Element 88 in our International Year of the Periodic Table series is radium. Radium is highly radioactive, but the dangers of radiation were only fully understood after it had been used for a number of years in consumer products.

Radium was one of the elements discovered by Marie Curie along with her husband, Pierre. It’s a highly radioactive metal which occurs naturally as a consequence of the radioactive decay of uranium and thorium. The curie, a historical unit of radioactivity, is based on the radioactivity of one of radium’s isotopes, Ra-226.

Radium was discovered at a time when the dangers of radioactivity were not known. Consequently, it was used in a number of applications in consumer products. Glow-in-the-dark watch dials used radium paint, and it was also used for supposed health benefits in products including toothpaste and even chocolate.

Some of these products posed clear risks to the public, while others endangered those who produced them. The case of the radium girls, the women who were tasked with painting watch dials with luminous radium paint, is well-documented. These women suffered from the horrendous effects of radium poisoning as a result of their work and had to fight long legal battles for the companies that employed them to admit responsibility.

Once the dangers of radiation were more widely appreciated, use of radium in consumer products ceased. Today, the element has few practical uses, and is mainly used as a radiation source for medical applications.

Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.