SAN FRANCISCO (AP) -- California's tobacco prevention program saved $134 billion in health care costs over the last two decades, according to a new study published Wednesday about the smoking control program's impacts in the most populous state.

California spent about $2.4 billion from 1989 through 2008 on one of the nation's most aggressive tobacco control programs, including buying up billboards and TV time to run ads against smoking, as well as promoting smoke-free environments and tobacco cessation programs.

The study by University of California, San Francisco researchers found that for every dollar spent on the state's anti-smoking program, health care costs dropped by about $56. Researchers attribute those savings to lower spending on health care due to people quitting or not starting, and those who do light up consuming fewer cigarettes each day.

"The California program has shifted people to being much, much lighter smokers," said Stanton Glantz, co-author of the study published Wednesday in the science journal PLOS ONE, and the director of the university's the Center for Tobacco Control Research and Education. "Reducing smoking reduces cancer, heart attacks, asthma attacks and a whole range of diseases, and what we found is those changes are reflected quickly in terms of health care costs."

Cigarette smoking continues to be the leading cause of preventable death and disease in the United States and throughout the world, according to the Centers for Disease Control and Prevention.

But smoking is not as common in California as it is in other pockets of the country. Smoking rates are among the nation's lowest in California, at 12.1 percent, and highest in Kentucky, at 24.8 percent, the CDC found in 2010. The rate in 1988 in California was 23.7 percent, according to the California Department of Public Health.

"Getting people to quit smoking is something we know a lot about ... but we as a society are not making the choices to do the things that we know work," said Dr. Tim McAfee, director of the CDC's office on smoking and health. "This study reinforces that in the grand scheme of things, extremely modest expenditures that states, the federal government and municipalities have made to address tobacco are remarkable bargains."

After factoring in population changes, as well as changes in health care technology and tobacco marketing, Glantz and his co-author James Lightwood found that increased spending on tobacco prevention in California lowered both the percentage of people who smoked and the number of cigarettes consumed by continuing smokers.

That, in turn, reduced health costs in California by a total of $134 billion, as compared to 38 other states that had no or limited tobacco control programs, according to the study.

McAfee said his office has talked with the authors to see how their methodology may be integrated with other efforts to highlight the economic costs of smoking, as well as the potential savings for states that implement sustained tobacco control programs.

Most of the $2.4 billion spent on tobacco control in California came from money raised through a 25-cents per pack tax measure that passed in 1988, as well as from private funds and federal funds, Lightwood said. Researchers' calculations on costs and savings to taxpayers did not take into account lost revenue from lower sales taxes on fewer cigarettes being sold, and the $2.4 billion represents total state spending in 2010 dollars.

Glantz, who was heavily involved in a campaign for a ballot measure last year that was promoted by Lance Armstrong and would have imposed an additional $1-per-pack tax on cigarettes to fund cancer research, did not count the money spent on the campaign as part of the $2.4 billion. That proposition ultimately was defeated by a well-financed opposition campaign from tobacco companies and other anti-tax groups.

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