From 1920, the work of the Swedish medical physicist Rolf Sievert led to a better understanding and control of radiation, helped by the well-known Geiger counter which allowed detection of ionizing radiation. This instrument was named after Hans Geiger, who invented the principle in 1908, and Walther Müller, who collaborated with Geiger in developing the technique further in 1928 to produce a “Geiger-Müller tube” or G-M tube that could detect different types of radiation. To implement a culture of safety, it is necessary to know what you are looking for.
That same year, 1928, the International Commission on Radiological Protection (ICRP), an independent, international, non-governmental organization which aimed to provide recommendations and guidance on radiation protection, was founded during the second International Congress of Radiology in Stockholm. It was originally called the International X-ray and Radium Protection Committee (IXRPC). In 1950 it was restructured, and renamed ICRP to take account of new uses of radiation outside the medical area.
Nevertheless, the better knowledge of ionizing radiation didn’t prevent what could be seen as the first worker radioprotection scandal and a serious breach of safety culture, leading to stronger protection laws: the Radium Girls at the United States Radium Corporation, in the late 1920s. Specialized in the business of producing radio-luminescent paint (made from a mix of radium and zinc sulphite) for dials, watches and aircraft instruments, the company was employing young women whose task was to hand-paint watch and gauge faces. As they were instructed to maintain a fine tip on their paintbrushes by licking them, many developed a condition called radium jaw (radium necrosis), a painful swelling and porosity of the upper and lower jaws that ultimately led to many deaths. Although the lawsuit was settled in 1928, the company continued hand painting operations until 1947, further boosted by World War II demand. Culture for safety was not paramount yet.
Another landmark in radioprotection and safety was reached by an English physicist, Louis Harold Gray, who worked mainly on the effects of radiation on biological systems — inventing the field of radiobiology.