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Environmental Toxicology and Chemistry

Christoph Schür, Sinja Rist, Anders Baun, Philipp Mayer, Nanna B Hartmann, Martin Wagner
Previous research reported the translocation of nano- and microplastics from the gastrointestinal tract to tissues in Daphnia magna, most prominently of fluorescent polystyrene (PS) beads to lipid droplets. For particles > 300 nm, such transfer is biologically implausible as the peritrophic membrane retains these in the daphnid gut. Thus, we aim at replicating the key study by Rosenkranz et al. (2009). We used confocal laser scanning microscopy to study the tissue transfer applying the original setup (neonates exposed to 20 and 1,000 nm PS beads at 2 µg L-1 for 4 and 24 h), the same setup with a fructose-based clearing, and a setup with a 1,000-fold higher concentration (2 mg L-1 )...
April 22, 2019: Environmental Toxicology and Chemistry
Bryant Gagliardi, Sara M Long, Vincent J Pettigrove, Philippa C Griffin, Ary A Hoffmann
Larval deformities have been observed in chironomids, and are thought to be associated with aquatic contaminant exposure. However, deformities have not been linked with contaminants in the absence of potential confounding variables including mortality in laboratory assays, which introduces a survivorship bias (SB). There is also a paucity of data on noncontaminant causes. Additionally, power analyses are rarely undertaken, meaning effect sizes detectable are usually uncertain. We therefore aimed to clarify factors associated with deformities, by running SB-free (i...
April 18, 2019: Environmental Toxicology and Chemistry
Sven Seidensticker, Christiane Zarfl, Olaf Arie Cirpka, Peter Grathwohl
Microplastic particles are ubiquitously detected in the environment. Despite intensive public and scientific discussions, their potential of transporting contaminants in rivers and oceans under environmental conditions is still under assessment. In this study, we measured sorption isotherms and kinetics in batch experiments using phenanthrene as typical hydrophobic wastewater contaminant and microplastic particles, differing in size and material. We observed a linear sorption isotherm for polyethylene, contrasted by nonlinear sorption of polyamide and polystyrene which could be described best by the Freundlich and Polanyi-Dubinin-Manes isotherms, respectively...
April 18, 2019: Environmental Toxicology and Chemistry
S E Belanger, G J Carr
Application Factors (AF) are routinely applied in the extrapolation of laboratory aquatic toxicity data to ensure protectiveness from exposure to chemicals in the natural environment. The magnitude of the AF is both a scientific and policy decision; however, in any case should be rooted in scientific knowledge so as to not be arbitrary. Information rich chemicals are often subjected to Species Sensitivity Distribution (SSD) analysis to transparently describe certain aspects of assessment uncertainty and are normally subjected to much smaller AF than screening information data sets...
April 17, 2019: Environmental Toxicology and Chemistry
Gregory J Carr, Scott E Belanger
This work proposes a framework on sample size for species sensitivity distribution analyses, with perspectives on Bayesian, frequentist, and even nonparametric approaches to estimation. A statistical sample size analysis intends to assure that the implementation of a statistical model will satisfy a minimum performance standard when relevant conditions are met. It requires that a statistical model be fully specified and how to measure its performance as a function of sample size. Defining the model conditions under which sample size is calculated is often the most difficult, and important, aspect of sample size analysis because if the model is not representative, then the sample size analysis will provide incorrect guidance...
April 17, 2019: Environmental Toxicology and Chemistry
Chuanyu Chang, Runsheng Yin, Hua Zhang, Linjun Yao
Heavy metals are rich in seleniferous areas, however, the bioaccumulation and health risk of heavy metals are poorly understood, given the fact that selenium can inhibit the phytotoxicity and bioavailability of many heavy metals. This study investigated the bioaccumulation of heavy metals in the soil-rice system in the Enshi seleniferous area, Central China. Soils were contaminated by Mo, Cu, As, Sb, Zn, Cd, Tl and Hg, due to the weathering of Se-rich shales. Among heavy metals, Cd and Mo have the highest bioavailability in soils...
April 17, 2019: Environmental Toxicology and Chemistry
Mathieu Renaud, Sónia Chelinho, Paula Alvarenga, Clarisse Mourinha, Patrícia Palma, JoséPaulo Sousa, Tiago Natal-da-Luz
Using organic wastes as soil amendments can be an important measure to improve soil quality and reduce waste accumulation and landfilling. However, their potential contaminant loads, can be a source of environmental concern. Consequently, legislation has been developed to regulate the use of these wastes in agricultural soils but only considers chemical parameters which are insufficient to establish their level of environmental risk. A possible solution is the use of Species sensitivity distributions (SSDs) to incorporate ecotoxicological data from test batteries in legislation...
