Dinâmica de metais-traço em solo e ambiente sedimentar estuarino como um fator determinante no aporte desses contaminantes para o ambiente aquático: revisão

Abstract

Trace metals, important contaminants of soils and sediments, have their environmental concentrations markedly increased in the past few decades including in semi arid regions where water demand also increased exponentially in the recent past. Many factors such as metal-enriched parental materials, agriculture practices with the progressively higher use of fertilizers, pesticides and soil correctives, municipal and industrial wastes disposal, atmospheric deposition due to automotive vehicles and industries emissions can contribute to the contamination of downstream drainage basins. Metal levels in the soils and sediments are an important indicative of their quality. However, they do not necessarily reflect the availability of the elements, to access metal availability it is necessary to know the forms they are present in a given soil or sediment. Several properties affect the form in which the metal is present in the soil, being the pH and redox potential (Eh) the most important ones. Thus the present paper provides a review of the trace-metal geochemical correlations in soil and sedimentary environments to understand their main sources, partition into geochemical phases and the resultant availability and mobility.