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 Thursday.
A main reason for the decline in secondhand smoke is the growing number of laws and policies that ban smoking in workplaces, bars, restaurants and public places, said researchers with the Centers for Disease Control and Prevention.
Another factor is the drop in the number of adult smokers: It has now inched below 20 percent, according to 2007 CDC data.
The new study found 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.
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 decline in secondhand smoke exposure was not as dramatic in black nonsmokers as it was in whites and Mexican-Americans. The proportion of blacks with a recent exposure to tobacco smoke dropped from 94 percent to about 71 percent, for whites it dropped from 83 to 43 percent and for Mexican-Americans, 78 to 40 percent.
The stats for children did not decline as dramaticall. Over 60 percent ages 4 through 11 had recent exposure to smoke in the 1999-2004.
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