TY - JOUR
T1 - Background values, distribution and contamination of metals in the sediments of the Pontevedra Ria (NW Spain)
AU - Marmolejo-Rodriguez, A. J.
AU - Cobelo-Garcia, A.
AU - Prego, R.
N1 - Funding Information:
Help from P. Herbello for sediment analysis, and Capt. J. Alonso and the crew of the R/V Mytilus (IIM-CSIC) for their assistance during the sampling campaigns are acknowledged. A.J. Marmolejo-Rodríguez would like to thank to COFAA-COTEPABE-IPN (Mexico) for financial support. This article is a contribution to the Spanish LOICZ programme through the coordinate project “Biogeochemical budget and modelling of metal fluxes in a Galician ria (METRIA),” funded by CICYT (ref. REN2003-04106-C03).
PY - 2007/11
Y1 - 2007/11
N2 - Thirty-seven surface sediment samples were taken in the Pontevedra Ria (NW Iberian Peninsula), and metal concentrations (Cd, Co, Cr, Cu, Fe, Ni, Pb, and Zn) and organic/inorganic parameters were determined in order to obtain a mapping of their distribution, background values and the status of contamination. Background values were obtained from Metal/Fe ratios obtained by regression lines using "clean" stations. Contamination was assessed by the use of normalized enrichment factors (NEF). The middle and outer parts of the ria, mostly influenced by oceanic water and scarce anthropogenic activities, showed a low/null contamination (NEF ∼ 1) for all the metals studied. However, the inner part of the ria, where most of the anthropogenic (urban and industrial) activities are located, showed a significant enrichment for Zn, Cu, and Pb, with NEF up to 5.2, 18, and 3.4, respectively. The rest of the metals were not significantly affected. Due to the hydrographic characteristics of the rias coastal systems, contamination sources are generally located well inland but in the high salinity region. Therefore rapid flocculation and accumulation of metal contaminants in sediments is favored close to their emission sources. Cadmium also showed a significant enrichment, strongly influenced by the presence of organic-rich sediments rather than contamination from point-sources. In the estuarine part of the ria, a significant enrichment was found for Cd, Cu, and Zn. However, it is unclear whether this is due to contamination by these two metals in the area or simply due to a difference in the lithogenic composition of the riverine sediments compared to the ria sediments.
AB - Thirty-seven surface sediment samples were taken in the Pontevedra Ria (NW Iberian Peninsula), and metal concentrations (Cd, Co, Cr, Cu, Fe, Ni, Pb, and Zn) and organic/inorganic parameters were determined in order to obtain a mapping of their distribution, background values and the status of contamination. Background values were obtained from Metal/Fe ratios obtained by regression lines using "clean" stations. Contamination was assessed by the use of normalized enrichment factors (NEF). The middle and outer parts of the ria, mostly influenced by oceanic water and scarce anthropogenic activities, showed a low/null contamination (NEF ∼ 1) for all the metals studied. However, the inner part of the ria, where most of the anthropogenic (urban and industrial) activities are located, showed a significant enrichment for Zn, Cu, and Pb, with NEF up to 5.2, 18, and 3.4, respectively. The rest of the metals were not significantly affected. Due to the hydrographic characteristics of the rias coastal systems, contamination sources are generally located well inland but in the high salinity region. Therefore rapid flocculation and accumulation of metal contaminants in sediments is favored close to their emission sources. Cadmium also showed a significant enrichment, strongly influenced by the presence of organic-rich sediments rather than contamination from point-sources. In the estuarine part of the ria, a significant enrichment was found for Cd, Cu, and Zn. However, it is unclear whether this is due to contamination by these two metals in the area or simply due to a difference in the lithogenic composition of the riverine sediments compared to the ria sediments.
KW - Anthropogenic impact
KW - Contamination point-sources
KW - Galicia
KW - Metals
KW - Ria sediments
UR - http://www.scopus.com/inward/record.url?scp=35648961385&partnerID=8YFLogxK
U2 - 10.1080/15320380701623370
DO - 10.1080/15320380701623370
M3 - Artículo
SN - 1532-0383
VL - 16
SP - 557
EP - 568
JO - Soil and Sediment Contamination
JF - Soil and Sediment Contamination
IS - 6
ER -