bluuebunny/crossref_metadata_2025 huggingface dataset:
Transformation of benzonitriles in anaerobic sediment and in sediment extract
Authors: Masunaga Shigeki , Lee Wolfe N. , Carriera Laura
Published: March 2010

Transformations of para-substituted benzonitriles in sediment and in sediment extract were studied. In raw anaerobic sediment, most of the benzonitriles were transformed to benzoic acids without benzamide intermediates. Very slow disappearance of benzonitrile in autoclave-sterilized sediment was explained by the chemical hydrolysis, while relatively rapid decrease in γ-irradiation-sterilized sediment indicated another abiotic mechanism. Hence, extracted protein fraction from sediment active against benzonitrile was surveyed. The obtained active fraction transformed para-substituted benzonitriles to corresponding benzoic acids without any intermediates, which resembled reported nitrilase enzyme activity. Quantitative structure-reactivity relationship (QSRR) analyses of para-substituted benzonitrile transformation-rate constants in raw sediment and in sediment extract fraction indicated that both of them had some correlation with hydrophobicity. This contrasted with the chemical hydrolysis of these compounds, which was controlled by electronic substituent constant (Hammett σp). This was an encouraging sign that the obtained sediment extract fraction is possibly responsible at least for part of the reaction in raw sediment. Various reaction mechanisms are present for degradation of xenobiotics in anaerobic sediment. This study presented the possible abiotic mechanism attributable to protein fraction in sediment. Further studies are necessary to understand the total reaction mechanisms in aquatic sediment.
Modeling silver binding to gills of rainbow trout (Oncorhynchus mykiss)
Authors: Janes Nancy , Playle Richard C.
Published: March 2010

Rainbow trout (Oncorhynchus mykiss, 1–3 g) were exposed to ∼0.1 μM silver (Ag) (∼11 μg.L−1 Ag) for 2 to 3 h in synthetic soft water (Ca, Na ∼ 300 μM, pH 6.5–7.5) to which was added Ca, Na, H+, dissolved organic carbon (DOC), CI, or thiosulfate (S2O3). Gills were extracted and gill Ag concentrations were measured using graphite-furnace atomic absorption spectrophotometry. The concentrations of cations (Ca, Na, H+) and complexing agents (DOC, CI, S2O3) needed to keep Ag off the gills were used to calculate conditional equilibrium binding constants (K) at the gills. Log K for Ag-gill binding was 10.0, with approximately 1.3 nmol Ag binding sites per fish. All experimentally determined log K values were entered into an aquatic chemistry equilibrium model, MINEQL+, to predict Ag binding at trout gills. For a series of natural waters, model-predicted gill Ag concentrations correlated well with observed gill Ag concentrations, with one exception, very hard city of Waterloo tapwater. This exception may indicate a kinetic constraint on the thermodynamic basis of the model.
Acephate affects migratory orientation of the white-throated sparrow (Zonotrichia albicollis)
Authors: Vyas Nimish B. , Hill Elwood F. , Sauer John R. , Kuenzel Wayne J.
Published: March 2010

Migratory white-throated sparrows (Zonotrichia albicollis) were exposed to acephate (acetylphosphoramidothioic acid O, S-dimethyl ester), an organophosphorus pesticide, to determine its effects on migratory orientation and behavior. Birds were also exposed to polarizer sheets to determine the mechanism by which acephate may affect migratory orientation. Adult birds exposed to 256 ppm acephate a.i. were not able to establish a preferred migratory orientation and exhibited random activity. All juvenile treatment groups displayed a seasonally correct southward migratory orientation. We hypothesize that acephate may have produced aberrant migratory behavior by affecting the memory of the migratory route and wintering ground. This experiment reveals that an environmentally relevant concentration of a common organophosphorus pesticide can alter migratory orientation, but its effect is markedly different between adult and juvenile sparrows. Results suggest that the survival of free-flying adult passerine migrants may be compromised following organophosphorus pesticide exposure.
Determination and genotoxicity of high molecular mass polycyclic aromatic hydrocarbons isolated from coal-tar-contaminated sediment
Authors: Marvin Chris H. , Lundrigan John A. , McCarry Brian E. , Bryant Douglas W.
Published: March 2010

A bioassay-directed chemical fractionation methodology was used to identify the principal mutagenic compounds in an organic solvent extract of coal-tar-contaminated sediment from Sydney Harbour, Nova Scotia. Biological assays with Salmonella typhimurium bacteria with the addition of oxidative metabolism indicated that the majority of the mutagenic activity observed in the sediment extract was associated with the higher molecular mass polycyclic aromatic hydrocarbons (PAHs). A normal phase high-performance liquid chromatography (HPLC) technique was developed to separate the PAH-rich solvent extracts into fractions containing isomeric PAHs of a single benzologue class. These fractions were analyzed by probe mass spectrometry and gas chromatography-mass spectrometry (GC-MS), and subjected to biological assays using strain YG1025 with the addition of oxidative metabolism (4% and 10% S9). Fractions containing compounds of molecular weights 252, 276, 278, and 302 amu exhibited mutagenic activities of 930 + 125, 510 + 100, 250 + 40, and 370 + 140 rev/mg sediment, respectively. The molecular weight 252 and 276 amu fractions were further analyzed using reversed-phase HPLC and GC-MS to identify the individual PAHs responsible for the observed biological activity. High molecular mass PAHs including benzo[a]pyrene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and compounds of molecular weight 302 amu were found to be responsible for the majority of the mutagenic activity displayed by this complex environmental mixture.
Response threshold levels of selected organic compounds for rainbow trout (Oncorhynchus Mykiss)
Authors: Kaiser Klaus L.E. , McKinnon Mark B. , Stendahl Douglas H. , Pett Brian W.
Published: March 2010

