bluuebunny/crossref_metadata_2025_split huggingface dataset:
In situ reproduction, abundance, and growth of young-of-year and adult largemouth bass in a population exposed to polychlorinated biphenyls
Authors: Reiser Dudley W. , Greenberg Emily S. , Helser Thomas E. , Branton Margaret , Jenkins Kenneth D. 
Published: November 2004

Abstract
We conducted a two-year field study (2000–2001) in the Housatonic River, Massachusetts (USA) to determine if we could detect in situ population-level effects on largemouth bass (Micropterus salmoides) exposed to elevated levels of polychlorinated biphenyls (PCBs). Calculated whole-body PCB concentrations in adult bass in 2002 averaged 121 mg/kg (range = 34–556 mg/kg). Polychlorinated biphenyl concentrations in young-of-year (YOY) composites in 2000 and 2002 averaged 28 mg/kg (range = 21–41 mg/kg) and 19 mg/kg (range = 16–24 mg/kg), respectively. Laboratory studies of fish have reported PCB toxicity at exposure levels below and within the range of those found in the Housatonic River. We evaluated five field-derived metrics: reproductive activity, relative abundance of YOY, YOY growth rates, adult growth, and adult condition to determine whether we could detect effects of PCBs in the largemouth bass population. These computed metrics, when compared with data sets assembled for numerous largemouth bass populations in North America, provided no evidence of population-level impairment. Results of this study suggest that PCB tissue concentrations associated with effects in laboratory studies do not necessarily translate to detectable effects on largemouth bass populations in their natural environment.
Evaluation of the protective effects of reactive sulfide on the acute toxicity of silver to rainbow trout (Oncorhynchus mykiss)
Authors: Mann Reinier M. , Ernste Mike J. , Bell Russell A. , Kramer James R. , Wood Chris M. 
Published: November 2004

Abstract
Acute 96-h toxicity tests were performed with juvenile rainbow trout (Oncorhynchus mykiss) exposed to AgNO3 in either the absence or the presence of 100 nM reactive sulfide to evaluate the protective effect of aqueous sulfides against ionic Ag toxicity. The sulfide was presented in the form of zinc sulfide (ZnS) clusters under oxic conditions. Silver was lost from the water column during the course of the experiment, so mean measured Ag concentrations were used to generate all median lethal concentration (LC50) data. The system was complicated in that Ag2S precipitated because of the need for large amounts of Ag to obtain lethal effects in the presence of ZnS. Some of the losses of Ag could be explained by complexation with ZnS and formation of solid Ag2S. Other losses were probably the result of partial adsorption to exposure-chamber walls or to complexation with ligands or functional groups within organic material produced by the fish. The LC50 (95% confidence interval) values generated using measured concentrations for total Ag were 139 (122-162) nM in the absence of sulfide and 377 (340-455) nM in the presence of 100 nM sulfide. The LC50 values generated using measured concentrations from filtered (pore size, 0.45 μm) water samples were 122 (105-145) nM in the absence of sulfide and 225 (192-239) nM in the presence of 100 nM sulfide. These results suggest a stoichiometric protection of sulfides up to a 2:1 ratio of Ag:sulfide. Greater accumulation of Ag at the gills was measured in fish exposed to AgNO3 in the presence of sulfide.
Ecological risk assessment of persistent toxic substances for the clam Tapes philipinarum in the lagoon of venice, italy
Authors: Micheletti Christian , Critto Andrea , Carlon Claudio , Marcomini Antonio 
Published: November 2004

Abstract
Because of contamination of sediments of the Lagoon of Venice, Italy, by inorganic pollutants (e.g., arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc) and organic pollutants (e.g., polychlorobiphenyls), as well as the ecological and economical relevance of the edible clam Tapes philipinarum, an ecological risk assessment was undertaken to ascertain the extent of bioaccumulation that would pose a significant risk. Risk was estimated by means of toxic units and hazard quotient approaches, by comparing the exposure concentration with the effect concentration. Clam exposure was estimated by applying previous results based on bioaccumulation spatial regression models. In addition, a comparison was made between sum of dioxin-like polychlorinated biphenyl (PCB) congeners and total PCB bioaccumulation provided by spatial regression models and by a partitioning model. The effect concentrations were calculated as tissue screening concentrations, as the product of pollutant sediment quality criteria and the bioaccumulation factor. Finally, the cumulative risk posed by selected inorganic pollutants and total PCBs was estimated and a map of risk was drawn. The resulting chemicals of potential ecological concern were mercury, cadmium, arsenic, and nickel, as well as, to a lesser extent, total PCBs.
Universal predictive models on octanol-air partition coefficients at different temperatures for persistent organic pollutants
Authors: Chen Jingwen , Harner Tom , Ding Guanghui , Quan Xie , Schramm Karl-Werner , Kettrup Antonius 
Published: November 2004

