bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of benthic invertebrate community structure and the sediment quality triad to evaluate metal-contaminated sediment in the upper clark fork river, montana
Authors: Canfield Timothy J. , Kemble Nile E. , Brumbaugh William G. , Dwyer F. James , Ingersoll Chris G. , Fairchild James F.
Published: March 2010

The upper Clark Fork River, above Flathead River, is contaminated with large amounts of As, Cd, Cu, Pb, Mn, and Zn ores from past mining activities. The contaminated area extends from the Butte and Anaconda area to at least 230 km downstream to Milltown Reservoir. Both the upper Clark Fork River and Milltown Reservoir have been designated as U.S. Environmental Protection Agency Superfund sites because of metal-contaminated bottom sediments. We evaluated the impacts of past mining activities on the Clark Fork River ecosystem using benthic invertebrate community assessment, residue chemistry, and toxicity testing. Oligochaeta and Chironomidae generally accounted for over 90% of the benthic invertebrate community in the soft sediment depositional areas. Taxa of Oligochaeta and Chironomidae were predominantly pollution tolerant. Higher numbers of Chironomidae genera were present at stations with higher concentrations of metals in sediment identified as toxic by the amphipod Hyalella azteca in 28-d exposures. Frequency of mouthpart deformities in genera of Chironomidae was low and did not correspond to concentrations of metals in sediment. Total abundance of organisms/m2 did not correspond to concentrations of metals in the sediment samples. Chemical analyses, laboratory toxicity tests, and benthic community evaluations all provide evidence of metal-induced degradation to aquatic communities in both the reservoir and the river. Using a weight-of-evidence approach-the Sediment Quality Triad - provided good concurrence among measures of benthic community structure, sediment chemistry, and laboratory toxicity.
Bioaccumulation of metals by Hyalella azteca exposed to contaminated sediments from the upper clark fork river, montana
Authors: Ingersoll Chris G. , Brumbaugh William G. , Dwyer F. James , Kemble Nile E.
Published: March 2010

Macroinvertebrates contaminated with metals in the Clark Fork River of Montana have been demonstrated to be a potentially toxic component in the diet of trout Because sediment was the suspected source of metals to these invertebrates, bioaccumulation of As, Cd, Cu, Pb, and Zn from sediment was evaluated by exposing the amphipod Hyalella azteca for 28 d in the laboratory to samples of sediment collected from depositional areas of the Clark Fork River Benthic invertebrates collected from riffles adjacent to the depositional areas were also analyzed for metals The pattern of metal accumulation between laboratory-exposed and field-collected animals was similar, however, the concentrations of metals in laboratory exposed amphipods were often 50 to 75% less than were the concentrations of metals in the field collected invertebrates These findings indicate that sediment is a significant source of metals to invertebrates in the Clark Fork River Additional studies should be conducted to determine threshold concentrations for effects of dietary metals on fish Long-term monitoring of the river should include sampling benthic invertebrates for metal accumulation
Dietary and waterborne exposure of rainbow trout (Oncorhynchus mykiss) to copper, cadmium, lead and zinc using a live diet
Authors: Mount David R. , Barth Anita K. , Garrison Tyler D. , Barten Karen A. , Hockett J. Russell
Published: March 2010

In two 60 d exposures, rainbow trout fry were fed brine shrimp (Artemia sp) enriched with Cu, Cd, Pb, and Zn both individually and as a mixture combined with As Dietary concentrations fed to trout were selected based on metal concentrations measured in invertebrates collected from the Clark Fork River (CFR), Montana In addition to dietary exposure, treatments also included simultaneous exposure to a mixture of waterborne metals at sublethal concentrations Fish in all treatments showed increased tissue metal concentrations from water and/or dietary exposure Despite these accumulations, trout showed no effects on survival or growth from dietary concentrations as high as 55 μg Cd/g dry weight, 170 μg Pb/g dry weight, or 1,500 μg Zn/g dry weight (corrected for depuration) Dietary Cu concentrations up to 350 μg Cu/g dry weight did not reduce survival or growth Fish fed Cu concentrations higher than those typical of CFR invertebrates (660 and 800 μg Cu/g dry weight, corrected for depuration) showed about 30% mortality with no effect on growth, waterborne Cu released from Artemia may have contributed to this mortality Trout exposed to diets with a mixture of Cu, Cd, Pb, Zn, and As close to that measured in CFR invertebrates showed lower weight than did control fish after 35 d, but this difference was no longer present after 60 d
Characterization of ecological risks at the milltown reservoir-clark fork river sediments superfund site, montana
Authors: Pascoe Gary A. , Blanchet Richard J. , Linder Greg , Palawski Don , Brumbaugh William G. , Canfield Tim J. , Kemble Nile E. , Ingersoll Chris G. , Farag Aïda , Dalsoglio Julie A.
Published: March 2010

