The term “contamination” means, quite simply, radioactive material where it is not supposed to be. Food, water or air is considered to be contaminated if it contains more or different types of radioactive material than would normally be present. Our bodies, for example, contain very small amounts of the radioactive elements potassium 40, carbon 14 and tritium. However, we are not considered to be contaminated because these elements exist within us naturally. On the other hand, the presence of strontium 90 (a byproduct of nuclear weapons testing) in food, water or air may be indicative of contamination.
“Radiation” refers to the particles and waves given off by radioactive material. The radiation given off by contaminants could be considered harmful if the levels are high enough and the exposure lasts long enough.
How Contamination Can Occur
Dust-sized radioactive particles released into the air during an incident could fall on fruits, vegetables or grains which could enter the food supply and be eaten by the public.