The discoverers of radioactivity and its potential uses are renowned, e.g. Madame Curie and Roentgen.

When was it discovered that human exposure to ionizing radiation including radioactive isotopes often caused leukemia, other cancers and highly malignant cell growth in general? What other aspects of this realization are documented, specifically, how it was discovered and by whom?

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    $\begingroup$ Excellent question - and something that is sometimes overlooked. $\endgroup$
    – user22
    Nov 5, 2014 at 7:15

1 Answer 1


Clark University have published a very comprehensive document Health Risks of Ionizing Radiation: An Overview of Epidemiological Studies, (Russ et al. 2006). In their introductory chapter they state that the harmful effects of ionising radiation, in this case, x-rays, were observed very quickly after their discovery, specifically,

X-rays were first discovered in late 1895 and dangers associated with exposure became apparent very quickly. In 1896 the first injuries due to x-ray exposure were recorded and in 1904 Thomas Edison’s assistant Clarence Dally was the first person recorded to have died as a result of x-ray exposure.

More detail of this is provided in the article A Brief History of Radiation Protection Standards (Inkret et al. 1995),

In July 1896, only one month after the discovery of x rays, a severe case of x-ray-induced dermatitis was published, and in 1902, the first dose limit of about 10 rad per day (or 3000 rad per year), was recommended.

This limit was not based on any biological limit, but on the, then, limit of detection. But, it was a start. The link between radiation and cancer came about in 1903:

By 1903, animal studies had shown that x rays could produce cancer and kill living tissue and that the organs most vulnerable to radiation damage were the skin, the blood-forming organs, and the reproductive organs.

and specifically for the element radium (from Russ et al. 2006):

Radium was discovered in 1898 and its use in medicine also spread very quickly. In the 1920s, sickness and death in watch dial painters, who ingested small amounts of radium in their work, taught scientists and doctors that internal exposure to radium could be harmful.

Around the same time, (from Inkert et al. 1995), standards were being formalised and developed particularly in reference to 'tolerance doses', with:

A tolerance dose was "assumed to be a radiation dose to which the body can be subjected without production of harmful effects.” Mutscheller presented his recommendation in a paper entitled, “Physical Standards of Protection Against Roentgen Ray Dangers,” which was published in 1925. Quite fortuitously, F. M. Sievert arrived at about the same limits using a similar approach.

A Sievert is now a unit of ionising radiation dosage.

Leading to the first internationally recognised radiation safety guidelines being published in 1928, and the founding of the International Commission on Radiological Protection.


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