bluuebunny/crossref_metadata_2025 huggingface dataset:
Movement of pesticides in soil columns as affected by anhydrous ammonia
Authors: Smith Sammie , Willis Guye H.
Published: March 2010

A soil column study was conducted to characterize the movement of permethrin [3-phenoxybenzyl(1RS)-cis, trans-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate], fenvalerate [(RS)-α-cyano-3-phenoxybenzyl(RS)-2-(4-chlorophenyl)-3-methylbutyrate], toxaphene (chlorinated camphene), trifluralin (α,α,α -trifluoro-2,6-dinitro-N,N-dipropyl-p-toluidine) and metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as-triazin-5(4H)-one] in soil as affected by fertilizer anhydrous NH3 application at 0, 50 and 150 kg N/ha. The soil columns were leached with three pore volumes of water and segmented. Under the saturated flow conditions used in the study, the insecticides were essentially immobile in the columns receiving no anhydrous NH3. About 5% permethrin was found 5 to 10 cm below the zone of application and about 9% fenvalerate and 16% toxaphene were found 5 to 20 cm below the zone of application in the soil columns receiving the highest level of anhydrous NH3. No appreciable amounts (<0.5%) of the insecticides occurred in the column leachates. There was no apparent enhancement of the mobility of the herbicides trifluralin and metribuzin due to anhydrous NH3 application. Extensive disappearance of trifluralin occurred at all anhydrous NH3 levels, and the disappearance of metribuzin increased with increasing anhydrous NH3 application. The observed enhanced leaching of the insecticides appears to support the hypothesis that soil humic substances, solubilized by NH3, can serve as pesticide carriers.
Chemistry and aquatic toxicity of raw oil shale leachates from piceance basin, Colorado
Authors: Meyer Joseph S. , Sanchez Deborah A. , Bergman Harold L. , McWhorter David B. , Brookman John A.
Published: March 2010

Leachates were collected during the period of 1981 to 1983 from several depths in two surface piles of raw, mined oil shale in the Piceance Basin of northwest Colorado. Although both piles were subject to similar climatic conditions, the composition of major inorganic ions in the leachates differed considerably because of different shale compositions. Acute toxicity to Daphnia magna and fathead minnows (Pimephales promelas) occurred when leachate conductivity exceeded 7,000 to 8,000 μmhos/cm and total dissolved solids exceeded 6 to 7 g/L (0.6 to 0.7% salt). D. magna were more sensitive than fathead minnows in acute toxicity tests, and D. magna 48-h LC50 values were as low as 13% of full-strength leachate. The lowest no observed effect concentration determined in D. magna 21-d chronic toxicity tests was 0.9% of full-strength leachate. Because of interactions among the major ions, the contributions to toxicity by trace elements and organic compounds in the oil shale leachates could not be differentiated from contributions by MgSO4, the major toxicant. This study demonstrated that toxic mechanisms occurring within complex chemical mixtures cannot always be identified on the basis of single-compound toxicity values, and that reconstituted mixtures of principal chemical components are useful in identifying toxicants and their interactions with other mixture constituents.
Fate of three phosphate ester flame retardants in small ponds
Authors: Muir D. C. G. , Lint D. , Grift N. P.
Published: March 2010

The fate of 14C-labeled t-butylphenyldiphenyl phosphate (tBPDP), 2-ethylhexyl diphenyl phosphate (EHDP) and tri(m-cresyl) phosphate (mTCP) was studied for up to 360 d following addition of each compound to artificial ponds (5 m3 volume) to give initial water concentrations of about 50 μg/L. Concentrations of each phosphate ester decreased rapidly, with half-lives of about 0.5 d for each compound. Concentrations of intact esters in bottom sediments decreased more slowly, with half-lives of 39 d for tBPDP and mTCP and 79 d for EHDP. A series of unidentified 14C-labeled nonpolar oxidation products, as well as diaryl phosphates, was isolated by TLC analysis of extracts of water and sediment. Concentrations of 197 ng/m3 tBPDP and 32 ng/m3 EHDP were detected in air (5 cm height) above the ponds during the first 18 h after the addition of the esters to the water. Volatilization losses during the experiment were estimated to represent less than 10% of the amounts added to the water initially. Maximum concentrations in fathead minnows (Pimephales promelas), ranging from 7.3 μg/g for mTCP to 10 μg/g for tBPDP, were observed 8 h after application. Chironomid larvae collected from bottom sediments accumulated concentrations that were 11- to 37-fold greater than levels of each compound present in sediment. After 360 d, most of the remaining 14C was present in bottom sediment, representing 24 to 30% of the amount originally added.
A multidisciplinary approach to the assessment of ocean sewage sludge disposal
Authors: Fava James A. , McCulloch Wayne L. , Gift James J. , Reisinger H. James , Storms Stephen E. , Maciorowski Anthony F. , Edinger John E. , Buchak Edward
Published: March 2010

This article presents a multidisciplinary approach to assess the hazards of ocean sewage sludge dumping. It combines physical and chemical sludge characteristics, estimated safe chronic levels and bioaccumulation potential with estimated environmental exposure (concentration and time) information. The hazard assessment was used to evaluate sewage sludges from 12 water pollution control plants operated by the New York City Department of Environmental Protection. Using a mathematical dispersion model, the worst-case minimum dilution after 4 h was predicted to be 11,500:1. Of the three marine species tested, mysid shrimp were found to be the most sensitive. Using an application factor of 0.05, estimated chronic safe levels were estimated, the values do not exceed the limiting permissible concentrations, after allowing for initial dilution. Also, the concentrations of the chemicals in the liquid sewage sludge phase were below ambient water quality criteria. The results suggest that the ocean disposal of sewage sludge does not appear to present the environmental hazard originally perceived.
Microbial transformation rates of AZO and triphenylmethane dyes
Authors: Michaels Glenda B. , Lewis David L.
Published: March 2010

