bluuebunny/crossref_metadata_2025 huggingface dataset:
Characterization of dioxin-like activity of sediments from a Czech River Basin
Authors: Hilscherova Klara , Kannan Kurunthachalam , Kang Youn-Seok , Holoubek Ivan , Machala Miroslav , Masunaga Shigeki , Nakanishi Junko , Giesy John P
Published: March 2010

Synthetic organic chemicals are present in environmental compartments as complex mixtures and therefore their potential effects are difficult to predict. In this study, in vitro bioassays using wild-type fish and rat hepatoma cell lines and their corresponding recombinant cell systems were used to evaluate 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like activity in extracts of sediments collected from rivers of the Czech Republic. All the sediment extracts elicited statistically significant responses in all the cell lines tested. For most sediment extracts, a complete dose–response relationship was obtained. The maximal efficacy of the samples was between 57 and 143% of the maximal induction elicited by TCDD. Greater responsiveness, sensitivity, and reproducibility were observed for recombinant than wild-type cells. Cell line-specific differences in the sensitivity to compounds present in the complex sediment extracts were observed. The TCDD equivalents (TCDD-EQs) determined from the different cell bioassays were correlated. Greater concentrations of TCDD-EQs were obtained with fish cell lines. The TCDD-EQs calculated from the results of chemical analysis of toxic equivalents (TEQs) were in good agreement with those determined by bioassays; the arly hydrocaron receptor (AhR)-effects of the identified chemicals appear to be generally additive. This indicates that most of the TCDD-like activity was accounted for by the compounds identified and quantified by instrumental analysis. Fractionation along with mass-balance calculations allowed identification of the active fractions and classes of compounds. Polycyclic aromatic hydrocarbons (PAHs) were found to be responsible for most of the AhR-mediated activity in sediments.
Response of phytoplankton communities to liquid creosote in freshwater microcosms
Authors: Sibley Paul K , Harris Megan L , Bestari Ketut T. (Jim) , Steele Tracey A , Robinson Richard D , Gensemer Robert W , Day Kristen E , Solomon Keith R
Published: March 2010

We assessed the response of phytoplankton communities in aquatic microcosms to single applications of liquid creosote. The creosote was applied to 14 microcosms at concentrations ranging from 0.06 to 109 mg/L. Two microcosms served as controls. Phytoplankton samples were collected from each microcosm one week and 1 d before treatment and at 7 and 21 d after treatment. Temporal changes (response–recovery) in phytoplankton community composition were assessed with principal response curves. Creosote had no direct toxic effect on the phytoplankton community based on total abundance and number of taxa. Population levels declined in all treatments between day −1 and day 7, but this trend mirrored a similar decline in the control microcosms. At both 7 and 21 d after treatment, population densities and number of taxa in most treatments exceeded those in the controls and exhibited a parabolic relationship relative to creosote concentration. This relationship was most pronounced at 21 d, at which time population densities and number of taxa at intermediate concentrations were up to twice those at low and high concentrations. This response pattern seems to represent an indirect response to impacts on zooplankton and a corresponding reduction in grazing pressure. In contrast, total algal biomass declined 52 to 97% relative to the controls at all but the lowest creosote concentration at 7 d. This apparent decline was due to a significant proliferation of the alga Closterium moniliforme in the controls and low creosote concentration. At 21 d, no difference was found in total biomass between treated and control microcosms. The results of this study suggest that creosote does not pose a significant direct risk to phytoplankton at concentrations likely to be encountered in most contaminated aquatic environments; however, stimulation of algal populations could occur in situations of long-term chronic exposure or spill events that remove predatory zooplankton populations.
Trace element accumulation in hawksbill turtles (Eretmochelys imbricata) and green turtles (Chelonia mydas) from Yaeyama Islands, Japan
Authors: Anan Yasumi , Kunito Takashi , Watanabe Izumi , Sakai Haruya , Tanabe Shinsuke
Published: March 2010

Concentrations of 18 trace elements (V, Cr, Mn, Co, Cu, Zn, Se, Rb, Sr, Zr, Mo, Ag, Cd, Sb, Ba, Hg, Tl, and Pb) were determined in the liver, kidney, and muscle of green turtles (Chelonia mydas) and hawksbill turtles (Eretmochelys imbricata) from Yaeyama Islands, Okinawa, Japan. Accumulation features of trace elements in the three tissues were similar between green and hawksbill turtles. No gender differences in trace element accumulation in liver and kidney were found for most of the elements. Significant growth-dependent variations were found in concentrations of some elements in tissues of green and hawksbill turtles. Significant negative correlations (p < 0.05) were found between standard carapace length (SCL) and the concentrations of Cu, Zn, and Se in the kidney and V in muscle of green turtles and Mn in the liver, Rb and Ag in kidney, and Hg in muscle of hawksbill turtles. Concentrations of Sr, Mo, Ag, Sb, and Tl in the liver, Sb in kidney, and Sb and Ba in muscle of green turtles and Se and Hg in the liver and Co, Se, and Hg in kidney of hawksbill turtles increased with an increase in SCL (p < 0.05). Green and hawksbill turtles accumulated extremely high concentrations of Cu in the liver and Cd in kidney, whereas the levels of Hg in liver were low in comparison with those of other higher–trophic-level marine animals. High accumulation of Ag in the liver of green turtles was also observed. To evaluate the trophic transfer of trace elements, concentrations of trace elements were determined in stomach contents of green and hawksbill turtles. A remarkably high trophic transfer coefficient was found for Ag and Cd in green turtles and for Cd and Hg in hawksbill turtles.
Heavy metals and selenium in feathers of great tits (Parus major) along a pollution gradient
Authors: Janssens Ellen , Dauwe Tom , Bervoets Lieven , Eens Marcel
Published: March 2010

