. The number of mixture components had no or only a limited effect on the biodegradation half times for three compounds when tested at environmentally relevant concentrations. In contrast, longer lag phases and half lives were observed for single compounds when tested at higher concentrations that approached aqueous solubility. The obtained results support that simultaneous testing of multiple chemicals at low concentrations can accelerate the generation of biodegradation kinetic data, which are more environmentally relevant compared with data from tests conducted with single chemicals at much higher concentrations.
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Affiliation(s)
- Rikke Hammershøj
- Technical University of Denmark , Department of Environmental Engineering , Bygningstorvet, Building 115 , 2800 Kgs. Lyngby , Denmark
| | - Heidi Birch
- Technical University of Denmark , Department of Environmental Engineering , Bygningstorvet, Building 115 , 2800 Kgs. Lyngby , Denmark
| | - Aaron D Redman
- ExxonMobil Biomedical Science, Inc. , Annandale , New Jersey 08801 , United States
| | - Philipp Mayer
- Technical University of Denmark , Department of Environmental Engineering , Bygningstorvet, Building 115 , 2800 Kgs. Lyngby , Denmark
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Brown TN, Armitage JM, Arnot JA. Application of an Iterative Fragment Selection (IFS) Method to Estimate Entropies of Fusion and Melting Points of Organic Chemicals. Mol Inform 2019; 38:e1800160. [PMID: 30816634 DOI: 10.1002/minf.201800160] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Accepted: 02/10/2019] [Indexed: 11/09/2022]
Abstract
The main objective of this study is to develop and evaluate novel Quantitative Structure-Property Relationships (QSPRs) for predicting entropy of fusion (ΔSM ) and melting point (TM ) of organic chemicals from chemical structure. The QSPRs are developed using the Iterative Fragment Selection (IFS) method that requires only 2D structural information from the user (SMILES codes) for property prediction. The QSPRs also provide information on the applicability domain for each calculation and uncertainty estimates for the predictions. The root mean square error (RMSE) for the external validation sets are 11.8 J mol-1 K-1 and 46.9 K for the ΔSM and TM QSPRs, respectively. The performance of the new QSPRs is comparable to other predictive methods but has advantages with respect to availability and ease of use as well as the guidance on applicability domain for each prediction. Limitations of the new QSPRs are discussed. The QSPRs are coded as a user-friendly, freely available tool.
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Affiliation(s)
| | - James M Armitage
- AES Armitage Environmental Sciences, Inc., Ottawa ON, Canada, K1L 8C3
| | - Jon A Arnot
- ARC Arnot Research and Consulting, Inc., Toronto ON, Canada, M4M 1W4.,Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto ON, Canada, M1C 1A4.,Department of Pharmacology and Toxicology, University of Toronto, Toronto ON, Canada, M5S 1A8
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14
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Thomas PC, Bicherel P, Bauer FJ. How in silico and QSAR approaches can increase confidence in environmental hazard and risk assessment. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2019; 15:40-50. [PMID: 30447098 DOI: 10.1002/ieam.4108] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/21/2018] [Accepted: 10/30/2018] [Indexed: 06/09/2023]
Abstract
In silico methods are typically underrated in the current risk assessment paradigm, as evidenced by the recent document from the European Chemicals Agency (ECHA) on animal alternatives, in which quantitative structure-activity relationships (QSARs) were practically used only as a last resort. Their primary use is still to provide supporting evidence for read-across strategies or to add credence to experimental results of unknown or limited validity (old studies, studies without good laboratory practices [GLPs], limited information reported, etc.) in hazard assessment, but under the pressure of increasing burdens of testing, industry and regulators alike are at last warming to them. Nevertheless, their true potential for data-gap filling and for resolving sticking points in risk assessment methodology and beyond has yet to be recognized. We postulate that it is possible to go beyond the level of simply increasing confidence to the point of using in silico approaches to accurately predict results that cannot be resolved analytically. For example, under certain conditions it is possible to obtain meaningful results by in silico extrapolation for tests that would be technically impossible to conduct in the laboratory or at least extremely challenging to obtain reliable results. The following and other concepts are explored in this article: the mechanism of action (MechoA) of the substance should be determined, as an aid verifying that the QSAR model is applicable to the substance under review; accurate QSARs should be built with high-quality data that were not only curated but also validated with expert judgment; although a rule of thumb for acute to chronic ratios appears applicable for nonpolar narcotics, it seems unlikely that a "one-value-fits-all" answer exists for other MechoAs; a holistic approach to QSARs can be employed (via reverse engineering) to help validate or invalidate an experimental endpoint value on the basis of multiple experimental studies. Integr Environ Assess Manag 2019;15:40-50. © 2018 SETAC.
