Journal of Environmental Protection, 2010, 1, 346-361
doi:10.4236/jep.2010.14041 Published Online December 2010 (http://www.SciRP.org/journal/jep)
Development of Emission Factors for
Quantification of Blasting Dust at Surface
Coal Mines
Surendra Roy1, Govind Raj Adhikari1, Trilok Nath Singh2
1National Institute of Rock Mechanics, Champion Reefs, Kolar Gold Fields, India; 2Department of Earth Sciences, Indian Institute of
Technology, Bombay, India.
Received August 11th, 2010; revised August 25th, 2010; accepted September 10th, 2010.
ABSTRACT
Environmental impact assessment (EIA) and environmental management plan (EMP) is a statutory requirement for
execution of new mining projects or for expansion of the operating projects. For this purpose, quantification of blasting
dust emission is required. This can be done by developing emission factors for blasting. The concept is similar to that of
specific charge in blasting. For mining operations other than blasting, quantification of dust can be done using emis-
sion factors. Emission estimation techniques are very limited for blasting. In this study, the emission factors were de-
veloped by carrying out a detailed field study at one of the largest opencast coal mines of India in all four seasons. Da-
ta on atmospheric and meteorological conditions were generated by installing sodar and automatic weather station at
the mine site. Respirable dust samplers were installed for monitoring of the dust emitted during coal or overburden
bench blasting. Emission factors for dust concentrations were developed in gram per cubic meter of rock excavated.
The developed emission factors were used to estimate dust emissions for adjacent mines due to similarity in mining and
meteorological conditions. Seasonal variations in moisture contents in benches, where dust was monitored, indicated
the lowest emission factors in monsoon due to high moisture in the bench materials. Similar field studies were also
conducted at another coalfield of India for two seasons. It was found that the emission factors are site-specific.
Keywords: Emission Factor, Blasting Dust, Particulate Matter, Surface Coal Mines
1. Introduction
Emission factor is a representative value to estimate the
quantity of a pollutant released to the atmosphere with an
activity associated with the release of that pollutant. It is
important for developing emission control strategies by
Central and State Government, consultants, and industry
[1]. Among different fugitive dust sources of mining ac-
tivities like topsoil stripping, drilling, overburden and
coal removal, material hauling, stock piles, etc. [2,3];
blasting produces very large quantities of dust. The dust
produced due to blasting in the form of total suspended
particulate matter (TSP) and particulate matter less than
10 μm (PM10) affects the surrounding environment, hu-
man beings, animals, and plants depending on the mete-
orological conditions at the mine site.
The concept of emission factor is analogous to specific
charge in rock blasting. Specific charge is a measure of
the mass of an explosive required to break a unit volume
or a unit mass of the rock. Considering the explosive
mass in units of kilograms and the rock quantity in cubic
meters or tons, the specific charge can be expressed in
kg/m3 or kg/t [4]. Specific charge indicates how much
explosive is needed for fragmentation of one cubic meter
of rock whereas emission factor indicates the amount of
dust emitted into the atmosphere during blasting of one
cubic meter of rock. A lower emission factor is desirable
as a higher value can cause air pollution in the mine and
surrounding areas.
Emission factor can be used to quantify the dust gen-
erated by blasting at the planning or operating stage of a
mine. Hence this is a useful tool for preparation of envi-
ronmental management plan. Previous work on air pollu-
tion due to surface coal mining mostly deals with moni-
toring and analysis of dust generated by different mining
operations. According to the United States of Environ-
mental Protection Agency [5], blasting presents formida-
ble logistic difficulties in sampling or sampler deploy-

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 347
ment. Hence USEPA did not recommend for further field
study.
Data from source-specific emission tests are usually
preferred. Realistic emission factors can only be devel-
oped with actual emissions data. The first issue which
must be faced while developing an emission factor is to
define a source category. In some cases, this may be
fairly simple and straightforward. But in case of fugitive
particulate matter emission, the definition of a source
category generally involves some compromises [2]. Dif-
ferent mining activities have been categorized into dif-
ferent source categories such as drilling as point source,
coal loading as point or area source, dragline as point or
area source, dozer as line or point source, blasting as area
source, etc [6]. For blasting, most of the researchers have
developed single-valued or predictive equations for cal-
culating emission factor in kilogram per blast and some
have estimated in kilogram per tonne of explosive con-
sumed. Often in the mine, the size of blast varies from
blast to blast. Therefore, the emission factors can be de-
veloped in gram per cubic meter of rock excavated. An
attempt was made to develop emission factor for PM10
and TSP by carrying out a detailed study at large open-
cast coal mines in India. Application of the emission
factor in other mines is also presented.
2. Overview on Blasting Emission Factors
The emission factors are usually expressed as the weight
of pollutant divided by a unit weight, volume, distance,
or duration of the activity emitting the pollutant depend-
ing on the operations carried out at surface mines [1]. For
example, it is expressed in kilogram per vehicle kilome-
ters traveled (kg/VKT) for scrapers, kg/hr for bulldozer,
kg/t for truck dumping coal or overburden, etc. Similarly
emission factors for blasting have been expressed in dif-
ferent units by the different countries.
Different researchers have developed different emis-
sion factors for blasting under different mining and me-
teorological conditions. Most of the works related to fu-
gitive emissions have been undertaken in the United
States. Some work has also been undertaken in Australia,
although the Australian work is not as comprehensive as
that of the US [7]. It is worth pointing out that the USE-
PA emission factors are published and are widely re-
ferred. The most comprehensive compilation of emission
factors is the USEPA document referred as AP-42 [8].
The emission factors developed and used by various
countries are summarized below.
2.1. Emission Factors for USA Mines
Cole and Kerch [3] reported TSP emission factor as 14.3
to 85.3 lb/blast for overburden and 25.1 to 78.1 lb/blast
for coal [9]. Emission factor for PM10 is not given. Axe-
tell and Cowherd [10] developed emission factor equa-
tion for coal or overburden for 30 μm size particles as
0.00022(A)1.5 in kg/blast, where A is the horizontal area
with blasting depth 21 m as it is reported in USEPA [1].
Axetell and Cowherd [11] developed the emission
factor equation for TSP as 961 A0.8 D-1.8 M-1.9 lb/blast for
coal or overburden, where A is the area blasted (sq ft); D
is the blasthole depth (ft); and M is the moisture content
(%). For the estimation of particulate < 15 μm, the equa-
tion is given as 2550 (A)0.6/(D)1.5(M)2.3 and for calcula-
tion of particulate < 2.5, the values obtained by TSP equ-
ation should be multiplied by 0.030. Single valued emis-
sion factors have also been mentioned for different mines.
For mine type A, the single-valued TSP emission factor
for overburden blasting is mentioned as 1690 lb/blast, but
for coal this value is not given. For mine type C, TSP
emission factor for coal and overburden is 25.1 lb/blast
and 14.2 lb/blast respectively. For mine type D, TSP
emission factor for coal is 78.1 lb/blast. For overburden,
the value is not given. For mine type E, the TSP emission
factor for coal and overburden is 72.4 lb/blast and 85.3
lb/blast respectively. This has been reported under sec-
tion 5.5 and 8.5 of “Fugitive Dust Emission factor Up-
date for AP-42” [6].
The current version of AP-42 section 11.9 was first
drafted in 1983 using the field data collected during the
late 1970s and early 1980s at Western surface coal mines.
Minor changes related to emissions from blasting and
estimating PM10 emissions were made in this version [6].
According to current version, the general equation for
TSP and PM-15 is reported as e = k (A)a/(D)b (M)d,
where e is the emission factor expressed in mass of emis-
sions per blast; A is the area blasted (area); D is the hole
depth; M is the material moisture content (%); and k, a, b,
and c are the regression values. The USEPA has reported
emission factor for particulate ≤ 30 μm for coal or over-
burden as 0.0005A1.5, where A is the horizontal area with
blasting depth ≤ 70 feet. For PM10, the values obtained
from this equation will be multiplied by 0.5.
2.2. Emission Factors for Australian Mines
National Pollutant Inventory [12] reported emission fac-
tors for Australian mines based on the particles emitted
per tonne of explosive used. The emission factor is re-
ported for the different particle size ranges emitted per
tonne of the explosive used. The emission factor for
particle size 0-2.5 μm, 2.5-15 μm and 15-30 μm is 5.1
kg/tonne, 46.0 kg/tonne and 49.9 kg/tonne respectively.
The emission factor for overburden blasting is 0.00022
A1.5 kg per blast, where A is the area to be blasted in m2.
Environment Australia [13] formulated the guidance
for application of emission factors in Australian condi-

