The nuclear crisis in Japan has a lot of travelers worried, with fears of radiation wafting into heavily populated areas, across the Pacific and up into the atmosphere plaguing the news wire every day.
Nuclear events of this magnitude bring a lot of variables — the type of reactor, fuel source and wind patterns can all play a role in the spread of radiation — and there are still a lot of unknowns when predicting how widely it will
Airplanes, in particular, are a particular concern because they can travel through potentially affected radiation clouds and expose their passengers to higher levels of in turn. But to what effect? The aluminum skins on most aircraft provide nearly an increased degree of protection against ambient air (not as good as lead), but radiation can still eventually seep through, and one also must consider the glass and acryllic in the windows.
There’s also the issue of circulated air throughout the cabin. This air comes from air processed through the engines, and if any radiation particles are present then it can potentially be filtered into the cabin.
In short, there are a variety of ways that a radiation cloud can potentially impact an airliner — and that’s why airlines fly around them. At present, a no-fly zone is in effect above any problematic reactors in Japan, and as the radiation cloud moves that zone will be adjusted in kind. As a result, any passenger traveling through the earthquake and tsunami ravaged country has little to fear about collecting radiation from their aircraft.
Being exposed to radiation from other passengers and their belongings, on the other hand, nobody can guarantee. Two passengers inbound from Japan into the United States were recently flagged with high radiation levels, and there are now concerns about whether or not that could have spread to other passengers and baggage.
Either way, if you have deep concerns about radiation it’s probably best to steer clear of the area. Just don’t expect your airline to cause any extended radiation exposure.