The core of the ITER thermonuclear fusion reactor (www.iter.org) will be made of tungsten, for its mechanical properties and low plasma sputtering yield. Nevertheless, plasma-wall interaction can trigger the formation of tungsten nanoparticles (W-NP) that can be released in the environment, Assessment of the toxic potentials of W-NP is thus needed.

Genotoxicity of W-NPs of size around 100 nm synthetized by planetary ball milling, plasma and laser abrasion were investigated on BEAS-2B immortalized bronchial cells by using a cytotoxicity kit, the alkaline comet (AC) and the cytokinesis-block micronucleus (CBMN) assays.

The physic-chemical characterization of W-NP showed that plasma and namely laser particles have higher specific surface area than milled ones. W-NP behavior in cell culture media is related to the mode of synthesis.

A time- and concentration-dependent cytotoxic effect was noted, whereas cytostasis was not affected by W-NPs. AC and CBMN assays showed that the primary DNA damage and frequency of micronuclei formation was concentration-dependent and in relation with the mode of production. Genotoxic potential of tritiated plasma W-NP are currently investigated. This type of study will be useful to define the environmental and human health risks in case of release of particles in the environment.