Effects of ZnO, TiO2 or Fe2O3 nanoparticles on the body mass, reproduction, and survival of eisenia fetida

Abstract

The increasing production of nanoparticles and its byproducts bring as a priority the necessity of understanding the interaction between earthworms and nanoparticles (NPs) in an agricultural soil. The present study addresses the effects of ZnO-, TiO2- or Fe2O3-NPs in the body mass change, reproduction and survival of Eisenia fetida. Earthworms were exposed to increasing concentrations of each NPs (0.0, 0.15 and 0.3 g NPs kg-1 dry soil, in an amended soil while total and bioavailable Zn, Ti and Fe were monitored in an aerobic incubation experiment of 60 days. Earthworms exposed to 0.15 g TiO2-NPs kg-1 dry soil and 0.3 g ZnO-NPs kg-1 dry soil did not lead to adults’ deaths. However, when soil was amended with 0.15 g Fe2O3-NPs kg-1 dry soil the survival decreased significantly compared with the control treatment. Cocoon production was not significantly different between treatments, suggesting that NPs have no effect on earthworm reproduction. ZnO-NPs at 0.3 g kg-1 dry soil enhanced juveniles on growing and survival. Although bioaccumulation of Ti in earthworm biomass was not statically different in treatments spiked with TiO2-NPs, there were significant differences between treatments amended with different doses of ZnO- and Fe2O3-NPs, showing that bioaccumulation of Zn and Fe in earthworms increases on par with dose. Meanwhile, the Fe bioaccumulation was significantly lower in earthworms exposed to Fe2O3-NPs than those in the control group.