bluuebunny/crossref_metadata_2025_split huggingface dataset:
Importance of the test volume on the lag phase in biodegradation studies
Authors: Ingerslev Flemming , Toräng Lars , Nyholm Niels 
Published: March 2010

Abstract
Increasing the total volume of test medium resulted in decreased lag times (T L) in biodegradability shake flask batch tests conducted with either surface water or with synthetic mineral medium inoculated with supernatant from settled activated sludge. Experiments were performed with test volumes ranging from 1.8 ml to 100 L using two 14C-labeled model chemicals, 2,4-dichlorophenoxyacetic acid (2,4-D) and p-nitrophenol (PNP), both of which are known to be readily degradable after variable lag phases. The TL ranged from 2.1 to 30.4 d for PNP and from 16 to 37 d for 2,4-D. Decreasing the test volume tended to increase the lag time, even when a single test batch was redistributed into smaller flasks. With 5 ml supernatant added to different volumes of mineral medium, lag times for PNP were independent of the test volume in a range from 10 to 1,000 ml. At small volumes of 10 ml or less, degradation failed randomly. Our findings are partly explained by the hypotheses that a sufficient total amount as well as a sufficient concentration of specifically degrading microorganisms or consortia of bacteria must be present initially for biodegradation to get started, from which follows that with too small inoculations or with too small test volumes, biodegradation may fail randomly. A straightforward practical implication of the findings is that the test volume in biodegradability tests can significantly influence the lag time and thus sometimes be decisive for the outcome in biodegradation studies.
Effects of extreme tidal range on characteristics of polychlorinated biphenyl distribution in sediment of industrial Incheon North Harbor, Korea
Authors: Kim Seung K , Lee Dong S , Oh Jae R , Kahng Sung H 
Published: March 2010

Abstract
This study investigated the influence of the high tidal range on the polychlorinated biphenyl (PCB) levels and the compositional characteristics in the sediments of the North Incheon Harbor basin, Korea. The results indicated that the high tidal range could induce complicated effects on the distribution and the compositional characteristics of PCBs. Significant differences in the total PCB concentration were found between the tidal and subtidal zones. Higher total PCBs in the tidal zone established a total PCB gradient in a transversal direction along the harbor basin. The large tidal range created tidal currents strong enough to grade the sediment particles, establishing a gradient of total PCBs corresponding to an observed sediment particle size along the longitudinal direction of the basin. Heterogeneous congener patterns were observed in some parts of the tidal zone where diverse physicochemical and microbiological conditions are to be expected. However, tidally driven, active sediment transport promoted spatial homogeneity in the congener pattern. Sedimentation rate of suspended solids appeared to overwhelm any induced heterogeneity in the PCB congener pattern. Consequently, the congener pattern within the harbor basin was fairly uniform and similar to that of a dominant input source.
Geochemistry and toxicity of aluminum in the saguenay river, québec, Canada, in relation to discharges from an aluminum smelter
Authors: Roy Robert L , Campbell Peter GC , Prémont Stéfane , Labrie Jacques 
Published: March 2010

Abstract
The transformation of bauxite to alumina, the first step in the production of metallic aluminum (Al), generates Al-rich effluents. One installation is located near Jonquière (QC, Canada), with the effluents being discharged into the Saguenay River. We undertook an integrated geochemical and ecotoxicological study to determine if these Al discharges affected the receiving water. In the spring, summer, and autumn of 1997, samples of river water were collected from stations upstream and downstream of the effluent outfalls and from a regional reference site. Samples were analyzed for Al (e.g., particulate and dissolved Al, total monomeric and organic monomeric Al, dissolved polymeric Al) and for parameters known to affect Al speciation (pH, SO4, fluoride, dissolved organic carbon). Parallel samples were used for ambient toxicity tests with fathead minnow and Ceriodaphnia dubia. Concentrations of total Al (231-596 μg/L) and dissolved Al (112-344 μg/L) at downstream stations were 1.1 to 3.7 times higher than those at the station immediately upstream. Average levels of total and dissolved Al exceeded the Québec provincial criterion of 87 (μ acid-recoverable Al/L, even at sites upstream of the plant. Inorganic monomeric Al at downstream stations ranged from 22 to 88 (μ/L. With the exception of a single elevated value observed at one downstream site, inorganic monomeric Al levels were&gt; 75 μg/L. Other studies in soft neutral-pH waters have shown that no toxic effects occur at this concentration of inorganic monomeric Al. None of the river water samples from stations 300 m downstream from the outfalls caused significant toxicity to C. dubia or fathead minnows. We suggest that expressing guidelines as monomeric inorganic Al would offer a more useful basis for comparison with ambient Al concentrations.
Influence of salinity onVibrio fischeriandlux-modifiedPseudomonas fluorescenstoxicity bioassays
Authors: Cook Sonja V , Chu Angus , Goodman Ron H 
Published: March 2010

