bluuebunny/crossref_metadata_2025_split huggingface dataset:
Site-specific marine water-quality criterion for cyanide
Authors: Brix Kevin V , Cardwell Rick D , Henderson Douglas G , Marsden Arnold R 
Published: March 2010

Abstract
A site-specific marine water–quality criterion for cyanide was developed for Puget Sound, Washington, USA. The U.S. Environmental Protection Agency (U.S. EPA) national cyanide water-quality criterion is driven by toxicity data for the eastern rock crab, Cancer irroratus, a species not resident to the U.S. western coast (West Coast). The reported LC50 for C. irroratus is six times lower than any other marine species tested. Cyanide acute toxicity tests were conducted using first stage zoeae of all four species of Cancer spp. resident to Puget Sound to develop a site-specific criterion for this water body. Testing with Puget Sound Cancer spp. reveals sensitivities 24 times less, on average, than C. irroratus. Recalculation of the Puget Sound water-quality criterion for cyanide, by substituting the new Cancer spp. data for the C. irroratus data, results in water-quality criterion protecting marine life against acute and chronic toxicity of 9.4 and 2.9 μg/L cyanide, compared to the U.S. EPA national value of 1.0 μg/L for both acute and chronic toxicity.
Effect of substituent size and dimensionality on potency of phenolic xenoestrogens evaluated with a recombinant yeast assay
Authors: Schultz T Wayne , Sinks Glendon D , Cronin Mark TD 
Published: March 2010

AbstractEstrogenicity was assessed using the Saccharomyces cerevisiae-based Lac-Z reporter assay and was reported as the logarithm of the inverse of the 50% molar β-galactosidase activity (log[EC50−1]). Previous studies indicated that the position, size, and shape of the nonphenolic moiety of xenoestrogens affects potency. In an effort to quantify the relationship between the size and shape of the nonphenolic moiety and estrogenic potency, a series of primarily hydrocarbon, para-substituted phenols were evaluated. There is a general trend of increase in estrogenicity with increased substituent size. Attempts were made to correlate estrogenic activity with a variety of molecular parameters. These parameters included two-dimensional molecular connectivity and other topological indices, molecular orbital properties and other assorted steric properties, as well as hydrophobicity. Regression analysis revealed that hydrophobicity, because of its colinearity with size, was moderately correlated with estrogenic activity (r2adj = 0.431). Among the parameters describing the bulk and/or shape of the molecule, the second-order path molecular connectivity for the substituent (2χp(sub) was the single best parameter correlated with estrogenicity. It modeled activity by the relationship log(EC50−1) = 0.925(2χp(sub) + 3.47; n = 28, s = 0.37, r2adj = 0.868, f = 179, p &gt; 0.0001. In this model, the active chemical domain is defined by the presence of the para-phenolic ring, while the potency is quantified by the values of the substituent connectivity index. A comparison of 3-, 5-, and 7-d estrogenicity and potency ratio, as compared with 17-β-estradiol, showed some compounds that were not active after the third day but that were active on the fifth and seventh days of exposure. Potency varied with length of exposure, but the potency ratio did not change. These results suggest that activity with this assay should be reported after 5 d of exposure.
An in situ system for exposing aquatic invertebrates to contaminated sediments
Authors: Crane Mark , Higman Mia , Olsen Tony , Simpson Peter , Callaghan Amanda , Fisher Tom , Kheir Rania 
Published: March 2010

AbstractAn in situ system was developed for exposing benthic invertebrates directly to contaminated sediments without exposure to natural overlying waters. This system was used to expose fourth instar Chironomus riparius Meigen larvae for 48 h at 13 uncontaminated river sites across southeast England and at sites along the contaminated River Aire in Yorkshire. Recovery of surviving C. riparius from uncontaminated sites was good (&gt;65%) except when indigenous predatory insect larvae were trapped within test systems. Recovery of survivors from the uncontaminated upstream site in the River Aire was also good (mean survival at Gargrave = 70%), but survival at the two contaminated downstream sites was significantly lower (mean survival of 17.5% at Esholt and 10% at Calverley Bridge). This study has shown that sediments can be isolated from overlying water and effectively bioassayed in situ.
Cadmium accumulation and its effects in growing pheasants Phasianus colchicus (L.)
Authors: Świergosz Renata , Kowalska Anna 
Published: March 2010

