2004 Progress Report: Bioturbation and Bioavailability of Residual, Desorption-Resistant Contaminants

EPA Grant Number: R828773C001
Subproject: this is subproject number 001 , established and managed by the Center Director under grant R828773
(EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).

Center: HSRC (2001) - South and Southwest HSRC
Center Director: Reible, Danny D.
Title: Bioturbation and Bioavailability of Residual, Desorption-Resistant Contaminants
Investigators: Reible, Danny D. , Fleeger, J. W. , Pardue, J.
Institution: Louisiana State University - Baton Rouge , Rice University
EPA Project Officer: Lasat, Mitch
Project Period: October 1, 2001 through September 30, 2006 (Extended to September 30, 2007)
Project Period Covered by this Report: October 1, 2003 through September 30, 2004
Project Amount: Refer to main center abstract for funding details.
RFA: Hazardous Substance Research Centers - HSRC (2001) RFA Text |  Recipients Lists
Research Category: Hazardous Waste/Remediation , Land and Waste Management

Objective:

The overall objective of the proposed research is to evaluate the bioavailability of the desorption-resistant fraction of contaminants using uptake and accumulation in tubificid oligochaetes. Work prior to this year on laboratory-inoculated sediments had suggested that the route of uptake (i.e., sediment ingestion or porewater absorption) and organism-specific factors (e.g., assimilation efficiency and elimination kinetics) control the kinetics of accumulation of the desorption-resistant fraction of polycyclic aromatic hydrocarbons (PAHs). The ultimate, or steady-state, accumulation, however, is controlled by porewater partitioning as defined by physicochemical measurements. The work this past year focused on testing the applicability of this paradigm to field-contaminated and aged sediments that exhibit extremely slow release kinetics in physicochemical measurements. These results continue to support the view that measurements or predictions of porewater concentrations can predict steady-state uptake of simple partitioning contaminants such as PAHs. A kinetic model of desorption was developed that also provided a good description of the partitioning behavior of PAHs in field-contaminated sediment with a minimum of adjustable parameters.

The experiments with field contaminated sediments, however, also suggested that the organisms may be able to access more contaminants than might be found in a fast-release fraction (as defined operationally herein by sediment desorption with XAD-2 for 20 hours) despite the fact that the fast-release fraction largely defines porewater concentrations and ultimately the steady-state accumulation in the organisms. The latter observation merits additional experimental evaluation. The implications of this phenomenon are especially unclear for contaminants that biomagnify and do not simply partition between sediment organic matter, porewater, and lipids. It is desired to monitor accumulation of both PAHs, which are considered simple partitioning contaminants, and polychlorinated biphenyls (PCBs), which are believed to biomagnify, in both tubificid oligochaetes and in an organism one step higher in the food chain. The latter organism, a grassy shrimp, should be able to illustrate the influence of biomagnification and food chain effects of limited bioavailability to the oligochaetes.

Progress Summary:

Project Rationale

Sediment quality is determined by the risks of contaminants to human and ecological receptors, which, in turn, is controlled by availability and exposure to those contaminants. A significant fraction of the organic contaminants in soils and sediments may not be readily available for uptake and organism effects. A desorption-resistant fraction is often observed that is released more slowly and in lesser amounts from contaminated sediments. The slowed rates of physicochemical release have been reflected in microbial degradation processes. Until recently, however, there has been limited assessment of the bioavailability of this fraction beyond microbial assays. Multicelluar animals, notably deposit feeding benthic organisms, represent a more intense environment for the assessment of bioavailability and are more directly linked to the food chain. Results with a limited set of laboratory-inoculated sediments and PAH contaminants suggest that the ultimate organism uptake of desorption-resistant contaminants is reduced compared to reversibly desorbed contaminants but is predictable with a biphasic equilibrium model. The preliminary work also suggests that the rate of uptake by benthic organisms is enhanced relative to that expected by physicochemical desorption measurements. This work is primarily aimed at confirming the preliminary results and extending the database of compounds and sediments for which bioavailability is understood. The ultimate goal is to develop a predictive model of biological availability based upon physicochemical availability.

