ABSTRACT
Concentrations of Al, V, Mn, Fe, Co, Cu, Ni, Zn, Sr, Mo, Cd, Sb, Pb, Th, U, REE, Na, K, Mg, Ca, Si, P, S, Ti, Cr and Ba were determined in the <63 microm fraction of bottom sediments of the Szczecin Lagoon and the Gdansk Basin, Baltic Sea, by ICP-MS, ICP-AES and XRF methods. Sediment samples from the Szczecin Lagoon displayed somewhat higher concentrations of P, Mn, Cr, Cu and possibly Cd, Pb and Zn in those collected in October 1997 after the exceptional flooding of the Oder River than in those collected in December 2000. The data suggest that the flood resulted in the enhanced transport of redox-sensitive and anthropogenic elements in the Oder River and their subsequent redeposition mainly in the western part of Szczecin Lagoon. The sediments of the Szczecin Lagoon also appear to be the most polluted with heavy metals within the Polish Exclusive Economic Zone (EEZ) of the Baltic Sea. Cd, Pb, Zn and Cu are anthropogenically enriched in top layers of sediment cores from the Gdansk Basin, but the decrease of these elements with depth in the core is not systematic. The rare earth element (REE) patterns in sediments from both these areas do not appear to have been greatly modified during transport from their source into the southern Baltic. Factor analysis (FA) of the compositional data shows that sediments from Szczecin Lagoon can be divided into three main groups depending on their composition. It is concluded that clay minerals and organic matter build aggregates and flocs, which effectively concentrate trace metals and sink down to form a 'fluffy layer'.
ABSTRACT
Concentrations of Cd, Pb, Zn, Cu, Ni, Co, Cr, Mn and Fe in the soft tissue of Turbo coronatus, Acanthopleura haddoni, Ostrea cucullata and Pitar sp., as well as in associated surface sediments (bulk and bioavailable metal concentrations) from the Gulf of Aden, Yemen, were determined by atomic absorption spectrophotometry method. Large differences between size-classes of molluscs in metal concentrations were recorded. Significant spatial differences in metal concentrations in both the soft tissue of the molluscs and associated sediments studied were mostly identified. Statistically significant correlations (p<0.01) between concentrations of selected metals were observed. A slope of the linear regression is significantly higher than unity for Fe (9.91) and Cd (3.45) in A. haddoni and for Ni (4.15) in T. coronatus, suggesting that the bioavailability of these metals is disproportionally increased with a degree of enrichment of the sediments in Fe, Cd and Ni, respectively. A slope constant approximating to unity (1.14) for Cu in A. haddoni relative to its concentration in sediment extract implies that bioavailability of this metal proportionally increased with growing concentrations of its labile forms in the associated sediment. The degree of contamination of Gulf of Aden waters by the metals studied is discussed and the potential ability of molluscs, especially A. haddoni and T. coronatus, as biomonitors of metallic pollutants is postulated.
ABSTRACT
Concentrations of Cd, Pb, Zn, Cu, Ag, Cr, Co Ni, Mn, andFe in soft tissues and byssi of blue mussel (Mytilus edulis) fromthree sites along the east coast of Kyushu Island, Japan, were determined byAAS method. Large inter-regional differences in metal concentrations in bothsoft tissues and byssi (Cu, Cd, and Pb and Cu, Pb, Co, Ni, Mn, and Fe,respectively) were recorded. Highly significant correlations (p< 0.01) were observed between tissue and byssal concentrations of Pb,Cu, Zn, and Mn. The tissue concentrations of Cu, Cd, and Pb were two ordersof magnitude greater in Mytilus edulis from expected to be themost contaminated locations compared to those from a nonindustrialized area. Intercomparison of the present study data with those published previouslyindicates that the soft tissue and especially byssus are useful in detectingsome areas of some metallic contaminants. The high concentrations of Cd, andespecially Pb and Cu, in Saganoseki mussels and moderately elevatedconcentrations of these metals in Akamizu mussels may be attributed to theanthropogenic emissions from a metallic refinery and an artificial fiberfactory, respectively. It is evident that, compared to the soft tissue, theincrease of Cu levels relative to Zn levels in the byssi of M.edulis are eight times higher, with a slope b (Cu/Zn) of 7.5 for byssusand 0.93 for soft tissue. This suggests that byssus, as compared to softtissue, is a more sensitive bioindicator for Cu. From the data obtained, thesoft tissue and especially byssi of M. edulis appear to be goodbioindicators for identification of coastal areas exposed to metalliccontaminants.
