Trophic transfer of silver nanoparticles from earthworms disrupts the locomotion of springtails (Collembola)

Understanding how nanomaterials are transferred through food chains and evaluating their resulting toxicity is important. However, limited research has been conducted on the toxic consequences of trophically transferred nanomaterials in terrestrial ecosystems. In this study, we documented the adverse effects of trophically transferred silver nanoparticles (AgNPs) in a soil-earthworm (Eisenia andrei)-Collembola (Lobelia sokamensis) food chain. We exposed E. andrei to soil with AgNPs at concentrations of 50, 200, and 500 mu g AgNPs/g soil dry weight and assessed their survival after 7 days. Trophic-transfer containers were then prepared and E. andrei that survived the 7 days test period were washed, killed in boiling water, and added to the containers with L. sokamensis. We noted negligible effects and low bioaccumulation at the lowest AgNP concentration (50 mu z AgNPs/g soil dry weight) in earthworms and the L. sokamensis that fed on them. The highest concentration of AgNPs (500 mu g AgNPs/g soil dry weight) resulted in juvenile earthworm mortality and increased transfer of AgNPs to Collembola, which subsequently inhibited their locomotion. To our knowledge, this is the first study to document the trophic transfer and adverse effects of AgNPs in a soil-earthworm-Collembola food chain, a common prey-decomposer interaction in soil ecosystems. (C) 2016 Elsevier B.V. All rights reserved.