The Dark Side of Luminous Watches: How Radioactive Materials Can Harm Your Health
For vintage watch collectors until well in the 60ties, the luminous dials of wrist watches and alarm clocks were marked with luminous paints containing Radium (Ra-226) or Promethium (Pm-147). These kind of watches are no longer manufactured today. This is not due to the radiation exposure to the persons wearing the watches but because of the radiological risk for the persons manufacturing them.
During the First World War soldiers could upgrade their pocket watch or wristwatch by applying on few dots of radium paint on the dial, next to the hour numerals. They could also replace the hands of their watch with radium-coated hands.
The women who painted radium hands and dials were known as the "Radium Girls". They were female factory workers who contracted radiation poisoning from ingesting radium paint, which they used to make the dials glow in the dark. The radium paint caused them to suffer from various health problems, such as anemia, bone fractures, necrosis of the jaw, and cancer. Their story has been told in books, films, plays, and documentaries.
If you have a radium watch, you should store it in a well-ventilated area and avoid wearing it or opening it. You should also check the radon levels in your home or workplace to ensure they are within safe limits. Wearing a radium watch as a daily can pose serious health risks and is not advised!
These early radioactive substances were replaced by Tritium well until the mid-90s. Some alternatives to radium for making luminous watches are:
Tritium, which is another radioactive element but with lower radiation and longer half-life than radium. It is still used in some watches today.
Promethium, which also emits low-level radiation but has a weaker glow than tritium. It was used in some watches in the 1960s and 1970s.
Strontium aluminate, which is a non-radioactive compound that absorbs light and re-emits it in the dark. It is also known as Super-LumiNova and is widely used in modern watches.
This article is not written to start chaos and sound the alarm but being aware makes it easier to handle the danger if there is one, be well Crunchers! 🍻
In addition to my thirst for learning, I have two captivating hobbies that allow me to express my diverse interests: collecting vinyl and watches. With a keen ear for music, I immerse myself in the ri...
I have a couple of vintage watches with Radium lume. To be honest I don't think there is a danger from wearing them. The main issue is ingesting radioactive material or it coming in direct contact with the skin. Radon gas can be an issue but I believe that's mainly if you have stored a large amount of Radium painted dial & hands in one location. That said I wouldn't wear a watch with Radium where the luminous material is crumbling off or where it has a cracked crystal.
As alpha emitters there is no risk. Alpha particles cant pass thru a single sheet of paper let alone human skin. The injestion of the radioactive luminous paint from licking their painting brushes was the very crux of the problem back then. There is no radioactive bogeyman. You get more radiation exposure flying in a plane cross country than wearing a vintage watch every day.
Radium-226 predominately emits alpha (~95%) and some gamma radiation.. alpha radiation ionizes anything around it and therefore can’t travel more than few mm in air and can be blocked by anything around it, for eg. Solid surface of watch.. The radiation poisoning was a concern for the workers who used to paint the dial during the era where there was a limited knowledge for radiobiology with regards to most isotopes. The byproduct is radon gas and which also occurs naturally. A ventilated area is a quick solution for that.
Also half-life is 1600 years, so it will outlast pretty much anything (tritium is only 12 years).
Pm-147 on the other hand has a half-life of 2.6 years.. most watches made in 60s would be non-radioactive at this point.
They stoppped using Ra-226 and Pm-147 dials markers for multiple reasons, viz, worker safety, disposal cost of a long lived isotopes and general scare about radioisotopes, lack of sales and availability of many alternatives.
#ball still makes watches that use Tritium gas sealed tubes that reacts with the chemical and emits light (glows in the dark). Low-energy beta that is blocked by the plastic tubes and other materials around it.
Enjoy your watches if you have them..🤓🥸
I love my tritium... It makes me feel more... active!