bluuebunny/crossref_metadata_2025 huggingface dataset:
Toxicity and metabolism of 2,4-dichlorophenol by the aquatic angiosperm Lemna gibba
Authors: Ensley Harry E. , Barber John T. , Polito Michael A. , Oliver Ana I.
Published: March 2010

The toxicity and metabolism of 2,4-dichlorophenol, with regard to the aquatic macrophyte Lemna gibba (duckweed), have been studied Toxicity is described in terms of the effect of 2,4-dichlorophenol (2,4-DCP) on the vegetative reproduction of duckweed over a 10-d growth period, the EC10 and EC50 were 2.5 and 9 2 μM, respectively. Metabolism of 2,4-dichlorophenol was monitored by incubation of the plants with radiolabeled substrate, and periodic sampling and analysis by reversed-phase HPLC of the plant growth medium Depending on the growth conditions, up to 95% of the 2,4-DCP was metabolized over a 6-d growth period. To analyze the metabolites, the plants were grown in the presence of sublethal concentrations of [U-14C]-2,4-DCP. The growth medium was lyophihzed and then mixed with the plants, extracted, and analyzed using reversed-phase HPLC, followed by scintillation counting of the fractions The major metabolite was isolated and identified as 2,4-dichlo-rophenyl-β-D-glucopyranoside by high-field NMR and MS. The structure of the metabolite was confirmed by synthesis and by enzymatic cleavage of the β-glucosidic linkage to afford 2,4-DCP. An important consequence of conjugate formation is the masking of the presence of 2,4-DCP to the usual analytical techniques used for its detection and quantitation. This finding is probably applicable to other contaminants and organisms.
Interaction of toxicants and communities: The role of nutrients
Authors: Lozano R. Barreiro , Pratt J.R.
Published: March 2010

The interaction between community nutrient status and toxicity was studied in laboratory microcosms containing natural periphyton communities The three experimental nutrient treatments (low, medium, high) increased by orders of mag nitude from 0 05 mg N per liter + 0 01 mg P per liter Communities were developed with nutrient treatments for 25 d and were then exposed to 3 5 mg/L diquat, a photosynthetic inhibitor, and studied for an additional 23 d The effects of toxicant addi tion were assessed by measuring changes in biomass (protein, chlorophyll), enzyme activity (alkaline phosphatase electron trans port), nutrient release, diurnal changes in microcosm oxygen (gross productivity), and toxicant fate The rate of diquat loss was lowest in the low nutrient treatment Gross photosynthesis was nearly eliminated by diquat in the low nutrient treatment and showed limited recovery Productivities in the medium and high nutrient treatments were equivalent and showed evidence of both effect (approximately 50% reduction) and recovery Protein biomass was reduced in low nutrient microcosms treated with diquat, but no effect on chlorophyll biomass was observed Diquat inhibited respiratory electron transport activity, and mi crocosms with low nutrient availability had limited ability to recover from the diquat stress These studies suggest that commu nity nutrient status affects both the magnitude of effect and the rate of recovery of processes following stress
Stream microcosm toxicity tests: Predicting the effects of fenvalerate on riffle insect communities
Authors: Breneman Dan H. , Pontasch Kurt W.
Published: March 2010

Stream microcosms were used to predict toxicity of the pyrethroid insecticide fenvalerate to riffle insect assemblages. Over a 30-d test period, stream microcosms were exposed in triplicate to 0.0, 0.01, 0.1, 1.0, or 10.0 μg/L fenvalerate. Effects were determined by statistically comparing insect abundances over all concentrations. Initial exposure resulted in a significant increase in drift in the 1.0- and 10.0-μg/L treatments. After 30 d, several taxa exhibited density reductions at 0.01 μg/L, but this reduction was significant for only one taxon. Densities of most other taxa decreased significantly at 0.1 μ/L. Significant reductions in species richness and total density also were observed at 0.1 μg/L fenvalerate. Overall, the results suggest that at environmental concentrations of 0.1 μg/L, mayflies and stoneflies would be eliminated and riffle beetles, caddisflies, and some chironomids would be present in significantly reduced numbers.
Integrated laboratory and field approach for assessing impacts of heavy metals at the Arkansas River, Colorado
Authors: Clements William H. , Kiffney Peter M.
Published: March 2010

This research employed an integrated laboratory and field approach to assess effects of heavy metals at the Arkansas River, a Colorado stream impacted by historic mining operations. Ambient metal levels, chronic toxicity, metal bioaccu-mulation by benthic organisms, and benthic community structure were examined at stations located upstream and downstream from California Gulch (CG), a U.S. Environmental Protection Agency Superfund site near Leadville, Colorado. Although each approach demonstrated effects of metals from CG, important differences among approaches were observed. Ambient metal concentrations and chronic toxicity tests conducted with Ceriodaphma dubia indicated reduced water quality at upstream and downstream stations. Because of temporal variability in metal levels, water samples collected for chronic toxicity tests did not reflect average exposure conditions. Instream monitoring of benthic communities was necessary to characterize metal impacts at the Arkansas River, but this approach had limitations. Levels of metals in periphyton and benthic invertebrates were significantly elevated at stations downstream from CG. Variation in metal levels among taxa and the absence of some taxa from some stations may limit the use of bioaccumulation studies for monitoring metal impacts. Benthic community structure was altered downstream from CG, but some metrics (e.g., species richness, abundance) were not affected by heavy metals because of the replacement of sensitive taxa by tolerant taxa. Because each of the approaches employed in this study provided different information on the degree of metal impacts, we recommend an integrated approach for assessing effects of metals on streams.
Degradation of PCBs by ferric ion, hydrogen peroxide and UV light
Authors: Pignatello Joseph J. , Chapa Guadalupe
Published: March 2010

