There is a huge difference between just being near radioactive materials that are giving off radiation, and actually being contaminated by them. Many deadly radioactive materials have radiation that would be stopped by a piece of paper.
Radioactive fallout carried in the wind, as happened with the Chernobyl nuclear accident, can have elements like Strontium90 end up in the grass that gets eaten by cows. Folk drink the milk and it ends up in their bones because Strontium can chemically replace Calcium. There, the radiation knocks bits out of the cells DNA, messing up the reproducing, and causing cancers like leukemia. Even now, there are parts of the UK where such farming is not permitted. Yet to look at, Strontium is a silvery-grey metal, very like Calcium, and they both oxidize into white chalk.
Most radioactive substances are not seen pure. Instead, they come mixed up as oxides or ores. A few cause blue glows when put in water. (Called Cherenkov Effect) See a http://en.wikipedia.org/wiki/Cherenkov_radiation" know that many radioactive things are in fact glowing brightly. Its just that the wavelength involved is not a visible one. Gamma radiation from Cobalt 60, used to treat cancers, is like and unseen light. It is deadly! it is just and urban myth that radioactive things visibly glow. Radioactive things do not normally glow visibly by themselves. They look exactly like their non-radioactive versions.
Glow-in-the-dark clock faces and pointers have in the past been made with phosphrescent paint mixed with Radium. This is no longer done, but many people got very ill making them. Many gemstones like rubies and sapphires are treated with radiation to improve their colours, and have to be kept for years in lead-lined safes until they become safe to handle.