bluuebunny/crossref_metadata_2025 huggingface dataset:
Fate and Effects of 5-Nitrofuroic Acid-2 (NFA) on a Marine Plankton Community in Experimental Enclosures
Authors: Kuiper J
Published: March 2009

The fate and effects of a single dose of 0.3 and 1.0 mg of 5-nitrofuroic acid-2 (NFA) per litre on a marine plankton community enclosed in large plastic bags (contents 1.5 m3) were studied. The plankton community was derived from North Sea coastal waters, and the model ecosystems were anchored in the harbor of Den Helder, the Netherlands, where they were exposed to a natural light and temperature regimen. Two experimental units were polluted with NFA; a third served as a control.

During four weeks the development of the phytoplankton, zooplankton, and bacteria was followed, as were a set of physicochemical parameters including nutrients, light, and temperature.

The nitro group was removed from the NFA within about one day of the addition of the compound to the model ecosystems, probably as a result of the exposure to light. The intact NFA inhibited the phytoplankton slightly; the remaining molecule produced no detectable effects in the system. The development of the enclosed community was very similar in the different bags.
Environmental Assessment of a Phthalate Ester, Di(2-Ethylhexyl) Phthalate (DEHP), Derived from a Marine Microcosm
Authors: Perez KT , Davey EW , Lackie NF , Morrison GE , Murphy PG , Soper AE , Winslow DL
Published: March 2009

This study tested the influence of system complexity on the environmental assessment of a chemical. Marine microcosms were perturbed with a phthalate ester, di(2-ethylhexyl) phthalate (DEHP).

Concentrations of 1, 10, and 100 µg of DEHP per litre were added to the water-column subsystem of marine microcosms for 30 days during the summer (18°C) and winter (1°C) seasons. Significant portions of the DEHP losses from the water-column subsystem during the experiments were due to the complete breakdown of the parent compound to carbon dioxide (CO2). In the benthic subsystem, DEHP concentrations in the sediment were increased by more than 50 and 250 times the concentration in the water column during the winter and summer seasons, respectively. Statistically significant (α = 0.05) reductions in the fluxes of ammonia (NH3) from the benthic subsystem were observed in microcosms receiving 100 µg of DEHP per litre during the summer. Concentrations of DEHP in selected bivalves ranged from 174 to 229 000 µg of DEHP per wet kilogram, depending upon the water column exposure concentrations and the season of the year.
Correlation Between the Autotrophic Index and Protozoan Colonization Rates as Indicators of Pollution Stress
Authors: Buikema AL , Cairns J , Yongue WH
Published: March 2009

The advantages of using microbial communities or multispecies in pollution assessment are discussed. Laboratory and field research assessing the effects of pollution on microbial community structure and function (that is, a ratio of autotrophy to total biomass, protozoan colonization rates, and species richness) indicates that the results are sensitive measures of pollution. The results of one test confirm the results of other tests. All the tests are quick, inexpensive, and reproducible.
Effects of Increasing Levels of Primary Production on Pentachlorophenol Residues in Experimental Pond Ecosystems
Authors: Robinson-Wilson EF , Boyle TP , Petty JD
Published: March 2009

The magnitude of primary production may influence the degradation and bioavailability of contaminants in aquatic ecosystems. The rate at which these contaminants degrade is important in considering the toxicity and ultimate effect and fate of the chemicals. The degradation and fate of pentachlorophenol (PCP), a biocide and common contaminant, was studied in replicate pond ecosystems at three levels of primary production: (1) low-nutrient phytoplankton ecosystems (low primary production), (2) high-nutrient phytoplankton ecosystems (medium primary production), and (3) macrophyte-dominated ecosystems (high primary production). The PCP treatments were of two types: (1) a single heavy treatment (1 mg/L) applied early in the experiment and (2) multiple treatments of 0.2, 0.2, 0.4, and 0.4 mg/L applied at monthly intervals.

The concentrations of PCP in water and mud were consistently lower in the macrophyte pond group than in the phytoplankton pond groups. The difference between the amount of PCP in the phytoplankton ponds and that in the macrophyte ponds were not apparently due to sorption onto the macrophytes. Therefore, the macrophytes were either actively degrading the PCP or incorporating it into their structure in a form that was not extractable. PCP residues in fish also reflected the lower bioavailability of PCP in the macrophyte ponds. Both the total PCP and the concentration of PCP in fish from the macrophyte ponds were lower than those for either of the phytoplankton pond groups. High primary production rates appear to increase the degradation rate of PCP in pond ecosystems.
Practical Applications and Comparisons of Environmental Exposure Assessment Models
Authors: Games LM
Published: March 2009

