Accumulation and depuration of organic micro-pollutants in marine hard bottom organisms

A method used in to estimate uptake of hydrophobic pollutants in marine hard bottom organisms is described. Radio-labelled toxicants (14C-PCB77 and 14C-BaP) were used in a closed continuous-flow system without making use of solvents. Concentrations of PCB77 and BaP in the water were relatively high and stable during the experimental periods (14 days). The experimental set-up gave a satisfactory dispersion of the toxicants in the water and the use of radiochemicals made analyses quick and inexpensive. Algae (Fucus vesiculosus) and mussels (Mytilus edulis) were exposed to the toxicants and uptake was principally rapid and significant. Algae exposed to PCB77 reached a steady-state level within 24 h. No steady-state level was observed for BaP during exposure. Mussels showed an approximately linear uptake rate with no steady state observed for either of the toxicants. Organisms moved to a clean environment showed no reduction in PCB77 content. For BaP a slow depuration rate was observed. The rapid uptake of PCB and BaP by the organisms, and the accumulation and retention of the substances in the tissue for a long time, may result in a considerable pool of toxicants stored in these organisms.