The U.S. Centers for Disease Control and Prevention (CDC) report that nearly three of every four U.S. homeowners banned smoking in their houses in 2003, up from 43 percent in 1993, the Associated Press reported May 24.

"That really says that people are starting to understand the hazards of secondhand smoke," said study author Corinne Husten.

Kentucky had the lowest percentage of homes where smoking is banned; Utah had the highest. However, the rate in Kentucky was still double what it was a decade prior.

Even in homes with at least one smoker, indoor smoking was banned in about one in three households. In homes with no smokers, the rate was 84 percent.

The study appears in the May 25, 2007 issue of the CDC's Morbidity and Mortality Weekly Report.