To dream about radiation, or to see others become sick from radiation in your dream, suggests that you need to get rid of something in your life that is causing you much sickness, stress or negativity.
This dream may also signal a part of yourself that needs to be healed, either physically or mentally. Perhaps you are indulging in too much self-pity, and need to stop feeling sorry for yourself. However, if you dreamed that you became sick from radiation, this is a warning that you are introducing something into your life that is harmful to your well-being.
This may be feelings of bitterness, jealousy or other bad feelings that are consuming you. Or, it could symbolize a person you have started to spend time with, who is very bad for you.