We evaluated the use of great tit (Parus major) feathers as biomonitors for heavy-metal pollution and tested whether there were differences in metal levels in feathers as a function of location, age (first year or older), or gender. In 1998 and 1999, we collected the outermost tail feathers of 185 great tits from four sites along a presumed pollution gradient and one reference site in Antwerp (Belgium) and analyzed them for calcium, selenium, and 13 heavy metals (silver, aluminum, arsenic, cadmium, cobalt, chromium, copper, iron, mercury, manganese, nickel, lead, and zinc). Silver, arsenic, cadmium, cobalt, copper, mercury, nickel, lead, selenium, and zinc concentrations were significantly higher closest to the pollution source (UM site) compared with the other four sites. Heavy-metal and selenium levels were on average 2 to 40 times higher at the UM site compared with the reference site. Aluminum, calcium, and iron levels were not significantly different among sites. We found no general age- or gender-related differences in metal levels except for arsenic and iron, where a significant interaction between site and gender was observed. Our results suggest that feathers of great tits might be useful biomonitoring tools because they reflect the environmental contamination by heavy metals well.
Development of copepod nauplii to copepodites—a parameter for chronic toxicity including endocrine disruption
Authors: Andersen Henrik Rasmus , Wollenberger Leah , Halling-Sørensen Bent , Kusk Kresten Ole
Published: March 2010

Test compounds including natural hormones, endocrine disrupters, environmentally occurringcompounds, and reference compounds were tested for acute toxicity and inhibitory effect on larval development in the copepod Acartia tonsa. Three compounds, 17α-ethinylestradiol, p-octylphenol, and tamoxifen, known for their differing effects on the vertebrate estrogen system, were potent inhibitors of naupliar development. Other estrogens, 17β-estradiol, estrone, and bisphenol A, had little potency. Testosterone and progesterone did not inhibit development, but the antiandrogen flutamide had inhibitory effect. Juvenile hormone III was a potent inhibitor, as was expected based on the literature, whereas 20-hydroxyecdysone had no effect. 3,4-Dichloroaniline was inhibitory on development, whereas other control compounds, potassium dichromate and 3,5-dichlorophenol, did not inhibit development. Six of the 17 test compounds had 50% lethal concentration to 50% effective concentration (EC50) ratios higher than 10. The results suggest that naupliar development, as a parameter, is able to detect hormonal disrupters in addition to other chemicals that have other specific modes of action.
Subchronic exposure of BALB/c and C57BL/6 strains of Mus musculus to the radioactive environment of the Chornobyl, Ukraine exclusion zone
Authors: Rodgers Brenda E , Chesser Ronald K , Wickliffe Jeffrey K , Phillips Carleton J , Baker Robert J
Published: March 2010

Environmental contamination resulting from the Chornobyl, Ukraine, disaster offers a unique opportunity to examine the in vivo biological effects of chronic, low-dose exposure to radiation. Laboratory studies of acute exposure to ionizing radiation have been used to estimate risk and potential human health effects by the extrapolation of laboratory data to situations of low-dose environmental radiation exposure. Few studies, however, have explored the biological consequences of low-dose exposure via in situ environmental radiation in a sentinel species. In the present study, laboratory strains of Mus musculus (BALB/c and 57BL/ 6) were placed in environmental enclosures in the Red Forest region of the Chornobyl exclusion zone. Blood samples were obtained every 10 d, and the micronucleus (MN) test was employed to assess the potential for cytogenetic damage from exposure to Chornobyl radiation. Radionuclide uptake was monitored throughout the study, and dose was estimated for each individual as well as for their offspring. Total dose for the mice experimentally exposed to this environment averaged 1162 mGy for BALB/c (30 d) and 1629 mGy for C57BL/6 (40 d). A higher MN frequency for both strains was observed at day 10, although this change was only statistically significant in the C57BL/6 mice (χ23 = 13.41, p = 0.003). Subsequent samples from C57BL/6 resulted in values at or less than the initial frequencies. In BALB/c mice, an increase in MN was also evident at day 30 (χ22 = 10.38, p = 0.006). The experimental design employed here allows for the incorporation of traditional laboratory strains, as well as transgenic strains of Mus, as sentinels of environmental radiation contamination.
Sexual disruption in a second species of wild cyprinid fish (the gudgeon, Gobio gobio) in United Kingdom Freshwaters
Authors: van Aerle Ronny , Nolanusan Monique , Jobling Susan , Christiansen Lisette B , Sumpter John P , Tyler Charles R
Published: March 2010

