Bioaccumulation and Sediment Accumulation of Organotin Compounds
Fish and shellfish tissue is made up of proteins, these contain nitrogen atoms. Important components of sediments are metal and silicon (hydr)oxides. Organotin compounds show a high affinity for substances containing nitrogen or oxygen atoms. This is because organotins easily form a five- or six-coordination state in which the tin element is coordinated by electronegative atoms (such as nitrogen, oxigen and sulfur). Therefore soils, sediments, particulate matter,... and also biota will act as a sink for organotin compounds. The sorption of positively charged organotins to sediments containing negatively charged surface sites is, together with the hydrophobic effect, considered as the most important explanation for the water to sediment fluxes of organotin compounds. In seawater also the salting-out effect has its part to play.
Keywords: Bioaccumulation, Organotin compounds, Sediment accumulation