The responses of 27 organic compounds, mainly chloromethanes, -ethanes, -ethenes, and -phenols, were investigated by exposing rainbow trout fingerlings to low microgram-per-liter concentrations in a darkened flow-through system for up to 1 h. Responses by the fish were followed continuously by observing ventilation rates (frequency and amplitude), swimming patterns, and general activity using the low-voltage electric fields generated by the fishes' activity. The lowest level of response was found for trichloroethylene at 5 μg/L. Dichloromethane, 1,1- and 1,2-dichloroethane, 1,1,1- and 1,1,2-trichloroethane, cis-1,2-dichloroethylene, 1,3-dichloropropene, and allyl acetate were responded to at concentrations of 10 μg/L, carbon tetrachloride at 15 μg/L, and 4-chlorophenol and 2,4-dichlorophenol at levels of 30 μg/L. Unsubstituted phenol was not responded to at levels of up to 50 μg/L.
Influence of developmental stage, salts and food presence on various end points using Caenorhabditis Elegans for aquatic toxicity testing
Authors: Donkin Steven G. , Williams Phillip L.
Published: March 2010

This study used a randomized block design to investigate the importance of several variables in using the free-living soil nematode Caenorhabditis elegans for aquatic toxicity testing. Concentration-response data were obtained on nematodes of various developmental stages exposed to four metals (Cd, Pb, Cu, and Hg) and a water-soluble organic toxicant, sodium pentachlorophenate (PCP), under conditions of varied solvent medium (with or without salts and with or without a bacterial food source). The end points measured were 24- and 96-h mortality LC50 value, as well as development of larval stages to adulthood and evidence of reproduction. The results suggest that nematodes of various ages respond similarly to a given toxicant for all end points measured, although adults cultured from eggs appeared more sensitive than adults cultured from dauer larvae. The most important environmental variable in determining toxicity was the medium in which the tests were conducted. The presence of potassium and sodium salts in the medium significantly (p < 0.05) reduced the toxicity of many test samples. The presence of bacteria had little effect on 24-h tests with salts, but was important in 96-h survival and development. Based on sensitivity and ease of handling, adults cultured from eggs are recommended in both 24-h and 96-h tests.
Inducibility of a molecular bioreporter system by heavy metals
Authors: Klimowski Laura , Rayms-Keller Alfredo , Olson Ken E. , Beaty Barry , Carlson Jon , Yang Ray S. H. , Tessari John
Published: March 2010

We have developed a molecular bioreporter model for detecting an invertebrate response to heavy metals. The bioreporter system, pMt2-luc, utilizes a Drosophila melanogaster metallothionein promoter to regulate luciferase expression in stably transformed mosquito cells. The LucC5 clone, which was isolated from pMt2-luc transformed, hygromycin-resistant C6/36 (Aedes albopictus) cells, demonstrated a 12-fold increase in luciferase-specific activity 48 h after exposure to 13 ppm copper (Cu). In addition to Cu, exposure of LucC5 cells to 19 ppm lead (Pb) or 3 ppm mercury (Hg) for 48 h induced luciferase expression threefold and fourfold, respectively. Exposures of up to 30 ppm arsenic (As), 8 ppm cadmium (Cd), 7 ppm chromium (Cr), or 5 ppm nickle (Ni) had no effect on luciferase induction. LucC5 cells exposed to metal mixtures of 13 ppm Cu and 19 ppm Pb yielded an additive response with a 14-fold increase in luciferase expression. When organic chemicals such as phenol (3 ppm) were mixed with 13 ppm Cu, 19 ppm Pb, or 3 ppm Hg a significant reduction in luciferase activity was noted. Additionally, atomic absorption spectroscopy suggested that two of the metals, Cu and Pb, show marked differences in accumulation within the LucC5 cell line.
Moult frequency of the isopod Porcellio scaber, as a measure of zinc-contaminated food
Authors: Drobne Damjana , Štrus Jasna
Published: March 2010

The effect of zinc-contaminated leaf litter (250–10,000 μ/g dry wt.) diets on molting in Porcellio scaber, a terrestrial isopod was measured under controlled conditions. The duration of the premolt stage, the period between two successive ecdyses and the rate of molting, was followed during the exposure. Increased zinc concentration in the food caused prolongation of the molt cycle and decreased molt frequency. The duration of the premolt stage was not changed. Molt cycle was not affected drastically due to food deprivation. The application of molt cycle response to contaminated food in toxicity tests is discussed.
Interaction of environmental xenobiotics with a multixenobiotic defense mechanism in the bay mussel Mytilus galloprovincialis from the coast of California
Authors: Galgani Francois , Cornwall Roger , Toomey Barbara Holland , Epel David D.
Published: March 2010

A multixenobiotic defense mechanism similar to a P-glycoprotein multidrug transporter was characterized in the gills of the mussel Mytilus galloprovincialis from Monterey, California. Using a fluorescent dye assay, we measured multixenobiotic transport activity in individual gill cells and assessed the effects of inhibitors or competitive substrates on activity. Natural products that inhibit the mammalian transporter also affected dye transport in the mussel gill. Four moderately hydrophobic pesticides (dacthal, chlorbenside, sulfallate, and pentachlorophenol) and four highly hydrophobic xenobiotics (p,p′-DDT, p,p′-DDD, p,p′-DDE, and Aroclor 1254) all inhibited the efflux of dye from the gills, indicating their interaction with a multixenobiotic transport mechanism in this organism. The reactivity with these highly hydrophobic compounds seen in M. galloprovincialis differs from related transporters found in other organisms. A protein in the gill cross-reacts with antibodies directed against the mammalian multidrug transport protein. The level of protein can be assessed easily by dot blot procedures and may facilitate quantitation of protein levels in field situations.
Response of aquatic communities from a vermont stream to environmentally realistic atrazine exposure in laboratory microcosms
Authors: Gruessner Barry , Watzin Mary C.
Published: March 2010

