bluuebunny/crossref_metadata_2025_split huggingface dataset:
A comparison between the multimedia fate and exposure models caltox and uniform system for evaluation of substances adapted for life-cycle assessment based on the population intake fraction of toxic pollutants
Authors: Huijbregts Mark A. J. , Geelen Loes M. J. , Hertwich Edgar G. , McKone Thomas E. , van de Meent Dik 
Published: January 2005

Abstract
In life-cycle assessment (LCA) and comparative risk assessment, potential human exposure to toxic pollutants can be expressed as the population intake fraction (iF), which represents the fraction of the quantity emitted that enters the human population. To assess the influence of model differences in the calculation of the population iF, ingestion and inhalation iFs of 365 substances emitted to air, freshwater, and soil were calculated with two commonly applied multimedia fate and exposure models, CalTOX and the uniform system for evaluation of substances adapted for life-cycle assessment (USES-LCA). The model comparison showed that differences in the iFs due to model choices were the lowest after emission to air and the highest after emission to soil. Inhalation iFs were more sensitive to model differences compared to ingestion iFs. The choice for a continental seawater compartment, vertical stratification of the soil compartment, rain and no-rain scenarios, and drinking water purification mainly clarify the relevant model differences found in population iFs. Furthermore, pH correction of chemical properties and aerosol-associated deposition on plants appeared to be important for dissociative organics and metals emitted to air, respectively. Finally, it was found that quantitative structure–activity relationship estimates for superhydrophobics may introduce considerable uncertainty in the calculation of population intake fractions.
Relationship between ethinylestradiol-mediated changes in endocrine function and reproductive impairment in Japanese medaka (Oryzias latipes)
Authors: Tilton Susan C. , Foran Christy M. , Benson William H. 
Published: January 2005

Abstract
Many biochemical endpoints currently areused to describe endocrine function in fish; however, the sensitivity of these parameters as biomarkers of impaired reproduction or sexual development is not well understood. In the present study, adult Japanese medaka (Oryzias latipes) were assessed for reproductive output and endocrine function, including circulating steroid concentrations, ex vivo steroidogenesis from the gonads, aromatase activity, hepatic estrogen receptor (ER), and plasma vitellogenin (VTG) after exposure to 0, 0.2, 5, 500, and 2,000 ng/L of 17α-ethinylestradiol (EE) for 14 d. The EE altered these biochemical responses at various sites along the hypothalamus-pituitary-gonadal axis at concentrations as low as 0.2 ng/L, but it only depressed reproductive function at concentrations of 500 ng/L or greater. Offspring also had reduced ability to hatch at 500 ng/L of EE, but this concentration did not produce any other observed changes in development or sexual phenotype. The reproductive parameters correlated well with VTG, ER, and gonadosomatic index (GSI) in both sexes of adult medaka, which could be indicative of the ER-mediated mode of action for EE. Vitellogenin and ER were elevated at higher concentrations of EE in both sexes, whereas GSI was decreased. Overall, most biochemical endpoints were more sensitive than reproduction or development to exposure, indicating that reproductive function may be relatively protected.
Whole-carcass residues of the rodenticide difenacoum in anticoagulant-resistant and -susceptible rat strains (Rattus norvegicus)
Authors: Atterby Helen , Kerins Gerard M. , MacNicoll Alan D. 
Published: January 2005

Abstract
The present study investigated the whole-carcass residue carried by resistant and susceptible laboratory rat strains following 5, 10, or 20 d of feeding on a diet of 25 mg difenacoum/kg bait. The mean whole-carcass residue of difenacoum was determined by high-performance liquid chromatography to be between 0.52 and 0.74 mg/kg body weight in all three rat strains tested. These values were considerably lower than some comparable data previously reported for other species and second-generation rodenticides as well as from mathematical models. The whole-carcass residue of extractable (i.e., nonrefractory) parent compound carried by highly resistant rats fed for 20 d (0.74 mg/kg body wt) is unlikely to present a significantly increased risk to predators compared to the amount carried by susceptible rats after 5 d of feeding (0.52 mg/kg body wt). However, resistant rats are more likely to be available for predation and to be carrying a whole-carcass residue of anticoagulant throughout the duration of a control program.
Insecticide species sensitivity distributions: Importance of test species selection and relevance to aquatic ecosystems
Authors: Maltby Lorraine , Blake Naomi , Brock Theo C. M. , Van den Brink Paul J. 
Published: January 2005

