bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of pre- and postnatal exposure to 3,3′,4,4′,5-pentachlorobiphenyl on physical development, neurobehavior and xenobiotic metabolizing enzymes in rats
Authors: Bernhoft A. , Nafstad I. , Engen P. , Skaare J.U. 
Published: March 2010

Abstract
An experiment was conducted to study the effects of the coplanar non-ortho-chlorinated congener 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126) in rats exposed during fetal development and postnatal suckling period. Two groups of eight dams were administered by gavage six doses of 10 and 20 μg/kg body weight of PCB-126 dissolved in corn oil every second day from days 9 to 19 of gestation. The corresponding control rats were treated with corn oil only. The physical development of the offspring was observed. From age 5 to 18 weeks, 12 randomly selected pups from each group were tested daily for visual discrimination with successively more demanding tasks in Skinner boxes. The effects of PCB-126 on hepatic xenobiotic metabolizing enzyme activities and the concentrations of PCB in the liver and brain were investigated in samples from pups of different age and from their mothers. The litter size, the body weights, and the survival of the exposed sucklings were reduced, and the onset of spontaneous movement and neuromuscular maturation were delayed, whereas the development of reflexes was not affected, as compared to controls The body weight was still reduced in a dose-related manner up to 18 weeks postpartum. Also, the postpartum body weight of the PCB-exposed mothers was reduced as compared to controls, but the difference disappeared at weaning. The hepatic enzyme activities of cytochrome P450 1A1 examined by ethoxyresorufin O-deethylase (EROD) and glutathione S-transferase (GST) toward 1-chloro-2,4-dinitrobenzene (CDNB) were increased in both the exposed pups and their mothers, and the relative liver weight was increased in the exposed pups. The behavior training in Skinner boxes did not reveal PCB effects on the learning performance or the activity level Hepatic PCB-126 residues were detected in samples collected throughout the experiment, whereas no detectable concentration was found in the brain We conclude that exposure of this PCB congener in utero and through lactation showed fetotoxic effects, delayed physical maturation, and induced liver xenobiotic metabolizing enzymes without causing neurobehavioral effects
Interspecies toxicity correlations of rat, mouse and Photobacterium phosphoreum
Authors: Kaiser Klaus L. E. , McKinnon Mark B. , Fort Farrel L. 
Published: March 2010

Abstract
This study investigates quantitatively the interspecies relationships of the acute toxicity of 684 organic chemicals to the rat, the mouse, and the luminescent marine bacterium Photobacterium phosphoreum, commonly known as the Microtox® test The results indicate significant relationships between the Microtox EC50 and rat and mouse LD50 values The goodness of fit increases strongly from the oral to the intraperitoneal to the intravenous route of administration for each of the mouse and rat Standard errors of the estimated rat values range from 0 52 to 0 72 log units of toxicity (after and before outlier removal, respectively) over a toxicity range of 4 6 (intraperitoneal) to 5 0 (oral) log units (mmol/kg body weight) of toxicity For each of the three routes of administration, rat and mouse data are also highly correlated This allows the computation of rat toxicities from mouse data and vice versa with standard errors of the estimates of 0 28 (intraperitoneal) to 0 30 (oral) log units
Biological alternatives to chemical identification for the ecotoxicological assessment of industrial effluents: The RTG-2 in vitro cytotoxicity test
Authors: Castaño Argelia , Vega Milagros , Blazquez Teresa , Tarazona Jose V. 
Published: March 2010

AbstractEcotoxicology is concerned with the effects of chemicals on biological systems Identifying components of complex aqueous effluents poses special problems, and can be useless if there is a lack of information on the biological effects of the identified chemicals Toxicity-based (bioassay directed) sample fractionation can be very useful, but the small amount of fractioned material is a constraint that can be solved by using in vitro tests The RTG 2 in vitro cytotoxicity test has been used to assess (a) the efficacy of a treatment plant in the aeronautics industry and (b) the exposure of fish and molluses cultured in Esteiro Bay to the effluent of a fish processing factory Ecotoxicological assessments could be done without identifying the responsible chemicals The RTG-2 test was used in combination with concentration/fractionation procedures It proved that the toxicity of the liquid wastes from the aeronautics industry was eliminated by the treatment, and that molluses and fish reared in Esteiro Bay had accumulated toxic chemicals dumped by the fish-processing factory A combination of the RTG-2 cytotoxicity test and HPLC proved to give useful information even for chemicals not identified by GC MS
Fetax interlaboratory validation study: Phase II testing
Authors: Gaudet-Hull Angela M. , Rayburn James R. , Bantle John A. , Burton Dennis T. , Turley Steven D. , Dawson Douglas A. , Dumont James N. , Finch Robert A. , Maurice Margaret A. , Fort Douglas J. , Linder Greg , Buchwalter David 
Published: March 2010