Approach

Methodology. In previous reports, many of the basic techniques employed in the project were discussed and these descriptions will not be repeated here. The fundamental approach has been to prepare sediments that effectively contain only the desorption-resistant fraction of contaminants and then monitor the accumulation of the contaminants in deposit-feeding tubificid oligochaetes that are exposed to the sediments. Deposit-feeding oligochaetes represent an intense processing environment for the sediments, and thus bioavailability tests employing these organisms are not complicated by the mass-transfer resistances that are inherently associated with microbial assays of bioavailability. Low residual concentrations have led to the use of radiolabled contaminants for much of the work to date. Both the kinetics and steady-state uptake into the oligochaetes have been measured. Uptake from sediment ingestion was compared to uptake from water alone to evaluate the influence of route of exposure on rate and extent of accumulation in the organism.

This past year focused on field-contaminated sediments to evaluate the generality of the prior results. Models are under development to assist in relating physicochemical desorption kinetics to observed uptake and accumulation. Finally, methods for evaluating the relationship between bioavailability to benthic organisms and trophic transfer up the food chain are under development. These methods will be discussed in more detail in the discussion of future work.

Outputs/Accomplishments

Experimental. Efforts over the past year have focused on:

  • Increasing the number of contaminants and sediments for extension of the porewater paradigm for the prediction of steady-state uptake in benthic organisms.
  • Comparing the rate and steady-state uptake of a range of PAHs from field-contaminated Anacostia sediments in the model organism tubificid oligochaete.
  • Developing a model of physicochemical sorption and desorption processes to relate the kinetics of desorption to the kinetics and extent of uptake.

Measured accumulations in the test organisms (as indicated by biota-sediment accumulation factors (BSAFs)—the ratio of lipid-normalized accumulation to organic carbon-normalized sediment concentration) after exposure to the field-contaminated Anacostia sediment are shown in Figure 1.

Figure 1. BSAF as a Function of Time of Exposure to Anacostia Sediments
Figure 1. BSAF as a Function of Time of Exposure to Anacostia Sediments

As shown in Figure 1, normalized accumulations were much less than unity, the expected value if the contaminants were readily and completely desorbed. Based upon the prior experiments, this reduction in BSAF should be correlated to porewater concentration of the respective PAHs. Figure 2 shows observed BSAF versus that predicted by porewater concentrations for the field-contaminated sediments. Also included in the figure are the data previously collected from laboratory-inoculated sediments and BSAF values for pyrene inferred from Millward, et al. (2001); and a similar estimate of BSAF values reported by Kosian, et al. (1999).

Figure 2. Predicted vs. Measured Accumulation
Figure 2. Predicted vs. Measured Accumulation

The accumulations in organisms exposed to Anacostia sediments are reasonably predicted by measured porewater concentrations as they were with the laboratory-inoculated sediments. The predicted BSAFs assume that the effect of desorption resistance is to reduce porewater concentrations without reducing the ratio of porewater concentrations to lipids. That is, the model assumes that steady state accumulation in the lipids is given approximately by Klw Cpw, where Klw is the lipid-water partition coefficient (approximately Koc) and Cpw is the porewater concentration. The high correlation (r2 = 0.94) between the predicted and the measured BSAFs strongly supports the paradigm that sediment porewater concentration controls the ultimate accumulation of a specific organic contaminant.

An alternative model for assessing the bioavailability and normalized accumulation in the organisms is through evaluation of the rapidly desorbed contaminant fraction from the field-contaminated sediment. This was assessed by exposing the Anacostia sediment to XAD-2 for 20 hours to remove any rapidly desorbed fraction. As shown in Table 1, this resulted in very small fractions of contaminant removal, suggesting that 90+% of the heavier PAHs were only slowly desorbing. Also included in Table 1, however, are single gut passage assimilation efficiencies. These represent the amount of contaminants that are absorbed by the organism during short-term exposures. These absorption efficiencies were determined by measuring accumulation in the organism by a short period of exposure (40 minutes) followed by allowing ingested sediment to pass through the gut for 4 hours. The 4-hour depuration period was conservatively based upon ½–2 hour gut passage times measured in inoculated sediment. As shown in Table 1, assimilation efficiencies were much higher than the measured fast-desorbing fraction of contaminants. These data should be viewed as preliminary in that there may be some processes that slow gut passage time in the field-contaminated sediment, or XAD-2 exposure may need to be continued for a longer period of time to estimate the fast-release fraction. These preliminary data suggest, however, that the porewater concentrations, and not the fast-release fraction, are better indicators of steady-state accumulation in the tubificid oligochaete.

