Mercury - The Midwife Group and Birth Center

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    NM617 Fetotoxic Presentation
Elizabeth Cook and GeorgAnna Wiley
    What’s the main way we get mercury in our bodies?
   Coal-fired power plants remain the largest source of mercury pollution in America
    (Sierra Club, 2008). Mercury is not a product of combustion. Rather, it is in coal
    and is thus released in the exhaust systems when coal is burned (Sierra Club,
    2006). Emitted mercury mixes with rain or snow falling back down into our water
    and land, and then bacteria transform it into the most toxic form of mercury:
    methylmercury. Fish consume the bacteria, then fish eat the contaminated fish,
    and levels accumulate as the mercury builds up in the muscle (not just the fat and
    skin!) (U.S. Geological Survey, 2002). Unfortunately, power plants emissions of
    mercury are not regulated under the federal clean air standards (Jordan &
    Nicholson, 2007). In fact, in spite of scientific evidence, the EPA has increased the
    levels of mercury considered safe for humans (Jordan & Nicholson, 2007).
                                    For the full story, visit
Here’s a diagram:

     (Sierra Club, 2008)
                                Where is mercury mainly found?
In the U.S., there are currently 12,000,000 acres of lakes and 400,000 miles river under advisory due to mercury pollution
     (Jordan & Nicholson, 2007)
Known areas of increased risk:
   Wetlands
   Dilute, low-pH lakes in Northeast and North-central United States
   Great Lakes
   Parts of the Florida Everglades
   Newly flooded reservoirs
   Coastal wetlands along Gulf of Mexico, Atlantic Ocean, and San Francisco Bay (USGS, 2002; Jordan &
    Nicholson, 2007)

Areas near industrial/manufacturing sources:
   Power plants
   Alkali and metal processing
   Coal incineration plants
   Gold mines

Natural sources:
   Volcanoes
   Geological deposits
   Ocean volatilization
   Some thermal springs
   Very rarely, a particular region with have an “outbreak” of mercury toxicity risks, such as Japan’s Minamata Bay in
    1960 (Jordan & Nicholson, 2007; Diner, 2007)
   Atmospheric deposition remains the primary source (USGS, 2002)
What are the different types of
                   Inorganic mercury (mercuric salts), found in:
   Antiseptics/disinfectants
   Anti-syphilitic agents
   Acetaldehyde production
   Chemical laboratory work
   Cosmetics (such as some illicit skin-lightening creams)
   Electrical equipment
   Embalming
   Explosives
   Fur hat processing
   Fungicides
   Ink manufacturing
   Mercury vapor lamps
   Mirror silvering
   Perfumes
   Photography
   Some illegal skin-lightening cream
   Spermicidal jellies
   Tattooing inks
   Taxidermy production
   Vinyl chloride production
   Wood preservatives (Diner, 2007; EPA, 2007; Jordan & Nicholson, 2007)
                  Elemental mercury (also inorganic, found in):
   Gold mines (used to extract gold, so also includes abandoned mines) (U.S. Geological Society, 2002).
   Batteries (look for batteries that are mercury free – they are out there!)
   Barometers
   Bronzing
   Calibration instruments
   Chlor-alki production
   Dental amalgams (ask your dentist – you can get fillings that do not have mercury, or the mercury can be
   Electroplating
   Fingerprinting products
   Fluorescent, neon, and mercury lamps (be careful when changing fluorescent bulbs!)
   Infrared detectors
   Jewelry industry
   Paints
   Paper pulp production
   Photography
   Silver and gold production
   Semiconductor cells
   Thermometers and Manometers (exposure occurs when they are broken and the vapor inhaled, however, in recent
    years mercury is much less widely used in these) (Diner, 2007; EPA, 2007; Jordan & Nicholson, 2007)
                                          Organic mercury:
Methylmercury is the organic form of mercury and is also the most toxic (U.S. Geological
   Society, 2002). Other than our waters, it can be found in:
  Vaccines containing thimerosal (anti-bacterial vaccine preservative), most notably in diphtheria-tetanus-
   whole cell pertussis (DTP), Haemophilus influenzae (HIB), hepatitis B vaccines, and seasonal influenza
   vaccines. It is found in U.S. manufactured vaccines for preschool-aged children except for some flu
   immunizations (Diner, 2007).
  Antiseptics
  Bactericidals
  Diapers
  Embalming agents
  Farming chemicals
  Fossil fuels
  Fungicides
  Germicides
  Histology products
  Insecticides
  Laundry products
  Pathology products
  Seed preservatives
  Wood preservatives
  Paper manufacturing – used as a catalyst for the formation of some chlorine compounds like paper pulp
   bleaching, so is released into the air by factories and ending up in our water supply
  Some paints (especially anti-mildew paints made prior to 1990)
(OTIS, 2007; Diner, 2007)
           What does methylmercury do to adults at high doses?