To establish whether the intersex condition seen in the roach (Rutilus rutilus) in United Kingdom (UK) rivers was species specific or a more general phenomenon in fish, evidence for sexual disruption was sought in a second cyprinid species, the gudgeon (Gobio gobio). Gudgeon were collected from the Rivers Aire and Lea (at locations that receive high-volume discharges of sewage treatment works [STW] effluent and that contain intersex roach) and from two still waters, and their gonads were examined histologically for evidence of intersexuality (the simultaneous presence of oocytes and testicular tissue). Intersex gonads were found at all sites, with the highest incidences occurring at one of the still waters (Lakeside Fisheries: 15%) and at sites on the River Aire (Thwaite Weir, Silsden Bridge, and Knostrop: 14, 13, and 12%, respectively). In the River Lea and Longton Park Lake, the incidence of intersexuality in gudgeon was 6%. In most cases, intersex gonads were characterized by a few primary oocytes/gonad section in an otherwise normal testis. However, at some sites on the River Aire (Thwaite Weir and Knostrop), the intersex condition was more severe. At Thwaite Weir, for example, more than half of the gonad in 40% of the intersex fish was comprised of ovarian tissue. Elevated concentrations of plasma vitellogenin both in male and in intersex fish indicated that fish had been exposed to estrogen(s). Some of the gudgeon were found at sites several kilometers downstream of any point discharge of STW effluent; therefore, the results likely are representative of this species in wild populations found in typical UK river ecosystems. Together with the findings in the roach, these data on the gudgeon confirm that sexual disruption in fish in UK rivers is not species specific.
Evaluation of bioassays versus contaminant concentrations in explaining the macroinvertebrate community structure in the Rhine-Meuse delta, The Netherlands
Authors: Peeters Edwin T H M , Dewitte Anouk , Koelmans Albert A , van der Velden Joan A , den Besten Pieter J
Published: March 2010

It is often assumed that bioassays are better descriptors of sediment toxicity than toxicant concentrations and that ecological factors are more important than toxicants in structuring macroinvertebrate communities. In the period 1992 to 1995, data were collected in the enclosed Rhine-Meuse delta, The Netherlands, on macroinvertebrates, sediment toxicity, sediment contaminant concentrations, and ecological factors. The effect of various groups of pollutants (polycyclic aromatic hydrocarbons, trace metals, oil, polychlorinated biphenyls) and of ecological variables on the structure of the macroinvertebrate community were quantified. Ecological factors explained 17.3% of the macroinvertebrate variation, while contaminants explained 13.8%. Another 14.7% was explained by the covariation between ecological variables and contaminants. Polycyclic aromatic hydrocarbons explained a larger part of the variation than trace metals. The contributions of oil and polychlorinated biphenyls were small but significant. Elevated contaminant concentrations were significantly associated with differences in the macroinvertebrate food web structure. The response in bioassays (Vibrio fischeri, Daphnia magna, Chironomus riparius) was susceptible to certain contaminants but also to certain ecological factors. There was a weak correlation between in situ species composition and bioassays; 1.9% of in situ macroinvertebrate variation was explained by the bioassay responses. This seems to contradict the validity of using bioassays for a system-oriented risk assessment. Possible reasons for this discrepancy might be the manipulations of the sediment before the test and a higher pollutant tolerance of the in situ macroinvertebrates. Thus, macroinvertebrate field surveys and laboratory bioassays yield different types of information on ecotoxicological effects, and both are recommended in sediment risk assessment procedures.
Modeling pentachlorophenol bioavailability and bioaccumulation by the freshwater fingernail clam Sphaerium corneum using artificial particles and humic acids
Authors: Guerrero Noemi R. Verrengia , Taylor Marina G , Wider Eva A , Simkiss Kenneth
Published: March 2010

The uptake of anthropogenic chemicals by benthic bivalves may occur through the water phase and also by the ingestion of particles from both the suspended matter and bottom sediments. Many chemicals sorb to sediments and, subsequently, are released in the digestive tract of animals. The assessment of sediment-bound chemicals has been difficult because of the complexity of the association between these chemicals and natural particles. To simplify this complexity, we previously devised a test system using artificial particles with known chemical structures. In the present work, we improved this experimental design by adding humic materials as a source of organic matter. Bioassays were conducted by exposing the fingernail clam Sphaerium corneum to sublethal levels of pentachlorophenol (PCP) in the presence or absence of the artificial particles, treated with or without a commercial preparation of humic acids. The results showed that the bioavailability and bioaccumulation could be explained on the basis of the interactions of PCP with the active groups and/or the backbone of the resins, both in systems with or without humic acids. This model may constitute a useful approach to modeling and predicting the uptake and accumulation of chemicals bound to natural sediments.
Air—water exchange of polycyclic aromatic hydrocarbons in the New York—New Jersey, USA, Harbor Estuary
Authors: Gigliotti Cari L. , Brunciak Paul A. , Dachs Jordi , Glenn Thomas R. , Nelson Eric D. , Totten Lisa A. , Eisenreich Steven J.
Published: March 2010

Polycyclic aromatic hydrocarbons (PAHs, n = 36) were measured in the gas and particle phases in the atmosphere and the dissolved and particle phases in the waters of the New York—New Jersey Harbor Estuary, USA, during a weeklong intensive field campaign in July 1998. Mean total (gas + particulate) phenanthrene and pyrene concentrations were 3.3 and 0.33 ng/m3, respectively, over Raritan Bay, and 14 and 1.1 ng/m3, respectively, over New York Harbor. Similar PAH profiles (p values < 0.01) in the atmospheric gas phase and the dissolved phase in water demonstrate the close coupling of the air and water compartments. Air—water exchange fluxes of PAHs estimated using shore-based air data lead to erroneous flux estimates when compared to those derived using over-water air samples. The gross absorptive air—water flux dominates atmospheric loadings (wet, dry particle, gas absorption) to the estuary for PAHs of molecular weight < 234 g/mol. Dry particle deposition is increasingly more important for the higher-molecular-weight, particle-bound PAH species. Gross volatilization dominates gross absorption for the majority of PAHs in the New York—New Jersey Harbor Estuary.
The effect of polycyclic aromatic hydrocarbons on the degradation of benzo[a]pyrene by Mycobacterium sp. strain RJGII-135
Authors: McLellan Sandra L. , Warshawsky David , Shann Jodi R.
Published: March 2010

