bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effects of dieldrin on the sperm ultrastructure of the earthworm Eudrilus eugeniae (oligochaeta)
Authors: Reinecke Sophiè A. , Reinecke Adriaan J. , Froneman Moya L. 
Published: March 2010

Abstract
Earthworms of the species Eudrilus eugeniae were exposed to dieldrin, using the contact filter paper method, to study the sublethal effects of the pesticide, which is still widely used in many parts of Africa, on the ultrastructure of spermatozoa. The concentrations ranged from 0.154 to 1.54 μg/cm2 and exposures lasted 48 h. The spermathecae were dissected out and prepared for electron microscopy. Dieldrin was extracted from the worms by steam distillation and analysed by ECD-gas chro-matography. A description of the sperm ultrastructure is presented. This study showed that dieldrin at relatively low concentrations caused structural damage, especially to the nucleus of the sperm. It is argued that this finding could contribute toward the development of a model for predicting environmental quality, based on sperm morphology, sperm motility, and sperm density. The sublethal effects of dieldrin on sperm morphology could provide a subanimal test for ecotoxicity since its effects will most probably be manifested at the population level.
Behavioral effects of pre- and postnatal exposure to individual polychlorinated biphenyl congeners in rats
Authors: Holene Edel , Nafstad Inger , Skaare Janneche Utne , Bernhoft Aksel , Engen Pat , Sagvolden Terje 
Published: March 2010

Abstract
Rats were exposed in utero and through mother's milk either to the coplanar PCB congener 3,3′,4,4′,5–CB (IUPAC no. 126) or to the mono-ortho-substituted PCB congener 2,3′,4,4′,5–CB (IUPAC no. 118). The different groups of mothers were exposed to 1 and 5 mg/kg body weight of PCB 118, and 2 μg/kg b.w. of PCB 126 every second day from day 10 to day 20 of gestation. The exposure did not affect the body weight of the dams or the size, weight, sex ratio, or physical development of the offspring. Operant behavioral testing revealed that the PCB-exposed offspring showed both poorer visual discrimination and higher activity level than did the controls. The coplanar PCB 126 congener was the most potent treatment. These results show that both PCB 118 and PCB 126 produced significant neurotoxic effects in the offspring of exposed females in absence of clinical maternotoxic and fetotoxic effects.
Aqueous sample preparation for bioassay using supercritical fluid extraction
Authors: Wolfe Martha F. , Hinton David E. , Seiber James N. 
Published: March 2010

Abstract
Supercritical fluid extraction (SFE) has become a valuable tool in the preparation of environmental samples for analysis. Most applications to date have been to extract compounds from solid matrices for later analysis by gas chromatographic or high-performance liquid chromatographic methods. The objective of this research was to extend SFE applications to aqueous samples extracted on EmporeTM (C18) solid-phase extraction disks. This technique, which essentially eliminated the use of conventional solvents in preparing the filtered samples, yielded extracts that were compatible with bioassay. The method included aqueous sample extraction onto C18 Empore disks and subsequent elution with supercritical CO2 to isolate and concentrate analytes of interest, using glass beads as an off-line trapping matrix. Analytes were then redissolved in reconstituted water and evaluated for toxicity using the larval medaka, Oryzias latipes, 96-h static toxicity bioassay. Tests with water spikes of molinate, thiobencarb, methyl parathion, and malathion extracted on disks and eluted by SFE gave quantitative recoveries (&gt;90%). Samples of a mixture of these compounds prepared using SFE produced an LC50 of 2.88 mg/L, compared with an LC50 of 2.60 mg/L produced by a water sample directly spiked with equivalent concentrations. Extracts of rice-field water prepared for bioassay and gas chromatographic analysis using the SFE method gave good recoveries without loss of biological activity.
Contaminant exposure and biochemical effects in outmigrant juvenile chinook salmon from urban and nonurban estuaries of puget sound, Washington
Authors: Stein John E. , Hom Tom , Collier Tracy K. , Brown Donald W. , Varanasi Usha 
Published: March 2010

