products in the lung also depends on numerous factors , including the particle size , breathing frequency , tidal volume and lung volume . Once inhaled and deposited on the bronchial epithelium , two of these solid decay products , polonium-218 and polonium-214 , deliver the majority of the radiogenic dose to the lung . These alpha-emitting radon decay products have been clearly identified as the primary cause of radon-induced lung cancer . Radon and radon decay products both will be called “ radon ” throughout this guide .
The Numbers and Public Health Impact
Despite enormous progress in reducing smoking rates over the past 50 years , lung cancer remains the leading cause of cancer mortality for both men and women in the United States , accounting for more than 26 percent of all cancer deaths . The Centers for Disease Control and Prevention estimates that more than 80 percent of lung
The National Comprehensive Cancer Network guidelines recommend LDCT screening beginning at age 50 for individuals with at least 20 pack-years of exposure if they have documented high radon exposure . cancer deaths are causally related to smoking . 3 In part because of the magnitude of smoking-induced cancers , the risk posed by the second leading cause of lung cancer — radon — often is overlooked or diminished in comparison .
Scientifically rigorous peer-reviewed epidemiologic studies ( described in the section “ The Science Behind the Risk Estimates ”) performed since the 1960s provided a solid scientific foundation for the U . S . Environmental Protection Agency ’ s ( EPA ) 2003 risk assessment , 4 which estimates that out of a total of 157,400 lung cancer deaths nationally in 1995 , 21,100 ( 13.4 %) were radon related . More recent direct estimates of the risk posed by radon , obtained from residential case-control studies performed globally , closely align with the 2003 EPA risk estimates . When compared to cancer mortality from all causes , radon-related lung cancer , if it were treated as a distinct disease category , would rank among the top 10 causes of cancer mortality and is considered a leading environmental cause of cancer mortality in the United States . 1
Cancer Mortality 2020
Cancer Type |
Estimated U . S . Deaths in 2020 4 , 5
|
1 . Lung and Bronchus |
135,720 |
2 . Colon and Rectum |
53,200 |
3 . Pancreas |
47,050 |
4 . Breast |
42,690 |
5 . Prostate |
33,330 |
6 . Liver and Intrahepatic Bile Duct |
30,160 |
7 . Leukemia |
23,100 |
Radon-Induced Lung Cancer |
21,100 * |
8 . Lymphoma ( Combined Hodgkin & Non-Hodgkin ) |
20,910 |
9 . Brain & Other Nervous System |
18,020 |
10 . Urinary Bladder |
17,980 |
11 . Esophagus |
16,170 |
12 . Kidney and Renal Pelvis |
14,830 |
13 . Ovary |
13,940 |
* The 21,100 radon-induced lung cancer deaths , based on risk estimates using U . S . demographic information from 1995 , |
are included in the estimate of lung and bronchus cancer deaths . |
Reducing the Risk from Radon | A Guide for Health Care Providers 3