Several environmental fate models have been developed that can be used for predicting concentrations of anthropogenic chemicals in the aqueous environment. Although individual models vary in their mathematical approach and the assumptions they are based on, all have in common basic premises concerning the factors controlling distribution and transformation of any chemical. The validity of the various assumptions made can best be tested by using the models to determine how well they predict observed concentrations of currently manufactured chemicals. In this paper, monitoring data for a surfactant, linear alkylbenzene sulfonate (LAS), are used to compare the utility and success of the exposure analysis modeling system (EXAMS), simplified lake stream analysis (SLSA), and fugacity models in predicting distribution and concentration within a single flowing stream. The results show that each model is most applicable at a particular stage in hazard assessment. Obtaining quantitative exposure predictions for generally released chemicals requires a better definition of the types of environments that will be encountered and a better understanding of the sediment-water interface.
Bioconcentration of Lindane and Naphthalene in Bluegills (Lepomis macrochirus)
Authors: Rodgers JH , Dickson KL , DeFoer MJ
Published: March 2009

The validity of models for prediction of the bioconcentration factors (BCFs) for organic chemicals in fish was tested with bluegills (Lepomis macrochirus Raf.) using lindane and naphthalene. In general, good agreement was observed between the calculated or predicted BCFs and experimentally determined BCFs. The uptake phase or time to accumulation of a steady-state body burden at a given chemical concentration was about one day for both chemicals. However, the depuration rates, K2, or loss of the chemicals from the fish were significantly different (for naphthalene, K2 = 0.88 to 1.20 day−1; for lindane, K2 = 0.38 to 0.53 day−1). The data provide additional evidence that differential loss rates may be the critical factor in controlling the BCFs for most organic chemicals.
Suitability of a Biochemical Method for Assessing the Exposure of Feral Fish to Lead
Authors: Hodson PV , Blunt BR , Whittle DM
Published: March 2009

A variety of biochemical techniques have been used to assess the response of fish to contaminants. These techniques may provide valuable tools for determining the degree of impact on real fish populations of contaminant exposure and for identifying areas of contamination. Many of these techniques have not proven useful because they were not sensible, sensitive, or specific. This paper reviews the use of erythrocyte δ-amino levulinic acid dehydratase (ALAD) activity to indicate lead exposure of fish, both in the laboratory and in field surveys of Great Lakes fish. The enzyme has proven to be a reliable tool in laboratory studies of lead effects on rainbow trout (Salmo gairdneri). The field survey demonstrated that ALAD activity is a suitable indicator of lead exposure of lake trout (Salvelinus namaycush) but that more research is required to confirm its applicability to other species.
Role and Application of Semicontrolled Ecosystem Research in the Assessment of Environmental Contaminants
Authors: Boyle TP
Published: March 2009

The procedures for assessing the toxic effects of potential environmental contaminants are hierarchical, being composed of the following four sequential steps: (1) single-species acute and chronic toxicity tests, (2) tests of ecological interactions with simple communities in laboratory microcosms, (3) experiments on chemical-induced changes in ecosystem structure and function, in which replicate pond and artificial stream ecosystems are used, and (4) use of techniques for assessment of the actual impact of the contaminant on natural ecosystems.

Experiments involving semicontrolled artificial ecosystems in ponds and streams are carried out over the course of one or two years to identify the magnitude of (1) the primary direct effects of contaminants on the principal elements of the biological community and (2) the secondary or indirect effects of stress due to changes in critical structural or functional variables of the ecosystem. The results from ecosystem-contaminant studies can be used to establish the applicability of laboratory bioassays, to examine the qualities that enable ecosystems to resist contaminant stress and recover from it, and to answer questions on the effect of long-term stress of chemicals with herbicidal or insecticidal properties.
Measuring Effects of Contaminant Stress on Fish Populations
Authors: Goodyear CP
Published: March 2009

The translation of a contaminant effect on the growth, behavior, or survival probability of individuals into a change in the size or productivity of a population involves the interspecies and intraspecies interactions that regulate population size. The result of these interactions may be to reduce or exaggerate the ultimate effect of the contaminant-induced stress and to cause the importance of the contaminant to vary with annual variations in the physical and biological environment. The interactions cause the density-dependent changes in growth, survival, and reproduction that are often associated with perturbations. These density-dependent responses of population characteristics confound the measurement of the population-level effects of contaminant stress in the field and their prediction on the basis of laboratory observations. For many, if not most, field situations the evaluation of population response necessarily involves the study of other biological and physical factors that affect population size.
An Efficient Algal Bioassay Based on Short-Term Photosynthetic Response
Authors: Giddings JM , Stewart AJ , O'Neill RV , Gardner RH
Published: March 2009

