The history of radon from a Swedish perspective.

Beginning in the 16th century, what was later found to be radon was thought to be causing sickness among miners. During the first decades of the 20th century, exposure to radon was seen as being healthy. During the 1940s, 1950s and 1960s researchers thought that the gamma radiation in residences could produce genetic damage. It was not until approximately 1970 that a quantitative risk estimate for lung cancer could be calculated for miners, and not until the 1990s that a risk estimate could be established based on epidemiological studies on radon in dwellings and lung cancer.