bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anaerobic biodegradation of halogenated and nonhalogenated N-, s-, and o-heterocyclic compounds in aquifer slurries
Authors: Adrian Neal R. , Suflita Joseph M. 
Published: March 2010

Abstract
The fate of several halogenated and nonhalogenated heterocyclic compounds in anoxic aquifer slurries was investigated Substrate depletion and methane formation were monitored in serum bottle incubations by HPLC and GC, respectively Pyridine, pyrimidine, thiophene, and furan were not mineralized following an 11-month incubation, but the corresponding carboxylated or oxygenated compounds were That is, &gt;74% of the theoretically expected amount of methane was recovered from nicotinic acid, uracil, or 2-furoic acid Chlorinated derivatives, like 2 chloro- or 6-chloronicotinic acid, as well as 4 chloro- and 5-chlorouracil resisted mineralization However, 5-bromouracil was reductively dehalogenated to stoichiometric amounts of uracil, whereas 2-chloropyrimidine was metabolized to a more polar unidentified compound that resisted further anaerobic biodegradation Microorganisms acclimated to 5-bromouracil were unable to transform 4 chloro or 5 chlorouracil These findings illustrate how the structure of heterocyclic contaminants influences their susceptibility to anaerobic decay
Predation of ducks poisoned by white phosphorus: Exposure and risk to predators
Authors: Roebuck B.D. , Nam Sae-Im , Walsh Marianne E. , Racine Charles H. , Reitsma Leonard , Steele Ben 
Published: March 2010

Abstract
White phosphorus (P4) has been identified as the cause of mortality for dabbling ducks and swans at an estuanne salt marsh in Alaska Predation of ducks poisoned by P4 was monitored to assess the extent and range of predator exposures to P4 Avian tissues were analyzed for P4 by gas chromatography We observed that both sick and dead dabbling ducks were common prey of bald eagles (Hahaeetus leucocephalus), herring gulls (Larus argentatus), and common ravens (Corvus corax) Frank signs of P4 intoxication attracted predators and rendered the ducks easy prey White phosphorus was found in the tis sue remains of ducks that had been preyed upon, thus providing positive evidence that predators were exposed to P4 Although P4 varied widely among individuals, P4 was generally highest in the gizzard contents followed by fatty tissues such as fat depots and the skin White phosphorus was identified in fatty tissues of one eagle and in one herring gull egg, thus providing direct evidence of absorption of P4 by predators
Fate of silicone degradation products (silanols) in soil
Authors: Lehmann R.G. , Varaprath S. , Frye C.L. 
Published: March 2010

Abstract
Silicone (polydimethylsiloxane, or PDMS) fluids are widely used in industrial and consumer products and may find their way into municipal sludges that are eventually applied to the land. Earlier studies showed that PDMS degrades in soil to low-molecular-weight, water-soluble silanols of the formula HO–[Si(CH3)2O]n–H. In this study, 200-cs [14C]PDMS (1, 10, 100 mg kg−1) was placed in 50 g Londo sandy clay loam, and the soil was dried to generate the desired silanols in situ. The soil was remoistened and incubated at 25°C, 12% moisture, and 21% O2. The ultimate PDMS degradation product was identified by GC-MS as dimethylsilanediol. During the next 4 months, from 25 to 50% of this substance was either volatilized from the soil, incorporated into the humus, or to a lesser extent oxidized to 14CO2. The latter two processes increased with addition of alfalfa to the soil. No trend was seen in the loss of dimethylsilanediol over different concentrations.
Toxicity of metal-contaminated sediments from the upper clark fork river, montana, to aquatic invertebrates and fish in laboratory exposures
Authors: Kemble Nile E. , Brumbaugh William G. , Brunson Eric L. , Dwyer F. James , Ingersoll Chris G. , Monda Dave P. , Woodward Dan F. 
Published: March 2010

