Teresa Casal Ed.S.Teresa Casal Ed.S.FCE LTERFCE LTER

Objectives-Objectives-Learn about the chemistry, the sources, Learn about the chemistry, the sources, cycling and health effects of mercury.cycling and health effects of mercury.Trace Hg as it travels through the Trace Hg as it travels through the Everglades.Everglades.Identify strategies to reduce the risk of Hg Identify strategies to reduce the risk of Hg ingestion.ingestion.Create a public service announcement to Create a public service announcement to alert the public of Hg toxicity.alert the public of Hg toxicity.

Once upon a time…Once upon a time…“On a planet, not called Mercury, ‘fluid

silver’ was used by Aristotle for religious rituals (it facilitated a smooth transition into the afterlife)

while Hippocrates prescribed it as a medicine (before malpractice became a practice)

Roman vanity had it applied as a cosmetic (guaranteed to have life altering results) and the Medievalists ‘bet their lives’ on it as an effective cure for syphilis

as time would tell…as time would tell………in the Pre - industrial era in the Pre - industrial era

many lined their coffins many lined their coffins while using it to extract gold while using it to extract gold and other metalsand other metals

… … and today, “quicksilver” and today, “quicksilver” used in alkaline batteries used in alkaline batteries has left its mark, ever ready has left its mark, ever ready to find its way into our to find its way into our lives…lives…

… …will we live happily ever will we live happily ever after???after???

Mercury in WonderlandMercury in WonderlandNo wonder they

called him the

“Mad Hatter”

Lewis Carroll’s character suffered from delirium and hallucinations typical of prolonged contact to the mercury used in the fur, felt and hat industry

From alchemy to From alchemy to chemistry chemistry

Mercury is…Mercury is… a natural elementa natural element odorlessodorless liquid metalliquid metal shinyshiny silver-whitesilver-white atomic number 80atomic number 80

On the flip side… On the flip side…

It is very persistent

It accumulates in the environment

And it is definitely very toxic

Oh… I get it! That’s why it’s

called PBT! A persistent, bioaccumulative

and toxic pollutant.

What’s the What’s the catch?catch?

•Manufacturing activities

•Mining

•Wastewater into waterways

•Dental material waste

•Fuel combustion

•Waste incineration

The cycle begins with man

Through the environment Through the environment Mercury filled rainfallMercury filled rainfall

Is absorbed by sulfate-reducing bacteria Is absorbed by sulfate-reducing bacteria Undergoes chemical changes (Hg to methyl mercury (MeHg+). Undergoes chemical changes (Hg to methyl mercury (MeHg+).

Concentrates as it moves up the food chainConcentrates as it moves up the food chain

And returns to manAnd returns to man Through contaminated foods

By exposure to mercury spills

From inhalation of Hg-containing particles

For newborns through contaminated mother's blood and breast milk

What is the bottom line?What is the bottom line? May cause cancer May cause cancer Damages the stomach and Damages the stomach and

large intestine large intestine Permanently damages the brain Permanently damages the brain

and kidneys and kidneys Permanently harms unborn Permanently harms unborn

children children Can cause lung damage, Can cause lung damage,

increased blood pressure and increased blood pressure and heart rate heart rate

Use the right bait…Use the right bait… Follow fish consumption Follow fish consumption

advisories advisories

Consume no more than Consume no more than one meal a week of the one meal a week of the species listed in the species listed in the advisory advisory

Stay within 0.3 mg Stay within 0.3 mg methyl mercury/kg in fish methyl mercury/kg in fish tissuetissue

to reel in the best catchto reel in the best catch Use small pan fish, Use small pan fish,

perch, rock bass, and perch, rock bass, and crappie (if less than 9 crappie (if less than 9 inches) inches)

Avoid older predatory Avoid older predatory fish (ie. walleye, bass, fish (ie. walleye, bass, and pike)and pike)

Nursing mothers, Nursing mothers, pregnant women, and pregnant women, and children under the age of children under the age of 15 should 15 should NOTNOT eat any eat any swordfish or shark. swordfish or shark.

In a nut shell…In a nut shell…

Now it is your turn to…Now it is your turn to…• Research the amount of Hg Research the amount of Hg

in different types of fish.in different types of fish.

• Create a public service Create a public service announcement to alert the announcement to alert the public of Hg toxicity.public of Hg toxicity.

ReferencesReferences EPA Persistent Bioaccumulative and Toxic Chemical

Program at http://www.epa.gov/pbt/mercury.htm

Mercury\Fact Sheet Methyl mercury - Ambient Human Health Water Quality Criteria - U_S_ EPA.htm

Florida International University, Research in Review; Florida’s Mercury Menace Issue, Fall & Winter, 1997

Mercury Physical and Chemical Properties at http://www.webelements.com/webelements/elements/text/Hg/key.html