Abstract
The aim of the study was to determineCdaccumulationand to assess its effects ontissue s ructure, levels of Fein the tissues, and levels of hematocrit and hemoglobin (Hb) in growing pheasants (Phasianus colchicus). During the three-week experiment, the birds were given food contaminated with 0.05, 40, or 70 μg Cd/g. The birds were weighed and sacrificed at 7-d intervals, and the liver, kidney, testes, muscles, and femur were dissected. Blood samples were taken before sacrifice. Livers were weighed at the seventh and 21st days. The Cd concentrations in all tissues and Fe levels in liver, kidney, muscles, and bone were measured at the seventh, 14th, and 21st days of exposure. Metals were determined by atomic absorption spectrometry. Kidney, liver, and testes were taken for histological analyses under a light microscope. Accumulation of Cd in the tissues was proportional to the dose and duration of exposure. The highest Cd concentration (∼142 μg Cd/g [dry wt]) was found in the kidneys of pheasants fed 70 μg Cd/g. The lowest Cd concentrations were found in muscle (0.03–1.08 μg/g [dry wt]). The mean levels of Cd in the blood of pheasants fed low and high doses of Cd were 0.048 and 0.095 μg/ml, respectively. The Cd accumulation in the tissues caused decreasing Fe and Hb levels in the tissues. The Fe decrease stimulated hematopoiesis in the liver. Despite this, Hb levels were not kept at normal values. Pathological changes from Cd exposure were found in the liver and testes, but the most severe damage was in the kidney. The growth of the pheasants was also slightly retarded. It may be concluded that accumulation of Cd at these levels, which also occurs in the tissues of wild birds from contaminated areas, may cause the same pathological changes and physiological dysfunction.
Use of freshwater rotifer Brachionus calyciflorus in screening assay for potential endocrine disruptors
Authors: Preston Benjamin L , Snell Terry W , Robertson Tish L , Dingmann Brian J 
Published: March 2010

Abstract
eports of the effectsofendocrinedisruptorsonaquatic invertebrates arebecoming increasingly common. However, little is known about the endocrine systems of most aquatic invertebrates, limiting the development of assays based on endocrine mechanisms. As a result, endocrine disruption is often inferred through the effects caused by the chemical of interest, making it difficult to rule out other mechanisms of toxicity. To be a good candidate for an endocrine disruptor, effects should be observed in processes known to be under endocrine control, at life stages where endocrine signals are known to be active, and at concentrations below acute and chronic toxic effects. We developed a 96-h reproductive assay using the freshwater rotifer Brachionus calyciflorus to screen for potential endocrine disruptors and examined cadmium, chlorpyrifos, naphthol, pentachlorophenol, estradiol, methoprene, precocene, nonylphenol, flutamide, and testosterone for effects on asexual and sexual reproduction. Flutamide, testosterone, and nonylphenol inhibited fertilization of sexual females at concentrations of 1, 10, and 50 μg/L, respectively. The fertilization no-observable-effect concentrations (NOECs) for these compounds were 5 to 200 times lower than previously described reproduction NOECs for B. calyciflorus. Sexual reproduction was inhibited with no effects on asexual reproduction, increasing the likelihood that these specific reproductive effects occurred through an endocrine mechanism. Rotifer reproduction assays may be a useful, rapid, and inexpensive method for screening compounds suspected to have endocrine disrupting activity in aquatic invertebrates.
Cellular and molecular basis of cadmium-induced deformities in zebrafish embryos
Authors: Cheng Shuk Han , Wai Albert Wing Kong , So Chun Hung , Wu Rudolf Shiu Sun 
Published: March 2010

Abstract
Cadmium is known to cause developmental defects in a varietyof vertebrate species, but relatively little is known about the underlying molecular mechanisms. In this study, we used zebrafish (Danio rerio) embryos as a model system to investigate cadmium-induced toxicities. Fertilized embryos collected at 5-h after fertilization were incubated for 18 h in culture media containing 1 to 1, 000 μM CdCl2. The median embryolethal concentration (LC50) was 168 μM, whereas the median effect concentration (EC50) for total adverse effect (mortality and developmental defects) was 138 μM. Six major types of deformities were observed: head and eye hypoplasia, hypopigmentation, cardiac edema, yolk sac abnormalities, altered axial curvature, and tail malformations. The frequency of malformations increased with cadmium concentration. Somites of embryos with altered axial curvature were investigated using the antimyosin antibody MF-20. This study demonstrated, to our knowledge for the first time, reduced myotome formation in cadmium-induced spinal deformity. Embryos with head and eye hypoplasia were studied using the anti-neural tissue antibody zns-2, and a poorly developed central nervous system was revealed. Head and eye hypoplasia were associated with lack of expression of the sonic hedgehog gene, which controls the patterning of the neural tube and somites. Genes involved in tail formations, such as evenskipped 1 and no tail, were ectopically expressed in embryos with tail malformations. Our data support the hypothesis that fish embryonic malformations induced by cadmium might be mediated through ectopic expression of developmental regulatory genes.
Toxicity of pesticides to aquatic microorganisms: A review
Authors: DeLorenzo Marie E , Scott Geoffrey I , Ross Philippe E 
Published: March 2010

