Radium, Tritium and other radioactive activators on watch dials and hands. Radium and Tritium contained as activators in luminous paint on watch dials and hands, besides other radioactive materials, are subject to never ending discussions amongst vintage watch collectors, especially those, who own lumed timepieces from earlier periods or are even working on them. Opinions differ from what concerns eventual health risks, not only amongst watch collectors, but also between professionals. Many ask themselves why those watches should still pose a threat to human health, whilst the 'glow' is long gone. True, the glow is gone - but not the radium (or many other radioactive substance used as an activator, as well as other substances following down the decay chain. The intention of this book is to give a general overview of radium- and tritium issues for the vintage watch collector interested in this subject. It is, in no way, addressing the physicists, chemists or nuclear scientists and will