New federal smog standards are not protective of either human health or the environment, according to state Department of Environmental Protection Secretary Kathleen McGinty, but that doesn't mean Allegheny County can meet them.

Ms. McGinty said the state urged the U.S. Environmental Protection Agency to follow the unanimous recommendations of its own scientific advisory committee that would have reduced the standard for ozone, the primary component of smog, to between 60 and 70 parts per billion. Instead, the EPA adopted a higher 75-ppb standard after consulting with the White House.

"Sound science must be used in setting public policy, and that has not happened in this case," Ms. McGinty said yesterday, shortly after the EPA announcement. "Unfortunately, this action is in keeping with the EPA's track record of ignoring science and making decisions based on politics."

Even at the higher level, the county will have no chance of meeting the new, tighter federal standards for smog-causing ground-level ozone, said Guillermo Cole, the Allegheny County Health Department spokesman.

"Our projections are that under a new tighter standard, we won't be in attainment based on our existing sources and data from the last three years," Mr. Cole said. For the latest three-year period for which statistics are available, the county's ozone average was 83 ppb.

The EPA estimated that 345 counties nationwide will not meet the new standard. In Pennsylvania, at least 12 of the 67 counties probably won't meet the standard, said Judith Katz, the EPA mid-Atlantic regional air division director.

In addition to Allegheny, those counties include five in the Philadelphia area and Armstrong, Beaver, Washington and Westmoreland in the state's southwest.

Allegheny flirted with attainment for smog-causing ozone after three years of low readings from 2004 through 2006, and petitioned the EPA for redesignation. But eight higher-than-allowed ozone readings on seven days last summer pushed the county back into nonattainment.

"We may have to scour around for sources that can be curtailed. It will be a challenge," Mr. Cole said. "We will also have to look for further cuts from power plants upwind."

Emissions from those coal-burning power plants in the Ohio River valley, west of the Pennsylvania border, produce more than one-third of the pollutants measured by county air monitors.