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Adams WJ, Garman ER. Recommended updates to the USEPA Framework for Metals Risk Assessment: Aquatic ecosystems. INTEGRATED ENVIRONMENTAL ASSESSMENT AND MANAGEMENT 2024; 20:924-951. [PMID: 37578034 DOI: 10.1002/ieam.4827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/04/2023] [Accepted: 08/08/2023] [Indexed: 08/15/2023]
Abstract
In 2007, the USEPA issued its "Framework for Metals Risk Assessment." The framework provides technical guidance to risk assessors and regulators when performing human health and environmental risk assessments of metals. This article focuses on advances in the science including assessing bioavailability in aquatic ecosystems, short- and long-term fate of metals in aquatic ecosystems, and advances in risk assessment of metals in sediments. Notable advances have occurred in the development of bioavailability models for assessing toxicity as a function of water chemistry in freshwater ecosystems. The biotic ligand model (BLM), the multiple linear regression model, and multimetal BLM now exist for most of the common mono- and divalent metals. Species sensitivity distributions for many metals exist, making it possible for many jurisdictions to develop or update their water quality criteria or guidelines. The understanding of the fate of metals in the environment has undergone significant scrutiny over the past 20 years. Transport and toxicity models have evolved including the Unit World Model allowing for estimation of concentrations of metals in various compartments as a function of loading and time. There has been significant focus on the transformation of metals in sediments into forms that are less bioavailable and on understanding conditions that result in resolubilization or redistribution of metals in and from sediments. Methods for spiking sediments have advanced such that the resulting chemistry in the laboratory mimics that in natural systems. Sediment bioavailability models are emerging including models that allow for prediction of toxicity in sediments for copper and nickel. Biodynamic models have been developed for several organisms and many metals. The models allow for estimates of transport of metals from sediments to organisms via their diet as well as their water exposure. All these advances expand the tool set available to risk assessors. Integr Environ Assess Manag 2024;20:924-951. © 2023 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).
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Mebane CA. Bioavailability and Toxicity Models of Copper to Freshwater Life: The State of Regulatory Science. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:2529-2563. [PMID: 37818880 DOI: 10.1002/etc.5736] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2023] [Revised: 05/23/2023] [Accepted: 08/21/2023] [Indexed: 10/13/2023]
Abstract
Efforts to incorporate bioavailability adjustments into regulatory water quality criteria in the United States have included four major procedures: hardness-based single-linear regression equations, water-effect ratios (WERs), biotic ligand models (BLMs), and multiple-linear regression models (MLRs) that use dissolved organic carbon, hardness, and pH. The performance of each with copper (Cu) is evaluated, emphasizing the relative performance of hardness-based versus MLR-based criteria equations. The WER approach was shown to be inherently highly biased. The hardness-based model is in widest use, and the MLR approach is the US Environmental Protection Agency's (USEPA's) present recommended approach for developing aquatic life criteria for metals. The performance of criteria versions was evaluated with numerous toxicity datasets that were independent of those used to develop the MLR models, including olfactory and behavioral toxicity, and field and ecosystem studies. Within the range of water conditions used to develop the Cu MLR criteria equations, the MLR performed well in terms of predicting toxicity and protecting sensitive species and ecosystems. In soft waters, the MLR outperformed both the BLM and hardness models. In atypical waters with pH <5.5 or >9, neither the MLR nor BLM predictions were reliable, suggesting that site-specific testing would be needed to determine reliable Cu criteria for such settings. The hardness-based criteria performed poorly with all toxicity datasets, showing no or weak ability to predict observed toxicity. In natural waters, MLR and BLM criteria versions were strongly correlated. In contrast, the hardness-criteria version was often out of phase with the MLR and, depending on waterbody and season, could be either strongly overprotective or underprotective. The MLR-based USEPA-style chronic criterion appears to be more generally protective of ecosystems than other models. Environ Toxicol Chem 2023;42:2529-2563. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.
