Tissue distribution and kinetics of dissolved and nanoparticulate silver in Iceland scallop (Chlamys islandica)

The fast expansion of the global nanotechnology market entails a higher environmental and human exposure to nanomaterials. Silver nanoparticles (AgNP) are used for their antibacterial properties; however, their environmental fate is yet poorly understood. Iceland scallops (Chlamys islandica) were exposed for 12 h to three different silver forms, dissolved Ag(I) (Ag-diss), small (S-NP, empty set = 10-20 nm) and large AgNP (L-NP, empty set = 70-80 nm), labeled with Ag-110m, and bioaccumulation kinetics and tissue distribution using in vivo gamma counting and whole-body autoradiography were determined. All Ag forms were readily and rapidly accumulated. Elimination process was also fast and bi-exponential, with mean biological half-life ranging from 1.4 to 4.3 days and from 17 to 50 days for fast and slow compartments, respectively. Most of the radioactivity concentrated in the hepatopancreas. Ag-diss and S-NP tissue distributions were similar indicating a rapid dissolution of the latter in the tissues, contrarily to L-NP which appeared to form long lasting aggregates in the digestive system. Estimated steady-state bioconcentration factors (BCF), ranging between 2700 and 3800 ml g(-1) for dissolved and particulate silver forms, showed that C islandica can accumulate significant quantities of Ag in a short time followed by an efficient depuration process. (c) 2013 Elsevier Ltd. All rights reserved.