Table 1. Fast-Release Fractions and Assimilation Efficiency for Anacostia Sediment

Compound

Fast-Release Fraction
(XAD-2 exposure for 20 hours)

Assimilation Efficiency
(measured by accumulation during short exposures)

Phenanthrene

-13 ± 35

63 ± 7

Pyrene

0 ± 3

77 ± 12

Chrysene

8 ± 7

81 ± 13

Benzo-k-fluoranthene

8 ± 13

75 ± 4

Benzo-a-pyrene

0 ± 2

88 ± 17

Note also that the measured single gut passage assimilation efficiencies are far higher than the fraction of contaminant that would be expected to be released from the sediments by physicochemical processes alone during the ½–2 hour gut exposure. Thus, Ilyodrilus templetoni appears able to effectively desorb tightly bound contaminants from the sediments after ingestion, and yet steady-state uptake is well described by porewater concentrations. This agreement with physicochemical predictions at steady-state accumulation may be a function of elimination or biodegradation of PAH, which allows the organism to achieve equilibrium with the surrounding porewater/sediment complex. The extent of solubilization of contaminants in digestive fluid has been proposed as a measurement of bioavailability (Mayer, et al., 1996; Weston and Mayer, 1998). Our data would suggest, however, that such measures would indicate only the rate of uptake of ingested contaminants and not the steady-state, or ultimate, bioavailability. This potentially controversial result, however, may be limited to the PAHs and organisms considered herein. Many organisms sorb and even metabolize PAHs relatively effectively (compared to more refractory compounds and potential biomagnifiers, such as PCBs).

Because the Anacostia sediments contain a variety of contaminants, we have also conducted preliminary studies that examine the joint behavior of PAHs and metals. In the amphipod Hyalella azteca, Cd and phenanthrene exhibit synergistic toxicity (more toxicity is expressed in joint exposures than predicted by separate exposures) and in the oligochaete I. templetoni, Cd and phenanthrene express antagonistic toxicity (they are less toxic in joint exposures than separate exposures predict). Kurt Gust, a Ph.D. student in Biological Sciences, is conducting this research for his dissertation.

Research funded by the Hazardous Substance Research Center (HSRC) was designed to determine if bioavailability explains these observations. Both species are benthic deposit feeders, and the routes of exposure for both include sediment ingestion and uptake from porewater. It is possible that the bioavailability of metals is affected by hydrocarbons (or vise-versa), and effects may be associated with the uptake route. Research examined phenanthrene effects on factors that might influence Cd bioavailability (e.g., pH, oxygen concentration, acid-volatile sulfides, and porewater concentration). Parameters that potentially affect Cd bioavailability were not influenced by phenanthrene. In H. azteca, the synergism did not occur in aqueous exposures, suggesting that uptake from sediment and/or food contributes to the increased uptake rate of Cd in the presence of phenanthrene, even though Cd is not likely to be more bioavailable. In I. templetoni, phenanthrene, as a narcotic, slows ingestion, altering the kinetics of Cd uptake and reducing the equilibrium tissue concentration and thus toxicity.

All of these effects were observed, however, at concentrations far exceeding that in the native Anacostia sediment. It is therefore not expected that these complications have significantly influenced the behavior of PAHs in the Anacostia sediment and in the tubificid test species.

