Integrating Chemical Measures of Hydrocarbon Bioavailabilty ......and Toxicity in MGP Site Sediments...
Transcript of Integrating Chemical Measures of Hydrocarbon Bioavailabilty ......and Toxicity in MGP Site Sediments...
Integrating Chemical Measures of Hydrocarbon Bioavailabilty into Risk-Based Management Strategies for Sediments
Joe Kreitinger and David Nakles The RETEC GroupNovember 10th, 2005
Can We Improve Technical Framework for Sediment Management?
Generic Site Specific
Look-Up Sediment Screening
Value
Chemical Tests to Predict Bioavailability
and Toxicity
Directly Measure
Bioavailability & Toxicity
Quality of Information
Uncertainty Confidence
Value of Improving Chemical Predictors of Sediment Toxicity
• Better information for remedial decision-making• Prioritize where resources are spent• Expedite site closures• Reduce costs
• More focused monitoring methods• Residuals following dredging• Long-term monitoring of caps • MNA evaluation
Assessing the Bioavailability of PAHsin Soils and Sediments
How did we get here? • Gas Research Institute: bioavailability research initiated in
1993• Published “Red Book”• Petroleum Environmental Research Forum study
followed• Conclusion: Bioavailability is important concept but
more carefully integrated studies were needed
• Two follow-on industry supported research programs initiated in 1997:• CA human health study: Lampblack-impacted soils
($1MM)• NY ecological study: PAH-impacted soils/sediments
(~ $3 MM)
Significant Collaborative Research with Academic and National Laboratories
Characterizing bioavailability and toxicity of PAHsin MGP site soils/sediments since 1993
• The RETEC Group (Ithaca, NY; Pittsburgh, PA)
• Gas Research Institute (Chicago, IL)
• Lawrence Berkeley National Laboratory (Berkeley, CA)
• Cornell University (Ithaca, NY)
• Stanford University (Palo Alto, CA)
• University of Texas (Austin, TX)
• University of North Dakota (Grand Forks, ND)
• Ohio State University (Columbus, OH)
• University of Maryland, (Baltimore, MD)
• US Army Engineering Research & Development Center
Approaches for Assessing Bioavailability
• Characterize carbon-types and assign carbon-specific partitioning coefficients?
• Determine sediment pore water chemical concentrations
• Use direct measurements of chemical release to predict bioavailability
• Directly measure uptake and toxicity to organisms directly
Survey of Hudson River Sediments Demonstrated Presence of Natural and Anthropogenic Carbon
wood lignite bituminous anthracite coal oxidized coalcoal
charcoal coke soot carbon coal tar pitch cenosphere
PAH binding (Koc) is very different for different types of carbon
(U. Ghosh et al. , 2003)
Two Chemical Methods have been Developed and Evaluated
• Solid Phase Micro Extraction (SPME)• Measures the dissolved concentration of PAHs in sediment pore water
• Supercritical Fluid Extraction (SFE)• Measures the release of PAHs in sediment samples
Do these measurements correlate to bioavailability?
