Radon-Smoking Synergy: A Population-Based Behavioral Risk Reduction Approach

Background. Radon and cigarette smoking have a synergistic, multiplicative effect on lung cancer rates. Smokers, and perhaps nonsmoking residents, of smoking households are at increased risk for lung cancer even when radon levels are relatively low. A behavioral risk reduction strategy emphasizing smoking cessation is proposed and data are presented from pilot studies and a short-term evaluation of a randomized intervention trial. Methods. Pilot studies, including radon testing, interviews, questionnaires, and focus groups, led to a three-arm randomized intervention trial comparing two kinds of written materials and telephone counseling. Smoking households were recruited by offering free radon test kits through an electric utility companies billing system. Three-month follow-up data were obtained by mail and phone. Results. Of an estimated 2,600 smoking households in the utility district, 1,220 requested a radon test kit, and 714 were randomized into three treatment conditions. Brief phone counseling (up to two short calls) significantly increased smoking quit rates, compared to written materials only, and was also related to other risk reduction behaviors (e.g., household ban on smoking). Conclusions. Offering free radon testing through a public utility billing system is an effective recruitment tool for reaching households at risk due to radon-smoking synergy. Brief telephone counseling is superior to written materials in reducing smoking and encouraging indoor smoking bans. Methods are needed to better inform smokers of their additional risk from exposure to even low levels of radon.