Aerosol Chemistry and Physics - Aerosols: Measurement, Dosimetry, and Health Effects - page 143

TABLE 6.5
Emission Factors (g kg −1 ) for Species from Biomass Burning

Open
Cooking

Patsari
Stoves

Charcoal
Burning

Dung
Burning Compound Chaparral

Carbon dioxide 1700 1500 1600 2400 900

Carbon monoxide 67 77 42 190 110

Methane 2.5 4.9 2.3 5.3 11

Total suspended particulate 15 4.6 3.3 2.4 —

Total particulate carbon — — — — 23

PM 2.5 12 6.6 — — —

Black carbon 1.3 0.83 0.74 1.0 0.53

Organic carbon 3.7 2.9 1.9 1.3 1.8

Source: Adapted from Akagi, S.K. et al., Atmos. Chem. Phys ., 11, 4039, 2011.

During a winter in Tibet, homes that used SBF for heating and cooking averaged roughly four
times higher average PM 2.5 concentrations (200 μg m −3 ) than homes that used methane (Gao et al.,
2009). Similarly, Siddiqui et al. (2009) found that indoor cooking with wood led to mean PM 2.5
concentrations in kitchens of 2.7 mg m −3 in semi-rural community in Pakistan. In kitchens with
natural gas fuel, PM 2.5 averaged 0.4 mg m −3 .

6.2.1.2 Fireplaces
Schauer et al. (2001) found PM 2.5 emission factors of 5-10 g kg −1 for several types of wood burned in a
ireplace, in general agreement with results of other investigators (Hildemann et al., 1991; McDonald
et al., 2000). Figure 6.4 illustrates the results of Schauer et al. for the composition of wood smoke from
pine and oak burning, at the top and bottom, respectively. When wood burns, its oxygenated organic
polymers (cellulose and lignins) decompose to distinctive fragments. Schauer et al. (2001) found that
18%-31% of the ine particulate organic carbon mass from wood burning was levoglucosan, a pyrolysis
product of cellulose. Hornig et al. (1984) suggested the use of this sugar anhydride as a wood smoke
marker. Methoxyphenols and resin acids are the next most abundant classes of identiied components
of ine wood smoke particles. Methoxyphenols are pyrolysis products of lignin, a biopolymer that
trees synthesize from aromatic vinyl alcohols to strengthen their cellulose frameworks.
Methoxyphenols from different types of wood yield characteristic composition patterns that can
be used as tracers (syringols for oak; guaiacols for pine and oak; Rogge et al., 1998; McDonald
et al., 2000; Schauer et al., 2001). Methoxyphenols are also found in the gas phase of wood smoke,
along with aldehydes, dicarbonyls, alkenes, and other compounds. Many wood smoke components
are irritants, some are genotoxic, and others (e.g., terpenes) can react with other indoor pollutants.

6.2.1.3 Tobacco
Although a wide range of tobacco smoke constituents have been identiied (Jenkins et al., 2000),
the most detailed characterization of secondhand smoke (SHS) (an updated term for environmental
tobacco smoke) composition was done by Rogge et al. (1994) who sampled exhaled mainstream
smoke and sidestream smoke in a vertical dilution tunnel. PM 2.5 emission factors are roughly 10-20 mg
cig −1 (Hildemann et al., 1991; Gundel et al., 1995, among others). Rogge et al. reported that nitrogen-
containing heterocyclic compounds are the most abundant class, when gas- and particulate-phase
concentrations of nicotine are included with other particulate N-compounds. Since nicotine is primarily
in the gas phase in fresh SHS, and very soon after emission it sorbs to indoor surfaces, its use as a
tracer for SHS exposure requires meeting particular conditions (Daisey, 1999). Nicotine, a tobacco-
speciic compound, is commonly used as a tracer for tobacco smoke exposure indoors (Hammond and