bluuebunny/crossref_metadata_2025 huggingface dataset:
Stream periphyton and benthic insect responses to additions of treated acid mine drainage in a continuous-flow on-site Mesocosm
Authors: Perrin C. J. , Wilkes B. , Richardson J. S.
Published: March 2010

An on-site continuous-flow trough mesocosm was used to examine changes in the composition and abundance of periphytic algae and benthic invertebrates from additions of a solution of treated acid mine drainage (AMD). Five control and five treatment troughs supported an assemblage of periphyton and invertebrates that colonized from water withdrawn from Foxy Creek, a stream that receives limed AMD from the Equity Silver Mine, central British Columbia, Canada. A water intake for the mesocosm was located upstream of the AMD discharge. The treated AMD was delivered to the apparatus through a pipeline laid in a canal that carried the AMD to Foxy Creek. After three weeks of colonization in the troughs, additions of one part AMD to 10 parts Foxy Creek water was delivered to the treatment troughs and continued for three weeks. Analyses of variance of measurements of abundance and biomass indexes contained high power values and indicated that the AMD addition did not significantly change the algal and insect composition and abundance. Advantages and disadvantages of the mesocosm with regard to the relative sensitivity of the measured parameters for use in examining effects of the AMD additions are discussed. The conclusion was that quantitative on-site experimentation using the mesocosm apparatus is a powerful approach in setting guidelines for AMD discharge mainly due to its capability of integrating ecosystem processes in experiments where hypothesis testing is possible.
The effect of 2-(Thiocyanomethylthio)benzothiazole on juvenile coho salmon (Oncorhynchus Kisutch): Sublethal toxicity testing
Authors: MacKinnon D. L. , Farrell A. P.
Published: March 2010

This study examined the sublethal toxicity of 2-(thiocyanomethylthio)benzothiazole (TCMTB), a wood preservative used in British Columbia's lumber industry, to coho salmon, Oncorhynchus kisutch. Swimming performance, oxygen consumption, and blood lactate levels were used as indicators of sublethal TCMTB toxicity. Assessment of swimming performance consisted of subjecting preexposed (48 h) fish to a series of increasing velocity increments within an annular swim chamber. An automated respirometer apparatus was used to measure oxygen consumption rates. Blood lactate levels were assayed upon termination of the respirometer trials. Reductions in critical swimming speed and elevations in blood lactate occurred in a concentration-dependent manner with thresholds of 10 and 7.5 μg/L, respectively. A similar concentration-dependent response was not observed with respect to oxygen consumption rates.
Copper and zinc in estuarine water: Chemical speciation in relation to bioavailability to the marine planktonic diatom Ditylum brightwellii
Authors: Rustenbil J. W. , Poortvliet T. C. W.
Published: March 2010

Availability of toxic trace metals in relation to phytoplankton growth was studied in water of the polluted Westerschelde (southwestern Netherlands). The prominent estuarine diatom Ditylum brightwellii was grown in bioassays with estuarine water (14%o salinity). Selective removal of Cu and Zn, and addition of a chelator (EDTA), had a positive effect on its cell division, whereas addition of Zn had an adverse effect, indicating an influence of in situ levels of Cu or Zn on estuarine phytoplankton growth. To study this in more detail, metal availability was manipulated in order to measure the responses of Ditylum brightwellii at different cellular levels of Cu and Zn. Metal speciation was approached with different metal-adsorbing resins and compared with cellular metal concentrations. Optimum positive correlations between cellular and column-adsorbed fractions of Cu and Zn were obtained, using an aluminum hydroxide-coated sulfonic acid resin (ALSA). Both ALSA-adsorbed and cellular Cu and Zn increased after a 4–h UV irradiation of Westerschelde water, whereas division rates and final cell numbers decreased. Opposite results were obtained after a partial removal of Cu and Zn with Chelex-100®: ALSA-adsorbed and cellular Cu and Zn were relatively lower, and this reduction caused a relative increase of final cell numbers. Addition of Cu caused a relative increase of both ALSA-adsorbed and cellular Zn, probably due to Cu-Zn exchange and a subsequent release of Zn from ligands in Westerschelde water. Increasing amounts of utile Zn or Cu may shorten the exponential-growth phase of Ditylum brightwellii in the Westerschelde. This effect was stronger in a medium from Restronguet Creek (UK) containing micromoles of dissolved Cu and Zn, due to drainage of copper and tin mines.
Effect of wastewater from olive oil mills on nitrogenase activity and growth of Azotobacter chroococcum
Authors: García-Barrionuevo A. , Moreno E. , Quevedo-Sarmiento J. , González-López J. , Ramos-Cormenzana A.
Published: March 2010

The effect of 1, 5, 10, 15, and 20% (v/v) of wastewater from olive oil mills (“alpechin”) was investigated in cells of Azotobacter chroococcum grown in chemically defined media (N-free or with NH+4) and dialyzed-soil media. Wastewater from olive oil mills at concentrations of 1 to 20% (v/v) significantly reduced dinitrogen fixation and growth of Azotobacter chroococcum in chemically defined N-free medium, whereas the presence of 1 to 15% had a stimulatory effect on dinitrogen fixation and growth of Azotobacter in dialyzed-soil medium. Azotobacter chroococcum grew on NH+4 media (without glucose) amended with alpechin, suggesting that these wastes were utilized by Azotobacter as a carbon source.
Leaching of soil-active herbicides in acid, low base saturated sands: Worst-case conditions
Authors: Stone Douglas M. , Harris Alfred Ray , Koskinen William C.
Published: March 2010

