The radiation limits Japanese authorities use to determine evacuation areas is too high according to ACRO. It has been fixed at 20 millisieverts per year, which is strongly criticized by many organizations including ACRO. The sievert is the unit used to measure the damage caused by radiation on the body. The limit set by the Japanese is two times more than the French one in case of nuclear accidents, and twenty times higher than the maximum allowable limit for the public under normal circumstances. But this is the limit set for adults and children alike by Japan
Be sure to check out the Nikkei’ Business Special Edition: “TEPCO Crime and Punishment” available here.