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Environmental Toxicology and Chemistry

Monizze Vannuci-Silva, Solange Cadore, Theodore B Henry, Gisela de A Umbuzeiro
Upon release into surface waters, engineered silver nanoparticles (AgNP) tend to settle to sediments and, consequently, epibenthic fauna will be exposed to them through the diet. We established Ag uptake and accumulation profiles over time in the haemolymph of a marine amphipod fed with a formulated feed containing AgNP or AgCl. Silver bioavailability was higher in organisms exposed to AgNP, indicating that the nanoparticles pose a higher risk of toxicity compared to similar concentrations of AgCl. This article is protected by copyright...
January 14, 2019: Environmental Toxicology and Chemistry
Stela S Kutsarova, Darina G Yordanova, Yordan Karakolev, Stoyanka Stoeva, Mike Comber, Christopher B Hughes, Eleni Vaiopoulou, Sabcho D Dimitrov, Ovanes G Mekenyan
Substances of unknown or variable composition, complex reaction products and biological materials (UVCBs) comprise about 40% of all registered substances submitted to the European Chemicals Agency. One of the main characteristics of UVCBs is that they have no unique representation. Industry scientists who are part of the scientific community have been working with academics and consultants to address the problem of a lack of a defined structural description. It has been acknowledged that one of the obstacles is the large number of possible structural isomers...
January 14, 2019: Environmental Toxicology and Chemistry
Ralf Dittrich, Benedikt Giessing, María M Benito, Anja Ruß, Christian Wolf, Manousos Foudoulakis, Steve Norman
The relationship between agricultural practices and the welfare of wild birds has gained increased attention over the last decades. To assess potential effects of chlorpyrifos (CHP) on the bird community, a multi-year multi-site monitoring program was carried out in treated pome orchards (UK) and treated citrus orchards (Spain). Constant-effort mist netting was conducted during several consecutive years in UK (2012-2014) and Spain (2010-2012). The general structure of the bird community and the presence of breeding species were analysed...
January 9, 2019: Environmental Toxicology and Chemistry
Rebecca Zitoun, Christel Hassler, Susan J Clearwater, Karen J Thompson, Anathea Albert, Sylvia G Sander
The production of accurate and reliable data on metal toxicity during ecotoxicological bioassays is important for credible environmental risk-assessments and management in aquatic environments. Actual measurements and reporting of contaminant concentrations in bioassays are, however, often disregarded and potential contaminant loss due to adsorption processes (e.g., wall-adsorption) in bioassays are widely omitted, which can have detrimental effects on calculated metal toxicity thresholds. In this study we assessed copper (Cu) mass-balance during a standard 48-h bioassay test with blue mussel (Mytilus galloprovincialis) embryos to evaluate effects on calculated toxicity endpoints...
January 9, 2019: Environmental Toxicology and Chemistry
Andrea Ridošková, Aurélie Pelfrêne, Francis Douay, Pavlína Pelcová, Vendula Smolíková, Vojtěch Adam
We assessed the relationship between the diffusive gradient in thin film (DGT) technique using the new ion-exchange resin Ambersep GT74 and the uptake of mercury (Hg) by a model plant cultivated on metal-contaminated agricultural soils under greenhouse conditions. Based on the total Hg content, 0.37 to 1.17% of the Hg passed to the soil porewater from the solid phase, and 2.18 to 9.18% of the Hg is DGT-available. These results were confirmed by calculating the R value (the ratio of the concentrations of bioavailable Hg measured by DGT and soil solution), which illustrated the strong bonding of Hg to the solid phase of soil and its extremely low mobility...
January 8, 2019: Environmental Toxicology and Chemistry
Jane M Rawlings, Scott E Belanger, Kristin A Connors, Gregory J Carr
A database was compiled for algal (OECD 201 Test Guideline [TG]), Daphnia magna (OECD 202 TG), acute fish toxicity (AFT, OECD 203 TG), and fish embryo toxicity (FET, OECD 236 TG) to assess the suitability and applicability of the FET in a threshold approach context. In the threshold approach, algal and Daphnia toxicity are assessed first after which a limit test is conducted at the lower of the two toxicity values using fish. If potential fish toxicity is indicated, a full LC50 assay is performed. This tiered testing strategy can significantly reduce the number of fish used in toxicity testing as algae or Daphnia are typically more sensitive than fish...
January 7, 2019: Environmental Toxicology and Chemistry
Stephanie Walsh, Isabelle Gosselin, David Lee, Marilyne Stuart
The objective of this study was to establish a culture of Hyalella azteca (H. azteca) that could be used for laboratory toxicity testing in low ionic strength waters with electrical conductivities of less than 200 µS/cm. A wild strain of H. azteca was collected from Twin Lake (TL), a small seepage lake with an electrical conductivity of 81 ± 27 µS/cm located on the property of Chalk River Laboratories (CRL) in Chalk River, Canada. To determine the minimum aqueous ion requirements for an optimal culturing medium for the TL strain, TL was monitored for water quality and ionic content over four years...
