MICRODOSIMETRY OF TRITIUM

Microdosimetric aspects of tritium radiotoxicity are discussed. The le vel of coincidence of tritium locations and of radiation-sensitive sit es does not appear to be decisive for relative effectiveness of tritiu m exposures. The actual target structure and dimensions seem to be of more importance. Particularly efficient germ cell destruction by chron ic exposures to tritiated water is unlikely to be explainable on the b asis of classical principles of microdosimetry. The phenomenological a pproach of investigating biological response functions may be a useful alternative for the interpretation of unexpected experimental results , especially when combined with bidimensional microdosimetry. The latt er allows for clustering of nanometer sites within a target of cellula r dimensions.