6
representative regions across the United States that have
high, medium, and low prevalence of CWP or PMF. The
data from these characterizations were to be used in the
model. However, while a model was constructed, it was not
comprehensive enough to provide valid results due to the
insufficient number of samples collected.
Characterization of Submicron-/Nano-scale Coal Dusts and
Their Effects on Miners’ Pneumoconiosis and Lung Cancer
for Underground Coal Mines—The Pennsylvania State
University
A characterization of submicron/nano-scale coal dust par-
ticles of different grades of coal and analyze the interaction
between nano-scale coal dust (NCD) and lung cells was
conducted. The toxicity of coal dust and its varying com-
position could be primary factors for CWP. Recent stud-
ies have confirmed that nano-sized particles are potentially
more toxic due to their unique physicochemical proper-
ties and easier uptake by living organisms. The underlying
mechanism of miners’ lung diseases due to the exposure
of NCDs is not well-understood and their role in CWP
is largely unknown. This characterization for NCD was
completed using different analysis methods: field emission
scanning electron microscopy, x-ray photoelectron spec-
troscopy (XPS), x-ray diffraction, and free radical analysis.
Additionally, testing to evaluate the biological effects of
NCD on lung tissue was completed several different tests
were conducted. Results showed that NCD has higher sur-
face area and pore volumes but the oxygen content in NCD
are lower than micron sized material. The higher surface
area of NCD and lower oxygen, which could be related
to weaker wetting behavior, indicates that inhalation of
NCD could have potentially higher adverse effects on min-
ers’ health by inducing cells to secrete inflammatory factors
which produces an inflammatory response in the lung tis-
sue cells.
Temporal and Spatial Characterization of Respirable Coal
Mine Dust—Michigan Technological University
Researchers from Michigan Tech conducted tests on coal
samples obtained from mines in Utah, Colorado, and
Indiana. The goal was to provide more information on the
variation of the RCMD during the mining cycle at mul-
tiple locations within the mine to reduce cumulative miner
exposure to RCMD. The characterization technologies
used included scanning electron microscopy with energy
dispersive x-ray spectroscopy (SEM/EDX), x-ray (micron
and nano) computed tomography, field-flow fractionation,
and micro x-ray fluorescence spectroscopy to determine
size and composition from individual particles. Results
showed that the elemental and mineral compositions of
RCMD particles vary with coal geology and mine activi-
ties. Nanoparticles were present in both the coal particles as
well as the silica particles. While the number of nanoparti-
cles can be high, the weight is low. Results of testing found
that the nano-sized fraction made up 3–10% by weight.
Generally, the percentage of nano-sized dust particles varies
with mine locations and mine activity as well.
Characterization of Respirable Coal Mine Dust Size
Distribution, Chemical Composition, and Source
Contributions—University of Nevada, Reno
A comprehensive assessment of respirable coal mine dust
(RCMD) particle characteristics was underway because
different particle characteristics (for example, composi-
tion and surface area) can potentially pose different health
hazards. An extensive literature review was completed
reviewing RCMD measurement methods, particle size
characterization, and chemical composition and methods
of determination. The collection of RCMD samples at
various locations in underground coal mines was also com-
pleted. These samples were analyzed from two mines, an
eastern coal mine and a western coal mine, to character-
ize the particle size distribution and determine the chemi-
cal composition of the material. Overall, the silica content
ranged from 4.9% -24.6%. The eastern coal mine samples
contained more calcium carbonate, thought to be related
to rock dusting practices. The western coal mine samples
contained more elemental carbon, due to the fact the mine
used diesel equipment underground. Analyzing the sam-
ples for transition metals (V, Cr, Fe, Ni, Cu, Al (oxide),
Zn (oxide), and Pb) showed that all concentrations were
below exposure limits (RELs) and limits for Immediately
Dangerous to Life and Health (IDLH) [38].
Real-Time Respirable Silica Monitors
NIOSH maintains a portfolio of contracts let to develop
real-time respirable dust and respirable silica dust monitors.
The goal is to develop an instrument that is low cost and
can provide real time results with accuracy and precision.
Two of the active contracts do not focus on developing
instrumentation, but rather focus on developing filters for
the CPDM that can be used for silica analysis. These two
contracts are considered an important step towards the goal
of developing near real-time respirable silica dust monitors.