Using field-collected and laboratory cultures, bacterial transformation rates for one azo and two triphenylmethane dyes were studied as a means of assessing the potential degradation of these compounds in aquatic environments. Transformation was measured as loss of color by spectrophotometry, and first- and second-order transformation rate coefficients were determined. Second- order coefficients (kb) were based on total colony-forming units (CFU) of bacteria in batch cultures. Percentages of total bacteria that transformed the dyes were determined by isolating bacterial colonies from field-collected samples and testing the isolates for the capacity to transform the dyes in dilute nutrient medium. The azo dye, Acid Orange 6, was not transformed under the aerobic conditions of these studies. Basic Violet 1 was transformed and k1 values ranged from -0.003 to -0.023 h−1, with a mean (kb) of 3.5 × 10−14L CFU−1 h−1. Basic Violet 3 also was transformed and k1 values ranged from -0.002 to -0.012 h−1, with a mean kb of 2.8 × 10−14 L CFU−1 h−1. The percentage of transformer bacteria for Basic Violet 1 ranged from 6 to 28%, with a mean of 13.5%, and the range for Basic Violet 3 was 0 to 24%, with a mean of 8.32%. Therefore, the triphenylmethane dyes were transformed at similar rates, and similar fractions of the total bacterial populations were involved in the transformation.
Organochlorine contaminants in passeriformes and other avian prey of the peregrine falcon in the western united states
Authors: Deweese L. R. , McEwen L. C. , Hensler G. L. , Petersen B. E.
Published: March 2010

About 1,150 individuals of 38 species of Passeriformes and other small birds were collected in 1980 at 36 locations in eight western U.S. states for organochlorine (OC) chemical analysis. The bird carcasses (less beak, tarsi, gastrointestinal tract, and feathers) were combined by species and location (4 to 15 specimens per sample) into 124 composited samples for analysis. Also analyzed were 77 single specimens of four species, to assess variation in residue concentrations in individual birds. The chemicals detected (greater than 0.05 ppm) were the following (in order of frequency): DDE, polychlorinated biphenyls (PCBs), hexachlorocyclohexane (HCH), heptachlor epoxide, oxychlordane, dieldrin and toxaphene. DDE accounted for 72% of total OC concentrations (ppm DDE/ppm total OCs) overall and PCBs accounted for 3%. DDE mean (geometric) residues were highest in tree swallows (Tachycineta bicolor Vieillot), 12.0 ppm; killdeer (Charadrius vociferus L.), 5.9 ppm; and Brewer's blackbirds (Euphagus cyanocephalus Wagler), 2.7 ppm. Eight migratory species showed mean DDE residues 13 times higher than those in four resident species (1.3 vs. 0.1 ppm, p < 0.05), but PCB residues were similar (0.03 vs. 0.02 ppm). Insectivorous species showed higher DDE, PCB and total OC residues than did either omnivores or granivores (p < 0.05). Males of some species showed higher residues of DDE, PCBs and total OCs than did females (p < 0.05). DDE residues, but not PCBs, in killdeer, Brewer's blackbirds and violet-green swallows (Tachycineta thalassina Swainson) were significantly related (0.01 < p < 0.08) to latitude and longitude of origin.

Concentrations of DDE in the carcass fat of some individual tree swallows and killdeer would be in the lethal range if 15 to 20% of the stored DDE were rapidly mobilized to the brain. Samples of 13 species contained DDE concentrations (greater than 3 ppm) considered sufficient to inhibit the normal reproduction of avian predators feeding on them. The evidence suggests that potentially harmful OC concentrations are present in certain western migrants and pose an even greater hazard to avian predators such as the peregrine falcon (Falco peregrinus Tunstall).
Assessment of the safety of dioctyl adipate in freshwater environments
Authors: Felder J.D. , Adams W.J. , Saeger V.W.
Published: March 2010

A safety assessment of dioctyl adipate (DOA) in freshwater environments was conducted. DOA is relatively insoluble in water and is likely to partition to sediment and biota in the aquatic environment. Biodegradation was found to be rapid and extensive under conditions simulating sewage systems and the natural environment. Measured environmental concentrations of DOA averaged less than 0.5 μg/L in natural surface waters. DOA was not acutely toxic to algae and fish at or above its water solubility of 0.78 ± 0.16 mg/L. It was acutely and chronically toxic to Daphnia magna at 480 to 850 and 24 to 52 μg/L, respectively. A bioconcentration study with bluegill showed that DOA is not an accumulative or persistent chemical in this species. The mean 28-d bioconcentration factor was 27. A comparison of the mean environmental water concentrations of DOA with laboratory chronic toxicity values for D. magna showed a safety margin of approximately three orders of magnitude. The conclusion drawn from this environmental safety assessment is that, under present use and disposal patterns, DOA presents a small hazard to the freshwater aquatic environment.
Qualitative and quantitative analyses of petroleum hydrocarbon concentrations in a trout stream contaminated by an aviation kerosene spill
Authors: Guiney Patrick D. , Sykora Jan L. , Keleti George
Published: March 2010