Effects of litter-humus treatments and precipitation acidity on the mobility of the soil-active herbicides hexazinone, tebuthiuron, and sulfometuron methyl were determined in 15- × 150-cm lysimeters with intact soil columns collected from six sites across the northern Lake states. Each column had received a cap of litter-humus from either a jack pine or mixed hardwood stand, or a quartz sand (control) and was preconditioned by treatment with rainwater acidified to pH 5.4 or 4.2, applied weekly throughout the growing season for four years. 14C-labeled material was added to the commercial formulation of each product and applied at 2.24 kg (active ingredient [a.i.])/ha of hexazinone and tebuthiuron and 42.5 g (a.i.)/ha of sulfometuron methyl. Acidified rainwater was applied weekly to approximate ambient precipitation; additional water was applied on three occasions. Soil water was sampled once at 10, 20, and 40 cm, and 10 times at the 150-cm level over the 130-d post-treatment. Sulfometuron methyl apparently had dissipated by 80 d post-treatment and was not detected below 20 cm. At the 150-cm level, hexazinone and tebuthiuron were detected in leachate beginning 52 and 66 d post-treatment, respectively. Leaching of both products was affected significantly by litter-humus treatment; by amount of applied rainwater, and for tebuthiuron, by site. The lack of a humus cover increased the amount of hexazinone at 150 cm by nearly threefold and tebuthiuron by nearly fivefold. The greatest leaching occurred after high applications of water and on the four sites with the lowest pH and base saturation. The combination of soil characteristics, litter-humus treatments, and applied precipitation provides reference values for worst-case conditions likely to be encountered in the Lake states region.
Aerobic biodegradation of cumene: An ecocore study
Authors: Williams Richard T. , Ziegenfuss P. Scott , Lee Christopher M.
Published: March 2010

A microcosm study was conducted to determine the mineralization and disappearance of cumene (isopropylbenzene) in an aerobic freshwater sediment/water test system. Ecocores (300 cm3) constructed of glass and Teflon® were filled with intact sediment cores and river water. [14C]-cumene was added to the water phase, and the ecocores were incubated in the dark at 23°C with periodic aeration. Volatile organics and CO2 released to the ecocore headspace were trapped in separate impingers. In one experiment, ecocores were sacrificed after 45 d of incubation, with removal by volatilization and biodegradation accounting for the majority of 14C initially added as cumene. In this experiment, cumene was mineralized to the extent of 47.2, 42.1, and 25.7% at cumene test concentrations of 2.5, 12.5, and 25 mg/L, respectively. In the second experiment the test concentration was 2.5 mg/L. Triplicate active ecocores and a poisoned control were sacrificed at days 1, 2, 3, 4, 5, 7, and 10. After 10 d, the mean extent of mineralization was 46.9%. The first-order mineralization rate constant at the test concentration of 2.5 mg/L was calculated to be 0.02 day−1 with a correlation coefficient (R2) of 0.83.
Humic acid effects on uptake of hexachlorobenzene and hexachlorobiphenyl by sheepshead minnows in static sediment/water systems
Authors: Lores Emile M. , Patrick James M. , Summers J. Kevin
Published: March 2010

The effect of humic acid on accumulation of hexachlorobenzene (HCB) and hexachlorobiphenyl (HCBP) by sheepshead minnows (Cyprinodon variegatus) from two separate experiments is presented. In the first experiment, static sediment/water exposure chambers were used to determine the effect of dissolved organic carbon (DOC), in the form of terrestrial humic acid (HA), on partitioning of HCB among sediment, water, and sheepshead minnows. Sediments from three geographically different locations were used to test the effect of added HA (0, 3, and 30 mg/L) on accumulation in fish of sediment-bound HCB. Total organic carbon levels in sediment and water and residues of HCB (14C-labeled and unlabeled) in sediment, water, and whole-body tissue were measured. Fish/sediment ratios or accumulation relative to sediment (ARS) indicated that addition of HA did not reduce accumulation of sediment-bound toxicants. ARS ranged from 7.5 ± 4 without added HA to 9.3 ± 4 with 30 mg/L added HA, but were not statistically different. In a second experiment using HCBP with 0 and 30 mg/L HA and sediment from one location, HCBP concentration in water averaged 0.29 μg/L in non-HA tanks, and 0.91 μg/L in the HA tanks, but both ARS ratios averaged 5.4. In conclusion, we believe that these tests indicate that HA does not significantly alter bioavailability of toxicants that are in equilibrium with sediment and water.
Intestinal absorption and biomagnification of organochlorines
Authors: Gobas Frank A.P.C. , McCorquodale Jim R. , Haffner G.D.
Published: March 2010

Dietary uptake rates of several organochlorines from diets with different lipid contents were measured in goldfish (Carassius auratus) to investigate the mechanism of intestinal absorption and biomagnification of organic chemicals. The results suggest that intestinal absorption is predominantly controlled by chemical diffusion rather than lipid cotransport. Data for chemical uptake in human infants are presented to illustrate that biomagnification is caused by the digestion of food in the gastrointestinal tract. The findings are discussed in the context of two conflicting theories for the mechanism of biomagnification, and a mechanistic model is presented for the dietary uptake and biomagnification of organic chemicals in fish and mammals.
Assessing sublethal levels of sediment contamination using the estuarine amphipod Leptocheirus plumulosus
Authors: McGee Beth L. , Schlekat Christian E. , Reinharz Eli
Published: March 2010