The direct and indirect effects of the herbicide atrazine were assessed at the community level under exposure patterns likely to be experienced by stream organisms in Vermont. Both attached algae and benthic invertebrates were collected from a clean site using artificial substrates and established in recirculating 120–L laboratory microcosms. On day 1 of the 14–d experiment, three of six microcosms were treated with 5 μg/L atrazine. Concentrations were gradually reduced by replacing a portion of the water in the systems over time so that by day 7, atrazine concentrations were only about 1 μg/L. Direct effects of atrazine on algal biomass were assessed by measuring chlorophyll a concentrations in samples of attached algae. No differences in chlorophyll a were found between treatment and control microcosms. Potential indirect effects of reduced algal food availability on benthic invertebrate communities were assessed by comparing assemblages in treatment and control microcosms using both a functional (feeding) group classification and taxonomic composition. There were no significant differences in the functional or taxonomic composition of the benthic invertebrate communities; however, a greater number of insects emerged from the treatment microcosms early in the experiment compared to controls, suggesting some response to atrazine. Further community-level testing is needed to more clearly determine if atrazine is affecting stream organisms.
Effects of rodeo® and garlon® 3A on nontarget wetland species in central Washington
Authors: Gardner Susan C. , Grue Christian E.
Published: March 2010

Purple loosestrife (Lythrum salicaria) is an invasive wetland perennial that became established in northeastern North America in the early 1800s. Despite its designation as a noxious weed, its distribution has continued to expand. Treatment with herbicides is the most widely used means of controlling purple loosestrife. This study examined the nontarget effects of two herbicides, Rodeo® and Garlon® 3A, currently used or being considered for use in controlling purple loosestrife in Washington State, respectively. Growth and/or survival of duckweed, Daphnia, and rainbow trout were monitored for at least 24 h following an application of each herbicide. Free-living water column and benthic invertebrates were monitored 24 h and 7 d post-spray using activity traps and sediment cores. Neither chemical was associated with significant decreases in survival or growth of the bioassay organisms, with the exception that growth of duckweed was reduced 48 h after exposure to Rodeo. Nor were significant decreases in the abundance of free-living aquatic invertebrates detected following the herbicide applications. Results suggest that neither herbicide, at the application rates used, poses a hazard to aquatic invertebrates in wetlands in central Washington. However, Rodeo, because it is a broad-spectrum herbicide, may pose a greater hazard to nontarget aquatic vegetation.
Comparison of the response of bacterial luminescence and mitochondrial respiration to the effluent of an oil refinery
Authors: Riisberg Marianne , Bratlie Ellen , Stenersen Jørgen
Published: March 2010

The effects of oil refinery effluents on rat mitochondrial respiration and on the luminescence of the bacterium Photo-bacterium phosphoreum were compared. Mitochondria from male Wistar rat livers were exposed to different concentrations of refinery effluents in a semiclosed 3–ml reaction vessel. Respiration was measured polarographically with an oxygen electrode. Effects on P. phosphoreum were measured by the standard test developed by Microbics. The mitochondrial method showed EC50s in the range from 1 to 7.5%, while Microtox gave EC50 in the range from 30 to 42%. The higher sensitivity of mitochondria may be exploited in the development of a sensitive biosensor for toxicity of oil refinery effluents.
Reproductive success, developmental anomalies, and environmental contaminants in double-crested cormorants (Phalacrocorax auritus)
Authors: Larson Jill M. , Karasov William H. , Sileo Louis , Stromborg Kenneth L. , Hanbidge Barbara A. , Giesy John P. , Jones Paul D. , Tillitt Donald E. , Verbrugge David A.
Published: March 2010

To test an association between environmental contaminants and the prevalence of congenital anomalies in colonial waterbirds, we collected representative eggs for chemical analysis from double-crested cormorant nests at colonies in Lake Michigan, Wisconsin, USA, and Lake Winnipegosis, Manitoba, Canada, and periodically revisited the nests to determine the hatching success, survivorship of hatchlings, and number of deformed hatchlings in the remainder of each clutch. Total concentrations of polychlorinated biphenyls (PCBs) in eggs were determined by capillary gas chromatography. The combined activity of planar chlorinated hydrocarbons (PCHs) in the eggs was measured in an in vitro bioassay based on the induction of ethoxyresorufin-O -deethylase (EROD) activity in rat hepatoma cells. The combined EROD induction activity was expressed as 2,3,7,8–tetrachlorodibenzo-p -dioxin equivalents (TCDD-EQ). Total concentrations of PCBs and TCDD-EQ were seven to eight times greater in eggs from Lake Michigan (7.8 μg/g and 138 pg/g, respectively) than in those from Lake Winnipegosis (1.0 μg/g and 19 pg/g, respectively). The proportion of eggs hatching at the Lake Michigan colony (59%) was less (p < 0.05) than at Lake Winnipegosis (70%), and the prevalence of hatchlings with deformed bills was greater (p < 0.001) at Lake Michigan (0.79 vs. 0.06%). However, within the Lake Michigan colony, concentrations of PCBs and TCDD-EQ were not correlated with either hatching success or the occurrence of deformities in nestlings.
In situ toxicity evaluations of turbidity and photoinduction of polycyclic aromatic hydrocarbons
Authors: Ireland D. Scott , Burton G. Allen , Hess George G.
Published: March 2010

