Nearly 21 percent of adult Americans still smoke, a rate that hasn’t changed significantly since 2004, according to the Centers for Disease Control and Prevention (CDC), the Associated Press reported Sept. 7.

According to the article, a major obstacle to lowering the smoking rate further is a lack of funding for smoking cessation programs and public health campaigns. However, it noted that cigarette taxes and non-smoking regulations have helped to push the smoking rate lower in some states.

In a separate report on secondhand smoke, CDC researchers analyzed a sample of over 30,000 nonsmokers during 2007-2008 and found that 40 percent had cotinine, a chemical in tobacco smoke, in their blood, down from 52 percent of nonsmokers during 1999-2000. The researchers also noted that more than half of American children between the ages of 3 and 11 live with smokers and are exposed to secondhand smoke.

The reports on adult smoking rates and secondhand smoke were published in the Sept. 27, 2010 issue of the CDC's Morbidity and Mortality Weekly Report (MMWR).