bluuebunny/crossref_metadata_2025 huggingface dataset:
Photochemical transformation of pyrene vapor deposited on eleven subfractions of a high-carbon coal stack ash
Authors: Miller Vernon R. , Wehry E. L. , Mamantov Gleb
Published: March 2010

A high-carbon coal stack ash has been separated by particle size and then by composition, into strongly magnetic, weakly magnetic, “nonmagnetic” mineral, heavy carbon and light carbon fractions. Eleven of these fractions have been characterized by bulk iron and carbon analyses and BET surface area determinations. The photochemical transformation of pyrene, deposited from the vapor phase onto these eleven ash fractions, has been studied. Appreciable phototransformation of adsorbed pyrene was observed for only three fractions; in those fractions, the bulk percentage of carbon (0.4–0.7%) and the specific surface area (0.50–0.68 m2/g) were both very low. For all fractions having bulk carbon percentages ≥ 4% and specific surface areas ≥ 2.85 m2/g, no detectable phototransformation of adsorbed pyrene was observed. There was no discernible correlation of photochemical reactivity of adsorbed pyrene with the iron content of the ash fractions. In general, the specific surface area of the fractions increased with increased carbon content; two different forms of carbon having different surface areas were observed.
Toxicity of parathion to captive european starlings (Sturnus vulgaris) — absence of seasonal effects
Authors: Rattner Barnett A. , Grue Christian E.
Published: March 2010

The effects of season on the toxicity of the prototypic organophosphorus insecticide parathion was evaluated using adult European starlings (Sturnus vulgaris) housed in outdoor pens. Groups of birds received oral doses of parathion in the fall, winter, spring and summer. Median lethal dosage, and brain and plasma cholinesterase inhibition, were found to be quite similar among seasons. Parathion may have been more toxic during hot weather (winter vs. summer LD50 estimate: 160 vs. 118 mg/kg; p < 0.1). In view of previous reports in which ambient temperature extremes and harsh weather have enhanced organophosphorus insecticide toxicity to birds, it is concluded that circannual toxicity studies should include measures of sensitivity (acute oral exposure) and vulnerability (dietary exposure) to better predict responses of free-ranging birds.
Effect of sediment spatial variance and collection method on cladoceran toxicity and indigenous microbial activity determinations
Authors: Stemmer B. L. , Burton G. A. , Sasson-Brickson G.
Published: March 2010

Quantitative assessments of sediment quality frequently are based on data derived from sediments collected by grab sampling. Often only one sediment or one composited sediment is collected at a sample site, thereby preventing any determination of spatial variance. The significance of spatial variance and collection method on cladoceran toxicity and indigenous microbial activities was determined at a creosote contaminated site in the Little Scioto River in Marion County, Ohio. Replicate sediments were collected on two occasions from a horizontal sample grid (110 m2 and 1.4 m2) using an Ekman dredge and hand core. Sediment particle size fractions did not vary significantly between replicate grab samples. Survival of Daphnia magna and Ceriodaphnia dubia in 48-h solid phase exposures varied, however, from 0 to 100% horizontally and vertically at the test site. Percent survival and β-glucosidase activity decreased in sediment sections below a 4 to 5 cm depth. Dredged sediments produced less toxicity to the daphnids than did core collected samples. The coefficient of variance was high (>40%) for both survival and hydrolase activities (alkaline phosphatase, β-galactosidase and β-glucosidase) between horizontal sediment replicates collected by either dredge or core. Subsample variance, however, was small (<20%). These results highlight the important role that sediment heterogeneity and collection method have on sediment quality assessments.
Rainbow trout liver activation systems with the ames mutagenicity test
Authors: Johnson B. Thomas
Published: March 2010

A poikilothermic metabolic activation system developed from liver homogenate of rainbow trout (Oncorhynchus mykiss, formerly Salmo gairdneri) was used in the Ames Salmonella/Mammalian Microsome Mutagenicity Test. Postmitochondrial fractions (S9) mediated four model promutagens – 2-aminoanthracene (2AA), 2-aminofluorene (2AF), benzo[a]pyrene (BaP) and 3-methylcholanthrene (3MC)–that require two different exogenous metabolic activation routes to form mutagens with Salmonella TA98 and TA100. The enzymatic activity of trout S9 was cytochrome P-450-like; it was heat labile and oxygen- and cofactor-dependent. Preincubation temperature significantly influenced the sensitivity of the fish-activated Ames test. Bacterial mutagenesis with trout activation significantly decreased as preincubation temperature increased; the optimum S9 activation temperature range for trout was 10 to 15°C compared with 37°C for the rat. The liquid-preincubation test was best adapted to the trout poikilothermic activation system; it was significantly more sensitive than the plate-incorporation test in detecting histidine revertants. The S9 activity of trout and rat was qualitatively similar in the Ames test: that is, both fractions metabolically activated 2AA, 2AF, BaP and 3MC to produce bacterial mutagenesis with Salmonella TA98 and TA100. The use of this ecologically relevant exogenous activation system in the short-term predictive genotoxicity testing of freshwater ecosystems is helpful in the assessment of potential hazards of chemical contaminants on fishery resources.
Anaerobic microbial degradation of acridine and the application of remote fiber spectroscopy to monitor the transformation process
Authors: Knezovich John P. , Bishop Dorothy J. , Kulp Thomas J. , Grbić-Galić Dunja , Dewitt John
Published: March 2010

