Japan's leaders are alternating pleas for calm with candid revelations about the danger posed by radiation from the Fukushima nuclear plant that sustained another explosion on Tuesday. Authorities confirm that radiation from the stricken plant has entered the atmosphere and accordingly, a no-fly zone has been established for an 18 mile radius above the nuclear plant.

One of the possible problems in getting updates on the situation has been a lack of transparency on the part of the nuclear power company. According to Reuters, Japan's Prime Minister Naoto Kan was furious about the delays in transmitting information and reportedly yelled "What the hell is going on?"

Asian nations including China, Thailand, Hong Kong, the Philippines and South Korea, Malaysia and Singapore will now be testing food imported from Japan. US ships that are docked in Japan cut back on outdoor activities and secured external ventilation systems.

In comparison with the world's previous disasters, Japan's nuclear disaster has not yet reached the proportions of the Chernobyl disaster as the reactor in Japan has a case. Parts of it shut also down automatically upon the earthquake. However, it has already eclipsed America's 1979 Three-Mile Island nuclear reactor disaster that did not result in the emission of serious radiation.

Later on Tuesday (Japanese time), Japan's chief Cabinet Secretary Yukio Edano claimed that radiation readings at the plant's front gates had returned to a level that would not be injurious to human health, This is a slight climb down from the Prime Minister's warning that radiation has reached a level that could have an effect on humans and therefore people were advised to stay indoors.