bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formation of benzo[a]pyrene and 7,12-dimethylbenz[a]anthracene adducts in vascular endothelia of cytochrome P4501A–induced chicken embryos
Authors: Granberg Lizette , Brunström Björn , Brandt Ingvar 
Published: November 2004

Abstract
Polycyclic aromatic hydrocarbons (PAHs) are widespread in the environment and birds may be exposed to PAHs via diet, from preening feathers contaminated with oil, or through contamination of the eggshell during embryo development. In the present study, tissue distribution and the cell-specific binding of two labeled PAHs, benzo[a]pyrene ([3H]BaP) and 7,12-dimethylbenz[a]anthracene ([3H]DMBA), were examined in chicken embryos exposed in ovo to CYP1A inducers. Tape-section auto-radiograms revealed high concentrations of radioactivity in the bile, liver, kidneys, heart, and leptomeninges. Light microscopy autoradiography of solvent-extracted tissue slices showed a high and selective binding in endothelial cells in certain blood vessels in brain, heart, lung, and chest muscle. Binding was also observed in blood vessel endothelial cells in the chorioallantoic membrane (CAM), an extraembryonal tissue lining the eggshell. Endothelial binding was confirmed in CAM exposed in vitro, implying that tissue-binding metabolites were formed in situ. The CYP1A inhibitor ellipticine abolished binding in the target endothelial cells in CAM. It is thus concluded that blood vessel endothelia in various tissues in birds can bioactivate environmental contaminants and be targets for their toxicity. In view of its critical position beneath the shell, the CAM could be an important target for toxicants following external exposure in oviparous species.
Ecotoxicologic impacts of agricultural drain water in the Salinas River, California, USA
Authors: Anderson Brian S. , Hunt John W. , Phillips Bryn M. , Nicely Patricia A. , Gilbert Kristine D. , de Vlaming Victor , Connor Valerie , Richard Nancy , Tjeerdema Ronald S. 
Published: November 2004

Abstract
The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California (USA). Large areas of this watershed are cultivated year-round in row crops, and previous laboratory studies have demonstrated that acute toxicity of agricultural drain water to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. We investigated chemical contamination and toxicity in waters and sediments in the river downstream of an agricultural drain water input. Ecological impacts of drain water were investigated by using bioassessments of macroinvertebrate community structure. Toxicity identification evaluations were used to characterize chemicals responsible for toxicity. Salinas River water downstream of the agricultural drain was acutely toxic to the cladoceran Ceriodaphnia dubia, and toxicity to C. dubia was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to the amphipod Hyalella azteca, a resident invertebrate. Toxicity identification evaluations (TIEs) conducted on sediment pore water suggested that toxicity to amphipods was due in part to OP pesticides; concentrations of chlorpyrifos in pore water sometimes exceeded the 10-d mean lethal concentration (LC50) for H. azteca. Potentiation of toxicity with addition of the metabolic inhibitor piperonyl butoxide suggested that sediment toxicity also was due to other non–metabolically activated compounds. Macroinvertebrate community structure was highly impacted downstream of the agricultural drain input, and a number of macroinvertebrate community metrics were negatively correlated with combined TUs of chlorpyrifos and diazinon, as well as turbidity associated with the drain water. Some macroinvertebrate metrics were also correlated with bank vegetation cover. This study suggests that pesticide pollution is the likely cause of ecological damage in the Salinas River, and this factor may interact with other stressors associated with agricultural drain water to impact the macroinvertebrate community in the system.
Sublethal effects of copper on coho salmon: Impacts on nonoverlapping receptor pathways in the peripheral olfactory nervous system
Authors: Baldwin David H. , Sandahl Jason F. , Labenia Jana S. , Scholz Nathaniel L. 
Published: November 2004