   Methylmercury negatively impacts the immune system, nervous system (such as
    coordination and the perception of touch, taste, and sight), as well as genetic and
    enzyme systems (U.S. Geological Society, 2002). This form is the most toxic to
    embryos/fetuses as they are 5 to 10 times more sensitive than adults to this
    element (U.S. Geological Society, 2002). Compared to other forms, methylmercury
    is easier to absorb and takes longer to eliminate (U.S. Geological Society, 2002).
   In 2003, the American Association of Poison Control Centers' Toxic Exposure
    Surveillance System reported mercury exposure in 3362 individuals with 44 having
    moderate pathologies and 6 having major pathologies, but no deaths (Diner, 2007)
                         What about elemental mercury?

   This can be absorbed via skin, inhalation, ingestion, and injections (Diner, 2007)
   When ingested, it can actually pass through the GI system without causing damage (U.S.
    Geological Society, 2002).
   Elemental mercury is a liquid at room temperature, but it also vaporizes at this temperature
    and is easily inhaled, of which 80% is absorbed (Diner, 2007).
         Occupation or activities where exposure is most likely

   Fishing, families of fishermen/women
   Dentistry workers (mercury vapor exposure may be a concern but studies are
    inconclusive) (Gardella & Hill, 2000)
   Beauticians (skin lightening agents)
   Painters
   Anyone exposed to fungicides (including household use)
   Paper mill workers
   Occupations and activities that require contact or close proximity to the above items place
    individuals at the greatest risk, particularly if over long periods of time (EPA, 2007).
             What about mercury exposure during pregnancy?

o   Methylmercury is the most common and most toxic form of mercury; it is commonly consumed in
    fish from polluted waters (U.S. Geological Society, 2002).
o   Mercury can cause injury at any point in pregnancy (OTIS, 2007; Diner, 2007), so avoid all mercury
    exposure if pregnant or may become pregnant within 12 months (Jordan & Nicholson, 2007)
o   1 in 5 US women has mercury levels above those recommended by the EPA; high enough to put a
    baby at risk (Sierra Club, 2008).
o   The National Institute of Environmental Health Sciences estimated that the value of the repercussions
    of mercury from coal burning power plants on fetuses at $1.3 billion each year (Sierra Club, 2006).
o   Mercury crosses the placenta easily and accumulates in embryonic and fetal tissues, particularly in the
    brain and CNS, which are most vulnerable, thereby concentrating into levels higher than in the mother
    (Gardella & Hill, 2000).
            Effects may include:
Prematurity and preterm delivery (Xue, Holzman, Rahbar,
        Trosko, & Fischer, 2006) Microcephaly
                     Cerebral palsy
                  Developmental delay
                    Mental retardation
                    Muscle weakness
           Seizures (OTIS, 2007; EPA, 2007)
                Corrosive gastroenteritis
                 Acute tubular necrosis
              Renal dysfunction (Diner, 2007)
              How much is too much?
   Currently, adverse effects in children are suspected to stem from prenatal
    exposures that resulted in maternal hair concentrations between 5 ppm for
    subtle developmental changes to 10-20 ppm for clinically obvious changes
    such as delayed walking (Dharan & Parviainen, 2006) or talking, cerebral
    palsy, and mental retardation (Sierra Club, 2008).

   The National Academy of Science-National Research Council
    recommends a maintaining a level below 58 parts per billion of mercury in
    cord blood or 12 parts per million of mercury in hair (Dharan & Parviainen,
                               What about our children?

