bluuebunny/crossref_metadata_2025 huggingface dataset:
Fate and metabolism of o-toluidine in the marine bivalve molluscs Mytilus edulis and Crassostrea gigas
Authors: Knezovich John P. , Crosby Donald G.
Published: March 2010

The in vivo fate and metabolism of a model aromatic amine (o-toluidine) were determined for mussels (Mytilus edulis) and oysters (Crassostrea gigas). o-Toluidine was found to be relatively nontoxic and was rapidly turned over in mollusc tissues. The biotransformation of o-toluidine and N-acetyl-o-toluidine was determined by the extraction and analysis of eliminated metabolites. The metabolism of [14C]o-toluidine in both bivalve species resulted in the formation of 2-nitrosotoluene, N-methyl-o-toluidine and N-formyl-o-toluidine. Small amounts of N-hydroxy-o-toluidine were detected in experiments with M. edulis. Mussels were found to be capable of N-deacetylation but oysters were not. The total extent of o-toluidine and N-acetyl-o-toluidine biotransformation in mussels from pristine waters was found to be greater than in mussels from contaminated waters.

The formation of N-oxidized metabolites is toxicologically important because this pathway constitutes the route of activation for mutagenic and carcinogenic aromatic amines. The formation of an N-formyl metabolite by these bivalves is also interesting, as this detoxication pathway has not been previously reported for marine invertebrates. The lack of carbon oxidizing pathways in these bivalves may be of limited toxicological significance because of their ability to utilize other detoxification (N-conjugation) pathways.
Airborne lead and trace elements in an indoor shooting range: A study of the DC national guard armory pistol range
Authors: Olmez Ilhan , Kotra J. P. , Lowery Sharon , Zoller William H.
Published: March 2010

Concentrations of airborne particulate lead in an indoor pistol range far exceeded the recently revised Occupational Safety and Health Administration target standard of 50 μg/m3, often by two or three orders of magnitude. A substantial fraction (40 to 50%) of the lead occurred on respirable-size particles (diameter ≤ 2 μm). Significantly elevated levels of Sb, Cu, As and Ba also resulted from the firing of .38 and .45 caliber pistols. The high levels of respirable, toxic elements observed indicate a potentially serious exposure for users and, in particular, the operators of such facilities.
Effects of lugworms and seagrass on kepone® (chlordecone) distribution in sediment/water laboratory systems
Authors: O'Neill Ellen J. , Monti Carol A. , Ahearn Donald G. , Pritchard Parmely H. , Bourquin Al W.
Published: March 2010

The influence of lugworms (Arenicola cristata Stimpson) and seagrass (Thalassia testudinum Koenig) on Kepone® (chlordecone) distribution in sediment/water systems was examined. Radiolabeled Kepone was introduced into continuous-flow sediment/water systems, and the dissolved and sorbed concentrations of Kepone were quantified. Lugworm activity decreased the Kepone concentration in the water and increased its concentration in the sediment. The presence of seagrasses did not appreciably affect the concentration of Kepone in the water. Bioturbation appeared to be the prime factor in the transport of Kepone from water to sediment.
Sorption dynamics of hydrophobic pollutants in sediment suspensions
Authors: Karickhoff Samuel W. , Morris Kenneth R.
Published: March 2010

Sorption of hydrophobic organic chemicals in natural sediment suspensions was found to frequently require extended time periods (days to weeks) for complete equilibration. Sorption dynamics could be described by a two-compartment model that distinguished rapid or “labile” exchange (requiring at most a few hours to achieve) from highly retarded or “nonlabile” sorption requiring days to weeks to occur. In general, one-half or less of the total sorption was labile. For highly hydrophobic chemicals and high solid concentrations, the labile fraction decreased to 0.1 or less in some systems. The kinetic exchange constant for nonlabile sorption varied inversely with the sorption equilibrium constant. That is, the more highly sorbed chemicals sorbed more slowly. For some sediments, air-drying to facilitate sample transport or storage was found to result in formation of highly stable aggregates that severely altered sorbent availability to hydrophobic chemicals. An understanding of sorption dynamics is important in describing the fate of highly sorbed pollutants in aquatic systems.
Comparison of pots versus microcosms for predicting agroecosystem effects due to waste amendment
Authors: Tolle Duane A. , Arthur Mickey F. , Chesson Jean , Van Voris Peter
Published: March 2010

Two laboratory test units (plastic flower pots and intact soil-core microcosms) were compared for their accuracy in predicting crop yield and element uptake in field plots. All three test units were amended with four treatment levels of unweathered, acidic fly ash (0, 100, 400 and 700 t/ha), fertilized with alfalfa meal and planted in late June with equivalent rates of Saranac alfalfa (Medicago sativa), Climax timothy (Phleum praetense) and Clintford oats (Avena sativa). Microcosms were more accurate than pots in predicting the dose-response yield curve for alfalfa/timothy grown in field plots. The hypothesis of parallelism between regression equations for alfalfa yield was rejected for pots versus field plots, but was not rejected for microcosms versus field plots. Neither of the two laboratory units accurately predicted the dose-response curves for oat grain or total oat yield. Pots were only slightly more accurate than microcosms in predicting the enrichment ratios (ERs) for alfalfa uptake of elements from field plots, based on statistical analysis of the distributions of In-ER ratios for 22 elements. The extra rooting depth of the 60-cm microcosms may provide more accurate yield data for long tap-rooted species like alfalfa, as well as permit a second year of accurate data on crop yield and element uptake.
Contaminants and bilateral asymmetry in yellow perch
Authors: Carline Robert F. , Lawai Marilyn V.
Published: March 2010

