bluuebunny/crossref_metadata_2025 huggingface dataset:
Sources of error in screening by flow cytometry for the effects of environmental mutagens
Authors: Tiersch Terrence R. , Wachtel Stephen S.
Published: March 2010

Flow cytometry is often used to detect DNA aneuploidy and mosaicism associated with malignancy or genetic damage. Yet DNA aneuploidy and mosaicism detected by flow cytometry may be more apparent than real. In contrast to the DNA mass observed for blood, we consistently found markedly different values and higher variability for DNA mass among other tissues collected from the same animal. Prepared mixtures of blood and other cells generated multiple fluorescence peaks identical to those that might be expected for aneuploid mosaicism. Moreover, analysis of tissues such as feather pulp, which contains a combination of cell types, yielded multiple fluorescence peaks that were not observed when blood alone was analyzed. Thus care should be exercised in classifying DNA values from different tissues as normal or abnormal, because the appearance of supernumerary fluorescence peaks might not always indicate the presence of abnormal cell populations.
Effects of the presence and absence of various fractions of dissolved organic matter on the toxicity of fenvalerate to Daphnia magna
Authors: Hodge Valerie A. , Fan Gary T. , Solomon Keith R. , Kaushik Narinder K. , Leppard Gary G. , Burnison B. Kent
Published: March 2010

Toxicity of fenvalerate to Daphnia magna, in the presence of particulate or dissolved organic matter, was investigated. Dissolved organic matter (DOM) was isolated from Jack Lake, Ontario (JL-DOM), and separated into four size fractions. A sample of fibrils from Lake St. George, Ontario, and two model substances, pectin and polygalacturonic acid, represented DOM of algal origin. Chlamydomonas reinhardii was included as a source of particulate organic matter for comparison. Daphnia magna (≤48 and ≤24 h old) was exposed to treatments of fenvalerate plus these sources of DOM. The end point of the static 48-h bioassays was the inability of daphnids to swim during a 10-s period after gentle prodding. Results from treatments with JL-DOM (10 × natural concentrations) and fibrils (4 mg/L) were analyzed independently. The EC50 of fenvalerate plus >0.2 μM JL-DOM (0.22 μg/L) was significantly lower than that of the >10-kD-molecular-weight fraction (1.99 μg/L), but neither was different from fenvalerate alone (0.91 μg/L). There were no significant differences between treatments including lake fibrils, pectin or polygalacturonic acid, or between age groups. No bioassays using Daphnia magna and algal fibrils as a source of DOM have been conducted previously. An adhesion phenomenon occurred between Daphnia magna and the DOM (JL-DOM and fibrils) in the presence of fenvalerate. DOM and fibrils aggregated on the spine and antennae of the daphnids, which impaired the ability of the organisms to swim. Adhesion increased as the concentration of fenvalerate increased but was absent in controls. This phenomenon may confound the results of bioassays that use immobility as an end point. Adhesion could be an important sublethal effect of fenvalerate, affecting daphnid survival and its role as a food source in aquatic systems.
Impurity variations in a carbon black: Characterization by the ames Salmonella mutagenicity assay and polycyclic aromatic hydrocarbon analysis
Authors: Agurell Eva , Löfroth Göran
Published: March 2010

Samples of a furnace carbon black, N-330, were collected from the production line during a period of three years. Following extraction with benzene and solvent exchange, the mutagenic response was determined with the Ames Salmonella assay in the TA98 and TA100 strains with and without addition of S9. The samples were mainly mutagenic in the presence of S9, showing that polycyclic aromatic hydrocarbons (PAHs) were the major mutagenic impurities. The mutagenic response varied 30-fold among the samples. Analysis of PAHs in the range from phenanthrene to coronerie also showed a wide variation between samples being correlated to the mutagenic response. The large concentration differences of impurities between batches implies that a single batch cannot be used for generalized toxicological studies. The presence of PAH and mutagenic impurities in the investigated carbon black is a significant source of these environmental pollutants compared to another source of concern, automobile exhaust.
Relationships between behavior and the inhibition of acetylcholinesterase in birds exposed to organophosphorus pesticides
Authors: Hart Andrew D. M.
Published: March 2010

Effects of sublethal acute doses of the organophosphate chlorfenvinphos on the behavior of captive starlings (Sturnus vulgaris) were investigated in four experiments. Effects were more complex and occurred at lower levels of exposure than in previous avian studies. Altered posture was associated with inhibition of brain acetylcholinesterase (AChE) activity to less than about 88% of the normal level. Reductions in flying and singing, and increased resting, were associated with inhibition of AChE to below 61 % normal. Substantial recovery of normal behavior occurred within 5 h of treatment. Feeding activity was reduced for over 8 h in birds with AChE inhibited to less than about 73% normal, accompanied by a proportionate loss of body weight. Flying activity was initially depressed for 1 to 2 h but then increased above normal levels. Singing of isolated males in response to the playback of recorded song decreased in proportion to the inhibition of AChE. Performance of a foraging task was unaffected by inhibition of AChE to as little as 57% normal. A review of relevant studies suggests that only broad generalizations, of limited practical value, can be made about the relationship between AChE inhibition and behavioral effects.
Stability of residues and brain cholinesterase activity in carcasses of northern bobwhite exposed to three organophosphate insecticides
Authors: Johnson Gregory D. , Palmer David A. , Krueger Henry O. , Fischer David L.
Published: March 2010

