We own a home in Bristow in Prince William County and it seems every other house has a radon pipe installed. On our cul-de-sac 6 out of 9 homes needed one. A lot of people are unaware of radon altogether and it is so spotty one house can have a problem and the one next door may not. Radon is a colorless, odorless, tasteless gas that occurs naturally in the ground. It is also radioactive and the second leading cause of lung cancer in non-smokers.
Our homes were built new in 2009, but a radon pipe was not an option upon building, but now it can be. Newer "high efficiency" homes can trap more radon so if an area is problematic it is easier to have the builder install a pipe while they are constructing a new home rather than later. It can be done later, but then it can make it more complicated with drilling in the basement or sometimes through the attic or garage and roof.
We called several radon mitigation companies and got one that installed it for us for $850. They did great work and our radon levels dropped from 6.4 to 0.2. Since our basement was finished already and it was too complicated to go up from our storage room and through the garage we opted for the back corner of our basement. The pipe is visible but can easily be enclosed.
Since long term radon exposure is the second leading cause of lung cancer and cancer is on the rise worldwide it is an important aspect of your home's health and your family's long term health.
For more information on the health risks and levels that require mitigation please see the EPA's link here http://www.epa.gov/radon/healthrisks.html