These studies characterise the effects of internal chronic contamination (right column of Figure 1) at low concentrations of radionuclides on major body functions:
- major body metabolism (cholesterol, xenobiotics, vitamin D, steroid hormones and iron) ;
- central functions (sleep, anxiety, memory) ;
- immunity ;
- cardiovascular system ;
- reproductive function(gametogenesis).
In order to understand the effects described, additional studies are carried out at the same time :
- Measurement of the quantity of radionuclides in the tissues and their location within the cell. Under these exposure conditions, these measurements can identify the organs of predilection for radionuclide accumulation, determine the relationship between the effects observed and the quantity and/or location of the radionuclides present in the organs as well as estimate the dose received by each of these organs.
- Identification of the mechanisms responsible for the biological effects observed. Studies to date have focused on the transporters involved in the uptake of uranium into kidney cells, the proteins binding uranium following in-vivo contamination, the role of uranium-mediated oxidative stress on the central nervous system and on the specific characteristics of the effects induced by enriched uranium compared to those generated by depleted uranium.