Why Did They Line Marie Curie’s Coffin with Lead?

Workers lined Marie Curie’s coffin with lead to contain the radioactivity emitted by her remains, a precaution they took during her burial in 1934.

When authorities exhumed her grave in 1995, they discovered this detail, revealing that someone understood the risks involved with her exposure to radium and polonium—elements she discovered.

When they moved her body to the Panthéon in Paris in 1995, they lined her coffin with 2.5 millimeters of lead to protect people from radiation.

Because a half-life means it takes 1,600 years for half of the radioactive material to decay, her remains and contaminated personal items (like her laboratory notebooks stored at the Bibliothèque Nationale de France) will stay hazardous until around the year 3500.

Doctors determined that Curie died from aplastic pernicious anemia, likely caused by her prolonged contact with radioactive materials, and concerns lingered about the safety of disturbing her grave after over 60 years. Radium chemically behaves like calcium, meaning it accumulated inside Marie Curie’s bones and tissues during her decades of pioneering research.

Prior to the exhumation, the French radiation protection agency prepared for potential hazards, equipping the team with protective clothing and monitoring equipment. As they opened the coffin, radiation readings confirmed their fears: Curie remained radioactive more than six decades after her death. The lead lining, initially unknown to the public, effectively mitigated the risk of radiation exposure.

This finding highlighted the enduring nature of radium’s half-life, as Curie’s remains and personal belongings are expected to remain hazardous for another 1,500 years.

Ironically, although she won two Nobel Prizes for her groundbreaking research on radioactivity—transforming fields such as medicine and physics—Curie’s own legacy prevents people from safely handling her body even today.

Marie Curie’s remains and belongings will remain significantly radioactive for roughly 1,500 more years due to the presence of radium-226, which has a half-life of about 1,600 years.

Content for this question contributed by Sam Kruger, resident of Santa Cruz, Santa Cruz County, California, USA