bluuebunny/crossref_metadata_2025 huggingface dataset:
Desorption and biodegradation of sorbed styrene in soil and aquifer solids
Authors: Fu Min Hong , Mayton Hilary , Alexander Martin
Published: March 2010

Approximately 40 and 18% of styrene freshly added to Lima loam and aquifer solids, respectively, was mineralized in 50 d Although measurements of equilibrium desorption under abiotic conditions showed that only 7 2 and 5 7% of sorbed styrene were present in aqueous solution at 150 h, 61 0 and 66 7% of the compound were desorbed from the soil and aquifer solids, respectively, in 16 d under nonequihbrium conditions Much of the nondesorbed styrene freshly added to the environ mental samples could be extracted with methanol Approximately 20% of the freshly added styrene not removed from columns of soil that had been repeatedly leached with water was mineralized in 49 d Styrene freshly added to a muck soil also was ex tensively mineralized However, if the compound was in soil for increasingly long periods in the absence of microbial activity, the extent of biodegradation by subsequently added microorganisms became progressively lower until <3% was mineralized in soils in which the chemical was present for four months Most of the styrene freshly added to Lima loam and Edwards muck could be extracted with acetomtrile, but <4% was extracted from soils containing the chemical for 123 d The biodegradation of styrene that has been in natural environments for some time thus is probably different from the transformations that occur with the freshly added compound
Pentachlorophenol: Uptake/elimination kinetics and metabolism in an aquatic plant, Eichhornia Crassipes
Authors: Roy Sashwati , Hänninen Osmo
Published: March 2010

Eichhornia crassipes [(Mart) Solms], an aquatic plant widely used for the treatment of wastewaters, was used to study uptake/elimination kinetics and metabolism of pentachlorophenol (PCP). PCP is a well-known industrial by-product and a major pollutant of the aquatic environment. The initial phase of PCP uptake by the plant was rapid and reached a nearly steady state between 24 and 48 h of exposure to PCP. The major by-products of PCP metabolism in Eichhornia crassipes were identified as ortho- and para- substituted chlorohydroxyphenols (chlorocatechols and -hydroquinones), -anisoles, and -veratroles. Partially dechlorinated products of PCP were also detected. A major portion of the absorbed PCP and metabolites was found in bound/conjugated form. The responses of the enzyme systems involved in the xenobiotic metabolism and antioxidative system were also studied following PCP exposure. A significant increase was observed in the activity of glutathione S-transferase (GST), a major conjugating enzyme, and in the activities of superoxide dismutase and ascorbate peroxidase (Halliwell-Asada pathway enzymes) of PCP exposed plants. Such responses of plant enzymes may be implemented as useful markers of aquatic pollution. The result related to the uptake and metabolism of PCP obtained from the present study suggests a crucial role of aquatic plants in determining the fate of environmental chemicals.
Effect of four environmental toxicants on plasma Ca and estradiol 17β and hepatic P450 in laying hens
Authors: Chen Shu-Wen , Dziuk Philip J. , Francis B. Magnus
Published: March 2010

In a previous study, we found that administration of phenobarbital to laying hens was associated with an increase in content of liver cytochrome P450 and a reduction in concentration of estradiol (E2) in serum Thus, we hypothesized that other xenobiotics such as environmental toxicants that affect P450 might also affect E2 in laying hens In experiment 1, we examined the effect of four environmental pollutants, three of which induce different isoenzymes of P450 and one inhibitor, on circulating E2 and related reproductive functions Aroclor 1254 (PCB), 20 mg/d, dichlorodiphenyltrichloroethane (DDT), 40 mg/d, or benzo[a]pyrene (BZ), 5 mg/d, was administered for 5 d An inhibitor, lead acetate (100 mg in glycerol/salme), was injected for 2 d Controls received corn oil or sodium acetate No significant difference was observed due to administration of lead Treatment with PCB or DDT decreased the concentration of E2 and increased P450 Only PCB significantly decreased plasma total calcium and egg lay Therefore in experiment 2, we determined the dose-response effect of PCB The PCB was given orally at doses of 0, 5, 10, and 25 mg in corn oil for 5 d The depression of concentrations of E2 was associated with the induction of P450 in a dose dependent manner Egg production and plasma total calcium were reduced by the two highest doses, but eggshell thickness was not different from control in all regimens Plasma E2 and plasma total calcium were negatively cor related with induction of P450 BZ is not a strong inducer of P450 and had no effect on E2 or reproduction, whereas DDT and PCB had a profound effect on P450 with consequent depression of circulating E2 These data indicate that the effects of envi ronmental pollutants on reproduction in birds can be mediated through increased P450, thereby increasing the metabolism of steroid hormones and depressing concentration in circulation
Biochemical and toxic effects of polychlorinated biphenyls (PCBs), dibenzo-P-dioxins (PCDDs) and dibenzofurans (PCDFs) in the cormorant (phalacrocorax carbo) after in ovo exposure
Authors: Van Den Berg Martin , Craane Bart L. H. J. , Sinnige Theo , VanMourik Sijmen , Van Der Gaag Marten , Lutke-Schipholt Ineke J. , Spenkelink Bert , Brouwer Abraham , Dirksen Sjoerd , Boudewun Theo
Published: March 2010

