Abstract: Large amount of dusts and poisonous gases generated during the excavation of highway tunnels have a significant adverse impact on the safety d heath of the tunnel construction personnel. This paper presents the results of using water bags as sealing of the lasting holes. The water fog generate from the blasting dilutes and absorbs the dusts and gases. Different locations of the water bags in the bore holes are tested and their effects are compared: bottom, bottom & top, and middle & top. All results show that the water bags are effective in dust and poisonous gas reduction. The most effective water bags locations are middle and top of the bore hole, where the dust reduction is between 30% and 35% and the blasting holes has a 4 to 9% improvement in the utilization.

Key words: Blasting with Water Seal, Tunnels, Dusts