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1

Use of blue crab (Callinectes sapidus) embryos for toxicity testing  

SciTech Connect

After fertilization, blue crab embryos develop in egg sacs attached to the female pleopods, often referred to as the sponge. Lipovitellin and lipid droplets in the egg sacs provide energy and nutrition for the developing embryos. Embryos were removed from the sponge and transferred to 24 well culture plates containing sea water with or without toxicants, Each well contained 10 embryos. After 7 to 10 days, embryos hatched to swimming zoea. The effects of toxicants at various concentrations on hatching were determined and the EC{sub 50} calculated. For example, the EC{sub 50} for tributyltin, fenvalerate and mercuric chloride were 50, 30 and 90 ng/liter, respectively. The hatching success of control embryos ranged from 95 to 98%. Formation of the heart, eyespot formation, appendage formation and utilization rate of lipovitellin were also effected by exposure to toxicants. At a low concentration of mercuric ion (30ng/liter) the heart formed, but there was no heart beat. Eyespot formation was abnormal in the presence of high concentrations of cadmium (2 {micro}g/liter) and zinc (5 {micro}g/liter), Crab embryos offer many advantages for toxicity testing of pure compounds or mixtures in water, including toxicity testing of sediment pore water. The crab embryos may also serve as models to understand the effect of specific toxicants on the heart and eye spots of crustaceans.

Lee, R.; O`Malley, K. [Skidaway Inst. of Oceanography, Savannah, GA (United States)

1995-12-31

2

The weaker points of fish acute toxicity tests and how tests on embryos can solve some issues  

E-print Network

Commentary The weaker points of fish acute toxicity tests and how tests on embryos can solve some list the main weaknesses of fish acute toxicity tests and suggest that multi-factorial embryo tests could solve many of these issues. Abstract Fish acute toxicity tests play an important role

Richner, Heinz

3

Assessment of Jatropha curcas L. biodiesel seed cake toxicity using the zebrafish (Danio rerio) embryo toxicity (ZFET) test.  

PubMed

Consequent to the growing demand for alternative sources of energy, the seeds from Jatropha curcas remain to be the favorite for biodiesel production. However, a significant volume of the residual organic mass (seed cake) is produced during the extraction process, which raises concerns on safe waste disposal. In the present study, we assessed the toxicity of J. curcas seed cake using the zebrafish (Danio rerio) embryotoxicity test. Within 1-h post-fertilization (hpf), the fertilized eggs were exposed to five mass concentrations of J. curcas seed cake and were followed through 24, 48, and 72 hpf. Toxicity was evaluated based on lethal endpoints induced on zebrafish embryos namely egg coagulation, non-formation of somites, and non-detachment of tail. The lowest concentration tested, 1 g/L, was not able to elicit toxicity on embryos whereas 100 % mortality (based also on lethal endpoints) was recorded at the highest concentration at 2.15 g/L. The computed LC50 for the J. curcas seed cake was 1.61 g/L. No further increase in mortality was observed in the succeeding time points (48 and 72 hpf) indicating that J. curcas seed cake exerted acute toxicity on zebrafish embryos. Sublethal endpoints (yolk sac and pericardial edema) were noted at 72 hpf in zebrafish embryos exposed to higher concentrations. The observed lethal endpoints induced on zebrafish embryos were discussed in relation to the active principles, notably, phorbol esters that have remained in the seed cake even after extraction. PMID:24464135

Hallare, Arnold V; Ruiz, Paulo Lorenzo S; Cariño, J C Earl D

2014-05-01

4

PAH toxicity at aqueous solubility in the fish embryo test with Danio rerio using passive dosing.  

PubMed

As part of the risk assessment process within REACh, prior to manufacturing and distribution of chemical substances their (eco)toxicological impacts have to be investigated. The fish embryo toxicity test (FET) with the zebrafish Danio rerio has gained a high significance as an in vitro alternative to animal testing in (eco)toxicology. However, for hydrophobic organic chemicals it remains a technical challenge to ensure constant freely dissolved concentration at the maximum exposure level during such biotests. Passive dosing with PDMS silicone was thus applied to control the freely dissolved concentration of ten PAHs at their saturation level in the FET. The experiments gave repeatable results, with the toxicity of the PAHs generally increasing with the maximum chemical activities of the PAHs. HPLC analysis confirmed constant exposure at the saturation level. In additional experiments, fish embryos without direct contact to the silicone surface showed similar mortalities as those exposed with direct contact to the silicone. Silicone oil overlaying the water phase as a novel passive dosing phase had no observable effects on the development of the fish embryos until hatching. This study provides further data to support the close relationship between the chemical activity and the toxicity of hydrophobic organic compounds. Passive dosing from PDMS silicone enabled reliable toxicity testing of (highly) hydrophobic substances at aqueous solubility, providing a practical way to control toxicity exactly at the maximum exposure level. This approach is therefore expected to be useful as a cost-effective initial screening of hydrophobic chemicals for potential adverse effects to freshwater vertebrates. PMID:25048891

Seiler, Thomas-Benjamin; Best, Nina; Fernqvist, Margit Møller; Hercht, Hendrik; Smith, Kilian E C; Braunbeck, Thomas; Mayer, Philipp; Hollert, Henner

2014-10-01

5

Toxicity evaluation of single and mixed antifouling biocides using the Strongylocentrotus intermedius sea urchin embryo test.  

PubMed

The present study evaluated the single and mixed toxicities of commonly used antifouling biocides (copper pyrithione, Sea nine 211, dichlofluanid, tolylfluanid, and Irgarol 1051) on the early embryogenesis of sea urchin Strongylocentrotus intermedius. Their toxicities were quantified in terms of the median effective concentration (EC50) reducing the embryogenesis success by 50%. For individual biocides to the embryos, the toxicity was in order of copper pyrithione>Sea nine 211>?tolylfluanid>dichlofluanid>Irgarol 1051. The toxicities of mixture (binary, ternary, quaternary, and quinary) of compounds, evaluated by toxic unit, additivity index, and mixture toxicity index, showed that the copper pyrithione-Sea nine 211 combination was the most toxic with the EC50 value of 7.87 nM in all mixtures. Synergistic enhancements of toxicity were observed for all mixtures except the combination of tolylfluanid-Sea nine 211, revealing antagonistic effect. Both the concentration addition and independent action concepts failed to accurately predict the mixture toxicities of the antifouling combinations; thus, a new log K(OW)-based model was developed to predict the combined toxicities of these antifouling chemicals, which were capable of predicting the mixture toxicities of antifouling biocides (R(2)=0.33). PMID:21154844

Wang, Heng; Li, Yan; Huang, Honghui; Xu, Xue; Wang, Yonghua

2011-03-01

6

Simple test for toxicity of number 2 fuel oil and oil dispersants to embryos of grass shrimp, palaemonetes pugio  

SciTech Connect

A simple test, using embryos of the grass shrimp Palaemonetes pugio, was employed to determine the toxicity of two commercial oil dispersants (Corexit 7664 and Corexit 9527) and toxicity of the water soluble fraction of Number 2 fuel oil (WSF oil) prepared with and without the addition of the dispersants. Tests revealed P. pugio embryos were similar to previously measured life stages in their sensitivity to WSF oil prepared without dispersants. They were approximately ten times more sensitive to water soluble fractions of dispersed oil, which may have been due to the approximately ten-fold increases in total hydrocarbons measured analytically. Both temperatures and salinity of the sea water affected toxicity of WSF prepared with dispersants, the most obvious effect being earlier onset of mortalities at higher temperatures. (Copyright (c) 1993 Pergamon Press Ltd.)

Fisher, W.S.; Foss, S.S.

1993-01-01

7

Large-Scale Assessment of the Zebrafish Embryo as a Possible Predictive Model in Toxicity Testing  

PubMed Central

Background In the drug discovery pipeline, safety pharmacology is a major issue. The zebrafish has been proposed as a model that can bridge the gap in this field between cell assays (which are cost-effective, but low in data content) and rodent assays (which are high in data content, but less cost-efficient). However, zebrafish assays are only likely to be useful if they can be shown to have high predictive power. We examined this issue by assaying 60 water-soluble compounds representing a range of chemical classes and toxicological mechanisms. Methodology/Principal Findings Over 20,000 wild-type zebrafish embryos (including controls) were cultured individually in defined buffer in 96-well plates. Embryos were exposed for a 96 hour period starting at 24 hours post fertilization. A logarithmic concentration series was used for range-finding, followed by a narrower geometric series for LC50 determination. Zebrafish embryo LC50 (log mmol/L), and published data on rodent LD50 (log mmol/kg), were found to be strongly correlated (using Kendall's rank correlation tau and Pearson's product-moment correlation). The slope of the regression line for the full set of compounds was 0.73403. However, we found that the slope was strongly influenced by compound class. Thus, while most compounds had a similar toxicity level in both species, some compounds were markedly more toxic in zebrafish than in rodents, or vice versa. Conclusions For the substances examined here, in aggregate, the zebrafish embryo model has good predictivity for toxicity in rodents. However, the correlation between zebrafish and rodent toxicity varies considerably between individual compounds and compound class. We discuss the strengths and limitations of the zebrafish model in light of these findings. PMID:21738604

Ali, Shaukat; van Mil, Harald G. J.; Richardson, Michael K.

2011-01-01

8

Alternative methods for toxicity assessments in fish: Comparison of the fish embryo toxicity and the larval growth and survival tests in zebrafish and fathead minnows.  

PubMed

An increased demand for chemical toxicity evaluations has resulted in the need for alternative testing strategies that address animal welfare concerns. The fish embryo toxicity (FET) test developed for zebrafish (Danio rerio) is one such alternative, and the application of the FET test to other species such as the fathead minnow (Pimephales promelas) has been proposed. In the present study, the performances of the FET test and the larval growth and survival (LGS; a standard toxicity testing method) test in zebrafish and fathead minnows were evaluated. This required that testing methods for the fathead minnow FET and zebrafish LGS tests be harmonized with existing test methods and that the performance of these testing strategies be evaluated by comparing the median lethal concentrations of 2 reference toxicants, 3,4-dicholoraniline and ammonia, obtained via each of the test types. The results showed that procedures for the zebrafish FET test can be adapted and applied to the fathead minnow. Differences in test sensitivity were observed for 3,4-dicholoraniline but not ammonia; therefore, conclusions regarding which test types offer the least or most sensitivity could not be made. Overall, these results show that the fathead minnow FET test has potential as an alternative toxicity testing strategy and that further analysis with other toxicants is warranted in an effort to better characterize the sensitivity and feasibility of this testing strategy. Environ Toxicol Chem 2014;33:2584-2594. © 2014 SETAC. PMID:25113410

Jeffries, Marlo K Sellin; Stultz, Amy E; Smith, Austin W; Rawlings, Jane M; Belanger, Scott E; Oris, James T

2014-11-01

9

ADAPTING THE MEDAKA EMBRYO ASSAY TO A HIGH-THROUGHPUT APPROACH FOR DEVELOPMENTAL TOXICITY TESTING.  

EPA Science Inventory

Chemical exposure during embryonic development may cause persistent effects, yet developmental toxicity data exist for very few chemicals. Current testing procedures are time consuming and costly, underlining the need for rapid and low cost screening strategies. While in vitro ...

10

Development of an embryo toxicity test with the pond snail Lymnaea stagnalis using the model substance tributyltin and common solvents.  

PubMed

The development of a chronic mollusc toxicity test is a current work item on the agenda of the OECD. The freshwater pond snail Lymnaea stagnalis is one of the candidate snail species for such a test. This paper presents a 21-day chronic toxicity test with L. stagnalis, focussing on embryonic development. Eggs were collected from freshly laid egg masses and exposed individually until hatching. The endpoints were hatching success and mean hatching time. Tributyltin (TBT), added as TBT-chloride, was chosen as model substance. The selected exposure concentrations ranged from 0.03 to 10 ?g TBT/L (all as nominal values) and induced the full range of responses. The embryos were sensitive to TBT (the NOEC for mean hatching time was 0.03 ?g TBT/L and the NOEC for hatching success was 0.1 ?g TBT/L). In addition, data on maximum limit concentrations of seven common solvents, recommended in OECD aquatic toxicity testing guidelines, are presented. Among the results, further findings as average embryonic growth and mean hatching time of control groups are provided. In conclusion, the test presented here could easily be standardised and is considered useful as a potential trigger to judge if further studies, e.g. a (partial) life-cycle study with molluscs, should be conducted. PMID:22846768

Bandow, Cornelia; Weltje, Lennart

2012-10-01

11

Estradiol Uptake, Toxicity, Metabolism, and Adverse Effects on Cadmium-Treated Amphibian Embryos  

Microsoft Academic Search

mium in 76.7, 80, and 83.3% of embryos, respectively. The results indicate that estrogenic endocrine disruptors could have an adverse effect on amphibian embryos and enhance the toxic effect of Cd on amphibian embryos. This study points to the possibility of using the AMPHITOX test as a screening method for potential endocrine disruption as well as the combined effects of

Osvaldo Fridman; Lucrecia Corró; Jorge Herkovits

2004-01-01

12

Toxic effects of colloidal nanosilver in zebrafish embryos.  

PubMed

A variety of consumer products containing silver nanoparticles (Ag NPs) are currently marketed. However, their safety for humans and for the environment has not yet been established and no standard method to assess their toxicity is currently available. The objective of this work was to develop an effective method to test Ag NP toxicity and to evaluate the effects of ion release and Ag NP size on a vertebrate model. To this aim, the zebrafish animal model was exposed to a solution of commercial nanosilver. While the exposure of embryos still surrounded by the chorion did not allow a definite estimation of the toxic effects exerted by the compound, the exposure for 48 h of 3-day-old zebrafish hatched embryos afforded a reliable evaluation of the effects of Ag NPs. The effects of the exposure were detected especially at molecular level; in fact, some selected genes expressed differentially after the exposure. The Ag NP toxic performance was due to the combined effect of Ag(+) ion release and Ag NP size. However, the effect of NP size was particularly detectable at the lowest concentration of nanosilver tested (0.01 mg l(-1)) and depended on the solubilization media. The results obtained indicate that in vivo toxicity studies of nanosilver should be performed with ad hoc methods (in this case using hatched embryos) that might be different depending on the type of nanosilver. Moreover, the addition of this compound to commercial products should take into consideration the Ag NP solubilization media. PMID:24395442

Olasagasti, Maider; Gatti, Antonietta M; Capitani, Federico; Barranco, Alejandro; Pardo, Miguel Angel; Escuredo, Kepa; Rainieri, Sandra

2014-05-01

13

Toxicity of trihalomethanes to common carp embryos  

SciTech Connect

Trihalomethanes recently have been identified in real and simulated effluents from power plants where chlorine is used for biofouling control. Toxicity of the four chlorine- or bromine-containing trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) to developing common carp (Cyprinus carpio) embryos was determined under conditions of intermittent (8-hour) toxicant renewal, based on percent hatch as the end point. Nominal median lethal concentrations (LC50) ranged from 161 mg/liter for chloroform to 53 mg/liter for dibromochloromethane. Decay studies conducted under conditions similar to those used for the toxicity studies, but in distilled water, indicated that (1) half-lives of the trihalomethanes ranged from 4.4 to 6.9 hours; (2) decay was due primarily to volatilization; (3) higher relative toxicity of dibromochloromethane probably was due to formation of a degradation product (likely Br/sub 2/). Correction of the nominal LC50 values to time-weighted mean concentrations over the period between toxicant changes gave weighted LC50 values of 97.2, 67.4, 33.5, and 52.3 mg/liter for chloroform, bromodichloromethane, dibromochloromethane, and bromoform, respectively. In addition, the period of water-hardening of fertilized eggs was not critical for expression of toxicity of dibromochloromethane. Comparison of these and other published data on effluent and toxic concentrations, persistence, and bioaccumulation of water-chlorination products suggests that trihalomethanes are not as environmentally critical as other chlorinated organic compounds or residual chlorine.

Mattice, J.S. (Oak Ridge National Lab., TN); Tsai, S.C.; Burch, M.B.; Beauchamp, J.J.

1981-03-01

14

Comparison of the mouse Embryonic Stem cell Test, the rat Whole Embryo Culture and the Zebrafish Embryotoxicity Test as alternative methods for developmental toxicity testing of six 1,2,4-triazoles  

SciTech Connect

The relatively high experimental animal use in developmental toxicity testing has stimulated the search for alternatives that are less animal intensive. Three widely studied alternative assays are the mouse Embryonic Stem cell Test (EST), the Zebrafish Embryotoxicity Test (ZET) and the rat postimplantation Whole Embryo Culture (WEC). The goal of this study was to determine their efficacy in assessing the relative developmental toxicity of six 1,2,4-triazole compounds, flusilazole, hexaconazole, cyproconazole, triadimefon, myclobutanil and triticonazole. For this purpose, we analyzed effects and relative potencies of the compounds in and among the alternative assays and compared the findings to their known in vivo developmental toxicity. Triazoles are antifungal agents used in agriculture and medicine, some of which are known to induce craniofacial and limb abnormalities in rodents. The WEC showed a general pattern of teratogenic effects, typical of exposure to triazoles, mainly consisting of reduction and fusion of the first and second branchial arches, which are in accordance with the craniofacial malformations reported after in vivo exposure. In the EST all triazole compounds inhibited cardiomyocyte differentiation concentration-dependently. Overall, the ZET gave the best correlation with the relative in vivo developmental toxicities of the tested compounds, closely followed by the EST. The relative potencies observed in the WEC showed the lowest correlation with the in vivo developmental toxicity data. These differences in the efficacy between the test systems might be due to differences in compound kinetics, in developmental stages represented and in the relative complexity of the alternative assays.

Jong, Esther de, E-mail: Esther.de.Jong@rivm.nl [Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Barenys, Marta [GRET-CERETOX, Toxicology Unit, Public Health Department, School of Pharmacy, University of Barcelona, Barcelona (Spain); Hermsen, Sanne A.B. [Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Department of Health Risk Analysis and Toxicology, NUTRIM, University of Maastricht, Maastricht (Netherlands); Verhoef, Aart [Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Ossendorp, Bernadette C.; Bessems, Jos G.M. [Centre for Substances and Integrated Risk Assessment, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands); Piersma, Aldert H. [Institute for Risk Assessment Sciences, Utrecht University, Utrecht (Netherlands); Laboratory for Health Protection Research, National Institute for Public Health and the Environment (RIVM), Bilthoven (Netherlands)

2011-06-01

15

Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta  

NASA Astrophysics Data System (ADS)

As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP, DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of H. diversicolor supertexta can be used to indicate toxicity of the PAEs.

Yang, Zhihui; Zhang, Xiangjing; Cai, Zhonghua

2009-05-01

16

Toxicity of selenium to developing Xenopus laevis embryos.  

PubMed

Se in the form of sodium selenite is toxic to Xenopus laevis embryos and tadpoles continuously exposed to concentrations above 1 ppm. Concentrations of 2 ppm and above result in severe developmental abnormalities and increased mortality. Uptake and loss of radioactive Se from water are rapid, but depuration is not complete indicating that some Se can remain bound by the organism. The facts that Se is toxic at low levels to Xenopus embryos and tadpoles, can cause developmental abnormalities, and accumulates in tissues suggest that increased release of Se compounds into the environment poses a potential threat to aquatic organisms. PMID:490681

Browne, C L; Dumont, J N

1979-07-01

17

DEVELOPMENTAL TOXICITY OF COPPER SULFATE AND METHYLENE CHLORIDE TO SHRIMP EMBRYOS  

EPA Science Inventory

The embryos of the grass shrimp (Palaemonetes pugio) have shown sensitivity to the water-soluble fraction of Number 2 fuel oil which indicates they may be a useful test species in estuarine developmental toxicity tests. Detailed concentration-response curves for copper sulfate an...

18

In Vivo Nanotoxicity Testing using the Zebrafish Embryo Assay  

PubMed Central

Nanoparticles are increasingly used for biomedical purposes. Many different diagnostic and therapeutic applications are envisioned for nanoparticles, but there are often also serious concerns regarding their safety. Given the fact that numerous new nanomaterials are being developed every day, and that not much is known about the long-term toxicological impact of exposure to nanoparticles, there is an urgent need to establish efficient methods for nanotoxicity testing. The zebrafish (Danio rerio) embryo assay has recently emerged as an interesting ‘intermediate’ method for in vivo nanotoxicity screening, enabling (semi-) high-throughput analyses in a system significantly more complex than cultured cells, but at the same time also less ‘invasive’ and less expensive than large-scale biocompatibility studies in mice or rats. The zebrafish embryo assay is relatively well-established in the environmental sciences, but it has not yet gained wide notice in the nanomedicine field. Using prototypic polymeric drug carriers, gold-based nanodiagnostics and nanotherapeutics, and iron oxide-based nanodiagnostics, we here show that toxicity testing using zebrafish embryos is easy, efficient and informative, and faithfully reflects, yet significantly extends, cell-based toxicity testing. We therefore expect that the zebrafish embryo assay will become a popular future tool for in vivo nanotoxicity screening. PMID:24179674

Rizzo, Larissa Y.; Golombek, Susanne K.; Mertens, Marianne E.; Pan, Yu; Laaf, Dominic; Broda, Janine; Jayapaul, Jabadurai; Mockel, Diana; Subr, Vladimir; Hennink, Wim E.; Storm, Gert; Simon, Ulrich; Jahnen-Dechent, Willi; Kiessling, Fabian; Lammers, Twan

2013-01-01

19

Virtual Embryo: Systems Modeling in Developmental Toxicity  

EPA Science Inventory

High-throughput screening (HTS) studies are providing a rich source of data that can be applied to chemical profiling to address sensitivity and specificity of molecular targets, biological pathways, cellular and developmental processes. EPA?s ToxCast project is testing 960 uniq...

20

Molecular Mechanisms of Toxicity of Silver Nanoparticles in Zebrafish Embryos  

PubMed Central

Silver nanoparticles cause toxicity in exposed organisms and are an environmental health concern. The mechanisms of silver nanoparticle toxicity, however, remain unclear. We examined the effects of exposure to silver in nano-, bulk-, and ionic forms on zebrafish embryos (Danio rerio) using a Next Generation Sequencing approach in an Illumina platform (High-Throughput SuperSAGE). Significant alterations in gene expression were found for all treatments and many of the gene pathways affected, most notably those associated with oxidative phosphorylation and protein synthesis, overlapped strongly between the three treatments indicating similar mechanisms of toxicity for the three forms of silver studied. Changes in oxidative phosphorylation indicated a down-regulation of this pathway at 24 h of exposure, but with a recovery at 48 h. This finding was consistent with a dose-dependent decrease in oxygen consumption at 24 h, but not at 48 h, following exposure to silver ions. Overall, our data provide support for the hypothesis that the toxicity caused by silver nanoparticles is principally associated with bioavailable silver ions in exposed zebrafish embryos. These findings are important in the evaluation of the risk that silver particles may pose to exposed vertebrate organisms. PMID:23758687

2013-01-01

21

DEVELOPMENTAL TOXICITY TESTING  

EPA Science Inventory

Contemporary developmental toxicity testing focuses on the evaluation of a variety of adverse developmental effects which include structural malformations, intrauterine death, growth retardation, and deficits in postnatal function. n the extrapolation of information from animal s...

22

Status and applications of echinoid (phylum echinodermata) toxicity test methods  

SciTech Connect

The use of echinoderms for toxicity testing has focused primarily on sea urchins and sand dollars (Strongylocentrotus purpuratus, Arbacia punctulata, Lytechinus pictus, and Dendraster excentricus, for example). The status and relative sensitivity of various test methods are described. The most frequently used test methods consist of short-term exposures of sea urchin sperm or embryos; these tests can be easily conducted at all times of the year by using species with complementary spawning cycles or laboratory conditioned populations of a single species. Data from reference toxicant and effluent toxicity tests are summarized. Information on the precision and sensitivity of echinoid test methods are limited and preclude rigorous comparisons with other test methods. The available data indicate that the sensitivity and precision of these methods are comparable to short-term chronic methods for other marine invertebrates and fish. Recent application of the sperm test in toxicity identification evaluations (TIEs) and studies of effluent toxicity decay and sediment toxicity illustrate the versatility of this rapid (10 to 60 min exposure) test method. Embryo tests typically use a 48 to 96 h exposure period and measure the occurrence of embryo malformations. Most recent applications of the embryo test have been for the assessment of sediment elutriate toxicity. Adult echinoderms are not frequently used to assess effluent or receiving water toxicity. Recent studies have had success in using the adult life stage of urchins and sand dollars to assess the effects of contaminated sediment on growth, behavior, and bioaccumulation.

Bay, S.; Burgess, R.; Nacci, D.

1993-01-01

23

Developmental toxicity and alteration of gene expression in zebrafish embryos exposed to PFOS  

SciTech Connect

Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant, the potential toxicity of which is causing great concern. In the present study, we employed zebrafish embryos to investigate the developmental toxicity of this compound. Four-hour post-fertilization (hpf) zebrafish embryos were exposed to 0.1, 0.5, 1, 3 and 5 mg/L PFOS. Hatching was delayed and hatching rates as well as larval survivorship were significantly reduced after the embryos were exposed to 1, 3 and 5 mg/L PFOS until 132 hpf. The fry displayed gross developmental malformations, including epiboly deformities, hypopigmentation, yolk sac edema, tail and heart malformations and spinal curvature upon exposure to PFOS concentrations of 1 mg/L or greater. Growth (body length) was significantly reduced in the 3 and 5 mg/L PFOS-treated groups. To test whether developmental malformation was mediated via apoptosis, flow cytometry analysis of DNA content, acridine orange staining and TUNEL assay was used. These techniques indicated that more apoptotic cells were present in the PFOS-treated embryos than in the control embryos. Certain genes related to cell apoptosis, p53 and Bax, were both significantly up-regulated upon exposure to all the concentrations tested. In addition, we investigated the effects of PFOS on marker genes related to early thyroid development (hhex and pax8) and genes regulating the balance of androgens and estrogens (cyp19a and cyp19b). For thyroid development, the expression of hhex was significantly up-regulated at all concentrations tested, whereas pax8 expression was significantly up-regulated only upon exposure to lower concentrations of PFOS (0.1, 0.5, 1 mg/L). The expression of cyp19a and of cyp19b was significantly down-regulated at all exposure concentrations. The overall results indicated that zebrafish embryos constitute a reliable model for testing the developmental toxicity of PFOS, and the gene expression patterns in the embryos were able to reveal some potential mechanisms of developmental toxicity.

Shi Xiongjie [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Graduate School of the Chinese Academy of Sciences, Beijing 100039 (China); Du Yongbing [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China); Lam, Paul K.S.; Wu, Rudolf S.S. [Department of Biology and Chemistry, City University of Hong Kong (China); Zhou Bingsheng [State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072 (China)], E-mail: bszhou@ihb.ac.cn

2008-07-01

24

Effects-driven chemical fractionation of heavy fuel oil to isolate compounds toxic to trout embryos.  

PubMed

Heavy fuel oil (HFO) spills account for approximately 60% of ship-source oil spills and are up to 50 times more toxic than medium and light crude oils. Heavy fuel oils contain elevated concentrations of polycyclic aromatic hydrocarbons (PAHs) and alkyl-PAHs, known to be toxic to fish; however, little direct characterization of HFO toxicity has been reported. An effects-driven chemical fractionation was conducted on HFO 7102 to separate compounds with similar chemical and physical properties, including toxicity, to isolate the groups of compounds most toxic to trout embryos. After each separation, toxicity tests directed the next phase of fractionation, and gas chromatography-mass spectrometry analysis correlated composition with toxicity, with a focus on PAHs. Low-temperature vacuum distillation permitted the separation of HFO into 3 fractions based on boiling point ranges. The most toxic of these fractions underwent wax precipitation to remove long-chain n-alkanes. The remaining PAH-rich extract was further separated using open column chromatography, which provided distinct fractions that were grouped according to increasing aromatic ring count. The most toxic of these fractions was richest in PAHs and alkyl-PAHs. The results of the present study were consistent with previous crude oil studies that identified PAH-rich fractions as the most toxic. PMID:24375845

Bornstein, Jason M; Adams, Julie; Hollebone, Bruce; King, Thomas; Hodson, Peter V; Brown, R Stephen

2014-04-01

25

Acute toxicity of agricultural pesticides to embryo-larval and juvenile African catfish Clarias gariepinus.  

PubMed

Acute toxicities of Tihan 175 O-TEQ, as well as its active ingredients flubendiamide and spirotetramat, and of Thionex 350 EC (active compound endosulfan) were measured for embryo-larval and juvenile stages of the African catfish Clarias gariepinus to assess risks of pesticide use in the cotton basin in Benin (West Africa). For embryo-larval stages, Tihan was more toxic (LC5048h 20 ppm) than Thionex (LC5048h 56 ppm), and flubendiamide was more toxic (LC5048h 2.0 ppm) than spirotetramat (LC5048h 8.44 ppm). All decreased hatching rates. Tihan and spirotetramat disturbed larval swimming coordination; flubendiamide induced tail cleavage. For juvenile fish, Thionex was more toxic (LC5096h 0.22 ppm) than Tihan (LC5096h 8.8 ppm), and flubendiamide (LC5096h 4.7 ppm) was more toxic than spirotetramat (LC5096h 6.0 ppm). Eggs were more resistant than juvenile fish to all tested pesticides except flubendiamide. Although Thionex was more toxic to juvenile fish, replacing Thionex with Tihan may be undesirable for survival of eggs and larvae. PMID:23334459

Agbohessi, P T; Imorou Toko, I; Houndji, A; Gillardin, V; Mandiki, S N M; Kestemont, P

2013-05-01

26

Embryo toxicity of pesticides and heavy metals to the ramshorn snail, Marisa cornuarietis (Prosobranchia).  

PubMed

An invertebrate embryo toxicity test with the ampullariid snail, Marisacornuarietis, to assess the toxicity of pesticides and heavy metals recently was established. Snail embryos were treated with atrazine (100, 1000, 10000, and 30000 microg/L), imidacloprid (10000, 25000, and 50000 microg/L), Ni(2+) (0.1, 1, 10, and 100 microg/L) or Zn(2+) (100, 200, 500, 1000, 2000, and 5000 microg/L). The effect of these substances was examined by monitoring the following endpoints: mortality, formation of tentacles and eyes, heart rate, hatching, and weight after hatching. Effects in term of a significant delay on the formation of both tentacles and eyes were found after treatment with 100 microg/L Ni(2+) or 200 microg/L Zn(2+). The heart rate was shown to significantly decrease at 25000 microg/L imidacloprid or 1000 microg/L Zn(2+). At 100 microg/L atrazine, 10 microg/L Ni(2+), or 1000 microg/L Zn(2+) a significant delay in hatching became visible. No significant mortality was observed for the tested concentrations of atrazine, imidacloprid, or Ni(2+), while 5000 microg/L Zn(2+) resulted in 100% mortality after 10d. The weight of freshly hatched individuals remained unaffected in all treatments. On the basis of the lowest observed effect concentrations (LOECs) recorded, we could show the M.cornuarietis embryo toxicity test (MariETT) to react up to three orders of magnitude more sensitive (for metals) and at least one order of magnitude more sensitive (for the tested organics) than the established Danio rerio embryo test. PMID:19278713

Sawasdee, Banthita; Köhler, Heinz-R

2009-06-01

27

Toxicity of crude oil chemically dispersed in a wave tank to embryos of Atlantic herring (Clupea harengus).  

PubMed

Tests of crude oil toxicity to fish are often chronic, exposing embryos from fertilization to hatch to oil solutions prepared using standard mixing procedures. However, during oil spills, fish are not often exposed for long periods and the dynamic nature of the ocean is not easily replicated in the lab. Our objective was to determine if brief exposures of Atlantic herring (Clupea harengus) embryos to dispersed oil prepared by standard mixing procedures was as toxic as oil dispersed in a more realistic model system. Embryos were first exposed to chemically dispersed Alaska North Slope crude and Arabian light crude oil for 2.4 h to 14 d from fertilization to determine if exposure time affected toxicity. Toxicity increased with exposure time, but 2.4-h exposures at realistic concentrations of oil induced blue-sac disease and reduced the percentage of normal embryos at hatch; there was little difference in toxicity between the two oils. Secondly, oil was chemically dispersed in a wave tank to determine if the resultant oil solutions were as toxic to herring embryos as laboratory-derived dispersed oil using a single exposure period of 24 h. Samples taken 15 min postdispersion were more toxic than laboratory-prepared solutions, but samples taken at 5, 30, and 60 min postdispersion were less toxic. Overall, the laboratory- and wave tank-derived solutions of dispersed oil provided similar estimates of toxicity despite differences in the methods for preparing test solutions, suggesting that laboratory and wave tank data are a reliable basis for ecological risk assessments of spilled oil. PMID:22488782

Greer, Colleen D; Hodson, Peter V; Li, Zhengkai; King, Thomas; Lee, Kenneth

2012-06-01

28

The toxicity of heavy metals to embryos of the American oyster Crassostrea virginica  

Microsoft Academic Search

The acute toxicity of 11 heavy metals to embryos of the American oyster Crassostrea virginica was studied and the concentrations at which 50% of the embryos did not develop were determined. The most toxic metals and their LC50 values were mercury (0.0056 ppm), silver (0.0058 ppm), copper (0.103 ppm) and zinc (0.31 ppm). Those metals that were not as toxic

A. Calabrese; R. S. Collier; D. A. Nelson; J. R. MacInnes

1973-01-01

29

Toxicity of different-sized copper nano- and submicron particles and their shed copper ions to zebrafish embryos.  

PubMed

Three sizes of copper nanoparticles (Cu NPs; 25 nm, 50 nm, and 100 nm), 1 submicron-sized particle, and Cu(NO3 )2 were added to the culture buffer of zebrafish embryos from 24 h postfertilization to 120 h postfertilization. In suspensions of Cu NPs and the Cu submicron-sized particle, the main contribution to the toxicity to zebrafish embryos was from the particle form of Cu particles (Cu NPparticle , >71%) rather than from dissolved Cu from the Cu particles (Cu NPion ). All particles tested as well as copper nitrate inhibited hatching, altered behavioral responses, and increased the incidence of malformations. Different kinds of abnormalities were observed in the morphology and behavior of the zebrafish embryos, depending on the particle size of the Cu suspensions tested. The median lethal concentrations of Cu NPparticle (25 nm, 50 nm, and 100 nm), the submicron-sized particle, and copper nitrate were 0.58 mg/L, 1.65 mg/L, 1.90 mg/L, 0.35 mg/L, and 0.70 mg/L, respectively. Submicron-sized particles and copper nitrate were more toxic than Cu NPs, and smaller Cu NPs were more toxic than larger Cu NPs. Dissolution of Cu NPs and the subsequent ion toxicity was not the primary mechanism of Cu NP toxicity in zebrafish embryos. PMID:24839162

Hua, Jing; Vijver, Martina G; Ahmad, Farooq; Richardson, Michael K; Peijnenburg, Willie J G M

2014-08-01

30

The Future of Toxicity Testing  

Microsoft Academic Search

In 2007, the U.S. National Research Council (NRC) released a report, “Toxicity Testing in the 21st Century: A Vision and a Strategy,” that proposes a paradigm shift for toxicity testing of environmental agents. The vision is based on the notion that exposure to environmental agents leads to adverse health outcomes through the perturbation of toxicity pathways that are operative in

Melvin E. Andersen; Mustafa Al-Zoughool; Maxine Croteau; Margit Westphal; Daniel Krewski

2010-01-01

31

VIRTUAL EMBRYO: SYSTEMS MODELING IN DEVELOPMENTAL TOXICITY - Symposium: SOT 2012  

EPA Science Inventory

High-throughput screening (HTS) studies are providing a rich source of data that can be applied to in vitro profiling of chemical compounds for biological activity and potential toxicity. Chemical profiling in ToxCast covered 965 drugs-chemicals in over 500 diverse assays testing...

32

FURTHER DEVELOPMENT OF RODENT WHOLE EMBRYO CULTURE: SOLVENT TOXICITY AND WATER INSOLUBLE COMPOUND DELIVERY SYSTEM  

EPA Science Inventory

In order to study the in vitro embryotoxicity and dysmorphogenesis of water insoluble compounds, solvents or chemical delivery systems of low toxicity and teratogenicity to the developing embryo must be found. Therefore, day 10.5 rat embryos were cultured for 2 days in whole rat ...

33

Effects of photoinduced toxicity of fluoranthene on amphibian embryos and larvae  

SciTech Connect

Embryos and newly hatched larvae of three amphibian species, the spotted salamander (Ambystoma maculatum), the northern leopard frog (Rana pipiens), and the African clawed frog (Xenopus laevis), were exposed to fluoranthene and ultraviolet (UV) light in two scenarios. Embryos were exposed in a laboratory setting from an early developmental stage through hatching under artificial UV light, and newly hatched larvae were exposed outdoors in varying sunlight intensity levels. Outdoor exposures indicated greater sensitivity in the toxic response than did laboratory exposures. In the laboratory, mortality and malformation of X. laevis were the most sensitive indicators of exposure. Xenopus laevis was also the most sensitive species tested to the effects of UV light alone. Hatching success of R. pipiens was monitored outdoors and was not a useful predictive endpoint in the determination of photoinduced toxicity; however, newly hatched larvae were sensitive to the effects of photoinduced toxicity. Amybstoma maculatum and X. laevis larvae were affected by low ({micro}g/L) concentrations of fluoranthene in sunlight. These findings suggest that low levels of polycyclic aromatic hydrocarbons could be acting synergistically with environmental factors such as UV light to place young amphibians at risk.

Hatch, A.C. [Oregon State Univ., Corvallis, OR (United States). Dept. of Zoology; Burton, G.A. Jr. [Wright State Univ., Dayton, OH (United States). Dept. of Biological Sciences

1998-09-01

34

DEVELOPMENTAL TOXICITY OF DI- AND TETRACHLOROETHANE AND DICHLOROPROPANE IN EMBRYO CULTURE  

EPA Science Inventory

DEVELOPMENTAL TOXICITY OF DI- AND TETRACHLOROETHANE AND DICHLOROPROPANE IN EMBRYO CULTURE. JE Andrews, H Nichols, and ES Hunter. Reproductive Toxicology Division, NHEERL, USEPA, RTP, NC. Disinfection of drinking water with chlorine results in numerous chlorinated byprodu...

35

Human endometrial cell coculture reduces the endocrine disruptor toxicity on mouse embryo development  

PubMed Central

Backgrounds Previous studies suggested that endocrine disruptors (ED) are toxic on preimplantation embryos and inhibit development of embryos in vitro culture. However, information about the toxicity of endocrine disruptors on preimplantation development of embryo in human reproductive environment is lacking. Methods Bisphenol A (BPA) and Aroclor 1254 (polychlorinated biphenyls) were used as endocrine disruptors in this study. Mouse 2-cell embryos were cultured in medium alone or vehicle or co-cultured with human endometrial epithelial layers in increasing ED concentrations. Results At 72 hours the percentage of normal blastocyst were decreased by ED in a dose-dependent manner while the co-culture system significantly enhanced the rate and reduced the toxicity of endocrine disruptors on the embryonic development in vitro. Conclusions In conclusion, although EDs have the toxic effect on embryo development, the co-culture with human endometrial cell reduced the preimplantation embryo from it thereby making human reproductive environment protective to preimplantation embryo from the toxicity of endocrine disruptors. PMID:22546201

2012-01-01

36

Toxicity of Buprofezin on the Survival of Embryo and Larvae of African Catfish, Clarias gariepinus (Bloch)  

PubMed Central

Buprofezin is an insect growth regulator and widely used insecticide in Malaysia. The present study evaluated the toxic effects of buprofezin on the embryo and larvae of African catfish (Clarias gariepinus) as a model organism. The embryos and larvae were exposed to 7 different concentrations (0, 0.05, 0.5, 5, 25, 50 and 100 mg/L) of buprofezin. Each concentration was assessed in five replicates. Eggs were artificially fertilized and 200 eggs and larvae were subjected to a static bath treatment for all the concentrations. The mortality of embryos was significantly increased with increasing buprofezin concentrations from 5 to 100 mg/L (p< 0.05). However, the mortality was not significantly different (p<0.05) among the following concentrations: 0 (control), 0.05, 0.5 and 5 mg/L. Data obtained from the buprofezin acute toxicity tests were evaluated using probit analysis. The 24 h LC50 value (with 95% confidence limits) of buprofezin for embryos was estimated to be 6.725 (3.167-15.017) mg/L. The hatching of fish embryos was recorded as 68.8, 68.9, 66.9, 66.4, 26.9, 25.1 and 0.12% in response to 7 different concentrations of buprofezin, respectively. The mortality rate of larvae significantly (p<0.05) increased with increasing buprofezin concentrations exposed to 24-48 h. The 24 and 48 h LC50 values (with 95% confidence limits) of buprofezin for the larvae was estimated to be 5.702 (3.198-8.898) and 4.642 (3.264-6.287) mg/L respectively. There were no significant differences (p>0.05) in the LC50 values obtained at 24 and 48 h exposure times. Malformations were observed when the embryos and larvae exposed to more than 5 mg/L. The results emerged from the study suggest that even the low concentration (5 mg/L) of buprofezin in the aquatic environment may have adverse effect on the early embryonic and larval development of African catfish. PMID:24098390

Marimuthu, Kasi; Muthu, Narmataa; Xavier, Rathinam; Arockiaraj, Jesu; Rahman, M. Aminur; Subramaniam, Sreeramanan

2013-01-01

37

Developmental toxicity and alteration of gene expression in zebrafish embryos exposed to PFOS  

Microsoft Academic Search

Perfluorooctanesulfonate (PFOS) is a persistent organic pollutant, the potential toxicity of which is causing great concern. In the present study, we employed zebrafish embryos to investigate the developmental toxicity of this compound. Four-hour post-fertilization (hpf) zebrafish embryos were exposed to 0.1, 0.5, 1, 3 and 5 mg\\/L PFOS. Hatching was delayed and hatching rates as well as larval survivorship were significantly

Xiongjie Shi; Yongbing Du; Paul K. S. Lam; Rudolf S. S. Wu; Bingsheng Zhou

2008-01-01

38

Gene expression profiling in zebrafish embryos exposed to diclofenac, an environmental toxicant.  

PubMed

Pharmaceuticals are continually released in the environment and therefore pollution from drugs is a pressing problem in the environment. Diclofenac, 2-[(2,6-dichlorophenyl)amino]phenylacetic acid is a FDA approved non-steroidal anti-inflammatory drug (NSAID) for the treatment of inflammation. This pharmaceutical has been found as pollutant in superficial waters. Danio rerio (zebrafish) embryo has been used as a model organism for acute pollutant toxicity tests in order to identify morphological alterations in development and death rate. Through the combination of mRNA differential display and quantitative Real Time experiments, we analyzed the alterations of gene expression in zebrafish embryos left to develop in the presence of diclofenac and thereby assess the molecular mechanism involved in ecotoxicity of diclofenac polluted waters. This approach, in embryos exposed to 1.25 mg/l drug for 48 h, allowed identifying 36 different genes, with both known and unknown functions, whose transcription is differentially regulated. The identity and ontological classification of these genes is presented. The wide variety of functional classes of transcripts isolated in this screen reflects the diverse spectrum of influences operating across diclofenac exposure. Of these 36 genes, several have been selected for detailed quantitative Real Time analysis to validate the screen. Our results, for the first time, provide an insight into some of the varied and novel molecular networks following zebrafish exposure to diclofenac polluted waters. PMID:21643954

De Felice, Bruna; Copia, Luisa; Guida, Marco

2012-03-01

39

Effects of storage temperature and duration on toxicity of sediments assessed by Crassostrea gigas oyster embryo bioassay  

SciTech Connect

The effects of temperature and duration of storage on the toxicity of estuarine sediments were investigated with the Crassostrea gigas oyster embryo bioassay. Sediments ranging from unpolluted (controls) to extremely polluted with heavy metals (>100 ppm Hg, Cu, Zn, and Pb) and total hydrocarbons (>1,000 ppm) were collected from sites in southwest France and northern Spain, Control sediments were toxic only at the highest concentrations tested and after freezing in liquid nitrogen ({minus}196 C). Polluted sediments significantly reduced the success of oyster embryogenesis. Analysis of variance showed that the effect of storage temperature on toxicity increased with the prolongation of storage. Prolonged storage of fresh (4 C) sediments resulted in a loss of toxicity, which was more rapid in the less-polluted sediments. Deep-frozen sediments ({minus}196 C) were highly toxic regardless of origin and storage time, and because deep-freezing causes spurious toxicity in the control samples, it cannot be recommended for toxicological studies. In the context of the assessment of sediment toxicity by embryo-larval bioassays, fresh (4 C) storage is recommended when sediments need to be stored for no longer than a few days. The advisable duration of fresh storage to avoid false-negative results is directly related to the degree of toxicity. Should the sediments require prolonged storage, freezing at {minus}20 C appears to be the best choice.

Beiras, R. [Univ. de Vigo, Galicia (Spain). Area de Ecoloxia; His, E. [IFREMER Station d`Arcachon (France). Quai Silohuette; Seaman, M.N.L. [Inst. of Marine Research, Kiel (Germany). Fisheries Biology Dept.

1998-10-01

40

Artifacts in ambient toxicity testing  

SciTech Connect

Short-term toxicity tests with fathead minnow (Pimephales promelas) larvae and Ceriodaphnia dubia can be used to estimate the acute or chronic toxicity of effluents or receiving water. The results of effluent toxicity tests may need to be interpreted differently from the results of ambient toxicity tests. In this paper we provide examples of common artifacts, which can cause either false positives or false negatives, that we have encountered when these tests are used in ambient assessments. The examples we provide are drawn from diverse effluent and ambient water toxicity tests conducted at the Oak Ridge National Laboratory from March, 1985 through November, 1991. Three types of artifacts which have been encountered when using these tests in ambient applications are explored here. One type involves unusual replicate-specific variance in survival of fathead minnow larvae. The second and third types of artifacts affect the C. dubia test and appear to be related to food availability.

Kszos, L.A.; Stewart, A.J.

1992-01-01

41

Artifacts in ambient toxicity testing  

SciTech Connect

Short-term toxicity tests with fathead minnow (Pimephales promelas) larvae and Ceriodaphnia dubia can be used to estimate the acute or chronic toxicity of effluents or receiving water. The results of effluent toxicity tests may need to be interpreted differently from the results of ambient toxicity tests. In this paper we provide examples of common artifacts, which can cause either false positives or false negatives, that we have encountered when these tests are used in ambient assessments. The examples we provide are drawn from diverse effluent and ambient water toxicity tests conducted at the Oak Ridge National Laboratory from March, 1985 through November, 1991. Three types of artifacts which have been encountered when using these tests in ambient applications are explored here. One type involves unusual replicate-specific variance in survival of fathead minnow larvae. The second and third types of artifacts affect the C. dubia test and appear to be related to food availability.

Kszos, L.A.; Stewart, A.J.

1992-10-01

42

Assessing the toxicity to fish embryos of surface water from the Watts Bar Lake/Clinch River system  

SciTech Connect

Successful reproduction of fish populations requires the successful development of offspring into new reproductive cohorts. In order to evaluate the ability of fish offspring to survive and develop properly in the Watts Bar Lake/Clinch River system downstream of the Department of Energy facilities in Oak Ridge, TN, a series of fish embryo-larval toxicity tests were conducted on surface water samples from Poplar Creek and the Clinch River adjacent to the Oak Ridge Reservation. Quarterly tests were conducted over an eighteen-month interval with embryos from laboratory stocks of the Japanese medaka (Oryzias latipes). Eggs obtained from largemouth bass (Micropterus salmoides) and redbreast sunfish (Lepomis auritus) collected from reference sites during their respective breeding seasons were fertilized in vitro for additional embryo-larval tests utilizing fish species indigenous to the Watts Bar/Clinch River system. Average survival of medaka embryos decreased significantly in water from Poplar Creek sites within the Oak Ridge Reservation, coincident with an increase in the prevalence of certain developmental abnormalities. Similar but less pronounced results were also obtained with redbreast sunfish embryos. Development of largemouth bass eggs was not adversely affected by any of the tested water samples. These findings suggest that the development of fish eggs and fry in certain reaches of the Watts Bar Lake/Clinch River system may be negatively impacted by activities on the Oak Ridge Reservation.

Ivey, L.J.; Niemela, S.L.; McCracken, M.K.; Greeley, M.S. Jr. [Oak Ridge National Lab., TN (United States)

1995-12-31

43

Developmental toxicity of cypermethrin in embryo-larval stages of zebrafish  

Microsoft Academic Search

Cypermethrin, a type II pyrethroid insecticide, is widely used throughout the world in agriculture, forestry, horticulture and homes. Though the neurotoxicity of cypermethrin has been thoroughly studied in adult rodents, little is so far available regarding the developmental toxicity of cypermethrin to fish in early life stages. To explore the potential developmental toxicity of cypermethrin, 4-h post-fertilization (hpf) zebrafish embryos

Xiangguo Shi; Aihua Gu; Guixiang Ji; Yuan Li; Jing Di; Jing Jin; Fan Hu; Yan Long; Yankai Xia; Chuncheng Lu; Ling Song; Shoulin Wang; Xinru Wang

2011-01-01

44

Developmental toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in artificially fertilized crucian carp (Carassius auratus) embryo.  

