Finland probes mystery spike in radioactivity
![Finland probes mystery spike in radioactivity](http://en.tengrinews.kz/userdata/news_en/2016/news_263202/thumb_b/photo_52330.jpg)
Finnish authorities are investigating a mysterious spike in levels of radioactive caesium-137 detected over Helsinki.
Finnish authorities are investigating a mysterious spike in levels of radioactive caesium-137 detected over Helsinki.