A 1-g/L two-phase mixture of the commercial PCB oil Aroclor 1242 in acidified water at 66°C was degraded by a photoassisted Fenton-type reaction consisting of Fe3+, H2O2, and UV light (300-400 nm). Up to 88% PCB removal and 85% dechlorination were obtained, without attempts at optimization. The order of reactivity was di- > tri-> tetra- - – higher chlorinated biphenyls, but the selectivity was weak. Perfluorinated surfactants added to increase PCB solubility or rates of dissolution had a detrimental effect on degradation. Minimal reaction was observed at room temperature.
Effects of humic acid-metal complexes on hepatic carnitine palmitoyltransferase, carnitine acetyltransferase and catalase activities
Authors: Lu Fung-Jou , Chen Young-Shin , Huang Tien-Shang
Published: March 2010

A significant increase in activities of hepatic carnitine palmitoyltransferase and carnitine acetyltransferase was observed in male Balb/c mice intraperitoneally injected for 40 d with 0 125 mg/0 1 ml/d humic acid-metal complexes. Among these complexes, the humic acid-As complex was relatively effective, whereas humic acid-25 metal complex was more effective, and humic acid-26 metal complex was most effective However, humic acid or metal mixtures, or metal such as As alone, was not effective Humic acid-metal complexes also significantly decreased hepatic catalase activity. A marked decrease of 60-kDa polypeptide in liver cytoplasm was also observed on SDS-polyacrylamide gel electrophoresis after the mice had been injected with the complexes. Morphological analysis of a histopathological biopsy of such treated mice revealed several changes in hepatocytes, including focal necrosis and cell infiltration, mild fatty changes, reactive nuclei, and hypertrophy Humic acid-metal complexes affect activities of metabolic enzymes of fatty acids, and this results in accumulation of hydrogen peroxide and increase of the lipid peroxidation The products of lipid peroxidation may be responsible for liver damage and possible carcino-genesis. Previous studies in this laboratory had shown that humic acid-metal complex altered the coagulation system and that humic acid, per se, caused vasculopathy. Therefore, humic acid-metal complexes may be main causal factors of not only socalled blackfoot disease, but also the liver cancer prevailing on the southwestern coast of Taiwan.
HPLC determination of tocopherol, retinol, dehydroretinol and retinyl palmitate in tissues of lake char (Salvelinus namaycush) exposed to coplanar 3,3′,4,4′,5-pentachlorobiphenyl
Authors: Palace Vince P. , Brown Scott B.
Published: March 2010

Tocopherol, retinol, dehydroretinol, and retinyl palmitate were measured by reversed-phase HPLC in liver, kidney, and plasma of lake char exposed to orally administered coplanar 3,3′,4,4′,5-pentachlorobiphenyl (PCB). Tocopherol concentrations were unaffected after eight weeks. Liver retinol, dehydroretinol, and retinyl palmitate concentrations were lower, whereas kidney retinyl palmitate was elevated in PCB-exposed groups. Tissue retinoid concentrations provide sensitive indicators of coplanar PCB exposure in fish.
Reuse and eluent stability studies of a weak cation exchange cartridge used for collection of ammonia in indoor air
Authors: Risner Charles H.
Published: March 2010

An active weak cation exchange sampling device for ammonia was restored for sampling with the use of 1 m HC1 and water. This process could be performed at least four times with no detrimental effects. The eluent of the device was found to be stable for four months at 2°C.
Off-season spawning and factors influencing toxicity test development with topsmelt Atherinops Affinis
Authors: Anderson B.S. , Hunt J.W. , McNulty H.R. , Turpen S.L. , Martin M.
Published: March 2010

Three separate groups of adult topsmelt (Atherinops a/finis) were spawned in rotation in laboratory culture over a two-year period to provide larvae for toxicity tests. Size and viability of embryos and larvae produced during the normal summer spawning period (May-August) were compared to those produced during the off season (October-April). Mean embryo viability was relatively high throughout the study (82%), whereas size of larvae varied. Larval size was significantly larger during the summer spawning period than in winter. A 7-d growth and survival toxicity test protocol was developed for topsmelt larvae. Variability of the protocol was assessed over a 12-month period using copper chloride as a reference toxicant. Precision of 12 toxicity tests using copper was high; the intralaboratory C.V. for copper LC50s was 19%. The 7-d larval protocol also gave comparable results in two interlaboratory toxicity tests using copper and complex effluent. This study demonstrates that topsmelt may be spawned throughout the year to provide larvae for toxicity tests and that topsmelt larvae have comparable sensitivity to other larval fishes commonly used in toxicity testing.
Age-specific toxicity of copper to larval topsmelt Ather1Nops Affinis
Authors: McNulty Hilary R. , Anderson Brian S. , Hunt John W. , Turpen Sheila L. , Singer Michael M.
Published: March 2010

