mercury toxic trace element occurs naturally anthropogenic sources methyl form of most concern ...
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MercuryMercury
Toxic trace element
Occurs naturally Anthropogenic
sources Methyl form of
most concern
Toxic trace element
Occurs naturally Anthropogenic
sources Methyl form of
most concern
Natural sourcesNatural sources
Hg0Hg0
Anthropogenic SourcesAnthropogenic Sources
Hg2+ HgpHg0
Mercury in the EnvironmentMercury in the Environment
Inorganic Hg is now the predominant source of methylated mercury
Fossil fuel burning
Inorganic Hg is now the predominant source of methylated mercury
Fossil fuel burning
Chemical Pollution 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
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 MercuryWetlands and Mercury
Methylmercury production.
Source of methylmercury for freshwaters.
Sink and source
Methylmercury production.
Source of methylmercury for freshwaters.
Sink and source
HgpHg2+Hg
Hg0
Mercury concentrations in wetlands associated with coal-fired power plants
(CFPPs)
Mercury concentrations in wetlands associated with coal-fired power plants
(CFPPs)
Richard Halbrook and Scott WeirCooperative Wildlife Research Laboratory,
Department of Zoology Southern Illinois University, Carbondale, Illinois
Richard Halbrook and Scott WeirCooperative Wildlife Research Laboratory,
Department of Zoology Southern Illinois University, Carbondale, Illinois
ObjectivesObjectives
Preliminary information 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
Specific protocols for monitoring mercury concentrations in wetland habitats
Preliminary information 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
Specific protocols for monitoring mercury concentrations in wetland habitats
Selection of Power PlantsSelection of Power Plants
Plants were selected on the following factors:Mercury emissionsPrevailing wind dataSuitable wetlands The plants selected are: Joppa, Baldwin,
Newton, and Southern Illinois Power Cooperative (SIPC)
Plants were selected on the following factors:Mercury emissionsPrevailing wind dataSuitable wetlands The plants selected are: Joppa, Baldwin,
Newton, and Southern Illinois Power Cooperative (SIPC)
Sample CollectionsSample Collections 45 total wetlands in May and June 2007 12 wetlands sampled from Baldwin and SIPC,
11 from Joppa, and 10 from Newton3 upwind and between 3-5km9 downwind
Range: 3-5km, 8-10km, and 13-15km
45 total wetlands in May and June 2007 12 wetlands sampled from Baldwin and SIPC,
11 from Joppa, and 10 from Newton3 upwind and between 3-5km9 downwind
Range: 3-5km, 8-10km, and 13-15km
Map of Wetlands, IL counties, CFPPsMap of Wetlands, IL counties, CFPPs
Collection MethodsCollection Methods
Sediment sampled with core augers 3 samples from each wetland Temperature (ºC)
Sediment sampled with core augers 3 samples from each wetland Temperature (ºC)
Tadpoles sampled with dip nets
Species, stage, mass, length
Tadpoles sampled with dip nets
Species, stage, mass, length
Sediment VariablesSediment Variables Oxidation-reduction
potential pH Texture
Oxidation-reduction potential
pH Texture
Mercury AnalysisMercury 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.
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.
StatisticsStatistics
SAS (v 9.1) Normality, Shapiro-Wilks Analysis of covariance ANOVA Pearson Correlation (Bonferroni Correction)
SAS (v 9.1) Normality, Shapiro-Wilks Analysis of covariance ANOVA Pearson Correlation (Bonferroni Correction)
Sediment ResultsSediment Results
Range
1 2 3 4
log S
ed
ime
nt
TH
g (
ng/g
dry
we
igh
t)
1.2
1.4
1.6
1.8
BaldwinJoppaSIPCNewton
Upwind vs DownwindUpwind vs Downwind
Baldwin Joppa SIPC Newton
log S
ed
ime
nt
TH
g (
ng/g
dry
we
igh
t)
0.0
0.5
1.0
1.5
2.0
DownwindUpwind
*
3 7 71 3 9 62
Tadpole Results (29 ponds)*Tadpole Results (29 ponds)*
*Mean + SE (n)
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
Tadpole Results Tadpole Results
Range
1 2 3 4
log T
ad
po
le T
Hg (
ng/g
we
t w
eig
ht)
1.2
1.4
1.6
1.8
2.0
BaldwinJoppaSIPCNewton
Tadpole upwind vs downwindTadpole upwind vs downwind
Baldwin Joppa SIPC Newton
log T
ad
po
le T
Hg (
ng/g
we
t w
eig
ht)
0.0
0.5
1.0
1.5
2.0
2.5
DownwindUpwind
2 4 24 1 6 3
AEisler 1987BTerhivuo et al. 1984CMacDonald et al. 2000DHealth Canada 2007
Concentrations of importance
Background conc Current StudyConcentrations
of concern
Sediment THg 20-60 ng/g (dw)A 8-82 ng/g (dw) 180 ng/g (dw)C
Aquatic Vertebrates THg
<80 ng/g (ww)B 5-318 ng/g (ww) 500 ng/g (ww)D
Correlations of Tadpole VariablesCorrelations of Tadpole Variables
THg Gosner StageTotal Length
(mm)Weight (g)
THg 1
Gosner Stage -0.25* 1
Total Length (mm)
-0.47*** 0.71*** 1
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
Current study IllinoisBullfrog Green frog
Whole body63.2 ng/g
45.1 ng/g
Burger and Snodgrass
2001
Savannah River, SW Carolina
Southern leopard frog
Body, Tail, Digestive tract
< 0.200 ng/g DL
Bank et al. 2007
Acadia National Park,
Maine
Bullfrog Green frog
Whole body composite
19.1 ng/g 25.1 ng/g
Unrine et al. 2005
Savannah River, W Carolina
Southern leopard frog
Carcass Gut
184 ng/g (dw) 1275 ng/g (dw)
Byrne et al. 1975
Yugoslavia Unspecified Whole body 410, 490 ng/g
Other CFPP studiesOther CFPP studies
Author Place Biological UnitDistance from
CFPPSpecies Conclusions
Anderson and Smith 1977.
