It's the carbon in coal that gives steel the strength and versatility for products such as bridges, buildings and automobiles. The U.S. is one of the top exporters of coal in the world. Most exported U.S. coal goes to Western Europe, Canada and Japan. Today, a few buildings are still being heated with coal. In the past , coal mining and burning had serious effects on the environment.
Federal law prohibits mining if there's too much dust in the air.
Today, miners use personal air samplers to test dust levels at regular intervals. Also, large fans on the surface force explosive gases out of mines, and dust is controlled by wetting coal or spraying limestone on the walls. In sufficient quantity, these could pose environmental problems. Some of these by-products may contribute to acid rain, though the exact causes and possible solutions are still being studied by scientists within and outside of the industry. Mining companies plan the reclamation process before digging.