Metals in the Hydrocycle.

1 Introduction.- 2 Interactions with Ligands, Particulate Matter and Organisms.- 2.1 Introduction.- 2.2 Metal Ions in Aquatic Systems.- 2.3 Speciation of Dissolved Metals.- 2.3.1 Physical Separation.- 2.3.2 ASV-Labile Species.- 2.3.3 Ion-Exchange Methods.- 2.3.4 Speciation Schemes.- 2.4 Interaction with Ligands.- 2.5 Interaction with Particulate Matter.- 2.5.1 Sorption Processes.- 2.5.2 Mechanisms.- 2.5.3 Sorption on Metal Oxides and Organic Substances.- 2.5.4 Sorption of Metal-Organic Complexes.- 2.5.5 Interactions in Natural Systems.- 2.6 Solid Speciation.- 2.7 Metal Interaction with Organisms.- 2.7.1 Metal Uptake by Organisms.- 2.7.2 Solid Speciation and Bioavailability.- 2.7.3 Transformation of Metal by Organisms.- 3 Sediments and the Transport of Metals.- 3.1 Introduction.- 3.2 Composition of Sediments.- 3.3 Transport of Sediments.- 3.4 Distribution and Deposition.- 3.5 Grain Size Effects.- 3.6 Anthropogenic Influences on Metal Concentrations in Sediments.- 3.6.1 Background Concentrations.- 3.6.2 Sediment Core Studies.- 3.6.3 Quantification of Environmental Impact.- 3.7 Early Diagenesis of Trace Metal Compounds in Sediments.- 3.7.1 Sampling of Interstitial Waters.- 3.7.2 Diagenetic Environments.- 3.7.3 Diagenetic Mobilization of Trace Metals.- 4 Metals in the Atmosphere.- 4.1 Introduction.- 4.2 Natural and Anthropogenic Emissions of Trace Metals.- 4.3 Atmospheric Particles.- 4.4 Deposition of Atmospheric Particles.- 4.5 Metal Concentrations in Urban, Rural and Remote Atmospheres.- 4.6 Environmental Impact of Airborne Trace Metals.- 4.6.1 Terrestrial Ecosystems..- 4.6.2 The Arctic and Antarctic Aerosol.- 4.6.2.1 Concentrations in Arctic and Antarctic Areas.- 4.6.2.2 Seasonal Changes.- 4.6.2.3 Origin of the Arctic Aerosol.- 4.6.3 Metals in the Oceanic Aerosol: Continental or Ocean Derived?.- 4.6.3.1 Formation of the Oceanic Aerosol.- 4.6.3.2 Sea Surface Microlayer.- 4.6.3.3 Composition of the Oceanic Aerosol.- 5 Metals in Continental Waters.- 5.1 Introduction.- 5.2 Metals in Rocks and Soils.- 5.2.1 Igneous and Metamorphic Rocks.- 5.2.2 Weathering and Element Migration.- 5.2.3 Chemistry of Sedimentary Rocks.- 5.2.4 Metals in Soils.- 5.2.4.1 Soil Constituents and Metal Binding.- 5.2.4.2 Trace Metal Concentrations in Soils.- 5.2.4.3 Metal Transfer from Soil to Plants.- 5.2.4.4 Problems with River-borne Metal Pollutants on Agricultural Soils.- 5.2.4.5 Land Disposal of Metal-Contaminated Waste Materials.- 5.3 Metals in Rivers.- 5.3.1 Trace Metals in River Water.- 5.3.2 Dissolved and Solid Transport.- 5.3.2.1 Geographical Variability.- 5.3.2.2 Seasonal Variability.- 5.3.3 Metals in River Sediment.- 5.3.3.1 Factors Affecting Compositions.- 5.3.3.2 Variability of Data.- 5.3.3.3 Influence of Grain Size.- 5.3.3.4 Metal Forms.- 5.3.4 Impact of Metals in River Systems.- 5.3.4.1 Distribution of Metal Pollutants.- 5.3.4.2 Historical Evolution.- 5.3.4.3 Metal Budgets and Local Inputs.- 5.3.5 Complexing Agents in River Systems.- 5.4 Metals in Lakes.- 5.4.1 Introduction.- 5.4.2 Accumulative Phases in Lake Sediments.- 5.4.3 Trace Metal Fluxes as Reflected in the Sediments.- 5.4.4 Metals Cycling in Lakes.- 5.4.5 Metals Cycling in Stratified Lakes.- 5.4.6 Atmospheric Inputs in Lakes.- 6 Metals in Estuaries and Coastal Environments.- 6.1 Introduction.- 6.2 Estuarine Circulation.- 6.3 Conservative and Non-Conservative Behaviour.- 6.4 Behaviour of Particulate Trace Metals During Estuarine Mixing.- 6.5 Iron and Manganese.- 6.6 Trace Metals in Estuaries: Field Investigations.- 6.7 Trace Metals in Estuaries: Laboratory Investigations and Simulations.- 6.8 Environmental Impact Studies.- 6.8.1 United States Estuaries and Coastal Areas.- 6.8.2 Mediterranean Sea.- 6.8.3 Western Europe.- 6.8.4 Environmental Impact of Metals in Biota.- 6.9 Estuaries as Sinks for Trace Metals?.- 7 Metals in the Ocean.- 7.1 Introduction.- 7.2 Vertical and Horizontal Distribution of Trace Metals..- 7.3 Particulates and Metal Behaviour.- 7.4 Composition of Oceanic Sediments.- 7.4.1 Marine Sedimentary Facies.- 7.4.2 Metal Concentrations.- 7.4.3 Metal Enrichment in Deep-Sea Sediments.- 7.4.3.1 Diagenetic Metal Enrichment-Manganese Nodules.- 7.4.3.2 Metal Enrichment from Hydrothermal Inputs.- 7.5 Cycling of Trace Metals Between Continents and Oceans.- 8 Summary and Qutlook.- References.