ABSTRACT
Explosive charges and plying of vehicles or locomotive for moving drilling equipment or for mucking leave fumes and unhealthy gases inside the tunnel. An efficient ventilation system to drive away these fumes and gases from the tunnel should be provided for all tunnels during construction 1 . The effect on humans of the carbon monoxide emitted by petrol-ignited engines and, to a small extent, by diesel engines is given in Table 10.1.
