[Waltham 16-a] Where do I store my Radium Dial Watch?

Hello, I am fairly new to Reddit so I don't know how to attach photos. Anyways, I just recently bought a ww2 issued Waltham pocket watch with a radium dial. I've been trying to research how to properly store such a watch. Most places say to not keep it in a closed container. I am wondering whether it be better to just keep out in the open air of my room or to keep it in a glass holder. If you have any suggestions I would love to hear them.