Epidemiologic studies of underground miners: New information from an old source

Over 100 years have passed since Harting and Hesse first described an unusual pattern of thoracic malignancy in the underground metal miners of Schneeberg. It is now known that these miners had primary cancer of the lung, caused by exposure to radon progeny released into the air of the mines from the ore. The early case series of Harting and Hesse, based on the Schneeberg miners, and of Pirchan and Sikl, based on the Joachamisthal mines, have been followed by epidemiologic studies of more formal design of uranium and other underground miners exposed to radon throughout the world. These studies have confirmed the causal association of radon and its progeny with lung cancer and provided quantification of the risk of lung cancer in relation to exposure to radon progeny. These studies have also provided insights concerning the effect of radon progeny on smokers and on nonsmokers. The findings of the epidemiologic studies have provided a clear imperative for reducing exposures of miners to radon progeny. Consequently, exposures of underground uranium miners to radon progeny have been lowered substantially over the last 50 years in countries reporting exposures of underground miners. The epidemiologic studies have also documented the substantial burden of radon-caused lung cancers among miners of uranium and other ores. While the causal link of radon with lung cancer in underground miners is now established and unquestioned, the risk of radon in indoor air remains a highly controversial issue. During the last few decades, there has been increasing recognition that radon is ubiquitous in indoor environments, in some instances at concentrations as high as measured in underground mines. As a foundation for risk management, the epidemiologic evidence from underground miners has been the primary basis for estimating the risk of indoor radon