Abstract
The sublethal effects of copper on the sensory physiology of juvenile coho salmon (Oncorhynchus kisutch) were evaluated. In vivo field potential recordings from the olfactory epithelium (electro-olfactograms) were used to measure the impacts of copper on the responses of olfactory receptor neurons to natural odorants (L-serine and taurocholic acid) and an odorant mixture (L-arginine, L-aspartic acid, L-leucine, and L-serine) over a range of stimulus concentrations. Increases in copper impaired the neurophysiological response to all odorants within 10 min of exposure. The inhibitory effects of copper (1.0–20.0 μg/L) were dose-dependent and they were not influenced by water hardness. Toxicity thresholds for the different receptor pathways were determined by using the benchmark dose method and found to be similar (a 2.3–3.0 μg/L increase in total dissolved copper over background). Collectively, examination of these data indicates that copper is broadly toxic to the salmon olfactory nervous system. Consequently, short-term influxes of copper to surface waters may interfere with olfactory-mediated behaviors that are critical for the survival and migratory success of wild salmonids.
Sorption of phenanthrene and atrazine by plant cuticular fractions
Authors: Chefetz Benny 
Published: November 2004

Abstract
Several studies have shown selective preservation of plant cuticular materials in soils. However, very little is known about their function as sorbents for the hydrophobic organic contaminants (HOCs) in the soil. In this study, we investigated the sorption and desorption of phenanthrene and atrazine by cuticular fractions of pepper (bulk, dewaxed, nonsaponifiable, and nonhydrolyzable) to better understand the sorptive activity of cuticular matter in soils. The bulk and dewaxed cuticles exhibited carbon-normalized distribution coefficients (Koc) for phenanthrene and atrazine in the range of that reported for soil humic substances, although both samples were rich in aliphatic structures. No hysteresis was observed in the desorption isotherms of either solute. The nonhydrolyzable residue exhibited a very high Koc value for atrazine, whereas the nonsaponifiable sample exhibited the lowest Koc value for both sorbates. Based on solubility parameter data, it is suggested that the nonsaponifiable sample be considered an intermediate between the physical and chemical mixture of pectin and cutan/lignin-like fractions, whereas the dewaxed cuticle is a chemical blending of cutin and pectin. The n-hexane-normalized sorption data suggest that the pepper cuticle can interact specifically with atrazine. This study leads to the conclusion that the contribution of aliphatic-rich plant biopolymers to the sorption of HOCs can be significant because of their preservation and accumulation in soils.
Tenax extraction mimics benthic and terrestrial bioavailability of organic compounds
Authors: ten Hulscher Theodora E. M. , Postma Jaap , den Besten Pieter J. , Stroomberg Gerard J. , Belfroid Angelique , Wegener Jan Willem , Faber Jack H. , van der Pol Joost J. C. , Hendriks A. Jan , van Noort Paul C. M. 
Published: November 2004

Abstract
Biota to sediment accumulation factors (BSAFs) are widely used to describe the potential accumulation of organic contaminants in organisms. From field studies it is known that these BSAFs can vary dramatically between sediments of different origin, which is possibly explained by the variation in bioavailability of organic contaminants in sediments. In the present study it is shown that the variability in BSAF values for different sediment samples obtained at two Dutch freshwater sites could largely be explained by the variation in Tenax-extractable concentrations in these sediments. Variations of a factor of about 50 could be explained. The ratio between concentrations in biota and Tenax-extractable concentrations in sediment varied slightly between sediments and contaminant class, but was close to the theoretically expected value of 2. This is a strong indication that Tenax-extractable concentrations of contaminants in sediments are an excellent indicator of available concentrations.
Joint algal toxicity of phenylurea herbicides is equally predictable by concentration addition and independent action
Authors: Backhaus Thomas , Faust Michael , Scholze Martin , Gramatica Paola , Vighi Marco , Grimme L. Horst 
Published: November 2004

Abstract
Photosynthesis-inhibiting phenylurea derivatives, such as diuron, are widely used as herbicides. Diuron concentrations clearly exceeding the predicted-no-effect concentration have been regularly measured in European freshwater systems. The frequently observed exposure to mixtures of phenylureas additionally increases the hazard to aquatic primary producers. Fluctuating numbers and concentrations of individual toxicants make experimental testing of every potential mixture unfeasible. Thus, predictive approaches to the mixture hazard assessment are needed. For this purpose, two concepts are at hand, both of which make use of known toxicities of the individual components but are based on opposite mechanistic suppositions: Concentration addition is based on the idea of similar mechanisms of action, whereas independent action assumes dissimilarly acting mixture components. On the basis of pharmacological reasoning, it was therefore anticipated that the joint algal toxicity of phenylurea mixtures would be predictable by concentration addition. Indeed, we could demonstrate a high predictive power of concentration addition for these combinations. Surprisingly, however, the opposite concept of independent action proved to be equally valid, because both concepts predicted virtually identical mixture toxicities. This exceptional case has previously been derived from theoretical considerations. Now, the tested phenylurea mixtures serve as an example for the practical relevance of this situation for multicomponent mixtures.
Lethal and sublethal effects of atrazine, carbaryl, endosulfan, and octylphenol on the streamside salamander (Ambystoma barbouri)
Authors: Rohr Jason R. , Elskus Adria A. , Shepherd Brian S. , Crowley Philip H. , McCarthy Thomas M. , Niedzwiecki John H. , Sager Tyler , Sih Andrew , Palmer Brent D. 
Published: November 2004