A comprehensive field and laboratory approach to the ecological risk assessment for the Milltown Reservoir-Clark Fork River Sediments Site, a Superfund site in the Rocky Mountains of Montana, has been described in the preceding reports of this series. The risk assessment addresses concerns over the ecological impacts of upstream releases of mining wastes to fisheries of the upper Clark Fork River (CFR) and the benthic and terrestrial habitats further downstream in Milltown Reservoir. The risk characterization component of the process integrated results from a triad of information sources: (a) chemistry studies of environmental media to identify and quantify exposures of terrestrial and aquatic organisms to site-related contaminants; (b) ecological or population studies of terrestrial vegetation, birds, benthic communities, and fish; and (c) in situ and laboratory toxicity studies with terrestrial and aquatic invertebrates and plants, small mammals, amphibians, and fish exposed to contaminated surface water, sediments, wetland soils, and food sources. Trophic transfer studies were performed on waterfowl, mammals, and predatory birds using field measurement data on metals concentrations in environmental media and lower trophic food sources. Studies with sediment exposures were incorporated into the Sediment Quality Triad approach to evaluate risks to benthic ecology. Overall results of the wetland and terrestrial studies suggested that acute adverse biological effects were largely absent from the wetland; however, adverse effects to reproductive, growth, and physiological end points of various terrestrial and aquatic species were related to metals exposures in more highly contaminated depositional areas. Feeding studies with contaminated diet collected from the upper CFR indicated that trout are at high risk from elevated metals concentrations in surface water, sediment, and aquatic invertebrates. Integration of chemical analyses with toxicological and ecological evaluations of metal effects on the wetland and fishery has provided an important foundation for environmental decisions at this site.
Contact toxicity of metals in sewage sludge: evaluation of alternatives to sodium chloride in the microtox® assay
Authors: Carlson-Ekvall C. E. Annika , Morrison Gregory M.
Published: March 2010

The presence of chloride ions in the Microtox® test can cause problems when testing metal toxicity, both due to extraction of metals from solid samples and formation of chloro complexes of metals in the liquid phase. To investigate alternatives to NaCl in the Microtox test, the toxicity of Cu, Cd, Pb, and Zn to Photobacterium phosphoreum was tested in 28 osmotic surrogates for NaCl. It was found that Na+ must be present to keep the blank luminescence stable for 30 min. The results point to NaClO4 as the most satisfactory surrogate solution as it has an inert behaviour and does not form complexes with any metal of environmental interest. Raw, digested, and reference sewage sludges were tested in the osmotic surrogates. The EC50 values for sludges were lower in solutions of NaNO3, Na2SO4, and NaClO4, and higher in sucrose, mannitol, and KCl, compared to NaCl. NaClO4 can be recommended as an osmotic surrogate for sewage sludge testing. Another problem with the Microtox assay is the lack of pH control in the cuvette. Copper toxicity tests were carried out in Tris buffer and KH2PO4 at two different concentrations and at pH 7 and 8. The results show that 1 mM phosphate buffer, pH 7.0, can be recommended for solid samples. However, owing to formation of KClO4 a buffer containing potassium is not recommended in combination with NaClO4.
Behavioral responses of Daphnia pulex exposed to carbaryl and Chaoborus kairomone
Authors: Dodson Stanley I. , Hanazato Takayuki , Gorski Patrick R.
Published: March 2010

An analysis of digitized three-dimensional video records of free-swimming Daphnia pulex identified six measurements of swimming behavior that can be used to quantify individual behavioral responses to pesticides or natural chemical signals. Protocols are given for measuring the parameters that showed statistically significant changes in pesticide treatments. The most efficient experimental design would involve observing as many animals as possible, with one observation per animal. Parameters most likely to be useful in future studies are velocity, turning angle, upward and downward angles during hops, variance in vertical position, and hopping frequency. The parameters varied in usefulness, defined as the ratio of within-treatment to among-treatment variance (F ratios). Velocity was the most useful (i.e., had the highest F ratio); hopping frequency was the least useful. Daphnia exhibited three kinds of swimming behavior, as defined by eight parameters: (a) “spinning” (extreme and continuous escape response) to acutely toxic levels of Carbaryl (40 ppb); (b) “irritation” (an increase in escape-like behavior) to low levels of Carbaryl (1 ppb); and (c) “null” behavioral responses to Chaoborus-conditioned water, in which there was no detectable change in any measurement of swimming behavior. In predation trials, bluegill sunfish preferentially selected individuals showing “spinning” behavior. Results from this and other studies of Daphnia swimming behavior suggest a conservative-swimming hypothesis for understanding constraints on Daphnia swimming behavior.
Development and field validation of a microcosm to simulate the mercury cycle in a contaminated pond
Authors: Saouter Erwan , Gillman Mark , Turner Ralph , Barkay Tamar
Published: March 2010

A microcosm consisting of water, sediment, and air compartments was used to simulate mercury geochemical cycling in a mercury-contaminated (μg L−1) pond at Oak Ridge, Tennessee. Total and dissolved mercury and total methylmercury were analyzed in water and sediment; total gaseous mercury and head-space mercury were analyzed in the water and head space, respectively. The production of gaseous mercury was correlated to dissolved mercury (0.2-μm filtration), and methylmercury was mainly produced in the sediment compartment. Addition of mercuric chloride to the system increased the production of head-space mercury by a factor of 10 but did not affect the methylation rate. Saturation of gaseous mercury in microcosm water varied from 480 to 1,500% of the solubility of elemental mercury and was controlled by unidentified factors. The microcosm maintained stable conditions for up to 3 weeks, and a mass balance indicated that it reasonably simulated the cycling of mercury in the pond. This microcosm could be used to test remedial treatments aimed at decreasing the amount of mercury that is available for accumulation by biota.
Identification of potential fish carcinogens in sediment from hamilton harbour, ontario, canada
Authors: Balch G.C. , Metcalfe C.D. , Huestis S.Y.
Published: March 2010