Recent emphasis on the incorporation of sublethal end points into sediment toxicity test methods follows the realization that acute lethality tests may not provide sufficient sensitivity for predicting subtle ecological effects of sediment contamination. To this end, a partial life-cycle test with the amphipod Leptocheirus plumulosus Shoemaker was evaluated for solid-phase testing of contaminated estuarine sediments. Initially, juvenile and adultLeptocheirus plumulosus and the amphipod Hyalella azteca were exposed to gradients of chemical contamination prepared by diluting field-collected contaminated sediment with texturally similar reference sediment. Ten-day exposure results indicate juvenile Leptocheirus plumulosus is more sensitive than adult Leptocheirus plumulosus and Hyalella azteca, with significant mortality of juvenile Leptocheirus plumulosus occurring in sediment diluted to 12.5% of the adult lowest-observed-effect concentration (LOEC). Long-term exposure (30 d) of juveniles to dilutions of the acute juvenile LOEC shows significant effects on growth in sediment concentrations below the lethal threshold. Effects on reproductive end points (proportion of gravid females, number of young) parallel growth effects. Evaluation of nontoxicant experimental variables indicates significant effects of temperature and feeding regime on sensitivity of juvenile Leptocheirus plumulosus to contaminated sediment.
Bioassay-directed fractionation of organic contaminants in an estuarine sediment using the new mutagenic bioassay, mutatox™
Authors: Ho Kay T.Y. , Quinn James G.
Published: March 2010

Bioassay-directed fractionation of organic compounds was performed on an organic solvent extract of a contaminated estuarine sediment from Black Rock Harbor, Connecticut, using the new mutagenic bioassay, Mutatox™. Chemical fractionation methods of the sediment extract included silica-gel-column chromatography (SGCC), followed by C18 reverse phase HPLC. Compound identification was performed using GC-MS. Mutatox analyses indicated that four of the eight HPLC fractions contained mutagenic or epigenetic compounds. GC-MS analyses detected known mutagenic polycyclic aromatic hydrocarbons (PAHs) in two of the four mutagenic fractions. GC-MS analyses of the other two mutagenic fractions (one operational blank and one sediment fraction) showed no known mutagenic compounds. SGCC and HPLC, combined with the Mutatox bioassay, were useful in reducing both the number and the complexity of fractions analyzed by GC-MS. The Mutatox bioassay is a promising tool for bioassay-directed fractionation.
Reproductive status and lipid content as factors in PCB, DDT and HCH contamination of a population of pike (Esox lucius L.)
Authors: Larsson Per , Okla Lennart , Collvin Lars
Published: March 2010

Levels of persistent pollutants, including PCBs, ΣDDT, and γ-hexachlorocyclohexane, were examined in a pike population inhabiting a eutrophic lake in southern Scandinavia. For females, levels of persistent pollutants decreased linearly with age, weight, or length. This decline was ascribed to the seasonal elimination of the lipophilic pollutants in roe, which contained up to 10 times higher fat levels compared to muscle and over 10 times the amounts of pollutants. Male pike contained higher levels of pollutants than females, probably due to the lower elimination via gonadal products, as germinal tissue constitutes only 2% of the male total body weight and has a lower fat content than ovaries. Female germinal tissue can account for as much as 15% of the body weight. No major fat deposits other than those in germinal tissue were found in pike, which also had a low muscle fat content, suggesting that the importance of roe elimination in removing pollutants may be greater in pike than in salmonids. Uptake of persistent pollutants can vary greatly within a species, owing to differences in sex, age, and so forth, as well as between species, owing to differences in fat deposition strategies.
Survival of bluegill and their behavioral responses during continuous and pulsed exposures to esfenvalerate, a pyrethroid insecticide
Authors: Little Edward E. , Dwyer F. James , Fairchild James F. , Delonay Aaron J. , Zajicejk James L.
Published: March 2010

Juvenile bluegill (Lepomis macrochirus) were exposed to the pyrethroid insecticide esfenvalerate [(S)-α-cyano-3-phenoxybenzyl-(S)-2-(4-chlorophenyl)-3-methyl butyrate], continuously for 90 d and for six 11-h pulses. No bluegill survived continuous exposure to esfenvalerate at 0.200 μg/L for 30 d or 0.100 μg/L for 60 d. The lowest-observable-effect concentration (LOEC) for survival in a 90-d continuous exposure of esfenvalerate was 0.025 μg/L. In comparison, no mortality occurred among fish exposed to pulsed doses of up to 0.200 μg/L. Behavioral responses, including gross body tremors, were highly sensitive indicators of toxicity among pulse-exposed fish, with symptoms appearing within 4 h of exposure to concentrations as low as 0.025 μg/L. Similar behavioral responses were observed after continuous exposure to 0.025 μg/L esfenvalerate. Behavioral responses were observed at concentrations an order of magnitude less than concentrations impacting growth or survival in simulated field studies. These results provide encouraging evidence that laboratory studies designed to simulate field exposure conditions can be predictive of concentrations causing mortality and other adverse effects.
Effect of primary productivity and vertical mixing on pcb dynamics in planktonic model ecosystems
Authors: Millard E.S. , Minns C.K. , Charlton C.C. , Halfon E.
Published: March 2010