Several studies have shown that contaminants can induce bilateral asymmetry in fishes. In this study five bilateral meristic characters from seven populations of yellow perch (Perca flavescens) from Ohio and Wisconsin were enumerated to determine if there were any relationships among the asymmetries for each character and the body burdens of contaminants. Bilateral characters included scales on, above and below the lateral line, pectoral fin rays and gill rakers. Contaminants found in yellow perch were primarily polychlorinated biphenyls, DDT and dieldrin. All populations were asymmetrical for each bilateral character, but the degree of asymmetry was not related to contaminant levels. Unless a direct relationship between asymmetry and contaminants can be shown, we do not believe that this phenomenon will be a useful biological monitor.
Anthracene bioconcentration in rainbow trout during single-compound and complex-mixture exposures
Authors: Linder Greg , Bergman Harold L. , Meyer Joseph S.
Published: March 2010

Rainbow trout were exposed for 72 h to [14C]anthracene alone and [14C]anthracene in an oil shale retort water. Tissue levels of [14C]anthracene were analyzed at 24, 48 and 72 h to determine non-steady-state bioconcentration factors (BCFs), and uptake and depuration rates were calculated from anthracene disappearance in exposure waters and metabolite appearance in depuration waters. Uptake rates (14.6 to 16.9 h−1) were similar to previously reported values; however, depuration rates (0.00158 to 0.00188 h−1) were very low. Consequently, measured non-steady-state BCFs after 72 h (9,000 to 9,200) for anthracene were higher than expected, probably because fish were not fed and had low excretion rates. Measured and estimated anthracene BCFs were lower in retort water exposures than in single-compound exposures because of slower uptake and faster depuration. We attribute slower uptake during retort water exposures to either decreased bioavailability of anthracene or rate-limiting transport of contaminants from uptake sites to storage and processing sites. Induction of mixed-function oxidases may have increased depuration from fish exposed to retort water. We conclude that bioconcentration of individual compounds from complex chemical mixtures may be difficult to predict based on single-compound kinetics.
Predicting single-species toxicity in natural water systems
Authors: Connolly John P.
Published: March 2010

A methodology is proposed to predict single-species toxicity in natural waters by using laboratory bioassay data which relate effect to a tissue concentration of toxicant or to injury accumulation. Such relationships should be independent of test conditions and therefore be transferable from lab to field. Data for endrin and copper are presented which illustrate relationships between tissue concentrations and mortality. A mathematical model of uptake and elimination of toxicants by fish is used to relate exposure concentration to tissue concentration and then to effect. Prediction of toxicity in a laboratory test in which the exposure concentration varies in time is presented as a first step in testing the methodology. Using a dose-response relationship determined from published data for zinc toxicity to rainbow trout in a constant exposure toxicity test, the survival time under time-varying exposure is calculated and compared to observed data. The model predicted survival times that were consistent with the observed times. Whole-body residue is used as the estimate of dose.

A methodology for considering chemicals for which tissue concentration is not a useful estimate of dose is also presented. Diazinon-induced acetylcholinesterase inhibition data are used to demonstrate this methodology.
Sites of benzidine, α-naphthylamine and p-toluidine retention in soils
Authors: Graveel John G. , Sommers Lee E. , Nelson Darrell W.
Published: March 2010

The binding of benzidine (4,4′-diaminobiphenyl), α-naphthylamine (1-aminonaphthalene) and p-toluidine (4-methylaniline) by three soils was studied by incubating soils amended with the aromatic amines and then sequentially extracting them with 60:40 (v/v) ethylacetate: methanol (EtAc: MeOH), ammonium acetate (NH4OAc) and sodium hydroxide (NaOH) as a function of time. Essentially all of the added α-naphthylamine and p-toluidine was extracted initially with EtAc: MeOH and NH4OAc, whereas only 21% of added benzidine was extracted by these reagents. After 24 h, a significant decrease was found for amines extractable with EtAc: MeOH and NH4OAc. During 63 to 84 d after incubation, a gradual increase in the proportion of amine recovered by NaOH extraction was found. Fractionation of the NaOH extract into humic and fulvic acids indicated that benzidine and α-naphthylamine were primarily associated with the humic acid fraction, whereas p-toluidine was in the fulvic acid fraction. Simultaneous measurement of 14CO2 evolved showed that the average decomposition rate was 2, 12 and 15% for benzidine, α-naphthylamine and p-toluidine, respectively. Results indicate that binding of benzidine, α-naphthylamine and p-toluidine to soils involves both rapid, reversible equilibrium with inorganic and organic components of soil and nucleophilic addition to the phenolic components of humus. These retention mechanisms may explain why benzidine, α-naphthylamine and p-toluidine resist decomposition in soils.
Aryl hydrocarbon hydroxylase levels in herring gull embryos from different locations on the great lakes
Authors: Ellenton Jennifer A. , Brownlee Lorna J. , Hollebone Bryan R.
Published: March 2010