A procedure is described for measuring the effects of toxicants on algal photosynthesis [carbon-14 bicarbonate (H14CO3) uptake] in 4-h experiments. The results for individual aromatic compounds and the water-soluble fraction (WSF) of a synthetic oil are presented as examples of applications of the bioassay. The toxicity of the WSF varied among the seven algal species tested, and the responses of some species were pH-dependent. With Selenastrum capricornutum as the test organism, the bioassay results were unaffected by variations in pH from 7.0 to 9.0, light intensity from 40 to 200 μeinsteins m−2s−1, culture density up to 0.5 mg chlorophyll a per litre, and agitation up to 100 rpm. The photosynthesis bioassay is simpler and faster (4 h versus 4 to 14 days), uses smaller culture volumes, and requires less space than static culture-growth tests. One person can conveniently test four materials per day, and the entire procedure, including preparation, exposure, and analysis, takes less than two days. The short incubation time reduces bottle effects such as pH changes, accumulation of metabolic products, nutrient depletion, and bacterial growth. Processes that remove or alter the test materials are also minimized. The data presented here indicate that algal photosynthesis is inhibited at toxicant concentrations similar to those that cause acute effects in aquatic animals. A model of a pelagic ecosystem is used to demonstrate that even temporary (seven-day) inhibition of algal photosynthesis can have a measurable impact on other trophic levels, particularly if the other trophic levels are also experiencing toxic effects.
Effects of Food Concentration, Animal Interactions, and Water Volume on Survival, Growth, and Reproduction of Daphnia magna Under Flow-Through Conditions
Authors: LeBlanc GA , Schoenfeld DA , Surprenant DC
Published: March 2009

The purpose of this study is to evaluate the effects of food concentration, animal interaction, and water volume on the survival, growth, and reproduction of Daphnia magna under flow-through conditions. A response surface design was used to determine the interactive, as well as the individual, effects of the three factors. The results indicated that there were no important interactive effects of the three factors on survival, growth, or reproduction of D. magna. Individual effects of the factors on reproduction were observed. Food concentration produced a linear trend, with increasing food concentration resulting in an increase in offspring production. The number of daphnids per container produced a quadratic trend, with the maximum offspring production occurring in vessels containing approximately 14 daphnids. Water volume produced a slight linear trend, with increasing water volume resulting in an increase in offspring production.
Resolving Some Practical Questions About Daphnia Acute Toxicity Tests
Authors: Barera Y , Adams WJ
Published: March 2009

Acute toxicity tests were performed with six age groups of Daphnia magna, ranging from ≤6 h to 216 h, and with five chemicals, selected on the basis of their physical and chemical properties as well as their acute toxicity to D. magna. The age of the daphnids did not significantly alter the 48-h EC50 values for the chemicals tested. The maximum difference observed in the 48-h EC50 values between the 6-h and 216-h age groups was a factor of 3.9 for linear alkylbenzene sulfonate (LAS). For purposes of standardization, it appears that D. magna up to 48 h of age at the beginning of the test can be used to conduct acute toxicity tests with most chemicals.

The results of static acute toxicity tests conducted with butylbenzyl phthalate (BBP) and D. magna in the presence and absence of several commonly used solvents indicate that the acute toxicity of this chemical is not altered by the use of a solvent carrier. The 48-h EC50 value for BBP without a solvent was 1.0 mg/L, compared with a range of 1.6 to 2.2 mg/L when acetone, dimethylformamide, ethanol, or triethylene glycol were used as solvent carriers. The acute toxicities of the solvents in the absence of BBP were also determined for D. magna. The values ranged from 9.3 to 52.4 g/L.

The results of static acute tests performed with D. magna and BBP in the presence of various concentrations of daphnid foods (algae or trout chow), indicate that the 48-h EC50 values increase proportionally with an increase in food concentrations. These results suggest that acute toxicity tests with D. magna should be conducted in the presence of food with chemicals with a high Koc if the results are to be used to select the test concentrations for a chronic study with daphnids. The type of food and the concentration used in the acute test should be the same as those used in a chronic test.
Fossil Energy Waste Sampling: A General Guideline
Authors: Crumrine KZ , Jung AD
Published: March 2009

The authors developed a fossil fuel energy waste general sampling guideline to provide users a manual for the collection of feedstock and solid wastes from coal-fired utility boilers and emerging energy facilities according to best available scientific procedures. We believe this manual will serve as a guide to sample collection personnel in preparing a descriptive site-specific test plan. The preparation and evaluation of the general guideline was sponsored by the U.S. Department of Energy, Laramie Technology Center. Included in the manual are detailed procedures for (1) selecting representative sampling locations, (2) collecting solid wastes, slurry waste, and sludges, and (3) processing samples.
Effect of Storage on Leaching Properties of Metal-Finishing Sludges
Authors: Saunders FM , Williams FM , Kutz RG
Published: March 2009

Leaching properties of thickened sludge suspensions and dewatered sludge cakes from an aluminum-anodizing and an electroplating plant were examined. Sludge specimens were examined before and after 27 to 207 days of storage under controlled conditions using the Environmental Protection Agency (EPA) extraction procedure (EP). Extracts were examined for silver, aluminum, cadmium, chromium, copper, mercury, nickel, lead, and zinc. Extract metal concentrations varied considerably with time of storage with no consistent pattern for all metals in either sludge.

The electroplating sludge was classified as hazardous using EPA standards for EP results. Cadmium levels in the sludge were initially 5 mg/L and increased to 13 mg/L following storage for 98 days for both the stored suspension and the stored dewatered cake specimens. Extract chromium and copper concentration decreased with storage time while those for lead decreased initially and then increased with storage time. Although extract metal concentrations for the aluminum-anodizing sludge varied with storage time, metal concentrations were well below levels designated as hazardous by EPA.