Abstract
Owing to the importance of octanol-air partition coefficients (KOA) in describing the partition of organic pollutants from air to environmental organic phases, the paucity of KOA data at different environmental temperatures, and the difficulty or high expenditures involved in experimental determination, the development of predictive models for KOA is necessary. Approaches such as this are greatly needed to evaluate the environmental fate of the ever-increasing list of production chemicals. Partial least squares (PLS) regression with 18 molecular structural descriptors was used to develop predictive models based on directly measured KOA values of selected chlorobenzenes, polychlorinated biphenyls (PCBs), polychlorinated naphthalenes, polychlorinated dibenzo-p-dioxins/dibenzofurans, polybrominated diphenyl ethers, polycyclic aromatic hydrocarbons, and organochlorine pesticides (OPs). An optimization procedure resulted in two temperature-dependent universal predictive models that explained at least 91% of the variance of log KOA. Model 1 was the more general of the two models that could be used for all the persistent organic pollutant (POP) classes investigated. Although model 1 performed poorly for select OPs, this was attributed to wide variability in structural types within this subset of POPs and their diversity compared to the other POP classes that were investigated. The exclusion of the structurally complex OP subset resulted in a more precise model, model 5. Intermolecular dispersive interactions (induced dipole-induced dipole forces) between octanol and solute molecules play a decisive role in governing KOA and its temperature dependence. Further investigations are needed to better characterize the steric structures of the POPs under study, especially of OPs.
Sorption of 2,4′-dichlorobiphenyl and fluoranthene to a marine sediment amended with different types of black carbon
Authors: Burgess Robert M. , Ryba Stephan A. , Perron Monique M. , Tien Rex , Thibodeau Laura M. , Cantwell Mark G. 
Published: November 2004

Abstract
Recents studies demonstrate that sedimentary black carbon (BC) affects the sorption of some hydrophobic organic contaminants (HOCs) to a greater extent than sedimentary organic carbon (OC). Among HOC, polycyclic aromatic hydrocarbons (PAHs) are known to interact extensively with BC. Currently, data on the sorption of various kinds of HOCs to different types of BC are limited. In this study, we amended a marine sediment with BC from several different sources, humic acid, and inert sand. Equilibration studies with 14C fluoranthene and the polychlorinated biphenyl (PCB) 3H 2,4′-dichlorinated biphenyl were performed to determine the magnitude of sorption as a function of contaminant and BC type. The magnitude of sorption to the BC-amended sediments was greater for the PAH than the PCB as compared to the sediment alone, humic acid, and sand. For example, differences between the log partition coefficient (KP) for the PAH and PCB ranged from 0.41 to 0.69 log units for humic acid and sand treatments, while differences ranged from 0.88 to 1.57 log units for the BC-amended sediments. As a result, BC-normalized partition coefficients (log KBC) for the PAH averaged 6.41, whereas the PCB log KBC values averaged 5.33. These results demonstrate that PAH sorption and most likely bioavailability are influenced strongly by the presence of BC of different types, while sorption of a nonplanar PCB was affected to a lesser degree.
Relationship between metabolism and bioaccumulation of benzo[α]pyrene in benthic invertebrates
Authors: Rust Aaron J. , Burgess Robert M. , Brownawell Bruce J. , McElroy Anne E. 
Published: November 2004

