Answer :

brittanycandace
Radiation is used for X-rays, MRIS, any type of cancer killing. 
Too much of radiation can be a dangerous thing... you could end up dying from a lot of exposure. 
The radiation used is gamma radiation. It causes a problem for staff/workers as it's highly penetrating meaning it can penetrate (go through) almost anything . The staff/workers will have a lot of exposure to this gamma radiation and too much exposure allows the radiation to kill cells, even the useful ones.