AbstractThis study compares the toxicological response of the marine bacteria Vibrio fischeri and a lux-modified soil and freshwater bacteria, Pseudomonas fluorescens, to saline contamination alone and in the presence of chromium and phenol. Saline solutions are more toxic to P. fluorescens than V. fischeri, and salinity can stimulate luminescence in V. fischeri. Vibrio fischeri is about 10 times more sensitive than P. fluorescens to chromium and phenol. However, the response of P. fluorescens to these toxicants is sensitive to changes in saline contamination, while the response of V. fischeri is not. Therefore, the P. fluorescens bioassay may be a more appropriate bioassay organism than V. fischeri when evaluating the toxicological impact of salinity within saline environmental samples.
Predicting ready biodegradability in the Japanese ministry of international trade and industry test
Authors: Tunkel Jay , Howard Philip H , Boethling Robert S , Stiteler William , Loonen Helene 
Published: March 2010

AbstractTwo new predictive models for assessing a chemical's biodegradability in the Japanese Ministry of International Trade and Industry (MITI) ready biodegradation test have been developed. The new methods use an approach similar to that in the existing BIOWIN© program, in which the probability of rapid biodegradation is estimated by means of multiple linear or nonlinear regression against counts of 36 chemical substructures (molecular fragments) plus molecular weight (mol wt). The data set used to develop the new models consisted of results (pass/no pass) from the MITI test for 884 discrete organic chemicals. This data set was first divided into randomly selected training and validation sets, and new coefficients were derived for the training set using the BIOWIN fragment library and mol wt as independent variables. Based on these results, the fragment library was then modified by deleting some fragments and adding or refining others, and the new set of independent variables (42 substructures and mol wt) was fit to the MITI data. The resulting linear and nonlinear regression models accurately classified 81% of the chemicals in an independent validation set. Like the established BIOWIN models, the MITI models are intended for use in chemical screening and in setting priorities for further review.
Potential for octylphenol to biodegrade in some english rivers
Authors: Johnson Andrew C , White Craig , Bhardwaj Lal , Jürgens Monika D 
Published: March 2010

Abstract
To study octylphenol biodegradation, samples of river water and sediments were taken from the Aire and Calderr vers in the United Kingdom, running through urban/industrial areas, as well as the Thames River running through a more rural area. Using laboratory microcosms, half-lives of 7 to 50 d were obtained for the water samples, with most curves fitting a zero-order reaction. The Calder River was sampled at four separate points along a 45-km length, encompassing rural to increasingly urban/industrial reaches. Little degradation was observed in the sample from the upland/rural reach, while half-lives of 8 to 13 d were seen in the more urban/industrial reaches. Mineralization of the phenyl ring, detected by evolution of 14CO2 from ring-labeled octylphenol, was only observed in water from the Calder River sample. Degradation rate was similar for a range of concentrations from 0.3 to 100 μ,g/L when tested with river water from the Thames River. No degradation was observed over 83 d when bed sediments were spiked with octylphenol and incubated under anaerobic conditions.
Algal growth inhibition test in filled, closed bottles for volatile and sorptive materials
Authors: Mayer Philipp , Nyholm Niels , Verbruggen Eric MJ , Hermens Joop LM , Tolls Johannes 
Published: March 2010

