在公布这一消息之前，日本政府上周发布数据显示，撤离区内35个地点的辐射量超过每年20毫希沃特，而这一数值被政府认为是安全线。
The government 's announcement follows the release of data last week showing radiation readings in 35 spots in the evacuation zone above the 20 millisieverts per year level deemed safe by the government .
毫希沃特