Potential Public Health Risks of Silica Sand Mining and Processing

Wayne L Feyereisn MD FACP

Disclaimer

• No financial disclosures• Research performed on personal time• References are based on peer reviewed

journal articles except where noted• “What is needed “ section is authors

conclusions based on the information presented.

The Main Message

What is Silica Sand?

Why is “our” sand important?

• It’s Round – therefore it works better to pipe it down wells and Prop open fractured layers of shale

• Its Hard- 8000 PSI of compression strength• Its Plentiful

Why our sand is plentiful

Why is it risky?

• Our lungs have a great clearing mechanism in the bronchi- Anything larger than 10 microns is effectively cleared. Deposited in the mucus layer, goes to our gut and gets cleared.

• Anything smaller than 10 microns, especially those particles smaller than 4 microns easily go all the way to the alveoli (air sacs )

Size Matters

Why is it risky?

What does it look like?

What else?

• Silicosis is a Class 1 Carcinogen- that is it is known to cause cancer.

• Implicated in cases of COPD Chronic Obstructive Pulmonary Disease

• Implicated in autoimmune diseases including– Scleroderma– Rheumatoid Arthritis– Lupus– Wegener’s Granulomatosis

Scleroderma Rheumatoid Arthritis

Lupus Wegener’s Granulomatosis

IgA Nephropathy

What is special about Silica?

What is special about Silica?

What is special about Silica?

• We have special cells (macrophages) to clear anything that makes it to the level of the alveoli (the air sacs).

• The macrophages have a limit about how much they can clear

• If the limit is exceeded, the cell dies, scar tissue happens. Scar tissue limits lung expansion and oxygen exchange= SILICOSIS

What is “the Limit”?

• This is the million dollar question.• Studies based on gold and hardrock mining.• Kreiss &Zehn 41.6 years• Exposure of .05 mg/m3 30 cases/100 workers• Exposure of 0.10 mg/m3 90 cases/100

workers.• Other studies Hnizdo & Suis-Cremer 1993,

Muir et al 1991, somewhat similar findings

What is the limit?

• Only 5 states have standards• The State of California has done several

research studies around sand and gravel mines and its OEHHS has set a standard of 3 ug/m3 as a maximal exposure risk (Myers 2010)

• It requires monitoring of air around all sand mines and processing plants

What is the big deal about standards?

Death rates by state 1996 to 2005 – MN 40 deaths in that period of time.

Niosh has a different standard of 50ug/m3

• How much respirable crystalline silica is the NIOSH REL (Reasonable exposure limits)?

• 500 micrograms (μg’s)• Photo: Geoff Plumlee, USGS

• NIOSH REL = 0.05 mg/m3 TWA • 0.05 mg/m3 = 50 micrograms (μg)

• mg/m3• 1 m3 of air = 1,000 liters• Normal breathing rate (moderate work, 1 work day) = 10 m3

(10,000 liters of air) • 50 micrograms x 10 m3 = 500 μg’s

Really-How much is this?

500 ug

Why is it difficult to figure out what the silica will do if you have daily

exposure?

Data from new cases 1993 to 2006 in Michigan and New Jersey –CDC eWorld

Its just the construction workers right?

Primary Cases of silicosis 2000-2002 in California by Occupation.

Facts and Fallacies

• Statements made by proponents of sand mining

• Facts about the issues they comment on

Proponent statement“Industrial Silica Sand is Safe”

• Depending on use for natural gas or for oil. Sand used for fracking is generally in the 20-70 sieve size range.

• Pure round sand, with no contaminants, after processing- “Should be safe”– BUT

We just take off the top layers which are the Industrial Sand that carries no health risk-we leave the rest alone

Silica Sand is a mix

• 25-50% of sand they mine they refer to as “fines”– Simply put this is sand below their usable size limit

of .2mm or 70 sieve– All sands are mixtures in their natural state though

there may be more fine sand at the bottom of a vein of sand than near the top.

