bluuebunny/crossref_metadata_2025 huggingface dataset:
A comparison of stream biological responses to discharge from wastewater treatment plants in high and low population density areas
Authors: Dyer Scott D. , Wang Xinhao
Published: March 2010

The ultimate purpose of this study was to identify broad relationships that may have relevance for the risk assessment of chemicals and materials that are discharged to receiving streams via municipal wastewater treatment plant (WWTP) effluents (e.g., consumer product ingredients). The effects of municipal wastewaters occurring in high population density (>500 persons per square mile, urban) and low population density (<500 persons per square mile, rural) environments were determined via analysis of biological, habitat, and water chemistry data collected both immediately upstream and downstream of 221 WWTPs in Ohio, USA. Several biological and chemistry indicators demonstrated poorer water quality in urban areas compared to rural areas. After considering the effect of river size, adverse effects downstream of WWTPs for both fish and macroinvertebrate communities were clearly identified for only urban areas. These data indicate that WWTP potency may be greater in urban areas compared to rural areas.
Modification of an ecotoxicological rating to bioassess small acid mine drainage-impacted watersheds exclusive of benthic macroinvertebrate analysis
Authors: Schmidt Travis S. , Soucek David J. , Cherry Donald S.
Published: March 2010

The modified ecotoxicological rating (METR) approach to synthesizing integrative bioassessment data into a single number ranging from 0 to 100 was found to differentiate between multiple levels of impacts from acid mine drainage (AMD). Our objective was to develop a more cost-effective and time-efficient bioassessment technique than previously used in other large scale ecotoxicological ratings (ETRs) by minimizing the number of parameters required to rank stations to only those most descriptive of the benthic macroinvertebrate community responses to AMD. Nineteen physical, chemical, toxicological, and ecological measurements were made at 38 stations in two adjacent watersheds. The most descriptive parameters were selected through multiple linear regression analysis, bivariate correlation analysis, and one-way analysis of variance. We found that habitat assessment, 30-d in situ Asian clam survival, mean conductivity, and mean total water column concentration of aluminum and manganese were the most descriptive parameters. The METR constructed from these parameters was equally effective at differentiating stations as were two previous published ETRs that incorporated up to 10 parameters, including benthic macroinvertebrate indices. When the METR was applied to a new watershed, the scores were significantly correlated with benthic macroinvertebrate indices for those stations.
Determining probable causes of ecological impairment in the Little Scioto River, Ohio, USA: Part 1. Listing candidate causes and analyzing evidence
Authors: Norton Susan B. , Cormier Susan M. , Suter Glenn W. , Subramanian Bhagya , Lin Edith , Altfater David , Counts Bernie
Published: March 2010

The Little Scioto River in north-central Ohio, USA, is considered to be biologically impaired based on the results of fish and invertebrate surveys. The causes for these impairments were evaluated by means of a formal method. Two of the impairments identified on the stream reach were characterized in detail to support the causal assessment. A list of six candidate causes was developed that included habitat alteration, polycyclic aromatic hydrocarbon contamination, metals contamination, low dissolved oxygen, ammonia toxicity, and nutrient enrichment. Evidence for the causal evaluation was developed with data from the site that associated each candidate cause with the biological responses. Evidence was also developed that drew on data from other locations and laboratory studies, including comparisons of site exposures with screening values and criteria. The formal method increased the transparency of the assessment; candidate causes were clearly listed and the pathways by which they may have produced effects were shown. Analysis of the evidence maximized the utility of available data, which were collected as part of monitoring and research programs rather than to specifically support a causal assessment. This case study illustrates how the stressor identification method can be used to draw conclusions from available data about the most likely causes of impairment and to show what additional studies would be useful.
Assessing relationships between human land uses and the decline of native mussels, fish, and macroinvertebrates in the Clinch and Powell river watershed, USA
Authors: Diamond Jerome M. , Bressler David W. , Serveiss Victor B.
Published: March 2010

The fee-flowing Clinch and Powell watershed in Virginia, USA, harbors a high number of endemic mussel and fish species but they are declining or going extinct at an alarming rate. To prioritize resource management strategies with respect to these fauna, a geographical information system was developed and various statistical approaches were used to relate human land uses with available fish, macroinvertebrate, and native mussel assemblage data. Both the Ephemeroptera, Plecoptera, Trichoptera (EPT) family-level index, and the fish index of biotic integrity (IBI) were lowest in a subwatershed with the greatest coal mining activity (analysis of variance [ANOVA], p < 0.05). Limited analyses in two other subwatersheds suggested that urban and agricultural land uses within a specified riparian corridor were more related to mussel species richness and fish IBI than land uses in entire catchments. Based on land uses within a riparian corridor of 200 m × 2 km for each biological site in the watershed, fish IBI was inversely related to percent cropland and urban area and positively related to pasture area (stepwise multiple regression, R2 = 0.55, p < 0.05). Sites less than 2 km downstream of urban areas, major highways, or coal mine activities had a significantly lower mean IBI value than those more than 2 km away (ANOVA, p < .05). Land use effects included poorer instream cover and higher substrate embeddedness (t test, p < 0.05). Weaker land use relationships were observed for EPT and mussel species richness. Episodic spills of toxic materials, originating from transportation corridors, mines, and industrial facilities, also have resulted in local extirpations of native species, particularly mussels. The number of co-occurring human activities was directly related to stream elevation in the Clinch River, with more human land uses in headwater areas. Approximately 60% of known U.S. Fish and Wildlife mussel concentration sites in the watershed are located within 2 km of at least two land use sources identified as potentially stressful in our analyses. Our results indicate that a number of land uses and stressors are probably responsible for the decline in native species. However, protection of naturally vegetated riparian corridors may help mitigate some of these effects.
Fate of tributyltin in a created tidal wetland
Authors: Anderson Britt-Anne , Unger Michael A. , Moore Kenneth A.
Published: March 2010

