Emission factors for carbonaceous particles and polycyclic aromatic hydrocarbons from residential coal combustion in China

Article abstract of DOI:10.1021/es0493650

Emission factors of carbonaceous particles, including black carbon (BC) and organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) were determined for five coals, which ranged in maturity from sub-bituminous to anthracite. They were burned in the form of honeycomb briquettes in a residential coalstove, one of the most common fuel/stove combinations in China. Smoke samples were taken through dilution sampling equipment, with a high volume sampler that could simultaneously collect emissions in both particulate and gaseous phases, and a cascade impactor that could segregate particles into six fractions. Particulate BC and OC were analyzed by a thermal-optical method, and PAHs in emissions of both phases were analyzed by GC-MS. Burning of bituminous coals produced the highest emission factors of particulate matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20 PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf) coal, while the anthracite honeycomb-briquette was the cleanest household coal fuel. The size-segregated results show that more than 94% of the particles were submicron, and calculated mass median aerodynamic diameters (MMAD) of all particles were under 0.3 μm. Based on the coal consumption in the residential sector of China, 290.24 Gg (gigagrams) of particulate matter, 5.36 Gg of BC, 170.33 Gg of OC, and 4.72 Gg of 20 PAHs mass were emitted annually from household honeycomb-briquette burning during 2000. Anthracite coal should be selected preferentially and more advanced burning conditions should be applied in domestic combustion, from the viewpoint of both climate change and adverse health effects.

Full text of DOI:10.1021/es0493650

Environ. Sci. Technol. 2005, 39, 1861-1867
carbonaceous emissions is believed to originate from China,
of which about 70% is due to coal burning (4).
Emission Factors for Carbonaceous
Particles and Polycyclic Aromatic
Hydrocarbons from Residential Coal
Combustion in China
Carbonaceous particles are usually divided into two
fractions, black carbon (BC) and organic carbon (OC). BC
has a strong absorptivity of solar radiation (5) and therefore
contributes to significant climate effects (6). Menon et al. (7)
suggested that precipitation trends in China over the past
decades, with increased rainfall in the south and drought in
the north, might be related to increased BC aerosols. BC also
contributed to the marked degradation of optical depths and
visibility in northern China (8) and lowered the crop yields
in China by reducing solar radiation that reaches the earth
Y I N G J U N C H E N , G U O Y I N G S H E N G ,
X I N H U I B I , Y A N L I F E N G ,
B I X I A N M A I , A N D J I A M O F U *
State Key Laboratory of Organic Geochemistry,
Key Laboratory of Guang Dong for Utilization and Protection
of Environmental Resources, Guangzhou Institute of
Geochemistry, Chinese Academy of Sciences,
(
(
9). In addition, BC can have adverse effects on human health
10), because fine BC particles can adsorb toxic pollutants
and penetrate deeply into the lungs (11). OC has the optical
property of mainly scattering solar radiation, and the ratio
of OC to BC may affect the degree of radiative forcing of the
atmosphere (12). Furthermore, OC often contains toxic
organic compounds, such as polycylic aromatic hydrocarbons
(PAHs) and their alkylated homologues, which are noted
carcinogens (13) and mutagens (14).
Some estimates had been made on the carbonaceous
aerosol emissions from coal combustion in China, and these
differed greatly among each other (4, 15-17). These differ-
ences derived primarily from the different emission factors
assumed. Unfortunately, to our knowledge, few accurate
measurements on carbonaceous emission factors from coal
burning have been reported based on experiments. The
emission factor of BC (EFBC) was usually calculated indirectly
Guangzhou 510640, People’s Republic of China
Emission factors of carbonaceous particles, including
black carbon (BC) and organic carbon (OC), and polycyclic
aromatic hydrocarbons (PAHs) were determined for five
coals, which ranged in maturity from sub-bituminous
to anthracite. They were burned in the form of honeycomb
briquettes in a residential coalstove, one of the most
common fuel/stove combinations in China. Smoke samples
were taken through dilution sampling equipment, with a
high volume sampler that could simultaneously collect
emissions in both particulate and gaseous phases, and a
cascade impactor that could segregate particles into six
fractions. Particulate BC and OC were analyzed by a thermal-
optical method, and PAHs in emissions of both phases were
analyzed by GC-MS. Burning of bituminous coals
produced the highest emission factors of particulate
matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20
PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf)
coal, while the anthracite honeycomb-briquette was the
cleanest household coal fuel. The size-segregated results
show that more than 94% of the particles were submicron,
and calculated mass median aerodynamic diameters (MMAD)
of all particles were under 0.3 µm. Based on the coal
consumption in the residential sector of China, 290.24 Gg
by multiplying the emission factor of particulate matter (EFPM
)
by the BC fraction of particles (FBC), while few FBC values
from coal combustion were determined directly; therefore,
the uncertainties of BC emission estimates were very high
(
15). The emission factor of OC (EFOC) was estimated from
the EFBC and heterogeneous ratio of BC/OC, and different
values were assumed (4, 18). In fact, EFBC and EFOC can vary
greatly with coal/stove types, combustion conditions, and
even burning stages (19).
The primary goal of this paper is to accurately quantify
the emission factors of carbonaceous aerosol, including BC
and OC, and PAHs from residential coal combustion in China.
The residential sector is selected preferentially for two
reasons. First, residential coal burning contributes the
greatest part of the total carbonaceous emissions because of
poor combustion conditions and lack of emission controls
in China (15). Second, residential coal combustion results in
the greatest indoor exposure to particles and PAHs, which
may cause the most extensive health damage in China (20).
In this work, five coals, covering a wide range of maturity,
are chosen and burned in the form of honeycomb briquettes
combined with domestic coalstove, which is advocated by
the Chinese government as a clean-coal-combustion system
and is expected to greatly reduce particulate emissions.
(
gigagrams) of particulate matter, 5.36 Gg of BC, 170.33 Gg
of OC, and 4.72 Gg of 20 PAHs mass were emitted
annually from household honeycomb-briquette burning
during 2000. Anthracite coal should be selected preferentially
and more advanced burning conditions should be applied
in domestic combustion, from the viewpoint of both
climate change and adverse health effects.
Experimental Section
Coalstove and Sampling System. The characteristics of the
five coals selected are shown in Table 1. These five raw coals
were all produced from state-owned coal mines and cover
Introduction
There is considerable concern about carbonaceous aerosol
emissions from coal combustion in China, due to its potential
influence on climate change (1) and adverse effects on human
health (2). About 1.2 billion tons of coal is consumed annually
in China, equivalent to approximately 70% of the primary
energy consumption, and more than 80% is burned directly
a wide range of maturity (vitrinite reflectance (R
to 2.50%), including a sub-bituminous (JP), three bituminous
XW, YM, and XA), and an anthracite (YX). These raw coals
O
) from 0.52%
(
were powdered and intermixed with clay to produce hon-
eycomb briquettes with a machine. The briquettes were 12-
hole columns with a height of 6 cm and diameter of 9.5 cm.
