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Browsing by Author "Monteiro, Rui J. R."

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  • Evidence for contrasting accumulation pattern of cadmium in relation to other elements in Senilia senilis and Tagelus adansoni from the Bijagós archipelago, Guinea-Bissau
    Publication . Catry, Teresa; Figueira, Paula; Carvalho, Lina; Monteiro, Rui J. R.; Coelho, Pedro Duarte; Lourenço, Pedro Miguel; Catry, Paulo; Tchantchalam, Quintino; Catry, Inês; Botelho, Maria J.; Pereira, Eduarda; Granadeiro, José Pedro; Vale, Carlos
    Shellfish harvesting in intertidal areas is a widespread and economically important activity in many countries across West Africa. However, in some areas, there is virtually no information concerning the levels of contaminants (and other elements related to nutritional aspects) in the harvested species. We collected sediments and several individuals of the West African bloody cockle Senilia senilis and of the razor clam Tagelus adansoni during the dry season of 2015 nearby three islands in the Bijagós archipelago, Guinea-Bissau. Aluminium, Ca, Fe, Mg, As, Cd, Co, Cr, Cu, Mn, Ni, Pb and Zn were determined in sediments and whole soft tissues of the two bivalves. Sediments showed uniformly low trace element concentrations, pointing to an ecosystem with low levels of trace element contamination. T. adansoni presented higher concentrations of most elements than S. senilis, with the exception of Cd that showed up to 40 times higher values in S. senilis than in T. adansoni from the same sites. Furthermore, Cd concentrations (25±8.7 mg kg(-1), dw) in S. senilis are clearly above the maximum level established for human consumption. Future studies should clarify whether biological factors are the major responsible for this unusual situation.
    2017Journal article Restricted access Show more
  • Major, minor, trace and rare earth elements in sediments of the Bijagós archipelago, Guinea-Bissau
    Publication . Carvalho, Lina; Figueira, Paula; Monteiro, Rui J. R.; Reis, Ana Teresa; Almeida, Joana C.; Catry, Teresa; Lourenço, Pedro Miguel; Catry, Paulo; Barbosa, Castro; Castro, Inês; Pereira, Eduarda; Pereira, Eduarda; Granadeiro, José Pedro; Vale, Carlos
    Sixty sediment samples from four sites in the Bijagós archipelago were characterized for fine fraction, loss on ignition, major, minor and trace elemental composition (Al, Fe, Ca, Mg, Ti, P, Zr, Mn, Cr, Sr, Ba, B, V, Li, Zn, Ni, Pb, As, Co, U, Cu, Cs and Cd), and the elements of the La–Lu series. Element concentrations were largely explained by the Al content and the proportion of fine fraction content, with the exception of Ca and Sr. Sediments showed enhanced Ti, U, Cr, As and Cd concentrations with respect to estimated upper crust values, most likely mirroring a regional signature. Rare earth elements were in deficit relatively to the North American Shale Composite (NASC), mainly in coarser material. No pronounced Ce-anomaly was observed, while Eu-anomalies were positive in most analyzed sediments.
    2017Journal article Restricted access Show more