The ability of Spartina alterniflora to degrade tributyltin (TBT) in contaminated dredge spoils was investigated in a created wetland at Little Creek Naval Amphibious Base in Norfolk, Virginia, USA. Concentrations of TBT up to 250 ng/g did not inhibit S. alterniflora growth over a 16-month period. Disappearance rates of TBT in vegetated and unvegetated treatments were similar, with half-lives of 300 to 330 d. Disappearance rates were not constant, but they were correlated to temperature changes and were possibly due to microbial degradation within the sediment. Of the initial amount of TBT in the sediment, only 0.4% accumulated in S. alterniflora biomass. Uptake of TBT by S. alterniflora was greatest in belowground biomass (43 ng/g). During plant senescence, most of the TBT was retained in the detrital material. Whereas S. alterniflora did not expedite the degradation of TBT, using TBT-contaminated dredge spoils to create wetlands is plausible. However, this should only be undertaken after further investigation into the potential for plant biomass to become a biovector for TBT.
Bioavailability of metals to the amphipodMonoporeia affinis: Interactions with authigenic sulfides in urban brackish-water and freshwater sediments
Authors: Wiklund Ann-Kristin Eriksson , Sundelin Brita
Published: March 2010

Could reduced eutrophication be a potential environmental threat because of increased mobility and bioavailability of trace metals? This question was addressed by oxygenating intact sediment cores, varying in redox potential and salinity, in a test system containing the amphipod Monoporeia affinis. Results show a low mobility of metals during oxygenation, and despite high concentrations of metals in sediments, only Pb showed a notable degree of bioaccumulation. Cadmium was bioaccumulated particularly in freshwater sediment, and body burden of Cd was related to salinity, porewater, and sediment concentrations. Despite high sediment and porewater concentrations of Cu and Zn, no relationship was recorded to body burden. For three of four tested metals, Cd, Pb, and Zn, metals in sediment were more important for body burdens in amphipods as compared to metals in porewater. Food, rather than interstitial water, therefore seems to be the main route of metal contaminants to these amphipods. Furthermore, this observed low release of metals from sediments and low body burden significance of porewater metals indicate that ameliorated oxygen conditions in contaminated sediments may be regarded as a minor environmental threat for one of the most important Baltic benthic organisms.
Purification and identification of a tributyltin-binding protein from serum of Japanese flounder,Paralichthys olivaceus
Authors: Shimasaki Yohei , Oshima Yuji , Yokota Yoshiko , Kitano Takeshi , Nakao Miki , Kawabata Shun-ichiro , Imada Nobuyoshi , Honjo Tsuneo
Published: March 2010

Tributyltin (TBT) is an industrial chemical used as an antifoulant in marine environments. Previously, we reported that TBT accumulates in the serum or plasma of some fishes and is bound to a high molecular weight compound in the serum of the Japanese flounder, Paralichthys olivaceus. In this study, we succeeded in purifying the TBT-binding protein (TBT-bp) from the serum of Japanese flounder by using gel filtration chromatography, anion exchange chromatography, and polyacrylamide gel electrophoresis, with a 2.6% yield and a 77-fold purification. The molecular mass of TBT-bp was approximately 46.5 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its isoelectric point was approximately 3.0 on isoelectric focusing-polyacrylamide gel electrophoresis. The TBT-bp contained 42% N-glycan. The cDNA nucleotide sequence of TBT-bp was determined by reverse transcription-polymerase chain reaction of Japanese flounder liver, and we deduced a sequence of 191 amino acids of mature TBT-bp. No sequence identical to the TBT-bp amino acid sequence was found within the SWISS-PROT (http://www.nig.ac.jp/) protein database; however, a lipocalin-like sequence pattern was observed. We concluded that the TBT-bp was a novel protein that has not yet been reported, although some DNA sequences from expressed sequence tags (ESTs) of Japanese flounder liver had a high identity. A high expression level of TBT-bp gene was found in the liver, but the gene was slightly detectable in the kidney and brain.
A framework for prioritizing fragrance materials for aquatic risk assessment
Authors: Salvito Daniel T. , Senna Ronald J. , Federle Thomas W.
Published: March 2010