Kerosene-range hydrocarbons were monitored in a small central Pennsylvania stream watershed, over two years (1982 to 1984), after a pipeline leak of about 1,310 barrels of aviation kerosene. This study, part of a two-phased program, was designed to detect and quantify hydrocarbon concentrations in freshwater environmental compartments impacted by the spill. Various methods of analysis were employed. Field conditions required careful documentation of methodologies and quality assurance practices for sample collection and analysis to ensure the validity of results. The concentration of kerosene-range hydrocarbons and total organic carbon in the contaminated stream water typically decreased during the initial months after the spill and generally remained at or below background levels after 3 months. Elevated concentrations of hydrocarbons, however, were detected in sediment samples and tissues of fish collected from two impacted bridge locations up to 14 months after the spill occurred. These two bridges were primary boom recovery sites during spill cleanup activities. Bottom sediments from pools near these sites contained approximately two to three times the corresponding hydrocarbon concentrations detected in fish tissues from the same area. This information appears to suggest that these surface sediments may have served as secondary storage sinks for residual, sinking product not recovered during the initial skimming operations. These residues were apparently available for uptake by resident fish. No kerosene-range hydrocarbons were detected in these surface sediments after 21 months, and other stream water quality parameters remained within normal limits. Our results indicated that fused-silica capillary GC offered high resolution and precision and provided reasonable detection limits for analyzing kerosene-range hydrocarbons in the contaminated environmental compartments investigated in this study.
Induction of hepatic microsomal monooxygenase activity in fish by exposure to river water
Authors: Melancon Mark J. , Yeo Steven E. , Lech John J.
Published: March 2010

The effect on hepatic monooxygenase activity of exposing carp (Cyprinus carpio) and bullheads (Ictalurus melas) to river water was examined. Hepatic microsomal ethoxyresorufin-O-deethylase activities in fish maintained continuously in dechlorinated city water were compared with those in fish exposed to river water pumped into laboratory tanks. Monooxygenase activity increased rapidly upon exposure to river water and was significantly elevated after 3 d of exposure. When river water-exposed fish were returned to dechlorinated city water, monooxygenase activity steadily returned to pre-exposure levels. This report includes two studies using carp performed in different years, and a more limited study using bullheads. Carp captured in an adjacent river that flowed into Milwaukee Harbor had high hepatic microsomal ethoxyresorufin-O-deethylase activity when compared with carp in the laboratory tanks. Under these carefully controlled conditions, the occurrence and reversibility of environmental induction of monooxygenase activity were clearly demonstrated.
The acute oral LD50 of technical pentachlorophenol in developing rats
Authors: St. Omer Vincent E. V. , Gadusek Frank
Published: March 2010

The acute oral LD50s for technical-grade pentachlorophenol (T-PCP) were calculated by the Litchfield-Wilcoxon method during the ontogenetic growth of 10- to 134-d-old rats. Signs of toxicity included accelerated respiration, hyperpyrexia, collapse, asphyxial convulsions and death followed by rapid rigor mortis. Young rats (not yet weaned, 10 and 20 d old) and adults (70 and 134 d old) were more susceptible to the toxic and lethal effects of T-PCP than were juveniles (25 to 50 d old). The LD50 (mg/kg) ranged from 50 to 180 for preweaned rats, from 220 to 230 for juveniles and from 80 to 120 for adults.
Orthene® toxicity to little brown bats (Myotis lucifugus): Acetylcholinesterase inhibition, coordination loss, and mortality
Authors: Clark Donald R. , Rattner Barnett A.
Published: March 2010

The 24-h LD50 of Orthener̀ (active ingredient acephate, acetylphosphoramidothioic acid o,s-dimethyl ester, CAS 30560-19–1) to little brown bats (Myotis lucifugus) was high (> 1,500 mg acephate/kg) and at least several times greater than the LD50 for mice (Mus musculus) (720 mg/kg). Twenty-four hours after dosing, all surviving mice appeared behaviorally normal, but 9 of 30 surviving bats could not right themselves when placed on their backs. When dead and incapacitated bats were combined to calculate an ED50 (median effective dose), the resultant estimate (687 mg/kg) did not differ (p > 0.05) from the LD50 for mice. Serum cholinesterase (ChE) activity in control bats was 3.2 times greater than in mice. The relationship between this naturally high level of ChE and the relative tolerance of bats to organophosphorus insecticides is unexplained. Toxicity of Orthene was clearly less than that reported elsewhere for methyl parathion (phosphorothioic acid o,o-dimethyl o-[4-nitrophenyl] ester, CAS 298–00-0). This finding may be useful in selection of a chemical for agricultural use, but conclusions about the safety of Orthene to this bat species, or to others, must remain tentative until confirmed by studies under field conditions. Because bats are long-lived with low reproductive rates and slow recruitment, any additional mortality in the wild could be critical to population survival.
Four independent approaches to developing sediment quality criteria yield similar values for model contaminants
Authors: Chapman Peter M. , Barrick Robert C. , Neff Jerry M. , Swart Richard C.
Published: March 2010

