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

Abstract

Abstract: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.

Contamination of a boatyard for maintenance of pleasure boats

“…The concentrations of Cu, Pb, Zn and Sn at both investigated sites were consistent with our findings. Similarly, very high levels of contaminants were shown in an extensive compilation of 34 investigations performed in the last 15 years of boatyards in Swedish coastal municipalities (Eklund and Eklund 2013). The concentrations were much lower in the surface compared to the subsurface at stations A and B and slightly lower at station C (Tables 2 and 3).…”

“…Since 2008, there has been a global ban of TBT for all sizes of ships due to the adoption of the AFS convention by the International Maritime Organization (IMO 2001). Albeit, the phasing out of TBT-based antifouling paints and of TBT and its degradation products, dibutyltin (DBT) and monobutyltin (MBT), is still observed in high concentrations in sediments at marinas, harbours and estuaries (Eklund et al 2008). Today, copper (e.g.…”

Valuation of ecotoxicological impacts from tributyltin based on a quantitative environmental assessment framework

“…boats and ships can be reduced by building more efficient boat washers where old boat paint is collected, or by collecting paint flakes from boat dry docking areas, where many boat owners remove old paint. Dredging is an alternative for decreasing the TBT concentrations in the sea as TBT compounds are deposited rather close to the source of exposure (Eklund et al 2008). (More information on biological effects and formal restrictions of TBT is provided in Appendix S1.…”

“…In the Baltic Sea, TBT and their degradation products are found in significant levels, and GES regarding TBT is not achieved at any assessed site within Sweden's territorial waters (Helcom 2010). Even actions for an immediate cessation of TBT discharge would not result in GES for centuries, due to the slow degradation rate of the chemical, as discussed in Eklund et al (2008).…”

“…This research field is hampered by the limited knowledge of ecological impacts following exposure to hazardous chemical pollutants. However, the detrimental biological effects of tributyltin (TBT) on marine biota are well recognized (e.g., Bryan et al 1987;Fisher et al 1990) and negative impacts of TBT pollution on the marine environment in the Baltic Sea have been documented (Eklund et al 2008). TBT has previously been used in a risk-based analysis by Moore and Postle (1994), but the authors were unable to include non-market values in the impacts caused by the compound.…”