The second leading cause of lung cancer in the United States—after tobacco smoke—is invisible and odorless radon gas, which is blamed for 20,000 lung cancer deaths . Unlike smoking, it’s not something people expose themselves to intentionally. The radioactive element uranium is ubiquitous, albeit in small amounts, in soil, an is gradually decomposes into radon, which naturally occurs in gaseous form. In 1985, scientists realized that this gas comes into homes through the foundation, which is generally slightly porous. In some cases, the building materials can emit radon—this is seldom enough to cause problems, but it can add to the radon from the soil. Whatever the source, it gets trapped by the walls and roof. It can’t be seen or smelled, but it can be spotted with radon testing kits.
It is estimated that one in 15 American homes has what is considered to be a high level of radon, more than 4 picocuries per liter of air. Picocuries per liter is the measurement of the concentration of a radioactive substance, based on the radioactive decay of radium, which Marie and Pierre Curie studied. Excess radon gas can cause cancer. Radon is the most common cause of lung cancer among non-smokers—more than secondhand smoke—and one reason for this is that secondhand smoke can be seen and often avoided, while radon gas cannot be.
That is why home testing is so important. Winter, when the doors and windows are closed, is ordinarily the season of peak radon concentration, meaning if radon levels are not dangerously high in the winter they are unlikely to be dangerously hi in other parts of the year. Test kits are available, for short-term testing over a period of to days to three months, or long-term testing that can be longer than that. The reason even short-term testing can last so long is that the intention is to get an average radon level over time.
There’s no way to completely remove radon gas from the home; there’s always be some around. However sealing up cracks in and near the foundation can help prevent more from entering, and ventilation can help get out what is already there. Specialized radon reduction can can even be installed that is designed to get radon gas out of the home.