bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth and survival of three marine invertebrate species in sediments from the hudson-raritan estuary, New York
Authors: Rice Casimir A. , Plesha Paul D. , Casillas Edmundo , Misitano David A. , Meador James P.
Published: March 2010

Sediments in the Hudson-Raritan estuary are known to contain high concentrations of anthropogenic contaminants, and marine organisms from this region exhibit numerous contaminant-related effects. To assess the pattern of sediment toxicity in depositional areas of this region, and to compare lethal and sublethal end points for different bioassay organisms, three benthic marine invertebrate species were exposed to sediments from 17 sites in the Hudson-Raritan estuary. Growth and mortality of the polychaete Armandia brevis and the sand dollar Dendraster excentricus were measured in all 17 sediments, while mortality and reburial ability of the amphipod Rhepoxinius abronius were assessed in nine sediments. Growth of polychaetes was determined by measuring the difference in weight after a 20-d exposure, whereas growth of sand dollars was assessed by measuring the difference in length and weight after a 28-d exposure. Amphipod mortality and reburial tests were conducted using the standard 10-d sediment bioassay. Significant growth reduction of polychaetes and sand dollars occurred in 11 of 17, and 3 of 17 sediments, respectively. Polychaete weight and sand dollar length correlated inversely and significantly with total sediment concentration of polycyclic aromatic hydrocarbons, polychlorinated biphenyls, and some selected elements. In contrast, significant mortality of polychaetes and amphipods occurred in 1 of 17 and 2 of 9 sediments, respectively, and impaired reburial ability of amphipods was not observed. Results of this study demonstrate that sediment contamination at depositional sites with the Hudson-Raritan estuary has potential to cause deleterious biological effects in indigenous benthic organisms. In addition, sublethal growth bioassays using polychaetes and sand dollars appear to be more sensitive in measuring the effects of sediment contamination than does the mortality-based bioassay using the amphipod Rhepoxinius abronius.
Effects of naturally weathered Exxon valdez crude oil on mallard reproduction
Authors: Stubblefield William A. , Hancock Gregg A. , Prince Harold H. , Ringer Robert K.
Published: March 2010

A one-generation reproductive toxicity study and a direct eggshell application toxicity study were conducted using the mallard (Anas platyrhynchos) to assess the toxicity of naturally weathered North Slope crude oil (WEVC), obtained following the Exxon Valdez spill. In the reproductive study, birds were fed diets containing 0, 200, 2,000, and 20,000 mg of WEVC/kg diet. No significant differences (p ≤ 0.05) in mortality, body weight, food consumption, reproductive parameters, or hatchling parameters were observed. Significant decreases in mean serum phosphorous, serum total protein, albumin, bilirubin, and calcium concentrations were observed in high-dose-group females; no differences were noted among males. Eggshell strength and thickness in the high-dose group were significantly reduced compared to controls. Trends toward increased liver weights and decreased spleen weights were observed in WEVC-treated birds. Applications of WEVC to developing eggs showed it to be less toxic than unweathered North Slope crude oil. Doses covering up to one-third of the shell area of developing mallard eggs (92 mg) resulted in no effects on developing embryos. Eggs treated with the control material, petrolatum, were adversely affected by applications covering approximately one-sixth of the eggshell (24 mg), suggesting inhibition of gas exchange. Neither material affected hatchling survival or growth.
Steady-state model of biota sediment accumulation factor for metals in two marine bivalves
Authors: Thomann Robert V. , Mahony John D. , Mueller Rosemarie
Published: March 2010

A model of the biota sediment accumulation factor (BSAF) is developed to relate the ratio of metal concentrations in two marine bivalves (Crassostrea virginica and Mytilus edulis) to sediment metal concentration. A generalized metal BSAF can be approximated by a simple relationship that is a function of sediment to water column partitioning, the bioconcentration factor (BCF), the depuration rate, the metal assimilation efficiency from food, the bivalve feeding rate, and the growth rate. Analyses of “Mussel Watch” data indicate that the median BSAF across stations varies by about three orders of magnitude from Zn, Cd, and Cu at the highest levels of BSAF = 1 to 10, while Cr has the lowest BSAF at 0.01. Total Hg is about 1.0 and Ni and Pb are approximately 0.1. Calibration of the model indicates that the food route of metal accumulation is significant for all metals but especially for Zn, Cd, Cu, and Hg where virtually all of the observed BSAF is calculated to be due to ingestion of metal from food in the overlying water. These results indicate a potential significance of the metal-binding protein metallothionein, which results in relatively high binding of metal and resulting low depuration rates.
Pilot scale validation of the river/fish bioaccumulation modeling program for nonpolar hydrophobic organic compounds using the model compounds 2,3,7,8-TCDD and 2,3,7,8-TCDF
Authors: Abbott Joan D. , Hinton Steven W. , Borton Dennis L.
Published: March 2010