Aryl hydrocarbon hydroxylase (AHH) levels were measured in the livers of herring gull (Larus argentatus) embryos to determine if monooxygenase activity in this species could be used as a “bioeffects” monitor of environmental contamination. Herring gull eggs were collected in 1981 from five locations on the Great Lakes Basin and from one clean colony on the Atlantic coast. Microsomal protein determinations and AHH assays were conducted on livers from the embryos at 20 and 25 d of incubation. Organochlorines (DDE, DDT, tetrachlorobenzene, pentachlorobenzene, hexachlorobenzene, heptachlor epoxide, chlordane, dieldrin, mirex, photomirex, polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin) were also measured in egg homogenates from each colony. The 25-d embryos were found to be the most suitable for AHH analysis, since they had a higher baseline level and a greater response than did the 20-d embryos. Specimens from two of the Great Lakes colonies had significantly higher AHH activities than was found for the Atlantic coast colony. These levels of AHH activity closely paralleled the concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin present in eggs gathered from the colonies in 1980. Further work regarding monooxygenase levels in herring gull embryos is discussed.
Geochemical investigations of polychlorinated dibenzo-p-dioxins in the subsurface environment at an abandoned wood-treatment facility
Authors: Pereira Wilfred E. , Rostad Colleen E. , Sisak Mary E.
Published: March 2010

The discharge of effluents containing creosote and pentachlorophenol into two unlined surface impoundments at a wood-treatment facility in Pensacola, Florida, resulted in contamination of the underlying sand and gravel aquifer. These wastes contained significant amounts of chlorinated dioxins, such as isomers of hexa- and heptachlorodibenzo-p-dioxins and octachlorodibenzo-p-dioxin, probably derived from commercial pentachlorophenol. Geochemical investigations of pond sludge, groundwater and porous media from the unsaturated and saturated zones indicated that these geologic materials were contaminated by chlorinated dioxins. The fate and movement of these compounds in the subsurface environment were studied using the technique of GC-MS-MS. Chlorinated dioxins migrated both vertically and horizontally in the subsurface and were present at considerable distances from the source of contamination. Concentrations of chlorinated dioxins in groundwater were several orders of magnitude lower than in porous media from the unsaturated and saturated zones. Ratios of the various isomers remained relatively constant in highly contaminated areas. However, in less contaminated areas, isomer ratios changed dramatically; at certain locations, one hexachlorodibenzo-p-dioxin isomer predominated. The environmental significance of these compounds is discussed.
Effects of application procedures and irrigation on degradation and movement of aldicarb residues in soil
Authors: Wyman Jeffrey A. , Jensen John O. , Curwen David , Jones Russell L. , Marquardt Terry E.
Published: March 2010

Aldicarb was applied to potato plants in two locations in Wisconsin to determine the effects of application procedures and irrigation on degradation and movement of aldicarb residues, plant uptake, insect control and crop yield. Two application procedures (3.36 kg. AI/ha applied in the furrows at planting and 2.24 kg AI/ha applied as a top-dress application consisting of a surface-applied band covered with soil at plant emergence) and two irrigation regimens (medium water use based on evapotranspiration and heavy water use based on evapotranspiration plus 60%) were tested. The emergence application was effective in reducing the downward movement of aldicarb residues without significantly affecting performance as measured by insecticidal efficacy, crop residues and yield. Excess irrigation increased downward movement of aldicarb residues in soil, diminished foliar residues and resulted in decreased insect control and crop yield. Differences in soil characteristics, primarily in water-holding capacity, were important in reducing downward movement of aldicarb in soil.
Measurement of water solubilities, octanol/water partition coefficients and vapor pressures of commercial phthalate esters
Authors: Howard Philip H. , Banerjee Sujit , Robillard Kenneth H.
Published: March 2010

Water solubilities, octanol/water partition coefficients and vapor pressures were measured for a variety of commercial phthalate esters, several of which were mixtures. The results provide insight into the applicability of the procedures, which were developed for pure compounds, to more complex industrial products and formulations.
Organic substances in the rainfall of Lake Superior: 1983
Authors: Strachan W. M. J.
Published: March 2010

In 1983, sampling for organic substances in rainfall was undertaken at two, open-lake locations at opposite ends of Lake Superior — Isle Royale and Caribou Island. Triplicate samples, averaging 22 litres, were collected in each time period (approximately 6 weeks) and analysed for α-BHC, lindane, heptachlor epoxide, dieldrin, endrin, DDT residues, methoxychlor, polychlorinated biphenyls and hexachlorobenzene. α- and δ-chlordane, mirex and toxaphene were also investigated but were not found in any of the samples. Concentrations of these compounds ranged from 0.01 to 65 ng/L. The east side of the lake received considerably lower concentrations in rainfall (on average, roughly 65% less) and the levels of most of the observed substances were higher at both locations in the spring and early summer. Estimates of direct loadings to the lake were made using volume-weighted concentrations. The highest was for α-BHC at 860 kg/year and the lowest for hexachlorobenzene at 3.7 kg/year; the loading estimate for polychlorinated biphenyls was 300 kg/year.
Chronic toxicity of tebuthiuron to an alga (Selenastrum capricornutum), a cladoceran (Daphnia magna), and the fathead minnow (Pimephales promelas)
Authors: Meyerhoff Roger D. , Grothe Douglas W. , Sauter Scott , Dorulla Georgia K.
Published: March 2010

