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Environmental Toxicology (environmental + toxicology)

Distribution by Scientific Domains

Life Sciences	62%

Selected Abstracts

Field assessments in conjunction with whole effluent toxicity testing

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 1 2000
Thomas W. La Point
Abstract 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. [source]

From Quantal Counts to Mechanisms and Systems: The Past, Present, and Future of Biometrics in Environmental Toxicology

BIOMETRICS, Issue 2 2000
A. John Bailer
Summary. As appreciation for human impact on the environment has developed, so have the experimental systems and associated statistical tools that quantify this impact. Toxicological study in particular has grown in its complexity and its need for advanced statistical support. Within this perspective, we describe statistical practice in environmental toxicology and risk assessment. We present two case studies, one from mammalian toxicology and one from aquatic toxicology, that highlight the evolution of statistical practice in environmental toxicology. [source]

Assessing the toxicity of TBBPA and HBCD by zebrafish embryo toxicity assay and biomarker analysis

ENVIRONMENTAL TOXICOLOGY, Issue 4 2009
Jun Hu
Abstract Tetrabromobisphenol A (TBBPA) and hexabromocyclododecane (HBCD) are two of the most widely used brominated flame retardants (BFRs). The biological toxicity effect of TBBPA and HBCD was studied by means of zebrafish embryo toxicity assays in combination with three biomarkers, including superoxide dismutase (SOD), lipid peroxidation, (LPO), and heat shock protein (Hsp70). The standard zebrafish embryo assay showed that high concentrations of TBBPA (,0.75 mg/L) can cause lethality or malformation. For HBCD within the concentration range (0.002,10 mg/L), no endpoint was observed. Furthermore, SOD activities of zebrafish embryos exposed to TBBPA were increased with the increasing concentrations. SOD activities in the group treated by HBCD showed an increase followed by a decline. Regardless of TBBPA or HBCD, LPO were increased along with the increase of the concentration. The change pattern of Hsp70 levels was the same with LPO. All these results showed that TBBPA and HBCD could cause oxidative stress and Hsp70 overexpression, inducing acute toxicity to zebrafish embryo in a short-term exposure. The study also indicates that the zebrafish embryo assay in combination with the biomarkers is effective in aquatic environmental toxicology and risk assessment. © 2008 Wiley Periodicals, Inc. Environ Toxicol, 2009. [source]

"What exactly are you inferring?"

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2008
A closer look at hypothesis testing
Abstract This critical review describes the confused application of significance tests in environmental toxicology and chemistry that often produces incorrect inferences and indefensible regulatory decisions. Following a brief review of statistical testing theory, nine recommendations are put forward. The first is that confidence intervals be used instead of hypothesis tests whenever possible. The remaining recommendations are relevant if hypothesis tests are used. They are as follows: Define and justify Type I and II error rates a priori; set and justify an effect size a priori; do not confuse p(E | H0) and p(H0 | E); design tests permitting Positive Predictive Value estimation; publish negative results; estimate a priori, not post hoc, power; as warranted by study goals, favor null hypotheses that are not conventional nil hypotheses; and avoid definitive inferences from isolated tests. [source]

Mentoring early career professionals in the society of environmental toxicology and chemistry North America

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005
Christopher G. Ingersoll President
No abstract is available for this article. [source]

A test of the community conditioning hypothesis: Persistence of effects in model ecological structures dosed with the jet fuel jp-8

ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2000
Wayne G. Landis
Abstract The foundation of the community conditioning hypothesis, the persistence of effects, was tested in a series of microcosm experiments. Experiments were conducted with the water-soluble fraction of the turbine fuel JP-8 using the standard protocols for the standardized aquatic microcosm (SAM). A repeat trial was conducted using the SAM protocol but with a 126-d test period, twice the standard duration. The results were examined using a variety of conventional univariate, multivariate, and graphical techniques. The principal conclusions were as follows. Effects are persistent in these model ecological systems long after the degradation of the toxicant. Patterns of impacts are detectable at concentrations 15 times lower than an experimentally derived single-species EC50. The replicate experiments are not replicable in the specific, but the broad pattern of the disruption of algal- herbivore dynamics followed by more subtle effects are consistently repeated. The durability of the indirect effects and therefore the information about historical events appears to be a consistent feature of these microcosm systems. The identity of the treatment groups persists. The critical features of the community conditioning hypothesis,persistence of information within ecologicalsystems and the reappearance of patterns and therefore the nonequilibrium dynamics,are again confirmed. The implications of these findings for environmental toxicology, monitoring, and ecological risk assessment are discussed. [source]

Microsatellite primers for the Atlantic coastal killifish, Fundulus heteroclitus, with applicability to related Fundulus species

MOLECULAR ECOLOGY RESOURCES, Issue 2 2005
STEPHANIE M. ADAMS
Abstract The mummichog (Fundulus heteroclitus), a common Atlantic coastal killifish, is a model vertebrate species for the study of molecular genetic variation in natural populations and of environmental toxicology. We report the development of a set of 20 microsatellite loci in this species. Average expected heterozygosity across all loci was 0.84 (range: 0.60,0.97), revealing a high level of variability at most loci. A survey of seven additional Fundulus species yielded one or two robust amplification products in over half (63%) of the species,primer combinations tested. Therefore, many of these loci will also prove useful in studies of other members of the genus Fundulus. [source]