Ecological investigations revealed differences in breeding success of cormorants (Phalacrocorax carbo) between two colonies in The Netherlands In this study the possible role of organohalogen pollutants was investigated. Thirty-nine cormorant eggs were collected from two colonies with marked differences in contamination Seventeen cormorant eggs were hatched in an incubator. The respiration rate was monitored regularly during the incubation. Hatchlings were euthanized at day 1 Several morphological parameters were measured PCBs and polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were analyzed in the yolk sac Blood and liver were collected for analysis of cytochrome P450, ethoxyresorufin-O-deethylation (EROD) and pentoxyresorufin-O-depentylation (PROD) activities, vitamin A, and thyroid hormone levels. Residue levels differed two- to five-fold for PCBs and 25% for PCDDs and PCDFs between both colonies Birds from the most contaminated colony showed an increased in ovo respiration rate, increased cytochrome P450 and EROD activity, and reduced plasma thyroid hormone and hepatic retinyl palmitate levels. Large interindividual differences were observed for all parameters The data were compared on an individual basis (n = 17) to detect any concentration-effect relationships. Significant (p < 0 05) concentration-effect relationships were observed for EROD induction, plasma free thyroxine reduction, yolk sac weight, relative liver weight, and head size. It is concluded these compounds may, at least in part, have played a role in the observed low breeding success of cormorants
Flow cytometric determination of the photoinduced toxicity of anthracene to the green algaSelenastrum Capricornutum
Authors: Gala William R. , Giesy John P.
Published: March 2010

Certain PAHs are photosensitizers and in the presence of solar radiation can cause toxicity to aquatic plants and animals. The photoinduced toxicity of anthracene to the green alga Selenastrum capncornutum was assessed by the use of flow cytometry to measure cell size, cellular chlorophyll concentration, and cell viability. Anthracene was slightly toxic in the absence of UV-A radiation. The detection of the direct toxicity of anthracene in this study at a concentration of 19 μg/L anthracene resulted from the use of sensitive flow cytometric measures. There was a significant interaction between anthracene and UV-A radiation, which, in combination, caused significant toxic effects on Selenastrum capncornutum. The most sensitive flow cytometric measure of toxicity was the stress index (SI), which was predictive of longer term effects on cell growth. The 28-h EC50 and EC10 for the SI for Selenastrum capncornutum were 16.1 and 8.3 μg/L anthracene, respectively, at 125 μW/cm2 UV-A. All combinations of anthracene and UV-A that inhibited algal growth also caused a significantly greater number of nonviable cells. The flow cytometric methods used in this study proved to be sensitive, predictive measures of the direct and photo-induced toxicity of anthracene and UV-A radiation to Selenastrum capricornutum.
Quantitative structure-activity relationships for toxicity of phenols using regression analysis and computational neural networks
Authors: Xu Lu , Ball J.W. , Dixon S.L. , Jurs P.C.
Published: March 2010

Quantitative structure-toxicity models were developed that directly link the molecular structures of a set of 50 alkylated and/or halogenated phenols with their polar narcosis toxicity, expressed as the negative logarithm of the IGC50 (50% growth inhibitory concentration) value in millimoles per liter. Regression analysis and fully connected, feed-forward neural networks were used to develop the models. Two neural network training algorithms (back-propagation and a quasi-Newton method) were employed. The best model was a quasi-Newton neural network that had a root-mean-square error of 0.070 log units for the 45 training set phenols and 0.069 log units for the five cross-validation set phenols.
Biodegradation of chlorobenzene by indigenous bacteria
Authors: Nishino Shirley F. , Spain Jim C. , Pettigrew Charles A.
Published: March 2010

Soil and ground water from four sites chronically contaminated with chlorobenzenes were examined to determine whether indigenous bacteria could degrade the contaminants and whether the addition of specific chlorobenzene-degrading bacteria enhanced the degradation rate At each site, chlorobenzene-degrading bacteria were readily isolated from chlorobenzene contaminated wells, whereas similar samples from noncontammated wells yielded no chlorobenzene degrading bacteria Isolates were tested for growth on a variety of substrates At a site contaminated with several solvents, a bioreactor was inoculated with the chlorobenzene degrading Pseudomonas sp strain JS150 Contaminated water was pumped through this bioreactor and a control bioreactor that had been colonized by indigenous microorganisms The contaminants were removed from both bioreactors, however, JS150 could not be recovered from the inoculated bioreactor after three weeks of operation A follow up lab study using ground water from the contaminated site confirmed the field results We conclude that chlorobenzene contamination of soil causes the development of indigenous degradative populations that have a competitive advantage over inoculated strains The mechanism and time course of this acclimation are poorly understood and require additional study
Photolysis of smoke dyes on soils
Authors: Adams Rebecca L. , Weber Eric J. , Baughman George L.
Published: March 2010

Photolysis of an azo, a quinophthalone, and several anthraquinone smoke dyes was studied on soil surfaces. Initially, rapid photodegradation of each dye occurred, followed by a period of much slower rate of loss, indicating that the remaining fraction of the dye was photochemicaily protected. The average mean depths of photolysis ranged from 0.33 to 0.68 mm for outdoor studies and from 0.42 to 0.73 mm for lab studies. The magnitude of the mean depths of photolysis suggests that photo-degradation of the dyes occurs through indirect photochemical processes. Photolysis products for only two of the dyes could be identified. Photolysis of Disperse Red 9 resulted in the formation of 1-aminoanthraquinone, whereas Solvent Yellow 33 photo-degraded to give 2-carboxyquinoline and phthalic anhydride. Reaction mechanisms involving sensitized photo-oxidation by singlet oxygen are consistent with the formation of these reaction products.
Refinery water (intake and effluent) quality: Update of 1970s with 1990s toxicity testing
Authors: Chapman Peter M. , Paine Michael D. , Moran Tim , Kierstead Ted
Published: March 2010

