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- Genotoxicity of copper oxide and silver nanoparticles in the mussel Mytilus galloprovincialisPublication . Gomes, Tânia; Araújo, Olinda; Pereira, Rita; Catarina Almeida, Ana; Cravo, Alexandra; Bebianno, Maria JoãoThough there is some information on cytotoxicity of copper nanoparticles and silver nanoparticles on human cell lines, there is no information on their genotoxic and cytotoxic behaviour in bivalve molluscs. The aim of this study was to investigate the genotoxic impact of copper oxide and silver nanoparticles using mussels Mytilus galloprovincialis. Mussels were exposed to 10 μg L⁻¹ of CuO nanoparticles and Cu²⁺ and Ag nanoparticles and Ag⁺ for 15 days to assess genotoxic effects in hemocytes using the comet assay. The results obtained indicated that copper and silver forms (nanoparticles and ionic) induced DNA damage in hemolymph cells and a time-response effect was evident when compared to unexposed mussels. Ionic forms presented higher genotoxicity than nanoparticles, suggesting different mechanisms of action that may be mediated through oxidative stress. DNA strand breaks proved to be a useful biomarker of exposure to genotoxic effects of CuO and Ag nanoparticles in marine molluscs.
- Metals in the shell of Bathymodiolus azoricus from a hydrothermal vent site on the Mid-Atlantic RidgePublication . Cravo, Alexandra; Foster, P.; Catarina Almeida, Ana; Company, Rui; Cosson, R.P.; Bebianno, Maria JoãoSpecimens of the mussel Bathymodiolus azoricus were collected from Menez Gwen, a relatively shallow (850 m) hydrothermal vent field on the Mid-Atlantic Ridge. Each bivalve shell (n = 21) was individually cleaned by selective chemical. The residual crystal matrix of each shell was individually analysed for the concentrations of the minor elements magnesium and strontium and the trace elements iron, manganese, copper and zinc. The chemical composition of the crystal matrix is unusual. B. azoricus is identified as a species having one of the most strontium impoverished shells amongst the marine molluscs. For a bimineral species the magnesium concentration is also extraordinary low. Despite originating from a trace metal rich environment; the metal concentrations in the shells were exceptionally low. Mean concentrations of iron, manganese, copper and zinc were 20.6, 3.7, 0.6 and 9.4 microg g(-1) respectively. Minor and trace element concentrations exhibited a marked intra-population variability. Copper concentrations increased and iron and zinc concentrations decreased with increasing shell weight. Due to its insensitivity to the high environmental levels of trace elements and the variability in intra-population concentrations induced by shell weight the crystal matrix of the shell of B. azoricus has little potential for use in environmental trace metal monitoring in areas contiguous to deep-sea hydrothermal vents.