Anaerobic microbial transformation of a polynuclear nitrogen heterocycle, acridine, was studied in laboratory microcosms with three different inocula: a stabilized, mixed culture growing on ferulic acid that was originally enriched from anaerobic sewage sludge, and sulfate-reducing and methanogenic aquifer materials from two sites at a groundwater aquifer contaminated by landfill leachate. Acridine degradation was investigated under methanogenic, denitrifying and sulfate-reducing conditions at concentrations of 1 to 6 μg/ml. Substrate degradation was followed using two standard analytical techniques (HPLC and GC-MS) and a new, in situ remote fiber spectroscopic (RFS) technique. This RFS was used successfully to follow changes in concentration of acridine with time, which indicates the technique has a significant potential for monitoring the degradation process in environmental media. Acridine was degraded extensively in one to three weeks under each of the conditions studied. A range of heterocyclic, homocyclic aromatic and aliphatic intermediates was identified by GC-MS analyses. On the basis of these compounds, a tentative route of anaerobic acridine transformation is proposed that begins with oxidation and proceeds through the common degradative route for oxidized aromatic compounds.
Sorption of organic acid compounds to sediments: Initial model development
Authors: Jafvert Chad T.
Published: March 2010

The adsorption to sediments and saturated soils of selected organic acid compounds was examined as a function of compound and sediment properties. Intrinsic compound properties examined included the dissociation constant (pKa) and hydrophobic character. Properties of the sediment examined included ionic strength and composition, organic carbon content and aqueous phase pH. By varying these properties, adsorption of both the neutral and anionic forms of these compounds was shown to occur. Adsorption of the neutral species occurs similarly to that of other hydrophobic compounds that do not contain acidic functional groups. Adsorption of the anionic species was influenced, however, by intrinsic chemical as well as electrostatic factors. Adsorption of the anionic species to a specific sediment was modeled as a linearly dependent function of pH. Compounds used in this study included 2,4-dinitro-o-cresol (DNOC), 2-(2,4,5-trichlorophenoxy)propanoic acid (silvex), pentachlorophenol (PCP), 4-chloro-α-(4-chlorophenyl)benzeneacetic acid (DDA) and 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB).
Lipid-partitioning and disposition of benzo[a]pyrene and hexachlorobiphenyl in lake michigan Pontoporeia hoyi and Mysis relicta
Authors: Gardner Wayne S. , Landrum Peter F. , Cavaletto Joann F.
Published: March 2010

Two Lake Michigan macroinvertebrates, Pontoporeia hoyi and Mysis relicta, exhibited major differences in the disposition of the lipophilic contaminants, [3H]benzo[a]pyrene (BaP) and [14C]2,4,5,2′,4′,5′-hexachlorobiphenyl (HCB). Interactions of these contaminants with major lipid classes (triacylglycerols and phospholipids) were examined by centrifuging aqueous whole organism homogenates of labeled animals into three discrete layers that were operationally defined as “buoyant-lipid,” “particle” and “aqueous” fractions. The buoyant-lipid fraction contained most of the energy storing triacylglycerols, whereas the particle and aqueous fractions contained most of the membrane phospholipids. During 2 to 4 d experiments, unmodified BaP and HCB partitioned among the three fractions in proportion to the distribution of total-lipids in both species, but in M. relicta most of the BaP was biotransformed into polar metabolites that were selectively found in the aqueous and particle fractions. Apparently HCB was not substantially biotransformed in either species but took longer (ca. 2 d) to reach steady state among lipid pools in M. relicta than it did in P. hoyi (< 1 d). Although the contaminants did not always completely reach steady state in the organisms with respect to the external environments during these relatively short experiments, they appeared to reach steady state among lipid pools within the organisms.
Aquatic toxicity testing using the nematode,Caenorhabditis elegans
Authors: Williams Phillip L. , Dusenbery David B.
Published: March 2010

A promising aquatic toxicity test has been developed using a species of free-living nematode, Caenorhabditis elegans. The testing was performed with soluble forms of Ag, Hg, Cu, Be, Al, Pb, Cr, As, Tl, Zn, Cd, Ni, Sr and Sb. The LC50 values for 1 to 4 d of exposure were determined and compared to the published invertebrate data. With Caenorhabditis elegans Pb, Cr and Cd were found to have the lowest 96-h LC50 (0.06 mg/L) and Sr had the highest LC50 (465 mg/L). All the metals except As have a significantly lower 96-h LC50 (from 20 to 15,000 times lower) than 24-h LC50. Comparison with published data for other invertebrates indicated that Caenorhabditis elegans was more sensitive to Pb, Cr and Be and less sensitive to As than any of the other organisms that have been tested. Given the ease in culturing and the extensive knowledge of the basic biology of Caenorhabditis elegans, coupled with the ecological abundance of nematodes, the method is worthy of further study to determine its usefulness as an aquatic test species.
Acute toxicity of isomers of the pyrethroid insecticide deltamethrin and its major degradation products to Daphnia magna
Authors: Day Kristin E. , Maguire R. James
Published: March 2010