What about the washed sand when its ready for transport its

safe correct?• Worker Exposure to Crystalline Silica During

Hydraulic Fracturing – Eric Esswein MSPH et al.

Silica exceeded exposure limits

• 92 of 116 (79%) air samples collected at hydraulic fracturing sites exceeded the NIOSH REL for PM2.5

• 36 of the 116 (31%) samples exceeded the NIOSH REL by a factor of 10 or more.

• The significance of these findings is that even if workers are properly using half-mask air-purifying respirators, they would not be sufficiently protected .

Silica sand is no different than Sandbox Sand

FallacyHow Industrial Silica Sand is different

• MAGNITUDE:1 cubic yard vs 1000’s of cubic yards at a sand mine

• DURATION:Sandbox’s operate for an hour Sand Mines operate for 16 hours day

• AGGITATION AND MANIPULATION: Front end loaders, crushers, blasting, trucking vs hand shovel and plastic bucket.

Silica Particulate Monitoring

This is a Sharp Thermoscientific Model 5030 It can detect PM2.5 down to0.5 ug/ m3

EOG Chippewa Falls

• Monitoring by Crispin Pierce PhD and students• Ongoing studies with perimeter monitoring.• Studying PM 10 PM2.5 Preliminary finding of

some readings above New York standards and at or near current California standards.

Ambient Silica is At or Near Standards from Other States

0

2

4

6

8

10

12Si

O2

Conc

entr

ation

(mg/

m3)

FALK

CA RfC 0.003 mg/m3

TX RfC 0.00027 mg/m3

EOGWOHL

Preliminary PM 4 silica data from an industry-sponsored study (John Richards, PhD) has measured the presence of silica at EOG (and the Towns of Howard and Cooks Valley mines) at around 0.0005—0.001 mg/m3).

Silica Standards

• Standards in 5 states for Silica in Ambient Air• California 3 mcg/m3- based on non-cancer (silicosis

risk)• Texas 0.27 mcg/m3- based on cancer risk exceeding

1/100,000• New York 0.6 mcg/m3• Minnesota NO STANDARD• Wisconsin NO STANDARD• Are you seeing a problem here?

PM2.5 Study EOG Plant Operating

By Crispin Pierce et al U of W Eau Claire

http://people.uwec.edu/piercech/InitialPM.pdf

PM 2.5 Under Varying conditions

Crispin Pierce et al http://people.uwec.edu/piercech/InitialPM.pdf

We use polyacrylamide as a flocculent and it is perfectly safe

• Fact or Fallacy?• Polyacrylamide IS safe. • It breaks down to Acrylamide- not safe at all– Heat breaks it down– Shear forces break it down

• Acrylamide is a neurotoxin, that is, it damages peripheral nerves and the brain. It also is considered a class 2b carcinogen

Acrylamide

• Its concentration can increase in a holding pond due to UV irradiation. It also after a period of time will start to decrease in concentration.

• It can be spread in a thin layer over dirt and be rendered inert.

• If it washes quickly through sand into the aquifer it is toxic

• .5 parts per billion makes water undrinkable– World Health Organization standard 2011

Spills don’t happen do they?

Preferred Sands Blair Wisconsin

Sand Spills don’t happen do they?When the pond spills so does the

acrylamide

Soderbeck mine near Grantsburg WI

bSediment-filled water overflows holding pond and flows downhill to creek

Polluted water flows to beaver dam, then to St. Croix River

Additional Medical Risks• Diesel Particulates– Known carcinogen in concentration– It shortens the lives of 22,000 people/year– http://www.4cleanair.org/comments/

cancerriskreport.pdf– Known risk for cardiovascular events -50%

increased risk of heart attacks with acute exposure. Greater risk walking or riding a bike than in a car.

