Publications by authors named "Markus Brinkmann"

62 Publications

Demonstration of an aggregated biomarker response approach to assess the impact of point and diffuse contaminant sources in feral fish in a small river case study.

Sci Total Environ 2021 Sep 1;804:150020. Epub 2021 Sep 1.

Department for Evolutionary Ecology and Environmental Toxicology, Goethe University, Max-von-Laue Straße 13, 60438 Frankfurt am Main, Germany; LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), 60325 Frankfurt am Main, Germany. Electronic address:

The assessment of the exposure of aquatic wildlife to complex environmental mixtures of chemicals originating from both point and diffuse sources and evaluating the potential impact thereof constitutes a significant step towards mitigating toxic pressure and the improvement of ecological status. In the current proof-of-concept study, we demonstrate the potential of a novel Aggregated Biomarker Response (ABR) approach involving a comprehensive set of biomarkers to identify complex exposure and impacts on wild brown trout (Salmo trutta fario). Our scenario used a small lowland river in Germany (Holtemme river in the Elbe river catchment) impacted by two wastewater treatment plants (WWTP) and diffuse agricultural runoff as a case study. The trout were collected along a pollution gradient (characterised in a parallel study) in the river. Compared to fish from the reference site upstream of the first WWTP, the trout collected downstream of the WWTPs showed a significant increase in micronucleus formation, phase I and II enzyme activities, and oxidative stress parameters in agreement with increasing exposure to various chemicals. By integrating single biomarker responses into an aggregated biomarker response, the two WWTPs' contribution to the observed toxicity could be clearly differentiated. The ABR results were supported by chemical analyses and whole transcriptome data, which revealed alterations of steroid biosynthesis and associated pathways, including an anti-androgenic effect, as some of the key drivers of the observed toxicity. Overall, this combined approach of in situ biomarker responses complemented with molecular pathway analysis allowed for a comprehensive ecotoxicological assessment of fish along the river. This study provides evidence for specific hazard potentials caused by mixtures of agricultural and WWTP derived chemicals at sublethal concentrations. Using aggregated biomarker responses combined with chemical analyses enabled an evidence-based ranking of sites with different degrees of pollution according to toxic stress and observed effects.
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http://dx.doi.org/10.1016/j.scitotenv.2021.150020DOI Listing
September 2021

Toxicokinetic Models for Bioconcentration of Organic Contaminants in Two Life Stages of White Sturgeon ().

Environ Sci Technol 2021 09 12;55(17):11590-11600. Epub 2021 Aug 12.

Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.

The white sturgeon () is an endangered ancient fish species that is known to be particularly sensitive to certain environmental contaminants, partly because of the uptake and subsequent toxicity of lipophilic pollutants prone to bioconcentration as a result of their high lipid content. To better understand the bioconcentration of organic contaminants in this species, toxicokinetic (TK) models were developed for the embryo-larval and subadult life stages. The embryo-larval model was designed as a one-compartment model and validated using whole-body measurements of benzo[]pyrene (B[]P) metabolites from a waterborne exposure to B[]P. A physiologically based TK (PBTK) model was used for the subadult model. The predictive power of the subadult model was validated with an experimental data set of four chemicals. Results showed that the TK models could accurately predict the bioconcentration of organic contaminants for both life stages of white sturgeon within 1 order of magnitude of measured values. These models provide a tool to better understand the impact of environmental contaminants on the health and the survival of endangered white sturgeon populations.
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http://dx.doi.org/10.1021/acs.est.0c06867DOI Listing
September 2021

Remobilization of pollutants during extreme flood events poses severe risks to human and environmental health.

J Hazard Mater 2022 01 19;421:126691. Epub 2021 Jul 19.

Department of Evolutionary Ecology and Environmental Toxicology, Institute of Ecology, Evolution and Diversity, Goethe University Frankfurt, Frankfurt am Main, Germany; LOEWE Centre for Translational Biodiversity Genomics (LOEWE-TBG), Frankfurt am Main, Germany. Electronic address:

While it is well recognized that the frequency and intensity of flood events are increasing worldwide, the environmental, economic, and societal consequences of remobilization and distribution of pollutants during flood events are not widely recognized. Loss of life, damage to infrastructure, and monetary cleanup costs associated with floods are important direct effects. However, there is a lack of attention towards the indirect effects of pollutants that are remobilized and redistributed during such catastrophic flood events, particularly considering the known toxic effects of substances present in flood-prone areas. The global examination of floods caused by a range of extreme events (e.g., heavy rainfall, tsunamis, extra- and tropical storms) and subsequent distribution of sediment-bound pollutants are needed to improve interdisciplinary investigations. Such examinations will aid in the remediation and management action plans necessary to tackle issues of environmental pollution from flooding. River basin-wide and coastal lowland action plans need to balance the opposing goals of flood retention, catchment conservation, and economical use of water.
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http://dx.doi.org/10.1016/j.jhazmat.2021.126691DOI Listing
January 2022

A Novel Multispecies Toxicokinetic Modeling Approach in Support of Chemical Risk Assessment.

Environ Sci Technol 2021 07 24;55(13):9109-9118. Epub 2021 Jun 24.

Toxicology Centre, University of Saskatchewan, Saskatoon S7N 5B3, Canada.

Standardized laboratory tests with a limited number of model species are a key component of chemical risk assessments. These surrogate species cannot represent the entire diversity of native species, but there are practical and ethical objections against testing chemicals in a large variety of species. In previous research, we have developed a multispecies toxicokinetic model to extrapolate chemical bioconcentration across species by combining single-species physiologically based toxicokinetic (PBTK) models. This "top-down" approach was limited, however, by the availability of fully parameterized single-species models. Here, we present a "bottom-up" multispecies PBTK model based on available data from 69 freshwater fishes found in Canada. Monte Carlo-like simulations were performed using statistical distributions of model parameters derived from these data to predict steady-state bioconcentration factors (BCFs) for a set of well-studied chemicals. The distributions of predicted BCFs for 1,4-dichlorobenzene and dichlorodiphenyltrichloroethane largely overlapped those of empirical data, although a tendency existed toward overestimation of measured values. When expressed as means, predicted BCFs for 26 of 34 chemicals (82%) deviated by less than 10-fold from measured data, indicating an accuracy similar to that of previously published single-species models. This new model potentially enables more environmentally relevant predictions of bioconcentration in support of chemical risk assessments.
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http://dx.doi.org/10.1021/acs.est.1c02055DOI Listing
July 2021

Are Honey Bees at Risk from Microplastics?