Illinois1 Lake,
Terrestrial soil< 15 km
Many fish species
Soil sig. > downwind, Lake sed > after ops began, Fish
conc very low
Wangen and Williams 1978.
New Mexico Terrestrial Soil 8-120 km N/A
Concentration as a function of distance were not significant
for 9 elements
Crockett and Kinnison 1979
Arizona Terrestrial Soil < 30 km N/ANo pattern in
concentric rings
Pinkney et al 1997.
Maryland Ponds 3 - 15 km
Fish (bluegill, green sunfish,
largemouth bass)
No pattern in concentric rings.Field results did not match
model
Current Study Illinois Ponds/Wetlands 3 - 15 kmBullfrog, green
frog larvae
No pattern for 3 of the CFPPs, Slight
pattern downwind of Newton CFPP
Using tadpoles as bioindicatorsUsing tadpoles as bioindicators
log pond mean tadpole THg (ng/g wet weight)
0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2
log p
on
d m
ea
n s
ed
ime
nt
TH
g (
ng/g
dry
we
igh
t)
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
ConclusionsConclusions Preliminary information 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)
Develop Specific protocols for monitoring mercury concentrations in wetland habitats
Preliminary information 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)
Develop Specific protocols for monitoring mercury concentrations in wetland habitats
Management ImplicationsManagement Implications
Concentrations of THg measured in sediment and tadpoles in wetlands surrounding Newton, Baldwin, Joppa, and SIPC CFPPs were are below levels of concern
Concentrations of THg measured in sediment and tadpoles in wetlands surrounding Newton, Baldwin, Joppa, and SIPC CFPPs were are below levels of concern
AcknowledgementsAcknowledgements
Illinois Sustainable Technology Center
Gary Bordson and the metals group at ISTC
Marvin Piwoni Cooperative Wildlife
Research Lab Department of Zoology
and Graduate School
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?Questions?
ConclusionsConclusions
With the exception of Newton, CFPPs did not have a significant pattern of THg concentrations in ponds 3-15 km downwind
Tadpole THg was negatively correlated with length
With the exception of Newton, CFPPs did not have a significant pattern of THg concentrations in ponds 3-15 km downwind
Tadpole THg was negatively correlated with length
Sediment THg and distanceSediment THg and distance
Range
1 2 3 4
log S
ed
ime
nt
TH
g (
ng/g
dry
we
igh
t)
1.2
1.3
1.4
1.5
1.6
1.7
1.8
9 9
10
10
Sediment VariablesSediment Variables
A = Pond means were used in these correlations*** = p < 0.01 (Bonferroni correction)
Sediment THgTemperature
(°C)pH
Redox potential
Pond area (m2)A Tadpole THgA
Sediment THg 1
Temperature (°C)
-0.16 1
pH -0.21 -0.22 1
Redox potential
0.24 0.16 -0.85 1
Pond area (m2)A 0.01 -0.26 0.23 -0.33 1
Tadpole THgA -0.05 -0.41 0.35 -0.14 0.01 1
TextureTexturelo
g s
ed
ime
nt
TH
g (
ng/g
dry
we
igh
t)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
6 15 1 2 1 13 20 8
Mercury across taxa
Mammals Birds Amphibians
MechanismMeHg causes
central nervous system damage
Central nervous system damage
Neurotoxicity (?)
Physiological effects
Behavioral impairment:
anorexia, lethargy
Weight loss, muscular
incoordination
Adults: ? Tadpoles:
swimming behavior
ReproductionReadily crosses placental barrier
Reduced hatchability and
clutch size, eggshell thinning
Effects on embryos (?)
Mercury and AmphibiansMercury and Amphibians
MeHgMeHgHg2+Hg2+200-400 ng/g 200-400 ng/g
THg THg body body burdenburden
Concentrations Concentrations similar to similar to fishfish
Local vs Regional vs GlobalLocal 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
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 ControlQuality Assurance/Quality Control
Laboratory Blanks Laboratory Reagent Spikes Replicates
Laboratory Blanks Laboratory Reagent Spikes Replicates
Tadpole Only:Tadpole Only:Matrix Quad Matrix Quad StudyStudy
Tadpole Only:Tadpole Only:Matrix Quad Matrix Quad StudyStudy
Sediment Only:Sediment Only:Matrix SpikeMatrix SpikeReference Reference MaterialMaterial
Sediment Only:Sediment Only:Matrix SpikeMatrix SpikeReference Reference MaterialMaterial
Tadpoles are kind of a painTadpoles are kind of a pain
Feeding behavior
Predation escape
Metamorphosis/Physiology
Feeding behavior
Predation escape
Metamorphosis/Physiology
Newton Power PlantNewton Power Plant
Range
1 2 3 4
log T
Hg (
ng/g
)
1.0
1.2
1.4
1.6
1.8
2.0
SedimentTadpole