Abstract
Juvenile chinook salmon (Oncorhynchus tshawytscha) were sampled in Puget Sound, Washington, for 2 consecutive years from contaminated urban estuaries, a nonurban estuary, and from the respective hatcheries to assess exposure to anthropogenic chemicals and to determine if biochemical changes were occurring as a consequence of exposure. Exposure to polycyclic aromatic hydrocarbons (PAHs), chlorinated hydrocarbons, and butyltins was determined. The mean concentrations of PAHs and PCBs in stomach contents and PCBs in liver were significantly higher in salmon from the urban estuaries compared to fish from the nonurban estuary in both sampling years. Higher hepatic concentrations of PCBs than DDTs were found in fish from the urban estuaries, but butyltins were rarely detected. Further, mean concentrations of fluorescent aromatic compounds in bile, an estimate of exposure to PAHs, and hepatic cytochrome P4501A and levels of hepatic DNA adducts were also significantly higher in salmon from the urban estuaries compared to either the nonurban estuary or the hatcheries. Results demonstrated increased exposure to chemical contaminants in outmigrant juvenile salmon during their relatively brief residence in urban estuaries of Puget Sound. Moreover, the exposure was sufficient to elicit biochemical responses, which suggest a potential for other biological effects to ensue.
Taxonomic level sufficient for assessing pollution impacts on the southern california bight macrobenthos—revisited
Authors: Ferraro Steven P. , Cole Faith A. 
Published: March 2010

Abstract
Taxonomic sufficiency is the pragmatic concept of identifying organisms only to the taxonomic level necessary and sufficient to meet a study's objectives. Sufficient taxonomy was determined for detecting differences in macrobenthic taxa richness, a dominance index, and three diversity indices between a reference and two pollution-impacted stations in the Southern California Bight using a wide variety of sampling protocols. A higher taxonomic level was deemed sufficient for a given measure and sampling protocol if the statistical power of t tests performed on data grouped to it was essentially the same as that when tests were performed on data grouped to all lower taxa. The sufficient taxon for the optimum sampling protocol was phylum except when assessing biological stimulation based on differences in mean log10(number of taxa) where it was species. Generic dominance and diversity indices were sufficient independent of the sample units tested (0.02, 0.06, and 0.1 m2) and sample size (n ≥ 2). We recommend family level identification of specimens collected using the optimum sampling protocol when assessing macrobenthic community impacts in the study area because familial analyses are very likely to be sufficient. Confounding effects of sampling variables need to be accounted for when determining the true cost efficiency of and the underlying reason(s) for the sufficiency of higher taxonomy.
Relative potency of polychlorinated dibenzo-p-dioxins and dibenzofurans for inducing mixed-function oxygenase activity in rainbow trout
Authors: Parrott Joanne L. , Dixon D. George , Hodson Peter V. , Servos Mark R. , Huestis Usan L. 
Published: March 2010

AbstractToxic equivalent factors (TEFs) were generated for various polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) to compare the relative potencies as inducers of liver mixed-function oxygenase (MFO) activity in rainbow trout (Oncorhynchus mykiss). Trout, dosed orally with one of five PCDD congeners, either [3H]-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), l,2,3,7,8-pentachlorodibenzo-p-dioxin (PnCDD), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,2,3,6,7,8-HxCDD), or [14C]-1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (1,2,3,4,7,8-HxCDD), or [14C]-1,2,3,4,6,7,8-heptachlorodibenzo-p-dioxin (HpCDD) or one of four PCDF congeners, either 2,3,7,8-tetrachlorodibenzofuran (TCDF), 1,2,3,7,8-pentachlo-rodibenzofuran (1,2,3,7,8-PnCDF), 2,3,4,7,8-pentachlorodibenzo furan (2,3,4,7,8-PnCDF), or 1,2,3,4,7,8-hexachlorodibenzofuran (HxCDF), showed increases in liver ethoxyresorufin O-deethylase (EROD) activity up to 250-fold. Liver concentrations of congeners were better predictors of EROD activity than oral dose. TEFs, ratios of the potency of each congener to that of TCDD, were calculated comparing “threshold” PCDD concentrations that induced EROD significantly above control levels. In cases of nonparallel dose-response curves between congeners, these comparisons are more relevant to environmental situations as PCDDs are compared at concentrations closer to those in the environment, instead of at higher pharmaceutical levels. Threshold-based TEFs were: PnCDD, 1.8; 1,2,3,6,7,8-HxCDD and 1,2,3,4,7,8-HxCDD, 0.4; HpCDD, 0.05; 2,3,4,7,8-PnCDF, 2; TCDF, 0.5; 1,2,3,7,8-PnCDF and HxCDF, 0.4. The ranking of potencies of the PCDFs was the same in fish as in mammalian tests, with the exception of PnCDD and 2,3,4,7,8-PnCDF, which were more potent to fish than was TCDD. Fish TEFs calculated at the threshold of EROD induction were about four to five times larger than international TEFs (I-TEFs), which are based on mammalian tests. At low concentrations typical of environmental exposures, TEFs may be different from mammalian-based TEFs.
Lesions and parasites in white suckers, Catostomus commersoni, in bleached-kraft pulp mill-contaminated and reference rivers
Authors: Couillard Catherine M. , Gagnon Pierre , Hodson Peter V. , Dodson Julian J. 
Published: March 2010

