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Mercury
Toxictrace
element
Occurs naturally
Anthropogenic
sources
Methyl form of
most concern
Natural sources
Hg0
Anthropogenic Sources
Hg2+ Hg0 Hgp
Mercury in the Environment
Inorganic Hg is now
the predominant
source of methylated
mercury
Fossil fuel burning
Chemical Pollution
Inorganic form and
methyl form both toxic
Becomes methylated
through natural
transformations
Biomagnification and
bioaccumulation
Top piscivorous wildlife
have some of the
highest levels
Source: USGS modified from Cleckner et al.
1998.
Wetlands and Mercury
Methylmercury
production.
Source of
methylmercury
for freshwaters.
Sink and
source
Hg0
Hg Hg2+
Hgp
Mercury concentrations in wetlands
associated with coal-fired power plants
(CFPPs)
Richard Halbrook and Scott Weir
Cooperative Wildlife Research Laboratory,
Department of Zoology
Southern Illinois University, Carbondale, Illinois
Objectives
Preliminaryinformation on total mercury (THg)
in wetlands associated with coal-fired
generating plants in Illinois
H1:Sediment and tadpole THg will be higher downwind
than upwind, and that concentrations will increase with
increasing distance downwind
H2:Sediment and tadpole THg concentrations will be
positively correlated
protocols for monitoring mercury
Specific
concentrations in wetland habitats
Selection of Power Plants
Plantswere selected on the following
factors:
Mercury emissions
Prevailing wind data
Suitable wetlands
The plants selected are: Joppa, Baldwin,
Newton, and Southern Illinois Power
Cooperative (SIPC)
Sample Collections
45 total wetlands in May and June 2007
12 wetlands sampled from Baldwin and SIPC,
11 from Joppa, and 10 from Newton
3 upwind and between 3-5km
9 downwind
Range: 3-5km, 8-10km, and 13-15km
Map of Wetlands, IL counties, CFPPs
Collection Methods
Sediment sampled with core
augers
3 samples from each wetland
Temperature (ºC)
Tadpoles sampled
with dip nets
Species, stage,
mass, length
Sediment Variables
Oxidation-reduction
potential
pH
Texture
Mercury Analysis
Total Hg in tadpoles
determined using a
Hydra AF cold vapor
mercury analyzer.
Tadpole digested by
EPA method 245.7.
Sediment digested by
EPA method 3051A.
Analyzed at ISTC.
Statistics
SAS (v 9.1)
Normality, Shapiro-Wilks
Analysis of covariance
ANOVA
Pearson Correlation (Bonferroni Correction)
Sediment Results
1.8
log Sediment THg (ng/g dry weight)
1.6
1.4
Baldwin
Joppa
1.2 SIPC
Newton
1 2 3 4
Range
Upwind vs Downwind
2.0
Downwind
Upwind
log Sediment THg (ng/g dry weight)
*
1.5
1.0
0.5
3 7 1 7 3 9 2 6
0.0
Baldwin Joppa SIPC Newton
Tadpole Results (29 ponds)*
Bullfrog Green Frog n
Homogenized 56.80 + 6.6 (35)a 45.46 + 5.9 (36)ab 71
Whole 86.52 + 24.8 (13)a 28.23 + 3.7 (16)b 29
n 48 52 100
*Mean + SE (n)
Tadpole Results
2.0
log Tadpole THg (ng/g wet weight)
1.8
1.6
1.4
Baldwin
Joppa
SIPC
1.2 Newton
1 2 3 4
Range
Tadpole upwind vs downwind
2.5
Downwind
Upwind
log Tadpole THg (ng/g wet weight)
2.0
1.5
1.0
0.5
2 4 4 1 6 2 3
0.0
Baldwin Joppa SIPC Newton
Concentrations of importance
Concentrations
Background conc Current Study
of concern
Sediment THg 20-60 ng/g (dw)A 8-82 ng/g (dw) 180 ng/g (dw)C
Aquatic
<80 ng/g (ww)B 5-318 ng/g (ww) 500 ng/g (ww)D
Vertebrates THg
AEisler1987
BTerhivuo et al. 1984
CMacDonald et al. 2000
DHealth Canada 2007
Correlations of Tadpole Variables
Total Length
THg Gosner Stage Weight (g)
(mm)
THg 1
Gosner Stage -0.25* 1
Total Length
-0.47*** 0.71*** 1
(mm)
Weight (g) -0.39*** 0.59*** 0.81*** 1
* = p < 0.10, *** = p < 0.01 (Bonferroni correction)
Tadpoles in the field
Author Location Species Tissue Mercury conc
Bullfrog 63.2 ng/g
Current study Illinois Whole body
Green frog 45.1 ng/g
Burger and Savannah
Southern Body, Tail, < 0.200 ng/g
Snodgrass River, SW
leopard frog Digestive tract DL
2001 Carolina
Acadia
Bank et al. Bullfrog Whole body 19.1 ng/g
National Park,
2007 Green frog composite 25.1 ng/g
Maine
Savannah
Unrine et al. Southern Carcass 184 ng/g (dw)
River, W
2005 leopard frog Gut 1275 ng/g (dw)
Carolina
Byrne et al.
