Difficulties in measuring radiation are increasing confusion in Japan. The government must weigh incomplete and sometimes contradictory data before making decisions.

Updated at 11:05 a.m. ET. TOKYO - Japan's government has doubled the estimate of how much radiation leaked from a tsunami-hit nuclear plant and says the damage to the reactors was greater than ...

Japan radiation - tiny rise in cancer risk. JAPAN. Updated Feb 28, 2013 10:27 p.m. FILE - In this April 7, 2011 file photo, Japanese police, wearing suits to protect them from radiation, search ...

Officials fear radiation contamination from local food but U.S. diners safe. March 21, 2011— -- Many Japanese citizens around the Fukushima nuclear plant have evacuated amid growing fears of ...

Photo Caption: This bomb casing at the National Museum of Nuclear Science & History is identical to Fat Man, the atom bomb that devastated Nagasaki, Japan, in 1945. Photograph by Forrest M. Mims ...

Could radiation from Japan's crippled Fukushima Daiichi nuclear plant reach the U.S.? Meteorologists and nuclear engineers say it is unlikely to travel very far.

Radiation poisoning of food supply in Japan 'is a lot more serious' than first feared, as eggs and milk go on 'danger list' By RICHARD SHEARS IN TOKYO Updated: 21:12 EDT, 21 March 2011 .