Polycyclic aromatic hydrocarbons (PAHs) are prevalent pollutants in the aquatic environment that can cause a wide range of toxic effects. Earlier studies have shown that toxicity of PAHs can be enhanced by ultraviolet (UV) radiation. In situ and laboratory exposures with Ceriodaphnia dubia were used to evaluate photoinduced toxicity of PAHs in wet-weather runoff and in turbid conditions. Exposure to UV increased the toxicity of PAH-contaminated sediment to C. dubia. Toxicity was removed when UV wavelengths did not penetrate the water column to the exposed organisms. A significant correlation was observed between in situ C. dubia survival and turbidity when organisms were exposed to sunlight. Stormwater runoff samples exhibited an increase in chronic toxicity (reproduction) to C. dubia when exposed to UV wavelengths as compared to C. dubia not exposed to UV wavelengths. Toxicity was reduced significantly in the presence of UV radiation when the organic fraction of stormwater runoff was removed. The PAHs are bound to the sediment and resuspended into the water column once the sediment is disturbed (e.g., during a storm). The in situ and laboratory results showed that photoinduced toxicity occurred frequently during low flow conditions and wet weather runoff and was reduced in turbid conditions.
An elisa assay for cytochrome P4501A in fish liver cells
Authors: Brüschweiler Beat J. , Fent Karl , Würgler Friedrich E.
Published: March 2010

An enzyme-linked immunosorbent assay (ELISA) for measuring cytochrome P4501A (CY1A) expression in vitro in fish hepatoma cells is described. Cells were cultured as monolayers in 96–microwell cell culture plates and exposed to polychlorinated biphenyl (PCB) congeners 77, 105, 153, and 169; 3–methylcholanthrene (3–MC), and β-naphthoflavone (BNF) for 3 d. Relative CYP1A protein content, CYP1A enzymatic activity, and total protein content were determined directly within the wells. At low concentrations of PCB 77, PCB 169, and 3–MC, the ethoxyresorufin-O - deethylase (EROD) activity was induced, but it was inhibited at high concentrations of these compounds. However, CYP1A protein content measured in an ELISA performed with intact cells increased monotonically in response to the concentration. No CYP1A induction was observed for PCB 105 and PCB 153. Because comparison between EROD activity and CYP1A amount gives information about the catalytic efficiency of CYP1A in the cells, this noncompetitive, solid-phase ELISA is recommended as a complementary method to the EROD assay. This novel ELISA method may be an accurate in vitro technique for a rapid and sensitive screening of CYP1A-inducible compounds.
Benzo[a]pyrene hydroxylase and glutathione s-transferase activities as biomarkers in Lymnaea palustris (mollusca, gastropoda) exposed to atrazine and hexachlorobenzene in freshwater mesocosms
Authors: Baturo Wojciech , Lagadic Laurent
Published: March 2010

Freshwater pond mesocosms were used to validate xenobiotic-metabolizing enzymes as biomarkers of contamination by atrazine and hexachlorobenzene (HCB) in a basommatophoran gastropod, Lymnaea palustris (Müller). Over long-term (21-d) exposure to 5, 25, and 125 μg/L atrazine and to 0.5, 1.25, and 5 μg/L HCB, the uptake and internal concentration of both pesticides were followed, and the activities of benzo[a]pyrene hydroxylase (BaPH) and glutathione S-transferases (GSTs) of pesticide-exposed snails were compared with those of control animals maintained in untreated mesocosms. Internally recovered HCB concentrations were much higher than internal atrazine concentrations, but the uptake of atrazine was faster than that of HCB. Although it affected the integrity of microsomal membranes, HCB had no relevant effects on BaPH and GST activities at concentrations which affected growth and fecundity, thus confirming the low inducibility of mollusc xenobiotic-metabolizing enzymes by chlorinated compounds. In contrast, atrazine markedly inhibited BaPH and both postmitochondrial and cytosolic GSTs at the same concentrations, which had no effects on growth or reproduction. Enzyme inhibition was negatively correlated with the maximal internal amount of atrazine and positively correlated with the bioconcentration factor, suggesting that effects on xenobiotic-metabolizing enzymes may affect pharmacokinetics of atrazine within the snail body. Correlation between the bioconcentration factor and enzyme inhibition may serve as a descriptor of the physiological status of animals and can also be used to indirectly estimate the pesticide concentration in the environment. Laboratory data were considered for the interpretation of results obtained in the mesocosms. In the biomarker context, BaPH and GST activities are proposed, along with other biochemical markers already identified in atrazine- and HCB-exposed L. palustris, as elements of a multiparametric approach of the ecotoxicological effects of pesticides on freshwater ecosystems.
Evaluation of interstitial water as a route of exposure for ammonia in sediment tests with benthic macroinvertebrates
Authors: Whiteman Frank W. , Kahl Michael D. , Rau Daniel M. , Balcer Mary D. , Ankley Gerald T.
Published: March 2010