The interactive and user-friendly PC-computer-based RIVER/FISH mechanistic modeling procedure was evaluated and found to provide credible simulations of aquatic organism bioaccumulation for nonpolar hydrophobic organic chemicals (NPHOCs) using a four-trophic-level food web calculation methodology. Model evaluation included calibration to observations of tetrachlorinated dibenzodioxin and -furan (TCDD/F) bioaccumulation in largemouth bass (Micropterus salmoides) and channel catfish (Ictalurus punctatus) that were exposed in pilot-scale experimental streams receiving biologically treated pulp mill effluent and subsequent comparison of model predictions without bioaccumulation parameter adjustment (validation) to similar but independently obtained bioaccumulation observations. When calibrated with site-specific information on NPHOC loading rates and organism feeding habits, model prediction uncertainty was within U.S. Environmental Protection Agency (EPA) established standards averaging 1.1 pg/g for the observations used for model validation, which all measured < 20 pg/g. The procedure appears suitable for field-scale applications provided the site-specific feeding habits of each organism in the simulated food web can be estimated accurately, all significant chemical loadings are quantified, and the natural variability of bioaccumulation processes is considered when interpreting simulation results.
Metabolism of different PCB congeners in plant cell cultures
Authors: Wilken Annelen , Bock Claudia , Bokern Maria , Harms Hans
Published: March 2010

The metabolism of 10 different congeners of polychlorinated biphenyls (PCBs) was tested in cell cultures of 12 different plant species. The rate of metabolism was determined through comparison with cells inactivated by treatment with perchloric acid. The metabolism of defined PCB congeners was strongly dependent on the plant species. In particular, two Fabaceae species exhibited high capacities for metabolizing different congeners. Except for PCB 15 (4,4′-dichlorobiphenyl), it was shown that a lower chlorination grade is associated with higher metabolism rates. Also, it was shown that substitution and molecular configuration play an important role in the metabolism of PCBs in plants. In studies with 14C-PCB 1 (2-chlorobiphenyl) in soybean cultures, one dihydroxylated and six different monohydroxylated compounds were detected after acid hydrolysis of polar metabolites (conjugates). Hydrolysis of metabolites of 14C-PCB 52 (2,2′,5,5′-tetrachlorobiphenyl) in wheat cell cultures yielded four monohydroxylated and three dihydroxylated metabolites.
Survey of nine organotin compounds in the netherlands using the zebra mussel (Dreissena Polymorpha) as biomonitor
Authors: Stäb Joan A. , Frenay Michel , Freriks Ivo L. , Cofino Wim P. , Th. Brinkman Udo A.
Published: March 2010

In the present survey zebra mussels were used as biomonitors to evaluate concentrations of nine organotin compounds (OTs) in Dutch fresh waters. To this end mussels were sampled at 56 locations throughout the country at the end of the summer of 1992. Variations in OT concentrations in zebra mussels were studied at two locations near potato crops that were sprayed with triphenyltin (TPT) in order to estimate the integration period over which body concentrations reflect the environmental quality. Apparent depuration half-life times in the field were calculated to be 100 to 200 d for TPT, which indicates that body burdens represent the TPT water quality over a long period of time. Results from the survey showed that OTs are still ubiquitously present in the freshwater environment in The Netherlands. Despite the implementation of legislation restricting the use of tributyltin (TBT), very high TBT body concentrations can still be found. The TPT was found in very high concentrations in mussels near sources of this fungicide. It was also discovered at remote locations. Possibly the presence of TPT there is due to transport via the air. The degradation products of TBT and TPT, the di- and mono-, -butyl- and -phenyltins, were also detected in nearly all mussels analyzed. Tricyclohexyltin (TCT) and fenbutatinoxide (FBTO), which are much less used organotin pesticides, were identified only in a few cases and do not appear to pose real environmental threats. Statistical analysis by means of principal component analysis was found to be a useful tool for evaluating the sources of OTs monitored by the zebra mussels.
A method to buffer the concentrations of free Zn and Cd ions using a cation exchange resin in bacterial toxicity studies
Authors: Knight Bruce , McGrath Steve P.
Published: March 2010

The chemical form or species of metal present in a growth system is crucial to the toxicity of that metal. A growth medium is described in which the free metal concentration of either Zn or Cd is known. A method using a cation exchange resin as a buffer to maintain free metal ion concentrations during microbial growth is discussed. Using a buffered system, free concentrations of 3.4 μg Cd L−1 and 57 μg Zn L−1 reduced the growth rate of a sensitive isolate of Rhizobium leguminosarum biovar trifolii. The results demonstrate that to assess the true toxicity of Cd and Zn, the free ion concentration must be considered and that small free concentrations must be buffered.
Lead and cadmium in wild birds in southeastern spain
Authors: Garcia-Fernandez Antonio Juan , Sanchez-Garcia Jose Antonio , Jimenez-Montalban Pedro , Luna Aurelio
Published: March 2010

The main purpose of this study was to monitor exposure to lead and cadmium in wild birds in Murcia, a southeastern region of Spain on the Mediterranean coast. This region lies on one of the African-European flyways. Samples of liver, kidney, brain, bone, and whole blood from several species of wild birds were obtained during 1993. We found a clear relationship between cadmium and lead concentrations in birds and their feedings habits. Vultures (Gyps fulvus) had the highest concentrations of lead (mean 40 μg/dl in blood), and seagulls (Larus argentatus and Larus ridibundus) the highest concentrations of cadmium (mean 4.43 μg/g in kidney). Insectivores had high concentrations of both metals, and diurnal and nocturnal raptors showed the lowest tissue concentrations. The finding that tissue and blood concentrations were generally not elevated suggests environmental (rather than acute) exposure. Birds from more industrialized areas of the region studied here had higher concentrations of both lead and cadmium.
Quantum chemical approach to estimate physicochemical compound properties: Application to substituted benzenes
Authors: Schüürmann Gerrit
Published: March 2010

