Coal dust accumulation in mines can lead to which of the following risks?

Coal dust accumulation in mines poses significant hazards, most notably the risk of fire and explosion. When coal dust is suspended in the air in sufficient concentrations, it can ignite easily when exposed to a spark or an open flame, leading to potentially catastrophic explosions. The explosive nature of coal dust is well-documented in mining operations, which is why strict regulations and safety measures are implemented to control dust levels.

Moreover, explosive incidents not only endanger the lives of miners but can also lead to expansive damage to mining infrastructure. This is why understanding the implications of dust accumulation, particularly coal dust, is crucial for maintaining safety protocols in mining environments.

While increased humidity, equipment malfunction, and reduced visibility can also be issues in mining operations, they are not directly linked to the particular dangers posed by coal dust in the same critical way that fire and explosion risks are. Thus, among the options, the most pressing risk associated with coal dust is indeed the potential for fire and explosion.