Radon, Asbestos and Tobacco Smoke

The sources just discussed primarily, but not exclusively, produce acute health effects. Some indoor pollutants that are not acutely associated with SBS produce only chronic effects. Two of the most notable of these are radon and asbestos. 

Radon is a carcinogen present in indoor air that is estimated by some studies to be responsible for about 1% of all lung cancers. 40 41 Other studies, however, question whether it is radon alone or radon in combination with cigarette smoke exposure that is responsible for the cancers. Even those studies that question the effect of radon exposure as a cause of 

Chronic residential exposure to asbestos is known to be the cause of a specific lung cancer—mesothelioma. 441 Here, too, tobacco smoke exacerbates the carcinogenic effect. Asbestos workers who smoke are 90 times as likely to develop lung cancer as compared to those who neither smoke nor work with asbestos. I45l 

The studies just cited address the risk of developing lung cancer following exposure to radon, asbestos, and tobacco. Though estimating these risks are complicated by human exposures to other environmental pollutants, both indoors and outdoors, I42 44 these and other similar studies do definitively establish the enhanced effects of exposure to mixtures on the development of lung cancer and other cancers. This subject is discussed further in Chapter 21. 

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