With respect, we consider this comparison to be utterly misleading. Why? Radiation and contamination are not the same thing. Taking a flight will expose one to cosmic radiation not radioactive contamination. When radioactive isotopes enter into water, crops, milk that leads to radioactive contamination. Contamination occurs when material that contains radioactive isotopes is no longer contained. It is important to remember that radiation cannot spread or get "in" or "on" people; rather it is radioactive contamination that can do precisely that. Here lies the essential difference between the two. Radioactive contamination and radiation exposure occur only if radioactive materials are released into the environment as the direct result of a nuclear accident, an event in nature -- such as ground radiation with radioactive isotopes -- or an act of war involving nuclear devices or radioactive isotopes. Such a release may expose living beings and contaminate their surroundings and their environment. Radioactive contamination occurs when radioactive material is deposited on or in an object or a living being. Radioactive materials released into the environment can cause air, water, surfaces, soil, plants, buildings, people or animals to become contaminated. A contaminated living being has radioactive materials on or inside their body. Read more: http://www.businessinsider.com/why-radiation-and-contamination-is-like-comparing-apples-and-oranges-2011-4#ixzz1ROOwq0gT