Human Health Effects from Cyanide, Mercury and Arsenic

1
Human Health Effects from Cyanide, Mercury and
Arsenic

• Western Mining Action Network
• September 29, 2007
• Amy Crook
• Centre for Science in Public Participation
• Victoria, British Columbia, Canada
• 250 721-3627
• acrook_at_csp2.org

2
How Are People Exposed to Toxic Chemicals?

• Industry discharges into air, water and food
• Major toxins discharged at mine sites are
  Mercury, Arsenic, Cyanide, Lead, Zinc, Cadmium,
  and others
• Dispersion of chemicals is global we all live
  downstream

3
Basic Toxicology Exposure-related Concepts

• Metals
• Persist in the environment forever
• Can bioconcentrate in our food and bodies
• Can cause damage with transient exposures

4
Primary Routes of Exposure
5
Who is most impacted from toxins?

• Those with highest exposure-workers and their
  families
• Those who live closest to the source
• Those who fish/hunt from contaminated areas
• Those with the most vulnerability-pregnant women,
  infants, children, sick and elderly
• Even transient exposures can have significant
  toxic impact

6
Child Health Exposures

• Prenatal
• -transplacental
• -developmental windows

• Postnatal
• pound per pound children eat, drink and breath
  far more than adults
• prolonged gastric emptying
• increased metabolic rate
• increased time indoors and on floors
• breast milk (still best to breastfeed, but breast
  milk now contains many contaminants)

7
Why dont we know more about toxic impacts?

• Good data hard to get and large scale
  epidemiology studies are rare
• Cant dose people with toxins and look at the
  response
• Data comes from accidents/spills- not a
  controlled lab setting w/good study design
• There is a long latency window between exposure
  and affect

8
Why dont we know more about toxic impacts?

• People are exposed to a mixture of toxins, not
  one at a time.
• Toxicity tests are designed to measure the
  effects of one toxin at a time, dont reflect
  reality.
• Interactive effects of toxins are important, but
  few studies look at chemical mixtures.
• Exposure rates are hard to measure in
  uncontrolled situations.
• Precautionary approach needed in estimating
  toxicity and allowing the discharge of toxic
  compounds.

9

An Overview of Mercury

Wet Deposition
Particulates Vapor
Combustion
Dry Deposition

Volcanoes
Industry Incinerators
Landfills
Farming

WasteWater Releases

Ground-water Flow
Volatilization
Pesticides Fertilizers
Runoff


Methylation Hg to HgCH3
Rain Streams to Groundwater
Sedimentation
to Streams, lakes, vegetation, soil
Bioaccumulation in Fish
10
Mercury Effects of Higher Dose Prenatal Exposure

• Mental retardation
• Seizures
• Cerebral palsy
• Disturbances of vision, hearing, sensation
• Abnormal gait
• Abnormal speech
• Disturbances of swallowing and sucking
• Abnormal reflexes

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MercuryDeclining Threshold of Harm
Level associated with
harmful effect
Regulatory standard

(maximum safe exposure or high
end exposure from allowed fish
contamination)
(micrograms/kg/day Hg)
DAILY INTAKE
FDA
WHO
ATSDR
EPA
YEAR
12
Mercury Exposures

• Advised Exposure Limit
• EPA Reference Dose (safe upper limit) 0.1
  microgram/kilogram/day
• Equivalent consumption limit
• Women 1.5 oz. swordfish or 7 oz. tuna/week
• Child 1 oz. tuna per 20 lb. body weight/week

13
Environmental Concerns of Mercury

• Methylmercury bioaccumulation in fish
• Elevated concentrations build up in river
  reservoirs above dams
• Previous mercury mining has left a legacy of
  tremendous health impacts. Tl'azt'en First Nation
  impacts from old Teck Cominco mine at Lake
  Pinchi.
• Large sources of mercury come from roasters at
  gold mines and from active cyanide heap leaches.

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Are the current standards protective?