The coalstove, the dilution sampling system, and the
emission sampling procedure were described in detail
(3). Therefore, roughly one-fourth of the global anthropogenic
*
Corresponding
author
phone:
86-2085290199;
fax:
8
6-2085290192; e-mail: fujm@gig.ac.cn.
1
0.1021/es0493650 CCC: $30.25

2005 American Chemical Society
VOL. 39, NO. 6, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
9
1861
Published on Web 02/01/2005

TABLE 1. Analytical Values of Five Raw Coals and Honeycomb Coal Briquettesa
JP
XW
YM
XA
YX
Proximate Analysis (wt (%), on air-dry (ad) basis)
a
moisture (Mad)
ash (Aad)
volatile (Vad)
fixed carbon (FCad)
3.33 (1.78)
7.83 (38.07)
35.55
1.16 (0.82)
37.66 (50.53)
27.82
0.85 (0.28)
20.79 (45.84)
23.30
0.90 (0.37)
13.78 (39.62)
21.47
1.22 (1.44)
8.82 (52.91)
6.68
53.29
33.36
55.06
63.85
83.28
Elemental Analysis (wt (%), on dry ash-free (daf) basis)
Cdaf
74.59
4.73
78.64
5.12
82.65
4.65
85.01
4.21
90.58
3.54
Hdaf
Ndaf
4.19
5.15
5.36
4.81
0.58
Odaf
16.22
0.28
10.24
0.86
5.72
1.61
4.22
1.76
0.050
0.050
1.70
1.92
0.67
0.039
0.210
2.50
Sdaf
H/C (daf)
0.063
0.217
0.52
0.065
0.130
1.12
0.056
0.069
1.27
O/C (daf)
vitrinite reflectance (RO (%))
a
Analytical values for honeycomb coal briquettes are listed in parentheses after the corresponding raw coals, only for moisture and ash contents
on an air-dry basis.
elsewhere (21) and are briefly summarized here. The coalstove
is the most common household stove for burning honeycomb
coal briquettes in China. It has a metallic outer cover and
thermal-insulated ceramic liner and can hold three briquettes
at one time. There is a 6 cm-diameter hole for air-control in
the outer cover near the bottom. The sampling system was
composed of a hood, three same-sized pipes, and a long
curved pipe, with a total volume of 270 L. All parts were
made of stainless steel, and Teflon was used for all gaskets
to avoid organic contamination. The samplers used included
a filter/PUF sampler, which could simultaneously collect
particulate and gaseous organic matter using a glass fiber
filter (GFF, 20 cm × 25 cm) and polyurethane foam (PUF, 6.5
cm diameter × 8 cm height) at the flow rate of 300 L/min,
and a size-segregation sampler (HiVol cascade impactor,
Thermo-Andersen Instrument Inc.), which could segregate
particles into six fractions with cutoff diameters of>7.2, 3.0-
54 and 14 s before being collected, respectively. No loss of
emissions and minor deposits in the pipes were observed.
Analytical Methods. The analytical procedure for PAHs
was given elsewhere (22), but a brief summary follows. Filter
samples were extracted ultrasonically three times with 150
mL of dichloromethane (DCM), and each extraction lasted
3
0 min. PUF samples were extracted for 72 h with DCM in
a Soxhlet apparatus. Surrogate deuterated PAHs were added
prior to extraction. The extracts were concentrated on a rotary
evaporator (B U¨ CHI Rotavapor R-114) and fractionated using
silica-alumina column chromatography. The PAH fractions
were concentrated using rotary evaporation followed by a
gentle stream of nitrogen, and internal standard (hexa-
methylbenzene) was added for quantification of individual
PAHs by GC-MS (HP-5890GC coupled with 5972MSD).
2
Portions of filter samples (1.5 cm ) were cut for analyzing
organic and elemental carbon contents (OC/EC) by a thermal-
optical carbon analyzer (Sunset Laboratory Inc., Forest Grove,
OR) with a modified NIOSH (National Institute of Oc-
cupational Safety and Health) thermal-optical transmission
7
.2, 1.5-3.0, 0.95-1.5, 0.49-0.95, and <0.49 µm at a flow
3
rate of 1.13 m /min. The laboratory room designed especially
for emissions testing had a filter system installed to provide
only particle-free air.
(
TOT) protocol (23). The punch aliquot of filter was heated
Sampling Procedure. The honeycomb coal briquettes
were ignited from the bottom using preweighed charcoal.
To reduce the interference from the igniting fire, the charcoal
was started with some paper and left to burn until the
temperature in the stove was high and smoking stopped,
and then the coal briquettes were placed into the stove.
Sampling periods lasted for 1.5-4 h, which started when the
coal briquettes were ignited and ended when the combustion
finished completely. The weights of honeycomb briquettes
before and after combustion were recorded to obtain the
actual weight of coal burned, which varied from 50 to 350
g, and about 10% of ash-free coal remained unburnt. The
air-control hole was fully opened to let the most air in during
combustion.
stepwise at temperatures of 310, 475, 575, and 650 °C in a
pure helium atmosphere for detecting the OC fraction, and
at temperatures of 550, 625, 700, 775, and 850 °C in an
oxidizing atmosphere of 2% oxygen (by volume) in a balance
of helium for detecting the EC fraction. The carbon evolved
at each temperature is oxidized to carbon dioxide (CO ) and
2
then reduced to methane (CH ) for quantification with a
4
flame ionization detector (FID). Some of OC pyrolyzes to EC
as the temperature increases in inert helium and is subtracted
from the elemental carbon area according to the initial laser
absorbance. At the end of every analysis, a fixed volume loop
of methane is injected automatically as an internal standard
to calculate the carbon results.
Quality Control. Field blanks and charcoal emission
samples were collected to determine background contami-
nation. As compared to coal emission samples, filter samples
for field blanks and charcoal emissions contained very low
particles and PAHs, while PUF samples of charcoal emissions
contained about 15% of the PAH concentrations of the coal
briquette emission samples. Therefore, the individual PAH
concentrations in charcoal PUF samples were subtracted
from coal emission samples. Surrogate standards were added
to all of the samples (including field blanks and charcoal
emissions) to monitor procedural performance and matrix
effects. The recoveries for deuterated PAHs ranged from 84%
to 105%, and PAH concentrations were corrected by the
recovery efficiency of the deuterated PAHs.
