Topic 1 - History of Radioactivity

Relevant Dates in Radiation Protection

1895
- Roentgen discovers X-rays
- X-ray injuries predated Roentgen’s discovery (Crooke's tubes developed in 1875)
1896
- Becquerel discovers radioactivity
- X-rays were used to treat cancer
1897
- Thomson measures charge to mass ratio of electrons
- First volume of American X-ray Journal (1897) listed 69 cases of x-ray injury
- Early experimental biologists discovered ionizing radiation caused lenticular cataracts in exposed animals.
- Interaction between electric fields of beta and orbital electrons
1898
- The Curies isolate polonium & radium
1899
- Rutherford identifies “alpha” and “beta” radiatio from uranium
1900
- Villard discovers gamma rays
- Thomson presents “plum pudding” model of the atom
1911
- Rutherford discovers the atomic nucleus
1911
- Georg von Hevessy conceives using radio tracers.
- Nobel Prize in 1943
1913
- Bohr presents theory of H atom
1917
- Rutherford produces first artificial nuclear transformation
1927
- Production of genetic mutations by exposure to X rays was first reported by H.J. Muller
1942
- First nuclear chain reaction
1945
- First atomic bomb

Medical Fads appeared in the 1920s - 1940s:
- Radium was ingested and injected in attempts to cure “ills”
- Devices were sold for home use to add radon to drinking water

Early experience demonstrated that ionizing radiation could produce sterility, damage tissues, and cause death
Research since 1942 has focused on mechanisms of radiation injury
Studies with animals
Studies with humans:
- misuses of radium,
- bomb survivors,
- miners,
- accidents,
- beneficial radiation therapies