Abstract
The objective of this study was to determine if the prevalences of lesions and parasites were different in white suckers (Catostomus commersoni) living upstream and downstream from a bleached-kraft pulp mill in the St. Maurice River, Quebec, Canada. Fish were sampled from two downstream and one upstream sites and were examined internally and externally. Fish living downstream from the mill had more abundant visceral fat, a higher prevalence of deformed fin rays, and a higher prevalence of black livers than fish caught upstream. They were also more frequently infested by intestinal parasites and less frequently infested by larvae of the nematode Eustrongylides in the mesentery. These changes could not be associated specifically to exposure to the pulp mill effluent since they were either explained by among-site differences in fish length or by an upstream-downstream ecological gradient other than the effluent gradient. This ecological gradient was demonstrated by comparison with a reference river, the Gatineau, that had similar physical characteristics but no pulp mill.
Toxicity and hazard ranking of s-triazine herbicides using microtox® two green algal species and a marine crustacean
Authors: Gaggi C. , Duccini M. , Bacci E. , Sbrilli G. , Bucci M. , Naby A.M. Hasab El 
Published: March 2010

Abstract
The acute toxicities of five s-triazines (atrazine, prometryn, simetryn, ametryn, terbutryn) were measured using two algae (one freshwater species, Selenastrum capricornutum, and one marine species, Dunaliella tertiolecta), Microtoxr̀ bacteria, and the brine shrimp, Artemia salma. The algae were one to three orders of magnitude more susceptible to tested compounds than were bacteria or brine shrimp. The transformation of effective concentrations of the chemicals, obtained from toxicity measurements, into percent of the saturation level in water is proposed as a first evaluation of potential hazard to aquatic systems. Simetryn was found to be the most hazardous s-triazine for all species tested.
Do aquatic insects avoid cadmium-contaminated sediments?
Authors: Hare Landis , Shooner Frédéric 
Published: March 2010

Abstract
The long-term colonization of profundal lake sediments having a range of spiked cadmium (Cd) concentrations (0.007 to 2.7 μol/g dry wt.) was measured in the field. Population densities of two of the most abundant colonizing insects (the chironomids Procladius [Holotanypus] sp., and Sergentia coracina) were unrelated to the Cd gradient, even though both taxa accumulated Cd in direct relation to its concentration in sediment. Cadmium concentrations in these taxa ranged from approximately 0.3 to 5 μg/g, and 1 to 65 μg/g, respectively, along the sediment Cd gradient. Cadmium concentrations in Chironomus (salinarius gp.) sp. larvae also responded positively to the sediment Cd gradient and ranged from 0.2 to 50 μg/g. In contrast with the two other taxa, the abundance of Chironomus (salinarius gp.) sp. larvae was negatively correlated with the sediment Cd gradient. To determine if the abundance pattern of Chironomus (salinarius gp.) sp. was the result of a behavioral or a toxic response, larvae of the three chironomid taxa were given a choice between field]control and Cd-spiked sediments in the laboratory. None of the taxa avoided the Cd-spiked sediments, suggesting that the lower abundance of Chironomus (salinarius gp.) sp. at high Cd concentrations in the field was due to Cd toxicity and not to avoidance of the Cd-rich sediments.
The acute whole effluent toxicity of storm water from an international airport
Authors: Fisher Daniel J. , Turley Steven D. , Turley Bonnie S. , Yonkos Lance T. , Ziegler Gregory P. , Knott Melvin H. 
Published: March 2010