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Porter DE, Morris JM, Trifari MP, Wooller MJ, Westley PAH, Gorman KB, Barst BD. Acute Toxicity of Copper to Three Species of Pacific Salmon Fry in Water with Low Hardness and Low Dissolved Organic Carbon. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2023; 42:2440-2452. [PMID: 37493065 DOI: 10.1002/etc.5724] [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: 02/14/2023] [Revised: 03/11/2023] [Accepted: 07/21/2023] [Indexed: 07/27/2023]
Abstract
Proposed development of a mine within Alaska's Bristol Bay watershed (USA) has raised concerns about the potential impact of copper (Cu) on Pacific salmon (Oncorhynchus spp.). We conducted 96-h flow-through bioassays using low-hardness and low dissolved organic carbon water to determine the acute lethal toxicity of Cu to sockeye (Oncorhynchus nerka), Chinook (Oncorhynchus tshawytscha), and coho salmon (Oncorhynchus kisutch) fry. We aimed to determine Cu toxicity under field-relevant water quality conditions and to assess three methods of calculating ambient Cu criteria: the biotic ligand model (BLM), a multiple linear regression model endorsed by the US Environmental Protection Agency, and the hardness-based model currently used by the State of Alaska. The criteria generated by all models were below 20% lethal Cu concentrations by factors ranging from 2.2 to 54.3, indicating that all criteria would be protective against mortality. The multiple linear regression-based criteria were the most conservative and were comparable to BLM-based criteria. The median lethal concentrations (LC50s) for sockeye, Chinook, and coho were 35.2, 23.9, and 6.3 µg Cu/L, respectively. We also used the BLM to predict LC50s for each species. Model predictions differed from empirical LC50s by factors of 0.7 for sockeye and Chinook salmon, and 1.1 for coho salmon. These differences fell within the acceptable range of ±2, indicating the model's accuracy. We calculated critical lethal Cu accumulation values for each species to account for differing water chemistry in each bioassay; the present study revealed that coho salmon were most sensitive to Cu, followed by sockeye and Chinook salmon. Our findings underscore the importance of considering site- and species-specific factors when modeling Cu toxicity. The empirical data we present may enhance Cu risk assessments for Pacific salmon. Environ Toxicol Chem 2023;42:2440-2452. © 2023 SETAC.
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Affiliation(s)
- Drew E Porter
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Water and Environment Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | | | - Michelle P Trifari
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Water and Environment Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Matthew J Wooller
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Water and Environment Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
- Alaska Stable Isotope Facility, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Peter A H Westley
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Kristen B Gorman
- College of Fisheries and Ocean Sciences, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - Benjamin D Barst
- Water and Environment Research Center, Institute of Northern Engineering, University of Alaska Fairbanks, Fairbanks, Alaska, USA
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Razmara P, Sharpe J, Pyle GG. Rainbow trout (Oncorhynchus mykiss) chemosensory detection of and reactions to copper nanoparticles and copper ions. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 260:113925. [PMID: 32369894 DOI: 10.1016/j.envpol.2020.113925] [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: 10/15/2019] [Revised: 12/20/2019] [Accepted: 01/05/2020] [Indexed: 06/11/2023]
Abstract