Presence of pesticide residues in animal tissues and inhibition of brain cholinesterase (ChE) activity are often used to document exposure of animals to organophosphorus and carbamate insecticides and determine if the animal's death resulted from exposure. Carcasses found during field studies can be several days old; therefore, it is important to determine how residue and ChE levels change over time after death. Objectives of this study were to determine pesticide residues in tissues and/or brain acetylcholinesterase (AChE) activity of northern bobwhite (Colinus virginianus) exposed to either sulprofos, methamidophos, or azinphos-methyl, and the extent to which residue and AChE levels change with decomposition of carcasses under field conditions. Test compounds were administered orally by gavage and/or in the diet to northern bobwhite at previously determined sublethal and lethal exposure levels. Birds surviving the dose were sacrificed and placed in crop fields. Carcasses were recovered following 0-, 24-, 48-, and in some cases 96-h intervals and analyzed for residues. Brain AChE activity was also determined for birds exposed to sulprofos. Residues were detected in all exposed birds and varied with dose. Results indicate that pesticide residues and brain AChE levels were stable under field conditions at least up to 48 to 96 h following death.
Chromosome damage in wild rodents inhabiting a site contaminated with aroclor 1254
Authors: Shaw-Allen Patricia L. , McBee Karen
Published: March 2010

An in situ investigation of structural chromosomal damage in wild rodents from a site contaminated with Aroclor 1254 was undertaken to compare effects observed in nature to those documented in previous laboratory studies. Laboratory assays indicate that Aroclor 1254 does not cause structural damage to chromosomes. However, the many variables at work in actual waste-site environments and receptor populations led us to question whether exposures under natural conditions could potentially lead to different results using the same assay systems. Individuals of three rodent species, Peromyscus leucopus, Sigmodon hispidus, and Reithrodontomys fulvescens, were collected from the contaminated site and three matched, pristine reference sites. Standard somatic metaphase chromosome preparations from bone marrow were examined for chromosomes lesions. Comparisons were made between conspecifics from the Aroclor-contaminated site and the reference sites. Significant increases in chromosome damage were not observed in animals from the Aroclor-contaminated site, indicating agreement between laboratory assays and an in situ application of this assay system.
Effects of ionizing radiation on breeding swallows at current radiation protection standards
Authors: Zach Reto , Hawkins Janice L. , Sheppard Steve C.
Published: March 2010

A field study was carried out involving breeding tree swallows (Tachycineta bicolor) to see whether human protection standards are also adequate for birds, as implied by an International Commission on Radiological Protection 1977 assumption. The swallows were provided with a grid of nest boxes with radiation levels up to 45 times the background level, or 6 μGy/h. Swallows were permitted to settle freely in the boxes for breeding, regardless of radiation level. The breeding performance was exceptionally high and was not influenced by experimental radiation exposure. The results were similar for the growth performance of nestlings. Thus numerous, apparently healthy young were raised to fledging in a radiation environment that corresponded to an annual dose of up to 50 mSv, which is the current limit for human occupational exposure. The corresponding limit for the public is lower, at 5 mSv/a. The results show that swallows are not affected during the nesting season by radiation doses above the limits for humans, provided birds and humans share a similar radiation environment.
The relationship of total copper 48-H LC50s toDaphnia magnadry weight
Authors: Lazorchak James M. , Waller William T.
Published: March 2010

A study was conducted with Daphnia magna to determine the effect of neonate weight loss or lack of weight gain on experimentally derived copper 48-h LC50s. Standard unfed tests as well as algal-fed (Selenastrum capricornutum) tests were used to look at weight loss and gain. No significant relationship was found between amount of weight loss and copper LC50s. However, dry weight of unfed and algal-fed control organisms could be used to predict total copper LC50s.
Phytotoxicity studies withLactuca sativain soil and nutrient solution
Authors: Hulzebos E.M. , Dirven-Van Breemen E.M. , van Dis W.A. , Herbold H.A. , Hoekstra J.A. , Baerselman R. , van Gestel C.A.M. , Adema D.M.M. , Henzen L.
Published: March 2010

The toxicity of 76 priority pollutants to lettuce (Lactuca sativa) was determined in soil and in nutrient solution. In the first case a static and in the latter a semistatic exposure was established Volatile and easily degradable compounds had high EC50 values in soil (> 1,000 μg/g). In nutrient solution, however, several of these compounds were rather toxic. Quantitative structure-activity relationships (QSARs) relating EC50 values to log Kow could be described for the toxicity in nutrient solution. Generally, the toxicity of the compounds increased with increasing lipophilicity. Deviations were (partly) caused by reactivity (N-containing compounds, double bonds in compounds), low lipophilicity (log Kow values < 1), and EC50 values close to solubility. To relate toxicity in soil and nutrient solution, soil EC50 values were recalculated to values in the soil pore water using calculated adsorption coefficients. Estimated pore-water EC50 values showed a good correlation with values determined in nutrient solution but were not equal to these values. The differences can be attributed to differences in exposure (static vs. semistatic).
Effects of sediment-bound bifenthrin on gizzard shad and plankton in experimental tank mesocosms
Authors: Drenner Ray W. , Hoagland Kyle D. , Smith J. Durward , Barcellona Wayne J. , Johnson Philip C. , Palmieri Mark A. , Hobson James F.
Published: March 2010