Currently there are 7 active contract and 1 completed con-
tract. An overview is provided for each.
representative regions across the United States that have
high, medium, and low prevalence of CWP or PMF. The
data from these characterizations were to be used in the
model. However, while a model was constructed, it was not
comprehensive enough to provide valid results due to the
insufficient number of samples collected.
Characterization of Submicron-/Nano-scale Coal Dusts and
Their Effects on Miners’ Pneumoconiosis and Lung Cancer
for Underground Coal Mines—The Pennsylvania State
University
A characterization of submicron/nano-scale coal dust par-
ticles of different grades of coal and analyze the interaction
between nano-scale coal dust (NCD) and lung cells was
conducted. The toxicity of coal dust and its varying com-
position could be primary factors for CWP. Recent stud-
ies have confirmed that nano-sized particles are potentially
more toxic due to their unique physicochemical proper-
ties and easier uptake by living organisms. The underlying
mechanism of miners’ lung diseases due to the exposure
of NCDs is not well-understood and their role in CWP
is largely unknown. This characterization for NCD was
completed using different analysis methods: field emission
scanning electron microscopy, x-ray photoelectron spec-
troscopy (XPS), x-ray diffraction, and free radical analysis.
Additionally, testing to evaluate the biological effects of
NCD on lung tissue was completed several different tests
were conducted. Results showed that NCD has higher sur-
face area and pore volumes but the oxygen content in NCD
are lower than micron sized material. The higher surface
area of NCD and lower oxygen, which could be related
to weaker wetting behavior, indicates that inhalation of
NCD could have potentially higher adverse effects on min-
ers’ health by inducing cells to secrete inflammatory factors
which produces an inflammatory response in the lung tis-
sue cells.
Temporal and Spatial Characterization of Respirable Coal
Mine Dust—Michigan Technological University
Researchers from Michigan Tech conducted tests on coal
samples obtained from mines in Utah, Colorado, and
Indiana. The goal was to provide more information on the
variation of the RCMD during the mining cycle at mul-
tiple locations within the mine to reduce cumulative miner
exposure to RCMD. The characterization technologies
used included scanning electron microscopy with energy
dispersive x-ray spectroscopy (SEM/EDX), x-ray (micron
and nano) computed tomography, field-flow fractionation,
and micro x-ray fluorescence spectroscopy to determine
size and composition from individual particles. Results
showed that the elemental and mineral compositions of
RCMD particles vary with coal geology and mine activi-
ties. Nanoparticles were present in both the coal particles as
well as the silica particles. While the number of nanoparti-
cles can be high, the weight is low. Results of testing found
that the nano-sized fraction made up 3–10% by weight.
Generally, the percentage of nano-sized dust particles varies
with mine locations and mine activity as well.
Characterization of Respirable Coal Mine Dust Size
Distribution, Chemical Composition, and Source
Contributions—University of Nevada, Reno
A comprehensive assessment of respirable coal mine dust
(RCMD) particle characteristics was underway because
different particle characteristics (for example, composi-
tion and surface area) can potentially pose different health
hazards. An extensive literature review was completed
reviewing RCMD measurement methods, particle size
characterization, and chemical composition and methods
of determination. The collection of RCMD samples at
various locations in underground coal mines was also com-
pleted. These samples were analyzed from two mines, an
eastern coal mine and a western coal mine, to character-
ize the particle size distribution and determine the chemi-
cal composition of the material. Overall, the silica content
ranged from 4.9% -24.6%. The eastern coal mine samples
contained more calcium carbonate, thought to be related
to rock dusting practices. The western coal mine samples
contained more elemental carbon, due to the fact the mine
used diesel equipment underground. Analyzing the sam-
ples for transition metals (V, Cr, Fe, Ni, Cu, Al (oxide),
Zn (oxide), and Pb) showed that all concentrations were
below exposure limits (RELs) and limits for Immediately
Dangerous to Life and Health (IDLH) [38].
Real-Time Respirable Silica Monitors
NIOSH maintains a portfolio of contracts let to develop
real-time respirable dust and respirable silica dust monitors.
The goal is to develop an instrument that is low cost and
can provide real time results with accuracy and precision.
Two of the active contracts do not focus on developing
instrumentation, but rather focus on developing filters for
the CPDM that can be used for silica analysis. These two
contracts are considered an important step towards the goal
of developing near real-time respirable silica dust monitors.
Currently there are 7 active contract and 1 completed con-
tract. An overview is provided for each.