Uptake and elimination of tributyltin in clams, Venerupis decussata

Abstract

This paper considers the use of Venerupis decussata as a bioindicator of tributyltin (TBT) exposure using kinetic approaches. Clams, V. decussata, were exposed in a daily renewal protocol to different TBTCl concentrations: 0.004, 0.0814, 0.242, 0.740 and 2.47 μg L−1. The time course of accumulation in the whole soft tissues was determined for a maximum exposure period of 60 days. In 2.47 μg L−1 a steady state was reached within 30 days and in lower exposure concentrations within 40 days. Bioconcentration factors (BCF) for TBT in clams ranged between 10 000 and 40 000. TBT data during the accumulation experiments were fitted to the one-order kinetic model and kinetic parameters, uptake and depuration rate constants, were calculated. Depuration was studied in a flow through system for a period of 100 days. TBT data during the depuration experiments were fitted to both one-compartment and two-compartment models. Using a one-compartment model, half-life values for TBT were calculated and ranged between 11 and 36 days, increasing for lower concentrations.