• Thresholds of harm for As, Hg Cn
• Is policy keeping up with the science?
• Compounded effects from multiple exposures and
  toxic mixtures
• Chemicals we dont even know yet
• Cumulative impacts from other factors nutrition,
  genetics, social, cultural, economic

15
How to assess if your community is at risk

• Attend the workshop by Sue Moodie, Lisa Sumi and
  Catherine Coumans Health Assessment for Mining
  Affected Communities Workshop, Sunday afternoon.

16
Questions to ask mining companies

• How much dust will be generated? Where will it
  go? Whats in it? Will it affect harvest areas,
  play areas, yards, haul roads, etc?
• Where will the waste water be discharged? Whats
  in it? Will it affect fish, wildlife, recreation
  and sacred areas?
• Where are the transportation routes for hauling
  ore, hazardous materials, and fuels? Are they
  close to homes, communities? Are the current
  roads capable of handling the extra traffic and
  weight? What are the plans to upgrade and
  maintain the road? Who pays for that?
• How will ore and hazardous materials spills be
  handled? Are the response plans and notification
  procedures adequate? Who pays for the clean up?

17
References

• Toxic impacts
• Sandra Steingraber. 2001. Having Faith- An
  Ecologists Journey to Motherhood. Perseus
  Publishing. Cambridge, Massachusetts.
• Daniel Peplow, Robert Edmonds. The effects of
  mine waste contamination at multiple levels of
  biological organization. Elsevier Ecological
  Engineering 24 (2005) 101119.
• Mercury
• Leonardo Trasande, Philip J. Landrigan, and Clyde
  Schechter. Public Health and Economic
  Consequences of Methyl Mercury Toxicity to the
  Developing Brain. Environmental Health
  Perspectives Volume 113, Number 5, May 2005.
  http//www.mineralpolicy.org/mercury.cfm
• LA Times, March 17, 2005. Possible Mercury,
  Autism Connection Found in Study.Thomas H. Maugh
  II Texas researchers have found a possible link
  between autism and mercury in the air and water.
• Reno Gazette-jounal, April 14, 2007. Researchers
  at UNR to study mining waste link to mercury.
  Jeff DeLong.

18
References

• Chan HM, Receveur. Environmental Pollution. 2000
  Oct110(1)1-2. Mercury in the traditional diet
  of indigenous peoples in Canada. Centre for
  Indigenous Peoples' Nutrition and Environment,
  McGill University Quebec, Canada.
• Hansen JC, Gilman AP. Int J Circumpolar Health.
  2005 Apr64(2)121-36. Exposure of Arctic
  populations to methylmercury from consumption of
  marine food an updated risk-benefit assessment.
  Centre for Arctic Environmental Medicine (CAM),
  University of Aarhus, Denmark.
• Stephen C. Jewett, Lawrence K. Duffy. Mercury in
  fishes of Alaska, with emphasis on subsistence
  species. Science Direct, STOTEN-10138 No of
  Pages 25. www.sciencedirect.com
• Environmental Protection Agency. Mercury Study
  Report to Congress An Assessment of Exposure
  to Mercury in the United States. Vol IV, 1997.
  http//www.epa.gov/ttnuatw1/112nmerc/volume4.pdf
• Environmental Protection Agency. Mercury Update
  Impact on Fish Advisories. EPA-823-F-99-016
  September 1999. http//www.epa.gov/ostwater/fish/m
  ercury.html

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References

• Greg Jones and Glenn Miller. October, 2005
  Mercury and Modern Gold Mining in Nevada.
  University of Nevada, Reno, NV
• Great Basin Mine Watch, Idaho Conservation League
  and Earthworks. August 2006. Three Nevada Gold
  Mines Grossly Under-Report Mercury Air Emissions.
• Cyanide
• Agency for Toxic Substances and Disease Registry
  (ATSDR). 2006. Toxicological Profile for Cyanide.
  Atlanta, GA U.S. Department of Health and Human
  Services, Public Health Service.

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