Abstract
The Frog Embryo Teratogenesis Assay—Xenopus (FETAX) is a 96 h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that helps in embryo staging and identifying malformations As part of the ASTM process, an interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FE TAX Six different laboratories participated in the study Each laboratory utilized one technician with the exception of one laboratory, which utilized two independent technicians In Phase I, FETAX proved to be more repeatable and reliable than many other bioassays However, some excessive variation was observed in a few laboratories Some of this variation may have been due to an initial lack of experience with the assay by some technicians Phase II, which is reported here, showed far less intralaboratory and interlaboratory variability than did Phase I Nonteratogens such as saccharin and sodium cyclamate showed the most consistent results, whereas more variability was observed for the teratogens caffeine and 5-fluorouracil Interlaboratory coefficient of variation values for all FETAX end points ranged from 7 3 to 54 7% The minimum concentration to inhibit growth proved to be the most variable end point for three of the four test chemicals, whereas the LC50 and EC50 (malformation) proved to be less variable
Excretion of cadmium and zinc during moulting in the grasshopper Omocestus viridulus (orthoptera)
Authors: Lindqvist Lars , Block Mats 
Published: March 2010

Abstract
Nymphs of Omocestus viridulus (Orthoptera) were reared on grass leaves containing known amounts of 109Cd or 65Zn. After the animals moulted to adults, contents of these metals were measured in the grasshoppers, in the cast of exuviae and in the feces produced during rearing. Dry weights of adult bodies and exuviae were lower for 109Cd-treated grasshoppers than for those given 65Zn. Exuviae accounted for only a minor part of the excreted 109Cd and 65Zn. The 109Cd was assimilated from food to a much smaller extent than was 65Zn. After 15 d of rearing, −50% of the ingested 65Zn, but only 10% of the ingested 109Cd, remained in the grasshoppers. Because the amount of 109Cd in the grasshopper nymphs decreased with time, whereas that of the exuviae were constant, content in exuviae constituted a larger portion of the total content of 109Cd with increasing time between feeding of 109Cd and moulting. For 65Zn there was no such trend.
Application of canonical variate analysis in the evaluation and presentation of multivariate biological response data
Authors: Adams S. Marshall , Ham Kenneth D. , Beauchamp John J. 
Published: March 2010

Abstract
We have applied canonical variate analysis procedures for evaluating multivariate responses of fish populations to various contaminant stressors. Using examples of fish populations experiencing high levels of PCBs in a reservoir and mixed contaminants in a stream, the significance of integrated stress responses among sample populations was compared statistically and graphically using two- and three-dimensional data presentations. For fish from both systems, the most powerful axis of discrimination among sample populations was correlated with the activity of the detoxification enzyme, EROD (7-ethoxyresorufin O-deethylase). Indicators of organ dysfunction were the variables most correlated with the second axis of discrimination among sites in the PCB-contaminated reservoir study. Indicators of lipid metabolism were the variables most correlated with the second and third axes of discrimination among stream fish. Canonical variate analysis procedures are useful for evaluating multivariate response data because they take into account the interrelations and associations among response variables and reveal the integrated nature of organism responses to stress. Using this procedure, the significance of integrated stress responses among different sample populations can be graphically compared and evaluated using two- or three-dimensional data presentations. These types of graphical displays help provide an understanding of the relationships among sample populations that may not be evident from tabular or other types of data summaries. In addition, this approach can be useful in helping to identify factors such as toxicants or other environmental stressors which impair the health of aquatic ecosystems.
New qsar models for polyhalogenated aromatics
Authors: Nevalainen Tapio , Kolehmainen Erkki 
Published: March 2010