More than 2,100 chemically defined organic chemicals are listed in the Research Institute of Fragrance Materials/Flavor and Extract Manufacturers' Association (RIFM/FEMA) Database that are used as ingredients of fragrances for consumer products. An approach was developed for prioritizing these fragrance materials for aquatic risk assessment by first estimating the predicted environmental concentration (PEC) of these fragrance materials in the aquatic environment based upon their physicochemical properties and annual volume of use. Subsequently, an effect level was predicted with a general quantitative structure—activity relationship (QSAR) for aquatic toxicity, and a predicted no-effect concentration (PNEC) was calculated from this effect level by using an assessment factor (AF) that accounts for uncertainty in the toxicity QSAR prediction. A conservative AF of 106 was applied to the endpoint predicted by the QSAR to provide an adequate margin of safety in the calculation of the PNEC. The PEC was compared to the PNEC to characterize the risk to freshwater aquatic organisms (e.g., Daphnia magna and Pimephales promelas). If the ratio of PEC to PNEC was below one, the material was considered to have negligible environmental risk and to be acceptable for the aquatic environment at current use levels. If this ratio exceeded one, the PNEC was refined by using more specific QSAR models (Ecological Structure—Activity Relationships [ECOSAR]). If the ratio continued to exceed one, the material became a candidate for further aquatic risk assessment procedures, which involve iterative steps to refine the PEC, the PNEC, or both by using measured ecotoxicological endpoints. Prioritization for this latter process can be based upon the magnitudes of the estimated PEC:PNEC ratios. When using the first tier of this approach, only 568 of 2,141 fragrance materials (26.5%) in the RIFM/FEMA Database had PEC:PNEC ratios greater than one. This percentage decreased to only 164 materials (7.7%) when PNECs were derived with ECOSAR. Comparison of predicted PECs and PNECs with those based upon measured data confirmed the conservatism and low risk for type I errors associated with the framework. These combined exercises demonstrated the ability of this highly precautionary risk-based screening approach to quickly prioritize a large number of materials without benefit of experimental ecotoxicological or fate data.
Fate and effects of triclosan in activated sludge
Authors: Federle Thomas W. , Kaiser Sandra K. , Nuck Barbara A.
Published: March 2010

Triclosan (TCS; 5-chloro-2-[2,4-dichloro-phenoxy]-phenol) is a widely used antimicrobial agent. To understand its fate during sewage treatment, the biodegradation and removal of TCS were determined in activated sludge. In addition, the effects of TCS on treatment processes were assessed. Fate was determined by examining the biodegradation and removal of TCS radiolabeled with 14C in the 2,4-dichlorphenoxy ring in laboratory batch mineralization experiments and bench-top continuous activated-sludge (CAS) systems. In batch experiments with unacclimated sludge, TCS was mineralized to 14CO2, but the total yield varied as a function of test concentration. Systems that were redosed with TCS exhibited more extensive and faster mineralization, indicating that adaptation was a critical factor determining the rate and extent of biodegradation. In a CAS study in which the influent level of TCS was incrementally increased from 40 μg/L to 2,000 μg/L, removal of the parent compound exceeded 98.5% and removal of total radioactivity (parent and metabolites) exceeded 85%. Between 1.5 and 4.5% of TCS in the influent was sorbed to the wasted solids, whereas >94% underwent primary biodegradation and 81 to 92% was mineralized to CO2 or incorporated in biomass. Increasing levels of TCS in the influent had no major adverse effects on any wastewater treatment process, including chemical oxygen demand, biological oxygen demand, and ammonia removal. In a subsequent experiment, a CAS system, acclimated to TCS at 35 μg/L, received two separate 4-h shock loads of 750 μg/L TCS. Neither removal of TCS nor treatment processes exhibited major adverse effects. An additional CAS study was conducted to examine the removal of a low level (10 μg/L) of TCS. Removal of parent equaled 94.7%, and biodegradation remained the dominant removal mechanism. A subsequent series of CAS experiments examined removal at four influent concentrations (7.5, 11, 20, and 50 μg/L) of TCS and demonstrated that removal of parent ranged from 98.2 to 99.3% and was independent of concentration. Although TCS removal across all experiments appeared unrelated to influent concentration, removal was significantly correlated (r2 = 0.87) with chemical oxygen demand removal, indicating that TCS removal was related to overall treatment efficiency of specific CAS units. In conclusion, the experiments show that TCS is extensively biodegraded and removed in activated-sludge systems and is unlikely to upset sewage treatment processes at levels expected in household and manufacturing wastewaters.
Organochlorine concentrations in the saimaa ringed seal (Phoca hispida saimensis) from Lake Haukivesi, Finland, 1981 to 2000, and in its diet today
Authors: Kostamo Auli , Hyvärinen Heikki , Pellinen Jukka , Kukkonen Jussi V. K.
Published: March 2010

Organochlorine and mercury (Hg) pollution has been one possible reason for a decline in the size of the population of the Saimaa ringed seal (Phoca hispida saimensis) in Lake Haukivesi, Finland. In this study, we analyzed changes in the concentrations of organochlorine compounds (OCls) and extractable organic halogen (EOX) in the blubber of Saimaa ringed seals that died from 1981 to 2000. In addition, the present concentrations and biomagnification factors of OCls and Hg from the main prey fish of ringed seal and pike (Esox lucius) were determined. Concentrations of pollutants in bream (Abramis brama) also were analyzed. The decline in the OCl concentrations in blubber was, on average, 25% during the two decades since polychlorinated biphenyls and DDT compounds were banned. Today, concentrations in blubber of Saimaa ringed seals are similar of those in ringed seals from the Arctic. Correspondingly in fish, the OCl and Hg concentrations were, on average, similar to those found in other studies on Finnish and Arctic areas. The low diet concentrations and metabolism of OCls also reflect the lower age correlation of OCls in the male ringed seals in the 1990s than in the 1980s. Biomagnification was considerably higher from fish to the ringed seal than from prey fish to pike because of higher feeding rate of ringed seals and differences in the metabolisms of these animals.
Modeling sorption isotherms of volatile organic chemical mixtures in model and natural solids
Authors: Li Jun , Werth Charles J.
Published: March 2010

