Impact of surface modification on the toxicity of zerovalent iron nanoparticles in aquatic and terrestrial organisms

• Published in: Ecotoxicology and environmental safety 2018-11, Vol.163, p.436-443
• Main Authors: Yoon, Hakwon, Pangging, Monmi, Jang, Min-Hee, Hwang, Yu Sik, Chang, Yoon-Seok
• Format: Article
• Language: English
• Subjects: Ecotoxicity; Nanotoxicity; Oxidative stress; Physicochemical property; Surface-modified nZVI
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2018.07.099

Nanoscale zerovalent iron (nZVI)-based materials are increasingly being applied in environmental remediation, thereby lead to their exposure to aquatic and terrestrial biota. However, little is known regarding the toxic effects of surface-modified nZVI on multiple species in the ecosystem. In this study, we systematically compared the toxicities of different forms of nZVIs, such as bare nZVI, carboxymethyl cellulose (CMC)-stabilized nZVI, tetrapolyphosphate (TPP)-coated nZVI and bismuth (Bi)-doped nZVI, on a range of aquatic and terrestrial organisms, including bacteria (Escherichia coli and Bacillus subtilis), plant (Arabidopsis thaliana), water flea (Daphnia magna) and earthworm (Eisenia fetida). The Bi- and CMC-nZVI induced adverse biological responses across all the test systems, except E. fetida, varying from cell death in E. coli and B. subtilis to inhibition of the physiological states in D. magna and A. thaliana. The particle characterization under exposure conditions indicated that the surface modification of nZVI played a significant role in their toxicities by changing their physicochemical properties. The underlying mechanisms by which nZVI induces toxicity might be a combination of oxidative stress and another mechanism such as cell membrane disruption, chlorosis and hypoxia. Overall, our findings could provide important implications for the development of environment-friendly nanomaterials and direct further ecotoxicological researches regarding interspecies exploration. [Display omitted] •The toxicity of surface-modified nZVIs was investigated with suitable model species.•Bi- and CMC-nZVI caused toxic effects on the tested organisms, except for earthworm.•Oxidative stress via the Fenton reaction mainly contributed to the toxicity endpoints.•Membrane disruption, chlorosis and hypoxia could be additional toxic factors.