Modalités de la contamination d'une chaine trophique marine benthique par l'argent 110 m

Abstract

110mAg contamination mechanisms in a marine benthic food chain. 3. Influence of the mode of contamination upon the distribution of the radionuclide. The distribution of alOnlAg was stndied in various invertebrates of a marine benthic food chain as a consequence of the immersion in contaminated seawater and/or ingestion of radioactive food. The studies on II~ distribution were carried out at the end of the experimental contamination (when equilibrium was rea&ed) and during the slow stage of elimination. APcer contamination via the surrounding water, uptake of ll0mAg occurs mainly in external organs: shells (34 ~ and mantle (16 ~ of the bivalve ScrobicuIaria plana, exoskeleton (40 ~ and gills (38 ~ of the crab Carcinus rnaenas. On the contrary, contamination via food is responsible for a considerable accumuiation of 11OrnAg in the digestive glands of S. plana (75 ~ and C. maenas (56 ~ Moulting plays an important role in the decontamination of crabs following immersion in radioactive seawater owing to the strong contamination of the exuviae. The elimination of ll0mAg from the different organs of the animals examined depends upon the mode of contamination: it is generally fast in external organs and slow in the digestive gland. Radiation doses for molluscs and crustaceans were calculated following experimental contaminations by water and food. A significant contamination of external organs is responsible for a radiation dose (in the centre of the test animals) weaker than that instigated by the accumulation of 110mAg in the digestive gland. Thus, with regard to contamination, the ambient water is important; but, from the point of view of irradiation, radioactive food is generally more important.

Bioavailability and toxicity of sediment-bound lead to a filter-feeder bivalve Crassostrea gigas (Thunberg)

“…1975, Kirchmann et al 1977, Terhaar et al 1977, Nakahara & Cross 1978. Amiard 1979, Ballester & Castellvi 1979, Hamdy & Prabhu 1979, Mann et al 1979, Dahlgaard 1981, Borchardt 1983, Flatau & Gauthier 1983, Harvey & Luoma 1985, Abbe & Sanders 1988, Martoja et al 1988, Amiard eta/.…”

Trophic transfer of silver to marine herbivores: A review of recent studies

“…Further, the duration of exposure had no significant effect on Ag efflux rates in mussels when it was accumulated from the dissolved phase. By contrast, Amiard [71] found that Ag in the clam Scrobicularia plana was lost at a faster rate following accumulation from the dissolved phase and with shorter‐term exposure. Further studies are required to understand the controls of various ligands or compounds (e.g., sulfides and metallothioneins) on Ag efflux in aquatic animals.…”