Parameters from single-component isotherm models were used in multicomponent isotherm models to predict the aqueous phase sorption of trichloroethylene (TCE) in the presence of tetrachloroethylene (PCE) in four zeolites, Tenax, and three natural solids. The Langmuir, the Polanyi-Dubinin, and the Freundlich or the Langmuir-Freundlich isotherm models were used to simulate single-component sorption in zeolites. The Langmuir two-site, the Polanyi-Dubinin two-site, and the Freundlich or the Langmuir-Freundlich isotherm models were used to simulate single-component sorption in Tenax and natural solids. Two-site models have been used previously to model sorption in soils and sediments, and they combine an adsorption component (e.g., Langmuir) with a linear partitioning component. By using parameters from the different single-component isotherm models, the multicomponent Langmuir, the ideal adsorbed solution theory, and the Polanyi theory were each used to predict multicomponent sorption. In general, the ability to predict TCE sorption in the presence of PCE depended more on the choice of the single-component model than the multicomponent model, and better results were obtained when the Freundlich or the Langmuir-Freundlich isotherm was used for single-component sorption. This suggests that the more mechanistically based Langmuir and Polanyi-type models may not adequately describe the distribution of adsorption sites in some model and natural solids. The Freundlich or the Langmuir-Freundlich model, although empirical, has greater flexibility in characterizing sorbent heterogeneity and results in better multicomponent model predictions. However, this last statement is tenuous, because more solids must be tested against various model combinations.
Adsorption behavior of toxic tributyltin to clay-rich sediments under various environmental conditions
Authors: Hoch Marion , Alonso-Azcarate Jacinto , Lischick Martin
Published: March 2010

The adsorption and desorption behavior of tributyltin (TBT) from aqueous solution to clay-rich sediments was studied under various conditions (pH, salinity) using the batch technique. Sediments containing illite, kaolinite, and montmorillonite in different proportions were used as sorbent materials. Several physicochemical parameters of the sediments (e.g., Brunauer-Emmett-Teller [BET] surface area, cation exchange capacity [CEC], total organic carbon [TOC]) were evaluated to assess the influence of sediment characteristics to the adsorption capacity for TBT. Adsorption isotherms were linear over the concentration range of 100 to 1,000 ng(Sn)/ml. The adsorption coefficient (Kd) values range from 29 to 70 at the pH value generally found in marine systems (pH 8). The adsorption capacity shows a maximum in the range of pH 6 and 7. Salinity is also an important factor in controlling TBT adsorption. The strongest adsorption was observed at salinity of 0‰, and it strongly decreases with increasing salinity. The adsorption mechanism is controlled by the properties of the clay minerals as well as the aquatic chemistry of TBT. Desorption takes place over the studied pH range (4–8) when contaminated samples interact with TBT-free water at given experimental conditions.
Resistance to cadmium and parasite infection are inversely related in two strains of a freshwater gastropod
Authors: Salice Christopher J. , Roesijadi Guritno
Published: March 2010

Phenotypes that are either resistant or susceptible to infection by the trematode parasite Schistosoma mansont exist in the tropical freshwater snail Biomphalaria glabrata. We tested the hypothesis that a cost of parasite resistance in B. glabrata is greater sensitivity to cadmium toxicity, using parasite-resistant and parasite-susceptible strains exposed to cadmium in the laboratory. Survival analysis showed that time to death for cadmium was significantly shorter in eggs, juveniles, and adults of the parasite-resistant BS90 strain in comparison with the parasite-susceptible NMRI strain. Cadmium exposure increased time to hatch in both strains, but the effect was greater in BS90. Percentage hatch decreased with increased cadmium; BS90 was again more sensitive than NMRI. Comparison of the median effective concentration (EC50) for hatching and median lethal concentrations (LC50s) for survival of juveniles and adults showed that the order for cadmium resistance was adults > juveniles > eggs in NMRI and adults > eggs > juveniles in BS90. Cadmium resistance of F1 and F2 progeny of BS90/NMRI crosses was intermediate to that of parental strains. Numerical estimates indicated that a single genetic factor was responsible for the difference in cadmium resistance in the two strains. These findings were consistent with the hypothesis that greater sensitivity to cadmium is a cost of resisting parasitic infection.
A field validation of two sediment-amphipod toxicity tests
Authors: Perraro Steven P. , Cole Faith A.
Published: March 2010

