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Human Health Effects from Cyanide, Mercury and Arsenic


Human Health Effects from Cyanide, Mercury and ... Daniel Peplow, Robert Edmonds. ... Science Direct, STOTEN-10138; No of Pages 25. ... – PowerPoint PPT presentation

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Title: Human Health Effects from Cyanide, Mercury and Arsenic

Human Health Effects from Cyanide, Mercury and
  • Western Mining Action Network
  • September 29, 2007
  • Amy Crook
  • Centre for Science in Public Participation
  • Victoria, British Columbia, Canada
  • 250 721-3627

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

Basic Toxicology Exposure-related Concepts
  • Metals
  • Persist in the environment forever
  • Can bioconcentrate in our food and bodies
  • Can cause damage with transient exposures

Primary Routes of Exposure
Who is most impacted from toxins?
  • Those with highest exposure-workers and their
  • 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

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)

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
  • Data comes from accidents/spills- not a
    controlled lab setting w/good study design
  • There is a long latency window between exposure
    and affect

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
  • 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


An Overview of Mercury

Wet Deposition
Particulates Vapor
Dry Deposition

Industry Incinerators

WasteWater Releases

Ground-water Flow
Pesticides Fertilizers

Methylation Hg to HgCH3
Rain Streams to Groundwater
to Streams, lakes, vegetation, soil
Bioaccumulation in Fish
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

MercuryDeclining Threshold of Harm
Level associated with
harmful effect
Regulatory standard

(maximum safe exposure or high
end exposure from allowed fish
(micrograms/kg/day Hg)
Mercury Exposures
  • Advised Exposure Limit
  • EPA Reference Dose (safe upper limit) 0.1
  • Equivalent consumption limit
  • Women 1.5 oz. swordfish or 7 oz. tuna/week
  • Child 1 oz. tuna per 20 lb. body weight/week

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
  • Large sources of mercury come from roasters at
    gold mines and from active cyanide heap leaches.

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

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.

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?

  • 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.
  • 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.

  • 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.
  • Environmental Protection Agency. Mercury Study
    Report to Congress An Assessment of Exposure
    to Mercury in the United States. Vol IV, 1997.
  • Environmental Protection Agency. Mercury Update
    Impact on Fish Advisories. EPA-823-F-99-016
    September 1999. http//

  • 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.