Finland says the low concentrations of radioactive material found in air samples pose no danger.

Invisible for humans, but detectable for radiation-filters. A cloud with tiny levels of radioactivity, believed to originate from western Russia, has been detected over Scandinavia and European Arctic.

Since 2014 St. Lawrence Islanders have been collecting sea water samples, knowing that the radiation would eventually show up. Now the signature of Fukushima has finally been identified, the northern most sample evidence of the plume. Fortunately the levels are low.