Environmental Chemistry and Toxicology of Mercury

The book that looks at mercury′s impact on the planet today

Recent research by the EPA has concluded that one in six womenof childbearing age have unsafe levels of mercury in their bodies,which puts 630,000 newborn babies each year at risk of neurologicalimpairment. Mercury poses severe risks to the health of animals andecosystems around the world, and this book provides the essentialinformation that anyone interested in environmental sciences shouldknow about the fundamentals of the entire mercury cycle.

Comprised of four parts that present an overview of mercury inthe environment, mercury transformations, transport, andbioaccumulation and toxicology, each chapter of EnvironmentalChemistry and Toxicology of Mercury includes the basic concepts ofthe targeted subject, a critical review of that subject, and thefuture research needs.

This book explains the environmental behavior and toxicologicaleffects of mercury on humans and other organisms, and provides abaseline for what is known and what uncertainties remain in respectto mercury cycling. The chapters focus on the fundamental scienceunderlying the environmental chemistry and fate of mercury. Thiswork will be invaluable to a wide range of policy experts,environmental scientists, and other people requiring acomprehensive source for the state of the science in thisfield.

PREFACE xiii

ACKNOWLEDGMENTS xv

CONTRIBUTORS xvii

1 OVERVIEW OF MERCURY IN THE ENVIRONMENT 1
Guangliang Liu, Yong Cai, Nelson O Driscoll, XinbinFeng, and Guibin Jiang

1.1 Introduction / 1

1.2 Toxicity and Health Risks of Mercury Exposure / 2

1.3 Sources of Mercury / 2

1.4 Overview of Mercury Biogeochemical Cycling / 7

1.5 Structure of the Book / 8

1.6 Concluding Remarks / 9

References / 9

PART I ANALYTICAL DEVELOPMENTS 13

2 ADVANCES IN SPECIATION ANALYSIS OF MERCURY IN THEENVIRONMENT 15
Yanbin Li, Yongguang Yin, Guangliang Liu, and YongCai

2.1 Introduction / 15

2.2 Sample Preparation for Hg Speciation in EnvironmentalSamples / 16

2.3 Application of GC Technique in Hg Speciation Analysis /32

2.4 Application of HPLC Technique in Hg Speciation Analysis /36

2.5 Application of Capillary Electrophoresis Techniques in HgSpeciation Analysis / 39

2.6 Application of X–Ray Absorption Spectroscopy in ProbingChemical Microenvironment of Hg / 40

2.7 Application of Stable Isotope Dilution Technique in MercurySpeciation Analysis / 41

2.8 Summary / 43

References / 44

3 MEASURING GAS PHASE MERCURY EMISSIONS FROM INDUSTRIALEFFLUENTS 59
Samuel J. Ippolito, Ylias M. Sabri, and Suresh K.Bhargava