Abstract
Single-species acute toxicity data and (micro)mesocosm data were collated for 16 insecticides. These data were used to investigate the importance of test-species selection in constructing species sensitivity distributions (SSDs) and the ability of estimated hazardous concentrations (HCs) to protect freshwater aquatic ecosystems. A log-normal model was fitted to a minimum of six data points, and the resulting distribution was used to estimate lower (95% confidence), median (50% confidence), and upper (5% confidence) 5% HC (HC5) values. Species sensitivity distributions for specific taxonomic groups (vertebrates, arthropods, nonarthropod invertebrates), habitats (saltwater, freshwater, lentic, lotic), and geographical regions (Palaearctic, Nearctic, temperate, tropical) were compared. The taxonomic composition of the species assemblage used to construct the SSD does have a significant influence on the assessment of hazard, but the habitat and geographical distribution of the species do not. Moreover, SSDs constructed using species recommended in test guidelines did not differ significantly from those constructed using nonrecommended species. Hazardous concentrations estimated using laboratory-derived acute toxicity data for freshwater arthropods (i.e., the most sensitive taxonomic group) were compared to the response of freshwater ecosystems exposed to insecticides. The sensitivity distributions of freshwater arthropods were similar for both field and laboratory exposure, and the lower HC5 (95% protection with 95% confidence) estimate was protective of adverse ecological effects in freshwater ecosystems. The corresponding median HC5 (95% protection level with 50% confidence) was generally protective of single applications of insecticide but not of continuous or multiple applications. In the latter cases, a safety factor of at least five should be applied to the median HC5.
Behavioral responses to sublethal cadmium exposure within an experimental aquatic food web
Authors: Riddell David J. , Culp Joseph M. , Baird Donald J. 
Published: January 2005

Abstract
The foraging and predator-avoidance behaviors of mayfly (Baetis tricaudatus) nymphs and predator-prey interactions were investigated under differing combinations of cadmium concentration and predation risk. Predators consisted of stonefly (Kogotus nonus) nymphs, juvenile brook trout (Salvelinus fontinalis), and longnose dace (Rhinichthys cataractae), either alone or in combination. Organisms were exposed to 0, 0.5, or 5.0 μg/L Cd for 7 d (invertebrates) or 30 d (vertebrates) prior to observation in artificial stream channels. Behavioral observations (20-min duration) were made both day and night over a 24-h period. Mayfly feeding rate was assessed by image analysis of grazed diatom mats cultured on ceramic tiles. Both predators and cadmium produced significant effects on the behavior of B. tricaudatus and K. nonus nymphs, with mayflies showing a hierarchical response in the presence of multiple predators. A significant increase in activity was observed in S. fontinalis exposed to 5.0 μg/L Cd, with significant decreases in capture efficiency of prey items apparent at 0.5 μg/L Cd. Conversely, the foraging behavior of R. cataractae was unaffected by cadmium, possibly as a result of species-specific cadmium tolerance. Such sublethal effects of a contaminant on the energy budgets of individuals and the interactions between species have implications for community structure in aquatic food webs.
Use of laboratory toxicity tests with bivalve and echinoderm embryos to evaluate the bioavailability of copper in San Diego Bay, California, USA
Authors: Rosen Gunther , Rivera-Duarte Ignacio , Kear-Padilla Lora , Chadwick D. Bart 
Published: January 2005