Estimation models for Henry's law constant (H), water solubility (Sw), vapor pressure (Pv), and octanol/water partition coefficient (Kow) of nonelectrolytes are derived from basic thermodynamic equations. The resultant regression equations require only two molecular descriptors, which are available from chemical structure through semiempirical quantum chemical calculations: free energy of solvation (δGs), and molecular contact surface area (CSA). Results are presented for a set of 17 benzenes with experimental data taken from literature, yielding squared correlation coefficients r2adj (adjusted for degrees of freedom) between 0.83 and 0.95. The discussion includes limitations from currently available continuum solvation models to calculate δGs, aspects of potential error compensation, and the suitability of this approach to understand macroscopic compound properties in terms of calculated quantities that represent distinct types of intermolecular interactions.
Short Communication: A comparison of the toxicity of 30 reference chemicals to Daphnia Magna and Daphnia Pulex
Authors: Lilius Henrik , Hästbacka Tom , Isomaa Boris
Published: March 2010

To determine whether significant differences exist in the sensitivity of different Daphnia species to toxicants, the acute toxicity of the first 30 MEIC (multicenter evaluation of in vitro cytotoxicity) reference chemicals was determined in two species of Daphnia: D. magna and D. pulex. Correlation and regression analysis of the EC50 data for immobilization showed a very good concordance (r = 0.97, slope = 1.02). A comparison between the EC50 data obtained for D. magna by two laboratories independently for the 50 MEIC chemicals also showed a good concordance (r = 0.93, slope = 0.91). In both comparisons the regression line did not differ significantly from the regression line for a 1:1 regression. We conclude that our study, including a set of reference chemicals, indicates there is no difference in the overall sensitivity of the two Daphnia species and the two clones of D. magna.
Physiological, reproductive and pathological effects of dietary bleached pulp mill effluent on mink (Mustela Vison)
Authors: Smits Judit E.G. , Wobeser Gary A. , Schiefer Bruno H.
Published: March 2010

In this study mink (Mustela vison) were exposed to whole bleached-kraft mill effluent (BKME) through their diets. The investigation examined clinical, biochemical, induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity, one-generational reproductive, and pathological effects on mink exposed to BKME through water containing 25% effluent, and diet containing 75% (pilot and first subchronic study) fish caught downstream of the BKME discharge point of the pulp mill. In a 6-week pilot study, no adverse effects were found on behavioral, gross pathological, histopathological, hematological, or biochemical variables tested. In an 8-month exposure study, no significant effects on these parameters, or on gestation, kit birth weight, kit survival, libido, estrus, sperm quality, or hormone levels were found. This was followed by a second 8-month study using double the number of mink (30 BKME-exposed, 30 controls), and modified dietary formulations. Whole fish was decreased to 45%, and 15% softwood-run BKME was added to the food. In this study, the liver somatic index was greater in exposed males (p = 0.068) than in control males. Hepatic EROD activity was 1.8 times greater in exposed female (p = 0.0001) and 2.0 times greater in exposed male (p = 0.0004) mink compared with controls.
Acute and chronic toxicity of ammonium nitrate fertilizer to amphibians from southern ontario
Authors: Hecnar Stephen Joseph
Published: March 2010

Increasing nitrate levels in surface and ground waters are of global concern. Effects of nitrates on human health are well documented, but effects on amphibians have received little attention. I exposed Bufo americanus (American toad), Pseudacris triseriata (chorus frog), Rana pipiens (leopard frog), and Rana clamitans (green frog) tadpoles to ammonium nitrate fertilizer in water. In acute tests, mortality varied among species (96-h LC50; 13.6-39.3 mg/L NO3-N) and significant weight loss occurred. In chronic tests (100 d; 0, 2.5, 5, 10 mg/L NO3-N) chorus frog and leopard frog tadpoles had significantly lower survivorship in the 10-mg/L treatments, but green frog survivorship was not affected. Number of chorus frogs metamorphosing was significantly lower in the 10-mg/L treatment, but development time was not affected. In acute exposures, reduced activity, weight loss, and physical abnormalities were observed. Toxic effects of ammonium nitrate occurred in all four species at concentrations that are commonly exceeded in agricultural areas globally. Nitrate fertilizers may play a role in the apparent global amphibian decline.
Avian exposure to organophosphorus and carbamate pesticides on a coastal South Carolina golf course
Authors: Rainwater Thomas R. , Leopold Vincent A. , Hooper Michael J. , Kendall Ronald J.
Published: March 2010

A field study was conducted to examine avian exposure to organophosphorus (OP) and carbamate (CA) pesticides applied to turf on a coastal South Carolina golf course. The number, distribution, and activity of birds on turfgrass were monitored from May 25 to August 27, 1993. Over 1,600 birds representing 23 species were counted on turfgrass during designated monitoring sessions and incidental observations. Most birds were observed during morning hours, on fairways, and on the back nine holes of the course. Foraging was the predominant behavior observed. Blood samples and footwashes were collected from red-winged blackbirds (Agelaius phoeniceus), common grackles (Quiscalus quiscula), and boat-tailed grackles (Quiscalus major) for measurement of plasma cholinesterase (ChE) activity and chemical residues, respectively. Reactivation of plasma ChE in 22 blood samples suggested CA exposure, but no overt signs of anti-ChE poisoning were observed in birds sampled. However, an incapacitated laughing gull discovered after an application of the CA bendiocarb (3.36 kg/ha) exhibited 87% depression of plasma ChE and displayed symptoms consistent with OP/CA intoxication. Pesticide exposure was confirmed by recovery of 50.33 μg bendiocarb in the footwash. Mole crickets (Scapteriscus spp.) that surfaced following the same chemical application contained bendiocarb residues and may have been ingested by foraging birds. Results of this study suggest a potential for avian exposure to OP and CA pesticides on the golf course, but few actual exposures and acute effects were observed.
Application of toxicity identification procedures to the echinoderm fertilization assay to identify toxicity in a municipal effluent
Authors: Bailey Howard C. , Miller Jeffrey L. , Miller Michael J. , Dhaliwai Bhupindar S.
Published: March 2010

