IN A NEW analysis of the possibility of developing lung cancer following exposure to radon, the National Research Council's Committee on the Biological Effects of Ionizing Radiation revises the risk downward from that in a report it issued eight years ago.
Radon is an odorless and colorless gas formed by the radioactive decay of uranium in soil (JAMA 1987;258:578-579).
It is regarded as a major pollutant because many of today's houses are tightly sealed against the weather and the gas tends to build up inside them.
The latest analysis concludes that lifetime exposure to radon for what is termed one working-level month increases an individual's chances of dying from lung cancer by 1½ times compared with someone who is exposed only to background levels of radon. For every 1 million people exposed over a lifetime to one working-level month of radon, there would be about 350 more deaths from lung