The aircraft flying rescue and relief missions in the area are returning to base coated in particulate radiation. The ship was at least 100 miles off the Japanese coast.Pentagon expected to announce that USS Ronald Reagan and sailors onboard were exposed to a month's worth of radiation in an hour; no signs of ill effects yet.
The US Pentagon was expected to announce that US sailors on the USS Ronald Reagan, an aircraft carrier were exposed to radiation when the carrier sailed into a radioactive cloud off the coast of Japan, according to a New York Times report.
US government officials told the NY Times that sailors and other military personnel onboard were exposed to a month's worth of radiation in an hour's time. They added that US helicopters flying humanitarian missions some 60 miles north of damaged Japanese reactors were coated with particulate radiation. The aircraft were washed off.
Also 60 miles away soldiers getting 1 months radiation in 1 hour. That dose is over 720 times the normal limit !
Clearly radioactive particulates have entered the atmosphere from this event. That is no longer in question.
Note that Chernobyl fallout did reach the US, even though the reactor explosion and cloud was not thrown thousands of feet into the air. While in only small amounts, some radiation it did land in America. Chernobyl is also much further away. Therefore, it is entirely possible to get a dose of RADS from Japan's multiple reactor meltdowns. 
Ironically -- A radio station in Charlotte, North Carolina -- WCBN -- Talk 1660 is warning people about increased radiation levels already. That is way back east about 3,000 miles away from the west coast
LOL !