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| Format: | Artículo científico |
| Language: | en |
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Universidad Autónoma de Baja California
2003
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| Online Access: | https://www.redalyc.org/articulo.oa?id=48029416 |
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Table of Contents:
- Presence, distribution and contamination levels of lead in the surface sediments of the Ria of Ferrol (NW Spain) Carmen Tubío Mª del Carmen Barciela Ricardo Prego Antonio Cobelo García Ciencias de la Tierra ria lead Galicia sediment contamination This article discuss, using sediment samples from the Ria of Ferrol, the need for a better understanding of the biogeochemicalcycle of lead in the Galician rias which, until now, was based on differing methodologies mainly applied to the biota in only fewareas of the most important rias from a socio-economic point of view. Thirty-five samples of superficial sediment were analysedfor lead (in the < 63 µm and total fractions) and opal percentage and organic carbon in the total. An analytical method is proposedemploying ETAAS, whereby the sediment is introduced directly as a slurry together with the optimised amount of chemicalmodifiers. The accuracy of the method was checked by means of a certified reference material, obtaining a sensitivity of2.72 µg g1 Pb with an RSD of 5.9%.Values of lead in the superficial sediment of the Ria of Ferrol ranged from 13.5 to 159.1 µg g1 for the fraction < 63 µm, andfrom 12.1 to 142.5 µg g1 for the total fraction. The distribution does not follow a decreasing trend from the innermost part of theria, as may have been expected, but rather the maximum values were found in the vicinity of the harbour area in the middle ria,indicating that rias behave as a lead deposition barrier avoiding the export of the metal to the open sea. Lead dispersion is mainlycontrolled by the tidal currents, given its lowest concentrations in the zones of strongest current, and also by the plankton,following the relationship obtained [Pb] = 48 [opal] + 16. A baseline lead concentration of 18.2 µg g1 was obtained for thefraction < 63 µm using core samples dated at 3745 ± 70 years before present. Applying this background values, the leadenrichment in the Ria of Ferrol is classified from moderate to considerable. 2003 artículo científico 0185-3880 https://www.redalyc.org/articulo.oa?id=48029416 en http://www.redalyc.org/revista.oa?id=480 Ciencias Marinas application/pdf Universidad Autónoma de Baja California Ciencias Marinas (México) Num.4 Vol.29