January 7, 2019: Environmental Toxicology and Chemistry
Jessica A Head, Sean W Kennedy
Exposure to dioxin-like compounds (DLCs) is consistently associated with concentration-dependent induction of cytochrome P4501A (CYP1A) enzymes in primary cultures of avian hepatocytes. We have previously demonstrated that the median effective concentration (EC50) for induction of this response is predictive of in vivo sensitivity to dioxin-like compounds in birds. Here we investigate sources of interindividual variation in the CYP1A response to TCDD in wild herring gulls, and consider how this variation may complicate dioxin sensitivity estimates based on the CYP1A bioassay...
January 7, 2019: Environmental Toxicology and Chemistry
Fan Wu, Bryan J Harper, Stacey L Harper
Potential differences in species susceptibility to nanoparticle (NP) contaminants make the use of multi-species community toxicity testing strategies beneficial in understanding NP risk to aquatic environments. Due to the limited knowledge of zinc oxide (ZnO) NPs fate and toxicity, we conducted multi-species exposures and compared the responses of individual species to the same species in a community comprised of algae (Chlamydomonas reinhardtii), bacteria (Escherichia coli), crustaceans (Daphnia magna), and zebrafish (Danio rerio)...
January 7, 2019: Environmental Toxicology and Chemistry
Mohammed A Khairy, Gregory O Noonan, Rainer Lohmann
The bioavailability and bioaccumulation of sedimentary hydrophobic organic compounds (HOCs) is of concern at contaminated sites. Passive samplers have emerged as a promising tool to measure the bioavailability of sedimentary HOCs and possibly to estimate their bioaccumulation. We thus analyzed HOCs including organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) in sediment, porewater and riverwater using low density polyethylene (LDPE) passive samplers, and in 11 different finfish species and blue crab from the lower Passaic River...
January 5, 2019: Environmental Toxicology and Chemistry
Hui Zhang, Zhi-Feng Chen, Zenghua Qi, Shi-Chao Yan, Wen-Wen Wei, Guoguang Liu, Zongwei Cai
Climbazole is an antifungal active ingredient used in personal care products. After application, this chemical reaches the aquatic environment and may pose a risk to fish. Here, we measured the transcriptional effects of essential genes related to a wide range of signaling pathways on zebrafish eleutheroembryos exposed to climbazole at environmentally relevant and predicted worst-case environmental concentrations, and explored the potential biomarkers via partial least squares discriminant analysis. Transcription analysis covering up to 73 genes revealed significant down-regulation of circadian rhythm- and steroidogenesis-related genes in zebrafish embryos-larvae after exposure to environmentally relevant concentrations of climbazole...
January 5, 2019: Environmental Toxicology and Chemistry
Kyle S Roush, Marlo K Sellin Jeffries
The presence of reproductive endocrine disrupting compounds (REDCs) in the environment poses a potential threat to fish and wildlife, as exposures are capable of altering sexual development, reproductive success and behavior. Fish-based screening assays are often utilized to screen for the presence of REDCs in surface waters and to assess single chemicals for potential endocrine disrupting activity. In an effort to improve such screening assays, the goal of this project was to determine whether GSI of female fathead minnows (Pimephales promelas), as assessed via external characteristics, influences their response to REDC exposure...
January 5, 2019: Environmental Toxicology and Chemistry
Cecília M S Pereira, Ronny Blust, Karel A C De Schamphelaere
It is well-known that temperature can affect the ecotoxicity of chemicals, including metals, to aquatic organisms. It was recently reported that nickel (Ni), a priority substance under the European Water Framework directive, showed decreasing chronic toxicity to Daphnia magna with increasing temperature, between 15°C and 25°C. Here, we performed a toxicokinetic study to contribute to an increased mechanistic understanding of this effect. More specifically, we investigated the effect of temperature on Ni uptake and elimination in D...
January 5, 2019: Environmental Toxicology and Chemistry
Amelie Schmolke, Farah Abi-Akar, Silvia Hinarejos
Discerning potential effects of insecticides on honey bee colonies in field studies conducted under realistic conditions can be challenging due to concurrent interactions with other environmental conditions. Honey bee colony models can control exposures and other environmental factors, as well as assess links among pollen and nectar residues in the landscape, their influx into the colony, and the resulting exposures and effects on bees at different developmental stages. We extended the colony model BEEHAVE to represent exposure to clothianidin via residues in pollen from treated corn fields set in real agricultural landscapes in the Midwest of the Unites States...