A field validation study of two sediment-amphipod toxicity tests was conducted using sediment samples collected subtidally in the vicinity of a polycyclic aromatic hydrocarbon (PAH)-contaminated Superfund site in Elliott Bay (WA, USA). Sediment samples were collected at 30 stations with a 0.1 m2 grab from which subsamples were taken for sediment toxicity testing and geochemical and macrofaunal analyses. Standard 10-d sediment-amphipod toxicity tests were conducted with Rhepoxynius abronius and Leptocheirus plumulosus. Sediments were analyzed for 33 PAHs, pentachlorophenol, polychlorinated biphenyls, acid-volatile sulfide, simultaneously extracted metals (Cd, Cu, Zn, Pb, Ni), total organic carbon, and grain size. Sediment temperature, oxygen-reduction potential, water depth, and interstitial water salinity were also measured. Polycyclic aromatic hydrocarbons, quantified as total PAH toxic units (TUPAH), were confirmed to be an important common causal agent of the changes in the two toxicity test (% survival R. abronius, % survival L. plumulosus) and five macrofaunal community (number of species, S; numerical abundance, A; total biomass, B; Swartz's dominance index, SDI; Brillouin's index, H) endpoints. Two other macrofaunal community metrics (the complement of Simpson's index, 1 — SI, and McIntosh's index, MI) were less sensitive to TUPAH than the two toxicity test endpoints. The sensitivities of R. abronius and L. plumulosus to TUPAH were statistically indistinguishable. Field validations were conducted by testing the association between or among each toxicity test endpoint, each of seven macrofaunal community metrics (S, A, B, SDI, H, 1 — SI, MI), and TUPAH by (1) Spearman's coefficient of rank correlation, (2) Kendall's coefficient of concordance, (3) G tests of independence, and (4) regression analysis. Some field validations based on multivariable tests of association (e.g., points 2 and 3) among toxicity test, field, and stressor endpoints produced false positive results. Both toxicity test endpoints were validated as indicators of changes in S, A, SDI, and H by all the methods tested. The resolution power of the relationships between the laboratory toxicity test and macrofaunal field endpoints was low (⩽ three classes) but sufficient to discriminate ecologically important effects. We conclude that standard sediment-amphipod toxicity tests are ecologically relevant and that, under the proper conditions, their results can be used for lab-to-field extrapolation.
Hydrocarbon composition and toxicity of sediments following theExxon valdezoil spill in Prince William Sound, Alaska, USA
Authors: Page David S. , Boehm Paul D. , Stubblefield William A. , Parker Keith R. , Gilfillan Edward S. , Neff Jerry M. , Maki Alan W.
Published: March 2010

An 11-year study of the 1989 Exxon Valdez oil spill found that spill residues on the oiled shorelines rapidly lost toxicity through weathering. After 1990, toxicity of sediments remained at only a few heavily oiled, isolated locations in Prince William Sound (AK, USA), as measured by a standard amphipod bioassay using Rhepoxynius abronius. Data from 648 sediment samples taken during the 1990 to 1993 period were statistically analyzed to determine the relationship between the total concentration of 39 parent and methyl-substituted polycyclic aromatic hydrocarbons (defined as total polycyclic aromatic hydrocarbons [TPAH]) and amphipod mortality and the effect of oil weathering on toxicity. A logistic regression model yielded estimates of the lower threshold, LC10 (lethal concentration to 10% of the population), and LC50 (median lethal concentration) values of 2,600, 4,100, and 10,750 ng/g TPAH (dry wt), respectively. Estimates of the threshold and LC50 values in this field study relate well to corresponding sediment quality guideline (SQG) values reported in the literature. For sediment TPAH concentrations >2,600 ng/g, samples with high mortality values (>90%) had relatively high fractions of naphthalenes and those with low mortality (<20%) had relatively high fractions of chrysenes. By 1999, the median sediment TPAH concentration of 117 ng/g for the post-1989 worst-case sites studied were well below the 2,600 ng/g toxicity threshold value, confirming the lack of potential for long-term toxic effects. Analysis of biological community structure parameters for sediment samples taken concurrently found that species richness and Shannon diversity decreased with increasing TPAH above the 2,600 ng/g threshold, demonstrating a correspondence between sediment bioassay results and biological community effects in the field. The low probability of exposure to toxic concentrations of weathered spill residues at the worst-case sites sampled in this study is consistent with the rapid overall recovery of shoreline biota observed in 1990 to 1991.
An assessment of in vitro androgenic activity and the identification of environmental androgens in United Kingdom estuaries
Authors: Thomas Kevin V. , Hurst Mark R. , Matthiessen Peter , McHugh Mathew , Smith Andy , Waldock Michael J.
Published: March 2010

Environmental androgens are a group of compounds that to date have received very little attention. In this study, a yeast-based androgen screen (YAS) was used to determine the level of in vitro androgenic activity in seven United Kingdom estuaries. Surface water, sediment pore water, and sediment particulate material solvent extracts collected from Southampton Water, the Thames, Mersey, Tees, Tyne, Clyde, and Forth were tested for in vitro androgenic activity. Eleven of the 41 surface water samples collected displayed androgenic activity >2 ng dihydrotestosterone (DHT) equivalents/L (3–9 ng DHT/L), while eight of the 39 sediment pore waters collected showed activity >45 ng DHT/L (51–187 ng DHT/L). High levels of androgenic activity were determined in the solvent extracts of sediments, with 10 of 39 samples exhibiting a level of androgenic activity >454 ng DHT/kg (1,020-15,300 ng DHT/kg). In vitro YAS testing of five selected sewage treatment works (STW) effluents entering these estuaries showed that measurable levels (34–635 ng DHT/L) of androgenic activity were observed in those receiving only primary treatment (Howdon STW and Irvine Valley Sewer) at the time of the survey. A toxicity identification evaluation (TIE) study of Irvine Valley Sewer effluent using the YAS assay was used to identify the natural steroids/steroid metabolites dehydrotestosterone, androstenedione, androstanedione, 5β-androstane-3α, 11β-diol-17-one, androsterone, and epi-androsterone as responsible for 99% of the in vitro activity determined in the effluent.
Application of postexposure feeding depression bioassays withDaphnia magnafor assessment of toxic effluents in rivers
Authors: McWilliam Ruth A. , Baird Donald J.
Published: March 2010