Separate approaches to determining marine sediment quality criteria yielded similar values for three contaminants. These values, including concentrations at or below which biological effects have been shown to be minimal and lowest concentrations at which biological effects have been shown to occur, range from (dry weight sediment): lead, 50 to 300 μg/g (ppm); polyaromatic hydrocarbons, 2.0 to 12.0 μg/g; polychlorinated biphenyls, 0.06 to 0.13 μg/g.
TSCATS: A database for chemical and subject indexing of health and environmental studies submitted under the toxic substances control act
Authors: Santodonato Joseph , Bush Christopher , Howard Phillip , Howard Karen , Delfavero Steven , Miles Paula C. , Merrick Eleanor T. , Smith Linda K. , Travers Linda A.
Published: March 2010

A large resource of unpublished technical data exists in the form of reports submitted by industry under the Toxic Substances Control Act (TSCA) to the U.S. Environmental Protection Agency. The TSCA Test Submissions (TSCATS) database was recently developed and made available to the public to allow computerized searching of test submissions according to specific chemical identity or type of study. Studies are categorized into three broad subject areas (health effects, environmental effects, environmental fate) and additional indexing terms are assigned from a controlled vocabulary describing the experimental protocol and certain observations of the test. Records from the on-line database also contain reference information to assist in locating the source document, and to identify the submitting organization and reason for submission of the test data.
The case against mercury (II) methylation by aquatic environmental methylsiloxanes
Authors: Frye Cecil L. , Chu Hsien-Kun
Published: March 2010

The literature relating to the methylation of mercury salts by methylsilicon species has been reviewed and critically assessed from the standpoint of potential ecological significance. The probability of such reactions occurring under any likely aquatic environmental conditions is shown to be extremely low. This conclusion is strongly reinforced by additional experiments in which water-soluble analogs of the methylsiloxanes (materials reportedly present as traces in some aquatic sediments) were shown to be completely unaffected by mercuric chloride at ambient laboratory temperatures. Few additional studies with other mercury salts (e.g., acetate or nitrate) or higher temperatures were performed because of their irrelevance to any likely aquatic environmental situation.
Fate of 1,3,6,8-tetrachlorodibenzo-p-dioxin in an outdoor aquatic system
Authors: Corbet Robert L. , Webster G. R. Barrie , Muir Derek C. G.
Published: March 2010

Three outdoor pools (5.5 m3) were treated with [14C]1,3,6,8-tetrachloridibenzo-p-dioxin (1,3,6,8-T4CDD) at concentrations of 98, 245 and 980 ng/L, and the movements and accumulation of the compound were monitored in air, water, sediment and vegetation over a 426-d period. The concentrations of 1,3,6,8-T4CDD in the air above the treated pools ranged from 8.4 to 18.8 ng/m3 during the first day after treatment. Total 14C concentration in the water column declined rapidly, with more than 90% lost from the water phase within 96 h (t1/2 = 14.0 to 28.5 h). The sediments were the major reservoir for the compound, accounting for 34 to 80% of the added compound at 34 d and 5 to 14% at 426 d. Total [14C]T4CDD concentrations in the sediments increased at 90 d, in part because of the end-of-season deposition of rooted vegetation. 1,3,6,8-T4CDD degraded in natural water in Pyrex flasks at similar rates in sterile and nonsterile waters (t1/2 = 6.3 to 8.0 d) in sunlight, but not under darkened conditions. A single, polar photodegradation product (retention time 0.82 relative to 1,3,6,8-T4CDD) was detected by HPLC, and 20% of the 14C was unextractable within 10 d. Similar degradation products were noted in the water and sediments (90 and 426 d). In duckweed (Lemna sp.) and (Potamogeton sp.), concentration factors for 1,3,6,8-T4CDD ranged from 2.5 to 3.4 × 104 and from 0.27 to 2.0 × 105, respectively. At 426 d posttreatment, 5 to 8% of the applied 1,3,6,8-T4CDD could be accounted for in all aquatic compartments, with an additional 4 to 6% of 14C present as unidentified polar products and unextractable residue.
Influence of soil characteristics on the adsorption of pirimicarb
Authors: Sanchez-Camazano M. , Sanchez-Martin M. J.
Published: March 2010

A study was made of the influence of soil properties and composition on the adsorption of pirimicarb (2-dimethylamino-5,6-dimethylpyrimidin-4-yl-dimethyl carbamate). Twenty-one soil samples with different characteristics were used to study the following parameters: adsorption by natural soils, correlations between adsorption and soil properties, and effect of the elimination of organic matter on adsorption. The adsorption isotherms obtained are, in general, of the L type of the Giles classification, in all cases fitting the Freundlich equation. A highly significant correlation between the distribution coefficient (Kd) and the clay content was observed. For the soils containing montmorillonite in the clay fraction, a fairly significant correlation was seen between Kd and the montmorillonite content. The maximum variability in adsorption for all the soils is explained by the multiple correlation between Kd and the values of the clay plus organic matter and pH (R2 = 0.68). In the soils containing montmorillonite, the correlations between Kd and the organic matter and smectite contents account for 80% of the variability in adsorption. Adsorption by the oxidized soils shows that organic matter can block the adsorption of the pesticide by the clay.
Effects of fluorene on microcosms developed from four natural communities
Authors: Stay Frank S. , Katko Albert , Rohm Christina M. , Fix Melissa A. , Larsen David P.
Published: March 2010