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 348
tions. In this report, equation for TSP estimation is men-
tioned as 0.008A1.5 kg/blast; where A is the area blasted
in m2. For PM10 estimation, the value obtained by TSP
equation should be multiplied by a factor 0.52. Later on,
Environment Australia [7,14] derived the TSP emission
factor equation as 344A0.8M-1.9D-1.8 kg/blast; where A the
area blasted in m2, D is the depth of blasthole (m) and M
is the moisture content (%). For estimation of PM10, it
will be multiplied by a factor of 0.52.
2.3. Emission Factors for European Mines
EEA (European Environmental Agency) emission in-
ventory guidebook [15] has stated that emission factors
estimation for open dust sources for coal mines as given
in the USEPA document AP-42 [6] can be used.
2.4. Emission Factors for Indian Mines
Chakraborty et al. [16] developed emission rates for var-
ious surface coal mining activities except blasting. Ghose
[17] calculated emission factors for different operations
of the surface coal mine but he has not reported dust
emission for blasting.
2.4.1. Remarks from the Overview
It is found that different countries have adopted different
emission factors for blasting. Some empirical equations
for emission factor include only area of blasts while other
use area of blast, blasthole depth and moisture content. In
most of the cases, emission factors have been expressed
in pound per blasts or kilogram per blasts or in kilogram
per tonne of the explosive used. No emission factors for
blasting have been developed for Indian mines.
Coal or overburden benches in the mine cover differ-
ent area of blasts as well as different blasthole depths
depending on the requirements. After blasting, a volume
of rock is broken and fragmented, which is the source of
dust emission into the atmosphere. It would be better to
develop emission factors in gram per cubic meter of rock
excavated.
3. Blasting Dust Sampling Problems
The plume from a blast is particularly difficult to sample
due to the vertical and horizontal dimensions of the
plume and the inability to place sampling equipment near
the blast [6]. To sample blasts, the exposure profiler
concept was modified. Balloon-suspended samplers
along with ground-based samplers were used for blasting
dust monitoring, which was found to be impractical un-
der field conditions. The location of the plume centerline
depended very much on the exact wind direction at the
time of the blast. Because the balloon sampling array
required at least one hour to set up, it was impossible to
anticipate the exact wind direction one hour in advance.
Therefore, the ground-based samplers were placed at
some distance apart when the wind was variable so that
some of the samplers were in the plume. The balloon
sometimes could not be moved to the plume centerline
quickly enough after the blast. In order to avoid equip-
ment damage from the blast debris and to obtain a repre-
sentative sample of the plume, the balloon-suspended
samplers were located 100 m downwind of the blast area.
This distance varied depending on the size of the blast
and physical constraints. These descriptions are given in
Section 3 of USEPA report [6]. Potential errors like
maintaining an isokinetic flow rate also occurred during
sampling. Balloon sampling being a substantial modify-
cation of the exposure profiling method reveals some-
what experimental technique. Hence it was difficult to
apply to blasting because technical limitations of the
technique combined with the infrequency of blasting
resulted in very few opportunities to perform the sam-
pling. This sampling method could not be used when
ground level winds were greater than about 6 m/s be-
cause the balloon could not be controlled on its tether.
Sometimes balloon was found to be damaged due to blast
debris. Because of logistical difficulties in sampler de-
ployment, further field studies were not recommended.
It is observed that even after modification of sampling
methodology, many problems occurred. No suitable me-
thod has been finalized for blasting dust monitoring.
Sampling of blasting dust has been considered as a diffi-
cult source of field testing.
4. Description of Mine Sites
Field investigations were carried out at two large open-
cast coal mines. The first mine is Dudhichua project,
Northern Coalfields Limited (NCL), Singrauli, Madhya
Pradesh, India. It is one of the largest opencast coal
mines of India and is surrounded by large opencast coal
mines namely Jhingurdha, Bina, Jayant, Amlohri, Nigahi,
Khadia, Block B and Krishnashila. These mines coming
under Singrauli coalfield are divided into two basins viz.
Moher sub-basin and Singrauli main basin. The present
coal mining activities of NCL are concentrated in Moher
sub-basin of 100 km2. All the coal seams are common for
all the mines of NCL except Jhingurdha seam which ex-
ists only in the Jhingurdha mine. In NCL, total coal pro-
duction was 63.65 Mt and overburden removal was 203
million m3 during 2008-09. Among them Dudhichua
project produced 13.27 Mt coal and removed 34.36 mil-
lion m3 overburden using 18990 t explosive. This project
is having an area of 8.68 km2 and located in the central
part of Moher basin of Singrauli Coalfields. The mine is
situated between latitudes 24°7’30” and 24°10’ north and
longitudes 82°40’ and 82°42’30” east. The area is undu-
lating with an average elevation of 325 m above MSL. It