The acute toxicities (4-h, 24-h and 48-h) of eight stereoisomers and four major breakdown products of deltamethrin to D. magna were determined. Parent deltamethrin (isomer 1) was the most toxic, with EC50 values in the range of 0.05 to 1.75 μg/L, concentrations that have been observed in the surface microlayer and subsurface water in field studies. The other three isomers (2-, 3- and 4-deltamethrin) were two- to tenfold less toxic than 1-deltamethrin. Isomers 1′, 2′, 3′ and 4′ plus the four breakdown products studied displayed no significant toxicity. Because 1-deltamethrin can be converted in natural water to 2′-, 3- and 4′- deltamethrin, and because 3-deltamethrin is toxic to D. magna, this isomerization is only a partial detoxification step as far as some aquatic organisms are concerned.
Disposition and metabolic fate of benzo[a]pyrene in the brown bullhead
Authors: Steward A. Ruth , Kandaswami Chithan , Ziper Craig , Rutkowski Joel P. , Sikka Harish C. , Chidambaram S.
Published: March 2010

We have investigated the biological fate of intraperitoneally administered benzo[a]pyrene (BP) in brown bullhead (Ictalurus nebulosus) maintained in flowing water. The tissue distribution of benzo[a]pyrene-derived radioactivity at 24 and 72 h after treatment was determined. The highest concentration of BP-derived radioactivity was in bile (3.7 and 12.3 μg BP equivalents/g bile at 24 and 72 h, respectively). Biliary radioactivity amounted to 16% of the radioactivity found in the fish at 72 h. The major components of bile collected at 72 h were glucuronides (24%), water-soluble conjugates unhydrolyzed by β-glucuronidase or arylsulfatase (57%) and unmetabolized BP (10%). The potentially genotoxic metabolite BP-7,8-dihydrodiol and its glucuronide represented 3% of the radioactivity of the bile at 72 h. High concentrations of BP-derived radioactivity were also present in liver and in kidney (920 and 290 ng equivalents of BP/g at 72 h, respectively). Although only low concentrations of BP-derived radioactivity were detected in muscle (60 ng eq/g at 72 h), the proportion of the BP-derived radioactivity found in this tissue at 72 h amounted to 16% of the radioactivity found in the fish. Unmetabolized BP represented 32% of the muscle radioactivity, and 96% of the radioactivity that could be extracted with ethyl acetate and characterized by HPLC. BP-7,8-dihydrodiol represented 0.2% of the muscle radioactivity. The amount of BP derivatives irreversibly bound to macromolecules and precipitable with trichloroacetic acid at 72 h amounted to 12 to 13% of the radioactivity present in each tissue. Furthermore, 21, 28 and 35% of the BP-derived radioactivity could not be extracted with ethyl acetate from the insoluble components of muscle, kidney and liver, respectively, at 72 h. These data indicate that significant amounts of active metabolic intermediates of BP capable of alkylating DNA and other macromolecules were formed in bullhead tissues.
Preparation of benthic substrates for sediment toxicity testing
Authors: Ditsworth George R. , Schults Donald W. , Jones Jill K. P.
Published: March 2010

A jar rolling apparatus was constructed to prepare test substrates using sediments spiked with laboratory chemicals, the toxicity of which were assessed with the Rhepoxynius abronius bioassay Test sediments were mixed by rolling them for several hours in one gallon glass jars Mixing was considered adequate based on the analytical results of sediment samples that were collected at locations along the longitudinal axis within each horizontally lying jar immediately after rolling However, because comparative standards did not exist, definitive conclusions of mixing thoroughness could not be drawn Coefficients of variation, used to assess mixing within jars, were 11.5% or less (mean 5.1%) Mixing was not significantly different among replicated jars but, in some jars, was significantly different among within jar sample locations
Acute avoidance reactions and behavioral responses of juvenile rainbow trout (Oncorhynchus mykiss) to garlon 4®, garlon 3A® and vision® herbicides
Authors: Morgan John D. , Vigers Gary A. , Farrell Anthony P. , Janz David M. , Manville John F.
Published: March 2010

Laboratory bioassay experiments were conducted with juvenile rainbow trout (Oncorhynchus mykiss) to determine the acute lethal (96-h LC50) values of the forest-use herbicides Garlon 3A®, Garlon 4®, and Vision® with 15% and 10% surfactant formulations, and the threshold concentrations of these herbicides that would cause behavioral effects. A Y-maze apparatus was used to determine the threshold concentration of each herbicide that elicited either an avoidance or a preference reaction from rainbow trout fry after a one-hour exposure period. Rainbow trout fry were observed for qualitative behavioral changes (e.g., increased coughing and ventilatory rates, loss of equilibrium, etc.) over a four-day period of exposure to a wide range of chemical strengths. Nominal concentrations of the herbicides eliciting threshold avoidance reactions in test fish were 150 ppm Vision-10% surfactant, 54 ppm Vision-15% surfactant, 19.2 ppm Garlon 4, and 800 ppm Garlon 3A, which were, respectively, 2, 2, 8, and 2 times the 96-h LC50 values determined for each herbicide. Preferential reactions to the herbicide solutions were not observed. Qualitative behavioral changes were observed in rainbow trout fry at levels from 25% (Garlon 4) to 50% (Garlon 3A, Vision-10% and -15% surfactants) of the 96-h LC50 values. Nominal concentrations of the herbicides causing threshold changes in fish behavior were 37.5 ppm Vision-10% surfactant, 13.5 ppm Vision-15% surfactant, 0.60 ppm Garlon 4, and 200 ppm Garlon 3A.
Effects of dissolved organic carbon on accumulation and acute toxicity of fenvalerate, deltamethrin and cyhalothrin to Daphnia magna (straus)
Authors: Day Kristin E.
Published: March 2010