Toxics 2021 May 15;9(5). Epub 2021 May 15.

Toxicology Centre, University of Saskatchewan, Saskatoon, SK S7N 5B3, Canada.

Microplastics (MPs) are ubiquitous and persistent pollutants, and have been detected in a wide variety of media, from soils to aquatic systems. MPs, consisting primarily of polyethylene, polypropylene, and polyacrylamide polymers, have recently been found in 12% of samples of honey collected in Ecuador. Recently, MPs have also been identified in honey bees collected from apiaries in Copenhagen, Denmark, as well as nearby semiurban and rural areas. Given these documented exposures, assessment of their effects is critical for understanding the risks of MP exposure to honey bees. Exposure to polystyrene (PS)-MPs decreased diversity of the honey bee gut microbiota, followed by changes in gene expression related to oxidative damage, detoxification, and immunity. As a result, the aim of this perspective was to investigate whether wide-spread prevalence of MPs might have unintended negative effects on health and fitness of honey bees, as well as to draw the scientific community's attention to the possible risks of MPs to the fitness of honey bees. Several research questions must be answered before MPs can be considered a potential threat to bees.
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http://dx.doi.org/10.3390/toxics9050109DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8156821PMC
May 2021

Development of a Comprehensive Toxicity Pathway Model for 17α-Ethinylestradiol in Early Life Stage Fathead Minnows ().

Environ Sci Technol 2021 04 23;55(8):5024-5036. Epub 2021 Mar 23.

Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5B3, Canada.

There is increasing pressure to develop alternative ecotoxicological risk assessment approaches that do not rely on expensive, time-consuming, and ethically questionable live animal testing. This study aimed to develop a comprehensive early life stage toxicity pathway model for the exposure of fish to estrogenic chemicals that is rooted in mechanistic toxicology. Embryo-larval fathead minnows (FHM; ) were exposed to graded concentrations of 17α-ethinylestradiol (water control, 0.01% DMSO, 4, 20, and 100 ng/L) for 32 days. Fish were assessed for transcriptomic and proteomic responses at 4 days post-hatch (dph), and for histological and apical end points at 28 dph. Molecular analyses revealed core responses that were indicative of observed apical outcomes, including biological processes resulting in overproduction of vitellogenin and impairment of visual development. Histological observations indicated accumulation of proteinaceous fluid in liver and kidney tissues, energy depletion, and delayed or suppressed gonad development. Additionally, fish in the 100 ng/L treatment group were smaller than controls. Integration of omics data improved the interpretation of perturbations in early life stage FHM, providing evidence of conservation of toxicity pathways across levels of biological organization. Overall, the mechanism-based embryo-larval FHM model showed promise as a replacement for standard adult live animal tests.
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http://dx.doi.org/10.1021/acs.est.0c05942DOI Listing
April 2021

Responses of juvenile fathead minnow (Pimephales promelas) gut microbiome to a chronic dietary exposure of benzo[a]pyrene.

Environ Pollut 2021 Jun 25;278:116821. Epub 2021 Feb 25.

Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Environmental Science, Baylor University, Waco, TX, USA.

The microbiome has been described as an additional host "organ" with well-established beneficial roles. However, the effects of exposures to chemicals on both structure and function of the gut microbiome of fishes are understudied. To determine effects of benzo[a]pyrene (BaP), a model persistent organic pollutant, on structural shifts of gut microbiome in juvenile fathead minnows (Pimephales promelas), fish were exposed ad libitum in the diet to concentrations of 1, 10, 100, or 1000 μg BaP g food, in addition to a vehicle control, for two weeks. To determine the link between exposure to BaP and changes in the microbial community, concentrations of metabolites of BaP were measured in fish bile and 16S rRNA amplicon sequencing was used to evaluate the microbiome. Exposure to BaP only reduced alpha-diversity at the greatest exposure concentrations. However, it did alter community composition assessed as differential abundance of taxa and reduced network complexity of the microbial community in all exposure groups. Results presented here illustrate that environmentally-relevant concentrations of BaP can alter the diversity of the gut microbiome and community network connectivity.
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http://dx.doi.org/10.1016/j.envpol.2021.116821DOI Listing
June 2021

Qualitative and quantitative analysis of microplastics and microfiber contamination in effluents of the City of Saskatoon wastewater treatment plant.

Environ Sci Pollut Res Int 2021 Feb 24. Epub 2021 Feb 24.

School of Environment and Sustainability (SENS), University of Saskatchewan, Saskatoon, Canada.

In recent years, contamination of the environment with microplastics has received increasing scientific and public attention. Wastewater treatment plants (WWTPs) are considered important emitters of microparticles into aquatic systems. Among these microparticles are microplastics from, e.g., cosmetic products, and microfibers that are released during laundry of textiles made from synthetic fibers. The purpose of this study was to qualitatively and quantitatively characterize microplastic and microfiber contamination in effluents of the City of Saskatoon WWTP, Saskatchewan, Canada. The WWTP discharges directly into the South Saskatchewan River, which is an important water resource of central economic and environmental importance to the Canadian Prairies. To achieve this goal, a reference dataset was developed by determining Raman and Fourier-transform infrared (FTIR) spectra of neat plastic standards. Subsequently, samples were obtained from the final effluent of the Saskatoon WWTP during winter, spring, and summer 2019 by use of fine-meshed plankton nets. Microplastics and microfibers were extracted using Fenton oxidation and filtration, counted, and their identity determined by comparing Raman and FTIR spectra of individual microplastics and microfibers with the previously developed reference dataset. The number concentrations of both microplastics and microfibers were relatively stable across seasons, and fibers accounted for 82% of the total number of synthetic microparticles. Although the average total number concentration of microplastics and microfibers was only 1.76 per liter of effluent, at an average daily discharge of 80 million liters, this would amount to the emission of 141 million particles into the river per day. While the environmental relevance of these findings remains to be demonstrated, these results are an important first step toward understanding the magnitude of microplastic contamination in the Canadian Prairies.
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http://dx.doi.org/10.1007/s11356-021-12898-7DOI Listing
February 2021

Toxicity of Weathered Sediment-Bound Dilbit to Early Life Stages of Zebrafish ().

Environ Sci Technol 2021 02 15;55(3):1721-1729. Epub 2021 Jan 15.

Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta T1K 3M4, Canada.

