Dispersion of radioactive emissions into the environment

The radioactive inventory is composed of gases and particles are all but differ in their radioactive half-life, so for example, are short-lived noble gases like krypton 85 m with 4.48 hours, but also the other half lived gases long, noble gases because they do not change chemically, ie remain in the air for years, but in a very diluted for the same spill in the air.
The other fission products if the particles can be deposited on the ground and enter a process of transfer in food chains, thus polluting plants and animals, it can contaminate food