Cd In Soft Tissues Research Articles

Accumulation and distribution of Cd, Cu, Pb and Zn in the soft tissue and shell of oysters collected from the northern coast of Qeshm Island, Persian Gulf, Iran

A study was conducted to determine the bioaccumulation and relationships of some essential and non essential metals in the different tissues of Saccostera cucullata to sediments by calculating their biota-sediment accumulation factor (BSAF) values and the correlation analysis. For this study, 53 rocky oysters (Saccostrea cucullata) and 15 surface sediment samples were collected from four stations in May 2010 of the intertidal zones of Qeshm Island, Persian Gulf, Iran. The results indicate that the highest BSAF values for Cu, Pb and Zn were found in the soft tissue. For Pb, the highest concentrations were obtained in the shell. The correlation results showed that there were correlations between concentrations of Cu and Cd in soft tissues with some fractions in sediment and concentrations of Pb in the shell with some fractions in the sediment. However, it was found that soft tissue of S. cucullata has the potential to be used as a biomonitoring agent for the contamination of Cu and Cd in sediments, as indicated by the high BSAF levels, the lower coefficient of variation (CV) values in soft tissue than in shell, and the significant positive correlation between concentrations of Cu and Cd in the soft tissue of oyster and in the sediment. In contrast, for Pb, higher BSAF values and lower CV values are found in the shell than in the soft tissue, and the significant positive correlation between Pb concentrations in the shell of oyster and sediment can be used as a biomonitoring material.

Heavy metals in Macoma balthica and extractable metals in sediments from the southern Baltic Sea

Concentrations of Zn, Cu, Ni, Fe, Mn, Co and Cd in soft tissues of Macoma balthica and their extractable forms in the adjacent sediments from 15 sampling sites in the southern Baltic Sea were determined by AAS. The samples were collected during cruises of M/S Hestia and R/V Baltica in July–August 2006. In order to estimate the degree of element bioaccumulation in the molluscs with respect to their extractable forms of the associated sediments, the bioaccumulation factor (BF) was calculated. ANOVA clearly indicates spatial differences between the concentrations of the metals, and factor analysis (FA) confirms that spatial variations exist between the concentrations of metals in M. balthica and their extractable forms in the adjacent sediments from the Gulf of Gdańsk and open Baltic waters. This differentiation can be explained by differences in environmental parameters between these two areas. M. balthica may be useful as a biomonitor of heavy-metal bioavailability and contamination in the Baltic Sea.

Regional variations of heavy metal concentrations in tissues of barnacles from the subtropical Pacific Coast of Mexico

Concentrations of Cd, Cu, Cr, Fe, Mn, Ni, Ag, Pb, and Zn in soft and hard tissues of barnacles from eight sampling sites in six harbours on the subtropical Pacific Coast of Mexico were determined by atomic absorption spectrophotometry. Some inter-regional differences in metal concentrations, especially concerning Zn, Mn, Fe, Cd, and Pb, were identified. The lowest concentrations of Cu, Cr, Fe, and Ag were observed in the barnacle populations from Ceuta Lagoon, an uncontaminated site with rural agriculture and semi-intensive shrimp farms in the surroundings. Conversely, the highest concentrations of: 1) Zn, Cu, and Ag were found in the soft tissues of Balanus eburneus from Mazatlán piers; 2) Pb, Ni, and Cd in the soft tissue of Megabalanus coccopoma from Puerto Vallarta; 3) Fe in the hard tissue of Balanus sp. from Guaymas Harbour; and 4) Mn in the hard tissue of M. coccopoma from Mazatlán Harbour. Inter-comparison of the present data indicates that the soft (mainly Cd, Cu, Pb, and Zn) and the hard (mainly for Fe and Mn) tissues are useful in detecting areas of selected metallic contaminants. Barnacles such as B. eburneus, M. coccopoma, and Fistulobalanus dentivarians appear to be convenient biomonitors for identification of coastal waters exposed to Cd, Pb, Cu, Zn, Ni, Mn, Fe, and Ag in the American region of the subtropical Pacific.

The effects of source and destination on growth and metal uptake in freshwater clams reciprocally transplanted among south central Ontario lakes

The relative contributions of genotype and environment to growth and metal uptake in freshwater unionid clams (Elliptio complanata) were evaluated using a reciprocal transplant experiment. In August 1985, comparable sites were selected in three south central Ontario lakes with alkalinities of 22, 153, and 238 μequiv.∙L−1. Shell length, height, and width varied in a manner that could not be related to lake alkalinities. There were differences among the clam populations in allelic frequencies (at the Pgm and Lap-2 loci). Clams were marked, measured, and reciprocally transplanted among the three lakes. In August 1986, marked individuals were recovered, remeasured, and analysed for levels of Cu, Zn, Mn, and Cd in soft tissues. The transplant source had a strong influence on clam growth during the post-transplant year. This source effect may result from genetic differences among the populations. Tissue metal concentrations at the end of the post-transplant year were a function of both source and destination. The use of freshwater clams as transplant biomonitors must be reassessed since there is a strong source component to growth and metal uptake. In transplant experiments a common source (a particular site within a particular lake) should be used, and post-transplant periods of more than 1 year may be necessary for the influence of the destination environment to dominate the influence of the source environment.

Shell weight as an independent variable in relation to cadmium content of mollusks

Shell weight of molluscs is introduced as alternative parameter for biological monitoring of heavy metals. Variability of metal concentration due to variations in soft-body weight can be eliminated by relating metal body burden to shell weight. A reformed 'Mussel Watch' concept IS outlined. Detailed investigation of Cd in mussels exemplifies advantages of the new approach. The relation of Cd body burden to shell weight is constant in relation to environmental Cd concentration. In contrast, conventional Cd concentration values of soft tissues, in general, are related to the physical condition of mussels. The dependency of condition and Cd concentration on individual size, tidal exposure, spawning, and nutrient supply is documented. Accumulation of Cd in soft tissues and formation of the calcareous shell are discussed in terms of influx of environmental ions and organismic immobilisation, together with their respective organic ligands.