All parts of the sampling system in contact with the flue
gas were cleaned thoroughly before sampling, and the system
was checked for leakage after assembly. During sampling,
the hood was hung above the stove without touching to collect
the emissions but not disturb the burning. The curved pipe
was immersed into cool water, which further dropped the
flue gas temperature to ambient (23-31 °C). The actual
emission temperature in the flue was recorded every 10 min.
Because the greatest emission rate of flue gas from the stove
was measured to be 30 L/min, the dilution ratios of additional
clean air to the emissions were at least 9:1 and 37:1,
respectively, for the filter/PUF sampler and the cascade
impactor, while the residence times of flue gas were about
1
862
9
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 39, NO. 6, 2005

TABLE 2. Emission Factors (g/kg) of Particulate Matter, Black Carbon, and Organic Carbon from Honeycomb Briquette Combustion
of Five Coals Based on Burned Dry Ash-Free Coal Weight
sub-bituminous
bituminous
anthracite
JP
XW
YM
XA
geomean
12.911
0.283
YX
EFPM
8.001
0.096
4.729
49.312
59.11
1.20
19.550
0.675
13.818
20.483
70.68
3.45
14.134
0.523
9.656
18.474
68.32
3.70
7.788
0.064
3.580
1.329
0.004
0.017
4.807
1.31
EFBC
EFOC
7.817
OC/BC
OC/PM (%)
BC/PM (%)
56.085
45.97
0.82
27.686
60.55
2.19
0.27
The reproducibility of the collecting procedure was
checked in three separate experiments for the filter/PUF
sampler and in two experiments for the cascade impactor.
The two sets of six-stage samples were combined for analysis,
while the three sets of GFF/PUF samples were analyzed
separately. All of the analytical results of PAHs in GFFs and
PUFs are reported as the arithmetical mean values, because
the relative standard deviations (RSD) were less than 20%.
Three to five portions for each GFF sample were analyzed
in the OC/EC analyzer to eliminate the nonuniformity of
filter samples. The RSDs for OC and EC among three separate
sets of filters were smaller than 15%. Therefore, the arith-
metical mean values were calculated to represent the OC
and EC results of various coal-burning emission samples.
briquette or anthracite coal. However, honeycomb coal
briquettes are thought to have reduced particulate emissions
by 5-9 times as compared to raw coal (34). Zhang et al. (29)
reported different EFPM values of 8.73 and 0.27 g/kg for
unprocessed coal and honeycomb briquette, respectively,
using the same coal and stove, but the coal type and stove
they used were different from that in the present work. The
different values of EFPM reported may be attributed to the
different coals selected and the combustion conditions
including stove types and burning temperatures (35), and
the differences of EFPM for various coal types and burning
conditions may be obviously greater than that from bri-
quetting. That is to say, the expected reduction of EFPM caused
by briquetting of coal may be offset by the differences due
to coal maturities and combustion conditions. Therefore,
the EFPM data in this study were comparable with others.
Sampling methods may also affect the measurements. In
general, the emission rate during the first few minutes of
coal ignition is up to 50 times higher than that during the
remainder of the burning period (19, 24). As an example, a
very low value of EFPM (7 mg/kg) for coal briquette combus-
tion was measured by Oanh et al. (30), who excluded the fire
induction period from sampling to reduce contamination
by supplementary fuels for ignition.
Results and Discussion
Particulate Emissions. The emission factors of particulate
matter (EFPM) from honeycomb briquette combustion of five
coals (based on burned dry ash-free coal (daf)) are presented
in Table 2. There are pronounced differences across all of
the coals. Bituminous coals yield the highest EFPM, and the
average value is 12.9 g/kg, while sub-bituminous and
anthracite produce 8 and 1.3 g/kg of particles, respectively.
Among the three bituminous coals, EFPM of XW is the highest
(
19.6 g/kg).
It should be noted that choked burning conditions (the
inlet was partially blocked), which usually occur in domestic
coal-use, are not included in the present experiments.
However, high emissions can result from choked combustion.
Bond et al. (19) obtained different values of 12 ( 17 and 9
It is accepted that coals with high volatile content have
higher particulate emissions than coals with less volatiles.
EFPM for bituminous coal was found to be 20 times higher
than that for anthracite burned in same stove (24). However,
coal combustion involves a series of complicated chemical
reactions, including pyrolysis, bond cleavage, and tar forma-
tion and further thermal oxidation, etc. (25, 26). Under
residential burning conditions, coal tar may be released into
the flue and form significant particulate matter (19). This is
confirmed by fluorescence micrographs of filter samples in
the present work, where many micro-drops of coal tar were
observed on the filters, especially those from high volatiles
bituminous coals. Coal tar yield has been found to be related
to volatile content and coal rank. High volatile bituminous
forms the most tar, followed by sub-bituminous and an-
thracite coal (27). On the other hand, Radke et al. (28) showed
(
5 g/kg for sampling with and without inclusion of choked
combustion, respectively. That is to say, the emission factors
of particulate matter from the typical practice of residential
coal combustion should be somewhat higher than these
reported values.
Particle Size Distribution. The weights of particles
collected on the six stage filters were recorded for calculating
the mass percentage of each stage to total weight and the
mass median aerodynamic diameter (MMAD, particle di-
ameter where one-half of the particle mass is smaller and
the other half is larger (36)) (Table 3). Submicron particles
(sum of the fifth and sixth stages, aerodynamic diameter is
<0.95 µm) dominate the particulate mass emitted from
honeycomb coal briquettes combustion, and the calculated
MMAD values are about 0.29 µm. Factually, these freshly
emitted particles should be finer if the cutoff size of the last
stage (backup filter) of the size-segregated sampler is not
limited to 0.49 µm. Bond et al. (19) found that particles emitted
from coal briquette and bituminous coal are largely in the
nuclei mode (20-100 nm). For comparison, the results of
field- and laboratory-scale studies on emissions from pul-
verized coal combustors indicated that the particle size
distributions are typically bimodal, and the fine particle mode
is around 0.1 µm, which appears to result from vaporization-
condensation processes (37, 38). This means that the fine
particles from a domestic coalstove can penetrate deeper
into the alveolar regions of the lung and pose greater threat
to human health (39).
O
that bituminous coal yields the most tar when its R (vitrinite
reflectance, a measure of the geological maturity of the
organic matter) is around 0.9%. Therefore, as anticipated,
among three bituminous coals in the present study, XW (R
O
is 1.12%, the closest to 0.9%) yields the highest EFPM, followed
by YM and XA. The sub-bituminous coal (JP) only produces
a EFPM similar to that of XA, although its volatile content is
the highest, and the anthracite (YX) yields the lowest value.
