Ecotoxicity of silver nanoparticles on earthworm Eisenia fetida : responses of the antioxidant system, acid phosphatase and ATPase.

Ecotoxicity of nanoparticles has received growing attention in recent years. This study investigated the influence of silver nanoparticles (Ag-NP) on earthworm Eisenia fetida. The experiment was performed with five test groups: control (without Ag-NP), 10 nm Ag-NP groups (20, 100 or 500 mg kg−1) and positive control (787 mg kg−1 AgNO3). After 14-day acute exposure, activities of various enzymes, including glutathione S-transferase (GST), glutathione reductase (GR), acid phosphatase (AP), and Na+, K+-ATPase were determined. Effects of Ag-NP with different sizes (10 and 80 nm) were also tested. Data showed that the activity of GR was significantly lower at 500 mg kg−1. The activities of AP and Na+, K+-ATPase were inhibited following the increase of Ag-NP concentration. When treated with Ag-NP with different sizes, activities of AP and Na+, K+-ATPase of the 10 nm group were significantly lower than the control group, but those of the 80 nm group were similar to the control group. Data indicate that Ag-NP may be harmful to the earthworm E. fetida at 500 mg kg−1, and the toxicity of Ag-NP with 10 nm size is greater than 80 nm. In addition, AP and Na+, K+-ATPase are sensitive biomakers to the effects of Ag-NP. [ABSTRACT FROM PUBLISHER]