Abstract
Electronic properties of polychlorinated dibenzo p dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs), and polychlorinated diphenyl ethers (PCDEs) were calculated using the semi-empirical AM1 method The calculated electronic descriptors — the energy of the lowest unoccupied molecular orbital (ELUMO), the energy of the highest occupied molecular orbital (EHOMO), the ELUMO-EHOMO gap (dE), and molecular polarizability — are related to the Ah receptor binding affinity values of PCDDs, PCDFs, and PCBs and immunotoxicity values for PCDEs The quantitative structure activity relationships (QSARs) based on chlorine substitution patterns were also constructed, and they proved to be very predictive for Ah receptor binding Significant correlations of the electronic factors were found between the dE and Ah receptor binding affinities for PCDDs, PCDFs, and PCBs and for immunotoxicity of PCDEs A combination of descriptors ELUMO and the total number of chlorine atoms attached to a molecule (nCl) gives significant correlation for the Ah receptor binding of PCDFs and for immunotoxicity of PCDEs Hydrophobicity values taken from the literature were shown to be non-significant for toxicity prediction of these polychlorinated compounds
A life-cycle inventory of baby diapers subject to Canadian conditions
Authors: Vizcarra A.T. , Lo K.V. , Liao P.H. 
Published: March 2010

Abstract
A life-cycle inventory of cloth and disposable diapers was conducted based on diapering habits in Canada The parameters evaluated were energy consumption, water consumption, raw materials consumption, atmospheric emissions, water-borne wastes, and solid wastes The results showed that cloth diapers consume more water and produce more waterborne wastes than do disposable diapers, whereas disposable diapers consume more raw materials and produce more solid wastes than do cloth diapers Sensitivity analyses proved these differences to be significant However, with respect to energy consumption and atmospheric emissions, the computed differences were assessed to be insignificant inasmuch as these may be offset by reasonable variations in cloth to-disposable diaper usage ratio, market sharing between home laundering and service laundering, number of laundry loads per week, laundry water temperatures, percentage of dryer drying and line drying, and drying time The Canadian inventory results were compared to those of three similar U S diaper life cycle inventories Although they differ numerically on the estimated rates of resource consumption and environmental releases, all the studies agree that cloth diapers consume more water and produce more waterborne wastes, whereas disposable diapers consume more raw materials and produce more solid wastes, their findings concerning energy consumption and atmospheric emissions were not as consistent The study concludes that neither diaper system can be considered absolutely superior environmentally
Toxicokinetics and toxicity of sediment-associated pyrene and phenanthrene in Diporeia spp.: Examination of equilibrium-partitioning theory and residue-based effects for assessing hazard
Authors: Landrum Peter F. , Dupuis Wendy S. , Kukkonen Jussi 
Published: March 2010

Abstract
The amphipod Diporeia spp. was exposed to pyrene(0.14 to 1.11 μmol g−1) or phenanthrene (0.08 to 0.62 μmol g−1)-dosed sediments for month-long exposures. Phenanthrene was only slightly toxic with 12±3% mortality at the highest sediment dose (0.62 μmol g−1). Failure to attain and maintain toxic residue body burdens, based on a nonpolar narcosis concentration of approximately 6 μmol g−1, accounts for the low mortality. Phenanthrene toxicokinetic parameters were essentially constant among all doses and consistent with previous measures. Sediment concentration was a poor representation of dose for mortality by pyrene. The relative pyrene distribution among the &lt;63-μm particles increased in the smallest-sized particles at larger doses. An apparent stimulation of pyrene accumulation was observed as a peak in uptake clearance values between sediment concentrations of 0.16 and 0.26 μmol g−1 dry sediment. (Uptake clearance is the amount of source scavenged of contaminant per mass of organism per time.) The pyrene particle-size distribution and the variation in kinetics with dose provide a partial explanation for the poor representation of dose by the sediment concentration. The pyrene body burdens provided a good dose response yielding LD50 values of 6.3 (4.6–41.7, 95% C.I.) and 9.4 (7.9–54.2) μmol g−1 for two experiments. These values are consistent with the residue concentrations for 50% mortality by a nonpolar narcosis mechanism. Comparing the experimental and predicted equilibrium partitioning-based sediment concentrations for 50% mortality, the equilibrium prediction overestimates the toxic pyrene sediment concentration by approximately a factor of ten. Diporeia behavior, differential particle-size distribution, and kinetic limitations appear as likely reasons for the variation between calculated and observed concentrations required to produce mortality.
Lethal body concentrations and accumulation patterns determine time-dependent toxicity of cadmium in soil arthropods
Authors: Crommentuijn Trudie , Doodeman Connie J A M. , Doornekamp Anja , Van Der Pol Joost J. C. , Van Gestel Cornelis A. M , Bedaux Jacques J. M. 
Published: March 2010

