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Environmental Toxicology and Chemistry

Sunandan Pakrashi, Cheng Tan, Wen-Xiong Wang
In this study, we tested whether the bioaccumulation in specific tissues of Daphnia magna could explain silver nanoparticles (AgNPs) toxicity. Daphnids were exposed to different concentrations of well suspended AgNPs and AgNO3 . The accumulations of Ag in the whole body, guts and non-gut tissues, as well as the mortality of daphnids were recorded over a period of 7 days. Regression analysis showed higher degree of positive correlation between the concentration of Ag in the non-gut tissues than gut tissues and the mortality of the daphnids...
July 19, 2017: Environmental Toxicology and Chemistry
Mark D Jankowski, Murray E Moore, Erik K Hofmeister
West Nile virus is primarily maintained cryptically primarily in avian (Passerine) populations where it is transmitted by Culex spp. mosquitoes. Mosquito control measures currently include physical activities to reduce mosquito breeding sites, the application of mosquito larvicides, or aerosolized insecticides to kill adults (adulticides) when arboviral diseases such as West Nile virus (WNV) or Zika virus are detected in mosquito populations. Organochlorine, organohosphorus, carbamate and pyrethroid insecticides are often used...
July 19, 2017: Environmental Toxicology and Chemistry
Fei Cheng, Huizhen Li, Hongxue Qi, Qian Han, Jing You
The importance of pyrethroids as potential stressors to benthic organisms has gradually become evident in urban creeks, however, the occurrence and toxicity of sediment-associated pyrethroids are rarely studied in large rivers. In this context, ten sediments from a large urban river (Guangzhou reach of the Pearl River in China) were assessed for pyrethroid occurrence and sediment toxicity to the benthic invertebrate Chironomus dilutus. Half of the sediments exhibited lethality to C. dilutus in a 10-d exposure and all survived midges showed significant change of enzymatic activity...
July 19, 2017: Environmental Toxicology and Chemistry
Margaret Whitney, Daniel Cristol
Mercury (Hg) is a ubiquitous environmental contaminant that affects avian reproduction and condition, in both aquatic and terrestrial species. Because Hg binds strongly to the keratin of growing feathers, molt is an important avenue for Hg elimination. We investigated the rate of depuration of Hg from songbird blood and organs (brain, kidney, liver, muscle) as a function of molt. We exposed 2 species of captive songbirds, European starling (Sturnus vulgaris) and zebra finch (Taeniopygia guttata), to environmentally relevant dietary Hg (1...
July 19, 2017: Environmental Toxicology and Chemistry
Jaeshin Kim, Shihe Xu
The accurate understanding of the fate of volatile methylsiloxanes (VMS) in air is crucial in determining persistence and concentrations in the environment. Although oxidation by atmospheric hydroxyl radicals (oOH) is considered as a major degradation mechanism for airborne VMS, the existing bimolecular rate constants with •OH measured and modeled for any given VMS compound varied greatly, depending on the approaches used to generate the data. The objectives of this study were to measure •OH reaction rate constants for four cyclic and four linear VMS based on a relative rate method using a newly designed atmospheric chamber and to establish structure-reactivity relationships for the kinetics...
July 18, 2017: Environmental Toxicology and Chemistry
Jian Li, Li-Yun Ma, Lu-Shuang Li, Li Xu
In this study, the photodegradation of three commonly used non-steroidal anti-inflammatory drugs, ketoprofen (KET), carprofen (CAR) and diclofenac acid (DIC), was conducted under UV irradiation. The kinetic results showed that the studied three pharmaceuticals obeyed to the first-order reaction with the decreasing rate constants of 1.54×10(-4) s(-1) , 5.91×10(-5) s(-1) and 7.78×10(-6) s(-1) for CAR, KET and DIC, respectively. Moreover, the main transformation products (TPs) were identified by ion-pair liquid-liquid extraction combined with injection port derivatization-gas chromatography-mass spectrometer and high performance liquidchromatography-quadrupole-time of flight mass spectrometer analysis...
July 18, 2017: Environmental Toxicology and Chemistry
David Deruytter, Jan M Baert, Nancy Nevejan, Karel A C DE Schamphelaere, Colin R Janssen
Little is known about the effect of metal mixtures on marine organisms, especially when exposed to environmentally realistic concentrations. This information is, however, required to evaluate the need to include mixtures in future environmental risk assessment (ERA) procedures. Here, the effect of Cu-Ni binary mixtures on Mytilus edulis larval development was assessed using a full factorial design that included environmentally relevant metal concentrations and ratios. The reproducibility of the results was assessed by repeating this experiment 5 times...
