San Diego has cleanest air in six decades
Despite population growth and more cars, smog level recedes
The United States Environmental Protection Agency announced today (May 16) that San Diego County is now breathing the cleanest air in more than six decades. The county has met the 1997 national air quality standard for smog, or ground-level ozone. The county meets the 0.08 parts per million federal standard for ozone, but still has not attained the 0.075 parts per million ozone standard adopted in 2008.