PubMed

2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent bioaccumulative environmental contaminant that is an endocrine disruptor. Embryos of various fish species are responsive to TCDD and have been used as an alternative method to the acute toxicity test with juvenile and adult fish. The TCDD test has similar endpoints of developmental toxicity. However, their sensitivity and signs of TCDD-induced toxicity are different depending on fish species and its habit. Crucian carp (Carassius auratus) - the sentinel species for persistent organic pollutants and a common foodfish in China, Japan, and Korea - was used to identify the developmental toxicity of TCDD. We obtained the fertilized eggs from the artificial fertilization of crucian carp (97.45% success rate). Embryos at 3h post fertilization (hpf) were exposed to no vehicle, vehicle (dimethylsulfoxide, 0.1% v/v) or TCDD (0.128, 0.32, 0.8, 2 and 5 ?g/L) for 1h and then fresh water was changed and aerated. Embryonic development and toxicity were monitored until 150 hpf. TCDD-exposed group showed no effects on embryo mortality and hatching rate from 6 to 126 hpf. On the other hand, the post-hatching mortality rate in TCDD-exposed group was increased in a dose-dependent manner, especially at high doses (0.8, 2 and 5 ?g/L). The LD50 for larval mortality was calculated to 0.24 ng TCDD/g embryo. Pericardial edema was continuously observed in larvae of TCDD-exposed groups from hatching complete time (78 hpf), followed by the onset of yolk sac edema. Hemorrhage and edema showed a significant increase depending on exposure concentration and time. Expression of TCDD-related CYP1A genes was evaluated quantitatively. Embryo and larvae in TCDD-exposed groups displayed a significant increase of CYP1A gene expression. Overall, we defined TCDD-induced toxicity in artificially fertilized crucian carp embryo and these results suggest that crucian carp can be applied as an early life stage model of TCDD-induced toxicity. PMID:24751158

Park, Yong Joo; Lee, Min Jee; Kim, Ha Ryong; Chung, Kyu Hyuck; Oh, Seung Min

2014-09-01

45

vEmbryo In Silico Models: Predicting Vascular Developmental Toxicity  

EPA Science Inventory

The cardiovascular system is the first to function in the vertebrate embryo, reflecting the critical need for nutrient delivery and waste removal during organogenesis. Blood vessel development occurs by complex interacting signaling networks, including extra-cellular matrix remod...

46

Toxicity of weathered coal tar for shortnose sturgeon (Acipenser brevirostrum) embryos and larvae.  

PubMed

Weathered coal tar collected from the Connecticut River near Holyoke, Massachusetts, was toxic to shortnose sturgeon embryos and larvae in whole sediment flow-through and elutriate static-renewal laboratory exposures. Sterile laboratory sand and clean Connecticut River sand, collected upstream from the coal tar deposits, produced no significant difference in toxicity to sturgeon embryos-larvae, while coal tar-contaminated sediment produced over 95% embryo-larval mortality. Hydrocarbon transfer and subsequent toxicity appeared to be via direct contact of the embryos with contaminated sediment, rather than via exposure to soluble hydrocarbons. This conclusion was supported by exposure of embryos and larvae to elutriates (e.g., water soluble extract) of coal-tar sediments, that resulted in embryo and larval mortality at low molecular weight PAH concentrations-0.47 mg/L, higher than would occur naturally. No decrease in petroleum hydrocarbon concentration was observed in sediments exposed to flowing water for 14 d, supporting the contention that soluble hydrocarbons were not responsible for the observed toxicity in whole sediment exposures under the conditions employed in this study. PMID:8785011

Kocan, R M; Matta, M B; Salazar, S M

1996-08-01

47

Comparison of diazinon toxicity to embryos of Xenopus laevis and Danio rerio; degradation of diazinon in water.  

PubMed

The aim of this study was to determine the toxic effect of diazinon (organophosphate insecticide) to embryos of Xenopus laevis and Danio rerio. The 96-h LC?? values showed higher toxicity of diazinon for X. leavis in standard solution (9.84 mg/L) compared to the pond water (12.64 mg/L). Teratogenic index for diazinon was 1.3 and 1.6, respectively. The 96-h LC?? diazinon values demonstrated similar sensitivity of embryos D. rerio (8.21-9.34 mg/L) and X. laevis in standard test solutions. Our results reflect that direct application of diazinon into the water can be associated with significant risks to aquatic organisms. PMID:21505793

Modra, Helena; Vrskova, Dagmar; Macova, Stanislava; Kohoutkova, Jana; Hajslova, Jana; Haluzova, Ivana; Svobodova, Zdenka

2011-06-01

48

Primary screening of the bioactivity of brackishwater cyanobacteria: toxicity of crude extracts to Artemia salina larvae and Paracentrotus lividus embryos.  

PubMed

Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuarine environments, towards the nauplii of the brine shrimp Artemia salina and embryos of the sea urchin Paracentrotus lividus. The A. salina lethality test was used as a frontline screen and then complemented by the more specific sea urchin embryo-larval assay. Eighteen cyanobacterial isolates, belonging to the genera Cyanobium, Leptolyngbya, Microcoleus, Phormidium, Nodularia, Nostoc and Synechocystis, were tested. Aqueous extracts of cyanobacteria strains showed potent toxicity against A. salina, whereas in P. lividus, methanolic and aqueous extracts showed embryo toxicity, with clear effects on development during early stages. The results suggest that the brackishwater cyanobacteria are producers of bioactive compounds with toxicological effects that may interfere with the dynamics of invertebrate populations. PMID:20411110

Lopes, Viviana R; Fernández, Nuria; Martins, Rosário F; Vasconcelos, Vitor

2010-01-01

49

AQUATIC ANIMALS IN TOXICITY TESTING  

EPA Science Inventory

Aquatic animals serve as useful models for toxicological evaluations that bridge the gap between real world and laboratory problems. Selected aquatic organisms are adaptable to laboratory experimentation in areas such as toxicity testing and chronic sublethal risks evaluation inc...

50

Effects of simulated weathering on the toxicity of selected crude oils and their components to sea urchin embryos.  

PubMed

Artificial weathering of Angolan crude and a Heavy Fuel Oil (HFO) was performed by evaporation and photooxidation. The aliphatic, aromatic, polar and asphaltene fractions of the fresh and weathered oils were isolated. The toxicity of the water accommodated fraction or an oil/fraction dissolved in DMSO was assessed using the sea urchin embryo test. Photooxidation was observed to decrease the aromatics content and increase polar compounds. A slight reduction in the toxicity of Angolan crude was observed following weathering for the water-accommodated fraction and the extract in DMSO, but no effect was seen for the Heavy Fuel Oil. For aliphatic compounds, the toxicity decreased in the order fresh>evaporated>photooxidated for both Angolan crude and HFO. Weathering slightly increased the toxicity of the aromatic and polar fractions of the oil. The aromatic fractions were responsible for most of the toxicity and the polar compounds were the second most important toxic components, despite having less or similar abundance than the aliphatic fraction. The toxic contribution of the aromatic compounds was higher for the HFO than for the Angolan crude. A decrease in the toxicity of Angolan crude following weathering correlated with a reduction in the toxicity of the aliphatic fraction. PMID:23747464

Rial, Diego; Radovi?, Jagoš R; Bayona, Josep M; Macrae, Kenneth; Thomas, Kevin V; Beiras, Ricardo

2013-09-15

51

Influence of storage methods, refrigeration or freezing, on the toxicity of wastewater samples to oyster embryos.  

PubMed

One of the main concerns in wastewater whole effluent assessment is the sampling phase and the sample chain of custody before any toxicity evaluation. The major problem is related to establishing the correct method for sample storage in order to perform toxicity bioassays. The toxicity of some domestic and glass factory industrial wastewater samples stored both by refrigeration at 4 +/- 1 degrees C for no more than three days, and freezing at -18 +/- 1 degrees C for no more than one month was compared via the embryo larval development bioassay with the oyster Crassostrea gigas. The results showed no significant differences between the toxicities of refrigerated and frozen wastewater samples. The wastewater classification, according to a score based on four toxicity classes, showed that the preservation methods did not alter the toxicity classification of the samples. In particular, it was demonstrated that the samples considered as 'not acutely toxic' after refrigeration were also found to have this classification after freezing. PMID:19603701

Libralato, G; Avezzù, F; Losso, C; Volpi Ghirardini, A

2009-05-01

52

Linking embryo toxicity with genotoxic responses in the freshwater snail Physa acuta: single exposure to benzo(a)pyrene, fluoxetine, bisphenol A, vinclozolin and exposure to binary mixtures with benzo(a)pyrene.  

PubMed

Genotoxic effects on fauna after waterborne pollutant exposure have been demonstrated by numerous research programmes. Less effort has been focused on establishing relationship between genotoxicity and long-term responses at higher levels of biological organization. Taking into account that embryos may be more sensitive indicators of reproductive impairment than alterations in fertility, we have developed two assays in multiwell plates to address correlations between embryo toxicity and genotoxicity. The potential teratogenicity was assessed by analyzing abnormal development and mortality of Physa acuta at embryonic stage. Genotoxicity was measured by the micronucleus (MN) test using embryonic cells. Our results showed that linkage between genotoxicity and embryo toxicity depends on mechanisms of action of compounds under study. Embryo toxic responses showed a clear dose-related tendency whereas no clear dose-dependent effect was observed in micronucleus induction. The higher embryo toxicity was produced by benzo(a)pyrene exposure followed by fluoxetine and bisphenol A. Vinclozolin was the lower embryo toxic compound. Binary mixtures with BaP always resulted in higher embryo toxicity than single exposures but antagonistic effects were observed for MN induction. Benzo(a)pyrene produced the higher MN induction at 0.04 mg/L, which also produced clear embryo toxic effects. Fluoxetine did not induce cytogenetic effects but 0.25mg/L altered embryonic development. Bisphenol A significantly reduced hatchability at 0.5mg/L while MN induction appeared with higher treatments than those that start causing teratogenicity. Much higher concentration of vinclozolin (5mg/L) reduced hatchability and induced maximum MN formation. In conclusion, while validating one biomarker of genotoxicity and employing one ecologically relevant effect, we have evaluated the relative sensitivity of a freshwater mollusc for a range of chemicals. The embryo toxicity test is a starting point for the development of a life cycle test with freshwater snails even for undertaking multigeneration studies focused on transgenerational effects. PMID:22417675

Sánchez-Argüello, Paloma; Aparicio, Natalia; Fernández, Carlos

2012-06-01

53

Individual and joint toxic effects of cadmium sulfate and ?-naphthoflavone on the development of zebrafish embryo*  

PubMed Central

This paper aims to evaluate the individual and joint toxicities of cadmium sulfate (CdSO4) and ?-naphthoflavone (ANF) in zebrafish embryos. As a result, CdSO4 caused both lethal and sub-lethal effects, such as 24 h post-fertilization (hpf) death and 72 hpf delayed hatching. However, ANF only caused sub-lethal effects, including 48 hpf cardiac edema and 72 hpf delayed hatching. Taking 24 hpf death and 48 hpf cardiac edema as endpoints, the toxicities of CdSO4 and ANF were significantly enhanced by each other. Consistently, both CdSO4 and ANF caused significant oxidative stress, including decreases in the reduced glutathione (GSH) level, inhibition of superoxide dismutase (SOD) activity, as well as increases in malondialdehyde (MDA) content in zebrafish embryos, but these mixtures produced much more significant alterations on the biomarkers. Co-treatment of CdSO4 and ANF significantly down-regulated the mRNA level of multidrug resistance-associated protein (mrp) 1 and cytochrome P450 (cyp) 1a, which constituted the protective mechanisms for zebrafish embryos to chemical toxins. In conclusion, co-treatment of CdSO4 and ANF exhibited a much more severe damage in zebrafish embryos than individual treatment. Meanwhile, production of oxidative stress and altered expression of mrp1 and cyp1a could be important components of such joint toxicity. PMID:25183031

Yin, Jian; Yang, Jian-ming; Zhang, Feng; Miao, Peng; Lin, Ying; Chen, Ming-li

2014-01-01

54

Toxicity testing using Caenorhabditis elegans  

SciTech Connect

Caenorhabditis elegans is a small free-living nematode that is representative of what may be the most abundant animal group. It has been promoted as a possible model organism for toxicity testing in the laboratory and in field evaluations in part because more is known about its biology than any other animal, Toxicity tests using C. elegans have been developed with lethality, reproduction, and behavior as end points. The tests have also been developed to varying degrees using standard laboratory media, water, and soil. The results of the tests when exposing C. elegans to a variety of metals, inorganic, and organic compounds indicate it is typically at least as sensitive as other species currently used, such as Daphnia and earthworms, and is generally much easier to maintain in the laboratory. The advantages and disadvantages of C. elegans and the state of development of the tests will be discussed.

Middendorf, P.J.; Dusenbery, D.B. [Georgia Institute of Technology, Atlanta, GA (United States); Williams, P.L. [Univ. of Georgia, Athens, GA (United States)

1995-12-31

55

Reproductive toxicity testing of vaccines  

Microsoft Academic Search

Vaccines play a major role in the prevention of human birth defects by protecting the pregnant woman from teratogenic or otherwise harmful infections. Until now, it has not been common practice to perform preclinical developmental toxicity tests for new vaccines. Despite the excellent safety record of vaccines, increased attention is now being given to the feasibility of screening new vaccines

François Verdier; Paul C Barrow; Joëlle Burge

2003-01-01

56

Zebrafish (Danio rerio) embryos as a model for testing proteratogens.  

PubMed

Zebrafish embryos have been shown to be a useful model for the detection of direct acting teratogens. This communication presents a protocol for a 3-day in vitro zebrafish embryo teratogenicity assay and describes results obtained for 10 proteratogens: 2-acetylaminofluorene, benzo[a]pyrene, aflatoxin B(1), carbamazepine, phenytoin, trimethadione, cyclophosphamide, ifosfamide, tegafur and thio-TEPA. The selection of the test substances accounts for differences in structure, origin, metabolism and water solubility. Apart from 2-acetylaminofluorene, which mainly produces lethal effects, all proteratogens tested were teratogenic in zebrafish embryos exposed for 3 days. The test substances and/or the substance class produced characteristic patterns of fingerprint endpoints. Several substances produced effects that could be identified already at 1 dpf (days post fertilization), whereas the effects of others could only be identified unambiguously after hatching at ? 3 dpf. The LC?? and EC?? values were used to calculate the teratogenicity index (TI) for the different substances, and the EC?? values were related to human plasma concentrations. Results lead to the conclusion that zebrafish embryos are able to activate proteratogenic substances without addition of an exogenous metabolic activation system. Moreover, the teratogenic effects were observed at concentrations relevant to human exposure data. Along with other findings, our results indicate that zebrafish embryos are a useful alternative method for traditional teratogenicity testing with mammalian species. PMID:21237239

Weigt, Stefan; Huebler, Nicole; Strecker, Ruben; Braunbeck, Thomas; Broschard, Thomas H

2011-03-15

57

Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to embryos of the fathead minnow (Pimephales promelas, Rafinesque)  

SciTech Connect

This study correlates the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) residue and its toxicity to the fathead minnow embryo exposed to levels lower than the TCDD solubility range. The TCDD tissue doses in the embryo/larvae were related to gross lesions, delayed hatching, and death. A 7-day bioconcentration factor on a lipid basis (BCF{sub L}) was calculated. Embryos at the blatsula stage were exposed to [{sup 3}H] TCDD water concentrations (0.37, 0.59, 1.2, 2.83, and 10.1 6 ng/L), a nontreatment control and a solvent carrier control. Lesions were qualified as mild and severe based on their onset and their pathogenesis. Thus, mild lesions developed just prior to hatching or post-hatching at the fifth day of development. The severe lesions appeared at the third day of development. Embryos with tissue doses {le}2.46 {+-} 1.34 ng/g consistently developed mild lesions, while embryos with tissue doses {ge} 12.07 {+-} 4.91 ng/g developed severe lesions. The lowest observable adverse effect level was 0.04 {+-} 0.02 ng/g. The calculated 7-day ED{sub 50} was 0.14 ng/g. There was no delayed hatching at any of the concentrations tested. Embryo death occurred at a tissue concentration {ge}2.46 ng/g. The calculated 7-day LD{sub 50} was 25.71 ng/g. The relationship between the concentration of TCDD in the water (x = ng/L) and in the tissue dose (y = ng/g) fitted a linear curve y = {minus}1,143 + 3,792.5x, r{sup 2} = 0.98. The calculated BCF{sub L} (wet weight) was dose dependent. Embryos with tissue doses of 0.04 and 0.16 ng/g had BCF{sub L} of 2,700 and 3,325, respectively. Embryos with tissue doses of 2.46, 12.07, and 37.07 ng/g, had a BCF{sub L} of 104,225, 106,625 and 91,075, respectively.

Olivieri, C.; Cooper, K. [Rutgers Univ., New Brunswick, NJ (United States). Cook Coll.

1995-12-31

58

Sediment-contact fish embryo toxicity assay with Danio rerio to assess particle-bound pollutants in the Tietê River Basin (São Paulo, Brazil).  

PubMed

The Tietê River and its tributary Pinheiros River receive a highly complex organic and inorganic pollutants load from sanitary sewage and industrial sources, as well as agricultural and agroindustrial activities. The aim of the present study was to evaluate the embryotoxic and teratogenic effects of sediments from selected locations in the Tietê River Basin by means of the sediment contact embryo toxicity assay with Danio rerio, in order to provide a comprehensive and realistic insight into the bioavailable hazard potential of these sediment samples. Lethal and sub-lethal effects were recorded, and high embryo toxicity could be found in the samples not only in the vicinity of the megacity São Paulo (Billings reservoir and Pinheiros River samples), but also downstream (in the reservoirs Barra Bonita, Promissão and Três Irmãos). Results confirm that most toxicity is due to the discharges of the metropolitan area of São Paulo. However, they also indicate additional sources of pollutants along the river course, probably from industrial, agricultural and agroindustrial residues, which contribute to the degradation of each area. The sediment contact fish embryo test showed to be powerful tool to detect embryo toxicity in sediments, not only by being a sensitive method, but also for taking into account bioavailability. This test provides an ecological highly realistic and relevant exposure scenario, and should therefore be added in ecotoxicological sediment quality assessments. PMID:21802730

Rocha, Paula Suares; Bernecker, Conny; Strecker, Ruben; Mariani, Carolina Fiorillo; Pompêo, Marcelo Luiz Martins; Storch, Volker; Hollert, Henner; Braunbeck, Thomas

2011-10-01

59

Toxicity of polychlorinated diphenyl ethers in Hydra attenuata and in rat whole embryo culture  

E-print Network

the toxicity of selected PCDEs in cultures of Hydra artenuata and post-implantation rat whole embryos. The toxicity of several closely related polychlorinated biphenyls (PCBs) was evaluated in both cultures and 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD...', 4, 4', 5-pentachlorodiphenyl ether, 2, 2;4, 4;5, 5 '- hexachlorodiphenyl ether, 2, 3, 3', 4, 4', 5-hexachlorodiphenyl ether, 3, 3, 4, 4- tetrachlorobiphenyl, or 2, 3, 7, 8-TCDD. Embryonic growth and development parameters (yolk sac diameter, crown...

Becker, Marion Carol

2012-06-07

60

Developmental toxicity of cypermethrin in embryo-larval stages of zebrafish.  

PubMed

Cypermethrin, a type II pyrethroid insecticide, is widely used throughout the world in agriculture, forestry, horticulture and homes. Though the neurotoxicity of cypermethrin has been thoroughly studied in adult rodents, little is so far available regarding the developmental toxicity of cypermethrin to fish in early life stages. To explore the potential developmental toxicity of cypermethrin, 4-h post-fertilization (hpf) zebrafish embryos were exposed to various concentrations of cypermethrin (0, 25, 50, 100, 200 and 400 ?g L?¹) until 96 h. Among a suite of morphological abnormalities, the unique phenotype curvature was observed at concentrations as low as 25 ?g L?¹. Studies revealed that 400 ?g L?¹ cypermethrin significantly increased malondialdehyde production. In addition, activity of antioxidative enzymes including superoxide dismutase and catalase were significantly induced in zebrafish larvae in a concentration-dependent manner. To further investigate the toxic effects of cypermethrin on fish, acridine orange (AO) staining was performed at 400 ?g L?¹ cypermethrin and the result showed notable signs of apoptosis mainly in the nervous system. Cypermethrin also down-regulated ogg1 and increased p53 gene expression as well as the caspase-3 activity. Our results demonstrate that cypermethrin was able to induce oxidative stress and produce apoptosis through the involvement of caspases in zebrafish embryos. In this study, we investigated the developmental toxicity of cypermethrin using zebrafish embryos, which could be helpful in fully understanding the potential mechanisms of cypermethrin exposure during embryogenesis and also suggested that zebrafish could serve as an ideal model for studying developmental toxicity of environmental contaminants. PMID:21840035

Shi, Xiangguo; Gu, Aihua; Ji, Guixiang; Li, Yuan; Di, Jing; Jin, Jing; Hu, Fan; Long, Yan; Xia, Yankai; Lu, Chuncheng; Song, Ling; Wang, Shoulin; Wang, Xinru

2011-10-01

61

Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa).  

PubMed

We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection. PMID:18704254

Augspurger, T P; Tillitt, D E; Bursian, S J; Fitzgerald, S D; Hinton, D E; Di Giulio, R T

2008-11-01

62

Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa)  

USGS Publications Warehouse

We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection. ?? 2008 US Government.

Augspurger, T.P.; Tillitt, D.E.; Bursian, S.J.; Fitzgerald, S.D.; Hinton, D.E.; Di Giulio, R.T.

2008-01-01

63

Chronic toxicity of heavy fuel oils to fish embryos using multiple exposure scenarios.  

PubMed

The chronic toxicity to rainbow trout (Oncorhynchus mykiss) embryos of heavy fuel oil (HFO) 6303, weathered HFO 6303, HFO 7102, and medium South American (MESA) crude oil was assessed by different exposure regimes. These included water accommodated fractions (WAF; water in contact with floating oil), chemically enhanced WAF (CEWAF; oil dispersed with Corexit 9500), and effluent from columns of gravel coated with stranded oil. Heavy fuel oil WAF was nontoxic and did not contain detectable concentrations of hydrocarbons, likely because the high density and viscosity of HFO prevented droplet formation. In contrast, chemically dispersed HFO and effluent from columns of stranded HFO contained measurable concentrations of alkyl polycyclic aromatic hydrocarbons (PAH), coincident with embryo toxicity. These exposure regimes enhanced the surface area of oil in contact with water, facilitating oil-water partitioning of hydrocarbons. Heavy fuel oil was consistently more toxic to fish than crude oil and the rank order of alkyl PAH concentrations in whole oil were sufficient to explain the rank order of toxicity, regardless of exposure method. Thus, the propensity of HFO to sink and strand in spawning shoals creates a long-term risk to developing fish because of the sustained release of PAHs from HFO to interstitial waters. Further, PAH monitoring is key to accurate risk assessment. PMID:24464524

Martin, Jonathan D; Adams, Julie; Hollebone, Bruce; King, Thomas; Brown, R Stephen; Hodson, Peter V

2014-03-01

64

Stage-dependent toxicity of bisphenol a on Rhinella arenarum (anura, bufonidae) embryos and larvae.  

PubMed

The acute and chronic toxicity of bisphenol A (BPA) was evaluated on the common South American toad Rhinella arenarum embryos and larvae by means of continuous and pulse exposure treatments. Embryos were treated continuously from early blastula (S.4) up to complete operculum (S.25), during early larval stages and by means of 24 h pulse exposures of BPA in concentrations ranging between 1.25 and 40 mg L(-1) , in order to evaluate the susceptibility to this compound in different developmental stages. For lethal effects, S.25 was the most sensitive and gastrula was the most resistant to BPA. The Teratogenic Index for neurula, the most sensitive embryonic stage for sublethal effects was 4.7. The main morphological alterations during early stages were: delayed or arrested development, reduced body size, persistent yolk plug, microcephaly, axial/tail flexures, edemas, blisters, waving fin, underdeveloped gills, mouth malformations, and cellular dissociation. BPA caused a remarkable narcotic effect from gill circulation stage (S.20) onwards in all the organisms exposed after 3 h of treatment with 10 mg L(-1) BPA. After recovering, the embryos exhibited scarce response to stimuli, erratic or circular swimming, and spasmodic contractions from 5 mg L(-1) onwards. Our results highlight the lethal and sublethal effectsof BPA on R. arenarum embryos and larvae, in the last case both at structural and functional levels. PMID:22052622

Wolkowicz, Ianina R Hutler; Herkovits, Jorge; Pérez Coll, Cristina S

2014-02-01

65

Use of toxicogenomics to predict the potential toxic effect of Benzo(a)pyrene on zebrafish embryos: ocular developmental toxicity.  

PubMed

Benzo(a)pyrene (BaP) is a representative polycyclic aromatic hydrocarbon (PAH), which is ubiquitous in the environment. The toxic effects of BaP on fish embryos have been described in detail, but some potentially toxic effects of BaP might have been neglected owing to the limitations of traditional techniques. In the present research, global transcriptional patterns were used to study the potentially toxic effects of BaP, as well as its underlying toxicological mechanisms. The expression levels of multiple genes were significantly changed by BaP exposure. The results of ontology assignments and cluster analysis showed that BaP could affect the processes of photoreceptor maintenance and phototransduction. We also conducted an experiment on phototactic response and found that larvae exposed to BaP displayed a decreasing response to light. In addition, BaP exposure decreased the cellular density of the ganglion cell layer (GCL) significantly. These results suggested that BaP exposure induced visual system developmental defects and dysfunction by perturbation of photoreceptor development related genes. Our results were helpful for an understanding of the toxicity of BaP. This study also indicated that microarray analysis was effective for predicting the potential toxicity of chemicals with high sensitivity and accuracy. PMID:24875912

Huang, Lixing; Zuo, Zhenghong; Zhang, Youyu; Wu, Meifang; Lin, Jackie Jin; Wang, Chonggang

2014-08-01

66

Triazole-induced toxicity in developing rare minnow (Gobiocypris rarus) embryos.  

PubMed

Using rare minnow (Gobiocypris rarus) at early-life stages as experimental models, the developmental toxicity of five widely used triazole fungicides (myclobutanil, fluconazole, flusilazole, triflumizole, and epoxiconazole) were investigated following exposure to 1-15 mg/L for 72 h. Meanwhile, morphological parameters (body length, body weight, and heart rate), enzyme activities (superoxide dismutase (SOD), glutathione S-transferase (GST), adenosine triphosphatase (ATPase), and acetyl cholinesterase (AChE)), and mRNA levels (hsp70, mstn, mt, apaf1, vezf1, and cyp1a) were also recorded following exposure to 0.2, 1.0, and 5.0 mg/L for 72 h. Results indicated that increased malformation and mortality, decreased body length, body weight, and heart rate provide a concentration-dependent pattern; values of 72 h LC50 (median lethal concentration) and EC50 (median effective concentration) ranged from 3 to 12 mg/L. Most importantly, the results of the present study suggest that even at the lowest concentration, 0.2 mg/L, five triazole fungicides also caused notable changes in enzyme activities and mRNA levels. Overall, the present study points out that those five triazole fungicides are highly toxic to the early development of G. rarus embryos. The information presented in this study will be helpful in better understanding the toxicity induced by triazole fungicides in fish embryos. PMID:25028328

Zhu, Bin; Liu, Lei; Gong, Yu-Xin; Ling, Fei; Wang, Gao-Xue

2014-12-01

67

Toxicity test: Fluorescent silicon nanoparticles  

NASA Astrophysics Data System (ADS)

Semiconductor nanoparticles ('quantum dots', QDs) are useful fluorescent materials because of their high fluorescent stability compared with existing organic fluorescent dyes. QDs were tested in many biochemical experiments, and the reported results suggested their advantages. However, when we consider their application at the clinical level, their large-scale use may be problematic because of their influence on the environment and the living body as a result of cadmium contained in existing mainstream QDs. Here we report on the characteristics of silicon particles (synthesised using the gas phase method and liquid phase method, currently in the development stage) as a substitute material, focusing on cell-level safety and the potential mechanisms of toxicity.

Fujoka, K.; Hanada, S.; Kanaya, F.; Hoshino, A.; Sato, K.; Yokosuka, S.; Takigami, Y.; Hirakuri, K.; Shiohara, A.; Tilley, R. D.; Manabe, N.; Yamamoto, K.; Manome, Y.

2011-07-01

68

Comparison of Methods to Obtain a Liquid Phase in Marine Sediment Toxicity Bioassays with Paracentrotus lividus Sea Urchin Embryos  

Microsoft Academic Search

Sediment toxicity bioassays using planktonic organisms are widespread tools in environmental quality assessment, but they\\u000a have limitations because the method for extracting and diluting the liquid phase may affect the final toxicity. The present\\u000a study compares the toxicity on sea urchin embryos and larvae of elutriates and pore water obtained from intertidal sediments\\u000a by various methods. The effects of mixing

R. Beiras

2002-01-01

69

Low-dose agrochemicals and lawn-care pesticides induce developmental toxicity in murine preimplantation embryos.  

PubMed Central

Occupational exposures to pesticides may increase parental risk of infertility and adverse pregnancy outcomes such as spontaneous abortion, preterm delivery, and congenital anomalies. Less is known about residential use of pesticides and the risks they pose to reproduction and development. In the present study we evaluate environmentally relevant, low-dose exposures to agrochemicals and lawn-care pesticides for their direct effects on mouse preimplantation embryo development, a period corresponding to the first 5-7 days after human conception. Agents tested were those commonly used in the upper midwestern United States, including six herbicides [atrazine, dicamba, metolachlor, 2,4-dichlorophenoxyacetic acid (2,4-D)], pendimethalin, and mecoprop), three insecticides (chlorpyrifos, terbufos, and permethrin), two fungicides (chlorothalonil and mancozeb), a desiccant (diquat), and a fertilizer (ammonium nitrate). Groups of 20-25 embryos were incubated 96 hr in vitro with either individual chemicals or mixtures of chemicals simulating exposures encountered by handling pesticides, inhaling drift, or ingesting contaminated groundwater. Incubating embryos with individual pesticides increased the percentage of apoptosis (cell death) for 11 of 13 chemicals (p embryo for 3 of 13 agents (p embryos (p embryo (p

Greenlee, Anne R; Ellis, Tammy M; Berg, Richard L

2004-01-01

70

Toxicity, uptake kinetics and behavior assessment in zebrafish embryos following exposure to perfluorooctanesulphonicacid (PFOS)  

PubMed Central

Perfluorooctanesulphonicacid (PFOS), a persistent organic contaminant, has been widely detected in the environment, wildlife and humans, but few studies have assessed its effect on aquatic organisms. The present study evaluated the effect of PFOS on zebrafish embryos. Zebrafish embryos exhibited bent spine and developmental toxicity after exposure to various PFOS concentrations (0.01-16.0 ?M) from 6 to 120 hour post-fertilization (hpf). The LC50 at 120 hpf was 4.39 ?M and the EC50 at 120 hpf was 2.23 ?M. PFOS induced apoptosis at 24 hpf was consistently located in the brain, eye, and tail region of embryos. PFOS elevated the basal rate of swimming after 4 days of exposure, and larvae exposed to PFOS (0.5-8.0?M) for only 1 h at 6 dpf swam faster with increasing PFOS concentration. Larvae exposed to 16.0 ?M PFOS for 24 h periods from 1 to 121 hpf showed the highest incidence of malformations in the 97-121 hpf window. Continuous exposure to PFOS from 1 to 121 hpf resulted in a steady accumulation with no evidence of elimination. Our results further the understanding of the health risks of PFOS to aquatic organisms and identify additional research needed on PFOS toxicology. PMID:20171748

Huang, Haihua; Huang, Changjiang; Wang, Lijun; Ye, Xiaowei; Bai, Chenglian; Simonich, Michael T.; Tanguay, Robert L.; Dong, Qiaoxiang

2014-01-01

71

Evaluation of the Developmental Toxicity of Caffeine and Caffeine Metabolites using the Frog Embryo Teratogenesis Assay— Xenopus (FETAX)  

Microsoft Academic Search

The developmental toxicities of caffeine and 13 metabolites, including theophylline, and paraxanthine and a synthetic methylxanthine analogue 3-isobutyl-methylxanthine (IBMX) were evaluated using the Frog Embryo Teratogenesis Assay—Xenopus (FETAX). Young X. laevis embryos were exposed to these compounds in each of two separate concentration–response experiments with and without an exogenous metabolic activation system (MAS). Results obtained from these studies indicated that

D. J. Fort; E. L. Stover; T. L. Propst; B. C. Faulkner; T. A. Vollmuth; F. J. Murray

1998-01-01

72

Testing for Toxic Algae By Tadd Barrow  

E-print Network

Testing for Toxic Algae By Tadd Barrow UNL Extension Educator, Water Quality Algae is a microscopic plant that occurs in all water. However, only certain conditions bring algae to the surface, making it toxic to animals, especially humans and dogs. Toxic algae often are naturally occurring from high

Nebraska-Lincoln, University of

73

Developmental toxicity of treated municipal wastewater effluent on Bombina orientalis (Amphibia: Anura) embryos.  

PubMed

Amphibian populations have been decreasing in urban freshwater systems in Korea. To elucidate the biological safety of treated wastewater effluent (TWE) in the Tancheon basin, the capital area of Korea, a 7-d-exposure Bombina orientalis embryo developmental toxicity assay was examined during the breeding season. In March, there were no significant differences in embryonic survival or malformation among the water samples. In July, following monsoon precipitation, embryonic lethality in TWE was significantly higher than in the upstream water sample. Malformation in TWE and TWE-mixed waters was significantly higher than in the control and upstream water samples. Tail muscle height of tadpoles also significantly decreased in TWE and TWE-mixed waters. Heavy metals were not detected in any samples. Total nitrogen, total phosphorous, and chemical oxygen demand in TWE markedly increased together with a decrease in dissolved oxygen in July. The increase in organic and inorganic loading following precipitation could have made TWE and TWE-mixed water not suitable for embryonic development. Though being managed based on physicochemical criteria, the water quality of TWE may not be sufficient to assure normal development of amphibian embryos. An amphibian developmental toxicity assay would be helpful for the water-quality management of TWE and urban freshwater systems in Korea. PMID:24436004

Park, Chan Jin; Ahn, Hyo Min; Cho, Seong Chan; Kim, Tae-Hoon; Oh, Jong-Min; Ahn, Hong Kyu; Chun, Seung-Hoon; Gye, Myung Chan

2014-04-01

74

Behavioural and developmental toxicity of chlorpyrifos and nickel chloride to zebrafish (Danio rerio) embryos and larvae.  

PubMed

In order to assess the combined toxicity of environmental chemicals with different modes of action in acute (2 h) and subchronic (11 d) exposures, embryos and larvae of Danio rerio were exposed to a heavy metal salt, nickel chloride (NiCl2), the insecticide chlorpyrifos (CHP) and their binary mixtures. Chlorpyrifos is an acetylcholine esterase inhibitor, which is likely to affect behaviour of the organism. NiCl2 targets the active sites of enzymes and is regarded as an unspecific toxicant for aquatic organisms. Several endpoints, such as locomotor activity, morphological abnormalities, and mortality of D. rerio embryos and larvae were studied. During acute exposures to > or =0.25 mg/L of chlorpyrifos, locomotor activity tended to increase. However, this activity decreased significantly at > or =7.5 mg Ni/L. Subchronic exposures to CHP resulted in behavioural changes at much lower concentrations (> or =0.01 mg/L) and considerably earlier than the observed increase in morphological abnormalities and mortality (LC(50) (10 d): 0.43 mg/L). Combined CHP and NiCl2 mixtures led to an antagonistic deviation from the concept of independent action, in the case of locomotor activity. Compared to developmental or survival parameters, behaviour was the most sensitive endpoint for CHP exposure in this study; therefore we recommend this parameter to complement already established endpoints. PMID:19477011

Kienle, Cornelia; Köhler, Heinz-R; Gerhardt, Almut

2009-09-01

75

Toxicity and cardiac effects of carbaryl in early developing zebrafish (Danio rerio) embryos  

SciTech Connect

Carbaryl, an acetylcholinesterase inhibitor, is known to be moderately toxic to adult zebrafish and has been reported to cause heart malformations and irregular heartbeat in medaka. We performed experiments to study the toxicity of carbaryl, specifically its effects on the heart, in early developing zebrafish embryos. LC50 and EC50 values for carbaryl at 28 h post-fertilization were 44.66 {mu}g/ml and 7.52 {mu}g/ml, respectively, and 10 {mu}g/ml carbaryl was used in subsequent experiments. After confirming acetylcholinesterase inhibition by carbaryl using an enzymatic method, we observed red blood cell accumulation, delayed hatching and pericardial edema, but not heart malformation as described in some previous reports. Our chronic exposure data also demonstrated carbaryl-induced bradycardia, which is a common effect of acetylcholinesterase inhibitors due to the accumulation of acetylcholine, in embryos from 1 day post-fertilization (dpf) to 5 dpf. The distance between the sinus venosus, the point where blood enters the atrium, and the bulbus arteriosus, the point where blood leaves the ventricle, indicated normal looping of the heart tube. Immunostaining of myosin heavy chains with the ventricle-specific antibody MF20 and the atrium-specific antibody S46 showed normal development of heart chambers. At the same time, acute exposure resulted in carbaryl-induced bradycardia. Heart rate dropped significantly after a 10-min exposure to 100 {mu}g/ml carbaryl but recovered when carbaryl was removed. The novel observation of carbaryl-induced bradycardia in 1- and 2-dpf embryos suggested that carbaryl affected cardiac function possibly through an alternative mechanism other than acetylcholinesterase inhibition such as inhibition of calcium ion channels, since acetylcholine receptors in zebrafish are not functional until 3 dpf. However, the exact nature of this mechanism is currently unknown, and thus further studies are required.

Lin, C.C.; Hui, Michelle N.Y.; Cheng, S.H. E-mail: bhcheng@cityu.edu.hk

2007-07-15

76

A novel algal toxicity testing technique for assessing the toxicity of both metallic and organic toxicants.  

PubMed

This study presents a closed-system algal toxicity test technique that is capable of detecting the effects of both organic and metallic toxicants. Toxicity testing was conducted by transferring adequate amounts of algal suspension, dilution water (with culture growth medium), and toxicants into 300-mL BOD bottles. The BOD bottles were completely filled up with no head-space left. The initial cell density and the exposure time were 15,000 cells/mL and 48 h, respectively. The performance of the above test method was evaluated using three heavy metals and six organic toxicants based on three different test endpoints, i.e., dissolved oxygen production, algal growth rate, and cell density. The proposed test revealed excellent test sensitivity and reproducibility. Currently, none of the existing algal toxicity test protocols is adequate for assessing the toxicity of organic chemicals. The closed-system algal toxicity tests developed by previous researchers also may not be ideal because the enlarged headspace and/or enriched bicarbonate buffer may result in either underestimations of the exposure concentrations or insensitive responses to both heavy metals and organic toxicants. Compared to the aforementioned algal toxicity test methods, the proposed technique in the present study has a more general applicability under conditions such as effluent samples containing both metals and organic toxicants or samples with unknown compositions. PMID:15899285

Lin, Jui-Ho; Kao, Wei-Chen; Tsai, Kuo-Pei; Chen, Chung-Yuan

2005-05-01

77

Toxic effects of pentachlorophenol, azinphos-methyl and chlorpyrifos on the development of Paracentrotus lividus embryos.  

PubMed

The application of many current-use pesticides has increased after the disuse of persistent, bioaccumulative or toxic ones as DDT or chlordane. Many of the used pesticides are considered less dangerous towards the environment for their physico-chemical properties. This study investigated the toxic effects of three current-use pesticides, pentachlorophenol (PCP), azinphos-methyl (AZM), and chlorpyrifos, on Mediterranean sea urchin Paracentrotus lividus early development and offspring quality. The experimental results showed that the most toxic pesticides were PCP and AZM at EC50 level. Nevertheless at low concentration PCP resulted the less toxic compound and showed EC1 value more protective than NOEC. PCP at high concentration seemed to modify cytoskeleton assembly, while at low concentrations, it could alter the deposition of the larval skeleton. OPs at low concentrations until 300 ?g/l showed a similar toxicological behaviour with a trend corresponding to the pesticide concentrations. At high concentration (500 ?g/l) the effect mainly observed was the embryos pre-larval arrest. This investigation highlighted the relevance to evaluate, in coastal seawaters, the levels of the used pesticides to understand the real impact on benthic populations mainly in sites characterized by intensive agriculture or floriculture activities, such as the coastal areas of the Mediterranean Sea. PMID:22101977

Buono, Silvia; Manzo, Sonia; Maria, Giovanna; Sansone, Giovanni

2012-04-01

78

POREWATER TOXICITY TESTING: AN OVERVIEW  

EPA Science Inventory

Sediments act as sinks for contaminants, where they may build up to toxic levels. Sediments containing toxic levels of contaminants pose a risk to aquatic life, human health, and wildlife. There is an overwhelming amount of evidence that demonstrates chemicals in sediments are re...

79

Selecting optimal eggs and embryonic developmental stages of fathead minnow (Pimephales promelas) for early life-stage toxicity tests.  

PubMed

Aquaculture research has indicated that fish embryo hatching success and larval survival can sometimes be predicted by embryo characteristics, such as blastomere cleavage patterns. An analogous strategy of individual assessment of spawned eggs could also be used to improve the quality of toxicity tests using early life-stages of fish where control-group survival determines experimental validity. Here we explored whether a simple method of assessing fathead minnow eggs and embryos for abnormalities could predict hatch success, and larval size at hatch, as indicators of embryo larval quality. Embryos were classified according to both their developmental stage and the presence of any abnormalities: uneven blastomere cleavage, atypical embryo size or shape, and the presence of inclusions in the yolk. Clutch size and fertilization rate did not predict embryo larval quality. Fewer abnormalities in embryos with ?32 cells correlated with longer larvae at hatch. Normal embryos were more likely to hatch successfully than abnormal embryos of the same clutch, but because abnormality rates were generally low, much of the variation in hatch success could not be attributed to visible embryo malformations. Blastomere symmetry may be a useful selection criterion in embryos <3 h postfertilization. Where toxicant exposures early in embryonic development are not required or possible, hatch success could be increased by using older embryos that have survived gastrulation. Purposeful selection of embryos with at least two blastomeres, blastomere symmetry, and few inclusions can improve control survival and improve the quality of any generated (sub)lethality data. In our laboratory, application of the egg-selection criteria significantly improved control group hatch success increasing it from a mean of 84.4 to 94.2%. PMID:24346244

Marentette, Julie R; Chiorean, Sorina; Lavalle, Christine; Sullivan, Cheryl; Parrott, Joanne L

2014-02-01

80

Toxicity Testing of Leachate from Waste Landfills Using Medaka ( Oryzias Latipes ) for Monitoring Environmental Safety  

Microsoft Academic Search

To investigate the environmental safety of waste disposal landfill sites and of land reclaimed from such sites, we evaluated\\u000a the toxicity of leachate from these sites by a combination of bioassays in the Japanese killifish medaka Oryzias latipes. We tested for lethal toxicity in adult and larval medaka and for hatching inhibition of embryos from eggs. As biochemical\\u000a evidence of

Kae Osaki; Shosaku Kashiwada; Norihisa Tatarazako; Yoshiro Ono

2006-01-01

81

INCREASING THE USEFULNESS OF ACUTE TOXICITY TESTS  

EPA Science Inventory

The conceptually and practically simple acute toxicity test provides information that is useful in the protection of aquatic life from pollution. Standardization increases the usefulness of routine acute tests by increasing their quality and comparability and allowing the study o...

82

RAPID AQUATIC TOXICITY ASSAY USING INCORPORATION OF TRITIATED-THYMIDINE INTO SEA URCHIN, 'ARBACIA PUNCTULATA', EMBRYO: EVALUATION OF TOXICANT EXPOSURE PROCEDURES  

EPA Science Inventory

Toxicity of substances in seawater was measured using growth inhibition of embryonic sea urchins during a short period after fertilization. Growth of Arbacia punctulata embryos was monitored by incorporation of tritium-labeled thymidine. The paper presents a comparison of toxican...

83

Toxicity of crude oil and pyrene to the embryos of beach spawning capelin (Mallotus villosus).  

PubMed

Due to a northward shift in oil and gas activities, there is an increasing need to understand the potential anthropogenic impacts of oil-related compounds on sub-Arctic and Arctic organisms, particularly those in coastal habitats. Capelin (Mallotus villosus), a key fish species in the Barents Sea ecosystem, undertakes aggregated spawning at both intertidal and subtidal coastal localities in northern Norway. To investigate the sensitivity of capelin embryos to oil compounds, newly fertilized capelin eggs were collected from a spawning beach and exposed until hatch (32 days) to either the water soluble fraction of crude oil or the single PAH compound, pyrene. Threshold levels for egg mortality, development and hatching success were determined. Concentrations of 40 ?g/L crude oil (?26 PAHs) and 55 ?g/L pyrene significantly increased embryonic mortality rates and decreased hatching success, compared with controls, indicating that a potential oil spill in the vicinity of capelin spawning grounds may cause significant impacts. No significant incidence of adverse effects such as yolk sac oedema, pericardia oedema, haemorrhages, craniofacial abnormalities, premature hatch or inhibited growth was observed. Histological studies of hatched larvae did not reveal specific sublethal effects in tissues and organs. Developmental delays and subsequent embryo death were noticed at the period of eye pigmentation in affected groups. Early life-history stages of capelin are sensitive indicators of PAH impacts, but the mechanisms responsible for the toxic effects require further investigation. PMID:22037118

Frantzen, Marianne; Falk-Petersen, Inger-Britt; Nahrgang, Jasmine; Smith, Timothy J; Olsen, Gro H; Hangstad, Thor Arne; Camus, Lionel

2012-02-01

84

Literature review on duckweed toxicity testing  

Microsoft Academic Search

Duckweed commonly refers to a group of floating, flowering plants of the family Lemnaceae. Duckweed plants are fast growing and widely distributed. They are easy to culture and to test. Some reports suggest that duckweed plants are tolerant to environmental toxicity. Other studies, however, indicate that duckweed plants are as sensitive to toxicity as other aquatic species. Duckweed plants are

W. Wang

1990-01-01

85

Mysids in toxicity testing — a review  

Microsoft Academic Search

The use of mysid shrimp, particularly the genusMysidopsis, along with specific testing procedures, has become accepted in aquatic toxicology. Investigators have developed methodologies for both culture and testing of these organisms. Acute and chronic (life cycle) toxicity tests in addition to dredge spoil and effluent tests with mysids are now becoming common. Attempts have been made to use mysids as

D. R. Nimmo; T. L. Hamaker

1982-01-01

86

Literature review on duckweed toxicity testing  

SciTech Connect

Duckweed commonly refers to a group of floating, flowering plants of the family Lemnaceae. Duckweed plants are fast growing and widely distributed. They are easy to culture and to test. Some reports suggest that duckweed plants are tolerant to environmental toxicity. Other studies, however, indicate that duckweed plants are as sensitive to toxicity as other aquatic species. Duckweed plants are especially suitable for use in complex effluent bioassays, and for testing herbicide pollution in the aquatic environment, lake and river pollution, sediment toxicity, and the like. Duckweed and algae represent different levels of complexity in the plant kingdom. They complement each other as phytotoxicity test organisms, instead of mutually excluding each other. Many duckweed species have been studied, primarily of the Lemna and Spirodela genera. Lemna minor and L. gibba have been recommended as standard test species. Differences in duckweed test methodology occur with regard to test types, test vessels, control tests, nutrient media, end points, and applications. 76 references.

Wang, W. (Illinois State Water Survey, Peoria (USA))

1990-06-01

87

Prevention of neural tube defects by and toxicity of L-homocysteine in cultured postimplantation rat embryos.  

PubMed

Mild hyperhomocysteinemia is frequently observed in mothers who gave birth to a child with a neural tube defect (NTD). In a previous study we showed L-homocysteine was embryotoxic to gestational day 10 (GD10) rat embryos in culture, however, no NTDs were observed. We therefore investigated the effect of L-homocysteine on the development of neural plate stage (GD9.5) rat embryos. Other objectives of this study were investigation into whether the embryotoxicity of L-homocysteine could be attenuated by compounds related to its metabolism and clarification of the mechanism of L-homocysteine embryotoxicity. In GD9.5 rat embryos L-homocysteine was not toxic at 1- and 2-mM concentrations. Rather at these concentrations it promoted development of the rat embryos in serum that without supplementation caused NTDs in the embryos. L-Methionine had the same preventive effect at even lower concentrations, but folinic acid (1 mM) did not improve embryonic development. N5-Methyltetrahydrofolate (5-CH3-THF) (100 microM), L-serine (6 mM), and L-methionine (6 and 12 mM) attenuated the embryotoxicity of L-homocysteine (6 mM) in GD10 rat embryos. Vitamin B12 (10 microM) completely abolished the embryotoxicity of L-homocysteine, which was shown to be mediated by catalysis of the spontaneous oxidation of L-homocysteine to the less toxic L-homocystine. In GD11 rat embryos, both L- and D-homocysteine were readily taken up when added to the culture (3 mM) and increased embryonic S-adenosylhomocysteine (SAH) levels 14- and 3-fold, respectively. This difference was shown to be caused by the stereospecific preference of SAH hydrolase. We propose the basis for L-homocysteine embryotoxicity is an inhibition of transmethylation reactions by increased embryonic SAH levels. PMID:7716742

Vanaerts, L A; Blom, H J; Deabreu, R A; Trijbels, F J; Eskes, T K; Copius Peereboom-Stegeman, J H; Noordhoek, J

1994-11-01

88

Automated Test Systems for Toxic Vapor Detectors  

NASA Technical Reports Server (NTRS)

The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/temperature/humidity (FIFH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy Space Center.

Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

1997-01-01

89

Automated Test Systems for Toxic Vapor Detectors  

NASA Technical Reports Server (NTRS)

The NASA Toxic Vapor Detection Laboratory (TVDL) at the Kennedy Space Center (KSC), Florida, has been using Personal Computer based Data Acquisition and Control Systems (PCDAS) for about nine years. These systems control the generation of toxic vapors of known concentrations under controlled conditions of temperature and humidity. The PCDAS also logs the test conditions and the test article responses in data files for analysis by standard spreadsheets or custom programs. The PCDAS was originally developed to perform standardized qualification and acceptance tests in a search for a commercial off-the-shelf (COTS) toxic vapor detector to replace the hydrazine detectors for the Space Shuttle launch pad. It has since become standard test equipment for the TVDL and is indispensable in producing calibration standards for the new hydrazine monitors at the 10 part per billion (ppb) level. The standard TVDL PCDAS can control two toxic vapor generators (TVG's) with three channels each and two flow/ temperature / humidity (FTH) controllers and it can record data from up to six toxic vapor detectors (TVD's) under test and can deliver flows from 5 to 50 liters per minute (L/m) at temperatures from near zero to 50 degrees Celsius (C) using an environmental chamber to maintain the sample temperature. The concentration range for toxic vapors depends on the permeation source installed in the TVG. The PCDAS can provide closed loop control of temperature and humidity to two sample vessels, typically one for zero gas and one for the standard gas. This is required at very low toxic vapor concentrations to minimize the time required to passivate the sample delivery system. Recently, there have been several requests for information about the PCDAS by other laboratories with similar needs, both on and off KSC. The purpose of this paper is to inform the toxic vapor detection community of the current status and planned upgrades to the automated testing of toxic vapor detectors at the Kennedy Space Center.

Mattson, C. B.; Hammond, T. A.; Schwindt, C. J.

1997-01-01

90

Estimating the gasoline components and formulations toxicity to microalgae (Tetraselmis chuii) and oyster (Crassostrea rhizophorae) embryos: An approach to minimize environmental pollution risk  

SciTech Connect

Even though petrochemical contamination frequently occurs in the form of oil spills, it is thought that a greater danger to coastal habitats is posed by chronic petrochemical toxicity associated with urban run-off, in which gasoline water-soluble-fraction (WSF) plays an important role. The hypothesis of the entrepreneurs, who were associated to the scientists uncharged of this research, was that recycled petrochemical waste may provide different gasoline formulations, having different toxic properties; the correlation between the gasoline formulations and their components' toxicological effects might contribute to the reformulation of the products, in such a way that the gasoline generated could be less toxic and less harmful to the environment. The aim of this research was to determine the toxic effects of 14 different types of gasoline (formulated, in accordance with National Petroleum Agency standards, from petrochemical waste), on Tetraselmis chuii (microalgae culture) and Crassostrea rhizophorae (embryos). Microalgae and oyster embryos were exposed to different gasoline formulations water-soluble fractions (WSF) at a range of concentrations (0%, 4.6%, 10.0%, 22.0%, 46.0%, and 100%), for 96 and 24 h, respectively. The tests were carried out under controlled conditions. End-points have been CI50-96h (concentration causing 50% growth inhibition in microalgae cultures) and EC50-24h (concentration causing abnormalities on 50% of the exposed embryos). Through these procedures, gasoline formulations, which represent the lowest environmental risk, were selected. Bioassays carried out on the 8 different gasoline components aimed to correlate gasoline toxicity with the toxic potential of its components. The analysis of principal components showed that the C9DI, a mixture of aromatic hydrocarbons of 9 carbon atoms, had the highest level of toxic potential, followed by C9S (a mixture of aromatics with 9-11 carbon atoms) and heavy naphtha. The results showed gasoline formulations 1-4 (monoaromatic hydrocarbons being the most conspicuous components) to be the least toxic, whilst formulations 12-14 (having higher content of C9DI, C9S and naphtha) were found to be the most harmful to organisms. This study led to the identification of the most toxic WSF gasoline components (C9DI and C9S), and to the possibility of developing more eco-compatible gasoline formulations.

Paixao, J.F. [Institute of Biology, Federal University of Bahia (Brazil); Nascimento, I.A. [Institute of Biology, Federal University of Bahia (Brazil) and Technology and Sciences Faculty, Salvador, Bahia (Brazil)]. E-mail: iracema@ftc.br; Pereira, S.A. [Institute of Biology, Federal University of Bahia (Brazil); Leite, M.B.L. [Institute of Biology, Federal University of Bahia (Brazil); Technology and Sciences Faculty, Salvador, Bahia (Brazil); Carvalho, G.C. [Institute of Biology, Federal University of Bahia (Brazil); BRASKEM, Petrochemical Complex, Camacari, Bahia (Brazil); Silveira, J.S.C. [BRASKEM, Petrochemical Complex, Camacari, Bahia (Brazil); Reboucas, M. [BRASKEM, Petrochemical Complex, Camacari, Bahia (Brazil); Matias, G.R.A. [Institute of Biology, Federal University of Bahia (Brazil); Rodrigues, I.L.P. [Institute of Biology, Federal University of Bahia (Brazil)

2007-03-15

91

ECVAM and new technologies for toxicity testing.  

PubMed

The development of alternative empirical (testing) and non-empirical (non-testing) methods to traditional toxicological tests for complex human health effects is a tremendous task. Toxicants may potentially interfere with a vast number of physiological mechanisms thereby causing disturbances on various levels of complexity of human physiology. Only a limited number of mechanisms relevant for toxicity ('pathways' of toxicity) have been identified with certainty so far and, presumably, many more mechanisms by which toxicants cause adverse effects remain to be identified. Recapitulating in empirical model systems (i.e., in vitro test systems) all those relevant physiological mechanisms prone to be disturbed by toxicants and relevant for causing the toxicity effect in question poses an enormous challenge. First, the mechanism(s) of action of toxicants in relation to the most relevant adverse effects of a specific human health endpoint need to be identified. Subsequently, these mechanisms need to be modeled in reductionist test systems that allow assessing whether an unknown substance may operate via a specific (array of) mechanism(s). Ideally, such test systems should be relevant for the species of interest, i.e., based on human cells or modeling mechanisms present in humans. Since much of our understanding about toxicity mechanisms is based on studies using animal model systems (i.e., experimental animals or animal-derived cells), designing test systems that model mechanisms relevant for the human situation may be limited by the lack of relevant information from basic research. New technologies from molecular biology and cell biology, as well as progress in tissue engineering, imaging techniques and automated testing platforms hold the promise to alleviate some of the traditional difficulties associated with improving toxicity testing for complex endpoints. Such new technologies are expected (1) to accelerate the identification of toxicity pathways with human relevance that need to be modeled in test methods for toxicity testing (2) to enable the reconstruction of reductionist test systems modeling at a reduced level of complexity the target system/organ of interest (e.g., through tissue engineering, use of human-derived cell lines and stem cells etc.), (3) to allow the measurement of specific mechanisms relevant for a given health endpoint in such test methods (e.g., through gene and protein expression, changes in metabolites, receptor activation, changes in neural activity etc.), (4) to allow to measure toxicity mechanisms at higher throughput rates through the use of automated testing. In this chapter, we discuss the potential impact of new technologies on the development, optimization and use of empirical testing methods, grouped according to important toxicological endpoints. We highlight, from an ECVAM perspective, the areas of topical toxicity, skin absorption, reproductive and developmental toxicity, carcinogenicity/genotoxicity, sensitization, hematopoeisis and toxicokinetics and discuss strategic developments including ECVAM's database service on alternative methods. Neither the areas of toxicity discussed nor the highlighted new technologies represent comprehensive listings which would be an impossible endeavor in the context of a book chapter. However, we feel that these areas are of utmost importance and we predict that new technologies are likely to contribute significantly to test development in these fields. We summarize which new technologies are expected to contribute to the development of new alternative testing methods over the next few years and point out current and planned ECVAM projects for each of these areas. PMID:22437818

Bouvier d'Yvoire, Michel; Bremer, Susanne; Casati, Silvia; Ceridono, Mara; Coecke, Sandra; Corvi, Raffaella; Eskes, Chantra; Gribaldo, Laura; Griesinger, Claudius; Knaut, Holger; Linge, Jens P; Roi, Annett; Zuang, Valérie

2012-01-01

92

Quantitative structure-activity relationships for the developmental toxicity of haloacetic acids in mammalian whole embryo culture.  

PubMed

Developmental toxicity in mouse whole embryo culture assay has been reported for acetic acid (AA) and a series of ten haloacetic acids, including mono-, di-, tri-fluoro (MFA, DFA, TFA), chloro (MCA, DCA, TCA), bromo (MBA, DBA, TBA), and monoiodo (MIA) acetic acids. Benchmark concentrations (BCm), calculated as the lower 95% confidence limit of molar acid concentration producing a 5% increase in embryos with neural tube defects, provided potency estimates for development of quantitative structure-activity relationships (QSARs). The best overall regression was obtained for the ten halo-acids (excluding AA) and related log (1/BCm) to the energy of the lowest unoccupied molecular orbital (Elumo) and acid dissociation constant (pKa) with a correlation coefficient of r = 0.97, and a sample size-adjusted r2 = 0.92. This QSAR suggested a common basis for the mechanism of HA activity, which would imply additivity for mixtures of these acids. Examination of QSARs for subsets of the total data set (e.g., monohaloacids) highlighted parameter relationships embedded in the total QSAR, helping to unravel the separate contributions of Elumo and pKa to the overall potency. The relevance of these parameters is discussed in terms of postulated mechanisms of developmental toxicity involving changes in intercellular pH and redox metabolism. The whole embryo assay results pertain to direct embryo exposure and toxicity without the confounding influence of maternal factors. The resulting QSAR model offers possible insight into the mechanism of embryo toxicity that will hopefully contribute to understanding of the more complex, in vivo teratogenicity problem. PMID:8910981

Richard, A M; Hunter, E S

1996-06-01

93

A high-throughput lab-on-a-chip interface for zebrafish embryo tests in drug discovery and ecotoxicology  

NASA Astrophysics Data System (ADS)

Drug discovery screenings performed on zebrafish embryos mirror with a high level of accuracy. The tests usually performed on mammalian animal models, and the fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, conventional methods utilising 96-well microtiter plates and manual dispensing of fish embryos are very time-consuming. They rely on laborious and iterative manual pipetting that is a main source of analytical errors and low throughput. In this work, we present development of a miniaturised and high-throughput Lab-on-a-Chip (LOC) platform for automation of FET assays. The 3D high-density LOC array was fabricated in poly-methyl methacrylate (PMMA) transparent thermoplastic using infrared laser micromachining while the off-chip interfaces were fabricated using additive manufacturing processes (FDM and SLA). The system's design facilitates rapid loading and immobilization of a large number of embryos in predefined clusters of traps during continuous microperfusion of drugs/toxins. It has been conceptually designed to seamlessly interface with both upright and inverted fluorescent imaging systems and also to directly interface with conventional microtiter plate readers that accept 96-well plates. We also present proof-of-concept interfacing with a high-speed imaging cytometer Plate RUNNER HD® capable of multispectral image acquisition with resolution of up to 8192 x 8192 pixels and depth of field of about 40 ?m. Furthermore, we developed a miniaturized and self-contained analytical device interfaced with a miniaturized USB microscope. This system modification is capable of performing rapid imaging of multiple embryos at a low resolution for drug toxicity analysis.

Zhu, Feng; Akagi, Jin; Hall, Chris J.; Crosier, Kathryn E.; Crosier, Philip S.; Delaage, Pierre; Wlodkowic, Donald

2013-12-01

94

Evaluation of effectiveness of EDTA and sodium thiosulfate in removing metal toxicity toward sea urchin embryo-larval applying the TIE.  

PubMed

Since the development of the TIE (Toxicity Identification and Evaluation) in 1988 it has been assumed that the capacity of EDTA and sodium thiosulfate to complex some metals, and thus remove their toxicity, can be applied to both freshwater and seawater ecotoxicological tests and the results subsequently interpreted. However, it is now known that there is a wide variability in the extent of this complexation. In this context, the removal of toxicity caused by the presence of Hg(2+), Cd(2+), Cu(2+), Cr(6+), Zn(2+), Ni(2+), Pb(2+), Ag(1+) and Se(2+), through metal complexation by EDTA and sodium thiosulfate, in relation to the performance of embryo-larval tests with the sea urchin Arbacia lixula was investigated. It was observed that EDTA was capable of removing the toxicity of Pb(2+), Zn(2+) and Cu(2+) while sodium thiosulfate only reduced the toxicity of Ag(1+). Compared to the complexation observed in freshwater ecotoxicological tests, the complexing agents used in this study (EDTA and sodium thiosulfate) have a lower capacity to complex metals in the marine ecotoxicological test with A. lixula. PMID:22627151

Resgalla, C; Poleza, F; Souza, R C; Máximo, M V; Radetski, C M

2012-09-01

95

Developmental toxicity and stress protein responses in zebrafish embryos after exposure to diclofenac and its solvent, DMSO.  

PubMed

One of the most frequently detected pharmaceuticals in environmental water samples is the anti-rheumatic drug, diclofenac. Despite its increasing environmental significance, investigations concerning the effects of this drug on the early developmental stages of aquatic species are lacking up to now. To determine the developmental toxicity and proteotoxicity of this drug on the growing fish embryos, eggs of zebrafish were exposed to six concentrations of diclofenac (0, 1, 20, 100, 500, 1000, and 2000 microg l(-1)) using DMSO as solvent. Early life stage parameters such as egg and embryo mortality, gastrulation, somite formation, movement and tail detachment, pigmentation, heart beat, and hatching success were noted and described within 48- and 96-h of exposure. After the 96-h exposure, the levels of stress proteins (hsp 70) were determined in both the diclofenac-treated and respective DMSO controls. Results showed no significant inhibition in the normal development until the end of 96 h for all exposure groups. However, there was a delay in the hatching time among embryos exposed to 1000 and 2000 microg l(-1). Late-hatched embryos (108 h) did not differ morphologically from normally hatched embryos. The mortality and average heart rate data did not show significant differences for all embryos in both diclofenac-treated and DMSO control groups. No significant malformations were likewise noted among all developing embryos throughout the exposure period. The levels of heat shock proteins in diclofenac-treated and control embryos did not differ significantly. DMSO control embryos, on the other hand, showed a concentration-dependent increase in hsp 70 levels. We suggest possible modulating effect of diclofenac in DMSO-triggered expression of stress proteins and this might have a possible repercussion on the use of DMSO as solvent in any toxicity assay. Since the present data indicate no significant embryotoxicity and proteotoxicity induced by diclofenac and due to the fact that the concentrations of diclofenac used in the present study is up to 2000-fold higher than the concentrations detected in the environment, it is unlikely that this drug would pose a hazard to early-life stages of zebrafish. PMID:15234162

Hallare, A V; Köhler, H-R; Triebskorn, R

2004-08-01

96

Toxicity of petroleum crude oils and their effect on xenobiotic metabolizing enzyme activities in the chicken embryo in ovo  

SciTech Connect

Microliter quantities of a Prudhoe Bay crude oil (PBCO) applied to the shell of fertile chick eggs during various stages of development induced cytochrome P-450 levels and mixed-function oxidase activities within the liver of the embryo. PBCO (5 ..mu..l) applied on Day 11 of incubation was found to maximally induce within 24 hr embryo hepatic cytochrome P-450 levels (fourfold), naphthalene hydroxylase (sixfold), benzo(a)pyrene 3-hyroxylase (14-fold), and 7-ethoxyresorufin O-deethylase (24-fold). Glutathione S-transferase was not induced. Crude oils are known to be highly toxic to avian embryos, especially during the early stages of development. The LD/sub 50/ of PBCO and Hibernia crude oil applied to the egg shell on Day 8 of incubation was found to be 1.3 and 2.2 ..mu..l, respectively. Mixed-function oxidase-dependent metabolism of crude oil components may be required for toxicity since administration of 20 ..mu..g of disulfiram in dioxane 1 hr prior to application of 1.3 ..mu..l of PBCO reduced embryo mortality from 60 to 20%.

Lee, Y.Z.; O'Brien, P.J.; Payne, J.F.; Rahimtula, A.D.

1986-01-01

97

Effects of Specific Dosages of Magnesium and Zinc on the Teratogenicity of Cadmium, Nickel, and Cobalt in Xenopus Embryos, as Assessed by the Fetax Test  

PubMed Central

The objective of this study was to determine if exposure to divalent cations, Cd2+, Ni2+, and Co2+ would lead to malformations in Xenopus laevis embryos, and whether addition of Mg2+ and Zn2+; separately and in combination, would reduce their toxicity and teratogenicity on the embryos of Xenopus laevis as assessed by 96-h FETAX tests. Results indicate that exposure to Cd2+, Ni2+ or Co2+ lead to an increase in toxicity and teratogenicity in embryos, whereas Mg2+, Zn2+, or a combination of them reduced the toxic and terato-genic effects of these divalent cations. Modulation of Cd2+, Ni2+ or Co2+ toxicity and teratogenicity by Mg2+ and Zn2+, varied with the metal. Zn2+ was observed to be a better suppressor of Co2+ toxicity and teratogenicity than Mg2+. In contrast, Ni2+, and Cd2+ teratogenicity was reduced more prominently by Mg2+. On the other hand, combination of Mg2+ and Zn2+ showed potentialization effect on all divalent cation toxicity and teratogenicity. We concluded that Mg2+ and Zn2+ reduced the toxicity and teratogenicity of Cd2+, Ni2+, Co2+. PMID:18648570

Boga, Ayper; Erdogan, Seref; Sertdemir, Yasar

2008-01-01

98

Evaluations of combined zebrafish (Danio rerio) embryo and marine phytoplankton (Diacronema lutheri) toxicity of dissolved organic contaminants in the Ythan catchment, Scotland, UK.  

PubMed

A wide variety of organic contaminants including pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) have previously been detected in surface waters in the river Ythan catchment, North East Scotland UK. While the concentrations detected were below Water Framework Directive Environmental Quality Standards (WFD-EQSs) environmental exposures to the diverse mixtures of contaminants, known and unknown, may pose chronic and/or sublethal effects to non target organisms. The present study assessed the embryo and algal toxicity potential of freely dissolved organic contaminants from the Ythan catchment using silicone rubber passive sampling devices (SR-PSDs) and miniaturised bioassay techniques. Zebrafish (Danio rerio) embryos and marine phytoplankton species (Diacronema lutheri) were exposed to extracts from SR-PSDs deployed at different locations along the river Ythan and an undeployed procedural blank. Statistically significant developmental and algal toxicities were measured in all tests of extracts from deployed samples compared with the procedural blanks. This indicates environmental exposure to, and the combined toxicity potential of, freely dissolved organic contaminants in the catchment. The present and previous studies in the Ythan catchment, coupling SR-PSDs and bioassay techniques, have both helped to understand the interactions and combined effects of dissolved organic contaminants in the catchment. They have further revealed the need for improvement in the techniques currently used to assess environmental impact. PMID:24407789

Emelogu, Emmanuel S; Seiler, Thomas-Benjamin; Pollard, Pat; Robinson, Craig D; Webster, Lynda; McKenzie, Craig; Heger, Sebastian; Hollert, Henner; Bresnan, Eileen; Best, Jennifer; Moffat, Colin F

2014-04-01

99

Toxicity Assessments of Near-infrared Upconversion Luminescent LaF3:Yb,Er in Early Development of Zebrafish Embryos  

PubMed Central

This study reports the effects of upconversion nanoparticles (UCNPs) LaF3:Yb,Er on zebrafish, with the aim of investigating UCNPs toxicity. LaF3:Yb,Er were prepared by an oleic acid/ionic liquid two-phase system, and characterized by transmission electron microscope and X-ray powder diffraction. 140 zebrafish embryos were divided into six test groups and one control group, and respectively were injected into 5, 25, 50, 100, 200, 400 ?g/mL LaF3:Yb,Er@SiO2 solution, and respectively were raised for 5 days. Each experiment was repeated ten times. Results showed that water-soluble LaF3:Yb,Er were successfully prepared, and did not exhibit obvious toxicity to zebrafish embryos under 100 ?g/mL, but exhibited chronic toxicities 200 ?g/mL in vivo, resulting in malformations and delayed hatching rate and embryonic and larval development. The excretion channels of LaF3:Yb,Er in adult zebrafish were mainly found in the intestine after being injected evenly for 24 h. In conclusion, the exploration of LaF3:Yb,Er for in vivo applications in animals and humans must consider UCNPs biocompatibility. PMID:23606912

Wang, Kan; Ma, Jiebing; He, Meng; Gao, Guo; Xu, Hao; Sang, Jie; Wang, Yuxia; Zhao, Baoquan; Cui, Daxiang

2013-01-01

100

Embryo Toxicity of 2,3,7,8-Tetrachlorodibenzo- p- Dioxin to the Wood Duck ( Aix sponsa )  

Microsoft Academic Search

We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD\\/g egg between 2003 and 2005. Injections were made into yolk prior\\u000a to incubation, and eggs were subsequently incubated and assessed weekly

T. P. Augspurger; D. E. Tillitt; S. J. Bursian; S. D. Fitzgerald; D. E. Hinton; R. T. Di Giulio

2008-01-01

101

Avian models for toxicity testing  

USGS Publications Warehouse

The use of birds as test models in experimental and environmental toxicology as related to health effects is reviewed, and an overview of descriptive tests routinely used in wildlife toxicology is provided. Toxicologic research on birds may be applicable to human health both directly by their use as models for mechanistic and descriptive studies and indirectly as monitors of environmental quality. Topics include the use of birds as models for study of teratogenesis and embryotoxicity, neurotoxicity, behavior, trends of environmental pollution, and for use in predictive wildlife toxicology. Uses of domestic and wild-captured birds are discussed.

Hill, E.F.; Hoffman, D.J.

1984-01-01

102

Toxicity and enantiospecific differences of two ?-blockers, propranolol and metoprolol, in the embryos and larvae of zebrafish (Danio rerio).  

PubMed

The risk presented by ?-blockers on aquatic organisms remains uncertain, particularly given the enantiospecific differences in toxicity of chiral ?-blockers. In this study, the toxicity of two ?-blockers, propranolol and metoprolol, was determined. The 96-h LC50 of propranolol in the zebrafish larvae was 2.48 mg/L, whereas 50 mg/L metoprolol did not result in death. Both ?-blockers decreased the heart rate and hatching rate and increased the mortality of the zebrafish embryos. Among these indicators, the heart rate was the most sensitive. However, the acute larval and embryo toxicity results displayed no enantioselectivity. Additionally, the transcriptional response of the genes encoding the ?-adrenergic receptors and those involved in other physiological processes, including the antioxidant response, detoxification, and apoptosis, in zebrafish larvae exposed to the ?-blockers was examined. Although the changes in gene transcription were fairly minor, significant enantioselectivity was observed for ?-blockers, suggesting that the transcriptional response was more sensitive for the evaluation of enantiospecific toxicity. Based on these results, the pharmaceutical drugs were not expected to pose a risk to fish; however, this conclusion should not be considered final. These results also demonstrated that the enantiospecific toxicity of chiral ?-blockers should be investigated when performing an ecological risk assessment. © 2013 Wiley Periodicals, Inc. Environ Toxicol 29: 1367-1378, 2014. PMID:23661550

Sun, Liwei; Xin, Lihua; Peng, Zuhua; Jin, Rong; Jin, Yuanxiang; Qian, Haifeng; Fu, Zhengwei

2014-12-01

103

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2013 CFR

...toxicity of substances, including testing that does not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR 1500...to reduce the number of test animals. The method of testing the toxic substances...

2013-01-01

104

16 CFR 1500.40 - Method of testing toxic substances.  

...toxicity of substances, including testing that does not require animals, are presented in the CPSC's animal testing policy set forth in 16 CFR...to reduce the number of test animals. The method of testing the toxic substances...

2014-01-01

105

Reproductive toxicity testing for pharmaceuticals under ICH  

Microsoft Academic Search

Reproductive toxicity testing of drugs is performed as a 2- or 3-segment package. The choice of species for routine studies with small molecule drugs is essentially limited to the rat, rabbit, mouse and minipig. The lack of alternative species is a threat to the successful screening of drugs for teratogenicity. A proposed revision of the ICH M3 guideline addresses contradictions

Paul C. Barrow

2009-01-01

106

Teratogenic and toxic effects of Lingzhi or Reishi medicinal mushroom, Ganoderma lucidum (W.Curt.:Fr.) P. Karst. (higher Basidiomycetes), on zebrafish embryo as model.  

PubMed

This paper highlights the teratogenic and toxic effects of Ganoderma lucidum (Lingzhi or Reishi mushroom) extract on zebrafish embryos. Hatchability, malformations, and lethality rate of zebrafish embryos were assessed to provide valuable information regarding the potential teratogenic activity of G. lucidum. Hatching was completed 48 h post treatment application (hpta) at 1% or lower concentrations of extract and embryo water. The hatching rate of embryos treated with 5% or higher concentrations was significantly lower (p> 0.05) than the control. Tail malformation was the most marked morphological abnormality in embryos at 72 hpta, which was obviously caused by 1% extract (55.56% tail malformation) and was observed in all embryos exposed to 5% of extract. Growth retardation was evident in embryos exposed to 5%, 10%, and 20%. However, lethal effect of extract of G. lucidum was dependent on dose and time of exposure. Mortality rates of embryos treated with 5% (44.44%) or higher concentrations of the extract was significantly higher (p > 0.05) than that of the control embryos at 72 hpta. These results suggest that G. lucidum extract has lethal and sub-lethal effects on zebrafish embryos. PMID:23510220

Dulay, Rich Milton R; Kalaw, Sofronio P; Reyes, Renato G; Alfonso, Noel F; Eguchi, Fumio

2012-01-01

107

Toxicity assessment of sediments from three European river basins using a sediment contact test battery.  

PubMed

The toxicity of four polluted sediments and their corresponding reference sediments from three European river basins were investigated using a battery of six sediment contact tests representing three different trophic levels. The tests included were chronic tests with the oligochaete Lumbriculus variegatus, the nematode Caenorhabditis elegans and the mudsnail Potamopyrgus antipodarum, a sub-chronic test with the midge Chironomus riparius, an early life stage test with the zebra fish Danio rerio, and an acute test with the luminescent bacterium Vibrio fischeri. The endpoints, namely survival, growth, reproduction, embryo development and light inhibition, differed between tests. The measured effects were compared to sediment contamination translated into toxic units (TU) on the basis of acute toxicity to Daphnia magna and Pimephales promelas, and multi-substance Potentially Affected Fractions of species (msPAF) as an estimate for expected community effects. The test battery could clearly detect toxicity of the polluted sediments with test-specific responses to the different sediments. The msPAF and TU-based toxicity estimations confirmed the results of the biotests by predicting a higher toxic risk for the polluted sediments compared to the corresponding reference sediments, but partly having a different emphasis from the biotests. The results demonstrate differences in the sensitivities of species and emphasize the need for data on multiple species, when estimating the effects of sediment pollution on the benthic community. PMID:20833427

Tuikka, A I; Schmitt, C; Höss, S; Bandow, N; von der Ohe, P C; de Zwart, D; de Deckere, E; Streck, G; Mothes, S; van Hattum, B; Kocan, A; Brix, R; Brack, W; Barceló, D; Sormunen, A J; Kukkonen, J V K

2011-01-01

108

Contact tests for pentachlorophenol toxicity to earthworms  

SciTech Connect

The standardized contact filter paper test (EEC and OECD) provides an effective screening test for toxicity to earthworms in a laboratory setting. A need exists for a reliable and inexpensive technique for non-laboratory settings where screening is desired, but facilities cannot provide for the acquisition and maintenance of the glass vials required by the standardized test. This study evaluated two modifications of the standardized test using clear polyethylene bags, with and without filter paper, with Eisenia fetida and domesticated surface-feeding earthworms. The tests were conducted according to EEC and OECD guidelines. Results of the modified tests corresponded in dose and effect to the standardized contact filter paper test indicating the usefulness of the modified tests.

Spontak, D.A. [Utah State Univ., Logan, UT (United States)

1994-12-31

109

Morphological development of testes in ostrich (Struthio camelus) embryo.  

PubMed

Although the histological structure of ostrich testis has been studied, very little information is currently available on the embryonic development of this organ. The aim of this study was to determine the sequence of the histological changes in diverse components of the testis in ostrich embryo from embryonic day (E) 20 to E42. The main findings were categorized into four histological features, i.e., development of sex cords, interstitial tissue and rete ducts, and the appearance of defective septa. While the lumen of sex cords, tunica albuginea, capsular rete ducts and Leydig cell precursors appeared at E26, the filum-shaped defective septa were visible at E36. The emersion of the lumen in the primary sex cords and formation of capsular rete ducts in the ostrich embryo is considerably different from that in other birds. However, tunica albuginea and Leydig cell precursors appeared in a similar pattern to those of other birds. An interesting observation was that the primordial germ cell (PGC)-like cells were completely distinct, while the capsular rete ducts were formed by trapping of some Sertoli cell aggregations in the tunica albuginea. This suggests that similar to the primary sex cords, the capsular rete ducts may originate from the Sertoli cell aggregations which had corralled some PGCs. Stereological estimations in the ostrich embryo testis showed the major proportion of testis is occupied by the seminiferous tubules, which is unlike the fowl embryo testis. PMID:24127229

Hassanzadeh, Belal; Nabipour, Abolghasem; Behnam Rassouli, Morteza; Dehghani, Hesam

2014-06-01

110

TOXICITY OF GUTHION AND GUTHION 2S TO XENOPUS LAEVIS EMBRYOS  

EPA Science Inventory

Differences in sensitivity to waterborne contaminants between wildlife species have prompted investigations on the sensitivity of amphibians to potentially hazardous environmental chemicals. he development of Xenopus laevis (African clawed frog) embryos exposed to the pesticide G...

111

Toxicity of Guthion (Trade Name) and Guthion (Trade Name) 2S to 'Xenopus laevis' Embryos.  

National Technical Information Service (NTIS)

Differences in sensitivity to waterborne contaminants between wildlife species have prompted investigations on the sensitivity of amphibiams to potentially hazardous environmental chemicals. The development of Xenopus laevis (African clawed frog) embryos ...

G. S. Schuytema, A. V. Nebeker, W. L. Griffis

1994-01-01

112

The Red Tide Toxin, Brevetoxin, Induces Embryo Toxicity and Developmental Abnormalities  

NSDL National Science Digital Library

This Environmental Health Perspectives journal article documents a study on the relationship between brevetoxin, a toxin produced by red tide-related dinoflagellates, and abnormalities in fish embryos. The article features color photographs, charts, and tables.

Kimm-Brinson, Karen L.; Ramsdell, John S.; Perspectives, Environmental H.

113

Reproductive Toxicity Testing: Evaluating and Developing New Testing Systems  

Microsoft Academic Search

Reproductive toxicity testing systems are used by national and international regulatory agencies. Protocols have not been standardized between agencies or even within certain agencies. Although there have been efforts at standardization, a certain amount of the differences between testing protocols is a reflection of the needs of the particular agency. New developments in in vitro techniques might lead to new

J. C. Lamb

1985-01-01

114

MAMMALIAN WILDLIFE (MINK AND FERRET) TOXICITY TEST PROTOCOLS (LC50, REPRODUCTION, AND SECONDARY TOXICITY)  

EPA Science Inventory

Protocols describing guidelines for conducting dietary LC50 and reproduction toxicity tests and for assessing the primary versus secondary toxicity of a test substance using carnivorous mammalian wildlife, specifically mink (Mustela vison) or European ferrets (Mustela putorius fu...

115

CHIRONOMIDAE TOXICITY TESTS--BIOLOGICAL BACKGROUND AND PROCEDURES  

EPA Science Inventory

Toxicity tests must be based on an understanding of the test animal's life cycle. The first section of this report describes the biological information needed to develop toxicity test procedures. The second section describes three categories of toxicity test systems - short-expos...

116

Ocular Toxicity Testing of Lunar Dust  

NASA Technical Reports Server (NTRS)

This slide presentation reviews the use of ocular testing to determine the toxicity of lunar dust. The OECD recommendations are reviewed. With these recommendations in mind the test methodology was to use EpiOcular, tissues derived from normal human epidermal keratinocytes, the cells of which have been differentiated on cell culture inserts to form a multi-layered structure, which closely parallels the corneal epithelium and to dose the tissue with 100 mg dust from various sources. The in-vitro study provides evidence that lunar dust is not severely corrosive or irritating, however, in vitro tests have limitations, and in vivo tests provides a more complete scenario, and information, it is recommended that in vivo tests be performed.

Meyers, Valerie E.

2010-01-01

117

Prediction and assessment of mixture toxicity of compounds in antifouling paints using the sea-urchin embryo-larval bioassay.  

PubMed

The ecotoxicological assessment of alternative "booster" biocides is urgently needed in order to develop environmentally acceptable antifouling paints. However, research has focused mainly on single compounds, and there is still a lack of data on their mixture toxicity. The present study investigated the single and mixture toxicity of three of the most widely used antifouling biocides: zinc pyrithione, chlorothalonil and Sea-Nine, using the sea-urchin (Paracentrotus lividus) embryo-larval bioassay. Also, the predictive ability of the concentration addition (CA) and independent action (IA) concepts for antifouling mixtures was evaluated. Both concepts failed to accurately predict the toxicity of the antifouling mixtures, with the exception of the zinc pyrithione and Sea-Nine mixture, which was accurately predicted by the IA concept, suggesting a dissimilar mode of action of those substances. In general, CA predicted consistently higher toxicity than IA; however, CA overestimated the toxicity of the studied mixtures by a factor of only 1.6, representing a reasonable worst-case approach to be used in the predictive hazard assessment of antifouling mixtures. Finally, the present study demonstrates that the risk of antifouling mixtures for the early developmental stages of sea urchin is higher than the risk of each single substance, and therefore, the inclusion of mixture considerations in the development of water quality criteria for antifouling compounds is strongly recommended. PMID:18586336

Bellas, Juan

2008-07-30

118

Toxicity of complex cyanobacterial samples and their fractions in Xenopus laevis embryos and the role of microcystins.  

PubMed

This work evaluated the effects of various cyanobacterial fractions in Frog Embryo Teratogenesis Assay Xenopus (FETAX) with African clawed frog embryos. Fractions were prepared from five biomasses with different dominant genera (Microcystis, Aphanizomenon, Anabaena, Planktothrix) and different microcystin content. Effects of following fractions were investigated: (I) homogenate of complex cyanobacterial biomass, (II) cell debris (pellet) after centrifugation of complex biomass, (III) supernatant after centrifugation of complex biomass (= crude aqueous extract), (IV) permeate after passing of crude extract through C-18 column (fraction devoid of microcystins), and (V) eluate from C-18 column (containing microcystins, if present). Besides classical parameters evaluated in 96 h FETAX (mortality, growth inhibition, malformations), we have also assessed the effects on biochemical markers of oxidative stress and detoxification (glutathione pool, GSH; activity of glutathione peroxidase, GPx; glutathione reductase, GR; activity of glutathione-S-transferase, GST). Complex biomass (I) and aqueous extract (III) were generally the most toxic fractions in terms of mortality and growth inhibition, whereas eluates containing microcystins (V) were generally less toxic. On the other hand, the same fraction (eluates) induced significant malformations in low concentrations but the effects were not related to the content of microcystins. Biomarkers were affected in variable manner but no significant effect or clear relation to microcystin content was observed. Our data support the hypothesis that microcystins are not the only or major toxic compounds in the complex cyanobacterial samples (at least for some species) and that more attention should be paid to other components of complex cyanobacterial biomass including non-specific parameters such as oxygen content or toxic ammonia released during bacterial decay of organic material. PMID:17092578

Burýsková, Blanka; Hilscherová, Klára; Babica, Pavel; Vrsková, Dagmar; Marsálek, Blahoslav; Bláha, Ludek

2006-12-30

119

Potential of Two Hydra Species as Standard Toxicity Test Animals  

Microsoft Academic Search

The potential for using pink hydra (Hydra vulgaris) and green hydra (Hydra viridissima) as a model invertebrate for the toxicity testing of xenobiotics was investigated. Test compounds were 4-chlorophenol, endosulfan, and copper. The reference toxicant 4-chlorophenol was used as a standard during toxicity testing to ensure the sensitivity of hydra did not change over time. Hydra had a low sensitivity

Carmel A. Pollino; Douglas A. Holdway

1999-01-01

120

A new screening test for toxicity testing of dental materials  

Microsoft Academic Search

Objectives: The development of a micro plate assay for cytotoxicity testing of dental materials based on a bioassay using brine shrimp larvae (artemia salina) as sensitive organisms.Methods: Brine shrimp larvae are commonly used for cytotoxicity assays in pharmacology. These larvae are sensitive to toxic substances. The ratio between dead larvae (no motility) and living larvae (high motility) in comparison to

M Pelka; C Danzl; W Distler; A Petschelt

2000-01-01

121

In vitro models for liver toxicity testing  

PubMed Central

Over the years, various liver-derived in vitro model systems have been developed to enable investigation of the potential adverse effects of chemicals and drugs. Liver tissue slices, isolated microsomes, perfused liver, immortalized cell lines, and primary hepatocytes have been used extensively. Immortalized cell lines and primary isolated liver cells are currently most widely used in vitro models for liver toxicity testing. Limited throughput, loss of viability, and decreases in liver-specific functionality and gene expression are common shortcomings of these models. Recent developments in the field of in vitro hepatotoxicity include three-dimensional tissue constructs and bioartificial livers, co-cultures of various cell types with hepatocytes, and differentiation of stem cells into hepatic lineage-like cells. In an attempt to provide a more physiological environment for cultured liver cells, some of the novel cell culture systems incorporate fluid flow, micro-circulation, and other forms of organotypic microenvironments. Co-cultures aim to preserve liver-specific morphology and functionality beyond those provided by cultures of pure parenchymal cells. Stem cells, both embryonic- and adult tissue-derived, may provide a limitless supply of hepatocytes from multiple individuals to improve reproducibility and enable testing of the individual-specific toxicity. This review describes various traditional and novel in vitro liver models and provides a perspective on the challenges and opportunities afforded by each individual test system. PMID:23495363

Soldatow, Valerie Y.; LeCluyse, Edward L.; Griffith, Linda G.; Rusyn, Ivan

2013-01-01

122

SAND SPIKED WITH COPPER AS A REFERENCE TOXICANT MATERIAL FOR SEDIMENT TOXICITY TESTING: A PRELIMINARY EVALUATION  

EPA Science Inventory

Routine use of solid-phase sediment toxicity tests for scientific and regulatory purposes necessitates the development of solid-phase reference toxicant materials. n order to evaluate an approach for developing such materials, 12 solid-phase 96-h reference toxicant tests were con...

123

EVALUATING THE EFFECTS OF FLY ASH EXPOSURE ON FISH EARLY LIFE STAGES: FATHEAD MINNOW EMBRYO-LARVAL TESTS  

SciTech Connect

On December 22, 2008, a dike containing fly ash and bottom ash in an 84-acre complex of the Tennessee Valley Authority's (TVA) Kingston Steam Plant in East Tennessee failed and released a large quantity of ash into the adjacent Emory River. Ash deposits extended as far as 4 miles upstream (Emory River mile 6) of the Plant, and some ash was carried as far downstream as Tennessee River mile 564 ({approx}4 miles downstream of the Tennessee River confluence with the Clinch River). A byproduct of coal burning power plants, fly ash contains a variety of metals and other elements which, at sufficient concentrations and in specific forms, can be toxic to biological systems. The effects of fly ash contamination on exposed fish populations depend on the magnitude and duration of exposure, with the most significant risk considered to be the effects of specific ash constituents, especially selenium, on fish early life stages. Uptake by adult female fish of fly ash constituents through the food chain and subsequent maternal transfer of contaminants to the developing eggs is thought to be the primary route of selenium exposure to larval fish (Woock and others 1987, Coyle and others 1993, Lemly 1999, Moscatello and others 2006), but direct contact of the fertilized eggs and developing embryos to ash constituents in river water and sediments is also a potential risk factor (Woock and others 1987, Coyle and others 1993, Jezierska and others 2009). To address the risk of fly ash from the Kingston spill to the reproductive health of downstream fish populations, ORNL has undertaken a series of studies in collaboration with TVA including: (1) a field study of the bioaccumulation of fly ash constituents in fish ovaries and the reproductive condition of sentinel fish species in reaches of the Emory and Clinch Rivers affected by the fly ash spill; (2) laboratory tests of the potential toxicity of fly ash from the spill area on fish embryonic and larval development (reported in the current technical manuscript); (3) additional laboratory experimentation focused on the potential effects of long-term exposures to fly ash on fish survival and reproductive competence; and (4) a combined field and laboratory study examining the in vitro developmental success of embryos and larvae obtained from fish exposed in vivo for over two years to fly ash in the Emory and Clinch Rivers. These fish reproduction and early life-stage studies are being conducted in conjunction with a broader biological monitoring program administered by TVA that includes a field study of the condition of larval fish in the Emory and Clinch Rivers along with assessments of water quality, sediment composition, ecotoxicological studies, terrestrial wildlife studies, and human and ecological risk assessment. Information and data generated from these studies will provide direct input into risk assessment efforts and will also complement and help support other phases of the overall biomonitoring program. Fish eggs, in general, are known to be capable of concentrating heavy metals and other environmental contaminants from water-borne exposures during embryonic development (Jezierska and others 2009), and fathead minnow embryos in particular have been shown to concentrate methylmercury (Devlin 2006) as well as other chemical toxicants. This technical report focuses on the responses of fathead minnow embryos to simple contact exposures to fly ash in laboratory toxicity tests adapted from a standard fathead minnow (Pimephales promelas) 7-d embryo-larval survival and teratogenicity test (method 1001.0 in EPA 2002) with mortality, hatching success, and the incidences of developmental abnormalities as measured endpoints.

Greeley Jr, Mark Stephen [ORNL; Elmore, Logan R [ORNL; McCracken, Kitty [ORNL

2012-05-01

124

Effluent toxicity test using developmental stages of the marine polychaete Hydroides elegans.  

PubMed

The US Environmental Protection Agency (USEPA) has established a suite of methods that use coastal invertebrate species as bioassay organisms to test industrial and domestic effluent as well as coastal waters for potential toxicity. Although these methods are used globally, the potential of such toxicity tests has not been adequately explored for Asian coastal waters. This study describes bioassay utilizing the gametes of Hydroides elegans to monitor coastal water quality and is based on the sensitivity of H. elegans embryo and larva to different concentrations of effluents and water samples collected from different regions of east coast of India. Among the water samples collected from different regions, seawater from Ennore station showed decrease in percentage of development, and 25% effluent concentration led to development arrest of H. elegans embryos. The different morphological effects produced by effluents clearly reflect the defect in early differentiation of embryonic cells. Since fertilization can be inhibited in the presence of any xenobiotic, both fertilization and early development can be used as a biological indicator for a rapid bioassay to monitor pollution. Toxicity tests utilizing early life stages of H. elegans are suitable for the assessment of effects produced by low levels of pollutants due to their high sensitivity to various contaminants relative to other marine species and also due to the relative simplicity of the bioassay. PMID:18317832

Thilagam, H; Gopalakrishnan, S; Vijayavel, K; Raja, P Vivek

2008-05-01

125

Comparison of bulk sediment and sediment elutriate toxicity testing methods  

EPA Science Inventory

Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

126

Antimony and thallium toxicity to embryos and larvae of fathead minnows (Pimephales promelas)  

SciTech Connect

Antimony, as antimony trioxide, is a commerically important metal used as a flame retarding agent. Thallium has industrial application as a catalyst for many organic reactions and in the production of alloys and electronic devices. Accordingly, both metals are potential pollutants through anthropogenic sources. The purpose of this study was to assess the effects of these metals on the embryos and larvae of fathead minnows (Pimephales promelas).

LeBlanc, G.A.; Dean, J.W.

1984-05-01

127

A Simple "in Vitro" Culture of Freshwater Prawn Embryos for Laboratory Investigations  

ERIC Educational Resources Information Center

Giant freshwater prawn ("Macrobrachium rosenbergii" De Man) embryos can be cultured "in vitro" to hatching in 15% (v/v) artificial seawater (ASW). This technique can be applied as a bioassay for testing toxicity or for the effects of various substances on embryo development and can be used as a simple and low-cost model for studying embryo

Porntrai, Supaporn; Damrongphol, Praneet

2008-01-01

128

Toxicity of glyphosate as Glypro and LI700 to red-eared slider (trachemys scripta elegans) embryos and early hatchlings.  

PubMed

More than 8.2 billion ha of cropland, gardens, and forests are treated with the herbicide glyphosate each year. Whereas the toxicity of glyphosate and associated adjuvants has been measured in other vertebrates, few, if any, studies have looked at their effects in reptiles. In some instances, management of turtle habitat requires control of successional stages through application of herbicides. Adults and juvenile turtles may be exposed directly, whereas embryos may contact the chemicals through the soil. In the present study, we exposed eggs of red-eared sliders (Trachemys scripta elegans) to single applications of herbicide ranging from 0 to 11,206 ppm wet weight of glyphosate in Glypro and 0 to 678 ppm of the surfactant, LI700. Hatching success at the highest concentration was significantly lower (73%) than in other treatments (80-100%). At hatch, turtles at the highest concentration weighed less than those at other concentrations. During a 14-d holding period, we observed dose-response relationships in the ability of hatchlings to right themselves when turned on their backs. At the end of the holding period, hatchlings at the highest dose level were still lighter, and somatic indices were lower, than those in other treatments. Genetic damage, as measured by flow cytometry, increased with treatment concentration except for the highest dose. We conclude that because of the high concentrations needed to produce effects and the protection offered by several centimeters of soil or sediment, glyphosate with LI700 poses low levels of risk to red-eared slider embryos under normal field operations with regards to the endpoints measured in the present study. Carelessness in handling glyphosate or failure to follow label directions may produce adverse effects. There also is a risk that the health of turtle embryos may be affected in ways not measured in the present study. PMID:17022419

Sparling, Donald W; Matson, Cole; Bickham, John; Doelling-Brown, Paige

2006-10-01

129

Perspectives on testing for toxic agents.  

PubMed

A series of observations and comments are made with respect to several areas of toxicology: these are briefly discussed. Some innovative areas receive discussion as representing substantial progress made in the field of toxicology in recent years. Topics included raise a number of questions: what agents should we test, and how should we go about selecting them; what is the importance of allowing for genetic diversity in carrying out tests that are meaningful for humans; and what is the relevance of studies in pharmacokinetics in the laboratory to humans. Human studies, because of ethical considerations, must be indirect, through access to available autopsy and surgical human tissues. Also, drug trials and clinical studies must be exploited. Cancer testing and evaluation is briefly commented on. Systemic toxicity is considered in respect to possible improved ways of determining the "NOEL," that is, the no-observed-effect level. Suggestions for improving study of mixtures of chemicals are considered. The rapid advances in molecular biology have significantly strengthened our ability to trace the action of chemicals in the body from exposure to disease. It is very important that training in toxicology be based on a sound disciplinary training in one of the classic fields of the biomedical sciences, such as biochemistry, pharmacology, molecular biology. It is concluded that advances in the past decade have made the practice of toxicology a much more scientific endeavor, especially in its use of the latest developments in basic biomedical sciences. PMID:3319572

Nelson, N

1987-11-01

130

Rapid in vivo testing of drug response in multiple myeloma made possible by xenograft to turkey embryos  

PubMed Central

Background: The best current xenograft model of multiple myeloma (MM) in immune-deficient non-obese diabetic/severe-combined immunodeficient mice is costly, animal maintenance is complex and several weeks are required to establish engraftment and study drug efficacy. More practical in vivo models may reduce time and drug development cost. We recently described a rapid low-cost xenograft model of human blood malignancies in pre-immune turkey. Here, we report application of this system for studying MM growth and the preclinical assessment of anticancer therapies. Methods: Cell lines and MM patient cells were injected intravenously into embryonic veins on embryonic day 11 (E11). Engraftment of human cells in haematopoietic organs was detected by quantitative real-time polymerase chain reaction, immunohistochemistry, flow cytometry and circulating free light chain. Results: Engraftment was detected after 1 week in all embryos injected with cell lines and in 50% of those injected with patient cells. Injection of bortezomib or lenalinomide 48?h after cell injection at therapeutic levels that were not toxic to the bone marrow dramatically reduced MM engraftment. Conclusion: The turkey embryo provides a practical, xenograft system to study MM and demonstrates the utility of this model for rapid and affordable testing therapeutics in vivo. With further development, this model may enable rapid, inexpensive personalised drug screening. PMID:22045188

Farnoushi, Y; Cipok, M; Kay, S; Jan, H; Ohana, A; Naparstek, E; Goldstein, R S; Deutsch, V R

2011-01-01

131

Developmental toxicity testing with FETAX: evaluation of five compounds.  

PubMed

The teratogenic potential of five compounds was evaluated with FETAX (Frog Embryo Teratogenesis Assay: Xenopus). Early embryos of Xenopus laevis were exposed for 96 h to 6-aminonicotinamide (6-AN), isoniazid (INH), urethane, nitrilotriacetate (NTA) or sodium cyclamate, in two separate static-renewal tests of each compound. Based on Teratogenic Index values, growth endpoints and the types and severity of the induced malformations, 6-AN, INH and urethane scored as having strong teratogenic potential. NTA and sodium cyclamate had little or no teratogenic potential. The results support continued evaluation of FETAX as a screening assay for chemical teratogens. PMID:2714209

Dawson, D A; Fort, D J; Newell, D L; Bantle, J A

1989-03-01

132

SURVIVAL OF BROOK TROUT EMBRYOS IN THREE EPISODICALLY ACIDIFIED STREAMS  

EPA Science Inventory

The authors evaluated brook trout Salvelinus fontinalis in three streams that undergo episodic acidification during critical periods of embryo development for survival of embryos from egg deposition to preemergence in natural redds and survival of sac fry in toxicity tests done i...