Yugoslavia Unspecified Whole body 410, 490 ng/g
1975
Other CFPP studies
Distance from
Author Place Biological Unit Species Conclusions
CFPP
Soil sig. > downwind,
Anderson and 1 Lake, Many fish Lake sed > after ops
Illinois < 15 km
Smith 1977. Terrestrial soil species began, Fish conc
very low
Concentration as a
Wangen and function of distance
New Mexico Terrestrial Soil 8-120 km N/A
Williams 1978. were not significant
for 9 elements
Crockett and No pattern in
Arizona Terrestrial Soil < 30 km N/A
Kinnison 1979 concentric rings
Fish (bluegill, No pattern in
Pinkney et al green sunfish, concentric rings.Field
Maryland Ponds 3 - 15 km
1997. largemouth results did not match
bass) model
No pattern for 3 of the
Bullfrog, green CFPPs, Slight pattern
Current Study Illinois Ponds/Wetlands 3 - 15 km
frog larvae downwind of Newton
CFPP
Using tadpoles as bioindicators
1.9
log pond mean sediment THg (ng/g dry weight)
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2
log pond mean tadpole THg (ng/g wet weight)
Conclusions
Preliminaryinformation on total mercury (THg)
in wetlands associated with coal-fired
generating plants in Illinois
H1:Sediment and tadpole THg will be higher downwind
than upwind, and that concentrations will increase with
increasing distance downwind (Newton CFPP Only)
H2:Sediment and tadpole THg concentrations will be
positively correlated (Rejected)
DevelopSpecific protocols for monitoring
mercury concentrations in wetland habitats
Management Implications
Concentrations of THg measured in sediment
and tadpoles in wetlands surrounding Newton,
Baldwin, Joppa, and SIPC CFPPs were are
below levels of concern
Acknowledgements
Illinois Sustainable
Technology Center
Gary Bordson and the
metals group at ISTC
Marvin Piwoni
Cooperative Wildlife
Research Lab
Department of Zoology
and Graduate School
Questions?
Conclusions
the exception of Newton, CFPPs did not
With
have a significant pattern of THg
concentrations in ponds 3-15 km downwind
Tadpole THg was negatively correlated with
length
Sediment THg and distance
1.8
10
log Sediment THg (ng/g dry weight)
1.7
9 9 10
1.6
1.5
1.4
1.3
1.2
1 2 3 4
Range
Sediment Variables
Temperature Redox Pond area
Sediment THg pH Tadpole THgA
(°C) potential (m2)A
Sediment THg 1
Temperature
-0.16 1
(°C)
pH -0.21 -0.22 1
Redox
0.24 0.16 -0.85 1
potential
Pond area
0.01 -0.26 0.23 -0.33 1
(m2)A
Tadpole THgA -0.05 -0.41 0.35 -0.14 0.01 1
A = Pond means were used in these correlations
*** = p < 0.01 (Bonferroni correction)
log sediment THg (ng/g dry weight)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
cl 1.8
ay
lo
am
6
lo
am
15
lo
am
y
sa
nd
1
sa
nd
2
sa
nd
y
cl
sa ay 1
nd
y
Texture
cl
ay
lo
am
13
sa
nd
y
lo
am
20
si
lt
lo
am
8
Mercury across taxa
Mammals Birds Amphibians
MeHg causes
Central nervous
Mechanism central nervous Neurotoxicity (?)
system damage
system damage
Behavioral Weight loss, Adults: ?
Physiological
impairment: muscular Tadpoles:
effects
anorexia, lethargy incoordination swimming behavior
Reduced
Readily crosses hatchability and Effects on embryos
Reproduction
placental barrier clutch size, (?)
eggshell thinning
Mercury and Amphibians
MeHg
Hg2+
200-400 ng/g
THg body
burden
Concentrations
similar to
fish
Local vs Regional vs Global
Contradicting results regarding the local
effects of coal-fired power plants
Studies have reported local impacts
Some have stated that local impacts are
overestimated
Atmospheric lifespan of mercury species
Quality Assurance/Quality Control
Laboratory Blanks
Laboratory Reagent
Spikes
Replicates
Sediment Only: Tadpole Only:
Matrix Spike Matrix Quad
Reference Study
Material
Tadpoles are kind of a pain
Feeding
behavior
Predation
escape
Metamorphosis
/Physiology
Newton Power Plant
2.0
Sediment
Tadpole
1.8
log THg (ng/g)
1.6
1.4
1.2
1.0
1 2 3 4
Range
