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Mercury Concentrations in Wetlands Associated With Coal-fired

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Mercury Concentrations in Wetlands Associated With Coal-fired Powered By Docstoc
					                 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
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                             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

				
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