Toxic impacts of rutile titanium dioxide in Mytilus galloprovincialis exposed to warming conditions

authors	Leite, C; Coppola, F; Monteiro, R; Russo, T; Polese, G; Silva, MRF; Lourenco, MAO; Ferreira, P; Soares, AMVM; Pereira, E; Freitas, R
nationality	International
journal	CHEMOSPHERE
author keywords	Climate changes; Mussels; Titanium dioxide; Oxidative stress; Metabolism; Histopathology
keywords	OXIDATIVE STRESS; TIO2 NANOPARTICLES; DIGESTIVE GLAND; HISTOPATHOLOGICAL INDEXES; RUDITAPES-DECUSSATUS; MEDITERRANEAN MUSSEL; BIOCHEMICAL MARKERS; THERMAL-STRESS; WASTE-WATER; ACCUMULATION
abstract	Climate change is leading to a gradual increase in the ocean temperature, which can cause physiological and biochemical impairments in aquatic organisms. Along with the environmental changes, the presence of emerging pollutants such as titanium dioxide (TiO2) in marine coastal systems has also been a topic of concern, especially considering the interactive effects that both factors may present to inhabiting organisms. In the present study, it has been assessed the effects of the presence in water of particles of rutile, the most common polymorph of TiO2, in Mytilus galloprovincialis, under actual and predicted warming conditions. Organisms were exposed to different concentrations of rutile (0, 5, 50,100 mu g/L) at control (18 +/- 1.0 degrees C) and increased (22 +/- 1.0 degrees C) temperatures. Histopathological and biochemical changes were evaluated in mussels after 28 days of exposure. Histopathological examination revealed similar alterations on mussels' gills and digestive glands with increasing rutile concentrations at both temperatures. Biochemical markers showed that contaminated mussels have an unchanged metabolic capacity at 18 degrees C, which increased at 22 degrees C. Although antioxidant defences were activated in contaminated organisms at 22 degrees C, cellular damage was still observed. Overall, our findings showed that histopathological impacts occurred after rutile exposure regardless of the temperature, while biochemical alterations were only significantly noticeable when temperature was enhanced to 22 degrees C. Thus, this study demonstrated that temperature rise may significantly enhance the sensitivity of bivalves towards emerging pollutants. (C) 2020 Elsevier Ltd. All rights reserved.
publisher	PERGAMON-ELSEVIER SCIENCE LTD
issn	0045-6535
year published	2020
volume	252
digital object identifier (doi)	10.1016/j.chemosphere.2020.126563
web of science category	Environmental Sciences
subject category	Environmental Sciences & Ecology
unique article identifier	WOS:000534377000073