A few questions need to be asked, which were not in the article:
What is the mass of the radioatctive material in the device?
What is the age of the radioative material in the device?
Cobalt 60 has a half life of 5.3 years, so if these are older devices the amount of radioactive material would be much less.
The only threat from this material is in use in a dirty bomb, or as a contaminant in either air, soil or water.
You can't make a bomb out of it, a fissile bomb that is.