sand mining and transport: potential health effects · exposures from sand mining, processing, and...
TRANSCRIPT
Sand Mining and Transport:
Potential Health Effects
Thomas M. Peters, PhD, CIH
Associate Professor
University of Iowa
Iowa City, IA
Midwest Environmental Health Policy Summit
Feb 2014
Hydraulic Fracturing Well
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http://www.sustainable.co.za/blog/2013/10/karoo-fracking-what-you-need-to-know/
Sand In The Heartland
• 500-million-year-old rock formations contain high quality silica sand
• Deposits particularly well-suited for hydraulic fracturing (fracking) – Round and hard
– Can be screened to be a certain size
• Ideal for use as a proppant to hold open fissures in stone in a frack well
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http://www.startribune.com/local/blogs/136612183.html
Example In Illinois
Ottawa Peru/Lasalle
Starved Rock
State Park
Sand Mining
Remove overburden
Extract deposit
http://www.mintpressnews.com/sand-land-fracking-industry-mining-iowas-
iconic-sand-bluffs-in-new-form-of-mountaintop-removal/63310/
Transport to processing
http://www.kenworth.com/news/news-
releases/2012/january/fleets-haul-in-savings-with-
kenworth-t660-regional-haulers.aspx
Sand Processing & Shipping
http://tanzaniacrusher.org/wp-
content/uploads/2013/04/sand-
line5.jpg
http://www.kaieteurnewsonline.com/2011/08/23/court-paves-
way-for-continuation-of-sand-loading-for-export/
Barge Truck
http://www.hulcher.com/industries/frac-sand/
Train
Many Complex Issues
• Community issues involved in deciding
whether to develop this resource
Pros
• Develop economic
base
• Increase jobs
Cons
• Increase pollution
• Increase noise,
trucking
• Road wear
• Loss of natural beauty
• Loss of tourism
http://buffalo.uwex.edu/files/2011/12/Revised-Economic-growth-mining-version-1-4.pdf 7
doi: http://dx.doi.org/10.2190/NS.23.1.c
Particulate Matter (PM)
Air Pollution
• Hot processes
– Vapor particle
– Dp < 1 µm
– Combustion (e.g., diesel
engine)
• Mechanical processes
– Dp > 1 µm
– Grinding, sanding,
excavating
Particle Diameter
Ma
ss
0.001 0.01 0.1 1 10 µm 1 10 100 1000 104 nm
Nucleate Condense
Vapor Mechanical
Generation
Dust
Mist
Spray
Fume
Smoke
Smog
http://www.huffingtonpost.com/2012/12/11/fracking-illinois-frac-sand-
starved-rock-state-park_n_2278005.html
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Basis for PM Regulation
• Increased respiratory symptoms, such as irritation of the airways, coughing, or difficulty breathing
• Decreased lung function
• Aggravated asthma
• Development of chronic bronchitis
• Premature death in people with heart or lung disease
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PM Regulations
• EPA (community health) – All particle types
– PM smaller than 10 um (PM10)
<155 ug/m3 over 24-hr
– PM smaller than 2.5 um (PM2.5)
<12 ug/m3 annual avg; <35 ug/m3 over 24-hr
– Only measured in 8 locations in Iowa
– State issues permits to ensure compliance
• MSHA and OSHA (worker health) – Respirable (~PM4)
Particles that enter the deep lung
All particle types and specific compounds
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Respirable Crystalline Silica
• Specific component of PM of concern for mining of sand – Silicosis (fibrosis or scarring of lung)
– Lung cancer
• Regulatory levels – OSHA
PM4 - 100 µg/m3
Protect workers
– Some states (MN, CA) PM4 - 3 µg/m3
Protect everyone, including venerable populations
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Silicosis
• Repeat injury;
granuloma
formation; scarring
• Gradual progression
• Once scarring,
generally
irreversible
Normal Alveolus Injured Alveolus
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Are there risks? We know PM and
respirable crystalline silica
are hazards. But what
about from sand activities?
What do we know
about exposures?
http://www.plasticisers.org/en_GB/science/risk-vs-hazard
Exposures From Sand Mining,
Processing, and Handling
• Sand mining and processing generate airborne PM and respirable crystalline silica – Blast, load, and haul
– Process activities such as crushing
– Shipping and disposal of “waste sand”
• Occupational exposures (miners, transporters) – Common to exceed OSHA standards for respirable
cyrstalline silica
– Ways to control are well documented
• Community exposures – Less clear
– No required monitoring
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Our Work:
Answer Several Questions
1. Is particulate matter from sand mining operations hazardous?
2. What are community exposures to PM and respirable crystalline silica?
3. What are risks of developing adverse health effects from inhalation of particulate matter from a sand mine?
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Is PM from sand mining operations
hazardous?
