Marie & Pierre Curie’s belongings: Even after more than 120 years, why everything Nobel Prize-winning couple touched is still kept in lead-lined boxes
Why are Marie Curie’s notebooks still radioactive?
Marie Curie’s notebooks were contaminated with radium-226, a radioactive element that she and Pierre Curie isolated after years of painstaking research.
According to the International Atomic Energy Agency (IAEA), the half-life of radium-226 is approximately 1,600 years. Half-life is the time it takes for half of the radioactive atoms in a substance to decay to a more stable form.
Because only a small fraction of the time had passed since Curie used the notebooks between 1899 and 1902, the notebooks remain measurably radioactive today.
As a result, the Bibliothèque Nationale de France stores manuscripts in lead-lined containers and researchers are required to wear protective equipment before examining them.
Marie Curie and Pierre Curie spent years isolating radium
The discovery of radium was far from easy. Working in an abandoned shed on Rue Lhomond in Paris, Marie and Pierre Curie processed approximately eight tons of pitchblende, a uranium-rich mineral, for almost four years.
Their laboratories lacked proper ventilation, temperature control, or modern safety equipment. Marie later recalled the physically demanding process: “I had to spend a whole day stirring a boiling mass with an iron rod almost as big as me. By the end of the day, I would collapse from exhaustion.”
Through thousands of rounds of chemical separation and crystallization, the pair eventually isolated just one-tenth of a gram of radium chloride.
Makeshift laboratory where history was written
The Curies conducted their research in a once-abandoned examination room behind the Municipal School of Industrial Physics and Chemistry.
The building had a leaky glass roof, no smoke extraction system and poor insulation.
While the temperatures inside became unbearable during the summer months, the fingers of the researchers who mixed the boiling chemical mixtures became numb during the winter months.
Despite the difficult conditions, the Curies believed that pitchblende contained an unknown radioactive element because it gave off more radiation than uranium alone could account for.
This observation eventually led to the discovery of polonium and radium.
The hidden dangers of radium are not fully understood
Although the Curies realized that radium could burn skin and damage tissue, scientists at the time did not fully understand the long-term health risks of ionizing radiation.
Pierre Curie even deliberately placed radium in his arm to observe the effects of radiation burns.
Marie frequently carried radium samples in her laboratory and kept some in her desk drawers at home.
The couple was amazed by the bright blue light emitted by radium.
They later described these evenings as follows: “The most beautiful and happiest of our lives.”
But long-term exposure eventually came at a devastating cost.
Marie Curie died in 1934 at the age of 66 from aplastic anemia, a disease widely linked to long-term radiation exposure. His daughter Irène Joliot-Curie, who also worked with radioactive materials, later died of leukemia.
Why are Marie Curie’s belongings still preserved today?
Radioactive contamination extends far beyond Curie’s notebooks. Many of his personal belongings, including laboratory notebooks, furniture, cookbooks and other items, continue to emit measurable radiation and are carefully stored, according to the Musée Curie in Paris.
When Marie Curie’s body was transferred to the Panthéon in Paris in 1995, officials placed her coffin in a lead liner because her remains still gave off detectable radiation.
Researchers who visit archives containing their work continue to follow strict security procedures.
Marie Curie changed science forever
Marie Curie’s discoveries transformed modern physics, chemistry and medicine. She coined the term “radioactivity” and became the first woman to receive a Nobel Prize.
In 1903, he shared the Nobel Prize in Physics with Pierre Curie and Henri Becquerel for their pioneering work on radioactivity.
He made history again by winning the Nobel Prize in Chemistry in 1911 for isolating radium and discovering polonium.
He remains the only person to receive Nobel Prizes in two different sciences.
Founded through his pioneering work, the Institut Curie remains one of the world’s leading centers for cancer research.
Scientific studies confirm radium’s long-lived nature
Studies by organizations such as the International Atomic Energy Agency (IAEA) and the US Centers for Disease Control and Prevention (CDC) explain why radium pollution has continued for centuries.
Radium-226 continuously emits ionizing radiation as it slowly decays into other radioactive elements, including radon gas.
Because only 120 years have passed since Marie Curie used her notebooks, scientists estimate that more than 90 percent of the original radioactivity remains.
This explains why manuscripts continue to require special treatment more than a century after they were written.
Marie Curie’s notebooks remain one of science’s most extraordinary works
There are few scientific documents that show the lasting impact of the discovery, like Marie Curie’s notebooks.
They preserve not only a handwritten record of one of history’s greatest scientific breakthroughs, but also physical traces of what transformed modern science.
Even though more than 120 years have passed, anyone who wants to read these pages still needs to take precautions against the invisible force that is changing the world.
Inputs from TOI