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 349
is at a distance of 63 km by road from Renukut in Uttar
Pradesh and 18 km from Singrauli railway station in
Madhya Pradesh. The general strike in Dudhichua block
is NW-SE and the dips are 1 in 20 to 1 in 25 (2 to 3°)
towards north-east. The lithology consists of mainly soil,
sandstone and coal. This mine was developed in ten
benches including three in coal and seven in overburden.
Large blasts are regularly conducted both in coal and
overburden benches using huge quantities of explosives,
thus increasing the potential for dust hazards in and
around the mine. The main mining and transport equip-
ment are electric shovels, draglines, dumpers, dozers, etc.
The second surface mine where field investigations
were conducted is Bharatpur opencast project. It is one of
the largest opencast coal mines of Mahanadi Coalfields
Limited (MCL) and is located in Angul district of Tal-
cher coalfields, Orissa, India. The mine is surrounded by
different opencast coal mines. It produced 11.02 Mt coal
in the year 2008-09 and removed 6.21 Mm3 of overbur-
den using 3824 t explosive. It is having an area of 6.81
km2 and located in the south central part of the Talcher
Coalfields. The mine is situated between latitudes
20°56’35” and 20°58’40” north and longitudes 85°06’30”
and 85°08’40” east. The area is gently undulating with
elevation from 92 m to 124 m above MSL. It is at a dis-
tance of 9 km, 12 km and 15 km by road from Talcher
town, Talcher railway station and Angul town respect-
tively. The general strike of the block is E-W and the
beds dip 2° to 10° towards north. The lithology consists
of mainly soil, sandstone and coal. The mine forms
benches in coal and overburden for excavation. Large
bench blasts being conducted both in coal and overbur-
den increases likelihood of dust pollution surrounding the
mine. The mining machinery deployed in this mine were
similar to those of Dudhichua project.
5. Methodology
In surface mines, heavy bench blasting was conducted
for excavation of overburden and production of coal. As
the dust dissipates with distance, the dust generated due
to blasting should be monitored surrounding the blast
location. Usually the site conditions make blasting dust
monitoring difficult because the benches to be blasted
had high wall on one side and undulating or plane ground
on the other side. Therefore, it was required to select a
plane surface along one side of the blast location so that
monitoring could be done by installing the dust samplers
in the downwind direction. Samplers could not be in-
stalled on the high wall side when the wind was blowing
in that direction.
Sometimes coal bench had no suitable locations but
overburden had suitable locations for dust monitoring.
All these practical problems caused variation in the
number of data collected for coal and overburden benches.
After the complete survey of the mine, suitable sites
surrounding the bench to be blasted were selected for
blasting dust monitoring during post-monsoon (October-
November), winter (January-February), summer (April-
May) and monsoon (August-September) at Dudhichua
project. Since the bench and blast parameters may vary
from season to season, particulate matter can also vary.
Therefore study was carried out in each season to obtain
different seasonal value. Moisture content of the benches
and the distances of sampling points from blast locations
were determined in each season. These parameters cor-
responded to blasting dust monitored benches.
At Bharatpur opencast project, dust monitoring was
conducted during post-monsoon (October-November)
and winter (January) seasons to assess whether emission
factors developed for Dudhichua project can be used for
Bharatpur opencast project. Since suitability of emission
factor had to be examined, therefore, one high polluting
season and another less polluting season were considered
for data collection at this project. Winter season being
the worst possible scenario of air pollution, Chakraborty
et al. [16] studied emission rates for various mining ac-
tivities only in this season. Chaulya [18] also observed
maximum particulate matter concentrations in winter. In
both the seasons, only coal benches were monitored.
Overburden benches were not monitored because the site
conditions were not suitable for dust sampling.
5.1. Moisture Content Determination
Moisture content is the ratio of the weight of water to the
weight of dry materials. It is expressed in percentage.
Samples of drill cuttings were collected and moisture
contents were determined at Coal Analysis Laboratory of
the mines. Moisture content is determined for coal and
overburden prior to blasting [6]. Moisture content has
restraining nature in dust generation and may vary from
season to season. Therefore, assessment of moisture
content was carried out in each season.
5.2. Collection of Blast Details
Blast details such as number of blastholes, blasthole
depth, burden, and spacing for coal and overburden
benches for each season was used for evaluation of the
volume of material blasted. The period during which
blasts were carried out was also noted because stability
classes and wind speed were required for calculation of
emission factor for each blast for the corresponding pe-
riod. The details corresponded to dust monitored benches.
5.2.1. At Dudhichua Project
In post-monsoon, 20 blasts were conducted, out of which
17 blasts were carried out during 13:00-14:00 and re-

