Mercury Contamination on Tribal Lands Leech Lake Water Quality Program

1. Mercury Contamination on Tribal Lands Leech Lake Water Quality Program

2. Mercury Facts • U.S. EPA estimates that more than 600,000 children each year may be exposed to dangerous levels of mercury in the womb • In 2002 health departments in 44 states issued advisories warning the public to limit or avoid their consumption of locally caught fish • 17 states have issued statewide warnings that cover every lake and stream • These warnings cover 12 million acres of lakes and 473,00 miles of streams • High mercury levels in fish affect Tribes in which fishing is a part of their subsistence lifestyle and cultural tradition

3. Mercury Basics -Mercury is naturally occurring element that is present throughout the environment. -It is one of the “transition metals” on the Periodic Chart of Elements. - Mercury also forms salts –mercury chloride (corrosive) -mercurous chloride (still used  in medicine) -mercury fulminate (used in explosives) -mercuric sulfide (paint pigment) -Mercury enters the atmosphere from natural processes such as volcano eruptions, groundwater seepage and evaporation from the oceans as well as human activity. -The majority of exposure in the U.S. is from methylmercury in fish

4. Forms of Mercury • Mercury in the environment shifts among forms • Organic mercury compounds • Ex.)Methylmercury • Can enter the body readily through lungs, skin and stomach • Form of Hg found in fish • Elemental Hg • Liquid at room temperature • Gives of vapor that can be inhaled into lungs and passed into bloodstream. • Inorganic mercury compounds • Can be absorbed through stomach if swallowed, or inhaled • Found mainly in as salts or in medicines and cosmetics

5. Where is the Hg coming from? • Coal-fired utility boilers • Hazardous waste combustors • Chlorine production • Industrial boilers • Medical waste incinerators • Municipal waste incinerators • Plants in the midwest and Texas create the majority of Hg emissions

6. Mercury Transport Pathways • Wet/dry deposition of particulate Hg • Volatilization • Reduction or oxidation • Photodegradation • Methylation • Hg is transfromed by sulfur bacteria • Need carbon as a food source for energy • 10% of Hg available is converted • Sulfur contaminated rain also largely contributes to increased methylation (fish 10x more contaminated since the industrial revolution) • Demethylation

7. Mercury to methlymercury -Once released, mercury can be deposited onto soil and into water bodies. -Bacteria in sediments convert mercury to methylmercury. -Taken up by tiny plants and animals -Fish that eat these organisms build up methylmercury in their bodies -As bigger fish eat smaller ones, the methylmercury is concentrated further up the food chain -"bioaccumulation“ -Therefore, the primary route of uptake is through human consumption of contaminated fish

8. Methlymercury bioaccumulation • Easily absorbed through gastrointestinal system • Total body burden of mercury is vital • Hg concentrations are higher in larger, older predatory fish • Tuna, Atlantic mackerel, shark and swordfish • In Minnesota, walleye and northern pike • Shrimp, canned light tuna, salmon, pollock and catfish have lower Hg content

9. Methylmercury basics -Food types seems to make no difference in absorption; 95% of ingested MeHg is absorbed -MeHg is distributed throughout the body and easily passes the placenta and blood-brain barriers -Half-life of MeHg is approximately 70 days  -Good biomarkers of exposure : Blood, hair and nails -Different forms of mercury may produce health effects in the same way (have a common mode of action)

10. Leech Lake Tribal lands • Leech Lake Tribal lands contain 865,000 acres of water • Wild rice grows abundantly and is harvested for subsistence by tribal members along with many species of fish. • Each of these food sources is heavily impacted by Hg contamination and are widely used foods on the reservation • In addition, other foods and medicinal sources may be equally affected.

11. The total measured annual Hg input for Leech lake is 7.67 pounds of which 87% was atmospheric loading. • The total export is 1.25 pounds and annual Hg stored is 6.42 pounds • Mercury in Leech Lake calculated avg. of 0.39 ppt, ranging from 0.22 to 0.94ppt. • Mercury Loads to Leech Lake • T=5.394qci • Q=the avg. daily flow for the period • C= the total Hg conc. of the water (mg/L) • I= the # of days in the period Data taken from a water quality assessment of the Leech Lake Watershed July 1997 by the LLDRM and the MTC

12. Mercury consumption guidance • Many state health agencies guidance for mercury concentrations in fish is 0.3- 0.5ppm (average American who consumes 5 lbs. of fish/yr.) • Leech Lake Environmental Dept. and MCT utilize a subsistence threshold mercury fish tissue concentration consumption guideline of 0.02ppm based on consumption of 180 lbs./yr. (15lbs./month)

13. Mercury in fish from Leech Lake • Ex) Mercury in Leech Lake Fish: • Northern pike: 0.16 ug/g---1.9lbs. Fish • Sucker: 0.26 ug/g---2 lbs. Fish • Walleye: 0.26 ug/g---2lbs. Fish • Muskie: 0.15 ug/g---1.9 lbs. fish • Bluegill: 0.028 ug/g---0.2 lbs. fish • Whitefish: 2.8 ug/g----2.8 lbs. fish • Larger the fish, more mercury. Predatory fish higher Hg concentrations as well. • Data taken from: Water quality assessment of the Leech Lake Watershed July 1997 by the LLDRM and the MTC

