Contamination spread around hemisphere

VIENNA (Kyodo) Radioactive materials released from the Fukushima No. 1 nuclear plant spread around the entire Northern Hemisphere in the two weeks following the March 11 disaster, an international nuclear watchdog said Thursday.

The Preparatory Commission for the Comprehensive Nuclear-Test-Ban Treaty Organization said minute traces of radioactive substances spread around the hemisphere by March 25 after being carried across the Pacific. But it said the amounts of such substances were far below levels that could affect human health.

The Vienna-based organization runs 63 monitoring stations worldwide, including one in Takasaki, Gunma Prefecture. Radioactive substances were detected by the Takasaki station March 12, then picked up by a station in eastern Russia on March 14, and next by one on the U.S. West Coast. The materials then crossed the Atlantic and reached Iceland on March 22, it said.

According to a simulation by a German research institute, the radioactive materials were carried from Fukushima to the United States on air currents, before dispersing from northern Canada to the Arctic Sea and spreading around the Northern Hemisphere.