Site Specific Information
• TOCNatural carbonAnthropogenic
• Correct KOC?• SPME Porewater Conc• SFE Rapidly Released Conc
Soil/Sediment Concentration
Equilibrium Partitioning Model
Biota Exposure
Hydrocarbon Narcosis Model
Toxicity Endpoint
Procedures for the
Derivation of
(EPA 2003)
Sediment Benchmarks: PAH Mixtures
Site Specific Measures Of Chemical Availability Reduce Uncertainty In Predicting Exposure
Solid Phase Microextraction (SPME) of Pore Water
• Uses sorbent microfiber• Accurately measures PAHs in pore water• Rapid – 30 minutes• Small sample size required
~ 20 ml of sediment~ 1.5 ml of pore water
• Very low detection limit~ pg/mL (ppt)
(Hawthorne et al., 2005b)
SPME Fiber Injection into GC/MS
Conventional EPA water analysis methods would require liter(s) of sediment pore water to achieve similar sensitivity
Detection limits for representative PAHs
EPA 8270 EQL
1 liter water
10 µg/l
10
10
10
10
SPME
1.5 ml water
0.5 µg/l
0.2
0.01
0.005
0.002
Naphthalene (2-ring)
Phenanthrene (3-ring)
Chrysene (4-ring)
Benzo(a)pyrene (5-ring)
Benzo(g,h,i)perylene (6-ring)
Why is SPME so much more sensitive for larger PAHs?All molecules collected by SPME are transferred to the GC
For 8270 only ca. 0.1% are injected
(Hawthorne et al. , 2005b)
Supercritical Fluid Extraction (SFE) of Sediments
• Extraction Conditions• Liquid CO2,200 atmos, 50◦C•40 minutes extraction
• Advantages• CO2 polarity is similar to lipids• Release rates correlate to water desorption• Solubility of PAHs in CO2 is proportional to their solubility in water• Little effect on OM matrix• Can be easily calibrated to biological uptake
(Hawthorne, 2002)
Illustrative SFE Release Curve for PAHs
0 30 60 90 120 150 180Time (Minutes)
0
0.2
0.4
0.6
0.8
1.0
F = Fraction of Chemical Rapidly Released at 40
minutes
Frac
tion
Of P
AH
Rel
ease
dD
urin
g SF
E Ex
trac
tion
0.0
0.2
0.4
0.6
0.8
1.0
0 20 40 60 80 100 120
Rapidly Released Fraction (F) can Vary Significantly Between Samples
SFE Extraction Time (min)
Total PAH Release Using SFE
Perc
ent E
xtra
cted
(%)
F = 0.75F = 0.75
F = 0.12F = 0.12
Soil HP3 (3,970 mg/kg)Soil HP3 (3,970 mg/kg)
Soil HP12 (3,030 mg/kg)Soil HP12 (3,030 mg/kg)
(Kreitinger et al. 2005)
Field Surveys and Case Studies to Assess Tools for Predict Bioavailability
Hyalella azteca28-day chronic toxicity
Chironomus tentans10-day acute toxicity
Cooperative Research and Development Agreement (CRADA) U.S. Army Corps of Engineers
Center for Contaminated Sediments
Generic Assessment Protocol Using Amphipods as Standard Sensitive Test Organisms
(EPA 2003)
1
10
100
1000
0 20 40 60 80 100
Test
Org
anis
m M
ean
Acu
te V
alue
(µ
mol
e PA
H /
g lip
id)
% Rank of Tested Organisms
Hyalella Chironomus
Leptocheirus19.0 µmole/g lipid is toxic to Leptocheirus – Marine test species13.9 µmole/g lipid is toxic to Hyalella –Freshwater test species
There is No Relationship Between [PAH] and Toxicity in MGP Site Sediments
Sediment Total PAH Concentration (mg/kg dry wt.)
