Radon gas

The presence of radon gas in homes has been recognized in recent years as an important health issue. This gas, which is inert and therefore doesn't bond easily to other elements, is produced by the decay of naturally occurring Uranium in the soil. Radon decays by alpha-particle emission, with a half-life of about 4 days, and subsequently produces other, highly radioactive isotopes. The major health concern over radon gas is that we inhale it, where it settles inside our lungs and subsequently decays by emission of harmful radiation.

The damage from radon is heightened from the fact that homes are becoming more and more well-insulated to guard against heat loss, which has the unfortunate side effect of decreasing ventilation through the homes which would otherwise disperse the radon gas. There are now kits which one can use to test for the presence of radon, and if found then the area's ventilation should be improved.