As the deleterious effects of radiation were yet unknown in the 20th century, the Curies conducted their research without any protection against radioactive substances. She was said to love the pretty blue-green light that the substances gave off in the dark, so she had carried test tubes containing radioactive isotopes in her pocket and stored them in her desk drawer. She was in poor health during her life, which was almost certainly caused by the considerable exposure to radiation.
Today, we are very well aware of the fact that radioactive radiation attacks our haematogen, the bone-marrow. Madame Curie died of leukaemia on 4th July 1934. She was interred at the cemetery in Sceaux, alongside her husband Pierre. In 1995, in honour of their achievements, the French transferred the remains of both to the Paris Pantheon.
The intensity of radioactivity to which the Curies were exposed to was so high that their laboratory apparatus, books and notes are still considered too dangerous to handle and are kept in lead-lined boxes.