Effects of selected nanoparticles on aquatic plants

摘要

This paper presents results of ecotoxicological assessment of nano-Al2O3 and nano-ZrO2 in relation to cyanobacteria, algae and higher plants. Bioindicators showed diverse sensitivity to nanocompounds. EC50 values were in the ranges: for nano-Al2O3 from 5.3 mg/L (Desmodesmus quadricauda) to 457.9 mg/L (Scenedesmus obliquus), for nano-ZrO2 from 19.6 mg/L (D. quadricauda) to 277 mg/L (Lemna minor). According to EU criteria, nano-Al2O3 proved to be toxic to D. quadricauda, harmful to Raphidocelis subcapitata and Microcystis aeruginosa and non-toxic for other species of algae and L. minor. Nano-ZrO2 was harmful to D. quadricauda and non-toxic to other tested species. Calculated predicted no effect concentration (PNEC) in the environment values were 0.0395 mg/L for nano-Al2O3 and 0.0416 mg/L for nano-ZrO2. The risk assessment, conducted on the basis of the predicted environmental concentration (PEC)/PNEC quotient, showed a low risk in relation to aquatic plants caused by the presence of nano-Al2O3 when PEC were calculated using the statistical extrapolation model of Aldenberg-Jaworska. Nanoparticles proved to be more toxic to tested bioindicators than their bulk counterparts. This indicates that the nano-form of a given substance may pose a greater hazard for the environment than the same substance in the large form.