Laura Torrent, within the framework of her PhD thesis, Dr. Mònica Iglesias, Dr. Eva Marguí and Dr. Manuela Hidalgo, in collaboration with other authors from the Department of Environmental Sciences of the University of Girona, and from the University of Ljubljana and the Jozef Stefan Institute, both from Ljubljana (Slovenia), have published the paper entitled “Uptake, translocation and ligand of silver in Lactuca sativa exposed to silver nanoparticles of different size, coatings and concentration”. The paper has been published in the Journal of Hazardous Materials.

The authors explain that the broad use of silver nanoparticles (AgNPs) in daily life products enhances their possibilities to reach the environment. Therefore, it is important to understand the uptake, translocation and biotransformation in plants and the toxicological impacts derived from these biological processes. In this work, Lactuca sativa (lettuce) was exposed during 9 days to different coated (citrate, polyvinylpyrrolidone, polyethylene glycol) and sized (60, 75, 100 nm) AgNPs at different concentrations (1, 3, 5, 7, 10, 15 mg L−1). Total silver measurements in lettuce roots indicated that accumulation of AgNPs is influenced by size and concentration, but not by nanoparticle coating. On the other hand, nanosilver translocation to shoots was more pronounced for neutral charged and large sized NPs at higher NP concentrations. Single particle inductively coupled plasma mass spectrometry analysis, after an enzymatic digestion of lettuce tissues indicated the dissolution of some NPs. Ag K-edge X-ray absorption spectroscopy analysis corroborated the AgNPs dissolution due to the presence of less Ag-Ag bonds and appearance of Ag-O and/or Ag-S bonds in lettuce roots. Toxicological effects on lettuces were observed after exposure to nanosilver, especially for transpiration and stomatal conductance. These findings indicated that AgNPs can enter to edible plants, exerting toxicological effects on them.

This work has been conducted within the “Natural Environment” research line of the Analytical and Environmental Chemistry research group.

The Spanish Ministry of Economy and Competitiveness financed this work through the project CGL2013-48802-C3-2-R (Program 2014). L. Torrent gratefully acknowledges a FPI grant from the Spanish Ministry of Economy and Competitiveness (Ref. BES-2014-070625). The authors acknowledge synchrotron facility ALBA (2016091810) for provision of the beamtime and Wojciech Olszewski for the help with the measurements. The authors are also thankful to Albert Salado and Miquel Frau for their contribution on the performance of this work.

The Slovenian Research Agency is acknowledged for financing this work through programs P1-0212, P1-0112 and projects J7-9418 and J7-9398.