Chronic toxicity studies were conducted with an alga (Selenastrum capricornutum), a cladoceran (Daphnia magna) and the fathead minnow (Pimephales promelas) to determine their relative sensitivities to tebuthiuron, a soil-applied herbicide. The alga was the most sensitive of the three species. The no observed effect concentrations for the studies with the fathead minnow (9.3 mg/L) and the cladoceran (21.8 mg/L) were higher than the algistatic concentration (1.5 mg/L) for Selenastrum. These concentrations are 8 to 121 times higher than the highest transient concentration of tebuthiuron reported for a catchment pond.
Enlarged livers and hepatic microsomal mixed-function oxidase components in tumor-bearing brown bullheads from a chemically contaminated river
Authors: Fabacher David L. , Baumann Paul C.
Published: March 2010

Hepatic mixed-function oxidase (MFO) components in tumor-bearing brown bullheads (Ictalurus nebulosus) from a chemically contaminated river and in bullheads from two relatively uncontaminated sites were compared to determine if the components in the river bullheads were induced. Induction of MFO components could be indicative of chemical contamination of the river water and of contaminant stress in the fish. In general, biochemical hepatic microsomal MFO component levels in bullheads from the river were the same as, or lower than, those in bullheads from uncontaminated sites. However, the liver weight as a percentage of body weight was significantly greater in bullheads from the river than in those from the uncontaminated sites. Thus, a comparison of bullheads from the river and the uncontaminated sites appeared to show that relative liver weight was indicative of chemical contamination of the river water and of contaminant stress in its fish. However, biochemical hepatic microsomal components measured in this study were apparently not adequate as indicators of chemical contamination of the river water or of contaminant stress in bullheads from the river.
A new fathead minnow (Pimephales promelas) subchronic toxicity test
Authors: Norberg Teresa J. , Mount Donald I.
Published: March 2010

The most commonly used test for evaluating the toxicity of effluents to fish and invertebrates has been the acute lethality test. However, effluents frequently are not acutely toxic, and so assessing the sublethal effects on fish and invertebrates is important. Described herein is a rapid method to estimate the chronic toxicity of effluents to the fathead minnow (Pimephales promelas). Tests are initiated using newly hatched minnow larvae and are run for 7 d under static-renewal conditions. It is a cost-effective, simple, short-term toxicity test, and survival and growth are the measures of effects. Approximately 70 tests using this technique have been run with various types of effluents. Included in this article are results from representative effluent tests and also from tests conducted using Dursban, zinc and copper. The results indicate that this subchronic toxicity test gives a good estimate of chronic toxicity.
Biotransformation of chlorinated organic solvents in static microcosms
Authors: Parsons Frances , Lage Gladys Barrio , Rice Ramona
Published: March 2010

The presence of trichloromethane and volatile chlorinated ethene compounds in local groundwater, where no use of these compounds could be determined, prompted a search for their source using models of the aquifer in the laboratory. Preliminary work indicated that chloroethene and cis- and trans-1,2-dichloroethene resulted from subsurface transformation of spilled tetra- and trichloroethene, which are commonly used as industrial degreasers. This study was undertaken to determine the interactions and subsurface factors, including the microbiota and commonly used chlorinated organic solvents, which brought about these transformations.

Static microcosms containing groundwater and sediments were spiked with four organic solvents (tetrachloroethene, trichloroethene, 1,1,1-trichloroethane, and tetrachloromethane) and analyzed by GC at intervals during a 16-week incubation period. Eh and pH were determined concurrently.

The environmental conditions within the microcosms, i.e., neutral to acid pH and reductive potential, indicated that reductive dehalogenation was the pathway by which the observed products were formed. An aqueous milieu and the presence of electron donors and microbial mediators are believed to be influential factors. Evidently, one carbon-halogen bond in each of the solvents was ruptured to yield a compound with one fewer chlorine than its precursor. The products of transformations in microcosms were exotic compounds also found in the groundwater. They were formed only in microcosms from which living microorganisms were cultured.
Bioconcentration kinetics of 2,3,7,8-tetrachlorodibenzo-p-dioxin in rainbow trout
Authors: Branson Dean R. , Takahashi Irene T. , Parker William M. , Blau Gary E.
Published: March 2010

The uptake and depuration rate constants for [14C]2,3,7,8-tetrachlorodibenzo-p-dioxin (14C-TCDD) in growing rainbow trout were obtained in a laboratory experiment involving a 6-h static water uptake exposure at 107 ng/L (ppt) followed by a 139-d flow-through depuration period. Improved mathematics were developed for estimating uptake and depuration rate constants and an equilibrium bioconcentration constant that accounts for growth dilution of the total chemical body burden. The uptake and depuration rate constants (k1' and k2) for 14C-TCDD in rainbow trout (whole fish) were determined to be 108 ± 3 ml water/g whole fish/d and 0.012 ± 0.001 d−1, respectively. Based on these data, the equilibrium bioconcentration constant for TCDD, defined as the ratio of uptake to depuration rate constants, was 9,270 ± 1,050, and the elimination half-life, t1/2, of the total body burden was 58 ± 5 d. Clinical observations of the fish concurred with those previously reported by other researchers.
Plasma leucine aminonaphthylamidase as an indicator of acute sublethal toxicant stress in rainbow trout
Authors: Dixon D. G. , Hill C. E. A. , Kempe E. J. , Hodson P. V. , Kaiser K. L. E.
Published: March 2010

Leucine aminonaphthylamidase (LAN) is a lysosomal enzyme that appears in blood plasma after cell death. Levels of plasma LAN (PLAN) were assayed to quantify toxicant stress in rainbow trout in a series of experiments. Blood samples were taken from groups of fish weighing 80 to 100 g following intraperitoneal (i.p.) and/or waterborne exposure to p-methylphenol (PMP) or carbon tetrachloride (CCl4).