Abstract
Microorganisms contribute significantly to primary production, nutrient cycling, and decomposition in estuarine ecosystems; therefore, detrimental effects of pesticides on microbial species may have subsequent impacts on higher trophic levels. Pesticides may affect estuarine microorganisms via spills, runoff, and drift. Both the structure and the function of microbial communities may be impaired by pesticide toxicity. Pesticides may also be metabolized or bioaccumulated by microorganisms. Mechanisms of toxicity vary, depending on the type of pesticide and the microbial species exposed. Herbicides are generally most toxic to phototrophic microorganisms, exhibiting toxicity by disrupting photosynthesis. Atrazine is the most widely used and most extensively studied herbicide. Toxic effects of organophosphate and organochlorine insecticides on microbial species have also been demonstrated, although their mechanisms of toxicity in such nontarget species remain unclear. There is a great deal of variability in the toxicity of even a single pesticide among microbial species. When attempting to predict the toxicity of pesticides in estuarine ecosystems, effects of pesticide mixtures and interactions with nutrients should be considered. The toxicity of pesticides to aquatic microorganisms, especially bacteria and protozoa, is an area of research requiring further study.
Response of zooplankton communities to liquid creosote in freshwater microcosms
Authors: Sibley Paul K , Harris Megan L , Bestari Ketut T. (Jim) , Steele Tracey A , Robinson Richard D , Gensemer Robert W , Day Kristen E , Solomon Keith R 
Published: March 2010

Abstract
In this study, the response of zooplankton communities to single applications of liquid creosote in model aquatic ecosystems (microcosms) was evaluated. Liquid creosote was applied to 14 microcosms at concentrations ranging from 0.06 to 109 mg/L. Two microcosms served as controls. Zooplankton samples were collected from each microcosm on days 7 and 1 before treatment and on days 2, 5, 7, 14, 21, 28, 43, 55, and 83 following treatment. Temporal changes (response-recovery) in composition of the zooplankton community were assessed using principal response curves (PRC). Creosote induced a rapid, concentrationdependent reduction in zooplankton abundance and number of taxa, with maximum response (50–100% reduction in population densities) occurring between 5 and 7 d after treatment. Taxa that dominated at the time of treatment experienced the greatest impact, as indicated by large, positive species weight values (&gt;1) from the PRC analysis. Many of these taxa recovered to pretreatment or control levels during the posttreatment period, with the degree and duration of recovery being strongly dependent on concentration. Creosote had little effect on species composition at less than 1.1 mg/L, because changes in the types and relative proportion of species contributed from Cladocera, Rotifera, and Copepoda were comparable to those observed in control microcosms. However, a significant shift in species composition was observed at concentrations greater than 1.1 mg/L; these microcosms were generally dominated by low numbers of rotifers, some of which had not been collected before treatment. Community-level effect concentrations (EC50s) were 44.6 and 46.6 μg/L at 5 and 7 d, respectively, based on nominal creosote. Corresponding no-effect concentrations were 13.9 and 5.6 μg/L. The results of this field study indicate that creosote may pose a significant risk to zooplankton communities at environmental concentrations potentially encountered during spills and/or leaching events.
Effects of nonylphenol ethoxylate exposure on reproductive output and bioindicators of environmental estrogen exposure in fathead minnows, Pimephales promelas
Authors: Nichols Krista M , Snyder Erin M , Snyder Shane A , Pierens Susan L , Miles-Richardson Stephanie R , Giesy John P 
Published: March 2010