April 15, 2019: Environmental Toxicology and Chemistry
Melina Alvarez, Cecile Du Mortier, Soledad Jaureguiberry, Andrés Venturino
The Pampa Húmeda region in Argentina is characterized by soybean, wheat, and maize production, with intensive application of agrochemicals such as herbicides and insecticides. We used a joint probabilistic approach to analyze the probabilities for environmental chlorpyrifos concentrations measured in the Pampa Húmeda to exceed acute or chronic Hazard Concentration-5 (HC5) values estimated from Species Sensitivity Distributions (SSD) for aquatic species. Chlorpyrifos concentrations in water ranged from 0.0005 to 10...
April 15, 2019: Environmental Toxicology and Chemistry
Jessica Head
Transgenerational epigenetic inheritance is an unconventional finding that challenges paradigms in fields as diverse as medicine and evolutionary biology. It suggests that the environmental experiences of individuals can affect the health of their descendants through mechanisms other than alteration of DNA code. This article is protected by copyright. All rights reserved.
April 12, 2019: Environmental Toxicology and Chemistry
Kevin J Rader, Richard F Carbonaro, Eric D van Hullebusch, Stijn Baken, Katrien Delbeke
The fate and effects of copper in the environment are governed by a complex set of environmental processes which include binding to inorganic and organic ligands in water, soil, and sediments. In natural waters, these interactions can limit copper bioavailability and result in copper transport from the water column to the sediment. In this work, data on the fate of copper added to lakes, microcosms, and mesocosms were compiled and analyzed to determine copper removal rates from the water column. Studies on copper behavior in sediment were also reviewed to assess the potential for remobilization...
April 10, 2019: Environmental Toxicology and Chemistry
Ke Zheng, Yujuan Fan, Zewen Zhu, Guangshi Chen, Caiming Tang, Xianzhi Peng
Freshwater system is an important source and vector of plastic debris in oceans. However, plastic debris in freshwater organisms have not been well studied. Occurrence, characterization, polymer composition, seasonal and spatial distribution of plastic debris were investigated in 9 species of wild freshwater fish from the Pearl River catchment, South China. Approximately 50% of the total fish (n=279) belonging to nine species were found to ingest plastic debris with an average abundances of 7.0 ± 23.8 items/individual, indicating wide presence plastic contamination in the Pearl River catchment...
April 5, 2019: Environmental Toxicology and Chemistry
RomanP Lanno, Koen Oorts, Erik Smolders, Katie Albanese, MJasim Chowdhury
The present study examined the effects of soil physical and chemical properties on the toxicity of lead (Pb) to earthworms (Eisenia fetida) and collembolans (Folsomia candida), and on bioaccumulation of Pb by earthworms, in soils amended with Pb salts. Toxicity tests were conducted in seven soils varying in soil properties (pH: 4.7-7.4, eCEC: 4-42 cmolc /kg, organic carbon: 10 - 50 g C/kg) that were leached and pH corrected after spiking with PbCl2 . EC50s based upon total soil Pb concentrations ranged from 35 to 5080 mg Pb/kg for earthworms and 389 to >7190 mg/kg for Collembola...
April 4, 2019: Environmental Toxicology and Chemistry
RobinJ Reash, LisaA Friedrich, MichaelC Bock, NormanM Halden, VinceP Palace
Evaluating potential ecological and human health risks of exposure to bioaccumulative trace elements is typically implemented using analysis of tissue samples. Increasingly, the microchemistry of fish calcified structures is used to elucidate the lifetime exposure to trace elements. In the present study we measured total Hg (THg), methylmercury (MeHg) and selenium (Se) in muscle tissue and otolith samples from 12 species of fish collected at reference sites and sites influenced by power plant wastewater. Muscle tissue concentrations of Se were sensitive to recent wastewater exposure magnitude, stream type, trophic level, and species (P < 0...
April 1, 2019: Environmental Toxicology and Chemistry
Moeris Samuel, Vanryckeghem Francis, Demeestere Kristof, Huysman Steve, Vanhaecke Lynn, KarelAC De Schamphelaere
In order to estimate mixture effects caused by the high number of chemicals simultaneously present in the environment, methods for routine effect assessment of environmentally realistic contaminant mixtures (ERCMs) are needed. Here, we repeatedly exposed the marine diatom Phaeodactylum tricornutum to SpeediskTM passive sampler extracts and observed statistically significant growth stimulation up to 6 % and 7 % for samples from inside and outside the harbor of Zeebrugge, respectively. These effects were found at summed contaminant concentrations (159 - 166 ng L-1 ) that were within a 1...