The effects of dissolved organic carbon (DOC) in the form of Aldrich humic acid on the accumulation and acute toxicities of three synthetic pyrethroids — fenvalerate, deltamethrin, and cyhalothrin—to Daphnia magna in laboratory experiments were investigated. Concentrations of DOC as low as 2.6 mg/L, 3.2 mg/L, and 3.1 mg/L for deltamethrin, fenvalerate, and cyhalothrin, respectively, resulted in a significant decrease in bioaccumulation. Acute toxicities of all three pyrethroids were found to decrease as DOC concentrations increased; e.g., at a DOC concentration of 15.5 mg/L, the acute toxicity of fenvalerate was reduced by a factor of 17. The percentages of deltamethrin and fenvalerate bound to DOC increased as DOC concentrations increased after 2-h and 24-h contact times. At low concentrations of DOC (e.g., 1.7 mg/L), as much as 40% of fenvalerate and 20% of deltamethrin were found sorbed to the dissolved material. After 24-h contact times, 76.4 and 80.8% of fenvalerate and deltamethrin, respectively, were bound to DOC. Reverse-phase partition coefficients (Krp) for both fenvalerate and deltamethrin were found to vary with DOC concentrations and were in the range 1.0 to 4.8 × 105 L/kg for fenvalerate and 0.9 to 5.6 × 105 L/kg for deltamethrin.
Environmental factors affecting toluene degradation in ground water at a hazardous waste site
Authors: Armstrong Anthony Q. , Hodson Robert E. , Hwang Huey-Min , Lewis David L.
Published: March 2010

The microbial ecology of pristine and contaminated ground water at a chemical waste disposal site was investigated. Recently, it was determined that ground water downslope from the disposal site contained elevated levels of toxic pollutants, including benzene, toluene, xylene and methylene chloride, as well as iron and manganese. Microbial mineralization and uptake of radiolabeled glucose and amino acids indicated a metabolically active microflora in both pristine (upslope from the contamination) and contaminated groundwater samples collected from monitoring wells at the site. However, microbial uptake and mineralization of glucose and amino acids were up to fourfold slower in the contaminated well water than in the control well. Rates of mineralization and uptake of toluene were easily measurable in water from the contaminated well but were negligible in water from the pristine well, suggesting that the subsurface microflora in the contaminated region had adapted to degrade toluene. Additions of the inorganic nutrients N, K and P enhanced toluene mineralization in water from the contaminated well, with the addition of K and P enhancing mineralization twofold. The addition of these inorganic nutrients, therefore, presents an opportunity for biorestoration of the site. An increase in the incubation temperature also enhanced toluene mineralization; however, manipulations of pH and dissolved oxygen concentration had no measurable effects.
Critical period of sensitivity to petroleum toxicity in the chicken embryo
Authors: Couillard Catherine M. , Leighton Frederick A.
Published: March 2010

Microliter amounts of South Louisiana crude oil (SLCO) or Prudhoe Bay crude oil (PBCO) were applied to the shell of fertile leghorn chicken eggs on day 8, 8.5 or 9 of incubation. Percent mortality and prevalence of grossly visible lesions were evaluated 96 h after treatment. The 96-h LD50s of SLCO at 8, 8.5 and 9 d of incubation were 2.6, 4.3 and 34.3 μl, respectively. Five μl PBCO caused nearly 100% mortality in 8 and 8.5-d-old embryos, while 12 μl caused 32% mortality in 9-d-old embryos. Liver necrosis, edema and increases in body weight and in the ratio of body weight to crown-rump length were found in embryos treated on day 8, 8.5 or 9 of incubation with either SLCO or PBCO. The 16-fold decrease in sensitivity of the embryo from day 8 to day 9 of incubation suggests that the chorioallantoic membrane may be important in the toxic action of petroleum oil.
Degradation and bound residue formation of atrazine in a Western Tennessee soil
Authors: Winkelmann D. A. , Klaine S. J.
Published: March 2010

Biological and physical degradation, and metabolite and soil-bound residue formation, of [U-ring-14C]atrazine (2-chloro-4-[ethylamino]-6-[isopropylamino]-1,3,5-triazine) were characterized in a western Tennessee soil using laboratory and field assays. Biological mineralization of [14C]atrazine was examined in the laboratory using intact surface soil cores in sealed microcosms. Physical mineralization was determined using gamma-radiation-sterilized soil microcosms. Metabolites measured were deethylatrazine (DEA), deisopropylatrazine (DIA), dealkylatrazine (DAA) and hydroxyatrazine (HYA). Atrazine was applied at a rate of 2.2 kg/ha (˜ 5.6 μg/g soil) to soil microcosms in two studies and 3.2 kg/ha to the field. Evolution of 14CO2 from [14C]atrazine in nonirradiated soil microcosms increased to 12 and 28% of the radiolabel added after 180 d incubation. Irradiated soil microcosms evolved less than 0.07% of the radiolabel as 14CO2 for both studies after the same period. The concentrations of metabolites throughout the laboratory and field studies were: HYA > DEA > DIA > DAA. The highest concentration of HYA detected during microcosm and field studies was approximately 0.5 μg/g soil. Atrazine dissipation rates and metabolite production in nonirradiated microcosms were comparable to field results. Atrazine concentrations after 180 d in nonirradiated microcosm and field samples were lower than HYA, and either equivalent to or greater than DEA. The DAA was not detected throughout microcosm or field studies. Rates of dissipation for atrazine followed first-order kinetics. Atrazine half-life, based on extractable residues, was approximately 21 d in the microcosm studies, compared to 14 d in surface field soil. Extractable 14C residues sampled from nonirradiated microcosms decreased in concentration during the incubation period. Soil-bound 14C residues increased and, at the termination of the two studies, accounted for 39 and 43% of the radioactivity added to nonirradiated microcosms. Bound 14C residues in irradiated microcosms accounted for 49 and 48% of the activity after 180 d. Similarity of results between microcosm and field studies suggests that those microcosms may be useful for predicting the fate of atrazine in surface soil.
Decreased survival of rainbow trout exposed to no. 2 fuel oil caused by sublethal preexposure
Authors: Steadman B. L. , Stubblefield W. A. , Lapoint T. W. , Bergman H. L. , Kaiser M. S.
Published: March 2010