Radiolabeled polychlorinated biphenyls (PCBs) [14C]-Aroclor 1242 were added to large planktonic model ecosystems. Two experiments were conducted to determine the influence of turbulent mixing and primary productivity on fate and transport of PCBs. High productivity increased the proportion of added PCBs that were adsorbed to particulate matter and sedimented. Retention of added PCBs within the model ecosystems increased the recovery in a budget of added PCBs. Volatilization losses increased at the high-mixing and low-productivity level. Highest recovery was with a high productivity-low mixing treatment. A third experiment was conducted in which PCBs adsorbed to clay were added to the hypolimnion of one model ecosystem. Results confirmed that PCBs unaccounted for in a budget of PCBs added to the epilimnion in the same manner were lost due to volatilization. A linear-fate model was developed to describe trends in PCB concentrations as well as fate of the added PCBs. Model parameters and predicted fate of added PCBs agreed closely with observed results. The model indicated that an unmeasured pool of particulate PCBs that were probably adsorbed to colloids and fine particulates was operationally measured with the soluble fraction.
Evaluation of five biocarriers as supports for immobilized bacteria: Comparative performance during high chemical loading, acid shocking, drying and heat shocking
Authors: Heitkamp Michael A. , Adams William J. , Camel Valérie
Published: March 2010

Immobilized bacteria technology (IBT) utilizes inert biocarriers to support high concentrations of chemical-degrading bacteria in reactors designed to provide optimal conditions for microbial activity. This study evaluated IBT performance in packed bed reactors (PBRs) using a porous inorganic biocarrier (diatomaceous earth), nonporous biocarriers (glass beads), and organic biocarriers having carbon adsorption properties (granular activated carbon) with different porosity. Each reactor was challenged with high chemical loading, acid, dryness, and heat shock conditions. Benchtop PBRs inoculated with ap-nitrophenol- (PNP)- degrading Pseudomonas sp. and fed a synthetic waste containing 100 to 1,300 mg/L of PNP showed removal of PNP from effluents within 24 h of start-up. Chemical loading studies showed maximum PNP removal rates of 6.45 to 7.35 kg/m3/d for bacteria in PBRs containing diatomaceous earth beads, glass beads, and activated coconut carbon. A lower PNP removal rate of 1.47 kg/m3/d was determined for the activated anthracite carbon, and this PBR responded more slowly to increases in chemical loading. The PBR containing bacteria immobilized on activated coconut carbon showed exceptional tolerance to acid shocking, drying, and heat shocking by maintaining PNP removal rates > 85% throughout the entire study. The other biocarriers showed nearly complete loss of PNP degradation during the perturbations (except for drying), but all recovered high rates of PNP degradation (> 98% removal) within 48 h after an acid shock at pH 2, within 8 d after an acid shock at pH 1.0, within 24 h after drying for 72 h, and within 48 h of heat shocking. The resiliency and high chemical removal efficiency demonstrated by immobilized bacteria in this study support the concept of using IBT for the biotreatment of industrial wastes.
Mercury and selenium in harbor porpoise (Phocoena phocoena) in norwegian waters
Authors: Teigen Sverre Weberg , Skaare Janneche Utne , Sand Gunhild , Bjørge Arne , Degre Eva
Published: March 2010

Concentrations of mercury and selenium have been determined in liver and kidney of 92 harbor porpoises (Phocoena phocoena) caught along the Norwegian coast. The hepatic and renal mercury concentrations ranged from 0.26 to 9.9 and 0.15 to 3.5 μg g−1, respectively, whereas the corresponding selenium concentrations ranged from 0.74 to 14.2 and 0.60 to 8.6 μg g−1, respectively. No significant differences in mean concentrations of mercury and selenium were found between females and males within the same age classes. However, the concentrations were positively correlated with age. The present results revealed a decreasing mercury concentration gradient from south to north along the Norwegian coast. In all age classes, a significant, positive correlation between the concentrations of mercury and selenium was found in both liver and kidney, the molar mercury-to-selenium ratio being 0.9660 and 0.2151, respectively. Implications of these findings for the biochemical and toxicological behavior of mercury and selenium in the harbor porpoise are considered.
Biotransformation of chlorinated aliphatic solvents in the presence of aromatic compounds under methanogenic conditions
Authors: Liang Li-Nuo , Grbić-Galić Dunja
Published: March 2010

Transformation of carbon tetrachloride (CT) and tetrachloroethylene (PCE) was studied under methanogenic conditions, in the presence or absence of toluene, ethylbenzene, phenol, and benzoate. Microbial inocula for the experiments were derived from three groundwater aquifers contaminated by jet fuel or creosote. CT and PCE were reductively dechlorinated in all the examined cases (CT to chloroform [CF]; PCE to trichloroethylene [TCE], trans-l,2-dichloroethylene [DCE], and vinyl chloride [VC]). In the aquifer microcosms, the electron donors used for the reductive transformations were most likely the unidentified organic compounds present on aquifer solids, or storage materials in microorganisms. Alternatively, molecular hydrogen from the anaerobic incubator atmosphere could have been used. The addition of benzoate caused a decrease in rates of dechlorination if benzoate was transformed. Phenol and ethylbenzene were not degraded and did not influence the transformation of CT or PCE. Toluene, in most of the studied cases, had no influence on reductive dechlorination of either CT or PCE. Only in microcosms derived from a JP-4 jet fuel-contaminated aquifer did the anaerobic degradation of toluene occur simultaneously with reductive dechlorination of PCE, suggesting that toluene might possibly have been used as an electron donor for reductive transformation of chlorinated solvents.
Defining and assessing ecological integrity: Beyond water quality
Authors: Karr James R.
Published: March 2010

