Ecotoxicity of selected carbon-based nanomaterials

The widespread use of the nanomaterials increases the emission of nano-pollutants into the water. Carbon nanomaterials are particularly interesting. They are characterized by relatively stable structure, which makes them able to migrate and accumulate in the environment. Therefore, the aim of this study was to determine the potential toxicity at the different trophic levels of four selected carbon nanostructures: graphene oxide (GO), reduced graphene oxide (rGO), multi-walled carbon nanotubes (MWCNTs) and oxidized multi-walled carbon nanotubes (f-MWCNTs) on indicators at three trophic levels. Producers was represented by Lemna minor in growth inhibition test. The ecotoxicological effect for consumers was estimated by acute tests on Artemia franciscana, Brachionus calyciflorus and Thamnocephalus platyurus, while the acute toxicity on decomposers was studied on bacteria Escherichia coli. Results show that the short-term exposure on MWCNTs, f-MWCNTs, GO and rGO can be toxic at three trophic levels. The influence of the tested materials was much higher for the consumers, than for the producers. The lowest toxicity from all researched carbon-based nanomaterials was presented by GO. Moreover, generation of high reactive form of oxygen, mechanical damage of cell wall and membrane is one of the main toxicity mechanism; thus, the toxicity depends heavily of the dose and the shape of the nanomaterials.