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15
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Schmidt SN, Armitage JM, Arnot JA, Mackay D, Mayer P. Linking algal growth inhibition to chemical activity: Excess toxicity below 0.1% of saturation. CHEMOSPHERE 2018; 208:880-886. [PMID: 30068031 DOI: 10.1016/j.chemosphere.2018.05.168] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 05/14/2018] [Accepted: 05/27/2018] [Indexed: 06/08/2023]
Abstract
Chemical activity quantifies the energetic level of an organic compound relative to its pure liquid [0-1], and several studies have reported that baseline toxicity generally requires chemical activities of 0.01-0.1. The first aim was to challenge this chemical activity range for baseline toxicity. Algal growth inhibition data (median effective concentrations, EC50) were compiled from two recent studies and included 108 compounds categorised as non-polar (mode of toxic action, MOA1) and polar (MOA2) narcotics. These data were linked to chemical activity by (1) plotting them relative to a regression for (subcooled) liquid solubility (SL), which served as visual reference for chemical activity of unity and (2) determining EC50/SL ratios that essentially equal median effective chemical activity (Ea50). Growth inhibition required chemical activity >0.01 for MOA1 and >0.001 for MOA2 compounds. The second aim was to identify compounds exerting excess toxicity, i.e., when growth inhibition occurred at chemical activity <0.001. From a recent review with 2323 data entries, 315 EC50 values passed our selection criteria. 280 of these EC50 values were within or near the baseline toxicity range (Ea50>0.001), and 25 compounds were found to exert excess toxicity (Ea50<0.001). Of these compounds, 16 are pesticides or precursors. Methodologically, this study includes two methods for translating EC50 values into the chemical activity framework, each having advantages and limitations. Scientifically, this study confirms that baseline toxicity generally requires chemical activities of 0.01-0.1 and extends the application of the chemical activity approach beyond baseline toxicity, by demonstrating its utility to identify compounds that exert excess toxicity.
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Affiliation(s)
- Stine N Schmidt
- Technical University of Denmark, Department of Environmental Engineering, Kgs. Lyngby, Denmark.
| | | | - Jon A Arnot
- ARC Arnot Research & Consulting Inc., Toronto, ON, Canada
| | - Donald Mackay
- Trent University, Department of Chemistry, Canadian Environmental Modelling Centre (CEMC), Peterborough, ON, Canada
| | - Philipp Mayer
- Technical University of Denmark, Department of Environmental Engineering, Kgs. Lyngby, Denmark
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16
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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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17
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Scholz S, Schreiber R, Armitage J, Mayer P, Escher BI, Lidzba A, Léonard M, Altenburger R. Meta-analysis of fish early life stage tests-Association of toxic ratios and acute-to-chronic ratios with modes of action. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:955-969. [PMID: 29350428 DOI: 10.1002/etc.4090] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 12/30/2018] [Accepted: 01/12/2018] [Indexed: 05/28/2023]
Abstract
Fish early life stage (ELS) tests (Organisation for Economic Co-operation and Development test guideline 210) are widely conducted to estimate chronic fish toxicity. In these tests, fish are exposed from the embryonic to the juvenile life stages. To analyze whether certain modes of action are related to high toxic ratios (i.e., ratios between baseline toxicity and experimental effect) and/or acute-to-chronic ratios (ACRs) in the fish ELS test, effect concentrations (ECs) for 183 compounds were extracted from the US Environmental Protection Agency's ecotoxicity database. Analysis of ECs of narcotic compounds indicated that baseline toxicity could be observed in the fish ELS test at similar concentrations as in the acute fish toxicity test. All nonnarcotic modes of action were associated with higher toxic ratios, with median values ranging from 4 to 9.3 × 104 (uncoupling < reactivity < neuromuscular toxicity < methemoglobin formation < endocrine disruption < extracellular matrix formation inhibition). Four modes of action were also found to be associated with high ACRs: 1) lysyl oxidase inhibition leading to notochord distortion, 2) putative methemoglobin formation or hemolytic anemia, 3) endocrine disruption, and 4) compounds with neuromuscular toxicity. For the prediction of ECs in the fish ELS test with alternative test systems, endpoints targeted to the modes of action of compounds with enhanced toxic ratios or ACRs could be used to trigger fish ELS tests or even replace these tests. Environ Toxicol Chem 2018;37:955-969. © 2018 SETAC.
