Butyltins in sediments from the Southern Baltic coastal zone: Is it still a matter of concern, 10 years after implementation of the total ban?

The study was done to assess butyltin contamination in sediments of the Southern Baltic coastal zone, ten years after implementation of the total ban on harmful organotin use in antifouling paints. Sediment samples were collected from two seaports of international significance: the Port of Gdańsk and the Port of Gdynia, as well as from the Szczecin Lagoon which plays a significant role as a shipping route connecting the Port of Szczecin with the Port of Świnoujście. Total concentrations of butyltins in the sediment samples ranged between 5.7 and 3321 ng Sn g-1 d.w. Eighty percent of the samples were found as highly and grossly contaminated with tributyltin. The results were compared with those recorded ten years ago. Despite the improvement, the butyltin contamination still gives rise to concern in the study area. According to the HELCOM recommendation, all samples exceeded the Good Environmental Status boundary for tributyltin in sediments.