The age-specific sensitivity of topsmelt (Atherinops affinis) larvae to copper was assessed. A series of 7-d growth and survival experiments were conducted using cohorts of larval fish isolated into different age groups of 0, 1, 3, 5, 7, 9, 11, 15, and 20 d post-hatch. Fish aged 0, 3, and 5 d were less sensitive to copper chloride than fish ≥7 d old. The median lethal concentration (LC50) for copper ranged from 365 μg L−1 in 0-d larvae, to 137 μg L−1 in 20-d larvae. NOECs remained relatively constant for all ages: 180 μg L−1 for 1- and 3-d-old fish, 100 μg L−1 for all other cohorts. Regression analysis indicated a significant negative correlation between LC50 and gill surface area (GSA; R2 = —0.793) and cutaneous surface area (CSA; R2 = —0.760. Although these correlations were expected because both morphometrics increase with age, the relationships between increasing respiratory surface area and LC50 may indicate that the increase in sensitivity with larval age is related to an increase in copper uptake, either cutaneously or branchially. GSA increased more than sevenfold between hatch and 20 d, whereas CSA increased only threefold throughout the same period.
Effect of xenobiotics on the respiratory activity of rat heart mitochondria and the concomitant formation of superoxide radicals
Authors: Stolze Klaus , Nohl Hans
Published: March 2010

The effects of the xenobiotics atrazine, benzene, butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), lindane, toluene, and xylenol on the respiration of isolated rat heart mitochondria were studied. Bioenergetic parameters such as respiratory control (RC) and ATP /oxygen (P/O) values decreased considerably in the presence of these substances, and a concomitant increase of superoxide radical (O2−) formation was observed. These observations were discussed in terms of partial damage of the inner mitochondrial membrane, impairing the maintenance of the proton gradient across this membrane. In the presence of protons, ubisemiquinone radicals (UQ −) present in the inner mitochondrial membrane are able to react with molecular oxygen, thereby generating superoxide radicals. The changes of membrane potential and P/O values show a linear inverse correlation with O2− formation rates, whereas this correlation with RC values was not linear.
Comparison of two strategies for assessing ecotoxicological aspects of complex wastewater from a chemical-pharmaceutical plant
Authors: Brorson Torbjörn , Björklund Ingvar , Svenstam Göran , Lantz Rolf
Published: March 2010

The potential environmental impact of wastewater from a chemical-pharmaceutical plant was evaluated by two different characterization strategies. The aim of the first strategy was to characterize the complex effluent before and after degradation by activated sludge. Chemical analyses (AOX, EOX, DOC, TOC, BOD, CODCr, N-total, N-NH4, N-NO2, N-NO3, P-total, and P-PO4) were performed on the undegraded and the degraded sample. Ecotoxicological tests were performed on the undegraded sample (acute toxicity, Microtox®, inhibition of respiration of activated sludge, inhibition of nitrification of activated sludge) and on the degraded sample (acute toxicity, Microtox). Moreover, the concentration of potentially bioaccu-mulating substances was determined in the degraded sample. The tests were done according to the STORK Project (characterization of persistent organic compounds in industrial effluents) initiated by the Swedish Environmental Protection Agency. The second characterization strategy was concentrated on single substances in the effluent. The amount of all discharged chemicals was estimated using mass-balance calculations or by chemical analysis of the water phase. Ecotoxicological data for several of the substances were drawn from the reference literature. For those without any ecotoxicological information, a limited set of tests was performed (Microtox, octanol/water partition coefficient, biodegradation). All substances were classified on the basis of environmental effects using acute toxicity, biodegradation, and bioaccumulation criteria.

The two different characterization strategies were useful when predicting environmental effects of wastewater from a chemical-pharmaceutical plant. From a practical and economical point of view, a stepwise approach including elements from both of the above strategies is recommended. A chemical-oriented strategy (discharged amount and ecotoxicological data for each compound) may be useful as a primary step for sorting out hazardous water phases from harmless ones. For less defined water phases, an extensive characterization program, including chemical analyses, acute toxicity testing, and ecotoxicological parameters, may give valuable information about environmental risks.
Evaluation of potential confounding factors in sediment toxicity tests with three freshwater benthic invertebrates
Authors: Ankley Gerald T. , Benoit Duane A. , Balogh James C. , Reynoldson Trefor B. , Day Kristin E. , Hoke Robert A.
Published: March 2010

We examined the effects of natural sediment physicochemical properties on the results of lab tests with the amphipod Hyalella azteca, the midge Chironomus tentans, and the ohgochaete Lumbriculus variegatus Ten-day exposures with the three species were conducted with 50 uncontaminated sediment samples from Lakes Erie, Huron, Superior, and Ontario, which differed markedly with regard to characteristics such as grain-size distribution, organic carbon content, and mineralogical composition Tests were conducted both with and without the addition of exogenous food Survival of Hyalella azteca, survival and growth of Chironomus tentans, and survival/reproduction and growth of Lumbriculus vanegatus were significantly greater in tests in which the animals were fed vs those in which they were not Approximately 10% of the tests in which Hyalella azteca was not fed and 80% of tests in which the amphipods were fed resulted in >80% survival, a common criterion for defining the acceptability of tests with Hyalella azteca in clean control sediments Similarly, a relatively high percentage of the tests in which Chironomus tentans was not fed would have failed a control survival criterion of 70% for the midge Hence, there is significant potential for false positive results if Hyalella azteca or Chironomus tentans is not fed during sediment tests Predictive modeling of the assay results in relationship to sediment physicochemical characteristics failed to reveal any additional factors that influenced survival of Hyalella azteca and Chironomus tentans, or reproduction and growth of Lumbriculus vanegatus in tests in which the organisms were fed However, linear modeling did suggest that growth of fed as well as unfed Chironomus tentans may have been influenced by gram size distribution of the test sediments
Uptake and loss of white phosphorus in american kestrels
Authors: Nam Sae-Im , Roebuck B.D. , Walsh Marianne E.
Published: March 2010

