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ISPAC2013 plenary talk - Environmental Forensics and PAHs


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Plenary talk at ISPAC conference on the use of polycyclic aromatic hydrocarbons (PAHs) in environmental forensics. Covers basics of what enviromental forensics investigations (EFIs) are and how PAHs can be used to help determine sources of releases (creosote, railway ties), oil sands development and oil spill releases (Macondo oil spill, gulf oil spill).

Published in: Environment

ISPAC2013 plenary talk - Environmental Forensics and PAHs

  1. 1. Use of PAHs in Environmental Forensics Presented by: Court Sandau, PhD, PChem ISPAC 2013 Corvallis, OR
  2. 2. Environmental Forensics • What is it? • Analytical issues with PAHs and EFI • Expanding PAHs (beyond 16) • PAHs and EFIs – examples and case studies 2 For case study on PAHs and a pipeline oil spill, see a part blog on our website: For more information on PAHs, click here to see our website page on PAHs.
  3. 3. Environmental Forensic Investigation The systematic examination of historical and environmental information (which may be used in litigation) to allocate responsibility for contamination “The application of scientific methods used to identify the origin and timing of a contaminant release” See our website for more information on environmental forensic investigations.
  4. 4. Disciplines in Environmental Forensics • Chemistry • Statistics • Engineering • Microbiology • Hydrogeology • Soil Science • Toxicology • Biology • Ecology • Litigation Experience • And others….
  5. 5. Birthplace of Environmental Forensics Exxon Valdez 1989 Term “Environmental Forensics” coined in Dr. Robert Morrison’s first books since it was used in a peer reviewed publication. 5
  6. 6. Crime Scene Investigations 6
  7. 7. Environmental Forensic Investigation
  8. 8. EFI Video Click here for link to video on slideshare.
  9. 9. Two Categories of EFIs Academic & Research Liability Driven
  10. 10. Litigation and Liability Driven EFIs • Adversarial process • Goal – make you look bad or incompetent while making themselves look good/sympathetic • They are trying to tell if you are telling the truth or not • Good science does not necessarily prevail • Unfortunately, science is complicated (scientific literacy 28% in 2007) • Need to prove it beyond a reasonable doubt 10
  11. 11. Differences Between Legal and Research • Documentation, Documentation, Documentation Project id. Address Project id.DateDate Date Notes and pictures/videos
  12. 12. Differences Between Legal and Research • Documentation • Sample Handling • Chain of Custody
  13. 13. Differences Between Legal and Research • Documentation • Sample Handling • Chain of Custody • Laboratory Competence • Standard Procedures • Communicating Results
  14. 14. Carpet Dust Sampling • Must follow standardized procedures where available • Difficult to change approaches • Validation required if methodology changes Designation: D 5438 – 05 Standard Practice for Collection of Floor Dust for Chemical Analysis1 This standard is issued under the fixed designation D 5438; the number immediately following the desig original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates th superscript epsilon (e) indicates an editorial change since the last revision or reapproval. 1. Scope 1.1 This practice covers a procedure for the collection of a sample of dust from carpets and bare floors that can be analyzed for lead, pesticides, or other chemical compounds and elements. 1.2 This practice is applicable to a variety of carpeted and bare floor surfaces. It has been tested for level loop and plush pile carpets and bare wood floors, specifically. 1.3 This practice is not intended for the collection and evaluation of dust for the presence of asbestos fibers. 1.4 The values stated in SI units are to be regarded as the standard. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety and health practices and determine the applica- bility of regulatory limitations prior to use. 2. Referenced Documents 2.1 ASTM Standards: 2 D 422 Test Method for Particle-Size Analysis of Soils D 1356 Terminology Relating to Sampling and Analysis of Atmospheres E 1 Specification for ASTM Thermometers E 337 Test Method for Measuring Humidity with a Psy- larger, embedded in carpet household vacuum cleaners 3.1.2 surface dust—soil proximately 5-µm equivalen adhering to floor surfaces a hold vacuum cleaners. 4. Summary of Practice 4.1 The sampling metho from work published in Rob (4). 4.2 Particulate matter is floor by means of vacuu through a sampling nozzle and the particles are separat cyclone is designed to effic approximately 5-µm mean However, much smaller par efficiencies. The sampling and suction adjustments to air velocity for the removal and bare floor surfaces, so be repeated. NOTE 1—Side-by-side compa upright vacuum cleaner revealed Designation: D 422 – 63 (Reapproved 2002)e 1 Standard Test Method for Particle-Size Analysis of Soils1 This standard is issued under the fixed designation D 422; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. HVS-3 Vacuum Cleaner
  15. 15. Commercial Laboratory PAH Analysis • Methods vary from lab to lab • Quantification – Semi-quantitative methods with surrogates – Quantitative methods with labeled internal standards • Analytes measured – Routine EPA – Routine EPA+ – Deluxe EPA compounds with substituted PAHs and then some (up to 63 compounds in an analysis)
  16. 16. 16 US EPA Priority Pollutants PAH Compounds benzo[k]fluoranthene benzo[a]pyrene benzo[b]fluoranthenepyrenefluoranthenechrysene fluorenephenanthreneacenaphthyleneanthraceneacenaphthenenaphthalene benzo[ghi]perylenedibenz[a,h]anthracene indeno[1,2,3-cd]pyrene benzo[a]anthracene 2-ring 3-ring 4-ring 5-ring 6-ring LMW HMW
  17. 17. Analysis of PAHs S Retention Time RelativeResponse
  18. 18. Interlaboratory Comparisons Method 8270C • Interlaboratory study conducted • Each lab measured homogeneous soil sample 4 times over a ~ week • Requested standard PAH method • Compared variability amoung labs and within each laboratory
  19. 19. Naphthalene
  20. 20. Fluorene
  21. 21. Pyrene 0.00 0.10 0.20 0.30 0.40 0.50 0.60 0.70 0.80 0.90 All Labs Lab A Lab B Lab C Lab D Lab E Lab F Lab G Lab H mg/kg Mean Value Maximum Value Minimum Value FAL - Coarse (0.40)
  22. 22. Results • Laboratory variability issues amoung laboratories • Sample to sample variability within the laboratories Variability can be measured and controlled with a good data validation program
  23. 23. Method Comparison - PAHs Low Resolution MS Method • EPA Method 8270C • Full Scan analysis • No confirmation ions or ratios • Inappropriate surrogate standards • Many versions of method High Resolution MS Method • Modified California Method (Carb 429) • IDMS quantitation • Less likely to have interferences present • Isotopically labeled standards • More accurate and precise • Better data = better decisions
  24. 24. PAH Analysis • Many interferences exist in low molecular weight range – Depends on matrix, clean up method • Specificity of HRMS allows better accuracy and precision • Comes at a cost – 4-6x Difference in measuring 252 versus 252.30928 Benzo(a)pyrene
  25. 25. Internal Standards vs. Surrogates naphthalene phenanthrene benzo(a)pyrene N+ O O- F * * * * * *13 C * * * * ** * * * *
  26. 26. Isotope Dilution Quantification • Standards behave exactly like compounds being analyzed • Loss of analytes during method, included in measurement • Matrix interferences in method, can usually be seen with standards as well • THE most accurate measurement available
  27. 27. Is more expensive better? Experiment: • SRM – determine accuracy • Duplicate – determine precision • Unknown duplicates to compare results Compared methods, not laboratories Lab A – ID-HRMS Lab B- LRMS, surrogates
  28. 28. PAH Comparisons 0 0.2 0.4 0.6 0.8 1 1.2 AcenaphtheneAcenaphthylene Anthracene Benzo(a)anthraceneBenzo(a)pyrene Benzo(b)fluoranthene Benzo(g,h,i)perylene Benzo(k)fluoranthene Chrysene Dibenz(a.h)anthracene Fluoranthene Fluorene Indeno(1,2.3-cd)pyrene 2-Methylnaphthalene Naphthalene Phenanthrene Pyrene Certified SRM Value Lab A Lab B Compound Concentration(ng/g) Standard Reference Material Overestimation