Due to high viscosity, bitumen extracted from the Alberta oil sands is diluted with natural gas condensates to form diluted bitumen (dilbit) to facilitate transport through pipelines. Dilbit that is spilled into or near a waterbody is subject to environmental weathering processes such as evaporation and interaction with sediments. This is the first study that assessed the toxicity of weathered sediment-bound dilbit (WSD) to fish early life stages. Exposure of zebrafish () embryos to water-soluble fractions (WSFs) or water-accommodated fractions (WAFs) of WSD from 30 min to 120 h postfertilization resulted in pericardial edema, yolk sac edema, and incidences of uninflated swim bladder. The presence of oil-mineral aggregates (OMAs) in the WAFs greatly increased toxicity, despite all fractions having similar concentrations of dissolved polycyclic aromatic hydrocarbons (PAHs). There were greater mRNA abundances in larvae exposed to WAFs, suggesting that there were differences in bioavailability of PAHs between fractions. However, there was little evidence that embryotoxicity was caused by oxidative stress. Results suggest that evaporation and sediment interaction do not completely attenuate toxicity of dilbit to zebrafish early life stages, and OMAs in exposures exacerbate toxicity.
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http://dx.doi.org/10.1021/acs.est.0c06349DOI Listing
February 2021

Bioavailability and impacts of estrogenic compounds from suspended sediment on rainbow trout (Oncorhynchus mykiss).

Aquat Toxicol 2021 Feb 9;231:105719. Epub 2020 Dec 9.

RWTH Aachen University, Institute for Environmental Research, Worringer Weg 1, 52074, Aachen, Germany; Goethe University Frankfurt, Department of Evolutionary Ecology and Environmental Toxicology, Max-von-Laue-Str. 13, 60438, Frankfurt am Main, Germany.

Numerous environmental pollutants have the potential to accumulate in sediments, and among them are endocrine-disrupting chemicals (EDCs). It is well documented that water-borne exposure concentrations of some potent EDCs, more specifically estrogenic- active compounds (ECs), can impair the reproduction of fish. In contrast, little is known about the bioavailability and effects of sediment-associated ECs on fish. Particularly, when sediments are disturbed, e.g., during flood events, chemicals may be released from the sediment and become bioavailable. The main objectives of this study were to evaluate a) whether ECs from the sediment become bioavailable to fish when the sediment is suspended, and b) whether such exposure leads to endocrine responses in fish. Juvenile rainbow trout (Oncorhynchus mykiss) were exposed over 21 days to constantly suspended sediments in the following treatments: i) a contaminated sediment from the Luppe River, representing a "hotspot" for EC accumulation, ii) a reference sediment (exhibiting only background contamination), iii) three dilutions, 2-, 4- and 8-fold of Luppe sediment diluted with the reference sediment, and iv) a water-only control. Measured estrogenic activity using in vitro bioassays as well as target analysis of nonylphenol and estrone via LC-MS/MS in sediment, water, fish plasma, as well as bile samples, confirmed that ECs became bioavailable from the sediment during suspension. ECs were dissolved in the water phase, as indicated by passive samplers, and were readily taken up by the exposed trout. An estrogenic response of fish to Luppe sediment was indicated by increased abundance of transcripts of typical estrogen responsive genes, i.e. vitelline envelope protein α in the liver and vitellogenin induction in the skin mucus. Altered gene expression profiles of trout in response to suspended sediment from the Luppe River suggest that in addition to ECs a number of other contaminants such as dioxins, polychlorinated biphenyls (PCBs) and heavy metals were remobilized during suspension. The results of the present study demonstrated that sediments not only function as a sink for ECs but can turn into a significant source of pollution when sediments are resuspended as during flood-events. This highlights the need for sediment quality criteria considering bioavailability sediment-bound contaminants in context of flood events.
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http://dx.doi.org/10.1016/j.aquatox.2020.105719DOI Listing
February 2021

Combined sediment desorption and bioconcentration model to predict levels of dioxin-like chemicals in fish.

Sci Total Environ 2021 Mar 9;758:143891. Epub 2020 Dec 9.

Goethe University Frankfurt, Department of Evolutionary Ecology and Environmental Toxicology, Max-von-Laue-Str. 13, 60438 Frankfurt am Main, Germany; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, China; Key Laboratory of Yangtze Water Environment, Ministry of Education, Tongji University, Shanghai, China. Electronic address:

Flooding and other sediment disturbances can lead to increases in sediment resuspension. In this context, it is of central importance to understand the kinetics of release from these sediments and the uptake of pollutants, such as polychlorinated biphenyls (PCBs) and polychlorinated dioxins and furans (PCDD/Fs), into aquatic organisms. In the present study, we parameterized a sediment desorption model based on experimentally determined rapidly-desorbing fractions of dioxin-like chemicals (DLCs). We coupled this desorption model with a physiologically-based toxicokinetic model for rainbow trout. This combined model was used to predict DLC concentrations in the muscle of exposed fish. The performance of this model was evaluated using a previously published dataset on DLC uptake from sediment suspensions during simulated re-suspension events. Predictions generally differed less than 10-fold from measured values, and the model showed a good global coefficient of determination (R) of 0.95. The root mean squared error (RMSE) for PCBs was 0.31 log units and 0.53 log units for PCDD/Fs. The results of our study demonstrate that the prediction of bioconcentration and related risk to fish resulting from sediment resuspension can be accurately predicted using coupled desorption and toxicokinetic models.
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http://dx.doi.org/10.1016/j.scitotenv.2020.143891DOI Listing
March 2021

Differences in the subcellular distribution of cadmium and copper in the gills and liver of white sturgeon (Acipenser transmontanus) and rainbow trout (Oncorhynchus mykiss).

Chemosphere 2021 Feb 1;265:129142. Epub 2020 Dec 1.

Toxicology Centre, University of Saskatchewan, Saskatoon, SK, S7N 5B3, Canada; Department of Biology, University of Saskatchewan, Saskatoon, SK, S7N 5E2, Canada.

