Impacts of Selenium on the Biogeochemical Cycles of Mercury in Terrestrial Ecosystems in Mercury Mining Areas

Transcription

1 Springer Theses Impacts of Selenium on the Biogeochemical Cycles of Mercury in Terrestrial Ecosystems in Mercury Mining Areas Bearbeitet von Hua Zhang 1. Auflage Buch. xxii, 193 S. Hardcover ISBN Format (B x L): 15,5 x 23,5 cm Gewicht: 491 g Weitere Fachgebiete > Geologie, Geographie, Klima, Umwelt > Geologie und Nachbarwissenschaften > Geochemie Zu Leseprobe schnell und portofrei erhältlich bei Die Online-Fachbuchhandlung beck-shop.de ist spezialisiert auf Fachbücher, insbesondere Recht, Steuern und Wirtschaft. Im Sortiment finden Sie alle Medien (Bücher, Zeitschriften, CDs, ebooks, etc.) aller Verlage. Ergänzt wird das Programm durch Services wie Neuerscheinungsdienst oder Zusammenstellungen von Büchern zu Sonderpreisen. Der Shop führt mehr als 8 Millionen Produkte.

2 Contents Part I Introduction 1 Research Background General Background Mercury Pollution is One of China s Major Environmental Problems SINOMER Project Physical and Chemical Properties of Mercury and Selenium Physical and Chemical Properties of Mercury Physical and Chemical Properties of Selenium Environmental Toxicology of Mercury and Selenium Toxicity and Health Risks of Mercury Exposure Toxicity and Health Benefits/Risks of Selenium Exposure Evidence for Topic Selection Selenium is a Natural Mercury Antagonist Selenium Pollution in Hg Mining Areas must be Considered References Advances in Research on the Mechanisms of Selenium Mercury Interactions and Health Risk Assessment Selenium Mercury Interactions and Their Mechanisms in Aquatic Ecosystems Selenium Mercury Interactions and Their Mechanisms in Terrestrial Ecosystems Mechanisms of Selenium Mercury Interactions in Mammals (and Humans) Protective Effects of Selenium Against Mercury Toxicity and the Mechanisms Thereof Implications of the Physiological Significance and Metabolic Processes of Selenium for the Toxicity of Mercury Exposure xiii

3 xiv Contents 2.4 New Model for the Assessment of the Health Risks of Mercury and a Relevant Proposal References Research Subject, Methods and Significance Research Subject Methods Sample Collection and Preparation Analytical Method Significance of this Study References Overview of the Study Area (Wanshan) Study Area Overview of Mine Area Geomorphology and Climate Water System in the Mine Area Agriculture and Population in the Mine Area Geology of the Area References Part II Biogeochemical Cycles of Mercury and Selenium and Their Interactions in River System 5 Biogeochemical Cycles of Mercury in River System Speciation, Tempo-Spatial Distribution and Migration of Total Mercury Total Mercury Particulate Mercury, Total Suspended Solid, SO 2-4 and Ca Dissolved Mercury Reactive Mercury Speciation, Tempo-Spatial Distribution and Migration of Methylmercury Unfiltered Methylmercury Ratio of Methylmercury to Total Mercury (%MeHg) Dissolved- and Particulate- Methylmercury Chapter Summary Total Mercury Methylmercury References

4 Contents xv 6 Biogeochemical Cycles of Selenium in River System Distribution, Source and Migration of Dissolved Total Selenium The Regional Distribution in Surface Water Potential Sources The Local Background Concentrations Comparison with Other Regions Relationship with Sulfate, ph, and DOC Distribution and Migration Characteristics of Selenium Speciation Se(VI) Se(IV) Se(org) Risk Consideration River Water Spring Water Chapter Summary References Interactions of Mercury and Selenium in River System References Part III Biogeochemical Cycles of Mercury and Selenium and Their Interactions in Soil-Rice System 8 Biogeochemical Cycles of Mercury in Soil-Rice System Mercury in Paddy Soil Mercury in Rice Grain Relationship Between Mercury in Rice and in Soil Mercury Distribution in Different Parts of Rice Chapter Summary References Biogeochemical Cycles of Selenium in Soil-Rice System Selenium in Soil Selenium in Rice Grain Relationship Between Selenium in Rice and in Soil Selenium Distribution in Different Parts of Rice Fractionation of the Selenium in Soil Water-Soluble Selenium Ligand-Exchangeable Selenium

5 xvi Contents Organic-Bound Selenium Fe/Mn/Al Oxide-, Amorphous Material-, Hydrate- and Carbonate-Bound Selenium Sulfide-Bound Selenium Residual-Bound Selenium Chapter Summary References Interactions of Mercury and Selenium in Soil-Rice System Selenium Levels Versus Mercury Levels in Grains Selenium Levels Versus Mercury Levels in Soil Selenium Translocation Versus Mercury Translocation in Soil-Rice System Distribution Pattern of Selenium Versus that of Mercury in Different Parts of Rice Possible Mechanisms of Formation of Hg Se Complex in Rhizosphere/Root Suppression Effect of Selenium on Uptake and Translocation of Mercury in Rice Impacts of Mercury on the Bioavailability of Selenium in Paddy Soil Chapter Summary References Part IV Health Risk Assessment for Human Exposure to Mercury and Selenium 11 Health Risk Assessment for Human Exposure to Mercury Calculation of Probable Daily Intake Mercury Levels in Different Exposure Media Probable Daily Intake Levels Contributions to Mercury Exposure form Different Media Risk Considerations General Characteristics of Mercury Exposure Food Consumption Advisories Percentage of Total Population Under Potential Health Risk Comments on Criteria of Mercury Risk Assessment Chapter Summary References

6 Contents xvii 12 Health Risk Assessment for Human Exposure to Selenium Calculation of Probable Daily Intake Selenium Levels in Different Exposure Media Probable Daily Intake Levels Contributions to Selenium Exposure form Different Media Risk Considerations Chapter Summary References Health Risk Assessment for Human Exposure of Mercury and Selenium Considering Selenium Mercury Interactions Proposal for a New Criterion Comparison of Different Criteria Scenario I, Criteria Considering Only Mercury Scenario II, Criteria Considering Only Selenium Scenario III, Criteria Considering Mercury and Selenium Independently Scenario IV, Criteria Considering Selenium Mercury Interactions Implications Chapter Summary References Part V Conclusions and Prospect 14 Conclusions River System Rice-Soil System Risk Considerations Research Needs and Future Outlook

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