To those who rush for salts :
Then why don't you rush to buy cows, vegetables.... but rush to buy salts ?? This is common sense that cows would be more likely be the one which is polluted by radiation than salts, as cow is on the higher edge of food chain. It eat vegetables, and vegetables absorb radiation from envirnoment.
Salts will never be in short supply, as it can be created by sea, sea is huge (70% of Earth is ocean) This is common knowledge. How much the sea will be polluted ? if it was really polluted, then 70% of earth will be polluted => All humans may die ?! So the level of radiation enough to cause Pacific Ocean pollution that harm health could be millions times bigger than the Japan one, if this is really the case, then you should rush for food, but not for salts.