Additional Medical Risks

• Diesel Particulates• http://www.catf.us/diesel/dieselhealth/county

.php?c=27169&site=0• Winona • The lifetime cancer risk from diesel soot in your community

exceeds the risk of all other air toxins tracked by EPA combined. 80th Percentile of all US Counties

• The average lifetime diesel soot cancer risk for a resident of Winona County is 1 in 22,418

• This risk is 45 times greater than EPA's acceptable cancer level of 1 in a million.

• How the Risk from Diesel Soot in Winona County Compares to Other Minnesota Counties:Rank Within State: 13 of 87 counties

Winona counties cancer risk is 45 times greater than EPA's acceptable cancer level of 1 in a million

Diesel use by mines

• EAW’s for Dobelstein and Yoder (example) each would use 500,000 gallons of diesel /year

• All of Minnesota’s diesel use per day of #2 diesel at the retail level is 250,000 gallons

Additional Medical Risks

• Traffic Safety– 1 in 5 collisions with trucks this size= death

• Water Quality– During Mining• Diesel and hydraulic leakage• Chemicals in sand hauled back to mine

Additional Medical Risks

• Water Quality Risks after mining complete– Alteration in pH due to sulfites exposed during

mining– Contaminants entering ground water through

Karst Topography- continued enhanced risk of chemicals and bacteria after finished with reduced filtration bed.

What is needed

• Silica air standards , review of current standards and determine which one, but choose one

• Require that all sand mining and processing operations install air monitors every 1000 feet on the perimeter and meet three standards:– The 3 or .27 or 0.6 ug/m3 standard for silica– The EPA PM 10 NAAQS standard– The EPA PM 2.5 standards

What is needed

• Acrylamide monitoring of pond water• Acrylamide monitoring of drying facilities at

sand processing site for air• Acrylamide monitoring of sand returned to

the sand mine• Minimize diesel use (no roadway transport of

sand)

What is needed.

• Sand mines and processing are coming AHEAD of the regulation-That is a problem

• The safest way to mine and process sand is:– Start by having the plant and processing facility in

the least densely populated area’s– -The further from the epicenter of this activity the

lower the risk• Rail spurs directly into the facility-No trucks to

transport

The Main Message

Questions?

Wayne L Feyereisn M.D. FACP

ReferencesSilica Sand Mining Information. Winona County. http://www.co.winona.mn.us/page/3038 Occupational silica exposure and risk of various diseases: an analysis using death certificates from 27 states of the United States. Calvert, G M 1; Rice, F L 2; Boiano, J M 1; Sheehy, J W 3; Sanderson, W T 1 Occupational & Environmental Medicine. 60(2):122-129, February 2003. Silica, crystalline (as respirable dust). Nov 2010. Centers for Disease Control and Prevention. http://www.cdc.gov/niosh/npg/npgd0684.html Exposure to silica and silicosis among tin miners in China: exposure–response analyses and risk assessment. Occup. Environ. Med. 58, 31–37. 2001. Chen, W., Zhuang, Z., AttWeld, M.D., Chen, B.T., Gao, P., Harrison, J.C., Fu, C., Chen, J.Q., Wallace, W.E.,

ReferencesSilicosis: State-Based Surveillance. Dec 2012. Nation Institute for Occupational Safety and Health. Centers for Disease Control and Prevention. http://www2a.cdc.gov/drds/worldreportdata/FigureTableDetails.asp?FigureTableID=2599&GroupRefNumber=F03-05 Worker Exposure to Crystalline Silica During Hydraulic Fracturing. May 2012. Esswein E, MSPH, Kiefer M, MS, Snawder J. PhD, Breitenstein M, BS. http://blogs.cdc.gov/niosh-science-blog/2012/05/silica-fracking/ Regulatory Toxicology and Pharmacology 43 (2005) 292–300. doi:10.1016/j.yrtph.2005.08.003. Development of a chronic inhalation reference level for respirable crystalline silica. Collins J, Salmon A, Brown J, Marty M, Alexee G. Silica Crystalline Forms. Oct 2009. Development Support Document. TCEQ. http://www.tceq.com/assets/public/implementation/tox/dsd/final/october09/silica_crystalline_forms.pdf Fracturing Sand Mining and Processing[Absract]. Epidemiology. 23(5s) (ISEE 2012 Conference Abstracts). September 2012. University of Wisconsin-Eau Claire. Pierce C, Fay K, Nelson G.

