Americans' smoking habits have improved in the last couple of decades as more families in the U.S. are ensuring that their homes are smoke-free zones.

Smoking bans in the U.S. have been imposed in many places such as restaurants, bars, workplaces and more. Smoking ban is also expected to be extended to public housing, apartments and in cars with children. With these bans in place, homes are believed to have become the main source of second-hand smoke (SHS), which is sometimes also referred as passive smoking. Healthcare professionals agree that SHS can expose non-smokers to asthma, heart problems and cancer.

In the 1990's, about 43 percent of the U.S. homes were smoke free. According to a study conducted by the U.S. Centers for Disease Control and Prevention (CDC), around 83 percent U.S. homes went smoke free by 2010 and 2011.

The CDC report suggests that the percentage of homes in the U.S., without an adult smoker and with smoke-free rules, increased from 57 percent to 91 percent. The report also indicates that the number of homes, with at least one adult smoker, with no-smoking rules increased from less than 10 percent to over 45 percent. Brian King, who is the lead author of the CDC study, suggests that there is still a lot of work needed as only about 45 percent of smokers ban smoking at home.

The report also revealed that smoking bans have helped in reducing the number of smokers in the U.S. The CDC revealed that about 18 percent Americans were reported to be smokers in 2012, when compared to 43 percent in 1965.

Brian King, who is the lead author of the CDC study, revealed that a smoker not smoking near non-smokers has become a social norm. However, CDC revealed that around 41,000 non-smokers in the U.S. still die due to SHS each year.

"Because 100 percent smokefree indoor environments are the only effective way to fully eliminate SHS exposure, efforts are warranted to educate the public about the dangers of SHS and to promote the adoption of smokefree home rules, particularly among subpopulations at greatest risk for exposure, such as those living in households with smokers, in states with lower prevalence of smokefree home rules, and in multiunit housing," per the CDC report.

The report also points out that the lowest smoke-free homes were in Kentucky that accounted for only 69.4 percent in 2010-2011; however, the percentage has increased threefold when compared to 1992-1993. At 94 percent, Utah has the highest percentage of smoke-free homes in the country.