Copper is known to interfere with fish olfaction. Although the chemosensory detection and olfactory toxicity of copper ions (Cu2+) has been heavily studied in fish, the olfactory-driven detection of copper nanoparticles (CuNPs)-a rapidly emerging contaminant to aquatic systems-remains largely unknown. This study aimed to investigate the olfactory response of rainbow trout to equitoxic concentrations of CuNPs or Cu2+ using electro-olfactography (EOG, a neurophysiological technique) and olfactory-mediated behavioural assay. In the first experiment, the concentration of contaminants known to impair olfaction by 20% over 24 h (EOG-based 24-h IC20s of 220 and 3.5 μg/L for CuNPs and Cu2+, respectively) were tested as olfactory stimuli using both neurophysiological and behavioural assays. In the second experiment, to determine whether the presence of CuNPs or Cu2+ can affect the ability of fish to perceive a social cue (taurocholic acid (TCA)), fish were acutely exposed to one form of Cu-contaminants (approximately 15 min). Following exposure, olfactory sensitivity was measured by EOG and olfactory-mediated behaviour within a choice maze was recorded in the presence of TCA. Results of neurophysiological and behavioural experiments demonstrate that rainbow trout can detect and avoid the IC20 of CuNPs. The IC20 of Cu2+ was below the olfactory detection threshold of rainbow trout, as such, fish did not avoid Cu2+. The high sensitivity of behavioural endpoints revealed a lack of aversion response to TCA in CuNP-exposed fish, despite this change not being present utilizing EOG. The reduced response to TCA during the brief exposure to CuNPs may be a result of either olfactory fatigue or blockage of olfactory sensory neurons (OSNs) by CuNPs. The observed behavioural interference caused by CuNP exposure may indicate that CuNPs have the ability to interfere with other behaviours potentially affecting fitness and survival. Our findings also revealed the differential response of OSNs to CuNPs and Cu2+.
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Affiliation(s)
- Parastoo Razmara
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada.
| | - Justin Sharpe
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
| | - Gregory G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, T1K 3M4, Canada
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Mebane CA, Chowdhury MJ, De Schamphelaere KAC, Lofts S, Paquin PR, Santore RC, Wood CM. Metal Bioavailability Models: Current Status, Lessons Learned, Considerations for Regulatory Use, and the Path Forward. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2020; 39:60-84. [PMID: 31880840 DOI: 10.1002/etc.4560] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 02/13/2019] [Accepted: 07/22/2019] [Indexed: 06/10/2023]
Abstract
Since the early 2000s, biotic ligand models and related constructs have been a dominant paradigm for risk assessment of aqueous metals in the environment. We critically review 1) the evidence for the mechanistic approach underlying metal bioavailability models; 2) considerations for the use and refinement of bioavailability-based toxicity models; 3) considerations for the incorporation of metal bioavailability models into environmental quality standards; and 4) some consensus recommendations for developing or applying metal bioavailability models. We note that models developed to date have been particularly challenged to accurately incorporate pH effects because they are unique with multiple possible mechanisms. As such, we doubt it is ever appropriate to lump algae/plant and animal bioavailability models; however, it is often reasonable to lump bioavailability models for animals, although aquatic insects may be an exception. Other recommendations include that data generated for model development should consider equilibrium conditions in exposure designs, including food items in combined waterborne-dietary matched chronic exposures. Some potentially important toxicity-modifying factors are currently not represented in bioavailability models and have received insufficient attention in toxicity testing. Temperature is probably of foremost importance; phosphate is likely important in plant and algae models. Acclimation may result in predictions that err on the side of protection. Striking a balance between comprehensive, mechanistically sound models and simplified approaches is a challenge. If empirical bioavailability tools such as multiple-linear regression models and look-up tables are employed in criteria, they should always be informed qualitatively and quantitatively by mechanistic models. If bioavailability models are to be used in environmental regulation, ongoing support and availability for use of the models in the public domain are essential. Environ Toxicol Chem 2019;39:60-84. © 2019 SETAC.
