Which of the following gases is NOT included in the list of mine gases?

Radon is the correct choice because it is not typically listed among the common gases associated with mining environments. Mine gases are usually those that can be produced during the extraction of minerals and coal, or as a result of the chemical reactions that occur in a mining setting. Methane, carbon dioxide, and carbon monoxide are commonly encountered in mines.

Methane is particularly significant because it can create explosive hazards in underground environments. Carbon dioxide can accumulate in areas of poor ventilation, posing asphyxiation risks. Carbon monoxide, a product of incomplete combustion and a hazardous gas, can lead to poisoning if not adequately managed. In contrast, while radon can exist in mining areas, especially in relation to uranium mines, it is often treated separately from the primary list of gases that miners traditionally monitor for danger.