A study, published in the British Medical Journal, said government protection policies focus mainly on the small number of homes with high radon levels and neglect the 95 percent of deaths linked to lower levels of radon.

Alastair Gray, Sarah Darby and colleagues at the University of Oxford assessed the contribution of indoor radon to lung cancer deaths in Britain and examined the cost-effectiveness of policies to control radon exposure. They then calculated the lifetime risk of lung cancer death before and after various interventions to control radon, and the costs involved.

The authors estimate that 1,100 deaths a year in Britain are related to radon -- about 3.3 percent of all deaths from lung cancer -- but less than 5 percent of radon related deaths occur from exposure above the current action level.

The authors argue that installing basic and inexpensive measures to prevent radon -- an air pollutant produced by the decay of uranium in the ground -- in all new homes would be more cost-effective and have greater potential for reducing lung cancer deaths caused by radon.

The study found that six out of seven radon related lung cancers occur in people who smoke or who have smoked in the past. The best way for current smokers to reduce risk is to stop smoking, the researchers said.