The Sad and Tragic Story of Francium

Francium is one of the rarest naturally occurring elements on Earth.  All isotopes of francium are radioactive; the most stable has a half-life of only 22 minutes.  (“Half-life” is the time it takes for half of a sample to break down.)  Experts believe that no more than 15 grams of francium (less than an ounce) exist throughout the world.

Francium was also one of the last naturally occurring elements to be discovered.  By the 1930s, only three boxes in the periodic table remained empty – atomic numbers 43, 85 and 87.  No. 87 was finally discovered in 1939 by 29-year-old Marguerite Perey at the Curie Radium Institute in Paris, who named it after France.

“It is my great hope that francium will be useful for the establishment of an early diagnosis of cancer,” Perey wrote.  At the time, radiation was viewed as a new scientific marvel.  For instance, radium was being used in face creams, tonics and candy.  Doctors sewed capsules of it into the surgical wounds of cancer patients.  Women painted it onto their teeth to make them glow.

But troubling effects had begun to occur.  Madame Marie Curie, Perey’s mentor who first coined the word “radioactivity,” had died from long-term radiation exposure five years before Perey’s discovery.  Women who worked with radium paint developed widespread bone cancer.  Contrary to being a cure-all for cancer, francium and other radioactive elements were actually highly toxic carcinogens.

In 1962, Perey became the first woman elected to the French Académie des Sciences (even Marie Curie was not given that honor).  But she spent the last 15 years of her life battling pervasive and crippling bone cancer before finally succumbing to it in 1975.

Today, scientists continue to discover more about the causes and treatments for cancer.  We now know that radiation emissions cause DNA mutations that can lead to cancer.  Dako, an Agilent Technologies Company, is committed to help improve cancer survival by improving diagnostics.  Dako partners with top-tier pharmaceutical companies to develop companion diagnostic tests, which are used to guide individualized treatment for patients.


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