133

The Bioaccumulation and Toxicity of Platinum Group Metals in Developing Chick Embryos  

NASA Astrophysics Data System (ADS)

Recent studies showed that platinum group metals (PGMs) such as Pt, Pd, and Rh from automobile catalytic converters, can accumulate in the soft tissues of a variety of living organisms. However, the effects of PGMs on bone and organs development of animals are not clearly understood. To examine these aspects, developing chick embryos were injected with 0.1, 1.0, 5, or 10 ppm solutions of Pt, Rh, Pd, or with a PGMs mixture. 1) Pathological Changes: were observed for all PGM treatments above 1 ppm. Bone Cells Assesment: Chondrocyte cells in thibiotarsus showed decreased diameter and length. 2) PGMs Accumulation in Tissues: was quantified by GFAAS spectrometry on finely ground tissue powder. 3) Bone Demineralization: was detected by micro-Raman spectroscopy imaging on paraffin embedded bone sections. 4) DNA Damage in Cells: was determined by using a Comet assay and fluorescence spectroscopy. Oxidative Damage in Tissues: was analyzed using a glutathione peroxidase assay. The overall results indicated that PGMs presence in our environment raises concerns about their long-term health effects on all organisms.

Pavel, Ioana; Monahan, Jennifer; Markopoulos, Marjorie; Gagnon, Zofia; Nejame, Britney; Cawley, Jacob; Reens, David

2008-10-01

134

RESULTS OF SOLID PHASE SEDIMENT TOXICITY TESTS WITH REDUCED SEDIMENT VOLUMES FOR SEDIMENT TOXICITY  

EPA Science Inventory

Development and standardization of sediment toxicity test methods for freshwater organisms have been underway for several years. Both EPA and ASTM have published methods for assessing the short-term (e.g., 10-d) toxicity of sediments to two benthic freshwater organisms (Hyalella ...

135

EVALUATION OF ALTERNATIVE REFERENCE TOXICANTS FOR USE IN THE EARTHWORM TOXICITY TEST  

EPA Science Inventory

The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However,the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants...

136

Toxicity Tests for Ensuring Succesful Industrial Wastewater Treatment Plant Operation  

NASA Astrophysics Data System (ADS)

Industrial wastewaters are complex and can be polluted by non-biodegradable end toxic organic compounds and are a serious threat to the environment. Chemical procedure alone cannot provide sufficient information. A complete evaluation of wastewaters should include ecotoxicological tests too, especially concerning the complex wastewaters. In the literature review the authors attempted to establish which is the more promising and suitable aquatic toxicology test for sewage treatment plant influent toxicity monitoring. A variety of types of organisms representing different trophic levels and many different species are used for aquatic toxicity testing. Toxicity characterization would be needed both for influents and effluents of wastewater treatment plant. For the purpose of screening biological wastewater treatment influent, toxicity to activated sludge microorganisms is important and toxicology tests here used are respirometry and bioluminescence toxicology tests. Respirometry toxicity tests are easy, fast and inexpensive compared to other approaches. Bioluminescence has been widely used, the most thoroughly investigated test system is the Microtox. The toxicity tests have also been compared by different authors. International, national and regional authorities use these tools to meet various regulatory and legislative requirements. Importance of biotesting has been emphasized also in EU legislation.

C?bere, B.; Falti?a, E.; Zel??ns, N.; Kalni?a, D.

2009-01-01

137

Developmental toxicity of a commercial herbicide mixture in mice: I. Effects on embryo implantation and litter size.  

PubMed Central

We investigated the developmental toxicity in mice of a common commercial formulation of herbicide containing a mixture of 2,4-dichlorophenoxyacetic acid (2,4-D), mecoprop, dicamba, and inactive ingredients. Pregnant mice were exposed to one of four different doses of the herbicide mixture diluted in their drinking water, either during preimplantation and organogenesis or only during organogenesis. Litter size, birth weight, and crown-rump length were determined at birth, and pups were allowed to lactate and grow without additional herbicide exposure so that they could be subjected to additional immune, endocrine, and behavioral studies, the results of which will be reported in a separate article. At weaning, dams were sacrificed, and the number of implantation sites was determined. The data, although apparently influenced by season, showed an inverted or U-shaped dose-response pattern for reduced litter size, with the low end of the dose range producing the greatest decrease in the number of live pups born. The decrease in litter size was associated with a decrease in the number of implantation sites, but only at very low and low environmentally relevant doses. Fetotoxicity, as evidenced by a decrease in weight and crown-rump length of the newborn pups or embryo resorption, was not significantly different in the herbicide-treated litters. PMID:12417478

Cavieres, Maria Fernanda; Jaeger, James; Porter, Warren

2002-01-01

138

Induction of cytochrome P450 3A1 expression by diallyl disulfide: protective effects against cyclophosphamide-induced embryo-fetal developmental toxicity.  

PubMed

The protective effects of diallyl disulfide (DADS) on cyclophosphamide (CP)-induced developmental toxicity and the possible mechanisms involved in this protection were investigated in rats. In order to study the mechanisms involved in the protection, we examined the effects of DADS on the expression of cytochrome P450 (CYP) 3A1 in the maternal liver and placenta and oxidative stress in the maternal hepatic tissues caused by CP. CP caused severe embryo-fetal developmental toxicity and hepatic oxidative stress. In contrast, DADS treatment significantly attenuated CP-induced developmental toxicity and oxidative damage in the maternal liver. DADS also significantly increased expression of CYP3A1 in the maternal liver and placenta. These results indicate that the protective effects of DADS against CP-induced developmental toxicity may be due to its ability to promote detoxification of CP, primarily by inducing CYP3A1 expression in the maternal liver and placenta, and its potent antioxidant effects. PMID:24769015

Kim, Sung-Hwan; Lee, In-Chul; Baek, Hyung-Seon; Moon, Changjong; Kim, Sung-Ho; Yoo, Jin Cheol; Shin, In-Sik; Kim, Jong-Choon

2014-07-01

139

Sensitivity or artifact? -- IQ Toxicity Test -- effluent values  

SciTech Connect

Several complex effluents were DAPHNIA MAGNA IQ TOXICITY TESTED -- (1.25 hours) and conventionally tested with Daphnia magna (48 hours). In many samples the IQ Technology yielded low EC50 values while the 48 hour exposures yielded no acute toxicity. Possible explanations have been suggested for this occurrence such as: genotoxicity, mutagenicity, substrate interference, and enzyme satiation. To identify the causative agent(s) of this response a Toxicity Identification Evaluation was performed on one of the samples. To define the nature of the response, THE SOS-CHROMOTEST KIT and THE MUTA-CHROMOPLATE KIT were utilized to characterize genotoxicity and mutagenicity respectively. The sample did not test positive for genotoxicity but tested positive for mutagenicity only after activation with S9 enzymes, suggesting the presence of promutagens. Additional work needs to be performed to correlate IQ TOXICITY TEST sensitivity with positive MUTA-CHROMOPLATE response.

Hayes, K.R.; Novotny, A.N.; Batista, N.

1995-12-31

140

Extrapolation of toxic indices among test objects  

PubMed Central

Oligochaeta Tubifex tubifex, fish fathead minnow (Pimephales promelas), hepatocytes isolated from rat liver and ciliated protozoan are absolutely different organisms and yet their acute toxicity indices correlate. Correlation equations for special effects were developed for a large heterogeneous series of compounds (QSAR, quantitative structure-activity relationships). Knowing those correlation equations and their statistic evaluation, one can extrapolate the toxic indices. The reason is that a common physicochemical property governs the biological effect, namely the partition coefficient between two unmissible phases, simulated generally by n-octanol and water. This may mean that the transport of chemicals towards a target is responsible for the magnitude of the effect, rather than reactivity, as one would assume suppose. PMID:21331180

Tichy, Milon; Rucki, Marian; Roth, Zdenek; Hanzlikova, Iveta; Vlkova, Alena; Tumova, Jana; Uzlova, Rut

2010-01-01

141

Extrapolation of toxic indices among test objects.  

PubMed

Oligochaeta Tubifex tubifex, fish fathead minnow (Pimephales promelas), hepatocytes isolated from rat liver and ciliated protozoan are absolutely different organisms and yet their acute toxicity indices correlate. Correlation equations for special effects were developed for a large heterogeneous series of compounds (QSAR, quantitative structure-activity relationships). Knowing those correlation equations and their statistic evaluation, one can extrapolate the toxic indices. The reason is that a common physicochemical property governs the biological effect, namely the partition coefficient between two unmissible phases, simulated generally by n-octanol and water. This may mean that the transport of chemicals towards a target is responsible for the magnitude of the effect, rather than reactivity, as one would assume suppose. PMID:21331180

Tichý, Milo?; Rucki, Marián; Roth, Zden?k; Hanzlíková, Iveta; Vlková, Alena; Tumová, Jana; Uzlová, Rút

2010-12-01

142

76 FR 38169 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data  

Federal Register 2010, 2011, 2012, 2013

...EPA-HQ-OPPT-2003-0006; FRL-8872-5] Toxic Substances Control Act Chemical Testing...test data on five chemicals listed in the Toxic Substances Control Act (TSCA) section...Office of Pollution Prevention and Toxics, Environmental Protection Agency,...

2011-06-29

143

76 FR 38170 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data  

Federal Register 2010, 2011, 2012, 2013

...EPA-HQ-OPPT-2005-0033; FRL-8872-4] Toxic Substances Control Act Chemical Testing...test data on 12 chemicals listed in the Toxic Substance Control Act (TSCA) section...Office of Pollution Prevention and Toxics, Environmental Protection Agency,...

2011-06-29

144

78 FR 69414 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data  

Federal Register 2010, 2011, 2012, 2013

...EPA-HQ-OPPT-2009-0112; FRL-9902-68] Toxic Substances Control Act Chemical Testing...to a test rule issued by EPA under the Toxic Substances Control Act (TSCA). The purpose...Office of Pollution Prevention and Toxics, Environmental Protection Agency,...

2013-11-19

145

Predictive modeling of developmental toxicity using EPA?s Virtual Embryo  

EPA Science Inventory

Standard practice in prenatal developmental toxicology involves testing chemicals in pregnant laboratory animals of two species, typically rats and rabbits, exposed during organogenesis and evaluating for fetal growth retardation, structural malformations, and prenatal death just...

146

Knockdown of AHR1A but not AHR1B exacerbates PAH and PCB-126 toxicity in zebrafish (Danio rerio) embryos  

PubMed Central

Various environmental contaminants are known agonists for the aryl hydrocarbon receptor (AHR), which is highly conserved across vertebrate species. Due to gene duplication events before and after the divergence of ray- and lobe-finned fishes, many teleosts have multiple AHR isoforms. The zebrafish (Danio rerio) has three identified AHRs: AHR1A and AHR1B, the roles of which are not yet well elucidated, and AHR2, which has been shown to mediate the toxicity of various anthropogenic compounds including dioxins, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). In this study, we sought to explore the role of the two AHR1 isoforms in PAH- and PCB-induced toxicity in zebrafish embryos utilizing morpholino gene knockdown of the AHR isoforms. Knockdown of AHR1B did not affect the toxicity of PAH mixtures or PCB-126, whereas knockdown of AHR1A exacerbated the cardiac toxicity caused by PAH mixtures and PCB-126. Knockdown of AHR1A did not impact the mRNA expression of CYP1A, CYP1B1, and CYP1C1 in exposed embryos, but it did result in increased CYP1 activity in exposed embryos. As has been shown previously, knockdown of AHR2 resulted in protection from PAH- and PCB-induced cardiac deformities and prevented CYP1 enzyme activity in exposed embryos. Co-knockdown of AHR1A and AHR2 resulted in an intermediate response compared to knockdown of AHR1A and AHR2 individually; co-knockdown did not exacerbate nor protect from PAH-induced deformities and embryos exhibited an intermediate CYP1 enzyme activity response. In contrast, co-knockdown of AHR1A and AHR2 did protect from PCB-126-induced deformities. These results suggest that AHR1A is not a nonfunctional receptor as previously thought and may play a role in the normal physiology of zebrafish during development and/or the toxicity of environmental contaminants in early life stages. PMID:24084256

Garner, Lindsey V.T.; Brown, Daniel R.; Giulio, Richard T. Di

2013-01-01

147

THE TOXCAST PROGRAM FOR PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

The United States Environmental Protection Agency (EPA) is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals...

148

The Toxicity Estimation Software Tool (T.E.S.T.)  

EPA Science Inventory

The Toxicity Estimation Software Tool (T.E.S.T.) has been developed to estimate toxicological values for aquatic and mammalian species considering acute and chronic endpoints for screening purposes within TSCA and REACH programs....

149

TOXICITY TESTING, RISK ASSESSMENT, AND OPTIONS FOR DREDGED MATERIAL MANAGEMENT  

EPA Science Inventory

Programs for evaluating proposed discharges of dredged material into waters of the United States specify a tiered testing and evaluation protocol that includes performance of acute and chronic bioassays to assess toxicity of the dredged sediments. Although these evaluations refl...

150

Bacterial and enzymatic bioassays for toxicity testing in the environment  

SciTech Connect

Microbioassays using bacteria or enzymes are increasingly applied to measure chemical toxicity in the environment. Attractive features of these assays may include low cost, rapid response to toxicants, high sample throughput, modest laboratory equipment and space requirements, low sample volume, portability, and reproducible responses. Enzymatic tests rely on measurement of either enzyme activity or enzyme biosynthesis. Dehydrogenases are the enzymes most used in toxicity testing. Assay of dehydrogenase activity is conveniently carried out using oxidoreduction dyes such as tetrazolium salts. Other enzyme activity tests utilize ATPases, esterases, phosphatases, urease, luciferase, beta-galactosidase, protease, amylase, or beta-glucosidase. Recently, the inhibition of enzyme (beta-galactosidase, tryptophanase, alpha-glucosidase) biosynthesis has been explored as a basis for toxicity testing. Enzyme biosynthesis was found to be generally more sensitive to organic chemicals than enzyme activity.107 references.

Bitton, G.; Koopman, B. (Department of Environmental Engineering Sciences, University of Florida, Gainesville (United States))

1992-01-01

151

Eugenic selection benefits embryos.  

PubMed

The primary question to be addressed here is whether pre-implantation genetic diagnosis (PGD), used for both negative and positive trait selection, benefits potential supernumerary embryos. The phrase 'potential supernumerary embryos' is used to indicate that PGD is typically performed on a set of embryos, only some of which will be implanted. Prior to any testing, each embryo in the set is potentially supernumerary in the sense that it may not be selected for implantation. Those embryos that are not selected, and hence destroyed or frozen, are 'actually supernumerary'. The argument to be advanced is hypothetical: If embryos may be said to benefit or be harmed by our actions, then PGD used to select for an embryo or embryos with the highest expected Wellbeing benefits potential supernumerary embryos. The argument shows that the 'non-identity' problem is not sufficient to show that eugenic selection does not benefit supernumerary embryos. PMID:22845885

Walker, Mark

2014-06-01

152

Rice seed toxicity tests for organic and inorganic substances  

USGS Publications Warehouse

Plant seed toxicity tests can be used to evaluate hazardous waste sites and to assess toxicity of complex effluents and industrial chemicals. Conventional plant seed toxicity tests are performed using culture dishes containing filter paper. Some reports indicate that filter papers might interfere with the toxicity of inorganic substances. In this study, a plastic seed tray was used. Rice was used as the test species. A comparison of results in the literature and this study revealed that variation of test species, methods, exposure duration, and other factors may affect the test results. The results of this study showed that the order of decreasing toxicity of metal ions was Cu>Ag>Ni>Cd>Cr(VI)>Pb>Zn>Mn>NaF for rice. The test results were similar to those reported in the literature for lettuce Ag>Ni>Cd,Cu>Cr (VI)>Zn>Mn, millet Cu,Ni>Cd>Cr(VI)>Zn>Mn, and ryegrass Cu>Ni>Mn>>Pb>Cd>Zn> Al>Hg>Cr>Fe. The order of decreasing toxicity of organic herbicides was paraquat, 2,4-D>>glyphosate>bromacil.

Wang, W.

1994-01-01

153

A COUPLED MICROSOMAL-ACTIVATING/EMBRYO CULTURE SYSTEM: TOXICITY OF REDUCED BETA-NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE (NADPH)  

EPA Science Inventory

An NADPH-dependent microsomal-activating system has been coupled to a rat embryo culture in vitro. No embryonic morphological abnormalities or decrease in final yolk sac or embryo DNA and protein contents occurred when 0.2 mM NADPH was used in this coupled system. In contrast, 1....

154

Neurobehavioral toxicity testing for risk assessment.  

EPA Science Inventory

Neurobehavioral evaluations are key components in neurotoxicity testing. In the realm of regulatory testing, these evaluations range from a functional observational battery (FOB) and an Irwin?s screen, which assess the neurological, motor, and functional integrity of the subject...

155

Evaluation of alternative reference toxicants for use in the earthworm toxicity test  

SciTech Connect

The use of the 14-d earthworm toxicity test to aid in the evaluation of the ecological impact of contaminated soils is becoming increasingly widespread. However, the method is in need of further standardization. As part of this continuing process, the choice of reference toxicants was evaluated. Reference toxicants were rated in relation to the following criteria: (a) reproducibility, (b) low human health hazard, (c) feasibility of measurement, and (d) chemical stability. Potassium chloride (KCl) and ammonium chloride (NH{sub 4}Cl) were evaluated as possible alternatives to the one currently in common use, 2-chloroacetamide. Potassium chloride rated the best for the combination of the four criteria, followed by NH{sub 4}Cl and 2-chloroacetamide. Coefficients of variation (C.V.s) from control charts of six definitive tests were use to measure reproducibility. The best reproducibility (lowest C.V.) was shown by KCl, followed by NH{sub 4}Cl and 2-chloroacetamide. Toxicants ranked KCl < NH{sub 4}Cl {much_lt} 2-chloroacetamide in terms of health hazard; and KCl = NH{sub 4}Cl > 2-chloroacetamide in terms of measurement feasibility. Both 2-chloroacetamide and NH{sub 4}Cl changed in concentration during testing. Evidence is also presented that 2-chloroacetamide degrades rapidly during testing, and that, as dead worms decay, ammonification may be adding another toxicant, ammonia, to tests.

Yeardley, R.B. Jr. [DynCorp-TAI, Cincinnati, OH (United States); Lazorchak, J.M. [Environmental Protection Agency, Cincinnati, OH (United States); Pence, M.A. [Technology Applications, Inc., Cincinnati, OH (United States)

1995-07-01

156

Optimization of culturing conditions for toxicity testing with the alga Oophila sp. (Chlorophyceae), an amphibian endosymbiont.  

PubMed

Eggs of the yellow-spotted salamander (Ambystoma maculatum) have a symbiotic relationship with green algae. It has been suggested that contaminants that are preferentially toxic to algae, such as herbicides, may impair the symbiont and, hence, indirectly affect the development of the salamander embryo. To enable testing under near-standard conditions for first-tier toxicity screening, the authors isolated the alga from field-collected eggs and identified conditions providing exponential growth rates in the apparent asexual phase of the alga. This approach provided a uniform, single-species culture, facilitating assessment of common toxicity end points and comparison of sensitivity relative to other species. Sequencing of the 18s ribosomal DNA indicated that the isolated alga is closely related to the recently described Oophila amblystomatis but is more similar to other known Chlamydomonas species, suggesting possible biogeographical variability in the genetic identity of the algal symbiont. After a tiered approach to culturing method refinement, a modified Bristol's media with 1?mM NH4 (+) as nitrogen source was found to provide suitable conditions for toxicity testing at 18?°C and 200?µmol?m(-2) s(-1) photosynthetically active radiation (PAR) on a 24-h light cycle. The validity of the approach was demonstrated with Zn(2+) as a reference toxicant. Overall, the present study shows that screening for direct effects of contaminants on the algal symbiont without the presence of the host salamander is possible under certain laboratory conditions. Environ Toxicol Chem 2014;33:2566-2575. © 2014 SETAC. PMID:25113146

Rodríguez-Gil, José Luis; Brain, Richard; Baxter, Leilan; Ruffell, Sarah; McConkey, Brendan; Solomon, Keith; Hanson, Mark

2014-11-01

157

Expression of storm water runoff toxicity in three test organisms  

SciTech Connect

Storm water toxicity was monitored at numerous locations in the San Francisco Bay Area, using the EPA protocol for short-term chronic toxicity tests with freshwater organisms in the ``screening`` mode. Toxicity to Selenastrum capricomutum and Pimephales promelas was prevalent in samples collected at industrial catchments but was rarely detected in samples collected from other land use catchments. On the other hand, Ceriodaphnia dubia responded in most samples collected from industrial, commercial, residential, and transportation corridor catchments. In further analyses of C. dubia test results, the median time to lethality (LT{sub 50}) was derived to allow comparisons of the relative intensity of toxicity, and the number of offspring per female per reproductive day (OFRD) was calculated to allow separation of mortality from reproductive effects. This approach revealed that most of the moderately toxic (LT{sub 50} of 5--7 days) storm water samples collected from catchments of mixed land use (stream stations) did not inhibit reproduction, and that most storm water samples collected from transportation corridors did inhibit reproduction. Toxicity identification evaluations (TIE) indicated that diazinon is the major cause of toxicity in many stream samples, suggesting an explanation for the differential sensitivity observed in different species.

Katznelson, R. [Woodward-Clyde Consultants, Oakland, CA (United States); Markel, R.P. [ToxScan, Inc., Watsonville, CA (United States)

1995-12-31

158

An invertebrate embryo test with the apple snail Marisa cornuarietis to assess effects of potential developmental and endocrine disruptors.  

PubMed

A novel invertebrate embryo test with the apple snail, Marisa cornuarietis, comprising a test protocol for the following developmental endpoints is described: formation of eyes and tentacles, heart rate, hatching, weight after hatching. To evaluate effects on embryonic development, the snails were treated in a first step with 250 or 500 microg/l cadmium. Sublethal effects in terms of a significant delay in hatching could be found in the 250 microg/l treated animals, whereas 500 microg/l Cd were lethal for the snail embryos. To test endocrine disrupting chemicals with this protocol, experiments with bisphenol A (50 microg/l, 100 microg/l) and 17alpha-ethinylestradiol (10 microg/l) were performed. In both treatments an increase of weight after hatching was observed as well as a significant decline in the heart rate of the embryos. As shown here, the sensitivity of M. cornuarietis embryos test is equal or even higher than other test species like zebrafish embryos and, therefore, this test can be regarded as an alternative or supplement for ecotoxicological studies. PMID:16481024

Schirling, M; Bohlen, A; Triebskorn, R; Köhler, H-R

2006-09-01

159

Application of toxicity tests into discharges of the pulp-paper industry in Turkey  

Microsoft Academic Search

The aim of this study was to investigate the acute toxicity of pulp-paper industry wastewater using traditional and enrichment toxicity tests and to emphasize the importance of toxicity tests in wastewater discharge regulations. Enrichment toxicity tests are novel applications and give an idea of whether there is potential toxicity or growth-limiting and -stimulating conditions. Different organisms were used such as

Delia Teresa Sponza

2003-01-01

160

Results of chronic toxicity tests conducted on selected A-area outfalls, June-August 1996  

SciTech Connect

In anticipation of possible toxicity testing requirements in the SRS`s new (1996) NPDES permit, toxicity tests were performed at selected A-Area NPDES outfalls in order to determine if the outfalls were toxic. Chronic definitive toxicity tests were conducted on Ceriodaphnia dubia using water collected from nine locations during the summer of 1996. Six of the nine locations were toxic.

Specht, W.L. [Westinghouse Savannah River Company, Aiken, SC (United States)

1997-07-01

161

The influence of time on lead toxicity and bioaccumulation determined by the OECD earthworm toxicity test.  

PubMed

Internationally agreed standard protocols for assessing chemical toxicity of contaminants in soil to worms assume that the test soil does not need to equilibrate with the chemical to be tested prior to the addition of the test organisms and that the chemical will exert any toxic effect upon the test organism within 28 days. Three experiments were carried out to investigate these assumptions. The first experiment was a standard toxicity test where lead nitrate was added to a soil in solution to give a range of concentrations. The mortality of the worms and the concentration of lead in the survivors were determined. The LC50s for 14 and 28 days were 5311 and 5395 microgPb g(-1)soil respectively. The second experiment was a timed lead accumulation study with worms cultivated in soil containing either 3000 or 5000 microgPb g(-1)soil. The concentration of lead in the worms was determined at various sampling times. Uptake at both concentrations was linear with time. Worms in the 5000 microg g(-1) soil accumulated lead at a faster rate (3.16 microg Pb g(-1)tissue day(-1)) than those in the 3000 microg g(-1) soil (2.21 microg Pb g(-1)tissue day(-1)). The third experiment was a timed experiment with worms cultivated in soil containing 7000 microgPb g(-1)soil. Soil and lead nitrate solution were mixed and stored at 20 degrees C. Worms were added at various times over a 35-day period. The time to death increased from 23 h, when worms were added directly after the lead was added to the soil, to 67 h when worms were added after the soil had equilibrated with the lead for 35 days. In artificially Pb-amended soils the worms accumulate Pb over the duration of their exposure to the Pb. Thus time limited toxicity tests may be terminated before worm body load has reached a toxic level. This could result in under-estimates of the toxicity of Pb to worms. As the equilibration time of artificially amended Pb-bearing soils increases the bioavailability of Pb decreases. Thus addition of worms shortly after addition of Pb to soils may result in the over-estimate of Pb toxicity to worms. The current OECD acute worm toxicity test fails to take these two phenomena into account thereby reducing the environmental relevance of the contaminant toxicities it is used to calculate. PMID:12475061

Davies, Nicola A; Hodson, Mark E; Black, Stuart

2003-01-01

162

Environmental toxicity testing of contaminated soil based on microcalorimetry.  

PubMed

Contaminated site assessment and monitoring requires efficient risk-management tools including innovative environmental toxicity tests. The first application of microcalorimetry for toxicity testing draw the attention to a possible new tool to increase sensitivity, to eliminate matrix effect and to study effect-mechanism. A Thermal Activity Monitor (TAM) microcalorimeter was used for measuring the heat production of various test organisms when getting in contact with sterile toxic soils. Well known bacterial (Azomonas agilis), animal (Folsomia candida) and plant test organisms (Sinapis alba) were tested for heat production. The heat response of selected testorganisms was measured in case of metal (Cu and Zn) and organic pollutant (Diesel oil, DBNPA and PCP) contaminated soils. In addition to the quantitative determination of the heat production, the mechanism of the toxic effect can be characterized from the shape of the power-time curve (slope of the curve, height and time of the maximum). In certain concentration ranges the higher the pollutant concentration of the soil the lower the maximum of the time-heat curve. At low pollutant concentrations an increased heat production was measured in case of A. agile and 20 and 200 mg Zn kg(-1) soil. The microcalorimetric testing was more sensitive in all cases than the traditional test methods. Our results showed that the microcalorimetric test method offers a new and sensitive option in environmental toxicology, both for research and routine testing. PMID:20549622

Gruiz, K; Feigl, V; Hajdu, Cs; Tolner, M

2010-10-01

163

Alternative methods in toxicology tests: in vitro toxicity.  

PubMed

Toxicity testing is required for new chemicals being introduced onto the market. The use of animals in evaluating chemical safety is costly and time consuming. Furthermore, there is the ethical need to develop alternative methods to reduce the required number of animals. The new in vitro assays offer numerous advantages such as speed, reproducibility and control of test conditions, and increased sensitivity. Although the dermal irritation assays might be substituted by the in vitro tests in the near future (Duffy, 1989), much work is required to evaluate organ toxicity with in vitro methods. We present data regarding the use of Balb/3T3 mice fibroblasts and primary rat hepatocytes as test systems for in vitro toxicity. The end-points we have analysed are total protein content, dye accumulation in lysosomes, reductase mitochondrial activity, intracellular content and leakage of enzymes into the medium. PMID:1367120

Cinelli, S; Falezza, A; Meli, C; Ciliutti, P; Vericat, J A

1991-01-01

164

Impact of toxicological properties of sulfonamides on the growth of zebrafish embryos in the water.  

PubMed

Extensive use of pharmaceutical compounds may result in contamination of water bodies lying adjacent to areas where there is a high level of human activity. To evaluate potential risks to fish embryos, three sulfonamides were investigated, by means of an extended zebrafish (Danio rerio) toxicity test. The bio-toxicity of antibacterial sulfonamides, at low concentrations, was investigated by observing lethal and sub-lethal effects on embryos and larvae. Results indicated that sulfonamides caused obvious toxic effects on spontaneous movements, heartbeats and hatching of t embryos, and also resulted in malformations in embryos and larvae. A significant toxicity effect was observed in zebrafish embryos and larvae that had been exposed to a low concentration of sulfadimidine (0.001 mg/L), and a significant difference was noted between the exposed and the blank control groups. Exposure to a low concentration of sulfonamide resulted in characteristic malformations, including pericardial edema, yolk sac edema, hemoglutinations, tail deformation and swim bladder defects. PMID:24141258

Lin, Tao; Chen, Yanqiu; Chen, Wei

2013-11-01

165

Economical test methods for developmental neurobehavioral toxicity.  

PubMed Central

The assessment of behavioral changes produced by prenatal or early postnatal exposure to potentially noxious agents requires both the designing of ad hoc tests and the adaptation of tests for adult animals to the characteristics of successive developmental stages. The experience in designing tests is still more limited than in the adaptation of tests, but several tests have already proven their usefulness; some examples are the suckling test, the homing test, and evaluations of dam-pup and pup-pup interactions. Functional observational batteries can exploit the development at specified postnatal ages of several reflexes and responses that are absent at birth in altricial rodent species with a short pregnancy such as the rat and the mouse. In neonates, the assessment of early treatment effects can rely not only on deviations from normal responding but also on changes in the time of appearance of otherwise normal response patterns. The same applies to other end points such as responses to pain and various types of spontaneous motor/exploratory activities, including reactivity to a variety of drug challenges that can provide information on the regulatory systems whose development may be affected by early treatments. In particular, the analysis of ontogenetic dissociations (i.e., differential early treatment effects depending jointly on developmental stage at the time of exposure, age of testing, and response end point) can be of considerable value in the study of treatments' mechanisms of action. Overall, it appears that behavioral teratological assessments can be effectively used both proactively, i.e., in risk assessment prior to any human exposure, and reactively. In the latter case, these assessments could have special value in the face of agents suspected to produce borderline changes in developing humans, whose innocuousness or noxiousness can be difficult to establish in the absence of hard evidence of teratogenicity. PMID:9182035

Bignami, G

1996-01-01

166

Reproductive toxicity of bisphenol A and cadmium in Potamopyrgus antipodarum and modulation of bisphenol A effects by different test temperature.  

PubMed

An OECD initiative for the development of mollusc-based toxicity tests for endocrine disrupters and other chemicals has recommended three test species with respective test designs for further standardisation. Preparing a subsequent pre-validation study we performed a reproduction test with Potamopyrgus antipodarum, determining the concentration range of the selected test substances, bisphenol A (BPA) and cadmium (Cd). At 16 °C, the recommended test temperature, the number of embryos in the brood pouch was increased by BPA and decreased by Cd (NOEC: 20 ?g BPA/L and 1 ?g Cd/L). Coinstantaneous BPA tests at 7 °C and 25 °C demonstrated a temperature dependency of the response, resulting in lower NOECs (5 ?g/L respectively). As expected, reproduction in control groups significantly varied depending on temperature. Additional observations of the brood stock showed seasonal fluctuations in reproduction under constant laboratory conditions. The recommended temperature range and test conditions have to be further investigated. PMID:21737193

Sieratowicz, Agnes; Stange, Daniela; Schulte-Oehlmann, Ulrike; Oehlmann, Jörg

2011-10-01

167

COMPARATIVE TOXICITY OF DIURON ON SURVIVAL AND GROWTH OF PACIFIC TREEFROG, BULLFROG, RED-LEGGED FROG, AND AFRICAN CLAWED FROG EMBRYOS AND TADPOLES  

EPA Science Inventory

The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla),bullfrog(Rana catesbeiana), red-legged frog(Rana aurora),and African clawed frog(Xenopus laevis)embryos and tadpoles were determined in static-renewal tests. P.regilla and X.laevis...

168

APPROPRIATE DURATIONS AND MEASURES FOR 'CERIODAPHNIA' TOXICITY TESTS  

EPA Science Inventory

The Mount-Norberg test, which employs a measure of the size of three broods over seven days, has been used extensively in toxicity testing. The authors have applied it to estimating sublethal ecosystem effects of complex effluents in the Raisin River drainage (of Michigan) on the...

169

Acute systemic toxicity—prospects for tiered testing strategies  

Microsoft Academic Search

After many years of controversy and debate, the LD50 test was finally deleted by the end of 2002. Three alternative animal tests, the Fixed Dose Procedure, the Acute Toxic Class Method and the Up and Down Procedure have been developed which give rise to significant improvements in animal welfare. They have recently undergone revision to improve their scientific performance but

P. A. Botham

2004-01-01

170

THE ROLE OF INORGANIC ION IMBALANCE IN AQUATIC TOXICITY TESTING  

EPA Science Inventory

Effluent toxicity testing methods have been well defined, but to a large part have not attempted to segregate the effects of active ionic concentrations and ion imbalances upon test and species performances. The role that various total dissolved solids in effluents have on regula...

171

Evaluation of 60 chemicals in a preliminary developmental toxicity test.  

PubMed

The number of chemicals in commerce which have not been evaluated for potential developmental toxicity is large. Because of the time and expense required by conventional developmental toxicity tests, an abbreviated assay is needed that will preliminarily evaluate otherwise untested chemicals to help prioritize them for conventional testing. A proposed short-term in vivo assay has been used in a series of studies in which a total of 60 chemicals were tested. Some were independently tested two or four times each. In this preliminary test, pregnant mice were dosed during mid-pregnancy and were then allowed to deliver litters. Litter size, birth weight, and neonatal growth and survival to postnatal day 3 were recorded as indices of potential developmental toxicity. Results in this assay and conventional mouse teratology tests were generally concordant. Conventional data were available for 14 chemicals (ten teratogens, one fetotoxin, three nonteratogens), of which 11 (nine teratogens, one fetotoxin, one nonteratogen) produced evidence of developmental toxicity. This included conventional data for three chemicals (ethylene glycol, diethylene glycol dimethyl ether, and triethylene glycol dimethyl ether) that were untested before the present study. As high priority candidates for conventional testing on the basis of results here, all were subsequently studied in a standard teratology assay and were confirmed to be teratogenic in mice. Additionally, one of them (ethylene glycol) plus a fourth high priority candidate for conventional study (diethylene glycol monomethyl ether) were subsequently tested in rats and were found to be teratogenic in that species. PMID:2884741

Hardin, B D; Schuler, R L; Burg, J R; Booth, G M; Hazelden, K P; MacKenzie, K M; Piccirillo, V J; Smith, K N

1987-01-01

172

PROPOSED TEST PROTOCOL TO DETERMINE TOXICANT LEACHING INTO POTABLE WATER  

EPA Science Inventory

Research was conducted to develop a general test protocol to identify the possible deterioration of water quality as a result of leaching of toxicants from distribution/transmission pipes and tanks during distribution and storage of potable water. The developed protocol was teste...

173

GENETIC VARIATION FOR COPPER RESISTANCE IN FATHEAD MINNOW TOXICITY TESTS  

EPA Science Inventory

Unexplained variation in the results of aquatic organism toxicity tests is a consistently observed and troubling phenomenon. Possible sources of variation include differences in condition or nutritional status of the population prior to the test, as well as age, density and hand...

174

Literature review on higher plants for toxicity testing  

Microsoft Academic Search

Phytotoxicity tests using higher plants in general are infrequently used as a part of ecotoxicology. Many reports assess herbicide toxicity merely on the basis of faunal species tests. This is inadequate because the herbicide impact is much greater on flora than on fauna. Environmental pollution by herbicides was likely to have been quite wide-spread during the past years (1964–1984) when

Wuncheng Wang

1991-01-01

175

Developmental toxicity testing of biopharmaceuticals in nonhuman primates: previous experience and future directions.  

PubMed

Developmental toxicity studies for pharmaceutical safety testing are designed to evaluate potential adverse effects of drug treatment on pregnancy and on the developing embryo/fetus. Biopharmaceuticals present specific challenges for developmental toxicity testing because the pharmacology of these molecules, which are frequently human-specific proteins, is often restricted to humans and nonhuman primates (NHPs). For those species-restricted molecules, the only option for the evaluation of potential effects on development of the human biopharmaceutical is to use NHPs. This article reviews each of the stages of development in cynomolgus macaques (the most frequently used NHP) and the potential exposure of the embryo, fetus, and infant following administration of a biopharmaceutical during pregnancy and lactation. Because the purpose of the NHP developmental studies is to identify potential human risks, a comparison between macaque and human development and potential exposure has been made when possible. Understanding the potential exposure of the conceptus relative to critical periods in development is essential to designing a scientifically based study that adequately addresses human risks. Some options for NHP study designs, including the option of combining end points into a single study, and the pros and cons of each of the study options have been reviewed. Developmental studies for biopharmaceuticals in NHPs need to be optimally designed on a case-by-case basis taking into consideration the pharmacology of the molecule, the type of molecule (antibody or non-antibody), the potential exposure relative to the development of potential target organs, the clinical use, and the ethical considerations associated with the use of NHPs. PMID:20926830

Martin, Pauline L; Weinbauer, Gerhard F

2010-12-01

176

Algal toxicity tests for environmental risk assessments of metals.  

PubMed

Current regulatory methods for assessing the effects of contaminants, and metals in particular, rely mainly on a limited number of standardized test methods and test species (OECD, ISO, ASTM, USEPA). However, these test protocols allow a certain degree of freedom in relation to physicochemical parameters or biological aspects, which may lead to large variability in test results. The current review, based on effects data and theoretical considerations reported in the literature, tried to determine and quantify the effect of variation of these factors on the outcome of metal toxicity tests with algae. Major physicochemical parameters that affect metal toxicity to algae are hardness, pH, preculture conditions, type of test medium, and presence of chelating agents: Literature data also clearly demonstrate the importance of test species or strain selection (inter- and intraspecies sensitivity variability) on the outcome of algal toxicity tests. For Zn, a factor of 8.3 is observed between the NOEC for Selenastrum capricornutum (currently renamed Pseudokirchneriella subcapitata) and Croococcus paris. An intraspecies difference for S. capricornutum of a factor of 60 is observed between various reported EC50S for Cd. Next to differences in physicochemical test conditions, possible adaptation or acclimation to deficient/elevated metal concentrations add to the reported differences: S. capricornutum became three times less sensitive to Zn when acclimated to 65 microg Zn/L compared to cultures in ISO medium. This review has revealed that currently accepted standard protocols used in regulatory frameworks contain a number of major shortcomings on the physicochemical and biological aspects of algal toxicity testing with metals. These shortcomings are summarized in Table 5, together with a number of suggestions that could help to modify and improve standard test protocols for evaluating metal toxicity to algae. Until now, important factors such as pH control during test performance, selection of test medium, test species, and the effects of possible adaptation/acclimation to natural metal concentrations have not been considered, which could have serious implications when the resulting unsuitable or irrelevant toxicity data are subsequently used for setting environmental management policies. These findings also have their consequences when extrapolating laboratory data to the field as the complexity of natural waters currently is not reflected in laboratory standard media. These media contain no dissolved organic matter, have a relatively high pH, and contain large amounts of essential nutrients. In addition, the limited number of laboratory test species do not reflect natural phytoplankton communities. Test procedures for assessing the environmental impact of metal contamination in a specified ecoregion should therefore be based on performing a battery of algal tests with species adapted to and tested under the specific natural conditions of the region. PMID:12868780

Janssen, Colin R; Heijerick, Dagobert G

2003-01-01

177

Can we reduce the number of fish in the OECD acute toxicity test?  

PubMed

OECD (Organisation for Economic Co-operation and Development) Guideline 203, Fish Acute Toxicity Test, states that the test should be performed using at least five concentrations in a geometric series with a separation factor not exceeding 2.2, with at least seven fish per concentration. However, the efficiency of this design can be questioned, because it often results in only one concentration that causes partial mortality (mortality >0% and <100%). We performed Monte Carlo computer simulations to assess whether more efficient designs could allow reductions in fish use. Simulations indicated that testing with six fish per concentration could yield 50% lethal concentration (LC50) estimates of quality similar to those obtained using seven fish. Experts attending a workshop organized to consider this finding and to identify the best methods for reducing fish use concluded that significant reductions could best be achieved by modifying the test paradigm. They suggested initiating testing using a 96-h fish embryo test instead of juvenile fish to cover the range from the upper threshold concentration (the lowest 50% effective concentration [EC50] in existing algae and daphnia studies) to the highest concentration with no mortality. This would be followed by a confirmatory limit test with juvenile fish at the highest concentration with no mortality or by a full test with juvenile fish, if a point estimate of the LC50 is required. PMID:21309020

Rufli, Hans; Springer, Timothy A

2011-04-01

178

Sensitivity and precision of whole effluent toxicity (WET) tests  

SciTech Connect

The US Environmental Protection Agency`s test method manuals recommend reference toxicant test be performed to determine test sensitivity and precision within a test and among tests over time. The levels of intra and interlaboratory precision with two reference toxicants (zinc and copper) were examined with six marine test species (Macrocystis pyrifera, Haliotis rufescens, Strongylocentrotus purpuratus, Dendraster excentricus, Mytilus spp., and Menidia beryllina) and with two freshwater test species (Ceriodaphnia dubia and Pimephales promelas). Data from the EPA`s Reference Toxicant Database were used in the analysis. Data was used if the tests met the specified test acceptability criteria. The test sensitivity was examined by calculation of the minimum significant difference (e.g. MSD) and will be discussed. Results were compared to the national final chronic value (FCV) for copper and zinc. Greater than 99% of the EC25 values were above the FCV for copper with Strongylocentrotus purpuratus, Dendraster excentricus and Macrocystis pyrifera. However, greater than 99% of the EC25 values were below the FCV for zinc with Haliotis rufescens.

Denton, D. [Environmental Protection Agency, San Francisco, CA (United States); Chapman, G. [Environmental Protection Agency, Newport, OR (United States); Fulk, F. [Environmental Protection Agency, Cincinnati, OH (United States)

1995-12-31

179

Acute toxicity testing with the European estuarine amphipod Corophium multisetosum  

Microsoft Academic Search

This study reports on the use of the estuarine amphipod Corophium multisetosum in acute toxicity testing. The species was successfully acclimated to the laboratory and was used in a water-only whole effluent\\u000a 96 h acute bioassay and in a 10 days whole estuarine sediment test. C. multisetosum response was compared to other species in 96 h bioassays, testing boiling cork

Ana Ré; A. M. Rodrigues; V. Quintino

2007-01-01

180

REPORT ON ALGAL TOXICITY TESTS ON SELECTED OFFICE OF TOXIC SUBSTANCES (OTS) CHEMICALS  

EPA Science Inventory

Algal (Selenastrum capricornutum) assays were performed on 11 chemicals selected from a larger list of candidate chemicals provided by the EPA's Office of Toxic Substances (OTS). imited chemical analysis of those chemicals that could be tested readily at ERL-C was performed in su...

181

Modulation of cupric ion activity by pH and fulvic acid as determinants of toxicity in Xenopus laevis embryos and larvae  

SciTech Connect

An ion-specific electrode measured cupric ion activity modulated by fulvic acid (FA) and pH in a series of modified Frog Embryo Teratogenesis Assay--Xenopus (FETAX) toxicity assays. Hydrogen ion concentration was the primary determinant of cupric ion activity, while FA played a smaller but significant role. Fulvic acid was a weak copper complexing agent at pH 5.50. At pH 5.50 there was slight reduction of ionic activity and a subsequent attenuation of copper toxicity with 5.0 mg/L FA. At pH 7.50, FA also had a mild attenuating effect on copper toxicity. At pH 6.50, copper was strongly complexed by FA at total copper (TCu) concentrations below its pH-dependent solubility limit. At TCu concentrations above the solubility limit FA enhanced toxicity. There was more cupric ion activity measured in the presence of 0.5 and 5.0 mg/L FA than without it at TCu concentrations above the solubility limit. The proposed mechanism for this behavior was FA action as a nucleation inhibitor. Under the chemical conditions of the pH 6.50 experiments, a stable supersaturation of copper was formed, resulting in a more toxic aqueous matrix.

Buchwalter, D.B. [Oregon State Univ., Corvallis, OR (United States). Toxicology Program]|[ManTech Environmental Technology, Inc., Corvallis, OR (United States); Linder, G. [ManTech Environmental Technology, Inc., Corvallis, OR (United States); Curtis, L.R. [East Tennessee State Univ., Johnson City, TN (United States). Dept. of Environmental Health

1996-04-01

182

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

Code of Federal Regulations, 2011 CFR

...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) Note: The EP...

2011-07-01

183

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

Code of Federal Regulations, 2013 CFR

...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) Note: The EP...

2013-07-01

184

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

Code of Federal Regulations, 2012 CFR

...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) Note: The EP...

2012-07-01

185

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) IX Appendix IX to Part...Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B) Note: The EP...

2014-07-01

186

40 CFR Appendix Ix to Part 268 - Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B)  

Code of Federal Regulations, 2010 CFR

...2010-07-01 2010-07-01 false Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method 1310B...IX Appendix IX to Part 268—Extraction Procedure (EP) Toxicity Test Method and Structural Integrity Test (Method...

2010-07-01

187

Miniaturized Embryo Array for Automated Trapping, Immobilization and Microperfusion of Zebrafish Embryos  

PubMed Central

Zebrafish (Danio rerio) has recently emerged as a powerful experimental model in drug discovery and environmental toxicology. Drug discovery screens performed on zebrafish embryos mirror with a high level of accuracy the tests usually performed on mammalian animal models, and fish embryo toxicity assay (FET) is one of the most promising alternative approaches to acute ecotoxicity testing with adult fish. Notwithstanding this, automated in-situ analysis of zebrafish embryos is still deeply in its infancy. This is mostly due to the inherent limitations of conventional techniques and the fact that metazoan organisms are not easily susceptible to laboratory automation. In this work, we describe the development of an innovative miniaturized chip-based device for the in-situ analysis of zebrafish embryos. We present evidence that automatic, hydrodynamic positioning, trapping and long-term immobilization of single embryos inside the microfluidic chips can be combined with time-lapse imaging to provide real-time developmental analysis. Our platform, fabricated using biocompatible polymer molding technology, enables rapid trapping of embryos in low shear stress zones, uniform drug microperfusion and high-resolution imaging without the need of manual embryo handling at various developmental stages. The device provides a highly controllable fluidic microenvironment and post-analysis eleuthero-embryo stage recovery. Throughout the incubation, the position of individual embryos is registered. Importantly, we also for first time show that microfluidic embryo array technology can be effectively used for the analysis of anti-angiogenic compounds using transgenic zebrafish line (fli1a:EGFP). The work provides a new rationale for rapid and automated manipulation and analysis of developing zebrafish embryos at a large scale. PMID:22606275

Akagi, Jin; Khoshmanesh, Khashayar; Evans, Barbara; Hall, Chris J.; Crosier, Kathryn E.; Cooper, Jonathan M.; Crosier, Philip S.; Wlodkowic, Donald

2012-01-01

188

Control group response variability in short-term toxicity tests  

SciTech Connect

The US EPA`s National Reference Toxicant Database (NRTDB) has afforded an excellent opportunity to examine and document variability in responses within control groups (i.e. zero concentration of the toxicant.) The NRTDB has compiled acute and chronic reference toxicant test results for eight species and currently contains results for 32 laboratories and generally eight to ten tests for a species within each laboratory. The Ceriodaphnia dubia Survival and Reproduction test and the Pimephales promelas (fathead minnow) Survival and Growth test are the most frequently represented chronic tests with 331 and 144 sets of test data, respectively. For this presentation, Ceriodaphnia dubia reproduction data, expressed as total numbers of young in the test period, and fathead minnow survival and growth data were analyzed using a variance components model. The information regarding the control population is useful in examining the sources of inter and intralaboratory variability of chronic testing. In addition, this control population response variability information will be valuable for characterizing what can be termed as ``practically equivalent responses`` between a control and an effluent. The preliminary analysis indicates considerable between-test variability; however, this variability is not consistent across laboratories. Results of further exploration on this issue will be presented.

