The Environmental Protection Agency announced it is tightening regulations on soot. Breathing in excess fine particulate matter can lead to asthma attacks, cancer, and heart and lung disease. It’s been linked to anywhere from tens of thousands to hundreds of thousands of premature deaths in the U.S. per year. The new rule will lower the amount of allowed fine particulate matter in the air from 12 micrograms per cubic meter to 9 micrograms.