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Environmental Toxicology and Chemistry

Svetlana Dolgova, Brian N Popp, Kevin Courtoreille, Rick H M Espie, Bruce Maclean, Mark McMaster, Jason R Straka, Gerald R Tetreault, Steve Wilkie, Craig E Hebert
Levels of biomagnifying contaminants are greatest in high trophic level biota, e.g. predatory birds such as gulls. Gull eggs have been used to assess contaminant spatial patterns and sources but such assessments must consider how organism trophic position may influence spatial inferences. Stable nitrogen isotopes (δ 15 N) in bulk tissue are routinely used in this context. However, bulk δ 15 N values are only useful if spatial differences in baseline δ 15 N values are considered. Amino acid-compound specific stable nitrogen isotope analysis (AA-CSIA) can generate estimates of baseline and trophic position δ 15 N from the same sample...
February 15, 2018: Environmental Toxicology and Chemistry
David K DeForest, Robert W Gensemer, Joseph W Gorsuch, Joseph S Meyer, Robert C Santore, Burt K Shephard, Jean M Zodrow
There is concern 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 to biotic ligand model (BLM)-based estimated chronic limits (ECL values, which are EC20 values [20% effect concentrations] for the embryo-larval life stage of the blue mussel [Mytilus edulis]-a sensitive saltwater species to Cu that has historically been used to derive saltwater Cu criteria)...
February 14, 2018: Environmental Toxicology and Chemistry
Carly J Nowicki, Donna R Kashian
Dreissenid mussels, Dreissena bugensis (quagga mussel) and D. polymorpha (zebra mussel), are prolific invasive species to the freshwaters of the United States and Western Europe. In the Great Lakes, D. polymorpha initially dominated the system since their invasion in the mid-1980 s; however, recently D. bugensis has displaced D. polymorpha as the dominant species. Dreissena bugensis has several competitive advantages over D. polymorpha, including greater tolerances to deeper and colder waters and lower respiration rates...
February 14, 2018: Environmental Toxicology and Chemistry
Changhui Liu, Karina Yew-Hoong Gin
The immunotoxicity of 4 commonly detected perfluoroalkyl substances (PFASs), namely, perfluorooctanesulfonate (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorodecanoic acid (PFDA) was investigated by measuring biomarkers of the immune profile of green mussels, Perna viridis. The biomarkers included neutral red retention, phagocytosis, and spontaneous cytotoxicity, all of which were tested on mussel hemocytes. Hemocytes are an important component of the invertebrate immune system...
February 5, 2018: Environmental Toxicology and Chemistry
Rebecca R Philipps, Xiaoyu Xu, Gary L Mills, Robert B Bringolf
Using a coupled method of Diffusive Gradients in Thin-films (DGT) exposure with aquatic organism bioassays, we assessed the use of DGT as a tool for estimating copper (Cu) bioavailability in contaminated waters. DGT accumulated Cu fraction could possibly be used as a surrogate for other assessments of metal bioavailability. Cu concentrations in fathead minnow (Pimephales promelas) and yellow lampmussel (Lampsilis cariosa) soft tissue were compared with DGT accumulated Cu after two, four, and six days of exposure to a Cu concentration series in static, water-only assays...
February 5, 2018: Environmental Toxicology and Chemistry
Justine-Anne Rowell, Marc-Alexandre Fillion, Scott Smith, Kevin J Wilkinson
As technological interest and environmental emissions of the rare earth elements (REE) increase, it is becoming more important to assess their potential environmental impact. Samarium (Sm) is a lanthanide of intermediate molar mass that is used in numerous high technology applications including wind turbines, solar panels and electric vehicles. The present study relates the speciation of samarium (Sm) determined in the presence of natural organic matter (NOM) to its bioavailability to the unicellular green alga, Chlamydomonas reinhardtii...
February 3, 2018: Environmental Toxicology and Chemistry
Maria D Pavlaki, Rui G Morgado, Amadeu M V M Soares, Ricardo Calado, Susana Loureiro
The present study assessed cadmium uptake and depuration rates in the euryhaline estuarine shrimp Palaemon varians under different exposure routes. Postlarval shrimp were exposed for four days under different exposure routes; through contaminated water, contaminated diet and a two-way exposure scenario where both contaminated water + diet were used. After exposure, postlarval shrimp were transferred to a clean medium and fed a non-contaminated diet for 96 h. Bioaccumulation via the different exposure routes was modeled with a standard first-order one-compartment toxicokinetics model and one with an additional parameter reflecting an inert fraction or storage compartment...