  29. 29. PAH Duplicate Results 0 20 40 60 80 100 120 BaA BaP BbF BkF CHRY FLUOR PHEN PYR Sample 1 Sample 2 0 20 40 60 80 100 120 BaA BaP BbF BkF CHRY FLUOR PHEN PYR Sample 1 Sample 2 Compounds Compounds Concentration (ng/g) Concentration (ng/g) Lab B Lab A 100% 92% 111% 100% 86% 94% 101% 90% RPD 3% 8% 15% 16% 18% 17% 27% 11% RPD
  30. 30. 0 5000 10000 15000 20000 25000 30000 35000 ACE ACY NAP 2-NAP FLR ANT PHEN FLUOR PYR BAA CHRY BBF BKF BAP B(ghi)P DB(ah)A IND 0 100 200 300 400 500 600 700 800 900 1000 ACE ACY NAP 2-NAP FLR ANT PHEN FLUOR PYR BAA CHRY BBF BKF BAP B(ghi)P DB(ah)A IND Results of On-Site Samples (unknowns) LRMS Method HRMS Method
  31. 31. Causes of Overestimation • Incomplete cleanup, residue matrix in extracts • Co-elution of other PAHs not being monitored
  32. 32. Data Quality for PAHs • Low resolution surrogate MS methods for PAHs can be highly variable between laboratories • Sites driven by PAH risk require IDMS – Sensitivity – for the guidelines – Specificity – for the interferences that are naturally present in samples • IDMS methods are suggested for forensics investigations – May reduce variability of diagnostic ratios
  33. 33. Diagnostic Ratios Ratios Values / Sources References Phenanthrene / Anthracene < 5 = Pyrogenic; > 5 = Petrogenic Neff et al., 2005 Fluorene / Pyrene + 1 = Pyrogenic. < 1 = Petrogenic Neff et al., 2005 Indeno(1,2,3-cd)pyrene / (Indeno(1,2,3-cd)pyrene + Benzo(g,h,i)perylene > 0.1 = Combustion Motelay-Massei et al 2007; Yunker et al., 2002 Fluoranthrene/ Pyrene < 1 = Petrogenic; >1 Pyrogenic Motelay-Massei et al 2007 LMW / HMW < 1 = Combustion Zhang et al 2005; Benzo(a)pyrene / Benzo(a)pyrene + Chrysene < 0.2 = Petrogenic; > 0.35 = Combustion Zhang et al 2005; Zhang et al 2007 • Decrease analytical variability with better methods • Some good, some not as good – use what fits? • Good for bulk characterization – what about further distinction of sources
  34. 34. Expanding the List of PAHs Alkylated-PAHs and Other PAHs C1-Phenanthrenes 1 2 3456 7 8 9 10 CH3 C2-Phenanthrenes Phenanthrene CH3 CH3 CH3 H3C CH2 CH3 C3-Phenanthrenes C4-Phenanthrenes… (?) CH3 CH3 CH3 CH2 H2C CH3 (5) (30) (?)
  35. 35. Chromatography Gets Busy C1-DBT C2-DBT C3-DBT C4-DBT
  36. 36. Additional PAHs – Biogenic (transformation of natural precursors) • Yulin et al. (1996) Biogenic Polycyclic Aromatic Hydrocarbons in an Alaskan Arctic Lake Sediment, Polycyclic Aromatic Compounds, 9(1-4). – Petrogenic (fossil fuels) – Pyrogenic (burning of organic materials) Phenanthrene Retene Perylene Click here for past blog on retene.
  37. 37. Petrogenic vs. Pyrogenic
  38. 38. Advanced – 2D-GC-TOF-MS • Cost – Highest • Interpretation – Difficult • Time – slow • Can look for anything organic • Advantage – separation + mass spectra id + sensitivity • Can be qualitative or semi-quantitative Diesel – Gas Station - Canada
  39. 39. Middle East Crude Oil Investigation Alkyl Phenanthrenes/Anthracenes Alkyl Naphthalenes Alkyl Benzenes Alkanes
  40. 40. Middle East Crude Oil 1 Saskatchewan Crude Middle East Crude Oil 2 Middle East Crude Oil 3 Middle East Crude Oil Investigation
  41. 41. 41 Stable Isotopes – CSIA “DNA” Fingerprinting -40 -35 -30 -25 -20 -15 δ13 C(‰) Compound • Stable isotope data gives a “signature” to samples • Samples may be linked or differentiated O
  42. 42. Case Study Residents have allegedly been exposed to PAHs released from a local industry. Exposure pathways include inhalation of ambient air and incidental ingestion of soil
  43. 43. Investigation A number of techniques were completed including: – Chemical fingerprinting – Molecular diagnostic ratios – Statistical Analysis • Cosine Theta Analysis
  44. 44. Sampling
  45. 45. 45 Suspected Source Unknown Human Habitation/ Background Chemical Fingerprint
  46. 46. Molecular Diagnostic Ratios 0 2 4 6 8 10 12 14 16 18 20 0.0 0.5 1.0 1.5 2.0 2.5 FLRN/PYR PHEN/ANTH Unknown Human Habitation Suspected Source Petrogenic Sources After Sicre et al 1987, Budzinski et al 1997, Tam et al 2001 and Neff et al 2005 Mixed Sources Pyrolytic SourcesMixed Sources