A carcinogenicity- and mutagenicity-directed fractionation approach was used to identify the carcinogenic compounds in contaminated sediments that are putatively responsible for the high prevalence of tumors in bottom-dwelling fish from Hamilton Harbour, Ontario. Mutagenic activity was detected with Ames tester strains (TA98, TA100) in relatively nonpolar fractions of sediment extract containing PAHs and nitrogen-containing aromatic compounds (NCACs). These fractions were also carcinogenic in an in vivo carcinogenicity bioassay with rainbow trout (Oncorhynchus mykiss). When a more polar extract fraction was tested for mutagenicity and carcinogenicity, weak mutagenic activity was detected with an O-acetyltransferase-enriched Ames tester strain (YG1024), and weak carcinogenic activity was detected in the rainbow trout assay. These data indicate that PAHs in contaminated Hamilton Harbour sediments are potent fish carcinogens, but it is also evident that other organic compounds in the sediment, such as NCACs and nitroarenes, may contribute to carcinogenicity.
The role of acid-volatile sulfide and interstitial water metal concentrations in determining bioavailability of cadmium and nickel from contaminated sediments to the marine polychaete Neanthes arenaceodentata
Authors: Pesch Carol E. , Hansen David J. , Boothman Warren S. , Berry Walter J. , Mahony John D.
Published: March 2010

This study investigated the influence of acid-volatile sulfide (AVS) and interstitial water (IW) metal concentrations on bioavailability and toxicity of Cd and Ni to an infaunal sediment-ingesting marine worm, Neanthes arenaceodentata. Ten-d exposures were conducted with sediments, contaminated primarily with Cd and Ni, from Foundry Cove (Hudson River, NY), and with uncontaminated sediments spiked with Cd or Ni. Molar ratios of simultaneously extracted metal (SEM)/AVS ranged from <0.02 to 44 for Cd-spiked, 0.02 to 241 for Ni-spiked, and <0.06 to 125 for Foundry Cove sediments. In all experiments, significant mortality was not observed when SEM/AVS ratios were <1.0 and interstitial water toxic units (IWTU) were <1.0 (toxic unit = IW metal concentration/LC50 value of water-only exposure). In the Cd and Ni-spiked experiments, when SEM/AVS ratios or IWTUs were >1.0, sediments were either lethal or worms did not burrow. Mortality of worms in Foundry Cove sediments was ≤20%, and worms burrowed in all these sediments. However, IW contained <1.0 TU (Ni + Cd) in all Foundry Cove sediments except one (IWTU = 1.69). Metal concentrations in worms generally increased with increases in sediment metal concentration, SEM/AVS molar ratio, and IW metal concentration. The presence of metal in worms from sediments with SEM/AVS ratios <1.0 may be evidence of release of Cd or Ni from oxidized metal sulfide (a result of burrowing), uptake of metal from ingested sediment, or adsorption to body surfaces. These results support the hypothesis that when the concentration of AVS in sediments exceeds that of divalent metals (Cd, Cu, Hg, Ni, Pb, Zn) sediments will not be acutely toxic. However, a greater number of sediments was correctly predicted to be nontoxic when interstitial water metal concentration of <1.0 TU was used.
A field evaluation of cytochrome P4501A as a biomarker of contaminant exposure in three species of flatfish
Authors: Collier Tracy K , Anulacion Bernadita F , Stein John E , Varanasi Usha , Goksøyr Anders
Published: March 2010

A study was conducted over the course of a year to determine the induction of hepatic cytochrome P4501A (CYP1A) in three species of benthic fish collected from a contaminated site compared to fish sampled from a less-contaminated site Juvenile fish were used to minimize effects of reproductive status and migration CYP1A was determined by two catalytic assays [aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O deethylase (EROD)] and by an immunoassay (ELISA) utilizing polyclonal antibodies raised against purified CYP1A from cod AHH activities were measured by a standard method (AHHstd) and by two variations of the standard method All three primary CYP1A measures (AHHstd, EROD, and ELISA) showed consistent between site differences, indicating that induction of CYP1A can be a reliable biomarker of contaminant exposure in fish if appropriate biological variables are controlled for in field studies Multiple ANOVA demonstrated that the AHHstd and ELISA data showed less variability due to species or temporal differences, and less unexplained variability, compared to the data from the EROD assay or either variation of the AHH assay For all measures, variability associated with site differences far outweighed species or temporal variability Immunoassay, while less sensitive than the AHHstd assay, is nonetheless recommended to be used in conjunction with catalytic assays because of the potential for samples to lose catalytic activity if not handled properly The current results suggest that the lower noncontaminant related variability of AHHstd makes this CYP1A measure potentially more useful for monitoring programs in which analysis of trends is a primary goal
Seasonal variation in the mixed-function oxygenase system and antioxidant enzymes of the mussel Mytilus galloprovincialis
Authors: Solé M. , Porte C. , Albaigés J.
Published: March 2010

