According to a new study, researchers reveal that all non-smoking hotel rooms cannot guarantee tobacco-free air as smoke from other rooms automatically fills non-smoking rooms as well.

Opting for a non-smoking area is not enough to ensure you're breathing tobacco-free air, say researchers of a new study. According to researchers from San Diego State University, smoke from rooms that allow smoking automatically travels to other places and fills the air of non-smoking rooms as well.

"(Nicotine residues and other chemical traces) don't stay in the smoking rooms," study author Georg Matt, a psychologist from San Diego State University, told USA Today. "They end up in the hallways and in other rooms, including non-smoking rooms."

In the study, researchers looked into 30 California hotels and found smoke residue on surfaces and in the air of both smoking and non-smoking rooms in hotels that allowed smoking in some designated areas. While the level of smoke residue in these hotels was way higher in "smoking" rooms, the level of in non-smoking rooms was higher than in 10 other smoke-free hotels that the researchers looked into. Non smoking rooms in hotels that had partial smoking bans were found to have 40 times more nicotine in the air than hotels that had complete smoking bans.

Authors of the study note that people who want to stay in a 100 percent tobacco-free environment should opt for hotels that have a complete smoking ban instead of just opting for a non smoking room in a hotel that allows partial smoking.

Guests who wish to protect themselves from exposure to tobacco smoke should avoid hotels that permit smoking and instead stay in completely smoke-free hotels," the researchers wrote.