 If such a source is abused, then the cobalt metal fragments do not tend to dissolve in water or become very mobile.If a cobalt or iridium source is lost at a ferrous metal scrapyard then it is often the case that the source will enter a furnace, the radioactive metal will melt and contaminate the steel from this furnace.In Mexico, some buildings have been demolished because of the level of cobalt-60 in the steel used to make them.