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Environmental Toxicology and Chemistry

Louise Helene Søgaard Jensen, Lars Michael Skjolding, Amalie Thit, Sara Nørgaard Sørensen, Carsten Købler, Kristian Mølhave, Anders Baun
Increasing use of engineered nanoparticles has led to extensive research into their potential hazards to the environment and human health. Cellular uptake from the gut is sparsely investigated and microscopy techniques applied for uptake studies can result in misinterpretations. Various microscopy techniques are used to investigate internalization of 10 nm gold nanoparticles in Daphnia magna gut lumen and gut epithelial cells upon 24h exposure and outline potential artefacts, i.e. high contract precipitates from sample preparation related to these techniques...
November 25, 2016: Environmental Toxicology and Chemistry
August J Steigmeyer, Jiamin Zhang, Jennifer M Daley, Xiaowei Zhang, G Allen Burton
It is difficult to assess the toxicity of a single stressor and establish a strong stressor-causality link when multiple stressors coexist. Toxicity Identification Evaluation (TIE) methodology uses a series of chemical and physical manipulations to fractionate compounds within a matrix and systematically identify potential toxicants. The current EPA application of TIE can provide valuable information, but often lacks ecological realism and is subject to laboratory-related artifacts. An in situ TIE Device (iTIED) was designed to assess the sources of toxicity in aquatic ecosystems...
November 25, 2016: Environmental Toxicology and Chemistry
Austin K Baldwin, Steven R Corsi, Michelle A Lutz, Christopher G Ingersoll, Rebecca Dorman, Christopher Magruder, Matthew Magruder
High concentrations of polycyclic aromatic hydrocarbons (PAHs) in streams can be a significant stressor to aquatic organisms. To understand the likely sources and toxicity of PAHs in Milwaukee-area streams, streambed sediment samples from 40 sites and parking lot dust samples from 6 sites were analyzed for 38 parent PAHs and 25 alkylated PAHs. Diagnostic ratios, profile correlations, principal components analysis, source-receptor modeling, and mass fractions analysis were used to identify potential PAH sources to streambed sediment samples, and land-use analysis was used to relate streambed sediment PAH concentrations to different urban-related land uses...
November 24, 2016: Environmental Toxicology and Chemistry
Jeffrey C Wolf, Gerd Maack
Agencies responsible for environmental protection are tasked with developing regulatory guidance that is based on the best available scientific evidence. Histopathology is a common endpoint in toxicologic bioassays; however, because of the subjective nature of this endpoint, and the advanced level of specialized training required for its effective utilization, the reliability of histopathology data can be inconsistent. Consequently, mechanisms for evaluating such data on a case-by-case basis are needed. The purposes of this review are to describe a methodology that can be used to evaluate the credibility of histopathology findings, and discuss the results of such assessments as applied to real-world data collected from the scientific literature...
November 24, 2016: Environmental Toxicology and Chemistry
Matthew Alloy, Thomas Ross Garner, Kristin Bridges, Charles Mansfield, Michael Carney, Heather Forth, Michelle Krasnec, Claire Lay, Ryan Takeshita, Jeffrey Morris, Shane Bonnot, James Oris, Aaron Roberts
The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions of barrels of crude oil into the Gulf of Mexico. Photo-induced toxicity following co-exposure to ultraviolet (UV) radiation is 1 mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Red drum and speckled seatrout are both important fishery resources in the Gulf of Mexico. They spawn near-shore and produce positively buoyant embryos that hatch into larvae in approximately 24 h. The goal of the present study was to determine whether exposure to UV as natural sunlight enhances the toxicity of crude oil to early lifestage red drum and speckled seatrout...
November 21, 2016: Environmental Toxicology and Chemistry
Mariana Noelia Mardirosian, Cecilia Inés Lascano, Guillermina Azucena Bongiovanni, Andrés Venturino
The Argentinean autochthonous toad Rhinella arenarum was selected to study the chronic toxicity of arsenic and the biochemical responses elicited by exposure to As in water during embryonic and larval development. A significant decrease in the total reactive antioxidant potential and in catalase activity was observed in individuals exposed chronically to sublethal concentrations of As, which is indicative of an oxidative stress situation. However, an antioxidant response was elicited during chronic exposure to As, as evidenced by the increase in endogenous reduced glutathione content and glutathione-related enzymatic activities such as glutathione -S-transferase and reductase...
