Browsing by Author "Blasco, Julián"
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- The use of biomarkers to assess the impact of pollution in coastal environments of the Iberian Peninsula: a practical approachPublication . Cajaraville, Miren P.; Bebianno, Maria João; Blasco, Julián; Porte, Cinta; Sarasquete, Carmen; Viarengo, AldoWithin the frame of the 2nd Iberian Congress of Environmental Contamination and Toxicology (University of the Basque Country, Leioa, June 1998) a workshop was held about the use of biomarkers in marine pollution monitoring. Among others, the following biomarkers received special attention: metallothionein induction, acetylcholinesterase inhibition, cytochrome P450 system induction, imposer, lysosomal enlargement and lysosomal membrane destabilisation, and peroxisome proliferation. These biomarkers can be used to evaluate exposure to and effect of different contaminants (metals, organic xenobiotics and organometallic compounds) and they can be measured using different methodological approaches (biochemistry, cytochemistry, immunochemical methods based on the use of biotechnology). Before the application of a set of biomarkers in pollution monitoring programmes, well-defined protocols of Quality Assurance have to be established to allow adequate comparison of results. It is also necessary to include analysis of standard reference materials and to obtain detailed knowledge of basal values and seasonal variations of the biomarkers in various species, as well as to integrate the information obtained with the different biomarkers, Marine bivalve molluscs such as mussels are appropriate sentinel species for most of the biomarkers proposed except for the induction of the cytochrome P450 system, which should be measured in fish, and the degree of imposer, which is a biomarker of exposure to TBT specifically measured in certain gastropod molluscs. As a result of the workshop, a battery of biomarkers of contaminant exposure and effects are proposed that could be incorporated into programmes monitoring the quality of the coastal environment in the Iberian Peninsula. These measures would be undertaken in conjunction with chemical measures of contaminant burdens in selected sentinel species.
- Trace metal concentrations in sediments from the southwest of the Iberian PeninsulaPublication . Blasco, Julián; Gomes, Tânia; García-Barrera, Tamara; Rodríguez-Romero, Araceli; Gonzalez-Rey, M.; Morán-Roldán, Fernando; Tromibini, Chiara; Miotk, Michal; Gómez-Ariza, José Luis; Bebianno, Maria JoãoMetal sediment concentrations (As, Cd, Cu, Hg, Ni, Pb and Zn) in surface sediments (0 to 5 cm) from 11 sampling stations in the southwest of the Iberian Peninsula (the Ria Formosa and the Guadiana River, the Ría de Huelva and the Bay of Cadiz) were determined in two seasonal periods (autumn 2006 and spring 2007). No seasonal metal concentration pattern was identified, as similar values were found in both periods. The highest concentrations of copper, zinc, lead and cadmium were reported in the Ria of Huelva area, and those of mercury and nickel in the Bay of Cadiz. The hazard potential index (HPiM) was determined to assess the potential risk associated with metal contamination (Cu, Cd, Pb and Zn), taking into account extractable (presumed bioavailable) fractions of these metals and site-specific sediment quality values. When the HPiM is >1 there is risk, and according to this index Ría de Huelva is polluted whereas the Bay of Cadiz is not.