Modeling. A mathematical model of sorption and desorption was developed to predict physicochemical desorption, which the results above suggest can predict steady-state uptake in the tubificid oligochaete. There are a variety of models and interpretations of desorption-resistant phenomena, however, the following ideas are well accepted:

  1. Approximately biphasic desorption phenomena result from organic carbon heterogeneity. Sediment/soil organic matter can be classified into two general categories, as amorphous or condensed phase organic matter. Terms such as “coal-derived” particles, “soot carbon”, “black carbon,” and “hard carbon” have been used to represent condensed phase organic carbon, which exhibits elevated adsorption capacity and a higher carbon-normalized partition coefficient.
  2. The desorption resistance of organic contaminants and aging effects (i.e., reduced contaminant release over simple reversible sorption behavior) results from the slow diffusion of contaminants from the condensed phase organic carbon and the increased equilibrium partition coefficient of this material.

The developed model has the following features that are consistent with these basic ideas:

  • Contaminant sorption and desorption into natural organic matter (“soft” or amorphous carbon) is assumed to be reversible and at rates that are controlled by diffusion in the pore space of this phase. There exist measurements in the literature of basic physical characteristics of this phase necessary to predict the rates and extent of sorption to this phase.
  • Contaminant sorption and desorption to condensed phase organic matter is assumed to be controlled by diffusion in a solid organic phase. Various equilibrium characteristics of this phase are known or can be measured but only broad guidance is available for the effective solid phase diffusion coefficient and the surface area to volume ratio of this phase (the single geometric parameter in the formulation of the model).

Early efforts toward model development were focused on attempting to separate the different organic fractions in sediment via size or density fractionation to define the amorphous and condensed phase carbon and to allow separate measurements of the key model parameters. This proved unsuccessful and ultimately it was decided to employ the operational definition suggested by Gustafsson, et al. (1997), which separates organic carbon on the basis of whether it is volatile or nonvolatile after treatment at 375°C.

Although it was not possible to separate the organic carbon fractions on the basis of size or density, it was possible to visually separate organic matter in coarse particle fractions (> 400 μm). The organic matter was visually separated into a woody fraction, a charred wood or charcoal fraction, a coal-like fraction, and a coal cinder fraction. The coal-like fraction was glassy and nonporous, while the coal cinder or soot fraction had the appearance of burned coal and was porous. The fractions also exhibited chemical differences, including different carbon contents, fractions of “hard” and “soft” carbons, and C/H ratio. Of these fractions, only the coal-derived particles (coal-like and coal cinder particles) had measurable fractions of hard carbon and exhibited effective partition coefficients considerably larger (by a factor of about 10) than expected from Koc. The characteristics of the coal-derived particles are shown in Table 2. The coarse coal-derived particles appear to be a good model of the condensed phase carbon. The model parameters for this phase, partition coefficient, etc. were based upon the characteristics of these particles. The properties of the amorphous or “soft” carbon, assumed to be similar to the woody organic matter, were available from literature sources, and confirmed by the characteristics of the wood-derived fraction of organic matter.

Table 2. Properties of Coal-Derived Coarse Particles—Utica River

Property

Coal-like particles

Coal cinder particles

foc

80.9%

28.8%

fochard

51.3%

74.3%

Anthracene Log Koc
(literature 4.33)

5.40

5.22

Chrysene Log Koc
(literature – 5.65)

6.35

6.62

Benzo-a-pyrene Log Koc
(literature 5.83)

6.32

6.86

The model was left with two adjustable parameters that can be calibrated to a particular sediment, the condensed phase diffusivity, and the volume to area ratio for the condensed phase carbon. It was assumed that the values of these parameters in the coarse particles may not be representative of fine particles of similar composition. These parameters can be calibrated to kinetic information on sorption and/or desorption for a particular compound and sediment, however, and then used to predict sorption and desorption for other time periods or for other contaminants, at least within the same compound class.

Calibration of the model using four different PAH compounds in two sediments resulted in a very good fit to the data with the following parameters:

Condensed phase diffusivity – 2 x 10-19 m2/s
Condensed phase volume to area ratio – 15 μm

This fit is illustrated in Figure 3, which predicts the fast-release fraction (as measured by treatment with XAD-2 for 20 hours) for the compounds in each sediment and Figure 4, which shows the apparent partition coefficient of the bulk sediment for the two sediments and four PAHs.

