Why did some users of radium-containing products die years after using them?

Users of radium-containing products died years after exposure because radium is a radioactive element that, when ingested or absorbed, acts similarly to calcium in the human body. Because of this chemical similarity, the body deposits radium directly into the bones.123

Once stored in the skeletal system, radium emits alpha particles that continuously irradiate the surrounding tissue from within. This internal exposure causes severe, long-term damage, including:12

• Bone Marrow Destruction: The radiation interferes with the production of red blood cells, leading to anemia and leukemia.23
• Tissue Necrosis and Cancer: The radiation causes painful ulcers, bone disintegration, and the development of bone cancer.142

In the case of the "Radium Girls," workers ingested the substance through a practice called "lip-pointing," where they used their lips to shape paintbrushes coated with radium-based luminescent paint. Because the damage is internal and progressive, symptoms often did not manifest until years after the initial exposure, at which point the radioactive poisoning had already caused irreversible systemic harm.124