80
Hg
200.59
Jiaoyan Huang
Class of Biogeochemical Cycles
2014
Outline

Introduction
 usage, species, health effect

Hg global cycle
 Hg emissions
 In the atmosphere
 In the aquatic environments
 In soil

The Minamata Convention
Mercury (Hg)
Hydr-argyrum (Hg)
Atomic number: 80; Atomic weight: 200.59
The oxidation states of Hg: 0, +1, and +2.
http://www.tracesciences.com/hg.htm
Species of Hg
Elemental: Hg0
Oxidized Hg (2+ or 1+): gases/particles
Inorganic Hg: HgCl2 HgO, Hg(NO3)2
Organic Hg: CH3Hg, (CH3)2Hg
Environment
Atmosphere
Water
Soil
Species
Elemental, oxidized Hg
Oxidized Hg
Elemental, Oxidized Hg
Usage of Hg
http://www.chem.unep.ch/MERCURY/Report/Chapter7.htm
Adverse Health Effect of Hg
Nervous system, renal, cardiovascular effects,
cancer, genotoxity, reproductive and
developmental effects, gastrointestinal (digestive
system) and hepatic (liver) effects, effects on the
skin, , effects on the immune system, effects on
the thyroid gland.
Minamata Disease
Victim: 12,615
Death: 1,246
http://pollutionpictures.blogspot.com/2010/07/minamata-diseasemercury-poisoning-1932.html
Global cycles-elements, water
Mass exchange between/among the
phases or transport between/among
regions. precipitation
Flux = mass/area/time=ΔC × MTC
Flux + reactions
Air-surface exchange and atmospheric Hg
behaviors.
Global Hg Cycle
Selin et al., 2009, copyright 2007 National Academy of Sciences, U.S.A.
Hg Distribution in Different Phase
Preindustrial
Modern
Lindberg et al., 2007 copyright, American Geophysical Union
Hg content in ice core
Hg emission sources
UNEP, 2013
Global anthropogenic Hg
emission map, 2010
UNEP 2013
Temporal variation of Hg
anthropogenic emission
UNEP 2013
Hg related chemical reactions
Lindberg et al., 2007
Atmospheric Hg chemical reactions
Subir et al., 2011
Atmospheric Hg depletion in Arctic
region-Lindberg et al., 2002, EST
Atmospheric Hg depletion in Arctic
region-Lindberg et al., 2002, EST
Atmospheric Hg depletion in Arctic
region-Lindberg et al., 2002, EST
Free troposphere
Most meteorological activity occurs in planetary boundary layer, local/regional
scale
Free troposphere is associated with jet stream and geostrophic winds, as the
pollutants reach this layer, they can be transported in global scale
http://asjohnson.wordpress.com/20
10/08/02/the-troposphere-101/
http://www.skybrary.aero/index.php/Planeta
ry_Boundary_Layer
Jet Stream-D. J. Jacob @ Harvard
Atmospheric GOM enrichment in west
US –Timonen et al., 2013 ACP
Atmospheric GOM enrichment in west
US –Timonen et al., 2013 ACP
Atmospheric Hg depositions
Dry deposition is associated to species,
meteorological conditions, surfaces, biochemical
process.
Wet deposition is considered as in cloud, fog,
dew, rain, snow.
Dry
Zhang et al., Atmos. Chem. Phys., 12, 4327–4340, 2012
Wet
http://nadp.sws.uiuc.edu/lib/data/2012as.pdf
Hg wet deposition in the western US
– Huang and Gustin, 2011 ES&T
Hg dry deposition
Exchange is usually not deposition only; bi-direction.
Surface, chemical/physical, biochemical prosperities, and
meteorological conditions.
Deposition
Remission
Henry's Law constant
Partitioning coefficient
Biogenic reactions
Reduction reactions
Zhang et al., 2003 ACP
Hg dry deposition in the western US
– Wright, et al. STOTEN
Hg movement from air to natural
surfaces
To soil
Dry Deposition
Wet Deposition
Throughfall
Litterfall
Overland Flow
Soil Water
Choi and Holsen, 2009
Emission
Biogenic reactions in soil
Stem flow
Hg emission from leaves
What is the total Hg input into soil?
Overall = litterfall + wet deposition?
Hg movement from air to natural
surfaces
To water
To snow
Where is the Hg going when snowmelt?
Runoff with water or back to air?
Lindberg et al., 2007 Ambio
Hg emissions from snow-Maxwell
et al., 2013 Plos One
Hg emissions from soil
Soil Hg content (Zehner and Gustin 2002; Engle et al., 2001;
Feng et al., 2005; Coolbaugh et al., 2002)
Moisture (Bahlmann et al., 2004; Gustin and Stamenkovic,
2005; Song et al., 2005; Lindberg et al., 1999)
Temperature (Feng et al., 2005; 1999; Gustin et al., 1997)
Solar radiation (Carpi et al., 1997; Zhang et al., 2001; Gustin
et al., 2002)
Relative humidity (Poissant and Casimir, 1998; Fu et al.,
2006)
Oxidants (Engle et al., 2005; Zhao et al., 2006)
Microbial activities (Fritsche et al., 2008)
Hg emissions from soil-Choi and
Holsen, 2009, EP
Hg emissions from soil-Briggs and
Gustin, 2011, WASP
Hg aqueous reactions
http://sofia.usgs.gov/geer/2000/posters/merc_cycle/
Hg Bioaccumulation
methylmercury
in lake water:1
microorganisms 105
for macroorganisms 106
fish, birds and humans are 107
http://www.ec.gc.ca/mercure-mercury/default.asp?lang=En&n=D721AC1F-1
Minamata Convention on Mercury
Minamata Convention on Mercury
Products
Hg contained production, export and import
will be banned by 2020.
Artisanal and Small-Scale Gold Mining
Countries need to draw up strategies to
reduce the amount of mercury used by smallscale miners
Power Stations to Cement Factories
The new treaty will control mercury emissions
and releases from various large industrial
facilities