The quality of two separate refinery intake waters and effluents was investigated Petro Canada (Oakville) and Novacor (Corunna Operations) This study comprised eight different test organisms and 22 different toxicity end points, was built on and complemented pioneering 1970s work at the Petro Canada refinery, and was designed to (a) determine any changes in effluent quality, (b) determine any previously unsuspected effluent toxicity, and (c) determine any potential for chronic toxicity in the effluent Although Petro Canada has steadily reduced contaminants in its effluent since the earlier study, toxicity has not changed and no new toxic effects were identified Effect thresholds for the most sensitive animal species (Daphma pulex) were 1 to 10% effluent in both studies The Novacor effluent had lesser effects on biota than the Petro-Canada effluent In take waters demonstrated toxicity in some tests Chronic effects on invertebrates and fish in receiving waters are predicted not to occur if the Novacor effluent is diluted 10- to 20 fold and the Petro Canada effluent is diluted 50- to 100 fold
Effect of indigenous animals on chronic end points in freshwater sediment toxicity tests
Authors: Reynoldson T.B. , Day K.E. , Clarke C. , Milani D.
Published: March 2010

Sediment toxicity tests were conducted using three species of benthic invertebrates, Chironomus riparius, Hyalella azteca, and Hexagenia limbata, with various densities of the oligochaete worm Tubifex tubifex. It was shown that indigenous animals, simulated by the presence of Tubifex tubifex, did not affect survival of the test species (P ≥ 0.05) but did reduce growth in all three test species and in two species at the lowest tested densities, equivalent to 1,460 worms per square meter. At densities of Tubifex tubifex equivalent to 20,000 m−2, the growth of Chironomus riparius was reduced by >90%, Hyalella azteca by >60%, and Hexagenia limbata by almost 50%. The densities of oligochaetes are equivalent to those found in many contaminated sites. Therefore, it is concluded that the presence of indigenous organisms can confound the interpretation of toxicity test results, based on chronic end points. It is recommended that removal of organisms be considered before toxicity tests are conducted with freshwater sediments from sites with large populations of benthic invertebrates, especially oligochaete worms.
Expert-system comparison of structural determinants of chemical toxicity to environmental bacteria
Authors: Pangrekar Jyotsna , Rosenkranz Herbert S. , Klopman Gilles
Published: March 2010

The CASE (computer automated structure evaluation) structure-activity relational expert system was used to analyze the toxicity of a database of chemical sets to environmental bacteria (aerobic heterotrophs, nitrosomonas, methanogens, and photobacteria [Microtox® test]). The analyses revealed that the data sets related to each of the antimicrobial activities, albeit containing a relatively small number of chemicals, are characterized by structural determinants significantly associated with the probability of antimicrobial activity, as well as with antibacterial potency. Although there were a number of similarities among the structural determinants associated with each of these antimicrobial activities, there were also features unique to each assay that presumably reflect species-specific targets of bactericidal activity. Overall the assay for antimethanogenic activity appears to be the most informative as well as the one most predictive of the activity in the other three assays.
Identification of multiple steroid hydroxylases inDaphnia magnaand their modulation by xenobiotics
Authors: Baldwin William S. , Leblanc Gerald A.
Published: March 2010

Steroid hydroxylase activities were characterized in Daphnia magna and evaluated for potential use as biomarkers of xenobiotic exposure. Microsomes prepared from Daphma magna generated a single NADPH-dependent metabolite of [14C]testosterone. However, intact daphnids excreted at least 10 polar metabolites of [l4C]testosterone into the test medium. Six of these metabolites were identified as 2α-, 16β-, 6β-, 6α-, 7α-, and 15α-[14C]hydroxytestosterone. The unidentified metabolites are also presumed to be hydroxylated products of testosterone, based on their relative migrations during TLC. The inefficient metabolism of [14C]testosterone during the in vitro microsomal incubations may have been due to the release of P450 inhibitors during microsome preparation. Exposure of daphnids to the P450 modulators phenobarbital, β-naphthoflavone, piperonyl butoxide, and malathion differentially inhibited the steroid hydroxylase activities. Results from this study indicate that Daphma magna expresses several P450 enzymes and that these enzymes are differentially modulated by xenobiotic exposure. Steroid hydroxylase activities may serve not only as a biomarker of toxicant exposure, but also as a predictor of toxicant effects involving perturbations of steroid hormone homeostasis.
Volatile halocarbons as tracers of pulp mill effluent plumes
Authors: Comba M.E. , Palabrica V.S. , Kaiser K.L.E.
Published: March 2010