Abstract
Exposure concentrations of many hydrophobic substances are difficult to maintain in algal growth inhibition tests performed in open agitated flasks. This is partly because such compounds tend to volatilize from aqueous solution and partly because of sorption to the algal biomass as well as to the test container. A simple filled closed bottle test with low algal densities and bicarbonate enrichment is described here as an approach to minimize the loss of test material from solution. The algal medium was enriched with 300 mg NaHCO3/L, the pH was adjusted to 7.0 by addition of HCl, and the resulting dissolved CO2 concentration supported maximum algal growth rates without pH drift for algal densities up to 4 mg dry weight/L. Two-day toxicity tests with kerosene were performed with this new test design and compared with an open bottle test and with a closed bottle test with headspace. Exposure concentrations of the volatile fraction of kerosene decreased by 99% in the open test, by 77% in the closed flask test with headspace, and by 16% in the filled closed bottle test. Algal growth inhibition was observed at much lower additions of kerosene in the new test design because of the improved maintenance of a constant exposure.
Developmental toxicity of estrogenic alkylphenols in killifish (Fundulus heteroclitus)
Authors: Kelly Sue A , Giulio Richard T. Di 
Published: March 2010

AbstractEstrogenic alkylphenols have been identified in the aquatic environment, and concern has arisen over the ability of these compounds to interact with and potentially disrupt vertebrate endocrine systems. Here we report that waterborne nonylphenol (NP) and 4-tert-octylphenol (4-t-OP) are toxic to the embryos and larvae of Fundulus heteroclitus, an estuarine teleost, causing both lethal and sublethal developmental abnormalities. Hatch success in surviving embryos is also adversely affected by alkylphenol exposure. Correlation analysis has indicated that decreased hatch success is strongly correlated to deformities in the torso/abdomen and tail of embryos. Larval exposure to the alkylphenols demonstrates that NP and 4-t-OP are lethal at concentrations an order of magnitude less than those lethal to embryos (NP larval 96-h LC50 = 0.95 μM [204 μg/L]; NP embryo 96-h LC50 = 24 μM [5 mg/L]). In evaluating the role of estrogenicity in developmental toxicity of the alkylphenols, we have found that tamoxifen, an estrogen receptor antagonist, can prevent embryo-lethality for NP and 4-t-OP While these embryos survive, some sublethal abnormalities are still evident, particularly in the torso and tail. The results of these studies suggest that the alkylphenols have the potential to cause developmental toxicity in aquatic organisms and that this may occur through disruption of estrogen-based signals.
Amphibians as indicators of wetland quality in wetlands formed from oil sands effluent
Authors: Pollet Ingrid , Bendell-Young Leah I 
Published: March 2010

AbstractFort McMurray, Alberta, Canada, is home to the largest oil sands mining operation in the world. Two of the companies currently mining the oil sands hope to use wetlands formed from oil sands effluent as part of their reclamation strategy required at mine closure. To evaluate the ability of these created wetlands to sustain amphibians, one population of Bufo boreas tadpoles and three different populations of Rana sylvatica tadpoles were exposed to oil sands process-affected water representative of a range of effluents expected to occur on the oil sands lease site at mine closure. Endpoints used to assess the response of the tadpoles to the process-affected waters included survival, growth, rate of development, and frequency of physical deformities. Bufo boreas held in process-affected waters displayed significantly reduced growth and prolonged developmental time (days to metamorphosis) as compared to those held in reference waters. The response of the three separate populations of R. sylvatica were population dependent. Two of the three populations responded similarly, demonstrating decreased survival and significantly reduced rates of growth when held in process-affected waters as compared to reference waters; the third was highly sensitive, displaying no growth and extremely poor survival in all exposures, suggesting different tolerances to the process-affected waters among different R. sylvatica tadpole populations. Amphibians such as B. boreas and R. sylvatica were sensitive indicators of effluent quality. Based on the effluents used in this study, wetlands formed from oil sands effluent will not support viable amphibian populations.
Classifying probabilities of acute toxicity in marine sediments with empirically derived sediment quality guidelines
Authors: Long Edward R , MacDonald Donald D , Severn Corinne G , Hong Carolyn B 
Published: March 2010

