Publicação
Addressing the effects of short-term exposure to TiO2 nanoparticles in fish gills: An ex-vivo approach
| datacite.subject.fos | Engenharia e Tecnologia::Engenharia do Ambiente | pt_PT |
| dc.contributor.advisor | Martins, Marta | |
| dc.contributor.advisor | Costa, Pedro | |
| dc.contributor.author | Silva, Mattia Esteves da | |
| dc.date.accessioned | 2018-05-14T15:20:40Z | |
| dc.date.available | 2018-05-14T15:20:40Z | |
| dc.date.issued | 2017-11 | |
| dc.date.submitted | 2017 | |
| dc.description.abstract | With the fast increase of world-wide consumption and lack of legislation of engineered nanomaterials (ENMs), it is expected an increase of artificial production and consequently, an increase of the number of nanoparticles (NPs) that are released into the environment. Most nanoparticles present in the aquatic environment, such as those of titanium oxide nTiO2, have effects on histopathological alterations on fish, creating several implications on their health, and, consequently influencing aquatic environment status. The effects caused by the exposure to two realistic concentrations of nTiO2 (20 and 200 μgL-1, plus controls) were evaluated in gills of fish (S. senegalensis), through a short-term ex vivo approach, meaning that exposure was accomplished after dissection of gills from the animals. Alterations in gills were analysed, such as the formation of metal deposits and the specific alterations to gas-exchange epithelial and chloride cells. Standard histological techniques were coupled with fluorescent techniques to assess aforesaid alterations. Quantitative ad semi-quantitative approaches were employed. Overall, the main alterations observed in gill exposed to nTiO2 treatments were epithelial lifting, chloride cells autolysis and goblet cell hypertrophy. Higher severity and dissemination of alterations was observed for gills exposed to the highest concentration (200 μg nTiO2 L-1). In accordance, the gill global histopathological condition indice (Ih) increased with the increase of nTiO2 concentration in water at T2 and T4. The number of CC (Chloride cells) and GC (Goblet cells) per interlamellar space also increased with the exposure to nTiO2, at T2, however without a clear relationship with the concentration. Metal deposits were found in gill macrophages, distributed consistently trough all treatments, failing to demonstrate any cause-effect relation between concentrations and time of exposure. Overall, the present study indicates that under ecologically-relevant concentrations of nTiO2 caused moderately histopathological lesions in gills of S. senegalensis. Although, the alterations in mucocytes indicated responses to the challenge, the exposure to TiO2 promoted osmotic imbalance. The present ex vivo study significantly contributed to define further procedures to nanotoxicity studies. | pt_PT |
| dc.identifier.tid | 202321630 | |
| dc.identifier.uri | http://hdl.handle.net/10362/36896 | |
| dc.language.iso | eng | pt_PT |
| dc.title | Addressing the effects of short-term exposure to TiO2 nanoparticles in fish gills: An ex-vivo approach | pt_PT |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | pt_PT |
| rcaap.type | masterThesis | pt_PT |
| thesis.degree.name | Mestre em Engenharia do Ambiente | pt_PT |