We examined the effects of bifenthrin, a synthetic pyrethroid insecticide, on gizzard shad (Dorosoma cepedianum) and plankton in an 8-d experiment using 16 outdoor tank mesocosms (5.5 m3). The replicated design included six treatments of sediment-bound bifenthrin (0-7,750 ng/L), a sediment-free control treatment, and a fish-free control treatment (with untreated sediment). The 8-d LC50s for gizzard shad were 521 and 207 ng/L, using bifenthrin concentrations in water 1 h after addition and average concentrations during the study, respectively. In the presence of bifenthrin, gizzard shad exhibited abnormal stress behaviors, including swimming slowly, gulping near the water surface, opercle flaring, and head shaking. Bifenthrin significantly reduced copepod nauplii density and turbidity, increased rotifer density and Secchi depth, and affected chlorophyll.
Screening of isolates and strains of Rhizobium leguminosarum biovar Trifolii for heavy metal resistance using buffered media
Authors: Chaudri Amar M. , McGrath Steve P. , Giller Kenneth E. , Angle J. Scott , Chaney Rufus L.
Published: March 2010

The computer program GEOCHEM-PC was used to calculate the metal ion activities of Cu, Zn, Cd, and Ni in defined media amended with various metal ion buffers at pH 6.6 or 6.0 so that the lowest-observed-effect concentrations (LOECs) of these metals to isolates and strains of Rhizobium leguminosarum biovar trifohi could be determined. Strains from the U.S. Department of Agriculture (USDA) Beltsville (MD) Rhizobium culture collection were generally more tolerant of the metals than any of the isolates from the sludge-treated soil (S-isolates) and those from farmyard manure-treated soil (F-isolates), although the S- were more metal resistant than the F-isolates. All isolates and strains, however, tolerated much larger concentrations in the buffered systems than those found in the solutions of soils from which they originated. Copper toxicity, using iminodiace-tate (IDA), occurred for the F- and S-isolates and USDA strains at concentrations of 16, 47, and 430 μg ml−1, respectively, corresponding to predicted ion activities of 0.002, 0.006, and 0.06 μg ml−1, respectively. The Zn LOECs for the F- and S-isolates, without a buffer, occurred at concentrations of 47 and 207 μg ml−1, respectively, corresponding to predicted ion activities of 37 and 157 μg ml−1, respectively. No toxicity occurred when nitrilotriacetate was used for Cd up to concentrations of 356 μg ml−1 (Cd ion activity of 2.6 μg ml−1). Nickel concentrations up to 0.6 μg ml−1 had no effect with ethylene-bis(oxyethylenenitrilo)tetraacetate (EGTA; Ni ion activity of 0.006 μg ml−1) and up to 186 μg ml−1 with IDA (Ni ion activity of 11 μg ml−1).
Impact of hexazinone and metsulfuron methyl on the zooplankton community of a boreal forest lake
Authors: Thompson D.G. , Holmes S.B. , Wainio-Keizer K. , Macdonald L. , Solomon K.R.
Published: March 2010

The impact of hexazinone and metsulfuron methyl herbicides on the zooplankton community of a typical boreal forest lake was investigated using in situ enclosures and a replicated multiple-treatment-level experimental design. Concentration-dependent reductions of zooplankton abundance in response to hexazinone treatment were readily apparent, whereas metsulfuron methyl generated only marginal effects. Field-based, nonlinear regression estimates of EC50 (<6.0 mg L−1) for hexazinone-induced reduction of zooplankton abundance suggest that abundance of various zooplankton taxa may be expected following chronic exposure to environmentally realistic concentrations of this herbicide (i.e., approximately 1 mg L−1). Time to recovery was proportional to exposure level, with definite recovery observed at the 0.01- and 0.1-mg L−1 concentrations of hexazinone. The reduced magnitude of impact, as well as the relative timing of response and recovery in the zooplankton as compared to the phytoplankton community, was consistent with the postulate that hexazinone effects were secondary in nature, resulting indirectly from reductions in phytoplankton biomass and DO. The data provide evidence to suggest that chronic exposure to hexazinone concentrations approximating 1 mg L1− or above may result in reduced primary productivity in lentic ecosystems, which may in turn cause reductions in zooplankton abundance.
Using QSAR to evaluate phenomenological models for sorption of organic compounds by soil
Authors: Brusseau Mark L.
Published: March 2010

The functional dependencies of equilibrium and nonequilibrium sorption parameters on solute molecular descriptors were analyzed for 29 organic compounds and two soils. Similar correlation patterns were obtained with all three evaluated size/shape descriptors (molecular surface area, van der Waals volume, molecular connectivity). The functional dependencies of equilibrium distribution coefficients on the solute molecular descriptors were analyzed for three systems used as phe-nomenological models of sorption by soil (octanol, reversed-phase HPLC packing material [RPLC], polymer). The correlation patterns exhibited by the three models were compared to those reported for the soil systems. The correlation patterns exhibited by the soil data were similar to the patterns exhibited by the polymer systems and dissimilar to those exhibited by the octanol and RPLC systems. In addition, the correlation pattern between the sorption rate coefficient and molecular connectivity was similar to that between polymer-diffusion coefficients and molecular connectivity. Hence, it appears that the polymer analog may be the most appropriate of the three models for representing both equilibrium and nonequilibrium sorption by soil. Based on these results, the polymer analog is suggested as the phenomenological model of choice for investigating and evaluating the sorption dynamics of low-polarity organic compounds in soil systems.
Degradation azo dyes by environmental microorganisms and helminths
Authors: Chung King-Thom , Stevens S. Edward
Published: March 2010