  47. 47. Cosine Theta Analysis An analysis of the matrix of similarity coefficients between several different samplesOrthogonal Dissimilar Co-linear, similar compositions Theoretical Vector 1.00, 0o Theoretical Vector 0.00, 90o Human Habitation/Background 0.995 Suspected Source 0.586 Unknown
  48. 48. Results of Study –Independent lines of evidence were developed to indicate the potential source of PAHs in soils –Multiple forensic techniques supported these lines of evidence –Conclusion: PAHs found at residence shared similar properties to those of human habitation or background – Not similar to the suspected source
  49. 49. Environmental Forensics in the Gulf Oil Spill • Reddy et al. sampled oil directly above well to conduct comprehensive characterization – Gas isotopes, GOR, fluid characteristics, API etc. – Fingerprinted with 2D-GC-TOF – Could distinguish between crudes Reddy et al. 2011, PNAS Early Edition, p.1-6
  50. 50. Environmental Forensics in the Gulf Oil Spill • Hall et al. took 41 samples (slicks, scrapings off rocks, grasses and debris, sand patties etc) • Oxidized hydrocarbons comprised of more than 50% of extractable hydrocarbons • Used 2D-GC-TOF of samples compared to oil to assess weathering of oil spill using chemometric techniques Hall et al. 2013, Marine Pollution Bulletin, in press
  51. 51. Environmental Forensics in the Oil Sands
  52. 52. Environmental Forensics in the Oil Sands
  53. 53. Alberta Oil Sands • Discovered by aboriginals and used to waterproof canoes – “tar sands” – “Tar sands” is a dirty term • In 1719, European fur traders received sample at Hudson’s Bay Company • In 1783, first European saw them personally • Development began in 1967 by (now known as) Suncor
  54. 54. Environmental Forensics in the Oil Sands • 2009 Kelly et al. (Schindler) examined water and snow PAHs near oil sands development • Upstream [PAC] < downstream [PAC] (p<0.05) • Study was generally ignored by industry but is cited as the first attempt to assess environmental impacts from oil sands development Kelly et al. 2009, PNAS, 106, 52, p.22346
  55. 55. Environmental Forensics in the Oil Sands • Kurek et al. sampled local lake sediments (no flow) • Sediment dating (Pb/Cs) combined with PAH analysis • PAHs sharply increased in lake sediments in ~1970 (but are still well below guidelines) • Important study: – Demonstrated that inputs were occurring – Established historical baseline (hadn’t been done previously) • No longer a question of if, now it is question of how much Kurek et al. 2013, PNAS, 110, 5, p.1761
  56. 56. Environmental Forensics in the Oil Sands • Jautzy et al. sampled local lake sediments (no flow) • Sediment dating (Pb/Cs) combined with PAH analysis & compound specific isotopic analysis • Additional line of evidence showing isotope shift in DBT • Increase due to deposition of bitumen in dust particles with erosion of open pit mines Jautzy et al. 2013, ES&T, 47, p.6155
  57. 57. Environmental Forensics in the Oil Sands • Lundin et al. sampled scat from wolf, moose and caribou around SAGD facilities • DNA testing, hormone testing, scat detection dogs, etc. • Higher concentrations of PAHs (NAP and alkyl-NAP) in moose scat near SAGD compared to control locations • Suggests that SAGD facilities may still be implicated Lundin et al. 2013, ISPAC 2013, Tues,11:00 AM
  58. 58. Environmental Forensics Resources
  59. 59. Societies and Organizations • International Network of Environmental Forensics (INEF) • Association for Environmental Health & Sciences (AEHS) Foundation • International Society of Environmental Forensics (ISEF)
  60. 60. University Degrees and Training • Masters degree – University of Strathclyde • Bachelor Degree – Bangor University • University of Florida – Certificate program • Many courses on Environmental Forensics offered at Universities • Environmental Forensics certification (AEHS Foundation and others)
  61. 61. Questions? Contact Info: Chemistry Matters Court Sandau Email: Twitter: @Chem_Matters Slideshare: Please visit our website for related information, case studies and blogs. Got a question, post it to our website, HERE.