This work describes the use of volatile halocarbons in a pulp mill effluent, including chloroform, bromodichloro-methane, and tri- and tetrachloroethylene, as tracers for the distribution and movements of effluent currents in a receiving water bay (Jackfish Bay) on the northern shore of Lake Superior. The results indicate the simplicity and usefulness of the technique and the significantly improved resolution of effluent plume delineation over the customary use of conductance profiles. Concentration patterns of the effluent volatiles suggest counterclockwise circulation of bay water that mixes with inflowing lake water at the eastern reach of the outer bay. The distribution of volatile contaminants is governed by the thermal regime of the receiving waters. During the summer months, the effluent plume wedges between the thermocline and epilimnion, mixing into the surface waters as the distance from the input source increases. In the fall, the colder effluent plume sinks into the hypolim-nion and is confined by a bay/lake water-density gradient. In the specific case at hand, the distribution patterns of chloroform and a brominated analog, bromodichloromethane, also suggest the release of chloroform from sediments in the bay.
Survey of receiving-water environmental impacts associated with discharges from pulp mills: 3. Polychlorinated dioxins and furans in muscle and liver of white sucker (Catostomus commersoni)
Authors: Servos Mark R. , Huestis Susanv Y. , Whittle D. Michael , Munkittrick Kelly R. , Van Der Kraakv Glen J.
Published: March 2010

Polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in white sucker liver samples from seven pulp and paper mill sites, and three reference sites in Ontario. The mills included five bleached-kraft mills, with and without secondary treatment, and two sulfite-mechanical mills. 2,3,7,8-T4CDD and 2,3,7,8-T4CDF were the dominant congeners detected in both liver and fillet samples at all of the pulp and paper mill sites, with mean 2,3,7,8-T4CDD toxic equivalent concentrations (TEQs) as high as 124 pg g−1 in liver tissue. Concentrations of PCDDs/PCDFs in liver tissues were severalfold higher than in fillet tissue, but this difference can be accounted for by lipid normalization. Biological information, including liver weight, gonad weight, MFO activity (ethoxyresorufin-O-deethylase, EROD), and plasma sex steroids, was measured on individual fish. There was no relationship between TEQs and condition factor, gonadosomatic index, liver somatic index, or circulating plasma 11-ketotestosterone. A weak negative correlation was observed between circulating plasma testosterone and TEQs. Although there was a positive correlation (r = 0.49, p < 0.001) between MFO activity (EROD) and TEQ, one site with very low chlorine use and low TEQs had EROD activity similar to levels observed at more contaminated sites. This finding, along with recent observations that MFO activity is rapidly cleared in pulp-mill-exposed fish, casts doubt on an exclusive causal relationship between MFO activity and PCDDs/PCDFs at these sites.
Intestinal survival, competition and translocation of biotechnology agents on intranasal exposure of C3H/HeJ mice
Authors: George S. Elizabeth , Kohan Michael J. , Claxton Larry D. , Taylor Maria S. , Brooks Harold G. , Creason John P.
Published: March 2010

Human exposure to environmentally released biotechnology agents may occur. Therefore, it is important to identify adverse health effects associated with this exposure. This study investigates colonization, competition, and translocation of biotechnology agents following intranasal challenge by sublethal doses of the environmental isolates Pseudomonas malto-phdia (BC6) and Pseudomonas aeruginosa (BC16, BC17, BC18, AC869) Two clinical Pseudomonas aeruginosa isolates (PAO1, DG1), are included for comparison. Following intranasal challenge by approximately 106 colony-forming units (cfu), recovery of the dosed strains were determined in C3H/HeJ mice at time intervals in the intestinal tract, mesenteric lymph node (MLN) complex, liver, and spleen. Intestinal bacterial populations also were enumerated. Strains BC6, AC869, DG1, and PAOl were detectable in all three intestinal regions 14 d following treatment. Strain BC17 was cleared 7 d posttreatment Strains BC18 and BC16 were detectable in two of the three intestinal sections A decrease in cecal lactose nonfermenting enteric bacilli was detected in strain BC6-treated mice Translocation of strains BC16, AC869, and PAOl occurred to the MLN, spleen, and liver. Strain BC18 was detectable in the liver, and strains BC17 and DG1 were recovered from both the MLN and the liver Pulmonary challenge can result in intestinal survival, competition and translocation.
Specific cross-reactivity of antibodies raised against two major stress proteins, stress 70 and chaperonin 60, in diverse species
Authors: Sanders B.M. , Martin L.S. , Nakagawa P.A. , Hunter D.A. , Miller S. , Ullrich S.J.
Published: March 2010

Immunoblot analysis using several antibodies raised against two major families of stress proteins, stress 70 and chaperomn 60 (cpn60), which are highly conserved in mammals, was carried out in diverse species often used in environmental research, including molluscs, annelids, crustaceans, echinoderms, and fish The study revealed surprisingly different patterns of antibody cross reactivity among species The monoclonal anti-stress 70 antibody (mAb) C92 was the least cross reactive for all species tested The mAbs anti-stress 70 N27, BRM-22, and 3a3 were more broadly cross reactive, but their binding specificities to stress 70 isoforms in the diverse species tested did not correlate with one another or follow taxonomic lines The polyclonal anti-stress 70 antibody reacted to proteins in the 70 to 74 kDa range in all fish examined and in most invertebrates When a polyclonal antibody (pAb) raised against cpn60 from a moth was used as a probe, specific binding was observed with proteins in the 60 to 64 kDa range in all fish examined and in most invertebrates However, the size and number of isoforms that reacted with the pAb were species specific These data suggest that these two major stress protein families are less highly conserved in invertebrates and fish than in mammals Therefore, to minimize misinterpretation when using antibodies in heterologous assays with species in which the stress response has not been well characterized, it is important to determine which isoforms of stress 70 react with a particular antibody and to take into account the differential regulation of each member of this multigene family
Diffusion method for the determination of acid-volatile sulfides (AVS) in sediment
Authors: Brouwer Henry , Murphy Tom P.
Published: March 2010