Emphasis in environmental protection is shifting from primary attention to human health to a more balanced consideration of human and ecological health. This shift provides opportunities and challenges to the scientific community. For example, success depends on development of operational definitions of ecological health and programs to measure that health. Ecological health is inextricably tied to concepts such as biological diversity and biological integrity. Water chemistry and toxicity testing have dominated water-quality programs for decades. Success in protecting the ecological health of water resources depends on our ability to supplement those methods with ecologically robust approaches. Existing definitions and approaches for measuring the quality of water resources provide a template to guide development of procedures to assess ecological health. Critical components of successful monitoring programs should include evaluations relative to regional expectations, use multimetric indexes that reflect the multivariate nature of biological systems, and include index components (metrics) that evaluate conditions from individual, population, assemblage, and landscape perspectives.
Concentrations and deposition fluxes of polynuclear aromatic hydrocarbons and heavy metals in the dated sediments of a rural english lake
Authors: Sanders Gordon , Jones Kevin C. , Hamilton-Taylor John , Dorr Helmut
Published: March 2010

Deposition fluxes have been estimated from concentrations of 12 polynuclear aromatic hydrocarbons (PAHs) and six heavy metals measured in sediment cores from Esthwaite Water, a rural English lake. Atmospheric deposition is a major source of PAHs and heavy metals (Cd, Cu, Pb, and Zn) to the lake, so trends in the core may indicate the long-term record of changes in the atmospheric loading of these pollutants. The cores were dated radiometrically and pollutant trends studied since about 1820. PAH fluxes began to increase from stable background levels around the turn of the century (4.1 μg ΣPAH per gram dry weight, 287 ng ΣPAH per centimeter squared per year), rising to maximum inputs between 1950 and 1970 (42.0 μg/g, 2,954 ng/cm2 per year). The deposition flux of PAHs has decreased steadily since then and is now less than half the maximum (18.0 μg/g, 1,238 ng/cm2 per year). In recent sediments (1900-1970), the relative proportions of individual PAHs making up the ΣPAH burden have remained virtually unchanged, with fluoranthene, pyrene, and benzo[ghi]perylene the most abundant compounds. However, perylene, a biogenically produced PAH, dominates the mixture in the sediments older than 1890. Cadmium, Cu, Ni, Pb, and Zn concentrations in the Esthwaite sediments broadly follow the same temporal trends as the PAHs, with varying peak inputs between 1925 and 1975. Concentrations in the modern (surface) sediments are now lower than in recent decades, with ΣPAH, Cd, and Pb showing the greatest reduction. However, fluxes of these contaminants to surface sediments are still greater than those deposited before 1840.
LAS removal and biodegradation in a wastewater treatment plant
Authors: Cavalli L. , Gellera A. , Landone A.
Published: March 2010

Linear alkylbenzene sulfonate (LAS) biodegrades easily and loses its tensioactive properties quickly through a primary biodegradation process, as many works of literature testify. Many studies have been carried out in laboratories or in pilot plants, whereas few have been undertaken in a wastewater treatment plant (WWTP). In Italy, unlike in other countries, no detailed investigation has been made so far to establish LAS biodegradation in real WWTP conditions. EniChem Augusta (EA) and Consorzio Po-Sangone (CPS) have worked together for over two years on this problem, taking into consideration the large (flow rate: approximately 400 × 103 m3/d) and central active sludge WWTP of the metropolitan area of Torino, north of Italy. Specific LAS data have been obtained, using established HPLC techniques, in influent and effluent streams, in the dissolved (waters) and adsorbed (suspended solids and sludges) phases, to reach a complete mass balance. LAS removal >99% and LAS biodegradation of approximately 85% have been observed. Attention also has been given to LAS intermediates of biodegradation, namely the sulfophenyl carboxylates (SPC), using HPLC and GC-MS techniques, the latter after derivatization. The SPCs have been found present only in the waters and not in the adsorbed phases (SS and sludges).
Behavior and fate of surfactants in soil
Authors: Kuhnt Gerald
Published: March 2010

Although a growing number of investigations have dealt with selected aspects of the behavior of surfactants in soil and their effects on various soil properties, systematic approaches like those applied to pesticides or heavy metals are still rare. Considering that soil is exposed to a considerable quantity of surfactants, it would appear necessary to do more intensified research in this field. Based on a comprehensive review of the literature, the author briefly outlines the behavior and fate of surfactants in soil and presents a synopsis from the viewpoint of a pedologist. Even at low concentrations, surfactants seem to alter soil physics, soil chemistry, and soil biology significantly, whereby sorption processes play a dominant role. The report tries to integrate the most important research results in this field and to interpret them against the background of the complex structure of the soil system.
Persistence and degradation of [14C]atrazine and [14C]deisopropylatrazine as affected by soil depth and moisture conditions
Authors: Kruger Ellen L. , Somasundaram L. , Coats Joel R. , Kanwar Ramesh S.
Published: March 2010

