Fate of pristine TiO2 nanoparticles and aged paint-containing TiO2 nanoparticles in lettuce crop after foliar exposure

Camille Larue (1) , Hiram Castillo-Michel (2) , Sophie Sobanska (3) , Nicolas Trcera (4) , Stéphanie Sorieul (5) , Lauric Cécillon (1) , Laurent Ouerdane (6) , Samuel Legros (7) , Géraldine Sarret (1)

1 ISTerre - Institut des Sciences de la Terre
2 ID21
3 LASIRE - Laboratoire Avancé de Spectroscopie pour les Intéractions la Réactivité et l'Environnement - UMR 8516
4 SSOLEIL - Synchrotron SOLEIL
5 CENBG - Centre d'Etudes Nucléaires de Bordeaux Gradignan
6 IPREM - Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux
7 CEREGE - Centre européen de recherche et d'enseignement des géosciences de l'environnement

Engineered TiO2 nanoparticles (TiO2-NPs) are present in a large variety of consumer products, and are produced in largest amount. The building industry is a major sector using TiO2-NPs, especially in paints. The fate of NPs after their release in the environment is still largely unknown, and their possible transfer in plants and subsequent impacts have not been studied in detail. The foliar transfer pathway is even less understood than the root pathway. In this study, lettuces were exposed to pristine TiO2-NPs and aged paint leachate containing TiO2-NPs and microparticles (TiO2-MPs). Internalization and in situ speciation of Ti were investigated by a combination of microscopic and spectroscopic techniques. Not only TiO2-NPs pristine and from aged paints, but also TiO2-MPs were internalized in lettuce leaves, and observed in all types of tissues. No change in speciation was noticed, but an organic coating of TiO2-NPs is likely. Phytotoxicity markers were tested for plants exposed to pristine TiO2-NPs. No acute phytotoxicity was observed; variations were only observed in glutathione and phytochelatin levels but remained low as compared to typical values. These results obtained on the foliar uptake mechanisms of nano- and microparticles are important in the perspective of risk assessment of atmospheric contaminations.

Keywords: Ecotoxicology Plant TiO 2 nanoparticle Micro-XRF Micro-XAS

Domains: Environmental Sciences

Camille Larue, Hiram Castillo-Michel, Sophie Sobanska, Nicolas Trcera, Stéphanie Sorieul, et al.. Fate of pristine TiO2 nanoparticles and aged paint-containing TiO2 nanoparticles in lettuce crop after foliar exposure. Journal of Hazardous Materials, 2014, 273, pp.17-26. ⟨10.1016/j.jhazmat.2014.03.014⟩. ⟨hal-02325207⟩