The duration of postinjection holding significantly affected PLAN activity in control and PMP-dosed rainbow trout; the largest increases occurred after 96 h. There were significant correlations between dose and PLAN activity after both PMP and CCl4 injection. PLAN levels of fish injected with PMP at doses of 0.075 to 0.75 of the 96-h i.p. LD50 were elevated by 27 to 63% relative to controls 96 h after injection. PLAN levels of fish injected with CCl4 at doses of 0.18 to 0.79 of the i.p. LD50 were elevated by 38 to 135% relative to controls 48 h after injection. Exposure of fish to a waterborne concentration of 0.028 mM PMP (0.41 96-h LC50) significantly increased PLAN activity after 48, 96 and 192 h; activities increased by 38 to 87% relative to controls. Elevated PLAN activity was strongly correlated with decreased plasma protein levels. The temperature and duration of plasma storage affected the measured PLAN activity of control and PMP-dosed rainbow trout. While diet modified PLAN activity, the gender of immature fish had no effect.

Hepatic lesions visible by light microscope were observed with waterborne PMP exposure; parenchymatous edema was closely associated with increased liver somatic index. There were, however, no visible lesions or changes in the index associated with the pulse i.p. doses of PMP and CCl4. In these cases, biochemical lesions preceded any evidence of histopathology.
Static acute toxicity of dibromonitrilopropionamide and selected degradation products to the fathead minnow (Pimephales Promelas rafinesque)
Authors: Mayes Monte A. , Blanchard Fred A. , Hopkins Daniel L. , Takahashi Irene T.
Published: March 2010

Dibromonitrilopropionamide (DBNPA) is the active ingredient in Dow Antimicrobials 7287® and 8536®. An important environmental feature of DBNPA is that it degrades very rapidly in water to a series of compounds including monobromonitrilopropionamide (MBNPA) and dibromoacetonitrile (DBAN). The objective of this study was to determine the toxicity of DBNPA, including the separate influences of the compound itself and of its degradation products, to the fathead minnow Pimephales promelas Rafinesque. The lability of DBNPA and the degradation products confounded the interpretation of the results. To aid in explaining the observed toxicity data, a model was used that treated DBNPA and its degradation products as a complex mixture, with the components having an assumed additive effect on the test species. Only DBNPA, MBNPA and DBAN were included in the evaluations because they were the primary components contributing to the toxicity of DBNPA, with 96-h LC50 values of 1.8, 3.4 and 0.55 mg/L, respectively. Analyses of the degradation and toxicity data confirmed the major role played by DBAN in the toxicity of initially applied DBNPA. They also suggested that in systems with nucleophilic activity, such as found in natural waters, there is a tendency to form more of the mono- and debrominated degradation products and fewer of the dibrominated degradation products, thus reducing the toxicity of initially introduced DBNPA.
Decomposition by planktonic and attached microorganisms improves chemical fate models
Authors: Lassiter R. R. , Burns L. A. , Parrish R. S.
Published: March 2010

Terms for decomposition by both suspended and attached microorganisms were included in a model to calculate the fate of chemicals in aquatic systems. This model differs from previous models primarily by the inclusion of a term for decomposition by aufwuchs in addition to a term for decomposition by planktonic microorganisms. Decomposition by aufwuchs is represented as occurring at a rate limited by the serial processes of transport to a planar surface and decomposition at the surface. Two sets of experiments were conducted using replicate laboratory microcosms, each maintained with six different environments. The predictive capability was good, as indicated by the absence of statistically detectable differences between predictions and laboratory measurements. In making the predictions, a set of parameters describing the characteristics of the chemical was required. Included in these parameters were the rate coefficients for the two microbial decomposition terms. With both microbial decomposition terms included, the fate model accounted satisfactorily for observed methyl parathion concentrations using only a single, environment-independent rate coefficient for each term.
Dynamics of organochlorine compounds in herring gulls (Larus argentatus): I. distribution and clearance of [14C]DDE in free-living herring gulls (Larus argentatus)
Authors: Norstrom Ross J. , Clark Thomas P. , Jeffrey Deborah A. , Won Henry T. , Gilman Andrew P.
Published: March 2010

Radiolabelled [14C]DDE was used as a model compound to determine important factors in the clearance of persistent lipophilic compounds in free-living herring gulls (Larus argentatus). Adult, breeding male and female gulls were dosed orally during incubation and then captured one week and one year later. After one week, [14C]DDE had equilibrated with native DDE in all tissues. The ratios of DDE levels on a lipid weight basis relative to whole body were as follows: muscle, 0.8 to 0.9; liver, 0.5 to 0.7; egg, 0.4; and brain, 0.1. The plasma/whole body lipid partition coefficient was 0.0041 ± 0.0014. The whole body annual average clearance rate was 0.95 ± 0.51 year−1 (half-life = 264 d). Native DDE levels in males were twice those in females, but no differences were found for [14C)DDE after one year. The lower levels in females do not appear to be related to excretion of DDE in eggs or higher monooxygenase activity, but they may be related to differences in feeding ecology. Additional physiological and ecological factors must therefore be included in a proposed two-compartment (plasma/whole body lipid) model of residue levels in eggs based on experimental data from caged gulls.
Growth inhibition and morphological effects of several chemicals in Arabidopsis thaliana (L.) HEYNH
Authors: Ratsch H. C. , Johndro D. J. , McFarlane J. C.
Published: March 2010