November 18, 2016: Environmental Toxicology and Chemistry
William J LaBarre, David R Ownby, Kevin J Rader, Steven M Lev, Ryan E Casey
This study evaluated the ability of two different bioretention stormwater control measures (SCMs), planter boxes and swales, to decrease the toxicity of sheet copper (Cu) roofing runoff to Daphnia magna. This study quantified changes in stormwater chemistry as it passed through the bioretention systems. The study also utilized the biotic ligand model (BLM) to assess whether the observed D. magna toxicity could be predicted by observed variations in water chemistry. Laboratory toxicity tests were performed using select storm samples with D...
November 17, 2016: Environmental Toxicology and Chemistry
Sara J Klapstein, Susan E Ziegler, David A Risk, Nelson J O'Driscoll
The present study examined potential effects of seasonal variations in photoreactive dissolved organic matter (DOM) on methylmercury (MeHg) photodemethylation rates in freshwaters. A series of controlled experiments were carried out using natural and photochemically preconditioned DOM in water collected from one lake in June, August, and October. Natural DOM concentrations doubled between June and August (DOC = 10.2-21.2 mg C L(-1) ) and then remained stable into October (DOC = 19.4 mg C L(-1) )...
November 17, 2016: Environmental Toxicology and Chemistry
Laura Murray, Michael D Rennie, Eva C Enders, Kerri Pleskach, Jonathan D Martin
Nanosilver (nAg) is a nanoparticle commonly incorporated into consumer products for its antimicrobial properties that has been detected in aquatic environments. Toxic effects of nAg on fish have been observed and may induce a stress response in fish in the form of increased blood plasma cortisol. In this study, effects of nAg exposure on Rainbow Trout (Oncorhynchus mykiss) were investigated over a 28 d period using blood plasma cortisol concentrations as an indicator of stress. Several morphometric measures (growth, Fulton's condition factor, and hepatosomatic index or HSI) were also taken during the experiment to investigate potential whole-body effects of exposure, and concentrations of nAg in fish muscle tissue were measured...
November 17, 2016: Environmental Toxicology and Chemistry
Frank A P C Gobas, S Victoria Otton, Laura F Tupper-Ring, Meara A Crawford, Kathryn E Clark, Michael G Ikonomou
This study applies a chemical activity-based approach to (i) evaluate environmental concentrations of di-ethylhexyl phthalate (DEHP) (n = 23,651) and its metabolite mono-ethylhexyl phthalate (MEHP) (n = 1,232) in 16 environmental media from 1,174 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 USEPA's Toxicity Forecaster (ToxCast) and other sources; and (ii) conduct a comprehensive environmental risk analysis...
November 17, 2016: Environmental Toxicology and Chemistry
Garth Herring, Collin A Eagles-Smith, Joshua T Ackerman
Variation in avian bilateral symmetry can be an indicator of development instability in response to a variety of stressors, including environmental contaminants. We used composite measures of fluctuating asymmetry to examine the influence of mercury concentrations in two tissues on fluctuating asymmetry within four waterbird species. Fluctuating asymmetry increased with mercury concentrations in whole blood and breast feathers of Forster's terns (Sterna forsteri), a species with elevated mercury concentrations...
November 16, 2016: Environmental Toxicology and Chemistry
Valeria Di Nica, Sara Villa, Antonio Finizio
The combined toxicities of binary mixtures of veterinary pharmaceuticals active compounds (PhACs) were examined using the bioluminescent bacterium Aliivibrio fischeri as a test organism (Microtox® test). Mixtures were prepared at an equitoxic ratio that corresponded to the IC10 of individual PhACs. In addition, we determined the toxicity of a multi-component mixture that contained all of the investigated PhACs mixed at the ratio corresponding to their individual values of Predicted No Effect Concentrations (PNEC)...
November 16, 2016: Environmental Toxicology and Chemistry
Lauren E Sweet, Jason Magnuson, T Ross Garner, Matthew M Alloy, John D Stieglitz, Daniel Benetti, Martin Grosell, Aaron P Roberts
The Deepwater Horizon oil spill in 2010 overlapped with the spawning of many pelagic fish species in the Gulf of Mexico, including mahi-mahi (Coryphaena hippurus). Polycyclic aromatic hydrocarbons (PAHs) released during the spill have been shown to cause photo-induced toxicity under ultraviolet (UV) radiation. In the present study, mahi-mahi embryos were exposed to high-energy water accommodated fractions of source and naturally weathered oils for up to 48 h. The timing of co-exposure with UV radiation varied between an early development exposure for 8 h or a late development exposure for 8 h...