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 350
maining during 14:00-15:00. In this season, 11 blasts
were monitored in coal and 9 blasts in overburden
benches. Only one coal bench was blasted frequently and
monitored in this season. For this coal bench, blasthole
depth for most of the blasts was 7.0 m to 7.5 m. Burden
was 7 m for all the blasts. Spacing was either 7 m or 8 m.
In case of overburden, blasts were conducted in different
benches. The blasthole depth varied from 12 m to 19 m.
Burden was from 6 m to 8 m and spacing was 6 m or 9
m.
In winter, all the 20 blasts were conducted during
13:00-14:00. Out of 20, 16 blasts were carried out in coal
and 4 blasts in overburden benches. The blasthole depth
varied from 7.0 m to 14.0 m in coal whereas from 10.5 m
to 18 m in overburden. Burden was either 6 m or 7 m in
coal and 8 m or 9 m in overburden. Spacing varied from
7.0 m to 8 m for coal and from 9 m to 10 m in overbur-
den.
In summer, out of 16 blasts, 2 blasts were conducted
during 14:00-15:00 and all others during 13:00-14:00. In
this season, 12 blasts were monitored in coal and 4 blasts
in overburden. In the coal, blasthole depth varied from
6.0 m to 13.0 m. Burden ranged from 3 m to 9 m or
spacing from 3 m to 9 m. In the overburden, blasthole
depth increased from 15.5 m to 20.0 m depending on the
height of the benches. Burden varied from 8 m to 10 m
while spacing was 9 m or 10 m.
In monsoon, all the 12 blasts were conducted during
13:00-14:00. Out of 12, 5 blasts were carried out in coal
and 7 blasts in overburden. In coal, blasthole depth var-
ied from 11 m to 12 m. Burden and spacing was either 7
m or 8 m. In the overburden, blasthole depth varied from
15 m to 18 m. Burden ranged from 8 m to 10 m while
spacing was 9 m to 10 m.
5.2.2. At Bharatpur Opencast Project
In post-monsoon, out of 10 blasts, 6 blasts were carried
out during 13:00-14:00 and remaining during 14:00-
15:00. All the blasts were monitored in coal seam-IV,
which was blasted by constructing three benches of 7 m,
7 m and 3 m high. Only this bench was suitable for dust
monitoring. Blasthole depths varied from 3 m to 7 m.
Burden and spacing varied from 3 m to 5 m.
In winter, blasts were conducted during different peri-
ods. Out of 10 blasts, 3 were conducted during 13:00-
14:00, 6 blasts during 14:00-15:00 and one during
15:00-16:00. Only coal seam-II was a suitable site for
blasting dust monitoring. Five benches were constructed
in this seam, among them only three benches were fre-
quently blasted and monitored. Blasthole depth of the
benches varied from 5 m to 8 m. Burden was either 4 m
or 4.5 m. Spacing varied from 4 m to 5 m.
5.3. Description of Dust Samplers
Respirable dust samplers, Instrumex IPM 115BL, were
used for measurement of particulate matter, both TSP
and PM10. This dust sampler utilises a two-stage collec-
tion system for fractionating the particulate matter sizes.
The first stage consists of a cyclone through which the
particles greater than 10 m sizes are separated from the
air stream by centrifugal forces acting on the solid parti-
cles. The separated particulate falls through the cyclone’s
conical hopper and is collected in the plastic cup placed
at its bottom [19]. PM10 is collected from the ambient air
in the second stage by filtering the air stream through the
glass microfibre filter. TSP consisted of both PM10 and
the particles greater than 10 m size. Whatman GF/A
filter papers of 203 mm × 254 mm size were used for
collection of PM10 and plastic cups for the particulate
matter greater than 10 µm size. The filter papers were
conditioned and desiccated [20] before and after sam-
pling. For determination of particulate matter mass, ini-
tial and final weight of plastic cups and filter papers were
taken using 235S Sartorius balance with sensitivity of
0.00001g. The flow rate of sampler was kept greater than
1.1 m3/min. The concentration of the particulate matter
was obtained from the difference (in micrograms) of the
final weight of filter papers exposed minus the initial
weight before exposure, divided by the sampled air vol-
ume (in cubic meter) [20,21].
5.3.1. Procedure for Dust Sampling
For particulate monitoring in an industrial area, often
respirable dust samplers are operated either in three shifts
of eight hours duration or continuously for twenty four
hours at fixed locations. In case of blasting dust moni-
toring, it is not possible to keep the samplers at a fixed
location because blast location changes time to time. Al-
so monitoring cannot be done for hours because the dust
emitted by blasting is dispersed quickly into the atmos-
phere. For the monitoring of dust, the sampler needs 230
V power supply for maintaining the flow rates greater
than 1.1 m3/min. In the mine, high voltage power of 6600
V was supplied by the main station through electric ca-
bles for the operation of heavy duty machineries such as
drill machines, shovels, and draglines. As high voltage
power could not be used for respirable dust samplers,
230 V power was taken only through the sockets of 230
V available inside the cabins of heavy duty machineries.
For the safety point of view, sometimes high voltage
power cable was disconnected from the heavy duty ma-
chineries. Hence samplers could not be operated. Alter-
native source of power supply was not available near the
blast bench. To overcome this problem, a petrol genera-
tor was also used for the operation of samplers depending
on the site condition. Since the amount of dust collected

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 351
by the samplers depends on the wind direction, the sam-
plers once installed in the downwind direction could not
be reinstalled due to deviation in wind direction at the
time of blasting. Mud, water logged area around the
blasting site and rain interfered the dust monitoring in
monsoon.
Dust samplers were installed at safe distances from the
blast site in the downwind direction. The safe distance or
distance depended on the size of blasts and on site condi-
tion. Also, installation of the samplers at a large distance
was not suitable because the blasting dust would get
mixed with the ambient air and hence it would be diffi-
cult to identify the contribution of dust by the blasting.
Before installation, many blasts were observed for the
accumulation period of dust in the downwind direction
and accordingly 20 minutes monitoring periods were
considered for sampling. After this period, the emitted
dust was dispersed completely into the atmosphere. Dur-
ing the blasting period, all other mining activities were
stopped, which is the usual practice for blast site clear-
ance. Therefore, blasting dust monitoring was not af-
fected by the other activities. The number of samplers
installed depended on the site conditions. They were in-
stalled either approximately parallel to blast locations or
at an increasing distance from the blast. All the partial or
non collection of particulate matter data due to change of
wind direction, getting the samplers tripped during mon-
itoring period, etc were discarded.
To assess the background dust concentrations, sam-
plers were operated for a duration of 20 minutes. The
dust collected was negligible. Hence the influence of
background dust concentrations was ignored for analysis.
5.4. Evaluation of Stability Classes Using Sodar
The details of sodar, installation and data generation for
Dudhichua project are presented in report [22]. Sodar
was operated continuously for 24-hours in post-monsoon,
winter, summer, and monsoon seasons at Dudhichua
project. In this analysis, stability classes, evaluated only
for blasting dust monitoring period was used.
After completing the study at Dudhichua project,
tri-axis monostatic (back-scattering) sodar was trans-
ported to Bharatpur opencast project and installed on the
roof of an office building. Sodar was operated continu-
ously for 24-hours in post-monsoon and winter at this
site and stability classes were determined using sodar
data for the blasting dust monitoring period for these
seasons.
5.5. Monitoring of Meteorological Parameters
The details of automatic weather station, installation and
results for Dudhichua project are presented in report [22].
The weather station was operated continuously for 24-
hours in post-monsoon, winter, summer, and monsoon at
Dudhichua project. But for the analysis, the data on wind
speed recorded during blasting dust monitoring period at
the mine site was used.
The same weather station was used at Bharatpur
opencast project. It was installed on the roof of an office
building adjacent to sodar. The weather station recorded
data continuously for 24-hours in post-monsoon and
winter. Wind speed data recorded during blasting dust
monitoring period were used for analysis.
6. Results and Discussion
6.1. Particulate Matter Concentrations
For Dudhichua project, particulate matters for coal and
overburden blasts at different locations in different sea-
sons are given in Tables 1 to 4. These tables include a
total of 20 blasts at 37 locations in post-monsoon (Table
1), 20 blasts at 52 locations in winter (Table 2), 16 blasts
at 32 locations (Table 3) in summer and 12 blasts in
monsoon at 30 locations (Table 4).
At Bharatpur opencast project, a total of 10 blasts at 19
locations in post-monsoon (Table 5) and 10 blasts at 20
locations (Table 6) in winter were monitored in coal.
The values of particulate concentrations are also men-
tioned in these tables.
6.2. Determination of Stability Classes Using
Mixing Height and Sodar Echograms
The details on mixing height and sodar echograms used
for determination of stability classes at Dudhichua pro-
ject for each season are presented in report [22]. The sta-
bility classes corresponding to the blasting dust monitor-
ing period at Dudhichua project are given in Tables 1 to
4. Similarly, stability classes determined for the blasting
dust monitoring period for two seasons at Bharatpur
opencast project are shown in Tables 5 to 6.
To assess the similarity in stability classes for both the
mine sites, percentage of atmospheric stability classes
was calculated in respective seasons. In post-monsoon,
only stability class A was observed to be 100% at the
each mine site. In winter, class A was 95% and B was
5% at Dudhichua project whereas class A occurred 90%
and B 10% at Bharatpur opencast project indicating that
there were some differences in stability classes at the
mine sites in this season.
6.3. Dispersion Coefficients
Two sets of dispersion coefficients are used in the Gaus-
sian plume models. The lateral dispersion coefficient (σy)
represents the horizontal spread of the plume perpen-
dicular to the direction of travel. The vertical dispersion
coefficient (σz) represents the spread of the plume in the