14. How are tribal lands more at risk? • Subsistence lifestyles of tribes consume 40 times more fish and game than the average American. • Many reservations within Minnesota and ceded territories which tribes hunt, fish and gather are located on or near wetlands where methylization is most likely to occur. • When fishing tribes face consumption advisories, it is a hard decision to risk the health of the tribe or their tradition and cultural ways

15. Health effects from Hg • Mercury is a well-known neurotoxin • Shown to cause learning problems, memory loss, numbness, loss of muscle coordination, tremors, deafness and changes in vision • Infants exposed to Hg in the womb are at risk for mental retardation, cerebral palsy and heart disease. • Since fish, wild rice and game species are main food sources for tribes, it is unfortunate that the exposure to methylmercury is high.

16. Methylmercury Health Effects -Effects of exposure during development or to adults can cause mortality at very high levels -At lower doses, delayed responses, neurological effects, effects on tests related to ability to learn and process information may occur -Not likely to be a human carcinogen (Tumors are seen in animals only at extremely toxic doses; neurological effects are observed at lower exposures) -Developing nervous system is a sensitive target for low dose MeHg exposure -Human and animal evidence shows cardiovascular effects -Animal evidence shows immune and reproductive effects

17. How do tribes address the threat of mercury locally? • There is a continuous effect to monitor, analyze and find areas of possible clean up of mercury contamination in and around their lands. • Although, Mercury sampling is expensive and labor-intensive and not every tribe is funded to conduct research • Public outreach to local tribes on the issues of mercury contamination • For example, Fond du Lac Band of the Lake Superior Chippewa in MN have been monitoring Hg for 7 years. • Sources in the area include coal-fired power plants within 150-200 miles, taconite plants that burn coal and some natural deposits. • This tribe and many others in MN conduct mercury-deposition studies as well as fish-tissue and sediment sampling.

18. Local Tribal Studies • Studies conducted at Fond du Lac Band of the Lake Superior Chippewa in MN have shown: • Hg levels are most elevated in shallow bodies of standing water, particularly where organic sediment is highest • A third of the reservation’s major lakes show high levels of Hg • 3,600 pounds of Hg was released in MN in 2000, and all but a fraction have volatized into our atmosphere. • Those emissions were responsible for 10-30% of the total deposition in the state • In addition, wild rice has not shown an elevated level of Hg, but has shown an elevated level in waterfowl that ingest wild rice • Mercury impacts on the reservation are not only health threats to tribal members, but also to the cultural focus and income source for the tribe.

19. Federal Regulatory Responses • In 2000, Clinton administration had set new mercury control proposals based research to cut mercury emissions by 50% by 2005. • Within months, Bush administration rescinded the Clinton proposals and replaced them with reducing emissions by 30% by 2010 and 70% by 2018. • In addition the Bush administration, has proposed that mercury be market-traded. • Bush has also allowed for upgrades of up to 30% of the facility’s worth with their having to install new pollution controls.

20. Conclusion -Ingested methylmercury represents the major mercury exposure for most people, especially for Native Americans -Health hazards of methylmercury vary with exposure level and are based largely on observations in humans. -Recent and continuing studies of U.S. populations help us to better understand who is exposed to and at what levels of methylmercury.

21. References: • Kathryn R. Mahaffey, Ph.D., “Methylmercury: Epidemiological Update,” USEPA, Washington D.C., Fish Forum, 2004: 5. • John Walke, David Hawkins, and Linda Greer, National Resources Defense Council, press release, 5 Dec. 2003. • 3 National Research Council, “Toxicological Effects of Methylmercury,” (National Academy Press, Washington, DC, 2000), 4. • Editorial, “Connect the Dots: What’s Shaping Mercury Rules?” Minneapolis Star Tribune, 18 Feb. 2004. • 5 Klaassen, C.D., (ed), Casarett and Doull’s Toxicology. 5th ed., 1996, New York: McGraw-Hill. • Elizabeth Weise, “Mercury Damage Irreversible,” USA Today, 9 Feb. 2004: D6. • http://www.epa.gov/air/mercuryrule/basic.htm • 9 Bill Becker, State and Territorial Air Pollution Program Administrators/Association of Local Air Pollution Control Officials, press release, 25 Feb. 2004. • Environmental Protection Agency, letter from Children’s Health Protection Advisory Committee to Michael Leavitt, 26 Jan. 2004. • 11 US EPA Office of Water, Draft Mercury Deposition Modeling Results, 2003. • Tom Atkeson, Don Axelrad, Curtis Pollman, Gerald Keeler, “Integrating Atmospheric Mercury Deposition and Aquatic Cycling in the Florida Everglades,” Florida Department of Environmental Protection, • October 2002, revised November 2003: ii,iii. • Hrabik, T.R., Watras, C.J., “Recent declines in mercury concentration in a freshwater fishery: isolating effects of de-acidification and decreased atmospheric mercury deposition in Little Rock Lake,” Elsevier, The Science of the Total Environment, 297 (2002) 229-237. • 14 National Wildlife Federation, “Mercury Deposition: Clean the Rain,” February 2004.