So far only known active smokers at risk of addiction to nicotine. But recent studies have shown that passive smokers are also vulnerable to nicotine addiction.

Exposed to smoke such as in the same room will have a direct measurable impact on the brain, and effects that appear similar to those happening in the brains of people who smoke.

The study, funded by the National Institute on Drug Abuse (NIDA) reveal that exposure to cigarette smoke can make people addicted to or evoke the same desire as smokers.The results of this study was published in the Archives of General Psychiatry on May 1st, 2011.

This study using positron emission tomography (PET), which showed that one hour exposure to cigarette smoke in a confined space is sufficient for nicotine to reach the brain and bind to receptors that normally targeted by the smoker. Known same thing happens in the brains of smokers and non-smokers.

In previous studies it is known that cigarette smoke exposure in passive smokers can increase the likelihood of children to become smokers in adolescence and make it more difficult to quit smoking as adults. The relationship shows that cigarette smoke work in the brain may promote smoking behavior.

“Exposure to tobacco smoke limited enough to make nicotine reaches the brain and alter its function. Exposure to a chronic and severe can increase levels of nicotine in the brain that increase vulnerability to nicotine addiction,” says NIDA Director, Nora D Volkow, MD, as quoted by the ScienceDaily.

In addition, passive smokers are also at risk of heart disease, lung cancer, a serious condition in children, including sudden infant death syndrome, respiratory infections and severe asthma.

“The results of this study provide clear evidence to support the policy of a ban on smoking in public places, especially in enclosed spaces and in the vicinity of children and pregnant women,” said Arthur Brody, MD, of UCLA’s Department of Psychiatry & Biobehavioral Sciences.