Environmental toxicity assessment of chromium (III) oxide nanoparticles using a phytotoxic, cytotoxic, and genotoxic approach

Chromium (III) oxide nanoparticles (NPs) have a wide range of industrial applications, particularly in the production of lithium-ion batteries; however, the toxicity of these NPs has not been studied extensively. The phytotoxicity and genotoxicity of chromium (III) oxide NPs have not been assessed, and only one study reported their cytotoxicity, underscoring the need to perform comprehensive toxicity studies on these NPs. Here, we showed that chromium (III) oxide NPs had no effect on germination rates, and only decreased root elongation in L. sativa as determined by root elongation and biomass studies. Chromium (III) oxide NPs had no phytotoxic effects under environmental realistic conditions, whereas they had cytotoxic effects against HK-2 and Raw 264.7 cells in vitro. However, the cytotoxicity of chromium (III) oxide NPs did not occur under environmentally realistic conditions. The genotoxicity of chromium (III) oxide NPs was not significant in HK-2 cells, suggesting that the potential environmental cytotoxicity of chromium (III) oxide NPs is limited. This study proposes comprehensive phytotoxicity, cytotoxicity, and genotoxicity testing tools that would be easy, safe, and effective for evaluating the toxicity of NPs. This integrated testing system could be an accurate and stable method for evaluating the toxicity of other nanomaterials.