Rainbow trout (Oncorhynchus mykiss) were exposed for 21 d to sublethal levels of No. 2 fuel oil (2FO). The four exposure concentrations ranged from 12 to 100 mg/L 2FO dispersed in water and resulted in 0 to 12% mortality. Following this exposure period (preexposure) the ability of preexposed trout to survive exposure to acutely lethal levels of 2FO was observed. Preexposure to either 50 or 100 mg/L 2FO consistently resulted in decreased survival and a lower LC50 for a given observation period. Unfortunately, because the LC50 determinations were not obtained independently, they could not be used to test statistically the effects of preexposure on survival. Therefore, two proportional hazard modeling techniques were applied to the data to test for effects due to preexposure. Both modeling techniques indicated that preexposure results in decreased survival of rainbow trout exposed to acutely toxic levels of 2FO. Thus, in contrast to preexposure to metals, which results in acclimation, preexposure to 2FO results in decreased survival.
Effects of sediment-bound endosulfan on survival, reproduction and larval settlement of meiobenthic polychaetes and copepods
Authors: Chandler G. Thomas , Scott Geoffrey I.
Published: March 2010

Endosulfan-contaminated muddy sediments were collected from a tidal creek bottom after rain runoff from an agricultural watershed and tested for their effects on larval settlement/growth, survival and reproduction of cultured meiobenthic polychaetes and copepods. Endosulfan (ES) strongly inhibited larval colonization and early juvenile growth of the cosmopolitan, euryhaline polychaete Streblospio benedicti. In laboratory microcosms, ES concentrations as low as 50 μg·kg−1 sediment significantly reduced the number of larval colonists by >50% relative to ES-free control sediments. Higher concentrations closer to actual field levels suppressed Streblospio benedicti colonization completely. Early growth of newly metamorphosed juveniles was depressed 36 and 40% relative to controls at ES concentrations of 50 and 100 μg·kg−1, respectively. In contrast, when the common benthic harpacticoid copepod Pseudobradya pulchella was chronically exposed to sediment ES as high as 200 μg·kg−1, survival and egg production were unaffected despite many examples of high ES toxicity to other crustaceans. Of more than 1,600 Pseudobradya pulchella tested, more than 95% survived ES concentrations of at least 200 μg·kg−1, and over 98% of 1,200 females produced normal clutches of eggs. Similarly, survival of another common benthic copepod, Nannopus palustris, was not significantly affected below a threshold concentration of 200 μg·kg−1 ES. At 200 μg·kg−1, however, Nannopus palustris' survival was significantly reduced relative to control and 50-μg·kg−1 ES treatments.
Acute and long-term toxicity of water-soluble cationic polymers to rainbow trout (Oncorhynchus mykiss) and the modification of toxicity by humic acid
Authors: Goodrich Mark S. , Dulak Linda H. , Friedman Marvin A. , Lech John J.
Published: March 2010

The toxicity of two classes of cationic polymers, epichlorhydrin/dimethylamine polyamines and quaternary amine copolymers, were investigated. Static bioassays of those polymers resulted in LC50 concentrations ranging from 271 μg/L to 1,733 μg/L. Under flow-through conditions the toxicity was 1.7 to 13.9 times greater, depending on the polymer used. Using a reference humic acid along with the polymers in toxicity studies, strong correlations were established between humic acid concentration and LC50. Even at a fairly low humic acid concentration (5 mg/L), the toxicity of the polymers was reduced 7- to 16-fold. At higher humic acid concentrations (50 mg/L), cationic polymer toxicity was reduced 33- to 75-fold.
The acute toxicity of selected metals to the freshwater mussel, Anodonta imbecilis
Authors: Keller Anne E. , Zam Stephen G.
Published: March 2010

The mussel fauna of many North American waters is declining, probably due to a combination of factors. The factors may include channelization and impoundment of rivers where the mussels once thrived, as well as the influx of pesticides and metal pollution from surrounding watersheds. Much is known about the effects of metal pollution on zooplankton and aquatic insects, but little is known about the response of freshwater mussels. With more and more species of mussels being listed as threatened or endangered, it is important that we begin to determine their range of sensitivity to pollutants so we can better protect them. Mussels have been labeled insensitive to metals because they can survive while containing high body burdens. However, almost no direct measurement of metal toxicity has been reported for unionid mussels. What little we do know has come from tests with adult mussels. In response to the need for such information, a series of laboratory toxicity tests were performed to assess the sensitivity of Anodonta imbecilis to six metals, a metal-containing effluent and four metal mixtures. Acute toxicity tests were performed on juvenile mussels reared in the laboratory. Overall, mussels were found to be as sensitive to metals as zooplankton and more sensitive than commonly tested fish and aquatic insects.
PC BEEPOP, an ecotoxicological simulation model for honey bee populations
Authors: Bromenshenk Jerry J. , Doskocil Jiri , Olbu Gerald J. , Degrandi-Hoffman Gloria , Roth Stephan A.
Published: March 2010

