Biomonitoring of Human Biomonitoring of Human Exposure to Biomass Burning Exposure to Biomass Burning

-- A Proposed Collaboration -- A Proposed Collaboration with GA Techwith GA Tech

Zheng (Jane) Li, Courtney D SandauZheng (Jane) Li, Courtney D Sandau

PAH and Combustion Exposure Biomarker SectionPAH and Combustion Exposure Biomarker SectionOrganic Analytical Toxicology BranchOrganic Analytical Toxicology Branch

Division of Laboratory SciencesDivision of Laboratory SciencesNational Center for Environmental HealthNational Center for Environmental Health

Centers for Disease Control and PreventionCenters for Disease Control and PreventionAtlanta, GA 30341Atlanta, GA 30341

What is Biomarker?What is Biomarker?

Biomarkers of exposure refer to Biomarkers of exposure refer to cellular, biochemical, cellular, biochemical, analyticalanalytical, or , or molecular measures that are obtained molecular measures that are obtained from biological media such as tissues, from biological media such as tissues, cells, or cells, or fluidsfluids and are indicative of and are indicative of exposure to an agent. exposure to an agent.

What is Biomonitoring?What is Biomonitoring?

AAssessment of internal dose exposure by measuring a toxicant, or its metabolite or reaction product (biomarker) in human blood, urine, saliva, adipose, or other tissue

Exposure and health effects Exposure and health effects pathwaypathway

External dose: air, water, food, soil

Internal dose: blood, serum, urine, tissue

Biologically effective dose: blood, tissue

Health effect

inhalationingestionskin absorption

Exposureassessment

Health effectsassessment

Location: nearness to source

PredictingPredicting levels of toxicants in people using environmental monitoringlevels of toxicants in people using environmental monitoringis very difficult and includes many assumptionsis very difficult and includes many assumptions

MathematicalModeling

Air levelsWater levels

Soil/dust levels

Food levels

Lifestyle factors

Personal habits

Nutritional status

Genetic factors

Lung, intestine and skin absorption coefficients

MANY OTHER FACTORS

Predictedlevels of toxicants

in people

Instead of predicting, we measure levels of chemicals in people

Biomonitoring provides unique Biomonitoring provides unique information for --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 uncertainty in assessing human risk

National Report on Human National Report on Human Exposure to Environmental Exposure to Environmental Chemicals (NHANES)Chemicals (NHANES)

http://www.cdc.gov/exposurereport

2001

1st NHANES report released

27 chemicals

2003 – 2nd NHANES report

116 Chemicals14 OH-PAHs:1-OH-pyrene3-OH-fluoranthene2/3-OH-fluorene1/2/3-OH-phenanthrene3/6-OH chrysene1/3-OH-benz[a]anthracene1/2/3-OH-benzo[c] phenanthrene

PAH & Combustion Exposure PAH & Combustion Exposure Biomarker LaboratoryBiomarker Laboratory

• CDC currently monitors Group A (2-4 aromatic CDC currently monitors Group A (2-4 aromatic ring) PAH-OH metabolites, conducted in our ring) PAH-OH metabolites, conducted in our laboratorylaboratory

• Newly developed method has LOD for most of 23 Newly developed method has LOD for most of 23 OH-PAHs at low pptOH-PAHs at low ppt

• Expanding to include metabolites of Group B (5 Expanding to include metabolites of Group B (5 and more aromatic ring, e.g. OH-benzo[a]pyrene), and more aromatic ring, e.g. OH-benzo[a]pyrene), and amino-PAHs, metabolites of NOand amino-PAHs, metabolites of NO22-PAH.-PAH.

• Initializing and developing methods to monitor Initializing and developing methods to monitor human exposure to biomass burninghuman exposure to biomass burning

Exposure Study on Biomass Exposure Study on Biomass Burning – a ChallengeBurning – a Challenge

• Large emissionsLarge emissions

• Numerous classes and uncountable Numerous classes and uncountable chemicals released in biomass fireschemicals released in biomass fires

• Various emission profiles from different Various emission profiles from different burning sourcesburning sources

• Particles and aerosols with organic Particles and aerosols with organic compounds condensed on the surface compounds condensed on the surface can be transported over long distancecan be transported over long distance

Emissions From Biomass Emissions From Biomass BurningBurning

CO, NOX, SO2, O3

Particulate Matter

Resin acids PAHs and alkyl PAHs

Anhydrosugars,e.g. levoglucosan

Methoxyphenols

PCDD and PCDF

Many others…Alkyl amides and nitriles

• One major group of compounds studied as One major group of compounds studied as biomarkersbiomarkers

• Softwood guaiacyl compdsSoftwood guaiacyl compds

• Hardwood syringyl compdsHardwood syringyl compds

• A urinary assay of methoxyphenols for A urinary assay of methoxyphenols for biomonitoring wood smoke exposure has biomonitoring wood smoke exposure has been developedbeen developed

Potential Markers for Biomass Potential Markers for Biomass Burning -- Methoxyphenols Burning -- Methoxyphenols

R

OCH3

OH

R

OCH3

OH

H3CO

• A major group of organic pollutants formed A major group of organic pollutants formed during incomplete combustionduring incomplete combustion

• Mutagenic and carcinogenicMutagenic and carcinogenic

• Most abundant ones are pyrene, Most abundant ones are pyrene, phenanthrene, fluoranthene, phenanthrene, fluoranthene, benzo(a/e)pyrene, chrysene, etc.benzo(a/e)pyrene, chrysene, etc.

