Uranium in the environment: occurrence, transfer, and biological effects.

The assessment of uranium chemical and radiological consequences depends on the physicochemical properties of these radioelements and the knowledge of their environmental fate. Although uranium is the source of all these fissionable isotopes, its fate in ecosystems has been poorly investigated. In this review, we have updated information concerning the fate of uranium in the different compartments of the environment, the possibility of transfer to man through the food chain, and the biological and toxicological effects of this metal at cellular, tissular, or organism levels. The physicochemical characteristics of uranium, as well as its regulatory statutes, were reviewed. The fate of uranium in the environment was presented by indicating sources of uranium emission and the possible routes of transfer to man. The biological alterations caused by uranium exposure were discussed, and finally, we presented results collected during our recent study. Some propositions on research to be done to advance the understanding of uranium occurrence in the environment were also given.