3.1 Introduction / 59

3.2 Standardized Methods for Measuring Mercury / 72

3.3 Mercury Continuous Emission Monitors (CEMs) / 81

3.4 Future Outlook / 95

References / 96

PART II SPECIATION AND TRANSFORMATION 111

4 ATMOSPHERIC CHEMISTRY OF MERCURY 113
Che–Jen Lin, Pattaraporn Singhasuk, and Simo O.Pehkonen

4.1 Introduction / 113

4.2 The Overall Picture / 114

4.3 Chemical Transformations in the Gas Phase / 118

4.4 Chemical Transformations in the Aqueous Phase / 131

4.5 Redox Chemistry at the Interface Between the Atmosphere andEarth s Surfaces / 136

4.6 Atmospheric Implications of the Identified Redox Pathways /139

4.7 Future Research Needs / 143

References / 144

5 MICROBIAL TRANSFORMATIONS IN THE MERCURY CYCLE 155
Chu–Ching Lin, Nathan Yee, and Tamar Barkay

5.1 Introduction / 155

5.2 Mercury Methylation / 158

5.3 Methylmercury Degradation / 168

5.4 Redox Cycling of Inorganic Hg / 169

5.5 Conclusions / 179

References / 180

6 PHOTOREACTIONS OF MERCURY IN AQUATIC SYSTEMS 193
Emma E. Vost, Marc Amyot, and Nelson J.O Driscoll

6.1 Significance of Mercury Photoreactions / 193

6.2 Concepts in Mercury Photoreactions / 194

6.3 Current Methods in Mercury Photochemistry / 209

6.4 Summary / 211

References / 212

7 CHEMICAL SPECIATION OF MERCURY IN SOIL AND SEDIMENT219
Ulf Skyllberg

7.1 Introduction / 219

7.2 Physicochemical Properties, Oxidation States, ChemicalForms, Structures, and Concentrations of Mercury in the Environment/ 220

7.3 Aqueous Phase: Major Ligands and Their Affinities forMercury(II) / 222

7.4 Liquid and Solid Phases of Mercury in Soils and Sediments /229

7.5 Reactions of Mercury(II) with Soil and Sediment ParticleSurfaces / 231

7.6 Stabilization of Nanoparticulate Mercury(II) Sulfides byNatural Organic Matter / 237

7.7 Solubility and Chemical Speciation of Mercury(II) in Soilsand Sediments / 237

7.8 Methods for Studying the Chemistry of Mercury(II) in Soilsand Sediments / 248

7.9 Future Research Needs / 249

References / 252

8 THE EFFECTS OF DISSOLVED ORGANIC MATTER ON MERCURYBIOGEOCHEMISTRY 259
Chase A. Gerbig, Joseph N. Ryan, and George R. Aiken

8.1 Introduction / 259

8.2 Dissolved Organic Matter / 260

8.3 Field Observations / 263

8.4 Effects of DOM on Mercury Distributions Between Solution andParticles / 265

8.5 Mercury Binding Strength / 268

8.6 Mercury Binding Environment / 271

8.7 Methylmercury Binding Strength and Environment / 274

8.8 DOM and Mercury Mineral Dissolution / 276

8.9 DOM and Mercury Mineral Precipitation / 280

References / 284

9 TRACKING GEOCHEMICAL TRANSFORMATIONS AND TRANSPORT OFMERCURY THROUGH ISOTOPE FRACTIONATION 293
Holger Hintelmann and Wang Zheng

9.1 Introduction / 293

9.2 Fractionation of Mercury Isotopes in Environmental Processes/ 300

9.3 Hg Isotope Variations in Nature / 315

9.4 Summary / 319

References / 320

PART III TRANSPORT AND FATE 329

10 ATMOSPHERIC TRANSPORT OF MERCURY 331
Oleg Travnikov

10.1 Introduction / 331

10.2 General Concepts of Mercury Cycling in the

Atmosphere / 331

10.3 Methods for Studying Atmospheric Mercury Transport /336

10.4 Assessments of Airborne Mercury Pollution / 342

10.5 Knowledge Gaps / 354

References / 356

11 ADSORPTION OF MERCURY ON SOLIDS IN THE AQUATIC ENVIRONMENT367
Guangliang Liu, Yanbin Li, and Yong Cai

11.1 Introduction / 367

11.2 Adsorption of Mercury on Solids / 369

11.3 Role of Colloids in Mercury Adsorption / 374

11.4 Concluding Remarks / 380

References / 381

12 EXCHANGE OF ELEMENTAL MERCURY BETWEEN THE OCEANS AND THEATMOSPHERE 389
Asif Qureshi, Matthew Macleod, Elsie Sunderland, and KonradHungerbu¨ hler