Toxicity was detected in a municipal effluent with the echinoderm fertilization assay. Dendraster excentricus appeared more sensitive to the effluent than did Strongylocentrotus purpuratus. A Phase 1 toxicity identification evaluation (TIE) was conducted using procedures adapted to the echinoderm fertilization bioassay. The Phase 1 TIE implicated cationic metals as the cause of toxicity, and follow-up investigations suggested that copper was the primary cation responsible. As part of the TIE, bioassays were conducted on ammonia and several cations. No-observable-effect concentrations for D. excentricus were ≥ 13.4 μg/L (Ag), ≥9.4 μg/L (Cd), 3.8 to 13.1 μg/L (Cu), ≥0.7 μg/L (Hg), and 10 mg/L (N, as total ammonia). The data also suggested that interspecific differences in sensitivity to copper and ammonia exist between Dendraster excentricus and Strongylocentrotus purpuratus.
A residue-based toxicokinetic model for pulse-exposure toxicity in aquatic systems
Authors: Hickie Brendan E. , McCarty Lynn S. , Dixon George D.
Published: March 2010

This pulse-exposure model (PULSETOX) is based on the simple one-compartment first-order kinetics (1CFOK) equation. It tracks the accumulation of waterborne organic chemicals by fish and predicts acute toxicity by means of previously established relationships between whole-body residues and lethality. The predictive capabilities of the model were tested with a data set of 27 acute pulse-exposure lethality tests with larval fathead minnows (Pimephales promelas) exposed to pentachlorophenol (PCP). Tests included eight single exposures (2 to 96 h) and 19 multiple exposures, which varied in the number (2 to 15) and duration (2 to 24 h) of pulses, and time interval between pulses (6 to 24 h). Experimental work included determination of 1CFOK kinetics parameters from [14C]PCP uptake and clearance, and from time-toxicity curves. Lethality was expected in any exposure regime where the fish reaches or exceeds the critical body residue (CBR) of 0.30 mmol PCP/kg fish (sd, ±0.02; n = 11). Using the CBR endpoint, the model accounted for between 90 and 93% of variability in the observed lethality data, depending on the toxicokinetic parameters employed. Predictive power of the model was optimized by using kinetics parameters derived from the toxicity curve for pulse-toxicity tests as shown by the regression: predicted LC50 = 1.04±(observed LC50) + 0.01 (p < 0.001, r2 = 0.94, n = 27).
An ecological risk assessment for the use of the biocide, dibromonitrilopropionamide (DBNPA), in industrial cooling systems
Authors: Klaine Stephen J. , Cobb George P. , Dickerson Richard L. , Dixon Kenneth R. , Kendall Ronald J. , Smith Ernest E. , Solomon Keith R.
Published: March 2010

A tiered approach was employed to determine risks posed to aquatic organisms exposed to dibromonitrilopropionamide (DBNPA). Tier one assessments used conservative exposure and toxicity data and indicated that potential toxicity warranted a more rigorous risk assessment. Tier two used discharge and stream flow data to develop a probabilistic model of DBNPA concentrations reaching the stream. Predicted 90th percentile in-stream DBNPA concentrations were compared to all available toxicity data for aquatic organisms at several different trophic levels. The EC10 for one organism was similar to the calculated 90th percentile of DBNPA concentrations in streams. Using the complete EC10 data set and comparing the 10th percentile EC10 with the 90th percentile environmental concentration, DBNPA did not pose a measurable risk to the aquatic ecosystem.
The carcinogenic potential of dacthal and its metabolites
Authors: Klopman Gilles , Fercu Dan , Rosenkranz Herbert S.
Published: March 2010

We evaluated the carcinogenic potential of Dacthal, an important herbicide, and its biodegradation product, tetrachloro-terephthalic acid, on the basis of their chemical and biological properties as well as by a variety of computational tools. We concluded that tetrachloroterephthalic acid does not present any substantial carcinogenic risk and that the observed rodent carcinogenicity of Dacthal is probably due to its impurities.
Temporal and vertical distribution of total ammonia nitrogen and un-ionized ammonia nitrogen in sediment pore water from the upper Mississippi River
Authors: Frazier Bradley E. , Naimo Teresa J. , Sandheinrich Mark B.
Published: March 2010