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 352
Table 1. Emission factors for coal and overburden in post-monsoon at Dudhichua project, NCL.
Dispersion
coefficient
(m)
Particulate matter
(µg/m3)
Calculated
emission factor
(g/m3)
Blast
no.
Date of
blasting
Blasting sche-
dule
No. of
dust
samplers
Distance
(m)
Stab.
class
Wind
speed
(m/s) σyσzPM10 TSP PM10 TSP
Volume of
rock
excavated
(m3)
Moisture
content
(%)
Rock
type
1 21.10.08 14:00-15:00 1 85 A 0.75 25172730119190.492.13 6720 13.97 Coal
2 23.10.08 13:00-14:00 1 90 A 0.90 25175083318 0.070.46 10500 13.97 Coal
3 25.10.08 13:00-14:00 1 135 A 1.08 34222621357 0.050.27 15120 4.68 OB
40 251711919964
35 2517291421613
4 26.10.08 14:00-15:00 3
35
A 1.71
2517 3742 37467
0.171.53 41328 3.53 OB
30 2517368422237
5 29.10.08 13:00-14:00 2 35 A 0.7725175380 35295 0.281.79 19836 4.68 OB
150 3821160610039
6 31.10.08 13:00-14:00 2 130 A 2.213321251515168 0.231.41 54720 4.29 OB
7 01.11.08 13:00-14:00 1 80 A 1.07 25172251149861.127.43 3456 3.78 OB
8 02.11.08 13:00 - 14:00 1 31 A 1.22251711187692 0.594.09 3675 13.97 Coal
35 25175675126
9 04.11.08 14:00-15:00 2 70 A 0.1925176582932 0.020.16 7718 13.97 Coal
70 25176905634
10 06.11.08 13:00-14:00 2 30 A 0.6225177216167 0.171.45 4043 13.97 Coal
75 25177813437
35 25176242047
11 10.11.08 13:00-14:00 3
35
A 1.15
251713325192
0.381.49 4410 13.97 Coal
12 13.11.08 13:00-14:00 1 90 A 0.5625172240152200.694.65 2940 13.97 Coal
130 33215023629
140 35229053057
13 14.11.08 13:00-14:00 3
155
A 1.35
39245661993
0.431.83 6248 13.97 Coal
35 251715178073
35 2517189611389
14 15.11.08 13:00-14:00 3
35
A 0.57
251714737391
0.311.72 4752 3.53 OB
15 16.11.08 13:00-14:00 1 85 A 0.6625172248101360.220.97 11025 13.97 Coal
95 25175152288
95 25179734832
16 17.11.08 13:00-14:00 3
95
A 0.18
251717557686
0.030.13 10633 13.97 Coal
17 18.11.08 13:00-14:00 1 130 A 0.61332132866259 0.280.52 19008 3.53 OB
100 25172371458
18 19.11.08 13:00 - 14:00 2 100 A 0.6225174221459 0.060.25 5880 13.97 Coal
80 2517181212176
80 251729852518219 21.11.08 13:00 - 14:00 3
80
A 0.54
251712917663
0.413.01 4320 6.24 OB
20 22.11.08 13:00 - 14:00 70 A 0.6125171134142400.172.15 6480 4.68 OB
OB: Overburden

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 353
Table 2. Emission factors for coal and overburden in winter at Dudhichua project, NCL.
Dispersion
coefficient
(m)
Particulate matter
(µg/m3)
Calculated
emission factor
(g/m3)
Blast
no.
Date of
blasting
Blasting
schedule
No. of
dust
samplers
Distance
(m)
Stab.
class
Wind
speed
(m/s)σy σz PM10 TSP PM10 TSP
Volume of
rock
excavated
(m3)
Moisture
content
(%)
Rock
type
1 24.1.09 13:00-14:00 1 70 A 0.7225 17 6321 382260.070.44 100440 7.55 OB
140 35 22722 4640
140 35 22912 5027
2 25.1.09 13:00-14:00 3
140
A 0.60
35 22669 4364
0.080.47 17472 10.82 Coal
80 25 17218317303
3 27.1.09 13:00-14:00 2 80 A 1.14 25 172822235990.080.63 59472 3.63 OB
30 25 17378731298
130 33 2116779727
4 29.1.09 13:00-14:00 3
130
A 1.41
33 21139111183
0.846.22 7923 15.5 Coal
100 25 17556 3404
100 25 17537 4565
5 31.1.09 13:00-14:00 3
100
A 1.13
25 17474 2824
0.080.56 11648 10.82 Coal
150 38 24172 1521
150 38 24176 1156
6 01.2.09 13:00-14:00 3
150
A 0.55
38 24472 2241
0.090.55 5600 10.82 Coal
60 25 171214337757
7 05.2.09 13:00-14:00 2 40 A 0.53 25 1712890432130.100.33 104904 5.7 OB
40 25 17217510079
40 25 17318224699
8 07.2.09 13:00-14:00 3
40
A 1.32
25 17149110010
0.915.97 5292 15.5 Coal
40 25 17538 1955
30 25 17128261309 08.2.09 13:00-14:00 3
30
A 0.69
25 17461 4555
0.211.15 4040 15.5 Coal
20 25 17146011021
20 25 1713586677
10 09.2.09 13:00-14:00 3
20
A 0.67
25 17172911727
0.301.92 5488 15.5 Coal
20 25 17201411260
30 25 1713356192
11 10.2.09 13:00-14:00 3
30
A 0.99
25 1711757610
0.754.17 3175 15.5 Coal
30 25 17807 2395
30 25 17603 334912 12.2.09 13:00-14:00 3
30
A 1.03
25 17234 12123
0.111.21 8114 15.5 Coal
30 25 1717938309
13 13.2.09 13:00-14:00 2 30 A 0.86 25 17130370540.140.70 15120 6.16 OB
30 25 1712105647
30 25 17920 499514 14.2.09 13:00-14:00 3
30
A 0.68
25 17738 6849
0.191.16 5488 15.5 Coal
30 25 1711616127
15 15.2.09 13:00-14:00 2 30 A 0.7425 171365102010.140.91 10584 15.5 Coal
100 25 17283 2353
100 25 17247 162816 17.2.09 13:00-14:00 3
100
A 0.46
25 17284 2748
0.040.30 5513 15.5 Coal
20 25 1714079505
20 25 1732831401917 18.2.09 13:00-14:00 3
30
A 0.47
25 1712869963
0.211.17 7203 15.5 Coal
66 25 17327713973
18 20.2.09 13:00-14:00 2 66 A 0.7425 17123980320.180.86 15092 10.82 Coal
16 18 12247711990
16 18 1221341983119 21.2.09 13:00-14:00 3
29
B 0.46
18 1215047755
0.060.41 11907 10.82 Coal
35 25 17391312377
20 22.2.09 13:00-14:00 2 35 A 0.4425 171420112410.231.04 8008 10.82 Coal
OB: Overburden