Abstract
In October 1990, the U.S. Environmental Protection Agency promulgated application requirements with deadlines for storm-water dischargers associated with industrial activity and certain municipal systems. Major airports have a number of hydrocarbon-based contaminants that could appear in storm-water runoff. In addition, ethylene, diethylene, and propylene glycol deicing and anti-icing mixtures are used during freezing and near-freezing weather. The objective of this study was to characterize the potential acute impact on aquatic life from industrial storm-water discharges from an international airport. Samples from winter storm events caused acute toxicity to both the fathead minnow (Pimephales promelas) and the daphnid (Daph-nia magna), with LC50 values for both species as low as 1.0 to 2.0% effluent. The toxicity of the samples was due to the various glycol-based deicer/anti-icer mixtures used during these events. High oxygen demands and elevated total nitrogen levels are other potential problems during anti-icing/deicing activities. Samples from rain events during the nonwinter months at the airport did not cause acute toxicity unless associated with fuel spills. As a result of this study, a new discharge permit has been issued for this airport, requiring the implementation of plans for the collection and recycling and/or disposal of the deicer/anti-icer mixtures.
A biomarker, P450 RGS, for assessing the induction potential of environmental samples
Authors: Anderson Jack W. , Rossi Steven S. , Tukey Robert H. , Vu Tien , Quattrochi Linda C. 
Published: March 2010

AbstractIn this study we describe the use of a transgenic cell line for the identification of potentially toxic compounds in test solutions and environmental samples. The reporter gene system (RGS), derived from a human liver cancer cell line, has been engineered such that the CYP1A1 gene, when activated by an inducer compound, will produce luciferase instead of P450. Eighteen hours after application of an inducer the reaction is stopped by rinsing, the cells lysed, and the cytoplasm measured for luminescence and protein content (for normalization). Induction by such compounds as dioxin, dioxin-like PCB congeners (co-planars), and polycyclic aromatic hydrocarbons (PAHs) infers these xenobiotics are present at levels that are potentially toxic, carcinogenic, or mutagenic to organisms. Multiple wells with attached cells in 2 ml of media were inoculated with various concentrations of toxicants in organic solvents (including DMSO, toluene, and dichloromethane). Volumes tested successfully thus far are 2 to 20 μl of solvent. Solvent extracts (using standard extraction methods) of aquatic sediments were directly applied to the assay system. Test results show significant RGS induction from concentrations of inducer compound that, if present in a typical 40-g sediment sample, would be (in ng/g or ppb): 0.05 for dioxin; 10 to 1,000 for a range of coplanar PCB congeners; about 2,000 for several Aroclor mixtures; and 300 for a mixture of PAHs. A mixture of pesticides at concentrations about four times the PAH levels did not produce an induction response. Results presented here indicate that testing for the presence of potentially toxic chemicals in environmental samples could be performed rapidly, with sensitivity and specificity using this RGS cell line.
Atmospheric deposition of pesticides in a small southern saskatchewan watershed
Authors: Waite Don T. , Sommerstad Hal , Grover Raj , Kerr Lorne A. , Westcott Neil D. , Irvine Don G. 
Published: March 2010

Abstract
Weekly atmospheric deposition samples were collected from early May to early September during 1984 to 1987 in a small agricultural watershed near Regina, Saskatchewan, an area in the midst of extensive agricultural pesticide use in the Canadian prairies. “Bulk” deposition samples were collected weekly in duplicate and analyzed for six herbicides (bromoxynil, 2,4–D, dicamba, diclofop, triallate, and trifluralin) and five insecticides (carbaryl, carbofuran, chlorpyrifos, deltamethrin, and dimethoate). In general, no significant differences were found among the duplicate samples. Over the 4-year period, the frequency of weekly detection of herbicides during the growing seasons was 0, 32, 39, 53, 58, and 67% for trifluralin, bromoxynil, triallate, diclofop, dicamba, and 2,4–D, respectively. For insecticides, only carbaryl and carbofuran were detected in one to two samples in the years for which the insecticides were analyzed. This infrequent detection reflected the relatively high detection limits set for the insecticides as compared to those for the herbicides. The seasonal herbicide atmospheric deposits during the growing period over the 4-year period (mg ha−1) ranged from 90 to 234 (bromoxynil), 386 to 1,374 (2,4-D), 20 to 219 (dicamba), 43 to 338 (diclofop), and 9 to 260 (triallate). Highest deposition rates were measured during and immediately following the spraying periods, with lesser, but significant, amounts also being detected during the harvest operations in August.
Recovery of known-age Hyalella azteca (amphipoda) from sediment toxicity tests
Authors: Tomasovic Michael J. , Dwyer F. James , Greer Ivan E. , Ingersoll Christopher G. 
Published: March 2010