We examined the temporal and vertical distribution of total ammonia nitrogen (TAN) and un-ionized ammonia nitrogen (NH3-N) in sediment pore water and compared the temporal patterns of TAN and NH3-N concentrations in overlying surface water with those in pore water. Pore water was obtained by core extraction and subsequent centrifugation. We measured TAN concentrations and calculated NH3-N concentrations from February through October 1993 at four sites in Pool 8, upper Mississippi River, at depths of 0 to 4, 4 to 8, and 8 to 12 cm below the sediment-water interface. Total ammonia nitrogen and NH3-N concentrations were significantly different among sampling dates (p = 0.0001) and sediment depths (p = 0.0001). Concentrations of TAN and NH3-N in surface water were significantly less than those in pore water from all sediment depths (p < 0.05). Concentrations in pore water ranged from 0.07 to 4.0 mg TAN/L and less than 1 to 20 μg NH3-N/L in winter, and from 0.07 to 10.0 mg TAN/L and 1 to 175 μg NH3-N/L in summer; greatest concentrations were usually found in sediments 8 to 12 cm deep. Annual mean TAN concentrations were positively correlated with silt and volatile solids content and were negatively correlated with sand content. Because of the high variability of TAN and NH3-N concentrations in pore water, sediment toxicity studies should take into account the season and the depth at which sediments are obtained. The annual mean NH3-N concentration in pore water at one site (55 μg/L) exceeded the concentration (30 μg/L) demonstrated to inhibit growth of fingernail clams in laboratory studies. However, these concentrations apparently were not lethal, as evidenced by the presence of fingernail clams at this site.
Improved method for estimating water solubility from octanol/water partition coefficient
Authors: Meylan William M. , Howard Philip H. , Boethling Robert S.
Published: March 2010

Water solubility is a critical property in risk assessments for chemicals, but measured values are often unavailable. The most practical approach to estimating solubility for diverse and complex structures involves regression against the logarithm of the octanol/water partition coefficient (log Kow). However, currently used equations were developed from relatively small training sets (200–300 compounds). Our objective was to upgrade log Kov-based methods by examining a much larger and diverse training set and, if possible, to improve estimation accuracy further by incorporating a series of simple correction factors. We also evaluated the contributions of melting temperature (Tm) and molecular weight (MW). Measured values of water solubility, log Kow and Tm (solids only) were available for all compounds in the training set (n = 1,450). The best equation for this dataset included log Kow, Tm, MW, and 12 correction factors as independent variables, with r2 = 0.970, SD = 0.409, ME = 0.313. Statistics for an independent validation set of 817 compounds were consistent with these results: r2 = 0.902, SD = 0.615, ME = 0.480. We found that Tm contributed significantly to estimation accuracy for solids; addition of MW also increased accuracy; measured values of log Kow and Tm produced more accurate solubility estimates than did estimated values; and the new method outperformed other widely used general-purpose equations based on log Kow.
Formation of hydroxyl radical (·OH) in illuminated surface waters contaminated with acidic mine drainage
Authors: Allen John M. , Lucas Shawn , Allen Sandra K.
Published: March 2010

Formation rates and steady-state concentrations of hydroxyl radical (·OH) in illuminated surface water samples collected in west-central Indiana that receive acidic mine drainage runoff are reported. Formation rates for ·OH in samples were measured by the addition of 1 × 10−3 M benzene prior to illumination in order to effectively scavenge all of the ·OH formed, thereby yielding phenol. The ·OH formation rates were calculated from the measured phenol formation rates. Steady-state concentrations of ·OH were measured by the addition of 5 × 10−7 M nitrobenzene to the samples prior to illumination. Estimated sunlight ·OH formation rates range from 16 μM h−1 to 265 μM h−1. Estimated sunlight steady-state ·OH concentrations range from 6.7 × 10−15 to 4.0 × 10−12 M. Both the formation rates and steady-state concentrations for ·OH are thus two to three orders of magnitude higher than values reported in the literature for other sunlit surface water samples. Due to the very high rates of formation and steady-state concentrations for ·OH in these samples, we conclude that aqueous-phase reactions involving ·OH represent a significant pathway by which organic pollutants in illuminated surface waters receiving acidic mine drainage runoff may be consumed.
Ceriofast™: An acute toxicity test based on Ceriodaphnia dubia feeding behavior
Authors: Bitton Gabriel , Rhodes Kimberly , Koopman Ben
Published: March 2010

We have developed a rapid acute toxicity test (CerioFAST™) based on suppression of feeding activity of Ceriodaphnia dubia in the presence of toxicants. The bioassay consists of a 1-h exposure period to a given toxicant. Yeast cells, stained with a fluorescent dye, are added 20 min before the end of the exposure period. Response to a toxic sample is indicated by the absence of fluorescence in the gut of the daphnids. CerioFAST was compared to the standard 48-h C. dubia acute bioassay, using heavy metals and organic compounds. CerioFAST EC50s of Cd, Cu, Pb, Ag, Zn, and carbofuran were in the 0.01–0.1-mg/L range, whereas EC50s of hexachloroethane, pentachlorophenol, trichlorophenol, and lindane were in the 1–10-mg/L range. CerioFAST EC50s of the heavy metals and organics were well correlated with EC50s obtained with the 48-h C. dubia bioassay.
Effects of two cholinesterase-inhibiting pesticides on freshwater mussels
Authors: Moulton Cynthia A. , Fleming W. James , Purnell Cyrilla E.
Published: March 2010

The freshwater mussel Elliptio complanata and the Asiatic clam Corbicula fluminea were exposed for 96 h at 21°C to aldicarb, a carbamate pesticide, and acephate, an organophosphate pesticide. Test pesticide concentrations ranged from 0 to 320 mg/L. We found no mortality under these conditions. Relative to controls, cholinesterase (ChE) activity in adductor muscle from E. complanata was significantly depressed at concentrations as low as 0.1 mg aldicarb/L and 1.3 mg acephate/L. Higher pesticide concentrations were required to inhibit ChE activity in whole bodies of C. fluminea than in adductor muscle of E. complanata. Raising the experimental temperatures from 21 to 30°C increased pesticide-induced mortality, with mussels dying at aldicarb or acephate concentrations of only 5 mg/L. Cholinesterase activities of adductor muscle depressed 94 to 96% relative to controls began to recover within 2 and 12 d, but they were not fully recovered for 12+ and 24+ d following aldicarb and acephate exposures. Both aldicarb and acephate at 5 mg/L reduced shell closure responsiveness of mussels, with more pronounced effects observed at 27°C than at 21°C. Our data support the usefulness of determining ChE activity in adductor muscle to identify the exposure of freshwater mussels to ChE-inhibiting pesticides.
Toxicity and bioconcentration potential of adsorbable organic halides from bleached laundering in municipal wastewater
Authors: Ong Say Kee , Degraeve G. M. , Silva-Wilkinson Robin A. , Mccabe Jim W. , Smith William L.
Published: March 2010

