Mercury Wet Deposition Across North America: Understanding and Monitoring

1. Mercury Wet Deposition Across North America: Understanding and Monitoring David Gay NADP Program Office, dgay@uiuc.edu, http://nadp.sws.uiuc.edu, (217) 244-0462

2. Topics for this Talk • What is the mercury problem? • Where and when is it occurring? • Why?

3. What is the mercury problem?

4. Primarily A Health Concern • Neurological disorders • Persistent bioaccumulative neurotoxin • Large problem in children to about age 7 • Birth defects • Learning disabilities • Problem in adults under certain conditions • Other disorders • Kidney disorders • Possible human carcinogen

5. Examples…. • Industry • “Mad Hatters” • Very high concentrations in water • 1960s Japan, daily fish consumption near industrial processing • Minimata, 111 deaths, Nigata, 120 deaths • 1970s, Iraq and contaminated grain • Alkyl mercury fungicide seed mistakenly used to prepare bread • More than 6,500 Iraqis hospitalized with neurological symptoms • 459 died

6. Focus typically… • Children and fetuses • Neurotoxicity: have no blood-brain barrier to mercury • Kidney disease • Others mentioned (autism, etc.) • NHANES ≈ children with 5.8 ug/L, still unknown • Potentially pregnant women passing Hg to fetus CDC's National Health and Nutrition Examination Survey (NHANES)

7. The problem is not elemental mercury…(It’s Methyl mercury)

8. Dry Deposition Wet Deposition Bacterial action (water and sediment) predatoryfish Bioaccumulation of Methyl Mercury Through Fall (wet+dry) Geologic Sources (soil, rock, base flow etc.) Litter Fall Hg Hg Hg Me-Mercury Concentration Methylation Small fish Zooplankton Water Body/pore water

9. So, if fish are the problem, then…Where is the problem?Which fish are the problem?

11. See EPA Mercury Site for Your State/Nation www.epa.gov/mercury

12. 4-8 meals per month 3 meals per month 2 meals per month 1 meal per month

13. From E. Sutherland, USEPA

14. Fish Repeatedly Mentioned • Shark • King mackerel • Tilefish • Swordfish • Grouper • Limit tuna consumption

15. Federal Drug Administration Advises…. • Pregnant women and women of childbearing age • Limit consumption of shark and swordfish to 1/month, particularly during the 1st trimester • Limit consumption other higher-concentration fish • Others • Limit regular consumption of high concentration fish, such as shark and swordfish to about 7 ounces per week (about one serving) • For fish < 0.5 ppm Hg, regular consumption should be limited to about 14 ounces per week

16. Where is the mercury coming from?

17. Total Deposition, In Summary • Atmospheric transport and deposition is the dominant pathway to most aquatic ecosystems • Between 40 and 75% of mercury input to lakes and streams is by wet deposition • probably less in West, where dry deposition dominates • (Sorensen et al., 1997; Scherbatskoy et al., 1997; Lamborg et al., 1995; Mason et al., 1997; Landis and Keeler, 2002; Mercury 2006 Committee Statement) • “New” mercury is more likely converted to organic form than “old” mercury

18. Total Deposition is… • Wet deposition + (good data) • Dry deposition + (very little data) • Litterfall + (very little data) • Throughfall + (very little data) • Methyl mercury deposition (very little data) • Geological input (very little data)

21. Modeled Dry Deposition Seigneur and others, ES&T, 2004, V38, 555-569

24. Trends in Mercury Concentrations

25. Where is mercury coming from?Who is to blame?

26. Oxidation (long lifetime) How Mercury is Wet Deposited? Hgp RGM RGM Hgo Hgo Hgp rainout Hgp RGM washout

27. 1.4-1.8 ng/m3 Typical atmospheric mercury species abundance Atmospheric Mercury Species Abundance Hg0 – Elemental mercury RGM – Reactive gaseous mercury Hgp – Particulate-bound mercury

28. Coal combustion Incineration Medical Trash Cremation Industrial emissions (chlor-alkali) Cement production (Hg in lime) Mining Hg use in gold and silver mining (amalgam formation) Mining for Hg taconite 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)? Sources of Mercury • Volcanoes (St. Helens) • Naturally enriched ores/soils • Plate tectonic boundaries • Cinnabar (HgS), taconite, others • Soils and rocks (0.08 to 0.5 ppm in crust) • Evaporation • Soils • Fresh water and OCEANS • Natural forest fires • Tree bark (wood fire places) • soils • Volatilization from rocks? • Wind Blown reintroduction • Mine tailings • Industrial contaminated soils • Evolving Gases • Mines, industrial areas • Waste facilities (municipal in particular) • Out of soil

29. Another Source…. • Estimated at 30% of total annual US emission • Forest fires >> ag. Fires • Most emission from Alaska

30. U.S. Atmospheric Emissions(metric tons per year)

31. Global Emissions(metric tons per year)

33. Measurements We can Make(or, what you can look for)

34. Mercury Deposition Network • Cooperative research program • Part of National Atmospheric Deposition Network • 109 sites • Federal, state, local and tribal governments members, private organizations • Measuring wet deposition of mercury

35. NADP’s Goal • To monitor the chemistry of precipitation (rain and snow) consistently and as accurately as we can, for long periods to determine changes over time (trends).

36. Tribal Organizations Yurok Tribe; Sac and Fox Nation; Pennobscot; Grand Traverse Band of Ottowa & Chippewa Indians; Mille Lacs Band of Ojibwe; Akwesasne Mohawk Tribe; Cheyenne River Sioux Tribe; Makah Nation; Quinault Indian Nation

37. Federal Agency Members

38. States and Tribal Organizations

39. University Members

40. Other Research Organizations

41. Mercury Deposition Network (MDN) Collects one-week precipitation-only samples with MDN wet-dry collector Measures precipitation with gage Analyses Total mercury Methyl mercury

42. Monitoring Sites

43. Dry Deposition ?

44. NADP’s Plan Working group formedEric Presto NADP Vice-Chair - TekranMartin Risch NADP NOS Chair - USGSDavid Schmeltz EPA Clean Air Markets Div.Tim Sharac EPA Clean Air Markets Div.David Gay NADP-MDN Coordinator Review scientific methods for measuring or estimating dry deposition of mercury Determine if these methods can be formalized into a network operation Develop Network Plan (currently here) Present this network plan for NADP acceptance

45. Candidate 2007-8 NADP Atmospheric Hg Network Sites

46. For More Information David Gay, NADP dgay@uiuc.edu 217.244.0462 http://nadpweb.sws.uiuc.edu/amn/

47. All of this information (including data) is on the web http://nadp.sws.uiuc.edu

48. Mercury Wet Deposition Across North America: Understanding and Monitoring David Gay NADP Program Office, dgay@uiuc.edu, http://nadp.sws.uiuc.edu, (217) 244-0462