Polychlorinated biphenyls and organochlorine pesticides in the freshwater mussel Hyridella menziesi from the Waikato River, New Zealand.

Abstract

It is now well established that past human activities have resulted in widespread environmental contamination with persistent chemicals, especially in aquatic ecosystems (Tanabe et al. 1994). The polychlorinated biphenyls (PCBs) and organochlorine pesticides are highly persistent and toxic, and extensive use has led to accumulation of their residues in a number of aquatic environments. This has raised toxicological concerns for both aquatic organisms and man based on historical and ongoing trends in the use of organochlorines (Voldner and Li 1995). While aquatic sediments are an ultimate sink for these anthropogenic compounds, their uptake and accumulation by biota, including shellfish and fish, has resulted in their build-up in the food chain. Marine mammals, particularly cetaceans, are one of the groups receiving high concentrations of persistent organochlorines (Tanabe et al. 1994). Organochlorine pesticides can enter aquatic ecosystems from atmospheric deposition as well as local pollution sources such as agricultural runoff, and industrial and domestic wastes. Similarly, PCBs inputs can occur directly from industrial usage or indirectly via the atmosphere.