Gast, L.C.; Shimp, C. [DynCorp, Cincinnati, OH (United States); Wang, Q.; Shukla, R. [UC Medical Center, Cincinnati, OH (United States). Dept. of Environmental Health; Fulk, F. [Environmental Protection Agency, Cincinnati, OH (United States)

1995-12-31

189

Functional toxicology: tools to advance the future of toxicity testing  

PubMed Central

The increased presence of chemical contaminants in the environment is an undeniable concern to human health and ecosystems. Historically, by relying heavily upon costly and laborious animal-based toxicity assays, the field of toxicology has often neglected examinations of the cellular and molecular mechanisms of toxicity for the majority of compounds—information that, if available, would strengthen risk assessment analyses. Functional toxicology, where cells or organisms with gene deletions or depleted proteins are used to assess genetic requirements for chemical tolerance, can advance the field of toxicity testing by contributing data regarding chemical mechanisms of toxicity. Functional toxicology can be accomplished using available genetic tools in yeasts, other fungi and bacteria, and eukaryotes of increased complexity, including zebrafish, fruit flies, rodents, and human cell lines. Underscored is the value of using less complex systems such as yeasts to direct further studies in more complex systems such as human cell lines. Functional techniques can yield (1) novel insights into chemical toxicity; (2) pathways and mechanisms deserving of further study; and (3) candidate human toxicant susceptibility or resistance genes. PMID:24847352

Gaytan, Brandon D.; Vulpe, Chris D.

2014-01-01

190

Comparisons of Sediment Test Volumes for Freshwater Solid Phase Sediment Toxicity Tests  

EPA Science Inventory

Laboratory tests with benthic macroinvertebrates are commonly used to assess the potential toxicity of contaminated sediments, and detailed standard test procedures have been developed for various species. For freshwater, two benthic organisms, Hyalella azteca and Chironomus dil...

191

Decreased Dissolution of ZnO by Iron Doping Yields Nanoparticles with Reduced Toxicity in the Rodent Lung and Zebrafish Embryos  

PubMed Central

We have recently shown that the dissolution of ZnO nanoparticles and Zn2+ shedding leads to a series of sub-lethal and lethal toxicological responses at cellular level that can be alleviated by iron-doping. Iron-doping changes the particle matrix and slows the rate of particle dissolution. To determine whether iron doping of ZnO also leads to lesser toxic effects in vivo, toxicity studies were performed in rodent and zebrafish models. First, we synthesized a fresh batch of ZnO nanoparticles doped with 1–10 wt % of Fe. These particles were extensively characterized to confirm their doping status, reduced rate of dissolution in an exposure medium and reduced toxicity in a cellular screen. Subsequent studies compared the effects of undoped to doped particles in the rat lung, mouse lung and the zebrafish embryo. The zebrafish studies looked at embryo hatching and mortality rates as well as the generation of morphological defects, while the endpoints in the rodent lung included an assessment of inflammatory cell infiltrates, LDH release and cytokine levels in the bronchoalveolar lavage fluid. Iron doping, similar to the effect of the metal chelator, DTPA, interfered in the inhibitory effects of Zn2+ on zebrafish hatching. In the oropharyngeal aspiration model in the mouse, iron doping was associated with decreased polymorphonuclear cell counts and IL-6 mRNA production. Doped particles also elicited decreased heme oxygenase 1 expression in the murine lung. In the intratracheal instillation studies in the rat, Fe-doping was associated with decreased polymorphonuclear cell counts, LDH and albumin levels. All considered, the above data show that Fe-doping is a possible safe design strategy for preventing ZnO toxicity in animals and the environment. PMID:21250651

Xia, Tian; Zhao, Yan; Sager, Tina; George, Saji; Pokhrel, Suman; Li, Ning; Schoenfeld, David; Meng, Huan; Lin, Sijie; Wang, Xiang; Wang, Meiying; Ji, Zhaoxia; Zink, Jeffrey I.; Madler, Lutz; Castranova, Vincent; Lin, Shuo; Nel, Andre E.

2014-01-01

192

Scanning respirometer for toxicity tests using micro-organisms  

NASA Astrophysics Data System (ADS)

A novel respirometer is developed for microbial toxicity tests. The respirometer is based on luminescent quenching of oxygen to measure the concentration of dissolved oxygen in cell vessels and evaluate the toxicity of chemicals by monitoring the effect of toxicants on cell respiration of micro-organisms. The oxygen sensing element is ruthenium complex absorbed on the surface of silica particles followed by immobilizing on a silicone rubber film. The oxygen sensing film is coated on the inner bottom of a transparent cell vessel. A sensing device scanning under the cell vessel is used for remote monitoring of the oxygen concentration inside the cell vessels so that a large number of samples can be handled in one batch. The sensing device includes the excitation light sources and an optical cable connected to a filter and a photomultiplier tube for detecting the luminescence in the cell vessel which can then be related to the dissolved oxygen concentration inside the cell vessel. The movement of the sensing device and data acquisition are controlled by a personal computer. The toxicity of heavy metals to activated sludge, soil bacteria and E. coli were tested using the present device. The scanning respirometer provides a new alternative for fast and large scale screening and monitoring of toxicants using micro-organisms.

Zhang, Min-Quan; Li, Xiang-Ming; Wong, Yuk-Shan; Kwan, FolkYear

1995-09-01

193

TOXICITY TEST USING LIFE STAGES OF 'CHAMPIA PARVULA' (RHODOPHYTA)  

EPA Science Inventory

A static-renewal, 11- to 14-day toxicity test has been developed using the life cycle of the marine red alga Champia parvula (C. Ag.) Harv. It measures the vegetative growth, formation of tetrasporangia (meiosis), and formation of cystocarps (sexual fusion). The procedure has bee...

194

COMPUTER INTERFACED TOXICITY TESTING SYSTEM FOR SIMULATING VARIABLE EFFLUENT LOADING  

EPA Science Inventory

Water quality criteria and standards are based primarily on toxicity tests carried out with single chemicals whose concentration is as nearly constant as possible. In the 'real world', however, organisms are exposed to mixtures of chemicals which usually have markedly fluctuating...

195

THE FUTURE OF TOXICITY TESTING AND ASSESSMENT OF ENVIRONMENTAL AGENTS  

EPA Science Inventory

The National Research Council's Board on Environmental Studies and Toxicology is conducting a two-part study to assess and advance current approaches to toxicity testing and assessment to meet regulatory data needs. The first part of the study was completed January 2006, in which...

196

Toxicity testing with freshwater algae in River Periyar (India)  

Microsoft Academic Search

A wide range of toxicity tests have been developed in the recent decades to predict the probable effect of new chemicals and effluents on aquatic ecosystem, utilizing different organisms such as algae, crustaceans, molluscs and fish (Sprague 1973; Walsh et al. 1980; Reish and Oshida 1986). Walsh et al. (1982) observed that \\

C. M. Joy

1990-01-01

197

Assessment of toxicity test endpoints for freshwater mussel larvae (glochidia).  

PubMed

The objectives of the present study were to determine if the viability of freshwater mussel larvae (glochidia) is an ecologically relevant endpoint for toxicity tests and to define the appropriate duration of those tests. The authors assessed 1) how viability (the shell closure response to sodium chloride) compares with infectivity (ability to attach to a host fish and successfully metamorphose to the juvenile stage), and 2) the decline of viability and infectivity over time after glochidia were released from female mussels. Glochidia of 7 mussel species were isolated from females, placed in water, and subsampled daily for 2 d to 5 d. Viability, when ?90%, was generally a good predictor of infectivity; however, when viability was <90%, infectivity was often disproportionately low, especially for glochidia collected near the end of the brooding period. Viability and infectivity declined more rapidly in natural water and sediment compared to reconstituted water. Following 24-h exposure to a toxicant (sodium chloride or copper), infectivity of the viable glochidia did not differ among concentrations of toxicants. The results indicate that viability is a valid proxy for infectivity and an ecologically relevant endpoint for standard toxicity tests with freshwater mussels for any test duration with control viability >90%. PMID:24122868

Fritts, Andrea K; Barnhart, M Christopher; Bradley, Megan; Liu, Na; Cope, W Gregory; Hammer, Edward; Bringolf, Robert B

2014-01-01

198

A FIELD VALIDATION OF TWO SEDIMENT-AMPHIPOD TOXICITY TESTS  

EPA Science Inventory

A field validation study of two sediment-amphipod toxicity tests was conducted using sediment samples collected subtidally in the vicinity of a polycyclic aromatic hydrocarbon (PAH)-contaminated Superfund site in Elliott Bay, WA, USA. Sediment samples were collected at 30 stati...

199

40 CFR 799.9355 - TSCA reproduction/developmental toxicity screening test.  

Code of Federal Regulations, 2010 CFR

...ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT (CONTINUED) ...intended to meet testing requirements of the Toxic Substances Control Act (TSCA) (15 U...Office of Prevention, Pesticides, and Toxic Substances (OPPTS) harmonized...

2010-07-01

200

In vitro Cell Culture Model for Toxic Inhaled Chemical Testing  

PubMed Central

Cell cultures are indispensable to develop and study efficacy of therapeutic agents, prior to their use in animal models. We have the unique ability to model well differentiated human airway epithelium and heart muscle cells. This could be an invaluable tool to study the deleterious effects of toxic inhaled chemicals, such as chlorine, that can normally interact with the cell surfaces, and form various byproducts upon reacting with water, and limiting their effects in submerged cultures. Our model using well differentiated human airway epithelial cell cultures at air-liqiuid interface circumvents this limitation as well as provides an opportunity to evaluate critical mechanisms of toxicity of potential poisonous inhaled chemicals. We describe enhanced loss of membrane integrity, caspase release and death upon toxic inhaled chemical such as chlorine exposure. In this article, we propose methods to model chlorine exposure in mammalian heart and airway epithelial cells in culture and simple tests to evaluate its effect on these cell types. PMID:24837339

Ahmad, Shama; Ahmad, Aftab; Neeves, Keith B.; Hendry-Hofer, Tara; Loader, Joan E.; White, Carl W.; Veress, Livia

2014-01-01

201

Operant behavior as a technique for toxicity testing.  

PubMed

Behavioral toxicology is a discipline which has evolved out of the need for data on the effects of toxic agents on the function of the central nervous system. To date the field is divided over the question of which behavioral models to use to detect behavioral toxicities. Operant conditioning and schedule-controlled responding have been used as baselines for testing pharmacological agents for nearly 40 years, and there is no reason that the developing field of behavioral toxicology cannot take advantage of the lessons learned during this 40-year period. Behaviors maintained by operant conditioning procedures have proven to be sensitive to a wide range of chemicals. Using these procedures, behavior has been shown to; be sensitive to toxic agents, provide data relevant to the question of behavioral specificity, provide a stable baseline for extended periods of time, and allow for the assessment of specific functions such as temporal discrimination, learning and memory, and sensory system function. PMID:2247041

Wenger, G R

1990-01-01

202

An evaluation of the whole effluent toxicity test method  

SciTech Connect

Whole effluent toxicity (WET) testing has become increasingly more important to the Environmental Protection Agency (EPA) and the States in the permitting of wastewater discharges from industry and municipalities. The primary purpose of the WET test is to protect aquatic life by predicting the effect of an effluent on the receiving stream. However, there are both scientific and regulatory concerns that using WET tests to regulate industrial effluents may result in either false positives and/or false negatives. In order to realistically predict the effect of an effluent on the receiving stream, the test should be as representative as possible of the conditions in the receiving stream. Studies (Rand and Petrocelli 1985) suggested several criteria for an ideal aquatic toxicity test organism, one of which is that the organism be indigenous to, or representative of, the ecosystem receiving the effluent. The other component needed in the development of a predictive test is the use of the receiving stream water or similar synthetic water as the control and dilution water in the test method. Use of an indigenous species and receiving water in the test should help reduce the variability in the method and allow the test to predict the effect of the effluent on the receiving stream. The experience with toxicity testing at the Savannah River Site (SRS) has yielded inconclusive data because of the inconsistency and unreliability of the results. The SRS contention is that the WET method in its present form does not adequately mimic actual biological/chemical conditions of the receiving streams and is neither reasonable nor accurate. This paper discusses the rationale for such a position by SRS on toxicity testing in terms of historical permitting requirements, outfall effluent test results, standard test method evaluation, scientific review of alternate test species, and concerns over the test method expressed by other organizations. This paper presents the Savannah River Site position that the EPA test is neither reasonable nor accurate and thus cannot adequately establish the impact of NPDES outfall discharges on receiving streams.

Osteen, D.V.

1999-12-17

203

Adaptation of the Daphnia sp. acute toxicity test: miniaturization and prolongation for the testing of nanomaterials.  

PubMed

Manufacturing of nanomaterials (NMs) is often complex and expensive, and their environmental risks are poorly understood or even unknown. An economization of testing NMs is therefore desirable, which can be achieved by miniaturizing test systems. However, the downsizing of test vessels and volumes can enlarge the surface/volume ratio (SVR) which in turn can affect the bioavailable concentration of adsorbing substances like NMs. The present study focused on the miniaturization of the acute toxicity test with Daphnia magna. The adaptations were verified with three reference substances, the non-adsorbing potassium dichromate (K2Cr2O7) and as potentially highly-adsorbing substances silver nanoparticles (AgNPs) and silver nitrate (AgNO3). The miniaturized test was conducted in 24-well microtiter plates (MT) and simultaneously compared to the OECD standard test (ST). Furthermore, the test duration was prolonged from 48 to 96 h since NMs tend to show effects only after extended exposure. The toxicity of K2Cr2O7 and AgNPs continued to increase within the prolonged test span. The test comparisons with K2Cr2O7 did not reveal any significant differences between ST and MT. AgNO3 toxicity was significantly decreased in MT compared to ST due to the enlarged SVR. The toxicity of AgNPs in MT after 24 h was equal to ST. Contrary to our expectations an exposure longer than 24 h resulted in an increase of AgNP toxicity in MT, possibly due to enhanced dissolution of silver. Microtiter plates are appropriate alternative test vessels for the Daphnia sp. acute toxicity test; thus, its miniaturization is feasible. The enlarged SVR has to be taken into account since it can affect the toxicity of potentially adsorbing substances. Furthermore, the standard test duration of 48 h might underestimate the toxicity of many substances, especially of NMs. PMID:24043504

Baumann, Jonas; Sakka, Yvonne; Bertrand, Carole; Köser, Jan; Filser, Juliane

2014-02-01

204

Effects of temperature and oxygen concentration in sediment toxicity testing.  

PubMed

Joint effects of temperature and oxygen concentrations for the results of sediment toxicity tests were studied at 10 and 20 degrees C with 40% and 80% dissolved oxygen (DO) saturation. Growth, feeding rate, and reproduction of Lumbriculus variegatus (Oligochaete) and growth, emergence, and survival of Chironomus riparius (Diptera) were tested in a polluted and in a reference sediment. Both the feeding of L. variegatus and the emergence of C. riparius were significantly retarded at low temperature. Additionally, differences in the sex ratio of the emerged adults of C. riparius were observed. The oxygen concentration alone did not have any significant effect on the endpoints, but significant combined effects of polluted sediment and low DO were observed on the biomass of L. variegatus. The standard sediment toxicity tests might offer only limited data for risk assessment of contaminated sediments at sites where the actual conditions largely differ from the laboratory conditions. PMID:18061670

Airas, Sari; Leppänen, Matti; Kukkonen, Jussi V K

2008-07-01

205

Improvement of in vivo genotoxicity assessment: Combination of acute tests and integration into standard toxicity testing  

Microsoft Academic Search

A working group convened at the 2009 5th IWGT to discuss possibilities for improving in vivo genotoxicity assessment by investigating possible links to standard toxicity testing. The working group considered: (1) combination of acute micronucleus (MN) and Comet assays into a single study, (2) integration of MN assays into repeated-dose toxicity (RDT) studies, (3) integration of Comet assays into RDT

Andreas Rothfuss; Masamitu Honma; Andreas Czich; Marilyn J. Aardema; Brian Burlinson; Sheila Galloway; Shuichi Hamada; David Kirkland; Robert H. Heflich; Jonathan Howe; Madoka Nakajima; Mike O’Donovan; Ulla Plappert-Helbig; Catherine Priestley; Leslie Recio; Maik Schuler; Yoshifumi Uno; Hans-Jörg Martus

2011-01-01

206

Validation of embryo tests for determining effects of fungal pest control agents on nontarget aquatic animals  

Microsoft Academic Search

Developing embryos of the inland silverside fish, Menidia beryllina, and grass shrimp, Palaemonetes pugio, were exposed to conidiospores of the fungal weed control agent, Colletotrichum gloeosporioides f. sp. aeschynomene and the entomopathogen, Metarhizium anisopliae. Only Metarhizium anisopliae caused significant (p=0.05) mortalities in the exposed embryos. Colletotrichum gloeosporioides did, however, cause fatal infections in adults when conidia were injected into the

F. J. Genthner; D. P. Middaugh; S. S. Foss

1995-01-01

207

The Role of Toxicity Testing in NASA's Future Missions  

NASA Technical Reports Server (NTRS)

NASA has deemed it necessary to perform the Toxicity Test (offgassing of toxic products) on all non-metallic materials proposed for use in habitable environments onboard the Shuttle and International Space Station flS,!J. This requirement stems from the desire to maintain a healthy, breathable atmosphere for the astronauts. As Shuttle missions have lengthened and with the habitation of the International Space Station, the need for understanding and controlling the contaminants in breathable atmospheres has increased. The increased duration of humans in space present two concerns to the astronauts with regard to their breathing air: 1. Breathing the on-board air. 2. Improved cleaning/filtering of existing air. Trends using existing toxicity data for materials and an understanding of the air cleaning/filtering capabilities in relation to Spacecraft Maximum Allowable Concentrations (SMAC) of offgassed components are explored. Recommendations are made for materials selection practices that should be followed to ensure a safe and healthy breathing environment for astronauts aboard these long term projects. The importance and relevance of Toxicity testing and materials selection in conjunction with the new NASA missions of creating a human presence on the Moon and traveling to Mars are described.

Whitfield, Steve; Davis, Samuel; Wise, Harry; Moore, Robin

2005-01-01

208

In situ toxicity testing with locally collected Daphnia  

SciTech Connect

Daphnia middlendorffiana from local tundra ponds were transplanted into five reserve pits (sumps with used drilling wastes and precipitation) at drill sites in the Prudhoe Bay oil field. Concurrently, Daphnia were transplanted into tundra ponds adjacent to the reserve pits (near ponds), into more distant but connected ponds (distant ponds), and into control ponds to evaluate the toxicity of the fluids along contaminant gradients. Twenty adult Daphnia were placed in eight waxed flow-through containers and exposed to the conditions of each test site. In each exposure container, the ratios of the number of dead Daphnia to the total number of adult Daphnia, the number of young Daphnia to the total number of adult Daphnia, the number of molting Daphnia to the total number of adult Daphnia, and the number of released ephippia to the total number of adult Daphnia were determined. The results not only indicate the utility of in situ testing of invertebrate toxicity but suggest that under certain conditions in situ tests may be more sensitive than traditional laboratory toxicity tests.

Snyder-Conn, E.

1993-07-01

209

Evaluation of the test of significant toxicity for determining the toxicity of effluents and ambient water samples.  

PubMed

The test of significant toxicity (TST) is a hypothesis-testing approach based on bioequivalence developed by the U.S. Environmental Protection Agency (U.S. EPA) for analyzing whole-effluent toxicity (WET) and ambient toxicity data. The present study compares results of acute and chronic toxicity tests of effluent, storm-water, and ambient (i.e., receiving-water) samples using both the TST and the standard no-observed-effect concentration (NOEC) approach. Valid WET data were analyzed from 890 tests provided by more than 25 dischargers in California and Washington, USA, representing the majority of test methods used in the U.S. WET program. An additional 3,201 freshwater chronic toxicity tests, obtained from ambient monitoring programs in California, were also analyzed. The TST and NOEC approaches both declared a low number (<6.5%) of tests toxic if effects were below the unacceptable toxicity regulatory management decision (RMD) of 25% effect in chronic tests or 20% effect in acute tests. However, those test methods having generally lower within-test variability and greater test power (e.g., urchin fertilization test) had a much lower percentage of tests declared toxic than the NOEC approach when effects were below the unacceptable toxicity RMD. In addition, the TST showed fewer tests to be nontoxic than NOEC if the test exhibited effects greater than the toxicity RMD (0.1 and 9.6% for TST and NOEC, respectively, for effluents and 0 and 9.5%, respectively, for ambient samples). Our results demonstrate that the TST is more likely to identify a toxic sample when effects are fairly substantial (? 25% effect in chronic testing and ? 20% effect in acute tests) and less likely to identify a sample as toxic when effects are negligible (? 10% effect). Furthermore, these results demonstrate that appropriate WET data interpretation benefits from having well-designed test methods with sufficient power to identify significant toxicity or biologically insignificant effects when they occur. PMID:23400869

Diamond, Jerry M; Denton, Debra L; Roberts, John W; Zheng, Lei

2013-04-01

210

78 FR 66700 - Toxic Substances Control Act Chemical Testing; Receipt of Test Data  

Federal Register 2010, 2011, 2012, 2013

...Vitro from ore; bleaching Mammalian Chromosome leather and masonry; Aberration; Validation...Toxicity in Rats; Boiling Point; In Vitro Chromosome Aberration Test. Castor oil, oxidized...Escherichia Coli); In Vitro Mammalian Chromosome Aberration in Chinese Hamster V79...

2013-11-06

211

Ambient Water Toxicity in San Francisco Bay: 1993-2002  

E-print Network

Thalassiosira Results: No toxicity observed Thalassiosira exhibited biostimulation #12;RMP Status & Trends Jeffrey Cotsifas, Stephen Clark, and Staff Pacific EcoRisk #12;RMP Status & Trends Monitoring 1993 (Year survival test with Americamysis bahia Results: No toxicity to bivalve embryo development; Slight toxicity

212

[Analysis performance of biological toxicity testing MTOXPlate using microplate].  

PubMed

Biological toxicities of heavy metals (Hg2+, Cd2+, Cr6+ and Pb2+), phenolic compounds (2,4-DCP, 2-CP, 4-CP, 2-NP and 4-NP), surface water and wastewater were determined with the MTOXPlate based on 11 genetically diverse microorganisms and the analysis endpoint of dehydrogenase activity inhibition. The results showed that the MTOXPlate had good performance for toxicity analysis of heavy metals and phenolic compounds. The EC50 values of Hg2+, Cd2+, Cr6+, Pb2+, 2,4-DCP, 2-CP, 4-CP, 2-NP and 4-NP detected by the MTOXPlate were 0.617, 21.05, 35.21, 11.22, 27.26, 64.29, 44.19, 85.89 and 33.84 mg x L(-1), respectively. The dehydrogenase activity inhibition of surface water was less than 20%. Moreover, the EC50 values of sewage and dyeing wastewater were 62.19% and 16.42%, respectively. Thus, the biological toxicity testing technology MTOXPlate could reflect the actual toxicity of surface water, sewage and dyeing wastewater. PMID:24191582

Lin, Yi-Yun; Zhang, Guo-Xia; He, Li-Ping; Sun, Guo-Ping; Xu, Mei-Ying

2013-08-01

213

Toxicity testing of medical device materials tested in human tissue cultures.  

PubMed

Rubber and plastic parts of medical devices were applied to human cell monolayers either directly or as aqueous extracts made at different time/temperature conditions. Thirteen rubber and twelve plastic samples were tested. The cultures were observed and photographed by use of a microscope with a camera before and after treatment with the test materials. The toxicity of the specimens was evaluated by comparison of the photographs. Alterations or disappearance of the cells or inhibited growth were interpreted as toxic effects of the materials. Twelve of the rubber and six of the plastic samples were evaluated as toxic in one or more of the systems. PMID:6722251

Haustveit, G; Torheim, B; Fystro, D; Eidem, T; Sandvik, M

1984-03-01

214

Toxicity Testing in the 21st Century: A Vision and a Strategy  

Microsoft Academic Search

With the release of the landmark report Toxicity Testing in the 21st Century: A Vision and a Strategy, the U.S. National Academy of Sciences, in 2007, precipitated a major change in the way toxicity testing is conducted. It envisions increased efficiency in toxicity testing and decreased animal usage by transitioning from current expensive and lengthy in vivo testing with qualitative

Daniel Krewski; Daniel Acosta Jr; Melvin Andersen; Henry Anderson; John C. Bailar III; Kim Boekelheide; Robert Brent; Gail Charnley; Vivian G. Cheung; Sidney Green Jr; Karl T. Kelsey; Nancy I. Kerkvliet; Abby A. Li; Lawrence McCray; Otto Meyer; Reid D. Patterson; William Pennie; Robert A. Scala; Gina M. Solomon; Martin Stephens; James Yager; Lauren Zeise

2010-01-01

215

Field assessments in conjunction with whole effluent toxicity testing  

SciTech Connect

Whole effluent toxicity (WET) tests are widely used to assess potential effects of wastewater discharges on aquatic life. This paper represents a summary of chapters in a 1996 Society of Environmental Toxicology and Chemistry-sponsored workshop and a literature review concerning linkages between WET testing and associated field biomonitoring. Most published studies thus far focus primarily on benthic macroinvertebrates and on effluent-dominated stream systems in which effluents demonstrate little or no significant acute toxicity. Fewer studies examine WET test predictability in other aquatic ecosystems (e.g., wetlands, estuaries, large rivers) or deal with instream biota such as fish and primary producers. Published results indicate that standards for the usual WET freshwater test species, Ceriodaphnia dubia and Pimephales promelas, may not always protect most of the species inhabiting a receiving stream. Although WET tests are useful in predicting aquatic individual responses, they are not meant to directly measure natural population or community responses. Further, they do not address bioconcentration or bioaccumulation of hydrophobic compounds; do not assess eutrophication effects in receiving systems; and lastly, do not reflect genotoxic effects or function to test for endocrine-disrupting chemicals. Consequently, a more direct evaluation of ecosystem health, using bioassessment techniques, may be needed to properly evaluate aquatic systems affected by wastewater discharges.

La Point, T.W.; Waller, W.T.

2000-01-01

216

A REVIEW OF SINGLE SPECIES TOXICITY TESTS: ARE THE TESTS RELIABLE PREDICTORS OF AQUATIC ECOSYSTEM COMMUNITY RESPONSES?  

EPA Science Inventory

This document provides a comprehensive review to evaluate the reliability of indicator species toxicity test results in predicting aquatic ecosystem impacts, also called the ecological relevance of laboratory single species toxicity tests....

217

CELLULAR TOXICITY IN CHINESE HAMSTER OVARY CELL CULTURES. 2. A STATISTICAL APPRAISAL OF SENSITIVITY WITH THE RABBIT ALVEOLAR MACROPHAGE, SYRIAN HAMSTER EMBRYO, BALB 3T3 MOUSE, AND HUMAN NEONATAL FIBROBLAST CELL SYSTEMS  

EPA Science Inventory

Chinese hamster ovary, rabbit alveolar macrophage, Syrian Hamster embryo, mouse, and human neonatal fibroblast cells were employed in a statistical evaluation of the relative sensitivity of the cells to toxic substances. The cells were exposed to 1,2,4-trichlorobenzene, 2,4-dimet...

218

Species-specific considerations in using the fish embryo test as an alternative to identify endocrine disruption.  

PubMed

A number of regulations have been implemented that aim to control the release of potentially adverse endocrine disrupters into the aquatic environment based on evidence from laboratory studies. Currently, such studies rely on testing approaches with adult fish because reliable alternatives have not been validated so far. Fish embryo tests have been proposed as such an alternative, and here we compared two species (medaka and zebrafish) to determine their suitability for the assessment of substances with estrogenic and anti-androgenic activity. Changes in gene expression (in here the phrase gene expression is used synonymously to gene transcription, although it is acknowledged that gene expression is additionally regulated, e.g., by translation and protein stability) patterns between the two species were compared in short term embryo exposure tests (medaka: 7-day post fertilization [dpf]; zebrafish: 48 and 96h post fertilization [hpf]) by using relative quantitative real-time RT-PCR. The tested genes were related to the hypothalamic-gonadal-axis and early steroidogenesis. Test chemicals included 17?-ethinylestradiol and flutamide as estrogenic and anti-androgenic reference compounds, respectively, as well as five additional substances with endocrine activities, namely bisphenol A, genistein, prochloraz, linuron and propanil. Estrogenic responses were comparable in 7-dpf medaka and 48/96-hpf zebrafish embryos and included transcriptional upregulation of aromatase b, vitellogenin 1 as well as steroidogenic genes, suggesting that both species reliably detected exposure to estrogenic compounds. However, anti-androgenic responses differed between the two species, with each species providing specific information concerning the mechanism of anti-androgenic disruption in fish embryos. Although small but significant changes in the expression of selected genes was observed in 48-hpf zebrafish embryos, exposure prolonged to 96hpf was necessary to obtain a response indicative of anti-androgenic activity. In contrast, for medaka clear anti-androgenic response, e.g. transcriptional downregulation of 11?-hydroxylase, 3?-hydroxysteroid-dehydrogenase, gonadotropin-releasing hormone receptor 2, was already observed at the pre-hatch stage. Together, this data suggests that medaka and zebrafish embryos would provide a beneficial alternative testing platform for endocrine disruption that involves additive information on interspecies and exposure time variability when using both species. PMID:24992288

Schiller, Viktoria; Zhang, Xiaowei; Hecker, Markus; Schäfers, Christoph; Fischer, Rainer; Fenske, Martina

2014-10-01

219

VALIDATION OF EMBRYO TESTS FOR DETERMINING EFFECTS OF FUNGAL PEST CONTROL AGENTS ON NONTARGET AQUATIC ANIMALS  

EPA Science Inventory

Developing embryos of the inland silverside fish Menidia beryllina and grass shrimp Palaemonetes pugio were exposed to conidiospores of the fungal weed control agent, Colletotrichum gloeosporioides, f. sp. aeschynomene, and the entomopathogen, Metarhizium anisopliae. nly Metarhiz...

220

FETAX interlaboratory validation study: Phase 2 testing  

Microsoft Academic Search

The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a 96-h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that

John A. Bantle; Dennis T. Burton; Douglas A. Dawson; James N. Dumont; Robert A. Finch; Douglas J. Fort; Greg Linder; James R. Rayburn; David Buchwalter; Angela M. Gaudet-Hull; Margaret A. Maurice; Steven D. Turley

1994-01-01

221

PHOTOACTIVATED POLYCYCLIC AROMATIC HYDROCARBON TOXICITY IN MEDAKA (ORYZIAS LATIPES) EMBRYOS: RELEVANCE TO ENVIRONMENTAL RISK IN CONTAMINATED SITES  

EPA Science Inventory

The hazard for photoactivated toxicity of polycyclic aromatic hydrocarbons (PAHs) has been clearly demonstrated; however, to our knowledge, the risk in contaminated systems has not been characterized. To address this question, a median lethal dose (LD50) for fluoranthene photoa...

222

A SURROGATE SUBCHRONIC TOXICITY TEST METHOD FOR WATERS WITH HIGH TOTAL DISSOLVED SOLIDS  

EPA Science Inventory

Total dissolved solids (TDS) are often identified as a toxicant in whole-effluent toxicity (WET) testing. The primary test organism used in WET testing, Ceriodaphnia dubia, is very sensitive to TDS ions, which can be problematic when differentiating the toxicity of TDS from those...

223

Sediment toxicity testing of Lake Orta after liming  

SciTech Connect

Lake Orta has been severely polluted by industrial effluents containing Cu, NH{sub 3}, Cr., Ni, and Zn. Ammonia oxidation caused a pH drop below 4. More than 60 papers have described the adverse chemical and biological changes which occurred in Lake Orta in the past several decades. In 1989, CaCO{sub 3} (10,900 tons) was added to the lake as a remedial action. The treatment was effective, improving water quality and allowing some original plankton, benthic, and fish populations to return. However, Cu and Cr are still present in the top 10 cm of sediment. The toxicity of the sediment was evaluated using multiple assays: Microtox (solid phase and pore water), Brachionus calyciflorus and Thamnocephalus platyurus Toxkits (pore water), seed germination and root elongation (solid phase and pore water). In addition, in situ and laboratory tests were conducted with Hyalella azteca and an indigenous species of Daphnia. Assays responses varied yet showed surficial sediments to be toxic. Toxicity increased with sediment in pre-liming deposition zones. Recovery of the ecosystem is evident, however the contaminated sediments may impede further improvement.

Baudo, R.; Beltrami, M.; Rossi, D. [CNR, Verbania-Pallanza (Italy). Ist. Italiano Idrobiologia; Gronda, A. [Ecotox LSD, Prenana Milanese (Italy); Abdel-Monem, A.M. [National Institutes of Oceanography and Fisheries, Cairo (Egypt); Burton, G.A. [Wright State Univ., Dayton, OH (United States)

1995-12-31

224

[Microbial test combination with Vibrio fischeri as a screening toxicity test  

PubMed

Two different microbial toxicity tests were investigated concerning the possibility to reduce animal experiments in product testing. In the acute bioluminescence test the inhibition of the bacterial luminescence was measured. In the chronic DMS test the inhibition of the microbial metabolism of DMSO to DMS was recorded. The combination of both tests with the same organism Vibrio fischeri enhances the power as a toxicological indicator. We used well known alcohols and tensides. For 15 substances, the correlation between the experimental results and the Draize eye irritation test (rs = 0,943) and the intravenous toxicity (rs = 0,958) was statistically significant. If both tests gave EC50-values >10000mg/L, the substance could be categorised as non or mild toxic. If the EC50-values were <5mg/L, an extremely toxic substance could be expected. Neither false positive nor false negative results have been found, therefore the application of the method as a screening test or as a part in a test battery is conceivable. PMID:11178509

Schicktanz, Silke; Frahne, Dietrich; Honnen, Wolfgang; Müller, Ewald

1998-01-01

225

Comparative toxicity of diuron on survival and growth of Pacific treefrog, bullfrog, red-legged frog, and African clawed frog embryos and tadpoles.  

PubMed

The effects of the herbicide diuron on survival and growth of Pacific treefrog (Pseudacris regilla), bullfrog (Rana catesbeiana), red-legged frog (Rana aurora), and African clawed frog (Xenopus laevis) embryos and tadpoles were determined in static-renewal tests. P. regilla and X. laevis embryos had reduced growth and developed increased deformities in diuron concentrations over 20 mg/L. Hindlimb bud and forelimb development were retarded in R. aurora following 14 days exposure to diuron concentrations of > 7.6 mg/L. Mean 14-day LC50s for P. regilla and X. laevis tadpoles were 15.2 and 11.3 mg/L diuron, respectively. The 21-day LC50 for R. catesbeiana tadpoles was 12.7 mg/L diuron. The 14-day LC50 for R. aurora tadpoles was 22.2 mg/L. The lowest NOAELs calculated in embryo tests were 14.5 mg/L for P. regilla (10 days) and 7.6 mg/L diuron for X. laevis (4 days). The lowest NOAELs calculated in tadpole tests were: P. regilla, 14.5 mg/L (14 days); R. catesbeiana, 7.6 mg/L (21 days); R. aurora, 7.6 mg/L (14 days); and X. laevis, > 29.1 mg/L (14 days). Diuron concentrations having an effect on survival, growth, and malformation in the laboratory were much higher than those found in normal field spray situations; field studies would be needed to determine the hazard to amphibians in areas of localized pooling of recently applied herbicide in the environment. PMID:9543507

Schuytema, G S; Nebeker, A V

1998-05-01

226

Organotypic liver culture models: Meeting current challenges in toxicity testing  

PubMed Central

Prediction of chemical-induced hepatotoxicity in humans from in vitro data continues to be a significant challenge for the pharmaceutical and chemical industries. Generally, conventional in vitro hepatic model systems (i.e. 2-D static monocultures of primary or immortalized hepatocytes) are limited by their inability to maintain histotypic and phenotypic characteristics over time in culture, including stable expression of clearance and bioactivation pathways, as well as complex adaptive responses to chemical exposure. These systems are less than ideal for longer-term toxicity evaluations and elucidation of key cellular and molecular events involved in primary and secondary adaptation to chemical exposure, or for identification of important mediators of inflammation, proliferation and apoptosis. Progress in implementing a more effective strategy for in vitro-in vivo extrapolation and human risk assessment depends on significant advances in tissue culture technology and increasing their level of biological complexity. This article describes the current and ongoing need for more relevant, organotypic in vitro surrogate systems of human liver and recent efforts to recreate the multicellular architecture and hemodynamic properties of the liver using novel culture platforms. As these systems become more widely used for chemical and drug toxicity testing, there will be a corresponding need to establish standardized testing conditions, endpoint analyses and acceptance criteria. In the future, a balanced approach between sample throughput and biological relevance should provide better in vitro tools that are complementary with animal testing and assist in conducting more predictive human risk assessment. PMID:22582993

LeCluyse, Edward L.; Witek, Rafal P.; Andersen, Melvin E.; Powers, Mark J.

2012-01-01

227

Tests for oil/dispersant toxicity: In situ laboratory assays  

SciTech Connect

As part of its readiness program in oil spill response, the Marine Pollution Control Unit (MPCU), Department of Transport, U.K. conducts annual field trials in the North Sea, approximately 30 nautical miles from the southeast coast of England. The trials take the form of controlled releases of crude oil or Medium Fuel/Gas Oil mix (MFO), with and without the application of Corexit 9527 dispersant. In 1994 and 1995 the authors conducted a series of in situ toxicity bioassays in association with these spills with included 48h LC50 tests for turbot (Scophthalmus maximus) and oyster (Crassostrea gigas) larvae, a 48 h oyster (C. gigas) embryonic development test and two full life-cycle assays using the copepods Acartia tonsa and Tisbe battagliai. Tests were also conducted in the Chesapeake Bay laboratory using estuarine species including the copepod Eurytemora affinis and the inland silverside Menidia beryllina. Here, the authors report on the results of these assays, together with 1996 in situ toxicity data resulting from Norwegian field trials in the northern North Sea.

Wright, D.A.; Coelho, G.M. [Univ. of Maryland System, Solomons, MD (United States); Aurand, D.V. [Ecosystem Management and Associates, Purcellville, VA (United States)

1995-12-31

228

Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos  

SciTech Connect

Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from an uncontaminated site (Chincoteague National Wildlife Refuge, VA) and three polluted sites (Cat Island, Green Bay, WI; Bair and West Marin Islands, San Francisco Bay, CA). Hepatic microsomal monooxygenases were induced up to 85-fold relative to the reference site, and was associated with concentrations of total PCBs and 11 PCB congeners that are presumed to express toxicity through the Ah receptor. TEQs [mathematically predicted; summed product of PCB congener concentrations using 5 different sets of toxic equivalency factors (TEFs)] were compared to TCDD-EQS [derived by bioassay; ethoxyresorufin-O-dealkylase activity of treated H4IIE rat hepatoma cells]. Although TEQs were up to 15-fold greater than TCDD-EQs, the pattern among sites was consistent and TEQs were highly correlated with TCDD-EQS. TEFs based on single congener mammalian studies yielded TEQs that greatly exceeded values from the H4IIE bioassay of field sample. TEFs generated from avian egg injection studies yielded TEQs that most closely approximated bioassay-derived TCDD-EQS. Cytochrome P450 parameters were related to TEQs and TCDD-EQS; adjusted r{sup 2} often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data document the general predictive value of TEQs and TCDD-EQs for P450 induction in field collected samples, but also indicate the need for development of TEFs for the species and biological end point of concern.

Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D. [National Biological Service, Laurel, MD (United States); [Upper Mississippi Science Center, LaCrosse, WI (United States); [Midwest Science Center, Columbia, MO (United States)

1995-12-31

229

Mosquito coil smoke inhalation toxicity. Part I: validation of test approach and acute inhalation toxicity.  

PubMed

Burning mosquito coils indoors to repel mosquitoes is a common practice in many households in tropical countries. The evaluation and assessment of the inhalation toxicity of smoke emitted from mosquito coils appear to be particularly challenging due to the complex nature of this type of exposure atmosphere. The potential health implications of the gases, volatile agents and particulate matter emitted from burning coils or incense have frequently been addressed; however, state-of-the-art inhalation toxicity studies are scarce. The focus of this paper was comparatively to evaluate and assess the appropriateness and practical constraints of the whole-body versus the nose-only mode of exposure for inhalation toxicity studies with burning mosquito coils. With regard to the controlled exposure of laboratory animals to complex smoke atmospheres the nose-only mode of exposure had distinct advantages over the whole-body exposure, which included a rapid attainment of the inhalation chamber steady state, minimization of particle coagulation and uncontrolled adsorption of condensate onto the chamber surfaces. While in whole-body chambers a different kinetic behaviour of volatile and particulate constituents was found which caused inhomogeneous, i.e. artificially enriched atmospheres with volatile components at the expense of aerosols, the nose-only mode of exposure provided maximum exposure intensities without losses of the particulate phase of the exposure atmosphere. Collectively, the results obtained support the conclusion that the dynamic nose-only mode of exposure is experimentally superior to the quasistatic whole-body exposure mode which provides the least control over exposure atmospheres and the outcome highly contingent on selected experimental factors. Acute inhalation toxicity studies in rats suggest that the most critical metrics of exposure are apparently related to (semi)volatile upper respiratory tract sensory irritants, whilst the asphyxic component, carbon monoxide, plays a role only at overtly irritant exposure levels. However, this study was conducted at exposure concentrations much higher than encountered by people in residential settings and the effects observed under these conditions may not be relevant to hazards from exposures at common use levels. Neither an acute 8 h exposure of rats nor the 1 h sensory irritation study in mice and rats provided experimental evidence that irritant particle-related effects had occurred in the lower respiratory tract. In summary, the protocols devised evaluate and assess the acute inhalation toxicity of mosquito coil smoke demonstrating that the nose-only mode of exposure of rats to the smoke of mosquito coils is suitable to assess the toxic potency of different coils. The nose-only mode has clear advantages over the whole-body exposure mode. The inhalation studies conducted show unequivocally that acute toxic effects are difficult to produce with this type of product even under rigorous testing conditions. PMID:16547916

Pauluhn, Jürgen

2006-01-01

230

KEPONE (TRADEMARK): CHRONIC EFFECTS ON EMBRYO, FRY, JUVENILE, AND ADULT SHEEPSHEAD MINNOWS ('CYPRINODON VARIEGATUS')  

EPA Science Inventory

The report discusses the toxicity of Kepone to, and uptake by embryo, fry, juvenile, and adult sheepshead minnows (Cyprinodon variegatus) using intermittent-flow toxicity tests. Concentrations of Kepone and percentage of adult fish surviving in a 28-day exposure were--Control, 95...

231

Evaluation of a phytoplankton toxicity test for water pollution assessment and control  

Microsoft Academic Search

A suggested standard test protocol for the short term14C assimilation algal toxicity test method (photosynthesis inhibition test) has been evaluated with natural phytoplankton and cultures of the marine diatomSkeletonema costatum. A number of test technical factors as well as the variability in the sensitivity of natural phytoplankton have been investigated, using potassium dichromate as a reference toxicant in all tests.

Kresten Ole Kusk; Niels Nyholm

1991-01-01

232

Toxic Substances Control Act (TSCA) Test Submissions data base (TSCATS) - comprehensive update tape. Data file  

Microsoft Academic Search

The Toxic Substances Control Act Test Submissions Data base (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the US Environmental Protection Agency by industry under the Toxic Substances Control Act. Test is broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The data

Merrick

1987-01-01

233

An interlaboratory comparison of sediment elutriate preparation and toxicity test methods  

EPA Science Inventory

Elutriate bioassays are among numerous methods that exist for assessing the potential toxicity of sediments in aquatic systems. In this study, interlaboratory results were compared from 96-hour Ceriodaphnia dubia and Pimephales promelas static-renewal acute toxicity tests conduct...

234

Interlaboratory Root Elongation Testing of Toxic Substances on Selected Plant Species.  

National Technical Information Service (NTIS)

Four contract laboratories and three EPA laboratories participated in the inter-laboratory testing of 10 toxic substances on a representative plant species from five families. Seeds were germinated on filter paper saturated in a solution of the toxic subs...

H. C. Ratsch

1983-01-01

235

Evaluation of municipal waste incinerator fly ash toxicity and the role of cadmium by two aquatic toxicity tests  

SciTech Connect

Fly ash from a municipal solid waste incinerator in Japan is regulated under the hazardous waste regulation Waste under Special Control, according to the Amendment of the Waste Disposal and Public Cleansing Law, because it contains high concentrations of heavy metals which are available for leaching. To evaluate the toxicity of fly ash, a fly ash leachate was prepared according to the Japanese standard leaching procedure. The chemical analysis of the leachate showed that possibly one of the most toxic substances was cadmium. The toxicity of the leachate and the cadmium was determined by algal assay and a Daphnia acute toxicity test. The results showed that the leachate was about seven times more toxic to the growth of algae and 20 to 30 times more toxic to the survival of Daphnia than expected from its cadmium concentration. The toxicity interaction between cadmium and the other constituents in the leachate was also examined. The toxicity of cadmium showed an additive effect with the other constituents in the leachate in algal assay. In the Daphnia test, however, cadmium showed an antagonistic effect.

Kaneko, Hidehiro [Yamanashi Univ., Kofu, Yamanashi (Japan). Dept. of Civil and Environmental Engineering] [Yamanashi Univ., Kofu, Yamanashi (Japan). Dept. of Civil and Environmental Engineering

1996-12-31

236

Toxicity testing of organic chemicals in groundwater polluted with landfill leachate  

SciTech Connect

A method for assessment of toxicity of nonvolatile organic chemicals contaminants in groundwater polluted with landfill leachate has been evaluated. The biotests utilized were composed of an algal growth inhibition test (Selenastrum capricornutum), a daphnia immobilization test (Daphnia magna), and a bacterial genotoxicity test (umuC, Salmonella typhimurium). The feasibility of the selected biotests was investigated for a series of groundwater samples collected along pollution gradients downstreams of two landfills in Jutland, Denmark. Two different approaches were used, direct toxicity testing of whole groundwater samples, and toxicity testing of concentrates obtained by solid-phase extraction. Direct testing of whole groundwater samples produced toxic responses, but the complex sample matrix masked the toxicity of the organic chemical contaminants of interest. Solid-phase extraction was used successfully as an on-site method that eliminated ion toxicity and produced biotest responses that reflected the toxicity of the nonvolatile organic chemical contaminants in the groundwater.

Baun, A.; Kloeft, L.; Bjerg, P.L.; Nyholm, N.

1999-09-01

237

Combined repeated-dose toxicity study of silver nanoparticles with the reproduction/developmental toxicity screening test.  

PubMed

Combined repeated-dose toxicity study of citrate-capped silver nanoparticles (7.9 ± 0.95 nm) with reproduction/developmental toxicity was investigated in rats orally treated with 62.5, 125 and 250 mg/kg, once a day for 42 days for males and up to 52 days for females. The test was performed based on the Organization for Economic Cooperation and Development test guideline 422 and Good Laboratory Practice principles. No death was observed in any of the groups. Alopecia, salivation and yellow discolouration of the lung were observed in a few rats but the symptoms were not dose-dependent. Haematology, serum biochemical investigation and histopathological analysis revealed no statistically significant differences between control group and the treated groups. Toxicity endpoints of reproduction/developmental screening test including mating, fertility, implantation, delivery and foetus were measured. There was no evidence of toxicity. PMID:23432083

Hong, Jeong-Sup; Kim, Suhyon; Lee, Sang Hee; Jo, Eunhye; Lee, Byungcheun; Yoon, Junheon; Eom, Ig-Chun; Kim, Hyun-Mi; Kim, Pilje; Choi, Kyunghee; Lee, Moo Yeol; Seo, Yeong-Rok; Kim, Younghun; Lee, Yeonjin; Choi, Jonghye; Park, Kwangsik

2014-06-01

238

Fractionating nanosilver: importance for determining toxicity to aquatic test organisms.  

PubMed

This investigation applied novel techniques for characterizing and fractionating nanosilver particles and aggregates and relating these measurements to toxicological endpoints. The acute toxicity of eight nanosilver suspensions of varying primary particle sizes (10-80 nm) and coatings (citrate, polyvinylpyrrolidone, EDTA, proprietary) was assessed using three aquatic test organisms (Daphnia magna, Pimephales promelas, Pseudokirchneriella subcapitata). When 48-h lethal median concentrations (LC50) were expressed as total silver, both D. magna and P. promelas were significantly more sensitive to ionic silver (Ag(+)) as AgNO(3) (mean LC50 = 1.2 and 6.3 ?g/L, respectively) relative to a wide range in LC50 values determined for the nanosilver suspensions (2 -126 ?g/L). However, when LC50 values for nanosilver suspensions were expressed as fractionated nanosilver (Ag(+) and/or <4 nm particles), determined by ultracentrifugation of particles and confirmed field-flow-fractograms, the LC50 values (0.3-5.6 ?g/L) were comparable to the values obtained for ionic Ag(+) as AgNO(3). These results suggest that dissolved Ag(+) plays a critical role in acute toxicity and underscores the importance of characterizing dissolved fractions in nanometal suspensions. PMID:21082828

Kennedy, Alan J; Hull, Matthew S; Bednar, Anthony J; Goss, Jennifer D; Gunter, Jonas C; Bouldin, Jennifer L; Vikesland, Peter J; Steevens, Jeffery A

2010-12-15

239

Tests for the toxicity assessment of cyanobacterial bloom samples.  

