1. Introduction Experimental Methods Conclusions Emissions of volatile organic compounds and particulate matter from small-scale peat fires I. George 1, R. Black 1,2, J. Walker 1, M. Hays 1, B. Preston 3, D. Tabor 1, B. Gullett 1 1 U.S. Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC 27711. 2 ORISE Fellow. 3 Arcadis, Durham, NC 27713. Email: george.ingrid@epa.gov. #A31C-0076 Volatile Organic Compounds Organic PM Characterization PM2.5 Mass, OC, EC  Peatland contains a significant fraction of terrestrial organic carbon and may become more vulnerable to fire due to human activities and climate change.  Air pollution emitted from peat fires can negatively impact regional air quality, visibility, climate and human health (Page et al., 2002; Rappold et al., 2011).  Peat fires tend to smolder over long periods of time and can release greater amounts of carbon into the atmosphere per unit area compared to burning of other types of biomass.  Despite the potential negative environmental impacts of peat fires, the gas and particulate emissions from peat burning have been poorly characterized.  The objective of this study was to quantify particulate matter (PM) and volatile organic compounds (VOCs) from controlled small-scale peat fire experiments to assess the atmospheric impact of peat burning emissions.  Peat samples were collected in two locations near the NC coast. Table 1 summarizes the composition of the samples.  Laboratory burning experiments of the peat samples were conducted in an open burning test facility located at Research Triangle Park, NC.  Continuous CO 2, CO, THC and O 2 were measured with a continuous emissions monitor (CEM). Typical CEM measurements for a burn test are shown in Figure 1.  VOCs were sampled using Summa canisters and analyzed by EPA Method TO-15 and gas-phase carbonyls were sampled and analyzed using EPA Method TO-11A.  OC, EC and organic particulate matter (PM) speciation analyses were conducted with Thermal Optical Analyzer and GC-MS on extracts of quartz filter samples taken during burning experiments, and PM2.5 mass was determined from teflon filter samples.  Emission factors (g/kg fuel burned) were calculated by the following equation: where C x is concentration of compound X (g/m 3 ), Q is dilution flow rate (m 3 /min), t is sampling time (min), M fb is mass of fuel burned (kg) determined from CO 2 and CO emitted. Table 1. Chemical composition of peat samples. Figure 1. Example CEM measurements for peat burn. MCE = ([CO2]/([CO 2 ]+[CO])). Figure 3. Emission factors for PM2.5 organic compounds: A) straight-chained alkanes and B) PAHs. Figure 2. Emission factors for A) VOCs and B) gas-phase carbonyls. Figure 4. PM2.5, OC and EC emission factors and EC/OC ratios averaged over 1 st and 2 nd half of burn tests. Figure 5. Organic chemical classes as fraction of PM2.5 mass averaged over 1 st and 2 nd half of burn tests. EF = C x × Q × t M fb AB  Highest emissions of VOCs from peat burning included propylene, BTEX, chloromethane (Figure 2A)  Acetaldehyde, formaldehyde and acetone had the highest EFs of gas-phase carbonyls (Figure 2B).  Pocosin sample had greater VOC and carbonyl emissions consistent with its higher carbon content.  Stumpy point peat produced greater CH 3 Cl as it has a higher Cl content.  Literature EF values are somewhat higher than measured in this work.  Several classes of organic compounds present in the PM organic fraction were quantified including alkanes, polycyclic aromatic hydrocarbons (PAHs), methoxyphenols and levoglucosan.  Straight-chained alkanes (Figure 3A) made up 0.6-9% of organic PM mass and indicate an odd over even carbon preference (odd/even ~1.3).  PAHs (Figure 3B) and methoxyphenols each made up less than 1% of the organic PM mass.  Major biomass burning biomarkers were detected in PM, including levoglucosan, retene, syringaldehyde, vanillin.  PM2.5 mass EF values ranged from ~0.1-22 g/kg with higher values observed during the first half of the burn tests (Figure 4).  OC mass made up a significant fraction of the PM2.5 mass.  EC/OC ratios were in the range of 0.002-0.05 and were consistent with literature values for peat fires.  The known OC fraction was composed mostly of alkanes and levoglucosan, the latter making up 0.06-10% of PM2.5 mass  First study to report emission factors of both gas- and particle-phase chemically-speciated organics from peat fires.  Emissions of toxic VOCs such as BTEX, chloromethane, formaldehyde, acetaldehyde and acrolein varied based on peat composition.  PM mass consisted mostly of organic matter, of which alkanes and levoglucosan made up significant fractions.  Several important biomass burning tracers were quantified in PM mass.  This work will improve the accuracy of models to predict the atmospheric and health impacts of peat fires. 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