Abstract
Sediments of the upper Clark Fork River, from the Butte and Anaconda area to Milltown Reservoir (230 km downstream), are contaminated with As, Cd, Cu, Pb, Mn, and Zn primarily from mining activities. The toxicity of pore water from these sediments was determined using Daphnia magna (48-h exposure), rainbow trout (96-h exposure), and Microtox®. However, pore-water data from these exposures were questionable because of changes in the toxicity of pore-water samples after 5 to 7 d of storage. Whole-sediment tests were conducted with Hyalella azteca (28-d exposure), Chironomus riparius (14-d exposure), rainbow trout (Oncorhynchus mykiss) 21- to 28-d exposure and Daphnia magna (2- to 22-d exposure). Sediment samples from Milltown Reservoir and the Clark Fork River were not generally lethal to test organisms. However, both reduced growth and delayed sexual maturation of amphipods were associated with exposure to elevated concentrations of metals in sediments from the reservoir and river. Relative sensitivity (most sensitive to least sensitive) of organisms in whole-sediment toxicity tests was: Hyalella azteca &gt; Chironomus riparius &gt; rainbow trout &gt; Daphnia magna. Relative sensitivity (most sensitive to least sensitive) of the three end points evaluated with Hyalella azteca was: length &gt; sexual maturation &gt; survival. The lack of lethal effects on organisms may be related to temporal differences in sediment, acid-volatile sulfide, or organic carbon.
Genetic variation in the temperature dependence of liver microsomal cyp2e1 activity, within and between species of the viviparous fish Poeciliopsis
Authors: Crivello Joseph F , Schultz R Jack 
Published: March 2010

Abstract
The temperature dependence of liver microsomal CYP2E1 (cytochrome P450 2E1) activity was examined in selected genotypes of the viviparous fish Poeciliopsis Activity of this enzyme, as a function of incubation temperature, was determined by measuring 6 OH-chlorzoxazone formation from chlorzoxazone, a specific CYP2E1 substrate Chlorzoxazone 6 hydroxylase activity was examined among five species of Poeciliopsis, as well as among nine genotypes within a species, P monacha Among Poeciliopsis genotypes, P monacha contained the greatest activity, 9 5 ± 1 5 U (where 1 U is defined as 1 μg 6 OH chlorzoxazone produced/min/mg protein, n = 6) with a temperature optimum (To) of 25°C The lowest activity was in P occidentalis, 0 65 ± 0 11 U, with a To of 27 to 28°C, P prolifica, P fasciata, P lucida, and P viriosa had intermediate levels of activities, 1 1 to 5 5 U, and To from 25 to 31°C To determine if metabolic differences exist within species, enzyme activity was examined from nine genotypes of P monacha by comparing expression among P monacha-lucida hybrids These hybrids were given identical paternal genomes of lucida but retained the original maternal monacha genomes sampled from wild gene pools The greatest activity was found in genotype T70 3 P Cw, 3 6 ± 0 1 U, at a To of 29°C, and the lowest was in genotype SV73 7s, 0 40 ± 0 12 U, at a To of 27°C The other naturally occurring genotypes, M65 24, M65–26 SV73 7v, as well as the laboratory produced synthetic hybrids, Syn4 and Syn5, had intermediate activities, 0 73 ± 0 38 to 2 1 ± 0 69 U, and To of 25 to 27°C No hybrid had activity levels as high as the maternal parent, P monacha, and only one had a To as low as either parent Apparently the genes involved in xenobiotic activity vary widely among the closely related species of Poeciliopsis but also within species suggesting that these phenotypes can be acted upon by natural selection
Snapping turtles (Chelydra serpentina) as biomonitors of lead contamination of the big river in missouri's old lead belt
Authors: Overmann Stephen R. , Krajicek James J. 
Published: March 2010

Abstract
The usefulness of common snapping turtles (Chelydra serpentina) as biomonitors of lead (Pb) contamination of aquatic ecosystems was assessed. Thirty-seven snapping turtles were collected from three sites on the Big River, an Ozarkian stream contaminated with Pb mine tailings. Morphometric measurements, tissue Pb concentrations (muscle, blood, bone, carapace, brain, and liver), δ-aminolevulinic acid dehydratase (δ-ALAD) activity, hematocrit, hemoglobin, plasma glucose, osmolality, and chloride ion content were measured. The data showed no effects of Pb contamination on capture success or morphological measurements. Tissue Pb concentrations were related to capture location. Hematocrit, plasma osmolality, plasma glucose, and plasma chloride ion content were not significantly different with respect to capture location. The δ-ALAD activity levels were decreased in turtles taken from contaminated sites. Lead levels in the Big River do not appear to be adversely affecting the snapping turtles of the river. Chelydra serpentina is a useful species for biomonitoring of Pb-contaminated aquatic environments.
The effects of motorway runoff on freshwater ecosystems: 1. Field study
Authors: Maltby Lorraine , Forrow David M. , Boxall Alistair B.A. , Calow Peter , Betton Clifford I. 
Published: March 2010

