DEVELOPMENTS IN DUST CONTROL IN COAL MINES.

The reduced incidence of coal workers' pneumoconiosis has been due, in the main, to improved dust control in mines. This in turn, during recent years, has been facilitated by the introduction of selective gravimetric sampling of respirable dust, a technique which has been shown to give results in good agreement with the health hazard. Much has been achieved by a preventative approach to dust control involving careful planning of mining operations and improvements in mining machinery design and methods of operation, and by improved ventilation. Exhaust ventilation, accompanied by air cleaning, is already used for dust control in headings, and it will become an increasingly important means of dust control for most mining systems. The paper concludes with a description of present developments in respirable dust sampling. Refs.