February 1, 2018: Environmental Toxicology and Chemistry
Jiamin Wan, Yongman Kim, Martin J Mulvihill, Tetsu K Tokunaga
It is commonly true that a diluted colloidal suspension is more stable over time than a concentrated one, because dilution reduces collision rates of the particles, therefore delays formation of aggregates. However, this generalization does not apply for some engineered ligand-coated nanoparticles (NPs). We observed the opposite relationship between stability and concentration of NPs. We tested four different types of NPs; CdSe-11-mercaptoundecanoic acid, CdTe-polyelectrolytes, Ag-citrate, and Ag- polyvinylpirrolidone...
January 25, 2018: Environmental Toxicology and Chemistry
Sebastian Kampe, Ralf Kaegi, Karsten Schlich, Claus Wasmuth, Henner Hollert, Christian Schlechtriem
Silver nanoparticles (AgNPs) are efficiently converted during the wastewater treatment process into sparingly soluble silver sulfides (Ag2 S). In several countries, sewage sludge is used as a fertilizer in agriculture. The bioavailability of sulfidized silver to the terrestrial isopod Porcellio scaber was investigated. Sewage sludge containing transformed AgNP was obtained from a lab-scale sewage treatment plant operated according to guideline OECD 303a. The results of transmission electron microscopy with energy dispersive x-ray of sludge samples suggest that AgNP were completely transformed to Ag2 S...
January 24, 2018: Environmental Toxicology and Chemistry
Angel Belles, Christine Franke, Claire Alary, Yann Aminot, James W Readman
The diffusivity of 145 compounds in polydimethylsiloxane (PDMS) material was determined in the laboratory using a film stacking technique. The results of this study were pooled with available literature data providing a final data set of 198 compounds with diffusivity (DPDMS ) spanning over ∼5 log units. The principal variables controlling the diffusivity of penetrants are investigated by comparing DPDMS within and between different homologous series. The dipole moment, molecular size and flexibility of penetrants appear to be the most prevalent factors controlling compounds diffusivity...
January 23, 2018: Environmental Toxicology and Chemistry
Joy A McGrath, Christopher J Fanelli, Dominic M Di Toro, Thomas F Parkerton, Aaron D Redman, Miriam Leon Paumen, Mike Comber, Charles V Eadsforth, Klaas den Haan
The Target Lipid Model (TLM) has been previously applied to predict the aquatic toxicity of hydrocarbons and other non-ionic organic chemicals and for deriving HC5 values, concentrations above which 95% of species should be protected. Several concerns were identified with the TLM-derived HC5 when applied in a substance risk assessment context. These shortcomings were addressed by expanding the acute and chronic toxicity databases to include more diverse taxonomic groups and increase the number of species. The TLM was recalibrated with these expanded databases resulting in critical target lipid body burdens and acute-to-chronic ratios that met the required guidelines for using species sensitivity distributions in substance risk assessment...
January 20, 2018: Environmental Toxicology and Chemistry
Greg J Carr, A John Bailer, Jane M Rawlings, Scott E Belanger
The fish acute toxicity test method is foundational to aquatic toxicity testing strategies, yet the literature lacks a concise sample size assessment. While various sources address sample size, historical precedent seems to play a larger role than objective measures. Here, a novel and comprehensive quantification of the effect of sample size on estimation of the LC50 is presented, covering a wide range of scenarios. The results put into perspective the practical differences across a range of sample sizes, from N = 5/concentration up to N = 23/concentration...
January 19, 2018: Environmental Toxicology and Chemistry
Stefan Scholz, Rene Schreiber, James Armitage, Philipp Mayer, Beate I Escher, Annegret Lidzba, Marc Léonard, Rolf Altenburger
Fish early life stage (FELS) tests (OECD test guideline 210) are widely conducted to estimate chronic fish toxicity. In these tests, fish are exposed from the embryonic to the juvenile life stage. In order to analyse whether certain modes of action are related to high toxic ratios (TR, i.e., ratios between experimental effect and baseline toxicity) and/or acute-to-chronic ratios (ACR) in the FELS test effect concentrations for 183 compounds were extracted from the US EPA ecotoxicity database. Analysis of effect concentration of narcotic compounds indicated that baseline toxicity could be observed in the FELS test at similar concentrations as in acute fish toxicity test...