PC BEEPOP is a computer model that simulates honey bee (Apis mellifera L.) colony population dynamics. The model consists of a feedback system of interdependent elements, including colony condition (e.g., initial size, reproductive potential of the queen and forager longevity), environmental variability (e.g., weather) and contaminant exposures. It includes a mortality module (BEEKILL) and a chemical-toxicity data base and probit analysis program (BEETOX). PC BEEPOP is a modified version of an cxisting colony dynamics model, BEEPOP, and can be used as a tool for environmental risk assessments. Results of sensitivity analysis and simulations of various climatic and toxic scenarios are discussed and compared to observed changes in the size and composition of honey bee colony populations.
A toxicological screen to determine in vitro survival and competition of environmentally applied pseudomonads with mouse fecal microbiota
Authors: Nelson Gail M. , Claxton L.D. , Creason J.P. , George S.E.
Published: March 2010

Engineered bacterial strains have been developed for several environmental uses, including bioremediation and application as biopesticides. Previous in vivo work in this laboratory examined the colonization and competition potential of Pseudomonas spp., isolated from a commercial product for PCB degradation with the intestinal flora of CD-1 mice. In the present study, the same pseudomonads and two additional Escherichia coli strains were evaluated by an in vitro tier testing approach developed to screen environmentally relevant microorganisms for their ability to colonize the mammalian intestinal tract and compete with the normal intestinal tract flora. In the initial tier, the competitor strains were tested for their ability to survive in anaerobic pure culture. Next, they were cultured anaerobically in the presence of mouse fecal microbiota. Finally, serial transfers were performed to monitor the survival and competition potential of each strain with the fecal microbiota. All of the tested strains survived for 48 h in pure culture, and all survived for 24 h in culture with the mouse fecal microbiota. Escherichia coli strains survived serial transfer through five cultures, although in declining numbers. Environmental Pseudomonas spp. survived transfer through three cultures but were not detected after four transfers. No effects of the competitor strains on the fecal microbiota were found. This in vitro system eventually will be used with human fecal microbiota. The potential consequences of human exposure to environmentally released microorganisms can then be extrapolated by comparison of human in vitro results with rodent in vitro and in vivo results in a parallelogram approach.
Studies of benzidine-based dyes in sediment-water systems
Authors: Weber Eric J.
Published: March 2010

The sorption and degradation of several benzidine-based dyes were studied in sedimentwater systems. Studies in resaturated sediment demonstrated that sorption was strongly dependent on pH and the nature and concentration of the inorganic salt in solution. Degradation of the dyes in anaerobic pond sediment followed pseudo-first-order kinetics with half-lives ranging from 2 to 16 d. Product studies indicated that the amount of recovered benzidine accounted for only 2 to 5% of lost Direct Red 28. Studies in pH-amended pond sediment demonstrated that degradation is inhibited when the dyes are strongly sorbed to the sediment.
Toxicity of CU, NI and Alkylbenzene Sulfonate (LAS) on the naturally occurring bacteria in the Rhône river plume
Authors: Martínez J. , Vives-Rego J. , Soto Y. , Bianchi M.
Published: March 2010

The toxicity of Cu++, Ni++, and linear alkylbenzene sulfonate to the bacterioplankton in the Rhóne River plume (Mediterranean Sea) was assessed by [3H]thymidine incorporation into trichloroacetic acid-insoluble material. This method proved useful to evaluate the toxic effect of three common pollutants to the natural bacterial population in a system with permanent mixtures of fresh and sea water. An important variability in the toxicity has been detected irrespective of bacterial density or activity. The variations in toxicity were associated with the changes of salinity, particulate matter, and nutrients in the river plume.
Microbial responses to large concentrations of herbicides in soil
Authors: Dzantor E. Kudjo , Felsot A.S.
Published: March 2010

To determine the effects of herbicide spills on microbial activity, soil was treated with excessive amounts (10,000 mg/kg) of formulated alachlor alone or as a mixture with formulated atrazine, metolachlor, and trifluralin. Soil was also treated with the same combinations of herbicides at a rate of 10 mg/kg, which is typical of normal farming practices. Simulated spills initially inhibited bacteria, but after 7 d, bacterial numbers had recovered to levels similar to those in untreated controls. Fungal populations were drastically reduced after 1 d and became undetectable after 7 and 21 d of incubation in the mixed herbicide and alachlor-only treatments, respectively. Dehydrogenase activities were severely depressed after 1 d in both high-level herbicide treatments and did not recover after 125 d. Esterase activities were depressed in soils receiving the mixture of herbicides but were generally unaffected in the alachlor-only treatment. Normally applied concentrations did not have any pronounced effect on bacterial and fungal populations or on the activities of soil dehydrogenase and esterase.

