Curie visited Poland for the last time in early 1934.[10][62] A few months later, on 4 July 1934, she died at the Sancellemoz Sanatorium in Passy, in Haute-Savoie, from aplastic anemia believed to have been contracted from her long-term exposure to radiation.[43][63] The damaging effects of ionising radiation were not known at the time of her work, which had been carried out without the safety measures later developed.[62] She had carried test tubes containing radioactive isotopes in her pocket,[64] and she stored them in her desk drawer, remarking on the faint light that the substances gave off in the dark.[65] Curie was also exposed to X-rays from unshielded equipment while serving as a radiologist in field hospitals during the war.[50] Although her many decades of exposure to radiation caused chronic illnesses (including near blindness due to cataracts) and ultimately her death, she never really acknowledged the health risks of radiation exposure.[66]
She was interred at the cemetery in Sceaux, alongside her husband Pierre.[43] Sixty years later, in 1995, in honour of their achievements, the remains of both were transferred to the Panthéon, Paris. She became the first—and so far the only—woman to be honoured with interment in the Panthéon on her own merits.[59]
Because of their levels of radioactive contamination, her papers from the 1890s are considered too dangerous to handle.[67] Even her cookbook is highly radioactive.[67] Her papers are kept in lead-lined boxes, and those who wish to consult them must wear protective clothing.[67]
In her last year she worked on a book, Radioactivity, which was published posthumously in 1935.[62]