Ecosystem-level responses were examined in microcosms developed from four different natural plankton communities and exposed to nominal concentrations of 0.12, 0.50, 2.0, 5.0 and 10.0 mg/L fluorene, a polynuclear aromatic hydrocarbon. The lowest observed (p < 0.05) effect level (LOEL) for dark respiration (Rni) was 0.12 mg/L fluorene in three of the four communities during the first 14 d. The LOEL for Rni in the fourth community was 5.0 mg/L. The LOEL of the net productivity/respiration ratio (Pn/Rni) was 0.12 mg/L in all four communities. These results suggest that the responses of these microcosms were not completely independent of their source communities. The sensitivities or LOEL values from these microcosm experiments were as low as those reported for chronic bioassays of the three most sensitive of seven standard test organisms. Comparisons between the responses of these microcosms and those reported for experimental ponds exposed to the same concentrations of fluorene suggest that these microcosms accurately reflect the types of changes and concentrations that cause change in pond ecosystems. However, slight but significant changes in the ecosystem-level variables gave no indication of the almost complete elimination of some zooplankton populations at 5.0 and 10.0 mg/L in the ponds and at 2.0, 5.0 and 10.0 mg/L in the microcosms. This lack of correspondence between population- and ecosystem-level measurements suggests that test measurements made at one hierarchical level of organization may not always be appropriate for estimating effects at other levels.
Use of respiratory-cardiovascular responses of rainbow trout (Salmo gairdneri) in identifying acute toxicity syndromes in fish: Part 3. Polar narcotics
Authors: Bradbury Steven P. , Henry Tala R. , Niemi Gerald J. , Carlson Richard W. , Snarski Virginia M.
Published: March 2010

The physiological responses of rainbow trout to acutely lethal aqueous concentrations of the suspected polar narcotics phenol, 2,4-dimethylphenol, aniline, 2-chloroaniline and 4-chloroaniline were examined. Visible signs of intoxication included tremors that progressed to whole-organism clonic seizures, followed by general depression and respiratory-cardiovascular collapse. Tremors and seizures were usually initiated with coughs. The most striking changes in the respiratory-cardiovascular parameters for all five toxicants included elevated cough frequency (coincident with seizures), ventilation frequency and hematocrit, and depressed gill oxygen uptake efficiency, arterial pH, total arterial oxygen and total arterial carbon dioxide. The physiological responses noted were attributed to the initial muscular activity associated with seizures followed by respiratory-cardiovascular collapse. Using phenol as a model compound, these effects were found to be reversible when intoxicated fish were exposed to chemical-free water. Principal components analyses of the physiological responses demonstrated that the 11 monitored variables were highly correlated. Interpretation of the principal components showed that responses within each toxicant-exposure group were distinct from those of the control group. The response data sets for the suspected polar narcotics (N = 20 fish) were combined with four fish acute toxicity syndromes (FATS) (N = 32 fish) previously described (respiratory uncoupler syndrome, respiratory irritant syndrome, acetylcholinesterase inhibitor syndrome and narcosis syndrome), and assessed using discriminant function analysis. This analysis showed that all 52 trout could be correctly classified into their respective FATS. As a result, two separate narcosis FATS, narcosis type I (previous work) and narcosis type II (this study), were defined. Identification of a narcosis type II syndrome supports the concept of developing quantitative structure-activity relationship models for polar narcotics in fish.
Multigeneration life-span tests of the nutritional adequacy of several diets and culture waters forCeriodaphnia dubia
Authors: Winner Robert W.
Published: March 2010

The effects of four diets [Chlamydomonas reinhardtii, Selenastrum capricornutum yeast-trout chow-Cerophyl (YTC) and YTC plus S. capricornutum] and two reconstituted waters on the vitality and fecundity of five to six life-span generations of Ceriodaphnia dubia were determined. The foods and waters were tested with and without a selenium supplement. The results indicate that healthy populations of this species can be maintained in reconstituted waters containing only four salts so long as the food is nutritionally adequate and the reconstituted water is formulated from an ultrapure base water. The adequacy of the YTC diet varies according to the nutritional adequacy of the constituents. Some batches of trout chow and Cerophyl were nutritionally deficient, causing unacceptably high mortality and abortions in cultures. These deficiencies were corrected by adding selenium to the culture water and using Selenastrum in conjunction with the YTC. The alga C. reinhardtii, if cultured in medium enriched with vitamins and selenium, proved quite adequate for maintaining healthy cultures of C. dubia. Animals maintained on the other alga S. capricornutum, exhibited a delay in reproductive maturation and a reduction in brood sizes, and they were frequently trapped in the surface film of the culture water.
Role of dietary choices in the ability of bobwhite to discriminate between insecticide-treated and untreated food
Authors: Bennett Richard S.
Published: March 2010

Tests were conducted to determine the dietary concentrations at which 14-d-old bobwhite (Colinus virginianus) chicks could discriminate between food treated (TRT) with two organophosphorus (OP) insecticides (chlorpyrifos and methyl parathion) and untreated (UNT) food. Results of subacute dietary LC50 tests using one feeder of TRT food per cage were compared with those of tests in which birds were presented with two feeders (one TRT and one UNT, 1:1) or 10 feeders (five TRT and five UNT, 5:5; or nine TRT and one UNT, 9:1). The dietary concentration above which birds discriminated between TRT and UNT feeders by consuming a greater proportion of UNT food was defined as the discrimination threshold (DT). The DT occurred at sublethal dietary concentrations in all chlorpyrifos tests (DT = 45 ppm in 1:1 test, 24 ppm in 5:5 test and 69 ppm in 9:1 test; LC50 = 647 ppm) but increased in the methyl parathion tests as the number of choices and the relative proportion of TRT feeders increased (DT = 10 ppm in 1:1 test, 46 ppm in 5:5 test and >126 ppm in 9:1 test; LC50 = 91 ppm). The different responses were probably due to differences in the intensity of sensory cues presented by the two chemicals as the chicks developed conditioned aversions to them. In all tests, mortality was inversely related to total food consumption. No relationship was found between mortality and the amount of active ingredient ingested per bird-day. Consequently, the ability to locate UNT feeders was more important than the amount of chemical ingested. When alternative food choices exist, vulnerability to poisoning can be influenced by the number and relative abundance of those choices, as well as a bird's ability to detect the chemical.
Marine complex effluent toxicity program: Test sensitivity, repeatability and relevance to receiving water toxicity
Authors: Schimmel Steven C. , Morrison George E. , Heber Margarete A.
Published: March 2010

