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Environmental Toxicology and Chemistry

Douglas B Sponsler, Reed M Johnson
The role of pesticides in recent honey bee losses is controversial, partly because field studies often fail to detect effects predicted by laboratory studies. This dissonance highlights a critical gap in the field of honey bee toxicology: there exists little mechanistic understanding of the patterns and processes of exposure that link honey bees to pesticides in their environment. We submit that 2 key processes underlie honey bee pesticide exposure: (1) the acquisition of pesticide by foraging bees and (2) the in-hive distribution of pesticide returned by foragers...
October 21, 2016: Environmental Toxicology and Chemistry
Cheng-Shiuan Lee, Nicholas S Fisher
Methylmercury (MeHg) is known to biomagnify in marine food chains, resulting in higher concentrations in upper trophic level animals than their prey. To better understand how marine copepods, an important intermediate between phytoplankton and forage fish at the bottom of the food chain, assimilate and release MeHg, we performed a series of laboratory experiments using the gamma-emitting radiotracer (203) Hg(2+) and Me(203) Hg with the calanoid copepod Acartia tonsa. Assimilation efficiencies (AEs) of Hg(2+) and MeHg ranged from 25 to 31% and 58 to 79%, respectively, depending on algal diets...
October 20, 2016: Environmental Toxicology and Chemistry
Daniel Esler, Brenda E Ballachey, Lizabeth Bowen, A Keith Miles, Rian D Dickson, John D Henderson
The authors quantified hepatic hydrocarbon-inducible cytochrome P4501A (CYP1A) expression, as ethoxyresorufin-O-deethylase (EROD) activity, in wintering harlequin ducks (Histrionicus histrionicus) captured in Prince William Sound, Alaska, during 2011, 2013, and 2014 (22 to 25 years following the 1989 Exxon Valdez oil spill). EROD activity was compared between birds from areas oiled by the spill and those from nearby unoiled areas. This work replicated studies conducted from 1998 to 2009 that demonstrated harlequin ducks using areas that were oiled in 1989 had elevated EROD activity, indicative of oil exposure, up to 2 decades post-spill...
October 20, 2016: Environmental Toxicology and Chemistry
Johanna M Kraus, Polly P Gibson, David M Walters, Marc A Mills
Riparian spiders are being used increasingly to track spatial patterns of contaminants in and fluxing from aquatic ecosystems. However, our understanding of the circumstances under which spiders are effective sentinels of aquatic pollution is limited. Here we test the hypothesis that riparian spiders may be effectively used to track spatial patterns of sediment pollution by polychlorinated biphenyls (PCBs) in aquatic ecosystems with high habitat heterogeneity. We found that spatial pattern of ΣPCB concentrations in two common families of riparian spiders sampled in 2011-2013 generally tracked spatial variation in sediment ΣPCBs across all sites within the Manistique River Great Lakes Area of Concern (AOC), a rivermouth ecosystem located on the south shore of the Upper Peninsula, Manistique, MI, that includes harbor, river, backwater, and lake habitats...
October 20, 2016: Environmental Toxicology and Chemistry
Jan-Dieter Ludwigs, Markus Ebeling, Timothy B Fredricks, Roger C Murfitt, Steven Kragten
The registration of pesticides follows guidance published by the European Food Safety Authority, EFSA. As a default, the EFSA guidance document on risk assessment for birds and mammals assumes that animals feed exclusively on pesticide-treated fields. However, the guidance document suggests refining the risk via the proportion of food animals obtain from a treated field or specific crop (expressed via the so-called PT value). The EFSA guidance equalizes the portion of food taken from a treated area per day with the portion of time spent potentially foraging over the course of a day within this area...
October 18, 2016: Environmental Toxicology and Chemistry
Kees Booij, Foppe Smedes, Steven Crum
Two laboratory performance studies with 21 and 11 participants were carried out for passive sampling of nonpolar chemicals in water, using silicone samplers that were deployed for 7 and 13 weeks at 2 river sites in the Netherlands. Target analytes were polychlorinated biphenyls, polycyclic aromatic hydrocarbons, polybrominated diphenyl ethers, hexachlorobutadiene, hexachlorobenzene, and a number of performance reference compounds (PRCs). Calculation of aqueous concentrations based on prescribed input values and a prescribed uptake model was also included...
October 18, 2016: Environmental Toxicology and Chemistry
Melissa Whitfield Aslund, Michael Winchell, Lisa Bowers, Sean McGee, Jane Tang, Lauren Padilla, Colleen Greer, Loren Knopper, Dwayne R J Moore
A probabilistic ecological risk assessment (ERA) was conducted to determine the potential effects of acute and chronic exposure of aquatic invertebrate communities to imidacloprid arising from labeled agricultural and non-agricultural uses in the United States. Aquatic exposure estimates were derived using a higher tier refined modeling approach that accounts for realistic variability in environmental and agronomic factors. Toxicity was assessed using refined acute and chronic community-level effect metrics for aquatic invertebrates (i...