Seasonal variations in the mixed-function oxygenase (MFO) system components (cytochrome P450, “418” peak, and NADPH-cytochrome c[P450] reductase) and antioxidant enzymes (catalase, superoxide dismutase [SOD], glutathione peroxidase [GPX], and DT-diaphorase) of the mussel Mytilus galloprovincialis have been evaluated. Its relation with contaminant body burden (PAHs, PCBs, DDTs, and lindane) as well as environmental parameters (water temperature, salinity, oxygen concentrations, and suspended matter) was determined. As a general trend, low MFO and antioxidant enzyme activities were detected in February-March, a peak in late April, and a gradual decrease with a minimum in June. This pattern was similar to tissue concentrations of PAHs, PCBs, DDTs, and lindane normalized to lipid weight. Cytochrome P450 content, however, exhibited a steady decrease from February to June. The observed seasonal variations are presumably related to the metabolic status of the animal, itself dependent on such factors as gonadal ripening, food availability, and the hydrological cycle, which regulates productivity in the area.
A modeling procedure to evaluate the coherence of independently derived environmental quality objectives for air, water and soil
Authors: van de Meent D. , de Bruijn J.H.M.
Published: March 2010

Sets of independently derived environmental quality objectives (EQOs) for air, water, and soil may not be coherent in that maintaining the concentration at EQO level in one compartment may lead to exceeding EQO levels in other compartments. A methodology to evaluate this coherence is suggested. Starting from a steady concentration in the compartment of focus (the primary compartment), steady-state concentrations in the adjacent (secondary) compartments are estimated using a multimedia fate model. If air is the primary compartment, steady-state concentrations in water and soil close to the equilibrium concentrations can be expected, and coherence of EQOs can be evaluated easily by means of an extended equilibrium partitioning procedure. If water or soil is the primary compartment, the steady-state concentration in air is usually well below the equilibrium concentration. Subequilibrium steady-state concentrations are sensitive to assumed model parameters. The procedure is illustrated with the results of a coherence analysis for seven chemicals for The Netherlands.
Enrichment of biogenic lipids, hydrocarbons and PCBs in stream-surface foams
Authors: Napolitano Guillermo E. , Richmond Jacqueline E.
Published: March 2010

Water and foam samples from five streams in eastern Tennessee were analyzed for lipid content, lipid-class composition, and polychlorinated biphenyls (PCBs). Total lipid contents and lipid-class compositions varied substantially among streams and between the water and foam fractions within streams. However, lipid contents in foams were always greater than in the water from the same site (up to 100-fold). Major lipid classes in the water and foam samples were phospholipids, free fatty acids, and hydrocarbons; these lipid classes indicate the stream status with respect to viable microbial biomass, organic decay, and petroleum pollution, respectively. Concentrations of PCBs in stream-water and foam samples were also measured, and a laboratory experiment using stream water, reconstituted natural foam, and Aroclor 1254 was conducted to assess partition ratios of PCBs for water and foam. The results of the field and laboratory studies showed that the foam concentrated PCBs (relative to the parent waters) by factors of up to 10. The concentration of biogenic lipids and lipophilic pollutants in natural foams may influence the downstream transport of pollutants and affect their bioavailability to stream organisms.
Facile synthesis and physical and spectral characterization of 2,6-di-tert-butyl-4-nitrophenol (DBNP): A potentially powerful uncoupler of oxidative phosphorylation
Authors: Rivera-Nevares José A. , Wyman John F. , Von Minden David L. , Lacy Nathan , Chabinyc Michael L. , Fratini Albert V. , Macys David A.
Published: March 2010

The compound 2,6-di-tert-butyl-4-nitrophenol (DBNP), a potentially powerful uncoupler of ATP-generating oxidative phosphorylation, has been physically and spectroscopically characterized using X-ray crystallography, differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), GC-MS spectrometry, Fourier-transformed IR (FTIR) spectrophotometry, UV-Vis spectrophotometry, and FT 1H- and 13C-NMR spectroscopy. However, DBNP is not commercially available; therefore, it had to be synthesized in the laboratory prior to toxicity studies. The DBNP was prepared from 2,6-di-tert-butylphenol (DBP) precursor in hexane through an electrophilic aromatic substitution process using NO2. A collective yield of 75% was obtained by using two empirically determined end points that prevented the coprecipitation of reaction by-products and resulted in the formation of DBNP in high purity. Excessive amounts of NO2 in reaction mixtures resulted in the decomposition of preformed DBNP. With a pKa value of 6.8 and a higher degree of lipophilicity, DBNP may prove to be a stronger uncoupler of oxidative phosphorylation than 2,4-dinitrophenol (pKa = 4.09) due to the expected enhancement of passive-diffusion kinetics across biological membranes at the physiological pH of 7.4. The present study is intended to provide analytical toxicologists, industrial hygiene monitors, and other professionals involved in chemical health and safety with a comprehensive source of basic information on the synthesis and analytical chemistry of DBNP.
Uptake, metabolism and toxicity of terbufos in the earthworm (Lumbricus terrestris) exposed to counter®-15G in artificial soils
Authors: Cobb G P , Hol E H , Allen P W , Gagne J A , Kendall R J
Published: March 2010