Abstract
Aricultural contaminants may be contributing to worldwide amphibian declines, but little is known about which agrichemicals pose the greatest threat to particular species. One reason for this is that tests of multiple contaminants under ecologically relevant conditions are rarely conducted concurrently. In this study, we examined the effects of 37-d exposure to the agrichemicals atrazine (4, 40, and 400 μg/L), carbaryl (0.5, 5, and 50 μg/L), endosulfan (0.1, 1, and 10 μg/L for 31 d and 0.1, 10, and 100 μg/L for the last 6 d), and octylphenol (5, 50, and 500 μg/L) and to a solvent control on streamside salamanders (Ambystoma barbouri) in the presence and absence of food. We found that none of the agrichemicals significantly affected embryo survival, but that hatching was delayed by the highest concentration of octylphenol. In contrast to embryos, larval survival was reduced by the highest concentrations of carbaryl, endosulfan, and octylphenol. Growth rates were lower in the highest concentrations of endosulfan and octylphenol than in all other treatments, and the highest concentration of endosulfan caused respiratory distress. Significantly more carbaryl, endosulfan, and octylphenol tanks had larvae with limb deformities than did control tanks. Refuge use was independent of chemical exposure, but 10 μg/L of endosulfan and 500 μg/L of octylphenol decreased larval activity. Systematically tapping tanks caused a greater activity increase in larvae exposed to 400 μg/L of atrazine and 10 μg/L of endosulfan relative to solvent controls, suggesting underlying nervous system malfunction. Hunger stimulated a decrease in refuge use and an increase in activity, but this response was least pronounced in larvae exposed to the highest concentration of any of the four agrichemicals, possibly because these larvae were the most lethargic. More studies are needed that concurrently examine the effect of multiple contaminants on amphibians so we can better identify effective mitigating measures.
Application of toxicity identification evaluation procedures for characterizing produced water using the tropical mysid, Metamysidopsis insularis
Authors: Elias-Samlalsingh Najila , Agard John B. R. 
Published: November 2004

Abstract
Toxicity identification evaluations (TIEs) were performed on seven produced water (PW) effluents from inland discharge facilities operated in Trinidad and Tobago, a Caribbean tropical country with one of the oldest commercial oil industries in the world. The research was performed to determine the presence and magnitude of toxicity and characterize which toxicants are responsible for observed effects. Marine effluent toxicity characterizations with Metamysidopsis insularis revealed high whole acute toxic-unit response for produced water ranged from 8.1 to &gt;17.0 acute toxic-unit (initial toxicity test) and 5.7 to 1,111 acute toxic-unit (baseline toxicity test). Toxicity test results for all sites except one, which had the highest toxicity, are comparative with similar studies on produced water. The toxicological causality of this complex mixture differed for each PW with nonpolar organics being consistently toxic in all samples. Other potential toxicants contributing to overall toxicity to a much lesser extent were metals, ammonia, and volatile organic compounds. With the use of sodium thiosulfate and filtration manipulations for only PW6 sample, there was very slight reduction in toxicity; therefore, oxidants and filterable materials were not a great contributing factor. Whole effluent toxicity also can be attributed to ionic imbalance and the very stable oil-in-water emulsion that consists of fine oil droplets (less than 0.1–10 μm with an average diameter of 2.5 μm). This investigation is the first of its type in Trinidad and demonstrates clearly the applicability of this test method and local test species for evaluating complex effluents in tropical environments.
Biologically incorporated dietary silver has no ionoregulatory effects in American red crayfish (Procambarus clarkii)
Authors: Mann Reinier M. , Grosell Martin , Bianchini Adalto , Wood Chris M. 
Published: November 2004