American kestrels (Falco sparverius) exposed to a diet containing white phosphorus (P4) had detectable quantities of P4 only in their fatty tissues. As early as 24 h postdosing, P4 was found in the fat depots and skin but not in other tissues such as the brain, heart, intestine, liver, kidney, and muscle. After 7 d of continuous exposure to P4-containing diet (6.4 μg P4 per gram of diet), the skin but not fat depots showed significant accumulation of P4. When P4-containing diet (6.4 μg P4 per gram of diet) was fed for 2 d followed by 3 d of feeding a diet containing less P4 (0.7 μg P4 per gram of diet), P4 was not detectable in the tissues. Upon refeeding with the higher dietary concentration of P4, P4 was again detectable in skin and fat. This cyclic dosing regimen indicates that tissue levels are sensitive to dietary levels of P4.
Culturing of fathead minnow (Pimephales promelas L.) larvae for aquatic toxicity testing: An observational note
Authors: Hutchinson Thomas H , Williams Timothy D
Published: March 2010

Dietary investigations have been conducted to improve the survival of fathead minnow (Pimephales promelas) larvae for aquatic toxicity testing purposes Data are presented that suggest that feeding fish larvae both protozoa and Artemia nauplu may produce more consistent levels of larval survival and growth when compared with fish larvae fed Artemia nauplu only
Effect of aeration of sediment on cadmium binding
Authors: Zhuang Yuanyi , Allen Herbert E. , Fu Gongmin
Published: March 2010

Acid-volatile sulfide (AVS) has been shown to be the dominant phase reacting with metals in anoxic sediments. The AVS in sediment decreases upon resuspension due to storms and dredging, and in winter when the rate of aeration processes exceeds that of the formation of sulfide. We conducted a series of lab aeration experiments in batch reactors to investigate the effects of aeration of sediment on the sulfide content of sediment and on the partitioning of cadmium, a model toxic metal, to the sediment. Aeration of sediment results in rapid decrease of the AVS. We studied the sediment characteristics for aeration periods of approximately a month. During this time, the concentrations of dissolved metals increased by 200 to 400% or more, relative to the concentrations present at the beginning of the test. The concentration of metal associated with AVS and with pyrite decreased. During the aeration, there are increases in the concentrations of hydrous iron and manganese oxides, and these materials become increasingly more important in the binding of cadmium. Following the aeration, >50% of the cadmium was associated with the extractable iron and manganese components of the sediment. Overall, the binding capacity of the sediments for cadmium decreased after aeration.
Submitochondrial particle response to linear alkylbenzene sulfonates, nonylphenol polyethoxylates and their biodegradation derivatives
Authors: Argese Emanuele , Marcomini Antonio , Bettiol Cinzia , Perin Guido , Miana Paola
Published: March 2010

The effects on mitochondrial respiratory parameters of linear alkylbenzene sulfonates (LAS), nonylphenol polyeth-oxylates (NPEO), and some of their biotransformation products, namely sulfophenyl carboxylates (SPCs), nonylphenol (NP), and nonylphenoxy acetic acid (NP1EC), were recorded by using the in vitro response of submitochondrial particles (SMP) from beef heart. The toxicity of these compounds was estimated by determining their effects on the energy-coupled reverse electron transfer (RET), which is induced by ATP and succinate at the first site level of the respiratory chain and reduces exogenous NAD+ to NADH. The toxicity of the substances, expressed as the toxicant concentration decreasing the reduction rate of NAD+ to an extent of 50% (EC50), ranged from 0.61 mg/L for a commercial LAS mixture to 18,000 mg/L for individual SPCs; from 1.3 mg/L for NPEO, with an average of 10 ethoxy units, to 8.2 and 1.8 mg/L for NP1EC and NP, respectively. These results were related to the molecular structure of each compound class and compared with the toxicity values obtained by a variety of biological systems currently used for toxicity testing. The acute toxicity data have demonstrated that (a) the SMP bioassay is suitable for reproducing the toxicological response of whole organisms, such as fishes and invertebrates, to the tested chemicals; and (b) the hydrophobic moiety of these compounds plays a significant role in eliciting their toxic effects. From a toxicological standpoint, attention must be paid to the occurrence in natural waters of residual LAS, whereas in the case of NPEO both unaltered surfactant and all biotransformation products need to be identified and quantified.
Back-propagation neural networks-recognition vs. prediction capability
Authors: Schüürmann Gerrit , Muller Eckhard
Published: March 2010

Literature data on biodegradation kinetics of organic compounds, together with a descriptor representation, are subjected to a systematic analysis of the performance of back-propagation neural-network models. The results show distinct dependencies on various model parameters, particularly on the number of iteration cycles. The application of leave-n-out procedures leads to general recommendations for a proper evaluation of the recognition and prediction power of this class of nonlinear structure-activity models.
Accumulation, depuration and growth effects of tributyltin in the freshwater bivalve Dreissena polymorpha under field conditions
Authors: VanSlooten Kristin Becker , Tarradellas Joseph
Published: March 2010

The uptake of tributyltin (TBT) in caged Dreissena polymorpha was investigated in a freshwater marina contaminated with TBT released from antifouhng paints Depuration was followed on bivalves transferred from the marina, where they live naturally, to a location without organotin contamination The butyltin concentration of the mussel tissues and the water was determined and the growth of the mollusks followed during 105 d The accumulation was extremely rapid, reaching a threshold of 63 μg/g dry weight after 35 d with a very high BCF of 900,000 No effect on growth or mortality was observed The elimination experiment showed a half life of 26 d without reaching a steady state after 105 d The mean ambient TBT water concentrations were 70 and 4 ng/L during the uptake and depuration experiments, respectively Rate constants have been cal culated The growth rate of the eliminating Dreissena polymorpha was half as high as the rate of the accumulating mussels and of those caged in the site with low TBT concentrations serving as reference The bivalves living naturally in the marina might have been affected during their larval or juvenile stages, resulting in a reduced growth rate of the adults, which remained diminished even when transferred to an area remote from known TBT sources
Feeding by clay-colored sparrows on grasshoppers and toxicity of carbofuran residues
Authors: Forsyth Douglas J. , Hinks Christopher F. , Westcott Neil D.
Published: March 2010

