Chemical characterization of fine particle emissions from the fireplace combustion of wood types grown in the Midwestern and Western United States

Results are presented from a series of source tests on the fireplace combustion of 10 wood species found in the Midwestern and Western United States: white oak, sugar maple, black oak, American beech, black cherry, white spruce, quaking aspen, douglas fir, ponderosa pine, and pinyon pine. Fine particle emission factors for total mass, organic, and elemental carbon, ionic species, elemental species including potassium, and over 250 individual organic compounds were determined. The data are intended for use in apportionment studies that utilize particulate organic compounds as specific tracers to identify the sources of ambient fine particles. The cellulose pyrolysis products levoglucosan, mannosan, and galactosan were quantified in each of the wood smokes studied; they act as molecular tracers for cellulose from combustion of all wood types. Differences in the emission rates of syringol- and guaiacol-type phenolic compounds from lignin and of resin acids can be used to distinguish between hardwood and softwood smoke emissions. The triterpenoid, friedelin, known to be present in the bark of white oak, is emitted in significant quantities from white oak combustion, but was not found in the emissions from any other North American wood species. Friedelin can potentially be utilized to trace particulate emissions back to specific geographic regions where white oak is used for firewood. These results, along with previously published data from the other U.S. regions, provide a complete set of emission factors of the prevalent chemical species found in wood smoke throughout the United States.