A study was conducted to assess the formation, biological treatability, toxicity, and bioconcentration potential of adsorbable organic halides (AOX) formed from the use of household bleach during laundering. Following treatment with a bench-scale activated sludge system, approximately 70% of the laundry AOX was removed from the wash water. Removal efficiency of AOX from typical domestic wastewater treated in the same manner was 54%. Chronic bioassays conducted with the treated bleached laundry wash water effluent resulted in no toxicity to fathead minnow or Ceriodaphnia dubia that could be attributed to laundry AOX, even at concentrations 40 times higher than the predicted environmental AOX concentration. Analysis of treated bleached laundry effluent for bioconcentratable organic compounds tentatively identified no bioconcentratable or lipophilic chlorinated hydrocarbons in the treated laundry wash water.
The use of chorioallantoic membranes as predictors of egg organochlorine burden
Authors: Pastor Dolors , Albaigés Joan , Ruiz Xavier , Jover Lluis
Published: March 2010

The distribution of organochlorine pollutants between yolks, embryos, and chorioallantoic membranes (CAMs) in pipping eggs of Audouin's gulls from the Ebro Delta was determined to assess the usefulness of CAMs as surrogates for predicting whole egg pollutant burdens. The reliability of predictions was checked using a concordance analysis based on four different parameters. The most abundant pollutants found were PCBs and DDTs, whereas levels of HCHs were much lower. Generally, the largest concentrations of contaminants were found in yolk sacs, followed by embryos and CAMs. The latter contained only 1.21% of the total concentration of organochlorines detected. Results show that CAMs could provide good predictions only for those pollutants being almost completely excreted to the CAM (e.g., hexachlorocyclohexanes, PCB52, and DDD). In the other organochlorines tested, the prediction obtained is too weak to recommend the use of CAMs for the estimation of their total burden in the eggs of Audouin's gull. This suggests that the reliability of CAMs as surrogates should be tested for each chemical and species, prior to their use in nonlethal monitoring programs.
The effects of water chemistry on the toxicity of copper to fathead minnows
Authors: Erickson Russell J. , Benoit Duane A. , Mattson Vincent R. , Leonard Edward N. , Nelson Henry P.
Published: March 2010

The effects of various water chemistry parameters on the toxicity of copper to larval fathead minnows were investigated. Increased pH, hardness, sodium, dissolved organic matter, and suspended solids each caused toxicity to decrease on the basis of total copper concentrations. In contrast, added potassium resulted in increased toxicity. Alkalinity had no observed effect on total copper LC50s, but its effects might have been masked by those of the cations added with it. In most cases, the effects of water chemistry were found to be similar for different endpoints (growth, survival at different durations), but there were differences in the relative magnitude of some effects across these endpoints. Over all experimental treatments, 96-h total copper LC50s varied 60-fold. Every water chemistry parameter also caused toxicity to vary significantly when expressed on the basis of cupric ion selective electrode measurements, sometimes more so than on the basis of total copper. Therefore, this study does not support attributing to cupric ion a singular importance in regulating toxicity to this test organism. A variety of copper species might be contributing to toxicity and it is evident that toxicity is also affected by water chemistry in ways not related to copper speciation.
Membrane burdens of chlorinated benzenes lower the main phase transition temperature in dipalmitoyl-phosphatidylcholine vesicles: Implications for toxicity by narcotic chemicals
Authors: van Wezel Annemarie P. , Cornelissen Gerard , van Miltenburg J. Kees , Opperhuizen Antoon
Published: March 2010

In the membrane of an organism that dies due to exposure to narcotic chemicals, the main phase transition temperature (Ttr) of the phospholipids is decreased and the fluidity is increased. The decrease in Ttr depends on the molar concentration of narcotics in the membrane (membrane burden) and is irrespective of the physicochemical properties of the chemicals. If membrane–water partition coefficients, exposure concentrations, and the amount of lipid in the system are known, membrane burdens of narcotic chemicals can be calculated and compared to membrane burdens that yield toxicity. The partition coefficients of a series of chlorobenzenes between phospholipid vesicles and water (Kmw) were measured at different temperatures in a new experimental set-up. Kmw's were higher in the liquid-crystalline phase than in the gel phase. Partitioning into the gel phase was entropy driven, partitioning into the liquid-crystalline phase was driven by entropy and enthalpy. The fluidity change in phospholipid vesicles, after accumulation of chlorobenzenes, was measured from the change in Ttr. The membrane burdens of various chlorobenzenes needed for a lowering of Ttr were comparable (e.g., 20–60 mmol/kg for a decrease of 1.0°C). The membrane burden needed in vivo for lethality by narcotic chemicals such as chlorobenzenes was calculated to be 40–160 mmol/kg membrane. By combining the in vivo and in vitro data, it can be concluded that in organisms that die due to exposure to narcotic chemicals, the fluidity of the membrane is increased.
Gut content weight and clearance rate for three species of freshwater invertebrates
Authors: Brooke Larry T. , Ankley Gerald T. , Call Daniel J. , Cook Philip M.
Published: March 2010