A bioassay that used postexposure feeding depression in Daphnia magna Straus as an endpoint previously had been developed under laboratory conditions. Laboratory studies revealed that this was a sensitive, robust endpoint, which could potentially be used in an in situ bioassay. This study adapted the laboratory bioassay for use in the field and deployed D. magna in situ at four known or suspected contaminated and reference sites. The bioassay was demonstrated to be reliable for use in the field because more than 90% of test organisms were recovered live from the test chambers after exposure allowing feeding rates to be measured after exposure. At each of the contaminated sites, significant depressions in postexposure feeding rates were recorded. Although depressions in postexposure feeding rates were apparent at all contaminated sites, with the exception of Langholm, no impacts were detected on the benthic macroinvertebrate community, when using the Biological Monitoring Working Party scoring system. This demonstrated that during this study, post-exposure feeding depression was a more reliable and sensitive endpoint to use to detect toxicity than were changes in community structure. Therefore, the postexposure feeding depression bioassay can offer a sensitive, robust, ecologically relevant diagnostic endpoint for use in water-quality assessment schemes.
Comparison of pesticide root zone model 3.12: Leaching predictions with field data
Authors: Russell Mark H. , Jones Russell L.
Published: March 2010

As part of a process to improve confidence in the results of regulatory modeling, predictions of the pesticide root zone model (PRZM) 3.12 were compared with measured data collected in nine different field leaching studies. Reasonable estimates of leaching were obtained with PRZM 3.12 in homogeneous soils where preferential flow is not significant. The PRZM 3.12 usually did a good job of predicting movement of bromide in soil (soil and soil pore-water concentrations were generally within a factor of two of predicted values). For simulations based on the best choices for input parameters, predictions of soil pore-water concentrations for pesticides were usually within a factor of three and soil pore-water estimates within a factor of 11. When the model input parameters were calibrated to improve the simulation of hydrology, predicted pesticide concentrations in soil pore water were usually within a factor of two of measured concentrations. Because of the sensitivity of leaching to degradation rate, the most accurate predictions were obtained with pesticides with relatively slow degradation rates. When conservative assumptions were used to define input pesticide parameters, predictions of pesticide concentrations were usually a factor of two greater than when using the best estimate of input parameters without any built-in conservatism.
Distribution of cytochrome P4501A1–inducing chemicals in sediments of the Delaware River-Bay system, USA
Authors: McCoy Daniel L. , Jones Jennifer M. , Anderson Jack W. , Harmon Michelle , Hartwell Ian , Hameedi Jawed
Published: March 2010

The Delaware River-Bays system, USA, was the subject of a study by the National Oceanic and Atmospheric Administration that involved chemical and biological analyses, including the use of the biomarker P450 human reporter gene system (HRGS) to document the occurrence and distribution of cytochrome P450 (CYP) 1A1-inducing compounds. Sediment extracts from 81 locations along the Delaware River, Delaware Bay and immediate coastline were tested by utilizing HRGS as an inexpensive screening test, and were also analyzed for polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls, with selected stations analyzed for dioxins and furans. Benthic community degradation has been observed when benzo[a]pyrene equivalents (BaPEq) exceeded 60 μg/g. The average levels of BaPEq for the largely industrialized upper, middle, and lower regions of the Delaware River were 107, 62, and 5 μg/g, respectively, excluding outliers. Tributaries leading into river averaged 21 μg/g BaPEq, whereas the central Bay and open coast had relatively low values (2.0 and 0.5 μg/g BaPEq, respectively). The HRGS values were highly correlated with total PAHs measured in the same sediment samples (r2 = 0.81). Overall, contamination levels consistently decreased from the upper and middle river sites as collection locations progressed down through the lower river and bay to the coast. Thus, despite the relatively high contaminant load in the river system, Delaware Bay and the immediate coastline seem to have relatively low levels of contaminants, and, therefore, impacts on the benthic organisms in the bay and coast would not be expected from these findings.
The physiology of copper tolerance in fathead minnows: Insight from an intraspecific, correlative analysis
Authors: Kolok Alan S. , Hartman Melissa M. , Sershan John
Published: March 2010

