The findings were released Wednesday, on the six-month anniversary of the ban.

UK researchers collected and analyzed tiny particles found in the air in the Lexington establishments on weekend nights both before and after the smoking ban took effect.

"Fine-particle air pollution was 11 times lower after the smoke-free law was enforced at area businesses," said UK's Kiyoung Lee, assistant professor in the UK College of Public Health.

Ellen Hahn, one of the air-quality study's principal investigators and an advocate of the ban, said the study shows that a significant portion of airborne fine particles in Lexington's indoor public places were produced from cigarettes.

Smoking ban opponents disagreed with the study's findings.

"We don't put a lot of stock in what they do," said Larry Dean, president of the Lexington-Fayette County Food and Beverage Association, which opposes the smoking ban. "We've seen them play with numbers."

Tucker Richardson, a Lexington attorney who represents about a dozen Fayette County establishments cited under the ban, said his clients would probably consider the study to be "horse hockey."

"They may be improving the air quality, but our bartenders and servers would much rather have their tips back," he said.