Mycobacterium sp. strain RJGII-135 is capable of degrading a wide range of polycyclic aromatic hydrocarbons (PAHs), including benzo[a]pyrene (BaP). In this study, critical aspects of degradation were investigated, including compound uptake, relative rates of PAH degradation, and the effects of co-occurring PAH substrates on BaP degradation and mineralization to CO2. Mycobacterium sp. strain RJGII-135 was capable of degrading phenanthrene, anthracene, and pyrene at a 10- to 20-fold greater rate than benz[a]anthracene (BaA) and BaP. A significant amount of phenanthrene and pyrene, 30% and 10%, respectively, was completely mineralized, whereas less than 4% of anthracene, BaA, and BaP was mineralized. The PAH uptake assays demonstrated that high amounts of BaP and BaA, 81% and 75% of added compound, respectively, could be recovered from bacterial cell fractions after a 4-h incubation compared with pyrene (61%), anthracene (53%), and phenanthrene (47%). The half-saturation constant (Km) for pyrene was threefold lower for pyrene over BaP, suggesting that the degradation system in Mycobacterium sp. strain RJGII-135 has a higher affinity for pyrene, reaching maximal degradative activity at lower concentrations. No hybridization to dioxygenase gene probes nahAc, bphA1, or tolC1C2 was detected. Studies to investigate competition between different PAH substrates demonstrated that the rate of BaP metabolism was influenced by the presence of a second PAH substrate. The BaP metabolism was inhibited when coincubated with BaA, pyrene, and anthracene. Phenanthrene did not inhibit but enhanced BaP metabolism sixfold. These data suggest that induction effects of components of complex mixtures may be as important as competitive metabolism when assessing the ability of bacteria to effectively degrade high-molecular-weight PAHs in the environment.
Phytoxicity of smelter-impacted soils in southwest Montana, USA
Authors: Redente Edward F. , Zadeh Holley , Paschke Mark W.
Published: March 2010

A century of copper smelting in southwest Montana, USA, destroyed vegetation for many kilometers surrounding the Washoe Smelter. Once the vegetation was lost, exposed soils were subject to wind and water erosion, which removed topsoil and left soil surfaces paved with gravel. A greenhouse study was conducted using soils from smelter-impacted and non-smelter-impacted sites near Anaconda, Montana. Bluebunch wheatgrass, Agropyron spicatum (Pursh) Scribn., and western yarrow, Achillea lanulosa Nutt., were grown for 50 d in unamended, fertilized, or limed treatments to determine if soil fertility, pH, or trace elements were limiting plant growth on soil from the impacted site. The addition of fertilizer significantly increased plant biomass of both species in soils from impacted and nonimpacted sites when compared to unamended and limed soil. The addition of lime had no effect on plant growth. When plant growth in fertilized smelter-impacted soil was compared to unamended nonimpacted soil, significantly more plant biomass was observed in the fertilized smelter-impacted soil. Shoot and root concentrations of trace elements were higher in plants grown in impacted soil compared to nonimpacted soil. The only element that was found to occur in concentrations reported to be phytotoxic was arsenic (As). However, toxicity thresholds for As, reported in the literature, were generated in agricultural species and do not likely have application to the native perennials used in this study.
Speciation of copper in sewage effluents and its toxicity to Daphnia magna
Authors: Van Veen Eleanor , Burton Nicola , Comber Sean , Gardner Michael
Published: March 2010

Copper complexation capacity was determined in a range of sewage treatment works final effluents and receiving waters, upstream and downstream of the discharge point. Forty-eight-hour immobilization tests on Daphnia magna were used to assess the toxicity of copper in the effluent matrix. Complexation capacities in effluents were typically in the range 50 to 100 μg Cu/L, with higher values being found in the poorer-quality effluents with higher dissolved organic carbon (DOC) concentrations. The tolerance of Daphnia to dissolved copper concentrations was more than quadrupled in a 50% effluent matrix, with the increase in tolerance being related to complexation capacity. Ligand concentrations in effluents were found to correlate strongly with effluent DOC. No such relationship was observed in surface waters. On mixing with river water, sewage-derived ligands behaved conservatively and were relatively stable over time scales of up to 10 d.
Cycling of weathered chlordane residues in the environment: Compositional and chiral profiles in contiguous soil, vegetation, and air compartments
Authors: Mattina Mary Jane Incorvia , White Jason , Eitzer Brian , Iannucci-Berger William
Published: March 2010