Abstract
Nonylphenol ethoxylates (NPEOs) were evaluated in the laboratory for potential effects on the reproductive physiology and fecundity of fathead minnows (Pimephales promelas). Groups of three adult male and three female fathead minnows were exposed in a continuous flow-through system to 0, 0.21, 0.65, 2.1, or 7.9 μg NPEO/L for 42 d. Rabbit anti-goldfish vitellogenin (VTG) antiserum was prepared and a competitive enzyme-linked immunosorbent assay (ELISA) was adapted for measurement of plasma VTG in fish following exposure. Plasma 17β-estradiol (E2) and testosterone (T) were also quantified by ELISA at the end of the exposure. Neither survival nor fecundity of fathead minnows exhibited a concentration-dependent response to NPEOs. No significant differences were observed in plasma VTG concentrations among treatments for males or females. Mean plasma VTG concentrations in females ranged from 291.7 to 895.1 μ VTG/ml among treatments and did not overlap with mean concentrations measured in the plasma of males, which ranged from less than the method detection limit (0.27 μg VTG/ml) to 3.2 μg VTG/ml. Plasma E2 concentrations exhibited a significant difference between males and females within all NPEO treatments, but no differences were observed among treatments. Similarly, plasma T concentrations did not exhibit a concentration-dependent response to NPEOs.
Sublethal effects of silver in zooplankton: Importance of exposure pathways and implications for toxicity testing
Authors: Hook Sharon E , Fisher Nicholas S 
Published: March 2010

Abstract
In aquatic environments, organisms are exposed to contaminants via direct uptake from water and bytrophic transfer. However, most toxicity tests only examine uptake via the dissolved phase. We compared the response of marine and freshwater crustacean zooplankton to silver following dissolved and food exposure. Silver, like other metals, concentrates in aquatic food chains and may exert toxicity. In standard solute exposure toxicity tests, Ag is toxic to zooplankton at concentrations of 400 nM for marine copepods and 100 nM for freshwater cladocerans, concentrations far greater than those in most waters. However, if Ag is accumulated from algal food, reproductive success decreases by &gt;50% when algae are exposed to only 1 nM Ag in copepods and 0.5 nM Ag in cladocerans. These concentrations are within an order of magnitude of those found in contaminated estuaries. Following dietary exposure, decreased egg production and viability occur when tissue Ag concentrations increase three- to fourfold to 0.3 ppm in cladocerans and 0.5 ppm in copepods. Assimilated Ag depresses egg production by reducing yolk protein deposition and ovarian development. Our results indicate that ecologically relevant toxicity tests should consider sublethal effects of contaminants obtained from food since these effects cannot be predicted from exposures to only dissolved contaminants.
Uptake, effects, and metabolism of cyanobacterial toxins in the emergent reed plant Phragmites australis (Cav.) Trin. ex steud
Authors: Pflugmacher Stephan , Wiegand Claudia , Beattie Kenneth A , Krause Eberhard , Steinberg Christian E W , Codd Geoffrey A 
Published: March 2010

Abstract
The commonly occurring cyanobacterial toxin microcystin-LR (MC-LR) was rapidly taken up by the emergent reed plant Phragmites australis with clear distribution in the different cormus parts of the plant. Highest uptake was detected in the stem, followed by the rhizome. Enzyme extracts of the rhizome system, the stem, and the leaf revealed the presence of soluble glutathione S-transferases (sGST) measured with the model substrate 1-chloro-2,4-dinitrobenzene. A significant elevation of sGST activity in the rhizome and stem parts of P. australis was detected after a 24-h exposure to 0.5 μg/L MC-LR. Rhizome, stem, and leaf tissues were also able to conjugate several microcystin toxins. However, no conjugation, either chemical nor enzymatic, was detected using the related cyanobacterial toxin nodularin as substrate. Highest glutathione S-transferase activity for the toxin substrates was detected in the pkat/mg range in the stem of P. australis. For MC-LR, a complete metabolism from the formation of a glutathione conjugate to the degradation of a cysteine conjugate in all cormus parts of the plant is reported. The stepwise degradation of the MC-LR-glutathione conjugate to a γ-glutamylcysteine and a cysteine conjugate was demonstrated by comparison with chemically formed reference compounds and by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. This is the first evidence for the uptake and metabolism of cyanobacterial toxins by an emergent aquatic macrophyte.
Negative correlation between plasma thyroid hormone levels and chlorinated hydrocarbon levels accumulated in seals from the coast of Hokkaido, Japan
Authors: Chiba Issei , Sakakibara Akihito , Goto Yoko , Isono Takeomi , Yamamoto Yukie , Iwata Hisato , Tanabe Shinsuke , Shimazaki Kenji , Akahori Fumiaki , Kazusaka Akio , Fujita Shoichi 
Published: March 2010

