<P> Her achievements included the development of the theory of radioactivity (a term that she coined), techniques for isolating radioactive isotopes, and the discovery of two elements, polonium and radium . Under her direction, the world's first studies were conducted into the treatment of neoplasms, using radioactive isotopes . She founded the Curie Institutes in Paris and in Warsaw, which remain major centres of medical research today . During World War I, she developed mobile radiography units to provide X-ray services to field hospitals . </P> <P> While a French citizen, Marie Skłodowska Curie, who used both surnames, never lost her sense of Polish identity . She taught her daughters the Polish language and took them on visits to Poland . She named the first chemical element that she discovered‍--‌polonium, which she isolated in 1898‍--‌after her native country . </P> <P> Marie Curie died in 1934, aged 66, at a sanatorium in Sancellemoz (Haute - Savoie), France, of aplastic anemia from exposure to radiation in the course of her scientific research and in the course of her radiological work at field hospitals during World War I . </P> <P> Maria Skłodowska was born in Warsaw, in the Russian partition of Poland, on 7 November 1867, the fifth and youngest child of well - known teachers Bronisława, née Boguska, and Władysław Skłodowski . The elder siblings of Maria (nicknamed Mania) were Zofia (born 1862, nicknamed Zosia), Józef (born 1863, nicknamed Józio), Bronisława (born 1865, nicknamed Bronia) and Helena (born 1866, nicknamed Hela). </P>

Which scientist lost their life in consequence of their discovery