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Affiliation(s)
| | | | | | - Stephen Lofts
- UK Centre for Ecology and Hydrology, Bailrigg, Lancaster, UK
| | | | | | - Chris M Wood
- University of British Columbia, Vancouver, British Columbia, Canada
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Pilehvar A, Town RM, Blust R. The interactive effect of copper(II) and conspecific alarm substances on behavioural responses of zebrafish (Danio rerio). Behav Brain Res 2019; 381:112452. [PMID: 31881231 DOI: 10.1016/j.bbr.2019.112452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 12/11/2019] [Accepted: 12/23/2019] [Indexed: 10/25/2022]
Abstract
Environmental contaminants such as metal ions can have detrimental effects on aquatic organisms at the molecular, organismal and population levels. In the present work, we examined the interactive effect of Cu(II) and conspecific alarm substance on zebrafish behavioural responses utilizing the novel tank diving assay. To this end, 3 novel tank diving tests (on day 0, 3 and 10 of the experimental phase) were conducted on zebrafish in 4 experimental groups: (1) control: no Cu(II) and no alarm substance, (2) Cu(II) only: exposed to 0.78 μM Cu(II) (25 % of the 240 h LC50) in the home tank for 10 days, (3) alarm substance only: exposed to alarm substance for 6 min concomitant with behavioural testing, and (4) Cu(II) + alarm substance: exposed to 0.78 μM Cu(II) in the home tank for 10 days and treated with alarm substance for 6 min during the behavioural testing. Results showed robust habituation response of zebrafish. Exposure to Cu(II) did not affect the behavioural phenotypes of zebrafish in the novel tank diving test or habituation responses. Alarm substance treatment evoked strong anxiety-like behaviour. Finally, zebrafish in the Cu(II) + alarm substance group lost their sensitivity to alarm substance in repeated novel tank assays throughout the concomitant Cu(II) exposure; this observation is tentatively ascribed to Cu(II)-induced olfactory impairment.
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Affiliation(s)
- Ali Pilehvar
- Laboratory of Systemic, Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium.
| | - Raewyn M Town
- Laboratory of Systemic, Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
| | - Ronny Blust
- Laboratory of Systemic, Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerp, Belgium
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Lari E, Razmara P, Bogart SJ, Azizishirazi A, Pyle GG. An epithelium is not just an epithelium: Effects of Na, Cl, and pH on olfaction and/or copper-induced olfactory deficits. CHEMOSPHERE 2019; 216:117-123. [PMID: 30366265 DOI: 10.1016/j.chemosphere.2018.10.079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 06/08/2023]
Abstract
While the toxic effects of several substances on fish olfaction are well known, studies on how water chemistry affects contaminant-induced olfactory toxicity are rare. In the present study, the effect of water pH or Na concentration on fish olfactory response and Cu-induced olfactory toxicity was investigated. Also, the effects of two sodium salts, NaCl and NaNO3, on olfaction were studied. Juvenile rainbow trout were exposed to 6 and 32 μg/L Cu, each under five different conditions (pH 9, pH 6.5, 20 or 40 mg/L sodium added, or culture water), for 10 days before characterizing fish olfactory response using electro-olfactography (EOG). The results demonstrated that reducing the pH to 6.5 or adding 20 or 40 mg/L Na impairs the fish response to a standard olfactory cue. None of the water treatments were protective against, or synergic with, the toxic effect of Cu on the olfactory system. Of the two Na salts, NaCl caused significantly higher impairment than NaNO3. The results of the present study demonstrate that water quality modifies contaminant-induced olfactory toxicity, but differently than what is known for other tissues (i.e. gill).
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Affiliation(s)
- Ebrahim Lari
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada.
