Soot pollution causes about 5,000 premature deaths each year in Pennsylvania and an estimated 500,000 asthma attacks, according to a report issued yesterday by an environmental group.

The report by the PennEnvironment Research and Policy Center also noted that soot and smog pollution lead to about 11,000 hospital admissions a year and hundreds of thousands of missed days from work and school.

"This report confirms what many Pennsylvanians know all too well--that air pollution has significant public health impacts," said Nathan Willcox, co-author of the report.

The report advocated several measures to improve air quality, including a Clean Vehicles Program aimed at reducing pollutants from new vehicles sold in Pennsylvania.

But Mr. Willcox noted that two bills pending in the legislature, House Bill 2141 and Senate Bill 1025, could derail implementation of the program.

In 1998, the state adopted the Clean Vehicles initiative, which would impose emissions standards that mirror those used on new cars sold in California and some other states, said Kurt Knaus, a spokesman for the Pennsylvania Department of Environmental Protection.

Those standards, which are stricter than federal standards, were to take effect on new cars sold in Pennsylvania beginning with the 2006 model year, he said. State environmental officials, however, have asked a state panel to delay implementation of the standards for two years.

While PennEnvironment has sued the state for seeking the delay, the two pending bills would block implementation of the Clean Vehicles Program, Mr. Willcox said.

Ted Leonard, executive director of the Pennsylvania AAA Federation, which supports the Senate bill, said the California standards could add as much as $3,000 to a new vehicle's cost. He also questioned whether the California standards would substantially reduce emissions compared to federal standards.

Mr. Knaus, however, said the California standards could reduce harmful pollutants by 10 percent or more and eventually save consumers money by making cars more fuel efficient.

State environmental officials also have said that if the Clean Vehicles Program is not implemented, tougher controls on air pollution would have to be imposed on factories, power plants and manufacturers.