Recent studies have shown that white sturgeon (Acipenser transmontanus) are more resistant to cadmium (Cd) compared to rainbow trout (Oncorhynchus mykiss), whereas they are more sensitive than rainbow trout when exposed to copper (Cu). Differences in the subcellular distribution of metals among species could be one of the factors responsible for the differences in the sensitivity to metals. Although, subcellular distribution has been studied extensively in many species with many metals, its direct role in species-specific differences in the sensitivity has not been well studied. The objective of this study was to evaluate the role of subcellular distribution of metals in species-specific differences in the sensitivity to metals between sturgeon and trout. We compared the subcellular distribution of metals Cd and Cu in the cellular debris, heat-stable proteins, heat-denatured fraction, metal-rich granules, and organelles fractions from the gills and liver after exposure of juveniles of both species to 1.25 and 20 μg/L Cd and Cu for 8 days, respectively. Sturgeon diverted a higher amount of Cd towards biologically inactive metal pool (BIM) and a lower amount towards the biologically active metal pool (BAM) compared to trout in both tissues. This explained why sturgeon are able to tolerate a relatively higher exposure level to Cd compared to trout. For Cu, there was no statistically significant species-specific differences in the amounts diverted towards either BAM or BIM; hence, white sturgeon's greater sensitivity to Cu was not explained by its subcellular distribution strategies.
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http://dx.doi.org/10.1016/j.chemosphere.2020.129142DOI Listing
February 2021

Contrast-enhanced ultrasound imaging for assessing organ perfusion in rainbow trout (Oncorhynchus mykiss).

Sci Total Environ 2021 Jan 5;750:141231. Epub 2020 Aug 5.

Department of Medical Imaging, University of Saskatchewan, Saskatoon, Saskatchewan, Canada. Electronic address:

Contrast-enhanced ultrasound (CEUS) imaging has great potential as a non-lethal, inexpensive monitoring tool in aquatic toxicology. It is a well-established clinical imaging approach that combines real-time, quantitative assessment of organ blood flow, with morphological data. In humans, it has been extensively used to measure changes in blood flow that can be attributed to cancer, inflammation, and other biological abnormalities. However, it has yet to be explored as a tool for fish physiology or environmental toxicology. In this study, our goal was to determine if CEUS could be used to visualize and measure blood flow in the liver of a rainbow trout. All rainbow trout received two injections of an ultrasound contrast agent, microbubbles. A subset received a third injection after administration of propranolol, a non-specific beta1 & 2-blocker, to determine if changes in blood flow could be detected. Ultrasound contrast time-intensity curves (TIC) were obtained, fit to a lognormal model, and different perfusion parameters were calculated. Contrast enhancement was observed in all rainbow trout livers, with high percentage between repeated measurements, including blood flow (80.6 ± 27.3%), area under the curve (73.2 ± 14%), blood volume (84 ± 14.2%) and peak enhancement (86.7 ± 7.5%). After administration of propranolol, we detected a non-significant (p > 0.05) increase in area under the curve (102.6 ± 44.2%), peak enhancement (77.3 ± 106.4), blood volume (48.2 ± 74.5%), and decrease in hepatic blood flow (-17.3 ± 37.1%). These data suggest that CEUS imaging is suitable to measure organ blood flow in fish, and demonstrates tremendous potential for exploring different organs, fish species, and effects of chemical contaminants in future studies.
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http://dx.doi.org/10.1016/j.scitotenv.2020.141231DOI Listing
January 2021

In vitro-in vivo and cross-life stage extrapolation of uptake and biotransformation of benzo[a]pyrene in the fathead minnow (Pimephales promelas).

Aquat Toxicol 2020 Nov 15;228:105616. Epub 2020 Sep 15.

Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Environment and Sustainability, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Global Institute for Water Security, University of Saskatchewan, Saskatoon, Saskatchewan, Canada.

Understanding internal dose metrics is integral to adequately assess effects environmental contaminants might have on aquatic wildlife, including fish. In silico toxicokinetic (TK) models are a leading approach for quantifying internal exposure metrics for fishes; however, they often do not adequately consider chemicals that are actively biotransformed and have not been validated against early-life stages (ELS) that are often considered the most sensitive to the exposure to contaminants. To address these uncertainties, TK models were parameterized for the rapidly biotransformed chemical benzo[a]pyrene (B[a]P) in embryo-larval and adult life stages of fathead minnows. Biotransformation of B[a]P was determined through measurements of in vitro clearance. Using in vitro-in vivo extrapolation, in vitro clearance was integrated into a multi-compartment TK model for adult fish and a one-compartment model for ELS. Model predictions were validated using measurements of B[a]P metabolites from in vivo flow-through exposures to graded concentrations of water-borne B[a]P. Significantly greater amounts of B[a]P metabolites were observed with exposure to greater concentrations of parent compound in both life stages. However, when assessing biotransformation capacity, no differences in phase I or phase II biotransformation were observed with greater exposures to B[a]P. Results of modelling suggested that biotransformation of B[a]P can be successfully implemented into in silico models to accurately predict life stage-specific abundances of B[a]P metabolites in either whole-body larvae or the bile of adult fish. Models developed increase the scope of applications in which TK models can be used to support environmental risk assessments.
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http://dx.doi.org/10.1016/j.aquatox.2020.105616DOI Listing
November 2020

Effects of weathered sediment-bound dilbit on freshwater amphipods (Hyalella azteca).

Aquat Toxicol 2020 Nov 12;228:105630. Epub 2020 Sep 12.

Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.

Bitumen mined in the oil sands region of Northern Alberta, Canada, is diluted with natural gas condensates to form dilbit, which is transported through pipelines. Sections of these pipelines come close to freshwater ecosystems. If dilbit is spilled into or near an aquatic environment, environmental weathering processes, such as evaporation and sediment interaction, influence the fate and toxicity of dilbit to aquatic organisms. To date, most studies of the effects of dilbit on the health of aquatic organisms have not considered weathering processes. Thus, the goal of this study was to assess the toxicity of weathered sediment-bound dilbit (WSD) to an aquatic organism. Adult freshwater amphipods (Hyalella azteca) were exposed directly to WSD or the water-soluble fraction (WSF) of WSD. Direct exposure to WSD resulted in oil-mineral aggregates adhering to the appendages and gas exchange structures of amphipods, causing acute lethality. After a 10-min exposure to WSD, amphipods consumed half as much oxygen and their appendage movement was impaired. Exposure to the WSF, which contained a total PAH concentration of 1.08 μg/L, did not result in acute lethality, or significantly affect respiration, activity or acetylcholinesterase activity. Results of the present study indicate that physical interaction with oil-mineral aggregates after a spill of dilbit is a threat to benthic invertebrates, whereas the WSF does not cause acute adverse effects. As the transport of dilbit through pipelines increases in North America, studies must incorporate environmental weathering processes when determining the effects of dilbit on aquatic organisms.
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http://dx.doi.org/10.1016/j.aquatox.2020.105630DOI Listing
November 2020

Detection of SARS-CoV-2 in raw and treated wastewater in Germany - Suitability for COVID-19 surveillance and potential transmission risks.