| | - Parastoo Razmara
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Sarah J Bogart
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
| | - Ali Azizishirazi
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada; British Columbia Ministry of Environment and Climate Change Strategy, 525 Superior Street, Victoria, BC V8V 1T7, Canada
| | - Greg G Pyle
- Department of Biological Sciences, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada
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Morris JM, Brinkman SF, Takeshita R, McFadden AK, Carney MW, Lipton J. Copper toxicity in Bristol Bay headwaters: Part 2-Olfactory inhibition in low-hardness water. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:198-209. [PMID: 30298944 DOI: 10.1002/etc.4295] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 05/20/2018] [Accepted: 10/08/2018] [Indexed: 06/08/2023]
Abstract
We investigated the olfactory toxicity of copper (Cu) to rainbow trout in low-hardness (27 mg/L as CaCO3 ) water formulated in the laboratory over a 120-h period using a flow-through design. The fish's response to an alarm cue (e.g., reduction in activity) was recorded to determine the exposure concentrations and durations that inhibited olfactory detection of the cue after 3, 24, 48, and 96 h of Cu exposure and after 24 h of clean water recovery following the 96-h exposure period. Exposures were conducted with a range of Cu concentrations from 0.13 (control) to 7.14 μg Cu/L (dissolved Cu). We observed a dose-dependent response in olfactory inhibition with a 20% reduction in the probability of responding to the alarm cue, relative to controls, at 2.7 and 2.4 μg Cu/L after 24 or 96 h of exposure, respectively. Olfactory inhibition manifested between 3 and 24 h of exposure. Our 24- and 96-h 20% olfactory inhibition estimates fell between the criteria derived using the biotic ligand model (BLM; criterion maximum concentration [CMC] and criterion continuous concentration [CCC] values were 0.63 and 0.39 μg Cu/L, respectively) and water hardness-based criteria (CMC and CCC values were 3.9 and 2.9 μg Cu/L, respectively). Therefore, the hardness-based criteria do not appear to be protective and the BLM-derived criteria do appear to be protective against Cu-induced olfactory inhibition given our test water chemistry. Neither the hardness-based criteria nor the BLM-derived criteria appear to be protective against our estimated Cu behavioral avoidance response concentrations at 24- and 96-h exposures (0.54 and 0.50 μg Cu/L, respectively). Environ Toxicol Chem 2019;38:198-209. © 2018 SETAC.
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DeForest DK, Gensemer RW, Gorsuch JW, Meyer JS, Santore RC, Shephard BK, Zodrow JM. Effects of copper on olfactory, behavioral, and other sublethal responses of saltwater organisms: Are estimated chronic limits using the biotic ligand model protective? ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2018; 37:1515-1522. [PMID: 29442368 DOI: 10.1002/etc.4112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Revised: 10/23/2017] [Accepted: 02/09/2018] [Indexed: 06/08/2023]
Abstract
There is concern over whether regulatory criteria for copper (Cu) are protective against chemosensory and behavioral impairment in aquatic organisms. We compiled Cu toxicity data for these and other sublethal endpoints in 35 tests with saltwater organisms and compared the Cu toxicity thresholds with biotic ligand model (BLM)-based estimated chronic limits (ECL values, which are 20% effect concentrations [EC20s] for the embryo-larval life stage of the blue mussel [Mytilus edulis], a saltwater species sensitive to Cu that has historically been used to derive saltwater Cu criteria). Only 8 of the 35 tests had sufficient toxicity and chemistry data to support unequivocal conclusions (i.e., a Cu EC20 or no-observed-effect concentration could be derived, and Cu and dissolved organic carbon [DOC] concentrations were measured [or DOC concentrations could be inferred from the test-water source]). The BLM-based ECL values would have been protective (i.e., the ECL was lower than the toxicity threshold) in 7 of those 8 tests. In the remaining 27 tests, this meta-analysis was limited by several factors, including 1) the Cu toxicity threshold was a "less than" value in 19 tests because only a lowest-observed-effect concentration could be calculated and 2) Cu and/or DOC concentrations often were not measured. In 2 of those 27 tests, the ECL would not have been protective if based only on a conservatively high upper-bound DOC estimate. To facilitate future evaluations of the protectiveness of aquatic life criteria for metals, we urge researchers to measure and report exposure-water chemistry and test-metal concentrations that bracket regulatory criteria. Environ Toxicol Chem 2018;37:1515-1522. © 2018 SETAC.
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Affiliation(s)
| | | | - Joseph W Gorsuch
- Gorsuch Environmental Management Services, Webster, New York, USA
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