I just found out that some watch faces and hands were painted with radium in the early 1900’s, to make them glow in the dark. According to a thread I found at the National Association of Watch and Clock Collectors, another on eBay, and an Australian government website, the radium is not a problem so long as it’s not ingested. The Radium Girls, who suffered radiation poisoning while painting watches in the early 1900s, handled thousands of watch parts, licked their brushes to keep them in shape, and painted their teeth, nails and faces with radium paint, for fun.
In my Steampunk pieces, I rarely use watch faces or hands, and when I do, they are often coated with resin, which would keep the paint from flaking off and being accidentally ingested. Most of the time, I use gears, bridges and other internal parts, combined with new materials, and these parts have no known association with radioactivity. I have never noticed any of my materials glowing in the dark, but just to be on the safe side, I will avoid using any watch faces and hands of unknown origin, in the future.
I do want to make it clear that, regardless of my precautions, I have no way to 100% guarantee the condition of any vintage, recycled or found parts, in regards to radioactivity, or to lead, nickel, aluminum or any other content. Steampunk, found art and jewelry items which contain vintage or recycled parts will be clearly described as such, in the item description.