title: A multidisciplinary approach for assessing the toxicity of marine sediments: analysis of metal content and elutriate bioassays using metal bioavailability and genotoxicity biomarkers.
abstract: The goal of this article is to verify the applicability of two different biological assays for studying a coastal area that is subject to anthropogenic inputs. Phytochelatins in the marine diatom Thalassiosira weissflogii were used as a biomarker of metal bioavailability. The frequency of genetic damage in the sensitive D7 strain of the yeast Saccharomyces cerevisiae was used to estimate the mutagenic potential. Biological assays were carried out using sediment elutriates. Sediments were collected at three selected sites located in the Gulf of Follonica (Tuscany, Italy), during a 2-year sampling period: Cala Violina (reference site) and the mouths of the rivers Pecora and Cornia, named sites V, P and C, respectively. The chemical characterization of each site was determined in terms of metal concentrations (As, Cd, Cr, Cu, Ni, Pb), measured in 11 sediment samples for each site. The results showed that metal concentrations in sediments from sites C and P were 2-10 times higher than the reference values (site V, year 2004). In addition, we found generally higher metal concentrations in the 2007 sediments than in the 2008 ones, including those of site V, due to the occurrence of an unexpected pollution event. This enabled us to obtain a pollution gradient to validate the proposed bioassays. In fact, the bioassays showed a potential biological hazard in the 2007 elutriates. Significant mutagenic effects were found in samples exhibiting higher concentrations of Cd and Cr. The induction of phytochelatins in T.                         weissflogii correlated positively with the Cd concentration in the elutriates.
authors.affiliation: Institute of Agricultural Biology and Biotechnology, CNR, via Moruzzi, 1, 56124, Pisa, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Frassinetti
authors.forename: Emanuela
authors.initials: E
authors.lastname: Pitzalis
authors.forename: Marco Carlo
authors.initials: MC
authors.lastname: Mascherpa
authors.forename: Leonardo
authors.initials: L
authors.lastname: Caltavuturo
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Morelli
mesh_terms: D001681:Biological Assay / Q000379:methods*; D001682:Biological Availability; D017377:Diatoms / Q000378:metabolism; D004784:Environmental Monitoring / Q000379:methods*; D005819:Genetic Markers; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*; D009152:Mutagenicity Tests; D054811:Phytochelatins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000493:pharmacokinetics / Q000633:toxicity*
chemical_list: D005819:Genetic Markers; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D054811:Phytochelatins