Abstract
Matching, marine sediment chemistry, and toxicity data(n = 1,513), compiled from three studies conducted in the United States, were analyzed to determine both the frequency of acute toxicity to amphipods and average percentage survival in laboratory bioassays within ranges in toxicant concentrations. We determined that the probability of observing acute toxicity was relatively low (&lt;10%) and that average control-adjusted survival equaled or exceeded 92% in samples in which sediment quality guidelines were not exceeded. Both the incidence of toxicity increased and average survival decreased as chemical concentrations increased relative to the guidelines. In sediments with highest contaminant concentrations, 73 to 83% of the samples were highly toxic, and average control-adjusted amphipod survival was 37 to 46%. Results of this study confirm that the relationships between sediment chemical concentrations and toxicity reported in a previous study were robust. Further, they indicate that numerical guidelines for saltwater sediments can be used to estimate the probability of observing toxic effects in acute amphipod tests.
Bioavailability of polycyclic aromatic hydrocarbons and polychlorinated biphenyls in rats from naturally contaminated soils—preliminary evaluation of the influence of soil parameters
Authors: Billeret Mikakline , Berny Philippe , Mazallon Michelle , Buronfosse Thierry 
Published: March 2010

AbstractIn order to assess the bioavailability of organic pollutants (polycyclic aromatic hydrocarbons [PAHs],polychlorobiphenyls [PCBs]) in polluted soils, male laboratory rats were exposed during 3 d and one night to two types of soil. These soils were highly polluted by PAHs (F2 soil) and by PCBs (S3 soil). They were diluted (1:1) either with an organic or a mineral matrix. Those matrices had different characteristics, and the purpose was to determine the influence of several soil parameters (organic matter) on the pollutants' bioavailability. Two categories of biomarkers were used: pollutant's burden and activities of microsomal liver and lung's cytochrome P450 1A-monooxygenase, namely, ethoxyresorufin-O-deethylase (EROD) activities. Absorption differed between exposed rats, depending on the pollutant and on the organ considered. Their EROD activity was well correlated with PAH and PCB burden, respectively. Moreover, EROD activity and pollutants burden in both organs depended on the dilution performed. The PAH bioavailability was lower after a dilution with organic matrices. In fact, those matrices had both the highest organic matter concentration and the lowest granulometry and appeared to adsorb more. Thus, organic pollutant bioavailability varies according to the soil characteristics. The most important parameters seemed to be organic matter and granulometry. The EROD activity and CYP1A1 dosage were good biomarkers and closely monitored the differences in bioavailability.
Estimations of vapor pressure and activity coefficients in water and octanol for selected aromatic chemicals at 25°C
Authors: Lee Sum Chi , Hung Hayley , Shiu Wan-Ying , Mackay Donald 
Published: March 2010

Abstract
A roupcontribution method is developed to estimate the supercooled liquid vapor pressure and the activity coefficients in water and octanol at 25°C of 98 selected monoaromatic compounds, many of which are or have been produced as chlorinated by-products in the manufacture of pulp and paper. The set includes alkylphenols, chlorinated phenols, anisoles, catechols, cymenes, guaiacols, syringols, and veratroles. The method can be used to estimate vapor pressures, solubilities in water, octanol-water partition coefficients, octanol-air partition coefficients, and Henry's law constants. It can also be used for predicting these partition coefficients as well as solubilities and vapor pressures for these and structurally similar compounds.
Brominated analogs of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone: Preparation of 3-chloro-4-(bromochloromethyl)-5-hydroxy-2(5H)-furanone and mutagenicity studies
Authors: Ramos Isabel , Lloveras Maia , Solans Xavier , Huici Alicia , Messeguer Angel 
Published: March 2010

AbstractThe brominated hydroxyfuranones sructurally related to the potent mutagen MXnamely3-chloro-4-(bromochlorome-thyl)-5-hydroxy-2(5H)-furanone (BMX-1), has been synthesized and characterized. The mutagenic activity of this bromohydro-xyfuranone together with those of its analogs BMX-2 and BMX-3 has been assessed by employing the Ames test with the Salmonella typhimurium strains TA98 and TA100. The mutagenic potencies in TA100 without S9 metabolic activation were 22.05 ± 3.15 revertants/ng for BMX-1, 28.64 ± 2.65 revertants/ng for BMX-2, and 37.29 ± 5.73 revertants/ng for BMX-3, whereas in the TA98 strain without metabolic activation, they were six- to ninefold lower. Studies carried out on the stability of these halogenated furanones suggest that the mutagenic activity observed is more related to the cyclic form of these derivatives.
Isomer-specific polychlorinated biphenyl determination in cetaceans from the mediterranean sea: Enantioselective occurrence of chiral polychlorinated biphenyl congeners
Authors: Jiménez Olga , Jiménez Begoña , Gonzalez Maria José 
Published: March 2010