Ammonia commonly is present at detectable concentrations in overlying and interstitial water in solid-phase sediment toxicity tests. There are scenarios in which it is desirable to discern ammonia toxicity from that caused by other contaminants. The objective of this study was to verify the technical basis for defining the bioavailability of ammonia in solid-phase sediment toxicity tests based on interstitial-(pore-) water concentrations of the compound. We compared the toxicity of ammonia in spiked-sediment versus water-only exposures with the oligochaete Lumbriculus variegatus, the midge Chironomus tentans, and the amphipod Hyalella azteca. Sediment exposures were conducted in a test system that enabled the maintenance of target concentrations of ammonia in pore water, while keeping overlying water concentrations of the compound below potential effect levels. To enable direct comparison of the water-only and sediment exposures, the same test conditions (including pH) were used for each. There was good correspondence between the LC50 values of water-only tests and spiked-sediment toxicity tests for both L. variegatus and C. tentans. Hyalella azteca apparently avoided the spiked sediments and was frequently observed in the less contaminated overlying water, thus limiting the evaluation of a pore-water exposure model for the amphipod. Overall, at least for some benthic species, ammonia bioavailability and toxicity can be accurately predicted from pore-water concentrations of the compound; however, the model maybe less robust for more epibenthic organisms, such as H. azteca.
Phytotoxicity, uptake and metabolism of 1,4-dichlorobenzene by plant cells
Authors: Jones Kevin C. , Wang Min-Jian , Bokern Maria , Boehme Christian , Harms Hans
Published: March 2010

Phytotoxicity, uptake, and metabolism of 14-dichlorobenzene (1,4-DCB) by carrot (Daucus carota L.), soybean (Glycine max. L.), tomato (Lycopersicon esculentum Mill.), and red goosefoot (Chenopodiun rubrum L.) cell suspension cultures were studied. Sealed glass systems were utilized for the investigation because 1,4-DCB is volatile. The sealed systems affect the growth of plant cells, but do not provide different results when testing xenobiotic uptake and metabolism. 1,4-Dichlorobenzene (40 μg in 40 ml medium) was taken up by carrot (49%), soybean (50%), and red goosefoot (62%) cells. Only the soybean cell cultures provided evidence of the existence of metabolites of this compound, probably conjugates of chlorophenols. Conditions for phytotoxicity tests were modified because the growth of cell cultures was affected when sealed for longer than 2 d. 1,4-Dichlorobenzene is toxic to cell cultures of the three tested plant species (tomato, soybean, and carrot). Concentrations of 0.5 mM caused 50% growth inhibition in carrot and soybean cultures. The tomato cultures were more sensitive, with 0.05 mM causing 50% growth inhibition.
A dynamic new alarm system for use in biological early warning systems
Authors: Sluyts Hilde , Van Hoof François , Cornet Anja , Paulussen Jozef
Published: March 2010

The Musselmonitor® (Delta Consult, Kapelle, The Netherlands) is a biomonitor that uses the valve position and the activity of eight Dreissena polymorpha to monitor the water quality. The normal behavior was studied to evaluate whether eight mussels are sufficient for reliable and reproducible data. The Musselmonitor was placed on a location with strong fluctuations of physical and chemical parameters. The results clearly indicate significant correlations between the valve position and the activity of the mussels and several parameters, such as temperature and concentration of suspended material (represented as turbidity and chlorophyll concentration). The valve position also indicates diurnal and seasonal rhythms in the natural behavior. A new data analyzing system was developed for the Musselmonitor, which takes into account the natural fluctuations in the behavior. The sensitivity of the dynamic data analyzing system was evaluated with copper (20, 40, 50, and 80 μg/L) in dosage experiments and the results were compared with the existing static alarm system. The study revealed that static threshold levels are insensitive and require a lot of experience. The dynamic alarm system works satisfactorily with the Musselmonitor and is very useful for the detection of discontinuities in the normal behavior.
Acute toxicity of three fire-retardant and two fire-suppressant foam formulations to the early life stages of rainbow trout (Oncorhynchus mykiss)
Authors: Gaikowski Mark P. , Hamilton Steven J. , Buhl Kevin J. , McDonald Susan F. , Summers Cliff H.
Published: March 2010

Laboratory studies were conducted with five early life stages of rainbow trout, Oncorhynchus mykiss, to determine the acute toxicities of five fire-fighting chemical formulations in standardized soft and hard water. Eyed egg, embryo–larvae, swim-up fry, and 60- and 90-d posthatch juveniles were exposed to three fire retardants (Fire-Trol LCG-R, Fire-Trol GTS-R, and Phos-Chek D75-F) and two fire-suppressant foams (Phos-Chek WD-881 and Silv-Ex). Swim-up fry were generally the most sensitive life stage, whereas the eyed-egg was the least sensitive. Toxicity of fire-fighting formulations was greater in hard water than in soft water for all life stages tested with Fire-Trol GTS-R and Silv-Ex and for 90-d-old juveniles tested with Fire-Trol LCG-R. The fire-suppressant foams were more toxic than the fire retardants. The 96-h median lethal concentrations (LC50s) were ranked from the most toxic to the least toxic formulation as follows (ranges are the lowest and highest 96-h LC50 calculated for each formulation): Phos-Chek WD-881 (11–44 mg/L), Silv-Ex (11–78 mg/L), Phos-Chek D75-F (218–>3,600 mg/L), Fire-Trol GTS-R (207–>6,000 mg/L), and Fire-Trol LCG-R (872–>10,000 mg/L). Toxicity values suggest that accidental entry of fire-fighting chemicals into aquatic environments could adversely affect fish populations.
Quantitative description of mixture toxicity: Effect of level of response on interactions
Authors: Haas Charles N. , Cidambi Kaushik , Kersten Sean , Wright Kenneth
Published: March 2010

