Japan raised the assessment of its nuclear crisis to the most severe rating Tuesday, on the same level as the Chernobyl disaster, the world's worst to date. Some answers to questions about the assessment and health and safety concerns:

Fears that Japan might start dumping some of its vast holdings of U.S. Treasury bonds to pay for earthquake reconstruction have eased in financial markets.

The Japanese government acknowledged Friday that it was overwhelmed by the scale of last week's twin natural disasters, slowing the response to the nuclear crisis that was triggered by the earthquake and tsunami that left at least 10,000 people dead.
The elderly couple fled their home on foot as the warning sirens blared. But they could not keep up with their neighbors and fell behind as the tsunami rushed in.
Fears about health risks rose dramatically in Japan Tuesday with news of a greater radiation release and renewed warnings to remaining residents within 20 miles to stay indoors.
The Japanese people could well be the world's most prepared people in coping with a nuclear power plant accident, a U.S. expert on radiation poisoning said Tuesday.
Fears about health risks rose dramatically in Japan Tuesday with news of a greater radiation release and renewed warnings to remaining residents within 20 miles to stay indoors.
The news from Japan sounds terrifying _ radioactive steam spewing from nuclear reactor explosions and frantic efforts to prevent a meltdown. So far, though, the health threat is not substantial if details that officials have released are correct, radiation experts said.

If you can keep your head when all about you are losing theirs, you probably aren't suited for a career in politics and certainly not in the media.