A simplified procedure using diffusion and a sulfide ion selective electrode is described for measuring acid-volatile sulfides (AVS) in sediment This method yielded at least 10% more AVS than the more common purge-and trap method The quantity of AVS (based on dry mass of sediment) was found to be dependent on acid concentration and on mass of wet sediment The mean recovery of known additions of sodium sulfide was 93 8 ± 6 7%
Comparison of 20-d bod and oecd closed-bottle biodegradation tests
Authors: Waggy Gene T. , Conway Richard A. , Hansen James L. , Blessing Ronald L.
Published: March 2010

This study correlated the 20-d Biochemical Oxygen Demand (BOD) test widely used in the United States with the closed-bottle test selected and refined by the Organization for Economic Cooperation and Development (OECD) for determining biodegradability of a product. Many chemical producers in the United States have 20-d BOD data on their products; it is important to use this information when valid both in the interim until OECD tests can be completed on these myriad products and in support of the OECD data when available. This paper presents comparative biooxidation data on 16 chemicals using both sealed-bottle tests. Similar data were obtained at the end of each test, after 20 d in the BOD test and 28 d in the closed-bottle test. The reduced microbial seed concentration in the closed-bottle test required longer incubation time to achieve these similar results. The best correlations were obtained at days 10 and 15, and the poorest was indicated at day 5. The environmental classification specified by the European Community is the same for these chemicals, >60% biooxidation for readily biodegradable classification or not, regardless of the biooxidation test. OECD biodegradation screening test data are included in this report; results from this test, which monitors dissolved organic carbon (DOC), support the biooxidation values obtained in both the OECD closed-bottle test and the 20-d BOD test.
A water-renewal system that accurately delivers small volumes of water to exposure chambers
Authors: Zumwalt D.C. , Dwyer F.J. , Greer I.E. , Ingersoll C.G.
Published: March 2010

This paper describes a system that can accurately deliver small volumes of water (50 ml per cycle) to eight 300-ml beakers. The system is inexpensive <$100), easy to build (<8 h), and easy to calibrate (<15 min), and accurately delivers small volumes of water (<5% variability).
Integral hazard assessment of side effects of pesticides in the netherlands—a proposal
Authors: De Snoo Geert R. , Canters Kees J. , De Jong Frank M. W. , Cuperus Ruud
Published: March 2010

Current pesticide registration procedures are discussed and three major shortcomings identified with regard to the quantification and evaluation of potential pesticide side effects on nature and the environment: (a) the absence of a framework for assessing the acceptability of damage; (b) the disregard for indirect side effects; and (c) the absence of field studies. With reference to the situation in The Netherlands, recommendations for overcoming these three shortcomings are presented. For priority species it is proposed that a population decline of more than 5% is unacceptable in target areas having ‘general environmental quality.’ Populations should have recovered after one year. Outside the target area and in areas having ‘special environmental quality’ there should be no decline at all in population densities. An integral decision tree is presented with which to incorporate assessment of indirect side effects in the registration procedure, achieving a better balance relative to direct side effects. Spectrum of action, scale of use, overlap of habitats, and compound efficacy are employed as criteria for assessing indirect side effects. The decision tree prescribes field trials in cases where lab testing indicates a moderate hazard or uncertainty. Finally, guidelines are presented for selecting appropriate pesticide field trials.
Preliminary culture and life-cycle experiments with the benthic amphipodAmpelisca abdita
Authors: Redmond Michele S. , Jones Jill K. P. , Scott K. John , Swartz Richard C.
Published: March 2010

The tube-dwelling amphipod Ampelisca abdita Mills 1964 has been used extensively in acute sediment toxicity tests and has been shown to be amenable to chronic testing. Ampelisca abdita was held in the lab through several generations when fed algal food in daily static renewals, although culturing success was not consistent. Algal food consisted of one or more of the following: the flagellate Pseudoisochrysis paradoxa Sutton, and the diatoms Phaeodactylum tricornutum Bohlin and Chaetoceros calcitrans (Paulsen) Tokano. Sensitivity of cultured animals to cadmium chloride in 96-h seawater-only tests (LC50s 0.28–0.58 mg Cd/L) was comparable to that of field-collected animals (LC50 0.20 mg Cd/L). A life-cycle test initiated with juveniles 8 to 10 d old resulted in production of young or fertilized broods in only two of the 12 sample containers in which young were expected. Amphipods were sexually mature at approximately 20 d of age at 25°C, and young were first produced at 34 to 36 d. Short-term tests were used to quantify growth of this species in 10 to 14 d. Results from a variety of experiments indicated that there are still one or more unresolved problems with the culture and chronic testing of Ampelisca abdita. Factors such as nutrition, flow rate, light, and temperature need to be examined further.
Calculation of soil cleanup criteria for carcinogenic volatile organic compounds as controlled by the soil-to-indoor air exposure pathway
Authors: Sanders Paul F. , Stern Alan H.
Published: March 2010