A plant life-cycle bioassay using Arabidopsis thaliana (L.) Heynh. was used to evaluate effects of several toxic chemicals. Plants were grown in vermiculite in a hydroponic system, with test chemicals added to the nutrient solution reservoir. Reduction in total biomass followed different patterns with the chemicals tested, and sensitivity increased in the order: fly ash > 2-(2-ethoxyethoxy)ethanol (DGME) > dalapon > trichloroacetic acid (TCA) > copper sulfate > bromacil > metribuzin. DGME, TCA and dalapon induced unusual morphological effects in which flower development was altered and pollination prevented. Reduced biomass, altered distribution of plant dry weight among vegetative, reproductive and mature seed, and morphological effects indicate that a plant life-cycle test is a valuable screening test.
Effect of simulated acid rain on growth and yield of Valencia orange, floradade tomato and slash pine in Florida
Authors: Hart Robin , Biggs R. H. , Webb P. G.
Published: March 2010

Direct effects of simulated acidic deposition on vegetation were studied in the laboratory under controlled conditions for three commercially important resources: slash pine, Floradade tomato and Valencia orange. Treatment was similar to convective rain in Florida in ion composition, total volume, frequency and rate of application, intensity and sulfate/nitrate ratio. The surface of the growth medium was covered with plastic during application of the solution. Water and nutrients optimum for growth were provided directly to the growth medium. No visible injury resulted from application of the simulated rain. No effects of pH treatments on vegetative growth of slash pine, orange or tomato were observed. However, fruit yield of tomato and orange differed significantly between plants subjected to different pH treatments. The yield of tomato was lower and that of orange was higher at the lower pH treatments. Calcium and magnesium levels were highest in the foliage of tomato plants receiving the pH 5.5 treatment. No differences in element levels of orange foliage were observed.
Toxicity of fluridone to aquatic invertebrates and fish
Authors: Hamelink Jerry L. , Buckler Denny R. , Mayer Foster L. , Palawski Donald U. , Sanders Herman O.
Published: March 2010

The acute and chronic toxicities of the herbicide fluridone to aquatic invertebrates and fish were evaluated. The acute median lethal concentrations (LC50s) of fluridone were 4.3 ± 3.7 mg/L (x̄±SD) for invertebrates (n = 15) and 10.4±3.9 mg/L for fish (n = 28). In chronic studies, no effects were detected when daphnids (Daphnia magna) were continuously exposed to fluridone concentrations of 0.2 mg/L or less for 32 d, amphipods (Gammarus pseudolimnaeus) to 0.6 mg/L or less for 60 d or midge larvae (Chironomus plumosus) to 0.6 mg/L or less for 30 d. Fathead minnows (Pimephales promelas) were not affected by continuous exposure to fluridone concentrations of 0.48 mg/L or less over their life cycle. The growth and survival of channel catfish (Ictalurus punctatus) were not adversely affected by continuous exposure to fluridone concentrations of 0.5 mg/L or less for 60 d after hatching. The channel catfish accumulated fluridone concentrations two to nine times greater than that in the water. The recommended application rate of 1 lb/acre of fluridone to a pond with an average depth of 3 ft provides a theoretical concentration of 0.1 mg/L. Thus, an initial fluridone concentration of 0.1 mg/L or less is recommended to control weeds in ponds. Consequently, fluridone is not expected to have adverse effects on the species tested or on similar nontarget aquatic organisms.
Acute toxicity of cadmium, copper, mercury and zinc to Tropocyclops prasinus mexicanus (Cyclopoida, copepoda) from three quebec lakes
Authors: Lalande Marc , Pinel-Alloul B.
Published: March 2010

This study deals with cultures of Tropocyclops prasinus mexicanus, a Cyclopoid copepod from three Quebec lakes (one polluted and two unpolluted), in a comparative toxicity test involving four heavy metals. Experiments were performed according to a static toxicity protocol. The 48-h EC50 of each individual metal and of the combination of metals were determined for each culture. The overall toxicity trend is mixture > Hg > Cu ≥ Cd ≥ Zn. Cultures from unpolluted and low-hardness lakes showed lower EC50 mean values than did the strain originating from the polluted lake with high water hardness.
Trace metals in mussels transplanted to San Francisco Bay
Authors: Smith D. R. , Stephenson M. D. , Flegal A. R.
Published: March 2010

Mussels (Mytilus californianus) transplanted to San Francisco Bay exhibited elevated trace metal concentrations compared with those in other mussel watch studies on the west coast of the United States. The highest concentrations of Ag, Cu, Hg, Mn, Pb and Zn were at the South Bay stations, and often in the Redwood Creek area. Ag and Hg concentrations were linearly correlated with station distance from the North Bay (San Pablo Bay), indicating that the South Bay is a major reservoir of these pollutants within San Francisco Bay.
Toxicity of sodium monofluoroacetate (Compound 1080) to mink and European ferrets
Authors: Hornshaw T.C. , Ringer R.K. , Aulerich R.J. , Casper H.H.
Published: March 2010

