(Sept. 29, 2006) -- Southern California continues to endure the worst overall air pollution in the country says the South Coast Air Quality Management District, examining data from the 2006 smog season (May 1-Oct 31) to date.

As of Sept. 27, the southland exceeded the federal 8-hour ozone health standard on 86 days, compared to 83 days during all of 2005 and 88 days in 2004. The peak 8-hour ozone concentration as of Sept. 27 was 0.143 parts per million (ppm), slightly below the peak of 0.145 ppm experienced in 2005 and 2004.

AQMD says Houston and the San Joaquin Valley also have severe ozone problems and periodically surpass the Southland in the number of ozone violations, but this year So. Cal surpassed both areas overall...on track to earn the dubious distinction of worst air quality in the nation.

"Personal exposure to air pollution is diminishing but not at the dramatic pace that we experienced during the past two decades," said Barry Wallerstein, AQMD's Executive Office. "This trend makes it imperative that we redouble our efforts to reduce emissions, particularly from mobile sources, in order to meet upcoming federal ozone and particulate matter standards."

The regional clean air agency says it plans to release an "updated blueprint for achieving healthful air" -- a Draft 2007 Air Quality Management Plan -- in early October. Under state and federal law, the plan must scientifically demonstrate how specific future air pollution control measures can achieve the emissions reductions needed to achieve health-based air quality standards, AQMD says.

The U.S. Environmental Protection Agency has enacted an 8-hour ozone standard, exceeded when ozone levels rise above 0.08 parts per million (ppm) during an 8-hour average...and southern California must meet that standard by 2021.