Bioaccumulation and Retention of 14C-hexachlorobenzene (HCB): I. The Marine Tropical Mussel Perna perna

摘要

HCB (hexachlorobenzene) is a ubiquitous pollutant, which is highly toxic to aquatic organisms; however, it is continuously generated and released to the environment. In order to explore the potential of the mussel Perna perna as a sentinel species for monitoring HCB contamination, we have investigated the accumulation and depuration kinetics of 14C-HCB in the mussel exposed to spiked sediment. The sediment, water and mussels were sampled periodically and submitted to solvent extraction for the determination of the radiocarbon and organism lipid content. The analysis showed that most of the radioactivity remained in the sediment as a potential long-term source of pollution, whereas the HCB concentration in the seawater was below the detection limit. The mussel soft tissues were contaminated very little; the residues were distributed as extractable and bound residues, which were strongly correlated with the lipid content of the mussel tissues. The sensitive radiotracer technique used allowed the detection of the small amounts of bound residues bioaccumulated; the latter could not be detected using conventional techniques. The bound residues were not depurated from mussel tissues when non-contaminated conditions were restored. The bioaccumulation factor (BAF) values were low, probably because these mussels were contaminated mainly by suspended matter, similar to what occurs in water-column organisms. Results also suggest that any detection of HCB in mussels would indicate a high overall level of environmental contamination.