The degradation of azodyes by environmental microorganisms, fungi, and helminths is reviewed. Azo dyes are used in a wide variety of products and can be found in the effluent of most sewage treatment facilities. Substantial quantities of these dyes have been deposited in the environment, particularly in streams and rivers. Azo dyes were shown to affect microbial activities and microbial population sizes in the sediments and in the water columns of aquatic habitats. Only a few aerobic bacteria have been found to reduce azo dyes under aerobic conditions, and little is known about the process. A substantial number of anaerobic bacteria capable of azo dye reduction have been reported. The enzyme responsible for azo dye reduction has been partially purified, and characterization of the enzyme is proceeding. The nematode Ascans lumbncoides and the cestode Momezia expansa have been reported to reduce azo dyes anaerobically. Recently the fungus Phanerochaete chrysosporium was reported to mineralize azo dyes via a peroxidation-mediated pathway. A possible degradation pathway for the mineralization of azo dyes is proposed and future research needs are discussed.
Relationship between acid volatile sulfide and the toxicity of zinc, lead and copper in marine sediments
Authors: Casas Atina M. , Crecelius Eric A.
Published: March 2010

It has been proposed that acid volatile sulfide (AVS) is an important sediment phase for determining the toxicity of certain trace metals. By evaluating the ratio of the molar quantities of simultaneously extracted metal (SEM) to AVS, the toxicity of metals to organisms in contact with sediment can be predicted. This study examines the role of AVS in predicting the toxicity of zinc, lead, and copper in marine sediments.

Sediment samples were titrated with zinc, lead, and copper and subsequently analyzed for SEM, pore-water (PW) metal, and AVS retention. In most cases, metal was not detected in the pore waters until the AVS was exceeded, suggesting that AVS is an adequate measure of the metal-binding capacity of a sediment. The [SEM]-to-[AVS] ratios were calculated and toxicities predicted for each spiking concentration where [SEM]/[AVS] > 1. A 10-d, flow-through, acute bioassay using the marine poly-chaete Capitella capitata was conducted to examine the prediction of toxicity from the metal titrations and the bioassay sediment chemistry data. In most cases, mortalities occurred as predicted. AVS and the [SEM]-to-[AVS] ratio proved useful as predictors of toxicity for zinc, lead, and perhaps copper. Another tool for predicting metal toxicity in sediments may be the [PW]/LC50 value; in every case where this ratio was >1, mortalities occurred.
Hepatic cadmium, metal-binding proteins and bioaccumulation in bluegills exposed to aqueous cadmium
Authors: Cope W. Gregory , Atchison Gary J. , Wiener James G.
Published: March 2010

We examined sublethal responses of juvenile bluegills Lepomis macrochirus to aqueous cadmium in two 28-d tests (test I, 0.0-8.4 μg Cd per liter; test II, 0.0-32.3 μg Cd per liter) in an intermittent-flow diluter. The experimental design was completely randomized, with two replicates in each of eight treatments (seven Cd exposures and one water control with 25 fish per replicate). Cadmium did not affect the growth of test fish. The mean whole-body concentrations of Cd in exposed fish were 1.8- to 44-fold those in controls in the two tests. Mean concentrations of hepatic nonthionein cytosolic Cd (not bound by metal-binding proteins, MBP) in all Cd treatments greatly exceeded those in controls, and mean concentrations of hepatic MBP in all treatments except one (0.8 μg Cd per liter in test I) exceeded those in controls. Nonthionein cytosolic Cd, hepatic MBP, and whole-body Cd in bluegills were linearly related to exposure concentrations within the range 0 to 20 μg Cd per liter. Much of the total Cd-binding capacity of hepatic MBP per fish was occupied by Cd after the 28-d exposures, although additional Cd-binding capacity remained unoccupied by Cd in fish in all treatments. The mean total Cd-binding capacity of hepatic MBP per fish, which ranged from 1.7 to 14 nmol Cd in test I and from 0.8 to 24 nmol Cd in test II, increased in a concentration-response manner at exposure concentrations below 13 μg/L. Nonthionein cytosolic Cd was the most sensitive indicator of Cd exposure, based on an LOEC of 0.8 μg Cd per liter.
Copper intake and health threat by consuming seafood from copper-contaminated coastal environments in taiwan
Authors: Han Bor-Cheng , Jeng Woei-Lih , Hung Tsu-Chang , Jeng Ming-Shiou
Published: March 2010

The purpose of this paper is to describe the impact of copper pollution on the main aquaculture coast of Taiwan and the potential risk from eating the green oysters cultured along the polluted coast. Our data show that the highest average concentration of copper (2,194 ± 212 μg/g) in oysters was observed in the Erhjin Chi estuary from 1986 to 1990 (after the “green oyster” incident) The copper concentration in both the seawater and the sediment collected along the Erhjin Chi estuary was also the highest in all sampling locations. Copper concentration in oysters collected from Erhjin Chi, Hsiangshan, and Anping from 1988 to 1990 was, respectively, 61, 29, and 22 times higher than that of 10 years ago The potential risk from consuming oysters is relatively higher than that of other seafoods due to the high bioaccumulation of oysters The oysters in the Erhjin Chi estuary had an average concentration of copper of 3,075 ± 826 μg/g during the past three years (1988-1990). The average copper intake from oysters for an adult with 70 kg body weight was 12.6 mg/d The estimate indicated that the average copper intake from the oysters for female individuals is 14 times more than that of international limits. Based on the average value, long-term intake of copper through consumption of oysters cultured along the Erhjm Chi estuary could be critical, especially for some high-risk groups.
Effect of chlorpyrifos on soil microbial activity
Authors: Pozo C. , Martinez-Toledo M. V. , Salmeron V. , Rodelas B. , Gonzalez-Lopez J.
Published: March 2010