Filtrate metals were shown to have minimal impact on EP test results and the majority of extracted metals were from suspended metal precipitates in the sludges. Sludge storage was shown to have a significant effect on EP test results, indicating a need to recognize it as a test variable.
Batch and Column Extraction Procedures for Organics in Solid Wastes
Authors: Maskarinec MP , Brown DK
Published: March 2009

Because of the possibility of contamination of aquifers by solid waste leachates, it is important to develop laboratory extraction procedures that predict the release of organic materials from landfills. This paper presents the results of a study comparing five laboratory extraction procedures with respect to the organic content of the extract. Nine solid wastes, representing a wide variety of matrices, were considered. The extraction procedures used were the Environmental Protection Agency Extraction Procedure (EPA-EP), a distilled water extractant, a citrate buffer extractant, a sodium ion-exchange resin extractant, and an upward-flow column extraction test.

Organic analysis of the batch extracts was carried out by isolation/concentration of the leachates with XAD-2 resin, followed by gas chromatography on fused silica capillary columns. In the case of the upward-flow column extraction, a cartridge containing XAD-2 was placed directly at the column exit; the resin was isolated/concentrated in a manner identical to the batch extracts.

The results were assessed both in terms of total chromatographable organics (TCO) and in terms of the levels of individual compounds. The column technique gave consistently higher results in terms of TCO. This effect is in large measure due to enhanced recovery of highly volatile compounds and nonpolar compounds. The results of the extraction of individual compounds were less consistent. The recovery of carboxylic acids, for example, depended primarily on pH. The recovery of volatile organics, on the other hand, was more closely related to the extraction vessel used than to the extractant.

Thus, it may be concluded that the column procedure most aggressively extracted organics from the solid wastes. However, the chemical nature of the organic material in the solid waste determines which of the batch extraction procedures is most aggressive.
Development of a Method for Determining Purgeable Organic Compounds in Solid Wastes
Authors: Warner JS , Slivon LE , Meehan PW
Published: March 2009

This study was undertaken to develop an improved method for determining the total content of individual volatile organic compounds in industrial solid wastes. The objective was the development of a method that would (1) be applicable to a wide range of specimen matrixes, (2) be applicable to a wide range of purgeable compounds, (3) have a detection range of 1 ppm to 100%, (4) give acceptable recovery and reproducibility, and (5) be easily performed at a reasonable cost.

The waste matrixes of interest included aqueous sludges, dry solids, soils, tars, oil, and oily sludges. The compounds of interest included purgeable halocarbons, hydrocarbons, ketones, ethers, esters, sulfides, and nitriles having boiling points in the range of −30 to 180°C.

The method developed involves a combination of solvent extraction and a purge and trap technique. The main features of the method are simply (1) solvent extraction with tetraglyme, a nonvolatile, water-miscible and oil-miscible solvent, (2) dilution of the extract with solvent as necessary, and (3) purge-and-trap analysis of an aliquot of the extract. Recommended techniques for the final analysis step include gas chromatography with detection by mass spectrometry, flame ionization, electron-capture, Hall electrolytic conductivity, or nitrogen and phosphorus specific thermionic detection to determine individual compounds, and microcoulometric analysis to determine the total purgeable organic halogen content.

In addition to meeting the specified requirements, the method has the advantage of being readily integrated with sampling and specimen handling to avoid losses of volatile compounds before analysis.
Evaluation of On-Site Soil for Use as an Impoundment Liner
Authors: Hansen LA , Weeks RE , Shrestha RK
Published: March 2009

The results of geotechnical and geochemical tests on four on-site soils considered for construction of a liner for a proposed uranium tailings impoundment are presented. The interaction of five heavy metals (arsenic, chromium, zinc, molybdenum, and manganese) with four clay soils was investigated by batch tests on pulverized specimens and column tests on compacted specimens. A prototype mill tailing solution was used for the column leaching tests.

Atterberg limits, metal concentrations, and X-ray diffraction analyses established two soil groups of similar composition. The batch and column tests established two soil groups having similar adsorption characteristics, but they included soils having different compositions. The results of batch and column tests were in general agreement, though a few significant differences in adsorption characteristics were noted. The testing established a tentative ranking of the relative sorptive capacities of the four soils for the five metals, though further testing is recommended.
Determining the Long-Term Effects of Interactions Between Waste Permeants and Porous Media
Authors: Haji-Djafari S , Wright JC
Published: March 2009

