Barbara Turoff, retired American, said, "I was going to go back anyway, just for a vacation, but I'm leaving earlier because I'm concerned because I really don't know the situation about the radiation. It keeps changing."

Other evacuees say the threat of radiation is scarier than the earthquake itself.

Thibault Brex, French evacuee, said, "If there was a radioactive cloud we just wouldn't know if it would come into our town. And with that you don't feel or hear anything, so you can't do anything and that's something we absolutely can't control no matter what people say. I was more worried about the radiation than about the earthquake. "

Scores of flights to Japan were halted or rerouted this week on fears of radiation leaks from the stricken nuclear plant -- and private jet companies say they've been inundated with requests to help evacuate people.

Some countries have begun testing their citizens returning from Japan for signs of radiation exposure.