FORCES - Evidence by topic - Back to: Proving the lies of the anti-tobacco cartel: The Evidence
AN ANTIDOTE TO RADON SCARE PROPAGANDA
RE: Radon causes cancer, smoking adds to risk-UK study. By Patricia Reaney, Reuters - London. 03:01 AM ET 05/19/98.
QUOTE FROM ARTICLE: Radon, a naturally occurring radioactive gas found in most homes,
and smoking can be a lethal combination, British researchers warned on Tuesday.
Scientists from the Imperial Cancer Research Fund (ICRF), who conducted a study into the effects of the odourless, colourless gas, said it causes one in 20 lung cancer cases in Britain -- mostly in conjunction with smoking.
"Residential radon really is a cause of lung cancer," Professor Sarah Darby told a news conference. "This study provides, for the first time, direct evidence of the risk associated with residential radon in the UK."
COMMENTS: Of epidemiologic studies with measured radon levels in the subjects' homes, comparable to the UK study, Ltourneau et al. is the most valuable, because it includes smokers while some others did not, and because of the much higher radon levels in Canada - much higher than in Finland, China, US, or the UK.
The UK study cited a mere 400 Bq (bequerels) per cubic meter as high exposure in Britain, which doesn't even break out of the lowest level of exposure in the Canadian study (0-1800 Bq/m3). Since the Canadian study found no risk from exposure to over 7201 Bq/m3, it is probable that none exists from residential levels of radon.
 [Ltourneau EG, Krewski D, Choi NW, Goddard MJ, McGregor RG, Zielinski JM, Du J. Case-control study of residential radon and lung cancer in Winnipeg, Manitoba, Canada. Am J Epidemiol 1994 Aug 15;140(4):310-321. 714 ever smokers, 24 never smokers. No risk after adjustment. 0-1800 Bq/m3, OR=1.0 (reference); 1801-3600 Bq/m3, 0.97 (95% CIs 0.63-1.48); 3601-7200 Bq/m3, 0.84 (0.51-1.39); 7201+ Bq/m3, 1.00 (0.69-1.46).]
In fact, studies of even high exposures to miners, upon which the speculation of risks at low levels are based, found a greater multiplication of risk for non-smokers than for smokers.
[National Research Council. Committee on the Biological Effects of Ionizing Radiations (BEIR IV). Health Risks of Radon and Other Internally Deposited Alpha-Emitters. Washington, DC: National Academy Press, 1988.]
Studies in the US not only fail to convincingly demonstrate a risk from residential radon, but there is a suggestion of declining risk with higher low-level exposure. Radon scare propagandists have attempted to dismiss the work of Bernard L. Cohen, who found that lung cancer rates actually decreased with increasing residential radon levels, as merely an ecological study, and claim that it must have been confounded. However, the data have been exhaustively subjected to statistical tests showing that confounding could not possibly account for his findings.
[Cohen BL. Test of the linear-no threshold theory of radiation carcinogenesis for inhaled radon decay products. Health Phys 1995 Feb;68(2):157-174]. "It is shown that uncertainties in lung cancer rates, radon exposures, and smoking prevalence are not important and that confounding by 54 socioeconomic factors, by geography, and by altitude and climate can explain only a small fraction of the discrepancy" [between the linear-no threshold theory that radon causes lung cancer in proportion to the dose, and actual decreasing rates of lung cancer with dose actually found]. This study covered more than half of all US counties, with about 90% of the US population.
Cohen BL. Lung cancer rate vs. mean radon level in U.S. counties of various characteristics. Health Phys 1997;72(1):114-119. "Plots of lung cancer rates corrected for smoking prevalence vs. average home radon levels are presented for U.S. counties with a wide variety of socioeconomic characteristics. The data are generally well described by the same negative slope linear, plus positive slope quadratic, `standard' curve. Plots are presented for geographic regions and these are also reasonably well fit by the standard curve. The findings are not consistent with predictions based on a linear no-threshold model."
Cohen BL. Problems in the radon vs lung cancer test of the linear no-threshold theory and a procedure for resolving them. Health Phys 1997;72(4):623-628. "It has been shown that lung cancer rates in U.S. Counties, with or without correction for smoking, decrease with increasing radon exposure, in sharp contrast to the increase predicted by the linear no-threshold theory. The discrepancy is by 20 standard deviations, and very extensive efforts to explain it were not successful. It is pointed out that, unless a plausible explanation for this discrepancy (or conflicting evidence) can be found, continued use of the linear no-threshold theory is a violation of "The Scientific Method." Various explanations that have been offered for ignoring these results are examined and shown not to be valid. A simple procedure for clearly settling the issue is proposed." And: "Our study has tremendous statistical power, including effectively nearly a million lung cancer deaths and 20 million deaths from other causes. The discrepancy with theory is by 20 standard deviations, which has a probability of occurring by chance equal to the inverse of the total number of electrons plus nuclei in the entire universe!"]
Cohen also conducted an unrelated study with different methodology, which also failed to find any evidence to support the theory predicting that radon risk begins at zero and rises smoothly with increasing exposure. Cohen analyzed 4438 lung cancer deaths, in comparison with the "nearly 1,000" in the UK study.
[Cohen BL. Questionnaire study of the lung cancer risk from radon in homes. Health Phys 1997;72(4):615-622. "First-time measurements of radon levels in homes, self-selected by occupants, were accompanied by questionnaires asking about people who had lived in the house and died of cancer. Responses were received before-measurement results were available. The ratio of lung cancer deaths to deaths from other cancers was plotted as a function of radon level in the house. The results seem to indicate essentially no dependence of this ratio on radon exposure, in sharp contrast to the strong increase with increasing radon exposure predicted by the theory which should have been easily observable. Possible explanations of the discrepancy are discussed. Use of two alternative control groups increases the discrepancy with theory. This work has no connection with the recent test of the linear nonthreshold theory in the low dose region by the same author."]
Counterpoint by
Carol Thompson
5-21-98
Smokers' Rights Action Group
P.O. Box 259575
Madison, WI 53725-9575
Phone: 608-249-4568
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