Slides from a presentation given at a Fracking and Health: Research Workshop held in London on the 15 November, 2013. Sponsored by the Irish Environmental Protection Agency

1. Occupational health issues
associated with fracking
John Cherrie
INSTITUTE OF OCCUPATIONAL MEDICINE . Edinburgh . UK
www.iom-world.org

2. Summary…
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Workplace regulations
Hazardous substances
Main potential risk from crystalline silica
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Silicosis, COPD, renal failure and lung cancer
Putting these risks in context
What can be done about this problem?
Appropriate health surveillance
Managing other risks to health

3. COSHH Regulations
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Finding out what the health hazards are
Undertaking a risk assessment
Providing control measures to reduce harm
to health
Making sure they are used
Keeping control measures in working order
Providing information, instruction and
training for employees and others
Undertaking monitoring and health
surveillance

4. Occupational Hazards
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Diesel engine exhaust
Volatile organic compounds
Hydrogen sulfide (H2S)
Acid gases (HCl)
Metals (Pb)
Aldehydes
Water and other additives
Respirable crystalline silica

5. Exposure to crystalline silica
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NIOSH measured exposure levels at
11 fracking sites in 5 states
NIOSH Recommended Exposure Limit
REL = 0.05 mg/m3 as an 8-hour
average
British Workplace Exposure Limit
WEL = 0.1 mg/m3
Esswein EJ, Breitenstein M, Snawder J, Kiefer M, Sieber WK (2013) Occupational
exposures to respirable crystalline silica during hydraulic fracturing. J Occup Environ Med
10: 347–356.

6. With permission from Eric J. Esswein, NIOSH

7. With permission from Eric J. Esswein, NIOSH

8. Crystalline silica
EssweinEJ, et al (2013) Occupational exposures to respirable crystalline silica during
hydraulic fracturing. J Occup Environ Med 10: 347–356.

9. Respirable crystalline silica in EU

10. Main hazards from crystalline silica
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Silicosis
Tuberculosis
Chronic obstructive pulmonary disease
Lung cancer
Chronic renal disease
Scleroderma
Rheumatoid arthritis

11. Risks from USA silica sand workers
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Steenland and Sanderson (2001)
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4,626 industrial sand workers
Average employment was 9 years and
estimated average exposure was 0.05 mg/m3
Cause of death
(SRR)
<0.1
mg/m3.yr
0.1-0.5
0.5-1.28
mg/m3.yr mg/m3.yr
>1.28
p for trend
mg/m3.y
r
Lung cancer
(15 yr lag)
1.0
0.78
1.51
1.57
Silicosis
1.0
1.22
2.91
7.39
Other resp. disease,
inc silicosis
1.0
1.63
1.45
2.4
0.07
<0.00001
0.02
Steenland K, Sanderson W (2001) Lung cancer among industrial sand
workers exposed to crystalline silica. Am J Ind Med 153: 695–703.

12. Risks from UK silica sand workers
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Brown and Rushton (2005)
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2,703 employees / former employees at seven
quarries
Overall geometric mean silica concentration was
0.09 mg/m3
Cause of death
(RR)
<0.13
mg/m3.yr
0.13-0.4
mg/m3.yr
0.4-1.0
mg/m3.yr
>1.0
mg/m3.yr
p for
trend
Lung cancer (no lag)
1.0
1.14
1.12
0.92
0.80
Non-malignant resp.
disease
1.0
1.33
0.98
1.12
0.98
Brown TP, Rushton L (2005) Mortality in the UK industrial silica sand
industry: 2. A retrospective cohort study. Occup Environ Med 62: 446–

13. Silica surface properties…
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IARC noted… “carcinogenicity in humans
was not detected in all industrial
circumstances studied, carcinogenicity may
be dependent on inherent characteristics of
the crystalline silica…”
Cancer and silicosis risk most probably arise
from inflammation
Key physicochemical parameters are
surface reactivity and particle size (surface
area)
Borm PJA, Tran L, Donaldson K (2011) The carcinogenic action of crystalline silica: A
review of the evidence supporting secondary inflammation-driven genotoxicity as a
principal mechanism. Crit Rev Toxicol 41: 756–770.

14. Surface treated quartz
Duffin R, Tran CL, Clouter A, Brown D, MacNee W, et al. (2002) The Importance of
Surface Area and Specific Reactivity in the Acute Pulmonary Inflammatory Response to
Particles. Ann OccupHyg 46: 242–245.

15. Health surveillance
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Where there is a reasonable likelihood of
silicosis developing, health surveillance will
be necessary.
Baseline assessment of health status
Clinical examination
Work history information
Chest x-rays
Symptoms questionnaire / lung function
Screening for chronic kidney disease?

16. Exposure controls
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Prevention through Design
Remote operations
Substitution (ceramic vs. sand)
Mini‐baghouse, screw augur assemblies
Passive enclosures, e.g. stilling curtains
Minimize distance that sand falls
End caps on fill nozzles
Effective respiratory
protection program

17. Questions?
NIOSH proposed mini-baghouse unit