Exposure to a sublethal (150 μg/L) concentration of copper (Cu) can reduce the critical swimming speed (Ucrit) of some fathead minnows (Pimephales promelas). The reduction is not consistent from one individual to the next, however, as some individuals experience dramatic reductions, while others maintain performance at preexposure levels. The objective of this experiment was to determine whether fish that experienced dramatic reductions in Ucrit were physiologically different from more resistant individuals. Individual variation in gill Na+-K+ activated adenosine triphosphatase (ATPase) activity was not significantly associated with variation reduction in Ucrit. Whole-body Cu was significantly related to reduction in Ucrit, and the relationship was surprisingly negative with the greatest reductions in Ucrit occurring in the fish with the lowest whole-body Cu concentrations. Whole-body Na+ was also significantly related to reduction in Ucrit, as the fish with the greatest whole-body Na+ experienced the smallest reduction in Ucrit. Fathead minnows are differentially susceptible to sublethal concentrations of Cu; this difference appears to be related to Na+ ionoregulation as well as the capacity of the fish to accumulate Cu.
Effect of soil copper content and pH on copper uptake of selected vegetables grown under controlled conditions
Authors: Ginocchio Rosanna , Rodríguez Patricio H. , Badilla-Ohlbaum Ricardo , Allen Herbert E. , Lagos Gustavo E.
Published: March 2010

A one-year greenhouse experiment was conducted to study the transfer of copper from contaminated agricultural soils to edible and nonedible structures of lettuce, tomato, and onion plants. Study soils were selected from two basins of central Chile (Santiago and Cachapoal) to represent two similar total soil copper gradients with different pH values. Results showed that free ionic Cu and Cu in saturation extracts were very low in comparison to total Cu contents of study soils (<0.002% and <0.04%, respectively). The concentrations of free ionic copper and of copper in saturation extracts were correlated to total Cu levels and to soil pH. Mean copper concentrations were higher in lettuce than in tomato and onion plants and in vegetables grown on acidic soils of the Cachapoal basin. However, copper levels in edible tissues of tomato and lettuce plants were similar to copper levels described for plants grown on unpolluted soils except for onion bulbs, which had higher values. This indicates that copper translocation to edible, above-ground structures seemed to be well regulated, as their concentrations were fairly constant. The study shows that Cu concentration in study vegetables depends on various factors, including plant species and tissue; site-specific soil factors, such as pH, organic matter, dissolved organic carbon, and conductivity; and several Cu pools, such as total, extractable, and free ionic Cu. Thus, our results support the intensity/capacity concept in that Cu concentration in plants or plant tissues depends not only on the availability of free copper ions in soil solution but also on other soil copper pools that supply the element to the soil solution.
Analysis of trace organic contaminants in sediment, pore water, and water samples from Onsan Bay, Korea: Instrumental analysis and in vitro gene expression assay
Authors: Koh Chul-Hwan , Khim Jong Seong , Villeneuve Daniel L. , Kannan Kurunthachalam , Giesy John P.
Published: March 2010

Persistent organic pollutants and alkylphenols (APs) were determined in sediment and water samples from Onsan Bay, Korea, by using instrumental analysis and in vitro gene expression cell bioassay. Polycyclic aromatic hydrocabons (PAHs) were the predominant compounds in sediments with concentrations as great as 573 ng/g dry weight. The PAH concentrations were elevated in sediment from inland rivers that flow through Onsan City (mean: 116 ng/g dry wt) and discharge into Onsan Bay. Concentrations of polychlorinated biphenyls (PCBs) in sediments ranged from <1.00 to 56.2 ng/g dry weight. Among different organochlorine (OC) pesticides analyzed (hexachlorobenzene, hexachlorocyclohexanes, chlordanes, and DDTs), DDT concentrations were the greatest, ranging from <0.01 to 7.58 ng/g dry weight. The spatial gradient of contaminant concentrations suggested that streams and rivers are the major sources of PCBs, PAHs, and APs to the bay. Maximum concentrations of nonylphenol, octylphenol, and bisphenol A in sediments were 860, 11, and 204 ng/g dry weight, respectively. Screening of Onsan Bay sediment samples for dioxinlike activity with the H4IIE-luc in vitro cell bioassay revealed that 17 of 22 samples contained significant dioxinlike activity. Further fractionation of sediment extracts indicated that mid-polar and more polar fractions were responsible for the significant dioxinlike activity. Based on a mass balance analysis, PAHs apparently accounted for only a small portion of dioxinlike responses elicited by sediment extracts. Only one raw extract of sediment elicited a significant estrogenic response by MVLN cells. The combination of instrumental analysis and in vitro bioassay was useful to assess sediment quality and characterize the causative agents or potential toxic compounds present.
Nonylphenol polyethoxylate adjuvant mitigates the reproductive toxicity of fomesafen on the freshwater snailLymnaea stagnalisin outdoor experimental ponds
Authors: Jumel Audrey , Coutellec Marie-Agnes , Cravedi Jean-Pierre , Lagadic Laurent
Published: March 2010

