Akhir 21, 1432 H/March 26, 2011, SPA -- Air detectors in Germany's Black Forest mountains have picked up radioactive iodine blowing in from Japan's Fukushima nuclear crisis site 9,000 kilometres away, but the amount is too little to be harmful, officials said Saturday, according to dpa. The instruments on Schauinsland mountain can distinguish between the much larger amount of radioactive iodine constantly emitted by the soil and rock of Germany and the nuclear power station iodine 131 from Japan. On Friday the Japanese-origin radioactivity had been 58 microbecquerels per cubic metre of air. On Saturday this rose to 500 microbecquerels, the German federal radiation protection office said. A spokesman in Salzgitter said this posed no health risk and was only a tiny fraction of the regular radioactivity in Germany's air. "We were expecting a slight rise," he said. "The traces are very, very tiny." Most radiation in Germany comes from radon, a gaseous element that occurs naturally as a decay product of uranium. It is common in many areas, seeping out from the soil. The office said iodine 131 had also been detected on both the West and East Coast of the United States and in Iceland and Sweden.