What changes occur in the mine atmosphere sealed within a fire area?

The conditions within a sealed fire area in a mine change significantly due to combustion processes. When a fire occurs, it consumes available oxygen, producing carbon dioxide and carbon monoxide as byproducts of incomplete combustion. In a sealed environment, where air circulation is restricted, the oxygen levels drop while carbon dioxide and carbon monoxide levels tend to rise as a result of the ongoing combustion.

This phenomenon poses serious safety risks, as increased concentrations of carbon dioxide can lead to asphyxiation, while carbon monoxide is a toxic gas that can cause severe health effects, including poisoning, even in relatively small quantities. Understanding this dynamic is crucial for mine safety management, particularly in developing effective emergency response strategies and ensuring the safety of workers.

The other options do not accurately reflect the changes in the mine atmosphere after a fire has been contained. For instance, the idea that nitrogen levels would decrease significantly is misleading since nitrogen is a stable and inert gas and does not typically react or change under burning conditions.