Although the radon concentration in some homes may reach levels found in mines, average domestic cumulative lifetime exposure to radon is about 5 to 15 times lower than for miners. However, because of uncertainties in using miner-based results, the precise public health consequences of domestic exposure to radon is currently an important unresolved issue. Studies of occupational groups have identified several other respiratory carcinogens, although it is difficult to assess their overall public health impact. It should be noted that the carcinogenic effect of some of these exposures, e.g., asbestos, is enhanced by tobacco smoke. The risk of developing these three diseases is substantially higher for workers in a number of asbestos industries, including miners and millers, and textile, insulation, shipyard, and cement workers.
Lung cancer is also one of the major effects of high doses of ionizing radiation.
Air pollution has been suspected as a cause of lung cancer, but it has been difficult to establish definite links. Although suggestive, the association of lung cancer and PAHs has not yet been conclusively demonstrated, as other components of air pollution may also be carcinogenic. Epidemiologic studies have provided support for some of these associations. The clearest and most consistent associations occur with the consumption of fresh fruits and vegetables. The precise component responsible is still uncertain, but most attention has been focused on carotenoids, particularly beta-carotene.