The worst-case accident would be enormous releases of radioactivity .

最糟糕的情况要数放射性物质的大量泄漏。

Radioactivity in water has been a mounting concern in japan .

水中的放射性物质在日本成为日益令人担忧的问题。

As a precaution , scientists are monitoring radioactivity in the air .

作为一项预防措施，科学家正在监测空气中放射性系数。

After detectors found a small amount of radioactivity , teams searched for 90 days .

一个探测仪测到微量放射性物质之后，搜索队搜寻了90天。

But a shortage of research labs capable of conducting accurate radioactivity tests stalled the process .

但由于缺少能够执行精确放射性检验的研究实验室，这个过程遇到阻碍。