The simultaneous exposure of a biological system to a mixture of toxic substances may result in an ideal or nonideal combination of effects. In an extension of linear isobole theory, models are quantitatively developed to describe these combinations, in which the nature of the nonideal effect combination may or may not be a function of the magnitude of predicted response (as opposed to only the proportions of the substances in a mixture). The approach is tested using data on rat carcinogenesis, drug action, and aquatic toxicity of pesticides. In the cases examined, the models predict substantial deviation from ideal behavior even under low doses.
Factors that affect the degradation of naphthenic acids in oil sands wastewater by indigenous microbial communities
Authors: Lai June W. S. , Pinto Linda J. , Bendell-Young Leah I. , Moore Margo M. , Kiehlmann Eberhard
Published: March 2010

The acute toxicity of wastewater generated during the extraction of bitumen from oil sands is believed to be due to naphthenic acids (NAs). To determine the factors that affect the rate of degradation of representative NAs in microcosms containing wastewater and the acute toxicity of treated and untreated wastewater, the effects of temperature, dissolved oxygen concentration, and phosphate addition on the rate of 14CO2 release from two representative naphthenic acid substrates, (linear) U-14C-palmitic acid (PA) and (bicyclic) decahydro-2-naphthoic acid-8-14C (DHNA), were monitored. Tailings pond water (TPW) contained microorganisms well adapted to mineralizing both PA and DHNA: PA was degraded more quickly (10–15% in 4 weeks) compared to DHNA (2–4% in 8 weeks). On addition of phosphate, the rate of NA degradation increased up to twofold in the first 4 weeks, with a concurrent increase in the rate of oxygen consumption by oil sands TPW. The degradation rate then declined to levels equivalent to those measured in flasks without phosphate. The observed plateau was not due to phosphate limitation. Decreases in either the dissolved oxygen concentration or the temperature reduced the rate. Phosphate addition also significantly decreased the acute toxicity of TPW to fathead minnows. In contrast, Microtox® analyses showed no reduction in the toxicity of treated or untreated TPW after incubation for up to 8 weeks at 15°C.
Enhanced accumulation of PCB congeners by baltic sea blue mussels, Mytilus edulis, with increased algae enrichment
Authors: Gilek Michael , Björk Mikael , Kautsky Nils , Broman Dag , Näf Carina
Published: March 2010

The objective of this study was to examine if natural variations in the quantity of phytoplankton-derived particulate and dissolved organic carbon influences the accumulation of polychlorinated biphenyls (PCBs) in the tissues of Baltic Sea blue mussels (Mytilus edulis L.). In a laboratory flow-through experiment we exposed M. edulis to the technical PCB mixture Aroclor® 1248 for 21 d at three different enrichments of the unicellular green algae Chlamydomonas sp., 0.10, 0.16, and 0.32 mg particulate organic carbon (POC)/L. Tissue and water concentrations were determined for seven PCB congeners (International Union of Pure and Applied Chemistry [IUPAC] 52, 101, 105, 118, 138, 153, and 180), and 21-d bioaccumulation factors were calculated against total water concentrations. Contrary to what would be expected, an increase in algae enrichment from 0.10 to 0.32 mg POC/L resulted in an enhanced PCB accumulation by a factor of approx. 2. This increase in PCB accumulation was more pronounced for PCB congeners with lower hydrophobicity. These observations have implications for the design of laboratory accumulation studies and potentially for PCB accumulation and cycling in field populations of suspension-feeding mussels in response to changes in eutrophication status.
Assessing the fate of new and existing chemicals: A five-stage process
Authors: Mackay Donald , Di Guardo Antonio , Paterson Sally , Kicsi Gabriel , Cowan Christina E.
Published: March 2010

A five-stage process is described for obtaining an understanding of the fate of a substance after discharge to the environment and for predicting the concentrations to which organisms in various environmental media will be exposed. These five stages are: classifying the substance as to its chemical type and collecting the appropriate physical, chemical, and reactivity data based on this classification; obtaining information on the substance's past, present, and/or proposed production, use, and discharges and, if appropriate, background concentrations; conducting an evaluative fate assessment with the objective of determining the general features of the substance's behavior; conducting a regional or far-field fate evaluation using regional climatic and geographic conditions, to determine the role of environmental conditions on the substance's behavior and estimate average regional concentrations; and conducting one or more local or near-field evaluations on points of entry and other potentially impacted sites to predict the exposure concentration. With this information on fate, risk can be assessed by comparing predicted environmental concentrations with no-effect concentrations. This paper contains a detailed discussion of stage 1 (classification into one of five categories) and a discussion of how multimedia models can be used to conduct the evaluative (stage 3), regional (stage 4), and near-field (stage 5) assessments.
The accumulation in lysosomes of the anionic detergent linear alkylbenzene sulfonate
Authors: Bragadin Marcantonio , Perin Guido , Raccanelli Stefano , Manente Sabrina
Published: March 2010

This in vitro study provides evidence that the anionic detergent linear alkylbenzene sulfonate (LAS) enters energized lysosomes from rat liver. Because LAS is lipophilic and negatively charged, the uptake is due to the presence of a positive inside potential induced by energization of lysosomes. This accumulation could explain some damage caused by sublethal doses of detergent in some aquatic species, as it has been found that LAS inhibits lysosomal enzymes such as acid phosphatase and alkaline phosphatase.
A 7-D toxicity test for marine pollutants using the pacific mysidMysidopsis intii.1. Culture and protocol development
Authors: Langdon Chris J. , Vance Mitch M. , Harmon Valerie L. , Kreeger Karen E. , Kreeger Dan A. , Chapman Gary A.
Published: March 2010

