Fish exposure to nano-TiO2 under different experimental conditions: Methodological aspects for nanoecotoxicology investigations

Effects of humic acid and ionic strength on TiO2 nanoparticles sublethal toxicity to zebrafish

“…The antioxidant defense systems include a series of antioxidative enzymes and low-molecular non-enzymatic antioxidants, such as SOD activities, CAT activities and contents of MDA and GSH, which were all appropriate for monitoring oxidative stress status of fish after exposure to nano metal oxides (Hao et al 2009;Xiong et al 2011;Hao and Chen 2012;Lee et al 2012;Clemente et al 2013), in spite of the fact that some of the biomarker responses appear inconsistent because the mechanism is indirect as a consequence of the occlusion of tissue surfaces rather than more readily interpreted doseresponse relations. Indeed, the biomarker response varied in different organs and organs varied different sensitivity (detailed below), indicating possibly different toxicity mechanism.…”

“…Despite the massive scientific research on the ecotoxicity of TiO 2 NPs to aquatic life, the findings are inconclusive and conflicting, which may arise from the complex environment behavior of NPs (Clemente et al 2012(Clemente et al , 2013. NPs tend to aggregate in the environment and therefore can be eliminated or captured by sedimentation (Zhu et al 2009;Yu et al 2011).…”

“…Furthermore, the body distribution, metabolism, and excretion of NPs are poorly understood and hampered by a lack of methods for measuring NPs in tissues. It remains possible that TiO 2 NPs could interfere or stimulate stress responses in fish (Menard et al 2011;Clemente et al 2013;Yang et al 2013), which was shown as oxidative response. However, the oxidative response could be caused by direct (primary) or indirect (secondary) effect by NPs or its released ions.…”

Genotoxicity, potential cytotoxicity and cell uptake of titanium dioxide nanoparticles in the marine fish Trachinotus carolinus (Linnaeus, 1766)

“…Much more likely, radicals induced by TiO 2 -NP are responsible for DNA damage in exposed cells (Reeves et al, 2008). There is therefore a consensus that studies on the effects of TiO 2 , as well as standardized protocols in nanoecotoxicology are necessary (Clemente et al, 2013).…”

Cosmetic Ingredients as Emerging Pollutants of Environmental and Health Concern. A Mini-Review

“…The partial information available on the physicochemical characteristics of the nanoparticles tested in different investigations and the different endpoints examined does not allow a reasonable comparison of the data obtained and thus does not permit firm conclusions to be drawn about the ecotoxicity of nano-TiO 2 . Therefore, even though in some papers nano-TiO 2 has been reported to have negligible effects on various aquatic organisms [84][85][86], a dramatic increase of the toxicity of this compound occurs in the presence of exposition to strong sunlight or UV radiation due to the production of ROS [87][88][89]. As far as ZnO is concerned, its toxicity for aquatic organisms is well documented; for example, for zebrafish [90,91], marine algae [92,93], sea urchins [94], and other marine organisms [95,96], nano-ZnO was classified "extremely toxic" [95].…”