The potential hazard of carbofuran-sprayed insects to clay-colored sparrows (Spizella pallida) was determined by measuring consumption of grasshoppers (Melanoplus sanguinipes) by nestlings and adults, attractiveness of dead vs. live grasshoppers, and toxicity of sprayed grasshoppers to adults. Hand-reared nestlings 8 to 10 and 14 to 22 d old ate mean quantities of grasshoppers per bird of 0.61 and 0.83 g, respectively, per bout of feeding when fed to satiety every hour from dawn to dusk. These rates of intake in the field could result in doses of 0.2 mg/kg body mass (14% of the LD50 for adults) in brief bouts of feeding if they were fed sprayed insects containing carbofuran at 2.5 μg/g, the mean concentration found after aerial application of 134 g a.i. per hectare. Nestlings 2 to 3 d old ingesting about 0.2 g grasshoppers in brief periods might receive lethal doses from carbofuran residues of 2.5 μg/g or the maximum concentration of 5.7 μg/g if they are more sensitive than adults. There was nonetheless no evidence of reduced survival among nestling passerines for 3 d following aerial spraying of carbofuran at 134 g/ha in a pasture. Captive adults preferred dead grasshoppers in trials in which live and dead grasshoppers were offered simultaneously. When six adults were provided with 24-h supplies of sprayed grasshoppers containing carbofuran at 2.6 μg/g, they showed no taste aversion and consumed quantities 24% greater than those eaten by control birds. No mortality resulted from eating the contaminated grasshoppers. Mean hopping activity by treated birds increased by 80%, relative to controls, 5 h after receiving poisoned grasshoppers, but the difference was not significant. Although captive adults consumed close to their body mass in grasshoppers daily, an LD50 of carbofuran from grasshoppers containing 2.5 μg/g would require rapid ingestion of 6.7 g, a quantity about 7x the birds' capacity for short-term ingestion. Our results, combined with observations of a related field study, suggest that adult and nestling passerines are able to tolerate the dietary exposure to carbofuran resulting from ingestion of grasshoppers sprayed at the rate of 134 g/ha. Conclusions about safety should not be drawn, however, until more field applications have been monitored.
Temporal induction of cytochrome p450 1a in the mirror carp (Cyprinus carpio) after administration of several polycyclic aromatic hydrocarbons
Authors: Van Der Weiden Martine E. J. , Hanegraaf Frank H. M. , Seinen Willem , Van Den Berg Martin , Eggens Martin L. , Celander Malin
Published: March 2010

High inductions of 7-ethoxyresorufin O-deethylation (EROD) activities, cytochrome P450 1A protein levels (P4501 A), and total cytochrome P450 content (P450) were observed 1,2,5, and 14 d after a single i.p. injection of 99.5 μmol/kg benzo[a]py-rene (BaP) and chrysene (Chrys). The highest inductions in EROD activities and P450 1A protein levels were seen 2 d after treatment, approximately 35- and 11-fold relative to the controls. Less pronounced increases of EROD activities and P450 1A protein levels, approximately 3- to 10-fold and 6-fold, respectively, were observed after treatment with equimolar concentrations of flu-oranthene (Fluor) and pyrene (Pyr). Benzo[ghi]perylene (BghiP) and the carrier dimethyl sulfoxide (DMSO) did not affect these parameters. The highest concentrations of PAHs in the liver, equivalent to 2 to 25% of the dose, were found 1 or 2 d after treatment. The highest percentage of the dose in the liver was observed for Chrys, followed by BghiP, BaP, Fluor, and Pyr. Poor correlations were found between hepatic concentrations of PAHs and P450 1A increases, which might be attributed to the rapid metabolism of these compounds.
Effects of 7,12-dimethylbenz[A]anthracene on immune function and mixed-function oxygenase activity in the european starling
Authors: Trust Kimberly A. , Hooper Michael J. , Fairbrother Anne
Published: March 2010

Immune function and hepatic MFO activity were examined in adult and nestling starlings administered a synthetic PAH, 7,12-dimethylbenz[a]anthracene (DMBA). Methods used to examine the starling immune system included immunopa-thology, macrophage phagocytosis, lymphocyte blastogenesis to concanavalin A, and hemagglutination of sheep erythrocytes (SRBC). Concomitant investigations of MFO activity were conducted in starlings exposed to DMBA. Ethoxyresorufin O-dealkylase (EROD) and pentoxyresorufin O-depentylase (PROD) were used as indicators of hepatic MFO activity. Changes in MFO activity were compared to chemically altered immune responses following DMBA exposure. Subcutaneous exposure of adult starlings to 125 mg/kg DMBA resulted in suppression of lymphocyte blastogenesis and antibody production to SRBC. EROD and PROD activity were increased 2.8- and 3.4-fold, respectively. Lymphocyte blastogenesis was impaired in adult starlings orally exposed to 125 mg/kg DMBA. The immune system of nestling starlings exposed orally to 100 mg/kg DMBA was altered, as evidenced by decreased phagocytic ability of macrophages and inhibition of lymphocyte blastogenesis. Oral exposure to DMBA did not induce MFO activity in starlings of either age class. Effects of DMBA on immune function and MFO activity in starlings varied with the age of birds and route and length of chemical exposure.
Bioaccumulation, biotransformation and DNA binding of pahs in feral eel (Anguilla anguilla) exposed to polluted sediments: A field survey
Authors: van der Oost Ron , Heida Henk , Satumalay Karel , van Schooten Frederik-Jan , Ariese Freek , Vermeulen Nico P. E.
Published: March 2010