Abstract
Time-dependent toxicity in bioassays is usually explained in terms of uptake and elimination kinetics of the toxicant By comparing different species with essentially different accumulation kinetics, a firm test of this concept may be made This article compares the sensitivity of six soil arthropods, the collembolans Orchesella cincta and Tomocerus minor, the oribatid mite Platynothrus peltifer, the isopods Porcellio scaber and Oniscus asellus, and the diplopod Cylindroiulus britannicus, when exposed to cadmium in the food Survival was determined at various time intervals, accumulation of cadmium in the animals was measured at one time interval Kinetic based toxicity models were fitted to the data, and estimates were obtained for lethal body concentration, uptake rate constant, elimination rate constant, and ultimate LC50 Two different accumulation patterns could be discerned, these were correlated with time-survival relationships One, species that have the possibility to eliminate cadmium will reach an equilibrium for the internal concentration and also an ultimate LC50 Two, species that are unable to eliminate cadmium but store it in the body will have an ultimate LC50 equal to zero For these species the time in which the lethal body concentration is reached is more important Taxonomically related species appeared to have comparable accumulation patterns, but lethal body concentrations differed It is concluded that knowledge of the accumulation pattern is indispensable for the evaluation of species' sensitivities to toxicants
Accumulation of polychlorinated biphenyl congeners from lake champlain sediments by Mysis relicta
Authors: Lester Deborah C. , McIntosh Alan 
Published: March 2010

Abstract
Polychlorinated biphenyl (PCB) levels in lake trout (Salvelinus namaycush) from Lake Champlain often exceed the F.D.A. “tolerance level” of 2 μg/g (wet weight). Of added concern are recent studies that suggest a relationship between the dioxin-like properties of non-ortho-substituted PCB congeners and impaired lake trout egg hatchability. Dietary accumulation of PCBs is thought to be an important exposure route for fish. The epibenthic freshwater shrimp Mysis relicta is an integral part of the benthic and pelagic food web in Lake Champlain and may act as a link between PCBs in sediments and lake trout. Previous investigations have shown that diurnal migrations of mysids enhance the movement and distribution of toxic contaminants, effectively coupling the benthic and pelagic zones. The objective of this research was to examine the role contaminated sediments play in the transfer of PCBs to mysids. Bioaccumulation was assessed by exposing mysids to such sediments in two ways: (a) with organisms screened from sediments; and (b) with organisms in direct contact with sediments. Accumulation of PCBs over the course of the 24-day exposure period was examined on the following days: 0, 3, 6, 12, 21, and 24. Eighty-nine individual PCB congeners were measured in tissue and sediment. Mysids in direct contact with sediments accumulated significantly higher levels of PCBs than did organisms screened from sediments. Mysids accumulated substantial levels of PCBs, suggesting they may play an important part in the transfer of PCBs from sediments into the Lake Champlain food web. It is clear from this research that sediments can play a critical role in the accumulation of PCBs by mysids.
Inhibition of acetylcholinesterase in the australian freshwater shrimp (Paratya australiensis) by profenofos
Authors: Abdullah A.R. , Kumar A. , Chapman J.C. 
Published: March 2010