The influence of nonylphenol polyethoxylates (NPEO), formulated astheadjuvant Agral® 90, on the effects of the diphenyl ether herbicide fomesafen in the pond snail Lymnaea stagnalis was investigated, with particular attention to the reproductive performances and underlying energetic and hormonal processes. Separate short-term exposures to low concentrations of fomesafen and fomesafen-Agral mixture were performed in the laboratory. Outdoor experimental ponds (mesocosms) were used for long-term exposures to higher chemical concentrations. At the concentrations used in the studies, NPEO were known as nontoxic in L. stagnalis. Fomesafen was mixed with the adjuvant in the 3:7 ratio recommended for agricultural uses (nominal herbicide concentrations of 22 and 40 μg/L in laboratory and mesocosm, respectively). In mesocosms, multiple application of fomesafen, leading to maximal herbicide concentrations of 60.33 ± 2.68 μg/L in water, resulted in reduced number of egg masses and altered glycogen metabolism in contaminated snails. These changes, as well as affected steroid-like levels in fomesafen-exposed snails, support the hypothesis of impaired neuroendocrine functions. When Agral 90 was added to the herbicide, results obtained in mesocosms showed that the adjuvant softened the impact of fomesafen. In mesocosms treated with the fomesafen-Agral mixture, significantly lower herbicide levels were found in the water (30.33 ± 14.91 μg/L at the end of the contamination period). Consequently, internal exposure of the snails to fomesafen was reduced when the herbicide was mixed with the adjuvant. Mitigation of the effects of fomesafen by the adjuvant may therefore result from nonionic surfactant activity of NPEO that prevented fomesafen from reaching the snails.
Demographic responses of the polychaeteDinophilus gyrociliatusto chromium exposure
Authors: Mauri Marina , Simonini Roberto , Baraldi Elena
Published: March 2010

The effects of chromium on the life history and demography of Dinophilus gyrociliatus (Polychaeta) were studied on a control and three treated cohorts kept in artificial seawater enriched with nominal concentrations of chromium at 1.0, 1.4, and 1.6 μg/ml. Survival and fecundity were significantly reduced by chromium. Fecundity was higher in the chromium treatments than in the control group at the beginning of the reproductive period; however, overall, the highest fecundity was observed in the control. Life expectancy, net growth rate, and generation time were also significantly reduced by chromium. The population growth rate (&LD) was higher in the treated animals than in the controls. The differences in &LD between the treated animals and the controls (ΔΛ) were almost completely due to the differences in the life tables observed during the first three weeks of life. The differences in survival between the treated and control animals did not contribute to ΔΛ. The contribution to ΔΛ of the slight increase in age-specific fecundity in the early reproductive events compensated for the marked decrease in overall fecundity in the treated animals. The complex effects of chromium enrichment on D. gyrociliatus underline the importance of analyzing both individual and population responses when assessing the effects of pollutants on organisms. Our results confirm that D. gyrociliatus might serve as an indicator species in confined areas of polluted seawater such as lagoons and harbors.
Detection of environmental androgens: A novel method based on enzyme-linked immunosorbent assay of spiggin, the stickleback (Gasterosteus aculeatus) glue protein
Authors: Katsiadaki Ioanna , Scott Alexander P. , Hurst Mark R. , Matthiessen Peter , Mayer Ian
Published: March 2010

We report the development and validation of a novel in vivo biomarker test for waterborne androgens. During breeding, male sticklebacks (Gasterosteus aculeatus) manufacture a glue protein, spiggin, in their kidneys that they use to build their nests. Spiggin production is under the control of androgens. Until now, however, it has only been possible to quantify its production by measurement of the height of kidney epithelial cells. In the present study, we report the development of an enzyme-linked immunosorbent assay (ELISA) for spiggin and demonstrate its application to the measurement of spiggin in the kidneys of female sticklebacks that have been exposed to androgens in water. Results from the ELISA procedure revealed a strong correlation with measurement of kidney epithelial cell height (r2 = 0.93). However, the ELISA was much quicker and had a considerably higher response range (100,000-fold vs fourfold). Clear, graded responses in spiggin production were obtained by exposing intact females to increasing concentrations of 17α-methyltestosterone and 5α-dihydrotestosterone over three-week test periods. The lowest effective concentrations for these two steroids were 100 ng/L and 3 μg/L, respectively. Female sticklebacks that were exposed to pulp mill effluent also produced spiggin in their kidneys. Possession of an androgen-regulated protein by the female stickleback makes it a unique bioassay organism for detecting androgenic contamination in the aquatic environment.
Development of photosynthetic biofilms affected by dissolved and sorbed copper in a eutrophic river
Authors: Barranguet Christiane , Plans Marc , Van Der Grinten Esther , Sinke Jan J. , Admiraal Wim
Published: March 2010

Photosynthetic biofilms are capable of immobilizing important concentrations of metals, therefore reducing bioavailability to organisms. But also metal pollution is believed to produce changes in the microalgal species composition of biofilms. We investigated the changes undergone by natural photosynthetic biofilms from the River Meuse, The Netherlands, under chronic copper (Cu) exposure. The suspended particles in the river water had only a minor effect on reduction of sorption and toxicity of Cu to algae. Biofilms accumulated Cu proportionally to the added concentration, also at the highest concentration used (9 μM Cu). The physiognomy of the biofilms was affected through the growth of the chain-forming diatom Melosira varians, changing from long filaments to short tufts, although species composition was not affected by the Cu exposure. The Cu decreased phosphate uptake and algal biomass measured as chl a, which degraded exponentially in time. Photosynthetic activity was always less sensitive than algal biomass; the photon yield decreased linearly in time. The protective and insulating role of the biofilm, supported by ongoing autotrophic activity, was indicated as essential in resisting metal toxicity. We discuss the hypothesis that the toxic effects of Cu progress almost independently of the species composition, counteracting ongoing growth, and conclude that autotrophic biofilms act as vertical heterogeneous units. Effective feedback mechanisms and density dependence explain several discrepancies observed earlier.