Biomonitoring of Human Exposure to Biomass Burning -- A Proposed Collaboration with GA Tech

1. Biomonitoring of Human Exposure to Biomass Burning -- A Proposed Collaboration with GA Tech Zheng (Jane) Li, Courtney D Sandau PAH and Combustion Exposure Biomarker Section Organic Analytical Toxicology Branch Division of Laboratory Sciences National Center for Environmental Health Centers for Disease Control and Prevention Atlanta, GA 30341

2. What is Biomarker? Biomarkers of exposure refer to cellular, biochemical, analytical, or molecular measures that are obtained from biological media such as tissues, cells, or fluids and are indicative of exposure to an agent.

3. What is Biomonitoring? Assessment of internal dose exposure by measuring a toxicant, or its metabolite or reaction product (biomarker) in human blood, urine, saliva, adipose, or other tissue

4. Location: nearness to source External dose: air, water, food, soil inhalation ingestion Exposure skin absorption assessment Internal dose: blood, serum, urine, tissue Biologically effective dose: blood, tissue Health effects assessment Health effect Exposure and health effects pathway

5. Air levels Water levels Soil/dust levels Food levels Nutritional status Predicted levels of toxicants in people Mathematical Modeling Lifestyle factors Personal habits Genetic factors Lung, intestine and skin absorption coefficients MANY OTHER FACTORS Predictinglevels of toxicants in people using environmental monitoringis very difficult and includes many assumptions Instead of predicting, we measure levels of chemicals in people

6. Biomonitoring provides unique information for -- • The public health response to a known or suspected excessive exposure to a toxicant(s) or a pollutant(s). • Health research to determine what toxicants and what internal dose levels cause disease or death • Human data significantly decrease uncertaintyin assessing human risk

7. National Report on Human Exposure to Environmental Chemicals (NHANES) http://www.cdc.gov/exposurereport 2003 – 2nd NHANES report 116 Chemicals 14 OH-PAHs: 1-OH-pyrene 3-OH-fluoranthene 2/3-OH-fluorene 1/2/3-OH-phenanthrene 3/6-OH chrysene 1/3-OH-benz[a]anthracene 1/2/3-OH-benzo[c] phenanthrene 2001 1st NHANES report released 27 chemicals

8. PAH & Combustion Exposure Biomarker Laboratory • CDC currently monitors Group A (2-4 aromatic ring) PAH-OH metabolites, conducted in our laboratory • Newly developed method has LOD for most of 23 OH-PAHs at low ppt • Expanding to include metabolites of Group B (5 and more aromatic ring, e.g. OH-benzo[a]pyrene), and amino-PAHs, metabolites of NO2-PAH. • Initializing and developing methods to monitor human exposure to biomass burning

9. Exposure Study on Biomass Burning – a Challenge • Large emissions • Numerous classes and uncountable chemicals released in biomass fires • Various emission profiles from different burning sources • Particles and aerosols with organic compounds condensed on the surface can be transported over long distance

10. Emissions From Biomass Burning CO, NOX, SO2, O3 Particulate Matter PAHs and alkyl PAHs Resin acids Anhydrosugars, e.g. levoglucosan PCDD and PCDF Alkyl amides and nitriles Many others… Methoxyphenols

11. Potential Markers for Biomass Burning -- Methoxyphenols • One major group of compounds studied as biomarkers • Softwood guaiacyl compds • Hardwood syringyl compds • A urinary assay of methoxyphenols for biomonitoring wood smoke exposure has been developed

12. Potential Markers for Biomass Burning -- PAHs • A major group of organic pollutants formed during incomplete combustion • Mutagenic and carcinogenic • Most abundant ones are pyrene, phenanthrene, fluoranthene, benzo(a/e)pyrene, chrysene, etc. • Alkyl-PAHs, e.g. pimanthrene and retene, suggested to be the major source specific biomarkers in pine smoke

13. PAHs, Source-specific Markers • Relative amounts of alkyl-PAHs to the parent PAHs – petrogenic source vs. combustion source • Relative amounts of unstable or kinetic PAHs to the more stable or thermodynamic PAHs – combustion or anthropogenic input • Acenaphthene and acenaphthylene – combustion source; cadalene and retene – plant source

14. Analytical Techniques • Extraction • Solid phase extraction (SPE) or silica/florisil column for further sample clean up • Gas chromatography/mass spectrometry • GC/Time-of-flight (TOF) MS • GC x GC/TOFMS • GC/high-resolution MS • Isotope dilution for precise and accurate measurements

15. 2-fluo 19 OH-PAH mix 6 minutes 3-fluo 1-nap 1-,2-,3-,4-,9-phen 2-nap 1-pyr 9-fluo 1-bcp 3-flran 3-chry 3-baa 1-baa 3-bcp 2-bcp 6-chry Identification of Unknown Markers -- GC/TOFMS LECO Pegasus III Fast GC/TOFMS Separation Full Scan Extensive library search Unknown peak identification De-convolution

16. Identification of Unknowns -- GC x GC/TOFMS • 4-Dimensional GC x GC-TOFMS • Two distinctive separation mechanisms, such as polar and non-polar • Improving resolution, reducing chromatographic co-elution – more accurate analyte identifications • Ideal for obtaining maximum information from complex samples

17. GC x GC/TOFMS Contour plot Mixture of 58 compds: 37 PCBs 11 PPs 1 BB 8 BDEs Courtesy slide from Jef Focant

18. GC x GC/TOFMS Contour plot Shade surface plot Courtesy slide from Jef Focant

19. Objectives • Identify source-specific markers for biomass combustions • Verify and confirm reported markers • Search for new ones • Identify optimal metabolites in human body for biomonitoring • Parent compounds or metabolites • Urine or blood • Perform studies on populations exposed to biomass burning

20. Possible Population/Field Studies • Exposure assessment to indoor air pollution caused by domestic biomass burning in developing countries, e.g. China, India, etc. • Occupational and residential exposure to forest fires • Exposure study on large scale agricultural burning, e.g. sugarcane burning in Brazil and Costa Rica

21. Thank You!