EMPHASIS ON RADON-222 (RADON)
Other than smoking related mortality, radon-induced lung cancer is likely the
leading environmental cause of cancer mortality in the United States. Table 1 presents
the ranking for radon induced lung cancer mortality versus cancer mortality for all
causes. Overall, radon-induced lung cancer is the seventh leading cause of cancer
mortality in the United States.
Table 1. Estimated U.S. Cancer Mortality for 2009 by Cancer Type*.
*Adapted from Jemal et al. 2009
Unlike many other indoor air pollutants that are correlated to outdoor air pollution,
radon gas concentrations in the home are related primarily to ingress of radon from
ground sources (EPA 1991) and to a lesser extent both waterborne radon entering the
home and emanation of radon from building materials. The EPA (1994) states “that the
primary factors that influence radon entry include 1) the radon content of the soil, 2) the
pressure differential between the interior of the home and the soil, 3) the air exchange
rate for the home, 4) the moisture content surrounding the home, and 5) the presence
and size of entry pathways.” These factors can be affected by climate change to
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