Just working in a hospital though not necessarily unsafe exposes you to more germs and radiation than the average person, that doesn't necessarily mean it's dangerous though.
It's not safe to be exposed to radioactive particals at anytime. Radiology departments however have very strict safety guidelines and rules. All radiology technicians are required to wear a Geiger counter which measures radiation exposure and radiation levels. If your tag shows you were exposed you are immediately sent home and not allowed to return to work until your levels return to normal.
Radiation is a very dangerous thing however as long as equipment is properly maintained and you and your coworkers follow rules and best practices you should be very safe.