Båtbottenfärger innehållande TBTO
huvudsaklig källa till TBT i miljön
Antifouling paint containing the biocide bisTributyltinoxide (TBTO) has been used since1960 to reduce the occurrence of fouling on hulls on boats/ships. January 1st, 2003 theantifouling paints containing TBTO were prohibited. This ban covered all use of paintcontaining the substance TBTO. The ban was introduced because of alarming observationssuch as development of imposex in aquatic non-target organisms. Imposex is the impositionof male sexual characteristics on mainly female marine snails and occurs due to exposure toTributyltin (TBT). Reproductive failure could be a consequence. After restrictions of TBTO,the substance has become less common in the environment. Despite this, the United NationsSpecialized Agency is worried. The substance still exists in the environment and will affectthe ambient nature. Above all, there is TBT in sediment and in water which may have aneffect on organisms living in water. As a consequence of this, TBT will also be transferred toboth biota and food. TBT has been observed in fish as well as in shellfish. The substance isbioaccumulating, which means that the substance will concentrate in lipofilic tissue. TBT willfor example be stored in the liver. In consideration of this, organisms living in the water areable to transport the substance further on, in the food chain. Bearing this in mind, the humanbeing at the top of the food chain is not without danger. According to the literature, thesubstance will not be biomagnified to a large extent, indicating that the risk for human beingsis limited. Tests carried out in Japan show that daily ingestion of TBT is clearly detectable inhumans. A risk for the humanity can therefore not be fully discharged. Further investigationsare needed in order to left out that the negative outcomes exist which are frequently asked forin chemical reports regarding the subject.