Dangerous gases such as [[methane]] can accumulate in mines and can explode if ignited, and the inhalation of dusts is also a health issue, so underground mines must be ventilated, typically with large fans located above ground which keep air circulating through the mine. | Dangerous gases such as [[methane]] can accumulate in mines and can explode if ignited, and the inhalation of dusts is also a health issue, so underground mines must be ventilated, typically with large fans located above ground which keep air circulating through the mine. |