Looks like the Nuclear Regulatory Commission doesn't trust the Japanese hazard reporting either

How Far from Fukushima Will Fallout Pose a Health Risk?

Amid conflicting evacuation recommendations, radiation experts say that exposures to date have been relatively low outside the power plant and that people in the U.S. will not face any danger

By John Matson 
March 18, 2011

http://www.scientificamerican.com/article.cfm?id=japan-nuclear-plume

The NRC's McIntyre says that the recommendation for additional evacuations in Japan is not incompatible with the standard 16-kilometer evacuation plan for a U.S. accident. "The 10-mile [16-kilometer] zone was always conceived as something that could be expanded as the situation warranted," he says. McIntyre notes that the NRC's shift—from publicly backing Japan's handling of the accident to publicly recommending a much stronger response—stems from the fact everyone is reliant on the Japanese authorities for accurate, up-to-date information on the situation. "Part of this is the difficulty in obtaining and assessing data. We're dependent on the Japanese for the data, pretty much," he says. "We're trying to get the information and assess it. Yesterday the information we had led our team to conclude that it was time to take action."

This tells me that the NRC isn't trusting the Japanese assurances of little risk from spreading radioactivity and is making their own assessment of the situation taking that into account.  It's certainly seemed that the Japanese officials have been less than honest and this is validation of that.  Perhaps if and when radiation arrives in Alaska, Hawaii, or the West Coast of the United States, the NRC will be more honest than their Japanese counterparts.  For now though my recommendation is DON'T DRINK FRESH MILK until it's known that no "hot spots" of radiation deposition have reached us.