Of all environmental challenges, the one that can get you into trouble fastest is air. You have to have it. No one reading this can go more than three minutes without it.

Perhaps down the line I'll get into discussion about how to deal with really scary airborne threats like cesium, but initially let's discuss the sorts of things that can be dealt with without a full body positive pressure suit: germs and heavy particles like mercury or just so much dust that you can't breath.

The answer to those problems is a decent filter mask.