Radon is a naturally occurring, cancer-causing gas that is both odorless and tasteless. The U.S. Surgeon General has actually warned that radon is the second leading cause of lung cancer in the United States today. The higher the level of radon in your home, the higher the risk of cancer. Even more concerning is the fact that numerous scientific studies of radon exposure have shown that children may be more sensitive to radon than adults, as they are still developing.
Radon poisoning often doesn't get the attention it requires because it is in fact naturally occurring. It's not the biproduct of manufacturing, or car pollution, or anything similar. It is a natural, radioactive gas that exists in the soil beneath a structure, and can find it's way in through a variety of ways.
Radon is virtually impossible to eliminate completely, but it is possible to reduce it to a safe inside a structure.