There is concern for potential error in the accurate estimation of chemical bioaccumulation in benthic organisms due to chemicals associated with gut contents (sediments). In this study the benthic macroinvertebrates Hexagenia limbata, Chironomus tentans, and Lumbriculus variegatus were exposed to five sediments from the Lower Fox River/Green Bay area of Wisconsin to determine the percentage of their weight due to gut contents and the rate at which guts were emptied when the animals were held in clean water. Upon removal from the test sediments, inorganic gut contents in H. limbata, C. tentans, and L. variegatus represented approximately 9, 10, and 10% of their whole body dry weights, respectively. Depuration rates were relatively rapid, with mayflies, midges, and oligochaetes losing approximately 75, 90, and 100% of their gut contents during the first 12 h of depuration. This suggests that a 12–24-h holding period in clean water at the conclusion of sediment bioaccumulation tests with the three species should be sufficient to eliminate potential bias in tissue residue concentrations due to gut contents.
Environmental monitoring for linear alkylbenzene sulfonates, dialkyltetralin sulfonates and their biodegradation intermediates
Authors: Trehy Michael L. , Gledhill William E. , Mieure James P. , Adamove John E. , Nielsen Allen M. , Perkins Herbert O. , Eckhoff William S.
Published: March 2010

Concentrations of linear alkylbenzene sulfonates (LAS), dialkyltetralin sulfonates (DATS), and their biodegradation intermediates are reported for the influents and effluents of 10 U.S. domestic wastewater treatment plants as well as upstream and downstream river waters and sediments. Three types of treatment facilities in 10 U.S. states were sampled and analyzed. Removals were calculated based on initial concentrations of LAS and DATS. A derivatization electron capture/gas chromatography/mass spectrometry method was employed. Its increased sensitivity and selectivity permitted the determination of environmental levels of LAS, DATS, and their biodegradation intermediates at low micrograms per liter (ppb) concentrations. The removal from four activated sludge and five trickling filter wastewater treatment facilities averaged 99.5% and 82.9% for LAS and 99.1% and 97.3% for LAS intermediates, respectively, for the activated sludge and trickling filter facilities. In the same plants, percent removals for DATS averaged 95% and 63.2% and DATS intermediates 59.1% and 58.7%, respectively. The removals obtained by a rotating biological contactor were similar to those observed in the activated sludge wastewater treatment facilities.
The biodegradability and nontoxicity of carboxymethyl cellulose (DS 0.7) and intermediates
Authors: VanGinkel Cornelis G. , Gayton Sarah
Published: March 2010

Carboxymethyl cellulose (CMC) with a degree of substitution of 0.7 is a water-soluble polymer. In some cases, CMC ends up in wastewater treatment plants and, ultimately, in the environment. Carboxymethyl cellulose degrades completely at low rates in the environment as demonstrated in a prolonged closed bottle test and in a semicontinuous activated sludge test. The continuous-flow activated sludge (CAS) test simulates sewage treatment plants. In the CAS test the CMC added to raw sewage prior to entering the bioreactor was partly biodegraded by microorganisms. The effluent from the reactor containing intermediates was then used in standard aquatic toxicity tests. No toxicity was shown in the effluent, which indicates that the intermediates formed by biodegradation are not toxic. Carboxymethyl cellulose intermediates produced by a pure culture of a CMC-degrading bacterium were also shown not to be toxic, because no effects were observed at the highest concentrations tested: 0.5 g/L for Selenastrum capricornutum (algae), 1.0 g/L for Daphnia magna (water flea), and 1.0 g/L for Brachydanio rerio (zebra fish). In addition, the nontoxicity of CMC to these aquatic organisms was established with no-effect concentrations of > 0.5 g/L.
Degradation of weathered diesel fuel by microorganisms from a contaminated aquifer in aerobic and anaerobic microcosms
Authors: Bregnard Thierry Pierre-Alain , Höhener Patrick , Häner Andreas , Zeyer Josef
Published: March 2010

A diesel fuel-contaminated aquifer in Menziken, Canton of Aargau, Switzerland, was in situ bioremediated from 1989 to 1994 by adding O2, NO−3 PO3−4, and NH+4 through an infiltration well. After a remediation time of 3.5 years, aquifer material from the contaminated zone was excavated and found to contain >106 hydrocarbon-degrading microorganisms/g and 1.15 ± 0.15 mg/g weathered diesel fuel comprizing mainly isoprenoid alkanes and an unresolved complex mixture (UCM) of unknown components. Samples of this material were incubated for up to 470 days in aerobic and anaerobic microcosms. The microbial activity was determined by measuring the production of inorganic carbon and the consumption of O2 and NO−3. The degradation of the weathered diesel fuel was quantified by infrared spectroscopy and by capillary gas chromatography. In aerobic microcosms, all isoprenoid alkanes and most of the UCM were biodegraded as long as a nitrogen source was present. The O2 consumption could be stimulated by adding KH2PO4 and by elevating the temperature to 22° C. In anaerobic microcosms with KNO3, NO−3 was consumed, inorganic carbon was produced, and the isoprenoid alkanes and the UCM were partially metabolized. In some selected microcosms, the NO−3 consumption rate was stimulated by adding external substrates such as toluene, o-xylene, m-xylene, p-xylene, n-alkanes, or fatty acids. Mineralization of toluene, naphthalene, and hexadecane to CO2 under denitrifying conditions was confirmed by using [14C]-labelled substrates.
The effect of phorate on wetland macroinvertebrates
Authors: Dieter Charles D. , Flake Lester D. , Duffy Walter G.
Published: March 2010

