Under the Waves: a look at Mercury in FishAshley McElroy

Walden UniversityPUBH 6165-6

What is Mercury?• Is a heavy metal.

• Naturally occurring in the environment.

• Combines with carbon to

make organic mercury compounds.

Information obtained on March 17, 2009 from http://www.greenfacts.org/en/mercury/l-2/mercury-1.htm

Information obtained on March 15, 2009 from http://www atsdr.cdc.gov/tfacts46.html#bookmark02

• Most common type of organic mercury is Methylmercury.

• Considered most toxic form of mercury.

• Methylmercury is found in many everyday foods.

• It is especially predominant in fish.Information obtained on March 15, 2009 from http://www.atsdr.cdc.gov/tfacts46.html#bookmark02

Methylmercury is formed in water and soil by small organisms. 

Here it is eaten by plankton and krill.

The plankton is eaten by fish. 

Nearly all fish have trace levels of mercury.

Fish that are larger in size or are older tend to have the highest levels of mercury.

Some types of fish have higher levels of mercury than other types.

Information obtained on March 23, 2009 from http://www.epa.gov/fishadvisories/advice/Information obtained on March 15, 2009 from http://www.atsdr.cdc.gov/tfacts46.html#bookmark02

Why Does this Matter?

Methylmercury follows the food chain.

Starting in fish and plankton.

Which is consumed by humans.

Leads to many health concerns.

Information obtained on March 20, 2009 from http://www.ag.unr.edu/naes/Impact_Details.aspx?ImpactID=40

Fish with High Levels of MercuryShark

Swordfish

King Mackerel

Tilefish

Information obtained on March 19, 2009 from http://www.cfsan.fda.gov/~frf/sea-mehg.html

Fish with Lower Levels of Mercury

SalmonSardinesTilapia HakeHaddock

Complete InformationAvailable at:http://www.cfsan.fda.gov/~frf/sea-mehg.html

Information obtained on March 19, 2009 from http://www.cfsan.fda.gov/~frf/sea-mehg.html

What about Omega-3 Fatty Acids?Are Okay , if……..

Molecular Distillation

Steam Deodorization Technologies

U.S. Standards for Contaminants

Information obtained on April 7, 2009 from http://www.edf.org/page.cfm?tagID=19376

Who is at Risk? Everyone

A fetus is most susceptible

Factors that influence level of health riskDose

AgeDuration Health

Information obtained on April 9, 2009 from http://www.epa.gov/hg/effects.htm

Health Hazards of Ingesting Methylmercury

Negative effects on brain

Negative effects on nervous system

Cognitive thinking impairment

Information obtained on April 9, 2009 from http://www.epa.gov/hg/effects.htm

Vision problems

Abnormal Sensations

Coordination problems

Speech Impairments

Information obtained on April 9, 2009 from http://www.epa.gov/hg/effects.htm

What can we do? Limit intake of fish to

once a week; or once a month if pregnant.

Stay away from fish with high levels of mercury.

Eat a variety of fish with low levels of mercury.

Limit fish intake to 12 ounces a week.

Information obtained on April 5, 2009 from http://www.epa.gov/fishadvisories/advice/factsheet.html

Importance of Fish Consumption Advisories

Potential health hazards.

Help the public choose

Fish Guide

Information obtained on April 9, 2009 from http://dnr.wi.gov/fish/consumption/

Fish Consumption Advisories in Oregon

Emigrant Reservoir in Jackson County

Portland Harbor

Cottage Grove Reservoir in Lane County

Dorena Reservoir in Lane County

Information obtained on April 9, 2009 from http://www.oregon.gov/DHS/ph/envtox/fishadvisories.shtml

Methylmercury is an organic form of mercury, that is considered the most toxic.

Methylmercury is found in a variety of fish.

Mercury is extremely dangerous to a fetus.

Consume fish that have low levels of mercury.

Look for fish advisories in your area.

References: Agency for Toxic Substances and Disease Registry (1999). ToxFaqs for Mercury. Retrieved

on March 15, 2009 from http://www.atsdr.cdc.gov/tfacts46.html#bookmark02

Environmental Defense Fund (2009). How Safe are Fish Oil Supplements? Retrieved on April 7, 2009 from http://www.edf.org/page.cfm?tagID=19376

Environmental Protection Agency (2009). Mercury. Retrieved on April 9, 2009 from http://www.epa.gov/hg/effects.htm#meth

Environmental Protection Agency (2004). What You Need to Know About Mercury in Fish and Shellfish. Retrieved on March 23, 2009 from http://www.epa.gov/fishadvisories/advice/

Green Facts Digest (2004) Scientific Facts on Mercury. Retrieved on March 17, 2009 from http://www.greenfacts.org/en/mercury/l-2/mercury-1.htm

Office of Research Facilities (2006). Mercury Health Hazards. Retrieved on April 7, 2009 from http://orf.od.nih.gov/Environmental+Protection/Mercury+Free/MercuryHealthHazards.htm

References Oregon Department of Human Services (2009). DHS Environmental Toxicology

Program. Retrieved on April 9, 2009 from http://www.oregon.gov/DHS/ph/envtox/fishadvisories.shtml

University of Nevada (2009). Assessment of Potential for Mercury Methylation in One of Reno Nevada’s Local Streams. Retrieved on March 20, 2009 from http://www.ag.unr.edu/naes/Impact_Details.aspx?ImpactID=40

U.S Department of Health and Human Services & Environmental Protection Agency (2006). Mercury Levels in Commercial Fish and Shellfish. Retrieved on March 17, 2009 from http://www.cfsan.fda.gov/~frf/sea-mehg.html

Wisconsin Department of Natural Resources (2008). Fish Consumption Advisories. Retrieved on April 9, 2009 from http://dnr.wi.gov/fish/consumption