ReferencesCrispin Pierce. Personal Communication and Posted Results. UW Eau Claire. http://www.uwec.edu/CONHS/programs/enph/silica/silicaresearch1.htm Environmental Degradation of Polyacrylamides II. Effects of Environmental (Outdoor) Exposure Ecotoxicology and Environmental Safety v.37, n.1, 1jun97Also see Monsanto, Roundup, and Glyphosate. Eldon A. Smith,*,1 Susan L. Prues,* and Frederick W. Oehme *GEO-CENTERS, Inc., at Naval Medical Research Institute Detachment (Toxicology), Building 433, Area B, 2612 Fifth Street, Wright-Patterson AFB, Ohio45433-7903; and †Comparative Toxicology Laboratories, College of Veterinary Medicine "Environmental degradation of polyacrylamides. II. Effects of environmental (outdoor) exposure." Ecotoxicology and Environmental Safety 37 (1): 76–91. (June 1997). DOI: 10.1006/eesa.1997.1527. Smith EA, Prues SL, Oehme FW http://www.mindfully.org/Plastic/Polymers/Polyacrylamides-Degradation1jun97.htm. Degradation of Polyacrylamide by Shear Forces. Taeho Rho, Jonseong Park et al “degradation of polyacrylamide in dilute solution” Polymer Degradation and Stability 51 (1996) 287-293 rnnfm.korea.ac.kr/publication/2008/1995_51_287.pdf

References

Basic Information about Acrylamide in Drinking Water. May 2012. United States Environmental Protection Agency. http://water.epa.gov/drink/contaminants/basicinformation/acrylamide.cfm Acrylamide in Drinking-water. WHO/SDE/WSH/03.04/71/Rev/1 http://www.who.int/water_sanitation_health/dwq/chemicals/acrylamide.pdf. National Toxicology Program, Department of Health and Human Services. Diesel exhaust particulates report on carcinogens. 12th Edition. 2011. http://ntp.niehs.nih.gov/ntp/roc/twelfth/profiles/DieselExhaustParticulates.pdf. International Agency for Research on Cancer. Monographs on the Evaluation of Carcinogenic Risks to Humans. Diesel and gasoline engine exhausts and some nitroarenes. Lyon (France): vol. 105; 2012. p. 5–12. Available at: http://www.iarc.fr/en/mediacentre/aircrews/2012/mono105-info.php.

ReferencesMcDonald JD, Campen MJ, Harrod KS, et al. Engine-operating load influences diesel exhaustComposition and cardiopulmonary and immune responses. Environ Health Perspective 2011; 119(8):1136–41. Pronk A, Coble J, Stewart PA. Occupational exposure to diesel exhaust: a literature review. J Expo Sci Environ Epidemiology 2009; 19:443–57. Acute exposure to diesel exhausts induces immediate platelet activation. Wauters A., Dreyfuss C., Hendrick P., Wijns W., Pradier O., Berkenboom G., Van De Borne P., Argacha J.-F. European Heart Journal. ESC Congress 2012 Munchen Germany... Conference Publication: (var.pagings). 33 (pp 307-308), August 2012. [Journal: Conference Abstract] Oxford University Press Diesel Soot Health Impacts. Clean air Task Force. http://www.catf.us/diesel/dieselhealth/faq.php?site=0 A Multi-City Investigation of Exposure to Diesel Exhaust in Multiple Commuting Modes. CATF Special Report 2007-1. Version 1.1 April 2010. L. Bruce Hill, Ph.D. James Gooch. http://www.catf.us/resources/publications/files/Multi_City_Commuter_Exposure_Report.pdf