Technical chlordane, a synthetic organic pesticide composed of 147 separate components, some of which exhibit optical activity, was used as an insecticide, herbicide, and termiticide prior to all uses being banned in the United States in 1988. It has been shown that food crops grown in soil treated decades earlier with technical chlordane translocate the weathered chlordane residues from the soil into root and aerial plant tissues. A rigorous analytical method is presented for the simultaneous, quantitative determination of both achiral and chiral components of technical chlordane in soil, plant, and air compartments using chiral gas chromatography interfaced to ion trap mass spectrometry and internal standard calibration. Using this method, we have observed differences in both the absolute and the relative amounts of trans- and cis-chlordane enantiomers and achiral trans-nonachlor between the soil compartment and various plant tissue compartments for several field-grown food crops. Changes in the relative amounts of the (+) and (−) enantiomers of trans- and cis-chlordane indicate enantioselective processes are in effect in the contiguous compartments of soil, plant roots, and aerial plant tissues. The data for zucchini (Cucurbita pepo L.), in particular, show an approximate fivefold enhancement in absolute concentration for total trans-chlordane, an eightfold concentration enhancement for total cis-chlordane, and a 2.5-fold enhancement for trans-nonachlor in the root relative to the soil matrix, the largest enhancements of any crop studied. This is the first comprehensive report of enantioselective processes into and through plant tissues for a variety of field-grown food crops. The selectivity will be related to observed insect toxicities of the enantiomers.
Relationship between feeding-induced ventilatory activity and bioaccumulation of dissolved and algal-bound cadmium in the Asiatic clamCorbicula fluminea
Authors: Tran Damien , Boudou Alain , Massabuau Jean-Charles
Published: March 2010

The influence of feeding-induced ventilatory adaptation on cadmium accumulation patterns was analyzed in quiescent Asiatic clam Corbicula fluminea studied in steady-state conditions at 15°C and 25°C and in air-equilibrated water. Ventilatory activity, algae inflow rate, amounts of inspired dissolved and algae-bound Cd, and whole-body and tissue-specific metal concentrations were studied during a 15-d exposure period at a low dissolved cadmium concentration of 2 μg/L and various algal concentrations of Scenedesmus subspicatus. Great care was taken not to externally stimulate animals. Four main results were obtained as regard to regulation of ventilatory activity and metal accumulation rate. First, at 25°C, feeding purposes strongly stimulated ventilatory activity, while at 15°C, it was independent of it except at 1 to 2 × 105 algae/ml. Second, Cd accumulation rate increased at higher temperature. Third, accumulation rate exhibited a positive correlation with the ventilatory flow rate. Fourth, no correlation was observed with the quantity of ventilated algae-bound Cd but, rather, with the quantity of ventilated dissolved Cd. It is concluded that the physiology of the animals can be fundamental in affecting metal accumulation process.
Does status of attachment influence survival time of zebra mussel, Dreissena polymorpha, exposed to chlorination?
Authors: Rajagopal Sanjeevi , Van Der Velde Gerard , Jenner Henk A.
Published: March 2010

Mussels colonize cooling water circuits of power stations by attaching themselves to the pipe or conduit walls using byssus threads. Once manually detached, they quickly try to reattach by producing new byssus threads. In many published reports on antifouling bioassays, the test specimens are exposed to the biocide in an unattached state. These mussels, while trying to reattach, are likely to expose themselves more frequently to the toxic compound when compared to firmly attached mussels. The results of the assay, therefore, could vary, depending on the status of the mussels used. In this paper, we test the hypothesis that the status of attachment could influence the toxicity response of mussels and show that byssally attached zebra mussel, Dreissena polymorpha (Pallas), is more resistant to chlorine than unattached ones. An average increase of 27% in the survival time was observed for attached mussels over unattached ones in the chlorine concentration range of 0.25 to 3 mg/L. It is conclusively shown that the increase in sensitivity of the unattached mussels was related to an increase in the byssal activity, quantified presently as the byssogenesis index. The results indicate that future laboratory toxicity experiments involving mussels should be carried out using byssally attached ones.
Analysis of hepatic vitamins A1, A2, their fatty acyl esters, and vitamin E for biomonitoring mammals feeding on freshwater fish
Authors: Käkelä Anne , Käkelä Reijo , Hyvärinen Heikki
Published: March 2010

In tissues of freshwater fish–feeding mammals, 3,4-didehydroretinol (A2) is a major form of vitamin A. In mink liver, with organochlorine exposure, this analog has been found to decrease more than retinol (A1) and thus has potential as a sensitive freshwater biomarker. The presence of the analogs A1 and A2 as alcohol and different fatty acyl esters, which react to polychlorinated biphenyls differently, necessitates detailed analyses achieved by using direct extraction of tissue homogenate. In direct hexane extraction, compared to total levels of the vitamins obtained in the saponification procedure, a large proportion of the vitamins was released only after repeated and long-time vortex mixing with the extraction solvent. Thus, in tissue extraction, the use of internal standardization alone can lead to a rough underestimation of the levels of these fat-soluble vitamins. For analyses of vitamins A1 and A2 in liver, we applied the argentation high-performance liquid chromatography, which provided good separation of individual A1 and A2 fatty acyl esters. We report retention times for numerous esters of A1 and A2 and, to aid identification, the change in their retention properties after adding AgNO3 to the mobile phase. The argentation did not affect the recoveries of any forms of the retinoids studied but destroyed half the vitamin E. Despite selective acylation of fatty acids into the vitamin A esters, the fatty acids of the esters were the same as those found to be the major fatty acids in the gas–liquid chromatography of total lipids. The goal of this work was to create a methodology that is suitable for biomonitoring alcoholic and esterified vitamins A1 and A2 in tissues of freshwater fish–feeding mammals.
The influence of redox potential on the degradation of halogenated methanes
Authors: Olivas Yolanda , Dolfing Jan , Smith Geoffrey B.
Published: March 2010