Figure 3. Fast-Desorption Fraction From Utica River and Rouge River Sediments for Four PAHs
Figure 3. Fast-Desorption Fraction From Utica River and Rouge River Sediments for Four PAHs

Figure 4. Comparison of Estimated and Observed Apparent Koc
Figure 4. Comparison of Estimated and Observed Apparent Koc

Attempts to model the sorption and desorption processes in laboratory-inoculated sediments suggested that aging in the laboratory for even 2–3 years is insufficient to develop a significant desorption-resistant fraction. That is, expected rates of diffusion in the condensed phase carbon are sufficiently slow that longer periods of contaminant exposure are required to fully develop a desorption-resistant fraction of contaminants. This suggests that our past attempts to employ laboratory-inoculated sediments to evaluate desorption-resistant phenomena require a high degree of analytical precision to be successful.

Recommendations and Rationale for Subsequent Work

The key conclusions from the work described above can be summarized as follows:

  • Measurements of availability of PAH contaminants to deposit-feeding oligochaetes continue to support the model that partitioning from porewater defines the steady-state accumulation in the organism, even from the desorption-resistant fraction of contaminants.
  • Toxicokinetic modeling and experiments suggest that route of exposure and route-specific parameters, such as organism assimilation efficiency and elimination rate for sediment ingestion, control the kinetics of uptake but not the steady-state uptake.
  • Porewater concentrations (and by inference the bioavailability) appear to be predictable via a biphasic diffusion model with two key parameters associated with the fraction of the organic matter responsible for desorption-resistant phenomena, the effective length scale of the organic matter (volume to area ratio), and the solid phase diffusivity.

These conclusions, although well-supported by the data collected to date, are limited to a relatively small set of contaminants, sediments, and organisms. The proposed work seeks to test the generality of the results by examining a broader range of sediments, and extend to other hydrophobic organic compounds, which, according to some evidence, may not behave as simple partitioning contaminants. PCB congeners often increase in tissue concentrations with increasing food chain length in aquatic systems, and thus biomagnify (Morrison, et al., 1996). On the other hand, the biomagnification potential of PAH is generally considered to be low, consistent with our observation that steady-state PAH accumulation is governed by thermodynamic equilibrium between porewater and lipids. Do PCBs behave fundamentally differently? PCBs appear to partition more strongly to lipids than sediment organic carbon (BSAFs in benthic invertebrates are typically 3–4 rather than near unity) but this is not evidence for biomagnification. Evidence for biomagnification is often based upon increased absolute concentrations during trophic transfer, but increased absolute concentrations would also be expected if lipid contents changed at different trophic levels. Gobas, et al. (1999) models biomagnification as a gut-related process in animals with a diet rich in lipids. Fugacity of PCBs increases with passage through the gut and this increase allows the predator to obtain a body burden that exceeds that of its prey. Absorption efficiency of lipids is higher than PCBs, which is thought to contribute to the high uptake of PCBs. Based upon our work, this process would increase the rate of PCB uptake but it is unclear if steady-state lipid-normalized accumulation would be changed. A series of experiments comparing accumulation of PCBs and PAHs during trophic transfer would help identify and contrast the potentially different behavior of these compounds. Tubificid oligochaetes that have accumulated PAHs and PCBs could be fed to a larger predator such as a grass shrimp (Palaemonetes pugio) to evaluate the effects of trophic transfer on accumulation. In principle, both the rate and steady-state accumulation of PAHs and PCBs could be measured and compared.

Proposed Efforts

Based upon the needs outlined above, the proposed project has three overall objectives:

  1. Confirmation of the results to date with field PAH-contaminated sediments, including comparing and contrasting accumulation of PCBs from field-contaminated sediment with that observed for PAHs.
  2. Continuation of the modeling efforts to better understand the relationship between desorption rates and the rate and steady-state extent of accumulation in organisms.
  3. Compare and contrast trophic transfer of PAHs and PCBs from tubificid oligochaetes to grass shrimp.