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Affiliation(s)
- Stefan Scholz
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Rene Schreiber
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - James Armitage
- Department of Physical and Environmental Sciences, University of Toronto Scarborough, Toronto, Ontario, Canada
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Lyngby, Denmark
| | - Beate I Escher
- Department of Cell Toxicology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
- Environmental Toxicology, Center for Applied Geosciences, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Annegret Lidzba
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
| | - Marc Léonard
- Environmental Research Department, L'Oréal Advanced Research, Aulnay sous Bois, France
| | - Rolf Altenburger
- Department of Bioanalytical Ecotoxicology, UFZ-Helmholtz Centre for Environmental Research, Leipzig, Germany
- Institute for Environmental Research (Biology V), RWTH Aachen University, Aachen, Germany
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18
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Gobas FAPC, Otton SV, Tupper-Ring LF, Crawford MA, Clark KE, Ikonomou MG. Chemical activity-based environmental risk analysis of the plasticizer di-ethylhexyl phthalate and its main metabolite mono-ethylhexyl phthalate. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2017; 36:1483-1492. [PMID: 27859543 DOI: 10.1002/etc.3689] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 09/30/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
The present study applies a chemical activity-based approach to: 1) evaluate environmental concentrations of di-ethylhexyl phthalate (DEHP; n = 23 651) and its metabolite mono-ethylhexyl phthalate (MEHP; n = 1232) in 16 environmental media from 1174 studies in the United States, Canada, Europe, and Asia, and in vivo toxicity data from 934 studies in 20 species, as well as in vitro biological activity data from the US Environmental Protection Agency's Toxicity Forecaster and other sources; and 2) conduct a comprehensive environmental risk analysis. The results show that the mean chemical activities of DEHP and MEHP in abiotic environmental samples from locations around the globe are 0.001 and 10-8 , respectively. This indicates that DEHP has reached on average 0.1% of saturation in the abiotic environment. The mean chemical activity of DEHP in biological samples is on average 100-fold lower than that in abiotic samples, likely because of biotransformation of DEHP in biota. Biological responses in both in vivo and in vitro tests occur at chemical activities between 0.01 to 1 for DEHP and between approximately 10-6 and 10-2 for MEHP, suggesting a greater potency of MEHP compared with DEHP. Chemical activities of both DEHP and MEHP in biota samples were less than those causing biological responses in the in vitro bioassays, without exception. A small fraction of chemical activities of DEHP in abiotic environmental samples (i.e., 4-8%) and none (0%) for MEHP were within the range of chemical activities associated with observed toxicological responses in the in vivo tests. The present study illustrates the chemical activity approach for conducting risk analyses. Environ Toxicol Chem 2017;36:1483-1492. © 2016 SETAC.