A study of the effects of the insecticide chlorpyrifos on soil microbial activity was made. Parameters included total bacterial populations, fungi, aerobic N2-fixing bacteria, denitrifying bacteria, nitrifying bacteria, nitrogenase activity, acid and alkaline phosphatases, arylsulfatase, and dehydrogenase. The presence of 2.0, 3.5, 5.0, and 10.0 kg/ha of chlorpyrifos significantly (p < 0.05) decreased aerobic dinitrogen-fixing bacteria and dinitrogen fixation, particularly after a second insecticide treatment The total number of bacteria increased significantly at concentrations of 2.0 to 10.0 kg/ha. Activities of acid and alkaline phosphatases and dehydrogenase significantly decreased initially at concentrations of 2.0 to 10.0 kg/ha, but recovered after 14 d to levels similar to those in control soil without chlorpyrifos. Fungal populations, nitrifying bacteria, and denitrifying bacteria were not affected as a consequence of the addition of the insecticide.
Chlorinated hydrocarbons in early life stages of the common snapping turtle (Chelydra serpentina serpentina) from a coastal wetland on lake Ontario, Canada
Authors: Bishop Christine A. , Lean David R S , Carey John H. , Brooks Ronald J. , Ng Peggy
Published: March 2010

To assess intra-clutch variation in contaminant concentrations in eggs, and to investigate the dynamics of chlorinated hydrocarbon accumulation in embryos of the common snapping turtle (Chelydra serpentina), concentrations of p,p DDE, hexachlorobenzene, trans nonachlor, cis-chlordane, and six PCB congeners were measured in eggs, embryos, and hatchhngs Samples were collected from Cootes Paradise, a wetland at the western end of Lake Ontario, Ontario, Canada The intra-clutch variation in chlorinated hydrocarbon concentrations within four snapping turtle clutches was determined by analyzing the first, last, and middle five eggs oviposited in the nest The first five eggs had the highest mean concentrations of all chlorinated hydrocarbons (wet weight basis), wet weight, and egg diameter On a lipid weight basis, the first five eggs contained the highest concentration of all compounds except total PCBs and cis chlordane The concentration of as chlordane (lipid weight basis) was the only parameter measured that was significantly different among the three sets of eggs At hatching, snapping turtles without yolk sacs contained from 55 2 to 90 5% of the absolute amount of organochlorine compounds measured in the egg at oviposition Eighteen days after hatching, the body burden of PCBs and pesticides decreased to 45 3 to 62 2% of that in the fresh egg The accumulation of organochlorine chemicals in embryonic turtles peaked at or just before hatching and then declined thereafter, which is consistent with trends reported in developing sea turtles, fish, and birds
Evaluation of screening procedures for bioconcentratable organic chemicals in effluents and sediments
Authors: Burkhard Lawrence P. , Sheedy Barbara R.
Published: March 2010

Screening procedures have been developed by the U.S. Environmental Protection Agency (EPA) to isolate and tentatively identify nonpolar organic chemicals in effluent and sediment samples with high potential to form chemical residues in aquatic organisms. The objective of this study was to determine if the sample components tentatively identified by the effluent-and sediment-screening procedures actually form chemical residues in aquatic organisms. This evaluation consisted of analyzing effluent and sediment samples from a field site with discharges from two coke-manufacturing facilities using the screening procedures. Effluent, sediment, crayfish (Decapoda), and sunfish (Lepomis sp.) samples from the field site were also prepared using conventional sample preparation procedures and analyzed for the tentatively identified chemicals (TIDs) reported by the screening procedures. Results of the screening procedures were then compared to the results of the analyses on the samples prepared using the conventional sample preparation procedures. For the effluent-screening procedure, 182 of 183 TIDs in Coke Plant 1 effluent and all of the 7 TIDs in Coke Plant 2 effluent were found in the crayfish, sunfish, and/or sediment samples downstream of the discharges. For the sediment-screening procedure, 92 of 93 TIDs and all of 47 TIDs in sediment samples from two sampling stations downstream of the discharges were found in the crayfish and/or sunfish samples.
Effects of storage time on toxicity of sediments from puget sound, Washington
Authors: Becker D. Scott , Ginn Thomas C.
Published: March 2010

The effects of sediment storage time were determined for three sediment toxicity tests: the amphipod test using Rhepoxynius abronius, the polychaete test using Neanthes sp., and the Microtoxr̀ test using Photobacterium phosphoreum. Sediments were collected from a reference area and a contaminated area in Puget Sound to determine the effects of storage time on each type of sediment. Toxicity comparisons were also made between the two kinds of sediment to simulate the manner in which the data might be analyzed in a regulatory or decision-making context. Sediments were stored at 4°C for as long as 16 weeks. Results of all three toxicity tests varied significantly with storage time for each type of sediment. Amphipod survival generally decreased with storage time, whereas luminescence in the Microtox test and polychaete biomass varied unpredictably. The significance of differences between results for the two sediments varied unpredictably with storage time for the amphipod and Microtox tests. By contrast, differences were consistently significant for all storage times for the polychaete test, primarily because of the large differences in the test response between sediments. These results suggest that effects of storage time are greater for results indicative of low to intermediate levels of toxicity than for results indicative of high levels of toxicity. It is recommended that sediments be tested as soon as possible after field collection to minimize the potential for alterations of toxicity during storage.
Biotransformation of di(2-ethylhexyl)phthalate by rainbow trout
Authors: Barron Mace G. , Albro Phillip W. , Hayton William L.
Published: March 2010