There are some EFPM values for residential coal combus-
tion published in other studies (19, 24, 29-33), which are
generally similar to the present results. For example, Bond
et al. (19) reported a value of 12 ( 17 g/kg for bituminous
coal although it was burned as raw coal, very close to the
present result (12.9 g/kg). Streets et al. (15) recently calculated
the EFPM values for residential coal burning from previous
results and reported 8 g/kg for bituminous and 0.5 g/kg for
VOL. 39, NO. 6, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
9
1863

TABLE 3. Mass Percentage (%) for Particulate Fractions of Six Size Cuts to Total Emission Mass and Mass Median Aerodynamic
Diameters (MMAD) in Honeycomb Briquette Combustion Emissions from Five Coals
coal
>7.2 µm
3.0-7.2
1.5-3.0
0.95-1.5
0.49-0.95
<0.49 µm
MMAD (µm)
JP
0.87
1.03
0.98
1.03
0.80
1.32
1.86
0.92
1.14
1.05
1.25
1.86
1.26
1.03
1.05
2.08
2.77
2.80
1.99
2.24
6.16
7.83
10.70
12.73
6.54
88.32
84.65
83.33
82.08
88.31
0.28
0.29
0.29
0.30
0.28
XW
YM
XA
YX
It has been found that the residence time of particles
emitted into the atmosphere before being sampled and the
dilution ratio of air to the emissions can significantly affect
the total particle number concentration and size distribution,
and longer residence time will shift the particles to larger
sizes while a greater dilution ratio will increase the concen-
tration of ultrafine particles (40, 41). As mentioned above,
the residence time and dilution ratio in the present experi-
ments are about 14 s and 37:1, respectively, which are much
too small as compared to the actual situation in domestic
living. On other words, there are uncertainties about the
particle size distribution in field combustion. However, a
conclusion can be drawn at least that adverse health effects
will occur when exposed in fresh emissions from residential
coal combustion.
not hot enough to burn volatilized organic matter, it is also
too cool to produce BC (47).
However, other EFBC and EFOC values assumed for
emission inventories are much higher and differ greatly with
each other (4, 15, 16, 18, 48, 49), and this can be due to the
different FBC (the BC fraction of particles) values and BC/OC
ratios they used. For example, although the EFBC values
calculated by Streets et al. (15) are much lower than other
assumptions, the FBC used (45% for bituminous and 24% for
briquette) are higher as compared to the present results (Table
2). Liousse et al. (18) presented the first estimate about OC
emissions, and assumed EFOC (33.3 g/kg) from EFBC of 10
g/kg and a BC/OC ratio of 0.3, while Cooke et al. (4) chose
a value of 1:2 for the BC:OC ratio and obtained a value of
about 10 g/kg for EFOC
.
BC and OC Emission Factors. Black carbon (BC) and
elemental carbon (EC) are terms describing the light-
absorbing fraction of carbonaceous aerosol. They are often
used interchangeably, although there are obvious differences
between them. BC is measured using an optical absorption
method, while EC is usually determined by a thermal-optical
technique. Turpin et al. (42) compared photoacoustic
spectroscopy with thermal-optical transmittance (TOT) when
measuring atmospheric EC (they did not discriminate these
terminologies) and found there was no significant difference
between the two data sets at the 95% confidence level.
Because the term of BC was used more frequently than EC
when the carbonaceous particulate matter emitted from coal
combustion was discussed, BC was selected in this paper
and the masses of BC and OC on filter samples were thought
to be equal to that of EC and OC analyzed by the NIOSH TOT
protocol (23).
It should be noted that different analytical protocols for
OC and EC are expected to give different results despite the
similar thermal-optical technology. For example, the maxi-
mum temperature selected for OC analysis in the oxygen-
free atmosphere usually varies from 550 to 900 °C and affects
the results, but the reason remains unclear. Chow et al. (50)
compared the IMPROVE (Interagency Monitoring of Pro-
tected Visual Environments) with the NIOSH protocols (23),
and concluded that NIOSH EC was typically less than half
of IMPROVE EC, and primarily attributed this difference to
the different allocation of carbon evolving at the NIOSH 850
°C temperature in a helium atmosphere (51). However,
Schauer et al. (52) suggested some organic compounds did
not pyrolyze or volatilize when the maximum temperature
in pure helium was too low, and therefore the EC value was
overestimated. In the present experiments, the maximum
temperature for detecting OC was 650 °C, which was
suggested by Sunset Laboratory for analyzing the GFF
samples.
PAH Emission Factors. The emission factors of 20 PAHs,
including 14 parent PAHs and 6 alkylated homologues, based
on burned coal-weight (daf) are presented in Table 4. It should
be noted that the PAH emissions here are the sum of both
particulate and gaseous phases, and the percentages of
particulate phase to the sum are also listed in Table 4.
The combustion of bituminous and sub-bituminous coals
produced 210.6 and 121.2 mg/kg of total 20 PAHs, while
anthracite (YX) yielded an amount 3 orders of magnitude
lower. The same tendencies were observed for some carci-
nogenic parameters other than sole BaP for the whole PAH
fraction in emissions from various coal combustions (Table
4). These parameters include ∑gen-PAHs (sum of six
carcinogenic PAHs, such as BaA, Chry, BbkF, BaP, DbahA,
and IncdP, which are classified as Group B2 (13)), BaPE (BaP-
equivalent carcinogenic power, introduced by Yassaa et al.
(53, 54)), and ∑BaPeq (sum of PAHs multiplied by their toxic
equivalency factors introduced by Nisbet and LaGoy (55)).
The PAH emission from various coals is found to have a
relationship with their volatile content, and the complete
combustion of coals with a high volatile content is more
difficult to achieve (30). Anthracite coal contains very little
volatile matter and can therefore burn more completely.
PAHs released from coal combustion are believed to
consist of two categories according to their formation
The emission factors of BC (EFBC) and OC (EFOC) for five
coals (daf) in this work are given in Table 2. The variation
tendencies of EFBC and EFOC among various coals are similar
to that of EFPM; that is, bituminous coals have the highest
values of EFBC (0.28 g/kg) and EFOC (7.82 g/kg), while
anthracite yields the lowest emission factors of BC (4 mg/kg)
and OC (17 mg/kg).
A good correlation is found between EFOC and EFPM (R2
)
0.99) of these coals, which is due to the fact that PM emitted
from bituminous and sub-bituminous coals consists mainly
of coal tar, as mentioned above. The ratio of OC/PM (FOC
)
is about 60%, and the maximum is 70% for XW (Table 2), and
organic matter (1.3 × OC) (18) contributes up to nearly 80%
of PM mass. Similar data have been reported when the indoor
levels of PM from smoky coal (XW) burned in open-pits were
collected (43, 44). Because coal tar is thought to be the
precursor to BC (45), good correlations of EFBC versus EFOC
2
2
(
R ) 0.94) and EFBC versus EFPM (R ) 0.90) are expected.