In March 1984, the U.S. Environmental Protection Agency (EPA) issued a significant change in procedures regulating toxic materials in effluents through the National Pollutant Discharge Elimination System (NPDES). Concurrent with this toxicity-based effluent control policy, the EPA established the marine/estuarine component of the Complex Effluent Toxicity Testing Program (CETTP). The CETTP was established to provide reliable, sensitive and environmentally meaningful test protocols that could be used to detect toxic industrial and municipal effluents within the NPDES. Five toxicity test methods have been developed and validated for the program since 1984 using a marine plant (Champia parvula), two invertebrate species (Arbacia punctulata and Mysidopsis bahia) and two fish species (Cyprinodon variegatus and Menidia beryllina). The laboratory precision test results for the methods were acceptable; coefficients of variation for all methods were less than 54%, averaging 34%. Numerous field tests were conducted using these methods and the results indicate that tests on receiving waters (in which effluent concentrations could be estimated through controlled dye studies) accurately reflect the toxicity of the effluents measured directly. Receiving water impacts, when observed, were generally near-field in nature. The test methods developed are sensitive, efficient, reliable and environmentally relevant measures of effluent toxicity and offer promise for reducing adverse impacts from point-source discharges in near-coastal waters.
Short- and long-term sediment toxicity test methods with the amphipod Grandidierella japonica
Authors: Nipper Marion G. , Greenstein Darrin J. , Bay Steven M.
Published: March 2010

Methods are described for conducting flow-through sediment toxicity tests with the marine amphipod Grandidierella japonica. Short-term (10-d) exposures were conducted at 15°C in 1-liter beakers containing a 2-cm layer of sediment and 700 ml overlying seawater. Long-term (28-d) tests were conducted in 1-liter beakers at 19°C with the weekly addition of food to the test chambers. Both methods were used to measure the toxicity of sediments from five locations in southern California. These sites included highly contaminated areas adjacent to large municipal wastewater outfalls and within industrialized harbors.

Both test methods were sensitive to levels of contamination found in the field, but produced different patterns of effects. Short-term mortality was greatest in amphipods exposed to the harbor sediments, while long-term exposure produced the greatest reductions in survival and growth at the Los Angeles County Outfall site. Amphipod survival was unaffected by variations in sediment grain size, while this characteristic appeared to have an important effect on growth.
Sublethal exposure to lead inhibits acquisition and retention of discriminate avoidance learning in green frog (Rana Clamitans) tadpoles
Authors: Strickler-Shaw Shari , Taylor Douglas H.
Published: March 2010

Green frog, Rana clamitans, tadpoles were exposed to 750 μg Pb/L as lead nitrate. Tadpoles used in learning acquisition tests were exposed for 6 d (144 h) and tadpoles used in retention (memory) tests were exposed for 5 d (120 h). Both lead-exposed and control tadpoles were conditioned, using shock avoidance, to associate illumination (conditioned stimulus) with shock (unconditioned stimulus). The mean response time, the number of avoidances and differences in the learning curves of the lead-exposed and control tadpoles were compared statistically. Learning acquisition tests showed increased response times and fewer avoidances in lead-exposed as compared to control tadpoles. Retention tests showed higher response times and no avoidances in lead-exposed tadpoles as compared to controls. These results indicate that sublethal exposure to lead adversely affected both acquisition learning and memory.
Acid neutralization in laboratory sediment-water microcosms from a rocky mountain subalpine lake (USA)
Authors: Bruns D. A. , O'Rourke T. P. , Wiersma G. B.
Published: March 2010

A laboratory sediment–water microcosm experiment for a Rocky Mountain subalpine lake was conducted over a 35-d incubation period. Three sets of treatments were acidified to a pH of 4.3 and compared with a set of control microcosms. Treatments included additions of nitric acid, sulfuric acid and both acids combined. All treatment microcosms demonstrated rapid pH recovery to near that of the controls (e.g., 6.2) and changes in ion concentration suggested that over 90% of this recovery could be accounted for by cation exchange and microbial reduction of sulfates and nitrates. Denitrification appeared to predominate in both sets of treatments that involved nitric acid while cation exchange (mostly calcium) was more important in the sulfuric acid treatment. These results are consistent with published findings for both laboratory and field studies and demonstrate the potential importance of sediments for acid neutralization in a Rocky Mountain lake.
Arsenic uptake and transfer in a simplified estuarine food chain
Authors: Lindsay Diane M. , Sanders James G.
Published: March 2010

