A characterization of the radiation hardness of PbWO4 scintillators by
means of transmission measurements will be described. The gamma radia
tion induced changes in the absorption spectra of PbWO4 crystals undop
ed as well as doped with trivalent ions will be illustrated. The chara
cteristics of the room temperature recovery of the radiation induced c
olour centres in these crystals will be reported.