Earthworms (Lumbricus terrestris) were exposed to COUNTER® 15G in artificial soils for 32 d in four treatment blocks Simulated rainfall and temperatures were used to approximate conditions during planting time in the U S corn belt Maximum mean uptake of terbufos was noted on the 8th d following pesticide treatment Terbufos sulfoxide uptake by earthworms was higher than terbufos uptake, and the concentration maximum was observed on day 16 post application Maximum concentrations of terbufos sulfone were detected in earthworm tissues on day 32 post application No significant earthworm mortality was observed on any single collection date, but temporal differences in mortalities were noted between control and treatment groups Total concentrations of terbufos and oxidative metabolites in L terrestris substantiate existing residue data from field investigations
A semistatic microplate-based phytotoxicity test
Authors: Radetski Claudemir Marcos , Ferard Jean-François , Blaise Christian
Published: March 2010

A novel phytotoxicity test is described herein that employs a microplate equipped with membrane-bottomed wells. This MultiScreen™ (Millipore Corp., Bedford, MA) microplate allows performance of a semistatic algal test, in which test medium is renewed periodically. With such a design, the algal test becomes comparable to other short-term tests used to evaluate chronic toxicity of chemicals and effluents. The EC50s obtained for Cu2+, Cd2+, Cr6+, atrazine, and one leachate sample (municipal sludge incinerator residue) with static and semistatic algal microplate tests were compared in this study. The semistatic microplate test revealed greater sensitivity than did the static microplate test.
PCB congeners and hexachlorobenzene biota sediment accumulation factors for Macoma nasuta exposed to sediments with different total organic carbon contents
Authors: Boese Bruce L. , Winsor M. , Lee H. , Echols S. , Pelletier J. , Randali R.
Published: March 2010

Deposit-feeding marine clams (Macoma nasuta) were exposed for 119 d to three sediment types that varied in total organic carbon (TOC) from 0.8 to 2.5%. Sediments were spiked with equal concentrations of 13 polychlorinated biphenyl congeners and hexachlorobenzene. Tissue residues were measured, and steady-state bioaccumulation factors (BAFs), the corresponding lipid, and TOC-normalized biota sediment accumulation factors (BSAFs) were determined. The BSAFs were less variable than were the BAFs with the exception of compounds with log Kow > 7. Many of the BSAFs exceeded 1.7, which is a calculated maximum value based on partitioning alone. Although BSAFs varied with sediment type and compound, the use of a BSAF of 4 as a screening level for neutral organic compounds in assessing dredge materials is supported by the present study.
Comparative toxicity of formulated glycol deicers and pure ethylene and propylene glycol to Ceriodaphnia dubia and Pimephales promelas
Authors: Pillard David A
Published: March 2010

Airlines use deicers to remove ice and snow from aircraft before flights, and to retard the inflight buildup of these materials Many of the deicers are formulated mixtures of ethylene glycol (EG) or propylene glycol (PG) and a variety of additives Because these deicers may be intentionally or accidentally released into aquatic ecosystems, the possibility exists for direct and indirect adverse effects on aquatic organisms Laboratory studies evaluated the comparative toxicity of formulated glycol deicers and pure materials on the water flea, Ceriodaphnia dubia, and fathead minnow, Pimephales promelas Acute (48 h and 96 h) and short-term chronic tests were performed according to U S Environmental Protection Agency (EPA) guidelines The formulated mixtures were found to be substantially more toxic than either of the pure glycol materials The 48 h LC50s for C dubia were 13,140 mg/L and 1,020 mg/L using formulated EG and PG, and 34,400 mg/L and 18,340 mg/L using pure EG and PG, respectively The 96 h LC50s for P promelas were 8,050 mg/L and 710 mg/L using formulated EG and PG, and 72,860 mg/L and 55,770 mg/L using pure EG and PG, respectively Chronic IC25s for C dubia were 3,960 mg/L and 640 mg/L using formulated EG and PG, 12,310 mg/L and 13,470 mg/L using pure EG and PG Chronic IC25s for P promelas were 3,660 mg/L and 110 mg/L using formulated EG and PG, 22,520 mg/L and 6,940 mg/L using pure EG and PG For airports that have stormwater discharge permits, numerical limits for EG and PG are generally listed, potential toxicity is assumed to be due to the glycol materials However, other compounds in the mixtures may either contribute substantially to, or in some cases overshadow, the toxicity of the glycol materials
Submitochondrial particles as toxicity biosensors of chlorophenols
Authors: Argese Emanuele , Bettiol Cinzia , Ghelli Anna , Todeschini Roberto , Miana Paola
Published: March 2010

An in vitro bioassay procedure was used to investigate the toxic action of chlorophenols on mitochondrial respiratory parameters The toxicity of these compounds was evaluated by determining their effects on the energy coupled reverse electron transfer (RET) in submitochondrial particles (SMPs) from beef heart mitochondria The bioassay procedure is based on the spectrophotometric recording of the effects of toxicants on the rate of NAD+ reduction, induced by ATP and succinate at the first site level of the respiratory chain The toxicity end point was expressed as the toxicant concentration that causes 50% inhibition of NAD+ reduction rate (EC50). The EC50 values determined for the 14 tested chlorophenols ranged from 17 mg/L for 2 chlorophenol to 0 081 mg/L for pentachlorophenol, indicating a general trend of increasing toxicity with increasing chlorine substitution Among chlorophenol isomers, which have the same number of chlorine atoms, a lesser toxicity was associated with ortho-substituted chlorophenols, whereas meta substituted chlorophenols were much more toxic The EC50 values were compared with the toxicity data for a variety of bioassays, by means of linear regression analysis High degrees of correlation obtained with toxicity tests involving different freshwater species demonstrate the ability of SMPs to reproduce the toxic effects of the tested compounds upon aquatic organisms This supports the assessment that the respiratory chain is the main target of this class of toxicants Results obtained with chlorophenols and, in previous studies, with other environmental contaminants confirm the suitability of the SMP bioassay as a prescreening or complementary short term test for monitoring aquatic toxicity
Mineralization of polycyclic and N-heterocyclic aromatic compounds in hydrocarbon-contaminated soils
Authors: Grosser Robert J. , Vestal J. Robie , Warshawsky David
Published: March 2010

