atmospheric mercury monitoring in canadanadp.slh.wisc.edu/conf/2009/session5/blanchard.pdf ·...
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Atmospheric Mercury Monitoring in CanadaCARA Mercury Monitoring:EC-TorontoP. Blanchard, D. MacTavish, R. Tanabe, M. Berthiaume, B. Vet, L. Zhang, C. EckleyEC-Halifax:R. Tordon, J. Dalziel EC-Montreal:L. Poissant, M. PiloteEC-Edmonton:B. Wiens, R. Mintz, M. LapalmeEC-Vancouver:C. EckleyMcGill University:P. Ariya, D. DeedsUniversity of Alberta:V. St. Louis, J. Graydon
Collaborators:EC-Toronto:S. Steffen, P. Lee, T. SchertzUniversity of Toronto:B. Branfireun
Why is mercury a concern in Canada?
• Mercury is toxic to humans and biota at levels found in the Canadian environment
– Indigenous populations in several areas of the Arctic have blood mercury levels that exceed U.S. and Canadian established guidelines
– Mercury is causing reproductive problems in wildlife at sites in Canada• Mercury is the primary trigger of human fish consumption advisories in
Canada• Aboriginal peoples, especially those in the Arctic, are particularly vulnerable
to mercury exposure due to high consumption levels of fish and marine animals
• Mercury levels are increasing in the arctic environment and, thus, potentially increasing risk to arctic peoples and wildlife
• Mercury is readily transported long distances, hence, global emissions impact levels of mercury in Canada
• Foreign emissions of mercury are increasing in some areas of the globe• The role of climate change in exacerbating this risk is uncertain
What are the trends in Canadian anthropogenic emissions of mercury to air?
Mercury Emissions Trends (without open sources)
0
5
10
15
20
25
30
35
40
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
Year
Rele
ases
(ton
nes)
All Other Sources
NPRI
Environment Canada, Pollution Data Branch
What are the recent trends in atmospheric levels of mercury in Canada?
10/15/2009 Page 4
a) Annual
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
2
2.1
INTE
RCEP
T19
9519
9619
9719
9819
9920
0020
0120
0220
0320
0420
05
FINA
L
TG
M i
n n
g/m
3
signif. increase regarding previous yearsignif. decrease regarding previous year
linear regression from daily averagesannual median
• Mercury concentrations in the Canadian atmosphere have decreased significantly (~10%) from 1997 to 2005.
• Decreases correspond with decreasing trends in mercury in precipitation as observed by co-located MDN stations.
Urban Affected Sites
Temme et al. (2007) Atmos. Env., 41, 135-153.
Emissions Map
Deposition Map
Landscape-based Risk Map
Ecological Risk Map
Predictive Modelling
Air
Watershed
Levels /Effects
Time
Trends
Canadian Clean Air Regulatory Agenda (CARA)
• Reduce emissions of SOx, NOx, VOCs, GHGs and Mercury.
• Regulation of industrial sectors
• Implementation requires research, monitoring, modelling and assessment.
• Timeline is 2007-2011.
• Total Gaseous Mercury (TGM) or Gaseous Elemental Mercury (GEM):
– In-situ continuous monitor, 5 min., ~1.5 ng/m3
• Mercury in precipitation: – precipitation collector, weekly sample, 5-15 ng/L.– US Mercury Deposition Network or sent to Canadian laboratory.– Methyl Mercury analyses at some sites.
• Mercury Speciation:– In-situ, research-grade system, 2-3 hours.– Gaseous Elemental Mercury– Particulate Mercury, pg/m3
– Reactive Gaseous Mercury (RGM) or Gaseous Oxidized Mercury (GOM), pg/m3
– Research into methodology improvements.
Atmospheric Mercury Measurements
Dastoor et al: Modelled Total Annual Mercury Deposition in Canada from Canadian Point Sources.
CAPMoN (GEM and/or Precip (MDN)) Speciation (GEM, RGM, pHg)Other GEM or Precip
• Historical site for GEM (CAPMoN), MDN (NADP- NS01)
• Speciation: Jan. 2009-
• Site audit August 2009 (Mark Olsen -USGS)
Eastern Canada: Kejimkujik National Park
Western Canada: near coal-fired power plants.
GEM: 2004-presentSpeciation (Genesee): 2008 to
present.
Hg
Hg
Hg
Hg
Dry deposition onto canopypHg, RGM, MeHg
Wet depositionHg(II), MeHg
Throughfall depositionHg(II), MeHg
Litterfall depositionHg(II), MeHg
PhotoreductionHg(II), MeHg
Stomatal uptakeHg(0)
Retention in the canopyHg(II), MeHg
Experimental Lakes Area Total Deposition: Vince St. Louis and Jenny Graydon (U. of Alberta)
The forest canopy can result in up to 8
times more Hg being deposited to the watershed than
to open areas
Dastoor et al: Modelled Mercury Deposition Across Canada (μg m-2 y-1).
R&D: Modelling Dry Deposition of Atmospheric Mercury
00.5
11.5
22.5
33.5
44.5
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ater ice
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nd la
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orn
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irrig
ated
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psur
ban
tund
rasw
amp
Des
ert
mix
ed w
ood
fore
sts
Tran
sitio
nal f
ores
t
U10m=6 m s-1
Unstable stratificationTwo scaling parameters α=10, β=10
(Zhang et al., 2003)
RG
M D
ry D
epos
ition
Vel
ocity
, cm
/s
Zhang et al. Atmospheric Environment, 2009
Gold Nanoparticle Microextraction of RGM:• Gold preconcentrates RGM
through adsorption and amalgamation
• Nanoparticles have high surface area, can be placed on portable fibers, filters and other surfaces.
• Microextraction exposes air stream to small quantity of nanoparticles
Atmospheric Pressure Chemical Ionization Tandem Mass Spectrometry used to detect mercury species.
R&D: New Methods for Mercury Speciation, Parisa Ariya et al. (McGill University)
Collaboration with NADP-MDN-AMNet
• CAPMoN sites part of MDN. Intercomparison sites.
• Canadian scientists participate in the development of SOP and QA/QC protocols used for both Canadian and US NADP-AMNet sites.
• Speciation data QC intercomparison:– Compare data quality control handling methods between
NADP program and EC’s RDMQ module. – Year-long data sets from sites have been exchanged
with NADP
WWW.MERCURY2011.ORG