Waste materials are often disposed in facilities constructed from natural earth materials. Frequently, the natural materials, especially clays, are emplaced to meet specifications designed to limit the migration of the wastes or their leachates from the disposal facility. However, as waste leachates permeate through earth materials, chemical reactions can occur which may cause the emplaced materials to no longer meet the disposal facility design specifications. A test procedure has been utilized to assess the long-term effects of waste leachates upon earth materials, that is, permeant-porous media interactions. The test consists of compacting representative specimens of the porous media to represent its field hydraulic conductivity, determining a reference hydraulic conductivity, based on a 0.01 N calcium sulfate (CaSO4) solution, site groundwater or tap water, and then changing the permeant to the anticipated waste leachate. Field-time conditions are accelerated by permeating the waste fluid through the porous media under pressure. By monitoring the time, flow, and chemistry of the permeant effluents and with assessments of hydrologic and geochemical parameters, it is possible to evaluate long-term characteristics of flow and mass transport through the porous media. Evaluation of the performance of waste disposal facilities, including changes in the hydraulic conductivity of the porous media due to chemical reactions with the permeant and calculation of retardation factors for solutes of interest, has been the primary concern of our testing. Retardation factors are defined as the dimensionless ratio of the average linear water velocity to solute migration velocity, and can be determined by monitoring the solute front advancement within the porous media in relation to a tracer that does not react with the porous media. The testing methods and evaluation of the results are presented.
Attenuation of Chlorocarbon Compounds by Clay Liner Materials of a Waste Disposal Facility
Authors: Iyengar SS , Treblow MD , Wright JC
Published: March 2009

Leachates generated from organic wastes in a disposal facility may have the potential to permeate the clay liner. The assessment of the potential migration of organic compounds from the disposal facility included investigating the adsorption of the organic fraction in natural waste leachates on clay liner materials, Distribution ratios (Kr) for four volatile compounds, four nonvolatile compounds, and two insecticides were determined in accordance with the proposed ASTM short-term batch method for the determination of distribution ratios. The pH of the leachates and types of clay specimens were found to have no significant effect on the magnitude of adsorption of the ten chlorocarbon compounds by the clays. However, the distribution ratios of some compounds did display limited concentration dependence. The distribution ratios were then normalized to the organic carbon content of each clay specimen and expressed as Koc values. The Koc values were related to each compound's water solubility and octanol/water partition coefficients by linear regression. The correlation coefficients indicated that both the water solubility and octanol/water partition coefficients of the organic compounds accounted for about 90% of the variation in the experimental Koc values. This suggests that the primary mode of interaction between the clay liner material and chlorocarbon compounds is hydrophobic in nature, and that most of the removal of the chlorocarbon compounds from solution was by adsorption onto the organic carbon fraction present in the clay liner materials.
The Great Bioassay Hoax, and Alternatives
Authors: White HH , Champ MA
Published: March 2009

A review of recent literature reveals large variations in results of bioassays, such as those proposed for solid waste testing. Sources of variation are categorized, and an estimate is made of the range in test results attributable to each source category. The age of the test organism is potentially the largest source of variation, and has effects up to five orders of magnitude on the outcome of bioassays. Other sources of variation have effects of several orders of magnitude, and nearly all sources have at least one-order-of-magnitude effect. It is concluded that bioassays cannot be used to predict the impact of contaminants introduced to an ecosystem or population, and therefore serve poorly as a tool in pollution management.

Three criteria are proposed for judging the utility of any pollution evaluation technique. These are: the ability to incorporate good scientific practice in any application; the relationship of the measured response to the natural field response; and the relationship of the measured response to important ecosystem processes. Multi-species tests in micro- and mesocosms usually satisfy these criteria better than single-species tests, and may also be used to help develop simpler tests that satisfy these criteria. The focus of impact evaluation must be on growth, reproduction, and survival, and parameters that can be related readily to them. Lastly, pollution management schemes have always recognized that human interests are the sole standard of which ecosystem effects are “harmful,” and which are not.
Methods Using Earthworms for the Evaluation of Potentially Toxic Materials in Soils
Authors: Neuhauser EF , Malecki MR , Loehr RC
Published: March 2009

The purpose of this study was to investigate the feasibility of using earthworms to indicate effects of potentially toxic wastes when such wastes are intentionally or accidentally added to soils. Initial work with metals has shown that earthworms exhibit specific growth and reproductive responses. These responses are related to the concentration and solubility of the metal. Of the metals tested, cadmium was found to be the most toxic, followed by nickel, copper, zinc, and lead.

The metal concentration in earthworm tissue and the background manure-metal mixture was measured, permitting the concentration factor to be computed. The concentration factor is the ratio of the metal in the worm tissue to that in the surrounding manure-metal mixture.

