ABSTRACT
Leaching of marine antifoulants containing Tributyltin (TBT) compounds resulted in seawater TBT concentrations ranging from 10 to 100 ng/L in many estuaries. A body of evidence indicates that, irrespective of which TBT compounds are added, the same chemical species are produced in seawater. One of the original attractions of TBT as a toxicant was its biodegradability, usually involving stepwise debutylation to dibutyltin (DBT) and monobutyltin (MBT). Observations on the time-course of TBT uptake in macroorganisms have demonstrated that times taken for the tissues to equilibrate with TBT levels in the environment are often measured in weeks or months rather than days. The highest subsurface seawater concentrations of TBT to which organisms are likely to be exposed are found in harbors and marinas and are of the order of 1000 ng/L. Tolerance to TBT is no guarantee of protection to an organism if major components of its diet are sensitive to the compound.