• Alkyl-PAHs, e.g. pimanthrene and retene, Alkyl-PAHs, e.g. pimanthrene and retene, suggested to be the major source specific suggested to be the major source specific biomarkers in pine smokebiomarkers in pine smoke

Potential Markers for Biomass Potential Markers for Biomass Burning -- PAHs Burning -- PAHs

• Relative amounts of alkyl-PAHs to the Relative amounts of alkyl-PAHs to the parent PAHs – petrogenic source vs. parent PAHs – petrogenic source vs. combustion sourcecombustion source

• Relative amounts of unstable or kinetic Relative amounts of unstable or kinetic PAHs to the more stable or thermodynamic PAHs to the more stable or thermodynamic PAHs – combustion or anthropogenic inputPAHs – combustion or anthropogenic input

• Acenaphthene and acenaphthylene – Acenaphthene and acenaphthylene – combustion source; cadalene and retene – combustion source; cadalene and retene – plant sourceplant source

PAHs, Source-specific MarkersPAHs, Source-specific Markers

Analytical TechniquesAnalytical Techniques

• Extraction Extraction • Solid phase extraction (SPE) or silica/florisil Solid phase extraction (SPE) or silica/florisil

column for further sample clean upcolumn for further sample clean up• Gas chromatography/mass spectrometryGas chromatography/mass spectrometry

– GC/Time-of-flight (TOF) MS GC/Time-of-flight (TOF) MS – GC x GC/TOFMSGC x GC/TOFMS– GC/high-resolution MSGC/high-resolution MS

• Isotope dilution for precise and accurate Isotope dilution for precise and accurate measurementsmeasurements

Identification of Unknown Identification of Unknown Markers -- GC/TOFMS Markers -- GC/TOFMS

19 OH-PAH mix6 minutes

1-n

ap

2-n

ap

9-fl

uo

3-fl

uo

2-fl

uo

1-,2-,3-,4-,9-phen

1-b

cp

2-b

cp 1-b

aa

6-

chry 3

-bcp

3-

chry

3-b

aa

3-

flra

n1-p

yr

LECO Pegasus III

Fast GC/TOFMS Separation

Full Scan Extensive library searchUnknown peak identification

De-convolution

Identification of Unknowns -- GC x Identification of Unknowns -- GC x GC/TOFMSGC/TOFMS

• 4-Dimensional GC x GC-TOFMS4-Dimensional GC x GC-TOFMS• Two distinctive separation Two distinctive separation

mechanisms, such as polar and non-mechanisms, such as polar and non-polarpolar

• Improving resolution, reducing Improving resolution, reducing chromatographic co-elution – more chromatographic co-elution – more accurate analyte identificationsaccurate analyte identifications

• Ideal for obtaining maximum Ideal for obtaining maximum information from complex samples information from complex samples

GC x GC/TOFMS GC x GC/TOFMS

Contour plot

Mixture of 58 compds:

37 PCBs11 PPs1 BB

8 BDEs

Courtesy slide from Jef Focant

GC x GC/TOFMS GC x GC/TOFMS

Contour plot Shade surface plot

Courtesy slide from Jef Focant

ObjectivesObjectives

• Identify source-specific markers for Identify source-specific markers for biomass combustions biomass combustions – Verify and confirm reported markersVerify and confirm reported markers– Search for new onesSearch for new ones

• Identify optimal metabolites in human Identify optimal metabolites in human body for biomonitoring body for biomonitoring – Parent compounds or metabolitesParent compounds or metabolites– Urine or bloodUrine or blood

• Perform studies on populations exposed to Perform studies on populations exposed to biomass burningbiomass burning

Possible Population/Field Possible Population/Field StudiesStudies

• Exposure assessment to indoor air pollution Exposure assessment to indoor air pollution caused by domestic biomass burning in caused by domestic biomass burning in developing countries, e.g. China, India, etc.developing countries, e.g. China, India, etc.

• Occupational and residential exposure to Occupational and residential exposure to forest firesforest fires

• Exposure study on large scale agricultural Exposure study on large scale agricultural burning, e.g. sugarcane burning in Brazil burning, e.g. sugarcane burning in Brazil and Costa Ricaand Costa Rica