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. First, in week 23 (June 2-8), iodine-131 was measured at the two air filter stations Svanhovd and Viksjøfjell near Kirkenes in short distance from Norway’s border to Russia’s Kola Peninsula. The same days, on June 7 and 8, the CTBTO-station at Svalbard measured tiny levels of the same isotope. CTBTO is the global network of radiological and seismic monitoring under the Comprehensive Nuclear-Test-Ban Treaty Organization. Norway’s nuclear watchdog, the DSA, underlines that...