Argentina 2 Argentina, La Plata River 2 Atomic absorption spectrophotometer 2 Bioavailability 2 Biological Availability 2 Biota 2 Cadmium 2 Chelation mixture 2 Coastal zones 2 Cobalt 2 Comparative Study 2 Environmental Pollutants 2 Environmental protection 2 Estuaries 2 Heavy metals 2 Iron 2 Lead 2 Metals 2 Nickel 2 Recoverable fraction 2 Rivers 2 Seasons 2 Sediments 2 Support, Non-U.S. Gov't 2 Water Pollutants, Chemical 2 Water analysis 2 Water quality 2 argentina 2 article 2 bioavailability 2