The comparative mineralization of eight polycyclic aromatic compounds in five soils collected from an abandoned coal tar refinery in eastern Ohio was determined. The soils showed differences only in total extractable hydrocarbon content of the soil chemical characteristics measured. The compounds studied included five polycyclic aromatic hydrocarbons (phenanthrene, anthracene, pyrene, and carcinogenic benz[a]anthracene and benzo[a]pyrene) and three N-heterocyclic aromatics (9H-carbazole, and carcinogenic 7H-dibenzo[c,g]carbazole and dibenz[a,j]acridine). Mineralization was measured by serum bottle radiorespirometry. Only phenanthrene, anthracene, pyrene, benz[a]anthracene, and carbazole were mineralized in the soils after 64 d. Two of the soils with eight to 15 times the hexane-extractable hydrocarbon content consistently showed more rapid initial rates and higher overall extents of mineralization compared to the other three soils. Overall extents of mineralization ranged from 38 to 55% for phenanthrene, 10 to 60% for anthracene, 25 to 70% for pyrene, background to 40% for benz[a]anthracene, and 25 to 50% for carbazole after 64 d. Extents of mineralization by indigenous soil microbiota appear to be more dependent on the chemical characteristics of the soil and not soil total biomass and activity. Cultures capable of degrading phenanthrene, anthracene, and pyrene were obtained following enrichment techniques. A Mycobacterium sp. capable of degrading these three compounds was isolated and reintroduced into two of the soils, resulting in mineralization enhanced above that of the indigenous soil microbial population. These data indicate that the future success of bioremediation methods relies on the characterization of environmental parameters affecting microbial degradation as well as the isolation of microbial populations that can reduce toxicity in the environment.
Simulated leachability of pesticides from recycled pesticide-container plastics
Authors: Kells Alice M. , Solomon Keith R.
Published: March 2010

The rate of leaching of pesticides from fence posts made with recycled high-density polyethylene plastics from pesticide containers was determined. Posts were 7.5 cm in diameter and contained 100, 50, or 25% pesticide-container plastics, with pesticide-free sources of low-density polyethylene used as the diluent. As posts are manufactured in a number of diameters, results are reported as μg/m2. The 7.5-cm posts had a surface area of about 0.5 m2. Trifluralin was the only pesticide detected in the leachates. Total amounts of trifluralin leached from these three products, using well water, were 17, 234, and 90 μg/m2 of the surface area of the posts, respectively. Total amounts leached using simulated acid rain were 85, 196, and 84 μg/m2 respectively. Weathering of posts for 1 year resulted in significantly lower concentrations of trifluralin in the leachate using simulated acid rain, total amounts of trifluralin leached were 4, 6, and 6 μg/m2 for the 100, 50, and 25% contents, respectively. The amount of trifluralin released in all instances was judged to be insufficient to cause injury to sensitive plants and did not exceed Canadian guidelines for the protection of drinking water for humans or livestock. Trifluralin levels in the leachate did exceed Canadian guidelines for the protection of aquatic life in some cases, suggesting caution in the use of the products in aquatic environments.
Influence of sediment composition on apparent toxicity in a solid-phase test using bioluminescent bacteria
Authors: Benton Michael J , Malott Michelle L , Knight Scott S , Cooper Charles M , Benson William H
Published: March 2010

Clean and spiked sediment formulations of various silt sand and clay sand ratios were tested for toxicity using a bioassay that utilizes bioluminescent bacteria Measured toxicities of clean and copper sulfate–spiked sediments were negatively but nonlinearly related with percent silt and percent clay, but no significant relationship existed between measured toxicity and sediment composition for methyl parathion–spiked formulations Results suggest that solid phase sediment bioassays using bioluminescent bacteria may be useful for testing the toxicities of single contaminants in formulated artificial sediments of known particle size composition, and for repeated samples collected from the same site However, extreme caution must be taken when testing sediments of varying composition or which may be differentially contaminated or contain a suite of contaminants
Chemical partitioning and bioavailability of lead and nickel in an estuarine system
Authors: Babukutty Y , Chacko Jacob
Published: March 2010

Sediments, water, and biota of an estuarine system were analyzed for concentrations of lead and nickel Sediments were sequentially extracted to obtain the different chemically extractable fractions (exchangeable, carbonate bound, Fe/Mn-oxide bound, organically bound, and residual fractions) of these metals Concentrations of these metals in the soft tissue of an estuarine bivalve Villorita cyprinoides var cochinensis were correlated with the concentrations of these metals present in the various sediment fractions, dissolved, and particulate phases in water The degree of correlation between these various environmental variables and biological factors was considered as the index of bioavailability Metal concentrations in the soft tissue and particulate phase of water were divided by the corresponding concentrations in the dissolved phase in water to obtain the bioconcentration ratio (BCR) and metal partitioning ratio (MPR), respectively These ratios were found to be useful in quantifying the metal bioavailability The relationship between other biological factors and environmental variables is also presented and discussed
Determination of dieldrin binding to dissolved organic material in sediment pore water using a reverse-phase separation technique
Authors: Kosian Patricia A. , Hoke Robert A. , van dermeiden Frances M. , Ankley Gerald T.
Published: March 2010

