By Julie Steenhuysen
CHICAGO (Reuters) - Fewer American adults are smoking cigarettes, and those who still smoke have cut back on the number of cigarettes they smoke, but the rate of decline has begun to slow, health experts said on Tuesday.
Smoking and exposure to secondhand smoke is the leading cause of preventable death and disease in the United States, killing an estimated 443,000 Americans each year.
"Any decline in the number of people who smoke and the number of cigarettes consumed is a step in the right direction. However, tobacco use remains a significant health burden for the people of United States," Centers for Disease Control and Prevention Director Dr. Tom Frieden said in a statement.
"States with the strongest tobacco control programs have the greatest success at reducing smoking."
The CDC report shows some 19.3 percent of American adults over the age of 18 -- roughly 45 million people -- were smokers in 2010, down from 20.9 percent in 2005.
Of those adults who still smoke, 78.2 percent, or 35.4 million people, smoke every day. But even these smokers are cutting back.
According to the CDC, the percentage of smokers who had fewer than 10 cigarettes a day rose to 21.8 percent in 2010, from 16.4 percent in 2005.
Only 8.3 percent of daily smokers have 30 or more cigarettes per day, down from 12.7 percent in 2005.
Even so, the rate of the decline between 2005 and 2010 is slower than in the previous five-year period, the CDC found.
"This slowing trend shows the need for intensified efforts to reduce cigarette smoking among adults," Dr. Tim McAfee, director of the CDC Office on Smoking and Health, said in a statement.
"We know what works: higher tobacco prices, hard-hitting media campaigns, graphic health warnings on cigarette packs, and 100 percent smoke-free policies, with easily accessible help for those who want to quit."
For every one smoking-related death, another 20 people live with a smoking-related disease, such as heart disease or lung cancer.
Smoking costs about $193 billion annually in direct health care expenses and lost productivity.
(Editing by Mohammad Zargham)