In Vitro and field studies on the environmental methylation of Tribultytin species

Abstract

TBT in a typical harbour environment is susceptible to degradation by various mechanisms to give predominantly DBT and MBT. It can also be degraded under anoxic conditions to Bu3SnMe. Such transformations of TBT should affect the mobility and toxicity of the contaminant. The importance of biological processes involved in the transformations of TBT under simulated environmental conditions was investigated. Furthermore, the headspace above contaminated harbour sediment and above spiked seawater and sediment-seawater mixtures was analysed for mixed butylmethyltin compounds by active and passive sampling, respectively. Air from harbour environments was also analysed using passive sampling techniques. It appears that, while both biologically active sediment-seawater mixtures and sterile controls are capable of degrading TBT to DBT and subsequently to MBT, degradation is more efficient in biologically-active mixtures.