Abstract
Two silver-contaminated diets were prepared by exposing juvenile rainbow trout for 8 d to waterborne silver thiosulfate as Ag at either 0.1 μg/L (low-Ag diet) or 80 mg/L (high-Ag diet). The level of total Ag accumulated in whole low-Ag fish was below the detection limit of analysis. Whole high-Ag fish accumulated Ag at 21.3 nmol/g. The livers of the low- and high-Ag fish accumulated Ag at 0.43 nmol/g and 1.01 μmol/g, respectively. The Ag-contaminated fish were then fed whole to adult crayfish in an 80-d dietary study to determine the effects of long-term trophic accumulation of Ag. In a second experiment, the livers of the high-Ag trout were fed to juvenile crayfish for either one or five weeks. Accumulation of Ag was demonstrated in both adult and juvenile crayfish. Silver accumulation in juvenile crayfish peaked at approximately 650 nmol/g at three weeks, after which Ag depuration occurred. In adult crayfish that consumed the high-Ag diet, the hepatopancreas accumulated more than 90% of assimilated Ag, rising 1,000-fold over control animals to approximately 740 nmol/g at 80 d. Crayfish that consumed the low-Ag diet had small, statistically insignificant elevations of Ag in some tissues. Dietary Ag had no effect on juvenile crayfish growth or adult mortality. Disturbances in osmoregulation, which are normally associated with acute waterborne Ag exposure, were not detected. Dietary Ag also had no effect on hemolymph concentrations of Na+, Cl−, Ca2+, Mg2+, or Cu; did not affect the concentration kinetics of Na+ or Cl− influx; and had no effect on the activity of gill Na+/K+-dependent adenosine triphosphatase. Hemolymph concentrations of glucose and lactate were similarly unaffected, indicating an absence of stress-related metabolic disturbance. However, a disproportionately low number of ecdysis events occurred among crayfish that consumed the high-Ag diet.
The effect of lead-contaminated soil from canadian prairie skeet ranges on the neutral red retention assay and fecundity in the earthworm Eisenia fetida
Authors: Booth Lynn , Palasz Fil , Darling Colin , Lanno Roman , Wickstrom Mark 
Published: November 2004

Abstract
The sublethal effects of lead (Pb) on the earthworm Eisenia fetida were evaluated in the laboratory using freshly spiked soil and soil collected from Canadian prairie skeet ranges. After a four-week exposure to soil spiked with lead acetate, earthworm neutral red retention time (NRRT), soil Pb concentrations, and earthworm Pb body burdens were measured. Lysosomal NRRT was reduced in a concentration-dependent manner (p &lt; 0.0001), and NRRT was negatively correlated with earthworm Pb body burdens (r = —0.80, p &lt; 0.0001). To evaluate the effects of aged Pb, earthworms were exposed to soil from three skeet ranges, and responses were compared with three matched reference sites. After a four-week exposure, NRRT, growth, fecundity, soil total Pb levels, and earthworm Pb body burdens were measured. The potentially bioavailable fraction of Pb in these sites was measured using a Ca(NO3)2 extraction. Growth and fecundity did not differ significantly between any of the skeet ranges and their reference sites. However, NRRT was significantly reduced in all three ranges compared with their respective reference sites (p &lt; 0.05), indicating that the neutral red retention assay (NRRA) may be useful for detecting toxicity and potential hazards at Pb-contaminated sites. Lysosomal NRRT was negatively correlated with soil Ca(NO3)2-extractable Pb (r = —0.80, p &lt; 0.0001) and soil total Pb (r = —0.73, p = 0.001). Lysosomal NRRT was negatively correlated (r = —0.67, p &lt; 0.002) with earthworm Pb tissue levels.
Effects of pharmaceutical mixtures in aquatic microcosms
Authors: Richards Sean M. , Wilson Christian J. , Johnson David J. , Castle Dawn M. , Lam Monica , Mabury Scott A. , Sibley Paul K. , Solomon Keith R. 
Published: November 2004

