Radiation protection: Uranium diffusion through skin (SIMS)

Uranium contamination in skin

A & B: structural representation of skin, 40Ca+,
field of view 200 x 200 µm2 (A) and 100 x 100 µm2 (B)
C & D: superimposed ion images of 238U+ (red) and 40Ca+ (green).

Uranium is a radioactive heavy metal naturally present in earth crust. Internal contamination of nuclear workers by actinides such as uranium may occur either by inhalation, ingestion or penetration through wounds or intact skin, and the SIMS technique is used to assess uranium transfer through the skin. Experiments have been performed in order to characterize uranium bioaccumulation process at skin pig. The results suggest that the stratum corneum is a good defense barrier against the incorporation of the radionuclide into the skin, but can also constitute a reservoir for the diffusion of the radionuclide if no decontamination treatment is applied.

This research carried out by IRSN (France) research center has resulted in a patent, and a pharmaceutical laboratory currently sells a decontamination cream (Cevidra® Calixarene). Its performance is based on the active ingredient - carboxylic acid calixarene, a chelating agent with high affinity for U, Pu, Am, Th, Co, Cs and Sr which prevents the penetration of these radionuclides in the body and thus avoids their fixation on the target organs (kidneys, bones and liver).

Using the IMS 7f-GEO, mapping of major and trace species can be obtained at cell level in biological samples with a lateral resolution reaching ~0.5 μm. Other strengths of the instrument include its versatility (mass spectra, depth profiling analysis, etc.), high throughput, as well as high sensitivity resulting in low detection limits for several elements of interest including heavy metals such as uranium...

Courtesy of David Suhard, IMS 7f laboratory in IRSN Fontenay-aux-Roses (France).

Adapted from: A. Spagnul et al, European Journal of Pharmaceutics and Biopharmaceutics 79(2), 258–267 (2011), DOI 10.1016/j.ejpb.2011.05.004
See also S. Grives et al, Journal of Pharmaceutical Sciences 104(6), 2008-2017 (2015). DOI 10.1002/jps.24431