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 354
Table 3. Emission factors for coal and overburden in summer at Dudhichua project, NCL.
Dispersion
coefficient
(m)
Particulate
matter
(µg/m3)
Calculated
emission factor
(g/m3)
Blast
no.
Date of
blasting
Blasting
schedule
No. of dust
samplers
Distance
(m)
Stab.
class
Wind
speed
(m/s) σy σz PM10 TSPPM10 TSP
Volume of
rock
excavated
(m3)
Moisture
content
(%)
Rock
type
150 26175455282
1 27.4.09 13:00-14:00 2
150
B 1.91
2617857 3728
0.070.46 31185 6.78 OB
2 04.5.09 13:00-14:00 1 150 A 1.3838 241340142150.161.68 40095 6.78 OB
100 251713455378
3 07.5.09 13:00-14:00 2
40
A 1.95
25172406 18015
0.654.06 8995 15.44 Coal
80 1812557832684
80 18128421346314 08.5.09 14:00-15:00 3
80
B 1.89
18127007 41335
0.110.56 100000 4.87 OB
5 10.5.09 13:00-14:00 1 150 B 1.7126 175730159651.283.55 12800 14.19 Coal
160 40259988431
160 4025130289116 11.5.09 13:00-14:00 3
160
A 2.43
40251005 4799
0.845.63 12000 14.19 Coal
100 2517156412514
100 2517142813300 7 12.5.09 13:00-14:00 3
100
A 0.90
25171035 4423
0.302.27 6400 14.19 Coal
8 13.5.09 13:00-14:00 1 150 A 1.7438 241949108290.191.06 61380 6.12 OB
60 2517150111830
90 251774472869 15.5.09 13:00-14:00 3
150
A 1.46
3824916 5114
0.392.82 8320 14.19 Coal
10 16.5.09 14:00-15:00 1 60 A 1.2025172749158680.412.38 12800 14.19 Coal
11 17.5.09 13:00-14:00 1 60 A 1.2825173333132062.419.55 2835 13.91 Coal
55 2517379813938
12 18.5.09 13:00-14:00 2
55
A 1.75
25171990 10131
0.602.48 13608 13.91 Coal
70 2517419715639
13 23.5.09 13:00-14:00 2
50
A 1.30
25174065 30604
0.281.58 30576 14.19 Coal
14 24.5.09 13:00-14:00 1 150 A 0.423824999 81870.38 3.13 3780 15.44 Coal
60 2517226211750
60 2517263313709
15 25.5.09 13:00-14:00 3
60
A 2.04
25173150 23155
0.432.60 20384 14.19 Coal
80 25179693706
80 2517153210907
16 27.5.09 13:00-14:00 3
80
A 1.49
25171284 10521
0.604.01 4992 14.19 Coal
OB: Overburden

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 355
Table 4. Emission factors for coal and overburden in monsoon at Dudhichua project, NCL.
Dispersion
coefficient
(m)
Particulate
matter
(µg/m3)
Calculated
emission factor
(g/m3)
Blast
no.
Date of
blasting
Blasting
schedule
No. of dust
samplers
Distance
(m)
Stab.
class
Wind
speed
(m/s)
σy σz PM10 TSPPM10 TSP
Volume of
rock
excavated
(m3)
Moisture
content
(%)
Rock
type
70 25175871876
70 25174822208
1 13.8.09 13:00-14:00 3
70
A 0.66
25175543376
0.090.42 6336 17.11 Coal
90 25173712865
2 15.8.09 13:00-14:00 2
120
A 0.49
30204161251
0.060.28 6468 17.11 Coal
3 22.8.09 13:00-14:00 1 80 A 0.5725 1773417230.030.06 27000 6.28 OB
70 25174481030
70 251757 831 4 24.8.09 13:00-14:00 3
70
A 0.97
25174981509
0.110.36 4851 17.11 Coal
60 25174072219
60 2517424813
5 25.8.09 13:00-14:00 3
60
A 1.07
25 17 378 602
0.120.37 5632 17.11 Coal
60 251744112542
6 26.8.09 13:00-14:00 2
90
A 2.29
25 17 416 883
0.040.63 38880 5.11 OB
100 25175261087
7 30.8.09 13:00-14:00 2
100
A 0.88
25173991338
0.110.30 5760 6.28 OB
35 251715328611
42 2517201112342
8 01.9.09 13:00-14:00 3
51
A 0.38
25171867 13383
0.110.73 9600 6.28 OB
15 25176912940
15 25175712374
9 02.9.09 13:00-14:00 3
15
A 0.61
25177414833
0.110.56 5888 17.11 Coal
50 251713975328
50 2517738291710 09.9.09 13:00-14:00 3
50
A 0.62
25176071708
0.090.34 9600 6.28 OB
50 18128642905
11 10.9.09 13:00-14:00 2
50
B 0.46
18128484868
0.050.21 6800 6.28 OB
70 25175982101
12 12.9.09 13:00-14:00 2
70
A 0.57
25174001290
0.020.08 20400 6.28 OB
OB: Overburden

