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Key Points in Responding to the Letter from Mr. Moody to State Governors
There are some serious flaws in the arguments put forth by Mr. Moody in his letter criticizing state and EPA radon programs. The following are some key points that states may find useful in developing a response if they have received the letter.
The Linear No-Threshold hypothesis is valid for residential doses of radon:
• The Linear No-Threshold Theory was used to extrapolate from miner studies to expected risk in residences.
• Dr. David J Brenner et al in their 2003 Proceedings of the National Academy of Sciences' Publication, Cancer risks attributable to low doses of ionizing radiation: Assessing what we really know, state: the linear no-threshold theory "is supported by experimentally grounded, quantifiable, biophysical arguments," and therefore "a linear extrapolation of cancer risks from intermediate to very low doses currently appears to be the most appropriate methodology."
• The radon-related lung cancer risk shown in the residential pooling studies (higher than that originally estimated from the miner studies) clearly shows that, if there is a threshold to indoor radon risk of lung cancer, it is below the level commonly found in homes, rendering the argument moot for purposes of protection of the public from the risk of indoor radon.
The study he is cited in Mr. Moody's argument is flawed:
• Cohen's 1995 study is known as an "ecological" study and is not meant to be used to determine risk
ecological studies look at average data. This is usually gathered at a geographic entity level, most commonly at the county level. For example, the average level of radon per county and the average rate of lung cancer per county. Without individual data we don’t even know the radon levels of the individuals who contracted lung cancer. We certainly cannot adjust for other causal factors such as smoking or occupational exposures.
• The newest, best science shows high risk at residential levels
The initial studies were carried out on miners and extrapolated for residential exposure. However, the recent residential pooling studies from North America, Europe, and China have demonstrated risk in homes which is actually greater than what was estimated from the miner studies. These residential studies had information on the individuals in the studies and compared the radon levels of those who developed lung cancer to those who did not. The studies also had individual information on other causal factors. Over eleven thousand patients with lung cancer and over twenty-one thousand controls without lung cancer participated in these studies.
o Publication of the residential data caused the U.S. Surgeon General to issue a second Health Advisory in which he identified indoor radon as the second leading cause of lung cancer in the United States and recommended that homes be tested.
As strong as the scientific consensus was before on radon, it is even stronger now. Recent developments include:
• The release of the President’s cancer Panel’s 2008-2009 Report on Reducing Environmental Cancer Risk, which highlighted the risk from indoor radon,
• The 2009 publication of the World Health Organization’s Handbook on Indoor Radon (recommending a new lower reference level of 2.7 pCi/L),
• The 2009 Health Physics Society’s revised position paper on indoor radon which endorses EPA’s recommendations.
The lung cancer risk posed by indoor radon is settled science. Those wishing to learn more should pursue the scientific literature on the subject rather than relying on general internet searches.
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