Lead and Mercury: Subtle Environmental Health Hazards

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Lead and MercurySubtle Environmental Health
Hazards

• For Introduction to Environmental Studies
• TESC January 8, 2003
• Dr. Jude Van Buren- DOH
• Office Director Environmental Health Assessment

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Overview of Workshop

• Lead Overview
• Slide show
• Mercury
• Fish Advisories in Washington State
• PBT (Persistent Biotoxins) Reduction
• Case Studies Minimata, Japan
• Gold mining in Brazil

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Objectives of Workshop

• To better understand the longevity and cycling of
  heavy metals in the environment and animal
  systems
• To acquire a basic knowledge of how these metals
  interact with animal tissue to cause adverse
  health effects (lead mimics other cations in
  organism mercury biotransforms and
  bioconcentrates)
• To recognize the complexity of environmental
  hazards and their adverse health, economic and
  social impacts
• To assist in developing a framework for how to
  address environmental issues

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What is lead poisoning?

• Considered to occur when a childs blood lead
  exceeds 10ug lead per deciliter of blood (ug/dl)
• Adverse health effects that result from exposure
  to lead include deficits in intelligence, and
  developmental and behavioral problems
• It is a major, preventable pediatric
  environmental health problem.
• It is silent most children have no symptoms.

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Who is at risk?

• Infants young children
• Children living in older housing
• with chipping, peeling, flaking paint or
• where remodeling is taking place
• Low-income children
• Pregnant women are at risk
• because of the danger lead can pose to the
• unborn child
• Premature birth
• Low birth weight

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Primary Pathways
Ingestion Children absorb appx. 50 Adults
absorb appx.10 Inhalation Childrens
respiratory uptake can be up to 2.7 times
higher than adults.
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Statewide Prevalence Survey Results (1999)
Weighted Children No. percent tested
elev elev 95 CI WA
State 548 8 0.9 (0, 1.9) Rest of
state 209 1 0.5 (0, 1.4) Hispanics
in 273 6 3.8 (0, 7.8) High-risk
area The survey estimates that there are
1,400 one and two year old children in WA
State with elevated blood lead levels.
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Facts
There are children with lead poisoning in
Washington State. Lead-contaminated soil is a
potential exposure source. Even children who
seem healthy can have high levels of lead in
their bodies. Childhood lead poisoning is
preventable.
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DOH Lead Program

• DOH has been working on lead issues since 1992.
• Activities included
• Establish Lead Task Force
• Mandate lab reporting of blood lead levels
• Create Childhood Blood Lead Registry
• Conduct studies
• Provide education and outreach
• Conduct environmental investigations
• Work with steering committees on legislation
• Provide enhanced screening opportunities

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The Hazard called MercuryWashingtons Efforts
to Reduce Mercury in the Environment

• Mercury cycle
• Chemistry of mercury
• Exposure to mercury
• Adverse health effects of mercury
• How mercury accumulates in fish
• Fish Advisory efforts
• Mercury reduction efforts

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Mercury cycling in the environment

• Mercury is a natural element that enters the
  environment from rock formations and volcanoes.
• Mercury that enters environment eventually makes
  its way into the air, water and food
• EPA estimates that the amount of mercury entering
  environment has increased fivefold due to coal
  burning power plants, waste incinerators, common
  consumer products such as fluorescent lights,
  thermostats, thermometers, dental amalgams

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Exposure to Mercury

• Human beings are exposed to mercury via 3 routes
• Eating certain long-lived, predatory fish that
  have accumulated mercury in their tissues via the
  food web
• Inhaling mercury from liquid mercury spills
  (enclosed spaces and somewhat from mercury
  amalgams)
• Skin absorption through contact with liquid
  mercury or creams containing mercury

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Exposure to Mercury Vapor

• Mercury spills in an enclosed space can evaporate
  and reach exposure levels high enough to cause
  health effects even from short term exposure (eg
  thermometers, blood pressure cuffs, jewelry
  thermostats and switches)
• Note mercury in outdoor air (and atmospheric) is
  generally not at concentrations high enough to
  cause adverse health effects

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How Mercury accumulates in fish most common
exposure source for mercury in humans

• Elemental mercury (Hg) from earths crust is
  released into the environment from anthropoegenic
  activities and volcanoes.
• Mercuric Chloride or mercurous chloride
• (Hg 2 or Hg2 2 from laboratory or medicinal
  sources (thus far all species are inorganic)
• Ethyl (CH3 Hg) or methyl (CH3-Hg-CH3) mercury
  is formed in GI tract or in sediments by
  micro-organisms that can methylate mercury now
  it is organic and bioavailable

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Toxicity of mercury As Lipophilic (fat-loving)
characterstics increase toxicity increases

• CH3-Hg-CH3) Hg 2 or Hg2 2 Hg
• Monomethyl mercuric or mercurous
  elemental
• Or dimethyl mercury mercury
• Mercury
• 90-95 absorbed 7 absorbed .01
• absorbed
• Fetus and developing child
• Absorb this form easier
• Than adults

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Adverse health effects of mercury

• Level of toxic effects depends on the route and
  amount of exposure and who the person is
• Neurotoxicant affects central nervous system
  especially in fetus and infants when nervous
  system is still developing
• Cardiovascular system toxicant especially for
  adults
• Note It takes weeks or months before effects
  are detectable after the adult has been exposed

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Populations at greatest risk for Mercury

• Mercury is especially hazardous to pregnant women
  and children
• Mercury can cross the placental barrier and can
  pass to the nursing child via breast milk.
• CDC estimates that 1 in 10 women of childbearing
  age is exposed to mercury at levels above that
  harm could occur
• NAS study (2000) estimated that 60,000 infants a
  year face increased risk of brain damage because
  pregnant moms had elevated body burden of mercury
  

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Fish Advisories

• Currently Washington has 13 local fish advisories
  issued across the state due to elevated levels of
  various contaminants.
• e.g. mercury in bass and perch in Lake Whatcom.