The purpose of this study was to develop a short-term (7-d) toxicity test for marine pollutants that is practical to perform at sites remote from a source of test organisms. Laboratory culture methods were developed that allowed successful long-term rearing of populations of the mysid Mysidopsis intii, a species indigenous to the Pacific coast of the United States. Mysidopsis intii was found to have a short life cycle of 20 d at 20°C, making it useful for chronic toxicity tests. A 7-d toxicity test was developed by comparing the sensitivities of various life stages of M. intii to sodium dodecyl sulfate (SDS). The most sensitive end point was found to be growth (final body length) of juveniles during the first 7 d after release. The sensitivity of mysids to SDS decreased with increasing age. To allow for shipping newly released juveniles to remote sites, a 7-d test was evaluated starting with 2-d-old mysids. The median lethal concentration for M. intii exposed to SDS at ages from 2 to 9 d was 4.59 mg/L (95% confidence limits, 4.21–5.00), and the maximum acceptable SDS concentration was 4.99 mg/L for both survival and growth.
The body ion loss biomarker. 2. Field validation in coal mine-polluted streams
Authors: Grippo Richard S. , Dunson William A.
Published: March 2010

We performed a field validation of the body ion loss biomarker by developing a predictive model of the level of impact of coal mining on receiving streams. Hatchery brook charr (Salvelinus fontinalis; wet mass = 1.25 to 32.2 g) were exposed in four mine-impacted streams that exhibited differing levels of acid and trace metals and in two unimpacted control streams. Net whole-body ion (Na, Ca) fluxes over a 4-h exposure were determined. Stepwise regression was used to develop predictive models of body ion flux over 4 h from measured stream water chemistry variables. The predictive power of the best model was assessed using cross validation. The best model predicting net sodium flux explained 48% of the variability in the model with six chemical variables (Mn, Zn, Mg, Al, Fe, and Na). The model of calcium flux explained 42% of the variation with eight variables (H+, Ca, Na, Mn, Al, Ni, Mg, and Zn). A multiple regression model derived from principal components analysis did not significantly improve the predictive power of these models. We conclude that whole-body net sodium flux and to a lesser extent whole-body net calcium flux are acute indicators of the level of impact of acid and trace metals in streams polluted by coal mine discharge and may be useful as biomarkers under field conditions.
Ethoxyresorufin-O-deethylase induction potency of polychlorinated diphenyl ethers in H4IIE rat hepatoma cells
Authors: Koistinen Jaana , Sanderson J. Thomas , Giesy John P. , Nevalainen Tapio , Paasivirta Jaakko
Published: March 2010

Polychlorinated diphenyl ethers (PCDEs) are structurally similar to polychlorinated biphenyls (PCBs), and some PCDE congeners have been reported to cause toxic responses similar to those caused by some of the non-ortho-substituted PCBs, which are mediated by the aryl hydrocarbon receptor (AhR). Twenty-nine PCDEs were tested for their potency as AhR agonists relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) by measuring their ability to induce the cytochrome P-450 1A1-associated enzyme activity, ethoxyresorufin-O-deethylase (EROD), in the H4IIE rat hepatoma cell bioassay. All PCDE congeners tested were found to be inactive as EROD inducers except for PCDE 156, which was a weak EROD inducer with a 2,3,7,8-TCDD equivalency factor of about 1.2 × 10−5. During this study we determined that small amounts of polychlorinated dibenzofurans (PCDFs) that occurred as impurities in the PCDE preparations were the cause of the apparent EROD induction initially measured in our experiments. Once the PCDF impurities were removed by purification on florisil, little or no activity could be attributed to the PCDEs.
Effects of acid-volatile sulfide on zinc bioavailability and toxicity to benthic macroinvertebrates: A spiked-sediment field experiment
Authors: Liber Karsten , Call Daniel J. , Markee Thomas P. , Schmude Kurt L. , Balcer Mary D. , Whiteman Frank W. , Ankley Gerald T.
Published: March 2010

Acid-volatile sulfide (AVS) has been proposed as the primary normalization phase for the development of sediment quality criteria for certain cationic metals. This study was designed to assist in this development by providing necessary field data on the relationships among season, AVS concentrations, and zinc bioavailability and toxicity in freshwater sediments. Zinc was spiked into uncontaminated sediments collected from a local pond, creating five simultaneously extracted metal (SEM) concentrations ranging from 0.8 to 12.0 μmol/g dry weight. The spiked sediments were transferred to 4-L plastic trays, returned to the bottom of the pond, and sampled on five dates during 1993-1994. Results revealed a pronounced increase in AVS concentration with increasing zinc concentration. Acid-volatile sulfide concentrations in zinc-spiked sediments displayed only minor seasonal variation but were lowest in surficial (0-2 cm) sediments. Acid-volatile sulfide concentrations always exceeded SEM concentrations at ≤6.0 μmol SEM/g; only at 12.0 μmol SEM/g did SEM/AVS ratios exceed 1.0. Zinc was rarely detected in pore water at any treatment and never at concentrations which should have posed a hazard to benthic macroinvertebrates. No substantial effect on colonization of zinc-spiked sediments by benthic macroinvertebrates was observed. Only oligochaetes (Naididae) were significantly reduced in abundance at the high zinc treatment, although reductions were occasionally evident for other taxa. Lack of noteworthy pore-water zinc concentrations and lack of associated, ecologically meaningful effects were attributed to the increase in AVS levels observed with increasing SEM zinc sediment concentration. The increases in AVS theoretically resulted from a replacement of natural iron and manganese sulfides with the more stable zinc sulfide complex.
Bioconcentration and depuration of avermectin B1a in the bluegill sunfish
Authors: van Den Heuvel W.J.A. , Halley B.A. , Ku C.C. , Jacob T.A. , Wislocki P.G. , Forbis A.D.
Published: March 2010