PubMed

Cyanobacterial (blue-green algal) blooms are one of the common consequences of the increasing eutrophication of surface waters. The production of cyanobacterial toxins and their presence in drinking and recreational waters represents a growing danger to human and animal health. Due to a lack of toxin standards and to resource limitations on the wide-scale use of analytical methods (e.g., high-performance liquid chromatography, enzyme-linked immunosorbent assay (ELISA)) in cyanobacterial toxin monitoring, it is necessary to assess and to develop additional methods for their detection and estimation. Microbiotests using invertebrates offer a possible approach for the inexpensive and straightforward detection and assessment of cyanobacterial bloom toxicity. Three microbiotests with: Thamnocephalus platyurus, Daphnia magna, and Spirostomum ambiguum were examined with bloom samples containing hepatotoxic microcystin-LR and up to five additional microcystin variants. Two kinds of cyanobacterial bloom sample preparations were tested: crude extracts (CE) and purified extracts (PE). The highest toxicity was found when CE was used for microbiotests. The sensitivity of microorganisms decreased from S. ambiguum to T. platyurus and to D. magna. A statistically significant correlation was found between microcystin concentration and T. platyurus biotest, and between mouse bioassay and S. ambiguum results. Addition of Me2SO (1%, v/v) is a possible method to increase the sensitivity of the microorganisms for microcystin-LR. PMID:11594024

Tarczynska, M; Nalecz-Jawecki, G; Romanowska-Duda, Z; Sawicki, J; Beattie, K; Codd, G; Zalewski, M

2001-10-01

240

Lethal and sublethal toxicity of the industrial chemical epichlorohydrin on Rhinella arenarum (Anura, Bufonidae) embryos and larvae.  

PubMed

Lethal and sublethal toxicity of the major chemical used in epoxide compounds, epichlorohydrin (ECH) was evaluated on the early life cycle of the common South American toad, Rhinella arenarum (Anura, Bufonidae). The stages evaluated were (according to Del Conte and Sirlin): early blastula (S.3-S.4), gastrula (S.10-S.12), rotation (S.15), tail bud (S.17), muscular response (S.18), gill circulation (S.20), open mouth (S.21), opercular folds (S.23) and complete operculum (S.25). The LC50 and EC50 values for lethal and sublethal effects were calculated. The early blastula was the most sensitive stage to ECH both for continuously and pulse-exposures (LC50-24h=50.9 mg L(-1)), while S.20 was the most resistant (LC50-24h=104.9 mg L(-1)). Among sublethal effects, early blastula was also the most sensitive stage (LOEC-48 h=20 mg L(-1)) and it has a Teratogenic Index of 2.5, which indicates the teratogenic potential of the substance. The main abnormalities were persistent yolk plugs, cell dissociation, tumors, hydropsy, oral malformations, axial/tail flexures, delayed development and reduced body size. ECH also caused neurotoxicity including scarce response to stimuli, reduction in the food intake, general weakness, spasms and shortening, erratic or circular swimming. Industrial contamination is considered an important factor on the decline of amphibian populations. Considering the available information about ECH's toxicity and its potential hazard to the environment, this work shows the first results of its developmental toxicity on a native amphibian species, Rhinella arenarum. PMID:24231313

Hutler Wolkowicz, Ianina R; Aronzon, Carolina M; Pérez Coll, Cristina S

2013-12-15

241

Toxicity testing with the marine algae, Symbiodinium kawagutii (Dinophyceae)  

SciTech Connect

The dinoflagellate, Symbiodinium kawagutii, is among the algal taxa which exist in symbiosis with a range of marine invertebrates. S. kawagutii is commonly found in association with the Hawaiian stony coral, Montipora verrucosa. The algae has been successfully cultured in the laboratory using a common marine algal growth media (Guillard f/2), and sufficient cell densities were achieved in a 96-hr bioassay to allow statistical evaluation of toxicity data. A 96-hr EC{sub 50} of 6.47 mg/L (95% C.I.: 3.54--9.88 mg/L) was calculated after exposure to potassium dichromate. Wide distribution of the coral host and ecological importance of the symbiosis make S. kawagutii an excellent candidate species for hazard evaluation in tropical marine ecosystems. Continuing research will seek to further refine the bioassay, including the use of a microplate technique for more rapid testing.

Gorrie, J.R.; Bidwell, J.R.; Rippingale, R.J. [Curtin Univ. of Technology, Bentley (Australia)

1994-12-31

242

Comparison of mathematically-predicted toxic equivalents (TEQs) and bioassay-derived dioxin-equivalents (TCDD-EQs) in heron embryos  

USGS Publications Warehouse

Pipping black-crowned night-heron (Nycticorax nycticorax) embryos were collected from an uncontaminated site (Chincoteague National Wildlife Refuge,VA) and three polluted sites (Cat Island, Green Bay, WI; Bair and West Marin Islands, San Francisco Bay, CA). Hepatic microsomal monooxygenases were induced up to 85-fold relative to the reference site, and was associated with concentrations of total PCBs and 11 PCB congeners that are presumed to concern.to express toxicity through the Ah receptor. TEQs [mathematically predicted; summed product of PCB congener concentrations using 5 different sets of toxic equivalency factors (TEFs)] were compared to TCDD-EQs [derived by bioassay; ethoxyresorufin-O-dealkylase activity of treated H411E rat hepatoma cells]. Although TEQs were up to 15-fold greater than TCDD-EQs, the pattern among sites was consistent and TEQs were highly correlated with TCDD-EQs. TEFs based on single congener mammalian studies yielded TEQs that greatly exceeded values from the H411E bioassay of field sample. TEFs generated from avian egg injection studies yielded TEQs that most closely approximated bioassay-derived TCDD-EQs. Cytochrome P450 parameters were related to TEQs and TCDD-EQs; adjusted r2 often exceeded 0.5 for the relation among mathematically predicted TEQs and cytochrome P450 measurements. These data document the general predictive value of TEQs and TCDD-EQs for P450 induction in field collected samples, but also indicate the need for development of TEFs for the species and biological end point of concern.

Rattner, B.; Hatfield, J.; Melancon, M.; Custer, T.; Tillitt, D.

1995-01-01

243

Custom-designed nanomaterial libraries for testing metal oxide toxicity.  

PubMed

Advances in aerosol technology over the past 10 years have enabled the generation and design of ultrafine nanoscale materials for many applications. A key new method is flame spray pyrolysis (FSP), which produces particles by pyrolyzing a precursor solution in the gas phase. FSP is a highly versatile technique for fast, single-step, scalable synthesis of nanoscale materials. New innovations in particle synthesis using FSP technology, including variations in precursor chemistry, have enabled flexible, dry synthesis of loosely agglomerated, highly crystalline ultrafine powders (porosity ? 90%) of binary, ternary, and mixed-binary-and-ternary oxides. FSP can fulfill much of the increasing demand, especially in biological applications, for particles with specific material composition, high purity, and high crystallinity. In this Account, we describe a strategy for creating nanoparticle libraries (pure or Fedoped ZnO or TiO?) utilizing FSP and using these libraries to test hypotheses related to the particles' toxicity. Our innovation lies in the overall integration of the knowledge we have developed in the last 5 years in (1) synthesizing nanomaterials to address specific hypotheses, (2) demonstrating the electronic properties that cause the material toxicity, (3) understanding the reaction mechanisms causing the toxicity, and (4) extracting from in vitro testing and in vivo testing in terrestrial and marine organisms the essential properties of safe nanomaterials. On the basis of this acquired knowledge, we further describe how the dissolved metal ion from these materials (Zn²? in this Account) can effectively bind with different cell constituents, causing toxicity. We use Fe-S protein clusters as an example of the complex chemical reactions taking place after free metal ions migrate into the cells. As a second example, TiO? is an active material in the UV range that exhibits photocatalytic behavior. The induction of electron-hole (e?/h?) pairs followed by free radical production is a key mechanism for biological injury. We show that decreasing the bandgap energy increases the phototoxicity in the presence of near-visible light. We present in detail the mechanism of electron transfer in biotic and abiotic systems during light exposure. Through this example we show that FSP is a versatile technique for efficiently designing a homologous library, meaning a library based on a parent oxide doped with different amounts of dopant, and investigating the properties of the resulting compounds. Finally, we describe the future outlook and state-of-the-art of an innovative two-flame system. A double-flame reactor enables independent control over each flame, the nozzle distances and the flame angles for efficient mixing of the particle streams. In addition, it allows for different flame compositions, flame sizes, and multicomponent mixing (a grain-grain heterojunction) during the reaction process. PMID:23194152

Pokhrel, Suman; Nel, André E; Mädler, Lutz

2013-03-19

244

Hepatotoxicity and subchronic toxicity tests of Morinda citrifolia (noni) fruit.  

PubMed

Morinda citrifolia (noni) fruit juice has been approved as a safe food in many nations. A few cases of hepatitis in people who had been drinking noni juice have been reported, even though no causal link could be established between the liver injury and ingestion of the juice. To more fully evaluate the hepatotoxic potential of noni fruit juice, in vitro hepatotoxicity tests were conducted in human liver cells, HepG2 cell line. A subchronic oral toxicity test of noni fruit was also performed in Sprague-Dawley (SD) rats to provide benchmark data for understanding the safety of noni juice, without the potential confounding variables associated with many commercial noni juice products. Freeze-dried filtered noni fruit puree did not decrease HepG2 cell viability or induce neutral lipid accumulation and phospholipidosis. There were no histopathological changes or evidence of dose-responses in hematological and clinical chemistry measurements, including liver function tests. The no-observed-adverse-effect level (NOAEL) for freeze-dried noni fruit puree is greater than 6.86 g/kg body weight, equivalent to approximately 90 ml of noni fruit juice/kg. These findings corroborate previous conclusions that consumption of noni fruit juice is unlikely to induce adverse liver effects. PMID:19797868

West, Brett J; Su, Chen X; Jensen, C Jarakae

2009-10-01

245

Results of acute and chronic toxicity tests conducted at SRS NPDES outfalls, July--October 1991  

SciTech Connect

Acute (48 hour LC50) and chronic (7-day reproductive impairment) toxicity tests were conducted on Ceriodaphnia dubia in water collected from 53 NPDES outfalls. All tests were conducted at the in-stream waste concentration. only 12 of the 53 outfalls showed no evidence of toxicity. Twenty-eight of the outfalls were acutely toxic, often producing 100% mortality during the first day of exposure. Fourteen outfalls had no discharge at the time of sampling and could not be tested. Three outfalls were not tested because their toxicity has been adequately characterized in other investigations. Elevated concentrations of total residual chlorine are suspected to be responsible for the observed toxicity of many NPDES outfalls, particularly the sanitary wastewater treatment plants. Chemical data from previous studies indicate that metals may also be present in toxic concentrations at many outfalls. Toxicity identification and reduction options are discussed.

Specht, W.L.

1992-01-01

246

Toxicity testing: the search for an in vitro alternative to animal testing.  

PubMed

Prior to introduction to the clinic, pharmaceuticals must undergo rigorous toxicity testing to ensure their safety. Traditionally, this has been achieved using in vivo animal models. However, besides ethical reasons, there is a continual drive to reduce the number of animals used for this purpose due to concerns such as the lack of concordance seen between animal models and toxic effects in humans. Adequate testing to ensure any toxic metabolites are detected can be further complicated if the agent is administered in a prodrug form, requiring a source of cytochrome P450 enzymes for metabolism. A number of sources of metabolic enzymes have been utilised in in vitro models, including cell lines, primary human tissue and liver extracts such as S9. This review examines current and new in vitro models for toxicity testing, including a new model developed within the authors' laboratory utilising HepG2 liver spheroids within a co-culture system to examine the effects of chemotherapeutic agents on other cell types. PMID:19839229

May, J E; Xu, J; Morse, H R; Avent, N D; Donaldson, C

2009-01-01

247

Sediment Toxicity Testing for Prospective Risk Assessment—A New Framework and How to Establish It  

Microsoft Academic Search

There is a recognised need to design a new framework for sediment toxicity testing that meets current scientific standards and regulatory requirements, such as reliable assessment of toxicity, which prevents any harmful effects on biodiversity, a strong capability to predict population- and community-level effects, and applicability of the results to decision-making. We propose a new framework for prospective sediment toxicity

M. A. Beketov; N. Cedergreen; L. Y. Wick; M. Kattwinkel; S. Duquesne; M. Liess

2012-01-01

248

INTRA- AND INTERLABORATORY VARIABILITY IN ACUTE TOXICITY TESTS WITH GLOCHIDIA AND JUVENILES OF FRESHWATER MUSSELS (UNIONIDAE)  

Microsoft Academic Search

Abstract—The present study evaluated,the performance,and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods,outlined in American,Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels,were,conducted,within a single laboratory and among,five laboratories. All tests met the test acceptability requirements (e.g., 90% control survival). Intralaboratory tests were

Ning Wang; Tom Augspurger; M. Chris Barnhart; Joseph R. Bidwell; W. Gregory Cope; F. James Dwyer; Steve Geis; I. Eugene Greer; Chris G. Ingersoll; Cynthia M. Kane; Thomas W. May; Richard J. Neves; Teresa J. Newton; Andy D. Roberts; David W. Whites

2007-01-01

249

Methods For Collecting , Culturing And Performing Toxicity Tests With Daphnia ambigua  

SciTech Connect

Toxicity tests conducted on water collected from impacted locations in SRS streams often failed chronic toxicity tests and sometimes failed acute toxicity tests (Specht 1995). These findings prompted SRS to determine the cause of the failures. Some SRS NPDES outfalls were also failing chronic toxicity tests, even though no toxicant could be identified and when TIEs were performed, none of the TIE treatments removed the toxicity. Ultimately, it was determined that the failures were due to the low hardness of SRS surface waters, rather than to the presence of a toxicant. The species of cladoceran that the EPA recommends for toxicity testing, Ceriodaphnia dubia, is stressed by the very low hardness of SRS waters. SRS developed an alternate species toxicity test that is similar to the EPA test, but uses an indigenous cladoceran, Daphnia ambigua (Specht and Harmon, 1997; Harmon et al., 2003). In 2001, SCDHEC approved the use of D. ambigua for toxicity testing at SRS, contingent upon approval by EPA Region 4. In 2002, EPA Region 4 approved the use of this species for compliance toxicity testing at SRS. Ultimately, the use of this species demonstrated that SRS effluents were not toxic, and most toxicity testing requirements were removed from the NPDES permit that was issued in December 2003, with the exception of one round of chronic definitive testing on outfalls A-01, A-11, and G-10 just before the next NPDES permit application is submitted to SCDHEC. Although the alternate species test was developed at SRS (1996-1998), the culture was transferred to a contract toxicity testing lab (ETT Environmental) located in Greer, SC in 1998. ETT Environmental became certified by SCDHEC to perform toxicity tests using D. ambigua in 2002, and at this time is the only laboratory certified by SCDHEC to perform tests with this species. Because of the expense associated with maintaining the D. ambigua culture for several years when no toxicity testing is required, SRS decided to suspend financial support associated with maintaining the cultures until testing is needed. The purpose of this document is to provide guidance on how to establish a laboratory culture of D. ambigua so that a culture can be restarted when needed.

Specht, Winona L.

2005-07-01

250

Effects of low dissolved oxygen on organisms used in freshwater sediment toxicity tests  

Microsoft Academic Search

Minimum dissolved oxygen requirements are part of standard guidelines for toxicity testing of freshwater sediments with several benthic invertebrates, but the data underlying these requirements are somewhat sparse. We exposed three common test organisms to ranges of dissolved oxygen concentrations to determine their responses in 10-d exposures, relative to published guidelines for sediment toxicity tests. The oligochaete, Lumbriculus variegatus, showed

Vincent R. Mattson; J. Russell Hockett; Terry L. Highland; Gerald T. Ankley; David R. Mount

2008-01-01

251

Toxicity of copper and zinc assessed with three different earthworm tests  

Microsoft Academic Search

At present, standardised earthworm acute toxicity and reproduction tests are used to assess the toxicity of heavy metal contaminated soils. These tests are, however, time-consuming, laborious and costly, and in addition, some sublethal responses may remain overlooked. Avoidance of metal contaminated soils by earthworms may be a useful parameter when assessing ecological risks with a low test effort. The objective

Tuomas Lukkari; Marjo Aatsinki; Ari Väisänen; Jari Haimi

2005-01-01

252

Periphyton photosynthesis as an indicator of effluent toxicity: Relationship to effects on animal test species  

Microsoft Academic Search

The use of freshwater and marine plants in effluent toxicity evaluations is uncommon despite the presence of test methods and recommendations for their use. It has been assumed that aquatic plants are less sensitive than animal test species and consequently, results from toxicity tests with invertebrates and fish have been used often as a surrogate data base. The study evaluated

M Lewis

1992-01-01

253

EROD induction in cultured chick embryo liver: A sensitive bioassay for dioxin-like environmental pollutants  

Microsoft Academic Search

A technique for studying 7-ethoxyresorufin O-deethylase (EROD) induction in chick embryo liver in vitro was developed. Livers from 8-d-old embryos were cultured in rotating vials at 37 C for 48 h in a medium to which DMSO-dissolved test compounds had been added. This bioassay proved to be highly sensitive to dioxin-like compounds, and its usefulness for assessing the toxic potency

B. Brunstroem; Magnus Engwall; Katarina Hjelm; Lars Lindqvist; Y. Zebuehr

1995-01-01

254

A rapid biochemical test for measuring chemical toxicity  

Microsoft Academic Search

Many chemicals undergo multiple transformations in the environment, owing to abiotic and biotic processes. Whether they bioaccu~te or not depends, among other things, on their toxicity to the biota. Therefore, toxicity to organisms affecting the transforming is obviously an importrant factor governing the fate and behaviour of a chemical compound in the natural environment. Numerous bioassay procedures employing fish (SASTRY

D. Liu

1981-01-01

255

Microfluidic EmbryoSort technology: towards in flow analysis, sorting and dispensing of individual vertebrate embryos  

NASA Astrophysics Data System (ADS)

The demand to reduce the numbers of laboratory animals has facilitated the emergence of surrogate models such as tests performed on zebrafish (Danio rerio) or African clawed frog's (Xenopus levis) eggs, embryos and larvae. Those two model organisms are becoming increasingly popular replacements to current adult animal testing in toxicology, ecotoxicology and also in drug discovery. Zebrafish eggs and embryos are particularly attractive for toxicological analysis due their size (diameter 1.6 mm), optical transparency, large numbers generated per fish and very straightforward husbandry. The current bottleneck in using zebrafish embryos for screening purposes is, however, a tedious manual evaluation to confirm the fertilization status and subsequent dispensing of single developing embryos to multitier plates to perform toxicity analysis. Manual procedures associated with sorting hundreds of embryos are very monotonous and as such prone to significant analytical errors due to operator's fatigue. In this work, we present a proofof- concept design of a continuous flow embryo sorter capable of analyzing, sorting and dispensing objects ranging in size from 1.5 - 2.5 mm. The prototypes were fabricated in polymethyl methacrylate (PMMA) transparent thermoplastic using infrared laser micromachining. The application of additive manufacturing processes to prototype Lab-on-a-Chip sorters using both fused deposition manufacturing (FDM) and stereolithography (SLA) were also explored. The operation of the device was based on a revolving receptacle capable of receiving, holding and positioning single fish embryos for both interrogation and subsequent sorting. The actuation of the revolving receptacle was performed using a DC motor and/or microservo motor. The system was designed to separate between fertilized (LIVE) and non-fertilized (DEAD) eggs, based on optical transparency using infrared (IR) emitters and receivers.

Fuad, Nurul M.; Wlodkowic, Donald

2013-12-01

256

Applicability of ambient toxicity testing to national or regional water-quality assessment  

USGS Publications Warehouse

Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Descriptions of existing conditions may be achieved by various kinds of chemical and hydrologic analyses, whereas information about the effects of such conditions on living organisms depends on biological monitoring. Toxicity testing is one type of biological monitoring that can be used to identify possible effects of toxic contaminants. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water-quality assessments. These purposes may include identification of areas that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. Toxicity-test results are most effective when used as a complement to chemical analyses, hydrologic measurements, and other biological monitoring. However, all toxicity-testing procedures have certain limitations that must be considered in developing the methodology and applications of toxicity testing in any large-scale water-quality-assessment program. A wide variety of toxicity-test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the selections made relative to four characteristics: (1) test species, (2) endpoint (acute or chronic), (3) test-enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity-test approaches vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing, whereby the test organism is exposed to naturally occurring substances that contain toxicant mixtures in an organic or inorganic matrix, is more likely to meet these needs than are procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful interpretation of ambient test results depends on the existence of accompanying chemical analysis of the ambient media. The ambient test substance may be water or sediments. Sediment tests have had limited application, but they are useful because most toxicants tend to accumulate in sediments and many test species either inhabit the sediments or are in frequent contact with them. Biochemical testing methods, which have been developing rapidly in recent years, are likely to be among the most useful procedures for large-scale water-quality assessments. They are relatively rapid and simple, and more. importantly, they focus on biochemical changes that are the initial responses of virtually all organisms to environmental stimuli. Most species are sensitive to relatively few toxicants, and their sensitivities vary as conditions change. Therefore, each test method has particular uses and limitations, and no single test has universal applicability. One of the most informative approaches to toxicity testing is to combine biochemical tests with other test methods in a 'battery of tests' that is diversified enough to characterize different types of toxicants and different trophic levels. However, such an approach can be costly, and if not carefully designed, it may not yield enough additional information to warrant the additional cost. The application of toxicity tests to large-scale water-quality assessments is hampered by a number of difficulties. Toxicity tests often are not sensitive enough to enable detection of most contaminant problems in the natural environment. Furthermore, because sensitivities among different species and test conditions can be highly variable, conclusions about the toxicant problems of an ecosystem are strongly dependent on the test procedure used. In addition, the experimental systems used in toxicity tests cannot replicate the complexity or variability of natural conditions, and positive test results cannot identify the source or nature of

Elder, John F.

1990-01-01

257

TERATOGENICITY OF CYCLOPHOSPHAMIDE IN A COUPLED MICROSOMAL ACTIVATING/EMBRYO CULTURE SYSTEM  

EPA Science Inventory

Using the coupled microsomal activating/embryo culture system, in vitro experiments were performed to establish the role of metabolism in the embryo toxicity and teratogenicity of cyclophosphamide. Cyclophosphamide in the coupled microsomal activating/embryo culture system produc...

258

Computational Systems Biology and Dose-Response Modeling in Relation to New Directions in Toxicity Testing  

Microsoft Academic Search

The new paradigm envisioned for toxicity testing in the 21st century advocates shifting from the current animal-based testing process to a combination of in vitro cell-based studies, high-throughput techniques, and in silico modeling. A strategic component of the vision is the adoption of the systems biology approach to acquire, analyze, and interpret toxicity pathway data. As key toxicity pathways are

Qiang Zhang; Sudin Bhattacharya; Melvin E. Andersen; Rory B. Conolly

2010-01-01

259

How much ``weight`` should be assigned to toxicity test results in ecological risk assessment?  

SciTech Connect

Toxicity tests are an integral part of ecological assessment activities such as Canada`s Environmental Effects Monitoring (EEM) programs and the USA`s Superfund program. Both of these types of programs encourage the use of the weight-of-evidence approach for the evaluation of ecological risks. This approach uses data from biological surveys, toxicity tests, and ambient media chemical analyses. Currently, there is no guidance available which identifies the relative importance of these different data types in the risk assessment. The quality of the data generated will necessarily determine the ``weight`` assigned to each line of evidence. Decisions often are made on the basis of toxicity test results. However, routine tests are conducted frequently without consideration of their appropriateness (e.g., species sensitivity, ecological relevance). Therefore, an evaluation was conducted to determine the relative sensitivities of various test methods used to assess toxicity from various industries. Different industries were selected to represent different classes of contaminants. For example, the pulp and paper industry releases organic compounds and the mining sector primarily releases heavy metals. The comparative sensitivities of toxicity tests will be illustrated for two industrial sector case studies. With a better understanding of toxicity test method sensitivity, the ecological risk assessor is better able to assign the appropriate weight to the toxicity test results in a risk characterization. This will allow toxicity testing programs to be focused and increase the confidence in the entire risk assessment and any resulting decisions.

Hull, R.N.; Gilron, G.L. [Beak Consultants Ltd., Brampton, Ontario (Canada)

1995-12-31

260

Toxicity of polybrominated diphenyl ethers (de-71) in chicken (Gallus gallus), mallard (Anas platyrhynchos), and American kestrel (Falco sparverius) embryos and hatchlings  

USGS Publications Warehouse

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01-20 mu g/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3', 4,4', 5-pentachlorobiphenyl; 0.002 mu g/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 mu g/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological changes in the bursa, but these responses were not observed in other species. Polychlorinated biphenyl congener 126 (positive control) reduced survival endpoints in chicken and kestrel embryos and caused sublethal effects (EROD induction, reduced bursal mass and follicle size) in chickens. Mallards were clearly less sensitive than the other species to administered penta-BDE and PCB 126. In a second experiment, the absorption of penta-BDE (11.1 mu g/g egg, air cell administered during early development) into the contents of chicken and kestrel eggs was determined at various intervals (24 h postinjection, midincubation, and pipping). By pipping, 29% of the penta-BDE administered dose was present in the egg contents in chickens, and 18% of the administered dose was present in kestrel egg contents. Based on uptake in kestrels, the lowest-observed-effect level on pipping and hatching success may be as low as 1.8 mu g total penta-BDE/g egg, which approaches concentrations detected in eggs of free-ranging birds. Because some penta-BDE congeners are still increasing in the environment, the toxic effects observed in the present study are cause for concern in wildlife.

McKernan, M.A.; Rattner, B.A.; Hale, R.C.; Ottinger, M.A.

2009-01-01

261

Toxicity of polybrominated diphenyl ethers (DE-71) in chicken (Gallus gallus), mallard (Anas platyrhynchos), and American kestrel (Falco sparverius) embryos and hatchlings.  

PubMed

Embryonic survival, pipping and hatching success, and sublethal biochemical, endocrine, and histological endpoints were examined in hatchling chickens (Gallus gallus), mallards (Anas platyrhynchos), and American kestrels (Falco sparverius) following air cell administration of a pentabrominated diphenyl ether (penta-BDE; DE-71) mixture (0.01-20 microg/g egg) or polychlorinated biphenyl (PCB) congener 126 (3,3',4,4',5-pentachlorobiphenyl; 0.002 microg/g egg). The penta-BDE decreased pipping and hatching success at concentrations of 10 and 20 microg/g egg in kestrels but had no effect on survival endpoints in chickens or mallards. Sublethal effects in hatchling chickens included ethoxyresorufin-O-dealkylase (EROD) induction and histological changes in the bursa, but these responses were not observed in other species. Polychlorinated biphenyl congener 126 (positive control) reduced survival endpoints in chicken and kestrel embryos and caused sublethal effects (EROD induction, reduced bursal mass and follicle size) in chickens. Mallards were clearly less sensitive than the other species to administered penta-BDE and PCB 126. In a second experiment, the absorption of penta-BDE (11.1 microg/g egg, air cell administered during early development) into the contents of chicken and kestrel eggs was determined at various intervals (24 h postinjection, midincubation, and pipping). By pipping, 29% of the penta-BDE administered dose was present in the egg contents in chickens, and 18% of the administered dose was present in kestrel egg contents. Based on uptake in kestrels, the lowest-observed-effect level on pipping and hatching success may be as low as 1.8 microg total penta-BDE/g egg, which approaches concentrations detected in eggs of free-ranging birds. Because some penta-BDE congeners are still increasing in the environment, the toxic effects observed in the present study are cause for concern in wildlife. PMID:19045936

McKernan, Moira A; Rattner, Barnett A; Hale, Robert C; Ottinger, Mary Ann

2009-05-01

262

Evaluation of three soil toxicity tests used to monitor acceptable endpoints  

SciTech Connect

Three terrestrial toxicity tests were used to evaluate the efficacy of biological treatment of creosote and pentachlorophenol impacted soils at a Superfund site. Microtox, 5-day lettuce seed, and 14-day earthworm toxicity tests were performed on 10 soil samples at the beginning and end of 3 months of land treatment. Secondary endpoints of root length and earthworm weight loss were also evaluated. EC50 and LC50 values were calculated using a Trimmed Logit Statistical Program and compared to toxicity of 10 background samples collected from the site. Results for initial soils demonstrated toxicity with three of the five endpoints. End treatment results showed no measurable toxicity using all endpoints. Toxicity testing results are critical for obtaining regulatory approval for the full-scale treatment system. Post treatment closure requirements for the site will be based on bioassay results. Evaluation of the three tests used showed the Microtox test to be the most sensitive to this type of toxicity. Lettuce seed germination results were the least sensitive of the three primary endpoints chosen. Of the secondary endpoint criteria, root length demonstrated reliable EC50 values and showed toxicity trends similar to Microtox and earthworm tests. The earthworm weight loss endpoint was not a useful toxicity measurement at 14 days.

Brinkmann, M.; Stroo, H.; Leuschner, A.; Leuteritz, D.; Stromberg, M.; Brourman, M.

1995-12-31

263

Anodonta imbecillis copper sulfate reference toxicant test, Clinch River - Environmental Restoration Program (CR-ERP)  

SciTech Connect

Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12-21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values.

Simbeck, D.J.

1997-06-01

264

PERIPHYTON PHOTOSYNTHESIS AS AN INDICATOR OF EFFLUENT TOXICITY: RELATIONSHIP TO EFFECTS ON ANIMAL TEST SPECIES  

EPA Science Inventory

The use of aquatic plants in effluent toxicity evaluations is uncommon despite the availability of test methods and numerous recommendations for their use. It has been assumed that aquatic plants are less sensitive than animal test species and consequently, results from toxicity ...

265

INTER-LABORATORY COMPARISON OF A SEDIMENT TOXICITY TEST USING THE MARINE AMPHIPOD, 'RHEPOXYNIUS ABRONIUS'  

EPA Science Inventory

An inter-laboratory comparison of the Swartz et al. (1985) amphipod sediment toxicity test was performed for seven marine sediments of varying toxicity. Five laboratories participated. Four a priori and one a posteriori hypotheses or criteria were tested for three end points (sur...

266

New technologies and approaches in toxicity testing and risk assessment (ESOT)  

EPA Science Inventory

The release of the National Research Council’s Report “Toxicity Testing in the 21st Century: A Vision and a Strategy” in 2007 initiated a broad-based movement in the toxicology community to re-think how toxicity testing and risk assessment are performed. Multip...

267

A review on the application of microbial toxicity tests for deriving sediment quality guidelines  

Microsoft Academic Search

The results of microbial toxicity tests are needed for the risk assessment of polluted sediments. In comparison with animals the anaerobic microorganisms are more tolerant to natural sediment conditions whereas they are more sensitive for a number of specific pollutants.Microbial toxicity tests from a literature search were classified in seven categories. Category A, B and C use polluted sediments and

Patrick van Beelen

2003-01-01

268

Terrestrial isopods -- a good choice for toxicity testing of pollutants in the terrestrial environment  

SciTech Connect

Terrestrial isopods are suitable invertebrates for testing the relative toxicities of chemicals present in the terrestrial environment. Terrestrial isopods respond in numerous ways to elevated concentrations of chemicals in their food, but only a few of these responses can be used as toxicological endpoints. The most suitable are changes in reproduction, food consumption, moult cycle duration, and structure of the digestive glands. These responses are able to provide accurate indications of sublethal toxicity. Toxicity tests with terrestrial isopods could be much more reliable through the use of positive controls. A positive control with a reference toxicant could also be supplemented by a reference endpoint. The most suitable reference endpoint is change of food consumption rate. Toxicity testing with terrestrial isopods is a very promising method for fast, routine, and inexpensive laboratory determination of the relative toxicities of chemicals in the terrestrial environment.

Drobne, D. [Univ. of Ljubljana (Slovenia). Dept. of Biology

1997-06-01

269

Survival of brook trout embryos in three episodically acidified streams  

SciTech Connect

The authors evaluated brook trout Salvelinus fontinalis in three streams that undergo episodic acidification during critical periods of embryo development for survival of embryos from egg deposition to preemergence in natural redds and survival of sac fry in toxicity tests done in situ. Twenty-five natural redds were used for comparisons among streams. Median survival to preemergence (range, 16-68%) was different among streams and was inversely related to stream concentration of inorganic monomeric aluminum. Survival to preemergence was not related to intragravel dissolved oxygen concentration, gravel quality, or depth or velocity of stream water at redd sites.

Fiss, F.C.; Carline, R.F.

1993-01-01

270

Development of a toxicity test system using primary rat liver cells.  

PubMed

A model in vitro rat liver parenchymal cellular toxicity system employing cells obtained by the in situ collagenase perfusion technique has been developed to detect potential liver toxicants. The initial evaluation of this test system was accomplished using cadmium chloride, chromium chloride, cobalt chloride, mercuric chloride, nickelous chloride, sodium arsenite, sodium selenite, and ammonium vanadate. Linear regression analysis of the dose response curves was used to determine the effective concentration at which the viability was reduced to 50% (EC50). The relative toxicity of the compounds was as follows: Cd greater than V = As greater than Se greater than Hg greater than Cr = Co greater than Ni. Since several of the compounds with very similar EC50s had significantly different dose response slopes, an additional parameter, lowest effective concentration tested (LECT) was employed to assess the relative toxicity. The LECT was determined using the Williams test and the relative toxicity of the compounds was found to be Cd = Se greater than V greater than As = Hg greater than Co greater than Cr = Ni. The primary objective in developing this rat liver cellular toxicity test system was to employ an in vitro test system utilizing metabolically active primary cells from a potential target organ. This study demonstrates the utility of this test system in determining the relative liver cell toxicity of a series of inorganic agents of differing toxicity. PMID:7319528

Inmon, J; Stead, A; Waters, M D; Lewtas, J

1981-11-01

271

Documentation of toxicity testing results on increased supernate treatment rate of 2700 gallons/batch  

SciTech Connect

In February 1991, Reactor Materials increased the rate of supernate treatment in the M-Area Dilute Effluent Treatment Facility (DETF) from 1800 gallons to [approximately]2700 gallons of supernate per 36,000 gallon dilute wastewater batch. The first release of the treated effluent began on March 3, 1991. A series of whole effluent toxicity tests was conducted on the DETF effluent to determine if the increased supernate concentration would result in any chronic toxicity affects in the receiving stream (Tims Branch). The toxicity tests were conducted at instream concentrations equivalent to DETF release rates of 5, 10, 15, 20, and 25 gallons/min. The test results, based on 7-day Ceriodaphnia dubia chronic toxicity, indicated no toxicity effects at any concentration tested. Supernate treatment in DETF continued at the higher concentration.

Pickett, J.B.

1992-07-06

272

Pilot study for ambient toxicity testing in Chesapeake bay. Year two report  

SciTech Connect

The primary goal of the ambient toxicity testing pilot study was to identify toxic areas in living resource habitats of the Chesapeake Bay watershed by using a battery of standardized, directly modified or recently developed water column, sediment and suborganismal toxicity tests. Tests were conducted twice at the following stations: Potomac River-Morgantown, Potomac River-Dahlgren, Patapsco River and Wye River. A suite of inorganic and organic contaminants was evaluated in the water column and sediment during these tests. Standard water quality conditions were also evaluated in water and sediment from all stations.

Hall, L.W.; Ziegenfuss, M.C.; Fischer, S.A.; Anderson, R.D.; Killen, W.D.

1992-11-01

273

Abcb4 acts as multixenobiotic transporter and active barrier against chemical uptake in zebrafish (Danio rerio) embryos  

PubMed Central

Background In mammals, ABCB1 constitutes a cellular “first line of defense” against a wide array of chemicals and drugs conferring cellular multidrug or multixenobiotic resistance (MDR/MXR). We tested the hypothesis that an ABCB1 ortholog serves as protection for the sensitive developmental processes in zebrafish embryos against adverse compounds dissolved in the water. Results Indication for ABCB1-type efflux counteracting the accumulation of chemicals in zebrafish embryos comes from experiments with fluorescent and toxic transporter substrates and inhibitors. With inhibitors present, levels of fluorescent dyes in embryo tissue and sensitivity of embryos to toxic substrates were generally elevated. We verified two predicted sequences from zebrafish, previously annotated as abcb1, by cloning; our synteny analyses, however, identified them as abcb4 and abcb5, respectively. The abcb1 gene is absent in the zebrafish genome and we explored whether instead Abcb4 and/or Abcb5 show toxicant defense properties. Quantitative real-time polymerase chain reaction (qPCR) analyses showed the presence of transcripts of both genes throughout the first 48 hours of zebrafish development. Similar to transporter inhibitors, morpholino knock-down of Abcb4 increased accumulation of fluorescent substrates in embryo tissue and sensitivity of embryos toward toxic compounds. In contrast, morpholino knock-down of Abcb5 did not exert this effect. ATPase assays with recombinant protein obtained with the baculovirus expression system confirmed that dye and toxic compounds act as substrates of zebrafish Abcb4 and inhibitors block its function. The compounds tested comprised model substrates of human ABCB1, namely the fluorescent dyes rhodamine B and calcein-am and the toxic compounds vinblastine, vincristine and doxorubicin; cyclosporin A, PSC833, MK571 and verapamil were applied as inhibitors. Additionally, tests were performed with ecotoxicologically relevant compounds: phenanthrene (a polycyclic aromatic hydrocarbon) and galaxolide and tonalide (two polycyclic musks). Conclusions We show that zebrafish Abcb4 is a cellular toxicant transporter and provides protection of embryos against toxic chemicals dissolved in the water. Zebrafish Abcb4 thus is functionally similar to mammalian ABCB1, but differs from mammalian ABCB4, which is not involved in cellular resistance to chemicals but specifically transports phospholipids in the liver. Our data have important implications: Abcb4 could affect bioavailability - and thus toxicologic and pharmacologic potency - of chemicals to zebrafish embryos and inhibition of Abcb4 therefore causes chemosensitization, that is, enhanced sensitivity of embryos to toxicants. These aspects should be considered in (eco)toxicologic and pharmacologic chemical screens with the zebrafish embryo, a major vertebrate model. PMID:23773777

2013-01-01

274

[Evaluation of the chorioallantoic membrane in the chick embryo to test the irritation potential of chemical and cosmetic products].  

PubMed

A large number of new chemicals and cosmetics are introduced every year and it is necessary to find a reliable method for the detection of potential irritants. Hitherto used, for this purpose, in vivo rabbit eye test (Draize's test) should be substituted by alternatives because of ethical and legal aspects. One of the most promising method predicting the irritant potential is test performed on the chorioallantoic membrane of the chick embryo (CAM-test) [5]. This membrane is a complete tissue including arteries, capillaries and veins and is technically easy to study. The aim of the study was to check reliability and sensitivity of the test. The principles of the method are simple. The test substance (pure, dissolved or suspended) is applied to the CAM at a volume of 200 microliters. The blood vessels and the remaining parts of the membrane are examined and scored for irritant effects (hyperaemia, lysis or coagulation) after 0.5, 2 and 5 minutes treatment. The numerical, time-dependent score (Table III) are summed to give a single numerical value indicating the irritation potential of the tested substance (Table II). The final assessment is based on the mean value from four experiments. A summary of the results of CAM irritation testing of some of chemicals and cosmetics is given in Tables IV, V and VI. Table VII shows results of assessment of irritation potential of various cosmetics tested by two methods: CAM and Draize eye tests. It was found that CAM test is a rapid and very sensitive method which can give an information on the potential of irritation of chemical substances and cosmetics. PMID:8619123

Mystkowska-Baczkowska, E T; Komar, A; Samos-Zieli?ska, J; Stroi?ska, W; Rogulska, T

1995-01-01

275

TWO SHORT-TERM TOXICITY TESTS FOR THE CALANOID COPEPOD 'EURYTEMORA HERDMANI' USING A COMPLEX EFFLUENT  

EPA Science Inventory

Test designs and methodologies for two short-term static renewal tests, a 96-hr lethality test and a 5-day reproductive test, are described and statistically evaluated. The tests were developed specifically for use in the assessment of the toxicity of mixed effluents to copepods....

276

Toxicity of the cryoprotectants glycerol, dimethyl sulfoxide, ethylene glycol, methanol, sucrose, trehalose and hypersaline solutions to the embryos and nauplii of some penaeid shrimp  

E-print Network

nitrogen (-196'C) and obtained 90% survival for late embryos. Baust and Lawrence (1980a) reported high survival for Anemia nauplii frozen to -14'C and some recovery from exposure to -22'C. Techniques used for successful cryopreservation of bovine... nitrogen (-196'C) and obtained 90% survival for late embryos. Baust and Lawrence (1980a) reported high survival for Anemia nauplii frozen to -14'C and some recovery from exposure to -22'C. Techniques used for successful cryopreservation of bovine...

Robertson, Stephen Michael

2012-06-07

277

Toxic actions of dinoseb in medaka ( Oryzias latipes) embryos as determined by in vivo 31P NMR, HPLC-UV and 1H NMR metabolomics  

Microsoft Academic Search

Changes in metabolism of Japanese medaka (Oryzias latipes) embryos exposed to dinoseb (2-sec-butyl-4,6-dinitrophenol), a substituted dinitrophenol herbicide, were determined by in vivo 31P NMR, high-pressure liquid chromatography (HPLC)-UV, and 1H NMR metabolomics. ATP and phosphocreatine (PCr) metabolism were characterized within intact embryos by in vivo 31P NMR; concentrations of ATP, GTP, ADP, GDP, AMP and PCr were determined by HPLC-UV;

Mark R. Viant; Christopher A. Pincetich; David E. Hinton; Ronald S. Tjeerdema

2006-01-01

278

THE ROLE OF IONORGANIC ION IMBALANCE IN AQUATIC TOXICITY TESTING  

EPA Science Inventory

This paper assessess the issue of ion imbalance, provides summary of applicable data, presents several successful technical tools to address toxicity resulting from salinity and ion imbalances, and discusses regulatory/compliance options to manage discharges with salinity/ion imb...

279

Testing, Toxicity and Exposure: How Safe is "No Unreasonable  

E-print Network

40,000 people a year Causes major pollution Contains a chemical that causes cancer in laboratory animals Produces toxic gases Causes major air pollution problems Causes billions of dollars in property and water; estimated or measured OVERLAP #12;10 10 Hazard Assessment Standard Battery of Studies Physical

Watson, Craig A.

280

Evaluation of Daphnia ambigua for Routine Aquatic Toxicity Testing at the Savannah River Site  

SciTech Connect

Short-term whole effluent toxicity testing, which is currently a requirement of the U.S. EPA`s National Pollution Discharge Elimination System (NPDES), commonly uses the cladoceran species Ceriodaphnia dubia. Despite the advantages to using a common test species to model the toxic effects of effluents, it could be argued that toxicity test results would be more meaningful if a wider variety of test organisms were commonly used. One particular argument against C. dubia is that tests conducted with this species do not always reflect local, site-specific conditions. The careful selection and use of an indigenous test species would produce a more realistic model of local instream effects and would account for regional differences in water quality. Permitted effluent discharges from Savannah River Site (SRS), a government weapons facility operated by the U.S. Department of Energy, require toxicity testing with C. dubia. However, water quality in these receiving streams is markedly different (lower pH and hardness) from standard laboratory water used for the culturing and testing of C. dubia, and it has been shown that this receiving water presents varying degrees of toxicity to C. dubia. Based on these results, it is possible that toxic effects observed during an effluent study could be the result of test organism stress from the dilution water and not the effects of SRS effluents. Therefore, this study addressed the substitution of C. dubia with an indigenous cladoceran species, Daphnia ambigua for routine regulatory testing at SRS. Given the indigenous nature of this species, combined with the fact that it has been successfully cultured by other investigators, D. ambigua was ideal for consideration as a replacement for C. dubia, but further study of the overall success and sensitivity of laboratory-reared D. ambigua was required. This investigation determined that D. ambigua could be laboratory cultured with only minimal changes to established regulatory protocol and that the life-cycle characteristics of this species were conducive to traditional acute and chronic aquatic toxicity test methods. Acute toxicity tests showed that when comparing LC50 values for C. dubia and D. ambigua, D. ambigua was less sensitive to some toxicants (sodium chloride, copper sulfate, and sodium lauryl sulfate) while more sensitive to others (chlorpyrifos). Results of chronic tests with copper sulfate and sodium chloride resulted in the same NOEC/LOEC values for both species. When exposed to unaltered SRS stream water, C. dubia demonstrated a `toxic` response for two of the three streams tested, while reproduction for D. ambigua was higher in all stream samples. Acute toxicity tests with sodium chloride in stream water, generally followed the sensitivity trend noted in tests conducted with regular laboratory water.

Specht, W.L. [Westinghouse Savannah River Company, Aiken, SC (United States); Harmon, S.M. [University of South Carolina, Columbia, SC (United States)

1997-09-01

281

Polychloroprene flexible foam as a reference material. [for fire toxicity tests  

NASA Technical Reports Server (NTRS)

Polychloroprene flexible foam was evaluated as a reference material for fire toxicity tests. A commercial sample was evaluated using nine different test conditions of the USF methodology. The material exhibited a wide range of relative toxicity depending on the test conditions. Times to incapacitation and times to death were shortest at 16 ml/sec (1 l/min) air flow, at any fixed heating rate and upper limit temperature.

Hilado, C. J.; Cumming, H. J.; Morford, R. H.

1977-01-01

282

Development and evaluation of multispecies test protocols for assessing chemical toxicity  

SciTech Connect

Toxicity testing is a well-recognized tool to assist in evaluating the hazards of chemicals to individual biological species. Multispecies toxicity tests, however, are now well developed. Three test systems were examined: the legume-Rhizobium symbiosis for N-fixation, soil microbial populations, and algal multispecies interactions. Test protocols were to be developed and tested using several different chemicals. Test protocols for the legume-Rhizobium and soil microorganisms systems were developed and are presented. The algal multispecies system will require more research, and thus no protocol was recommended at this time. Separate abstracts were prepared for each test system. (ACR)

Garten, C.T. Jr.; Suter, G.W. II; Blaylock, B.G. (eds.)

1985-06-01

283

Toxicity assessment of pesticides to Pseudokirchneriella subcapitata under air-tight test environment.  

PubMed

This paper presents the toxicity data of seven pesticides including atrazine, parathion, dichlorvos, malathion, fenthion, 2-methyl-4-chlorophenoxyacetic acid, and pentachlorophenol on Pseudokirchneriella subcapitata based on a new algal toxicity testing technique conducted under air-tight environment. The dissolved oxygen production and the cell density were adopted as the response endpoints. Median effective concentrations (EC50) range from 0.0035 to 3.40 mg/L (DO production) and from 0.0067 to 3.12 mg/L (cell density). No-observed-effect concentration (NOEC) was determined using the Dunnett's test. NOEC values are with in the range of 0.001-1.20 mg/L. In general, the two test endpoints revealed similar sensitivities. From comparisons of literature data also based on Pseudokirchneriella subcapitata, it is clear that conventional batch tests tend to underestimate the toxicity of pesticides due to their open test environment. Closed-system tests, i.e., microplate test, respirometer test, and our BOD-bottle test, generally provide better assessment to the effects of pesticides. Data based on our test method reveals much higher toxicity (3-100 times) than that from the conventional batch tests. Furthermore, for organophosphorus insecticides, results from the present study show that Pseudokirchneriella subcapitata is less sensitive than Daphnia magna and rainbow trout, but is more susceptible than fathead minnow. The closed-system test applied in this study provides more adequate assessment for the toxicity of pesticides than the conventional batch tests. PMID:16297537

Yeh, Huei Jiun; Chen, Chung Yuan

2006-04-17

284

TOXICITY REDUCTION TEST TO ASSIST IN PREDICTING LAND TREATABILITY OF HAZARDOUS ORGANIC WASTES  

EPA Science Inventory

Migration of toxic organics contained in the water soluble fraction (WSF) of land applied hazardous wastes poses the most serious threat to ground-water resources. A toxicity reduction (TR) test system is being proposed that will serve to determine if, and to what extent, attenua...

285

Application of Neomysis awatschensis as a standard marine toxicity test organism in China.  

PubMed

The small mysid crustacean Neomysis awatschensis was collected in the west coast of Jiaozhou Bay, Qingdao, China in 1992 and acclimated and cultured in laboratory conditions since then. Standard acute toxicity tests using 4-6 d juvenile mysids of this species were conducted and the results were compared with Mysidopsis bahia, a standard toxicity test organism used in the US in terms of their sensitivities to reference toxins, as well as their taxonomy, morphology and geographic distributions. Because of its wide distribution along the Chinese coast, similar sensitivity to pollutants as M. bahia, short life history, small size and the ease of handling, this study intended to use N. awatschensis as one of the standard marine organisms for toxicity testing in China. The species were applied to acute toxicity evaluations of drilling fluid and its additives, organotin TPT and toxic algae, and to chronic (life cycle) toxicity assays of organotin TPT and a toxic dinofalgellate Alexandrium tamarense, respectively. Using N. awatschensis as a standard toxicity testing organism in marine pollution assessment in China is suggested. PMID:14758898

Yan, Tian; Zhou, Ming-jiang; Tan, Zhi-jun; Li, Zheng-yan; Li, Jun; Yu, Ren-cheng; Wang, Li-ping

2003-11-01

286

Reproductive toxicity testing of pharmaceutical compounds to support the inclusion of women in clinical trials  

Microsoft Academic Search

1 The potential for toxicity to reproduction and the developing fetus is an important concern requiring attention during the development of new medicines. However, there are differences in the opinions of the regulatory authorities in Europe, Japan and the USA regarding the nature and amount of data from reproductive toxicity tests that should be available at the various stages of

Chris Parkinson; Kate E Thomas; Cyndy E Lumley

1997-01-01

287

EVALUATION OF TESTS WITH EARLY LIFE STAGES OF FISH FOR PREDICTING LONG-TERM TOXICITY  

EPA Science Inventory

Partial and complete life-cycle toxicity tests with fish, involving all developmental stages, have been used extensively in the establishment of water-quality criteria for aquatic life. During extended chronic exposures of fish to selected toxicants, certain developmental stages ...

288

INTERLABORATORY ROOT ELONGATION TESTING OF TOXIC SUBSTANCES ON SELECTED PLANT SPECIES  

EPA Science Inventory

Four contract laboratories and three EPA laboratories participated in the inter-laboratory testing of 10 toxic substances on a representative plant species from five families. Seeds were germinated on filter paper saturated in a solution of the toxic substance and incubated for 1...