Sci Total Environ 2021 Jan 18;751:141750. Epub 2020 Aug 18.

Institute of Medical Virology, University Hospital, Goethe University Frankfurt, Paul-Ehrlich-Str. 40, D-60590 Frankfurt, Germany. Electronic address:

Wastewater-based monitoring of the spread of the new SARS-CoV-2 virus, also referred to as wastewater-based epidemiology (WBE), has been suggested as a tool to support epidemiology. An extensive sampling campaign, including nine municipal wastewater treatment plants, has been conducted in different cities of the Federal State of North Rhine-Westphalia (Germany) on the same day in April 2020, close to the first peak of the corona crisis. Samples were processed and analysed for a set of SARS-CoV-2-specific genes, as well as pan-genotypic gene sequences also covering other coronavirus types, using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Additionally, a comprehensive set of chemical reference parameters and bioindicators was analysed to characterize the wastewater quality and composition. Results of the RT-qPCR based gene analysis indicate the presence of SARS-CoV-2 genetic traces in different raw wastewaters. Furthermore, selected samples have been sequenced using Sanger technology to confirm the specificity of the RT-qPCR and the origin of the coronavirus. A comparison of the particle-bound and the dissolved portion of SARS-CoV-2 virus genes shows that quantifications must not neglect the solid-phase reservoir. The infectivity of the raw wastewater has also been assessed by viral outgrowth assay with a potential SARS-CoV-2 host cell line in vitro, which were not infected when exposed to the samples. This first evidence suggests that wastewater might be no major route for transmission to humans. Our findings draw attention to the need for further methodological and molecular assay validation for enveloped viruses in wastewater.
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http://dx.doi.org/10.1016/j.scitotenv.2020.141750DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7434407PMC
January 2021

Mechanisms of pH-Dependent Uptake of Ionizable Organic Chemicals by Fish from Oil Sands Process-Affected Water (OSPW).

Environ Sci Technol 2020 08 19;54(15):9547-9555. Epub 2020 Jul 19.

School of Environment and Sustainability (SENS), University of Saskatchewan, 44 Campus Drive, Saskatoon S7N 5C8, Canada.

Uptake and effects of ionizable organic chemicals (IOCs) that are weak acids in aqueous solution by fish can differ as a function of pH. While the pH-dependent behavior of select IOCs is well-understood, complex mixtures of IOCs, e.g., from oil sands process-affected water (OSPW), have not yet been studied systematically. Here, we established an in vitro screening method using the rainbow trout gill cell line, RTgill-W1, to investigate pH-dependent cytotoxicity and permeation of IOCs across cultured epithelia using ultra-high-performance liquid chromatography with high-resolution mass spectrometry (UPLC-HRMS). The assay was benchmarked using model chemicals and technical mixtures, and then used to characterize fractions and reconstituted extracts of field-collected OSPW. Significant pH-dependent cytotoxicity of individual IOCs, acidic fractions, and reconstituted extracts of OSPW was observed. In vitro data were in good agreement with data from a 96 h in vivo exposure experiment with juvenile rainbow trout. Permeation of some IOCs from OSPW was mediated by active transport, as revealed by studies in which inhibitors of these active transport mechanisms were applied. We conclude that the RTgill-W1 in vitro assay is useful for the screening of pH-dependent uptake of IOCs in fish, and has applications for in vitroin vivo extrapolation, and prioritization of chemicals in nontarget screenings.
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http://dx.doi.org/10.1021/acs.est.0c02522DOI Listing
August 2020

Validation of the micro-EROD assay with H4IIE cells for assessing sediment contamination with dioxin-like chemicals.

Environ Pollut 2020 Oct 9;265(Pt B):114984. Epub 2020 Jun 9.

School of Environment and Sustainability (SENS), University of Saskatchewan, Saskatoon, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, Canada; Global Institute for Water Security (GIWS), University of Saskatchewan, Saskatoon, Canada; Centre for Hydrology, University of Saskatchewan, Saskatoon, Canada.

In vitro bioassays have been used as a bioanalytical means of detecting dioxin-like compounds (DLCs) in environmental matrices and have been suggested as a tool for quantifying DLCs in sediments. The present study evaluated the relationship between bioanalytical results from the micro-7-ethoxyresorufin-O-deethylase (EROD) bioassay and chemical analytical results in 25 sediment samples collected from rivers across Germany. Sediments were collected, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) were extracted from the sediments, biological toxicity equivalent quotients (BEQs) were determined by micro-EROD assay and toxicity equivalent quotients (TEQs) were calculated from chemical analysis. Correlations between BEQs and TEQs were evaluated, and linear regression modeling was performed, excluding 6 samples as validation data, to derive equations for predicting TEQs from BEQs. Validation data was tested to evaluate predictive capabilities of the models. Correlations were observed between BEQ and TEQ for PCDD/Fs (r=0.987), PCBs (r=0.623), measured sum of PCDD/F and PCBs (r = 0.975) and calculated sum of PCDD/F and PCBs (r = 0.971). The modeling equations provided low variances as evaluated by mean absolute error (MAE) (≤10.3 pg/g) and root mean square error (RMSE) (≤15.8 pg/g) indicating that expected TEQs could be reasonably well calculated from BEQs. Predicted TEQs from validation data fell within the 95% probability intervals of the test data and had low variances (MAE≤6.5 pg/g) and (RMSE≤10.7 pg/g). Our results indicate that the micro-EROD bioassay can be used as a screening tool for DLCs in sediment and has the capability to be used as an alternate method to chemical analysis for quantifying dioxin-like potential of sediments.
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http://dx.doi.org/10.1016/j.envpol.2020.114984DOI Listing
October 2020

Differential responses of gut microbiota of male and female fathead minnow (Pimephales promelas) to a short-term environmentally-relevant, aqueous exposure to benzo[a]pyrene.

Chemosphere 2020 Aug 12;252:126461. Epub 2020 Mar 12.

Toxicology Centre, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Veterinary Biomedical Sciences, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Department of Environmental Sciences, Baylor University, Waco, TX, USA.