Two deterministic models that calculate volatilization of contaminants from soil were compared and used to calculate soil cleanup criteria for carcinogenic volatile organic compounds so that acceptable total doses would not be exceeded through the inhalation of indoor air. A hypothetical scenario was used which assumed that subsurface contaminant diffuses through a layer of clean soil and then is swept into the building interior via advection, where long-term inhalation of contaminant was assumed to occur. The first model was one of three recently described by Little et al. It assumed a constant source concentration and infinite thickness for the contaminated soil zone, and resulted in a steady-state interior air concentration. The model was modified to allow for first-order decay of the contaminant source. The second model was adapted from the behavior assessment model of Jury et al. It calculated time-dependent volatilization, simulated the depletion of source contaminant via both volatilization and degradation, and could be used with a contaminated zone of finite thickness. For a given chemical, the predicted total exposure (and the resulting cleanup criteria) varied by up to seven orders of magnitude, depending on the model, whether a finite or infinite contaminated soil layer thickness was used and whether degradation was considered. When calculating soil cleanup standards for volatile organic compounds in the part-per-million range or lower, it appears to be important to consider contaminant source depletion with time and the actual thickness of the contaminated soil layer.
Considerations in performing life-cycle assessments on forest products
Authors: Miner Reid A. , Lucier Alan A.
Published: March 2010

Life-cycle assessment (LCA) is a theoretically attractive approach for evaluating resource consumption and environmental emissions associated with the production, use, and disposal of products. Current LCA guidelines suggest adherence to conventions that can significantly affect results. Conventions of special importance in LCAs of forest products are those pertaining to sustainability of natural resources, recyclability and biodegradability of products, and use of renewable energy in manufacturing processes. More general methodological issues (e.g., relating emissions to impacts, site-to-site variability in loads, data quality) are also important in forest-product LCAs.
Literature review and evaluation of the EPA food-chain (Kenaga) nomogram, an instrument for estimating pesticide residues on plants
Authors: Fletcher John S. , Nellessen James E. , Pfleeger Thomas G.
Published: March 2010

The Kenaga nomogram is a simple device that was developed by the U.S. Environmental Protection Agency (EPA) in the early 1980s and is currently used to predict the maximum potential pesticide residue levels in the food chain of wildlife before pesticide registration. To evaluate the accuracy of this nomogram, predicted levels were compared to levels reported in the literature. Data (obtained from the UTAB database developed by the University of Oklahoma) demonstrated that day-0 levels predicted by the nomogram were often exceeded. Data from the UTAB database exceeded the nomogram predictions by the following percentages listed by crop: short range grass, 0; leafy crops, 3; long grass, 4; pods/seeds, 8; fruits, 19; and forage (legumes), 22. Minor modification of the nomogram is recommended. Recommended modifications would result in an elevation of the predicted residue levels for fruits and forage (legume) crops.
Embryotoxicity of extracts from lake ontario rainbow trout (oncorhynchus mykiss) to japanese medaka (oryzias latipes)
Authors: Harris G.E. , Metcalfe T.L. , Metcalfe C.D. , Huestis S.Y.
Published: March 2010

Various preparative techniques were used to extract nonpolar organic compounds from the muscle tissue of Lake Ontario rainbow trout (Oncorhynchus mykiss). In this extract, PCBs and organochlorine compounds were detected in nanogramper-milliliter quantities, and polychlorinated dibenzo-p-dioxins and dibenzofurans were detected in picogram-per-milliliter quantities. The extract and various subfractions of the extract were tested for embryotoxicity in a bioassay with embryos of Japanese medaka (Oryzias latipes). The whole extract was embryotoxic to medaka, as were an extract fraction containing PCBs (fraction A) and extract fractions containing nonpolar organochlorine compounds (fractions B and C). When subfractions prepared from fraction A were tested for embryotoxicity, a subfraction containing non-ortho-substituted PCB congeners was embryo-toxic, whereas subfractions containing mono-ortho- and di-ortho-substituted PCB congeners were relatively nontoxic. Pathological lesions characteristic of exposure to planar halogenated aromatic hydrocarbons were observed only in embryos exposed to the non-ortho-PCB subfraction. The non-ortho-PCB subfraction of fraction A was more toxic than the original fraction A, which indicates that nontoxic PCBs reduce the toxicity of the non-ortho-PCBs through some unknown mechanism. This study indicates that organochlorine compounds and non-ortho-substituted PCBs have the potential to be embryotoxic to early life stages of Great Lakes fish, but nontoxic contaminants can modify this toxic response. These data are relevant to the interpretation of correlations between embryo mortalities and concentrations of persistent organic contaminants in Great Lakes salmonids.
Bioaccumulation of organotin compounds in the red sea bream (pagrus major) by two uptake pathways: Dietary uptake and direct uptake from water
Authors: Yamada Hisashi , Takayanagi Kazufumi , Tateishi Masahiro
Published: March 2010