The toxicity of sodium monofluoroacetate (Compound 1080) to mink (Mustela vison) and European ferrets (Mustela putorius furo) was evaluated through LC50 and reproduction tests. Subacute dietary exposure to Compound 1080 resulted in dose-dependent decreases in body weights and feed consumption in both species. The mink were more sensitive to Compound 1080 than were the ferrets. The 28-d dietary LC50 for mink and for ferrets was calculated to be 3.2 and 9.4 ppm, respectively. Dietary exposure to 0.80 ppm Compound 1080 for 2 months prior to breeding severely impaired reproduction in the mink, which was presumed to be due to oligo- or aspermia. In young, rapidly growing ferrets, red and white blood cell counts were adversely affected by dietary concentrations of Compound 1080 as low as 1.08 ppm. The 28-d LC50 test, however, revealed that young, rapidly growing animals may be unsuitable for tests of this duration unless precautions are taken to assure that they do not “outgrow” potentially lethal concentrations of the test chemical.
A method for measuring the biodegradation of organic chemicals
Authors: Boatman Rodney J. , Cunningham Suzanne L. , Ziegler Donald A.
Published: March 2010

An automated gas-chromatographic measurement of carbon dioxide is described and its application to a biodegradation screening test procedure is demonstrated. The biodegradation test system consists of 20-ml glass vials containing aqueous solutions of a test chemical and an acclimated microbial inoculum. The vials and their contents are sealed with rubber septa. At specified time intervals, the contents of selected vials are acidified. Subsequent automated headspace determination of carbon dioxide provides a measure of cumulative biological degradation. To demonstrate the validity of the overall test procedure, the biodegradabilities of eight organic compounds were measured: aniline, benzaldehyde, ethylenediaminetetraacetic acid, ethylene glycol, linear alkylbenzene sulfonate, nitrilotriacetic acid, p-nitrophenol and N-methylaniline. Biological degradation was also monitored by measuring residual test chemical concentrations. There was excellent internal consistency of results by comparison of carbon dioxide evolution values with specific chemical analyses. Both the results of carbon dioxide measurements and specific chemical analyses are discussed in relation to literature values derived from similar screening test procedures. It is concluded from this study that automated headspace determination of carbon dioxide has several advantages over existing test methods. It is further concluded that application of this headspace procedure in the screening test described provides an accurate, albeit conservative, estimate of biodegradability, with positive results indicating a low potential for environmental persistence.
Diatoms in daphnid culture and bioassay
Authors: Keating Kathleen Irwin , Dagbusan Brenda Caballero
Published: March 2010

For daphnids, the diatom Nitzschia frustulum is both a nutritionally desirable food and a source of essential organics not adequately provided by several green algae commonly fed daphnids in bioassays. Although a diet based on only one alga, Chlamydomonas reinhardti, generated more progeny per individual Daphnia pulex, progeny from broodmates fed diets differing only in that they also included diatoms were consistently more tolerant in acute toxicity bioassays. Feeding studies and bioassays were done in wholly defined inorganic media (MS system) that had contributed all essential inorganic nutrients for more than 100 consecutive generations of test daphnids. This limited the possibility of misinterpretation due either to deficiencies resulting from the absence of essential inorganics or to variations in media. Algae were grown in wholly defined inorganic media, versions of A-MS (algal version) that were similar to animal media excepting that additional N, P and Si, and the three vitamins (B12, thiamine, biotin) known to be needed by many algae were included.
Chloroform sorption to New Jersey coastal plain ground water aquifer solids
Authors: Uchrin Christopher G. , Mangels Gary
Published: March 2010

Studies examining the adsorption/desorption characteristics of chloroform to New Jersey coastal plain aquifer solids were performed. Adsorption to the Cohansey aquifer solids, a coarse-to-fine-grade sand with a 4.4% organic matter content (2.6% organic carbon content), and to the Potomac-Raritan-Magothy aquifer solids, a sandy loam with a 2.2% organic matter content (1.3% organic carbon content), was found to be dependent on adsorber mass. Equilibrium adsorption could be characterized by either linear or Freundlich isotherms. Greater adsorption was achieved to the Cohansey material, which was attributed to its greater organic matter (carbon) content. Calculated normalized organic carbon partition coefficients were compared with values obtained from literature correlations. Consecutive desorption experiments displayed an apparent hysteresis.
Relative sensitivity of three daphnid species to selected organic and inorganic chemicals
Authors: Elnabarawy Mohamed T. , Welter Alphonse N. , Robideau Rochelle R.
Published: March 2010

Static acute and renewal chronic tests were conducted with Daphnia magna, Daphnia pulex and Ceriodaphnia reticulata to determine their relative sensitivities to selected organic and inorganic chemicals: 2-chloroethanol, 2,4-pentanedione, pentachlorophenol, hexachloroethane, 2,2,2-trichloroethanol, 2-methyl-1-propanol, 2-methyl-2,4-pentadiol, Endrin®, silver, lead, chromium, cadmium, copper, arsenic and mercury. The three species tested yielded comparable acute EC50 values for most chemicals tested. The acute EC50 values for D. magna, D. pulex and C. reticulata varied twofold for hexachloroethane, Endrin, cadmium, arsenic and mercury. Chronic EC50 values for the three species were within one order of magnitude for 2-chloroethanol, 2,4-pentanedione, cadmium, chromium and silver. Differences in the sensitivities of these three popular cladoceran test species were within one order of magnitude. Reproductive impairment in all three test species appeared to be a more sensitive indicator of chronic toxicity than survival. This study suggests that the 7-d Ceriodaphnia chronic test may be used as an alternative short-term method for the screening of chemical toxicities.
Water quality-based criteria for toxics: Scientific, regulatory, and political considerations: Site-specific water quality criteria from in-stream monitoring data
Authors: Van Hassel John H. , Gaulke Alan E.
Published: March 2010

