EPA Tightens Soot Standards

The U.S. EPA announced the strongest national air quality standards in the country's history. These National Ambient Air Quality Standards (NAAQS) address fine and coarse particle pollution, also known as particulate matter (PM). PM is a complex mixture of extremely small particles and liquid droplets in the air (i.e. dust, soot and particles too small to see).

The standards address two categories of particle pollution: fine particles and inhalable coarse particles. Fine particles are 2.5 micrometers in diameter and smaller; inhalable coarse particles have diameters between 2.5 and 10 micrometers. Exposure to particle pollution is linked to a variety of significant health problems ranging from aggravated asthma to premature death in people with heart and lung disease. The final action significantly strengthens EPA's previous daily fine particle standard – by nearly 50 percent – from 65 micrograms of particles per cubic meter to 35 micrograms of particles per cubic meterof air. This standard increases protection of the public from short-term exposure to fine particles.

By revising the daily fine particle standard, it will yield additional estimated health benefits valued at between $9 billion to $75 billion a year. These standards will reduce premature deaths, heart attacks and hospital admissions for people with heart and lung disease. EPA is also retaining the current annual standard for long-term exposure to fine particles at 15 micrograms percubic meter. Based on recently updated benefits estimates, meeting this standard will result in benefits ranging from $20 billion to $160 billion a year. EPA is revoking the annual coarse particle standard because the available evidence does not suggest an association between long-term exposure to coarse particles at current ambient levels and health effects. (Source: EPA) (Wash Post article)

For more information about the final standards announced on Sept 21, 2006: http://epa.gov/pm/naaqsrev2006.html