The objective of our study was to examine the partitioning of dieldrin in sediment interstitial (pore) water. Clean sediments obtained from three northeastern Minnesota lakes, Airport Pond (AP), Pequaywan (PQ) Lake, and West Bearskin (WB) Lake, were spiked with dieldrin at five different concentrations. Pore water was isolated by centrifugation, and a reversephase C18 column technique was used to separate freely dissolved dieldrin from dissolved organic carbon (DOC)-bound dieldrin. Results showed DOC-bound dieldrin was generally >30% when pore-water DOC concentrations were >20 mg/L. Pore-water DOC partition coefficients (KDOC) were determined for AP, PQ Lake, and WB Lake using the ratio of the DOC-bound chemical concentration (normalized to DOC) to the freely dissolved chemical concentration. The individual partition coefficients were compared by one-way analysis of variance. Statistical analysis revealed that KDOC values were not significantly different. This suggests that under our experimental procedures, KDOC values are not significantly different among pore waters obtained from the three northeastern Minnesota lake sediments. A pooled KDOC was calculated using least-squares regression and compared to the mean of all individual KDOC values. The KDOC is best represented for this region by a pooled log10  KDOC value of 4.43. Our observed KDOC was compared to KDOC values predicted from published KDOC and Kow (octanol/water partition coefficient) relationships. Our observed value was in close agreement with predicted values.
Spatial and temporal variations in toxicity in an urban-runoff treatment marsh
Authors: Katznelson Revital , Jewell William T. , Anderson Susan L.
Published: March 2010

Toxicity tests have not been widely used to assess the performance of urban-runoff treatment facilities. In the present study, Ceriodaphnia dubia toxicity tests were used to quantify toxicity of urban runoff at Crandall Creek and the downstream Demonstration Urban Stormwater Treatment (DUST) March in Fremont, California. Acute toxicity, expressed as the median time to lethality (LT50) for C. dubia, was used to compare the relative intensities of toxicity in the system. During or shortly after storm events, horizontal and vertical gradients in LT50 and electrical conductivity were observed, with high correlation between the two parameters. Toxicity diminished as time passed after the storm. The performance of the DUST Marsh as a treatment facility was evaluated for three aspects: detention, dilution, and toxicity removal. We found that toxic storm water generated by small- to medium-sized storms (5 to 25 mm rain) was contained in the marsh. Toxicity was greatly reduced upon dilution of storm water with pre-existing marsh water, and mixing of the water column increased the rate of toxicity diminution. Toxicity reduction, above and beyond that attributable to dilution, was evident in the marsh. Results of this study demonstrate the potential use of toxicity assessments as an integral component of marsh design and management.
Growth, fecundity and glycogen utilization in Lymnaea palustris exposed to atrazine and hexachlorobenzene in freshwater mesocosms
Authors: Baturo Wojciech , Lagadic Laurent , Caquet Thierry
Published: March 2010

Freshwater mesocosms were used to study the long-term sublethal effects of atrazine and hexachlorobenzene (HCB) on a basommatophoran gastropod, Lymnaea palustris (Müller). Growth, fecundity, and biochemical parameters related to polysaccharide metabolism (glycogen content and polysaccharide-hydrolyzing enzyme activity) of pesticide-exposed snails were compared with those of control animals maintained in untreated mesocosms. HCB inhibited body growth and stimulated egg production, whereas atrazine had no relevant effect on these physiological parameters. Also, HCB stimulated the activity of polysaccharide-hydrolyzing enzymes, suggesting that changes in the metabolism of reserve polysaccharides (glycogen) may be involved in the inhibition of growth and increase of fecundity. In contrast, atrazine had no effect on the metabolism of polysaccharides. It is concluded that the effects of HCB are related to its neurotoxicity that would have affected the neurohormonal control of growth and reproduction of exposed snails. It is suggested that polysaccharide-hydrolyzing enzymes may be used as biomarkers to predict the effects of neurotoxic pesticides on freshwater snail populations.
Effects of sediment-bound polydimethylsiloxane on the bioavailability and distribution of benzo[a]pyrene in lake sediment to Lumbriculus variegatus
Authors: Kukkonen Jussi , Landrum Peter F.
Published: March 2010

