Irène Joliot-Curie’s work on radioactive isotopes forms the basis of much biomedical research and cancer treatment today.
A scientific childhood
Irène Curie was born on 12 September 1897 in Paris, to Marie Curie (another of our 175 Faces of Chemistry) and Pierre Curie, a French physicist. With two great scientists as parents, it seems almost inevitable that Irène would become a renowned scientist and indeed she did, although her sister, Ève, took a less scientific path. Irène’s interest in science started with informal classes in a teaching cooperative arranged by her mother for her daughters and the children of other professors from the Sorbonne, such as the mathematician Paul Langevin and chemist, Jean Baptiste Perrin. When the cooperative ceased, Irène started formal education at Collège Sévigné, where she studied for her baccalauréat.
During the First World War, Irène worked with her mother in the radiography corps at the front, using the new X-ray equipment Marie to treat soldiers. After the war, she joined the Institut du Radium in Paris, again working as assistant to her mother. In October 1925, the mother and daughter team were joined by a new assistant – Frédéric Joliot, a first-class engineering graduate who had accepted a research scholarship following his military service. While Irène worked on her doctorate on the alpha rays of polonium, she trained Frédéric in laboratory techniques and they discovered many shared interests, marrying a year later in October 1926. Two children, Hélène and Pierre, followed in 1927 and 1932.
Building on the work of Irène’s mother, the Joliot-Curies, who signed their work jointly from 1928, bombarded elements with alpha particles emitted from the polonium discovered by Irène's parents. This resulted in the production of radioactive isotopes of the usually stable elements nitrogen, phosphorus and aluminium. As these unstable atoms broke down after the bombardment stopped, Irène and Frédéric noted the production of neutrons and positrons, evidence that radioactive isotopes of known elements had been created. The artificially-produced radioactive isotopes, which were revealed to the Academy of Sciences in 1934, were useful to follow chemical changes and physiological processes, such as absorption of radioiodine by the thyroid gland, in biomedical research and also for the treatment of cancer.
In a completely different field, their work was an important step towards releasing energy from atoms, forming the basis for the techniques later used to cause the nuclear fission of uranium. In 1935, a year after Marie Curie died of leukaemia that developed due to her own research, Irène and Frédéric were jointly awarded the Nobel Prize for chemistry “in recognition of their synthesis of new radioactive elements”. With this award, the Curies became, and remain to this day, the family with the most Nobel laureates to date, with one each in physics for Irène, Frédéric and Pierre, and two for Marie in physics and chemistry.
The Joliot-Curies subsequently received many degrees and accolades, but Irène took time out to raise their children. As the children grew older, she developed an interest in socialism and politics, including the suffragette movement, and she became an elected professor at the Sorbonne in 1937.
During the Second World War, Irène contracted tuberculosis and spent several years convalescing in Switzerland, away from her husband and children in occupied France. Occasional visits to see them resulted in detention by German troops, which led her to take the children back to Switzerland in 1944. After several operations in the 1950s, her health deteriorated further, yet she still drew up plans for a new nuclear physics laboratory at the Université d’Orsay, south of Paris, so that scientists could work with large particle accelerators in more spacious surroundings than were currently available in Paris. Sadly, like her mother, Irène died of leukaemia related to her exposure of polonium, succumbing on 17 March 1956 at the Curie Hospital in Paris, aged just 58 years. Frédéric died two years later.
Irène’s contribution to science was recognised in 1991 when the Joliot-Curie crater on Venus was named after her, and the Curie and Joliot-Curie legacy continues to this day, with Irène’s children both esteemed scientists – Hélène Langevin-Joliot a nuclear physicist and Pierre Joliot-Curie a noted biologist and researcher for the French National Centre for Scientific Research.
The Royal Society of Chemistry's annual Joliot-Curie Conference on diversity in science is named in honour of Irène and Frédéric.
Words by Sarah-Jane Cousins
Published June 2014