289

Anaerobic degradation and toxicity of commercial cationic surfactants in anaerobic screening tests  

Microsoft Academic Search

Anaerobic biodegradability and toxicity on anaerobic bacteria of di(hydrogenated tallow) dimethyl ammonium chloride (DHTDMAC) and two esterquats have been investigated. A batch test system containing municipal digester solids as a source of anaerobic bacteria, based on the method proposed by the ECETOC, has been applied. To evaluate the potential toxicity of such surfactants on anaerobic sludge, a co-substrate, an easily

M. T. Garc??a; E. Campos; J. Sánchez-Leal; I. Ribosa

2000-01-01

290

The SWIFT periphyton test for high-capacity assessments of toxicant effects on microalgal community development  

Microsoft Academic Search

The SWIFT periphyton test was developed as a simple and high-capacity approach for assessing toxicant effects on the succession of natural communities. Attached microbial communities (periphyton) were developed over a 7 to 9 day period on artificial glass substratum submerged at sea and then transferred to a controlled indoor environment for 4 day incubation with toxicants. Added nutrients and continuous light over

Tobias Porsbring; Åsa Arrhenius; Thomas Backhaus; Mats Kuylenstierna; Martin Scholze; Hans Blanck

2007-01-01

291

[Effect of Equisetum hyemale on experimental hyperlipemia in rats and its toxic test].  

PubMed

The results of an experimental study in rats fed with Equisetum hyemale and hyperlipid food have proved that inhibiting effects on the elevation of triglyceride and cholesterol can be obviously observed in both high and low doses of Equisetum. The study also shows that Equisetum hyemale can antagonize the hyperlipemia in rats. The acute toxic test has proved its low toxicity. PMID:8323687

Xu, C F; Bian, X Y; Qu, S M; You, L H; Qi, Z M; Cheng, W; Liu, X J; Liu, W Z; Ren, S J

1993-01-01

292

Computerized In Vitro Test for Chemical Toxicity Based on Tetrahymena Swimming Patterns  

NASA Technical Reports Server (NTRS)

An apparatus and a method for rapidly determining chemical toxicity have been evaluated as an alternative to the rabbit eye initancy test (Draize). The toxicity monitor includes an automated scoring of how motile biological cells (Tetrahymena pyriformis) slow down or otherwise change their swimming patterns in a hostile chemical environment. The method, called the motility assay (MA), is tested for 30 s to determine the chemical toxicity in 20 aqueous samples containing trace organics and salts. With equal or better detection limits, results compare favorably to in vivo animal tests of eye irritancy.

Noever, David A.; Matsos, Helen C.; Cronise, Raymond J.; Looger, Loren L.; Relwani, Rachna A.; Johnson, Jacqueline U.

1994-01-01

293

Periphyton photosynthesis as an indicator of effluent toxicity: Relationship to effects on animal test species  

SciTech Connect

The use of freshwater and marine plants in effluent toxicity evaluations is uncommon despite the presence of test methods and recommendations for their use. It has been assumed that aquatic plants are less sensitive than animal test species and consequently, results from toxicity tests with invertebrates and fish have been used often as a surrogate data base. The study evaluated the ability of these animal toxicity tests to provide safe concentrations for in-stream periphyton. The toxicity of several samples of a treated municipal effluent were determined during a five-month period by monitoring short-term changes in periphyton photosynthesis (carbon-14 uptake) and by observing the effects on young production and survival of cultured daphnids and the fathead minnow. The effect levels from the various tests were compared. The effluent was seldom acutely toxic to Daphnia magna and the fathead minnow (Pimephales promelas) but it was consistently acutely and chronically toxic to Ceriodaphnia dubia. Chronic effect levels ranged between 17 and 71% effluent. Significant inhibition and stimulation of periphyton photosynthesis occurred at concentrations of 6 to 39% effluent. Periphyton photosynthesis was a more sensitive effect parameter than animal survival and in some cases than Ceriodaphnia reproductive performance. The results indicate that effluent toxicity tests conducted routinely with daphnids and fish may not be sufficient to predict effects on indigenous flora in receiving waters.

Lewis, M.A.

1992-01-01

294

Assessment of four different test designs for Hyalella azteca 10 days sediment toxicity test  

SciTech Connect

The purpose of this study was to assess the adequacy of four experimental designs of the Hyalella azteca 10 days sediment toxicity test. The authors conducted a series of sediment toxicity tests using an EPA recommended experimental design (8 chambers with 10 organisms per treatment) and three other designs. These had the same total number of organisms (80) per treatment and the same sediment:water ratio (1:1.5) but different number of chambers (4,2,1). The number of organisms recovered, the time to sort and count the animals, as well as the time to make a water change were compared for these four designs. Logistic regression was used to analyze the recovery data while one-way analysis of variance methods were used to analyze the time responses. The results showed that the four treatments were comparable in terms of proportion of organisms recovered. However, the sorting time and the water change time decreased as the number of chambers decreased, making those designs with less chambers more desirable.

Ramirez-Romero, P. [Autonomous Metropolitan Univ., Mexico City (Mexico). Hydrobiology Dept.; [Miami Univ., Oxford, OH (United States). Zoology Dept.; Oris, J.T.; Bailer, J.; DePoy, M. [Miami Univ., Oxford, OH (United States)

1995-12-31

295

Concentration-time data in toxicity tests and resulting relationships  

NASA Technical Reports Server (NTRS)

Periodic analyses for carbon monoxide and methane in the animal exposure chamber during pyrolysis of polyethylene at 800 C without forced air flow showed that the concentrations of these compounds increased with exposure time. These observations, and similar observations for polyurethane flexible foam, permitted the calculation of carbon monoxide toxicity in terms of a DP (Death Product Concentration) value, in addition to flammability in terms of HC (Hydro Carbon) value. Observed DP values exceeding the critical DP(CO) value of 47,200 ppm-min for carbon monoxide may indicate that lethal exposures were reached earlier but not immediately manifested because of the time delay involved in physiological processes. On the basis of this DP(CO) value, carbon monoxide could have been the sole toxicant in the case of polyethylene, polypropylene, polyoxymethylene, polystyrene, polycarbonate, ethylene propylene diene rubber, and wood.

Hilado, C. J.; Brauer, D. P.

1979-01-01

296

The use of phytotoxicity tests (common duckweed, cabbage, and millet) for determining effluent toxicity  

Microsoft Academic Search

The objective of this study was to use higher plants for detecting effluent toxicity. Eight effluent samples were obtained from three industrial sources prior to their entry into a sewer system. The tests were the duckweed reproduction test, and root growth tests using cabbage and millet. The results of repeated phytotoxicity tests were reproducible. Of the three industrial sources, the

Wuncheng Wang; Judson M. Williams

1990-01-01

297

Studies with the USF/NASA toxicity screening test method - Oxygen concentrations with various test conditions  

NASA Technical Reports Server (NTRS)

Continuing efforts to increase the versatility of the USF/NASA toxicity screening test method have included the use of different test conditions in order to simulate various fire environments. The use of air flow at flow rates of 16 to 48 ml/sec maintains oxygen concentrations above 19 percent throughout the 30 min exposure period, compared to above 16 percent without forced air flow. These levels of oxygen are well within the tolerance range of mice, and approach the oxygen levels found in many real fire situations. Proposed minimum oxygen levels based on experience with rats are unduly restrictive on the use of other species such as mice, and tend to eliminate the cost savings which may more than justify the selection of mice.

Hilado, C. J.; Cumming, H. J.; Solis, A. N.

1977-01-01

298

Coal- and oil-shale liquids tested for toxic effects  

SciTech Connect

The advent of liquid chemicals and fuels derived from coal and oil shale has presented some potential health problems. A number of projects are under way to determine the possible toxic effects of these fuels and chemicals on humans and animals. The preliminary data from these studies are briefly reviewed. A consensus is that there are some dangers but they can be overcome with appropriate chemical processing.

Not Available

1986-04-28

299

Whole sediment toxicity tests for metal risk assessments: on the importance of equilibration and test design to increase ecological relevance.  

PubMed

Current laboratory-based approaches for predicting metal toxicity in sediments exhibit a number of limitations. The most important are (1) a lack of sufficient equilibration resulting in unrealistically low pH values or unnaturally high porewater metal concentrations and (2) an inadequate test design regarding the metal concentrations selected for spiking. The present study illustrates that by explicitly accounting for these limitations, one obtains reliable and environmentally realistic toxicity data, thus advancing the metal risk assessments of sediments. To this end, a toxicity test design with natural sediments was developed in which the administered metal concentrations were selected to comprise a range of the difference between the molar concentration of simultaneously extracted metals and acid volatile sulfides (SEM-AVS) closely surrounding zero. In addition, the test design presented includes a 35- or 40-d equilibration period with overlying water renewal during which conductivity, pH, and metal concentrations in the overlying water are monitored. This allows toxicity testing to start after equilibrium for these parameters has been reached. This test design was applied to Ephoron virgo (Olivier, 1791), Gammarus pulex (Linnaeus, 1758), and Lumbriculus variegatus (Mueller, 1774) exposed to Zn and Pb. These tests indicated that the general concept of absence of toxicity when SEM-AVS<0 could not be rejected. However, the onset of Zn toxicity occurred at lower concentrations than generally assumed. PMID:23401179

Vandegehuchte, Michiel B; Nguyen, Lien T H; De Laender, Frederik; Muyssen, Brita T A; Janssen, Colin R

2013-04-01

300

Development and application of a marine sediment pore-water toxicity test using Ulva fasciata zoospores  

USGS Publications Warehouse

An acute (96 h) pore-water toxicity test protocol using germination and growth of Ulva fasciata zoospores as endpoints was developed to test the toxicity of marine and estuarine sediment pore-water samples. Tests with an organic toxicant (sodium dodecyl sulfate; SDS), three metals (Cd, Cu, and Zn), and ammonia (NH3) were conducted to determine zoospore sensitivity. Zoospore germination and gametophyte growth were as sensitive to SDS as sea urchin (Arbacia punctulata) fertilization and embryological development. Zoospore sensitivity to metals was greater than or comparable to that of adult macroalgae. Zoospores were less sensitive to NH3 than were other commonly used toxicity test organisms. Test results using this algal assay with sediment pore-water samples with high NH3 concentrations were compared with results from sea urchin fertilization and embryological development tests for the same samples. Ulva fasciata zoospore germination was not affected by samples with high NH3 concentrations that were toxic in both sea urchin tests. Zoospore tolerance of NH3 and sensitivity to other contaminants indicate that their response may be useful in toxicity identification evaluation studies with pore-water samples that contain high concentrations of unionized NH3.

Hooten, R.L.; Carr, R.S.

1998-01-01

301

What Food and Feeding Rates are Optimum for the Chironomus dilutus Sediment Toxicity Test Method?  

EPA Science Inventory

Laboratory tests with benthic macroinvertebrates are commonly used to assess the toxicity of both contaminated sediments and individual chemicals. Among the standard procedures for benthic macroinvertebrates are 10-d, 20-d, and life cycle exposures using the midge, Chironomus ...

302

EVALUATION OF A SHORT-TERM CHRONIC EFFLUENT TOXICITY TEST USING SHEEPSHEAD MINNOW (CYPRINODON VARIEGATUS) LARVAE  

EPA Science Inventory

In response to recent changes in National Pollutant Discharge Elimination System (NPDES) permit regulations, rapid (7-day) static renewal toxicity tests have been developed to detect chronic (sublethal and lethal) effect concentrations of municipal and industrial effluents on fre...

303

EPA'S TOXCAST PROGRAM FOR PREDICTING HAZARD AND PRIORITIZING TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS  

EPA Science Inventory

EPA is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals that likely represent the greatest hazard to human ...

304

EPA's Toxcast ? Program for Predicting Hazard and Priortizing Toxicity Testing of Environemntal Chemicals (T)  

EPA Science Inventory

EPA is developing methods for utilizing computational chemistry, high-throughput screening (HTS) and various toxicogenomic technologies to predict potential for toxicity and prioritize limited testing resources towards chemicals that likely represent the greatest hazard to human ...

305

USE OF MARSH PLANTS FOR TOXICITY TESTING OF WATER AND SEDIMENT  

EPA Science Inventory

The freshwater wetland plants, Echinochlo crusgalli crusgalli andEchinocloa crusgalli zelayensis, and the saltmarsh plant, Spartina alterniflora, were exposed to the herbicides, metolachlor and norflurazon, in two types of toxicity tests: eed germination and early seedling growth...

306

A Roadmap for the Development of Alternative (Non-Animal) Methods for Systemic Toxicity Testing  

EPA Science Inventory

Systemic toxicity testing forms the cornerstone for the safety evaluation of substances. Pressures to move from traditional animal models to novel technologies arise from various concerns, including: the need to evaluate large numbers of previously untested chemicals and new prod...

307

Modifying Foods and Feeding Regimes to Optimize the Performance of Hyalella azteca during Chronic Toxicity Tests  

EPA Science Inventory

The amphipod Hyalella azteca is commonly used to assess the toxicity of sediments and waters. However, laboratories have reported varying success in maintaining healthy cultures and in obtaining consistent growth and reproduction (where applicable), especially during tests...

308

DEVELOPMENT OF EPA'S TOXCAST PROGRAM FOR PRIORITIZING THE TOXICITY TESTING OF ENVIRONMENTAL CHEMICALS.  

EPA Science Inventory

EPA is developing methods for utilizing computational chemistry, high-throughput screening (HTS)and genomic technologies to predict potential toxicity and prioritize the use of limited testing resources....

309

EP-toxicity test of saturated GT-73 resin and resin in grout  

SciTech Connect

The results of EP-toxicity tests on mercury saturated Duolite{reg sign} GT-73 cation exchange resin clarify options for the ultimate disposal of spent resin. Samples of GT-73 saturated with mercury passed the EP-toxicity test, indicating that fully spent resin may be classifed as solid''-not hazardous''-waste and stored or disposed-of as such. Samples of GT-73 resin saturated with mercury and then incorporated into Portland Type 1 cement did not pass the EP-toxicity test and fall into the hazardous waste'' category. Samples of GT-73 resin less-than-saturated with mercury which were in corporated in Portland Type 1 cement passed the EP-toxicity test and may be classified as solid waste.'' Other commercially available materials are being investigated for incorporating fully spent GT-73 resin in a solid waste form.

Bibler, J.P.

1985-04-24

310

Intra- and interlaboratory variability in acute toxicity tests with glochidia and juveniles of freshwater mussels (Unionidae).  

PubMed

The present study evaluated the performance and variability in acute toxicity tests with glochidia and newly transformed juvenile mussels using the standard methods outlined in American Society for Testing and Materials (ASTM). Multiple 48-h toxicity tests with glochidia and 96-h tests with juvenile mussels were conducted within a single laboratory and among five laboratories. All tests met the test acceptability requirements (e.g., >or=90% control survival). Intralaboratory tests were conducted over two consecutive mussel-spawning seasons with mucket (Actinonaias ligamentina) or fatmucket (Lampsilis siliquoidea) using copper, ammonia, or chlorine as a toxicant. For the glochidia of both species, the variability of intralaboratory median effective concentrations (EC50s) for the three toxicants, expressed as the coefficient of variation (CV), ranged from 14 to 27% in 24-h exposures and from 13 to 36% in 48-h exposures. The intralaboratory CV of copper EC50s for juvenile fatmucket was 24% in 48-h exposures and 13% in 96-h exposures. Interlaboratory tests were conducted with fatmucket glochidia and juveniles by five laboratories using copper as a toxicant. The interlaboratory CV of copper EC50s for glochidia was 13% in 24-h exposures and 24% in 48-h exposures, and the interlaboratory CV for juveniles was 22% in 48-h exposures and 42% in 96-h exposures. The high completion success and the overall low variability in test results indicate that the test methods have acceptable precision and can be performed routinely. PMID:17867871

Wang, Ning; Augspurger, Tom; Barnhart, M Chris; Bidwell, Joseph R; Cope, W Gregory; Dwyer, F James; Geis, Steve; Greer, I Eugene; Ingersoll, Chris G; Kane, Cynthia M; May, Thomas W; Neves, Richard J; Newton, Teresa J; Roberts, Andy D; Whites, David W

2007-10-01

311

Teratogenic effects of organic extracts from the Pearl River sediments on Xenopus laevis embryos.  

PubMed

Toxicity of organic extracts from the Pearl River sediments was investigated with Xenopus laevis embryos. The effects of sediment organic extracts on the mortality, body length and malformation of X. laevis embryos were tested by the Frog Embryo Teratogenesis Assay-Xenopus (FETAX). The 96-h LC?? values for X. laevis embryos ranged from 62 to 137 g/L (g extracted sediment per L), and the toxicity effect on body length of larvae was not significant under 20 g/L. However, the teratogenic effects produced by sediment organic extracts were diverse, including edema, hypopigmentation, cardiac and ocular malformations, abdomen recurved and curved spine. The percentage of malformations increased with increasing sediment organic extracts, and even reached almost 100% at 10 and 20 g/L in Guangzhou district. A gradient of pollution in the Pearl River sediments was discerned from the teratogenic toxicity. Guangzhou district showed higher teratogenic toxicity compared with Panyu and Nansha districts as a possible consequence of high levels of PAHs, PCBs, OCPs and NP in the sediments. The teratogenic effects of organic extracts from the Pearl River sediments were successfully assessed which indicated the feasibility of teratogenic potential studies of sediments using X. laevis embryos. PMID:24361698

Zhang, Cong; Liu, Xinhui; Wu, Dan; Liu, Guannan; Tao, Li; Fu, Wenjun; Hou, Jing

2014-01-01

312

Applicability of ambient toxicity testing to national or regional water-quality assessment  

USGS Publications Warehouse

Comprehensive assessment of the quality of natural waters requires a multifaceted approach. Based on experimentation designed to monitor responses of organisms to environmental stresses, toxicity testing may have diverse purposes in water quality assessments. These purposes may include identification that warrant further study because of poor water quality or unusual ecological features, verification of other types of monitoring, or assessment of contaminant effects on aquatic communities. A wide variety of toxicity test methods have been developed to fulfill the needs of diverse applications. The methods differ primarily in the full selections made relative to four characteristics: (1) test species, (2) endpoints (acute or chronic), (3) test enclosure type, and (4) test substance (toxicant) that functions as the environmental stress. Toxicity test approachs vary in their capacity to meet the needs of large-scale assessments of existing water quality. Ambient testing is more likely to meet these needs than are the procedures that call for exposure of the test organisms to known concentrations of a single toxicant. However, meaningful interpretation of ambient test results depend on the existence of accompanying chemical analysis of the ambient media. The ambient test substance may be water or sediments. Sediment tests have had limited application, but they are useful because of the fact that most toxicants tend to accumulate in sediments, and many test species either inhabit the sediments or are in frequent contact with them. Biochemical testing methods, which have been developing rapidly in recent years, are likely to be among the most useful procedures for large-scale water quality assessments. They are relatively rapid and simple, and more importantly, they focus on biochemical changes that are the initial responses of virtually all organisms to environmental stimuli. Most species are sensitive to relatively few toxicants and their sensitivities vary as conditions change. One of the most informative approaches for toxicity testing is to combine biochemical tests with other test methods in a ' battery or tests ' that is diversified enough to characterize different types of toxicants and different trophic levels. (Lantz-PTT)

Elder, J. F.

1989-01-01

313

Morphing Embryos  

NSDL National Science Digital Library

Quicktime movies morph human, pig, fish and chick embryos. from Odyssey of Life, Nova Online. No explanation of what is developing, only VERY small morphing movies of early development. Low detail, no explanation.

NOVA Online, Odyssey of Life (WGBH Audience and Member Services)

2005-11-14

314

Visible Embryo  

NSDL National Science Digital Library

a comprehensive resource of information on human development from conception to birth, designed for both medical student and interested lay people. The Visible Embryo offers a detailed pictorial account of normal and abnormal development.

Carmen Arbona (Mouseworks)

2006-01-30

315

Genotoxicity and toxicity evaluations of ECF cellulose bleaching effluents using the Allium cepa L. test.  

PubMed

Toxicity and genotoxicity tests were performed on root cells of Allium cepa in order to evaluate wastewater quality following an ECF cellulose bleaching process. The results revealed a toxic effect of the effluent, with inhibition of meristem growth and generally lower values of metaphase, anaphase and telophase indices at pH 10.5 than pH 7 for all effluent concentrations. The genotoxicity effect was different from the toxic effect given that the micronucleus and the chromosomal aberration tests in anaphase-telophase cells were low over all ranges of the studied effluent concentrations. PMID:22990817

Roa, O; Yeber, M C; Venegas, W

2012-08-01

316

Acute toxicity tests on raw leachate from a Malaysian dumping site.  

PubMed

Leachate samples collected from the Ampar Tenang open dumping site at Dengkil, Malaysia, were analyzed for acute toxicity. Two in vivo toxicity tests, Acute Oral Toxicity (AOT) and Primary Skin Irritation (PSI), were performed using Sprague Dawley rats and New Zealand Albino rabbits, respectively. The leachate samples were also analyzed chemically for nitrate and phosphate, ammonia-nitrogen, Kjeldahl-nitrogen and Chemical Oxygen Demand (COD). Results from both the AOT and PSI tests showed that the leachate did not contribute to acute toxicity. The AOT test yielded a negative result: no effect was observed in at least half of the rat population. The PSI test on rabbits produced effects only at a leachate concentration of 100%. However, the skin irritation was minor, and the test returned a negative result. The four chemical tests showed high levels of nutrient pollution in the leachate. The nitrate and phosphate concentrations were 2.1 mg/L and 23.6 mg/L, respectively. Further, the ammonia-nitrogen concentration was 1,000 mg NH(3)-N/L the Kjeldahl-nitrogen level was 446 mg NH(3)-N/L, and the Chemical Oxygen Demand was 1,300 mg/L. The in vivo toxicity and chemical analyses showed that the leachate is polluted but not acutely toxic to organisms. PMID:20107265

Sujá, Fatihah; Yusof, Arij; Osman, Md Anuar

2010-01-01

317

Toxicity tests of soil contaminated by recycling of scrap plastics  

SciTech Connect

The present investigation studied the toxicity of soil contaminated by untreated discharge from a factory that recycles used plastics. The nearby agricultural areas and freshwater fish ponds were polluted with high concentrations of Cu, Ni, and Mn. Water extracts from the contaminated soil retarded root growth of Brassica chinensis (Chinese white cabbage) and Cynodon dactylon (Bermuda grass) where their seeds were obtained commercially. The contaminated populations of C. dactylon, Panicum repen (panic grass), and Imperata cylindrica (wooly grass) were able to withstand higher concentrations of Cu, Ni, and Mn, especially C. dactylon, when compared with their uncontaminated counterparts.

Wong, M.H.; Chui, V.W. (Hong Kong Baptist College, Kowloon (Hong Kong))

1990-03-01

318

Evaluation of anticoccidial drugs in chicken embryos  

Microsoft Academic Search

Infections ofEimeria tenella in chicken embryos were used to compare the anticoccidial activity of ten drugs. The minimal inhibitory concentration (MIC) and minimal toxic concentration (MTC) were affected by the time of inoculation into the embryos and by the chemical nature of the compounds. Some compounds (nicarbazin, amprolium) had no effect on the development of coccidia when they were injected

M. Q. Xie; T. Fukata; J. M. Gilbert; L. R. McDougald

1991-01-01

319

Cross-Sector Review of Drivers and Available 3Rs Approaches for Acute Systemic Toxicity Testing  

PubMed Central

Acute systemic toxicity studies are carried out in many sectors in which synthetic chemicals are manufactured or used and are among the most criticized of all toxicology tests on both scientific and ethical grounds. A review of the drivers for acute toxicity testing within the pharmaceutical industry led to a paradigm shift whereby in vivo acute toxicity data are no longer routinely required in advance of human clinical trials. Based on this experience, the following review was undertaken to identify (1) regulatory and scientific drivers for acute toxicity testing in other industrial sectors, (2) activities aimed at replacing, reducing, or refining the use of animals, and (3) recommendations for future work in this area. PMID:20484382

Seidle, Troy; Robinson, Sally; Holmes, Tom; Creton, Stuart; Prieto, Pilar; Scheel, Julia; Chlebus, Magda

2010-01-01

320

Development of an alternative artificial soil for earthworm toxicity testing in tropical countries  

Microsoft Academic Search

The standard soil invertebrate toxicity tests developed by OECD and ISO use an artificial soil as the test substrate, which contains sphagnum peat as a component. This type of peat is not widely available. Investigation of possible alternative substrates using locally available materials therefore is vital for performing such ecotoxicity tests, particularly in the tropics. We studied the suitability of

Cornelis A. M. van Gestel

2009-01-01

321

Effect of indigenous animals on chronic end points in freshwater sediment toxicity tests  

Microsoft Academic Search

Sediment toxicity tests were conducted using three species of benthic invertebrates, Chironomus riparius, Hyalella azteca, and Hexagenia limbata, with various densities of the oligochaete worm Tubifex tubifex. It was shown that indigenous animals, simulated by the presence of Tubifex tubifex, did not affect survival of the test species (P [>=] 0.05) but did reduce growth in all three test species

T. B. Reynoldson; K. E. Day; C. Clarke; D. Milani

1994-01-01

322

Revolutionizing Toxicity Testing For Predicting Developmental Outcomes (DNT4)  

EPA Science Inventory

Characterizing risk from environmental chemical exposure currently requires extensive animal testing; however, alternative approaches are being researched to increase throughput of chemicals screened, decrease reliance on animal testing, and improve accuracy in predicting adverse...

323

40 CFR 797.1400 - Fish acute toxicity test.  

Code of Federal Regulations, 2011 CFR

...findings are recorded. (v) The dissolved oxygen concentration, pH, temperature...During static tests, the dissolved oxygen concentration, temperature...During flow-through tests, dissolved oxygen, temperature and pH...

2011-07-01

324

40 CFR 797.1400 - Fish acute toxicity test.  

...findings are recorded. (v) The dissolved oxygen concentration, pH, temperature...During static tests, the dissolved oxygen concentration, temperature...During flow-through tests, dissolved oxygen, temperature and pH...

2014-07-01

325

40 CFR 797.1400 - Fish acute toxicity test.  

Code of Federal Regulations, 2013 CFR

...findings are recorded. (v) The dissolved oxygen concentration, pH, temperature...During static tests, the dissolved oxygen concentration, temperature...During flow-through tests, dissolved oxygen, temperature and pH...

2013-07-01

326

40 CFR 797.1400 - Fish acute toxicity test.  

Code of Federal Regulations, 2010 CFR

...findings are recorded. (v) The dissolved oxygen concentration, pH, temperature...During static tests, the dissolved oxygen concentration, temperature...During flow-through tests, dissolved oxygen, temperature and pH...

2010-07-01

327

40 CFR 797.1400 - Fish acute toxicity test.  

Code of Federal Regulations, 2012 CFR

...findings are recorded. (v) The dissolved oxygen concentration, pH, temperature...During static tests, the dissolved oxygen concentration, temperature...During flow-through tests, dissolved oxygen, temperature and pH...

2012-07-01

328

DEVELOPMENT OF A FATE/TOXICITY SCREENING TEST  

EPA Science Inventory

A shake-flask screening test was designed to rapidly evaluate the relative degradation rates of a wide spectrum of chemicals, each compared to methyl parathion. Test chemicals evaluated were bolero, bravo, dibutylphthalate, dimilin, dursban, endosulfan, hoelon, pentachlorobenzene...

329

Toxic Substances Control Act (TSCA) Test Submissions Database (TSCATS) - comprehensive update (on magnetic tape). Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

NONE

1996-07-01

330

Relative toxicity testing of spacecraft materials. 2: Aircraft materials  

NASA Technical Reports Server (NTRS)

The relative toxicity of thermodegradation (pyrolysis/combustion) products of aircraft materials was studied. Two approaches were taken to assess the biological activity of the pyrolysis/combustion products of these materials: (1) determine the acute lethality to rats from inhalation of these pyrolysates and (2) examine the tendency for sublethal exposure to the pyrolysates to disrupt behavioral (shock avoidance) performance of exposed rats. The ralative importance of lethality vs. behavioral effects in selection of a material may be dictated by whether or not individuals potentially exposed to such products, would have an opportunity to escape if they were behaviorally capable of doing so. If so, the second parameter would assume greater importance, but if not the first parameter may be of much greater importance in selecting materials.

Lawrence, W. H.

1980-01-01

331

[TRH test after subtotal thyroid resection for diffuse toxic goiter].  

PubMed

Altogether 25 patients were examined one month after subtotal resection of the thyroid for diffuse toxic goiter. A wide spectrum of the TSH to TRH reaction was detected. The nature of this reaction made it possible to single out 4 groups of patients with a progressively decreasing and even paradoxical response of TSH to TRH. There were no correlations between the nature of the TSH to TRH reaction and the patients' thyroid status in the pre- and postoperative period, time-period of disease and the expression of autoimmune processes. Profound changes in function of the pituitary-hypothalamo-thyroid system were found in most of the patients at the above mentioned time after operation. PMID:3937156

Ibragin, M d; Bazarova, E N; Kandror, V I

1985-01-01

332

Establishment of quality assurance procedures for aquatic toxicity testing with the nematode Caenorhabditis elegans  

SciTech Connect

In this study initial data were generated to develop laboratory control charts for aquatic toxicity testing using the nematode Caenorhabditis elegans. Tests were performed using two reference toxicants: CdCl{sub 2} and CuCl{sub 2}. All tests were performed for 24 h without a food source and of 48 h with a food source in a commonly used nematode aquatic medium. Each test was replicated 6 times with each replicate having 6 wells per concentration with 10 {+-} 1 worms per well. Probit analysis was used to estimate LC{sub 50} values for each test. The data were used to construct a mean ({bar x}) laboratory control chart for each reference toxicant. The coefficient of variation (CV) for three of the four reference toxicant tests was less than 20%, which demonstrates an excellent degree of reproducibility. These CV values are well within suggested standards for determination of organism sensitivity and overall test system credibility. A standardized procedure for performing 24 h and 48 h aquatic toxicity studies with C. elegans is proposed.

Freeman, M.N.; Marse, T.J.; Williams, P.L. [Univ. of Georgia, Athens, GA (United States). Environmental Health Science Program

1998-12-31

333

Testing the use of the water milfoil (Myriophyllum spicatum L.) in laboratory toxicity assays.  

PubMed

Tests aiming to determine the toxic properties of compounds discharged into aquatic systems have relied more on fish or invertebrates than on primary producers and among a number of producers; algae are the most popular test organisms. Macrophytes are important ecological elements in freshwaters and are therefore potentially key organisms for use in toxicity testing of compounds suspected of acting in primary producers. The most common macrophyte used in toxicity testing is Lemna sp., but as a floating plant, it has the limitation of being exposed to toxic compounds only through its lower leaf surface, including roots and rhizoids. Therefore, it is questionable whether tests with Lemna may accurately predict potential effects on submersed and exposed plant species, which have different routes of exposure and morphology. Few other submersed macrophytes have been tested, notably Myriophyllum. In the Iberian peninsula M. spicatum is the most common species within its genus and has been presented as a good bioaccumulator of heavy metals (Wang et al. 1996) and as being sensitive to several toxicants (e.g. Hanson et al. 2003). The aim of this study was to assess the potential of M. spicatum as a testing organism in laboratory assays, by obtaining axenic cultures of this plant and exposing them to several reference compounds to determine the sensitive endpoints. PMID:17492386

Sánchez, David; Graça, Manuel A S; Canhoto, Jorge

2007-06-01

334

The luminescent bacteria toxicity test: its potential as an in vitro alternative.  

PubMed

During the past several years, the use of animals for toxicity testing has come under critical surveillance. For ethical and economic reasons, various techniques have been developed and proposed as potential alternatives for some of the whole animal toxicity assays. One assay proposed as an alternative to animal testing is the luminescent bacteria toxicity test (LBT), provided under the trade name of Microtox. The sensitivity and specificity of the LBT was compared with two commonly used toxicity tests--the L-929 Minimal Eàgle's Medium (MEM) elution cytotoxicity test and the Draize test. Cytotoxicity and LBT test data from 709 medical device and biomaterial extracts were compared using a positive/negative ranking system which provided a measurement of false positive and false negative results. These data were compiled from nine separate laboratories producing or using a wide variety of biomaterials and medical device products. The LBT was more sensitive than the tissue culture assay and displayed few false negatives. LBT EC50 values were compared with eye irritancy categories for a group of 34 chemicals and 27 personal care products. As with tissue culture, the LBT was more sensitive and produced minimal false negatives. The data from this study indicate the LBT has potential as a rapid, simple method to screen biomaterials and personal care products for toxicity and irritancy. PMID:2336974

Bulich, A A; Tung, K K; Scheibner, G

1990-01-01

335

Sporadic mortality in chronic toxicity tests using Pimephales promelas (Rafinesque): Cases of characterization and control  

SciTech Connect

In whole effluent toxicity tests, organisms are exposed to various effluent concentrations for a specific time period to estimate the potential effects of an effluent on a receiving stream. Laboratories typically have good success performing valid chronic toxicity tests. However, some difficulty in conducting valid chronic whole effluent toxicity tests with Pimephales promelas (fathead minnow) has been encountered as a result of sporadic control mortality. Some investigators report an interference that causes anomalous patterns of survival in chronic fathead minnow tests. This interference has been termed sporadic mortality phenomenon. Characteristics of sporadic mortality phenomenon include high variability among replicates, nonmonotonic dose responses, mortality beginning on or about day 4 of the test, and fungal growths often observed on the larvae. Histopathologic examinations often indicate bacterial and/or fungal infections on fish exhibiting symptoms of sporadic mortality phenomenon. The most plausible explanation of sporadic mortality phenomenon is a naturally occurring pathogen or pathogens that interfere with the test method. This interference may invalidate tests or falsely indicate toxicity. Sporadic mortality phenomenon can be reduced or eliminated by sample treatments intended to inactivate (heating, antibiotics, or ultraviolet light) or remove (filtration) pathogenic microorganisms. These methods must be used with forethought because of their potential to alter the toxicity of a sample.

Downey, P.J.; Fleming, K.; Guinn, R.; Chapman, N.; Varner, P.; Cooney, J.D.

2000-01-01

336

An evaluation of nickel toxicity to Ceriodaphnia dubia and Daphnia magna in a contaminated stream and in laboratory tests  

Microsoft Academic Search

Seven-day tests with Ceriodaphnia dubia were used to document ambient toxicity in two industrially contaminated streams in southeastern Tennessee. Low survival of Ceriodaphnia dubia was linked to concentrations of Ni below EPA water quality criteria. A toxicity identification evaluation consisting of Ceriodaphnia dubia, Daphnia magna, and Pimephales promelas toxicity tests with Ni, chemical analyses, and experiments with a Ni-selective resin

Lynn Adams Kszos; Arthur J. Stewart; Paul A. Taylor

1992-01-01

337

EPA?s ToxCast Program for Predicting Toxicity and Prioritizing Chemicals for Further Screening and Testing  

EPA Science Inventory

Testing of environmental and industrial chemicals for toxicity potential is a daunting task because of the wide range of possible toxicity mechanisms. Although animal testing is one means of achieving broad toxicity coverage, evaluation of large numbers of chemicals is challengin...

338

Application of leaching tests for toxicity evaluation of coal fly ash  

SciTech Connect

The toxic properties of coal fly ash samples obtained from various coal combustion power plants were evaluated in this work using physicochemical analyses and bioassays. Physicochemical analyses showed that heavy metals present in solid samples included Cr, Cu, Mn, Ni, Pb, and Zn. The results of the chemical analysis of eluates deduced by the application of standard leaching tests according to EN 12457-2 and Toxicity Characteristic Leaching Procedure (TCLP) methods indicated that the compounds contained in fly ashes could potentially be transferred to the liquid phase depending upon the leaching method used. Heavy metal concentrations were higher in TCLP eluates, indicating that the initial pH value of the leaching medium significantly affected the transfer of these elements to the liquid phase. Tests conducted with the photobacterium Vibrio fischeri (Microtox test), the crustacean Daphnia magna, and the rotifer Brachionus calyciflorus were used to assess toxicity of eluates obtained by both leaching tests. Daphnia magna was the most sensitive test organism. The EN 12457-2 method proved to be more reliable for toxicity evaluation of eluates. In contrast, the TCLP method showed some interference owing to acetic acid toxicity, and precipitation occurred after pH adjustment of eluates from acid to neutral range. The toxicity of both fly ashes and the corresponding solid leaching residues of EN 12457-2 and TCLP leaching tests was also measured using the Microtox Basic Solid phase Test. The results generated with this bioassay indicated that toxicity was greatly influenced by the pH status of the solid samples.

Tsiridis, V.; Samaras, P.; Kungolos, A.; Sakellaropoullos, G.P. [Technological Educational Institute for West Macedonia, Kozani (Greece). Dept. for Pollution Control Technology

2006-08-15

339

Hazard evaluation of soil contaminants with aquatic animals and plant toxicity tests  

SciTech Connect

Deleterious effects upon the biota should be one of the principal characteristics used to perform the initial assessment of contamination and the acceptable level of clean-up at hazardous waste sites. Acute toxicity tests are probably the best means for conducting rapid preliminary assessment of distribution and extent of toxic conditions at a site. On the other hand acute toxicity tests may not be adequate indicators of potential effects at critical life stages or responses to longer term exposure to contaminants. Chronic toxicity tests are generally more sensitive than acute tests, and can be used to predict {open_quotes}no effect{close_quotes} or {open_quotes}safe{close_quotes} levels of contamination. In addition, chronic tests provide a better index of field population responses and more closely mimic actual exposure in the field. Partial chronic tests such as the 7 d Ceriodaphnia sp. survival and reproduction test and 7 d fathead minnow survival and growth test are widely used to predict effects upon critical stages in the life cycle of chemical and mixtures. The overall objective of this project was to evaluate the potential hazard of contaminants at an abandoned oil refinery upon aquatic ecosystems within the vicinity. A battery of acute and partial chronic toxicity tests were used to evaluate potential effects of contaminated soil and leachates of soil upon rice seed germination and root growth, Ceriodaphnia acute survival, fathead minnow acute survival, Microtox acute response, 7 d Ceriodaphnia survival and reproduction, and 7 d fathead minnow survival and growth. The specific tests used to accomplish the overall objective included; (1) To estimate phytotoxicity of the soil at the selected contaminated areas within the refinery, (2) to determine potential for leaching at the selected contaminated areas within the refinery, and (3) to assess the relative toxicity of each of the six contaminated areas in the refinery. 13 refs., 3 tabs.

Ramanathan, A. [Oklahoma State Univ., Stillwater, OK (United States)] [Oklahoma State Univ., Stillwater, OK (United States); Burks, S.L. [Water Quality and Ecotoxicology Assessment, Inc., Stillwater, OK (United States)] [Water Quality and Ecotoxicology Assessment, Inc., Stillwater, OK (United States)

1996-12-31

340

Results of Toxicity Tests on SRS NPDES Outfalls A-01, A-11, and G-10, January - September 2002  

SciTech Connect

The results of the 10 rounds of toxicity tests that were performed on SRS NPDES outfalls A-01, A-11 and G-10 indicate that there would have been no toxicity failures if these tests had been compliance tests. Except for one set of test results for G-10, all of the tests resulted in NOECs of 100 percent effluent. All of the tests met the criteria of less than a 25 percent mean reduction in reproduction for any quarter and less than a 40 percent reduction in any single test. Therefore, there is no reasonable potential to discharge toxic effluents in toxic amounts.

Specht, W.L.

2002-11-01

341

EVALUATION OF THE PEEP INDEX AND RECOMMENDED TOXICITY TESTS  

E-print Network

, comprising these tests: (1) bacterial luminescence (Microtox); (2) algal growth, (3) survival and reproduction of Ceriodaphnia and (4) acute mortalityof rainbow trout. The batterysatisfiesthe key requirements

342

Benefits and costs to mussels from ejecting bitterling embryos: a test of the evolutionary equilibrium hypothesis  

Microsoft Academic Search

Two major hypotheses of host-parasite interactions have been proposed to explain cases where hosts do not defend themselves against parasites. The evolutionary lag hypothesis suggests that there has been insufficient time for a host response to evolve, whereas the evolutionary equilibrium hypothesis proposes that host defence does not evolve because it carries costs that outweigh the benefits. We tested potential

Suzanne C. Mills; Martin I. Taylor; John D. Reynolds

2005-01-01

343

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2010 CFR

...around the trunk of the animal. The ends of the...subjects. In the testing of unctuous...one-half of the animals are further prepared...c) Procedures for testing. The sleeve is slipped onto the animal which is then...

2010-01-01

344

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2012 CFR

...around the trunk of the animal. The ends of the...subjects. In the testing of unctuous...one-half of the animals are further prepared...c) Procedures for testing. The sleeve is slipped onto the animal which is then...

2012-01-01

345

16 CFR 1500.40 - Method of testing toxic substances.  

Code of Federal Regulations, 2011 CFR

...around the trunk of the animal. The ends of the...subjects. In the testing of unctuous...one-half of the animals are further prepared...c) Procedures for testing. The sleeve is slipped onto the animal which is then...

2011-01-01

346

Current developments in reproductive toxicity testing of pesticides  

Microsoft Academic Search

A protocol to evaluate the potential developmental and reproductive effects of test chemicals has been developed by the Life Stages Task Force of the International Life Sciences Institute (ILSI)\\/Health and Environmental Sciences Institute (HESI) Agricultural Chemical Safety Assessment (ACSA) Technical Committee. Since the original publication, several international groups have provided public comment on conducting the test. The extended one-generation reproductive

Ralph L. Cooper

2009-01-01

347

DIETARY TOXICITY TEST FOR 2% DRC1339TREATED BROWN RICE ON NONTARGET AVIAN SPECIES  

Microsoft Academic Search

In Louisiana and Texas DRC-1339-treated brown rice is used to manage blackbird populations that cause severe damage to newly planted rice. Nontarget bird species have been observed on some DRC-1339 bait sites. We conducted dietary toxicity tests to provide additional data on the toxicity of DRC-1339 to the following nontarget species observed on DRC-1339 bait sites: savannah sparrows (Passerculus sandwichensis),

JOHN L. CUMMINGS; DARRYL L. YORK; KIRK J. SHIVELY; PATRICIA A. PIPAS; RANDAL S. STAHL; JAMES E. DAVIS

348

Evaluation of the OECD 421 reproductive toxicity screening test protocol using butyl benzyl phthalate  

Microsoft Academic Search

The OECD421 reproductive toxicity screening test protocol was evaluated using the reproductive and developmental toxicant butyl benzyl phthalate (BBP). Female rats were orally exposed from 14 days premating to 6 days postpartum. Male rats were exposed for 29 days. At 1000 mg\\/kg bw\\/day effects were found on body weight gain and food consumption, on spermatogenesis, time to conception, pregnancy rate,

A. H. Piersma; A. Verhoef; P. M. Dortant

1995-01-01

349

Toxic actions of dinoseb in medaka (Oryzias latipes) embryos as determined by in vivo 31P NMR, HPLC-UV and 1H NMR metabolomics.  

PubMed

Changes in metabolism of Japanese medaka (Oryzias latipes) embryos exposed to dinoseb (2-sec-butyl-4,6-dinitrophenol), a substituted dinitrophenol herbicide, were determined by in vivo (31)P NMR, high-pressure liquid chromatography (HPLC)-UV, and (1)H NMR metabolomics. ATP and phosphocreatine (PCr) metabolism were characterized within intact embryos by in vivo (31)P NMR; concentrations of ATP, GTP, ADP, GDP, AMP and PCr were determined by HPLC-UV; and changes in numerous polar metabolites were characterized by (1)H NMR-based metabolomics. Rangefinding exposures determined two sublethal doses of dinoseb, 50 and 75 ppb, in which embryos survived from 1-day post fertilization (DPF) through the duration of embryogenesis. In vivo (31)P NMR data were acquired from 900 embryos in 0, 50, and 75 ppb dinoseb at 14, 62, and 110 h (n = 6 groups) after initiation of exposure. After 110 h, embryos were observed for normal development and hatching success, then either preserved in 10% formalin for growth analysis or flash frozen and extracted for HPLC-UV and (1)H NMR analysis. Dinoseb exposure at both concentrations resulted in significant declines in [ATP] and [PCr] at 110 h as measured by in vivo (31)P NMR (p < 0.01), HPLC-UV (p < 0.001) and NMR-based metabolomics. Reduced eye growth and diminished heart rate occurred in a concentration-dependent fashion. Metabolic effects measured by in vivo (31)P NMR showed a significant increase in orthophosphate levels (P(i); p < 0.05), and significant decreases in [ATP], [PCr] and the PCr/P(i) ratio (p < 0.05). Metabolomics revealed a dose-response relationship between dinoseb and endogenous metabolite changes, with both dinoseb concentrations producing significantly different metabolic profiles from controls (p < 0.05). Metabolic changes included decreased concentrations of ATP, PCr, alanine and tyrosine, and increased concentrations of lactate with medaka embryotoxicity. This study demonstrated that medaka embryos respond to dinoseb with significant changes in metabolism, reduced growth and heart rates, and increased abnormal development and post-exposure mortality. All three analytical methods confirmed similar trends, and utilization of PCr to compensate for ATP loss was found to be a consistent indicator of sublethal stress-one that could be used to quantify stress associated with medaka embryotoxicity. PMID:16290222

Viant, Mark R; Pincetich, Christopher A; Hinton, David E; Tjeerdema, Ronald S

2006-03-10

350

Determining the relative sensitivity of benthic diatoms to atrazine using rapid toxicity testing: a novel method.  

PubMed

Herbicides pose a potential threat to aquatic ecosystems, especially to phototrophic organisms such as benthic diatoms. Benthic diatoms may be a valuable indicator of the toxic impacts of herbicides in aquatic systems. However, this requires information on the herbicide sensitivity of a wide range of freshwater benthic diatom taxa. Unfortunately this information is only available for a limited number of species as current methods of developing new algae toxicity tests on individual taxa are lengthy and costly. To address this issue, we developed a new rapid toxicity test method to test natural benthic communities, from which the relative herbicide sensitivity of many individual taxa can be derived. This involved the collection of natural benthic communities from rocks in situ, which were placed directly into laboratory toxicity tests. Sensitivity data for several diatom genera in a 48 hour exposure toxicity test were produced, without the need for cultures or multiple site visits. After exposure to the highest treatment of atrazine (500 ?g L(-1)) there were significant declines of healthy cells in the most sensitive genera: Gomphonema declined by 74%, Amphora by 62%, Cymbella by 54% and Ulnaria by 34% compared to control levels. In contrast, the genera, Eunotia, Achnanthidium and Navicula, had no statistically significant decline in cell health. This method can identify the diatom taxa most at risk of herbicide toxicity within the natural benthic diatom community. The rapid toxicity testing method presented is a simple and effective method to obtain sensitivity data for multiple taxa within a natural benthic diatom community in a relatively short period of time. PMID:24742551

Wood, Rebecca J; Mitrovic, Simon M; Kefford, Ben J

2014-07-01

351

Aquatic toxicity of forty industrial chemicals: Testing in support of hazardous substance spill prevention regulation  

NASA Astrophysics Data System (ADS)

The U.S. Environmental Protection Agency is presently developing hazardous substance spill regulations to help prevent water pollution. Aquatic animal toxicity data are used as criteria for the designation and categorization of substances as hazardous, even though this type of data is not available for many industrial chemicals. Static 96-hr. toxicity tests were conducted with 40 such chemicals to provide basic toxicity data for regulatory decision making. Thirty-two of the 40 chemicals tested were hazardous to aquatic life as determined by 96-hr. LC 50's less than or equal to 500 mg/l. All 40 chemicals were tested with the fresh-water fathead minnow, Pimephales promelas, and ten chemicals were also tested with the salt-water grass shrimp, Palaemonetes pugio.

Curtis, M. W.; Ward, C. H.

1981-05-01

352

Dispersed oil toxicity tests with biological species indigenous to the Gulf of Mexico. Final report  

SciTech Connect

Static and flowthrough aquatic acute toxicity testing protocols were utilized on eggs and larvae of seven commercially important invertebrates and fishes from the Gulf of Mexico. Test organisms were exposed to Central and Western Gulf oils, dispersed oil, and Corexit 9527. Species included brown shrimp (Penaeus aztecus), white shrimp (Penaeus setiferus), blue crab (Callinectes sapidus), eastern oyster (Crassostrea virginica), red drum (Sciaenops ocellatus), inland silverside (Menidia berylina), and spot (Leiosomus xanthurus). Atlantic menhaden (Brevoortia tyrannus) was also tested because gulf menhaden were not available. Mysids (Mysidopsis bahia) were evaluated as part of a chronic toxicity assessment.

Fucik, K.W.; Carr, K.A.; Balcom, B.J.

1994-08-01

353

Correlation of the five test methods to assess chemical toxicity and relation to physical properties.  

