Sealed radioactive sources need to be kept under regulatory control during their entire
life time until they are safely disposed of or have decayed to accepted clearance levels [3].
SRS that are no longer in use present significant risks both in developed and in developing
countries. In the former a large number of SRSs are under good control, while in the latter the
control may be poor. However, it is worth noting that not only the adequacy of control but it is
also the number of sources that influence the risk