The determination of site-specific water quality criteria generally involves the recalculation of national criteria using laboratory-derived toxicity data or the conducting of bioassays using site water. Because of uncertainty of predictions of in-stream biological responses to contamination, an alternative procedure using stream benthic surveys and water quality data was applied at the Appalachian Power Company Clinch River Plant on the Clinch River in southwestern Virginia. Benthic surveys of riffle transects at four stations located upstream and downstream of the plant showed no significant differences among sites, except just below the effluent discharge site. During low-flow periods there were significant decreases at this site in the percentage of mayflies in the organisms collected.

Effluent and ambient chemical data were examined statistically with respect to the biological data. Increased copper concentrations were significantly associated with decreases, from reference levels, in percent mayflies at the impacted area. A linear equation was derived relating decreased percent mayflies to increased copper concentrations. A no effect level based on the least detectable difference in percent mayflies produced a total recoverable copper criterion of 34.2 μg/L. Criteria or impact estimates derived from in-stream data possess many advantages; they are a valuable tool for reducing uncertainty through integrated field-laboratory assessments.
Potential impact of selected agricultural chemical contaminants on a northern prairie wetland: A microcosm evaluation
Authors: Johnson B. Thomas
Published: March 2010

An aquatic, multicomponent microcosm simulating a northern prairie wetland was used to assess the potential effects of six extensively used agricultural pesticides on this important wildlife habitat. Using a nested experimental design, 16 4-liter aquatic microcosms were treated with three concentrations of each of the pesticides carbofuran, fonofos, phorate, atrazine, treflan and trial-late. The microcosm units were incubated for 30 d in an environmental chamber, with a 16-h light:8-h dark cycle, maintained at 20°C. Specific limnological, biological and toxicological parameters were monitored over time by observing the interactions of water, animals, sediment and plants with the pesticides. The laboratory protocol was designed as an initial, rapid, economical screening test to determine the effect, but not the fate, of chemical contaminants in terms of toxicity, impaired productivity and community biochemical functions.

Static acute toxicity tests with Daphnia magna and Chironomus riparius suggested that carbofuran, fonofos, phorate and triallate were very toxic to aquatic invertebrates. For D. magna the 48-h EC50 values were 48, 15, 19 and 57 μg/L, respectively. Invertebrate viability tests indicated rapid changes in the toxicological persistence of these pesticides after microcosm interaction. Populations of D. magna were established in the 10 μg/L test concentration of carbofuran, phorate, triallate and fonofos at 1, 1, 14 and 28 d, respectively. Preexposure of the wetland sediments to either triallate or fonofos did not appear to change the relative toxicological persistence of each compound in the water column. Changes in pH, alkalinity, conductivity, dissolved oxygen, total nitrogen and total phosphorus were also observed with different pesticide treatments. Atrazine significantly reduced gross primary productivity and inhibited algal and macrophytic growth. In general, there was no evidence of significant inhibition of microbial functions in the water or hydrosoil of the treated microcosms. The respiratory electron transfer system, phosphatase activity, oxygen consumption and mineralization of dissolved organic carbon were not significantly impacted by any of these pesticides in hydrosoils. However, the impact of atrazine, fonofos and triallate on invertebrates and plants in the microcosm—both key elements in wetland productivity—would suggest that caution be used in application of these pesticides in or near wetland habitats.
Characterization of chemical waste site contamination and determination of its extent using bioassays
Authors: Thomas J. M. , Skalski J. R. , Cline J. F. , McShane M. C. , Simpson J. C. , Miller W. E. , Peterson S. A. , Callahan C. A. , Greene J. C.
Published: March 2010

Bioassays were used in a three-phase research project to (a) assess the comparative sensitivity of test organisms to known classes of chemicals, (b) determine if the chemical components in field soil and water samples of unknown chemical composition could be inferred from laboratory studies using pure chemicals and (c) investigate kriging (a relatively new statistical “mapping” technique) and bioassays as methods to define the areal extent of chemical contamination.

The algal assay generally was most sensitive to samples of pure chemicals, soil elutriates and water from eight sites with known chemical contamination. Bioassays of nine samples of unknown chemical composition from the Rocky Mountain Arsenal site showed that a lettuce seed soil contact phytoassay was most sensitive. Preliminary evidence suggests that bioassays might be a useful tool in broadly identifying classes of toxic components of contaminated soil. Nearly pure formulations of insecticides and herbicides were less toxic than were their counterpart commercial formulations. This finding indicates that chemical analysis alone may fail to correctly rate the severity of possible environmental toxicity. Finally, we demonstrate that the lettuce seed phytoassay and kriging techniques can be used to map contamination in a portion of the Rocky Mountain Arsenal site and aid in cleanup decisions.