At 10 mg/kg, all the herbicides degraded by 80 to 90% within one year; there was no difference between degradation of alachlor applied alone or as a herbicide mixture. With high concentrations of herbicides, degradation was negligible after one year of incubation.
Evaluation of baltic herring and icelandic cod liver oil for embryo toxicity, using the japanese medaka (oryzias latipes) embryo larval assay
Authors: Cooper Keith R. , Liu Hong , Bergqvist Per-Anders , Rappe Christoffer
Published: March 2010

These studies were carried out to determine if oils obtained from wild fish populations were contaminated with polychlorinated-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) and, if they were contaminated, would they result in embryo toxicity as measured by the Japanese medaka (Oryzias latipes) embryo larval bioassay (ELA). Three fish oils [Baltic herring oil (HO 1); Baltic herring oil spiked with 44 parts per trillion (pptr) of 1,2,3,7,8,9-HxCDD, 120 pptr OCDD and 130 pptr 2,3,7,8-TCDF (HO 2*); and a commercially available cod liver oil (CL)] and a corn oil sample were tested for embryo toxicity in a static renewal protocol. The ELA assay was selected due to its sensitivity to biological effects following dioxin and dibenzofuran exposure. Two of the fish oils (HO 1 and HO 2*) were from Baltic herring collected from the Gulf of Bothnia, Sweden, and the third was a commercially available Icelandic cod liver oil. The Baltic herring oil contained higher levels of both PCDDs and PCDFs than the cod liver oil: 2,3,7,8-TCDD, 5X; 1,2,3,7,8-PeCDD, 5X; 1,2,3,6,7,8-HxCDD, 6X; 2,3,7,8-TCDF, 3X; 1,2,3,7,8,-PeCDF, 3X; 2,3,4,7,8-PeCDF, 4X; 1,2,3,4,7,8/1,2,3,4,7,9-HxCDF, 3X; 1,2,3,6,7,8-HxCDF, 4X; and 1,2,3,4,6,7,8-HpCDF, 2X. The HO 1 sample resulted in 30 to 90% death, whereas the HO 2* sample caused 100% death. The major lesions were hemorrhage, cardiac effects and tissue necrosis. The time to lesion occurrence and the types of lesions were similar to those observed in studies using pure 2,3,7,8-TCDD. The rearing solution control, corn oil control and cod liver oil samples caused no mortality or lesions. The lethality and lesions caused by these oils in the ELA system were similar to those reported in Salmo Salter with the M74-syndrome from Sweden. The use of contaminated fish oils, therefore, may be one cause of poor viability in hatchery salmon reared in Sweden, and care should be taken when using naturally occurring fish or fish oils in nondefined feeds.
Use of field lysimeters for comparison of mobility and persistence of granular and ec formulations of the soil insecticide isazofos
Authors: Bowman Bruce T.
Published: March 2010

Mobility and persistence of two formulations of the insecticide isazofos (emulsifiable concentrate (EC), granular) were compared by using 75-cm × 15-cm field lysimeters, packed with Plain-field sand, and two moisture regimes (natural rainfall, supplementary watering). Atrazine was applied to all lysimeters as an internal reference. Effluent was monitored for isazofos, its metabolite CGA17193, atrazine and desethylatrazine. Selected cores were sectioned and analyzed for each chemical at weeks 1, 2, 4, 8, 12 and 21. None of the applied chemicals or their metabolites leached from soil cores receiving only rainfall throughout the 21-week study. The mobility ranking under supplementary watering in Plainfield sand cores was CGA17193 ≫ desethylatrazine > atrazine > isazofos EC > isazofos granular. The first-order half-life of isazofos was 2.0 and 2.7 weeks, respectively, in EC and granular formulations. Evaporative losses accounted for 44 to 67% and 72 to 100% of incident precipitation on the supplementary watering and rainfall lysimeters, respectively.
Evaluation of the frog embryo teratogenesis assay: Xenopus (FETAX) as a model system for mixture toxicity hazard assessment
Authors: Dawson Douglas A. , Wilke Teresa S.
Published: March 2010

The joint toxic action for several binary mixtures was determined with FETAX (frog embryo teratogenesis assay Xenopus) to evaluate the malformation and lethality end points for potential value in mixture toxicity studies. Nine combinations of developmental toxicants were selected for testing at malformation-inducing concentrations, based on presently accepted modes of teratogenesis of each chemical and on the primary types of malformations each had elicited in earlier tests. Two combinations were selected for embryolethal end point testing. Three mixture ratios (3 1, 1 1, 1 3) were tested for each combination, with each combination being tested on three or four separate occasions Individual tests of each chemical were simultaneously conducted for each combination to serve as positive controls (i.e., 1 0 and 0 1 solutions). Toxic unit analysis was used to determine the type of joint action for each combination. Concentration addition was observed for three combinations in which both chemicals were thought to have the same mode of teratogenesis. The other six combinations, with the chemicals having different modes of action, showed a response additive joint action Response addition was also seen for both combinations tested at the embryolethal end point, with an exception for one mixture ratio that was antagonistic. The results indicate FETAX should be useful for mixture toxicity hazard assessment, especially when the malformation end point is considered.
Pathways analysis method for estimating water and sediment criteria at hazardous waste sites
Authors: Fordham Carolyn L. , Reagan Douglas P.
Published: March 2010

