Late last week, the Environmental Protection Agency proposed tighter limits to one of the country's most dangerous air pollutants: fine particulate matter, or soot. But while the long-awaited move could save thousands of lives per year, health experts say it's still not enough.
Soot is also known as fine particulate matter because its fragments are so small — 2.5 microns in diameter or less. When inhaled into the lungs over time, these harmful materials can cause damage leading to premature death, heart attacks and cancer. Sources for the deadly pollutant include construction sites, power plants, and refineries. Those who live nearby (disproportionately low-income households and people of color) face the greatest risk of exposure.