Abstract
Pharmaceuticals have a wide range of biological properties and are released into the environment in relatively large amounts, yet little information is available regarding their effects or potential ecological risks. We exposed outdoor aquatic microcosms to combinations of ibuprofen (a nonsteroidal anti-inflammatory drug), fluoxetine (a selective serotonin reuptake inhibitor), and ciprofloxacin (a DNA gyrase—inhibiting antibiotic) at concentrations of 6, 10, and 10 μg/L, respectively (low treatment [LT]); 60, 100, and 100 μg/L, respectively (medium treatment [MT]); and 600, 1,000, and 1,000 μg/L, respectively (high treatment [HT]). We maintained these concentrations for 35 d. Few responses were observed in the LT; however, effects were observed in the MT and HT. Fish mortality occurred in the MT (&lt;35 d) and in the HT (&lt;4 d). Phytoplankton increased in abundance and decreased in diversity (number of taxa) in the HT, with consistent trends being observed in the MT and LT. Zooplankton also showed increased abundance and decreases in diversity in the HT, with consistent trends being observed in the MT. Multivariate analyses for zooplankton and phytoplankton suggested interactions between these communities. Lemna gibba and Myriophyllum spp. showed mortality in the HT; growth of L. gibba was also reduced in the MT. Bacterial abundance did not change in the HT. All responses were observed at concentrations well below the equivalent pharmacologically active concentrations in mammals. Although the present data do not suggest that ibuprofen, fluoxetine, and ciprofloxacin are individually causing adverse effects in surface-water environments, questions remain about additive responses from mixtures.
The influence of pH and salinity on the toxicity of heavy metals in sediment to the estuarine clam Ruditapes philippinarum
Authors: Riba Inmaculada , Delvalls T. Ángel , Forja Jesús M. , Gómez-Parra Abelardo 
Published: November 2004

Abstract
An approach is presented for determining the influence of two key variables, pH and salinity(S), on the toxicity of four common heavy metals bound to sediments in estuaries. Two samples of environmental sediment taken from two estuaries in southern Spain (the Huelva estuary and the Guadalquivir River estuary), together with a dilution of toxic mud from the Aznalcóllar (Spain) mining spill (April 1998) were used to determine their toxicity at different values of pH (6.5, 7.5, and 8.5) and salinity (10, 20, and 30) on the estuarine clam Ruditapes philippinarum. Two different endpoints, sublethal, indicated by clam reburial (median effective burial time [ET50]), and relative mortality (median lethal concentration [LC50]), were used to quantify the toxicity associated with the heavy metals. Neither salinity nor pH was found to influence the toxic responses measured by the behavioral endpoint (ET50). However, a strong effect on the LC50 related to pH and salinity was detected, with the toxicity of the heavy metals being increased at low values of both variables (pH = 6.5 and S = 10). The mechanism of heavy metals uptake through water may explain this influence of pH and salinity on the lethal toxicity detected. The results show differences in the toxicity of these heavy metals bound to sediments depending on whether the origin of metal contamination is chronic or acute.
Isoform-specific quantification of metallothionein in the terrestrial gastropod Helix pomatia I. molecular, biochemical, and methodical background
Authors: Dallinger Reinhard , Chabicovsky Monika , Berger Burkhard 
Published: November 2004

Abstract
The biomarker concept is an important approach of modern ecotoxicology based on the detection and quantification of molecular, biochemical, cellular, or physiological alterations in organisms as the result of exposure to toxic compounds. In the present study, the biomarker potential of two metallothionein (MT) isoforms from hepatopancreas and mantle tissue of the Roman snail, Helix pomatia L., is evaluated. This species possesses two MT isoforms with specific functions: The Cd-specific isoform (Cd-MT) is predominantly induced and expressed in the hepatopancreas upon Cd exposure. It binds and inactivates this potentially toxic trace element. The second isoform is Cu-specific (Cu-MT), primarily expressed in the mantle tissue and responsible for the homeostatic regulation of Cu. The differential expression and metal-specificity of the two isoforms make them potential candidates for a dual MT biomarker system based on an isoform-specific approach. This study shows that Cd-MT and Cu-MT of H. pomatia can reliably be quantified by a differential metal saturation approach that could be used for environmental biomarker studies. The approach works by virtue of the following preconditions: The two isoforms differ from each other with respect to their molecular and biochemical features, they show metal-specific binding preferences, they are organ-specific, they exhibit distinct induction patterns in response to the metals to which they bind, and their biological and functional background is thoroughly known.