FRIDAY, Dec. 14, 2012 (HealthDay News) -- As many as 29 million U.S. apartment dwellers who have no smoking rules for their own homes are exposed to secondhand smoke seeping in from neighboring apartments and common areas, federal officials reported Friday.
"A quarter of all Americans live in some form of multi-unit housing, and these individuals and families are potentially exposed to secondhand smoke that enters their home from somewhere else," said Dr. Tim McAfee, director of the U.S. Centers for Disease Control and Prevention's Office on Smoking and Health.
"There had been individual studies done looking at effects of secondhand smoke in apartments, but this is the first time that we had tried to figure out how it all hangs together nationally," he added.
Exposure to secondhand smoke in apartments is not something a renter can control, McAfee said. "Even if they had a smoke-free home rule, they are being involuntarily exposed to secondhand smoke from their neighbors," he said.
The best way to protect people living in apartments is by prohibiting smoking in all units and shared areas of a building, McAfee said. This can be accomplished by state or city laws or by individual landlords, he said.
McAfee said many U.S. cities are thinking about banning smoking in apartments. Also, more apartment buildings are becoming smoke-free. And, the U.S. Department of Urban Development and Housing is encouraging public housing around the country to be smoke-free, he added.
The only thing a person can do is not rent an apartment in a building where smoking is allowed, McAfee said.
Many people, however, don't want smoking in their building and, over time, there will be more and more smoke-free apartment buildings, McAfee predicted. "I think this will be one of those things, like smoking in restaurants and workplaces, where we are going to see a switch pretty quickly," he said.
The findings were published in the Dec. 14 issue of the CDC's Nicotine & Tobacco Research.
To estimate the number of non-smokers exposed to secondhand smoke in their apartments, the researchers multiplied the estimated number of apartment dwellers with smoke-free homes by the approximately 45 percent of those reporting secondhand smoke seepage that had been gleaned from other studies.
In the United States about 79 million people live in apartments; 62.7 million of those people do not allow smoking in their homes. The number of apartment dwellers varies state to state, from a low of 10 percent in West Virginia to a high of almost 52 percent in New York, the researchers said.
The researchers calculated that 27.6 million to 28.9 million of those people living in apartments have been exposed to secondhand smoke. This also varies by state, with some 27,000 people exposed in Wyoming to almost 5 million in California.
Secondhand smoke, which experts call a "known human carcinogen," has been linked to lung cancer, cancers of the voice box and throat, brain, bladder, rectum, stomach and breast, as well as childhood leukemia, according to the American Cancer Society.
Danny McGoldrick, vice president of research for the Campaign for Tobacco-Free Kids, said landlords should make their apartment buildings smoke-free.
"While the majority of multi-unit housing residents make their homes smoke-free, nearly half of them are affected by infiltration of smoke from other residents," he said. "Owners of multi-unit housing can protect their tenants from the harms of secondhand smoke and save on maintenance and insurance costs by making their properties smoke-free."
For more on secondhand smoke, visit the U.S. Centers for Disease Control and Prevention.