Oros and Simoneit (46) had reported EFBC values of 1.4
g/kg for bituminous and 0.5 g/kg for sub-bituminous coal
from laboratory-scale combustion, several times higher than
the present results, while the EFOC values were very close to
our measurements. The different coal types and combustion
conditions may contribute to the difference of EFBC, and the
reason may be similar to that for different EFPM. As an
example, the difference of EFBC between YM and XA in this
work is greater than 10 times (Table 2). When the flame is
1
864
9
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 39, NO. 6, 2005

TABLE 4. Emission Factors of PAHs from Honeycomb Briquette Combustion of Five Coals Based on Burned Dry Ash-Free Coala
sub-bituminous
JP (mg/kg)
bituminous
anthracite
XW (mg/kg)
YM (mg/kg)
XA (mg/kg)
total
P%d
geomeanc
total
YX (µg/kg)
PAHsb
total
P%d
total
P%
d
total
P%
d
total
P%d
Flu
4.160
25.817
8.620
6.302
2.237
2.947
4.998
5.251 100
2.511 100
1.613 100
1.604 100
0.833 100
1.778 100
0.338 100
10.537
8.546
16.476
9.988
1.901
4.728 100
69.009
52.175
6.22
11.064
45.307
8.791
3.22
46.22
52.30
98.90
97.08
99.85
99.67
5.805
84.855
8.093
15.96
34.09
46.99
94.07
94.14
99.83
99.66
1.165
38.204
1.728
3.495
1.208
2.697
10.055
5.279
4.260
1.048
0.899
1.994
2.436
0.738
4.508
3.418
14.858
5.376
1.135
8.247
75.206
37.541
112.74 7
2.847
21.971
4.115
1.61
4.214
52.762
4.972
5.784
2.327
4.318
11.833
5.211
5.418
1.771
1.073
2.158
3.171
0.663
16.180
13.643
37.532
19.768
2.760
15.040
9.136
91.318
2.260
5.215
4.908
0.241
2.376
2.669
2.065
0.190
0.922
0.657
1.219
1.244
1.914
1.245
3.386
1.629
0.275
0.137
0.05
0.08
0.10
1.47
1.70
33.64
32.57
85.17
92.20
Phe
Ant
Fluo
Pyr
31.31
30.19
92.18
93.66
99.81
99.68
9.51
14.45
81.72
85.16
99.70
99.37
6.436
8.603
2.973
4.887
3.506
6.106
BaA
Chry
BbkF
BeP
BaP
10.378
3.862
15.879
6.942
100
100
100
4.880
100
100
100
100
100
100
7.649
100
100
100
100
100
100
100
100
100
100
100
100
2.155
2.458
100
IncdP
DbahA
BghiP
Cor
0.942
1.461
100
100
100
100
0
1.595
3.161
2.692
4.865
0.440
0.897
Mflu
14.33
33.772
28.090
54.456
41.339
4.583
14.61
27.827
26.452
65.343
34.758
4.043
20.94
4.47
C2-Flu
Mphe
Dmphe
Mpyr
Mchry
46.84
69.23
88.32
98.99
58.79
82.69
96.24
99.28
99.96
56.04
69.78
89.09
98.64
99.96
31.52
40.10
75.84
97.52
99.91
0
0.46
0.75
8.91
100
18.598
106.40 3
180.83 7
287.24 0
3.751
23.819
5.004
22.181
160.28 1
180.60 4
340.88 4
5.324
36.008
7.461
∑
∑
∑
BaPE
∑
∑
Parent-PAHs
Alkyl-PAHs
PAHs
105.676 124.42 0
104.923 8.585
210.599 133.00 5
3.775
26.365
5.254
121.184
2.785
17.246
3.619
0.859
7.054
1.399
gen-PAHs
BaPeq
a
Unit of emission factors for sub-bituminous and bituminous honeycomb coal briquettes is mg/kg, while unit for anthracite coal is µg/kg.
b
Abbreviations of PAHs: Flu, fluorene; Phe, phenanthrene; Ant, anthracene; Fluo, fluoranthene; Pyr, pyrene; BaA, benz[a]anthracene; Chry,
chrysene; BbkF, benzo[b+k]fluoranthene; BeP, benzo[e]pyrene; BaP, benzo[a]pyrene; IncdP, indeno[1,2,3-c,d]pyrene; DbahA, dibenz[ah]anthracene;
BghiP, benzo[ghi]perylene; Cor, coronene; Mflu, methylfluorenes; C2-Flu, C2-fluorenes; Mphe, methylphenanthrenes; Dmphe, dimethylphenanthrenes;
Mpyr, methylpyrenes; Mchry, methylchrysenes; ∑Parent-PAHs, sum of 14 parent PAHs above; ∑Alkylated-PAHs, sum of six alkylated PAHs above;
∑
PAHs, sum of all 20 PAHs listed; BaPE, benzo[a]pyrene- equivalent carcinogenic power (BaPE ) BaA × 0.06 + BbkF × 0.07 + BaP + DbahA ×
0.6 + IncdP × 0.08); ∑gen-PAHs, sum of six carcinogenic PAHs (BaA, Chry, BbkF, BaP, DbahA, and IncdP); ∑BaPeq, sum of individual PAHs multiplied
by their toxic equivalency factors. Geometric average of the results of three bituminous coals. d PAHs in particulate phase in percentage of total
c
PAHs detected in both particulate and vapor phases.
TABLE 5. Emission Estimates for China of PM, BC, OC, and PAHs from Residential Combustion of Five Honeycomb Coal Briquettes
during 2000
c
emissions (Gg)d
emission factors (g/kg)
percentage (%)a consumption (Tg)b EFPM
EFBC
EFOC
EFPAHs
PM
BC OC
PAHs
-
4
-4
anthracite
17.57
78.07
5.557
1.329 0.004 0.017 1.33 × 10
7.385 0.022
0.094 7.39 × 10
bituminous and
sub-bituminous
total
24.693
11.455 0.216 6.894 1.913
282.85 8 5.334 170.23 4 4.723
31.629e
290.244 5.356 170.328 4.723
a
Percentage of anthracite and bituminous coal in whole yield of raw coal in 2000 in China (refer to http://www.cct.org.cn/cct/). b Teragram or
Mt. c Emission factors for bituminous are the geomean value of a sub-bituminous and three bituminous coals. d Gigagram or kilotonnes. 40%
of whole consumption of raw coal in residential sector (79.07 Tg) (refer to 61).
e
pathways. One category is derived from free PAHs trapped
in original coals, and the other is formed through pyrolysis
and pyrosynthesis during coal burning (56). A large amount
of coal tar is produced during the devolatilization period in
coal burning, and this tar is composed mainly of aromatic
species released either directly into the flue gas or reformed
to other PAHs through further thermal degradation (26).
