Growth inhibition of aquatic plant caused by silver and titanium oxide nanoparticles

Abstract

Emerging nanomaterials are of great concern to aquatic environment. The inhibitory effects of silver nanoparticles (Ag-NP) and titanium oxide nanoparticles (TiO2-NP) on the growth of aquatic plant duckweed were evaluated. Lemna paucicostata was used as a test organism, and the test method was followed by the OECD test guideline 221. Ag-NP (50 nm) and TiO2-NP (2-3 nm) inhibited the growth of Lemna in different manner and the EC50s were calculated as 13. 8 and 538. 5 ppm, respectively. The LOECs of Ag-NP and TiO2-NP were calculated to be 1 and 125 ppm, respectively. The results showed that Ag-NP could cause growth inhibition of Lemna in low concentration range (≥1 ppm), but TiO2-NP appeared toxic effect to the growth of Lemna in the concentration range of ≥250 ppm, which was over two orders higher than the previously reported concentration of TiO2-NP determined in the aquatic environment. © 2011 Korean Society of Environmental Risk Assessment and Health Science and Springer.