There's bad news and good news about smoking in the United States, according to 2 recent studies.

On the negative side, declines in adult smoking rates seem to have stalled, according to the latest figures from the US Centers for Disease Control and Prevention (CDC). On the other side, a separate CDC report shows nonsmokers being exposed to less secondhand smoke -- definitely good news.

The new findings point to a need to beef up anti-tobacco efforts, the authors and other experts say.

"Effective interventions have been identified for decreasing initiation and increasing cessation, but they have not been implemented adequately," the authors of the report on current smoking trends write.

Translation: We know how to keep people from starting to smoke and how to help them quit, but we're just not doing it enough.

Strategies that could help include restrictions on smoking in public places, laws that make it harder for kids to get cigarettes, and subsidies to help smokers afford quitting programs and tools like counseling or nicotine replacement products.

The first report shows that the percentage of US adults who are current smokers didn't budge between 2004 and 2005, holding steady at just under 21%. That figure had been decreasing slowly for the past 8 years.

The finding is based on a national survey of more than 31,000 people. It was published in Morbidity and Mortality Weekly Report, a CDC publication.

The chief executive officer of the American Cancer Society, John Seffrin, PhD, called the finding "troubling." Smoking is the leading cause of preventable death in the United States, and the main cause of lung cancer (both small cell and non-small cell), the biggest cancer killer among both men and women in the country. Smoking is also linked to many other types of cancer, as well as heart disease, stroke, emphysema, and bronchitis, to name just a few ailments.

Because of the terrible toll smoking takes on people's health, public health officials are trying to get smoking rates down to 12% among adults by 2010. If the current trend continues, the country won't meet that goal, the study notes.

The authors of the report suspect a couple of factors are behind the current stall. Funding for state tobacco-control programs has been cut by more than 26% since 2002. Meanwhile, tobacco company spending on promoting their products has more than doubled since 1998. They spent more than $15 billion in 2003 alone, largely on discounts to keep the price of cigarettes down.

"More than 75 cents of every dollar the tobacco industry spends on marketing is now spent reducing the price of tobacco products, an effort aimed directly at undermining successful efforts to reduce smoking by passing strong tobacco-control measures like smoke-free laws and increased taxes," Seffrin said.

The second CDC report shows that smoke-free laws are making an impact.

As part of a large periodic study of US health, researchers measured levels of cotinine -- a byproduct of nicotine -- in the blood of nonsmokers. That's a way of gauging how much smoke they've been exposed to.

Overall, the levels dropped by about 70% between 1988 and 2002. The most likely explanation, the authors say, is that smoke-free laws were, in fact, keeping nonsmokers away from dangerous secondhand smoke.

Such laws are gaining momentum in the US. In last week's midterm voting, Arizona and Ohio passed laws making all workplaces, including restaurants and bars, smoke-free. Nevada passed a similar act prohibiting smoking in restaurants, bars that serve food, grocery and convenience stores, shopping malls, and other retail stores. Hawaii is set to go smoke-free on Nov. 16, the 30th anniversary of the Great American Smokeout.

Citations: "Tobacco Use Among Adults -- United States, 2005." Published in the Oct. 27, 2006 Morbidity and Mortality Weekly Report (Vol. 55, No. 42: 1145-1151). First author: P. Mariolis, PhD, US Centers for Disease Control and Prevention.

"Trends in the Exposure of Nonsmokers in the US Population to Secondhand Smoke: 1988-2002." Published in the June, 2006 Environmental Health Perspectives (Vol. 114, No. 6: 853-858). First author: James L. Pirkle, US Centers for Disease Control and Prevention.