Abstract
The potential influence of polycyclic aromatic hydrocarbon (PAH) metabolism on bioaccumulation is well accepted, but rarely has been examined in many species of benthic invertebrates that commonly are found in contaminated sediments, or used in bioaccumulation or toxicity tests. In this study, the relative ability of 11 species of near-shore benthic invertebrates to metabolize and bioaccumulate a model PAH, benzo[α]pyrene (BαP), was evaluated. Species examined included six polychaetes (Clymenella torquata, Nereis virens, Nereis succinea, Nephtys incisa, Spio setosa and Cirriformia grandis), three bivalves, (Macoma balthica, Mya arenaria, and Mulinia lateralis), and two amphipods (Ampelisca abdita and Leptocheirus plumulosus). After 7 d of exposure to sediments spiked with radiolabeled BαP, metabolites comprised between 6.1% (Clymenella torquata) to 85.7% (Nereis succinea) of total accumulated BαP, with individual species from the same phylogenetic groups showing large differences in their ability to metabolize this PAH. Bioaccumulation factors (BαP in tissue/BαP in sediment) were inversely related to the species' ability to metabolize PAH, highlighting the importance of considering metabolism when interpreting bioaccumulation across several species. These data argue strongly against the continued use of the large polychaete Nereis virens, one of the species showing the greatest ability to metabolize BαP, for bioaccumulation testing when PAHs are being considered. Other commonly used test species had relatively low levels of metabolism (Ampelisca abdita, Leptocheirus plumulosus, and Macoma balthica), supporting their use in evaluation of potential PAH impact on the environment.
Oil spill impact modeling: Development and validation
Authors: French-McCay Deborah P. 
Published: November 2004

Abstract
A coupled oil fate and effects model has been developed for the estimation of impacts to habitats, wildlife, and aquatic organisms resulting from acute exposure to spilled oil. The physical fates model estimates the distribution of oil (as mass and concentrations) on the water surface, on shorelines, in the water column, and in the sediments, accounting for spreading, evaporation, transport, dispersion, emulsification, entrainment, dissolution, volatilization, partitioning, sedimentation, and degradation. The biological effects model estimates exposure of biota of various behavior types to floating oil and subsurface contamination, resulting percent mortality, and sublethal effects on production (somatic growth). Impacts are summarized as areas or volumes affected, percent of populations lost, and production foregone because of a spill's effects. This paper summarizes existing information and data used to develop the model, model algorithms and assumptions, validation studies, and research needs. Simulation of the Exxon Valdez oil spill is presented as a case study and validation of the model.
Chronic toxicity and body residues of the nonpolar narcotic 1,2,3,4-tetrachlorobenzene in Chironomus riparius
Authors: Leslie Heather A. , Kraak Michiel H. S. , Hermens Joop L. M. 
Published: November 2004

Abstract
The use of internal concentrations as a doseparameter for baseline toxicity requires an understanding of the relationship between accumulation level and toxic effects, not only for acute but also for chronic exposure. In this study of chronic toxicity of the nonpolar narcotic 1,2,3,4-tetrachlorobenzene (TeCB) to Chironomus riparius, the chronic median lethal concentration (LC50) was determined to be 0.99 (0.54–1.82) μM, the median sublethal effect concentration (EC50) for growth was 0.76 (0.73–0.97) μM, and the chronic (sublethal) no-observed-effect concentration (NOEC) was 0.24 ± 0.01 μM. An acute-to-chronic ratio of 9.8 was calculated from a previously determined acute LC50 value and this NOEC. The chronic critical body residue (CBR), 136 mmol/kg lipid, was the same as the acute CBR, previously determined. The similarity of the chronic and acute CBRs lends support to the exposure time independent aspect of baseline toxicity theory. An implication of this is that internal concentrations estimated by biomimetic sampling devices may be compared to acute CBR data to determine chronic baseline toxicity risk. Such sampling devices, solid-phase microextraction (SPME) fibers, were simultaneously exposed during the toxicity test. The results of this study suggest that body residues estimated with SPME may be used to predict baseline toxicity for various exposure durations.
Water-extractability, free ion activity, and pH explain cadmium sorption and toxicity to Folsomia candida (Collembola) in seven soil-pH combinations
Authors: van Gestel Cornelis A. M. , Koolhaas Josée E. 
Published: November 2004