PubMed

Biological tests using Orizias latipes (LC50 and oxygen uptake test), Moina macrocopa (LC50), and Dugesia japonica (head regeneration test and LC50) were carried out in order to clarify the mutual relationship of these test methods. The oxygen uptake rate of O. latipes was not effective to assess chemical toxicity. Adding the results of the growth inhibition test of Tetrahymena pyriformis (Yoshioka, Y., Ose, Y., and Sato, T. (1985). Sci. Total Environ. 43, 149-157), the correlation coefficients between each two test methods were calculated. The test results except EC50 and LC50 of D. japonica showed a good relation to each other. We determined the solubility and the n-octanol/water partition coefficient (P) of some chemicals used in the test. Log P interpreted the toxicity in mol/liter unit but not in mg/liter. Solubility was not a useful descripter neither in mol/liter nor in mg/liter unit. PMID:3093184

Yoshioka, Y; Ose, Y; Sato, T

1986-08-01

354

Toxic Substances Control Act (TSCA) test submissions database (tscats) - comprehensive update (on magnetic tape). Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

NONE

1995-12-31

355

Toxic Substances Control Act test submissions database (TSCATS) - comprehensive update. Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data is submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test is broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

Not Available

1993-01-01

356

Toxic Substances Control Act (TSCA) Test Submissions Database (TSCATS) - comprehensive update (on magnetic tape). Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

NONE

1996-12-31

357

Toxic Substances Control Act (TSCA) Test Submissions data base (TSCATS). Comprehensive update tape. Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data is submitted to the US Environmental Protection Agency by industry under the Toxic Substances Control Act. Test is broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

Not Available

1990-03-01

358

Toxic Substances Control Act (TSCA) test submissions database (TSCATS) - comprehensive update (on magnetic tape). Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects, and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data.

NONE

1996-09-01

359

Toxic Substances Control Act (TSCA) Test Submissions data base (TSCATS) - comprehensive update tape. Data file  

SciTech Connect

The Toxic Substances Control Act Test Submissions Data base (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the US Environmental Protection Agency by industry under the Toxic Substances Control Act. Test is broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The data base allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects, and environmental fate. Additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, as well as the submitting organization and reason for submission of the test data. TSCATS on magnetic is updated quarterly in March, June, September and December each year. Each update is a complete restatement of the entire data base.

Merrick, E.

1987-09-01

360

Toxic Substances Control Act (TSCA) test submissions database (TSCATS) - comprehensive update (on magnetic tape)  

SciTech Connect

The Toxic Substances Control Act Test Submissions Database (TSCATS) was developed to make unpublished test data available to the public. The test data are submitted to the U.S. Environmental Protection Agency by industry under the Toxic Substances Control Act. Test data are broadly defined to include case reports, episodic incidents, such as spills, and formal test study presentations. The database allows searching of test submissions according to specific chemical identity or type of study when used with an appropriate search retrieval software program. Studies are indexed under three broad subject areas: health effects, environmental effects, and environmental fate. additional controlled vocabulary terms are assigned which describe the experimental protocol and test observations. Records identify reference information needed to locate the source document, the submitting organization, and reason for submission of the test data.

NONE

1996-04-01

361

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2011 CFR

...medium and test solutions should be prepared by adding a commercial, synthetic, sea salt formulation or a modified synthetic seawater formulation to distilled/deionized water to a concentration of 30 parts per thousand. (vi) Carriers. Nutrient...

2011-07-01

362

40 CFR 797.1050 - Algal acute toxicity test.  

Code of Federal Regulations, 2010 CFR

...medium and test solutions should be prepared by adding a commercial, synthetic, sea salt formulation or a modified synthetic seawater formulation to distilled/deionized water to a concentration of 30 parts per thousand. (vi) Carriers. Nutrient...

2010-07-01

363

Current Development in Reproductive Toxicity Testing of Pesticides  

EPA Science Inventory

A protocol to evaluate the potential developmental and reproductive effects of test chemicals has been developed by the Life Stages Task Force of the International Life Sciences Institute (ILSI)/Health and Environmental Sciences Institute (HESI) Agricultural Chemical Safety Asses...

364

40 CFR 797.1950 - Mysid shrimp chronic toxicity test.  

Code of Federal Regulations, 2010 CFR

...oxygen concentration, pH, temperature, salinity, the concentration of test substance...oxygen concentration, temperature, salinity, and pH shall be measured weekly in...temperature should not exceed 1 °C, while salinity changes should not exceed 5...

2010-07-01

365

40 CFR 797.1950 - Mysid shrimp chronic toxicity test.  

Code of Federal Regulations, 2011 CFR

...oxygen concentration, pH, temperature, salinity, the concentration of test substance...oxygen concentration, temperature, salinity, and pH shall be measured weekly in...temperature should not exceed 1 °C, while salinity changes should not exceed 5...

2011-07-01

366

SIMULTANEOUS MULTIPLE SPECIES TESTING: ACUTE TOXICITY OF 13 CHEMICALS TO 12 DIVERSE FRESHWATER AMPHIBIAN, FISH, AND INVERTEBRATE FAMILIES  

EPA Science Inventory

The test series developed methods for testing a compliment of aquatic organisms in a single test that satisfies the freshwater acute toxicity requirements for setting water quality criteria. Species tested included fathead minnows Pimephales promelas, rainbow trout Salmo gairdner...

367

An Evaluation Of The Performance Of Five Types Of Sediment Toxicity Tests  

Microsoft Academic Search

The relative sensitivity, analytical precision, discriminatory power, concordance among end-points and concordance with sediment chemistry were compared among five sediment toxicity tests. The tests were performed with aliquots of 15 composited, homogenized sediment samples collected in San Francisco Bay and Tomales Bay, California. The end-points evaluated were: survival and avoidance of solid phase sediments by the amphipods Rhepoxynius abroriius and

Edward R. Long; Michael F. Buchman

1989-01-01

368

Effects of Low Dissolved Oxygen on Organisms Used in Freshwater Sediment Toxicity Tests  

EPA Science Inventory

This manuscript describes the results of tests to determine the tolerance of three benthic organisms to reduced dissolved oxygen (DO). These three organisms are those recommended by EPA for use in toxicity testing of contaminated sediments. The results of the exposures indicate ...

369

Evaluation of reproduction as an endpoint in chronic toxicity tests with the amphipod Hyalella azteca  

SciTech Connect

In 1994, USEPA published ``Methods for Measuring the Toxicity and Bioaccumulation of Sediment-associated Contaminants with Freshwater Invertebrates`` (EPA/600/R-94/024). Within that document a Hyalella azteca 10-d survival test for sediments is described. The 10-d survival test provides a measure of acute toxicity from moderately to highly contaminated sediments. In addition to survival, growth during the 10-d test can be measured and could be a more sensitive endpoint. However, the ecological significance of reduced growth is questionable. Reproduction may be a more sensitive endpoint than growth or survival and its ecological importance is not questionable. The objective of this research is to develop a Hyalella azteca sediment toxicity test with a reproductive endpoint. The reproductive test will closely resemble the 10-d test but will be longer in duration and may require isolation of amphipods from the sediment for reproduction. Presently, reproductive effects of different diets and water types have been evaluated. A preliminary test protocol has been developed and is being tested and refined. This presentation will provide the most current results of this ongoing research. This study will be used to develop standard methods for measuring chronic toxicity in sediments using Hyalella azteca.

Brunson, E.L.; Dwyer, F.J.; Ingersoll, C.G. [NBS, Columbia, MO (United States)

1995-12-31

370

DREDGED MATERIAL EFFECTS ASSESSMENT: SINGLE-SPECIES TOXICITY/BIOACCUMULATION AND MACROBENTHOS COLONIZATION TESTS  

EPA Science Inventory

Toxicity tests and bioaccumulation tests conducted according to methods established by the U.S. Environmental Protection Agency/Corps of Engineers in 1977 have been used to evaluate potential environmental impacts of ocean disposal of dredged materials. ur objective was to compar...

371

SALINITY TOLERANCE OF DAPHNIA MAGNA AND POTENTIAL USE FOR ESTUARINE SEDIMENT TOXICITY TESTS  

EPA Science Inventory

Daphnia magna Straus, a common organism used for freshwater sediment toxicity tests, was evaluated to determine its tolerance to salinity and suitability for tests with estuarine water and sediments. Daphnids were exposed for 2 to 21 days to salinity in a variety of water-only te...

372

APPROACH TO ENVIRONMENTAL RISK ASSESSMENT USING AVIAN TOXICITY TESTS (JOURNAL VERSION)  

EPA Science Inventory

Toxicity tests results are often condensed into a single endpoint (LC50) to facilitate their use in environmental management. The single number cannot distinguish between two tests with equal LC50s but dissimilar slopes at LC50 and it cannot describe the response at low and high ...

373

INTERLABORATORY COMPARISON OF A REDUCED VOLUME MARINE SEDIMENT TOXICITY TEST METHOD USING AMPHIPOD AMPELISCA ABDITA  

EPA Science Inventory

The U.S. Environmental Protection Agency has standardized methods for performing acute marine amphipod sediment toxicity tests. A test design reducing sediment volume from 200 to 50 ml and overlying water from 600 to 150 ml was recently proposed. An interlaboratory comparison wa...

374

Determination of the Number of Cells in Preimplantation Embryos by Using Noninvasive Optical Quadrature Microscopy in Conjunction with Differential Interference Contrast Microscopy  

PubMed Central

The number of cells in a preimplantation embryo is directly correlated to the health and viability of the embryo. There are currently no methods to count the number of cells in late-stage preimplantation embryos noninvasively. We assessed the ability of optical quadrature microscopy (OQM) to count the number of cells in mouse preimplantation embryos noninvasively. First, to test for possible light toxicity, we exposed two-cell mouse embryos to OQM and differential interference contrast (DIC) microscopy and assessed their ability to develop to the blastocyst stage. We found no inhibition of development from either mode of microscopy for up to 2 h of light exposure. We also imaged eight-cell to morula stage mouse preimplantation embryos by OQM nd developed two methods for counting the number of cells. The contour signature method (CSM) used OQM images alone and the phase subtraction method (PSM) used both OQM and DIC images. We compared both methods to standard cell counting techniques and found that the PSM was superior to all other noninvasive cell counting methods. Our work on mouse embryos should be applicable to human embryos. The ability to correctly count the number of cells in human preimplantation embryos could lead to the transfer of fewer embryos in in vitro fertilization (IVF)clinics and consequently a lower rate of high-risk multiple-infant births. PMID:17367551

Newmark, Judith A.; Warger, William C.; Chang, ChihChing; Herrera, Gustavo E.; Brooks, Dana H.; DiMarzio, Charles A.; Warner, Carol M.

2008-01-01

375

The influence of different artificial soil types on the acute toxicity of carbendazim to the earthworm Eisenia fetida in laboratory toxicity tests  

Microsoft Academic Search

Field populations of earthworms have shown a varied response in mortality to the fungicide carbendazim, the toxic reference substance used in agrochemical field trials. The aim of this study was to determine the influence of soil conditions as a potential cause of this variation. Laboratory acute toxicity tests were conducted using a range of artificial soils with varying soil components

Sian R. Ellis; Mark E. Hodson; Philip Wege

2007-01-01

376

U-937 Toxicity Testing of Lunar Dust Stimulant (JSC-1A-vf)  

NASA Technical Reports Server (NTRS)

With NASA planning to extend the human presence to the moon by 2020, the dangers of the lunar environment must be assessed and appropriate countermeasures must be developed. Possible toxic effects of the lunar dust are of particular importance to human health because of the dust's chemical composition, reactivity, and small size. This project focuses on the toxicity of lunar dust stimulant (JSC-1A-vf), in both its active and passive forms, using U-937 human monocyte cells. Simulant was mechanically activated from its passive form by grinding, and its ability to produce hydroxyl radicals was determined. To test for toxicity, active and passivated simulant was diluted in media and applied to the cells for various time periods. Toxicity was then estimated using flow cytometry on the Guava Personal Cell Analysis system. Preliminary results suggest that passivated stimulant is slightly toxic, with an increase in toxicity for activated stimulant. Toxicity results may be affected by cell lysing behavior and quenching of hydroxyl radical production by the cell media.

Bales, Kristyn; Hammond, Dianne; Wallace, William; Jeevarajan, Antony

2007-01-01

377

Using biodynamic models to reconcile differences between laboratory toxicity tests and field biomonitoring with aquatic insects  

USGS Publications Warehouse

Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature. ?? 2007 American Chemical Society.

Buchwalter, D. B.; Cain, D. J.; Clements, W. H.; Luoma, S. N.

2007-01-01

378

Handbook of acute toxicity of chemicals to fish and aquatic invertebrates : summaries of toxicity tests conducted at Columbia National Fisheries Research Laboratory, 1965-78  

USGS Publications Warehouse

Acute toxicity is a major subject of research at Columbia National Fisheries Research Laboratory for evaluating the impact of toxic chemicals on fishery resources. The Laboratory has played a leading role in developing research technology for toxicity testing and data interpretation. In 1965-78, more than 400 chemicals were tested against a variety of invertebrates and fish species representative of both cold- and warm-water climates. The use of acute toxicity tests for assessing the potential hazard of chemical contaminants to aquatic organisms is well documented (Boyd 1957; Henderson et al. 1960; Sanders and Cope 1966; Macek and McAllister 1970). Static acute toxicity tests provide rapid and (within limits) reproducible concentration-response curves for estimating toxic effects of chemicals on aquatic organisms. These tests provide a database for determining relative toxicity of a large number of chemicals to a variety of species and for estimating acute effects of chemical spills on natural aquatic systems; they also assist in determining priority and design of additional toxicity studies. Acute toxicity tests usually provide estimates of the exposure concentration causing 50% mortality (LC50) to test organisms during a specified period of time. For certain invertebrates, the effective concentration is based on immobilization, or some other identifiable endpoint, rather than on lethality. The application of the LC50 has gained acceptance among toxicologists and is generally the most highly rated test for assessing potential adverse effects of chemical contaminants to aquatic life (Brungs and Mount 1978; American Institute for Biological Sciences 1978a). The literature contains numerous papers dealing with the acute toxicity of chemicals to freshwater organisms. However, there is a tremendous need for a concise compendium of toxicity data covering a large variety of chemicals and test species. This Handbook is a compilation of a large volume of acute toxicity data from the Columbia Laboratory and its field laboratories. It presents definitive acute toxicity data on 271 chemicals tested against a variety of freshwater invertebrates and fishes. The chemicals represent all major groups of pesticides, as well as numerous industrial chemicals. This compilation should serve as a useful database for the many agencies and organizations dealing with research and management programs concerned with the impact of chemicals on aquatic resources. The Columbia Laboratory has played a major role in developing currently used standard methodology for static acute toxicity testing. The use of standardized methodology greatly reduces variation in results. The data presented here have been carefully scrutinized to eliminate tests that failed to follow acceptable procedures. Handling of test organisms and procedures for static toxicity tests followed those described by Lennon and Walker (1964) and Macek and McAllister (1970), and conform well with those recommended by Brauhn and Schoettger (1975) and the Committee on Methods for Toxicity Tests with Aquatic Organisms (1975). The species of fish and invertebrates that were tested are listed in phylogenetic order in Tables 1 and 2. Fish were obtained from Federal and State hatcheries as either eggs or fry. Original stocks of invertebrates were collected and cultured from wild populations with no known source of contamination; these populations were replenished regularly. The invertebrates were cultured in the Laboratory by methods similar to those described by Sanders and Cope (1966). Test chemicals usually consisted of technical or analytical grade samples of known purity. Formulations of the chemicals were also tested when available. When purity of test chemicals was known, all calculated concentrations were based on percent active ingredients. Stock solutions were prepared immediately before each test, with commercial grade acetone as the carrier solvent. Occasionally, ethanol or dimethyl-formamide was substituted. Solvent concentrations did not exceed 0.5 mL/L in final dilution water. Test

Johnson, W. Waynon; Finley, Mack T.

1980-01-01

379

Silica gel as a particulate carrier of poorly water-soluble substances in aquatic toxicity testing.  

PubMed

Aquatic toxicity tests were originally developed for water-soluble substances. However, many substances are hydrophobic and thus poorly water-soluble, resulting in at least two major implications. Firstly, toxicity may not be reached within the range of water solubility of the tested compound(s), which may result in the formation of solids or droplets of the tested substance and consequently an uneven exposure. Secondly, because of multi-phase distribution of the tested substance it may be complicated to keep exposure concentrations constant. To overcome such problems, we have introduced silica gel as a particulate carrier in a toxicity test with the benthic copepod Nitocra spinipes. The main objective of the current study was to evaluate whether a controlled exposure could be achieved with the help of silica gel for testing single poorly water-soluble substances. A secondary objective was to evaluate whether an equilibrium mass balance model could predict internal concentrations that were consistent with the toxicity data and measured internal concentrations of two model hydrophobic substances, i.e., the polybrominated diphenyl ethers BDE-47 and BDE-99. Larval N. spinipes were exposed for 6 days to BDE-47 and BDE-99, respectively, in the silica gel test system and, for comparative reasons, in a similar and more traditional semi-static water test system. Via single initial amounts of the model substances administered on the silica gel, effects on both larval development and mortality resulted in higher and more concentration-related toxicity than in the water test system. We conclude that the silica gel test system enables a more controlled exposure of poorly water-soluble substances than the traditional water test system since the concentration-response relationship becomes distinct and there is no carrier solvent present during testing. Also, the single amount of added substance given in the silica gel test system limits the artefacts (e.g., increased chemical load in test system) that a semi-static renewal may introduce when testing substances that partition to non-water phases. However, measured and modelled internal concentrations did not match toxicity, which may indicate that chemical equilibrium was not reached during the test. Further experiments are thus needed to explain the processes behind the observed positive effects of silica gel and a kinetic model would likely also be more appropriate to describe the concentrations and distributions in the two test systems. PMID:17418433

Breitholtz, Magnus; Ricklund, Niklas; Bengtsson, Bengt-Erik; Persson, N Johan

2007-05-31

380

Background variability in whole effluent chronic toxicity test statistics for Ceriodaphnia dubia and Pimephales promelas  

SciTech Connect

Past studies have shown considerable variability in whole effluent toxicity tests in terms of LC{sub 50}`s and NOEC`s from reference toxicant tests. However, this approach cannot differentiate between variability in test organisms themselves from the variable response to a toxicant. A data base of control treatments in chronic WET tests was constructed allowing evaluation of mean performance of WET test organisms Ceriodaphnia dubia and Pimephales promelas not subjected to chemical stress. Surrogate test series were then constructed by randomly selecting replicates from this control data base. These surrogate test series were analyzed using standard EPA statistical procedures to determine NOEC`s for survival and both NOEC`s and IC{sub 25} for reproduction and growth. Since NOEC`s have a significance level (p) of 0.05, it follows that approximately 5% of the tests could ``fail`` simply due to chance and this was, in fact, the case for these surrogate tests. The IC{sub 25} statistic is a linear interpolation technique, with 95% confidence intervals calculated through a bootstrap method. It does not have a statistical check for significance. With the IC{sub 25} statistic, 10.5% of the Ceriodaphnia tests indicated toxicity (i.e. an IC{sub 25} of less than 1 00% ``effluent``), while this increased to 37% for fathead minnows. There appear to be fundamental flaws in the calculation of the IC{sub 25} statistic and its confidence intervals, as currently provided in EPA documentation. Until these flaws are addressed, it is recommended that this method not be used in the analysis of chronic toxicity data.

Canton, S.P. [Chadwick and Associates, Inc., Littleton, CO (United States)

1994-12-31

381

A discussion of the impact of US chemical regulation legislation on the field of toxicity testing.  

PubMed

Proposals for revising the principal United States law governing industrial chemicals, the Toxic Substances Control Act, have been under consideration in the US Congress for the past several years, and some version of such legislation may be passed in the near future. Concurrently, a desire to move away from current testing methods for ethical, scientific, and practical reasons has led to multi-million dollar investments in in vitro and computational toxicology methods and programs. Legislative language has the potential to endorse this transition and facilitate its fruition, or conversely enshrine in vivo testing methods for the foreseeable future. New legislation also has the potential to substantially increase the numbers of animals used in toxicity tests in the near term. However, there are a number of policies that, used effectively, can reduce the overall number of animals used in new toxicity tests. We present recent legislative proposals in the context of current testing programs and discuss their potential impacts on animal use, test method innovation, and achievement of desired legislative objectives. Discussions like these are essential to judiciously select policies that reduce the use of animals in toxicity testing and protect human health and the environment. PMID:21624455

Sullivan, Kristie; Beck, Nancy; Sandusky, Chad; Willett, Catherine

2011-09-01

382

Combinatorial QSAR Modeling of Chemical Toxicants Tested against Tetrahymena pyriformis  

E-print Network

of Pharmacy, CB 7360, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, Laboratories containing 983 unique compounds tested in the same laboratory over a decade against Tetrahymena pyriformis. A modeling set including 644 compounds was selected randomly from the original set and distributed to all

383

Toxics testing performance evaluation for GB and GD  

SciTech Connect

Residues resulting from demilitarization, treatment, cleanup, and testing of military chemical agents at Dugway Proving Ground (DPG), Utah, are currently listed as hazardous wastes by the State of Utah Department of Environmental Quality. The US Army Test and Evaluation Command believes that certain categories of waste generated at DPG are not hazardous. To demonstrate this, analytical methods capable of quantitatively measuring the concentrations of chemical agents, including GB and GD, in the different waste media must be available. Argonne National Laboratory has developed methods to analyze metal substrate, spent hypochlorite decontamination fluid, and soil matrices for GB and GD. These methods involve the use of sorbent cartridge preconcentration and thermal desorption combined with gas chromatography using flame photometric detection to achieve the desired sensitivity and specificity. This report describes the methods and presents results for these three common waste matrices. The test results indicate that these methods can be used to quantitatively determine concentrations of GB and GD in the low parts-per-billion range in all sample media tested.

O`Neill, H.J.; Schneider, J.F.; Brubaker, K.L.; Kimmell, T.A.; Anderson, A.W.

1997-10-01

384

40 CFR 797.1930 - Mysid shrimp acute toxicity test.  

Code of Federal Regulations, 2011 CFR

...oxygen concentration, pH, temperature, salinity, the concentration of test substance...dissolved oxygen concentration temperature, salinity, and pH shall be measured at the beginning...temperature shall not exceed 1 °C, while salinity changes shall not exceed 5...

2011-07-01

385

40 CFR 797.1930 - Mysid shrimp acute toxicity test.  

Code of Federal Regulations, 2010 CFR

...oxygen concentration, pH, temperature, salinity, the concentration of test substance...dissolved oxygen concentration temperature, salinity, and pH shall be measured at the beginning...temperature shall not exceed 1 °C, while salinity changes shall not exceed 5...

2010-07-01

386

Effects of diet on seven-day Ceriodaphnia dubia toxicity tests  

SciTech Connect

The purpose of this study was to evaluate the effects of four diets on the results of seven-day Ceriodaphnia dubia toxicity tests. Survival and reproduction were used as indices to detect the sensitivity of this species to acute and chronic copper stress. All toxicity tests were conducted using the moderately hard reconstituted water recommended in 1989 by the U.S. Environmental Protection Agency. Diet differentially affected the acute and chronic toxicity of copper. Daphnids fed Selenastrum capricornutum (alga) showed the greatest sensitivity, followed by those fed the alga Chlamydomonas reinhardti, then by animals fed a Yeast-Cerophyll[sup TM]-Trout Food (YCTF) mixture plus Selenastrum, and finally by animals fed YCTF alone. These differences may result from the poor nutritional adequacy of Selenastrum when fed alone, the different caloric contents of the diets, the increased toxicant uptake by the organisms through ingestion of copper-laden algal cells, and/or copper ions sequestered by fats and insoluble substances in YCTF. The authors recognize that diet is an important variable in seven-day toxicity tests, and that the selection of a diet should not be based only on its effects on long-term culturing of C. dubia, but also on its possible effects on test results.

Cerda, B.; Olive, J.H. (Univ. of Akron, OH (United States))

1993-06-01

387

Sensitivity of screening-level toxicity tests using soils from a former petroleum refinery  

SciTech Connect

The authors tested five composite soil samples from a former refinery. The samples included a reference soil (Mineral Oil and Grease, MO and G < 40 ppm), thermally-treated soil, biotreated soil, and two untreated soils. They evaluated toxicity using the earthworm E. foetida, lettuce, cress, barley, Microtox, green algae, fathead minnow, and D. magna. The endpoints measured were lethality, seed germination, root elongation, growth, and bioluminescence. Toxicity, as measured by the number of positive responses, increased as follows: biotreated soil < untreated soil No. 1 < reference soil < thermally-treated soil and untreated soil No. 2. The biotreated soil generated only one positive response, whereas the thermally-treated soil and untreated soil No. 2 generated five positive responses. The most sensitive and discriminant terrestrial endpoint was lettuce root elongation which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was barley seed germination for which no toxicity was detected. The most sensitive and discriminant aquatic endpoint was green algae growth which responded to untreated soil No. 1, thermally-treated soil, and reference soil. The least sensitive was D. magna for which no toxicity was detected. Overall, soil and aqueous extract toxicity was spotty and no consistent patterns emerged to differentiate the five soils. Biotreatment significantly reduced the effects of the contamination. Aqueous toxicity was measured in the reference soil, probably because of the presence of unknown dissolved compounds in the aqueous extract. Finally, clear differences in sensitivity existed among the test species.

Pauwels, S.; Bureau, J.; Roy, Y.; Allen, B.; Robidoux, P.Y.; Soucy, M.

1995-12-31

388

Evaluation of the smoke density chamber as an apparatus for fire toxicity screening tests  

NASA Technical Reports Server (NTRS)

The smoke density chamber is perhaps the most widely used apparatus for smoke measurements. Because of its availability, it has been proposed as an apparatus for evaluating fire toxicity. The standard apparatus and procedure were not found suitable for toxicity screening tests using laboratory animals, because not enough materials of interest produced animal mortality or even incapacitation under standard test conditions. With modifications, the chamber offers greater promise as a screening tool, but other tests specifically designed to measure relative toxicity may be more cost-effective. Where one-dimensional heat flux is a requirement, the chamber is the most suitable apparatus available. It should be improved in regard to visibility of animals and ease of cleaning.

Hilado, C. J.; Labossiere, L. A.

1976-01-01

389

Quick, portable toxicity testing of marine or terrigenous fluids, sediments, or chemicals with bioluminescent organism  

SciTech Connect

A hand-held, battery-operated instrument, which measures bioluminescence inhibition of the microscopic marine dinoflagellate Pyrocystis lunula, is capable of field-testing substances for toxicity. The organism is sensitive to ppb of strong toxicants. It tolerates some solvents in concentrations necessary for testing lipophylic samples. A test consumes only micrograms of sample. This method requires no adjustments for salinity, pH, color, or turbidity. It has been used successfully to test oil-well drilling fluids, brines produced with oil, waters and sediments from streams and lakes and petroleum-plant effluents containing contaminants such as benzene. The test is non-specific; however, if the substance is known, the end-point effects a direct measurement of its concentration. One-hour toxicity screening tests in the field produce results comparable to the standard four-hour laboratory test. Keeping the sample in the dark during incubation and testing, together with shortness of the overall procedure, eliminates anomalies from light-sensitive substances. Day-to-day variation, as well as among test replicates, is less than 10%. This quick method yields results comparable with a quick test that uses Photobacterium phosphoria, and with 96-hour tests that use Mysidopsis bahia, Artemia salina, Gonyaulax polyedra, Pimephales promelas, Ceriodaphnia dubia, and Cyprinodon variegatus.

Sabate, R.W.; Stiffey, A.V.; Dewailly, E.L. [Lumitox Gulf L.C., New Orleans, LA (United States)

1995-12-31

390

Use of standard effluent toxicity tests for protection of endangered and threatened species  

SciTech Connect

Water quality criteria and many other environmental assessment tools are based on the results of laboratory toxicity tests. For a variety of reasons, these tests are typically conducted using one of several common laboratory species; results from these tests are then extrapolated with the intention of providing protection for other species not tested directly. This surrogate species approach is particularly necessary for threatened and endangered (listed) species, for which direct toxicity testing is often impractical. However, without direct knowledge of listed species sensitivity, it is not possible to be certain whether these species are adequately protected by current environmental practices. Moreover, the level of protection intended by water quality criteria (e.g., 95% of species) may not be sufficient to meet the requirements of the Endangered Species Act. The authors conducted short-term chronic toxicity tests using Ceriodaphnia dubia and fathead minnows and two listed species, bonytail chub and Colorado squawfish. Methods for Ceriodaphnia dubia and fathead minnow tests were as described by USEPA for effluent testing under the NPDES program; tests with listed species were patterned after the fathead minnow test procedures. Tests were conducted with; (1) ammonia, (2) carbaryl, and (3) a mixture of carbaryl, copper, 4-nonylphenol, pentachlorophenol, and permethrin. Preliminary data analysis indicates that the two listed species respond in a similar manner as the fathead minnow. The sensitivity of listed species to contaminant exposures and implications for regulatory procedures will be discussed.

Henke, C.E.; Dwyer, F.J.; Ingersoll, C.G.; Mount, D.R. [National Biological Service, Columbia, MO (United States); Mayer, F.L. [Environmental Protection Agency, Gulf Breeze, FL (United States)

1995-12-31

391

Embryotoxicity of 3,3',4,4'-tetrachloroazobenzene and 3,3',4,4'-tetrachloroazoxybenzene in the chick embryo.  

PubMed

The toxicity of 3,3',4,4'-tetrachloroazobenzene (TCAB) and 3,3',4,4'-tetrachloroazoxybenzene (TCAOB) to chick embryos was examined. TCAB or TCAOB was dissolved in corn oil and injected into the air cell of fertile chicken eggs. The time of injection had a major effect on embryo mortality as eggs injected with TCAB or TCAOB on the fourth day of incubation had a higher incidence of embryo mortality than eggs injected on days 11-13. Both TCAB and TCAOB were more toxic than all other chemicals that have been tested in the chick embryo with the exception of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Comparing the potency of the two compounds, TCAOB was more potent than TCAB in the chick embryo with an estimated LD50 of 12 ng and 44 ng respectively. Rump edema was the major abnormality observed in embryos treated with either TCAB or TCAOB. Other malformations included altered feather pattern and lack of down, hemorrhage, external viscera, reduced body size, failure to withdraw the yolk sac, beak malformation, dilation of blood vessels, and monomicropthalmia. The results of this investigation suggest that both TCAB and TCAOB are teratogenic in the chick embryo. PMID:7092323

Schrankel, K R; Kreamer, B L; Hsia, M T

1982-01-01

392

Effects of physiochemical properties of test media on nanoparticle toxicity to Daphnia magna Straus.  

PubMed

The physicochemical property of standard test media significantly influenced the aggregation and dissolution of Ag, CuO and ZnO nanoparticles (NPs) and the toxicity of the NPs to Daphnia magna. For all the NPs, the highest amount of metal ions was released from the ISO medium, whereas acute toxicity to D. magna was highest in the moderately hard water medium (EC50 = 4.94, 980, and 1,950 ?g L(-1) for Ag, CuO, and ZnO, respectively). By comparing EC50 values based on the total and dissolved concentrations of NPs with those of metal salt solutions, we found that both particulate and dissolved fractions were likely responsible for the toxicity of Ag NPs, whereas the dissolved fraction mostly contributed to the toxicity of CuO and ZnO NPs. PMID:25063370

Seo, Jaehwan; Kim, Soyoun; Choi, Seona; Kwon, Dongwook; Yoon, Tae-Hyun; Kim, Woo-Keun; Park, June-Woo; Jung, Jinho

2014-09-01

393

Relating results from earthworm toxicity tests to agricultural soil  

USGS Publications Warehouse

The artificial soil tests of the European Economic Community and of the Organization for Economic Cooperation produce data relating earthworm mortality to pesticide concentrations in soil under laboratory conditions. To apply these results to agricultural soils it is necessary to relate these concentrations to amounts of pesticide applied per area. This paper reviews the relevant published literature and suggests a simple relation for regulatory use. Hazards to earthworms from pesticides are suggested to be greatest soon after application, when the pesticides may be concentrated in a soil layer a few millimeters thick. For estimating exposure of earthworms, however, a thicker soil layer should be considered, to account for their movement through soil. During favorable weather conditions, earthworms belonging to species appropriate to the artificial soil test have been reported to confine their activity to a layer about 5 cm. If a 5-cm layer is accepted as relevant for regulatory purposes, then an application of 1 kg/ha would be equivalent to 1-67 ppm (dry) in the artificial soil test.

Beyer, W.N.

1992-01-01

394

Effects of temperature on in situ toxicity testing  

SciTech Connect

With increasing concern over the impacts and perturbations to receiving waters as a result of storm water runoff and contaminated sediments, many investigators have turned towards in situ testing for direct response data. In situ testing has been shown to be an effective assessment tool. In order to further evaluate the limitations of this method, temperature effects were evaluated. There is concern that laboratory to stream transfer of test organisms may induce significant stress if water temperatures are too cool. This study was designed to specifically address the issue of temperature tolerance and attenuation of Hyalella azteca, Ceriodaphnia dubia and Pimephales promelas in in situ conditions. Temperature tolerance is of importance in areas where receiving waters are subject to low or fluctuating temperatures as well as areas of more temperate climates. In this study, the organisms where exposed to temperatures as low as 2 C for variable lengths of time, removed and allowed to come to ambient laboratory temperatures then monitored for acute or chronic responses. No effects on survival were observed after 48 h. at 5 C; however lower temperatures increased mortality.

Rowland, C.D.; Burton, G.A. Jr. [Wright State Univ., Dayton, OH (United States)

1994-12-31

395

Ecotoxicity of aged uranium in soil using plant, earthworm and microarthropod toxicity tests.  

PubMed

Discrepancies about probable no effect concentrations (PNEC) for uranium in soils may be because toxicity tests used freshly contaminated soils. This study used 3 soils amended with a range of uranium concentrations 10 years previously. The toxicity tests with northern wheatgrass (Elymus lanceolatus); earthworm (Eisenia andrei) were not affected below ~1,000 mg U kg(-1), and the soil arthropod Folsomia candida was not affected below ~350 mg U kg(-1). Survival of Orthonychiurus folsomi was diminished 20% (EC(20)) by ~85-130 mg U kg(-1), supporting a PNEC in the range of 100-250 mg U kg(-1) as derived previously. PMID:22033655

Sheppard, S C; Stephenson, G L

2012-01-01

396

Morphological transformation and effect on gap junction intercellular communication in Syrian hamster embryo cells as screening tests for carcinogens devoid of mutagenic activity.  

PubMed

A large fraction of chemicals observed to cause cancer in experimental animals is devoid of mutagenic activity. It is therefore of importance to develop methods that can be used to detect and study environmental carcinogenic agents that do not interact directly with DNA. Previous studies have indicated that induction of in vitro cell transformation and inhibition of gap junction intercellular communication are endpoints that could be useful for the detection of non-genotoxic carcinogens. In the present work, 13 compounds [chlordane, Arochlor 1260, di(2-ethylhexyl)phthalate, 1,1,1-trichloro-2, 2-bis(4-chlorophenyl)ethane, limonene, sodium fluoride, ethionine, o-anisidine, benzoyl peroxide, o-vanadate, phenobarbital, 12-O-tetradecanoylphorbol 13-acetate and clofibrate] have been tested for their ability to induce morphological transformation and affect intercellular communication in Syrian hamster embryo cells. The substances were selected on the basis of being proven or suspected non-genotoxic carcinogens, and thus difficult to detect in short-term tests. The data show that nine of the 13 compounds induced morphological transformation, and seven of the 13 inhibited intercellular communication in hamster embryo cells. Taken together, 12 of the 13 substances either induced transformation or caused inhibition of communication. The data suggest that the combined use of morphological transformation and gap junction intercellular communication in Syrian hamster embryo cells may be beneficial when screening for non-genotoxic carcinogens. PMID:10793297

Rivedal, E; Mikalsen, S O; Sanner, T

2000-04-01

397

Development of miniaturized acute toxicity tests for Daphnia magna and Pimephales promelas  

SciTech Connect

Standard EPA methods for conducting static, 48-hour, acute toxicity tests using Daphnia magna and Pimephales promelas (fathead minnows) can be miniaturized to successfully yield accurate LC50/EC50 values. The screening procedure involves exposing the test organisms to 1 mL of test solution, in test chambers which consist of the wells on 48-well microliter plates. Toxicity of the microliter plates and solvent, DO concentration, organism biomass to test solution ratio, partitioning of the chemicals and dilution of the test solution during transfer of the test organisms were examined. Survival and exposure were not significantly altered using non-standard test chambers. Toxicity of linear alkylbenzene sulfonate (LAS), pentachlorophenol (PCP), kepone, and sodium lauryl sulfate (SLS) was determined using D. magna and fathead minnows. Serial dilutions were made and 1 mL aliquots pipetted into the wells. Daphnia magna, < 24 hours old, and newly hatched fathead minnows, were transferred into the wells, twenty individuals per concentration, one per well. Dose-response curves were established for all test compounds. LC50/EC50`s values obtained using miniaturized methods strongly correlated with those obtained using standard EPA procedures. The tests were repeated a number of times with coefficient of variances for D. magna ranging from 10% with kepone to 64% with SLS. For fathead minnows CVs ranged from 0% with PCP to 23% with kepone. It was concluded that current methods can be miniaturized, yet still provide accurate information regarding toxicity for compounds in limited supply. This method may also be amenable to effluent testing i.e. TIE fractions. Other benefits include reducing the amount of equipment and space needed to conduct a test and the time involved.

Powell, R.L.; Kimerle, R.A.; Moser, E.M.; McKee, M.J.

1995-12-31

398

Harmonization of Animal Clinical Pathology Testing in Toxicity and Safety Studies  

Microsoft Academic Search

Ten scientific organizations formed a joint international committee to provide expert recommendations for clinical pathology testing of laboratory animal species used in regulated toxicity and safety studies. For repeated-dose studies in rodent species, clinical pathology testing is necessary at study termination. Interim study testing may not be necessary in long-duration studies provided that it has been done in short-duration studies

Kurt Weingand; Geoff Brown; Robert Hall; Dai Davies; Kent Gossett; Doug Neptun; Trevor Waner; Toshiaki Matsuzawa; Paul Salemink; Wilhelm Froelke; Jean-Pierre Provost; Gianni Dal Negro; John Batchelor; Mamoru Nomura; Horst Groetsch; Alphons Boink; Jon Kimball; David Woodman; Malcolm York; Eva Fabianson-Johnson; Michel Lupart; Elsa Melloni

1996-01-01

399

Relative toxicity of pyrolysis gases from materials - Effects of chemical composition and test conditions  

NASA Technical Reports Server (NTRS)

Relative toxicity test data on 270 materials are presented, based on test procedures developed at the University of San Francisco. The effects of chemical composition, using data on 13 types of synthetic polymers and eight types of fabrics, are discussed. Selected materials were evaluated using nine test conditions with the USF method, and using methods developed at the FAA Civil Aeromedical Institute, Douglas Aircraft Company and San Jose State University.

Hilado, C. J.; Cumming, H. J.

1978-01-01

400

AQUATIC TOXICITY TESTS TO CHARACTERIZE THE HAZARD OF VOLATILE ORGANIC CHEMICALS IN WATER: A TOXICITY DATA SUMMARY. PARTS 1 AND 2  

EPA Science Inventory

This summary presents acute and chronic toxicity test data and bioconcentration factors compiled over a 2-year period on fish and invertebrates exposed to several representative chemicals from 5 chemical classes (chlorinated ethanes, chlorinated benzenes, chlorinated ethylenes, c...

401

Long-term Lethal Toxicity Test with the Crustacean Artemia franciscana  

PubMed Central

Our research activities target the use of biological methods for the evaluation of environmental quality, with particular reference to saltwater/brackish water and sediment. The choice of biological indicators must be based on reliable scientific knowledge and, possibly, on the availability of standardized procedures. In this article, we present a standardized protocol that used the marine crustacean Artemia to evaluate the toxicity of chemicals and/or of marine environmental matrices. Scientists propose that the brine shrimp (Artemia) is a suitable candidate for the development of a standard bioassay for worldwide utilization. A number of papers have been published on the toxic effects of various chemicals and toxicants on brine shrimp (Artemia). The major advantage of this crustacean for toxicity studies is the overall availability of the dry cysts; these can be immediately used in testing and difficult cultivation is not demanded1,2. Cyst-based toxicity assays are cheap, continuously available, simple and reliable and are thus an important answer to routine needs of toxicity screening, for industrial monitoring requirements or for regulatory purposes3. The proposed method involves the mortality as an endpoint. The numbers of survivors were counted and percentage of deaths were calculated. Larvae were considered dead if they did not exhibit any internal or external movement during several seconds of observation4. This procedure was standardized testing a reference substance (Sodium Dodecyl Sulfate); some results are reported in this work. This article accompanies a video that describes the performance of procedural toxicity testing, showing all the steps related to the protocol. PMID:22525984

Manfra, Loredana; Savorelli, Federica; Pisapia, Marco; Magaletti, Erika; Cicero, Anna Maria

2012-01-01

402

Use of bioassay-based whole effluent toxicity (WET) tests to predict benthic community response to a complex industrial effluent  

Microsoft Academic Search

Whole effluent toxicity (WET) tests are a usefulmonitoring tool because they provide a rapid andreplicable measure of the potential ecotoxicologicaleffect of effluents. Although WET tests have beenincorporated into toxicity-based effluent limits toprotect receiving systems from adverse effects, fewstudies have attempted to quantitativelyfield-validate laboratory-derived toxicity thresholds.In this study, we examine the ability of WET tests topredict response thresholds of an invertebratecommunity

Helen C. Sarakinos; Joseph B. Rasmussen

1997-01-01

403

Developing guidance on statistics for determining endpoints in Canadian toxicity tests  

SciTech Connect

A growing concern among Canadian toxicologists in government, private consulting, and industry regarding the need for better guidance, and practice, in the determination of toxicity test endpoints led Environment Canada in 1993 to form a Statistical Advisory Committee and start the development of statistical guidelines. Work is underway on a statistical guidance document for toxicological testing. The basic objective is to present sound statistical guidance on reporting toxicity test results, including choice of endpoints and methods of estimation. Specific objectives include: (1) consideration of the assumptions and characteristics underlying different methods of endpoint estimation and recommendations on which to use; (2) methods of assessing goodness-of-fit of models used for estimating endpoints, and the importance of reporting these; (3) recognition of deficient and irregular data, remedies available, and when to use them; and (4) the statistical principles of good test design. Consideration will be given to the use of hypothesis testing vs point estimation, the use of non-linear estimation of the ICp, the problems presented by hormesis (i.e. stimulation at low concentrations), and the analysis of dual-response tests (e.g. survival and reproduction in one test). The document is aimed at all parties involved in the conduct of toxicity tests or interpretation of results and is intended to complement the instructions in the existing biological test methods of Environment Canada.

Scroggins, R.P. [Environment Canada, Ottawa, Ontario (Canada); Atkinson, G.F. [Environment Canada, Hull, Quebec (Canada); Sprague, J.B. [Sprague Associates Ltd., Salt Spring Island, British Columbia (Canada)

1995-12-31

404

Static renewal tests using Anodonta imbecillus (freshwater mussels). Anodonta imbecillis copper sulfate reference toxicant test, Clinch River-Environmental Restoration Program (CR-ERP)  

SciTech Connect

Reference toxicant testing using juvenile freshwater mussels was conducted as part of the CR-ERP biomonitoring study of Clinch River sediments to assess the sensitivity of test organisms and the overall performance of the test. Tests were conducted using moderately hard synthetic water spiked with known concentrations of copper as copper sulfate. Toxicity testing of copper sulfate reference toxicant was conducted from May 12--21, 1993. The organisms used for testing were juvenile fresh-water mussels (Anodonta imbecillis). Results from this test showed an LC{sub 50} value of 1.12 mg Cu/L which is lower than the value of 2.02 mg Cu/L obtained in a previous test. Too few tests have been conducted with copper as the toxicant to determine a normal range of values. Attachments to this report include: Toxicity test bench sheets and statistical analyses; Copper analysis request and results; and Personnel training documentation.

Simbeck, D.J.

1993-12-31

405

An Apparatus for Oxygenating Test Solutions in which Fish are used as Test Animals for Evaluating Toxicity  

Microsoft Academic Search

An apparatus is described which may be used to supply adequate concentrations of dissolved oxygen to fish test jars without “blowing out” volatile toxic components. The apparatus provides for an interface contact between pure oxygen and the sample for gentle agitation to facilitate adequate oxygen absorption and diffusions. Experimental data prove that the use of the apparatus has no apparent

W. B. Hart; Roy F. Weston; J. G. Demann

1948-01-01

406

PREDICTING CHRONIC LETHALITY OF CHEMICALS TO FISHES FROM ACUTE TOXICITY TEST DATA: THEORY OF ACCELERATED LIFE TESTING  

EPA Science Inventory

A method for modeling aquatic toxicity date based on the theory of accelerated life testing and a procedure for maximum likelihood fitting the proposed model is presented. he procedure is computerized as software, which can predict chronic lethality of chemicals using data from a...

407

Development of a chronic sediment toxicity test for marine benthic amphipods  

SciTech Connect

The results of the research effort culminated in the development of a research method for assessing the chronic toxicity of contaminated marine and estuarine sediments using the benthic amphipod, Leptocheirus plumulosus. The first chapter describes the efforts at collecting, handling, and culturing four estuarine amphipods from Chesapeake Bay, including L. plumulosus. This chapter includes maps of the distribution and abundance of these amphipods within Chesapeake Bay and methodologies for establishing cultures of amphipods which could be readily adopted by other laboratories. The second chapter reports the development of acute and chronic sediment toxicity test methods for L. plumulosus, its sensitivity to non-contaminant environmental variables, cadmium, two polynuclear aromatic hydrocarbons, and contaminated sediment from Baltimore Harbor, MD. The third chapter reports the authors attempts to develop a chronic sediment toxicity test with Ampelisca abdita.

DeWitt, T.H.; Redmond, M.S.; Sewall, J.E.; Swartz, R.C.

1992-12-01

408

Chip-based liver equivalents for toxicity testing--organotypicalness versus cost-efficient high throughput.  

PubMed

Drug-induced liver toxicity dominates the reasons for pharmaceutical product ban, withdrawal or non-approval since the thalidomide disaster in the late-1950s. Hopes to finally solve the liver toxicity test dilemma have recently risen to a historic level based on the latest progress in human microfluidic tissue culture devices. Chip-based human liver equivalents are envisaged to identify liver toxic agents regularly undiscovered by current test procedures at industrial throughput. In this review, we focus on advanced microfluidic microscale liver equivalents, appraising them against the level of architectural and, consequently, functional identity with their human counterpart in vivo. We emphasise the inherent relationship between human liver architecture and its drug-induced injury. Furthermore, we plot the current socio-economic drug development environment against the possible value such systems may add. Finally, we try to sketch a forecast for translational innovations in the field. PMID:23722971

Materne, Eva-Maria; Tonevitsky, Alexander G; Marx, Uwe

2013-09-21

409

Natural sunlight and residual fuel oils are an acutely lethal combination for fish embryos.  

PubMed

The majority of studies characterizing the mechanisms of oil toxicity in fish embryos and larvae have focused largely on unrefined crude oil. Few studies have addressed the toxicity of modern bunker fuels, which contain residual oils that are the highly processed and chemically distinct remains of the crude oil refinement process. Here we use zebrafish embryos to investigate potential toxicological differences between unrefined crude and residual fuel oils, and test the effects of sunlight as an additional stressor. Using mechanically dispersed oil preparations, the embryotoxicity of two bunker oils was compared to a standard crude oil from the Alaska North Slope. In the absence of sunlight, all three oils produced the stereotypical cardiac toxicity that has been linked to the fraction of tricyclic aromatic compounds in an oil mixture. However, the cardiotoxicity of bunker oils did not correlate strictly with the concentrations of tricyclic compounds. Moreover, when embryos were sequentially exposed to oil and natural sunlight, the bunker oils produced a rapid onset cell-lethal toxicity not observed with crude oil. To investigate the chemical basis of this differential toxicity, a GC/MS full scan analysis was used to identify a range of compounds that were enriched in the bunker oils. The much higher phototoxic potential of chemically distinct bunker oils observed here suggests that this mode of action should be considered in the assessment of bunker oil spill impacts, and indicates the need for a broader approach to understanding the aquatic toxicity of different oils. PMID:20435358

Hatlen, Kristin; Sloan, Catherine A; Burrows, Douglas G; Collier, Tracy K; Scholz, Nathaniel L; Incardona, John P

2010-08-01

410

Acute toxicity tests and meta-analysis identify gaps in tropical ecotoxicology for amphibians.  

PubMed

Amphibian populations are declining worldwide, particularly in tropical regions where amphibian diversity is highest. Pollutants, including agricultural pesticides, have been identified as a potential contributor to decline, yet toxicological studies of tropical amphibians are very rare. The present study assesses toxic effects on amphibians of 10 commonly used commercial pesticides in tropical agriculture using 2 approaches. First, the authors conducted 8-d toxicity assays with formulations of each pesticide using individually reared red-eyed tree frog (Agalychnis callidryas) tadpoles. Second, they conducted a review of available data for the lethal concentration to kill 50% of test animals from the US Environmental Protection Agency's ECOTOX database to allow comparison with their findings. Lethal concentration estimates from the assays ranged over several orders of magnitude. The nematicides terbufos and ethoprophos and the fungicide chlorothalonil were very highly toxic, with evident effects within an order of magnitude of environmental concentrations. Acute toxicity assays and meta-analysis show that nematicides and fungicides are generally more toxic than herbicides yet receive far less research attention than less toxic herbicides. Given that the tropics have a high diversity of amphibians, the findings emphasize the need for research into the effects of commonly used pesticides in tropical countries and should help guide future ecotoxicological research in tropical regions. PMID:24934557

Ghose, Sonia L; Donnelly, Maureen A; Kerby, Jacob; Whitfield, Steven M

2014-09-01