A lot of people here have studio's right on top of the ground/partially underground or in basements.
Our basement was just tested for radon and we have a level of 11. I haven't built the studio, but installing a system to dissipate these dangerous levels is a priority.
It's recommended that you test every 2-3 years and always after any construction such as finishing a basement is done.
It's the 2nd leading cause of lung cancer. 21,000 deaths each year in the US. If you are a smoker, the radon/smoking combination has a synergistic effect which greatly increases your risk.
This web site has a lot of information on it:
http://www.epa.gov/iaq/radon/healthrisks.html
Be sure to test for Radon
Originally posted at johnlsayers.com, topic 4644.
Great point! I just posted a link to this thread from the sticky "Safety during Demolition/Construction" thread so this one doesn't get lost. :)