Abstract
The effects of motorway runoff on the water quality, sediment quality, and biota of small streams were investigated over a 12-month period. Downstream of motorway runoff discharges there was an increase in the sediment concentrations of total hydrocarbons, aromatic hydrocarbons, and heavy metals and an increase in the water concentrations of heavy metals and selected anions. Hydrocarbon contamination of sediments was positively correlated with potential contaminant loading (i.e., length of road drained/stream size). The greatest effect was observed at Pigeon Bridge Brook, a small stream receiving drainage from a 1,500-m stretch of the Ml motorway. The dominant PAHs in contaminated sediment at this site were phenanthrene, pyrene, and fluoranthene, whereas the dominant metals were zinc, cadmium, chromium, and lead. Differences between the station upstream and downstream of discharges in the diversity and composition of the macroinvertebrate assemblages were detected in four out of the seven streams surveyed. However, there was no evidence of an effect on either the diversity or abundance of epilithic algae. The diversity of the aquatic hyphomycete assemblage was only affected at the most impacted site. Reductions in macroinvertebrate diversity were associated with reductions in the processing of leaf litter and a change from an assemblage based on benthic algae and coarse particulate organic matter to one dependent upon fine particulate organic matter.
The importance of the exposure route when testing the toxicity of pesticides to saprotrophic isopods
Authors: Vink Karen , Tompot Anouk , Hermans Maartje , van Straalen Nico M. , Dewi Istiana , Bedaux Jack 
Published: March 2010

Abstract
When effects of pesticides are tested on nontarget invertebrates, substrate exposure is mostly used. Routes of uptake of pesticides by saprotrophic invertebrates may, however, also occur through the food, since the litter layer will be their main food source. These organisms live in close contact with the soil surface and litter layer. The ecotoxicity of the pesticides benomyl, carbofuran, and diazinon was investigated in a series of experiments. The toxicity was tested in lethal concentrations (leading to LC50 estimations), and sublethal concentrations leading to no-observed-effect concentration (NOEC) estimations on growth. Both substrate and dietary exposure were used to evaluate the most critical exposure route for each case. For food exposure, the chemicals were offered in ground leaves, while for substrate exposure the test organisms were kept on treated sand. Experiments were done with the tropical isopod Porcellionides pruinosus. For all three pesticides, substrate exposure was more critical than dietary exposure. The LC50 values (active ingredient per dry mass of food or soil) for benomyl, carbofuran, and diazinon, when mixed with food, were &gt;31,000, 485, and 74.15 μg/g, respectively, and when mixed with sand 1,221, 21.41, and 3.03 μg/g, respectively. Sublethal effects on body growth were found for benomyl (NOEC = 1,000 μg/g) and diazinon (NOEC = &lt;8.71 μg/g) after dietary exposure, but no effects were found in the course of the experiment for substrate exposure. Based on the results, it is concluded that the exposure route is of great importance for determining lethal effects as well as sublethal effects of pesticides on nontarget invertebrates in soil. The most critical exposure route depends both on the mode of action of the chemical and on the toxicological end point considered.
Biomonitoring of heavy metals in the pacific basin using avian feathers
Authors: Burger Joanna , Gochfeld Michael 
Published: March 2010

Abstract
We used avian feathers to biomonitor heavy-metal distribution in several areas in the Pacific Basin including Papua New Guinea, Australia, New Zealand, China, Johnston Atoll, Hawaii, and Costa Rica. This paper is a preliminary synthesis of data gathered by the Pacific Basin Biomonitoring Project. We examined levels of mercury, lead, cadmium, selenium, chromium, and manganese. For sooty terns (Sterna fuscata) and brown noddy (Anous stolidus) mercury levels were lower in the Pacific than in Puerto Rico in the Atlantic, but this was reversed for lead and cadmium. Adult birds had higher metal levels in their feathers than did young birds of the same species from the same area. Cadmium levels were higher in terrestrial species; lead, chromium, and manganese were highest in coastal species; and mercury and selenium were highest in marine species. Mercury levels were lowest in forest species, intermediate in species that eat insects and small vertebrates, and highest in species that eat intermediate to large fish. Lead levels were highest in species feeding in industrialized estuaries of Hong Kong.
Potency of 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), alone and in combination with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), to produce lake trout early life-stage mortality
Authors: Zabel Erik W. , Cook Philip M. , Peterson Richard E. 
Published: March 2010