Abstract
Copper concentrations in parts of San Diego Bay (CA, USA) exceed ambient water quality criteria (WQC; currently 3.1 μg/L dissolved, U.S. Environmental Protection Agency [U.S. EPA]). In order to better understand the bioavailability of copper to water-column organisms in the bay, toxicity tests were performed with copper added to surface water collected from various sites in the estuary over a three-year period. The species and endpoints used, bivalve and echinoderm embryo-larval development, are among the most sensitive in the U.S. EPA's national toxicity dataset, which is used to derive WQC. No toxicity was observed in ambient bay water samples, as indicated by high proportions of normally developed larvae in control treatments, averaging 93 ± 5% across all sites and all sampling events. Median effects concentrations (EC50), obtained by copper spiking of ambient water samples, ranged from 1.7 to 3.4 times lower at sites located near the mouth compared to sites near the back of the bay. These data indicate a gradient in complexation capacity increasing from the mouth to the back of the bay, which is consistent with similar trends in dissolved organic carbon and total suspended solids. For the bay as a whole, estimates for total recoverable and dissolved water-effect ratios (WER) ranged from 2.07 to 2.27 and 1.54 to 1.67, respectively. Water-effect ratios of this magnitude suggest that adoption of a somewhat higher site-specific WQC for San Diego Bay still would achieve the level of protection that is intended by the WQC guidelines.
Detection and evaluation of endocrine-disruption activity in water samples from Portuguese rivers
Authors: Quirós Laia , Céspedes Raquel , Lacorte Silvia , Viana Paula , Raldúa Demetrio , Barcelò Damià , Piña Benjamin 
Published: January 2005

Abstract
Water samples (n = 183) from Portuguese rivers were tested for the presence of endocrine disruptors using the recombinant yeast assay (RYA) combined with chemical identification of compounds having endocrine-disruption properties by liquid chromatography coupled to mass spectrometry. Ten selected locations were sampled monthly for a period of 20 months, from April 2001 to December 2002. More than 90% of samples showed either no detectable or low levels of estrogenicity (&lt;0.1 ng/L of estradiol equivalents). The remaining samples (17 in total, 9.3%) showed estrogenicity values ranging from 0.1 to 1.7 ng/L of estradiol equivalents; only two samples showed values greater than 1 ng/L of estradiol equivalents. Most highly estrogenic samples (13 of 17 samples) originated in five sampling sites clustered in two zones near Porto and Lisbon. Chemical analysis detected alkylphenolic compounds (octyl- and nonylphenol plus nonylphenol ethoxylates) in all samples, albeit at concentrations less than 1 μg/L for each compound in 80% of samples. Total analyte concentration exceeded 10 μg/L in only 10 samples, with all but one of those originating from only two sampling sites. In these two locations, a good correlation was observed between the concentrations of octylphenol, nonylphenol, and to a lesser extent, bisphenol A in the samples and their estrogenicity values as calculated by RYA. We conclude that estrogenic activity can be explained by alkylphenol contamination in only these sites; for the remainder, we propose that pesticides and urban waste may be the main factors responsible for estrogenic contamination.
Mode of action and aquatic exposure thresholds of no concern
Authors: de Wolf Watze , Siebel-Sauer Angela , Lecloux Andre , Koch Volker , Holt Martin , Feijtel Tom , Comber Mike , Boeije Geert 
Published: January 2005

Abstract
Threshold concepts of toxicological concern are based on the possibility of establishing an exposure threshold value for chemicals below which no significant risk is to be expected. The objective of the present study is to address environmental thresholds of no toxicological concern for freshwater systems (ETNCaq) for organic chemicals. We analyzed environmental toxicological databases (acute and chronic endpoints) and substance hazard assessments. Lowest numbers and 95th-percentile values were derived using data stratification based on mode of action (MOA; 1 = inert chemicals; 2 = less inert chemicals; 3 = reactive chemicals; 4 = specifically acting chemicals). The ETNCaq values were derived by multiplying the lowest 95th percentile values with appropriate application factors; ETNCaq,MOA1–3 is approximately 0.1 μg/L. A preliminary analysis with complete MOA stratification of the databases shows that in the case of MOA1 or MOA2, the ETNCaq value could be even higher than 0.1 μg/L. A significantly lower ETNCaqMOA4 value was observed based on the long-term toxicity information in the European Centre for the Ecotoxicology and Toxicology of Chemicals database. Application of the ETNCaq value in a tiered risk-assessment scheme may help chemical producers to set data-generation priorities and to refine or reduce animal use. It also may help to inform downstream users concerning the relative risk associated with their specific uses and be of value in putting environmental monitoring data into a risk-assessment perspective.
Toxicity of fluoroquinolone antibiotics to aquatic organisms
Authors: Robinson April A. , Belden Jason B. , Lydy Michael J. 
Published: January 2005