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 356
Table 5. Emission factors for coal and overburden in post-monsoon at Bharatpur opencast project, MCL.
Dispersion
coefficient
(m)
Particulate matter
(µg/m3)
Calculated
emission factor
(g/m3)
Blast
no.
Date of
blasting
Blasting
schedule
No. of
dust
samplers
Distance
(m)
Stab.
class
Wind
speed
(m/s)
σyσzPM10 TSP PM10 TSP
Volume of
rock
excavated
(m2)
Moisture
content
(%)
Rock
type
1 29.10.09 14:00-15:00 1 21 A 0.1725172068135460.100.67 5528 5.93 Coal
30 251711456466
30 25171776120402 02.11.09 13:00-14:00 3
30
A 0.24
25171403 12084
0.080.53 7350 9.96 Coal
3 03.11.09 13:00-14:00 1 30 A 2.4625177315768 1.3710.82 2100 5.93 Coal
100 25173921543
100 25174903890 4 05.11.09 13:00-14:00 3
100
A 3.37
25175813846
1.519.54 1750 9.96 Coal
33 25174461530
33 25173222398
5 06.11.09 13:00-14:00 3
33
A 1.12
25174973218
0.251.44 2975 5.93 Coal
100 2517142477
6 08.11.09 14:00-15:00 2
100
A 1.79
25172371305
0.160.73 3500 9.96 Coal
56 25172541004
7 09.11.09 13:00-14:00 2
56
A 0.27
2517118459
0.150.59 540 21.26 Coal
8 09.11.09 14:00-15:00 1 100 A 0.79251710437689 0.251.82 5355 5.93 Coal
100 25172852289
9 10.11.09 13:00-14:00 2
100
A 1.95
25173483566
0.393.58 2552 9.96 Coal
10 10.11.09 14:00-15:00 1 70 A 1.2225177806190 0.322.56 4725 5.93 Coal
vertical direction [23]. For known stability classes, σy and
σz as horizontal and vertical dispersion coefficients as a
function of downwind distances from the source using
Pasquill-Gifford curves [24] were determined using Fig-
ures 1 and 2. The dispersion coefficients for Dudhichua
project are shown in Tables 1 to 4.
For known stability classes, for Bharatpur opencast
project, the horizontal and vertical dispersion coefficients
were also evaluated by Figures 1 and 2. The values of
dispersion coefficients are shown in Tables 5 and 6.
6.4. Wind Speed
Wind speeds for the corresponding blasting period re-
corded at Dudhichua project are given in Tables 1 to 4. It
can be seen that there were no significant seasonal varia-
tions in wind speed. Wind speeds monitored at Bharatpur
opencast project are given in Tables 5 and 6.
To compare the wind speeds, average of wind speed at
the mine sites was calculated for respective seasons. The
average wind speed in post-monsoon at Dudhichua pro-
ject and Bharatpur opencast project was 0.87 m/s and
1.34 m/s respectively. In winter, the average wind speed
at Dudhichua project was 0.78 m/s and at Bharatpur
opencast project was 0.83 m/s. No significant differences
in wind speeds were observed at the mine sites during the
concerned seasons.
6.5. Calculation of Emission Factors
For known dust concentrations, dispersion coefficients
and wind speeds, emission rates for blasting were calcu-
lated using the following modified Pasquill and Gifford
formula (1,25,26).

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 357
Table 6. Emission factors for coal and overburden in winter at Bharatpur opencast project, MCL.
Dispersion
coefficient (m)
Particulate
matter
(µg/m3)
Calculated
emission
factor
(g/m3)
Blast
no.
Date of
blasting
Blasting
schedule
No. of dust
samplers
Distance
(m)
Stab.
class
Wind
speed (m/s)
σy σz PM10 TSP PM10 TSP
Volume
of rock
excavated
(m3)
Moisture
content
(%)
Rock
type
40 25 17 10105093
1 08.01.10 14:00-15:00 2
40
A 0.96
25 17 20096314
0.913.44 2552 4.34 Coal
55 25 17 10536345
2 08.01.10 14:00-15:00 2
55
A 0.96
25 17 11325789
0.794.39 2126 3.25 Coal
44 25 17 10956935
3 09.01.10 13:00-14:00 2
44
A 0.89
25 17 9866268
1.167.35 1280 10.25 Coal
25 25 17 11815996
4 10.01.10 14:00-15:00 2
25
A 0.61
25 17 10416012
0.784.23 1386 3.25 Coal
75 25 17 5212661
5 11.01.10 13:00-14:00 2
75
A 0.63
25 17 5212661
0.170.77 2977 10.25 Coal
100 25 17 238971
6 11.01.10 14:00-15:00 2
80
A 1.37
25 17 2621894
0.191.11 2835 4.34 Coal
40 25 17 353612326
7 11.01.10 14:00-15:00 2
40
A 1.37
25 17 363811368
1.224.01 6480 3.25 Coal
55 25 17 12585325
8 12.01.10 13:00-14:00 2
70
A 0.56
25 17 7514826
0.361.81 2520 3.25 Coal
60 25 17 7222049
9 13.01.10 14:00-15:00 2
60
A 0.78
25 17 5182860
0.652.58 1188 10.25 Coal
35 18 12 7412430
10 14.01.10 15:00-16:00 2
35
B 0.18
18 12 6582124
0.070.23 1448 10.25 Coal
,0x
y
z
Q
Cu


 (1)
where Cx,0 is the pollutant concentration (g/m3), Q is the
pollutant emission rate (g/s), п = 3.14159, u is the mean
wind speed (m/s), σy is the horizontal dispersion coeffi-
cient, σz is the vertical dispersion coefficient.
TSP and PM10 values for different seasons indicated
pollutant concentrations (Cx,0) in (1). Blasting was con-
sidered as volume source and hence emission factors
were calculated in gram per cubic meter of the rock ex-
cavated. Emission factors for different blasts for different
seasons for Dudhichua project are given in Tables 1 to 4.
The statistics of emission factors for coal and over-
burden for all the seasons is shown in Table 7. It is ob-
served that the average emission factor for PM10 and TSP
in coal blasts is higher than that for overburden blasts,
indicating that per cubic meter of coal bench blasted
emits more dust into the atmosphere than overburden.
This may be explained by the higher in-situ percentage of
dust in coal compared to overburden.
The emission factors for all the blasts of Bharatpur
opencast project were also calculated for post-monsoon
and winter using the procedures as followed for Dudhi-
chua project. The emission factors for the Bharatpur
opencast project are shown in Tables 5 and 6. Some
variations were found in the emission factors when com-
pared for the respective seasons of the mines indicating