Abstract
Toxicity of cadmium to Folsomia candida was determined in soils at different pHs (3.5, 5.0, and 6.5). The Langmuir sorption constant (KL), based on pore-water or water-extractable concentrations, showed a pH-related increase of cadmium sorption that was most pronounced when using free Cd2+ ion activities ({Cd2+}s). Two-species Langmuir isotherms that used total cadmium concentration ([Cd]) or {Cd2+} and pH in the water-extractable fractions gave the best description of cadmium sorption on all soils together. Cadmium concentrations causing 50% reduction of growth and reproduction (median effective concentrations [EC50s]) differed by a factor of 4.5 to 20 when based on total soil concentrations and increased with increasing pH. However, when based on water-extractable or pore-water [Cd] or {Cd2+}, EC50s decreased with increasing pH, but differences between soils were still a factor of 4.5 to 32. The EC50s differed by less than a factor of 2.2 when based on body [Cd] in the surviving animals. Two-species Langmuir isotherms were used to relate body [Cd] in survivors to {Cd2+}, corrected for pH in water-extractable or pore-water fractions. An excellent description of effects on growth and reproduction was found when related to the body concentrations predicted in this way; the difference in EC50s between soils was reduced to a factor &lt;2. This demonstrates that F. candida is mainly exposed to cadmium through the soil solution, and suggests that principles of a biotic ligand model approach may be applicable for this soil organism.
Organophosphorus pesticides in storm-water runoff from southern California (USA)
Authors: Schiff Kenneth , Sutula Martha 
Published: November 2004

Abstract
Large quantities of the organophosphorus (OP) pesticides diazinon and chlorpyrifos are applied to California (USA) watersheds every year, but few data are available on the sources of OP pesticides in urban watersheds. The goal of this study was to characterize diazinon and chlorpyrifos concentrations from different land uses indicative of source categories in urban southern California watersheds. This characterization included analysis of 128 runoff samples from eight different land uses over five storm events. Diazinon was consistently detected (93% of samples) during this study, whereas chlorpyrifos was not consistently detected (12% of samples). The mixed agricultural land use had the highest flow weighted mean (FWM) concentration of diazinon (4,076 ng/L), which exceeded the next-highest land-use categories (commercial and residential) by one to two orders of magnitude (324–99 ng/L, respectively). Open space had the lowest concentration of diazinon (&lt;20 ng/L). Concentrations of diazinon at replicate land-use sites and during replicate storm events at the same site were highly variable. The difference in diazinon FWM concentrations among replicate sites ranged from 1.5-fold to 45-fold. The difference in diazinon FWM concentrations among storms at the same site ranged from 1.25-fold to 30-fold. Part of this variability is a response to the temporal patterns observed within a storm event. The majority of land-use site-events had peak concentrations before peak flow indicating a first-flush effect, but this was not always a predictable temporal trend. The first-flush effect was rarely evident in terms of mass loadings because flows can range orders of magnitude during a single event in highly impervious urban watersheds. Flow variability thus overwhelms the variability in diazinon concentrations attributable to the first-flush effect.
Plasma sex steroid concentrations and gonadal aromatase activities in African clawed frogs (Xenopus laevis) from South Africa
Authors: Hecker Markus , Giesy John P. , Jones Paul D. , Jooste Alarik M. , Carr James A. , Solomon Keith R. , Smith Ernest E. , Van Der Kraak Glen , Kendall Ronald J. , du Preez Louis 
Published: November 2004

Abstract
Adult African clawed frogs (Xenopus laevis) were collected from a corn-growing region (CGR) and a non-corn-growing region (NCGR) with different exposure profiles for atrazine and related triazines. Physical, chemical, and biological parameters from the catchment areas were also measured. Frogs were surveyed for possible effects of exposure to triazine herbicides on plasma testosterone (T) and estradiol (E2) titers, gonadal aromatase activity, and gonad growth (GSI). Concentrations of both T and E2 varied among locations and were correlated to some accessory factors, such as pH, several ions, and metals. Greatest median plasma T concentrations (males: 19 ng/ml; females: 16 ng/ml) occurred in frogs inhabiting NCGR as compared to those from the CGR (males: 4 ng/ml; females: 1 ng/ml). Median E2 concentrations were also greater in frogs collected from the NCGR (males: 3 ng/ml; females: 28 ng/ml) than those in frogs from the CGR (males: 2 ng/ml; females: 5 ng/ml). Because some exposure to agricultural chemicals at both regions occurred, as did simultaneous exposures to multiple chemicals, a regression analysis was employed. Negative correlations were observed between plasma T concentrations and concentrations of atrazine, deisopropylatrazine, deethylatrazine, and tertbuthylazine in females and between T and diaminochlorotriazine in males. Estradiol in females exhibited a significant negative correlation with atrazine and deethylatrazine. No correlations were observed between gonadal aromatase activity or GSI and any of the agricultural chemicals measured. Median aromatase activities in ovaries varied among sampling sites ranging from 7 to &gt;3,000 times greater than those in males when measurable. Testicular aromatase activity was below the detection limit of the assay in male frogs at most of the sites. Although exposure to agricultural inputs did not affect aromatase activities, effects of atrazine or coapplied pesticides on sex steroid homeostasis cannot be excluded at this point.
Dynamic in-stream fate modeling of xenobiotic organic compounds: A case study of linear alkylbenzene sulfonates in the Lambro River, Italy
Authors: Deksissa Tolessa , De Pauw Dirk , Vanrolleghem Peter A. 
Published: November 2004