Abstract
Newly fertilized lake trout (Salvelinus namaycush) eggs were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3′,4,4′,5-pentachlorobiphenyl (PCB 126), or their combination, and sac fry mortality was used to determine toxic potencies. The toxic equivalency factor (TEF) for PCB 126 was 0.0030. The dose-response curve for the PCB 126/TCDD mixture based on TCDD toxic equivalents was not significantly different from that for TCDD alone, suggesting additivity between the two congeners in causing sac fry mortality.
Monoaromatic hydrocarbon transformation under anaerobic conditions at seal beach, California: Laboratory studies
Authors: Ball Harold A. , Reinhard Martin 
Published: March 2010

Abstract
Anaerobic biotransformation of several aromatic hydrocarbons found in gasoline including benzene, toluene, ethylbenzene, m-xylene, p-xylene, and o-xylene (BTEX) was studied in batch anaerobic laboratory microcosms. Aquifer sediment and ground water were obtained from the site of a historic gasoline spill at Seal Beach, California. Sulfate is present in the site ground water at 80 mg/ L, and sulfate-reducing activity appears to be the dominant intrinsic BTEX bioremediation process where nitrate is absent. In the laboratory, the microcosms were set up with different electron acceptors (sulfate and nitrate) in site ground water and various defined anaerobic media to estimate intrinsic biodegradation rates and to suggest conditions under which anaerobic bioremediation could be enhanced. In unamended microcosms, anaerobic biotransformation of toluene and m+p-xylene (m-xylene and p-xylene were measured as a summed parameter) occurred at a rate of 7.2 and 4.1 μg L−1 h−1, respectively, with sulfate as the apparent electron acceptor. Addition of nitrate stimulated nitrate-reducing conditions and increased rates of toluene and m+p-xylene biotransformation to 30.1 and 5.4 μg L−1 h−1, respectively. The catabolic substrate range was altered to include ethylbenzene in the nitrate-amended microcosms, suggesting an apparent preferential use of different BTEX compounds depending on the electron acceptor available. Under all the conditions studied, more than twice the amount of nitrate or sulfate was used than could be accounted for by the observed BTEX degradation. Benzene transformation was not observed under the conditions studied. Although methane was detected in microcosms prepared with anaerobic media lacking nitrate and sulfate, methanogenic biotransformation of BTEX compounds was not observed. The results of these experiments indicate that indigenous microorganisms from the Seal Beach aquifer have significant capability to degrade BTEX hydrocarbons and that intrinsic processes in the Seal Beach aquifer may remediate a portion of the hydrocarbon contamination in situ without intervention. However, the data also suggest that intervention by nitrate addition would enhance the rate and extent of anaerobic BTEX biotransformation.
Occurrence and accumulation of pesticides and organic contaminants in river sediment, water and clam tissues from the san Joaquin River and tributaries, California
Authors: Pereira Wilfred E. , Domagalski Joseph L. , Hostettler Frances D. , Brown Larry R. , Rapp John B. 
Published: March 2010

Abstract
A study was conducted in 1992 to assess the effects of anthropogenic activities and land use on the water quality of the San Joaquin River and its major tributaries. This study focused on pesticides and organic contaminants, looking at distributions of contaminants in water, bed and suspended sediment, and the bivalve Corbicula fluminea. Results indicated that this river system is affected by agricultural practices and urban runoff.
Sediments from Dry Creek contained elevated concentrations of polycyclic aromatic hydrocarbons (PAHs), possibly derived from urban runoff from the city of Modesto; suspended sediments contained elevated amounts of chlordane. Trace levels of triazine herbicides atrazine and simazine were present in water at most sites. Sediments, water, and bivalves from Orestimba Creek, a westside tributary draining agricultural areas, contained the greatest levels of DDT (1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane), and its degradates DDD (1,1-dichloro-2,2-bis[p-chlorophenyl]ethane), and DDE (1,1-dichloro-2,2-bis[p-chlorophenyl]ethylene). Sediment adsorption coefficients (Koc), and bioconcentration factors (BCF) in Corbicula of DDT, DDD, and DDE at Orestimba Creek were greater than predicted values. Streams of the western San Joaquin Valley can potentially transport significant amounts of chlorinated pesticides to the San Joaquin River, the delta, and San Francisco Bay. Organochlorine compounds accumulate in bivalves and sediment and may pose a problem to other biotic species in this watershed.
Effects of the insecticide dursban® 4E (active ingredient chlorpyrifos) in outdoor experimental ditches: II. Invertebrate community responses and recovery
Authors: van den Brink Paul J. , Van Wijngaarden René P. A. , Lucassen Wil G. H. , Brock Theo C. M. , Leeuwangh Peter 
Published: March 2010