The bioaccumulation and elimination of organotin compounds in Pagrus major during dietary uptake and/or direct uptake from water were studied. When tributyltin (TBT) and triphenyltin (TPT) compounds were accumulated in fish from seawater and from feed simultaneously, about one-quarter of the bioaccumulation was due to the dietary uptake. The biomagnification factors (BMFs) were 0.26 to 0.38 for TBT and 0.57 for TPT. BMF was not significantly altered by the concentration nor the species of chemicals in the feed. The assimilation efficiency of ingested TBT and TPT was 9.5 to 12.7 and 19.6%, respectively, and percentage retention was 24.2% for TBT and 60.1% for TPT. The BMF, percentage retention, and assimilation efficiency of TBT were all lower than those of TPT, suggesting that TPT compounds are more easily accumulated by dietary uptake than TBT compounds. Compared to PCBs and methylmercury chloride, the assimilation efficiency and the percentage retention of organotin compounds were low. These lower values imply that the risk of bioaccumulating the ingested organotin compounds might be smaller than for PCBs and methylmercury chloride.
Influence of acclimation and exposure temperature on the acute toxicity of cadmium to the freshwater snailPotamopyrgus antipodarum(hydrobiidae)
Authors: Møller V. , Forbes V.E. , Depledg M.H.
Published: March 2010

Forty-eight-hour acute toxicity tests were performed to determine the influence of acclimation temperature (5, 15, and 20°C) and exposure temperature (5, 15, and 20°C) on the toxicity of cadmium to the freshwater gastropod Potamopyrgus antipodarum. Mortality varied with cadmium concentration and treatment conditions, but did not conform to conventional sigmoid concentration-response (i.e., dose-response) relationships. Because the shapes of the concentration-response curves were treatment dependent, a nontraditional approach for data analysis was employed. Regardless of acclimation temperature, mortality increased with increasing exposure temperature, and at all exposure temperatures snails acclimated at 15°C were most susceptible to cadmium toxicity. Estimated LC50 values were within 1 to 4 mg Cd/L. Although the shapes of the concentration-response curves were different for each treatment, the slopes were generally quite steep, indicating a uniform response for the whole population. At a given Cd concentration, acclimation temperature and exposure temperature accounted for 57 and 40%, respectively, of the variation in mortality, and LC50s changed by a factor of four. The results indicate that changes in environmental variables can alter both the degree of response and the response distribution of a population, and that past as well as prevailing environmental conditions can influence organismic responses to toxicants.
Acute and short-term chronic effects of continuous and intermittent chlorination on mysidopsis bahia and menidia beryllina
Authors: Fisher Daniel J. , Burton Dennis T. , Yonkos Lance T. , Turley Steven D. , Turley Bonnie S. , Ziegler Gregory P. , Zillioux Edward J.
Published: March 2010

Intermittent chlorination to inhibit biofouling in condensers is a widespread practice in the power generation industry. Because the U.S. Environmental Protection Agency's water quality criteria for chlorine were based on continuous chlorine exposure of test organisms, it is possible that effluent discharge limits derived from these criteria are overprotective to aquatic organisms exposed only intermittently. The toxicity of 96-h acute and 7-d short-term chronic exposures under continuous and intermittent chlorination (2-, 4-, 6-, and 8-h daily exposures) to two saltwater species was determined.

Mysids (Mysidopsis bahia) were found to be more sensitive to chlorine than inland silversides (Menidia beryllina) when exposed continuously under acute and short-term chronic conditions. No difference was found between the acute toxicity responses of mysids and silversides exposed to intermittent chlorination. In contrast, a difference in short-term chronic toxicity was found between the two species exposed to intermittent chlorination. All intermittent chlorine exposures were less toxic to both species than the continuous exposures. The acute-to-chronic ratios (ACR) for silversides exposed to both continuous and intermittent chlorination indicate that ACRs of approximately 1.5 can be used with acute data to estimate chronic toxicity of chlorine. The ACRs for mysids exposed to both continuous and intermittent chlorine range from 3.1 to 6.1.
Sulfur analogues of polychlorinated dibenzo-P-dioxins, dibenzofurans and diphenyl ethers as inducers of CYP1A1 in mouse hepatoma cell culture and structure-activity relationships
Authors: Kopponen Paivi , Sinkkonen Seija , Poso Antti , Gynther Jukka , Karenlampi Sirpa
Published: March 2010

Three sulfur containing compounds, 2,3,7,8 tetrachlorothianthrene (TCTA), 2,3,7,8 tetrachlorodibenzothiophene (TCDT), and 3,3,4,4 tetrachlorodiphenyl sulfide (TCDPS), were analyzed for their CYP1A1 inducing potencies – measured as aryl hydrocarbon hydroxylase (AHH) and 7 ethoxyresorufin O-deethylase (EROD) activities – in mouse hepatoma cell culture Hepa 1 Marked differences in the induction potencies were observed among the three compounds studied and between 2,3,7,8 tetrachlorodibenzo p dioxin (TCDD) and its sulfur analogue The estimated EC50 values for TCDD, TCTA, and TCDT were about 8 pM, 700 pM, and 7 5 nM, respectively TCDPS did not elicit any AHH/EROD induction Comparative molecular field analysis (CoMFA) was not able to predict correctly the biological potency of TCTA and TCDT The most important reason for the poor performance of the model may be the positive point charge of sulfur in TCTA and TCDT
Role of oxygen at the TiO2 interface during photodegradation of biologically difficult-to-degrade anthraquinone-sulfonate dyes
Authors: Kiwi John
Published: March 2010