To determine the influence of redox potential on the reaction mechanism and to quantify kinetics of the dechlorination by digester sludge, the test compounds trichlorofluoromethane (CFCl3), carbon tetrachloride (CCl4), and chloroform (CHCl3) were incubated in the presence of sludge and variable concentrations of reducing agent. Different sources of dehalogenation were examined, including live sludge and heat-killed sludge, and abiotic mechanisms were quantified in the absence of sludge. Batch incubations were done under redox conditions ranging from +534 to -348 mV. The highest rates for the dehalogenation of the three compounds were observed at -348 mV. The dechlorination rate of all the compounds by the heat-resistant catalysts was approximately twofold higher than the live treatments. It was proposed that the higher degradation rates by heat-killed sludge were due to the absence of physical barriers such as cell wall and cell membranes. There was no abiotic dechlorination of CFCl3, whereas CCl4 and CHCl3 were both reduced in the absence of sludge catalyst by Ti (III) citrate at ≥2.5 mM. The degradation pathways of CFCl3 and CHCl3 appeared to be only partially reductive since the production of reduced metabolites was low in comparison with the total amount of original halogenated compounds degraded. For CFCl3, the partial reductive degradation implied that different intra- and extracellular pathways were concurrent. The Gibbs free energy and the redox potential for the dehalogenation reactions utilizing Ti (III) citrate and acetate as electron donors are reported here for the first time.
Health of lake whitefish (Coregonus clupeaformis) with elevated tissue levels of environmental contaminants
Authors: Mikaelian Igor , De Lafontaine Yves , Harshbarger John C. , Lee Lucy L. J. , Martineau Daniel
Published: March 2010

Lake whitefish (Coregonus clupeaformis) were collected in 1996 from the St. Lawrence River, Quebec, Canada. Histologic examination was performed on major organs of 497 specimens and on the liver of 48 additional individuals. Preneoplastic and neoplastic hepatic changes consisted of vacuolated cell (n = 65), clear cell (n = 17), and acidophilic (n = 16) foci of altered hepatocyte, hepatocellular carcinoma (n = 12), cholangioma (n = 5), and cholangiocarcinoma (n = 28). Six fish were intersexes (1.2%), and 11.7% of the ovaries (26/223) had ducts containing spermatogonia or more differentiated cells of the male germ cell line. Asynchronous nodular maturation of the testes was present in 8.2% of the male fish (22/267). The mean hepatic concentrations of various contaminants, including polychlorinated biphenyls (PCBs), chlorobenzenes, pesticides, and trace metals, were 6 to 8 times higher in lake whitefish than in three other fish species (Ictalurus punctatus, Catostomus commersoni, and Stizostedion vitreum) collected at the same site. Condition factor of lake whitefish from this study was lower than that previously reported 40 to 50 years ago at this site and from contemporary pristine sites in the Great Lakes, USA. The presence of liver neoplasms, gonadal lesions, and a decreased condition factor in lake whitefish from the St. Lawrence River may be etiologically related to elevated tissue concentrations of toxic chemical contaminants.
Biochemical biomarkers of pollution in the clam Chamaelea gallina from South-Spanish littoral
Authors: Rodríguez-Ortega Manuel J. , Alhama José , Funes Victoria , Romero-Ruíz Antonio , Rodríguez-Ariza Antonio , López-Barea Juan
Published: March 2010

Fourteen biochemical pollution biomarkers were analyzed in the clam Chamaelea gallina sampled at seven South-Spanish littoral sites at different times in 1999. They included enzymes that regenerate reduced nicotinamide adenine dinucleotide phosphate (NADPH) or maintain the cytosol-reduced (glucose-6-P- and isocitrate dehydrogenases, glutathione reductase), that decompose reactive oxygen species (catalase, superoxide dismutase, glutathione peroxidase), or detoxify glutathione-reactive electrophiles (soluble and microsomal glutathione transferases, glyoxalases II and I). The levels of reduced glutathione, malondialdehyde, and metallothionein and the glutathione redox status were also determined. Clams from Huelva sites with higher contaminant loads and metallothionein levels showed higher antioxidant and glutathione-related activities and a decreased glutathione level, lower malondialdehyde content, and a less oxidized glutathione status. This suggests that clams chronically exposed to contaminants released by Huelva and Guadalquivir Estuaries are better protected from oxidative stress than reference animals. Most biomarkers showed six-month cyclicity with up to threefold amplitudes, further supporting the inverse relationship between antioxidant defenses and oxidative damages. Thus the lower antioxidant defenses in June fit to maximum oxidative damages, whereas the high antioxidant defenses found in March and September through October agree with lower lipid damages and less oxidized glutathione status. The effect of environmental or endogenous factors on this cyclic response is discussed.
Citrate-mediated increase in the uptake of weathered 2,2-bis(p-chlorophenyl)1,1-dichloroethylene residues by plants
Authors: White Jason C. , Kottler Bennett D.
Published: March 2010

Experiments were conducted to determine the ability of citrate to enhance the plant uptake of weathered 2,2-bis(p-chlorophenyl) 1,1-dichloroethylene (p,pǐ-DDE) from soil. Plots containing three rows of clover, mustard, hairy vetch, or rye grass were constructed in soils containing p,pǐ-DDE. On 11 occasions, the rows of each crop received water or sodium citrate (0.005 or 0.05 M). For each crop, there were significant reductions in p,pǐ-DDE concentration in the soil fractions (near root and rhizosphere) closely associated with the plant versus bulk soil. The roots of each crop accumulated 2 to 5 times more of the weathered contaminant (dry wt) than present in the bulk soil. Citrate (0.05 M) increased the concentration of p,pǐ-DDE in the roots of clover, mustard, and hairy vetch by 39% compared with vegetation that received water. In batch desorption studies, the release of weathered p,pǐ-DDE was significantly greater in the presence of 0.05 M citrate than in water. Citrate increased the extracted aqueous concentrations of five metal ions (Al, Fe, Ca, K, Mn) from soil by five- to 23-fold over distilled water. We hypothesize that citrate physically disrupts the soil through chelation of structural metal ions and release of bound humic material, facilitating p,pǐ-DDE availability and uptake by plants.
Effects of handling on heat shock protein expression in rainbow trout (Oncorhynchus mykiss)
Authors: Washburn Barbara Shayne , Moreland Jason J. , Slaughter Ann M. , Werner Inge , Hinton David E. , Sanders Brenda M.
Published: March 2010

