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Current Mercury Monitoring Approaches in Tribal Country. David Gay NADP Program Office, dgay@uiuc.edu, http://nadp.sws.uiuc.edu, (217) 244-0462. What Can Be Measured? . Mercury Cycle. Deposition is a very good starting point!. It is the starting place of Hg moving into the biosphere;
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Current Mercury Monitoring Approaches in Tribal Country David Gay NADP Program Office, dgay@uiuc.edu, http://nadp.sws.uiuc.edu, (217) 244-0462
What Can Be Measured? Mercury Cycle
Deposition is a very good starting point! • It is the starting place of Hg moving into the biosphere; • It is rather simple, • Straightforward • Inexpensive • Little training or experience needed.
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
Oxidation (long lifetime) How Mercury is Wet Deposited? Hgp RGM RGM Hgo Hgo Hgp rainout Hgp RGM washout
What is the NADP?
A Cooperative Research Program (Un. Of Illinois) • Measure wet deposition, dry deposition & litterfall concentrations of mercury • North America • Taiwan, Mexico, South America • Owned and operated by our members • Decisions made by our members • Started in 1978, 35th year • Over 400,000 precipitation samples
dry wet
Mercury Deposition Network (MDN) Collects one-week precipitation-only samples with MDN wet-dry collector Measures precipitation with gage Analyses Total Mercury Methyl Mercury Other options
Atmospheric Mercury Network (AMNet) • A New NADP Network • Measure: • Hg species (Tekran system) • meteorology and land cover variables • Elemental mercury (Hg0) • Gaseous oxidized mercury (GOM) • Particulate bound mercury (PBM) • Estimate Dry Deposition
Coming Soon: Dry Deposition Estimates • flux (F ) = air concentration x dry deposition velocity (Vd) • F= Vdeposition * Concentrationair • where: • Ra as aerodynamic resistance, Rb as quasi-laminar resistance, and Rc as canopy resistance
Product • Weekly estimates of dry deposition of • GOM • PBM2.5 • Downward dry deposition of GEM • Working & coming soon • No evasion estimate (re-emission) • Not net deposition
Results And what can be done with this information
What factors are affecting fish concentrations of Hg? Water pH Total dissolved solids Dissolved sulfate Hg is overwhelmingly deposition Overwhelmingly anthropogenic Wiener et al., 2006 Environmental Science and Technology Vol40 p 6261.
Current Mercury Monitoring Approaches in Tribal Country David Gay NADP Program Office, dgay@uiuc.edu, http://nadp.sws.uiuc.edu, (217) 244-0462
Questions and Answers • Chris Lee/TAMS • Joe Painter/Winnebago • Cody Barta/Sac and Fox of Kansas