The fate of atrazine and one of its degradation products deisopropylatrazine has been investigated using radiotracers under laboratory conditions. The metabolic route and rate were investigated under saturated and unsaturated conditions, with samples of soil taken from four depths down to 120 cm. The major degradation products identified from [14C]atrazine and [14C]deisopro-pylatrazine treatments were deethylatrazine and didealkylatrazine, respectively. The detected minor degradation products were hydroxyatrazine, deethylhydroxyatrazine, and deisopropylhydroxyatra-zine. Under unsaturated conditions atrazine and deisopropylatrazine were least persistent in the top 30 cm, and their persistence increased with increase in depth. The half-life of atrazine under unsaturated conditions increased with depth and ranged from 41 to 231 d for the studied depths, whereas the half-life of deisopropylatrazine ranged from 32 to 173 d. Deisopropylatrazine was more susceptible to mineralization than atrazine, and the amount of mineralization decreased with increase in depth. Bound residues were formed to a greater extent in surface soils. Under saturated conditions at the 90- to 120-cm depth, the half-life of atrazine was 87 d. Deisopropylatrazine was less persistent in saturated soil than in unsaturated soil at the 90- to 120-cm depth, with a half-life of 58 and 173 d, respectively. The increased degradability of deisopropylatrazine as compared with atrazine and the decreased persistence of deisopropylatrazine under saturated soil conditions provides a logical explanation for its relatively low concentrations in ground water as compared with atrazine.
Sources and impacts of irrigation drainwater contaminants in arid wetlands
Authors: Lemly A. Dennis , Finger Susan E. , Nelson Marcia K.
Published: March 2010

Arid wetlands are being contaminated by subsurface agricultural irrigation drainage throughout the western United States. Historic freshwater inflows have been diverted for agricultural and municipal use, and remaining freshwater supplies are not sufficient to maintain the integrity of these important natural areas once they are degraded by irrigation drainwater. Waterfowl populations are threatened in the Pacific and Central Flyways; migratory birds have been poisoned by drainwater contaminants on at least six national wildlife refuges. Subsurface irrigation drainage is the most widespread and biologically important source of contaminants to wetlands in arid regions of the country. The case history of poisoning at Kesterson National Wildlife Refuge in California and studies at other locations by the U.S. Department of the Interior provide detailed information on the toxicity of drainwater contaminants to fish and wildlife. Biogeochemical conditions favorable for the production of toxic drainage are found throughout the western states. Two actions seem necessary to prevent further drainage-related degradation of arid wetlands. First is a reduction in the amount of contaminants reaching these wetlands, possibly involving regulatory intervention through the National Pollutant Discharge Elimination System permit process. Second, a better balance must be achieved in the way fresh water is allocated between agriculture and wildlife. Federally subsidized water has supported agriculture at the expense of wetlands for nearly 100 years in the western United States. This trend must be reversed if arid wetlands and their fish and wildlife populations are to survive.
Salinity and temperature effects on chronic toxicity of 2,4-dinitrophenol and 4-nitrophenol to sheepshead minnows (Cyprinodon variegatus)
Authors: Linton Tyler Keith , Mayer Foster L. , Simon Tasha L. , Malone Janice A. , Marking Leif L.
Published: March 2010

Toxicity tests (28-d early-life-stage) were conducted to determine the effects of nine combinations of salinity (15, 20, 25 ppt) and temperature (22, 27, 32°C) on the toxicity of 2,4-dinitrophenol (2,4-DNP) and 4-nitrophenol (4-NP) to sheepshead minnows (Cyprinodon variegatus). The highest tested concentration having no observed effect (NOEC) on mortality and growth was derived weekly. The NOECs at test termination indicated that the survival and growth of fish exposed to 2,4-dinitrophenol were not significantly affected by salinity, temperature, or the salinity temperature interaction. However, 28-d NOECs of fish surviving from 4-nitrophenol exposures were significantly affected by temperature, but the highest value exceeded the lowest by only a factor of two. The overall data suggest that variations of salinity and temperature do not change the NOEC; only the exposure time required to attain the same NOEC is altered.
The toxicokinetic behavior of chlorobenzenes in earthworm (Eisenia andrei) experiments in soil
Authors: Belfroid Angélique , Sikkenk Marieke , Seinen Willem , Hermens Joop , van Gestel Kees
Published: March 2010

The toxicokinetic behavior of some chlorobenzenes in earthworms (Eisenia andrei) kept in soil was studied. To determine elimination kinetics, worms were exposed to chlorobenzenes for 7 d, followed by a depuration period of 15 or 35 d. Elimination of chlorobenzenes by earthworms kept in soil was best fitted using a bi-exponential elimination curve. The half-life belonging to the slow phase was in good agreement with measured elimination half-lives for the same compounds by earthworms kept in water. Accumulation of chlorobenzenes in earthworms was studied by exposure over 50 d. Equilibrium was rapidly achieved within 7 d. BAFs based on the concentration in soil and on the concentration in the interstitial water were calculated. BAFs of 1,2,3,4-tetrachlorobenzene and pentachlorobenzene in earthworms kept in soil and BCFs in earthworms kept in water were comparable, demonstrating that uptake proceeds mainly via the interstitial water. For hexachlorobenzene, the BAF was much larger than the BCF, which suggests that intestinal uptake for this compound is an important complementary route.
Chemical fate and transport in a domestic septic system: Unsaturated and saturated zone geochemistry
Authors: Wilhelm Sheryl R. , Schiff Sherry L. , Robertson William D
Published: March 2010