• Collected sand types – Unprocessed sand from mine
– Processed frac sand
• Characterize physicochemical properties – Size distribution
– Composition
• Evaluating toxicity – Cell testing (in vitro)
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Done
On-going
Summer
Sieve Analysis
40
60
80 100
Mesh Sizes Mine
Sand
Processed
Sand
• Largest sand
removed
• Some ‘fines’
removed but a lot
still present
• ‘Fines’ present
health hazard Particle Diameter, µm
‘fines’
‘fines’
Sand is not one size
Wind Simulation
Median Diameter = 2 μm
Wind blowing over mine sand or processed sand can generate
airborne respirable particles
Next, we will assess crystalline silica content
Mass C
oncentr
ation
Respirable (< 4 µm)
Particle Diameter, µm
What are community exposures to
PM and respirable crystalline silica?
• Atmospheric dispersion modeling
• Air monitoring and sampling
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Sites to Model
• Processing Plant with Sand Piles
• Sand Mine
Model Inputs And Receptors Processing Plant
Property Line
Preschool
Hospital
Model Inputs
Wind Rose
Receptors • Dust emission rates
for sources
• Topography
• Meteorological data
Sand Processing
Emission Sources Sand from mine
Dry to
remove
moisture
Silo Storage
Load on
trains
Wash &
Screen
PM10 Without Fugitive Emissions
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Preschool
Hospital
Highest values
Open Mine Modeling
• WDNR Lists the following as sources of PM
– Drilling
– Blasting
– Crushing
– Screening
– Conveyers/Stackers
– Material Handling
– Paved Hauling
Air Sampling And Monitoring
• Traditional air sampling – EPA reference method sampling in towns
with heavy mining
– Respirable crystalline silica monitoring outside homes
• Real-time monitoring – First deployment trains carrying sand
– Other processes (load barges, processing plants, etc)
• Low-cost detectors – <~$1k for continuous monitoring of mine or
process
Starting Up
Summer
Starting Up
Real-time Monitoring
Camera
Sound and
Vibration
Triggers
Particle Monitor
60-80 trains per day
pass on two tracks
0 100 200 300 400 500
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:54
1
3:1
9
13
:44
1
4:1
0
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:36
1
5:0
3
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:29
1
5:5
5
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:21
1
6:4
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:12
1
7:3
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:03
1
8:2
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:52
1
9:1
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:43
2
0:0
8
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:33
2
0:5
8
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:23
2
1:4
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:12
2
2:3
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:02
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3:2
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:52
0
:17
0
:41
1
:06
1
:31
1
:55
2
:20
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:45
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:10
3
:35
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:00
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:24
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:49
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:14
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:39
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:03
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:28
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:53
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:17
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:42
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:07
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:32
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:56
9
:21
9
:46
1
0:1
1
10
:35
1
1:0
0
11
:25
Time
0
1
12
:54
1
3:1
9
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:43
1
4:0
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14
:33
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4:5
9
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:25
1
5:5
0
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:16
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6:4
1
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:06
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7:3
0
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:55
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8:1
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:43
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9:0
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:32
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9:5
6
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:21
2
0:4
5
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:09
2
1:3
3
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:57
2
2:2
2
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:46
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3:1
0
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:34
2
3:5
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0:2
3
0:4
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1:1
1
1:3
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1:5
9
2:2
3
2:4
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3:1
1
3:3
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4:0
0
4:2
4
4:4
8
5:1
2
5:3
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6:0
0
6:2
4
6:4
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7:1
2
7:3
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8:0
0
8:2
4
8:4
8
9:1
2
9:3
6
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:01
1
0:2
5
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:49
1
1:1
3
Time
trains
Trains Cause Spike In PM10
Almost all spikes in
concentration correlate
with train passing
Sometimes
spike missing or
much lower
Train
No Train
Night Clear problem with
train detection;
suspect wind
PM
10, µ
g/m
3
Next: Associate types of trains from pictures with spikes
Low-Cost Detectors
• Best practices to suppress dust from sand
mining operations are available
• However, no monitoring is performed to
ensure practices are followed
– EPA monitors are too expensive ($20K each)
• We will apply low-cost detectors ($400) to
assess PM concentrations near sand mines
Summer
Summary
• Sand is big business in the Heartland of the US
• Sand mining operations present complicated
issues that state agencies and local
communities must deal with
• We hope to answer some key questions related
to ambient air exposures
– PM4 / respirable crystalline silica
– PM2.5 / PM10
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