No, you will be run through the full decontamination riggamarole if you escape (que mood music and lighting) "the contaminated zone". With camera's rolling the entire time.

There is more appearence to substance to securing the masses. A chemical or radiological device is dangerous to those near the release point. Real nukes... so long as you aren't in the major fall out areas, big deal, you can't avoid it.

Bioweapons, on the other hand... Wierd stuff happens with germs. It would be worth while.