Determinación de valores geoquímicos de fondo para la evaluación del enriquecimiento por metales y metaloides en los sedimentos estuarinos del Río Nalón (Norte de España)

This study aims at establishing the regional background levels and upper thresholds (geochemical baseline) for some potentially toxic elements (As, Cr, Hg, Pb, Sb and Zn) in coastal sediments from two boreholes of the Nalón estuary, N-Spain. By applying a statistical approach, the outliers were identified and removed from the original dataset along with elemental concentration values not representative of the natural sedimentary environment. Results showed significant enrichments in element concentrations at the most recent sedimentary layers. This enrichment has been attributed to historical anthropogenic activities developed within the drainage the basin, and, for Hg, As and Sb, it is mainly due to mining contributions