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Fish Advisories

• Numbers do not reflect the extent of
  contamination, but rather the level at which
  states have looked.
• Ecologys potentially Bioaccumulative Toxins
  (PBT) program is expanding the number of
  contaminants, water bodies, and fish to be tested
  for.
• Testing for contaminants will likely expand the
  number of fish advisories.

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Fish Advisories

• Statewide advisory for mercury in canned tuna
  expands the list of commercial fish listed by FDA
  
• Note - recent FDA panel recommended advice
  similar to DOHs with regard to canned tuna.
• Specific advice given to WIC (Women, Infants and
  Children Supplemental Food Programs

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Issue Summary Fish Advisories

• Women of Childbearing Age Children Under 6
• General
• Do not eat any shark, swordfish, tilefish, king
  mackerel or either fresh caught or frozen tuna
  steaks.
• Limit canned tuna, based on bodyweight. (Women
  weighing 135 pounds or more should eat no more
  than 1 can (6oz) per week Child
  eat no more than ½ can (3oz) per week)
• Specific
• Duwamish River, Eagle Harbor, Lake Roosevelt,
  Lake Whatcom, Sinclair Inlet

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Advice on consuming fish from the Duwamish River

• Eat no more than one meal per month of any
  combination of bottomfish (English sole, starry
  flounder) or pelagic fish (perch) from the
  Duwamish, or rockfish from Elliott Bay
• Polychlorinated biphenyls (PCBs) are elevated in
  fish that live year-round in the Duwamish River
  (not salmon)
• Pregnant women or those considering pregnancy
  should pay special attention to the advisory

English sole
Rockfish
Flounder
Perch
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Advice on consuming fish from the Duwamish River

• Do not eat the hepatopancreas of crabs
• Shellfish advisories already exist.
• Avoid eating shellfish from the Duwamish (and the
  majority of King County coastline due to
  potential chemical and biological contamination)

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• Simplified fact sheet translated into Laotian.
  This same flyer was also translated into
  Vietnamese, Cambodian, Hmong, Russian and
  Spanish.
• These flyers serve as an aid while providing our
  message in person at community meetings.
• A more detailed fact sheet (English and Spanish)
  was sent by mail to a wider audience.

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Washingtons Response to Mercury Mercury Chemical
Action Plan

• Goals 1)Virtual elimination of use and release
  of anthropogenic (human caused) mercury
• 2)Minimize human exposure to anthropogenic
  mercury
• Recommendations
• Ongoing, planned, and proposed
• Short-term, mid-term, and long-term

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Reduction Plan Process 2002 Legislative
Direction

• develop a planned strategy for the reduction of
  mercury from the environment.
• Involve advisory committee in plan development
  with balanced representation
• Issue draft plan for 60-days public comment
• Finalize plan by end of 2002

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Mercury Action Plan Advisory Committee

• Local Government
• King County
• City of Tacoma
• Southwest Clean Air Agency
• Public Health
• Whatcom County Health Dept.
• Yakima County Health District
• Inst. Of Neurotoxicology
• Community Groups
• Physicians for Social Responsibility
• WashPIRG
• Environmental Groups
• People for Puget Sound
• WA Toxics Coalition
• WA Wilderness Recreation Coalition

• Agriculture
• General Agriculture
• Fishing Industry
• Business
• Dental
• Medical
• Mining
• Recycling
• Retail/Manufacturing
• Private Utilities
• Crematoria
• Small Businesses
• Auto Manufacturers

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HighlightsEst. Hg in Products Disposed of in
WA Annually
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Highlights Completed Ongoing Hg Reductions

• Replaced Mercury Dairy Manometers in WA
• "Fish Facts for Good Health" brochure for Women,
  Infant and Child (WIC) Program
• Automobile Light Switches in State Vehicles
• Local Toxics Control Account Grants awarded to
  local governments
• Developing Letter to all Ob-Gyn and Pediatricians
  on benefits of eating fish and mercury in fish
• Hospital mercury workshops planned
• Working with Washington State Dental Association
  to assure proper disposal of dental amalgam
• Working with WA Poison Control Center on Mercury
  Cleanup Brochure

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Ongoing Work on Mercury Reductions

• Research and Monitoring of Mercury
• Mercury fish screening survey (Jun-Dec 2002)
  Public Awareness Survey
• Landfill Gas Study
• Education and Outreach
• Information sharing WA Quicksilver Review,
  publications, meetings/presentations.
• Incorporate DOH community competent practice
  /experience for statewide fish advisory for
  mercury.
• Propose community involvement in action
  thermometer exchange, auto switch exchange,
  recycling, information sharing.
• Ecology and Health web sites updated/ refined.

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Mercury Issue Summary

• Neurotoxin can damage brain, lung, kidneys,
  liver
• Fetus and young children at greatest risk
• Consumption of contaminated fish most common
  route of exposure
• Reduction efforts at international, national,
  state and local levels