In addition to aiding in digestion of food and uptake of nutrients, microbiota in guts of vertebrates are responsible for regulating several beneficial functions, including development of an organism and maintaining homeostasis. However, little is known about effects of exposures to chemicals on structure and function of gut microbiota of fishes. To assess effects of exposure to polycyclic aromatic hydrocarbons (PAHs) on gut microbiota, male and female fathead minnows (Pimephales promelas) were exposed to environmentally-relevant concentrations of the legacy PAH benzo[a]pyrene (BaP) in water. Measured concentrations of BaP ranged from 2.3 × 10 to 1.3 μg L. The community of microbiota in the gut were assessed by use of 16S rRNA metagenetics. Exposure to environmentally-relevant aqueous concentrations of BaP did not alter expression levels of mRNA for cyp1a1, a "classic" biomarker of exposure to BaP, but resulted in shifts in relative compositions of gut microbiota in females rather than males. Results presented here illustrate that in addition to effects on more well-studied molecular endpoints, relative compositions of the microbiota in guts of fish can also quickly respond to exposure to chemicals, which can provide additional mechanisms for adverse effects on individuals.
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http://dx.doi.org/10.1016/j.chemosphere.2020.126461DOI Listing
August 2020

New Insights into the Toxicokinetics of 3,4-Dichloroaniline in Early Life Stages of Zebrafish ().

Toxics 2020 Mar 1;8(1). Epub 2020 Mar 1.

School of Environment and Sustainability, University of Saskatchewan, Saskatoon, SK S7N 5C8, Canada.

In the fish embryo toxicity (FET) test with zebrafish () embryos, 3,4-dichloroaniline (3,4-DCA) is often employed as a positive control substance [...].
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http://dx.doi.org/10.3390/toxics8010016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7151730PMC
March 2020

Bone resorption and body reorganization during maturation induce maternal transfer of toxic metals in anguillid eels.

Proc Natl Acad Sci U S A 2019 06 13;116(23):11339-11344. Epub 2019 May 13.

Department of Ecosystem Analysis, Institute for Environmental Research, RWTH Aachen University, 52074 Aachen, Germany.

During their once-in-a-lifetime transoceanic spawning migration, anguillid eels do not feed, instead rely on energy stores to fuel the demands of locomotion and reproduction while they reorganize their bodies by depleting body reserves and building up gonadal tissue. Here we show how the European eel () breaks down its skeleton to redistribute phosphorus and calcium from hard to soft tissues during its sexual development. Using multiple analytical and imaging techniques, we characterize the spatial and temporal degradation of the skeletal framework from initial to final gonadal maturation and use elemental mass ratios in bone, muscle, liver, and gonadal tissue to determine the fluxes and fates of selected minerals and metals in the eels' bodies. We find that bone loss is more pronounced in females than in males and eventually may reach a point at which the mechanical stability of the skeleton is challenged. P and Ca are released and translocated from skeletal tissues to muscle and gonads, leaving both elements in constant proportion in remaining bone structures. The depletion of internal stores from hard and soft tissues during maturation-induced body reorganization is accompanied by the recirculation, translocation, and maternal transfer of potentially toxic metals from bone and muscle to the ovaries in gravid females, which may have direct deleterious effects on health and hinder the reproductive success of individuals of this critically endangered species.
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http://dx.doi.org/10.1073/pnas.1817738116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6561237PMC
June 2019

Corrigendum to "Assessing the fate of brown trout (Salmo trutta) environmental DNA in a natural stream using a sensitive and specific dual-labelled probe" [Sci. Total Environ. 655 (2019) 321-327].

Sci Total Environ 2019 07 17;672:1045. Epub 2019 Apr 17.

School of Environment and Sustainability (SENS), University of Saskatchewan, Saskatoon, SK, Canada; Global Institute for Water Security (GIWS), University of Saskatchewan, Saskatoon, SK, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada. Electronic address:

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http://dx.doi.org/10.1016/j.scitotenv.2019.04.158DOI Listing
July 2019

Ecotoxicity of Nitrogen, Sulfur, or Oxygen Heterocycles and Short-Chained Alkyl Phenols Commonly Detected in Contaminated Groundwater.

Environ Toxicol Chem 2019 06 13;38(6):1343-1355. Epub 2019 May 13.

Department of Ecosystem Analysis, Institute for Environmental Research, ABBt-Aachen Biology and Biotechnology, RWTH Aachen University, Aachen, Germany.

Nitrogen, sulfur, or oxygen heterocyclic aromatic hydrocarbons (NSO-HETs) and short-chained alkyl phenols (SCAPs) are commonly detected in groundwater at contaminated sites and in the surrounding environment. It is now scientific consensus that these chemicals pose a risk to human and ecosystem health. However, toxicity data are comparably fragmentary, and only few studies have addressed the ecotoxicity of NSO-HETs and SCAPs in a systematic and comparative fashion. To overcome this shortcoming, we tested 18 SCAPs, 16 NSO-HETs, as well as the homocyclic hydrocarbons indane and indene in the Microtox® assay with Aliivibrio fischeri, the growth inhibition test with Desmodesmus subspicatus, the acute immobilization assay with Daphnia magna, as well as the fish embryo toxicity test with embryos of the zebrafish (Danio rerio). Because of the physicochemical properties of the tested chemicals (limited water solubility, volatility, and sorption to test vessels), actual exposure concentrations in test media and their dissipation over time were analytically quantified by means of gas chromatography with mass spectrometry. Analytically corrected effect levels (median effect and lethal concentrations) ranged from 0.017 to 180 mg L , underlining the environmental relevance of some NSO-HETs and SCAPs. Para-substituted phenols showed the overall greatest toxicities in all 4 toxicity tests. We provide, for the first time, a complete high-quality data set in support of better environmental risk assessments of these chemicals. Environ Toxicol Chem 2019;38:1343-1355. © 2019 SETAC.
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http://dx.doi.org/10.1002/etc.4423DOI Listing
June 2019

Bioactivation of Quinolines in a Recombinant Estrogen Receptor Transactivation Assay Is Catalyzed by N-Methyltransferases.

Chem Res Toxicol 2019 04 28;32(4):698-707. Epub 2019 Mar 28.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment , Nanjing University , Nanjing , China.

