Food is necessary for nutrition and energy. Some food can be good for maintaining healthy life, but some might slowly killing you. Although human is entering second decade of 21st century, I bet many people still do not know that some food is radioactive, even the dose is not deadly. No matter what, this information should be aware everyone.
A very good example of “radioactive” food is banana, due to the radioactive potassium-40 it contains. Occasionally, it is used as scale to measure the dangers of radiation by comparing exposures to the radiation created by banana which is named as banana equivalent dose. In other words, it also refers to radiation exposure received by eating a single banana. It is used to ease the measurement of radiation leaks from nuclear plant as it is commonly too small (picocurie).
Other food which are moderately radioactive are potatoes, sunflower seeds, kidney beans, nuts and so on. While the most radioactive food known until now is brazil nuts which reaches as high as 6600 picocuries per kilo. Informing knowledge about this does not mean to ask people not to eat food like this. But, one must at least know not to eat too much bananas (or other radioactive food), when they have to go through radiation sensor, or else they might have to end up their day in quarantine zone.