A heavy fog across the Tennessee River and downtown Chattanooga, as shown from this vantage point from Stringer's Ridge.

The U.S. Environmental Protection Agency announced today that Chattanooga now meets federal smog standards.

EPA Regional Administrator Gwen Keyes Fleming said Chattanooga met the fine particulate standards over the past three years to comply with the government's smog standards adopted in 1997.

"This accomplishment signifies that the citizens of Chattanooga are breathing cleaner air and leading healthier lives," Keyes said.

The official notice of Chattanooga's achievement was published in today's Federal Registrar.

EPA announced similar attainment of its smog standards in Knoxville in March and in Rome, Ga., in April.

"The private and corporate citizens of Hamilton County again have shown that they can meet any challenge," Bob Colby, director of the Chattanooga-Hamilton County Air Pollution Control Bureau, said in a statement today. "We are pleased to be a small part of their success in improving air quality for the benefit of all."

EPA's announcement is based upon air quality monitoring data for fine particulate matter from 2007 through 2010.

Particulate matter pollution, especially fine particles, contains microscopic solids or liquid droplets that are so small that they can get deep into the lungs and cause serious health problems, according to EPA

Particles can cause premature death and a wide range of lung and heart disease, including heart attacks and asthma.