Abstract
This article describes the long-term effects on the macro invertebrate and zooplankton community in outdoor experimental ditches after a single application of the insecticide chlorpyrifos. Nominal concentrations of 0.1, 0.9, 6, and 44 μg/L of chlorpyrifos were applied to two mesocosms each, while four served as controls. Both macroinvertebrates and zooplankton were sampled from 4 weeks before to 55 weeks after treatment. The macroinvertebrate and zooplankton data sets were combined into one data set and analyzed using the multivariate ordination technique “redundancy analysis.” The method provided a clear description of the effects on the invertebrate community in time while still showing the effects at the species level. Crustacea and Insecta showed a rapid, concentration-dependent decrease in numbers after insecticide application (direct effects). An increase in gastropods and Oligochaeta was found, suggesting indirect effects. The start of recovery of the invertebrate populations affected was found to depend not only on the susceptibility of the taxa but also on ecological characteristics, such as the length of the life cycle. A no-observed-effect concentration of 0.1 μg/L could be derived both at the species and the community level. Safe concentrations, based on no-observed-short-term-effect levels for some characteristic indigenous taxa susceptible to chlorpyrifos, also appeared to protect the total invertebrate community in the long term. The invertebrate community at all treatment levels was considered to have recovered after 24 weeks posttreatment.
The natural petroleum hydrocarbon background in subtidal sediments of prince william sound, Alaska, USA
Authors: Page David S. , Boehm Paul D. , Douglas Gregory S. , Bence A. Edward , Burns William A. , Mankiewicz Paul J. 
Published: March 2010

Abstract
A natural regional petroleum hydrocarbon background has been identified in the subtidal sediments of Prince William Sound that is readily distinguished from Exxon Valdez spill oil by chemical fingerprinting methods. This hydrocarbon background is derived from natural petroleum seeps in the eastern Gulf of Alaska. The Alaska Coastal Current carries fine-grained sediments and associated hydrocarbons from seep areas to the east into Prince William Sound, where they are deposited on the seafloor. The analysis of age-dated sediment cores indicates that this process has been going on for the past 160 years, and probably for many thousands of years. In addition, results of a stratified random study of nearshore subtidal sediments conducted in 1990 show that this is a general phenomenon throughout the sound and is significant even in shallow water (3 to 30 m). For example, oleanane, a saturate petroleum biomarker found in Prince William Sound prespill background petroleum and seep sources but not in Exxon Valdez petroleum, is present in subtidal sediment samples from locations throughout the sound. This supports the conclusion that seep areas to the east are major sediment sources for the sound. Moreover, polycyclic aromatic hydrocarbon mixing model calculations show that, although Exxon Valdez spill-oil residues are present in nearshore subtidal sediments, they generally form a small increment on the natural background. The recognition of preexisting natural and anthropogenic hydrocarbon sources in a spill area is a fundamentally important component of any natural resource damage assessment.
Uptake of zinc by the midge larvae Chironomus riparius at different salinities: Role of speciation, acclimation, and calcium
Authors: Bervoets Lieven , Verheyen Rudolf , Blust Ronny 
Published: March 2010

Abstract
The uptake of zinc by the freshwater midge larvae Chironomus riparius was studied as a function of salinity. Fourth instar larvae were exposed to a salinity range up to 10‰ by diluting chemically defined seawater with chemically defined river water. The effect of prior acclimation at five different salinities on zinc uptake rate was examined. Solutions of different composition were tested to discriminate between the effect of the free zinc ion concentration, the free zinc ion activity, and the free calcium ion activity. Zinc uptake rate decreased with increasing salinity in all exposure solutions. Prior acclimation at salinities up to 10% did not influence zinc uptake rate. Changes in the free zinc ion activity explained most of the observed variation (58%). Changes in calcium ion activity had only a minor effect on zinc uptake (1%). Besides these effects the salinity of the exposure also influences the physiology of the larvae, altering zinc uptake when larvae are transferred from one salinity to another (6%). The combination of the different effects explained 65% of the total variation in zinc uptake by midge larvae. The remaining variation could not be explained by the experimental design and was attributed to natural variation in zinc uptake among midge larvae.