Spatial distribution and temporal trends of butyltin compounds (TBT, DBT & MBT) in short sediment cores of the SW Portuguese Shelf (western Iberian Margin, NE Atlantic)

Mário Mil-Homens; C Marisa R Almeida; Sofia Dias; Warley Soares; Piet van Gaever; Henko de Stigter; Miguel M Santos; André Santana; Mafalda Freitas; Fátima Abrantes; Miguel Caetano

doi:10.1016/j.scitotenv.2023.165872

Spatial distribution and temporal trends of butyltin compounds (TBT, DBT & MBT) in short sediment cores of the SW Portuguese Shelf (western Iberian Margin, NE Atlantic)

Sci Total Environ. 2023 Nov 20:900:165872. doi: 10.1016/j.scitotenv.2023.165872. Epub 2023 Jul 28.

Authors

Affiliations

¹ IPMA, Divisão de Oceanografia e Ambiente Marinho, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6 1495-165 Algés, Portugal; CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal. Electronic address: mario.milhomens@ipma.pt.
² CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Departamento de Química e Bioquímica, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto, Portugal.
³ IPMA, Divisão de Geologia e Georecursos Marinhos, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Algés, Portugal.
⁴ NIOZ, Royal Netherlands Institute for Sea Research, Department of Ocean Systems, Landsdiep 4, 1797SZ 't Horntje - Texel, the Netherlands.
⁵ CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal; Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal.
⁶ CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
⁷ IPMA, Divisão de Geologia e Georecursos Marinhos, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6, 1495-165 Algés, Portugal; CCMAR, Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
⁸ IPMA, Divisão de Oceanografia e Ambiente Marinho, Instituto Português Do Mar da Atmosfera, I.P., Avenida Doutor Alfredo Magalhães Ramalho, 6 1495-165 Algés, Portugal; CIIMAR/CIMAR-LA, Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Terminal de Cruzeiros de Leixões, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal.

PMID: 37517731
DOI: 10.1016/j.scitotenv.2023.165872

Abstract

Spatial patterns and temporal trends of the butyltin compounds tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) were investigated in a set of sediment samples collected along the SW Portuguese continental shelf. This region did not reach the Good Environmental Status (GES) in accordance with the Marine Strategy Framework Directive (MSFD) during a first evaluation carried out in 2012. Overall, MBT and DBT were the predominant organotin species detected, but high concentrations of TBT were found in and around disposal sites for dredge sludge derived from the dredging in navigation channels, harbours, and shipyard facilities of the Tagus and Sado estuaries. Although Portuguese regulations for monitoring sediment quality in relation to dredging activities consider only PAH, PCB and HCB, they also dictate that other organic contaminants such as butyltin compounds (BTs) should be monitored if suspicion of high values exists, but no action limits are defined for these (MAOTDR, 2007). Without action limits, the monitoring recommendation given in the regulations is not put into practice. Considering their toxicity, BT derivates should be integrated in the legislation, because they represent an environmental threat in the relocation of dredged material, especially when derived from harbour and shipyards areas. Based on this study, we recommend giving more attention to the amounts and impacts of BTs in sediments at dredged material disposal sites (DMDS) and their surroundings. Or even better, in order to be more efficient, monitoring should be done at the source of the dredged materials and not at the sink. In case it is not done, the monitoring of concentrations of TBT (and other BTs) in sediments and organisms, including imposex studies, at all Portuguese sites for disposal of dredged material receiving slightly to strongly contaminated dredged material must be developed.

Keywords: Butyltin compounds; Marine sediments; Portuguese shelf; Temporal variation.