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Affiliation(s)
- Frank A P C Gobas
- School of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia, Canada
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia, Canada
| | - S Victoria Otton
- School of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Laura F Tupper-Ring
- School of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia, Canada
| | - Meara A Crawford
- School of Resource and Environmental Management, Simon Fraser University, Burnaby, British Columbia, Canada
| | | | - Michael G Ikonomou
- Institute of Ocean Sciences, Ocean Sciences Division, Fisheries and Oceans Canada, Sidney, British Columbia, Canada
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19
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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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20
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Bragin GE, Parkerton TF, Redman AD, Letinksi DJ, Butler JD, Paumen ML, Sutherland CA, Knarr TM, Comber M, den Haan K. Chronic toxicity of selected polycyclic aromatic hydrocarbons to algae and crustaceans using passive dosing. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2016; 35:2948-2957. [PMID: 27152493 DOI: 10.1002/etc.3479] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Revised: 01/15/2016] [Accepted: 05/03/2016] [Indexed: 06/05/2023]
Abstract
Because of the large number of possible aromatic hydrocarbon structures, predictive toxicity models are needed to support substance hazard and risk assessments. Calibration and evaluation of such models requires toxicity data with well-defined exposures. The present study has applied a passive dosing method to generate reliable chronic effects data for 8 polycyclic aromatic hydrocarbons (PAHs) on the green algae Pseudokirchneriella subcapitata and the crustacean Ceriodaphnia dubia. The observed toxicity of these substances on algal growth rate and neonate production were then compared with available literature toxicity data for these species, as well as target lipid model and chemical activity-based model predictions. The use of passive dosing provided well-controlled exposures that yielded more consistent data sets than attained by past literature studies. Results from the present study, which were designed to exclude the complicating influence of ultraviolet light, were found to be well described by both target lipid model and chemical activity effect models. The present study also found that the lack of chronic effects for high molecular weight PAHs was consistent with the limited chemical activity that could be achieved for these compounds in the aqueous test media. Findings from this analysis highlight that variability in past literature toxicity data for PAHs may be complicated by both poorly controlled exposures and photochemical processes that can modulate both exposure and toxicity. Environ Toxicol Chem 2016;35:2948-2957. © 2016 SETAC.
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Affiliation(s)
- Gail E Bragin
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
| | | | - Aaron D Redman
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
| | | | - Josh D Butler
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
| | | | | | - Tricia M Knarr
- ExxonMobil Biomedical Sciences, Annandale, New Jersey, USA
| | | | - Klaas den Haan
- Conservation of Clean Air and Water in Europe (CONCAWE), Brussels, Belgium
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21
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Echeveste P, Galbán-Malagón C, Dachs J, Berrojalbiz N, Agustí S. Toxicity of natural mixtures of organic pollutants in temperate and polar marine phytoplankton. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 571:34-41. [PMID: 27470667 DOI: 10.1016/j.scitotenv.2016.07.111] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 07/15/2016] [Accepted: 07/15/2016] [Indexed: 06/06/2023]
Abstract
Semivolatile and persistent organic pollutants (POPs) undergo atmospheric transport before being deposited to the oceans, where they partition to phytoplankton organic matter. The goal of this study was to determine the toxicity of naturally occurring complex mixtures of organic pollutants to temperate and polar phytoplankton communities from the Mediterranean Sea, the North East (NE) Atlantic, and Southern Oceans. The cell abundance of the different phytoplankton groups, chlorophyll a concentrations, viability of the cells, and growth and decay constants were monitored in response to addition of a range of concentrations of mixtures of organic pollutants obtained from seawater extracts. Almost all of the phytoplankton groups were significantly affected by the complex mixtures of non-polar and polar organic pollutants, with toxicity being greater for these mixtures than for single POPs or simple POP mixtures. Cocktails' toxicity arose at concentrations as low as tenfold the field oceanic levels, probably due to a higher chemical activity of the mixture than of simple POPs mixtures. Overall, smaller cells were the most affected, although Mediterranean picophytoplankton was significantly more tolerant to non-polar POPs than picophytoplankton from the Atlantic Ocean or the Bellingshausen Sea microphytoplankton.
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Affiliation(s)
- Pedro Echeveste
- Department of Global Change Research, Institut Mediterrani d'Estudis Avançats (CSIC-UIB), Mallorca, Illes Balears, Spain.
