Smoking rates in Philadelphia have reached their lowest levels in recent history, city officials announced Thursday.

Smoking among adults in the city has fallen by almost 15 percent since 2008, Philadelphia Health Commissioner Dr. Donald F. Schwarz said at an event marking the American Cancer Society's 37th annual Great American Smokeout.

Forty thousand adults in Philadelphia have given up smoking since 2008, Schwarz said, attributing the decline to the city's Clean Indoor Air Law, a federal increase in cigarette excise tax, and the "Get Healthy Philly" initiative.

The Great American Smokeout press conference took place at The Restaurant School at Walnut Hill College, which Schwarz praised for its work becoming the city's first college to ban smoking entirely.

Thirty of the United States's fifty largest cities by population prohibit smoking indoors in all private workplaces, restaurants, and bars, the Centers for Disease Control and Prevention (CDC) also announced Thursday.

In 2000, only one city-San Jose, California-had such a law, according to a CDC press release. With 60 percent of the largest cities covered by either local or state indoor smoking bans, nearly half of Americans are covered, according to the release.

Still, smoking remains the number one cause of death across the nation, including in Philadelphia.

Secondhand smoke exposure kills 49,400 nonsmokers by heart disease and lung cancer each year, the CDC estimates. A total of 443,000 Americans are killed by cigarette use, according to CDC estimates.

Contact Jonathan Lai at 215-854-2771,, or on Twitter @elaijuh.