Tributyltin Originates from Pleasure Boats in Sweden in Spite of Firm Restrictions

The temporal and spatial distributions of organic tin compounds, irgarol and metals in sediments from a marina and the harbor of a small town near Stockholm, Sweden were investigated as part of a study of the environmental impacts of anti-fouling paint. The upper (0-2 cm) sediment layer was collected at seven stations in the marina and eight stations in the small town harbor; two reference stations were also sampled. High levels of tributyltin (TBT) were detected in sediment that decreased along a spatial gradient moving away from the slipway in the marina. TBT was ten times higher in the surface sediment when compared to subsurface layers (10 cm deep). The highest concentrations of TBT were found at the slipways (up to 2000 g TBT/kg DW) of the harbor. Analysis of accumulated sediments obtained from a collection basin situated beneath a boat washer revealed very high concentrations of TBT (63 000 g/kg DW). These data provide persuasive evidence that TBT is still being released from pleasure craft even though it has been banned for use on such boats for 19 years. The source of the TBT is most likely from older paint that has been covered with newer coats. Our observations, together with other literature-based data, suggest that TBT is still being released into the environment and poses a serious ecological problem at marinas throughout the world.