The biotransformation of di(2-ethylhexyl)phthalate (DEHP) was studied in rainbow trout (Oncorhynchus mykiss) following intravascular administration. Methyl-esterified metabolites were identified using rodent-derived standards and nonlinear gradient elution HPLC; metabolites were confirmed by gas chromatography. Similarities between the biotransformation of DEHP by rainbow trout and mammalian species included (a) mono-ethylhexyl phthalate (MEHP) appeared to be the obligatory first step in DEHP metabolism; (b) the phthalate ring was not oxidized; (c) phthalic acid was a minor metabolite; and (d) several metabolites contained multiple oxidations of the 2-ethylhexyl moiety of MEHP. No metabolites unique to rainbow trout were identified. However, fewer oxidized metabolites were identified in rainbow trout than in mammalian species, possibly due to limited mitochondrial metabolism of MEHP in rainbow trout. The amount of biliary MEHP glucuronide after intravascular administration of DEHP was substantially less than reported in rainbow trout exposed to DEHP via the water. Results confirmed that DEHP metabolism in rainbow trout proceeds by initial rapid formation of MEHP, followed by excretion or extensive oxidation by microsomal P450.
Aquatic toxicity variability for fresh- and saltwater species in refinery wastewater effluent
Authors: Bleckmann Charles A. , Rabe Bruce , Edgmon Sheila J. , Fillingame Drew
Published: March 2010

The U.S. Environmental Protection Agency (EPA) has established test requirements for toxicity reduction or toxicity identification evaluations (TR/TIE) of wastewater effluents. Interpretations of test results are complicated by factors other than toxicity when essentially freshwater wastewaters flow into estuaries and the effluent permit requires marine organisms for testing. This paper reports the results of an investigation of potential freshwater surrogate species, and Microtoxr̀, for use in such a TIE. Of the five species tested, mysid shrimp were found to be most sensitive to unidentified toxicants in petroleum refinery wastewater. No strong correlations of this sen0itivity to that of other organisms, or to several wastewater constituents, were identified. The two marine species specified in the effluent permit were more sensitive to the toxicants than were the freshwater species.
Second-round interlaboratory comparison of hepatic ethoxyresorufin-O-deethylase activity in white sucker (Catostomus commersoni) exposed to bleached-kraft pulp mill effluent
Authors: van den Heuvel Michael R. , Dixon D. George , Munkittrick Kelly R. , Stegeman John J.
Published: March 2010

Livers were collected from six male and six female white sucker (Catostomus commersoni) at both a bleached-kraft pulp mill effluent (BKME)-exposed site and a reference site during the 1992 spring spawning migration. A semistandardized methodology for 7-ethoxyresorufin-O-deethylase (EROD) analysis was proposed that featured similar physical and chemical conditions yet allowed for different instrumentation and techniques. Postmitochondrial supernatants (PMSs) were analyzed for EROD activity by 14 laboratories, and repeat EROD analyses were performed within one laboratory to estimate within-laboratory variability. All laboratories found significantly higher levels of EROD activity (approximately threefold) in males from the BKME-exposed site; only 5 of 14 laboratories found significantly higher levels in exposed females. Data from three labs were dropped from the analysis because of outlying values. The mean coefficient of variation (C.V.) for the remaining 11 laboratories was 34.7%, which was not significantly different from the C.V. determined for six analyses by one technician (28.4%). The mean C.V. for five analysts within one laboratory was significantly lower (16.4%) than either of the former values. There was no difference in absolute values or the variability of microplate and conventional EROD assay data. Analysis of Bradford and Lowry protein data showed that both assays have low variability (C.V.s = 16.8 and 17.4%, respectively); these two techniques produced very similar estimates of protein content. Immunochemical analysis demonstrated a significant correlation existed among microsomal P4501A concentration and EROD activity. Sources of commercially available resorufin standard were tested, and the mean molar extinction coefficient was 54.0 ± 1.1 cm−1 mM−1.
[3H]-2,3,7,8-TCDD uptake and elimination kinetics of medaka (Oryzias latipes)
Authors: Schmieder Patricia , Lothenbach Douglas , Tietge Joseph , Erickson Russell , Johnson Rodney
Published: March 2010

Uptake and elimination rate constants for [3H]-2,3,7,8-tetrachlorodibenzo-p-dioxin ([3H]TCDD) were estimated by exposing medaka (Oryzias latipes) to [3H]TCDD in flowing water with no solvent carriers. Uptake was determined from body burdens measured on exposure days 0, 2, 4, 6, 10, and 12. Elimination was quantified from whole fish after 28, 90, and 175 d in uncontaminated water. Medaka accumulated [3H]TCDD at a rapid rate, achieving residues 24,000 times the water concentration after 12 d, with no indication of approach to steady state. After 6 months in uncontaminated water, the pg TCDD/g decreased by 69%, much of the decrease due to growth dilution as evidenced by only a 47% decrease in the pg TCDD/fish. Uptake and elimination rate constants (2,300 ml/g/d and 0.0045/d, respectively) were estimated by fitting a one-compartment, linear, mass-balance model to the data, adjusting for growth rate. The experimental design, including solvent-free delivery of [3H]TCDD, exposure at concentrations below maximum water solubility, and measurement of fish growth and lipid content during a 6-month elimination phase, resulted in a predicted steady-state bioconcentration factor (BCF) for medaka of 510,000, a number considerably higher than previously reported for dioxin BCFs. Kinetic parameters were used to successfully predict TCDD BCF in medaka exposed independently.
Air monitoring in the arctic: Results for selected persistent organic pollutants for 1992
Authors: Fellin Phil , Dougherty Donna , Barrie Len A. , Toom Desiree , Muir Derek , Grift Norbert , Lockhart Lylie , Billeck Brian
Published: March 2010

