Organotin pollution from pleasure craft at Paraty, a tourist area of Southeastern Brazil: amelioration or interference?

Abstract

Some organotin compounds, such as TBT, are endocrine disruptors and harm marine ecosystems. Even after the global ban on organotins, increasing imposex levels have been detected in Stramonita haemastoma analyzed in 2004 and 2011 in some locations at Paraty, a tourist area in southeastern Brazil. The results of this study indicate that particulate and dissolved organic carbon and xenoestrogens might be interfering in this syndrome's development, leading to underestimation of imposex evaluation. Chemical analysis of three mangrove swamp sediments in the area showed the presence of TBT (16.0 - 205.7 ng Sn g-1), DBT (10.1 - 16.4 ng Sn g-1) and MBT (10.1 - 10.2 ng Sn g-1) even at the reference sites. The concentrations of butyltins and the increased incidence of imposexat some stations indicate recent inputs of TBT in the study area due to its illegal use on small vessels.