12.1 Introduction / 389

12.2 Models of Gas Exchange of Elemental Mercury at theAir Sea Interface / 390

12.3 Field Studies of Ocean–To–Air Fluxes of Mercury / 398

12.4 Rate Constants for Reduction and Oxidation of MercurySpecies in Ocean Waters / 400

12.5 Modeling Studies Estimating Oceanic Air Sea Exchange/ 411

12.6 Conclusions and Future Directions / 415

References / 416

13 EXCHANGE OF MERCURY BETWEEN THE ATMOSPHERE AND TERRESTRIALECOSYSTEMS 423
Mae Sexauer Gustin

13.1 General Overview / 423

13.2 Methods and Tools Applied for Measurement and Understandingof Air Terrestrial Surface Exchange / 425

13.3 Measured Fluxes / 433

13.4 Conclusions / 442

References / 444

PART IV BIOACCUMULATION, TOXICITY, AND METALLOMICS 453

14 BIOACCUMULATION AND BIOMAGNIFICATION OF MERCURY THROUGHFOOD WEBS 455
Karen Kidd, Meredith Clayden, and Tim Jardine

14.1 Introduction / 455

14.2 Mercury in Aquatic and Terrestrial Organisms / 457

14.3 Mercury within Organisms / 464

14.4 Factors Affecting Mercury in Biota / 465

14.5 Biomagnification of Mercury Through Food Webs / 474

14.6 Mercury Stable Isotopes in Bioaccumulation Studies /481

14.7 Case Study Kejimkujik National Park and HistoricSite, Nova Scotia, Canada / 482

14.8 Conclusions / 484

References / 485

15 A REVIEW OF MERCURY TOXICITY WITH SPECIAL REFERENCE TOMETHYLMERCURY 501
Mineshi Sakamoto, Katsuyuki Murata, Akiyoshi Kakita, andMasanori Sasaki

15.1 Introduction / 501

15.2 Global Mercury Emission into the Atmosphere / 502

15.3 Metabolism and Toxicity of Chemical Forms of Mercury /503

15.4 Risk Assessment of Prenatal Exposure to Methylmercury /509

15.5 Risks and Benefits of Fish Consumption for BrainDevelopment / 510

15.6 Exceptional Methylmercury Exposure Through Rice / 510

15.7 Summary / 511

References / 511

16 METALLOMICS OF MERCURY: ROLE OF THIOLANDSELENOL–CONTAINING BIOMOLECULES 517
Feiyue Wang, Marcos Lemes, and Mohammad A.K. Khan

16.1 Introduction / 517

16.2 Metallomics of Mercury / 517

16.3 Mercury and Methylmercury Complexes with Thiol–ContainingBiomolecules / 519

16.4 Mercury and Methylmercury Binding to Selenol–ContainingBiomolecules / 522

16.5 Lability of Mercury or Methylmercury Complexes with Thiolsor Selenols / 524

16.6 Thiol–Containing Biomolecules in the Uptake and Metabolismof Mercury / 526

16.7 Selenium Aided Biomineralization of Mercury andMethylmercury / 529

16.8 Analytical and Modeling Approaches / 531

16.9 Conclusion / 538

References / 538

17 HUMAN HEALTH SIGNIFICANCE OF DIETARY EXPOSURES TOMETHYLMERCURY 545
Anna L. Choi and Philippe Grandjean

17.1 Introduction / 545

17.2 Methylmercury Exposure / 546

17.3 Nutrients in Fish and Seafood / 548

17.4 Major Prospective Cohort Studies / 549

17.5 Health Effects / 552

17.6 Cardiovascular Outcomes / 555

17.7 Nutrient and Methylmercury Exposure as Predictors ofDevelopmental Outcomes / 556

17.8 Confounding Variables / 557

17.9 Risk Assessment and Exposure Imprecision / 558

17.10 Conclusions / 559

References / 561

INDEX 569

Guangliang Liu, PhD, is Research Scientist in the Departmentof Chemistry and Biochemistry, Florida International University,where he manages the Mercury Laboratory.

Yong Cai, PhD, is Professor in the Department ofChemistry and Biochemistry, Florida International University. Hehas been working on environmental chemistry and the geochemistry ofmercury for almost twenty years.

Nelson O′Driscoll, PhD, is Canada Research Chair inEnvironmental Biogeochemistry and Associate Professor in theDepartment of Earth and Environmental Science, AcadiaUniversity.

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