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 358
Figure 1. Horizontal dispersion coefficient σy vs downward
distance from source.
Figure 2. Vertical dispersion coefficient σz vs downward
distance from source.
that emission factors are site-specific.
6.5.1. Influence of Moisture Content on Emission
Factors
Since the moisture content in mine benches vary from
season to season, the calculated PM10 and TSP emission
Table 7. Emission factors for coal and overburden for Dud-
hichua project, NCL.
Emission factor (g/m3 )
Coal Overburden
Statistics
TSP PM10 TSP PM10
Minimum 0.13 0.02 0.06 0.02
Maximum 9.55 2.41 7.43 1.12
Mean 2.08 0.38 1.17 0.18
Standard
deviation 2.04 0.43 1.53 0.22
factors in different seasons for different blasts were plot-
ted for all the data (Figures 3 (a), (b)). Emission factors
for PM10 and TSP are higher in summer and the lowest in
monsoon indicating higher dust emission in summer. The
presence of higher moisture content in monsoon might be
the reason for decrease in emission factor in this season.
The particulate emissions depend on the moisture content
of the material blasted [3,6]. The emissions are lower
when the moisture content is higher and vice versa.
Though there is no control method or emission reduction
technique for blasting in coal and overburden [7], mois-
ture content influenced the emissions of blasting dust.
6.5.2. Frequency Distribution of Emission Factors
Histograms with normal distribution curve of PM10 and
TSP emission factors were plotted by combined data sets
of 68 blasts including coal and overburden (Figures 4(a),
(b)) using SPPS software version 13.0. For PM10 emis-
sion factor, frequency was the highest for the range of
0.02-0.25 g/m3 and for TSP, the highest frequency oc-
curred for the range 0.06-1.00 g/m3 indicating that max-
imum number of emission factors occurred in this range.
The emission factor values are normally distributed in
positive direction. Most of the areas of histograms are
under normal distribution curve. According to McClave
and Sincich [27], histograms display the frequency of the
measurements falling into specified intervals. The normal
distribution plays a very important role in the science of
statistical inference. Its physical appearance is that of a
symmetrical bell-shaped curve, a histogram is said to be
approximately normal when the areas of the rectangles
are approximately equal to corresponding areas under a
normal curve [28].
7. Application of Emission Factor for
Quantification of Blasting Dust
Each mine of NCL regularly conducts more than two
large blasts everyday for excavation of coal or overbur-

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 359
(a) (b)
Figure 3. (a) Seasonal variations in emission factors of PM10 at Dudhichua project; (b) Seasonal variations in emission factors
of TSP at Dudhichua project.
(a) (b)
Figure 4. (a) Histograms with normal distribution curve for PM10 emission factors at Dudhichua project; (b)Histograms with
normal distribution curve for TSP emission factors at Dudhichua project.
den removal. The excavated materials during 2008-09
revealed that thousands of blasts were conducted in the
mines (Table 8). As a result, huge amount of dust would
have emitted into the atmosphere and would have de-
pleted the air quality in and around the mining area. It
would certainly be interesting to quantify the dust gener-
ated by blasting. Once the amount of dust generation is
ascertained, the impact on air environment can be evalu-
ated and proper mitigative measures would be thought of
for control of dust pollution caused by blasting in the
area. The quantification of blasting dust can be done by
the emission factor. At Dudhichua project, the average
emission factor for coal was 0.38 g/m3 and 2.08 g/m3 for
PM10 and TSP respectively. For overburden benches,
these were 0.18 g/m3 and 1.17 g/m3 for PM10 and TSP
respectively. Since mining, geological conditions and
meteorological parameters of this area are identical; these
emission factors can be used to quantify the dust gener-
ated for known volume of overburden and coal. Accord-
ing to USEPA [1] and Cole and Kerch [3], a mine-spe-
cific emission factor can be used only if the characteris-
tics of the mine for which emission estimate is needed
are very similar to those of the mine for which the emis-
sion factor was developed. Using the emission factors,
the quantity of dust emitted during 2008-09 were calcu-
lated for the volume of rock excavated during this period
(Table 8). From this table, it is clear that huge amount of
dust were emitted during production of coal and removal
of overburden. This calculated dust emission can help the
mining officials to know which of the mines generated
high dust into the atmosphere and accordingly they could
adopt control measures for high dust emitting mines.
Considering that NCL is planning to increase production,
the dust emission will certainly increase in future unless

Development of Emission Factors for Quantification of Blasting Dust at Surface Coal Mines 360
Table 8. Calculated particulate emissions for coal production and overburden removal at different mines of NCL during
2008-09.
Particulate emissions (kg) Particulate emissions (kg)
Name of the mine Coal production
(million m3) PM10 TSP
Overburden
removal
(million m3) PM10 TSP
Jhingurdha 2.38 904 4950 4.56 821 5335
Bina 3.36 1277 6989 27.16 4889 31777
Jayant 8.04 3055 16723 25.83 4649 30221
Kakri 1.81 688 3765 12.13 2183 14192
Dudhichua 8.19 3112 17035 34.36 6185 40201
Amlohri 3.26 1239 6781 24.02 4324 28103
Nigahi 7.20 2736 14976 39.41 7094 46110
Khadia 2.27 863 4722 15.64 2815 18299
Block B 2.12 806 4410 9.17 1651 10729
Krishnashila 0.67 255 1394 10.48 1886 12262
Total 39.30 14934 81744 203 36497 237229
dust control measures are adopted. The emission factors
can be used by mining officials to determine the expected
annual emissions, which can be used to categorize the
mines generating high or low dust due to blasting opera-
tion. The emission factors provide engineers, planners,
and regulators with a tool for assessing the potential en-
vironmental impacts of planned or existing blasting dust
emission so that control efforts can be applied in a
cost-effective manner. Hence the computed emission
factors have an immense significance in the field of en-
vironmental protection. The developed emission factor
for blasting dust can also be used during EIA study and
hence preparation of EMP.
8. Conclusions
 For the conditions of Dudhichua project, the aver-
age emission factor for coal was 0.38 g/m3 for
PM10 and 2.08 g/m3 for TSP. For overburden, the
average emission factor was observed to be 0.18
g/m3 and 1.17 g/m3 for PM10 and TSP respectively.
These values can be used to estimate the emission
quantities generated due to blasting.
 Seasonal variation in emission factors indicated
that the emission factor was the lowest in monsoon
due to higher moisture content in this season.
 As all the mines of NCL are located adjacent to
each other and mining and meteorological condi-
tions are identical, emission factors developed for
Dudhichua project can also be applied for all the
adjacent mines.
 The emission factors for Bharatpur opencast pro-
ject for post-monsoon and winter seasons were
compared with those for Dudhichua project, which
shows that emission factors are site-specific, unless
geo-mining and meteorological conditions are
identical.
9. Acknowledgements
This research work is a part of Ph. D. work of the prince-
pal author. The financial support from the Ministry of
Coal, Government of India through Central Mine Plan-
ning & Design Institute Limited, Ranchi is gratefully
acknowledged. We are also thankful to the management
of Dudhichua project, Northern Coalfields Limited and
Bharatpur opencast project, Mahanadi Coalfields Limited
for providing necessary facilities during the field study.
The authors are thankful to the Director, National Insti-
tute of Rock Mechanics, for his permission to publish
this paper. Thanks are also due to Mr. T. A. Renaldy for
his help in conducting the field study.
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