depleted Uranium, dust, toxicity, radiotoxicity, synergistic effects
Depleted Uranium (DU) is mostly composed by the natural radioactive isotope U238 and it is a by-product of the enrichment process, that part of the nuclear reactors fuel cycle that produces the nuclear fuel to be used in nuclear power plants. Concerning chemical toxicity, Uranium, being a heavy metal, is known to have toxic effects on specific organs in the body, the kidney in particular. Concerning DU radiotoxicity, the most important pathways for DU exposure are in case of ingestion or inhalation. There is growing evidence in the scientific literature, resulting both from in vitro and in vivo analyses, that current models of the mechanisms of toxicity of uranium dust are not fully satisfactory. They should be refined in order to obtain more effective predictions regarding health effects. The approach based solely on the determination of radiological toxicity must be disregarded. Chemical toxicity of uranium has to be reconsidered as the primary mechanism through which uranium dust can cause health effects at long term. With regard to the radiological toxicity, the so-called “spectator effect” should be included in the new model. Finally, the synergy between chemical and radiological toxicity must be taken into account too.