Preparing for the End....

http://gizmodo.com/5986734/ride-out-north-koreas-preemptive-strike-in-these-24-cold-war-fallout-shelters?popular=true

I actually remember several of these pamphlets and designs from my childhood.  And....I'm certainly not an expert of radioactivity -But I'm assuming that if you're getting air from outside, you're getting that too...
I'm also amused/horrified to see that at least one of these shelters has a door that only opens outward.  What if debris from the bombing falls against it?  How does one escape entombment?