These and other studies in our laboratory have demonstrated that the methods described in this paper may be used to predict the effect of land-applied or atmospherically deposited residues on the soil biota.
Margins of Safety for Aquatic Communities
Authors: Mount DI
Published: March 2009

The margin of safety is the difference between the expected effect concentrations and the expected ambient concentrations. Two sources of variability, error in the test data and unknown information, necessitate a margin of safety. Inclusion of site-specific considerations can substantially reduce needed margins. The choice of the appropriate confidence level should be based on the importance of the decision and not on habit.
Multimedia Modeling of the Fate of Environmental Chemicals
Authors: Eschenroeder A
Published: March 2009

The development of a methodology for preliminary assessment of a chemical's behavior in the environment is the objective of the work reported here. The model produces concentration estimates used in the exposure calculations that support risk analysis. It goes beyond traditional fate models by explicitly treating transfer and transformation in air, soil, and biota as well as in water. This multimedia formulation is generalized in its capability to accept various types of chemicals and modes of their release into the environment. The first version of the model described here is designed for manual execution using a programmable calculator; however, the logic is structured to allow future substitution of computer-aided modules. These features were adopted to meet requirements of lead time, ease in application, and model evaluation. The development efforts have generated scientific narratives, flow charts, user instructions, and generic environmental data sets for various regions. These outputs are described and directions for future work are summarized.
Estimation of Soil Sorption Constants of Organic Chemicals by High-Performance Liquid Chromatography
Authors: Swann RL , McCall PJ , Laskowski DA , Dishburger HJ
Published: March 2009

A new method using reverse-phase high-performance liquid chromatography for the estimation of soil sorption constants has been developed. The method provides a simple rapid estimate of a chemical's tendency to partition in a soil matrix. Data generated in this way can be used in the first approximation for fate and hazard assessment of chemicals.
Prediction of Chemical Mobility in Soil from Sorption Coefficients
Authors: McCall PJ , Swann RL , Laskowski DA , Vrona SA , Unger SM , Dishburger HJ
Published: March 2009

Several methods of evaluation have been proposed to classify the mobility of chemicals through soil. The Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) guidelines recommend use of soil columns to assess mobility, whereas the Toxic Substances Control Act (TSCA) guidelines propose the use of soil thin-layer chromatography (TLC). The soil sorption coefficient of a chemical has been recognized as the major factor controlling its mobility; however, confidence in this measurement as a sole means to estimate mobility has not been demonstrated.

Therefore, column leaching experiments have been conducted which correlate the soil adsorption coefficient with movement. Soil columns, eluted under controlled conditions with 50 hectare cm (20 acre in.) of water, have been studied with nine chemicals and three soil types. A simple relationship has been developed which demonstrates that, when the soil adsorption coefficient is known along with the organic carbon content of the soil, predictions regarding movement by means of leaching can be made.

Since a standard adsorption coefficient based on organic carbon content, Koc, can be determined independent of other soil properties, prediction of movement of a chemical through any soil is possible if the organic carbon content of the soil is known.
A Risk Assessment of Toxicants to Aquatic Life Using Environmental Exposure Estimates and Laboratory Toxicity Data
Authors: Parkhurst MA , Onishi Y , Olsen AR
Published: March 2009

Laboratory toxicity data can be combined with computer migration and fate models to assess the risks of contaminants to aquatic life from point and nonpoint discharge sources. Environmental exposure to selected species is estimated from overland and in-stream transport modeling. A statistical code uses LC50 and maximum acceptable toxicant concentrations (MATC) data to predict the frequency and duration of dissolved contaminant concentrations that exceed median lethal and sublethal concentrations to the species of concern. Two pesticides, alachlor (an actual case) and toxaphene (a hypothetical case), are analyzed to demonstrate the hazard assessment process. The overall methodology provides a means of comparing relatively the toxic effects of different chemicals and also provides a framework for future fate and risk assessment studies.
Role of Environmental Chemistry-Fate Modeling in Environmental Hazard Assessment: An Overview
Authors: Lee GF , Jones RA
Published: March 2009

In accord with the requirements of the Toxic Substances Control Act, new and expanded-use chemicals must be screened for their potential environmental hazards prior to large-scale manufacture and use. This environmental hazard assessment for aquatic systems should have two basic components: aquatic toxicology and environmental chemistry-fate information. Environmental chemistry-fate considers the transport pathways and ultimate disposition of the chemical in the environment, what transformations of the chemical occur, and the rates of these transformations, and it provides an estimate of the expected concentrations of a contaminant in various environmental compartments. A hazard assessment is made by proceeding through a series of testing levels or tiers which develop information on the toxicology of the chemical and its environmental chemistry-fate until a decision can be made that the environmental risk associated with the manufacture and use of the chemical is acceptable or unacceptable. The principles discussed herein are equally applicable to implementing water quality criteria into state water quality standards and assessing the environmental significance of any chemical entering an aquatic system.
Bioaccumulation and Chronic Toxicity of Bis(tributyltin) Oxide (TBTO): Tests with a Saltwater Fish
Authors: Ward GS , Cramm GC , Parrish PR , Trachman H , Slesinger A
Published: March 2009

