"Federal regulators have announced the results of a September inspection blitz targeting 13 coal mines in seven states 'previously cited for violations regarding respirable dust sampling ... inadequate dust control ... and hazard complaints' involving excessive coal dust."

"More than 120 new violations were found, including failures to maintain adequate ventilation and water-spraying equipment underground, which work together to suppress coal dust and minimize its inhalation by coal miners.

'Inadequate ventilation, insufficient air quantities and improperly maintained dust controls expose miners to risk of explosions and black lung,' says Joe Main, assistant secretary of labor for mine safety and health.

Excessive coal dust was cited as a major cause of the massive explosion that ripped through the Upper Big Branch coal mine in West Virginia in 2010, killing 29 coal miners"

Howard Berkes reports for NPR's The Two-Way blog October 31, 2012. [2]