October 18, 2016: Environmental Toxicology and Chemistry
Danielle L Duncan, Mark G Carls, Stanley D Rice, Michael S Stekoll
Polycyclic aromatic hydrocarbons (PAHs) from creosote exposure in the laboratory resulted in deleterious effects in developing Pacific herring (Clupea pallasi) embryos and potentially toxic concentrations of PAHs were measured using passive water samplers at one of three harbor field sites in Juneau, Alaska. Aqueous TPAH concentrations of 4.6 and 8.4 µg/L from creosote exposure resulted in skeletal defects and ineffective swimming in hatched larvae in the laboratory (EC10s), and were the most sensitive parameters measured...
October 14, 2016: Environmental Toxicology and Chemistry
Wenzhong Tang, Chao Zhang, Yu Zhao, Baoqing Shan, Zhixin Song
A comprehensive and detailed investigation of heavy metal pollution, toxicity and ecological risk assessment was conducted for the surface river sediments of the Haihe Basin in China based on 220 sampling sites selected in 2013. The average concentrations of Cr, Cu, Ni, Pb, and Zn in the sediments were 129, 63.4, 36.6, 50.0, and 202 mg/kg, respectively. As indicated by geo-accumulation index and pollution load index, most surface river sediments of the Haihe Basin were contaminated with the investigated metals, especially in junction region of Zi Ya He and Hei Long Gang watersheds...
October 12, 2016: Environmental Toxicology and Chemistry
Vurtice C Albright, Colin R Wong, Richard L Hellmich, Joel R Coats
Silencing genes of a pest with double-stranded RNA is a promising new pest management technology. As part of the environmental risk assessment for dsRNA-based products, the environmental fate and the potential for adverse effects to on-target organisms should be characterized. In the present study, a non-bioactive dsRNA was spiked into the water column of a water and sediment microcosm to mimic drift from a spray application run off of unbound dsRNA or transport of plant tissues. Dissipation of dsRNA in the water column and partitioning into sediment was determined...
October 12, 2016: Environmental Toxicology and Chemistry
Anton Ribbenstedt, Lukas Mustajärvi, Magnus Breitholtz, Elena Gorokhova, Philipp Mayer, Anna Sobek
Ecotoxicity testing is a crucial component of chemical risk assessment. Still, due to methodological difficulties related to controlling exposure concentrations over time, data on long-term effects of organic chemicals at low concentrations are limited. The aim of the present study was therefore to test the applicability of passive dosing to maintain stable concentrations of the organochlorine bacteriocide triclosan in the water phase during a 6-week multi-generation population development test with the harpacticoid copepod Nitocra spinipes...
October 12, 2016: Environmental Toxicology and Chemistry
Yuanyuan Wang, Pingli Dai, Xiuping Chen, Jörg Romeis, Jianrong Shi, Yufa Peng, Yunhe Li
Because of its ecological and economic importance, the honey bee Apis mellifera is commonly used to assess the environmental risk of insect-resistant, genetically modified plants. In the current laboratory study, feeding-exposure experiments were used to determine whether pollen from transgenic rice harms A. mellifera worker bee. In one experiment, the survival and mean acinus diameter of hypopharyngeal glands of adult bees were similar when bees were fed on pollen from Bt rice lines or from a non-Bt rice line, but bee survival was significantly reduced when they received pollen that was mixed with potassium arsenate as a positive control...
October 7, 2016: Environmental Toxicology and Chemistry
Yeisson Gutiérrez, Hudson V V Tomé, Raul N C Guedes, Eugênio E Oliveira
Backswimmers (Hemiptera: Heteroptera: Notonectidae) are insect predators in a wide variety of freshwater habitats. These insects are well known due to their role as mosquito biocontrol agents, their capability of preying on immature fishes and frogs, and because they are often the first to colonize aquatic habitats. As a consequence, these predators may face intended or unintended insecticide (e.g., insecticides) exposures that may lead to death or to impairment of essential behaviors (e.g., swimming and position in the water column)...
October 5, 2016: Environmental Toxicology and Chemistry
Simon Pouil, Michel Warnau, François Oberhänsli, Jean-Louis Teyssié, Paco Bustamante, Marc Metian
Diet is an important pathway for metal uptake in marine organisms, and assimilation efficiency (AE) is one of the most relevant parameter to quantify trophic transfer of metals along aquatic food webs. The most commonly used method to estimate this parameter is pulse-chase feeding using radiolabelled food. This approach is, however, based on several assumptions that are not always tested in experimental context. The present work aimed at validating the approach by assessing single-feeding and multiple-feeding approaches, using a model species (the turbot Scophthalmus maximus)...
