Oyster concentration factors

Figure 7.7 20-d concentration factors (Cfs) in whole SPMDs and Pacific oysters (Crassostrea gigas) exposed to 10,100, and 250 ng L of PAHs. 

Whole Body Radionuclide Concentration Factors and Turnover Rates. A series of experiments were performed to determine the turnover rates and concentration factors of Co, Cs, Mn, and Zn in the marine clam Mya arenaria and the oyster Crassostrea gigas. 

The concentration in the soft tissues of oysters on an ash weight basis was Zn - Fe > Mn > Co (Table II). The concentration factors of the stable elements, Co, Mn, and Zn were higher than those determined by radionuclide studies in the laboratory (cf. Tables I and II). 

Trace Metal Concentrations and Concentration Factors in the Oyster Crassostrea glgas... 

Animals were removed from the test solutions, dissected, weighed, and the radionuclides quantified. After a 24 h exposure, the concentration factors in the oysters differed both with the test material and with the element (Table V). In the tissues, concentration factors of both elements generally were high in the gills and the digestive gland and stomach and low in the muscle and the blood. 

The accumulation of Mn and Zn from the water by oysters was followed in groups of animals held in different concentrations of Mn and Zn in the water (2, 5, or 10 Ug/1) and the same concentration of Zn and Mn. Concentration factors of both Mn and Zn were lower in animals maintained in water containing 5 or 10 g/1 (Figure 6). This... 

Copper-64 and Zinc-65 Concentration Factors in Oyster Soft Tissues After 24-h Exposure to Test Materials... 

Concentration factors and rate constants determined experimentally in the oyster Crassostrea gigas and the clam Mya arenaria differ widely with species and element. The physical form of the element in the water affects turnover also accumulation of radionuclides of Co, Cs, Mn, and Zn is greater in water containing suspended particles. The chemical form of the element in the water affects its accumulation. When glycine, ethylenediaminetetraacetate (EDTA), yellow stuff , or clay are added to seawater, the accumulation of Cu and Zn by the oyster differs with each test material glycine increases and EDTA decreases the accumulation of both elements. 

BIO ACCUMULATION when released to water, will bioconcentrate in aquatic organisms which cannot metabolize Oysters (Crassostrea virginica) from oil treated enclosure 2 days exposure, oysters concentration 0.36 pg/g, water concentration 1.9 pg/L, accumulation factor (oysters/water) 190 8 days exposure oysters concentration 0.30 pg/g, water concentration 0.1 pg/L, accumulation factor (oysters/water) 3,000... 

Cu, Pb, Cd, and Zn have been determined in seawater by pulsed stripping analysis. A similar analysis of the metallic content of fish, seaweed, and oysters inhabiting this water indicates that there are biological concentration factors of 10 to 10 for these trace metals. 

For Tc, probably present as pertechnetate, the concentration factor (CF) varies according to biological species (Table 3). The CF is high for seaweed ( 10 ) and low for fish fillet ( 10). For lobster (tail muscle) recent results showed that the CF is 10, which is a factor of 10 higher than previously measured in laboratory experiments. For edible parts of mussels and oysters, the CF is about 500 and 300, respectively. After the ingestion of contaminated lobster from the Irish Sea, 4-7% of Tc was retained in the body lyear after intake. Thus, there seems to be a long-term compartment in the body retaining Tc and the dose conversion factor should be revised. 

Tc activity concentration factors were measured in fish in the Irish marine environment. The mean annual Tc level in filtered seawater (<0.45 pm) is 21-45 mBq/1 for seawater from the western Irish Sea in 1995-1998, and 0-0.44 mBq/1 from the south and west coasts in 1998. In seawater, technetium exists predominantly as the pertechnetate ion (Tc04 ), which is highly soluble. Weighted mean Tc specific activities in fish, prawns, and mussels landed at northeast ports in 1996-1998 are 0.15-0.37, 63-88, and 18-37 Bq/kg wet weight, respectively. Concentration factors for Tc in seafood from the western Irish Sea are 6,850 for lobster (tail meat), 2,800 for prawns (edible), 970 for mussels (edible part), 280 for oysters (edible part), and 12 for fish (edible part) (Smith et al. 2001). 

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