Abstract
Recovery of 1-, 7-, 14-, or 21-d-old Hyalella azteca from sediment was evaluated. Recovery of 1- and 7-d-old amphipods was below an acceptability criterion of 80% survival for sediment tests. Another important aspect to consider when conducting sediment tests with H. azteca is defining mortality. A second study was conducted to evaluate the decomposition rate of dead amphipods in sediment. Regardless of sediment type, ≥ 90% of the amphipods started to break apart within 12 h of death; specifically, the head separates from the body. Therefore, if an immobile amphipod with its head and body intact is recovered in sieved material, it was probably alive within 12 h of the end of the test (an amphipod may be alive before sieving but may die during the sieving process). However, immobile amphipods removed from the sediment surface before sieving are known to be dead.
Distribution and excretion of Cd, Hg, methyl-Hg and Zn in the predatory beetle Pterostichus niger (coleoptera: Carabidae)
Authors: Lindqvist Lars , Block Mats , Tjälve Hans 
Published: March 2010

Abstract
Excretion and distribution of cadmium (Cd), mercury (Hg), methylmercury (methyl-Hg), and zinc (Zn) were studied in the predatory beetle, Pterostichus niger. Specimens of P. niger were fed with insect larvae containing 109Cd, 203Hg, methyl-203Hg, or 65Zn. After ingestion of the larvae, the metal contents in the beetles were measured daily for 30 d by γ-spectrometry. Additional beetles were used for autoradiography 5, 15, and 19 d after ingestion of the metals. Excretion of the metals was fast during an initial interval but occurred thereafter at a slow rate. After 2 weeks, the contents of Cd and inorganic Hg had decreased to approximately 1% of the ingested amounts. For Zn and methyl-Hg, higher levels were retained in the beetles. Thus, after 30 d, Zn content was 20% of the ingested amount, whereas for methyl-Hg 60% was retained in the body. Autoradiography showed high levels of all metals in the gut. For methyl-Hg, in contrast to inorganic Hg, there was also an evenly distributed labelling in most body tissues. This labelling was also seen for Zn, although at a lower level than for methyl-Hg. Cadmium showed a localisation in the integument, which was not seen for the other metals. Our results show that patterns of uptake and excretion of the examined metals in P. niger vary considerably and that the distribution pictures show specific features for the individual metals.
Toxicity testing with artificial streams: Effects of differences in current velocity
Authors: Lowell Richard B. , Culp Joseph M. , Wrona Frederick J. 
Published: March 2010

Abstract
When designing toxicity tests with lotic organisms, the role of current velocity is a key consideration when evaluating the test organism's response. We conducted a series of short-term toxicity experiments with the mayfly Baetis tricaudatus Dodds to determine the effect of current velocity on mayfly response to the reference toxicant sodium chloride. The tests were run at three substratum-level velocities: low (0 cm/s), medium (6 cm/s, typical of estimated intrasubstratum velocities in the field), and high (12 cm/s). The end points measured for the mayflies were immobilization and number of molts. The animals showed signs of stress, and the EC50 was lower in the 0 cm/s treatment, probably due to insufficient delivery of oxygen to the gills. This did not, however, lead to much change in sensitivity (measured as lowest-observed-effect concentration; LOEC) to the reference toxicant. Furthermore, neither EC50 nor LOEC differed between 6 and 12 cm/s. This suggests a threshold between 0 and 6 cm/s above which the effect of current velocity was no longer measurable. These results provide initial support for the recommendation that short-term toxicity tests using lotic organisms should ensure that the animals are exposed to at least some flow. Long-term tests, and those with different toxicants, may require further fine-tuning of current velocity.