Assessing exposure, uptake and toxicity of silver and cerium dioxide nanoparticles from contaminated environments

Abstract

The aim of this project was to compare cerium oxide and silver particles of different sizes for their potential for uptake by aquatic species, human exposure via ingestion of contaminated food sources and to assess their resultant toxicity. The results demonstrate the potential for uptake of nano and larger particles by fish via the gastrointestinal tract, and by human intestinal epithelial cells, therefore suggesting that ingestion is a viable route of uptake into different organism types. A consistency was also shown in the sensitivity of aquatic, fish cell and human cell models to Ag and CeO2 particles of different sizes; with the observed sensitivity sequence from highest to lowest as: nano-Ag > micro Ag > nano CeO2 = micro CeO2. Such consistency suggests that further studies might allow extrapolation of results between different models and species.

Figure 1

Composite Z-stack image of C3A human hepatocyte cell line treated with silver nanoparticles. Cells were treated for 2 h with Ag NP at a concentration of 31.25 μg/cm². Red represents the F-actin cytoskeleton, blue the nuclei and green the particles. The faint grey line drawn from the particle in the center of the main frame indicates its position in the two sections on the sides and confirms its location within the cell.