Oligochaetes, Lumbriculus variegatus, were exposed to Lake Michigan sediment spiked in the laboratory with polydimethylsiloxane (PDMS) at two different concentrations (50 and 150 μg g−1). Additionally, these sediment samples and one without PDMS were spiked with benzo[a]pyrene (BaP) (about 190 pg g−1). The accumulation of PDMS and BaP, survival, wet weight, and defecation of the animals were monitored. Lumbriculus variegatus accumulated sediment-associated BaP rapidly and achieved steady state within 96 to 168 h. The BaP uptake clearances (ks, g sediment g−1 animal h−1) were 0.069, 0.060, and 0.056 for BaP only, BaP with low-dose PDMS, and BaP with high-dose PDMS exposures, respectively. The BaP bioaccumulation factor was reduced by PDMS in the sediment. Only very low concentrations of PDMS were found associated with the worms, which suggests some surface sorption or association with material in the gut. Elimination of BaP in clean sediment was rapid, but elimination in water was much slower. Elimination rate constants for BaP, ke, were 0.0229 ± 0.0011 h−1 for sediment and 0.0004 ± 0.0004 h−1 water-only depuration. The PDMS was excreted within 10 h both in sediment and water-only depuration exposures, indicating that most of the measured body burden was due to the sediment-associated material inside the organisms' gut. Animals were not purged before analyses, and several approaches were investigated for estimating the contribution of the intestinal contents. Based on both measurements and calculations, sediment-associated BaP in the gut contributes less than 10% of total body burden. Thus, a 10-h water-only purge was found to be the most appropriate method for eliminating the gut-content influence on the body burden.
Uptake, bioavailability and elimination of hydrophobic compounds in earthworms (Eisenia andrei) in field-contaminated soil
Authors: Belfroid Angelique , van den Berg Martin , Seinen Willem , Hermens Joop , van Gestel Kees
Published: March 2010

Uptake, accumulation, and elimination of hydrophobic organic chemicals in earthworms (Eisenia andrei) exposed to field-contaminated Volgermeerpolder soil was studied Earthworms were able to take up chlorobenzenes and polychlorobiphenyls (PCBs), but body burdens did not exceed concentrations measured in the soil For the chlorobenzenes, steady state concentrations in the worms and biota to-soil accumulation factor (BSAF) values were much smaller than expected based on earlier experiments, suggesting a decreased bioavailability in the Volgermeerpolder soil Comparison of the PCB accumulation pattern in worms to the pattern in soil showed that biotransformation of the studied PCBs is of minor importance in this species Elimination of all chemicals studied was monophasic, with the exception of hexachlorobenzene, which showed a biphasic elimination The elimination half life for the initial fast phase of this compound is comparable to the elimination measured in previous studies Elimination rate constants decreased with increasing log Kow
Effects of the synthetic pyrethroid insecticide, esfenvalerate, on larval leopard frogs (Ranaspp.)
Authors: Materna Elizabeth J. , Rabeni Charles F. , Lapoint Thomas W.
Published: March 2010

Leopard frog (Rana spp.) tadpoles exposed to esfenvalerate in the laboratory experienced a decrease in activity at concentrations as low as 1.3 μg/L and exhibited a convulsive, twitching response at concentrations of 3.6 μg/L. The 96-h median lethal concentration was 7.29 μg/L. Temperature influenced amphibian mortality; the mortality concentration-response slope at 22°C was significantly greater than at 18°C. Tadpoles exposed in a pond showed the same responses (inactivity, convulsive actions, and death) at similar concentrations as laboratory test organisms. Surviving tadpoles from laboratory tests resumed normal behavior 1 week after being placed into clean water, but most of those tadpoles that exhibited convulsive behavior during initial exposure eventually died. Tadpoles surviving pond exposures showed no later mortality, but rather exhibited a negative density-growth relation. Measured pyrethroid concentrations in ponds and streams adjacent to sprayed fields do not exceed levels associated with convulsive twitching or mortality in larval amphibians; however, they do exceed concentrations associated with inactivity and fish and invertebrate mortality, which may indirectly affect larval amphibians.
Evaluation of soil toxicity at joliet army ammunition plant
Authors: Simini Michael , Wentsel Randall S. , Checkai Ronald T , Phillips Carlton T. , Chester Nancy A , Major Michael A
Published: March 2010

Environmental toxicity testing and chemical analyses of soil were performed as part of an ecological risk assessment at the Joliet Army Ammunition Plant (JAAP), Johet, Illinois Soils were collected from an area where munitions were loaded, assembled, and packed (area L7, group 1), and from an area where waste explosives were burned on unprotected soil (area L2) Control samples were collected from an adjacent field Soil toxicity was determined using early seedling growth and vigor tests, earthworm survival and growth tests, and Microtox® assays Relative toxicity of soils was determined within each area based on statistical significance (p = 0 05) of plant and earthworm growth and survival, and the effective concentration at which luminescence of the bacterium Photobacterium phosphoreum was reduced by 50% (EC50) in the Microtox assay Samples were designated as having high, moderate, or no significant toxicity Soil that had significant toxicity according to at least one test, and representative samples showing no toxicity, were analyzed for munitions via HPLC Chemical residues found in soils were 2,4,6 trinitrotoluene (TNT), 1,3,5 trinitrobenzene (TNB), 2,4 dinitrotoluene (2,4-DNT), 2,6 dinitrotoluene, 2 amino-4,6-DNT, 4-ammo-2,6 DNT, 1,3,5 trinitro 1,3,5 triazine (RDX), and octahydro-1,3,5,7 tetramtro-l,3,5,7-tetrazocme (HMX) All soils with no significant toxicity were void of these chemicals However, some soils void of munitions still showed toxicity that may have been caused by elevated levels of heavy metals Linear regressions of toxicity test results vs chemical concentrations showed that TNT and TNB accounted for most of the soil toxicity Lowest observable-effect concentrations (LOEC) of TNT were de termined from these data This study presents a simple, relatively inexpensive methodology for assessing toxicity of soils containing TNT, RDX, and other contaminants related to munitions production