November 16, 2016: Environmental Toxicology and Chemistry
Andreia C M Rodrigues, Carlos Gravato, Carla Quintaneiro, Maria D Bordalo, Oksana Golovko, Vladimír Žlábek, Carlos Barata, Amadeu M V M Soares, João L T Pestana
Caddisflies have been included in ecotoxicological studies due to their sensitivity and ecological relevance. The present study aimed to assess the sub-lethal effects of an anthranilic diamide insecticide, chlorantraniliprole (CAP), to Sericostoma vittatum. CAP, used worldwide, is a persistent compound that has been found in surface waters at concentrations from 0.1 to 9.7 µg/L. CAP targets the ryanodine receptors and this ecotoxicological assessment was focused on biomarkers related to neurotransmission, biotransformation, oxidative stress damage and on energy processing related endpoints (feeding, energy reserves and cellular metabolism)...
November 10, 2016: Environmental Toxicology and Chemistry
Ève A M Gilroy, Patricia L Gillis, Laura E King, Nicholas A Bendo, Joseph Salerno, Marina Giacomin, Shane R de Solla
The toxicity and bioconcentration of three pharmaceuticals (amitriptyline, iopamidol and sertraline) were examined using multiple life stages (larval, juvenile, and adult) of the unionid mussel Lampsilis siliquoidea. The endpoints examined varied with life stage, but included survival, behavior (algal clearance rate, filtering frequency), and oxidative stress. Iopamidol was not toxic at concentrations up to 101 mg/L. Sertraline was the most toxic chemical (LC/EC50 = 0.02-0.04 mg/L), but exposure did not induce oxidative stress...
November 10, 2016: Environmental Toxicology and Chemistry
Frances J Alexander, Catherine K King, Amanda J Reichelt-Brushett, Peter L Harrison
The risk of a major marine fuel spill in Antarctic waters is increasing, yet there are currently no standard or suitable response methods under extreme Antarctic conditions. Fuel dispersants may present a possible solution, however little data exist on the toxicity of dispersants or fuels to Antarctic species, thereby preventing informed management decisions. Larval development toxicity tests using 3 life history stages of the Antarctic sea urchin Sterechinus neumayeri were completed to assess the toxicity of physically dispersed, chemically dispersed and dispersant only water accommodated fractions of an intermediate fuel oil (IFO 180) and the chemical dispersant Slickgone NS...
November 4, 2016: Environmental Toxicology and Chemistry
Georgina Guzmán-Rangel, Liske Versieren, Hao Qiu, Erik Smolders
Zinc (Zn) and arsenic (As) are typically present as mixed contaminants in mining-impacted areas, however, their joined effects have rarely been evaluated. The present study was set-up to test if Zn(2+) and H2 AsO4(-) (further: As) mixture toxicity to plants is additive or if interactions occur. Barley (Hordeum vulgare) root elongation was measured in resin buffered nutrient solutions. The design included ranges of single element concentrations and combinations at three different Ca(2+) concentrations (0.5, 2...
November 3, 2016: Environmental Toxicology and Chemistry
Michael B Griffith
Anthropogenic sources increase freshwater (FW) salinity and produce differences in constituent ions compared to natural waters. Moreover, ions differ in physiological roles and concentrations in intracellular (IC) and extracellular (EC) fluids. Four FW taxa groups are compared to investigate similarities and differences in ion transport processes and what ion transport mechanisms suggest about the toxicity of these or other ions in FW. Although differences exist, many ion transporters are functionally similar and may belong to evolutionarily conserved protein families...
November 3, 2016: Environmental Toxicology and Chemistry
Wolfgang Larisch, Trevor N Brown, Kai Uwe Goss
In the scientific field of physiologically based Toxicokinetic (PbTk) modeling the complexity of the model used depends on the complexity of the problem leading to a broad range of existing models from simple one-box-models to complex multi compartment-models. Most of these models work with lumped parameters, for example an uptake efficiency parameter, which can only be obtained with a fit of experimental data. The authors' goal was a model that is completely based on well defined physiological and physicochemical parameters...
November 3, 2016: Environmental Toxicology and Chemistry
Rodrigo Orrego, Craig B Milestone, L Mark Hewitt, John Guchardi, Tatiana Heid-Furley, Alison Slade, Deborah L MacLatchy, Douglas Holdway
This study examined the potential of pulp mill effluent from pulp producing countries (Canada, Brazil, New Zealand) to affect fish reproduction. Specifically, the estrogenic effects in juvenile rainbow trout (Oncorhynchus mykiss) pulse-exposed to 11 different mill effluent extracts (intra peritoneal IP-injections of SPE-DCM non-polar fraction). The results indicated that effluent extracts were estrogenic in juvenile trout irrespective of the gender, reflected by increasing level of plasma vitellogenin (VTG) (Brazil > New Zealand > Canada)...
November 3, 2016: Environmental Toxicology and Chemistry
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