Samples of sediment and eel taken from six sites in Amsterdam with different levels of water pollution were analyzed for 16 parental PAHs In addition, biliary PAH metabolites and hepatic PAH-DNA adducts were determined in the eel to evaluate biomomtoring techniques for PAH exposure There was a clear difference between PAH profiles in sediments and eel Mainly two- and three-ring PAHs were detected in eel, whereas four-ring PAHs predominated in the sediments Because PAH bioaccumulation was highest in eel from the reference sites, tissue levels of the parental PAH are probably not the most accurate monitor of PAH exposure in fish An elevated excretion of 1 OH pyrene (determined by synchronous scan fluores cence) was observed in the bile of fish from three of the four polluted sites, indicating that this parameter may be used as a biomarker for PAH exposure A significant increase in PAH-DNA adduct levels (determined by 32P postlabeling) was observed in the liver of eel from all polluted sites Therefore, this parameter seems to be a sensitive biomarker for exposure to mutagenic and carcinogenic PAHs
In vitro adrenal bio activation and effects on steroid metabolism of DDT, PCBs and their metabolites in the gray seal (Halichoerus grypus)
Authors: Lund Bert-Ove
Published: March 2010

The irreversible binding of the DDT metabolites o,p DDD [2 (2-chlorophenyl) 2(4-chlorophenyl) 1,1-dichloroethane] and MeSO2 DDE [3 methylsulfonyl 2,2-bis(4 chlorophenyl) 1,1-dichloroethene], as well as their potential to inhibit mitochondrial steroid 11β-hydroxylation in the gray seal adrenal gland, was studied The adrenal bioactivated both o,p -DDD and MeSO2 DDE in vitro The irreversible binding of o,p DDD was, however, 17 times higher than that of MeSO2-DDE In both cases, the enzymes responsible for the activation resided primarily in mitochondria, and inhibitory effects of cytochrome P450 inhibitors (metyrapone and SKF 525A) and NADPH omission indicated mitochondnal P450 enzymes as responsible for the bioactivation Forty micromolar concentrations of o,p DDD and p,p DDT [2-(4 chlorophenyl)-2(4 chlorophenyl) 1,1,1-trichloroethane] inhibited 11β hydroxylation of glucocorticoids (10 μM) by approximately 25 % In contrast, none of the studied compounds — MeSO2-DDE, p,p DDE, some PCBs, and methylsulfonyl-PCBs (40 μM) - affected the mitochondrial 11β-hydroxylase activity Bioactivation of environmental pollutants such as DDT and PCB metabolites and inhibition of P450 11β hydroxylase are discussed as possible reasons for the generation of the adrenocortical hyperplasia observed in Baltic seals
Boron and silicon: Effects on growth, plasma lipids, urinary cyclic amp and bone and brain mineral composition of male rats
Authors: Seaborn Carol D. , Nielsen Forrest H.
Published: March 2010

Because boron resembles silicon in its chemical properties, an experiment was performed to determine if excessive dietary boron would affect the response to silicon deprivation and, conversely, if silicon would influence the effects of an excessive intake of boron. Male weanling Sprague-Dawley rats were assigned to groups of six or 12 in a two-by-two factorially arranged experiment. Supplemented to a ground corn/casein diet containing 1.2 μg silicon and 3 μg boron per gram were silicon as sodium metasilicate at 0 or 50 μg/g and boron as orthoboric acid at 0 or 500 μg/g diet. At nine weeks, animals fed high dietary boron had significantly decreased final body weights, liver-weight-to-body-weight ratios, urinary cAMP concentrations, plasma triglyceride, cholesterol, glycine, valine, leucine, and lysine concentrations and skull copper, sodium, and manganese concentrations. High dietary boron also significantly increased brain-weight-to-body-weight ratios, magnesium concentrations of femur, brain, and plasma, zinc concentration of femur, and iron concentration of skull. The bone mineral findings suggest that excess dietary boron exerts subtle effects on bone composition. Dietary silicon affected blood urea nitrogen, hematocrit, hemoglobin, and the concentrations of plasma threonine and aspartic acid in animals fed excess boron. Depression of the testes-weight-to-body-weight ratio of animals fed 500 μg boron per gram diet was most marked in animals not fed silicon. Although excessive dietary boron did not markedly enhance the response of rats to silicon deprivation, dietary silicon affected their response to high dietary boron. Thus, dietary silicon apparently can influence boron toxicity.
Sediment toxicity, contamination and amphipod abundance at a DDT- and dieldrin-contaminated site in San Francisco Bay
Authors: Swartz Richard C. , Cole Faith A. , Lamberson Janet O. , Ferraro Steven P. , Schults Donald W. , Deben Waldemar A. , Lee Ii Henry , Ozretich Robert J.
Published: March 2010

