Avaliação temporal da poluição por antiincrustantes organoestânicos no litoral do Estado do Rio de Janeiro: antes e após o banimento nacional e internacional

• Autor(a) principal: Borges, Camila de Leon Lousada
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/13875
• topic: Organotin; Imposex; Stramonita haemastoma; Temporal assesment; Ban; Organoestânicos; Imposex; Stramonita haemastoma; Avaliação temporal; Banimento; CNPQ::CIENCIAS EXATAS E DA TERRA::OCEANOGRAFIA::OCEANOGRAFIA QUIMICA

Antifoulings paints are used to prevent of fouling organisms on underwater structures, especially hull vessels. Organotin compounds (OTs) used in these paints, including tributyltin, are endocrine disrupters and caused damage to various ecosystems. In the case of the gastropod mollusks, such pollution causes females acquire male characteristics, such as penis and vas deferens, a phenomenon known as imposex. The International Maritime Organization (IMO) established a ban on OTs-based paints on ships, in 2008. In Brazil, the NORMAN 23, prohibited the use in 2007, but the Navy had suspended its use since 2003. However, deleterious effects of these compounds are still detected in several countries, including along the Brazilian coast. This work aimed to make a temporal time series assessment (1997-2012) of organotins pollution on the coast of Rio de Janeiro State using as bioindicator the species Stramonita haemastoma. The study area included five regions: Paraty, Ilha Grande, Ilha Grande Bay, Guanabara Bay and Arraial do Cabo. In each biomonitoring station were collected 30 sexually mature individuals of the specie S. haemastoma through free diving in apnea and analyzed using the non-destructive method proposed by Fernandez et al, (2007). Butyltin chemical analyzes were made in surface sediments of mangroves of Paraty (Mangrove close to the sources and Saco do Mamanguá mangrove) and Ilha Grande (Aventureiro mangrove) the last two being considered the reference areas. In all five areas studied along the coast of the State of Rio de Janeiro were recorded stations with high levels of imposex. Although many stations present a decrease in rates, in most there was an increase or maintenance in the high percentage of imposex after the ban. The average concentrations of the mangrove butyltin (S1), close to local sources, were 205.7 ± 16.8 ng (Sn) of TBT g-1, 16.4 ± 1.3 ng (Sn) g -1 of DBT and 10.0 ± 2.9 ng (Sn) g-1 MBT. In the areas of reference: the Saco do Mamanguá mangrove (S2) were 16.0 ± 0.8 ng (Sn) g -1 of TBT, 10.1 ± 1.4 ng (Sn) g -1 of DBT and 10, 1 ± 2.2 ng (Sn) g-1 of MBT and Aventureiro mangrove (S3) with 18.1 ± 4.2 ng (Sn) of TBT g-1, 15.3 ± 0.5 ng (Sn)g-1 DBT and 10.2 ± 1.5 ng (Sn). g-1 MBT. The degradation rates were 0,1, 1,3 and 1,4 respectively indicating recent inputs of these compounds. The results of this study indicate that dissolved and particulate organic carbon and xenoestrogens may be interfering with the development of the syndrome, leading to underestimation of assessment of imposex. Butyltins concentrations and increased or high continued incidence of imposex after the ban on most stations show that despite the ban on the use of TBT in antifouling paints in Brazil, they are still being used illegally, especially in small boats. This study is essential to propose measures to mitigate and control of organotin compounds, even the new TBT-free antifoulings, which also have negative environmental effect. This is because the areas where high levels of imposex recorded wil be the more critical for monitoring the effects of these new antifoulings.