Monitoring the septic system at a single family home provides quantitative information on geochemical evolution of septic tank effluent along its travel path In both the unsaturated and saturated (groundwater) zones, microbiological and chemical reactions occur that bring the effluent closer to equilibrium with the subsurface conditions In the unsaturated zone, 90% of the DOC is removed from the effluent, mostly by aerobic oxidation, and NH+4 in the effluent is almost completely ox ldized to NO−3 As these reactions occur in the tile field, the oxygen content of the soil gas is partially depleted Calcite dissolution from the soils in the unsaturated zone buffers the acidity of the oxidation reactions and increases Ca2+ concentrations In the saturated zone, organic carbon oxidation in the effluent plume apparently decreases dissolved oxygen concentrations to <10 mg/L Potassium is retarded relative to other cations, and dissolved PO43 from the effluent is detectable in the ground water directly beneath the tile field but appears to be advancing very slowly, if at all, within the plume In addition NO3− concentrations remain above drinking-water standards (10 mg/L NO3 N) in the groundwater plume
Freshwater benthic algal population and community changes due to acidity and aluminum-acid mixtures in artificial streams
Authors: Genter Robert B. , Amyot Daniel J.
Published: March 2010

Communities of freshwater benthic algae were exposed to water acidified daily to pH 4.8 alone and in mixtures with 50, 100, or 500 μg L−1 Al. Daily acidification to nominal pH 4.8 in acidified treatments exposed algae to a range of pHs that led to a variety of Al species of different toxicity. Calcium concentrations in stream water were higher in acidified and Al treatments on day 1, and dissolved Al in stream water was higher in the highest Al treatment on days 1, 7, and 28; otherwise acid and Al treatments did not significantly alter Al and Ca in the exposure water. Calcium bioaccumulation by periphyton was lower in acidified and Al treatments on all sampling days. Concentrations of Mg in water and periphyton did not differ between treatments. The artificial stream system generated alkalinity to buffer acidified water; the amount of generated alkalinity returned to approximately the same levels for the first week, but the amount of alkalinity generated during the second week appeared to decline, and acid-only and acid-Al mixtures diverged in their ability to generate alkalinity during the third and fourth weeks. Aluminum in acidified water inhibited abundance of diatoms and green and blue-green algae more than the effects of acid stress alone. The green filamentous alga Mougeotia showed a slight (but not statistically significant) increase in abundance in the acid-only treatment. The middle-Al treatment (nominally 100 μg L−1 Al and acid) generated more alkalinity and had higher abundance of some algal taxa on days 14 and 28, even though measured Al concentrations in water and periphyton fell between low- and high-Al-treatment levels. Community-level tests, combining a taxonomic analysis of algal population abundance with chemical analysis of water and bioaccumulation, provide valuable insight to assess anthropogenic stress.
Model for uptake of xenobiotics into plants: Validation with bromacil experiments
Authors: Trapp Stefan , Matthies Michael , McFarlane Craig
Published: March 2010

This paper documents a conceptual model for the uptake of anthropogenic organic chemicals into plants. The model describes the dynamic uptake from soil, solution, or atmosphere, and the metabolism and accumulation of xenobiotic chemicals in roots, stems, leaves, and fruits. The goal was to develop an easy and rapid tool that would be numerically stable and require only a few well-known input data. The model is applicable to different plant species and most (nondissociating) organic chemicals. Processes considered are (a) diffusive exchange, soil/roots, and air/leaves; (b) mass flows in xylem and phloem; and (c) metabolism. The model is tested with laboratory studies on the uptake of the herbicide bromacil under various controlled conditions. No adjustments to the parameter values were required for successful simulations.
Biodehalogenation, reductive dehalogenation by Methanobacterium Thermoautotrophicum. Comparison with nickel(I)octaethylisobacteriochlorin anion. An F-430 model
Authors: Castro C.E. , Helvenston M.C. , Belser N.O.
Published: March 2010

The reductive dehalogenation of 1,1,2-tnchloroethane, chloroform, fluorotrichloromethane, carbon tetrachloride, 1,1,1-tnchloroethane, and ethylene dichlonde by Methanobactenum thermoautotrophicum occurs slowly at 60°C in the listed order. Vinyl chloride and chloroacetic acid are inert. The average t1/2 for nearly all substrates is approximately 100 h and varies by a factor of approximately two. In contrast, an active site model for factor F-430, Ni1octaethyhsobactenochlorin, brings about the same transformations with astonishing speed and vast differences in specific rates It is suggested that despite the enormous reducing capacity of this anaerobe, the overall reduction process is limited by permeation factors.
Organochlorine compounds in pine needles: Methods and trends
Authors: Strachan William M. J. , Kylin Henrik , Eriksson Göran , Jensen Soren
Published: March 2010

During April 1989, needles from Scotch pine (Pinus sylvestris) trees were collected from a network of stations in West Germany, Denmark, Norway, and Sweden. Samples from selected stations were analyzed for hexachlorobenzene (HCB), pen-tachlorophenol (PCP), hexachlorocyclohexane isomers (α-HCH and γ-HCH [lindane]), DDT, and DDE. Accumulation of the investigated compounds was observed in up to four needle-year classes. γ-HCH decreased from south to north; the pattern for α-HCH was uniform; DDT/DDE also decreased from south to north. HCB was uniform throughout the sample area, and PCP was high in northern Sweden. Interpretation of trends was not altered by expressing concentrations on a fresh- or dry-weight basis or on a surface-area basis. The range of concentration variation for equivalent samples was 2 to 49% relative standard deviation; averages were 20 to 23%. There were no differences among trees facing the same open direction; among different directions, trees open to the south collected more DDT, but this was not the case with other substances. There were no differences between trees of different ages. Samples at 4 to 5 m had lower contaminant levels than from 1.5 m.
Evaluation of peroxidase as a biochemical indicator of toxic chemical exposure in the aquatic plant Hydrilla Verticillata, Royle
Authors: Byl Tom D. , Sutton Heather D. , Klaine Stephen J.
Published: March 2010