Hydroxylation of polyaromatic compounds through cytochromes P450 (CYPs) is known to result in potentially estrogenic transformation products. Recently, there has been an increasing awareness of the importance of alternative pathways such as aldehyde oxidases (AOX) or N-methyltransferases (NMT) in bioactivation of small molecules, particularly N-heterocycles. Therefore, this study investigated the biotransformation and activity of methylated quinolines, a class of environmentally relevant N-heterocycles that are no native ligands of the estrogen receptor (ER), in the estrogen-responsive cell line ERα CALUX. We found that this widely used cell line overexpresses AOXs and NMTs while having low expression of CYP enzymes. Exposure of ERα CALUX cells to quinolines resulted in estrogenic effects, which could be mitigated using an inhibitor of AOX/NMTs. No such mitigation occurred after coexposure to a CYP1A inhibitor. A number of N-methylated but no hydroxylated transformation products were detected using liquid chromatography-mass spectrometry, which indicated that biotransformations to estrogenic metabolites were likely catalyzed by NMTs. Compared to the natural ER ligand 17β-estradiol, the products formed during the metabolization of quinolines were weak to moderate agonists of the human ERα. Our findings have potential implications for the risk assessment of these compounds and indicate that care must be taken when using in vitro estrogenicity assays, for example, ERα CALUX, for the characterization of N-heterocycles or environmental samples that may contain them.
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http://dx.doi.org/10.1021/acs.chemrestox.8b00372DOI Listing
April 2019

Assessing the fate of brown trout (Salmo trutta) environmental DNA in a natural stream using a sensitive and specific dual-labelled probe.

Sci Total Environ 2019 Mar 17;655:321-327. Epub 2018 Nov 17.

School of Environment and Sustainability (SENS), University of Saskatchewan, Saskatoon, SK, Canada; Global Institute for Water Security (GIWS), University of Saskatchewan, Saskatoon, SK, Canada; Toxicology Centre, University of Saskatchewan, Saskatoon, SK, Canada. Electronic address:

Environmental DNA (eDNA) analysis in the aquatic environment has emerged as a promising tool for diagnosis of the ecological status in comprehensive monitoring strategies and might become useful in context of the European Water Framework Directive (WFD) and other legislations to derive stressor-specific indicators. Despite many studies having made significant progress for the future use of eDNA in terms of ecosystem composition and detection of invasive/rare species in inland waters, much remains unknown about the transport and fate of eDNA under natural environmental conditions. We designed a specific dual-labelled probe to detect brown trout (Salmo trutta, L.) eDNA and used the probe to describe the fate of eDNA released from an aquaculture facility into the low mountain range stream Wehebach, Germany. The probe was shown to be specific to brown trout, as ponds housing rainbow trout (Oncorhynchus mykiss) did not test positive. Even though we observed different strengths of eDNA signals for three ponds containing different brown trout quantities, no significant correlation was found between biomass (kg/L) and eDNA quantity. Our results indicate that the release of DNA from brown trout might be life stage and/or age-dependent. The effluents of the aquaculture facility were a source of high levels of eDNA which resulted in the greatest abundance of brown trout eDNA directly downstream of the facility. Despite the natural occurrence of brown trout in the Wehebach, as shown by ecological investigations conducted by authorities of the federal state of North Rhine-Westphalia (Germany) and personal observations, we observed a significant decrease of relative abundance of eDNA in the Wehebach within the first 1.5 km downstream of the aquaculture. Our results suggest that concentrations of eDNA in running waters rapidly decrease under natural conditions due to dilution and degradation processes, which might have important implications for the utility of eDNA in environmental research.
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http://dx.doi.org/10.1016/j.scitotenv.2018.11.247DOI Listing
March 2019

Looking back - Looking forward: A novel multi-time slice weight-of-evidence approach for defining reference conditions to assess the impact of human activities on lake systems.

Sci Total Environ 2018 Jun 19;626:1036-1046. Epub 2018 Feb 19.

Institute of Geosystems and Bioindication, Technische Universität Braunschweig, Langer Kamp 19c, 38106 Braunschweig, Germany.

Lake ecosystems are sensitive recorders of environmental changes that provide continuous archives at annual to decadal resolution over thousands of years. The systematic investigation of land use changes and emission of pollutants archived in Holocene lake sediments as well as the reconstruction of contamination, background conditions, and sensitivity of lake systems offer an ideal opportunity to study environmental dynamics and consequences of anthropogenic impact that increasingly pose risks to human well-being. This paper discusses the use of sediment and other lines of evidence in providing a record of historical and current contamination in lake ecosystems. We present a novel approach to investigate impacts from human activities using chemical-analytical, bioanalytical, ecological, paleolimnological, paleoecotoxicological, archeological as well as modeling techniques. This multi-time slice weight-of-evidence (WOE) approach will generate knowledge on conditions prior to anthropogenic influence and provide knowledge to (i) create a better understanding of the effects of anthropogenic disturbances on biodiversity, (ii) assess water quality by using quantitative data on historical pollution and persistence of pollutants archived over thousands of years in sediments, and (iii) define environmental threshold values using modeling methods. This technique may be applied in order to gain insights into reference conditions of surface and ground waters in catchments with a long history of land use and human impact, which is still a major need that is currently not yet addressed within the context of the European Water Framework Directive.
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http://dx.doi.org/10.1016/j.scitotenv.2018.01.113DOI Listing
June 2018

A rapid and sensitive fluorometric method for determination of aldehyde oxidase activity.

Toxicol Appl Pharmacol 2018 02 9;341:30-37. Epub 2018 Jan 9.

Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada; School of Environment and Sustainability, University of Saskatchewan, 44 Campus Drive, Saskatoon, Saskatchewan S7N 5B3, Canada. Electronic address:

Previous research has characterized the important role of aldehyde oxidases (AOX) in biotransformation of N-heterocyclic therapeutic drugs and environmental contaminants in mammals. Research pertaining to AOX activity in non-mammalian vertebrates, however, is scarce, despite its biological role as a potentially important metabolic pathway for xenobiotics. One of the limiting factors of research on AOX is that available photometric methods are relatively insensitive, limited in throughput, and prone to cross-reactivity from other enzymes. Therefore, this study aimed to develop a novel and improved fluorometric AOX assay. This assay is based on the conversion of the exogenous aldehyde substrate 4-(dimethyl)amino cinnamaldehyde to its corresponding fluorescent acid by AOX, and was evaluated using partially purified hepatic cytosol from rat, human, and rainbow trout. Purification of native cytosol by heat treatment and ammonium sulfate precipitation resulted in increased specific activity of AOX. Michaelis-Menten kinetic parameters (Kand V) were comparable to values previously generated by photometric methods. Furthermore, effects of the inhibitor hydralazine on AOX activity revealed half maximal inhibitory concentrations comparable to those generated using conventional methods. Product identity was confirmed by liquid chromatography and mass spectrometry. In summary, this study successfully developed a rapid and sensitive assay for determination of AOX activity in across different vertebrate species that is 4- to 10-fold more sensitive compared to conventional absorbance-based methods. It can be applied in environmental, toxicological, and pharmacological studies relating to identification of AOX substrates, as well as the induction of AOX expression through drugs and environmental contaminants.
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http://dx.doi.org/10.1016/j.taap.2018.01.006DOI Listing
February 2018

Generalized concentration addition accurately predicts estrogenic potentials of mixtures and environmental samples containing partial agonists.

