BEIR VI radon: The rest of the story.

The National Academy of Sciences (USA) conducted an extensive review on the health effects of radon (BEIR VI). This was a well written and researched report which had impact on regulations, laws and remediation of radon in homes. There were a number of problems with the interpretation of the report and three are focused on here. First, most of the radiation dose used to estimate risk was from homes with radon levels below the US Environmental Protection Agency's action level so that remediation had minor impact on total calculated attributable risk. Remediation of the high level homes (i.e., above the action level) would therefore have a minor impact on the calculated "population attributable risk". In individual homes with very high levels of radon, remediation may minimally reduce individual risk. Second, the conclusion communicated to the public, regulators and law makers was "Next to cigarette smoking radon is the second leading cause of lung cancer." This is not an accurate evaluation of the report. The correct conclusion would be: Next to cigarette smoking, high levels of radon combined with cigarette smoking is the second leading cause of lung cancer. In the never-smokers, few cancers could be attributable to radon. Thirdly, there is little question that high levels of radon exposure in mines combined with cigarette smoke and other significant insults in the mine environment produces excess lung cancer. However, the biological responses to low doses of radiation are different from those produced by high levels and low doses may result in unique protective responses (e.g. against smoking-related lung cancer). These three points will be discussed in detail. This paper shows that in contrary to the BEIR VI report, risk of lung cancer from residential radon is not increased and radon in homes appears to be helping to prevent smoking-related lung cancer. Thus, laws requiring remediation of homes for radon are providing little if any public health benefits.