Abstract
Profenofos induced significant inhibitory effects on the AChE activity of Paratya australiensis ranging from &gt;40% inhibition at sublethal concentrations of 0.1 to 1.0 μg/L to &gt;80% inhibition at lethal concentrations of ≥10 μg/L. Sublethal chronic exposure (21 d) at a concentration of 0.15 μg/L caused persistent reduction in AChE activity of up to 60%, whereas recovery of AChE activity to normal levels from a 24-h exposure to 0.1 μg/L profenofos required less than 9 d. Shrimp were exposed to 0.1 μg/L profenofos for 24 h and then allowed a period of recovery in pesticide-free water; at the end of this treatment the AChE activity of affected shrimp approached control level. Subsequent 24-h exposures with intermittent stay in pesticide-free water for the same duration as the initial recovery phase resulted in greater inhibition in AChE activity as compared to the initial 24-h exposure. Furthermore, the AChE activity of shrimp at the end of the recovery phases remained significantly depressed.
Ecological assessment for the wetlands at milltown reservoir, missoula, montana: Characterization of emergent and upland habitats
Authors: Linder Greg , Hazelwood Robert , Palawski Don , Malloy John , Dubois Kristi , Bollman Michael , Wilborn David , Ott Suean , Pascoe Gary , Dalsoglio Julie 
Published: March 2010

AbstractWetlands in mining districts in the western United States are frequently impacted by heavy metal contaminated sediments The present study summarizes a soil contamination evaluation and an ecological assessment completed for a Superfund site located at Milltown Reservoir wetlands (MRW) in western Montana For wetlands, as well as upland habitats adjacent to wetlands, biological evaluations in the field and laboratory should be considered critical components in the ecological risk assessment process Depending upon habitat type, field and laboratory methods have been developed for hazard and risk assessment that lend themselves directly to the Superfund ecological risk assessment process, and that consider contaminant bioavailability and subtle expressions of adverse biological effects associated with chronic exposures As part of an ecological risk assessment for MRW, field surveys and a variety of biological test methods (e g., terrestrial and aquatic tests) were critical to the wetland evaluation For evaluating heavy metal effects at MRW, field and laboratory methods within the ecological assessment included wetlands delineation and preliminary plant and wildlife survey, vegetation tests in emergent and upland habitats, soil macroinvertebrate (earthworm) tests, preliminary studies using amphibian and bacterial test systems, soil characterizations, and chemical analysis of soils, sediments, and biological materials In conjunction with chemical analyses, these biological and ecological evaluations yielded an integrated evaluation of ecological effects and exposure at MRW The data gathered from laboratory and field work at MRW suggested that biological and ecological effects were subtle in their expression in the wetland In conjunction with sediment contamination evaluations, these studies should reduce the uncertainty associated with the baseline ecological risk assessment for MRW
Use of benthic invertebrate community structure and the sediment quality triad to evaluate metal-contaminated sediment in the upper clark fork river, montana
Authors: Canfield Timothy J. , Kemble Nile E. , Brumbaugh William G. , Dwyer F. James , Ingersoll Chris G. , Fairchild James F. 
Published: March 2010

Abstract
The upper Clark Fork River, above Flathead River, is contaminated with large amounts of As, Cd, Cu, Pb, Mn, and Zn ores from past mining activities. The contaminated area extends from the Butte and Anaconda area to at least 230 km downstream to Milltown Reservoir. Both the upper Clark Fork River and Milltown Reservoir have been designated as U.S. Environmental Protection Agency Superfund sites because of metal-contaminated bottom sediments. We evaluated the impacts of past mining activities on the Clark Fork River ecosystem using benthic invertebrate community assessment, residue chemistry, and toxicity testing. Oligochaeta and Chironomidae generally accounted for over 90% of the benthic invertebrate community in the soft sediment depositional areas. Taxa of Oligochaeta and Chironomidae were predominantly pollution tolerant. Higher numbers of Chironomidae genera were present at stations with higher concentrations of metals in sediment identified as toxic by the amphipod Hyalella azteca in 28-d exposures. Frequency of mouthpart deformities in genera of Chironomidae was low and did not correspond to concentrations of metals in sediment. Total abundance of organisms/m2 did not correspond to concentrations of metals in the sediment samples. Chemical analyses, laboratory toxicity tests, and benthic community evaluations all provide evidence of metal-induced degradation to aquatic communities in both the reservoir and the river. Using a weight-of-evidence approach-the Sediment Quality Triad - provided good concurrence among measures of benthic community structure, sediment chemistry, and laboratory toxicity.