SSR reviewed the state of knowledge of the emissions of coal dust from trains and its potential health and environmental impacts, with a focus on the transport of coal from mines in the workhorse of domestic coal mining, the Powder River Basin.
Images from Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Union_Pacific_Coal_Train_Douglas_WY.JPG and http://commons.wikimedia.org/wiki/File:Coal_mine_Wyoming.jpg