Under the relatively low temperatures during residential coal
combustion, a higher PAHs yield is expected, especially from
bituminous and sub-bituminous coal with high volatile
content. The poor air-supply in residential burning conditions
may be another reason for the high production of PAHs.
Ledesma et al. (26) concluded that most of the PAH mass is
produced when the oxygen ratio is under 30% during
bituminous coal burning. This indicates that it may be
possible to decrease emission factors by improving the
aeration conditions in residential combustion.
Previous studies on the emission factors of PAHs from
various residential coal combustors are generally similar to
our measurements (30-32, 46, 57). As indicated in those
studies, the rank of coal (maturity) is an important factor
that affects PAH emissions from residential combustion.
Anthracite burning emits PAHs with a mass 3 orders of
magnitude lower than bituminous. The burning conditions
also affect PAHs emissions. For example, Oros and Simoneit
(
46) sampled including the smoldering conditions and
reported the values of 2 orders of magnitude higher than
that of others. Furthermore, large-scale combustors such as
power plants have very low PAH emission factors, which are
in the same order or even lower than that from anthracite
in residential combustion, although most of the power plant
fuels are bituminous coals (58-60).
Primary Estimates of Carbonaceous Particle and PAH
Emissions. Primary estimates about the emissions of BC,
VOL. 39, NO. 6, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
9
1865

OC, and PAHs from residential coal combustion using
honeycomb coal briquettes can be made simply as shown
in Table 5. The total consumption of raw coal in the residential
sector of China was about 79 Tg (Teragrams) during 2000 (3),
in which 40% (31.6 Tg) was burned as honeycomb briquettes.
Streets et al. (15) had assumed that briquettes would comprise
(9) Chameides, W. L.; Yu, H.; Liu, S. C.; Bergin, M.; Zhou, X.; Mearns,
L.; Wang, G.; Kiang, C. S.; Saylor, R. D.; Luo, C.; Huang, Y.; Steiner,
A.; Giorgi, F. Case study of the effects of atmospheric aerosols
and regional haze on agriculture: an opportunity to enhance
crop yields in China through emission controls?Proc. Natl. Acad.
Sci. U.S.A. 1999, 96, 13626-13633.
(10) Kunzli, N.; Kaiser, R.; Medina, S.; Studnicka, M.; Chanel, O.;
Filliger, P.; Herry, M.; Horak, F.; Puybonnieux-Texier, V.; Quenel,
P.; Schneider, J.; Seethaler, R.; Vergnaud, J. C.; Sommer, H.
Public-health impact of outdoor and traffic-related air pollu-
tion: a European assessment. Lancet 2000, 356, 795-801.
4
1% of domestic raw coal for the year 2020. Cheng (61)
supposed that the briquette yield of China was 80 Mt during
000. The mass of briquettes contained a large part of ash
2
and clay, because the average ash content on air-dry basis
of the five briquettes in the present work was about 45%.
Using the percentages of anthracite (17.57%) and bituminous
(
11) Hamilton, R. S.; Mansfield, T. A. Airborne particulate elemental
carbon: its sources, transport and contribution to dark smoke
and soiling. Atmos. Environ. 1991, 25, 715-723.
(
78.07%, including sub-bituminous and bituminous) in the
(12) Ghan, S. J.; Chuang, C. C.; Easter, R. C.; Penner, J. E. A
parametrization of cloud droplet nucleation, Part II: Multiple
aerosol types. Atmos. Res. 1995, 36, 39-54.
whole yield of raw coal (http://www.cct.org.cn/cct/), al-
though more anthracite coal is expected to be utilized in
large cities where raw coal is not available, there are 5.56 Tg
of anthracite and 24.69 Tg of bituminous coal burned as
honeycomb briquettes. So, the emissions of particulate
matter, black and organic carbon, and PAH mass can be
estimated, and the results are 290.24 Gg (gigagrams) for PM,
(
13) USEPA. Integrated Risk Information System (IRIS) on Polycyclic
Organic Matter. National Center for Environmental Assessment,
Office of Research and Development, Washington, DC, 1999;
http://www.epa.gov/ttn/atw/hlthef/polycycl.html.
(14) Durant, J. L.; Lafleur, A. L.; Busby, W. F., Jr.; Donhoffner, L. L.;
Penman, B. W.; Crespi, C. L. Mutagenicity of C24 14 PAH in
H
Human Cells Expressing CYP1A1. Mutat. Res. 1999, 446, 1-14.
15) Streets, D. G.; Gupta, S.; Waldhoff, S. T.; Wang, M. Q.; Bond, T.
C.; Bo, Y. Y. Black carbon emissions in China. Atmos. Environ.
5
.36 Gg for BC, 170.33 Gg for OC, and 4.72 Gg for total PAHs.
(
As compared to the BC emissions of 605.4 Gg from domestic
coal combustion by Streets et al. (15), honeycomb coal
briquettes contribute less than 1%. However, it should be
stressed that the emission factors of BC, OC, and PAHs could
be underestimated in some degree because they were
obtained only for flaming conditions, while smoldering
2
001, 35, 4281-4296.
(
16) Streets, D. G.; Bond, T. C.; Carmichael, G. R.; Fernandes, S. D.;
Fu, Q.; He, D.; Klimont, Z.; Nelson, S. M.; Tsai, N. Y.; Wang, M.
Q.; Woo, J.-H.; Yarber, K. F. An inventory of gaseous and primary
aerosol emissions in Asia in the year 2000. J. Geophys. Res. 2003,
1
08, 8809.
(
choking condition) was excluded because of the difficulties
(17) Cooke, W. F.; Wilson, J. J. N. A global black carbon aerosol model.
J. Geophys. Res. 1996, 101, 19395-19409.
of sampling. Furthermore, other residential burning condi-
tions of coal (60 wt %) besides briquette, such as unprocessed
raw coal, whose emission factors of carbonaceous particles
and PAHs are thought to be higher, remain uncertain and
need further urgent investigations before any accurate
estimates for emissions from residential coal combustion in
China can be made.
(
18) Liousse, C.; Penner, J. E.; Chuang, C.; Walton, J. J.; Eddleman,
H.; Cachier, H. A global three-dimensional model study of
carbonaceous aerosols. J. Geophys. Res. 1996, 101, 19411-19432.