Desorption and Bioavailability of Contaminants from Field Sediments. In order to complete the current work with a range of field-contaminated sediments, it is necessary to extend the modeling efforts to the prediction of sorption/desorption phenomena to Anacostia sediments and to extend the accumulation and bioavailability experiments to Rouge River and Utica River sediments. The extractable contaminants, as measured by sorption onto XAD-2, can be compared to assimilation efficiency in the gut of the organism to contrast extraction efficiency by physicochemical and biological processes and to identify the significance of any differences to steady-state uptake. As indicated previously, experiments to date have not shown any influence of extraction (assimilation) efficiency on steady-state uptake.

The Anacostia River sediments also contain PCBs and accumulation of selected PCBs in the organisms will also be monitored. BSAF for selected PCBs congeners present in the highest concentrations will be measured. This will later be compared to normalized accumulation in organisms that are fed the oligochaetes for evaluation of trophic transfer of PCBs. This is described in more detail later.

Trophic Transfer of PAHs and PCBs. Understanding trophic transfer is necessary to fully appreciate the potential impact of these chemicals to human and ecosystem health because predation on the benthic community represents a significant route of exposure to aquatic food webs. Furthermore, values derived from exposure to sediments (e.g., BSAF) are being used to assess contaminant impacts on nonbenthic organisms, including swimming invertebrates and fishes (Maruya, et al., 1997; Burkhard, 2003), primarily to set conservative criteria for environmental impacts. Nonbenthic organisms may have low BSAF values because they do not readily assimilate contaminants or because they do not derive energy from food webs that originate in the sediment. Unfortunately, no laboratory measurements are available to compare to field values of BSAF and trophic transfer factors for a single species to determine the validity of the use of BSAF for nonsediment animals. Trophic transfer factors are similar to BSAF in that they are normalized for lipid content and represent the ratio of lipid-normalized PCB or PAH concentration in a predator to its prey.

Trophic transfer of PAH and PCB from tubificid oligochaetes to an invertebrate predator will be studied. Some PCB congeners increase in tissue concentrations with increasing food chain length in aquatic systems, and thus biomagnify (Morrison, et al., 1996). On the other hand, the biomagnification potential of PAH is generally considered to be low. Tubificid oligochaetes are often found in contaminated sediments in very high densities. They are also common prey for many different fishes and invertebrates (Bouguenec and Giani, 1989). P. pugio are common invertebrates found in salt marshes and are known as predators on small invertebrates such as annelids (Fleeger, et al., 1999). Grass shrimp are also commonly used as field and laboratory test organisms (Rayburn and Fisher, 1997; Smith and Weis, 1997).

I. templetoni will be cultured on field-collected sediment from the Anacostia River until their tissues reach equilibrium for PCB and PAH. They will be fed to grass shrimp using the methods of Wallace (Wallace and Lopez, 1996; Wallace, et al., 1998). Briefly, worms will be ground up by tissue homogenization and placed in small gelatin capsules. Capsules will be fed to grass shrimp. Previous research suggests that grass shrimp will completely ingest the capsules. We plan to feed each grass shrimp 15 I. templetoni per day (which represents about 12 percent of the mass of a grass shrimp) for 30 days. Then shrimp will be sacrificed and, after determining body burdens and lipid contents, trophic transfer factors will be calculated for specific PAHs and PCB congeners. Field-generated BSAF values for grass shrimp have been measured and comparisons to trophic transfer factors will be made to determine if grass shrimp take up toxicants at a high rate. If the rate of bioaccumulation is slow, it will suggest that low values of BSAF in the field are due to slow ingestion or rapid depuration of the chemical; if trophic transfer factors are high but BSAF is low from the field, it will suggest that the grass shrimp does not benefit from bottom sediments and its food web does not originate in the sediments.

Specifically, we will test two hypotheses concerning bioaccumulation (i.e., biomagnification) across trophic levels in a food web that begins with contaminated sediment. First, we will test the prediction by Gobas, et al. (1999) that a deposit feeder with a diet low in lipid content should have a lower trophic transfer factor (i.e., BSAF) than a predator with a diet rich in lipids feeding on these organisms. To our knowledge, this prediction has not been tested across a food web beginning with a deposit-feeding worm to a predator by following the same compounds. Comparisons in trends between PAH and PCB should be revealing and will suggest if current models of biomagnification are generally effective and predictive. Second, we will test if PAH and PCB achieve different lipid-normalized tissue concentrations in a predator feeding on a single prey species with known levels of contamination. PCBs may bioaccumulate differently if they partition more strongly to lipids than to the sediment organic carbon (compared to PAH) or if PCBs are eliminated at slower rates than are PAH.

