Rain falling on the United States contains radioactive material from Japan at levels that exceed federal safety thresholds.
Federal officials on Tuesday urged calm in the wake of the discovery of iodine-131, which blew across the Pacific Ocean from the stricken Fukushima nuclear power plant, in rainwater.
The tests that detected the radioactive material were conducted by the Massachusetts Department of Public Health and by nuclear power plant operators in Pennsylvania.
Update: New York Post, Dec. 22, 2013: Navy sailor Lindsay Cooper knew something was wrong when billows of metallic-tasting snow began drifting over USS Ronald Reagan. [...] she and scores of crewmates watched a sudden storm blow toward them from the tsunami-torn coast of Fukushima, Japan. The snow was caused by the freezing Pacific air mixing with a plume of radioactive steam [...] Senior Chief Michael Sebourn, a radiation-decontamination officer, was assigned to test the aircraft carrier for radiation. The levels were incredibly dangerous and at one point, the radiation in the air measured 300 times higher than what was considered safe, Sebourn told The Post.