A simplified food chain of phytoplankton species, Artemia sp., and Palaemonetes pugio was used to study pathways of arsenic uptake in estuarine ecosystems. Uptake of arsenic by phytoplankton was significant; however, only small amounts of arsenic were incorporated by Artemia and no significant increases in arsenic content of P. pugio were found in those organisms exposed to arsenic-contaminated food or to elevated water concentrations.
Enhanced anaerobic biodegradation of vinyl chloride in ground water
Authors: Barrio-Lage Gladys A. , Parsons Frances Z. , Narbaitz Roberto M. , Lorenzo Pedro A. , Archer Horace E.
Published: March 2010

The enhanced biotransformation of vinyl chloride (VC) under anaerobic conditions was studied using static microcosms and a flow-through column packed with soil from a study site. Vinyl chloride was found to be resistant to transformation in the static microcosms in five months of incubation; however, 89% of the vinyl chloride that was dissolved in the water was transformed when the microbiota in the columns was stimulated with a mixture of nutrients. In the presence of nutrients such as methane, methanol, ammonium phosphate and phenol, the main products of biotransformation were nonchlorinated organics such as methane and ethylene. Sodium acetate, added to the water and soil, did not enhance the biotransformation of VC because acetate-utilizing bacteria were not found at the study site and none developed in soil sample after the 21 d allowed for adaptation. Four biodegradation mechanisms of vinyl chloride under anaerobic conditions were recognized in this study: (a) reductive dechlorination to ethylene; (b) mineralization to methane; (c) formation of chloromethane, probably followed by methane formation; and (d) bio-oxidation to CO2, where acetate and citrate were added. A pseudo-first-order rate constant of 1.01 × 10−3 months−1 and a t1/2 of 57.2 years were calculated for the disappearance of vinyl chloride in soil and water microcosms under anaerobic conditions, without bioenhancement.
Degradation of methomyl in chlorinated water
Authors: Miles Carl J. , Oshiro Wendy C.
Published: March 2010

Methomyl degrades rapidly in chlorinated water and the rate increases with decreasing pH, increasing temperature and increasing chlorine concentrations. Reaction rate with free chlorine is 1,000-fold faster than with chloramine. Methomyl forms methomyl sulfoxide and N-chloromethomyl before degrading to acetic acid, methanesulfonic acid and dichloromethylamine.
Kinetics of chloroguaiacols and other chlorinated phenolic derivatives in rainbow trout (salmo gairdneri)
Authors: Niimi A. J. , Kissoon G. P. , Lee H. B.
Published: March 2010

Chlorinated phenolic derivatives are important chemical constituents that are present in pulp and paper mill effluents. Subadult rainbow trout (Salmo gairdneri) were exposed to six dichloroto terachloroguaiacols, two chlorinated vanillins and trichlorosyringol through waterborne and dietary exposure. Equilibrium concentrations were attained within 2 d in waterborne exposed fish, and bioconcentration factor (BCF) values ranged from 1 to 270 among the guaiacols, less than 5 for the chlorovanillins and 125 for trichlorosyringol. Dietary exposure indicated these chemicals are poorly absorbed and have half-lives of less than several days. The kinetics of these chemicals are consistent with residue levels reported in fish collected from waters receiving mill effluents where waterborne uptake appears to be the primary mode for accumulation.
Toxicity of heavy metals in cultured hepatocytes
Authors: Denizeau Francine , Marion Michel , Chtaib Mohamed , Schmit Jean-Pierre
Published: March 2010

The cytotoxicity of three heavy metals that are representative environmental contaminants was investigated in primary cultures of rat hepatocytes. The cells were exposed to Cd, Ag or Hg and to mixtures comprised of Cd and either Ag or Hg at various concentrations. Incorporation of [3H]arginine ([3H]Arg) into proteins was used to monitor cytotoxic effects. In parallel, the uptake of metals by the cells was also determined. Concentration-response profiles for each individual agent show that among the metals studied Cd is the most cytotoxic. This effect is not due to preferential uptake because the amounts of Ag and Hg accumulated by the cells (at low exposure concentrations) were similar to those of Cd. When Ag was used in combination with Cd, amino acid incorporation data showed no evidence of modulated toxicity. In contrast, when Hg was added with Cd, the results suggested the possibility of interaction: The reduction in incorporated [3H]Arg was more pronounced than that expected on the basis of individual responses. Measurement of metal uptake by the cells revealed that intracellular levels of Ag were comparable whether Cd was present or not. Similarly, the amount of Cd accumulated by the hepatocytes was not significantly affected by the presence of Ag or Hg. In conclusion, the present data describe the cytotoxicity of nonessential heavy metals in hepatocytes and their concomitant accumulation by the cells. It is therefore possible to examine one phenomenon in relation to the other. The results are further discussed in the light of the bioinorganic properties of the metals investigated.
Effects of methyl parathion on red-winged blackbird (Agelaius Phoeniceus) incubation behavior and nesting success
Authors: Meyers S. Mark , Cummings John L. , Bennett Richard S.
Published: March 2010

