Radon is a type of radioactive gas released when the uranium contained in soil and rocks breaks down. After being released, radon dissolves in water underground or moves into the air, sometimes building up in places which are not well ventilated, such as mines and caves. In areas with a lot of uranium in the ground, radon gas may seep into homes and build up inside rooms such as basements. Radon and lung cancer are linked because breathing radon gas is known to increase the risk of lung cancer, as has been observed in workers in uranium mines. In fact, radon is the second most frequent cause of lung cancer in many countries, after smoking.
The long term effects of radon on the lungs are caused by the fact that, as the gas breaks down, minute radioactive particles are produced, which are then inhaled. Cells in the lining of the lungs are damaged by these particles and, over time, lung cancer can develop. Research into the link between radon and lung cancer has shown that smokers are at greater risk than nonsmokers of developing cancer after exposure to radon.
Lung cancers can give rise to symptoms such as breathing problems, coughing up blood, wheezing and pain. Although a cure is not often possible, surgery sometimes allows a tumor to be removed before it has spread. Radiotherapy and chemotherapy are other treatments which may be used.
Although home radon gas levels are usually lower than those found in uranium mines, studies into the effects of radon have shown that they can still be high enough to present a slightly increased risk of lung cancer. People concerned about the connection between radon and lung cancer can measure the levels of radon gas in their own homes using special detectors. The amount of radon in a home varies according to how much uranium is in the ground around and beneath the house, the available gaps in the building through which radon can enter, and how the house is ventilated.
There are a number of different options for reducing radon gas in the home, such as improving ventilation, including under the floor if possible, or sealing any cracks in floors and walls through which gas can seep. What is called a radon sump, an electric fan which draws away air from underneath the house, can effectively lower radon levels. Alternatively, what is known as positive ventilation may be helpful, where a fan blows fresh air into the home. Typically, the use of these methods reduces radon levels, so that they fall inside the ranges which researchers into radon and lung cancer have decided are acceptable for health.