July 15, 2017: Environmental Toxicology and Chemistry
Ellyn Ritchie, Patrick Boyd, Annamaria Lawson-Halasz, Jalal Hawari, Stacey Saucier, Richard Scroggins, Juliska Princz
Within Canada, screening-level assessments for chemical substances are required in order to determine whether the substances pose a risk to human health and/or the environment, and as appropriate, risk management strategies. In response to the volume of metal and metal-containing substances, process efficiencies were introduced using a metal moiety approach, wherein substances that contain a common metal moiety are assessed simultaneously as a group, wherein the moiety of concern would consist of the metal ion...
July 14, 2017: Environmental Toxicology and Chemistry
Maeva Giraudo, Guillaume Cottin, Marta Esperanza, Pierre Gagnon, Amila O De Silva, Magali Houde
Benzotriazole UV-stabilizers (BZT-UVs) are compounds used in many applications and products to prevent photochemical degradation. Despite their widespread presence in aquatic ecosystems and persistence in the environment, there are very limited data on their effects and toxicity, and their modes of action remain largely unknown. The objectives of this study were to evaluate the chronic effects of two BZT-UVs, 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV-234) and 2-(2H-benzotriazol-2-yl)-4,6-di-tert-pentylphenol (UV-328), on the freshwater green algae Chlamydomonas reinhardtii and the freshwater crustacean Daphnia magna...
July 14, 2017: Environmental Toxicology and Chemistry
Lucas B Thompson, Gerardo L F Carfagno, Kurt Andresen, Andrea J Sitton, Taylor Bury, Laura L Lee, Kevin T Lerner, Peter P Fong
Engineered nanoparticles are aquatic contaminants of emerging concern exerting ecotoxicological effects on a wide variety of organisms. We exposed cetyltrimethylammonium bromide capped spherical gold nanoparticles to wood frog and bullfrog tadpoles with conspecifics and in combination with the other species continuously for 21 days, then measured uptake and localization of gold. Wood frog tadpoles alone and in combination with bullfrog tadpoles took up significantly more gold than bullfrogs. Bullfrog tadpoles in combination with wood frogs took up significantly more gold than controls...
July 13, 2017: Environmental Toxicology and Chemistry
Rachael U Akpiri, Roseline S Konya, Nikolas J Hodges
Sponges are a potential alternative model species to bivalves in pollution biomonitoring and environmental risk assessment in the aquatic ecosystem. Here, a novel in vivo exposure sponge culture model was developed from field collected and cryopreserved sponge (Hymeniacidon perleve) cells to investigate the genotoxic effects of environmentally relevant metals in the laboratory. Sponge cell aggregates were cultured and exposed to non-cytotoxic concentrations (0-0.4 mg/L) of cadmium chloride, nickel chloride, and sodium dichromate as quantified by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide and DNA-strand breaks assessed by the comet assay...
July 10, 2017: Environmental Toxicology and Chemistry
Marie Perkins, Benjamin D Barst, Justine Hadrava, Niladri Basu
Many bird species are exposed to methylmercury (MeHg) at levels shown to cause sub-lethal effects. While MeHg sensitivity and assimilation can vary among species and developmental stages, underlying reasons (such as MeHg toxicokinetics) are poorly understood. We investigated Hg distribution at the tissue and cellular levels in birds by examining Hg speciation in blood, brain, and liver and Hg subcellular distribution in liver. We used MeHg egg injection of white eghorn chicken (Gallus gallus domesticus), sampled at 3 early-developmental stages, and embryonic ring-billed gulls (Larus delawarensis) exposed to maternally-deposited MeHg...
July 10, 2017: Environmental Toxicology and Chemistry
Tyler Frankel, Lance Yonkos, Jack Frankel
The synthetic progestin levonorgestrel (LNG) is commonly utilized as a component of human oral contraceptives. LNG enters the environment as a component of wastewater treatment plant effluent, and has been measured at low ng/L concentrations in surface waters. LNG has been shown to activate fish androgen receptors, causing the physical masculinization of females, changes in reproductive behavior, and decreases in fecundity. In this present study, the effects of LNG exposure on early stage oogenesis in the fathead minnow (Pimephales promelas) was examined...
July 6, 2017: Environmental Toxicology and Chemistry
Shanshan Wang, Ruilian Yu, Gongren Hu, Qichao Hu, Quan Zheng
PM2.5 (particulate matter with diameter ≤ 2.5 µm) is a serious atmospheric pollutant. Composition and source analyses are essential for controlling PM2.5 . Rare earth elements (REEs) have received little attention as a component of PM2.5 . In the present study, PM2.5 samples were collected in urban and suburban areas in Xiamen, and analyzed for REEs. The concentration range of total REEs (∑REE) is 12.07 to 98.45 mg/kg with the mean of 38.53 mg/kg in urban PM2.5 , and 16.44 to 160.62 mg/kg with the mean of 42...
