From Great Britain: radon, smoking, and lung cancer

One wonders, though, if this is cost-effective.

http://www.ncbi.nlm.nih.gov/pubmed/21109305

Lung-cancer reduction from smoking cessation and radon remediation: A preliminary cost-analysis in Northamptonshire, UK.
Groves-Kirkby CJ, Timson K, Shield G, Denman AR, Rogers S, Phillips PS.
Environ Int. 2010 Nov 23. [Epub ahead of print]