Students Supported

Xiao Xia Lu, Ph.D. graduate in Chemical Engineering, currently postdoctoral fellow.

Younzhou Chai, Ph.D. student in Chemical Engineering.

Kurt Gust, Ph.D. student in Biological Sciences.

References:

Bouguenec V, Giani N. Aquatic oligochaeta as prey for invertebrates and vertebrates: a review (in French). Acta Oecologica–Oecologia Applicata 1989;10:177-196.

Burkhard LP. Factors influencing the design of bioaccumulation factor and biota-sediment accumulation factor field studies. Environmental Toxicology and Chemistry 2003;22:351-360.

Fleeger JW, Carman KR, Webb S, Hilbun N, Pace MC. Consumption of microalgae by the grass shrimp, Palaemonetes pugio. Journal of Crustacean Biology 1999;19:324-336.

Gobas FAPC, Wilcockson JB, Russell RW, Haffner GD. Mechanism of biomagnification in fish under laboratory and field conditions. Environmental Science & Technology 1999;33(1):133-141.

Gustafsson O, Haghseta F, Chan C, Macfarlane J, Gschwend PM. Quantification of the dilute sedimentary soot phase: implications for PAH speciation and bioavailability. Environmental Science & Technology 1997;31:203-209.

Kosian PA, West CW, Pasha MS, Cox JS, Mount DR, Huggett RJ, Ankley GT. Use of nonpolar resin for reduction of fluoranthene bioavailability in sediment. Environmental Toxicology and Chemistry 1999;18(2):201-206.

Maruya KA, Risebrough RW, Horne AJ. The bioaccumulation of polynuclear aromatic hydrocarbons by benthic invertebrates in an intertidal marsh. Environmental Toxicology and Chemistry 1997;16:1087-1097.

Mayer LM, Chen Z, Findlay RH, Fang JS, Sampson S, Self RFL, Jumars PA, Quetel C, Donard OFX. Bioavailability of sedimentary contaminants subject to deposit-feeder digestion. Environmental Science & Technology 1996;30(8):2641-2645.

Millward RN, Fleeger JW, Reible DD, et al. Pyrene bioaccumulation, effects of pyrene exposure on particle-size selection, and fecal pyrene content in the oligochaete Limnodrilus hoffmeisteri (Tubificidae, Oligochaeta). Environmental Toxicology and Chemistry 2001;20(6):1359-1366.

Morrison HA, Gobas FAPC, Lazar R, Haffner GD. Development and verification of a bioaccumulation model for organic contaminants in benthic invertebrates. Environmental Science & Technology 1996;30:3377-3384.

Rayburn JR, Fisher WS. Developmental toxicity of three carrier solvents using embryos of the grass shrimp, Palaemonetes pugio. Archives of Environmental Contamination and Toxicology 1997;33:217-221.

Smith GM, Weis JS. Predator-prey relationships in mummichogs (Fundulus heteroclitus (L)): Effects of living in a polluted environment. Journal of Experimental Marine Biology and Ecology 1997;209:75-87.

Wallace WG, Lopez GR. Relationship between subcellular cadmium distribution in prey and cadmium trophic transfer to a predator. Estuaries 1996;19:923-930.

Wallace WG, Lopez GR, Levinton JS. Cadmium resistance in an oligochaete and its effect on cadmium trophic transfer to an omnivorous shrimp. Marine Ecology Progress Series 1998;172:225-237.

Weston DP, Mayer LM. In vitro digestive fluid extraction as a measure of the bioavailability of sediment-associated polycyclic aromatic hydrocarbons: sources of variation and implications for partitioning models. Environmental Toxicology and Chemistry 1998;17(5):820-829.