The accumulation and depuration of bis(tributyltin) oxide (TBTO), a widely used active ingredient in antifouling paints, and its acute and chronic toxicity to sheepshead minnows (Cyprinodon variegatus) were determined. Equilibrium between the concentration of carbon-14-labeled-TBTO in seawater and in fish tissues was not reached after 58 days of exposure. The maximum observed bioconcentration factor in whole fish was ×2600. The maximum observed bioconcentration factors for the muscle, viscera, and remains were ×1810, ×4580, and ×2120, respectively. Sheepshead minnows depurated 52 percent of the 14C-TBTO within 7 days and 74 percent after 28 days. The 21-day median lethal concentration (LC50) for sheepshead minnows exposed to TBTO was 0.96 ppb. The only statistically significant effect observed in the life-cycle test was mortality of the F0 fish in the mean measured TBTO concentration of 4.8 ppb. There was an obvious concentration-response relationship in mortality of the F1 fish, although, no statistically significant differences in mortality were detected between the control and the TBTO-exposed treatments. The surviving F1 fish exhibited no signs of abnormal development, nor was growth decreased as a result of F0 exposure to TBTO concentrations <-1.0 ppb. Tissue samples from the life-cycle test, analyzed for total tin, confirmed the bioconcentration of TBTO, showed the accumulation to be concentration dependent, and indicated that the fish were actively metabolizing TBTO into its lower and less toxic alkyl moieties.
Metabolites of Benzo[a]pyrene in Aroclor 1254-Treated Mullet
Authors: Tan B , Kilgore MV , Elam DL , Melius P , Schoor WP
Published: March 2009

This paper presents a systematic approach to the separation and characterization of benzo[a]pyrene (BaP) metabolites using the efficient analytical technique of high-pressure liquid chromatography (HPLC). Hepatic supernatant (S-9) preparations from Aroclor 1254-treated mullet (Mugil cephalus) were used to study the in vitro metabolism of BaP. The lipid-soluble hydroxylated products were extracted in ethyl acetate prior to HPLC analysis. Three diols (9,10; 7,8; and 4,5) and two phenols (9 and 3) of BaP were isolated and identified. From their relative retention times, the other metabolites noted were likely to be unresolvable quinones. The results obtained in the mullet were compared with those obtained in the rat (Rattus norvegicus).
Analysis of Variance as a Method for Examining Contaminant Residues in Fish: National Pesticide Monitoring Program
Authors: Schmitt CJ
Published: March 2009

Contaminant monitoring programs are designed to determine temporal and geographic trends in residue concentrations. Obvious interpretive problems may arise from analytical changes, inconsistent replication, and other activities that upset a program's continuity. Less obvious difficulties, related to the inherent nonnormality of residue data and the abilities of the data to meet many of the assumptions required by statistical methods, present themselves during the analysis, testing, and interpretation of results.

Statistical analysis of monitoring data is traditionally accomplished by testing the differences between location or time-period means with a two-way factorial analysis of variance (AOV) in which variation accrues from locations, time periods, time × location interaction, and error. Without replication, interaction is usually assumed to be absent when main effects are tested, which is a questionable practice with residue data. Adding the species, species type, or sample type effects to the two-way factorial results in a three-way factorial involving more complex interactions. An alternative to the full factorial AOV—analysis as a partially nested factorial—is presented for use when the species collected are not common to all locations and time periods. All analyses are illustrated by using a selected subset of National Pesticide Monitoring Program data for organochlorine residues in freshwater fish.

Depending on the monitoring program's objectives and how the stations were selected, location effects may be considered random rather than fixed. This may result in a mixed-model AOV and alter the computation of F-ratios for time-period main effects, possibly changing the outcome of significance tests and resulting conclusions regarding temporal trends.
Comparison of Bacterial Luminescence and Fish Bioassay Results for Fossil-Fuel Process Waters and Phenolic Constituents
Authors: Lebsack ME , Anderson AD , DeGraeve GM , Bergman HL
Published: March 2009

A number of fossil-fuel process waters and some phenolic constituents were tested in a luminescent bacterial system, and the results were compared with either static or flow-through acute bioassays with fish. Luminescence was decreased in a concentration-dependent manner after the addition of an oil shale process water. The concentration causing 50 percent inhibition of luminescence (EC50) was reproducibly determined for all the tested waters and compounds. The EC50 values for a group of fossil-fuel process waters correlated with 96-h rainbow trout flow-through median lethal concentrations (LC50s) but not with 96-h flow-through LC50s for fathead minnows. For another group of process waters, the EC50s for luminescence inhibition had a significant correlation to static 24-h LC50s with fathead minnows. Both rainbow trout and fathead minnow LC50s were lower than luminescence EC50s for the phenolic compounds. Inhibition of bacterial luminescence may be of value in predicting the toxicity of complex effluents to aquatic biota, especially when semicontinuous monitoring is required. However, in each case the bacterial bioluminescence assay should be calibrated periodically with acute bioassays using aquatic biota.
Statistical Analysis of Fish Chronic Toxicity Test Data
Authors: McClave JT , Sullivan JH , Pearson JG
Published: March 2009

This paper presents methodology for the analysis of chronic toxicity test data. Emphasis is given to the determination of the lowest tested concentration whose mean response differs significantly from the control. In particular, the analysis of variance (ANOVA) approach for analyzing chronic toxicity test data is discussed in some detail.