| | - Cristóbal Galbán-Malagón
- Departamento de Ecología y Biodiversidad, Universidad Nacional Andrés Bello, Santiago, Chile; Department of Environmental Chemistry, IDAEA-CSIC, Barcelona, Catalunya, Spain
| | - Jordi Dachs
- Department of Environmental Chemistry, IDAEA-CSIC, Barcelona, Catalunya, Spain
| | - Naiara Berrojalbiz
- Department of Environmental Chemistry, IDAEA-CSIC, Barcelona, Catalunya, Spain; Norges Geotekniske Institutt, Oslo, Norway
| | - Susana Agustí
- Department of Global Change Research, Institut Mediterrani d'Estudis Avançats (CSIC-UIB), Mallorca, Illes Balears, Spain; Red Sea Research Center, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia
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22
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Heger S, Bluhm K, Brendt J, Mayer P, Anders N, Schäffer A, Seiler TB, Hollert H. Microscale In Vitro Assays for the Investigation of Neutral Red Retention and Ethoxyresorufin-O-Deethylase of Biofuels and Fossil Fuels. PLoS One 2016; 11:e0163862. [PMID: 27684069 PMCID: PMC5042516 DOI: 10.1371/journal.pone.0163862] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/15/2016] [Indexed: 11/21/2022] Open
Abstract
Only few information on the potential toxic effectiveness of biofuels are available. Due to increasing worldwide demand for energy and fuels during the past decades, biofuels are considered as a promising alternative for fossil fuels in the transport sector. Hence, more information on their hazard potentials are required to understand the toxicological impact of biofuels on the environment. In the German Cluster of Excellence "Tailor-made Fuels from Biomass" design processes for economical, sustainable and environmentally friendly biofuels are investigated. In an unique and interdisciplinary approach, ecotoxicological methods are applied to gain information on potential adverse environmental effects of biofuels at an early phase of their development. In the present study, three potential biofuels, ethyl levulinate, 2-methyltetrahydrofuran and 2-methylfuran were tested. Furthermore, we investigated a fossil gasoline fuel, a fossil diesel fuel and an established biodiesel. Two in vitro bioassays, one for assessing cytotoxicity and one for aryl hydrocarbon receptor agonism, so called dioxin-like activity, as measured by Ethoxyresorufin-O-Deethylase, were applied using the permanent fish liver cell line RTL-W1 (Oncorhynchus mykiss). The special properties of these fuel samples required modifications of the test design. Points that had to be addressed were high substance volatility, material compatibility and low solubility. For testing of gasoline, diesel and biodiesel, water accommodated fractions and a passive dosing approach were tested to address the high hydrophobicity and low solubility of these complex mixtures. Further work has to focus on an improvement of the chemical analyses of the fuel samples to allow a better comparison of any effects of fossil fuels and biofuels.
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Affiliation(s)
- Sebastian Heger
- RWTH Aachen University, Institute for Environmental Research, Department of Ecosystem Analysis, Aachen, Germany
| | - Kerstin Bluhm
- RWTH Aachen University, Institute for Environmental Research, Department of Ecosystem Analysis, Aachen, Germany
| | - Julia Brendt
- RWTH Aachen University, Institute for Environmental Research, Department of Ecosystem Analysis, Aachen, Germany
| | - Philipp Mayer
- Technical University of Denmark, Department of Environmental Engineering, Kongens Lyngby, Denmark
| | - Nico Anders
- RWTH Aachen University, Chemical Engineering, Enzyme Process Technology, Aachen, Germany
| | - Andreas Schäffer
- RWTH Aachen University, Institute for Environmental Research, Chair of Environmental Biology and Chemodynamcis, Aachen, Germany
- Chongqing University, College of Resources and Environmental Science, Chongqing, China
- Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing, China
| | - Thomas-Benjamin Seiler
- RWTH Aachen University, Institute for Environmental Research, Department of Ecosystem Analysis, Aachen, Germany
| | - Henner Hollert
- RWTH Aachen University, Institute for Environmental Research, Department of Ecosystem Analysis, Aachen, Germany
- Chongqing University, College of Resources and Environmental Science, Chongqing, China
- Nanjing University, State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing, China
- Tongji University, College of Environmental Science and Engineering and State Key Laboratory of Pollution Control and Resource Reuse, Shanghai, China
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23
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Butler JD, Parkerton TF, Redman AD, Letinski DJ, Cooper KR. Assessing Aromatic-Hydrocarbon Toxicity to Fish Early Life Stages Using Passive-Dosing Methods and Target-Lipid and Chemical-Activity Models. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:8305-8315. [PMID: 27398931 DOI: 10.1021/acs.est.6b01758] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Aromatic hydrocarbons (AH) are known to impair fish early life stages (ELS). However, poorly defined exposures often confound ELS-test interpretation. Passive dosing (PD) overcomes these challenges by delivering consistent, controlled exposures. The objectives of this study were to apply PD to obtain 5 d acute embryo lethality and developmental data and 30 d chronic embryo-larval survival and growth-effects data using zebrafish with different AHs; to analyze study and literature toxicity data using target-lipid (TLM) and chemical-activity (CA) models; and to extend PD to a mixture and test the assumption of AH additivity. PD maintained targeted exposures over a concentration range of 6 orders of magnitude. AH toxicity increased with log Kow up to pyrene (5.2). Pericardial edema was the most sensitive sublethal effect that often preceded embryo mortality, although some AHs did not produce developmental effects at concentrations causing mortality. Cumulative embryo-larval mortality was more sensitive than larval growth, with acute-to-chronic ratios of <10. More-hydrophobic AHs did not exhibit toxicity at aqueous saturation. The relationship and utility of the TLM-CA models for characterizing fish ELS toxicity is discussed. Application of these models indicated that concentration addition provided a conservative basis for predicting ELS effects for the mixture investigated.
