Uptake and elimination of tributyltin in clams, Venerupis decussata

This paper considers the use of Venerupis decussata as a bioindicator of tr ibutyltin (TBT) exposure using kinetic approaches. Clams, V. decussata, wer e exposed in a daily renewal protocol to different TBTCl concentrations: 0. 004, 0.0814, 0.242, 0.740 and 2.47 mu g L-1. The time course of accumulatio n in the whole soft tissues was determined for a maximum exposure period of 60 days. In 2.47 mu g L-1 a steady state was reached within 30 days and in lower exposure concentrations within 40 days. Bioconcentration factors (BC F) for TBT in clams ranged between 10 000 and 40 000. TBT data during the a ccumulation experiments were fitted to the one-order kinetic model and kine tic parameters, uptake and depuration rate constants, were calculated. Depu ration was studied in a flow through system for a period of 100 days. TBT d ata during the depuration experiments were fitted to both one-compartment a nd two-compartment models. Using a one-compartment model, half-life values for TBT were calculated and ranged between 11 and 36 days, increasing for l ower concentrations. (C) 1999 Elsevier Science Ltd. All rights reserved.