The paper presents four experimental designs that have different experimental units, that is, the units on which the observations or measurements are made. The first type of experimental design is a completely randomized design in which the aquaria are the experimental units. The second is a nested design, with aquaria nested in concentration and fish nested in aquaria. The third is also a nested design, in which aquaria are nested in concentrations, fry chambers are nested in aquaria, and fish are nested in chambers. The fourth is a two-factor design in which sex is crossed with concentration. The final section of the paper is a general discussion of the utility of the ANOVA approach, its limitations, and the identification of some areas that still need research.
Development and Evaluation of a Flow-Through Growth Inhibition Test with Duckweed (Lemna minor)
Authors: Bishop WE , Perry RL
Published: March 2009

Duckweed, Lemna minor, has been proposed as a “typical” aquatic macrophyte suitable for laboratory toxicity testing and useful in the environmental hazard assessment of chemicals. The development of a standard, reproducible, flow-through growth inhibition test with duckweed that employs a precisely controlled flow rate, automatic nutrient and test material delivery system, and constant light intensity is described. The test materials included a heavy metal; anionic, nonionic, and cationic surfactants; and an aquatic herbicide. Growth inhibition was measured as a reduction in frond count, dry weight, and root length. Results based on frond count were found to provide the most useful information per unit of laboratory time. The 7-day median effective concentration (EC50) based on frond count ranged from 0.0031 mg/litre for the herbicide to 43 mg/litre for an anionic surfactant. The ecological relevance of EC50 measurements for duckweed growth is unknown.

Results obtained with duckweed were compared with acute toxicity data for fish and aquatic invertebrates. For all materials except the herbicide, duckweed was the least sensitive species. The data developed indicate that for many materials, criteria developed for fish and invertebrates may be extended to include the macrophyte community.
Thermal Degradation of Cable and Wire Insulations
Authors: Alvares NJ , Lipska-Quinn AE , Hasegawa HK
Published: March 2009

The major proportion of available flammable materials in energy research facilities consists of the coverings and insulations for electrical conductors in control, power, and diagnostic circuits. Since quantitative information on flammability of insulations is sparse, we initiated a program to investigate these properties. Our objective is to develop data applicable to predictions of fire risk parameters for large experimental energy facilities and, ultimately, new power generating plants. Our procedures involve measuring evolution of corrosive products as well as other thermal degradation products in air and nitrogen. We use a thermogravimetric analyzer to study effects of heating rate on modes of degradation and a heat release rate calorimeter to survey effects of thermal irradiance levels on product generation and the heat release rate of insulation materials.

Thermal measurements—heat release rate, flame spread rate, and ease of ignition—show that common insulating materials are not easily ignited and that they burn with relatively little heat output and slow flame spread. However, when conditions are right, thermal rate parameters can interact to produce intense, fast-moving fires. Such conditions occur where the surface-to-volume ratios of conductors are great, enhancing both fuel availability and heat feedback from flames. In large energy research and production facilities, this condition is common.
Legal, Scientific, and Political Cooperation—The Impossible Dream
Authors: Beck JR
Published: March 2009

The scientific community in the United States is losing credibility, especially in the biological sciences. The reasons range from expediency to ignorance to basic motivation. Lawyers and politicians have entered decision-making areas of science because of these obvious problems. How to work with these other professions in light of the difficulties is the theme of this paper.
Improved Method of Assessing Pesticide Hazards to Nontarget Game Birds Under Simulated Field Conditions
Authors: Glahn JF , Lamper LD
Published: March 2009

A large portable enclosure method for assessing hazards of vertebrate pesticides to nontarget game birds under simulated field conditions is described. In each (9.8 by 2.4 by 1.2-m) enclosure, small groups of test birds are exposed to one of several levels of pesticide treatment similar to the U.S. Environmental Protection Agency's protocol for large-pen simulated field studies. The versatility of portable enclosures allows tests to be conducted over various natural or cultivated food crops to simulate various patterns of pesticide use. Birds are given free choice of dry bait pesticides and naturally occurring food crops. During testing, the enclosures are moved daily over similarly treated areas to provide a constant pesticide exposure factor and to replenish the available forage for test birds. A fluorescent particle tracer is used in the pesticide formulation to assess the daily acceptance of pesticide material by the test birds from fecal analysis. Advantages and possible applications of this method are discussed.
Approach for Assessing Feed Loss Damage by Starlings at Livestock Feedlots
Authors: Glahn JF , Otis DL
Published: March 2009

The problems of assessing damage in a feedlot situation are discussed with reference to past approaches. The rationale of bird activity indexes as an indirect estimate of feed loss is presented as a feasible assessment technique. Preliminary regression models of bird activity were generated using time-lapse photography and paired with feed consumed over time. These regression models predict that for every 1000 bird-minutes of starling activity, 4.80 kg of pelletized feed is consumed, whereas the model for a granular hog meal predicts only 0.59 kg of feed consumed for every 1000 starling-minutes. The practical basis of this method in utilizing observers to estimate bird activity is discussed in relation to problems of estimation and sampling bird activity.