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David Gay Illinois State Water Survey, Champaign, IL, dgay@uiuc 217.244.0462 PowerPoint Presentation
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David Gay Illinois State Water Survey, Champaign, IL, dgay@uiuc 217.244.0462

David Gay Illinois State Water Survey, Champaign, IL, dgay@uiuc 217.244.0462

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David Gay Illinois State Water Survey, Champaign, IL, dgay@uiuc 217.244.0462

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  1. Wet Deposition of Mercury In The U.S. Results from the NADP Mercury Deposition Network, 1996-2004 David Gay Illinois State Water Survey, Champaign, IL, dgay@uiuc.edu 217.244.0462

  2. Goal of this Presentation…. • To introduce you to the Mercury Deposition Network. • Show what we know about the deposition of mercury.

  3. What is the Mercury Deposition Network? • A Cooperative Research Program • Part of National Atmospheric Deposition Network • 92 sites • Federal, State, Local and Tribal Governments members, private organizations • Measuring wet deposition of mercury • Our Charge: • to determine if trends exist in wet deposition of mercury over time

  4. Federal Agency Members

  5. University Members

  6. Tribal Organizations

  7. Other Organizationsand States

  8. Why monitor Mercury in Precipitation?

  9. Why monitor Mercury in Precipitation? • Atmospheric transport and deposition is the dominant pathway to most aquatic ecosystems. • Between 50 and 75% of the mercury input to lakes and streams is by wet deposition (probably less in the West).

  10. Lake Ocean methylation methylation From Ellen’s Presentation….. Mercury Emissions Contribute to Exposure to Mercury Atmospheric deposition • Fishing • commercial • recreational • subsistence • Impacts • Best documented impacts on the developing fetus: impaired motor and cognitive skills • Possible cardiovascular, immune, and reproductive system impacts Humans and wildlife affected primarily by eating contaminated fish Wet and Dry Deposition Emissions to the Air Mercury transforms into methylmercury in soils and water, then can bioaccumulate in fish Emissions and Speciation Ecosystem Transport, Methylation, and Bioaccumulation Atmospheric Transport and Deposition Consumption Patters Human Exposure • The primary pathway of human exposure to mercury in the U.S. is through eating contaminated fish. • Power plants emit approximately 48 tons of mercury and are the largest source of mercury emissions in the U.S. (approximately 41%).

  11. How Mercury is Wet Deposited Hgp RGM Hgo Hgp RGM

  12. 1.4-1.8 ng/m3 Typical Atm. Mercury Species Abundance Atmospheric Mercury Species Abundance Hg0 – Elemental Mercury RGM – Reactive Gaseous Mercury Hgp – Particulate Bound Mercury

  13. How Mercury is Wet Deposited Hgo oxidation RGM

  14. Picture of the sampler here

  15. MDN Sites (2005)

  16. What the Data Show….

  17. Mercury Concentrations in Precipitation 2003

  18. Mercury Concentrations in Precipitation Mercury Wet Deposition, 2003

  19. Possible Reasons for High Mercury Deposition in the Summer • Higher rainfall amounts • Higher temperatures • Higher oxidant levels • Southerly air flow • Strong thunderstorms • Higher emissions (ocean)

  20. Seigneur and others, ES&T, 2004, V38, 555-569 WET DEPOSITION Modeled and Measured

  21. Trends In Wet Deposition

  22. Trends • Seasonal Kendall and Sen’s (non-parametric) • 5 years of data for 4 seasons • Run seasonally • Very small, slight changes, but • none significant

  23. Dry Deposition

  24. Measurements of Dry Deposition • ? • Very few measurements • Very few calculations of dry deposition

  25. Modeling Deposition DRY DEPOSITION Seigneur and others, ES&T, 2004, V38, 555-569

  26. Plans for Dry Deposition Manually Operated Mercury Species Sampling Monitoring station for manually-operated sampling system EPA Method IO-5 Gold-Trap Method for Hg0 i Sampling box for manual system

  27. Methods are: -Lab Tested -Widely used -QA challenged -EPA Accepted Automated Hg Speciation PHg RGM Hg0

  28. Future Directions for MDN • Expand network coverage in the western U.S., southern Canada, and Mexico • Provide “before” and “after” mercury deposition data related to future controls on mercury emissions • Develop better methods to monitor dry deposition of mercury • Monitor additional trace metals

  29. Wet Deposition of Mercury In The U.S. Results from the NADP Mercury Deposition Network, 1996-2004 David Gay Illinois State Water Survey, Champaign, IL, dgay@uiuc.edu 217.244.0462

  30. Coal combustion Incineration Medical Trash Cremation Industrial emissions (chlor-alkali) Cement production (Hg in lime) Hg use in gold and silver mining (amalgam formation) Mining of Hg Automobile Recycling Mercury in Landfills Fluorescent lamps dental amalgams (also in sewers) Thermometers Batteries Discarded electrical switches Others will surface Other carbon fossil fuels (gas/oil/diesel)? Anthropogenic Sources of Mercury

  31. Natural Sources of Mercury • Volcanoes (St. Helens) • Naturally enriched ores/soils • Plate tectonic boundaries • Cinnabar (HgS), taconite, others • Soils and rocks (0.5 ppm in crust) • Evaporation • Soils • Fresh water and OCEANS • Natural forest fires (wood fire places?) • Mine tailings • Tree bark, volatilization from rocks?

  32. Many Mercury Sources • Volcanoes (St. Helens) • Enriched ores/soils • Tectonic (plate) boundaries • Cinnabar (HgS), taconite, others • Soils and rocks (0.5 ppm in crust) • Evaporation • Soils • Fresh water and Oceans • Forest fires • (wood fire places?) • Tree bark, volatilization from rocks? • Coal combustion • Incineration • Industrial emissions • (chlor-alkali) • Cement production (lime) • Hg use in mining and Mining of Hg • Automobile Recycling • Mercury in Landfills • Fluorescent lamps • dental amalgams (also in sewers) • Thermometers, batteries • electrical switches • Taconite