A dynamic 42‒d study was conducted to evaluate the bioconcentration of [3H]avermectin B1a in the bluegill sunfish (Lepomis macrochirus). A mean water concentration of 0.099 μg/L was maintained for a 28‒d exposure period. Radioassay throughout the exposure period indicated a gradual uptake of radioactivity that reached steady state at about 10 to 14 d; the day 28 tissue residue values were 6.8, 3.0, and 11 μg/kg, in whole fish, fillet, and viscera, respectively. Following this 28‒d uptake period, fish were placed in control water for 14 d to permit monitoring of elimination of radioactivity. Radioassay indicated 91 to 95% clearance, with the tissue residues dropping by day 14 of the depuration period to 0.32, 0.27, and 0.53 μg/kg, respectively. A one‒compartment kinetic model was used for analysis of the uptake‒depuration data and yielded for whole fish an uptake rate constant of 12 L kg‒1 d‒1, a depuration rate constant of 0.21 d‒1 (t½ of 3.3 d), and a steady‒state residue concentration of 5.5 μg/ kg. The corresponding bioconcentration factor (BCF) for whole fish was 56 L/kg. Uptake and depuration rate data for fillet and viscera were not significantly different (α= 0.05) than the values for whole fish. The BCF values for fillet and viscera were 28 and 84 L/kg, respectively. The data are consistent with rapid depletion of abamectin (and the structurally related anthelmintic ivermectin) from the tissues of other animals (rats, sheep, cattle). Abamectin does not strongly bioconcentrate in aquatic organisms and would not be expected to biomagnify.
Transboundary pollution: Persistent organochlorine pesticides in migrant birds of the Southwestern United States and Mexico
Authors: Mora Miguel A
Published: March 2010

The hypothesis that migratory birds accumulate persistent organochlorine pesticides (POPs) during the winter in Latin America has been prevalent for many years, particularly since 1,1,1-trichloro-2,2–bis(p-chlorophenyl)ethane (DDT) was banned in the United States in 1972. It has been suggested that peregrine falcons (Falco peregrinus), black-crowned night herons (Nycticorax nycticorax), white-faced ibises (Plegadis chihi), various migratory waterfowl and shorebirds, and other avian species accumulate higher concentrations of POPs while on migration or on their wintering grounds in Latin America. Nonetheless, the data obtained thus far are limited, and there is no clear pattern to suggest that such accumulation occurs on a widespread basis. In this review wildlife contaminant studies conducted along the U.S.-Mexico border and throughout Mexico are discussed. The results for the most part seem to indicate that no major accumulation of 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene) (DDE), the most persistent organochlorine compound, has occurred or been reported for most parts of Mexico. The majority of the DDE values in birds from Mexico were similar to those reported in birds from the southwestern United States during the same years. More work needs to be done, particularly in those cotton-producing areas of Mexico where DDT was applied heavily in the past (e.g., Chiapas and Michoacan). Because DDT is still used for malaria control and may still be used in agriculture in Chiapas, this state is probably the one where most migrant species would still be at a significant risk of increased accumulation of DDE and DDT.
Agrochemical use on banana plantations in Latin America: Perspectives on ecological risk
Authors: Henriques William , Jeffers Russel D , Lacher Thomas E , Kendall Ronald J
Published: March 2010

Developing tropical nations have greatly expanded their agricultural production during the past decade. Substantial areas of tropical ecosystems have been altered to accommodate agriculture. Banana cultivation is responsible for much of this habitat alteration. Substantial use of agricultural chemicals is required to successfully cultivate bananas, and this has raised concern over the effects of these chemicals on workers, wildlife, and tropical environments in general. We review the practice of banana cultivation and address the major chemical inputs to plantations. Numerous cases of pesticide-related health problems in Latin American plantation workers have been documented, and most were attributable to incorrect use and handling. A review of known wildlife-related impacts of agricultural chemicals commonly used in banana plantations raises substantial concerns about the large-scale environmental impacts in tropical terrestrial and aquatic environments. We recommend the application of an environmental risk assessment process to the use of agricultural chemicals on banana plantations. The process should follow the paradigm as outlined by the U.S. Environmental Protection Agency. Such a study would create a precedent for the assessment of environmental risk in the tropics.
Impact of petroleum pollution on aquatic coastal ecosystems in Brazil
Authors: Da Silva Eduardo Mendes , Peso-Aguiar Marlene Campos , De Fátima Teixeira Navarro Maria , De Barros E Azevedo Chastinet Carla
Published: March 2010

Although oil activities generate numerous forms of environmental impact on biological communities, studies of these impacts on Brazilian coastal ecosystems are rare. Results of tests for the content of oil in sediments and organisms indicate a substantially high rate of degradation. Results for uptake of polycyclic aromatic hydrocarbons in bivalves suggested the recent occurrence of oil spills and that these organisms differed in their capabilities to bioconcentrate oil. The mangrove community has suffered constant inputs of oil and has responded with increased numbers of aerial roots, generation of malformed leaves and fruits by plants, and a decrease in litter production. Studies of the impact of oil on rocky shore communities and the toxicity of oil and its by-products to marine organisms have confirmed the results reported in the literature. Presently most of the available studies deal with the macroscopic effects of oil on organisms and have indicated that the nature of oil, climate characteristics, the physical environment, and the structure of the community influence the symptoms of oil contamination in organisms of coastal waters. Longterm studies should be carried out to assess changes in community structure, sublethal effects in populations, and the resilience of contaminated ecosystems.