The Nuclear Industrial Safety Agency took the stage to address the worries surrounding the white cloud that appeared at the troubled Fukushima Daiichi nuclear plant Wednesday morning, stoking fresh concerns over a spike in radioactive levels.

The tension at the somber seven-minute news conference could have been cut with a knife -- or a ringtone.

The damage to the No. 3 reactor allowed some radioactive steam to seep out, causing an increase in radiation levels at the plant's gate. Save for the clicks of cameras and laptop-typing, the bespectacled agency official's monotone voice was the only sound in the room and over the three Japanese TV channels broadcasting the event live to the country.

Seated behind a low table and a row of microphones, the official read off the once-obscure radiation levels: They peaked at 10:45 a.m., 6,400 microsieverts, then fell at 10:54 a.m. to 2,900 microsieverts.

'We are investigating the case,' he said.

Pensive silence. Then...rrrrring! The official blushed, fumbled to turn the ring off and apologized. But if the report in the drop in radiation to what is deemed safer levels didn't ease anxious listeners, the usually unwelcome interruption in movie theaters and dinner conversations was greeted with nervous laughter.

And no, he did not pick up the phone.

出问题的福岛第一核电站周三早晨冒出白烟，导致人们对辐射水平升高产生新的担忧。日本原子力安全保安院（Nuclear Industrial Safety Agency）出面消除这些白烟引起的不安。

Kyodo News/Associated Press图片：超强地震袭击日本沉闷的新闻发布会持续了7分钟，气氛紧张的可怕，彷佛得用刀──或是手机铃声──才能割裂一般。

因三号反应堆受损，部分放射性蒸汽溢出，导致该电站大门处辐射水平上升。日本三个电视频道向全国直播了此次发布会。除了拍照声和笔记本打字声，这位戴眼镜的保安院官员单调的声音是屋内唯一的响声，也是三个电视频道上唯一的声音。

这位官员坐在矮桌后面，面前是一排麦克风。他读出了曾经对多数人都过于晦涩的辐射水平：上午10点45分，辐射达到6400微西弗的最高水平，在10点54分降至2,900微西弗。

他说，我们正在进行调查这个事情。

屋内一片沉寂。接着...手机铃声大作！这位官员涨红了脸，匆忙关掉了铃声并道歉。但如果辐射水平降至被认为是安全水平的报告未缓解听众的焦虑情绪，通常在电影院和晚餐聊天时出现的扫兴手机铃声此时则使人们紧张得笑了起来。

是的，他没有接那个电话。