Mercury Levels in Tennessee Fish
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Mercury Levels in Tennessee Fish May, 2007 Prepared by: Gregory M. Denton Tennessee Department of Environment and Conservation Division of Water Pollution Control 7th Floor, L & C Annex 401 Church Street Nashville, Tennessee 37243 TABLE OF CONTENTS I. Acknowledgements 1 II. Introduction 2 III. Tennessee Waters Where Mercury Trigger Points Are Exceeded By Average Fish Tissue Concentrations 9 IV. Miscellaneous Sampling Stations Where Mercury Trigger Points Are Exceeded By Average Fish Tissue Concentrations 35 V. Literature Cited 38 APPENDIX A: April TDEC Press Release Announcing New Mercury Advisories 39 APPENDIX B: Current Fish Tissue Advisories in Tennessee 42 TABLES Page 1. Weighted Average Mercury Levels in East Fork Poplar Creek 9 2. Weighted Average Mercury Levels in North Fork Holston River 11 3. Weighted Average Mercury Levels at Holston River Mile 91.0 11 4. Weighted Average Mercury Levels at Holston River Mile 96.0 12 5. Weighted Average Mercury Levels at Holston River Mile 107.0 12 6. Weighted Average Mercury Levels at Holston River Mile 109.9 12 7. Weighted Average Mercury Levels at Holston River Mile 118.0 13 8. Weighted Average Mercury Levels at Holston River Mile 121.0 13 9. Weighted Average Mercury Levels at Holston River Mile 135.0 13 10. Weighted Average Mercury Levels at Holston River Mile 141.0 14 11. Weighted Average Mercury Levels in Norris Reservoir at the Dam Forebay 15 12. Weighted Average Mercury Levels in Norris Reservoir at Mile 113.5 16 13. Weighted Average Mercury Levels in Norris Reservoir at Mile 125.0 16 14. Weighted Average Mercury Levels in Watauga Lake at the Dam 17 15. Weighted Average Mercury Levels in Watauga Lake at Mile 45.5 17 16. Weighted Average Mercury Levels in the Hiwassee River at Mile 7.4 18 17. Weighted Average Mercury Levels in the Hiwassee River at Mile 12.0 19 18. Weighted Average Mercury Levels in the Hiwassee River at Mile 15.4 19 19. Weighted Average Mercury Levels in the Hiwassee River at Mile 18.6 19 20. Weighted Average Mercury Levels in the Hiwassee River at Mile 37.0 20 21. Weighted Average Mercury Levels in South Holston Lake at the Dam 21 22. Weighted Average Mercury Levels in South Holston Lake at the Stateline 21 23. Weighted Average Mercury Levels in the Emory River at Mile 7.0 22 24. Weighted Average Mercury Levels in the Emory River, Mile 14.5 – 22.0 22 25. Weighted Average Mercury Levels in the French Broad River at Rankin Bridge 24 26. Weighted Average Mercury Levels in the French Broad River at mile 77.5 24 27. Weighted Average Mercury Levels in the Mississippi River at Mile 710.7 26 28. Weighted Average Mercury Levels in the Mississippi River at Mile 724.6 26 29. Weighted Average Mercury Levels in the Mississippi River at McKellar Lake 26 30. Weighted Average Mercury Levels in the Mississippi River at Mile 735.0 27 31. Weighted Average Mercury Levels in the Mississippi River at Mile 754.0 27 32. Weighted Average Mercury Levels in the Mississippi River at Mile 786.0 28 33. Weighted Average Mercury Levels in the Mississippi River at Mile 817.8 28 34. Weighted Average Mercury Levels in the Mississippi River at Mile 773.5 29 35. Weighted Average Mercury Levels in the Wolf River at Mile 1.5 30 36. Weighted Average Mercury Levels in the Wolf River at Mile 9.3 31 37. Weighted Average Mercury Levels in the Loosahatchie River at Mile 1.5 31 38. Weighted Average Mercury Levels in the Loosahatchie River at Mile 5.0 32 39. Weighted Average Mercury Levels in the Loosahatchie River at Mile 17.0 32 40. Weighted Average Mercury Levels in Tellico Lake at the Dam 33 41. Weighted Average Mercury Levels in Tellico Lake at Mile 15.0 33 42. Weighted Average Mercury Levels in Buffalo River at Mile 17.7 34 43. Weighted Average Mercury Levels in Buffalo River at Mile 73.1 34 44. Miscellaneous Stations Where Mercury Samples Have Been Elevated 35 I. Acknowledgements Fish sample collection assistance was provided to the Tennessee Department of Environment and Conservation (TDEC) by the Aquatic Biology Section within the Department of Health’s Environmental Laboratory and the Tennessee Wildlife Resources Agency. Samples were analyzed by the Environmental Laboratory. TDEC’s Debbie Arnwine, Linda Cartwright, and Rebecca James developed and managed the fish tissue database. Agencies that provided additional fish tissue data for this project include the Environmental Protection Agency, Tennessee Valley Authority, the U. S. Geological Survey, the U. S. Army Corps of Engineers, Oak Ridge National Laboratory, the Olin Corporation, and the Tennessee Wildlife Resources Agency. Additionally, the states of Mississippi, Virginia, and North Carolina provided data for shared waterbodies. The department is indebted to these organizations for their assistance in this project. The Pigeon River in Tennessee was previously posted due to the accumulation of dioxin in fish flesh. However, the posting was lifted in 2002 following the documentation of lower levels. (Photo by Greg Denton) 1 II. Introduction