Radon basics- Pt 2- why is Louisville high, and what can I do?

Hello Kentucky, and Louisville in particular!  I'm glad you asked.

Radon is a gas that is the byproduct of uranium decay, so the radon levels occurring naturally are a function of the geology under our homes.  In the process of the decay, the gas seeps up through the ground and into the atmosphere.  The half life is short, but it's a continuous process and essentially doesn't stop.

So why so homes in Louisville have higher concentrations of radon than other parts of the country, and why does a home have a higher radon level than, say, the outdoors?

We've addressed the first part (Louisville, southern Indiana, and Oldham county are all atop some large uranium deposits).  The reason it concentrates in the home is that our HVAC systems create a negative pressure that essentially acts like suction, drawing outside air inward.  Newer homes with better insulation and tighter seals (more efficient building envelopes) aren't as leaky as their older predecessors, which usually means they have higher radon levels.  Be forewarned:  we have seen elevated radon levels in every type of home, including older homes on crawl spaces. 

So there you have it.  When you are buying a home, it is always a good idea to get the radon level checked.  For a short timeframe like that it's best to get a continuous radon monitor, which will give hourly readings of the radon levels and will average the levels at the end of the test or inspection.

Next week: radon mitigation