Journal Articles on this Report : 7 Displayed | Download in RIS Format

Other subproject views: All 36 publications 13 publications in selected types All 9 journal articles
Other center views: All 279 publications 92 publications in selected types All 63 journal articles
Type Citation Sub Project Document Sources
Journal Article Chen W, Kan AT, Newell CJ, Moore E, Tomson MB. More realistic soil cleanup standards with dual-equilibrium desorption. Ground Water 2002;40(2):153-164. R828773 (2004)
R828773 (Final)
R828773C001 (2004)
R828773C004 (2002)
R828773C004 (2004)
R826694C700 (Final)
R831718 (Final)
  • Abstract from PubMed
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  • Journal Article Kan AT, Fu G, Tomson MB, Al-Thubaiti M, Xiao AJ. Factors affecting scale inhibitor retention in carbonate-rich formation during squeeze treatment. SPE Journal 2004;9(3):280-289. R828773 (2004)
    R828773 (Final)
    R828773C001 (2004)
    R828773C004 (2004)
  • Abstract: SPE Journal-Abstract
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  • Journal Article Lu X, Reible DD, Fleeger JW, Chai Y. Bioavailability of desorption-resistant phenanthrene to the oligochaete Ilyodrilus templetoni. Environmental Toxicology and Chemistry 2003;22(1):153-160. R828773 (2004)
    R828773 (Final)
    R828773C001 (2002)
    R828773C001 (2003)
    R828773C001 (2004)
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  • Journal Article Lu X, Reible DD, Fleeger JW. Bioavailability and assimilation of sediment-associated benzo[a]pyrene by Ilyodrilus templetoni (oligochaeta). Environmental Toxicology and Chemistry 2004;23(1):57-64. R828773 (2004)
    R828773 (Final)
    R828773C001 (2003)
    R828773C001 (2004)
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  • Journal Article Reible D, Mohanty S. A levy flight-random walk model for bioturbation. Environmental Toxicology and Chemistry 2002;21(4):875-881. R828773 (2004)
    R828773 (Final)
    R828773C001 (2002)
    R828773C001 (2003)
    R828773C001 (2004)
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  • Journal Article Thibodeaux LJ, Valsaraj KT, Reible DD. Bioturbation-driven transport of hydrophobic organic contaminants from bed sediment. Environmental Engineering Science 2001;18(4):215-223. R828773 (2004)
    R828773 (Final)
    R828773C001 (2002)
    R828773C001 (2003)
    R828773C001 (2004)
    R825513C011 (Final)
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  • Journal Article Work PA, Moore PR, Reible DD. Bioturbation, advection, and diffusion of a conserved tracer in a laboratory flume. Water Resources Research 2002;38(6):24-1–24-9. R828773 (2004)
    R828773 (Final)
    R828773C001 (2003)
    R828773C001 (2004)
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  • Supplemental Keywords:

    bioturbation, bioavailability, biodegradation, BSAF,, RFA, Scientific Discipline, Waste, Water, Contaminated Sediments, Environmental Chemistry, Microbiology, Environmental Microbiology, Hazardous Waste, Bioremediation, Hazardous, degradation, microbial degradation, bioavailability, biodegradation, contaminated sediment, turbificid oligochaetes, contaminated soil, PAH, contaminants in soil, bioremediation of soils, natural recovery, desorption-resistant contamination, biochemistry, phytoremediation, bioturbation

    Relevant Websites:

    http://www.hsrc-ssw.org Exit

    Progress and Final Reports:

    Original Abstract
  • 2002 Progress Report
  • 2003 Progress Report
  • 2005
  • 2006
  • Final

  • Main Center Abstract and Reports:

    R828773    HSRC (2001) - South and Southwest HSRC

    Subprojects under this Center: (EPA does not fund or establish subprojects; EPA awards and manages the overall grant for this center).
    R828773C001 Bioturbation and Bioavailability of Residual, Desorption-Resistant Contaminants
    R828773C002 In-Situ Containment and Treatment of Contaminated Sediments: Engineering Cap Integrity and Reactivity
    R828773C003 Phytoremediation in Wetlands and CDFs
    R828773C004 Contaminant Release During Removal and Resuspension
    R828773C005 HSRC Technology Transfer, Training, and Outreach