(19) Bond, T. C.; Covert, D. S.; Kramlich, J. C.; Larson, T. V.; Charlson,
R. J. Primary particle emissions from residential coal burning:
optical properties and size distributions. J. Geophys. Res. 2002,
1
07, 8347.
20) Florig, H. K. China’s air pollution risks. Environ. Sci. Technol.
997, 31, 275A-279A.
(
Acknowledgments
1
This work was funded by the Chinese National Natural
Science Foundation (No. 4013010). We would like to thank
Prof. Xinming Wang and Mr. Zhengyue Li for their help in
designing the sampling equipment, and Dr. Daishe Wu,
Jingkui Mi, and Bofu Ning for collecting raw coal samples.
Thanks are also given to Mr. Tongshou Xiang and Huizhi
Zhang for technical assistance with instrumental analyses,
and to Prof. Bernd R.T. Simoneit for his great help in revising
this paper.
(21) Chen, Y. J.; Bi, X. H.; Mai, B. X.; Sheng, G. Y.; Fu, J. M. Emission
characterization of particulate/gaseous phases and size as-
sociation for polycyclic aromatic hydrocarbons from residential
coal combustion. Fuel 2004, 83, 781-790.
(
22) Bi, X. H.; Sheng, G. Y.; Peng, P. A.; Chen, Y. J.; Zhang, Z. Q.; Fu,
J. M. Distribution of particulate- and vapor-phase n-alkanes
and polycyclic aromatic hydrocarbons in urban atmosphere of
Guangzhou, China. Atmos. Environ. 2003, 37, 289-298.
23) Birch, M. E.; Cary, R. A. Elemental carbon-based method for
monitoring occupational exposures to particulate diesel exhaust.
Aerosol Sci. Technol. 1996, 25, 221-241.
(
(
(
(
(
(
24) Butcher, S. S.; Ellenbecker, M. J. Particulate emission factors for
small wood and coal stoves. J. Air Pollut. Control Assoc. 1982,
Literature Cited
3
2, 380-384.
(
1) Jacobson, M. Z. Control of fossil-fuel particulate black carbon
and organic matter, possibly the most effective method of
slowing global warming. J. Geophys. Res. 2002, 107, 4410.
2) Lighty, J. S.; Veranth, J. M.; Sarofim, A. F. Combustion aerosols:
factors governing their size and composition and implications
to human health. J. Air Waste Manage. Assoc. 2000, 50, 1565-
25) Solomon, P. R.; Hamblen, D. G.; Carangelo, R. M.; Serio, M. A.;
Deshpande, G. V. General model of coal devolatilization. Energy
Fuels 1988, 2, 405-422.
(
26) Ledesma, E. B.; Kalish, M. A.; Nelson, P. F.; Wornat, M. J.; Mackie,
J. C. Formation and fate of PAH during the pyrolysis and fuel-
rich combustion of coal primary tar. Fuel 2000, 79, 1801-1814.
27) Mitra, A.; Sarofim, A. F.; Bar-Ziv, E. The influence of coal type
on the evolution of polycyclic aromatic hydrocarbons during
coal devolatilization. Aerosol Sci. Technol. 1987, 6, 261-271.
28) Radke, M.; Schaefer, R. G.; Leythaeuser, D.; Teichm u¨ ller, M.
Composition of soluble organic matter in coals: relation to
rank and liptinite fluorescence. Geochim. Cosmochim. Acta 1980,
1
618.
3) China Statistical Yearbook, 2003; China Statistics Press: Beijing,
004.
4) Cooke, W. F.; Liousse, C.; Cachier, H.; Feichter, J. Construction
of a 1° × 1° fossil fuel emission data set for carbonaceous aerosol
and implementation and radiative impact in the ECHAM4
model. J. Geophys. Res. 1999, 104, 22137-22162.
(
(
2
4
4, 1787-1800.
(
5) Jacobson, M. Z. Strong radiative heating due to the mixing state
(29) Zhang, J.; Smith, K. R.; Ma, Y.; Ye, S.; Jiang, F.; Qi, W.; Liu, P.;
Khalil, M. A. K.; Rasmussen, R. A.; Thorneloe, S. A. Greenhouse
gases and other airborne pollutants from household stoves in
China: a database for emission factors. Atmos. Environ. 2000,
34, 4537-4549.
(30) Oanh, N. T. K.; Reutergardh, L. B.; Dung, N. T. Emission of
polycyclic aromatic hydrocarbons and particulate matter from
domestic combustion of selected fuels. Environ. Sci. Technol.
1999, 33, 2703-2709.
of black carbon in atmospheric aerosols. Nature 2001, 409, 695-
6
97.
6) Andreae, M. O. The dark side of aerosols. Nature 2001, 409,
71-672.
(
(
6
7) Menon, S.; Hansen, J.; Nazarenko, L.; Luo, Y. F. Climate effects
of black carbon aerosols in China and India. Science 2002, 297,
2250-2253.
(
8) Qiu, J.; Yang, L. Variation characteristics of atmospheric aerosol
optical depths and visibility in North China during 1980-1994.
Atmos. Environ. 2000, 34, 603-609.
(31) U.S. Environmental Protection Agency. Compilation of Air
Pollutant Emission Factors, AP-42, 5th ed.; 1996; Vol. I, Chapter
1
866
9
ENVIRONMENTAL SCIENCE & TECHNOLOGY / VOL. 39, NO. 6, 2005

1
:
External Combustion Sources, http://www.epa.gov/ttn/
(47) Bond, T. C. Light absorption by primary particles from fossil-
fuel combustion: implications for radiative forcing. Ph.D.
Dissertation, University of Washington, 2000; p 383.
(48) Penner, J. E.; Eddleman, H.; Novakov, T. Towards the develop-
ment of a global inventory for black carbon emissions. Atmos.
Environ. 1993, 27A, 1277-1295.
chief/ap42/ch01.
(
32) Mumford, J. L.; Harris, D. B.; Williams, K.; Chuang, J. C.; Cooke,
M. Indoor air sampling and mutagenicity studies of emissions
from unvented coal combustion. Environ. Sci. Technol. 1987,
2
1, 308-311.
(
33) Hangebrauck, R. P.; Lehmden, D. J. V.; Meeker, J. E. Emissions
of polynuclear hydrocarbons and other pollutants from heat-
generation and incineration processes. J. Air Pollut. Control
Assoc. 1964, 14, 267-278.
(49) Parungo, F.; Nagamoto, C.; Zhou, M. Y.; Hansen, A. D. A.; Harris,
J. Aeolian transport of aerosol black carbon from China to the
ocean. Atmos. Environ. 1994, 28, 3251-3260.
