Radon and lung cancer: What does the public really know?

Radon causes approximately 21,000 deaths annually from lung cancer, making it the second most important cause of lung cancer after smoking. However, the extent of public knowledge about radon is unclear. We systematically reviewed the epidemiologic literature in order to assay the public's understanding about radon and specifically, whether radon is known to cause lung cancer. Radon knowledge has most often been gauged via telephone and in-person responses to the question, "Have you heard about radon?" Our review of 20 such studies reveals that although many individuals have "heard about" radon, many segments of the population, particularly individuals younger than thirty and those with less education, do not know what radon is. Of those who have heard about radon, the majority of respondents in many studies did not know that radon causes lung cancer. Conversely, misinformation about radon is common; approximately 50% of respondents in many studies reported the erroneous belief that radon causes headaches. This suggests that the public has confused the effects of radon with those of carbon monoxide. Rates of radon testing and mitigation are correpondingly low and appear to reflect cognitive defense mechanisms by which individuals believe that their risks from radon are lower than the risks faced by others. Our review suggests that public information materials about radon require revision. Specifically, these should emphasize that radon causes lung cancer and that household carbon monoxide detectors do not detect it. Radon education provided by realtors at the time of residential home sales may be a promising venue to increase radon testing and remediation.