Not to minimize the danger faced by first responders here who will put their lives on the line if something like this ever occurs, but for your average Joe Citizen, I would say that the dangers of radiation from a dirty bomb, another Chernobyl type accident, etc. are very overhyped. Now, if a nuclear bomb actually detonated, that's all she wrote. And if I were a fire fighter or doing hazmat and a dirty bomb went off, then I would gear up with everything I could, including the kitchen sink, but I'm not a first responder. Just trying to give a Big Picture perspective to the discussion here. The danger of a dirty bomb is mostly psychological, not physical.

Putting aside the first question of "Well, what's the actual chance of a dirty bomb going off anywhere in the US?", then there's the question of what the damaging health effects would be? I see that you've done some reading from credible sources, like the CDC, about how experts think you should respond. And it all sounds frighteningly dangerous, but if you read medical literature that describes the actual risk involved, you'll probably be surprised that even if a dirty bomb went off right in your own city and you walked around in the stuff, on average, you're still more likely to die while driving or crossing the street or from your Happy Meal-a-day diet than from anything associated with the dirty bomb. There's plenty of credible info accesible on the web. Here's just one article on the dangers of plutonium from some of our friendly neighborhood experts over at Lawrence Livermore National Laboratory.

The 20th anniversary of the Chernobyl disaster was just a couple weeks ago. There's been an incredible amount of research into the health effects of that event, particularly in the most affected areas in Ukraine, Russia, and Belarus. And you know what? Except for a small but detectable increase in childhood thyroid cancers (the majority treatable, by the way), there's no detectable increase in cancer or leukemia above the background noise of all the other reasons people die of every year, including the usual assortment of cancers. I'm not saying that radiation doesn't cause cancer or doesn't kill or doesn't burn your skin or doesn't have any health effects--I'm saying that when taking a bird's eye look on all these millions of people who were directly and indirectly exposed to radiation from Chernobyl--some close, some farther away--there's little to see. "Only" 28 workers died from acute radiation syndrome (ARS) and about 125 diagnosed with ARS in the immediate aftermath of that disaster. And over 600,000 workers (called "liquidators") actually worked on the clean up over the years. And even among these people, the vast, vast majority of them are still going to die from the usual stuff. If you're interested in some summaries of the research done about the effects of Chernobyl, go to the International Atomic Energy Agency's website , you can find links to the IAEA's summary of the Chernobyl disaster, and a link to the WHO's 2006 report on the topic. A lot of good stuff in there.

So, in reality, sheltering in place at home or at work with the ventilation/air conditioning off for a relatively short while until the fallout settles or is dispersed will significantly reduce your already small risk of ever being negatively affected by a dirty bomb blast. Leave the lead-lined suit to Superman to protect him from kryptonite.