October 5, 2016: Environmental Toxicology and Chemistry
Nicole D Wagner, André J Simpson, Myrna J Simpson
The use of consumer products and pharmaceuticals that act as contaminants entering waterways through runoff and wastewater effluents alters aquatic ecosystem health. Traditional toxicological endpoints may underestimate the toxicity of contaminants, as lethal concentrations are often orders of magnitude higher than those found within freshwater ecosystems. While newer techniques examine the metabolic responses of sublethal contaminant exposure, there has been no direct comparison with ontogeny in Daphnia. It was hypothesized that Daphnia magna would have distinct metabolic changes after 3 different sublethal contaminant exposures, because of differences in the toxic mode of action and ontogeny...
October 5, 2016: Environmental Toxicology and Chemistry
Hung T Vu, Michael J Keough, Sara M Long, Vincent J Pettigrove
Fungicides are used widely in agriculture and have been detected in adjacent rivers and wetlands. However, relatively little is known about the potential effects of fungicides on aquatic organisms. The present study investigated the effects of 2 commonly used fungicides, the boscalid fungicide Filan(®) and the myclobutanil fungicide Systhane(™) 400 WP, on life history traits (survival, growth, and reproduction) and energy reserves (lipid, protein, and glycogen content) of the amphipod Austrochiltonia subtenuis under laboratory conditions, at concentrations detected in aquatic environments...
October 5, 2016: Environmental Toxicology and Chemistry
Anne M Taylor, Katelyn J Edge, Rodney P Ubrihien, William A Maher
A weight of evidence approach in environmental assessment includes the use of biomonitor organisms to measure biologically available contaminant concentrations and lethal and sublethal responses in an exposure, dose, and response framework. Corbicula australis was assessed as a test species for metal toxicity using in situ river sediment exposures at 4 locations in the Molonglo River (New South Wales, Australia), which has a legacy of sediment metal contamination, following 8 decades of mining in its upper reaches...
October 5, 2016: Environmental Toxicology and Chemistry
Marco Parolini, Sara Castiglioni, Stefano Magni, Camilla Della Torre, Andrea Binelli
Cannabis is the most used illicit drug worldwide and in some countries a new regulatory policy makes it legal under some restrictions. This situation could lead to a substantial increase in environmental levels of the cannabis active principle (Δ-9-tetrahydrocannabinol [Δ-9-THC]) and its main metabolite, 11-nor-9-carboxy-Δ(9) -tetrahydrocannabinol (THC-COOH). Although previous studies have highlighted the toxicity of Δ-9-THC, the adverse effects of THC-COOH on aquatic organisms is completely unknown, even though such effects could be more significant because the environmental concentrations of THC-COOH are higher than those of the parent compound...
October 5, 2016: Environmental Toxicology and Chemistry
Melissa Whitfield Aslund, Roger L Breton, Lauren Padilla, Michael Winchell, Katie L Wooding, Dwayne R J Moore, R Scott Teed, Rick Reiss, Paul Whatling
A probabilistic risk assessment of the potential direct and indirect effects of acute dimethoate exposure to salmon populations of concern was conducted for 3 evolutionarily significant units (ESUs) of Pacific salmon in California. These ESUs were the Sacramento River winter-run chinook, the California Central Valley spring-run chinook, and the California Central Valley steelhead. Refined acute exposures were estimated using the Soil and Water Assessment Tool, a river basin-scale model developed to quantify the impact of land-management practices in large, complex watersheds...
October 5, 2016: Environmental Toxicology and Chemistry
Kasun S Abeysinghe, Xiao-Dong Yang, Eben Goodale, Christopher W N Anderson, Kevin Bishop, Axiang Cao, Xinbin Feng, Shengjie Liu, Christos Mammides, Bo Meng, Rui-Chang Quan, Jing Sun, Guangle Qiu
Mercury (Hg), deposited from emissions or from local contamination, can have serious health effects for humans and wildlife. Traditionally, Hg has been seen as a threat to aquatic wildlife, because of its conversion in suboxic conditions into bioavailable methylmercury (MeHg), but it can also threaten contaminated terrestrial ecosystems. In Asia, rice paddies in particular may be sensitive ecosystems. Earthworms are soil dwelling organisms that have been used as indicators of Hg bioavailability, however the MeHg concentrations they accumulate in rice paddy environments are not well known...
October 4, 2016: Environmental Toxicology and Chemistry
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