Laboratory bioassays were conducted to determine the utility of peroxidase (POD) activity as a biochemical indicator of contaminant exposure in the aquatic plant Hydrilla verticillata, Royle. The plants were exposed to anthracene, sulfomet-uron methyl (Oust®), Cd2+, Cr6+, Cu2+, Mn2+, and Se4+ in concentration factors of 10. POD was extracted and measured by spectrophotometric assay. There was a significant increase in POD activity after a 5-d exposure to each of the chemicals at 1 mg/L. The optimum pH for POD activity after exposure to the chemicals was 5.5 to 6.0. The increase in POD was found to be dose dependent for each of the chemicals. The lowest concentration of chemical to induce a significant POD increase was 0.01 mg/L for anthracene, Oust, Cd, Cr, and Cu; 0.1 mg/L for Se; and 1.0 mg/L for Mn.
Toxicity of 2,3,7,8-tetrachlorodibenzo-P-dioxin to brook trout (lsalvelinus fontinalis) during early development
Authors: Walker Mary K. , Peterson Richard E.
Published: March 2010

The sensitivity of early life stages of brook trout (Salvelinus fontinalis) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxicity was investigated. Newly fertilized eggs were exposed for 48 h to water containing either acetone or a range of concentrations of [3H]TCDD dissolved in acetone. Eggs were then transferred to TCDD-free water and observed through development. TCDD concentrations of 101 to 470 pg/g in the eggs caused dose-related increases in sac-fry mortality associated with yolk-sac edema, hemorrhages, and arrested development. These signs of TCDD-induced toxicity resemble blue-sac disease. The NOELs and LOELs for sac-fry mortality were 135 and 185 pg TCDD/g egg, respectively, whereas the LD50 and LD100 (95% fiducial limits) were 200 (179-215) and 324 (283-488) pg/g egg, respectively. The time course and signs of TCDD toxicity to brook trout during early development are essentially identical to those observed in both rainbow trout and lake trout following TCDD exposure of their eggs via water or injection, and in lake trout exposed to maternally derived TCDD. Brook trout sac fry are intermediate in sensitivity to TCDD-induced lethality compared to lake trout and rainbow trout.
Evaluation of heavy-metal ion toxicity in fish cells using a combined stress protein and cytotoxicity assay
Authors: Ryan John A. , Hightower Lawrence E.
Published: March 2010

All organisms, from bacteria and yeast to humans, respond to physical and chemical stressors by increasing the synthesis of a small group of ‘cellular stress proteins.’ We have developed a simple in vitro system for quickly screening environmentally relevant stressors to detect stress-induced proteins that are good candidates for biomarkers. Polyacrylamide gel electrophoresis was used to detect stressor-induced, concentration-dependent changes in cellular stress protein levels in two fish cell culture systems, whereas simultaneous in vitro neutral red uptake cytotoxicity assays measured the stressor's effect on cellular physiology. There was a direct concentration-dependent relationship between sublethal cytotoxic effects and the increases in stress protein levels. Increases of 50 to 200% were detected in stress proteins from desert topminnow, Poeciliopsis lucida, hepatoma-derived cell cultures exposed to cadmium (six proteins) or copper (four proteins). Three proteins showed similar increases in winter flounder, Pleuronectes americanus, kidney cell cultures exposed to the same stressors. Increases in the evolutionarily conserved heat-shock protein hsp70 were detected in each experiment; its level increased with increasing stressor concentrations.
Influence of species and sex on metal residues in freshwater mussels (family unionidae) from the St. Lawrence river, with implications for biomonitoring programs
Authors: Metcalfe-Smith Janice L.
Published: March 2010

The implementation of freshwater mussel watch programs has been hindered by a lack of information on biological factors affecting the levels of contaminants accumulated by these organisms. This study investigated the influence of species and sex on metal residues in Elliptio complanata and Lampsilis radiata radiata (Family Unionidae) from the St. Lawrence River. Mussels were collected from sites representing a wide range of types and degrees of metal pollution. Composite samples of five specimens (males and females combined) per species per site and five specimens per sex per species per site were analyzed for residues of 12 metals in the soft tissues to determine the effects of species and sex, respectively, on variability in the data. Interspecific differences in bioaccumulation were observed for most metals; however, concentrations were frequently correlated between species and the differences could therefore be quantified. Elliptio complanata demonstrated a broader response range to the same exposures than Lampsilis radiata radiata for most metals, suggesting that it may be more sensitive to changes in pollution status. Differences in metal uptake between the sexes were less pronounced than differences between species, and male specimens displayed less variability than females. Consideration of these factors in mussel biomonitoring programs should greatly improve sensitivity and precision.
Effects of different food doses on cadmium toxicity to Daphnia magna
Authors: Kluttgen Birgit , Ratte Hans Toni
Published: March 2010

Chronic toxicity tests were conducted with Daphnia magna using cadmium concentrations of 0, 0 5, 1, 2, and 5 μg/L Cd with algae doses of 0 8, 4, 8, and 16 106 cells/d of Chlorella saccharophila for each In this way we were able to determine the effects of cadmium on the life table data of individuals, under different nutritional conditions The development of juvemles was found to be inhibited by cadmium at low food doses, whereas body length and reproduction were strongly affected at higher food levels The molting interval of adults and the development rate of embryos proved to be unaffected by cadmium Cadmium stressed animals lived longer than did the unstressed controls The intrinsic rate of natural increase was generally reduced by cadmium, independent of the food dose