You probably realize that inhaling coal dust would be bad for you. But for the people who spend long shifts working in mines to extract the stuff, it’s a tangible occupational hazard. Even with protective gear and federal regulations on dust exposures, tiny particles of dust can enter miners' lungs, causing a plethora of respiratory diseases.
For the last few decades, it looked like mining conditions were improving, along with the health outcomes among most miners. In 1970, the federal government implemented the Federal Coal Mine Health and Safety Act, which created the first national standard for safety regulations, including limits for the amounts of dust that coal miners could be exposed to. The Act mandated annual inspections at all underground coal mines, and introduced steep penalties for violations. It also provided health benefits and compensations for miners afflicted with fatal lung diseases like Progressive Massive Fibrosis, or black lung.