July 3, 2017: Environmental Toxicology and Chemistry
Marco Kraas, Karsten Schlich, Burkhard Knopf, Franziska Wege, Ralf Kägi, Konstantin Terytze, Kerstin Hund-Rinke
The use of silver nanoparticles (AgNPs) in consumer products such as textiles, leads to a discharge of AgNPs into wastewater and consequently to a transfer of the AgNPs to soil ecosystems via biosolids used as fertilizer. In urban wastewater systems (e.g. sewer, wastewater treatment plant (WWTP), anaerobic digesters) AgNPs are efficiently converted into sparingly soluble silver sulfides (Ag2 S), mitigating the toxicity of the AgNPs. However, long-term studies on the bioavailability and effects of sulfidized AgNPs on soil microorganisms are lacking...
July 3, 2017: Environmental Toxicology and Chemistry
Erwan Saouter, Karin Aschberger, Peter Fantke, Michael Z Hauschild, Aude Kienzler, Alicia Paini, Rana Pant, Anita Radovnikovic, Michela Secchi, Serenella Sala
The scientific consensus model USEtox® is developed since 2003 under the auspices of the UNEP-SETAC Life Cycle Initiative as a harmonized approach for characterizing human and freshwater toxicity in life cycle assessment (LCA) and other comparative assessment frameworks. Using physicochemical substance properties, USEtox® quantifies potential human toxicity and freshwater ecotoxicity impacts by combining environmental fate, exposure and toxicity effects information, considering multimedia fate and multi-pathway exposure processes...
July 3, 2017: Environmental Toxicology and Chemistry
Allison S Cardwell, William J Adams, Robert W Gensemer, Eirik Nordheim, Robert C Santore, Adam C Ryan, William A Stubblefield
The chemistry, bioavailability, and toxicity of aluminum (Al) in the aquatic environment is complex and affected by a wide-range of water quality characteristics (pH, hardness, dissolved organic carbon). Data gaps in Al ecotoxicology exist for pH ranges representative of natural surface waters (pH 6-8). To address these gaps, a series of chronic toxicity tests were performed at pH 6 with eight freshwater species, including two fish (Pimephales promelas and Danio rerio); an oligochaete (Aeolosoma sp.); a rotifer (Brachionus calyciflorus); a snail (Lymnaea stagnalis); an amphipod (Hyalella azteca); a midge (Chironomus riparius); and an aquatic plant (Lemna minor)...
July 1, 2017: Environmental Toxicology and Chemistry
Tyler D Hoskins, Maria Dellapina, Michelle D Boone
Studies of endocrine-disrupting contaminants have focused on early-life exposures, but later exposures could impact fitness. We exposed adult frogs (Acris blanchardi) at reproduction to ecologically relevant atrazine concentrations (0, 1, or 10 µg/L) in outdoor arenas. We measured likelihood of breeding and number of resulting tadpoles. Atrazine did not impact probability of breeding nor tadpoles produced, suggesting anuran reproductive success may not be impacted by short-term exposure to low concentrations...
June 28, 2017: Environmental Toxicology and Chemistry
Lia Emi Nakagawa, Alan Roberto Costa, Ricardo Polatto, Cristiane Mazarin do Nascimento, Solange Papini
Residential indoor environments are potential sources of exposure to pyrethroids, which have low acute toxicity to humans but are allergenic and suspected endocrine disruptors. The present study evaluated the persistence of the pyrethroids cypermethrin and beta-cyfluthrin on indoor surfaces and in house dust. Cypermethrin and beta-cyfluthrin were applied and maintained on aluminum foils and in dust samples for 112 d under controlled conditions and for 12 mo in a test house; periodically, they were quantified by high-performance liquid chromatography...
June 22, 2017: Environmental Toxicology and Chemistry
David K DeForest, Robert C Santore, Adam C Ryan, Brian G Church, M Jasim Chowdhury, Kevin V Brix
The US Environmental Protection Agency's (USEPA's) current ambient water quality criteria (AWQC) for lead (Pb) in freshwater were developed in 1984. The criteria are adjusted for hardness, but more recent studies have demonstrated that other parameters, especially dissolved organic carbon (DOC) and pH, have a much stronger influence on Pb bioavailability. These recent studies have been used to support development of a biotic ligand model (BLM) for Pb in freshwater, such that acute and chronic Pb toxicity can be predicted over a wide range of water chemistry conditions...
June 21, 2017: Environmental Toxicology and Chemistry
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