Toxicol In Vitro 2018 Feb 21;46:294-303. Epub 2017 Oct 21.

Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.

Cell-based bioanalytical tools are considered one alternative to overcome limitations of sensitivities of instrumental, analytical chemistry for monitoring estrogenic chemicals in the environment. Because these tools also reflect non-additive interactions of chemicals in mixtures, their outcomes often deviate from outcomes of chemical analytical approaches that assume additivity, e.g. the concentration addition (CA) model. Often this is because CA is unable to adequately represent effects of partial agonists, i.e. estrogens with lesser efficacies compared to 17β-estradiol. A generalized concentration addition (GCA) model has been proposed to address this shortcoming. In the present study, we investigated effects of mixtures of isomers of nonylphenol as partial model agonists in a cell-based estrogenicity assay. Whether the GCA model was able to more accurately predict the outcomes of these and previously published mixture experiments was evaluated, as well as the potency of a set of comprehensively characterized sewage effluent samples, compared to CA. If samples contained partial agonists, the GCA model consistently predicted potencies of mixtures and extracts of environmental samples more accurately than did the CA model. These findings enable more accurate estimations of potencies of estrogenicity explained by concentrations of agonists and partial agonists, thus significantly improving the ability to identify causative chemicals.
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http://dx.doi.org/10.1016/j.tiv.2017.10.022DOI Listing
February 2018

In vitro tools for the toxicological evaluation of sediments and dredged materials: intra- and inter-laboratory comparisons of chemical and bioanalytical methods.

Environ Sci Pollut Res Int 2018 Feb 14;25(5):4037-4050. Epub 2017 Sep 14.

Department of Ecosystem Analysis, Institute for Environmental Research, ABBt-Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.

The implementation of in vitro bioassays for the screening of dioxin-like compounds (DLCs) into management guidelines of dredged material is of increasing interest to regulators and risk assessors. This study reports on an intra- and inter-laboratory comparison study between four independent laboratories. A bioassay battery consisting of RTL-W1 (7-ethoxy-resorufin-O-deethylase; EROD), H4IIE (micro-EROD), and H4IIE-luc cells was used to assess aryl hydrocarbon receptor-mediated effects of sediments from two major European rivers, differently contaminated with DLCs. Each assay was validated by characterization of its limit of detection (LOD) and quantification (LOQ), z-factor, reproducibility, and repeatability. DLC concentrations were measured using high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS) and compared to bioassay-specific responses via toxicity equivalents (TEQs) on intra- and inter-laboratory levels. The micro-EROD assay exhibited the best overall performance among the bioassays. It was ranked excellent (z-factor = 0.54), reached a repeatability > 75%, was highly comparable (r  = 0.87) and reproducible (83%) between two laboratories, and was well correlated (r  = 0.803) with TEQs. Its LOD and LOQ of 0.5 and 0.7 pM 2,3,7,8-TCDD, respectively, approached LOQs of HRGC/HRMS measurements. In contrast, cell lines RTL-W1 and H4IIE-luc produced LODs > 0.7 pM 2,3,7,8-TCDD, LOQs > 1.7 pM 2,3,7,8-TCDD, and repeatability < 70%. Based on the data obtained, the micro-EROD assay is the most favorable bioanalytical tool, and via a micro-EROD-based limit value, it would allow for the assessment of sediment DLC concentrations; thus, it could be considered for the implementation into testing and management guidelines for dredged materials.
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http://dx.doi.org/10.1007/s11356-017-0094-zDOI Listing
February 2018

Project house water: a novel interdisciplinary framework to assess the environmental and socioeconomic consequences of flood-related impacts.

Environ Sci Eur 2017 10;29(1):23. Epub 2017 Jul 10.

Institute for Environmental Research, RWTH Aachen University, Worringerweg 1, 52074 Aachen, Germany.

Protecting our water resources in terms of quality and quantity is considered one of the big challenges of the twenty-first century, which requires global and multidisciplinary solutions. A specific threat to water resources, in particular, is the increased occurrence and frequency of flood events due to climate change which has significant environmental and socioeconomic impacts. In addition to climate change, flooding (or subsequent erosion and run-off) may be exacerbated by, or result from, land use activities, obstruction of waterways, or urbanization of floodplains, as well as mining and other anthropogenic activities that alter natural flow regimes. Climate change and other anthropogenic induced flood events threaten the quantity of water as well as the quality of ecosystems and associated aquatic life. The quality of water can be significantly reduced through the unintentional distribution of pollutants, damage of infrastructure, and distribution of sediments and suspended materials during flood events. To understand and predict how flood events and associated distribution of pollutants may impact ecosystem and human health, as well as infrastructure, large-scale interdisciplinary collaborative efforts are required, which involve ecotoxicologists, hydrologists, chemists, geoscientists, water engineers, and socioeconomists. The research network "project house water" consists of a number of experts from a wide range of disciplines and was established to improve our current understanding of flood events and associated societal and environmental impacts. The concept of project house and similar seed fund and boost fund projects was established by the RWTH Aachen University within the framework of the German excellence initiative with support of the German research foundation (DFG) to promote and fund interdisciplinary research projects and provide a platform for scientists to collaborate on innovative, challenging research. Project house water consists of six proof-of-concept studies in very diverse and interdisciplinary areas of research (ecotoxicology, water, and chemical process engineering, geography, sociology, economy). The goal is to promote and foster high-quality research in the areas of water research and flood-risk assessments that combine and build off-laboratory experiments with modeling, monitoring, and surveys, as well as the use of applied methods and techniques across a variety of disciplines.
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http://dx.doi.org/10.1186/s12302-017-0121-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5504220PMC
July 2017
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