Regardign radioactivity and the time delay to detect.. well you basically must look for it.. it doe snot come out ina nomral test. You need to know that first, you ahve a poisoned patient.. and then guess that radioactivity can be the case...
"Radioactivity", but not Polonium - radioactive thallium - was mentioned much earlier than this weekend. How much time does one need to check out urine for a pretty strong alpha radiation?