Heterogeneous photocatalysis via TiO2 suspensions is effective in anthraquinone 2 sulfonic acid sodium salt (ASS) degradation The presence of oxygen promotes the observed semiconductor powder oxidation of the substrate Degradation of ASS in aerated dispersions of TiO2 needed about 24 h at 60°C Added H2O2 enhances the degradation rate considerably As the pH increases, the H2O2 produced also increases Also, peroxide production was observed as the concentration of TiO2 is increased owing to the availability of more surface states for the reaction The Langmuir adsorption isotherm of ASS on TiO2 Degussa P-25 shows that ASS adsorbs readily on the TiO2 particles The observed rate for H2O2 production decreased as the concentration of isopropanol (hole scavenger) is increased, suggesting an oxidative pathway as the main reaction responsible for H2O2 photoproduction The degradation of ASS is a result of indirect action due to light mainly absorbed by TiO2 The experiments described here demonstrate the feasibility of dyestuff decomposition via semiconductor powders
Partitioning of 14c-labelled 2,2′,4,4′-tetrachlorobiphenyl between water and fish lipids
Authors: Ewald Goran , Larsson Per
Published: March 2010

The partitioning of 14C labelled 2,2,4,4 tetrachlorobiphenyl (TCB) between fish lipids and water was studied in a continuous flow system Fish lipids with high phospholipid content (>20% by weight) accumulated significantly less TCB than did fish lipids with low phospholipid content (<10% by weight) The results suggest that the bioconcentration factor of a hydrophobic compound is species specific depending on lipid composition
An Elisa assay for avian serum butyrylcholinesterase: A biomarker for organophosphates
Authors: Khattab Ahmed D , Walker Colin H , Johnston Gail , Siddiqui M.K. , Saphier Peter W
Published: March 2010

A competitive enzyme linked immunosorbent assay (ELISA) for the quantification of butyrylcholinesterase (BChE) (EC 3 1 1 8) substance concentration in avian serum samples is described The assay is based on polyclonal (rabbit) anti pigeon BChE coupled with biotin The binding of the biotinylated antibody to immobilized antigen is competitively inhibited by an added standard or test antigen, and the amount of label bound antibody is inversely related to the concentration of antigen The assay yields positive reactions with as little as 0 15 ng/ml of antigen The assay was employed to investigate changes in the quantities of BChE in avian serum, following exposure to organophosphorus insecticides, which are not measured by the standard bioassay of this enzyme The applicability of the assay to metabolic and toxicological studies is demonstrated, and the de termination of the specific activity of BChE is recommended as a rational diagnostic tool after measurement of both activity and concentration of the enzyme
Chemical degradation of cyanides by fenton's reagent in aqueous and soil-containing systems
Authors: Aronstein Boris N. , Lawal Raheem A. , Maka Andrea
Published: March 2010

A study was conducted on the effects of pH of the medium, composition of Fenton's reagent, and the effect of soil's preequilibration with the chemical, on the degradation of 14C-labeled free and complex cyanide in aqueous and soil-containing systems The application of Fenton's reagent (1% H2O2, 10 mM FeSO4) resulted in degradation of 80% and 67% of potassium cyanide in aqueous systems at pH 7 2 and 10 0, respectively No appreciable amount of K4[Fe(CN)6] was degraded at either pH tested Under the alkaline condition, negligible amounts of cyanide were converted to HCN and were removed from liquid phase due to precipitation In the soil systems containing uncontaminated topsoil or manufactured gas plant (MGP) soil, both freshly amended with free cyanide, 80% of the compound was degraded by the Fenton's reagent of the same composition Similar to the aqueous systems, no complex cyanide was degraded in soil slurries In both soils, previously equilibrated with free and complex cyanides, the extent of degradation caused by Fenton's reagent was not more than 6% at either pH However, at alkaline pH, up to 21% of previously added complex cyanide was leached out into a liquid phase where it could be further degraded The optimum composition of Fenton's reagent under alkaline pH was found to be 1% of H2O2 and 1 mM FeSO4 We suggest that the application of Fenton's reagent under alkaline conditions may be useful in a combined physicochemical treatment for the remediation of sites contaminated with cyanides
Hydrogen-bonding interactions between the herbicide glyphosate and water-soluble humic substances
Authors: Piccolo A. , Celano G.
Published: March 2010

In this study, infrared spectroscopy (IR) was used to investigate the mechanism of interaction between the widely used herbicide Glyphosate [N-(phosphonomethyl) glycine] and a water-soluble humic acid (HA) obtained from a purified Leonardite Aliquots of the purified humic solution were set to pH 4, 5, and 6, and added with Glyphosate volumes corresponding to increasing percentages of total acidity of the water soluble HA The IR spectra of the HA-Glyphosate complexes showed two bands at 1,168 and 1,090 cm−1 for the stretchings of the P=O and P—O bonds, respectively, as they appear in the spectrum of Glyphosate alone where the phosphono group is involved in hydrogen bondings occurring in Glyphosate dimers Conversely, when the complex solutions were brought back to the starting pH levels (4, 5, and 6), the two IR bands of the phosphono group were shifted to higher frequencies (1,195 and 1,134 cm−1, respectively), suggesting that the P—O bonds were no longer involved in hydrogen bondings This behaviour supports the occurrence of hydrogen bondings in the Glyphosate-HA complex In fact, the IR band shift in the herbicide-HA complex indicates that, because the Glyphosate molecules are distributed along the humic macromolecule, they are too far apart to form the Glyphosate dimers again when the initial conditions are restored The hydrogen-bonding interaction between HA and Glyphosate evidenced in this study may well be responsible for the transport of Glyphosate in lower soil depths through the adsorption of Glyphosate on water soluble humic substances