In the early 20th century, glow-in-the-dark watches and clocks were popular and commonplace. They were often given as gifts to British and American servicemen, as well. The unique glow was created by painting radium on the dials, a compound which breaks down into radon – a colorless, odorless gas that remains present in the environment. It’s considered safe at certain levels, but a recent study out of the University of Northampton and Kingston University has discovered that the watches and clocks can emit the carcinogenic, radioactive gas at a rate up to 12 times higher than the maximum “safe” level.
Researchers looked at 30 different specimens as part of an international report on radon exposure, and used radiation detectors to test the samples. They found the watches produced 13,400 becquerels per meter cubed – public health organizations have determined that indoor spaces should aim for no more than 100 becquerels per meter cubed to be safe.
“These results show that the radon emitted from individual watches can potentially pose a serious cancer risk,” one of the researches said in a statement. “This is of concern because, in addition to military watches being particularly prized by collectors, many individual radium-dial watches are kept as mementos by ex-servicemen and their descendants.”
There is an established link between radon and lung cancer.
If you or someone in your family has one of these watches, make sure to research and practice proper handling and storage techniques. And if you need more convincing, check out what happened to the poor girls who helped manufacture the things back in the day – it’s not pretty.