REDUCING MERCURY EXPOSURE FROM FISH IN

THE GREAT LAKES

Nathan Reynolds

Introduction to Nutrition

IMPH 2013-2014

GEOGRAPHICAL CONTEXT

Comprised of 5 LakesSuperior, Michigan, Huron, Erie and Ontario

1/5 of the world’s fresh water Bound by 8 States and 1 Province

Minnesota, Wisconsin, Illinois, Indiana, Michigan, Ohio Pennsylvania and New York Ontario

HISTORY

Steam ships started navigating the Great Lakes waterways in 1816

Initially transported timber, fur, grain, meat products, dairy, minerals, copper

By the late 19th and 20th century, the Great Lakes region was known as the “Industrial Belt” of America

Heavy metal mining, automobile manufacturing, steel smelting and oil refining were integral parts of the economy

Utilized steam ships and coal-powered locomotives to carry products to New England

Mercury as a waste product

MERCURY TRENDS IN GREAT LAKES

Source: McGoldrick, D., Clark, M., and Murphy, E. 2012. "Contaminants in Whole Fish", In: U.S. EPA and Environment Canada. 2012. State of the Great Lakes 2012

BIOMAGNIFICATION

The tendency for the concentration of a substance to increase based on food chain energetics and life longevity of species

Predatory Great Lake Fish types• Lake Trout

• Brown Trout

• Bass

• Walleye

AVERAGE PPM OF MERCURY IN POPULAR SPORT FISH

Source: University of Toledo. www.eng.utoledo.edu/aprg/courses/dm/risk/tablefigmercpaper.pdf

ModerateHigh

HEALTH HAZARDS

Once contaminated fish are consumed, methylmercury is readily absorbed. It binds to L-Cysteine, forming a Methylmercury-Cysteine (MeHg-Cys) conjugate, which can easily translocate the Blood-Brain Barrier via amino acid carriers

Accumulation of mercury in neural tissue Passes through placenta to developing fetus and can cause

Cognitive impairment, primitive reflexes and hyperkinesia

Exposure in infants and children can causePoorer neurological status, impaired development, impaired motor skill development

Source: Kerper LE, Ballatori N and Clarkson TW. Methylmercury transport across the blood-brain barrier by an amino acid carrier. Am J Physiol. 1992;262(5 pt2):R761-5. Mergler D, Anderson HA, Chan LHM, Mahaffey KR, Murray M, Sakamoto M and Stern AH. Methylmercury Exposure and Health Effects in Humans: A Worldwide Concern. Royal Swedish Academy of Sciences. 2007; 36(1):3-11.

RISK GROUP

Estimated Number of individuals that consume >104 meals of Great Lakes fish per year

State Estimated

Illinois 376,000

Indiana 161,000

Michigan 324,000

Minnesota 107,000

New York 1,054,000

Ohio 352,000

Pennsylvania 342,000

Wisconsin 140,000

   

Total 2,856,000.00

Source: Imm P, Knobeloch L, Anderson HA and the Great Lakes Sport Fish Consortium. Fish Consumption and Advisory Awareness in the Great Lakes Basin. Environ Health Perspect. 2005;113(10):1325 - 1329

Source: Environmental Protection Agency. Trends in Blood Mercury Concentrations and Fish Consumption Among U.S. Women of Childbearing Age NHANES, 1999-2010. 2013.

Distribution of blood THg (μg/L), by reported frequency of fish consumption in 30 days, women aged 16-49 years, NHANES 1999-2010

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