Fewer American adults smoked in 2004 than in 2003, the US Centers for Disease Control and Prevention (CDC) reported Thursday. The agency released two reports detailing steady progress against tobacco's hold on millions of US residents.

About 44.5 million US adults (20.9% of the population) were current smokers in 2004, the agency reported. That's down from 2003, when 45.4 million US adults (21.6%) smoked. The figures are based on the National Health Interview Survey, a telephone survey of more than 31,000 US residents over age 18.

What's more, smokers also appear to be lighting up less than in the past. Back in 1993, daily smokers averaged nearly 20 cigarettes a day, but by 2004, that number was down to just under 17 a day. A recent study from Denmark found that smokers may lower their lung cancer risk slightly by cutting back on how much they smoke -- although another study showed that even a few cigarettes a day can raise a smoker's risk of dying prematurely.

"No level of tobacco use is safe," the CDC report says. "The best option for any smoker is to quit completely."

The report notes that people still aren't kicking the habit fast enough to meet the agency's 2010 goal of a US smoking rate under 12%. Nevertheless, any decline in smoking is good news, said Tom Glynn, senior director of international tobacco control for the American Cancer Society.

"We see a steady downturn [in smoking rates] over the past 25 years, and if you look at it from that perspective, the progress has been astounding," he said. "You also need to look at the progress made despite the obstacles."

RESOURCES: Great American Smokeout Kick the Habit Quitlines and Other Support

What obstacles? Tobacco advertising, for one. According to the Federal Trade Commission, the tobacco industry spent more than $15 billion in 2003 on advertising and promotion of its products. That's more than $40 million a day. By contrast, many states have dramatically cut the funds they devote to anti-tobacco programs.

The second CDC report details the states which have made the most progress in trimming their smoking rates. Utah leads the way: Only 10.5% of adults there smoke. California is next with 14.8%, followed by Idaho with 17.5%. The nation's worst performers are Kentucky, where 27.6% of adults smoke, followed by West Virginia (26.9%) and Oklahoma and Tennessee (26.1%).

Those findings are based on another phone survey of US adults, the 2004 Behavioral Risk Factor Surveillance System.

Both CDC reports emphasize the importance of state tobacco-control programs for curbing the national smoking rate. Such programs include things like advocating for smoking restrictions, higher tobacco taxes, and better insurance coverage of quitting programs and medications.

Many states also provide telephone quitlines to help people beat their cigarette addiction. Smokers can get connected to a service in their state by calling 1-800-QUIT NOW (1-800-784-8669), the number for the North American Quitline Consortium. The American Cancer Society also offers quitline services.

Citations: "Cigarette Smoking Among Adults -- United States, 2004." Published in the Nov. 11, 2005 Morbidity and Mortality Weekly Report (Vol. 54, No. 44: 1121-1124). First author: E. Maurice, MS, CDC Office on Smoking and Health.

"State-Specific Prevalence of Cigarette Smoking and Quitting Among Adults -- United States, 2004." Published in the Nov. 11, 2005 Morbidity and Mortality Weekly Report (Vol. 54, No. 44: 1124-1127). First author: N. Kuiper, MPH, CDC Office on Smoking and Health.