                                                                             (that’s me and my daughter!)
   Mercury is excreted in breastmilk (Diner, 2007).
   Methyl mercury does not cause obvious structural malformations in humans, so the
    devastating effects, which may not be obvious at birth, become evident only as indications
    of abnormal neurologic development unfold (Gardella & Hill, 2000). Particularly
    developmental and learning disabilities in small children (Sierra Club, 2008).
   Children are very susceptible to mercury toxicity because their brains are growing rapidly
    (Sierra Club, 2008). Children under age 6 should be protected from high mercury exposure
    (Jordan & Nicholson, 2007)
   EPA statistics show that 630,000 children at risk based on elevated mercury levels in
   The Immunization Safety Review Committee of the IOM currently states that "the
    evidence favors rejection of a causal relationship between thimerosal-containing vaccines
    and autism." This appears to be supported by two recent cohort studies done in the UK to
    assess a relationship between thimerosal use and autism. Further conclusive research needs
    to be done, but perhaps the casual link between thimerosal and autism is not as strong as it
    was once thought (Diner, 2007).
                      Can I ever eat fish again?!?

   Fish and shellfish contain high-quality protein and other essential
    nutrients, are low in saturated fat, and contain omega-3 fatty acids (EPA,
   Eating a variety of fish and shellfish can help keep our hearts healthy, and
    contribute to children's proper growth and development (EPA). However,
    nearly all fish and shellfish contain traces of mercury (EPA). In fact, fish is
    the main method of mercury consumption (Jordan & Nicholson, 2007).
    Risk is based on amount and/or frequency of consumption, and levels in
    the fish and shellfish.
                                       Some tips are:

   Small ocean fish (catfish, pollock, salmon), shellfish (king crab, shrimp), canned fish (light
    tuna), fast food fish choices, and fish sticks usually fine
   Canned albacore (white) and tuna steaks usually worse than canned light tuna
   Completely avoid large, predatory species like tuna, shark, swordfish, king mackerel, and
    tilefish (EPA, 2007). These fish contain methylmercury at concentrations that are 10-20
    times higher than fish such as herring, cod, pollack, shrimp, or scallops
   Mercury is also present in sushi (Sierra Club, 2008).
   The EPA maintains documentation of mercury levels of major freshwater and saltwater
    lakes and rivers, so you can check your local health department to investigate your are, or
   Keep a wallet-sized fish guide in your wallet to be aware of what fish is higher risk, such
    as those listed at:
   Be aware of what fish are safe to eat, you can use this safe fish chart from the Children’s
    Health Environmental Coalition (2004) from:
For the visual learners:


 Swordfish           King mackerel
         How can I avoid consuming mercury in fish?
   Options for avoiding the mercury in mercury-contaminated fish are more limited than for
    fish contaminated with PCBs, dioxins and other organic contaminants. Here are some tips:
   Smaller or younger fish tend to have lower concentrations of mercury than older, larger
    fish within the same water body.
   Choose those that don’t live on the bottom of waterways, like lobsters.
   Mercury concentrates in the muscle tissue of fish. So, unlike PCBs, dioxins and other
    organic contaminants that concentrate in the skin and fat, mercury cannot be filleted or
    cooked out of fish (U.S. Geological Society, 2002).
   Choose wild-caught salmon, not farm-raised (or “ocean raised” as some companies now
    disguise the farming under a new name) as they have less environmental toxins (CNN,

    {a pic of farm raised salmon}

   Monitor local advisories about fish in your area if you fish. To find levels near you visit:
   Try not to eat the same fish or shellfish more than once a week (Children’s Health
    Environmental Coalition, 2004).
               Do you want to super-size that order?

   remember portion sizes? These are often large in the US, so remember for an adult, a
    serving size is about 4 to 6 ounces (Children’s Health Environmental Coalition, 2004).
    Three to 4 ounces is the size of the palm of your hand or a deck of cards.
   Portions are less for children—about 2 to 3 ounces (or one tuna fish sandwich) (Children’s
    Health Environmental Coalition, 2004).
   Try to limit fish intake to 12 ounces a week of a variety of fish and shellfish that are lower
    in mercury (EPA, 2007). If no advisory for your area, eat up to 6 ounces per week of fish
    from local waters, but don't eat any other fish that week (Children’s Health Environmental
    Coalition, 2004).
   The EPA suggests women limiting fish intake to no more than 350 g/wk, or 12 ounces,
    before and during pregnancy.                                      (a portion size of chicken, uncooked)
      What if I eat more than the recommended
            amount of fish and shellfish?