A model was developed to estimate surface water and sediment criteria for the protection of animal populations and ecosystems at a hazardous waste site where the major contaminants of concern to wildlife populations included persistent, bioaccumulative chemicals. The model evaluates potential exposure pathways for a site and estimates acceptable concentrations in abiotic media for each exposure pathway. To estimate criteria based on food web exposure, the model utilizes a site-specific food web and addresses bioaccumulation in multiple food chains that terminate in a high-trophic-level species. The input data for the food web were obtained from on-site sampling as well as from literature sources. The pathways analysis model can be applied to other hazardous waste sites by selecting appropriate species and chemical specific input parameters to include in the model. Estimated criteria can be compared to on-site analytical data to evaluate risk to wildlife populations.
Recovery of foraging behavior of atlantic salmon exposed to a simulated commercial application of fenitrothion
Authors: Morgan M. J. , Kiceniuk J. W.
Published: March 2010

Fenitrothion is an organophosphate insecticide, used to control forest pests, that has often been sprayed in areas containing streams inhabited by Atlantic salmon (Salmo salar). This study simulated the exposure of Atlantic salmon during operational spraying of fenitrothion to determine if there would be effects on foraging behavior and the length of time required for recovery from any effect. The foraging sequence of the Atlantic salmon exhibited only minor effects of exposure, and the number of ingested prey was not affected. However, the reaction distance of the salmon to prey decreased significantly for those exposed to fenitrothion. The decline in reaction distance was still evident six weeks after exposure.
Application of multispectral techniques to the precise identification of aldehydes in the environment
Authors: Richardson Susan D. , Thruston Alfred D. , Collette Timothy W. , Mcguire John M.
Published: March 2010

By using gas chromatography coupled with low- and high-resolution electron-impact mass spectrometry, low- and high-resolution chemical ionization mass spectrometry, and Fourier transform infrared spectroscopy, eight straight-chain aldehydes were identified in a water sample taken from the overflow pipe of a municipal sewer line that contained a combination of industrial and domestic sewage. This combination of infrared and mass spectral techniques yielded precise identifications of n-hexanal, n-heptanal, 2-heptenal, n-octanal, 2-octenal, n-nonanal, 2-decenal, and 2-undecenal. These findings were significant because few straight-chain aldehydes have been identified in the environment, and all those previously found were saturated.
Role of respiration in the accumulation of organic xenobiotics by the amphipod Diporeia sp.
Authors: Landrum Peter F. , Stubblefild Christina R.
Published: March 2010

Accumulation of hydrophobic organic xenobiotics is thought to occur by passive diffusion across the respiratory membrane of aquatic organisms. This route has been confirmed with fish. However, aquatic invertebrates tend to remove organic xenobiotics from water much more efficiently than oxygen, based on the relative uptake clearances. Uptake clearance is the rate coefficient that describes the volume of water stripped of analyte per g of organism per h. For the amphipod Diporeia sp., formerly classified as Pontoporeia hoyi, ratios of the contaminant uptake clearances to oxygen clearance were essentially constant at 3.9 ± 0.4 (X + SE) for benzo[α]pyrene (BaP), 3.8 ± 0.3 for hexachlorobiphenyl (HCBP), and 4.2 ± 0.6 for phenanthrene (Phe). Therefore, based on the membrane transport efficiencies of nonpolar xenobiotics (60–80%) and oxygen (approximately 63%) in fish, and the uptake clearance for organic xenobiotics by Diporeia sp., either xenobiotics are accumulated through routes other than across the respiratory membrane or the accumulation efficiency of oxygen from water is much lower in amphipods than it is in fish. The variability in the uptake clearance for both BaP and HCBP was best described by regressions with the surface area-to-volume ratio, whereas the uptake clearance for the more hydrophilic Phe was best described by a total surface area relationship.
Effects of biologically treated bleached kraft mill effluent on cold water stream productivity in experimental stream channels
Authors: Hall Timothy J. , Haley Richard K. , Lafleur Lawrence E.
Published: March 2010

Large-scale outdoor experimental streams were used in a series of effluent addition studies to determine the compatibility of biologically treated bleached kraft mill effluent with satisfactory production of salmonid fishes. Results are reported for 9- to 10-month studies at effluent concentrations representing from 0.5 to 2.0 mg/L of effluent 5 d biochemical oxygen demand (BOD5) addition (1.3–5.1% v/v), as well as for an extended 3.5-year study at 0.5 BOD5 addition (1.5% v/v). The series of studies indicated a pattern of greater rainbow trout (Oncorhynchus mykiss) cumulative production and average weight in streams receiving effluent and better survival in the control streams. The final long-term study also indicated that successful maturation, spawning, hatching, larval development, and juvenile growth could take place during conditions of continuous effluent exposure. Measurements of the supporting food web suggest that effluent can increase periphyton production at low concentrations through nutrient additions but that higher effluent concentrations may reduce periphyton production due to the effect of color on underwater light transmittance. Macroinvertebrate populations increased in the streams receiving effluent.
Behavior assessment of a volatile chemical in the Rhine river
Authors: Brüggemann R. , Trapp S. , Matthies M.
Published: March 2010

The concentrations of 1,2-dichloroethane due to a spill into the Rhine River are calculated with a one-dimensional dispersion-advection model. Particular attention was given to the hydrologic variety along the river by a careful selection and estimation of the governing parameters. The calculated results are in good agreement with observed concentrations for three sites of measurement at the middle Rhine. At two neighboring sites in the lower Rhine there is a striking discrepancy. Using Monte-Carlo simulations, it can be shown that uncertainties of the input parameters cannot explain the overestimated concentrations. Possibly, the elimination is increased by shallow water zones in the lower Rhine.