ABSTRACT
We have evolved in a naturally radioactive environment, and naturally radioactive elements have always been present in our environment. Natural sources include cosmic rays, gamma rays from the earth, radon decay products in the air, and various radionuclides in food and drink. Artificial sources include fallout from the testing of nuclear weapons in the atmosphere, discharges of radioactive waste from the nuclear industry, and accidental releases. Food may become contaminated with radionuclides by a number of routes. These include uptake of radionuclides by plants from the soil or from deposition onto the upper parts of the plants. The mobility, solubility, and fate of radionuclides in the environment are governed principally by their chemical forms. Deposition of radionuclides from the atmosphere to vegetation surfaces represent a direct pathway of plant contamination and is more important than root uptake in the short term following deposition.
