More than 8 in 10 US homes forbid smoking

Health officials say smoking is banned in more than eight out of 10 U.S. homes—nearly twice what the numbers were two decades ago.

The Centers for Disease Control and Prevention found smoking is even forbidden in nearly half of homes where an adult smoker resides, up from one in 10 households with smokers in the early 1990s.

CDC experts attribute the changes to shrinking smoking rates and a shift in how many people think it's OK to smoke around nonsmokers.

The government surveyed adults in about 200,000 U.S. homes in 2010 and 2011. The results were compared to previous versions of the same survey.

Health officials estimate secondhand smoke causes 41,000 deaths among nonsmoking adults each year.

The CDC released the study Thursday.