The Arctic is generally considered to be a pristine environment and has few direct inputs of organochlorine compounds (OCs), including pesticides, herbicides, polychlorinated biphenyls, or polycyclic aromatic hydrocarbons (PAHs). In spite of this, airborne concentrations of persistent organic pollutants (POPs) are comparable to those in more populated and industrialized regions of North America and Europe. Atmospheric transport and condensation of compounds at low temperature conditions are important factors contributing to the presence of contaminants in the Arctic. A long-term program has been established to measure the airborne concentrations of POPs in the Arctic. The first station at Alert was established in January 1992. The concentrations measured in the first year of monitoring for 18 compounds that are representative of different compound classes are presented. Seasonal variations for PAHs are similar to those for Arctic haze and peak during winter. For example, in the coldest period, October to April, benzo[a]pyrene concentrations were found to average 20 pg/m3, whereas, in contrast, during the relatively warm May to September period, average levels were 1.0 pg/m3. For OCs, the seasonal cycle was not as pronounced as that for PAH compounds. For example, α-hexachlo-rocyclohexane was found at Alert at average concentrations of 62 and 57 pg/m3, respectively, during cold and warm periods. It is postulated that air concentrations are influenced by advection from distant source regions as well as exchange with local (Arctic Ocean) surfaces.
Quality control considerations for the determination of acid-volatile sulfide and simultaneously extracted metals in sediments
Authors: Brumbaugh William G. , Arms Jesse W.
Published: March 2010

The determination of acid-volatile sulfide (AVS) and simultaneously extracted metals (SEMs) in sediment by treatment with dilute HCl shows promise as a tool for predicting the potential for metal toxicity to sediment-dwelling organisms. Effective quality control measures must be developed if this method is to become a reliable procedure and to ensure comparability of data. However, establishing quality control measures that assess procedural errors for an operationally defined method can be problematic. For example, preextraction spikes added for assessing the accuracy of AVS and SEMs may be poorly recovered due to adsorption or reaction with sediment constituents. For a variety of sediment types, we found preextraction spikes of sulfide, mercury, and copper to be prone to variable recoveries for the AVS/SEM procedure; recoveries averaged 76.3% (SD, 20.9) for sulfide, 61.9% (39.6) for Hg, and 90.1% (12.7) for Cu. The average recovery was near 100% for preextraction spikes of sediments for Cd, Ni, Pb, and Zn, and the recoveries of preextraction blank spikes for all analytes were consistently 95 to 105%. Binding of Cu or Hg with sulfides is sufficiently strong that 1 N hydrochloric acid will not necessarily keep the spiked metal in the dissolved state. This does not mean that the SEM procedure is invalid for these metals, only that the quality control of procedural error is difficult to assess. However, Hg will generally not be detected when measured as an SEM because of its tendency to adsorb onto sulfide minerals even at extremely low pH. Some reference sediments may be useful for assessing consistency of AVS determinations; we measured 5.97 ± 0.65 μmol/g in National Institute of Standards and Technology (NIST) 1645 and 1.34 ± 0.14 μmol/g in NIST 2704 for repeated determinations conducted over the past 3 years. Apparently, some sediments may contain an oxidation-resistant sulfide component that can release low to moderate AVS when treated with dilute HCl.
Monitoring exposure of nestling songbirds to agricultural application of an organophosphorus insecticide using cholinesterase activity
Authors: McInnes Pamela F. , Andersen David E. , Hoff Dale J. , Hooper Michael J. , Kinkel Linda L.
Published: March 2010

In June 1992 we collected 53 blood plasma samples from nestling red-winged blackbirds (Agelaius phoeniceus), house sparrows (Passer domesticus), and brown-headed cowbirds (Molothrus ater) at five study sites in northwestern Minnesota to evaluate the feasibility of using plasma and brain cholinesterase (ChE) activity and reactivation as a means of assessing exposure of nontarget organisms to the operational use of ChE- inhibiting insecticides in an agricultural setting. Three sites were adjacent to sugar beet fields that were likely to be treated with chlorpyrifos as Lorsban® (an organophosphorus [OP] insecticide) for control of sugar beet root maggot (Tetanops myopaeformis), and two sites were distant from fields likely to be treated (reference sites). Application of chlorpyrifos in fields surrounding study plots was monitored through contact with landowners and direct observations. Cholinesterase activity levels (total cholinesterase [ChE], acetylcholinesterase [AChE], and butyrylcholinesterase [BChE]) in nestling plasma were measured and tested for reactivation (ChE and AChE) in the presence of 2–PAM, an indication of exposure to an organophosphorus insecticide. In addition, 11 nestlings were euthanatized and in these samples we measured brain ChE activity and reactivation, and we analyzed gastrointestinal tracts and carcass washes for chlorpyrifos residues. Total ChE and BChE activity were lowest in similar-aged nestlings at sites adjacent to treated beet fields (ChE, t = −2.51, d.f. = 21, p = 0.033; BChE, t = −2.56, d.f. = 21, p = 0.043). Nestlings from sites that were near fields where chlorpyrifos was applied were more likely to exhibit plasma AChE reactivation than nestlings from reference sites where OP or carbamate insecticide application was improbable (x2 = 3.805, d.f. = 1, p ∼ 0.05). The magnitude of plasma ChE reactivation was highest within 1 to 3 d of insecticide application, although significant reactivation was measured up to 11 d after application of chlorpyrifos. Plasma AChE reactivation in the presence of pyridine-2–aldoxime methochloride (2–PAM) appeared to be a more sensitive indicator of exposure to chlorpyrifos than plasma ChE or BChE activity levels.
The community conditioning hypothesis and its application to environmental toxicology
Authors: Matthews Robin A. , Landis Wayne G. , Matthews Geoffrey B.
Published: March 2010