As part of an effort to validate the use of heat shock proteins (HSPs) as biomarkers of exposure to and effects of contaminants, we evaluated the effect of two handling regimens on the induction of HSP 60 and 70 in rainbow trout (Oncorhynchus mykiss). Fish were acclimated to laboratory conditions for several weeks before the beginning of the experiment. Fish were then captured by net, placed in a cooler for 1 h while being transported in a truck, returned to their original tanks, then sacrificed 6 to 8 h later. Tricaine methane sulfonate (MS-222) was used during different phases of handling to reduce handling stress. Heat-stressed fish were included in the experiment as a positive control. Muscle, liver, gills, and heart were analyzed for HSP 60 and 70 by immunoblotting. We found no effect of any handling regimen on the induction of HSPs. These findings suggest that the capture and transport of fish for environmental monitoring purposes should not interfere with the use of stress proteins as biomarkers.
Sublethal effects in avocet and stilt hatchlings from selenium-contaminated sites
Authors: Hoffman David J. , Marn Carolyn M. , Marois Katherine C. , Sproul Elaine , Dunne Mary , Skorupa Joseph P.
Published: March 2010

Excess selenium (Se) in the aquatic food chain is embryotoxic and teratogenic to avocets, stilts, and other waterbirds. American avocet (Recurvirostra americana) and black-necked stilt (Himantopus mexicanus) eggs were collected from three sites in the Tulare Lake Basin of California, USA, and hatched in the laboratory. These sites included the Tulare Lake Drainage District-north (TLDD-N, water 2.5 ppb Se), TLDD-south (TLDD-S, water 8.6 ppb Se), and Westfarmers (WF, water 190 ppb Se). Highest egg Se concentrations occurred at WF (geometric mean 31.4 ppm dry wt for avocets and 20.5 ppm dry wt for stilts). Mean egg Se concentrations were 6.7 ppm for avocets and 8.4 ppm for stilts at TLDD-S, and 3.3 ppm for avocets and 2.3 ppm for stilts at TLDD-N. Hatching success and incidence of malformations did not differ among sites, but yolk sac-free hatching weights and bone lengths were less for avocets at the WF site, whereas liver weights and liver to body weight ratios were greater at that site. With increasing Se concentration, oxidative stress was most apparent in avocet hatchlings from WF: hepatic glutathione (GSH) peroxidase activity increased, glucose-6-phosphate dehydrogenase activity decreased, and oxidized glutathione (GSSG) concentration as well as the ratio of GSSG to reduced GSH concentration increased. In stilts, hepatic GSH concentration was lower in WF hatchlings. In conclusion, our findings of Se-impaired embryo growth and hepatotoxicity in avocet hatchlings suggest that oxidative stress observed in hatchlings may be related to these biological effects and may serve as a potential bioindicator of subsequent impaired functions.
Spatial trends and bioaccumulation of organochlorine pollutants in marine zooplankton from the Alaskan and Canadian Arctic
Authors: Hoekstra Paul F. , O'Hara Todd M. , Teixeira Camilla , Backus Sean , Fisk Aaron T. , Muir Derek C. G.
Published: March 2010

Planktonic copepods (Calanus glacialis and C. hyperboreus; n = 37) and water (n = 19) were collected to examine the spatial distribution and bioaccumulation of organochlorine contaminants (OCs) in the Alaskan and Canadian Arctic. The rank order of total OC (σ OC) group concentrations in Calanus samples was toxaphene ≥ σ polychlorinated biphenyls (PCBs) > σ hexachlorcyclohexane (HCH). σ DDT > σ chlordane-related compounds (CHLOR) > σ chlorobenzenes (ClBz). The dominant analyte was α-HCH in all water and zooplankton samples. The most abundant toxaphene congener in water and zooplankton samples was the hexachlorobornane B6-923. Organochlorine contaminant group concentrations in Alaskan zooplankton and water samples were lower than those in samples collected from sites in the eastern Canadian Arctic. Comparison of PCB and toxaphene congener profiles in zooplankton and water samples suggests that biotransformation by cytochrome P-4502B isozymes is low in Calanus, and limited phase I metabolism may occur. The log relationship of bioaccumulation factor (log BAF) versus octanol-water partition coefficient (log Kow) relationship was near 1: 1 for OCs within the log Kow range of 3 to 6. A curvilinear model provided a better relationship between these two variables when OC compounds with log Kow > 6 were included. These results suggest that hydrophobic OCs (log Kow 3-6) in Calanus species are at equilibrium with the water concentrations and that physical partitioning, rather than biotransformation, is the major factor governing OC profiles in marine zooplankton.
Genetic effects of mercury contamination on aquatic snail populations: Allozyme genotypes and DNA strand breakage
Authors: Benton Michael J. , Malott Michelle L. , Trybula Jan , Dean Deborah M. , Guttman Sheldon I.
Published: March 2010