January 19, 2018: Environmental Toxicology and Chemistry
Cynthia D Franci, Angelika Aleksieva, Emily Boulanger, Jonas Brandenburg, Theresa Johnston, Asya Malinova, Jessica A Head
Birds are receptors of concern for polycyclic aromatic hydrocarbons (PAHs), and yet limited data describing the relative potency of PAH congeners are available for avian species. Here, we determine embryonic LD50 values for 5 PAH congeners in chicken (Gallus gallus) and one PAH congener in Japanese quail (Coturnix japonica). Graded concentrations of each test compound were injected into the air cell of chicken or quail eggs before incubation. Embryos were monitored through development (quail) or hatching (chicken)...
January 19, 2018: Environmental Toxicology and Chemistry
Joseph S Meyer, David K DeForest
A meta-analysis was conducted of studies that reported behavior and chemo/mechanosensory responses by fish, amphibians, and aquatic invertebrates in Cu-containing waters and also reported sufficient water chemistry for calculation of hardness-based and biotic ligand model (BLM)-based water quality criteria (WQC) for Cu. The calculated WQC concentrations were then compared to the corresponding 20% impairment concentrations (IC20) of Cu for those behavior and chemo/mechanosensory responses. The hardness-based acute and chronic WQC for Cu would not have been protective (i...
January 17, 2018: Environmental Toxicology and Chemistry
Craig E Hebert, Brian N Popp
Temporal trends in levels of biomagnifying contaminants, such as mercury (Hg), in top predators can provide insights into changes in contaminant bioavailability through time. However, interpreting contaminant temporal trends in predators can be confounded by temporal changes in their diets which, in turn, could affect organism trophic position and exposure to biomagnifying contaminants. To address this issue, bulk stable nitrogen isotope analysis, i.e. analysis of whole tissue, is widely incorporated into contaminant monitoring programs for the estimation of organism trophic position...
January 17, 2018: Environmental Toxicology and Chemistry
Mohd Anuar Mohd Firdaus, Annika Agatz, Mark E Hodson, Omar S A Al-Khazrajy, Alistair B A Boxall
Nanopesticides are novel plant protection products offering numerous benefits. As nanoparticles behave differently from dissolved chemicals, environmental risks of these materials could differ from conventional pesticides. Here we used soil-earthworm systems to compare the fate and uptake of analytical grade bifenthrin to that of bifenthrin in traditional and nano-encapsulated formulations. Apparent sorption coefficients for bifenthrin in the nano-treatments were up to 3.8 times lower than in the non-nano treatments whereas dissipation half-lives of the nano-treatments were up to two time longer...
January 17, 2018: Environmental Toxicology and Chemistry
Amelie Schmolke, Richard Brain, Pernille Thorbek, Daniel Perkins, Valery Forbes
Extrapolating from organism-level endpoints, as generated from standard pesticide toxicity tests, to populations is an important step in threatened and endangered species risk assessments. We apply a population model for a threatened herbaceous plant species, Boltonia decurrens, to estimate the potential population-level impacts of 3 herbicides. We combine conservative exposure scenarios with dose-response relationships for growth and survival of standard test species, and apply those in the species-specific model...
January 17, 2018: Environmental Toxicology and Chemistry
Amanda E Poste, Mikhail V Pastukhov, Hans Fredrik Veiteberg Braaten, Ted Ozersky, Marianne Moore
Despite global efforts to reduce anthropogenic mercury (Hg) emissions, the timescale and degree to which Hg concentrations in the environment and biota respond to decreased emissions remains challenging to assess or predict. Here we characterize long-term trends, life-history patterns in Hg accumulation and toxicological implications of Hg contamination for a freshwater seal from one of the world's largest lakes (Lake Baikal, Siberia) using contemporary tissues and archival teeth. Stable isotope analysis and Hg analyses of soft tissues (muscle, liver, kidney, blood, brain, heart) and teeth from 22 contemporary seals revealed rapid changes in diet and Hg accumulation in the first year of life with a stable diet and increase in tissue Hg throughout the rest of life...
January 17, 2018: Environmental Toxicology and Chemistry
Melanie Raby, Monica Nowierski, Dmitri Perlov, Xiaoming Zhao, Chunyan Hao, David G Poirier, Paul K Sibley
Neonicotinoids are a group of insecticides commonly used in agriculture. Due to their high water solubility, neonicotinoids can be transported to surface waters and have the potential to be toxic to aquatic life. The present study assessed and compared the acute (48 or 96 h) toxicity of 6 neonicotinoids (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, and thiamethoxam) to 21 laboratory-cultured and field-collected aquatic invertebrates spanning 10 aquatic arthropod orders. Test conditions mimicked species' habitat, with lentic taxa exposed under static conditions, and lotic taxa using recirculating exposure systems...
January 16, 2018: Environmental Toxicology and Chemistry
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