In this paper we present the community conditioning hypothesis, “ecological communities retain information about events in their history.” This hypothesis, which was derived from the concept of nonequilibrium community ecology, was developed as a framework for understanding the persistence of dose-related responses in multispecies toxicity tests. We present data from three standardized aquatic microcosm (SAM) toxicity tests using the water-soluble fractions from turbine fuels (Jet-A, JP- 4, and JP-8). In all three tests, the toxicants depressed the Daphnia populations for several weeks, which resulted in algal blooms in the dosed microcosms due to lower predation rates. These effects were short-lived, and by the second and third months of the experiments, the Daphnia populations appeared to have recovered. However, multivariate analysis of the data revealed dose/response differences that reappeared during the later part of the tests, often due to differences in other consumers (rotifers, ostracods, ciliates), or algae that are not normally consumed (filamentous green algae and bluegreen “algae”). Our findings are consistent with ecological theories that describe communities as the unique product of their etiologies. The implications of this to environmental toxicology are that almost all environmental events leave lasting effects, whether or not we have observed them.
Coal and deodorizer residues in marine sediments—contaminants or pollutants?
Authors: Chapman Peter M. , Downie James , Maynard Allan , Taylor Laura A.
Published: March 2010

Sediment studies around the diffuser of a relatively untreated major marine municipal sewage discharge indicated that 1,4-dichlorobenzene (1,4-DCB) and polycyclic aromatic hydrocarbons (PAHs) were among the contaminants of concern. Subsequent investigations revealed that elevated PAH concentrations were due to the shipwreck of a collier in the 1890s and were apparently not bioavailable. Coal is a common contaminant in marine and freshwater sediments and may be responsible, in some cases, for high PAH contaminant concentrations not resulting in pollution (i.e., biological effects) and can also affect total organic carbon measurements and normalizations. Little information exists regarding 1,4-DCB, whose main source to sewage appears to be toilet block deodorizers and which appears to be a useful marker of the extent of contamination for untreated sewage discharges. Correlative analyses suggest it is a pollutant, but this remains to be confirmed by experimental testing.
Dissociation constants of chloroguaiacols in water: A comparison of measured and predicted values
Authors: Gundersen Jennifer L. , MacIntyre William G.
Published: March 2010

Chloroguaiacols are common components of bleached-kraft pulp mill effluent known to bioaccumulate in aquatic organisms and to sorb on particulate material and sediments. Ionization properties of the chloroguaiacols must be known in order to explain their sorptive behavior in aquatic systems. To obtain this information, thermodynamic acid dissociation constants (pKa) of guaiacol (o-methoxyphenol) and nine chloroguaiacols have been determined by spectrophotometric methods. These experimental pKa values have been compared with literature values, values predicted by the Hammett equation, and predictions by quantum chemical calculations using MOPAC 6.0 with AM1 and MNDO Hamiltonian operators. Experimental and predicted acidities were strongly correlated, and the correlation equations obtained have been used to calculate pKa values for those chloroguaiacols that were unavailable for experimental measurement.
Effects of selected reducing agents on microbiologically mediated reductive dechlorination of aroclor® 1242
Authors: McCue Joseph J. , Gauger Kennedy W. , Holsen Thomas H. , Kelly Robert L. , Cha Daniel K.
Published: March 2010

The effect of various chemical reducing agents on the anaerobic microbial reductive biotransformation of polychlorinated biphenyls (PCBs) was investigated using Aroclor® 1242 at a concentration of 600 μg/g soil and microorganisms eluted from Hudson River sediments. The investigation sought to determine how various reducing agents influenced PCB dechlorination rates, patterns, and acclimation periods. Three reducing agents were incorporated into culture media: amorphous ferrous sulfide, sodium sulfide with sodium thioglycollate, and sodium sulfide with amorphous ferrous sulfide. All cultures were incubated statically under methanogenic conditions and ambient incubation temperatures of about 20°C. Cultures utilizing both sodium sulfide and ferrous sulfide together demonstrated the most extensive removal of meta- and para-chlorines, the highest average dechlorination rate, the greatest dechlorination of tri- and tetrachlorinated biphenyls, and the greatest accumulation of dichlorobiphenyl homologues. Overall, treatments incorporating ferrous sulfide, alone or in combination with sodium sulfide, demonstrated the ability to more effectively dechlorinate tri-ortho-substituted tetrachlorobiphenyls and pentachlorobiphenyls which had commonly positioned chlorines. Under these same conditions, dichlorobiphenyls, which are more amenable to aerobic dechlorination conditions, increased from 25% (molar basis) initially to levels greater than 60%.