December 21, 2018: Environmental Toxicology and Chemistry
Yuxuan Zhang, Peiyong Guo, Yanmei Wu, Xiaoyan Zhang, Meixian Wang, Simin Yang, Yinshi Sun, Jun Deng, Haitao Su
Phenicol antibiotics, such as chloramphenicol (CAP), thiamphenicol (TAP) and florfenicol (FLO), are commonly used in the veterinary and aquaculture fields to treat diseases and have been frequently detected in aquatic environments. Nevertheless, there is limited information regarding the effects of phenicol antibiotics on aquatic non-target species. Thus, the present study aims to investigate the long-term (21-d) influence on the reproduction and growth of and the acute (24-h) oxidative response and tissue damage in the crustacean Daphnia magna after exposure to phenicol drugs, including their environmental concentrations...
December 20, 2018: Environmental Toxicology and Chemistry
Ellen D G Michiels, Lucia Vergauwen, Foon Yin Lai, Raewyn M Town, Adrian Covaci, Alexander L N van Nuijs, Steven J Van Cruchten, Dries Knapen
Fish (embryo) toxicity test guidelines are mostly based on aquatic exposures. However, in some cases, other exposure routes can be more practical and relevant. Micro-injection into the yolk of fish embryos could offer a particular advantage for administering hydrophobic compounds, such as many endocrine disruptors. Single dose micro-injection was compared to continuous aquatic exposure in terms of compound accumulation and biological responses. 17α-ethinyl estradiol (EE2) was used as a model compound. First, the optimal solvent and droplet size were optimized, and needle variation was assessed...
December 20, 2018: Environmental Toxicology and Chemistry
David R Mount, Russell J Erickson, Brandy B Forsman, Terry L Highland, J Russell Hockett, Dale J Hoff, Correne T Jenson, Teresa J Norberg-King
In previous work we intensively studied the acute responses of the cladoceran, Ceriodaphnia dubia, to major geochemical ions (Na+ , K+ , Ca2+ , Mg2+ , Cl- , SO4 2- , and HCO3 - /CO3 2- ), culminating in the development of models to predict acute toxicity from ionic composition. To quantitatively evaluate whether the toxicological behavior of major ions observed for C. dubia extends to chronic toxicity, we conducted 58 chronic toxicity tests with individual major salts and binary mixtures thereof. Chronic responses paralleled those demonstrated previously for acute exposure, specifically: 1) similar relative toxicity of individual salts; 2) different Na salts showing similar potency when exposure is expressed as osmolarity; 3) toxicity of Mg, Ca, and K salts related to cation activity; 4) decreased toxicity of Na and Mg salts when Ca activity is increased at less than toxic concentrations; 5) additive behavior for salt mixtures sharing a common cation; and 6) independent behavior for salt mixtures with dissimilar cations, except Mg/Ca mixtures which appeared additive...
December 20, 2018: Environmental Toxicology and Chemistry
Leslie J Saunders, Simon Fontanay, John W Nichols, Frank A P C Gobas
In vitro biotransformation studies were performed to support the bioaccumulation assessment of three hydrophobic organic ultraviolet filters (UVFs), 4-methylbenzylidene camphor (4-MBC), 2-ethylhexyl-4-methoxycinnamate (EHMC), and octocrylene (OCT). In vitro depletion rate constants (kdep ) were determined for each UVF using rainbow trout liver S9 fractions. Incubations performed with and without added cofactors showed complete (4-MBC) or partial (EHMC and OCT) dependence of kdep on NADPH addition, suggesting that hydrolysis of EHMC and OCT by NADPH-independent enzymes (e...
December 20, 2018: Environmental Toxicology and Chemistry
Kevin Cailleaud, Anne Bassères, Clémentine Gelber, J F Postma, A T M Ter Schure, P E G Leonards, A D Redman, G F Whale, M J Spence, M Hjort
Hazard assessment of refinery effluents is challenging due to their compositional complexity. Therefore, a weight of evidence approach using a combination of tools is often required. Previous research has focused on several predictive tools ranging from sophisticated chemical analyses - biomimetic extraction to quantify the potentially bioaccumulative substances (PBS), two dimensional gas chromatography (GCxGC), modelling approaches to link oil composition to toxicity (PETROTOX) and Whole Effluent Toxicity (WET) assessments using bioassays...
December 19, 2018: Environmental Toxicology and Chemistry
Benjamin D Barst, Paul E Drevnick, Derek C G Muir, Nikolaus Gantner, Michael Power, Günter Köck, Nathalie Chéhab, Heidi Swanson, Frank Rigét, Niladri Basu
Non-anadromous forms of Arctic char (Salvelinus alpinus), those that are restricted to lakes and rivers, typically have higher mercury concentrations than anadromous forms that migrate to and from the sea. Using tissue burden data from the literature and our own analyses, we performed a screening-level risk assessment of methylmercury for non-anadromous Arctic char. Our assessment included 1569 fish distributed across 83 sites. Site-specific mean total mercury concentrations in non-anadromous Arctic char muscle varied considerably from 0...
December 18, 2018: Environmental Toxicology and Chemistry
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