Effects of Amorphous Silica Nanopowders on the Avoidance Behavior of Five Soil Species-A Screening Study.

Silica nanoparticles (SiONPs) are one of the most used in commercial products and biomedical tools, however, their environmental effects have not been fully described. Although negative effects of SiONPs on the behavior of freshwater invertebrates have been reported, the knowledge is limited, especially the effect of nanopowders in terrestrial organisms. Accordingly, the aim of the present study is to understand the effects of SiONPs on the avoidance behavior of five soil species, whose niche may differ thus contributing to differential harmful SiONPs effects. Hence, avoidance assays testing SiONPs concentrations of 0, 10, 100, 250, 500 and 1000 mg/kg were performed with , , , and . SiONPs induced different behavioral effects, depending on the invertebrate ecology/habitat, exposure route and physiology. and did not avoid contaminated soil; however, and significantly avoided SiONPs spiked soil. Since these terrestrial worms (oligochaetes) live mostly burrowed in the soil, this can provide greater opportunity for SiONPs' uptake. On the other hand, the other tested organisms mainly living on the upper part of the soil did not avoid the SiONPs spiked soil. The avoidance data obtained here also highlight the need for further studies to understand whether (or not) the detected behavioral responses are linked to either neurotransmission processes or sensorial aspects of the biological models.