The impact of TiO2 nanoparticles on uptake and toxicity of benzo(a)pyrene in the blue mussel (Mytilus edulis)

Abstract

Nanoparticles are emerging contaminants of concern. Knowledge on their environmental impacts is scarce, especially on their interactive effects with other contaminants. In this study we investigated effects of titanium dioxide nanoparticles (TiO2NP) on the blue mussel (Mytilus edulis) and determined their influence on the bioavailability and toxicity of benzo(a)pyrene (B(a)P), a carcinogenic polyaromatic hydrocarbon (PAH). Blue mussels were exposed to either TiO2NP (0.2 and 2.0 mg L -1 ) or B(a)P (20 µg L -1 ) and to the respective combinations of these two compounds. Aqueous contaminant concentrations, the uptake of Ti and B(a)P into mussel soft tissue, effects on oxidative stress and chromosomal damage were analyzed. The uncoated TiO2NP agglomerated rapidly in the seawater. The presence of TiO2NP significantly reduced the bioavailability of B(a)P, shown by lowered B(a)P concentrations in exposure tanks and in mussel tissue. The activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were impacted by the various exposures regimes, indicating oxidative stress in the contaminant exposure groups. While SOD activity was increased only in the 0.2TiO2NP exposure group, CAT activity was enhanced in both combined exposure groups.The GPx activity was increased only in the groups exposed to the two single compounds. In hemocytes, increased chromosomal damage was detected in mussels exposed to the single compounds, which was further increased after exposure to the combination of compounds. In this study we show that the presence of TiO2NP in the exposure system reduced B(a)P uptake in blue mussels. However, since most biomarker responses did not decrease despite lower B(a)P uptake in combined exposures, the results suggest that TiO2NP can act as additional stressor, or potentially alters B(a)P toxicity by activation.

Behavior and Bio-Interactions of Anthropogenic Particles in Marine Environment for a More Realistic Ecological Risk Assessment

“…In contrast, higher TCDD accumulation was observed in whole mussel tissues in the presence of n-TiO 2 but not in the digestive gland. A lower benzo(a)pyrene accumulation upon co-exposure to TiO 2 is reported by Farkas et al (2015) in blue mussel M. edulis. Probably, B(a)P was less bioavailable to mussels due to adsorption to TiO 2 agglomerates.…”

Nanoparticles in the environment: where do we come from, where do we go to?

“…Also, the combined exposure of metallic NP with other chemical stressors delivered contradictory results. The presence of TiO 2 NP reduced the uptake of phenols [ 203 ] and polycyclic aromatic hydrocarbons [ 204 ], which, however, did not necessarily reduce the combined toxic effects of those organic chemicals and TiO 2 NP, suggesting a significant contribution of the NP to the biological responses. On the contrary, the accumulation of perfluorooctanesulfonate in fish was facilitated in the presence of TiO 2 NP.…”

Testing the bioaccumulation of manufactured nanomaterials in the freshwater bivalveCorbicula flumineausing a new test method

“…57 TiO 2 NPs are of great ecotoxicological interest due to their potential to alter the bioavailability and thus the toxicity of coexisting contaminants like heavy metals or organic compounds in aquatic organisms like fish and bivalves. [58][59][60][61][62][63] For the evaluation of the bioaccumulation potential of the MNMs applied in this study, total metal concentrations were analysed in the whole animals and the distribution of accumulated material in the soft tissue was determined. In addition, particle concentrations and particle sizes were measured in the different tissue compartments of the animals to allow the differentiation between bioaccumulation of dissolved and particulate material.…”