Abstract
Using a conceptual hydraulic model, a one-dimensional dynamic river water quality model has been developed to assess the short-term fate of linear alkylbenzene sulfonates (LAS) in the river compartments water and benthic sediment. The model assumes local equilibrium sorption and that both dissolved and sorbed chemical are available for biodegradation. To investigate the interaction of nutrient dynamics and organic contaminant fate, the model is coupled with a basic water quality model. On the basis of the Lambro River (Italy) as a case study, the result shows that the model predictions agree well with the measured data set. The model output sensitivity to model parameters has been tested, and the results depict that the model is highly sensitive to the biodegrading parameters. Also, a comparison of a steady state with a dynamic simulation and the effect of nutrient dynamics on the LAS fate in the Lambro River as a scenario analysis are presented. The results indicate the usefulness of the proposed model for the short-term simulation of organic contaminant fate in unsteady environmental conditions.
Effects of trichloroethylene and perchloroethylene on wild rodents at Edwards Air Force Base, California, USA
Authors: Spring Sarah E. , Miles A. Keith , Anderson Michael J. 
Published: November 2004

Abstract
Effects of inhalation of volatilized trichloroethylene (TCE) or perchloroethylene (PCE) were assessed based on the health and population size of wild, burrowing mammals at Edwards Air Force Base (CA, USA). Organic soil-vapor concentrations were measured at three sites with aquifer contamination of TCE or PCE of 5.5 to 77 mg/L and at two uncontaminated reference sites. Population estimates of kangaroo rats (Dipodomys merriami and D. panamintinus) as well as hematology, blood chemistry, and histopathology of kangaroo rats and deer mice (Peromyscus maniculatus) were compared between contaminated and uncontaminated populations. Maximum soil-gas concentrations associated with groundwater contamination were less than 1.5 μl/L of TCE and 0.07 μl/L of PCE. Population estimates of kangaroo rats were similar at contaminated and reference sites. Hematology, blood chemistry, and histopathology of kangaroo rats and deer mice indicated no evidence of health effects caused by exposure. Trichloroethylene or PCE in groundwater and in related soil gas did not appear to reduce the size of small mammal populations or impair the health of individuals.
Effect of extraction conditions on trace element solubilization in deposit feeder digestive fluid
Authors: Weston Donald P. , Judd Jeffrey R. , Mayer Lawrence M. 
Published: November 2004

Abstract
In vitro extraction of sediments using digestive fluid of deposit-feeding invertebrates has been advocated as a measure of in vivo bioavailability, but the standard procedure used for the extractions alters fluid properties relative to in vivo conditions. In vivo fluid properties (redox potential [Eh], pH, dissolved oxygen) were measured in the gut of the polychaete Arenicola brasiliensis, and then the effects of gut evacuation, elevated temperature, and atmospheric exposure on these properties and/or metal and metalloid extraction capability of the fluid was assessed. The midgut of A. brasiliensis has an electropositive Eh of about +170 to +230 mV, a neutral pH, and little or no dissolved oxygen. Exposure to the atmosphere during in vitro extraction increased gut fluid oxygen content and affected the ability of the fluid to extract some trace elements from sediment particles, particularly Pb, Ni, Cu, Mn, and As. Even for these substances, however, the effects of oxygen exposure on extractability by gut fluid typically were small (&lt;2-fold difference in amount extracted). For Cr, Hg, Se, Cd, Fe, and Zn, the effects of oxygen exposure usually were minor and inconsistent in direction. Maintaining anaerobic conditions during in vitro contaminant extractions is necessary when the experimental objective is to mimic accurately in vivo conditions and predict trace element extraction in the gut. If using metal extractability as a relative measure for sediment risk assessment purposes, a high degree of accuracy may not be required, and aerobic in vitro extractions could be suitable and produce only minor errors in extractability relative to in vivo conditions.