Marie Curie

Working in a converted shed at the School of Physics and Chemistry in Paris, Marie Curie and her husband Pierre set out in the late 1890s to investigate a strange property Henri Becquerel had noticed in uranium salts, the ability to fog a photographic plate through paper without any external source of energy. Marie Curie coined the word radioactivity for the phenomenon and showed, through careful measurement, that it was a property of the atom itself rather than of any chemical reaction. Processing tons of a uranium ore called pitchblende by hand, the Curies isolated two new elements far more radioactive than uranium: polonium, which Marie named for her native Poland, and radium, in 1898.

In 1903 the Curies shared the Nobel Prize in Physics with Becquerel for their work on radioactivity, the Nobel committee's initial shortlist did not include Marie at all, she was added only after Pierre insisted, in writing, that the recognition belonged to both of them. She became the first woman to win a Nobel Prize. Pierre died in a street accident in 1906, and Marie took over his professorship at the Sorbonne, becoming its first female professor. In 1911 she won a second Nobel Prize, this time in Chemistry, for isolating pure radium metal and determining its atomic weight, the first person of either sex to win two Nobel Prizes and, to date, the only person to win them in two different sciences.

The same radioactivity that made Marie Curie famous also killed her. She and her colleagues worked for decades with almost no protection, carrying test tubes of radioactive isotopes in her pockets and storing them in her desk drawer, and she remarked in her own notes on the pretty blue-green light the materials gave off in the dark, unaware of what steady exposure to that light was costing her. She died in 1934 of aplastic anemia, a bone marrow failure now understood to be a direct consequence of decades of radiation exposure, her cataracts, a well documented ailment of her later years, are attributed to the same cause.

Curie's exposure was not confined to the laboratory. During the First World War she developed mobile radiography units, small X-ray machines mounted in vehicles that could be driven to field hospitals near the front, nicknamed petites Curies, and trained young women to operate them, the units are credited with helping treat more than a million wounded soldiers by letting surgeons locate bullets and shrapnel without moving the patient. She drove some of the units herself and received no special protective equipment for the work, at a time when the dangers of radiation exposure were only beginning to be understood.

Her legacy is still, literally, radioactive. Curie's laboratory notebooks, and even her cookbook, remain contaminated with radium at levels that will persist for another millennium and more, and they are kept at the Bibliotheque Nationale de France in lead-lined boxes, visitors who wish to consult them must sign a waiver and wear protective clothing. Her own body was buried in a lead-lined coffin when she was reinterred at the Pantheon in Paris in 1995, the first woman honored there for her own achievements rather than as the wife of a man interred beside her.