d. gay, schmeltz, sharac, nat. tribal conf. for env. management, billings, mt, june 26, 2008, slide...
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D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 1
Current Mercury Monitoring Approaches in Tribal Country
David Gay
NADP Program Office, [email protected], http://nadp.sws.uiuc.edu, (217) 244-0462
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 2
What Can Be Measured?
Mercury Cycle
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 3
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.
Bioaccumulation of Methyl Mercury
Bacterial action(water and sediment)
Zooplankton Small fish predatory fish
Water Body/pore water
Me-Mercury
Concentration
Dry Deposition
Wet Deposition Geologic Sources(soil, rock, base flow etc.)
Methylation
Hg Hg Hg
Through Fall(wet+dry)
Litter Fall
How Mercury is Wet Deposited?
Hgo
RGMHgp
Hgp
RGM
HgoHgp
RGM
rainout
washout
Oxidation (long lifetime)
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 7
Tribal Lands and Mercury Sources
• 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
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 11
Mercury Deposition Network (MDN)
Collects one-week precipitation-only sampleswith MDN wet-dry collector
Measures precipitation with gage
AnalysesTotal MercuryMethyl MercuryOther options
Atmospheric Mercury Network (AMNet)
Atmospheric Mercury, Cape Hedo, Okinawa, 2004
0
1
2
3
4
5
84 88 92 96 100 104 108 112 116 120
Julian Day, UTC, 2004
Ele
me
nta
l H
g (
ng
/m3 ) a
nd
CO
(pp
b/1
00
)
0
10
20
30
40
50
PH
g a
nd
RG
M (
pg
/m3 )
Hg(0) PHg RGM CO
• 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
cba
d
RRR
1 V
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
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 30
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 31
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 32
D. Gay, Schmeltz, Sharac, Nat. Tribal Conf. for Env. Management, Billings, MT, June 26, 2008, Slide 33
• What factors are affecting fish concentrations of Hg?– Water pH– Total dissolved solids– Dissolved sulfate
• Hg is overwhelmingly deposition
• Overwhelmingly anthropogenic
Wiener et al., 2006Environmental Science and Technology Vol 40 p 6261.
Current Mercury Monitoring Approaches in Tribal Country
David Gay
NADP Program Office, [email protected], http://nadp.sws.uiuc.edu, (217) 244-
0462