Which of the following is NOT a mechanism for radon transport?

Radon is a naturally occurring radioactive gas that is found in soil and rock and can migrate into buildings through various mechanisms. Among the listed options, radiation is not a mechanism for radon transport.

Emanation refers to the process by which radon gas is released from the soil or building materials, while diffusion describes the movement of radon gas from areas of higher concentration to areas of lower concentration, allowing it to enter structures. Air pressure differences also contribute to the migration of radon by creating a pressure gradient that encourages the gas to flow into buildings, especially through cracks or openings in foundations.

Thus, while emanation, diffusion, and air pressure differences are all fundamental mechanisms by which radon can be transported, radiation pertains to the emission of energy as particles or waves, which does not facilitate the movement of radon gas itself.