(50) Chow, J. C.; Watson, J. G.; Pritchett, L. C.; Pierson, W. R.; Frazier,
C. A.; Purcell, P. G. The DRI thermal/optical reflectance carbon
analysis system: description, evaluation and applications in U.
S. air quality studies. Atmos. Environ. 1993, 27A, 1185-1201.
(51) Chow, J. C.; Watson, J. G.; Crow, D.; Lowenthal, D. H.; Merrifield,
T. Comparison of IMPROVE and NIOSH carbon measurements.
Aerosol Sci. Technol. 2001, 34, 23-34.
(52) Schauer, J. J.; Mader, B. T.; Deminter, J. T.; Heidemann, G.; Bae,
M. S.; Seinfeld, J. H.; Flagan, R. C.; Cary, R. A.; Smith, D.; Huebert,
B. J.; Bertram, T.; Howell, S.; Kline, J. T.; Quinn, P.; Bates, T.;
Turpin, B.; Lim, H. J.; Yu, J. Z.; Yang, H.; Keywood, M. D. ACE-
Asia intercomparison of a thermal-optical method for the
determination of particle-phase organic and elemental carbon.
Environ. Sci. Technol. 2003, 37, 993-1001.
(
(
(
34) Edwards, R. D.; Smith, K. R.; Zhang, J.; Ma, Y. Implications of
changes in household stoves and fuel use in China. Energy Policy
2
004, 32, 395-411.
35) Zhang, J.; Smith, K. R. Hydrocarbon emissions and health risks
from cookstoves in developing countries. J. Expos. Anal. Environ.
Epidemiol. 1996, 6, 147-161.
36) Kavouras, I. G.; Stephanou, E. G. Particle size distribution of
organic primary and secondary aerosol constituents in urban,
background marine, and forest atmosphere. J. Geophys. Res.
2
002, 107.
(37) Markowski, G. R.; Ensor, D. S.; Hooper, R. G. A submicron aerosol
mode in flue gas from a pulverized coal utility boiler. Environ.
Sci. Technol. 1980, 14, 1400-1402.
(
(
(
53) Yassaa, N.; Meklati, B. Y.; Cecinato, A.; Marino, F. Organic
aerosols in urban and waste landfill of Algiers metropolitan
area: occurrence and source. Environ. Sci. Technol. 2001, 35,
38) McElroy, M. W.; Carr, R. C.; Ensor, D. S.; Markowski, G. R. Size
distribution of fine particles from coal combustion. Science 1982,
215, 13-19.
3
06-311.
39) Dockey, D. W.; Pope, C. A.; Xu, X.; Spengler, J. D.; Ware, J. H.;
Fay, M. E.; Ferris, B. G.; Speizer, F. E. An association between
air pollution and mortality in six U.S. cities. N. Engl. J. Med.
(
54) Yassaa, N.; Meklati, B. Y.; Cecinato, A.; Marino, F. Particulate
n-alkanes, n-alkanoic acids and polycyclic aromatic hydrocar-
bons in the atmosphere of Algiers City Area. Atmos. Environ.
1
993, 329, 1753-1759.
2
001, 35, 1843-1851.
(
(
(
(
(
(
(
40) Robinson, A. L.; Pandis, S. N.; Lipsky, E.; Stanier, C. Sampling,
analysis, and properties of primary PM2.5: application to coal-
fired utility boilers. Annual Technical Progress Report, August,
(
(
(
55) Nisbet, C.; LaGoy, P. Toxic Equivalency Factors (TEFs) for
Polycyclic Aromatic Hydrocarbons (PAHs). Regul. Toxicol.
Pharmacol. 1992, 16, 290-300.
56) Mastral, A. M.; Callen, M. S. A review on polycyclic aromatic
hydrocarbon (PAH) emission from energy generation. Environ.
Sci. Technol. 2000, 34, 3051-3057.
57) Johnson, N. D.; Scholtz, M. T.; Cassaday, V.; Davidson, K. MOE
Toxic Chemical Emission Inventory for Ontario and Eastern
North America. Prepared for the Air Resources Branch, Ontario
Ministry of the Environment, Rexdale, Ontario. Draft Report
No. P.89-50-5429/OG, 1990; p 146.
2001.
41) Chow, J. C.; Watson, J. G. Recent developments in source
characterization, presented at the regional particulate matter
workshop, May 15-17, Hong Kong and Guangzhou, People’s
Republic of China, 2002.
42) Turpin, B. J.; Huntzicker, J. J.; Adams, K. M. Intercomparison
of photoacoustic and thermal-optical methods for the mea-
surement of atmospheric elemental carbon. Atmos. Environ.
1
990, 24A, 1831-1835.
(
58) Levendis, Y. A.; Atal, A.; Carlson, J. B. On the correlation of CO
and PAH emissions from the combustion of pulverized coal
and waste tires. Environ. Sci. Technol. 1998, 32, 3767-3777.
59) Yang, H. H.; Lee, W. J.; Chen, S. J.; Lai, S. O. PAH emission from
various industrial stacks. J. Hazard. Mater. 1998, 60, 159-174.
60) Masclet, P.; Bresson, M. A.; Mouvier, G. Polycyclic aromatic
hydrocarbons emitted by power stations, and influence of
combustion conditions. Fuel 1987, 66, 556-562.
43) Mumford, J. L.; He, X. Z.; Chapman, R. S.; Cao, S. R.; Harris, D.
B.; Li, X. M.; Xian, Y. L.; Jiang, W. Z.; Xu, C. W.; Chuang, J. C.;
Wilson, W. E.; Cooke, M. Lung cancer and indoor air pollution
in Xuan Wei, China. Science 1987, 235, 217-220.
(
(
44) Chung, J. C.; Wise, S. A.; Cao, S. R.; Mumford, J. L. Chemical
characterization of mutagenic fractions of particles from indoor
coal combustion: a study of lung cancer in Xuan Wei, China.
Environ. Sci. Technol. 1992, 26, 999-1004.
(
61) Cheng, Y. Q. On spreading the application of clean coal
45) Richter, H.; Howard, J. B. Formation of polycylic aromatic
hydrocarbons and their growth to soot - a review of chemical
reaction pathways. Prog. Energy Combust. Sci. 2000, 26, 565-
technology in China. China Coal 1998, 24, 12-16.
608.
Received for review April 26, 2004. Revised manuscript re-
ceived December 13, 2004. Accepted December 14, 2004.
46) Oros, D. R.; Simoneit, B. R. T. Identification and emission rates
of molecular tracers in coal smoke particulate matter. Fuel 2000,
79, 515-536.
ES0493650
VOL. 39, NO. 6, 2005 / ENVIRONMENTAL SCIENCE & TECHNOLOGY
9
1867