Sediment toxicity to the amphipod Eohaustonus estuanus, sediment contamination, and the abundance of amphipods were examined along a contamination gradient in the Launtzen Channel and adjacent parts of Richmond Harbor, Call forma Dieldnn and DDT were formulated and ground at this site from 1945 to 1966 Sediment contamination by both dieldrin and the sum of DDT and its metabolites (EDDT) was positively correlated with sediment toxicity and negatively correlated with the abundance of amphipods excluding Grandidierella japonica The maximum dieldnn and ΣDDT concentrations in toxic units were 0 018 and 9 43, respectively, indicating that ΣDDT was the dominant ecotoxicological factor Concentrations of PAHs, PCBs, and metals were not sufficient to cause appreciable toxicity, except at one PAH contaminated station Relations between ΣDDT, sediment toxicity, and amphipod abundance are similar at three ΣDDT contaminated sites The 10 d LC50 for ΣDDT in field-collected sediment was 2,500 μg/g organic carbon (OC) for Eohaustonus estuanus in this study, 1,040 μg/g OC for Rhepoxymus abromus exposed to Palos Verdes Shelf, California, sediment, and 2,580 μg/g OC for Hyalella azteca exposed to sediment from a freshwater stream system near Huntsville, Alabama The threshold for 10 d sediment toxicity occurred at about 300 μg ΣDDT/g OC The abundance of amphipods (except Grandidierella japonica) was reduced at EDDT concentrations > 100 μg/g OC Correlations between toxicity, contamination, and biology indicate that acute sediment toxicity to Eohaustonus estuanus, Rhepoxymus abromus, or Hyalella azteca in lab tests provides reliable evidence of biologically adverse sediment contamination in the field
Evaluation of the resident-species procedure for developing site-specific water quality criteria for copper in blaine creek, kentucky
Authors: Dobbs Michael G. , Farris Jerry L. , Cherry Donald S. , Cairns John , Reash Rob J.
Published: March 2010

Acute toxicity tests were performed on each of nine different organisms in Blaine Creek (Lawrence County, KY) water to determine 48-h LC50 values for copper (Cu). Blaine Creek is the receiving stream for Kentucky Power Company's Big Sandy Plant fly-ash pond discharge. Selection of the nine tested species and integration of the results were based on the U.S. Environmental Protection Agency's (EPA's) resident-species procedure. The following LC50 (μg Cu/L) values were obtained (hardness 100-120 mg/L as CaCO3): Daphnia pulex  37; Physella sp. 109; Isonychia bicolor  223; Pimephales promelas  284; Stenonema sp. 453; Eurycea bislineata  1,120; Chironomus riparius  1,170; Orconectes sp. 2,370; Lepomis macrochirus  4,300. A final acute value (FAV) of 10.1 μg Cu/L (hardness 50 mg/L as CaCO3) was derived using the Blaine Creek database, which is lower than the EPA's national FAV (18.5 μg/L). The differences in FAVs were due to the effect of database size, not differences in the relative sensitivity of test organisms. Our findings provide caution for dischargers who may choose to use the resident-species procedure for future site-specific water-quality-criteria demonstrations. The resident-species procedure, because of the inherent conservative bias of the calculation process, tends to produce more stringent criteria when used on a site-specific basis. A modified recalculation procedure, in conjunction with site-specific metal bioavailability data, was judged to be the most appropriate method for deriving site-specific Cu criteria for Blaine Creek.
Detection of Genotoxic Insult as DNA strand breaks in fish blood cells by agarose gel electrophoresis
Authors: Theodorakis Christopher W. , D'Surney Steven J. , Shugart Lee R.
Published: March 2010

DNA, isolated from the blood cells of bluegill sunfish (Lepomis macrochirus) exposed in the lab to bedded sediment collected from a site contaminated with genotoxic compounds (i e, PAHs, PCBs, and heavy metals), was examined for strand breakage by agarose gel electrophoresis Before electrophoresis the blood cells were embedded in agarose plugs and incubated with proteinase After electrophoresis under both neutral (pH 7) or alkaline (pH 12) conditions, the median molecular length (MML) of the DNA distributed in the gel was determined These quantitative measures were used to estimate the difference in the number of double and single strand breaks between DNA preparations Both types of strand breakage were found to be greater in fish exposed to sediment contaminated with genotoxic compounds as compared to nonexposed fish A statistically significant correlation was demonstrated between the MML value obtained by the electrophoretic assay reported here and the F value (measure of DNA double strandedness) obtained by the alkaline unwinding assay
Complex mixture analysis using protein expression as a qualitative and quantitative tool
Authors: Bradley Brian P. , Gonzalez Carole M. , Bondf Jayne-Anne , Tepper Bruce E.
Published: March 2010

Some proteins in organisms exposed to chemicals in stressful amounts or toxic concentrations show increased expression, others show decreased expression These inducible and repressible proteins together potentially provide qualitative and quantitative diagnoses of components in complex mixtures of chemicals We examined sets of proteins synthesized by Daphmamagna after exposure to mixtures of a catiomc polyamide epichlorhydrim adduct (Kymene) and a combined assortment of water extractable substances from chemi thermal mechanical pulp (CTMP) in lab water Proteins were identified, after extracting from Daphma magna, by gel filtration and silver staining, or by radiolabelmg and then gel separation Patterns of proteins induced by Kymene® and by CTMP extracts were distinguishable in lab water, but there was interaction between them The method of identifying and quantifying Kymene, however, was successful using lab simulations of mixtures The method was tested using wastewater samples from a paper manufacturing plant Kymene could be detected against variable levels and types of additional substances But, again, there was interference, perhaps due to Kymene binding to other anionic polymers sometimes present in the samples Interpretations from analyses of protein expression were consistent with results from sublethal Ceriodaphnia dubia assays
Survey of receiving-water environmental impacts associated with discharges from pulp mills: 1. Mill characteristics, receiving-water chemical profiles and lab toxicity tests
Authors: Robinson Richard D. , Carey John H. , Solomon Keith R. , Smith Ian R. , Servos Mark R. , Munkittrick Kelly R.
Published: March 2010

