Research
| Title： | Tissue distribution of Ag and oxidative stress responses in the freshwater snail Bellamya aeruginosa exposed to sediment-associated Ag nanoparticles |
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| First author： | Bao, Shaopan; Huang, Jiaolong; Liu, Xiawei; Tang, Wei; Fang, Tao |
| Journal： | SCIENCE OF THE TOTAL ENVIRONMENT |
| Years： | 2018 |
| DOI： | 10.1016/j.scitotenv.2018.07.011 |
| Abstract： | Silver nanoparticles (AgNPs) are among the most widely used engineered nanomaterials and may eventually accumulate in sediments. Limited information is currently available regarding the toxicity, bioaccumulation and distribution of sediment-associated AgNPs in aquatic organisms. In the present study, a freshwater snail Bellamya aeruginosa was exposed via sediment to commercial Ag particles of four nominal sizes: 20 nm (AgNPs-20), 40 nm (AgNPs-40), 80 nm (AgNPs-80), and < 10 mu m (bulk Ag), and to silver nitrate at sub-lethal concentrations (1, 10 and 100 mu g Ag/g sediment). Ag burden and biomarkers of oxidative stress were assessed in different tissues of B. aeruginosa: hepatopancreas, gonad, foot and digestive tracts. All five Ag types were available for uptake by B. aeruginosa when spiked into sediment, and Ag accumulation in different tissues presented the following pattern: hepatopancreas > gonad approximate to digestive tracts > foot. Snails accumulated higher levels of Ag from aqueous Ag than from particulate Ag. In contrast, AgNPs-40 and AgNPs-80 treatments occasionally induced higher oxidative stress than aqueous Ag, indicating the significant role of nanoparticle itself in exerting toxicity. Size-dependent toxicity of AgNPs in sediment was also found, with AgNPs-20 showing lower toxicity than other Ag particles. Overall, this study demonstrated that the toxicity of sediment-associated AgNPs to B. aeruginosa varies with size and differs from aqueous Ag. (C) 2018 Elsevier B.V. All rights reserved. |
