Fewer inhaling secondhand smoke

CDC study credits bans at bars, work

ATLANTA - Nearly half of nonsmoking Americans are still breathing in cigarette fumes, but the percentage has declined dramatically since the early 1990s, according to a government study released yesterday.

A main reason for the decline in secondhand smoke is the growing number bans on smoking in workplaces, bars, restaurants, and public places, researchers with the Centers for Disease Control and Prevention said.

Another factor is the drop in the number of adult smokers: It has now inched below 20 percent, according to 2007 CDC data. The study found that about 46 percent of nonsmokers had signs of nicotine in their blood in tests done from 1999 through 2004. That was a steep drop from 84 percent when similar tests were done in the late 1980s and early 1990s.

But health officials stopped short of celebrating.

"It's still high," said Cinzia Marano, one of the study's authors. "There is no safe level of exposure."

Cigarettes cause lung cancer and other deadly illnesses in nonsmokers who inhale smoke, studies have shown.

For nonsmoking adults, secondhand smoke increases their lung cancer risk by at least 20 percent and their heart disease risk by at least 25 percent. Children exposed to secondhand smoke are at increased risk of asthma attacks, ear problems, acute respiratory infections, and sudden infant death syndrome, health officials say.

The report drew its data from the National Health and Nutrition Examination Survey, a government study that sends trailers out to communities. Participants are asked about their health and get blood tests and physical exams.

The blood tests check for cotinine, a byproduct of nicotine that usually is detectable for up to four to five days. The blood tests are important, because many people underestimate their exposure to secondhand smoke, said Terry Pechacek, associate director for science in the CDC's Office on Smoking and Health.