   The half-life of methylmercury is 44-80 days in humans (OTIS,
    2007). Mercury is removed from your body in a few months (Sierra
    Club, 2008).
   One week's consumption of fish does not significantly affect the
    level of methylmercury in the body. If you eat a lot of fish one
    week, cut back for the next week or two. Overall, try to average the
    recommended amount per week (EPA, 2007).
           Let’s all get tested!
A non-profit study is underway by Sierra Club to
 inexpensively detect levels of mercury in hair
    “An ounce of prevention is worth a pound of
o   Working environments should have a mercury vapor level
    below 0.01 mg/m3 (Dharan & Parviainen, 2006).
o   Be careful when handling fluorescent light bulbs. If
    broken, they may release mercury (EPA, 2007).
o   If a woman reports exposure to mercury, her exposure can
    be quantified clinically with hair testing (especially long-
    term or chronic exposure) or blood test (especially for
    recent exposure) (OTIS, 2007).
            Exercise your rights under the 1st
•   The Bush administration has proposed a national plan to increase the allowable
    levels of mercury by 3 times (Sierra Club, 2008). Therefore, change must occur at
    the state level to initiate steps to clean up mercury and reduce allowable levels in
    your neighborhood. Contact your governor about this issue, and get involved. To
    find out how, check out:

•   To reduce mercury in our country, US residents need to petition state legislators
    to support emission reductions and to install existing efficient technology to
    capture mercury emissions from coal burning plants (Sierra Club, 2006).

•   To email President Bush, contact your senator, state representative, or
    legislator, find them at:
    Go on, send him an email!!!

again, that website is
   Children’s Health Environmental Coalition. (2004). Safe Fish CHEC List
    For children, teens and all women of childbearing age. Retrieved May 13, 2008,

   CNN. (2005). Study: Farmed Salmon More Contaminated than Wild. Retrieved
    May 13, 2008, from

   Dharan, V. & Parviainen, K. (2006). Psychosocial and Environmental Pregnancy
    Risks. Retrieved May 13, 2008, from

   Diner, B. (2007). Toxicity, Mercury. Retrieved May 10, 2008, from

   Environmental Protection Agency. (2008). What You Need to Know about Mercury
    in Fish and Shellfish. Fish Advisories. Retrieved May 13, 2008, from
   EPA. (2007). Mercury: Basic Information. Environmental Protection Agency.
    Retrieved May 10, 2008, from

   Gardella, J. & Hill, J. (2000). Environmental Toxins Associated With Recurrent
    Pregnancy Loss. Semin Reprod Med 18(4):407-424.

   Jordan, R. & Nicholson, T. (2007). Let’s Talk, NM617 Module 9. Hyden, KY:
    Frontier School of Midwifery and Family Nursing.

    Office of Citizen Services and Communications. (2008). Contact Elected Officials. Retrieved
    May 13, 2008, from
    OTIS. (2007). Methylmercury and Pregnancy. Organization of Teratology Information

    Sierra Club. (2006). The Clean Air Mercury Rule: Weak Control Standards for Coal-Fired
    Power Plants. Retrieved May 13, 2008, from

    Sierra Club. (2008). The Mercury Cycle. Retrieved May 13, 2008, from
USGS. (2002). Mercury in the Environment: Fact Sheet 146-00. U.S. Geological
Survey. Retrieved May 10, 2008, from

Xue, F., Holzman, C., Rahbar, M., Trosko, K., & Fischer, L. (2006). Maternal Fish
Consumption, Mercury Levels, and Risk of Preterm Delivery. Environmental Health
Perspective, 115:42–47.

                          !!!!The End!!!!!

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