Free-living female red-winged blackbirds (Agelaius phoeniceus) were captured on their nests and given oral doses of 0, 2.37 or 4.21 mg/kg methyl parathion in a propylene glycol carrier during incubation. Birds were released immediately after dosing and observed for 5 h to document behavioral effects, amount of time spent off the nest after dosing and time spent incubating. Each nest was monitored until nestlings fledged or until all nestlings died or disappeared. For each nest, the time of abandonment, hatching success and fledging success were determined. In addition, prefledging weights were obtained for all nestlings in nests at 8 d after hatch. Although methyl parathion caused ataxia, lacrimation and lethargy and significantly depressed cholinesterase activity (>35%) at 4.21 mg/kg, there were no apparent adverse effects on reproduction. Females receiving 4.21 mg/kg methyl parathion were able to return to their nests, resume incubation, successfully hatch their clutch and rear their young. Nestlings of poisoned females did not have significantly different body weights at 8 d compared to controls, indicating that methyl parathion did not disrupt the females' ability to forage and deliver adequate food to nestlings. Band returns from the following year indicated that treatment birds returned and nested in nearly the same proportion as did controls and other red-winged blackbirds occupying the ponds. There was no indication that a single oral dose of methyl parathion (2.37 or 4.21 mg/kg) decreased over-winter survival.
Metal contamination in liver and muscle of northern pike (Esox lucius) and white sucker (Catostomus commersoni) and in sediments from lakes near the smelter at flin flon, manitoba
Authors: Harrison S. E. , Klaverkamp J. F.
Published: March 2010

Northern pike (Esox lucius Linnaeus), white sucker (Catostomus commersoni Lacépède) and sediment cores were obtained from 13 lakes located 4.5 to 84 km from the base metal smelter at Flin Flon, Manitoba, Canada. Zn, Cu, Cd, Hg, Se, Pb and As concentrations were determined in liver and muscle of fish. Depth profiles of Zn, Cu, Cd, Hg and Se concentrations were determined in sediment cores. The area receiving significant metal deposition from the smelter is smaller than previously estimated. Increases in metal concentrations in depth profiles of sediment cores appear to coincide with the onset of smelting operations at Flin Flon. Metal concentrations in fish from two lakes near the smelter dropped between 1976 and 1982, after a tall stack (250 m) was installed on the smelter. Metal concentrations in muscle were poor indicators of metal concentrations in sediments. Concentrations of Cd and Se in liver of northern pike, and concentrations of Zn, Cu, Cd and Se in liver of white sucker were greatest in the most contaminated lakes. Concentrations of Hg in fish declined with increased proximity to the smelter. Limnological variables seemed to have little influence on metal concentrations in fish.
Copper toxicity to Paratya australiensis: II. Influence of bicarbonate and ionic strength
Authors: Daly Helen R. , Campbell Ian C. , Hart Barry T.
Published: March 2010

The acute toxicity of copper to the Australian freshwater shrimp, Paratya australiensis, was shown to decrease in solutions of increasing alkalinity brought about by the addition of NaHCO3. This effect could not be explained merely in terms of changes in copper speciation in the solutions. Estimates of the free copper(II) ion concentration of the LC50 values were made using both copper ion selective electrodes measurements and chemical equilibrium computer calculations. Whereas there were discrepancies between the estimates obtained using these two methods, both indicated an apparent increase in tolerance of P. australiensis to the free copper(II) ion in more alkaline waters. An additional set of experiments, in which NaCl was added to test waters in place of NaHCO3, demonstrated that the increased tolerance of P. australiensis to copper in higher alkalinity waters was caused by a combination of physiological effects associated with increased ionic strength of the test waters and, to a lesser extent, changes in metal speciation in test waters. Further study of the reason for the discrepancy between estimates of copper(II) concentrations derived from ion selective electrode measurements and computer calculations is required.
Toxicity of fluoranthene in sediment to marine amphipods: A test of the equilibrium partitioning approach to sediment quality criteria
Authors: Swartz Richard C. , Schults Donald W. , Ditsworth George R. , Lamberson Janet O. , Dewitt Theodore H.
Published: March 2010

The toxicity of fluoranthene in sediment to the marine benthic amphipods, Rhepoxynius abronius (Barnard) and Corophium spinicorne (Stimpson) was determined in relation to the equilibrium partitioning approach to the development of sediment quality criteria. Toxicity tests were conducted with well-sorted fine sands at three levels of organic carbon (OC), 0.18, 0.31 and 0.48%. Measured interstitial water concentrations of fluoranthene less than 50 μg/L were highly correlated with predictions based on the equilibrium partitioning model. LC50s based on bulk (total) fluoranthene concentrations increased significantly with increasing sediment OC. LC50s based on fluoranthene concentrations in interstitial water were not significantly different between 0.18 and 0.48% OC or between 0.31 and 0.48% OC, but the LC50 at 0.31% OC was significantly higher than that at 0.18% OC. The regression of sediment OC on bulk fluoranthene LC50 was linear, indicating that the concentration of fluoranthene in interstitial water was constant at equitoxic conditions, as predicted by the equilibrium partitioning model. The 10-d LC50 of fluoranthene in interstitial water (23.8 μg/L) was intermediate between the U.S. Environmental Protection Agency's (U.S. EPA) acute (40 μg/L) and chronic (16 μg/L) water quality values for fluoranthene. Within the limitations of these experiments (i.e., one chemical, two species, sandy sediment with low carbon content), the results indicate that sediment quality criteria derived from the equilibrium partitioning model and water quality criteria would protect sensitive benthic invertebrates. The epibenthic, tube-dwelling Corophium was less sensitive to test sediments than the infaunal, free-burrowing Rhepoxynius, possibly because of different routes of exposure to fluoranthene. There was a close correspondence between estimates of sediment quality for fluoranthene based on distinctly different methodologies including equilibrium partitioning, apparent effects threshold, toxicity tests applied to experimentally spiked sediment and toxicity tests applied to field-collected sediment.