Sahara sands enable cesium to travel

Windy periods can bring Cs¹³⁷ over the European continent so that in some places air borne radioactivity can increased by a factor up to 11. This Cesium usually brought by Saharan winds has been quickly attributed to the fallout of French nuclear tests made in Algeria, but in fact it comes mostly from American and Soviet nuclear tests that represent 95% of Cesium deposits on earth. Cesium are everywhere in the northern hemisphere where nuclear tests where performed but where also the Chernobyl reactor exploded. Cesium is absorbed by plants and trees but is released in the atmosphere when plant rot or trees are burning, nevertheless health hazard is considered to be low. (A.C.)