Abstract
Toxicity tests were performed with seven fluoroquinolone antibiotics, ciprofloxacin, lomefloxacin, ofloxacin, levofloxacin, clinafloxacin, enrofloxacin, and flumequine, on five aquatic organisms. Overall toxicity values ranged from 7.9 to 23,000 μg/L. The cyanobacterium Microcystis aeruginosa was the most sensitive organism (5-d growth and reproduction, effective concentrations [EC50s] ranging from 7.9 to 1,960 μg/L and a median of 49 μg/L), followed by duckweed (Lemna minor, 7-d reproduction, EC50 values ranged from 53 to 2,470 μg/L with a median of 106 μg/L) and the green alga Pseudokirchneriella subcapitata (3-d growth and reproduction, EC50 values ranged from 1,100 to 22,700 μg/L with a median 7,400 μg/L). Results from tests with the crustacean Daphnia magna (48-h survival) and fathead minnow (Pimephales promelas, 7-d early life stage survival and growth) showed limited toxicity with no-observed-effect concentrations at or near 10 mg/L. Fish dry weights obtained in the ciprofloxacin, levofloxacin, and ofloxacin treatments (10 mg/L) were significantly higher than in control fish. The hazard of adverse effects occurring to the tested organisms in the environment was quantified by using hazard quotients. An estimated environmental concentration of 1 μg/L was chosen based on measured environmental concentrations previously reported in surface water; at this level, only M. aeruginosa may be at risk in surface water. However, the selective toxicity of these compounds may have implications for aquatic community structure.
Toxicity assessment of mono-substituted benzenes and phenols using a Pseudomonas initial oxygen uptake assay
Authors: Huang Ded-Shih , Whang Thou-Jen , Cheng Fei-Chen , Wu Ya-Ping , Wang Yi-Ting , Luo Wen-I , Wang Yane-Shih 
Published: January 2005

Abstract
A methodology is presented for assessing the toxicity of chemical substances through their inhibitory action toward the Pseudomonas initial oxygen uptake (PIOU) rate. The current studies reveal that the PIOU assay is rapid, cost-efficient, and easy to perform. The oxygen uptake rate was found to be associated with a putative benzoate transporter and highly dependent on benzoate concentration. The putative benzoate transporter has been shown to follow Michaelis–Menten kinetics. Most phenols were found to be noncompetitive inhibitors of the benzoate transporter. The inhibition constant (Ki) of these noncompetitive inhibitors can be related to the concentration causing 50% oxygen uptake inhibition in Pseudomonas putida. Modeling these data by using the response–surface approach leads to the development of a quantitative structure–activity relationship (QSAR) for the toxicity of phenols ((1/Ki) = –0.435 (±0.038) lowest-unoccupied-molecular orbital + 0.517 (±0.027)log KOW −2.340 (±0.068), n = 49, r2 = 0.930, s = 0.107, r2adj = 0.926, F = 303.1). A comparison of QSAR models derived from the Ki data of the PIOU method and the toxicity data of 40-h Tetrahymena pyrifomis growth inhibition assay (Tetratox) indicated that there was a high correlation between the two approaches (r2 = 0.925).
Polycyclic aromatic hydrocarbon behavior in bioactive soil slurry reactors amended with a nonionic surfactant
Authors: Kim Han S. , Weber Walter J. 
Published: January 2005

Abstract
The effects of an ethoxylated sorbitan fatty ester nonionic surfactant (Tween 80) on the bioavailability of polycyclic aromatic hydrocarbons (PAHs) were examined by using soil-free and dense-slurry (67% solids content, by wt) systems containing a creosote-contaminated field soil. The dispersed-micelle-phase PAHs in soil-free systems were not readily bioavailable to the mixed consortium of microbes indigenous to the creosote-contaminated soil. Instead, the microbes partially and preferentially utilized readily available portions of the surfactant as carbon sources (16–18% of the initial surfactant dose). This selective microbial attack resulted in destabilization of dispersed-phase micelles and significant decreases in molar solubilization ratio and micelle-water partition coefficient values. Remarkably high dosages (&gt;20 g/L) of Tween 80 were required to enhance mobilization of the sorbed PAHs via micelle association because of the sorption of Tween 80 to the soil employed. The PAHs released from the destabilized micelles in soil-slurry systems either associated with sorbed-phase surfactants or readsorbed to soil organic matter too rapidly to be biologically accessed, even by the acclimated PAH-degrading microbes present. The work provides important new information and practical insights to surfactant solubilization and mobilization technology applications for the bioremediation of PAH-contaminated soils and sediments.
Relationships between Cd and Zn partitioning and geochemical composition in sediments from Chinese Rivers
Authors: Peng Shu-Heng , Wang Wen-Xiong , Chen Jingsheng 
Published: January 2005

