at Fukushima, Asahi Shimbun reported that by 24 March the accident might have emitted 30,000 to 110,000 terabecquerels of iodine-131. A widely cited Austrian Meteorological Service report estimated the total amount of I-131 radiation released as of 19 March ranged from 10 petabecquerels to 700 petabecquerels . A Japanese government estimate issued April 12 calculated the total I-131 release at 130 to 150 petabecquerels total release by the April date. The amount of I-131 released from the Fukushima site has been enormous relative to the US incident.

The half-life of I-131 is only eight days, but the Japanese authorities have not been able to gain control of the reactors or fuel rods at the site. It is likely I-131 is still being released.