Background is probably a bit lower depending on where you're at. My counter went through airport security luggage scans 'cause they wouldn't let me wear it through the metal detector. It beeps for a few seconds and then comes out about a days' dose of natural radiation higher. The count was higher than 300 CPM, but obviously only shortly. That poor bloke might stay at 300 (if ingested and he can't scrub it off) for a while but it's still not very discouraging long-term. Pilots have about that at cruising altitude.