Maria Salomea Skłodowska was a lonely, steadfast child, who devoured books, and was capable of surprising her family and teachers with her mnemonic abilities. As a teenager, being determined and rational, she joined the “Flying University”, a clandestine association that nurtured positivism, against Tsarist oppression in Poland. At the age of eighteen she made an agreement with her sister Bronisława: Maria was to work as a housekeeper, three hours by train, four by sleigh, away from Warsaw, in order to help her sister in her medicine studies and, once she graduated, she would return the favour. And so, six years later, Maria moved to her sister’s home in Paris, studied at the Sorbonne, and became Marie Skłodowska. Within a few years, she won, with her husband Pierre Curie, the Nobel Prize for Physics and became the first woman to hold a professorship at Sorbonne University. She then won the Nobel Prize for Chemistry and is still known to be the only person who has been awarded two Nobel Prizes in different scientific fields.
Radioactivity is the phenomenon by which an atomic nucleus emits particles, disintegrating itself, in order to transmute into a more stable nucleus.
Each atom consists of a nucleus of protons and neutrons around which electrons orbit. Protons in the nucleus, positively charged, should electrically repel each other and therefore cause the nucleus to explode. Then why do they remain cohesive in the nucleus? Because, in addition to the electromagnetic force, there is another force, called strong force, that keeps them together and “glues” them to neutrons. The role of neutrons is to decrease electric repulsion between protons and “cement” them together. However, when there are too many neutrons or protons, the atom is unstable and decays radioactively emitting part of its protons and/or neutrons, and transforming itself into a lighter, more stable atom.
Within a few years, she won, with her husband, the Nobel Prize for Physics, she became the first woman to hold a professorship at Sorbonne University and she then won the Nobel Prize for Chemistry.
Marie Curie began to devote herself to the study of radioactivity towards the end of 19th century, when the word “radioactivity” had not yet been coined – it was she who later proposed it. Until then, Antoine H. Becquerel had detected spontaneous radioactivity in only one element, uranium. The Polish scientist began building an instrument capable of accurately measuring the amount of radiation of uranium, by using the studies of her husband Pierre. Subsequently she demonstrated the emission of radiation also from thorium. She then moved to the study of pitchblende, a mineral rich in natural uranium. Together with her husband, she realised that some samples of pitchblende emitted more radiation than pure uranium would have done: a new radioactive element must have been hidden inside the material.
The Curie couple dedicated themselves to the systematic analysis of tons of pitchblende, in a laboratory/shed next to which a workshop was built in order to prepare the samples to be studied. Breaking down pitchblende, liquefying it, filtering it, purifying it, measuring and analysing it became the daily routine of the Curies, who made it their life a mission, dedicating their entire days to their work. Thanks to this tireless effort, in 1898 they were able to isolate the new element 330 times more radioactive than uranium, which they called “polonium” to bring honour to Skłodowska’s Polish origins. Soon after, they understood that in infinitesimal quantities another radioactive element must have been present, which they named “radium”. To understand the hard work behind these studies, just consider that in four years, using 2.8 tons of pitchblende, the Curies were able to obtain a total of 100 milligrams of radium chloride.
The Curies’ dedication, alongside the discovery of the radioactivity of uranium by Antoine H. Becquerel, was rewarded with the Nobel Prize in Physics in 1903. In 1906, after the accidental death of her husband, Marie Curie began teaching at the Sorbonne and two years later she officially obtained professorship and was the first female professor at the Parisian university. In 1911 she obtained her second Nobel Prize, this time for Chemistry. Apart from holding down a career, despite her husband’s death, she was also able to raise two daughters equally brilliant: the eldest, Irène also became a scientist and thanks to her studies on artificial radioactivity, together with her husband too, also won the Nobel Prize for Chemistry in 1935. Her second daughter, Ève, a writer and concert pianist, together with her husband received the Nobel Peace Prize awarded to UNICEF in 1965, an organization in Greece for which she was ambassador.
Beyond the academic and personal achievements of Marie Curie and her family, her studies gave birth to a real trend of radioactivity.
Even if radioactivity began to be used intelligently in medicine, particularly in tracers or as an experimental treatment for cancer, it is also true that to radioactive materials were unjustifiably attributed to beneficial properties. Real companies were born (American Radium Products Company, National Radium Company, Bailey Radium Laboratories, etc..) all specialised in the trade of radioactive gadgets, radioactive drinks, cosmetics, toothpastes, pillows, straps to be tied around the glands that they wanted to stimulate (thyroid, testicles, ovaries, etc.). Even the American Medical Association, to unmask possible fraudsters, began a sever control of radioactive products on the market, in order to eliminate those that did not actually guarantee the promised radioactivity.
It did not end well. The poisoning case of the radium girls, workers of the Radium Corporation who painted the dials of luminous watches with radioactive paint, thinning the brushes with their lips. This followed by the case of Eben Byers, industrialist, successful golfer and well-known playboy who drank bottles of a radioactive-containing substance for two years and died, his body literally falling apart. Both cases dampened the enthusiasm about radioactivity. Spontaneous bone and skull fractures, tooth loss, organ failure, brain abscesses and tissue necrosis were the most striking consequences of radioactive use/abuse in the roaring twenties.
Marie Curie herself had largely underestimated the impact of radioactivity on the human body. Both she and her husband used no protection whatsoever in handling the radioactive samples they studied. It was actually, she, herself who wrote that the two of them were fascinated by the shiny tubes of radium salt that they carried in their jacket pockets. She, on the other hand, died at the age of 66 of aplastic anaemia, a blood disease that originally was probably due to the radioactivity absorbed by her body.
After her death her house was turned into the headquarters of the Curie Foundation but many inhabitants of the neighbourhood, according to the newspaper Le Parisien, ended up unexplainably with cancer over the years. The rooms were cleansed only in 1991, a useful operation despite the time lost, to tell the truth, considering that radium remains radioactive for thousands of years. Indeed, even today the laboratory notes, manuscripts, cookbooks and other objects belonging to the Polish scientist are kept in specially sealed containers, which can be opened only if wearing a protective suit. Marie Curie Skłodowska, along with her husband Pierre, is buried in the Pantheon in Paris, and her grave is wrapped in lead, too.