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Affiliation(s)
- Josh D Butler
- Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc. , 1545 US Highway 22 East, Annandale, New Jersey 08801, United States
| | - Thomas F Parkerton
- Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc. , 800 Bell Street, Houston, Texas 77002, United States
| | - Aaron D Redman
- Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc. , 1545 US Highway 22 East, Annandale, New Jersey 08801, United States
| | - Daniel J Letinski
- Toxicology & Environmental Sciences Division, ExxonMobil Biomedical Sciences, Inc. , 1545 US Highway 22 East, Annandale, New Jersey 08801, United States
| | - Keith R Cooper
- Environmental Sciences Department, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
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24
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Kang HJ, Lee SY, Kwon JH. Physico-chemical properties and toxicity of alkylated polycyclic aromatic hydrocarbons. JOURNAL OF HAZARDOUS MATERIALS 2016; 312:200-207. [PMID: 27037474 DOI: 10.1016/j.jhazmat.2016.03.051] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Revised: 03/12/2016] [Accepted: 03/19/2016] [Indexed: 06/05/2023]
Abstract
Crude oil and refined petroleum products contain many polycyclic and heterocyclic aromatic hydrocarbons, in particular, alkylated PAHs. Although alkylated PAHs are found in significantly higher quantities than their corresponding unsubstituted PAHs, the most studies on the physico-chemical properties and toxicities of these compounds have been conducted on unsubstituted PAHs. In this study, we measured crucial physico-chemical properties (i.e., water solubility, partition coefficients between polydimethylsiloxane and water (KPDMSw), and partition coefficient between liposomes and water (Klipw)) of selected alkylated PAHs, and evaluated their toxicity using the luminescence inhibition of Aliivibrio fischeri and growth inhibition of Raphidocelis subcapitata. In general, the logarithms of these properties for alkylated PAHs showed good linear correlations with log Kow, as did those for unsubstituted PAHs. Changes in molecular symmetry on the introduction of alkyl groups on aromatic ring structure significantly altered water solubility. The inhibition of bacterial luminescence and algal growth by alkylated PAHs can be explained well by the baseline toxicity hypothesis, and good linear relationships between log Kow or log Klipw and log (1/EC50) were found.
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Affiliation(s)
- Hyun-Joong Kang
- Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea
| | - So-Young Lee
- Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea
| | - Jung-Hwan Kwon
- Division of Environmental Science and Ecological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul02841, Republic of Korea.