Abstract
Chlorinated hydrocarbon (CHC) levels in the blubber of larga seals (Phoca largha) and ribbon seals (Phoca fasciata) collected from the coastal waters of Hokkaido, Japan, were determined in order to assess the hormonal effects of CHC exposure in free-ranging pinnipeds. Plasma thyroid hormone levels, including total thyroxine (T4), free thyroxine (free T4), total triiodothyronine (T3), and free triiodothyronine (free T3), were also measured. Higher concentrations of polychlorinated biphenyl congeners (PCBs), dichlorodiphenyltrichloroethane and its metabolites, and chlordane compounds were found in the range of 380 to 2,600 ng/g, 350 to 2,600 ng/g, and 120 to 760 ng/g on a wet-weight basis, respectively. Spearman rank correlation analyses showed that in larga seals, plasma total T3 and free T3 levels negatively correlated with levels of all the CHCs analyzed, although there was no such correlation between total or free T4 levels and CHC concentrations. In ribbon seals, total T3 levels significantly decreased with an increase of di-ortho PCB (PCB170 and 180) residues. These findings indicated that the plasma T3 deficiency could be associated with some CHC exposure in larga and ribbon seals and that the responses of plasma thyroid hormones may be useful biomarkers for CHC exposure in ribbon seals.
Effect of copper on hatching and development of larvae of the estuarine crab Chasmagnathus granulata (Decapoda, Brachyura)
Authors: Zapata Valeria , Greco Laura López , Rodríguez Enrique M 
Published: March 2010

Abstract
Ovigerous females of the estuarine crab Chasmagnathus granulata were exposed to 0.05, 0.1, 0.5, and 3 mg/L of copper during the egg incubation period. Regarding egg loss, a higher effect was observed at higher copper concentrations: 80% of the females lost their eggs at 0.5 mg/L, whereas no hatching was seen in those exposed to 3 mg/L. A significant decrease was found in the number of hatched larvae in females exposed to 0.5 mg/L, as was a significant decrease in the duration of the incubation period. In addition, several morphological abnormalities were seen and observed. Hydropsy and atrophy of the dorsal spine, pleon, and maxillipeds occurred at the higher copper concentrations, as found in previous studies with other pollutants. Hyperpigmentation of the cephalothorax and pleon was the only abnormality observed at every concentration assayed. Hypopigmented eyes were also evident. This pathology showed that among all defects observed at 0.5 mg/L, hypopigmented eyes had the highest incidence and might be a specific response to copper.
Assessment of sediment contamination by spermiotoxicity and embryotoxicity bioassays with sea urchins (Paracentrotus lividus) and oysters (Crassostrea gigas)
Authors: Geffard Olivier , Budzinski Helene , Augagneur Sylvie , Seaman Matthias N L , His Edouard 
Published: March 2010

Abstract
Gametes (sperm) and fertilized eggs (embryos) of the Mediterranean sea urchin, Paracentrotus lividus, and the Japanese oyster, Crassostrea gigas, were used to investigate the toxicity of two marine sediments, one polluted by polycyclic aromatic hydrocarbons (PAH) and the other by heavy metals. The sediment samples were freeze-dried for storage, and three different treatments were used for analysis: whole sediment, unfiltered elutriate, and filtered elutriate. The two sediments were toxic to sea urchin spermatozoa but not to oyster spermatozoa, and embryotoxicity was almost always the more sensitive endpoint for toxicity assessment. As a rule, whole sediment was more toxic than the elutriates by nearly two orders of magnitude. With respect to embryotoxicity, the whole sediments and the elutriates of the PAH-contaminated sediment were more toxic to oyster embryos, whereas the elutriates of the sediment polluted by heavy metals had stronger effects on sea urchin embryos. The results confirm that bioassays with Japanese oyster embryos provide a more sensitive appraisal of toxicity in the marine environment than bioassays with other developmental stages. As a whole, Mediterranean sea urchins and Japanese oysters were similar in overall sensitivity and are therefore both equally suited as bioassay organisms, but tests with oysters are more reproducible because of the better performance of the controls.