Abstract
Asorption isotherm experiments were conducted to determine the distribution coefficients (Kd) for Cd and Zn between water and sediments from twelve rivers in eastern China. The low metal concentration (&lt;10−10 M) added into the sediment-water system enabled the direct measurements of linear adsorption isotherms. When other solution parameters, such as ionic strength, were controlled, sediment geochemical characteristics were the major factors affecting metal distribution. The Kd was highly dependent on the total organic carbon contents and Fe-Mn oxide at pH = 7.0, and was affected significantly by the carbonate content in the sediments due to its control of pH. The Kd of the Huanghe sediments, which had the highest carbonate concentration (13.1%), increased sharply for both Cd and Zn when the pH increased. A quantitative model using the experimentally obtained phase distribution coefficients (Kd)i was applied to study the effects of different geochemical phases in the sediment on metal distributions. The (Kd)i of carbonate was correlated significantly with the carbonate content in the sediment, whereas the (Kd)i of total organic carbon (TOC) and Fe-Mn oxide phases were highly pH dependent. Using the (Kd)i for each geochemical phase, the calculation showed that about 91% and 85% of sorbed Cd and Zn, respectively, added to the batch reactors were distributed among the three major geochemical phases: TOC, Fe-Mn oxide, and carbonate. Total organic carbon was the most important binding phase for Cd, and Fe-Mn oxide for Zn. Furthermore, adsorption experiments with simulated sediments show the importance of interactions between different geochemical phases on metal partitioning.
Turner Syndrome
Authors: Sybert Virginia P. 
Published: January 2005

AbstractTurner syndrome affects 1/3000 females. The natural history of this sex chromosome aneuploidy is marked by problems in lymphatic development, skeletal development and growth, gonadal function, cardiac and renal malformations, and a number of specific cognitive findings. An increased risk for hypothyroidism, sensorineural hearing loss, hypertension, and other problems is recognized. Evaluation and management are reviewed.
Influence of processing conditions on the weld line in doubly injection‐molded glassy polycarbonate and polystyrene: Microindentation hardness study
Authors: Boyanova M. , Calleja F. J. Baltá , Fakirov S. , Kuehnert I. , Mennig G. 
Published: January 2005

AbstractThe microhardness (H) technique has been used to characterize the quality of the weld line in injection‐molded tensile bars from a two‐component machine in which both melt streams from the same material can be independently controlled. More specific, the influence of melt temperature and indentation location (closer or further from the sample edge parallel to the injection direction and across the weld line) has been followed on polycarbonate (PC) and polystyrene (PS) glassy samples. For both polymers at lower melt temperatures, a strong H decrease (between 15 and 50%) followed by a sharp increase in a narrow distance (around 0.10 mm), is observed. When the melt temperature increases up to 300°C (for PC) and 270°C (for PS), a much smaller H decrease is observed in the central part of the samples. However, closer to the tensile bar edges (2 mm) the weld line remains undetectable by microhardness measurements. The present results reveal that the processing temperature affects the broadening of the weld line through the conditions for effective mutual interdiffusion of chains from the two fronts coming from opposite sides. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24:14–20, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20028
Wear and thermal effects in low modulus polymer‐based composite friction materials
Authors: Haddadi E. , Abbasi F. , Shojaei A. 
Published: January 2005

AbstractThe wear properties of low modulus polymer‐based friction materials were studied. The wear equation W = K Pa Vb tc was used to correlate the wear of polymer‐based friction material sliding against cast iron with the wear coefficient (K), load (P), speed (V), and time (t). The parameters were determined experimentally by varying only one variable at a time and keeping the other two variables constant. The wear rate of selected polymer‐based friction material was compared with cast iron friction material. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 1181–1188, 2005