Abstract
Isomer-specific concentrations of 41 polychlorinated biphenyls (PCBs) and the enantiomeric ratios (ER) of nine chiral PCBs were determined in the liver of four cetacean species—Risso's dolphin (Grampus griseus), bottlenose dolphin (Tursiops truncatus), fin whale (Balaenoptera physalus), and long-finned pilot whale (Globicephala melaena)—found dead in the Mediterranean Sea. The total PCB concentration (sum of 41 congeners) ranged from 484 to 63,200 ng/g wet weight. The 2,3,7,8 tetra-chlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQs), as defined by the World Health Organization (WHO), ranged from 4.3 to 1,454 pg/g wet weight. The contribution of mono-ortho PCBs was consistently higher than non-ortho PCB congeners, in whale species, whereas in dolphins this predominance was not so clear. The PCB profiles were dominated by congeners 138, 153, and 180 in almost all the investigated samples. Comparison of PCB profiles by using principal component analysis allowed to separate the species into different groups. Polychlorinated biphenyls 170 and 180 seem to be eliminated by the two whale species, and PCB 180 also seems to be eliminated by Risso's dolphins. The PCBs 95, 132, 149, and 176 revealed an enantiomeric excess of the second eluted enantiomer in almost all the cetaceans investigated, where 136 and 174 were racemic or almost racemic. It is the first time that an enantiomeric excess of PCB 84 and 91 has been reported in biological samples. Although it was only possible to calculate them in two dolphin liver samples, the high values of enantiomeric excess found are surprising (86.3 and 32% for PCB 91 and 84, respectively).
Evidence of two metabolic pathways for degradation of 2-methylphenanthrene by Sphingomonas sp. strain (2MPII)
Authors: Budzinski Hélène , Nadalig Thierry , Raymond Natalie , Matuzahroh Ni' , Gilewicz Michèle 
Published: March 2010

Abstract
A pure bacterial strain of Sphingomonas sp. DSM 11572 (named 2MPII) has been isolated from a Mediterranean coastal sediment. This strain is able to use 2-methylphenanthrene (2-MP) as a growth substrate. In order to understand the degradation processes and their selectivity, we have elucidated the metabolic pathways of 2-MP degradation. In this respect, in this paper, we report the identification of several metabolites resulting from the oxidation of 2-MP by the Sphingomonas sp. Metabolites of 2-MP, identified by gas chromatography coupled to mass spectrometry in culture media, belong to two distinct metabolic pathways. The first pathway involves, in the first step, the double hydroxylation of an aromatic ring catalyzed by a di-oxygenase. This pathway generates before the opening of the aromatic ring. The exact double hydroxylation positions have not been totally elucidated. The second pathway is initiated by the hydroxylation of the methyl side chain by a mono-oxygenase. It leads, by the oxidation of the methyl group, to the formation of alcohol, aldehyde, and carboxylic acid.
Importance of maternal transfer of the photoreactive polycyclic aromatic hydrocarbon fluoranthene from benthic adult bivalves to their pelagic larvae
Authors: Pelletier Marguerite C , Burgess Robert M , Cantwell Mark G , Serbst Jonathan R , Ho Kay T , Ryba Stephan A 
Published: March 2010

AbstractLaboratory experiments were conducted to determine if maternal transfer of polycyclicaromatichydrocarbons (P AH) from benthic adult bivalves could result in phototoxicity to their pelagic larvae when exposed to ultraviolet light (UV). In these experiments, adult bivalves were exposed to water or sediments amended with the model photoreactive PAH, fluoranthene. Elevated adult fluoranthene tissue concentrations were correlated with embryo concentrations. Embryonic mortality was enhanced by exposure to ultraviolet light when adult tissue fluoranthene levels were greater than 5,000 μg/g lipid. While the exposure concentrations used in this experimental system were high, ultraviolet light exposure levels were low. Also, some of the PAHs are more potent than the model compound used in this study. These results indicate that maternal transfer of photoactive PAHs from organisms living in contaminated sediments may represent a significant adverse effect to populations of benthic bivalves.