This survey examined the relationship between environmental responses at pulp mill sites and the pulping process (kraft vs. sulphite/thermomechanical pulping), effluent treatment (primary vs. secondary treatment), and bleaching technology used by pulp mills. This manuscript is the first in a series of four; it reviews the location and operating characteristics of mills included in the survey and provides background information on water chemistry that is relevant to the other components of the survey. In addition, lab 7-d toxicity tests of receiving water were conducted using fathead minnows (Pimephales prome-las) and the cladoceran Cenodaphma dubia with water samples collected upstream (reference) and downstream (plume) of effluent discharges at 11 Canadian pulp and paper mills; these samples were collected at the same time as fish surveys were conducted. Survival of fathead minnow larvae was significantly reduced at four of the 11 downstream sites. Ceriodaphnia reproduction was significantly higher at six of the 11 downstream sites and significantly lower at two downstream sites. There were no significant effects on fathead minnow larva growth or adult Cenodaphma survival at any of the examined downstream sites. Negative effects in the toxicity tests were generally associated with the low dilution discharge of primary treated effluent with a previous history of acute toxicity. Fathead minnow and Cenodaphnia tests were generally correlated with historical data on benthic mac-roinvertebrate community responses. Neither toxicity test predicted the physiological changes in wild fish that are presented in accompanying papers.
Survey of receiving-water environmental impacts associated with discharges from pulp mills: 2. Gonad size, liver size, hepatic erod activity and plasma sex steroid levels in white sucker
Authors: Munkittrick Kelly R. , Servos Mark R. , Van Der Kraak Glen J. , McMaster Mark E. , Portt Cam B. , Van Den Heuvel Michael R.
Published: March 2010

Fish collected from the receiving areas of 12 Canadian pulp mills were examined, including sites receiving effluent from kraft mills using chlorine as well as sulfite mills. Field collections included sampling of receiving water for chemistry and toxicity testing, and sampling of local fish for organ weights, hepatic MFO (ethoxyresorufin-O-deethylase, EROD) activity, plasma steroid levels, and levels of liver dioxins. The main objectives of this study were to determine whether the discharge of effluent from pulp mills to sites other than Jackfish Bay was associated with physiological or biochemical disruptions in wild fish, whether there was any correlation between waste treatment and the presence of biological responses in wild fish, and whether there was any association between the use of chlorine as a bleaching agent and these responses. Although white sucker collected near bleached-kraft mills exhibited the highest EROD induction and dioxin levels, elevated enzyme activity was observed in fish from sites that did not use chlorine, and depressions in plasma sex steroid levels was not correlated with the level of EROD activity. The absence of chlorine bleaching or the presence of secondary treatment did not eliminate responses in fish, including decreased circulating levels of sex steroids, decreased gonadal size, and increased liver size. This survey has shown that (a) induction of hepatic EROD enzymes and depressions of plasma sex steroid levels during gonadal growth are found downstream of several pulp mills; (b) these changes are seen at some mills without chlorine bleaching and at mills that have secondary treatment; (c) substantial dilutions of nontoxic effluent do not appear to remove these responses; (d) the dominant factor determining the presence or absence of responses appeared to be dilution level; and (e) lab toxicity tests on invertebrates, rainbow trout, and fathead minnows could not predict the presence of these responses in wild fish.
Survey of receiving-water environmental impacts associated with discharges from pulp mills: 4. Bioassay-derived 2,3,7,8-tetrachlorodibenzo-P-dioxin toxic equivalent concentration in white sucker (catostomus commersoni) in relation to biochemical indicators of impact
Authors: Van Den Heuvel Michael R. , Servos Mark R. , Dixon D. George , Munkittrick Kelly R. , Van Der Kraak Glen J. , McMaster Mark E. , Portt Cameron B.
Published: March 2010

The H4IIE rat hepatoma bioassay was used to measure 2,3,7,8-tetrachlorodibenzo-p-dioxin toxic equivalent concentrations (TECs) in livers of white sucker (Catostomus commersom) collected downstream from eight Ontario pulp mills and five reference sites. Subsamples of liver were also chemically analyzed for dioxins and furans. Bioassay-derived TECs were compared with TECs calculated from chemical residues using toxic equivalency factors (TEFs) specifically generated for the H4IIE cell line. This indicated that the bioassay-derived TECs could be accounted for largely by the additive effect of the dioxin and furan congeners. Seven of the eight examined mills had significantly higher TECs than the corresponding reference locations. The bioassay-derived TECs were highest at mills that used kraft pulping and chlorine bleaching. Although lower than the kraft mills, the thermomechanical (TMP) and sulfite mills also had higher TECs than the adjacent reference locations. The TECs were compared with hepatic 7-ethoxyresorufin-O-deethylase activity (EROD), as well as with concentrations of the plasma steroid hormones 17β-estradiol, 11-ketotestosterone, and testosterone. Significant correlations were found between EROD activity and TECs in both male and female white sucker. The correlation for males was stronger than that for females. Some of the variability in this relationship for females could be explained by a multivariate regression that added 17β-estradiol to the analysis; a strongly negative relationship between 17β-estradiol and EROD activity was superimposed on the positive EROD-TEC relationship. No significant correlations were found between TECs and 11-ketotestosterone in males, 17β-estradiol in females, and gonadosomatic indexes in either sex. There were significant negative correlations between TECs and testosterone in both sexes.