The effects of phorate, an organophosphorus insecticide, on aquatic macroinvertebrates was studied in littoral mesocosms in South Dakota wetlands. In 1991 and 1992, four mesocosms were constructed in each of three wetlands. In each wetland, one mesocosm was a reference and phorate concentrations of 1.2, 2.4, and 4.8 kg/ha were applied to treatment mesocosms. Phorate caused mortality to amphipods and chironomids throughout the study. Leeches and snails were resistant to phorate. Few living macroinvertebrates were present in mesocosms after phorate treatment and populations recovered only slightly after 1 month. Macroinvertebrate taxa that were sensitive to phorate included: Odonata, Hemiptera, Culicidae, Heliidae, Ephemeroptera, Acarina, Coleoptera, Stratio-myidae, and Hydracarina. Taxa that were tolerant to phorate included: Hirudinea, Gastropoda, Oligochaeta, and Ostracoda.
Rodent neurotoxicity bioassays for screening contaminated great lakes fish
Authors: Beattie M. Kate , Gerstenberger Shawn , Hoffman Richard , Dellinger John A.
Published: March 2010

Standard laboratory rat neurotoxicity protocols were used to study the consequences resulting from the consumption of walleye (Stizostedion vitreum), whitefish (Coregonus chupeaformis), and lake trout (Salvelinus namaycush) from Lake Superior (LS) and the consumption of carp (Cyprinus carpio) from Little Lake Butte des Morte (LLBM) near Oshkosh, Wisconsin, USA. Two 90-d subchronic studies are described, including a 45-d exposure to fish diets using male Sprague-Dawley hooded rats, and a 90-d exposure to fish diets using female rats of the same species. Behavioral alterations were tested using a battery of behavioral tests. In addition, pharmacologic challenges using apomorphine and D-amphetamine were administered to the rats to reveal latent neurotoxic effects. Cumulative fish consumption data were recorded daily, weight gain recorded weekly, and behavioral data collected prior to exposure, and on days 7, 14, 55 ± 2, 85 ± 2. Motor activity data were collected on days 30 ± 2, 60 ± 2, and 90 ± 2 of the feeding protocols. Brain tissue from rodents fed these fish were subsequently analyzed for either mercury (Hg) or polychlorinated biphenyls (PCB). Mercury concentrations were increased in the brains of the walleye-fed rats, and PCB concentrations ranged from 0.5 nl/L to 10 nl/L in the brains of rats fed carp from LLBM, a Lake Michigan tributary. Adult male rats fed LLBM carp for 45 d exhibited the greatest behavioral responses to the dopaminergic agonist apomorphine on the accelerating rotarod, although these differences were not significant. The 90-d exposure of LS walleye or Hg-spiked LS walleye resulted in behavioral alterations on tactile startle response and second footsplay. D-Amphetamine challenge caused changes in tactile startle response, second footsplay, and accelerating rotarod performance after consuming walleye diets. Rats fed LLBM carp had altered behavioral responses to apomorphine on the accelerating rotarod.
Increased cadmium excretion in metal-adapted populations of the midge Chironomus riparius (diptera)
Authors: Postma Jaap F. , VanNugteren Paul , De Jong Marion B. Buckert-
Published: March 2010

Cadmium kinetics were studied in cadmium-adapted and nonadapted field populations of the midge Chironomus riparius. Accumulation and elimination experiments were carried out using first-generation laboratory-reared animals. Differences between populations were, therefore, assumed to have a genetic basis. Larvae were dissected to analyze the guts and the remainder of the larvae separately. First-order one-compartment models were not always successful in describing accumulation processes, probably due to acclimation. No interpopulation differences were observed in larval development based on dry weights, whereas some differences existed based on pupation rate. In most cases more than 80% of the total amount of cadmium was found in the guts of all populations. Larvae from cadmium-adapted populations showed a decreased net accumulation rate as well as higher equilibrium values (15–20%) compared to nonadapted populations. In addition, cadmium excretion efficiency was increased for cadmium-adapted larvae, which was due to an increased elimination rate from the guts. It was concluded that exposure to high cadmium concentrations in the field resulted in populations of C. riparius with an increased storage capability and an increased excretion efficiency, especially regarding the guts.
Accumulation and depuration of resin acids and fichtelite by the freshwater mussel Hyridella menziesi
Authors: Burggraaf Shane , Langdon Alan G. , Wilkins Alistair L. , Roper David S.
Published: March 2010

Freshwater mussels incubated in the effluent of a kraft pulp and paper mill rapidly accumulated resin acids and fichtelite in their tissues, approaching a steady state in 7 d or less. Mean bioconcentration factors (BCFs) for individual resin acids varied from 110 to 330 L/kg dry wt. for 14-chlorodehydroabietic acid and abietic acid, respectively. The mean BCF for fichtelite was 4,900 L/kg dry wt., at least an order of magnitude greater than that of the resin acids. Resin acids were depurated rapidly from mussel tissue (biological half-lives of 3 d), whereas fichtelite concentrations declined more slowly (biological half-life 12 d). Depuration kinetics for these compounds appeared to be described by a first-order process. The possibility that the uptake process for fichtelite is zero order is explored.