March 29, 2019: Environmental Toxicology and Chemistry
Sarah H Peterson, Joshua T Ackerman, Matthew Toney, Mark P Herzog
Feathers are widely used to represent mercury contamination in birds. Yet, few recommendations exist that provide guidance for using bird feathers in mercury monitoring programs. We conducted a literature review and 5 experiments to show that mercury concentrations vary substantially within (vane >100% higher than calamus) and among (>1000%) individual feathers from the same bird. We developed a research tool and guidelines for using bird feathers for mercury studies based on three components: 1) variability of feather mercury concentrations within an individual bird (coefficient of variation [CV]), 2) desired accuracy of the measured mercury concentration, and 3) feather and bird mass...
March 29, 2019: Environmental Toxicology and Chemistry
BryanM Hedgpeth, AaronD Redman, RebeccaA Alyea, DanielJ Letinski, MartinJ Connelly, JoshD Butler, Heping Zhou, MarkA Lampi
The OECD 236 Fish Embryo Acute Toxicity Test guideline relies on 4 endpoints to describe exposure related effects (coagulation, lack of somite formation, tail-bud detachment from yolk-sac, and presence of heartbeat). Danio rerio (zebrafish) embryos were used to investigate these endpoints along with a number of additional sublethal effects (i.e. cardiac dysfunction, pericardial edema, yolk sac edema, tail curvature, hatch success, pericardial edema area, craniofacial malformation, swim bladder development, fin development, and heart rate) following 5 d exposures to 7 petroleum substances...
March 28, 2019: Environmental Toxicology and Chemistry
N Kumar, O Awoyemi, A Willis, C Schmitt, L Ramalingam, N Moustaid-Moussa, J Crago
Azole fungicides have entered the aquatic environment through agricultural and residential runoff. In the present study, we compared the off-target toxicity of tebuconazole, propiconazole, and myclobutanil using embryo-larval zebrafish as a model. The aim of this study was to investigate a relative toxicity of tebuconazole, propiconazole, and myclobutanil using multiple level endpoints such as behavioral endpoints and enzymatic and molecular biomarkers associated with their mode of action. Zebrafish embryos were exposed to azoles at environmentally relevant and high concentrations, 0...
March 28, 2019: Environmental Toxicology and Chemistry
CorieA Fulton, KaraE Huff Hartz, JohnD Reeve, MichaelJ Lydy
Fluvalinate has been extensively used in the United States to combat honey bee colony loss due to Varroa destructor mites. The objectives of the current research project were to investigate the extent of fluvalinate contamination in commercially available wax and to define exposure pathways to larval and adult honey bees. All of the commercial wax tested contained elevated fluvalinate concentrations, indicating a need for regulation of the sources of wax being rendered for resale. Based on the negative logarithm of the partition coefficient between wax and pollen (-0...
March 24, 2019: Environmental Toxicology and Chemistry
Richard F Carbonaro, Kevin J Farley, Katrien Delbeke, Stijn Baken, Jose J Arbildua, Patricio H Rodriguez, Kevin J Rader
Metals present in concentrates are in a solid form and not bioavailable, but they can dissolve or potentially transform to more soluble forms. Transformation/dissolution (T/D) laboratory protocols have been developed to assess the importance of dissolution of sparingly soluble metal substances in the context of hazard classification, however these tests represent worst-case scenarios for metal bioavailability since attenuation mechanisms such as complexation, sorption, and transport to the sediment are not considered...
March 23, 2019: Environmental Toxicology and Chemistry
Melody J Gavel, Sarah D Richardson, Rebecca L Dalton, Catherin E Soos, Brendan Ashby, Landon McPhee, Mark R Forbes, Stacey A Robinson
Neonicotinoids are widely used insecticides that are detectable in agricultural waterways. These insecticides are of concern due to their potential impacts on non-target organisms. Pesticides can affect development of amphibians and suppress the immune system, which could impact disease susceptibility and tolerance. No previous studies on amphibians have examined the effects of these insecticides on differential blood cell proportions or corticosterone concentrations (a general stress hormone). We investigated the effects of chronic exposure to two neonicotinoids, thiamethoxam and clothianidin, on immunometrics of wood frogs (Lithobates sylvaticus)...
March 22, 2019: Environmental Toxicology and Chemistry
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