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Vergauwen L, Schmidt SN, Stinckens E, Maho W, Blust R, Mayer P, Covaci A, Knapen D. A high throughput passive dosing format for the Fish Embryo Acute Toxicity test. CHEMOSPHERE 2015; 139:9-17. [PMID: 26026258 DOI: 10.1016/j.chemosphere.2015.05.041] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2015] [Revised: 05/08/2015] [Accepted: 05/12/2015] [Indexed: 05/20/2023]
Abstract
High throughput testing according to the Fish Embryo Acute Toxicity (FET) test (OECD Testing Guideline 236) is usually conducted in well plates. In the case of hydrophobic test substances, sorptive and evaporative losses often result in declining and poorly controlled exposure conditions. Therefore, our objective was to improve exposure conditions in FET tests by evaluating a passive dosing format using silicone O-rings in standard 24-well polystyrene plates. We exposed zebrafish embryos to a series of phenanthrene concentrations until 120h post fertilization (hpf), and obtained a linear dilution series. We report effect values for both mortality and sublethal morphological effects based on (1) measured exposure concentrations, (2) (lipid normalized) body residues and (3) chemical activity. The LC50 for 120hpf was 310μg/L, CBR50 (critical body residue) was 2.72mmol/kg fresh wt and La50 (lethal chemical activity) was 0.047. All values were within ranges expected for baseline toxicity. Impaired swim bladder inflation was the most pronounced morphological effect and swimming activity was reduced in all exposure concentrations. Further analysis showed that the effect on swimming activity was not attributed to impaired swim bladder inflation, but rather to baseline toxicity. We conclude that silicone O-rings (1) produce a linear dilution series of phenanthrene in the 120hpf FET test, (2) generate and maintain aqueous concentrations for reliable determination of effect concentrations, and allow for obtaining mechanistic toxicity information, and (3) cause no toxicity, demonstrating its potential as an extension of the FET test when testing hydrophobic chemicals.
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Affiliation(s)
- Lucia Vergauwen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium.
| | - Stine N Schmidt
- Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, 2800 Kgs. Lyngby, Denmark
| | - Evelyn Stinckens
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Walid Maho
- Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Ronny Blust
- Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen, Belgium
| | - Philipp Mayer
- Department of Environmental Engineering, Technical University of Denmark, Miljoevej 113, 2800 Kgs. Lyngby, Denmark
| | - Adrian Covaci
- Toxicological Centre, Department of Pharmaceutical Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Dries Knapen
- Zebrafishlab, Veterinary Physiology and Biochemistry, Department of Veterinary Sciences, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
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26
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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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van der Heijden SA, Hermens JLM, Sinnige TL, Mayer P, Gilbert D, Jonker MTO. Determining high-quality critical body residues for multiple species and chemicals by applying improved experimental design and data interpretation concepts. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1879-1887. [PMID: 25594358 DOI: 10.1021/es505078r] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Ecotoxicological effect data are generally expressed as effective concentrations in the external exposure medium and do thus not account for differences in chemical uptake, bioavailability, and metabolism, which can introduce substantial data variation. The Critical Body Residue (CBR) concept provides clear advantages, because it links effects directly to the internal exposure. Using CBRs instead of external concentrations should therefore reduce variability. For compounds that act via narcosis even a constant CBR has been proposed. Despite the expected uniformity, CBR values for these compounds still show large variability, possibly due to biased and inconsistent experimental testing. In the present study we tested whether variation in CBR data can be substantially reduced when using an improved experimental design and avoiding confounding factors. The aim was to develop and apply a well-defined test protocol for accurately and precisely measuring CBR data, involving improved (passive) dosing, sampling, and processing of organisms. The chemicals 1,2,4-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 2,3,4-trichloroaniline, 2,3,5,6-tetrachloroaniline, 4-chloro-3-methylphenol, pentylbenzene, pyrene, and bromophos-methyl were tested on Lumbriculus variegatus (California blackworm), Hyalella azteca (scud), and Poecilia reticulata (guppy), which yielded a high-quality database of 348 individual CBR values. Medians of CBR values ranged from 2.1 to 16.1 mmol/kg wet weight (ww) within all combinations of chemicals and species, except for the insecticide bromophos-methyl, for which the median was 1.3 mmol/kg ww. The new database thus covers about one log unit, which is considerably less than in existing databases. Medians differed maximally by a factor of 8.4 between the 7 chemicals but within one species, and by a factor of 2.6 between the three species but for individual chemicals. Accounting for the chemicals' internal distribution to different partitioning domains and relating effects to estimated concentrations in the target compartment (i.e., membrane lipids) was expected to but did not decrease the overall variability, likely because the surrogate partition coefficients for membrane lipid, storage lipid, protein, and carbohydrate that were used as input parameters did not sufficiently represent the actual partitioning processes. The results of this study demonstrate that a well-designed test setup can produce CBR data that are highly uniform beyond chemical and biological diversity.
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Affiliation(s)
- Stephan A van der Heijden
- Institute for Risk Assessment Sciences, Utrecht University , Yalelaan 104, 3584 CM Utrecht, The Netherlands
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