Statutory Authority The Department of Environment and Conservation is identified by the Tennessee Water Quality Control Act as having the primary statutory responsibility to ensure that the quality of our lakes, streams, rivers, wetlands, and reservoirs support the public’s reasonable uses of them. In order to establish a foundation for accomplishing this responsibility, the act establishes a partnership between the Tennessee Water Quality Control Board and the department for goal setting activities which include (1) the identification of designated uses for each waterbody, (2) promulgation of protection criteria specific to each use, and (3) creation of an antidegradation policy. The department then has the primary responsibility to monitor the quality of waters statewide to determine the extent goals have been met and to report to the public the results of these assessment activities. Particular attention is given in the act to the commissioner’s responsibility to investigate and take action upon evidence of direct human health threats. Section 69‐3‐107(15) states that the commissioner should: Inspect waters of the state where good cause is shown that the public health is threatened by pollutants in the waters, and, upon verification by the commissioner, post or cause to be posted such signs as required to give notice to the public of the potential or actual dangers of specific uses of such waters or restrictions of uses of such waters; Types of Stream Postings There are two primary justifications for a stream posting. The first is when bacteria or other pathogens pose a direct threat to humans who may come in contact with contaminated waters. The second is when toxic or carcinogenic materials accumulate in fish flesh to the extent that human consumption poses an unreasonable threat. Stream postings, where justified, are communicated to the public in multiple ways: • Signs warning the public concerning the nature of the threat, plus the activities that should be avoided, are posted at obvious access points, • Press releases are issued and information is included in departmental publications such as the 305(b) Report, 2 • A list of current postings is maintained on the department’s webpage, • Information concerning advisories is directly provided to fishermen by the Tennessee Wildlife Resources Agency. • Public meetings are held as requested. Fish consumption advisories have been caused by multiple bioaccumulative pollutants in Tennessee. Some of the major causes are organic contaminants such as PCBs, chlordane, and dioxin, plus the highly toxic metal mercury. A list of the current fishing advisories in Tennessee is in Appendix B. Fishing advisories are intended to provide information to the public – TDEC has no authority to control or restrict fishing. Only the Tennessee Wildlife Resources Agency is given that authority by statute and may close fisheries to commercial or recreational harvesting. (Catch and release poses no threat to human health where fishing advisories have been issued.) Mercury Effects, Exposure Pathways, and Sources Mercury is a metal with a well‐documented link to environmental harm and human health impacts. Ingested mercury is readily carried throughout the body by the bloodstream and easily migrates through the placenta to the developing fetus. The consumption of contaminated fish is considered to be the major pathway of exposure for most people. Mercury has been distributed globally and because many populations have been exposed to mercury in various amounts, human health effects studies have been undertaken in multiple locations. High dosage exposure to mercury occurred in Japan and Iraq. Observed effects included death, mental retardation, cerebral palsy, deafness, blindness, and severe motor impairment. Three large epidemiological studies were recently completed which investigated effects from lower‐level mercury exposures in children. In the Seychelles Islands, no statistically significant differences were documented. However, in the Faroe Islands, diminished memory, attention, and language skills were noted in children exposed to higher mercury levels. In New Zealand, exposed children also exhibited neurological deficiencies in tests. According to EPA, effects were noted in some of the studies at levels “within the range of some U. S. population exposures” (EPA, 2001). 3 Additionally, mercury studies have been undertaken in the Amazon, Ecuador, French Guiana, Madeira, Mancora, Peru, northern Quebec, and Germany. Effects were noted in all but one of these investigations. There are natural sources of mercury such as volcanoes, geysers, weathering of rocks, and forest fires. However, there are significant anthropogenic sources of mercury such as historic industrial uses, waste incineration, and the burning of coal. Water Quality Criterion for Methylmercury Under the Federal Clean Water Act, EPA is given responsibility for investigating the human health and ecological effects of water pollutants and developing guidance which the states reply upon in setting water quality criteria.