Allozyme data and DNA strand break frequencies were compared among populations of Pleurocera canaliculatum from five sites with varying mercury contamination on the North Fork Holston River (NFHR) in southwestern Virginia, USA. Allozyme genotype frequencies for four loci were significantly different between populations from the three most highly contaminated sites and those from two lesser contaminated sites. In addition, heterozygosity at three of these loci was significantly lower in the populations from the most highly contaminated sites. The DNA strand break frequency was significantly correlated to whole-body total mercury concentration in snails from three sites. These data add to the evidence supporting the use of DNA strand breakage as an indicator of chemical contamination and the use of allozyme analysis as a marker of contamination and possible selection for pollution resistance. However, the relationship between contaminant-induced changes in the genetic variation of enzymes of central metabolism and the functionalities upon which selection for resistance may act remain unclear, and mechanisms other than selection for resistance must be considered. Use of enzymes from other biochemical pathways may be appropriate for other species or for those under other chemical pollution pressures.
Environmentally relevant concentrations of ammonium perchlorate inhibit thyroid function and alter sex ratios in developing Xenopus laevis
Authors: Goleman Wanda L. , Carr James A. , Anderson Todd A.
Published: March 2010

Embryos and larvae of the South African frog Xenopus laevis were exposed to ammonium perchlorate (AP) or control medium for 70 d. The dosage levels (59 ppb, 14,140 ppb) bracketed a range of perchlorate concentrations measured in surface waters at the Longhorn Army Ammunition Plant (LHAAP) in Karnack, Texas, USA. The experiment also included a 28-d nontreatment recovery period to assess the reversibility of AP effects. There were no significant effects of AP on mortality or hatching success. There were no effects of AP on developmental abnormalities such as bent/asymmetric tails or edema. Ammonium perchlorate inhibited forelimb emergence, the percentage of animals completing tail resorption, and hindlimb development during the 70-d exposure period. Only the upper AP concentration reduced whole-body thyroxine content, whereas both concentrations caused significant hypertrophy of the thyroid follicular epithelium. Both concentrations of AP caused a skewed sex ratio, significantly reducing the percentage of males at metamorphosis. The effects of AP on metamorphosis and thyroid function were reversed during the 28-d nontreatment recovery period. We conclude that AP inhibits thyroid activity and alters gonadal differentiation in developing X. laevis. These effects were observed at concentrations at or below concentrations reported in surface waters contaminated with ammonium perchlorate, suggesting that this contaminant may pose a threat to normal development and growth in natural amphibian populations.
Influence of metal (Cd and Zn) waterborne exposure on radionuclide (134Cs, 110mAg, and 57Co) bioaccumulation by rainbow trout (Oncorhynchus mykiss): A field and laboratory study
Authors: Ausseil Olivier , Adam Christelle , Garnier-Laplace Jacqueline , Baudin Jean-Pierre , Casellas Claude , Porcher Jean-Marc
Published: March 2010

Field and laboratory experiments were carried out to assess the influence of Cd and Zn on the contamination levels of 110mAg, 57Co, and 134Cs in rainbow trout. During a four-week prior exposure phase, two fish groups were held in tanks in the Lot River (France) at a reference (<0.05 μg Cd/L and 68 μg Zn/L) and at a polluted site (1.5 μg Cd/L and 152 μg Zn/L). During a subsequent phase, organisms were brought back to the laboratory, where the radionuclide accumulation and depuration were studied for 14 and 7 d, respectively. During this second phase, the water used in the experiments was brought back from the two sites on the Lot River in order to work under the same chemical conditions. The potential effect of chronic exposure to stable metals on several biomarkers has been explored: Plasma analysis indicated the disruption of certain variables linked to the energetic metabolism and to the maintenance of the ionic balance. In contrast, no significant disruption of the measured enzyme activities was observed. With regard to the bioaccumulation of radionuclides, concentrations in fish exposed to metals are much lower than those in fish from the control group. Various hypotheses are proposed to link fish metabolic profiles due to metal exposure to the radiocontamination of organisms.
Investigation of effects of trifluoroacetate on vernal pool ecosystems
Authors: Benesch Jody A. , Gustin Mae S. , Cramer Grant R. , Cahill Thomas M.
Published: March 2010

Trifluoroacetate (CH3COO-, TFA) is a breakdown product of hydrochlorofluorocarbons and hydrofluorocarbons and is released by the heating of Teflon® products. Because of its chemical properties, concentrations in evaporative wetlands are predicted to increase with time. This study focused on assessing the impact of this haloacetic acid on vernal pool soil microbial communities as well as vernal pool and wetland plant species. Microbial respiration for three vernal pool soils and an agricultural soil was not affected by TFA exposures (0, 10, 100, 1,000, and 10,000 μg/L), and degradation of TFA by microbial communities was not observed in soils incubated for three months. Trifluoroacetate accumulated in foliar tissue of wetland plant species as a function of root exposure concentration (100 and 1,000 μg/L TFA), and accumulation was found to stabilize or decrease after the second or third month of exposure. Seeds accumulated TFA as a function of root exposure concentration; however, germination success was not affected. No adverse physiological responses, including general plant health and photosynthetic and conductance rates, were observed for root exposures at the TFA concentrations used in this study. Based on the soils and plant species used in this study, predicted TFA concentrations will not adversely affect the development of soil microbial communities and vernal pool plant species.