Perc
ent S
urvi
val (
%)
0
20
40
60
80
100
120
1 10 100 1000 10000
Nontoxic Sediment
Toxic Sediment
EPA Hyalella azteca 28-day Test
0
20
40
60
80
100
120
1 10 100 1000 10000
BL Control - H. azteca BL - H. aztecaBL Control - C. tentans BL - C. tentansNY Control - H. azteca NY - H. azteca
High total PAHs did not exhibit toxicity to H. azteca or C. tentans at an Aluminum Smelter Site
Perc
ent S
urvi
val (
%)
Sediment Total PAH Concentration (mg/kg)
H. H. aztecaaztecaPitchPitch--spiked Control spiked Control
(51 mg/kg)(51 mg/kg)
C. C. tentanstentansPitchPitch--spiked Controlspiked Control
(~60 mg/kg)(~60 mg/kg)
Toxicity to H. azteca Can be Predicted by Estimating PAHs in Porewater
0
20
40
60
80
100
120
0.001 0.01 0.1 1 10 100
Nontoxic Sediment
Toxic Sediment
SPME Pore Water PAH Conc. (µmoles/L)
Surv
ival
(%
)
NONTOXIC TOXIC
EPA Hyalella azteca 28-day Test
Toxicity to H. azteca Can be Predicted by Estimating SFE Rapidly Released PAHs
SFE Rapidly Released PAHs (mmoles/kg TOC)
Surv
ival
(%
)
0
20
40
60
80
100
120
0.01 0.1 1 10 100 1000 10000
Nontoxic Sediment
Toxic Sediment
NONTOXIC TOXIC
EPA Hyalella azteca 28-day Test
Integration Within Risk-Based Decision Making
• Use Simple Screening Tools:• To focus toxicity testing• Appropriate for the size of the problem
• Implement Case-Studies:• Assure appropriate toxicity endpoints• Gain regulatory acceptance
1. Anticipated Approach Using Sediment Contaminant Bioavailability Assessment (SCBA)
No Further Action
Predict Nontoxic
No Further Action
Predict Toxic
Address
Predict Toxic
Address
No Further Action
No
Yes Uncertain Toxicity
> Background PAH
YesChemistry Screen
Fails for Total PAHs
No
SPME/SFEChemistry
Screen
Amphipod Toxicity Test
Predict Nontoxic
No Further Action
2. Anticipated Approach Using Sediment Contaminant Bioavailability Assessment (SCBA)
Predict Toxic
Address
Predict Nontoxic
No Further Action
Uncertain Toxicity
SPME/SFEChemistry
Screen
Four case studies are on-going to answer the
question:
“How well does the SPME/SFE chemistry screen predict toxicity
to amphipods?”
3. Anticipated Approach Using Sediment Contaminant Bioavailability Assessment (SCBA)
Predict Toxic
Address
Amphipod Toxicity Test
Predict Nontoxic
No Further Action
Additional studies will be required to answer:
“How well does the amphipod toxicity testing predict toxicity to other
aquatic life?”
Soil/Sediment Bioavailability Program
Interaction with regulatory agencies is key
• Conduct technical workshops to key State Regulatory Agencies and EPA
• New York DEC and DOH• New Jersey DEP• California EPA
• Developed Five-Year to Support Integration of Bioavailability Concepts into Federal and State Regulatory Guidance
Sediment Bioavailability Program
Major Program Tasks• Task 1 - Conduct Case Studies• Task 2 - ASTM/EPA Approval of Analytical Methods• Task 3 - Technology Transfer
• Conferences• Peer-Review Publications
• Task 4 – Support Regulatory Guidance Development by EPA and ITRC• Task 5 - Communication and Coordination
Proposed Alliance Sediment Contaminant Bioavailability Program
Industry Alliance
Case Studies(Task 1)
• Utility Industry• Aluminum Industry• Steel Industry?• Others …..?
Program Support(Tasks 2-5)
2. Analytical Methods3. Technology Transfer4. Regulatory Guidance Support5. Alliance Communication & Coordination
Program Advisory Board (PAB)
Project ManagerRETEC
Science Advisory Board (SAB)
Current Members
Interested Parties
Sediment Contaminant Bioavailability Alliance
Multi-Industry Approach to Move Forward
CASE STUDIES/ State Regulatory
Participation
Utility Aluminum Petroleum Navy Industry Industry Industry Industry DOD Support
COMMUNICATIONPeer Reviewed Technical Publications
Synthesis Report for ITRC
IMPLEMENTATION
ITRC Industry/Gov’tAnalysis Support
EPA and/or ASTM Standard Method
Development
Presentation Summary
• Simple screening tools are needed whichare appropriate for small “everyday” projects• Interaction with state regulatory agenciesis required to define “risk endpoints” requiring protection• Case studies are necessary for gainingacceptance and to evaluate the effect of bioavailability data on sediment management