Tokyo Electric Power Co, which operates the plant, later allowed workers to re-enter after establishing there was no fire and that radiation level in the area had not risen.

BBC: Fukushima workers in hospital after radiation exposure

However, after those two months, the situation in Japan needed to be re-evaluated and people allowed to return to most areas below reasonable radiation levels, levels in which many of us elsewhere in the world live.

FORBES: Fukushima -- Fear Is Still the Killer

When the sides were heated, the electrons in the atoms become agitated and emit radiation, which bounces around the container, being continuously absorbed and re-emitted.

WSJ: Book Review: Surfaces and Essences

Mothers of young children have been particularly aggressive about prodding the government to increase food testing, and to re-evaluate the safety limit and impose more restrictions, such as a ceiling on radiation measurements in school lunches.

WSJ: Radioactive Traces Found in Japan Baby Formula